Monday, July 25, 2016


ARIHANT TECHNO SOLUTIONS

IoT Based IEEE PROJECTS- 2016-2017

ATS_IOT16_001 - IoT Healthcare Analytics: The Importance of Anomaly Detection
          Healthcare data is quite rich and often contains human survival related information. Analyzing healthcare data is of prime importance particularly considering the immense potential of saving human life and improving quality of life. Furthermore, IoT revolution has redefined modern health care systems and management. IoT offers its greatest promise to deliver excellent progress in healthcare domain. In this talk, proactive healthcare analytics specifically for cardiac disease prevention will be discussed. Anomaly detection plays a prominent role in healthcare analytics. In fact, the anomalous events are to be accurately detected with low false negative alarms often under high noise (low SNR) condition. An exemplary case of smartphone based cardiac anomaly detection will be presented..

ATS_IOT16_002 - Effective ways to use Internet of Things in the field of medical and smart health care
          The recent advancements in technology and the availability of the Internet make it possible to connect various devices that can communicate with each other and share data. The Internet of Things (IoT) is a new concept that allows users to connect various sensors and smart devices to collect real-time data from the environment. However, it has been observed that a comprehensive platform is still missing in the e-Health and m-Health architectures to use smartphone sensors to sense and transmit important data related to a patient's health. In this paper, our contribution is twofold. Firstly, we critically evaluate the existing literature, which discusses the effective ways to deploy IoT in the field of medical and smart health care. Secondly, we propose a new semantic model for patients' e-Health. The proposed model named as `k-Healthcare' makes use of 4 layers; the sensor layer, the network layer, the Internet layer and the services layer. All layers cooperate with each other effectively and efficiently to provide a platform for accessing patients' health data using smart phones.

ATS_IOT16_003 - A conceptual framework for IoT-based healthcare system using cloud computing
          Internet of Things (IoT) envisions a future in which anything/anyone/anyservice can be linked by means of appropriate information and communication technologies which will bring technological revolution in the fields of domestics, smart homes, healthcare systems, goods monitoring and logistics. This paper presents the applications of IoT and addresses some essential parameters and characteristics of each of the applications of IoT. In this paper, we have deeply explored the role of IoT in healthcare delivery and its technological aspects that make it a reality and examine the opportunities. A cloud based conceptual framework has been proposed which will be beneficial to the healthcare industry implementing IoT healthcare solutions.

ATS_IOT16_004 - The Internet of Things in Healthcare: Potential Applications and Challenges
          Exciting new applications of Internet of Things (IoT) technology are arising, particularly in healthcare, where the leveraging effects can significantly improve patients' well-being while alleviating the problem of scarce resources. But the hype around these applications far outpaces the reality. Furthermore, there is a real risk that these leveraging technologies will disassociate caregivers from patients, potentially resulting in a loss of caring. In this article, the authors review some of the most promising applications for IoT in healthcare and the significant challenges ahead.

ATS_IOT16_005 - IoT based smart healthcare kit
          The paper presents the design and implementation of an IOT-based health monitoring system for emergency medical services which can demonstrate collection, integration, and interoperation of IoT data flexibly which can provide support to emergency medical services like Intensive Care Units (ICU), using a INTEL GALILEO 2ND generation development board. The proposed model enables users to improve health related risks and reduce healthcare costs by collecting, recording, analyzing and sharing large data streams in real time and efficiently. The idea of this project came so to reduce the headache of patient to visit to doctor every time he need to check his blood pressure, heart beat rate, temperature etc. With the help of this proposal the time of both patients and doctors are saved and doctors can also help in emergency scenario as much as possible. The proposed outcome of the project is to give proper and efficient medical services to patients by connecting and collecting data information through health status monitors which would include patient's heart rate, blood pressure and ECG and sends an emergency alert to patient's doctor with his current status and full medical information.








Tuesday, July 5, 2016


ARIHANT TECHNO SOLUTIONS

NS3 IEEE PROJECTS - 2016-2017

ATS_16NS3_001 - Analytical Model and Performance evaluation of Long Term Evolution for vehicle Safety Services
In traffic jam or dense vehicle environment, vehicular ad-hoc networks (VANET) can’t meet safety requirement due to serious packet collision. The traditional cellular network solves packet collision, but suffers from long end-to-end delay. 3GPP Long Term Evolution (LTE) overcomes both drawbacks, thus it may be used instead of VANET in some extreme environments. We use Markov models with the dynamic scheduling and semipersistent scheduling (SPS) to evaluate how many idle resources of LTE can be provided for safety services and how safety applications impact on LTE traditional users. Based on the analysis, we propose to reserve the idle radio resources in LTE for vehicular safety services (LTE-V). Additionally, we propose the weighted-fair-queueing (WFQ) algorithm to schedule beacons for safety services using LTE reserved resource. Numerical results verify that the proposed mechanism can significantly improve the reliability of safety application by borrowing limited LTE bandwidth. We also build NS3 simulation platform to verify the effectiveness of the proposed Markov models. Finally, the reliability of applications including cooperation collision warning, slow vehicle indication and rear-end collision warning using DSRC with LTE-V are evaluated. The simulation results demonstrate that the stringent QoS requirement of the above three applications can be satisfied even under heavy traffic.

ATS_16NS3_002 - Using MPTCP subflow association control for heterogeneous wireless network optimization
Multipath TCP (MPTCP) was designed to increase the throughput and reliability of TCP, with specific motivation coming from scenarios including data center and cloud computing. The use of MPTCP has been recently explored to support heterogeneous wireless networks (HetNets) involving hosts that have multiple network interfaces. However, current solutions generally involve many simplifying assumptions. In this paper, we propose a new framework to collect scheduling information from various scheduling network entities and conduct optimization from a global view. The framework uses the existing or readily accessible MPTCP parameters. Under this framework, we introduce a centralized optimization algorithm to realize general proportional fairness of user throughput. Based on results from NS3 simulations, we provide evidence that the approach provides a low cost solution for improved performance from the perspectives of both applications and network operators.

ATS_16NS3_003 - Simulation Model and Comparison for Satellite Links in Ku and Ka Bands for Standards-based on DVB-S2 and NS3
This work generates a simulation model to understand the effects of attenuation in broadcasting satellite links like for data links and especially to determine the feasibility of using a high performance satellite backhaul for new generation data networks, faced with different scenarios especially in areas where rainfall attenuates and degrades the RF satellite links. Predictive models have been assembled delivered by the ITU and its recommendations for rain attenuation and the links are integrated with DVB-S2 and NS3 standards, where the simulated model will be obtained which with a position geographical coordinates as a reference of the remote station VSAT, will result in operating modes, signal strength and availability of the satellite link given. This certainly makes it a tool to study and design that many papers omitted on the research part and it becomes necessary to be applied in new models of propagation and attenuation in regions where it is desired to conduct the study, achieving thus a greater precision in the quality of links and a more encouraging panorama to deploy networking data systems high reliability and high transmission rates based on next generation 4G and future 5G networks.

ATS_16NS3_004 - HDEER: A Distributed Routing Scheme for Energy-Efficient Networking
The proliferation of new online Internet services has substantially increased the energy consumption in wired networks, which has become a critical issue for Internet service providers. In this paper, we target the network-wide energy-saving problem by leveraging speed scaling as the energy-saving strategy. We propose a distributed routing scheme-HDEER-to improve network energy efficiency in a distributed manner without significantly compromising traffic delay. HDEER is a two-stage routing scheme where a simple distributed multipath finding algorithm is firstly performed to guarantee loop-free routing, and then a distributed routing algorithm is executed for energy-efficient routing in each node among the multiple loop-free paths. We conduct extensive experiments on the NS3 simulator and simulations with real network topologies in different scales under different traffic scenarios. Experiment results show that HDEER can reduce network energy consumption with a fair tradeoff between network energy consumption and traffic delay.

ATS_16NS3_005 - Explore and Analyze the Performance Factors on Wi-Fi Sensing Starvation Problems
Wi-Fi wireless communication has become a basic service in public areas. But the quality is not stable due to the factors that are influenced by 1) a limited number of channels results in access interference, 2) various transmission ranges, carrier sensing and hidden terminal starvation problems, and 3) the barriers reduce the quality of transmissions. This work aims to explore and analyze the factors to show the level of performance effect on various transmission ranges of access points. Accordingly, this study designs several simulation cases to evaluate whether a small cell size can provide high performance co-existing with a large cell size by controlling the effect of the sensing ranges, transmission ranges, traffic types, data rates, and packet sizes. Network Simulation 3 (NS3) tool is used to implement the simulation cases and compare the results. We discussed our findings on these factors that affect the levels of starvation caused by the various signal ranges.

ATS_16NS3_006 - AUV-aided communication method for underwater mobile sensor network
Underwater Wireless Sensor Networks (UWSNs) are getting growing interest because of wide-range applications. However, the underwater acoustic communication technology is constrained by the nodes' continuous movement, limited communication bandwidth and node energy, which bring great challenges to UWSNs. In order to handle these challenges and to achieve an efficient energy consumption, many researches have been carried. A significant problem in Underwater Wireless Sensor Networks (UWSNs) is the difficulty of energy limit. This paper proposes an AUV-aided acoustic communication protocol, namely AA-RP (AUV-Aided Routing Method Integrated Path Planning), which integrates the AUV's dynamic path planning algorithms into the routing protocol. This integrated communication method relies on two phases: AAR (AUV-Aided Network Routing) and RAPP (Routing Aided Path Planning). AA-RP utilizes the cooperation of multi-tasks to reduce energy consumption for network and avoids hot spot and zone problem with a dynamic GN (Gateway Node) schemes. In order to evaluate the performance of the proposed method, we make the simulation with NS3, which contains a UAN (Underwater Acoustic Network) module. The simulation results show that the method can reduce the network energy consumption with a good delivery ratio.

ATS_16NS3_007 - Multi-channel routing protocol for dynamic WSN
Effective strategies are required to ensure efficient data collection for wireless sensor networks deployed in harsh environment, and where propagation conditions are unstable. In this paper, we propose a scheduled based routing protocol that use both topological and link quality information to adapt to environment changes. The multiples channels is used to enable parallel transmissions and hence allow fast data gathering at the sink while reducing collisions. Our protocol is using a duty cycling technique to save energy. NS3 simulation results show that our protocol is adapting well to change in the topology and maintains almost similar traffic flows as in stable conditions of functioning.

ATS_16NS3_008 - Increasing network lifetime by energy-efficient routing scheme for OLSR protocol
One of the main considerations in designing routing protocols for Mobile Ad-Hoc Network (MANET) is to increase network lifetime by minimizing nodes' energy consumption, since nodes are typically battery powered. Many proposals have been addressed to this problem; however, few papers consider a proactive protocol like Optimized Link State Routing Protocol (OLSR) to better manage the energy consumption. Some of them have explored modifications to the MPRs selection mechanism, whereas others have investigated multiple cross layer parameters to increase the network lifetime. In this paper, we explored both modification to MPR selection and integrating appropriate routing metrics in the routing decision scheme to lessen effects of reason that lead to more energy consumption. Our power-aware version of OLSR is proven by simulations in NS3 under a range of different mobile scenarios. Significant performance gains of 20% are obtained in network lifetime for our modified OLSR and little to no performance gains in term of Packet Delivery Ratio (PDR).

Monday, July 4, 2016

ARIHANT TECHNO SOLUTIONS

WIRELESS / OPTICAL COMMUNICATIONS 
IEEE PROJECTS - 2016-2017

ATS_COMM16_001 - Performance of Low-Complexity Uniform Power Loading OFDM Systems With Reduced Feedback Over Rayleigh Fading Channels
In this paper, we consider a low-complexity uniform power loading scheme for orthogonal frequency division multiplexing (OFDM) systems with two reduced feedback mechanisms and analyze its performance over Rayleigh fading channels. In the first feedback mechanism, the receiver feeds back to the transmitter the channel gains and the indices of the best M subchannels; while for the second feedback mechanism, the receiver feeds back only the indices of the best M subchannels. The available power budget is equally distributed over the best M subchannels for both feedback mechanisms. We derive closed-form expressions for the achievable capacity and an upper bound on the outage capacity of the first and second mechanisms, respectively. A simple elimination algorithm is provided to find the optimal number of best subchannels M that maximizes the achievable capacity. Numerical results show the dependence of the optimal number of the best subchannels M on the system parameters. Additionally, the presented results interestingly show that the low-complexity uniform power loading scheme can achieve up to 98.72% of the channel capacity, obtained using the well-known waterfilling solution, when the optimal value of M is used. Moreover, the uniform power loading scheme can achieve up to 88.86% of the energy efficiency at reduced complexity.

ATS_COMM16_002 - Impact of Inter-Relay Cooperation on the Performance of FSO Systems with any Number of Relays
In this paper, we study the impact of inter-relay cooperation on the performance of Decode-and-Forward (DF) cooperative Free Space Optical (FSO) communication systems with any number of relays. The idea of inter-relay cooperation (IRC) was introduced very recently where the relay-relay links are activated for further boosting the system performance. We evaluate the outage probability under forward and forwardbackward IRC that constitute the two variants of this transmission strategy. We also derive the diversity orders that can be achieved over a composite channel model that takes both turbulence-induced fading and misalignment-induced fading into consideration. We present a comprehensive asymptotic analysis that is effective for tackling the usefulness of IRC with an arbitrary number of relays and for deriving the network conditions under which implementing IRC in any of its variants can be beneficial for enhancing the diversity order of the FSO system. The introduced framework answers the question on what is the optimal solution for a particular FSO network (among the parallel-relaying solution with no IRC, forward IRC or forwardbackward IRC).

ATS_COMM16_003 - The Ergodic Rate Density of Slotted and Unslotted CSMA Ad-Hoc Networks
The performance of random Wireless Ad-hoc Networks (WANETs) is primarily limited by their self-interference. The utilization of a decentralized Carrier Sensing Multiple Access (CSMA) protocol protects the participating receivers from the presence of strong interferers and enhances the performance compared to the simpler ALOHA protocol. In this work we analyze the Ergodic Rate Density (ERD) of slotted and unslotted CSMA WANETs in the small back-off probability regime. Our main result is the derivation of simple expressions which describe the ERD of CSMA WANETs as a function of the back-off probability, the path-loss exponent and the ERD of the same WANET when applying the ALOHA protocol. The ERD expressions for both the slotted and the unslotted variants are shown to grow with the back-off probability. For the slotted variant the gain of CSMA over ALOHA is equal to the back-off probability. On the other hand, for the unslotted variant this gain is smaller by a constant factor, which is within the range of 0.57 to 0.67 for all cases of practical interest. Simulation results validate the precision of the derived expressions and demonstrate their capability to predict the optimal system parameters with very good accuracy

ATS_COMM16_004 - Self-Sustainable Communications with RF Energy Harvesting: Ginibre Point Process Modeling and Analysis
RF-enabled wireless power transfer and energy harvesting has recently emerged as a promising technique to provision perpetual energy replenishment for low-power wireless networks. The network devices are replenished by the RF energy harvested from the transmission of ambient RF transmitters, which offers a practical and promising solution to enable self-sustainable communications. This paper adopts a stochastic geometry framework based on the Ginibre model to analyze the performance of self-sustainable communications over cellular networks with general fading channels. Specifically, we consider the point-to-point downlink transmission between an access point and a battery-free device in the cellular networks, where the ambient RF transmitters are randomly distributed following a repulsive point process, called Ginibre α-determinantal point process (DPP). Two practical RF energy harvesting receiver architectures, namely time-switching and power-splitting, are investigated. We perform an analytical study on the RF-powered device and derive the expectation of the RF energy harvesting rate, the energy outage probability and the transmission outage probability over Nakagami-m fading channels. These are expressed in terms of so-called Fredholm determinants, which we compute efficiently with modern techniques from numerical analysis. Our analytical results are corroborated by the numerical simulations, and the efficiency of our approximations is demonstrated. In practice, the accurate simulation of any of the Fredholm determinant appearing in the manuscript is a matter of seconds. An interesting finding is that a smaller value of α (corresponding to larger repulsion) yields a better transmission outage performance when the density of the ambient RF transmitters is small. However, it yields a lower transmission outage probability when the density of the ambient RF transmitters is large. We also show analytically that the power-splitting architecture outperfor- s the time-switching architecture in terms of transmission outage performances. Lastly, our analysis provides guidelines for setting the time-switching and power-splitting coefficients at their optimal values.

ATS_COMM16_005 - Queue-Aware Energy-Efficient Joint Remote Radio Head Activation and Beamforming in Cloud Radio Access Networks
In this paper, we study the stochastic optimization of cloud radio access networks (C-RANs) by joint remote radio head (RRH) activation and beamforming in the downlink. Unlike most previous works that only consider a static optimization framework with full traffic buffers, we formulate a dynamic optimization problem by explicitly considering the effects of random traffic arrivals and time-varying channel fading. The stochastic formulation can quantify the tradeoff between power consumption and queuing delay. Leveraging on the Lyapunov optimization technique, the stochastic optimization problem can be transformed into a per-slot penalized weighted sum rate maximization problem, which is shown to be nondeterministic polynomial-time hard. Based on the equivalence between the penalized weighted sum rate maximization problem and the penalized weighted minimum mean square error (WMMSE) problem, the group sparse beamforming optimization-based WMMSE algorithm and the relaxed integer programming-based WMMSE algorithm are proposed to efficiently obtain the joint RRH activation and beamforming policy. Both algorithms can converge to a stationary solution with low-complexity and can be implemented in a parallel manner, thus they are highly scalable to large-scale C-RANs. In addition, these two proposed algorithms provide a flexible and efficient means to adjust the power-delay tradeoff on demand.

ATS_COMM16_006 - Analysis of Downlink Connectivity Models in a Heterogeneous Cellular Network via Stochastic Geometry
In this paper, a comprehensive study of the downlink performance in a heterogeneous cellular network (or HetNet) is conducted via stochastic geometry. A general HetNet model is considered consisting of an arbitrary number of open-access and closed-access tiers of base stations (BSs) arranged according to independent homogeneous Poisson point processes. The BSs within each tier have a constant transmission power, random fading factors with an arbitrary distribution and arbitrary path-loss exponent of the power-law path-loss model. For such a system, analytical characterizations for the coverage probability are derived for the max-SINR connectivity and nearest-BS connectivity models. Using stochastic ordering, interesting properties and simplifications for the HetNet downlink performance are derived by relating these two connectivity models to the maximum instantaneous received power (MIRP) connectivity model and the maximum biased received power (MBRP) connectivity models, providing good insights about HetNets and their downlink performance in these complex networks. Furthermore, the results also demonstrate the effectiveness and analytical tractability of the stochastic geometric approach to study the HetNet performance.

ATS_COMM16_007 - A New Cyclic-Prefix Based Algorithm for Blind CFO Estimation in OFDM Systems
Real-world wireless communication channels are typically highly underspread: their coherence time is much greater than their delay spread. In such situations, it is common to assume that, with sufficiently high bandwidth, the capacity without channel state information (CSI) at the receiver (termed the noncoherent channel capacity) is approximately equal to the capacity with perfect CSI at the receiver (termed the coherent channel capacity). In this paper, we propose a lower bound on the noncoherent capacity of highly underspread fading channels, which assumes only that the delay spread and coherence time are known. Furthermore, our lower bound can be calculated recursively, with each increment corresponding to a step increase in bandwidth. These properties, we contend, make our lower bound an excellent candidate as a simple method to verify that the noncoherent capacity is indeed approximately equal to the coherent capacity for typical wireless communication applications. We precede the derivation of the aforementioned lower bound on the information capacity with a rigorous justification of the mathematical representation of the channel. Furthermore, we also provide a numerical example for an actual wireless communication channel and demonstrate that our lower bound does indeed approximately equal the coherent channel capacity.

ATS_COMM16_008 - Comments on “Energy-Efficient Uplink Multiuser MIMO”
In the paper “Energy-efficient Uplink Multi-user MIMO,” it was mentioned that the employed linear receiver does not change the variance of the elements of the noise vector. Then, the performance was calculated based on this proposition. In this note, we show that this proposition does not hold by providing the counter examples. In addition, we analyze how the performance will be affected by fixing this proposition.

ATS_COMM16_009 - Performance Characterization of Relay-Assisted Wireless Optical CDMA Networks in Turbulent Underwater Channel - Optical Communications
In this paper, we characterize the performance of relay-assisted underwater wireless optical code division multiple access (OCDMA) networks over turbulent channels. In addition to scattering and absorption effects of underwater channels, we also consider optical turbulence as a log-normal fading coefficient in our analysis. To simultaneously and asynchronously share medium among many users, we assign a unique optical orthogonal code (OOC) to each user in order to actualize OCDMA-based underwater network. The most significant challenge in underwater optical communication is in the ability to extend the short range of its coverage. In order to expand the viable communication range, we consider multi-hop transmission to the destination. Moreover, we evaluate the performance of a relay-assisted point-to-point UWOC system as a special case of the proposed relay-assisted OCDMA network. Our numerical results indicate significant performance improvement by employing intermediate relays, e.g., one can achieve 32 dB improvement in the bit error rate (BER) of 10-6 using only a dual-hop transmission in a 90 m point-to-point clear ocean link.

ATS_COMM16_010 - Efficient Tracking Area Management Framework for 5G Networks
One important objective of 5G mobile networks is to accommodate a diverse and ever-increasing number of user equipment (UEs). Coping with the massive signaling overhead expected from UEs is an important hurdle to tackle so as to achieve this objective. In this paper, we devise an efficient tracking area list management (ETAM) framework that aims for finding optimal distributions of tracking areas (TAs) in the form of TA lists (TALs) and assigning them to UEs, with the objective of minimizing two conflicting metrics, namely paging overhead and tracking area update (TAU) overhead. ETAM incorporates two parts (online and offline) to achieve its design goal. In the online part, two strategies are proposed to assign in real time, TALs to different UEs, while in the offline part, three solutions are proposed to optimally organize TAs into TALs. The performance of ETAM is evaluated via analysis and simulations, and the obtained results demonstrate its feasibility and ability in achieving its design goals, improving the network performance by minimizing the cost associated with paging and TAU.

ATS_COMM16_011 - Location Verification Systems Under Spatially Correlated Shadowing
The verification of the location information utilized in wireless communication networks is a subject of growing importance. In this work, we formally analyze, for the first time, the performance of a wireless location verification system (LVS) under the realistic setting of spatially correlated shadowing. Our analysis illustrates that anticipated levels of correlated shadowing can lead to a dramatic performance improvement of a received signal strength (RSS)-based LVS. We also analyze the performance of an LVS that utilizes differential received signal strength (DRSS), formally proving the rather counter-intuitive result that a DRSS-based LVS has identical performance to that of an RSS-based LVS, for all levels of correlated shadowing. Even more surprisingly, the identical performance of RSS and DRSS-based LVSs is found to hold even when the adversary does not optimize his true location. Only in the case where the adversary does not optimize all variables under his control, do we find the performance of an RSS-based LVS to be better than a DRSS-based LVS. The results reported here are important for a wide range of emerging wireless communication applications whose proper functioning depends on the authenticity of the location information reported by a transceiver.

ATS_COMM16_012 - An Efficient Bayesian PAPR Reduction Method for OFDM-Based Massive MIMO Systems
We consider the problem of peak-to-average power ratio (PAPR) reduction in orthogonal frequency-division multiplexing (OFDM) based massive multiple-input multiple-output (MIMO) downlink systems. Specifically, given a set of symbol vectors to be transmitted to K users, the problem is to find an OFDM-modulated signal that has a low PAPR and meanwhile enables multiuser interference (MUI) cancelation. Unlike previous works that tackled the problem using convex optimization, we take a Bayesian approach and develop an efficient PAPR reduction method by exploiting the redundant degrees-of- freedom of the transmit array. The sought-after signal is treated as a random vector with a hierarchical truncated Gaussian mixture prior, which has the potential to encourage a low PAPR signal with most of its samples concentrated on the boundaries. A variational expectation-maximization (EM) strategy is developed to obtain estimates of the hyperparameters associated with the prior model, along with the signal. In addition, the generalized approximate message passing (GAMP) is embedded into the variational EM framework, which results in a significant reduction in computational complexity of the proposed algorithm. Simulation results show our proposed algorithm achieves a substantial performance improvement over existing methods in terms of both the PAPR reduction and computational complexity.

ATS_COMM16_013 - Coupled Detection and Estimation Based Censored Spectrum Sharing in Cognitive Radio Networks
A novel spectrum sharing strategy based on coupled detection and estimation is proposed for cognitive radio networks. The proposed approach is able to tradeoff throughput for reduced interference at the primary user (PU) via censored transmissions. We derive the optimum censoring strategy that maximizes the throughput of the cognitive radio system under an average interference power constraint at the PU. We then extend the proposed framework to jointly optimize the censoring and the power allocation strategies of the secondary user (SU) that maximize the throughput of the secondary network under average transmit power and average interference power constraints. Finally, we provide extensive simulation results to demonstrate the enhanced performance of the proposed censoring based spectrum sharing approach.

ATS_COMM16_014 - Joint Resource Allocation and Relay Selection in LTE-Advanced Network Using Hybrid Co-Operative Relaying and Network Coding
The problem of joint resource allocation and relay selection is studied for bidirectional LTE-advanced relay networks. The bidirectional communication between user equipment (UE) and eNodeB (eNB) is performed via direct transmission, co-operative relaying (CoR), or a combination of network coding (NC) and CoR (NC/CoR). In this paper, an enhanced three-time-slot per cycle time-division duplexing (TDD) scheme is proposed for LTE-Advanced frame architecture to accommodate a hybrid transmission scheme. More specifically, we formulate the problem of joint resource assignment, relay selection, and bidirectional transmission scheme selection as a combinatorial optimization problem with the objective to maximize the total product of backlog and rate (back-pressure principle). Two approaches are considered to solve our combinatorial optimization problem. First, a graph-based framework is proposed in which the problem is transformed into a maximum weighted Clique problem (MWCP). In addition, our problem is also transformed into a three-dimensional assignment problem (3DAP) which is solved using a hybrid ant colony optimization (ACO) algorithm. Using simulations, it is concluded that the hybrid transmission scheme outperforms all conventional nonhybrid schemes. Moreover, the simulation results confirm that while the two proposed solutions provide similar results, the ACO algorithm is faster due to its lower complexity.

ATS_COMM16_015 - A General MIMO Framework for NOMA Downlink and Uplink Transmission Based on Signal Alignment
The application of multiple-input multiple-output (MIMO) techniques to nonorthogonal multiple access (NOMA) systems is important to enhance the performance gains of NOMA. In this paper, a novel MIMO-NOMA framework for downlink and uplink transmission is proposed by applying the concept of signal alignment. By using stochastic geometry, closed-form analytical results are developed to facilitate the performance evaluation of the proposed framework for randomly deployed users and interferers. The impact of different power allocation strategies, namely fixed power allocation and cognitive radio inspired power allocation, on the performance of MIMO-NOMA is also investigated. Computer simulation results are provided to demonstrate the performance of the proposed framework and the accuracy of the developed analytical results.

ATS_COMM16_016 - Achievable Rates of Secure Transmission in Gaussian MISO Channel With Imperfect Main Channel Estimation
A Gaussian multiple-input single-output (MISO) fading channel is considered. We assume that the transmitter, in addition to the statistics of all channel gains, is aware instantaneously of a noisy version of the channel to the legitimate receiver. On the other hand, the legitimate receiver is aware instantaneously of its channel to the transmitter, whereas the eavesdropper instantaneously knows all channel gains. We evaluate an achievable rate using a Gaussian input without indexing an auxiliary random variable. A sufficient condition for beamforming to be optimal is provided. When the numberof transmit antennas is large, beamforming also turns out to  be optimal. In this case, the maximum achievable rate can be expressed in a simple closed form and scales with the logarithm of the number of transmit antennas. Furthermore, in the case when a noisy estimate of the eavesdropper’s channel is also available at the transmitter, we introduce the SNR difference and the SNR ratio criterions and derive the related optimal transmission strategies and the corresponding achievable rates.

ATS_COMM16_017 - A Comparison of MIMO Techniques in Downlink Millimeter Wave Cellular Networks With Hybrid Beamforming
Large antenna arrays will be needed in future millimeter wave (mmWave) cellular networks, enabling a large number of different possible antenna architectures and multiple-input multiple-output (MIMO) techniques. It is still unclear which MIMO technique is most desirable as a function of different network parameters. This paper, therefore, compares the coverage and rate performance of hybrid beamforming enabled multiuser (MU) MIMO and single-user spatial multiplexing (SM) with single-user analog beamforming (SU-BF). A stochastic geometry model for coverage and rate analysis is proposed for MU-MIMO mmWave cellular networks, taking into account important mmWave-specific hardware constraints for hybrid analog/digital precoders and combiners, and a blockage-dependent channel model which is sparse in angular domain. The analytical results highlight the coverage, rate, and power consumption tradeoffs in multiuser mmWave networks. With perfect channel state information at the transmitter and round robin scheduling, MU-MIMO is usually a better choice than SM or SU-BF in mmWave cellular networks. This observation, however, neglects any overhead due to channel acquisition or computational complexity. Incorporating the impact of such overheads, our results can be re-interpreted so as to quantify the minimum allowable efficiency of MU-MIMO to provide higher rates than SM or SU-BF.

ATS_COMM16_018 - Network Selection and Channel Allocation for Spectrum Sharing in 5G Heterogeneous Networks
The demand for spectrum resources has increased dramatically with the advent of modern wireless applications. Spectrum sharing, considered as a critical mechanism for 5G networks, is envisioned to address spectrum scarcity issue and achieve high data rate access, and guaranteed the quality of service (QoS). From the licensed network's perspective, the interference caused by all secondary users (SUs) should be minimized. From secondary networks point of view, there is a need to assign networks to SUs in such a way that overall interference is reduced, enabling the accommodation of a growing number of SUs. This paper presents a network selection and channel allocation mechanism in order to increase revenue by accommodating more SUs and catering to their preferences, while at the same time, respecting the primary network operator's policies. An optimization problem is formulated in order to minimize accumulated interference incurred to licensed users and the amount that SUs have to pay for using the primary network. The aim is to provide SUs with a specific QoS at a lower price, subject to the interference constraints of each available network with idle channels. Particle swarm optimization and a modified version of the genetic algorithm are used to solve the optimization problem. Finally, this paper is supported by extensive simulation results that illustrate the effectiveness of the proposed methods in finding a near-optimal solution.

ATS_COMM16_019 - A Scheduling Algorithm for MIMO DoF Allocation in Multi-Hop Networks
Recently, a new MIMO degree-of-freedom (DoF) model was proposed to allocate DoF resources for spatial multiplexing (SM) and interference cancellation (IC) in a multi-hop network. Although this DoF model promises many benefits, it hinges upon a global node ordering to keep track of IC responsibilities among all the nodes. An open question about this model is whether its global ordering property can be achieved among the nodes in the network through distributed operations. In this paper, we explore this question by studying DoF scheduling in a multi-hop MIMO network, with the objective of maximizing the minimum throughput among a set of sessions. We propose an efficient DoF scheduling algorithm to solve it and show that our algorithm only requires local operations. We prove that the resulting DoF scheduling solution is globally feasible and show that there exists a corresponding feasible global node ordering for IC, albeit such global ordering is implicit. Simulation results show that the solution values obtained by our algorithm are relatively close to the upper bound values computed by CPLEX solver, thereby indicating that our algorithm is highly competitive.

ATS_COMM16_020 - On the Capacity of the Intensity-Modulation Direct-Detection Optical Broadcast Channel - Optical Communications
The capacity of the intensity-modulation direct-detection optical broadcast channel (OBC) is investigated, under both average and peak intensity constraints. An outer bound on the capacity region is derived by adapting Bergmans' approach to the OBC. Inner bounds are derived by using superposition coding with either truncated-Gaussian (TG) distributions or discrete distributions. While the discrete distribution achieves higher rates, the TG distribution leads to a simpler representation of the achievable rate region. At high signal-to-noise ratio (SNR), it is shown that the TG distribution is nearly optimal. It achieves the symmetric-capacity within a constant gap (independent of SNR), which approaches half a bit as the number of users grows. It also achieves the capacity region within a constant gap. At low SNR, it is shown that on-off keying (OOK) with time-division multiple-access (TDMA) is optimal. This is interesting in practice since both OOK and TDMA have low complexity. At moderate SNR (typically [0,8] dB), a discrete distribution with a small alphabet size achieves fairly good performance.

ATS_COMM16_021 - Secure Broadcasting with Imperfect Channel State Information at the Transmitter
We investigate the problem of secure broadcasting over fast fading channels with imperfect main channel state information (CSI) at the transmitter. In particular, we analyze the effect of the noisy estimation of the main CSI on the throughput of a broadcast channel where the transmission is intended for multiple legitimate receivers in the presence of an eavesdropper. Besides, we consider the realistic case where the transmitter is only aware of the statistics of the eavesdropper's CSI and not of its channel's realizations. First, we discuss the common message transmission case where the source broadcasts the same information to all the receivers, and we provide an upper and a lower bound on the ergodic secrecy capacity. For this case, we show that the secrecy rate is limited by the legitimate receiver having, on average, the worst main channel link and we prove that a nonzero secrecy rate can still be achieved even when the CSI at the transmitter is noisy. Then, we look at the independent messages case where the transmitter broadcasts multiple messages to the receivers, and each intended user is interested in an independent message. For this case, we present an expression for the achievable secrecy sum-rate and an upper bound on the secrecy sum-capacity and we show that, in the limit of large number of legitimate receivers K, our achievable secrecy sum-rate follows the scaling law log ((1-α)log(K)), where α is the estimation error variance of the main CSI. The special cases of high SNR, perfect and no-main CSI are also analyzed. Analytical derivations and numerical results are presented to illustrate the obtained expressions for the case of independent and identically distributed Rayleigh fading channels.

ATS_COMM16_022 - General Stochastic Channel Model and Performance Evaluation for Underwater Wireless Optical Links - Optical Communications
In underwater wireless optical communications (UWOC), absorption and scattering characterize the link properties since photons may suffer these two processes with energy loss and direction change, respectively, when interacting with water molecules or suspended particles. In this work, we consider the effects of absorption and scattering on the probability distribution, i.e., normalized intensity distribution, of photons in space and time domains. Our prior work proposed a stochastic channel model to represent the spatial-temporal probability distribution of propagated photons only for nonscattering and single scattering components of UWOC links. However, multiple scattering will dominate the scattering behavior of the underwater environment with long communication distance and/or more turbid water type. In this work, we take into account all three types of components including nonscattering, single and multiple scattering, and present a more general stochastic channel model which fits well with Monte Carlo simulations in turbid water environment such as coastal and harbor water. Based on the proposed channel model, we also evaluate the performance of path loss, scattering richness, and attenuation of UWOC links. Numerical results suggest that multiple scattering can compensate the path loss overestimated by traditional approaches. Furthermore, scattering richness and attenuation tend to increase but have opposite effects to raise and reduce the received probabilities of higher order scattered photons, respectively, as link range increases.

ATS_COMM16_023 - Achieving High Energy Efficiency and Physical-Layer Security in AF Relaying
For transmitting data in a secret and energy-efficient manner in collaborative amplify-and-forward relay networks, the secure energy efficiency (EE) defined as the secret bits transferred with unit energy is maximized to satisfy each node power constraint and target secrecy rate requirement, based on physical security framework. The secure EE is maximized by joint source and relay power allocation, which is a nonconvex optimization problem. To cope with this difficulty, a solution scheme and corresponding algorithms are developed by jointly applying fractional programming, exact penalty, alternate search, and difference of convex functions programming. The key idea of the scheme is to convert the primal problem into simple subproblems step by step, such that related methods are adopted. It is verified that, compared with secrecy rate maximization, the proposed scheme improves the secure EE significantly yet with a certain loss of the secrecy rate due to the tradeoff between secure EE and secrecy rate. Furthermore, the proposed scheme achieves higher secure EE and secrecy rate than total transmission power minimization does, while with a certain increase of power consumption. These results indicate that a reasonable balance among secure EE, secrecy rate, and power consumption can be reached by the proposed scheme.

ATS_COMM16_024 - A Batch-based MAC Design with Simultaneous Assignment Decisions for Improved Throughput in Guard-band-constrained Cognitive Networks
The adjacent channel interference (ACI) resulting from imperfect filtering can severely degrade the performance of any wireless communication system. Despite this fact, most of previously proposed medium access control (MAC) protocols for cognitive radio networks (CRNs) were designed while ignoring the effects of ACI (assuming ideal filtering). The effect of ACI can be reduced by introducing guard bands (GBs). However, this solution comes at the expense of degrading spectrum efficiency. In this paper, we develop an efficient GB-aware MAC protocol that attempts at maximizing network throughput while improving fairness in CRNs. Unlike most of previously proposed GB-aware MAC protocols that perform channel assignment sequentially, our MAC performs the channel assignment for multiple CR links simultaneously (the so-called batch method). Batching enables concurrent channel assignment for multiple CR links, which consequently allows for concurrent data transmissions. Batching can be realized by introducing an admission control phase for CR users to share their control information. The batch method can effectively provide distributed decisions that achieve better throughput while reducing the number of GBs. Our MAC also allows the CR users to utilize the reserved GBs of primary networks under predefined FCC power constraints. Simulation results indicate that our protocol achieves significant performance improvement compared to previous GB-aware protocols.

ATS_COMM16_025 - Impact of Antenna Correlation on the BER Performance of a Cognitive Radio Network with Alamouti STBC
This letter presents an average bit error-rate (BER) performance analysis for spectrum sharing in a cognitive radio network in which primary and secondary users employ Alamouti space-time block coding (STBC) under correlated antennas over Rayleigh fading channels. Closed-form expressions are derived for the cumulative density function (CDF) of the secondary user’s signal-to-noise-ratio (SNR) under correlated antennas. Then, closed-form expressions are derived for the average BER of the system with coherent modulation schemes as well as with noncoherent modulation techniques. Using numerical evaluation results from the derived expressions, verified by Monte Carlo simulations, the impacts of antenna correlation on the average BER of the system in different cases are evaluated.

ATS_COMM16_026 - Heterogeneous Cellular Network with Energy Harvesting Based D2D Communication
The concept of mobile user equipment (UE) relay (UER) has been introduced to support device-to-device (D2D) communications for enhancing communication reliability. However, as the UER needs to use its own power for other UE's data transmission, relaying information in D2D communication may be undesirable for the UER. To overcome this issue, motivated by the recent advances in energy harvesting (EH) techniques, we propose a D2D communication provided EH heterogeneous cellular network (D2D-EHHN), where UERs harvest energy from an access point (AP) and use the harvested energy for D2D communication. We develop a framework for the design and analysis of D2D-EHHN by introducing the EH region (EHR) and modeling the status of harvested energy using Markov chain. The UER distribution is derived, and a transmission mode selection scheme including the efficient UER selection method is proposed. The network outage probability is derived in close form to measure the performance of D2D-EHHN. Based on our analysis results, we explore the effects of network parameters on the outage probability and the optimal offloading bias in terms of the outage probability. Particularly, we show that having a high EH efficiency enhances the performance of D2D-EHHN, but can also degrade, especially for dense network.

ATS_COMM16_027 - Artificial Noise Aided Secrecy Information and Power Transfer in OFDMA Systems
In this paper, we study simultaneous wireless information and power transfer (SWIPT) in orthogonal frequency division multiple access (OFDMA) systems with the coexistence of information receivers (IRs) and energy receivers (ERs). The IRs are served with best-effort secrecy data and the ERs harvest energy with minimum required harvested power. To enhance the physical layer security for IRs and yet satisfy energy harvesting requirements for ERs, we propose a new frequency-domain artificial noise (AN) aided transmission strategy. With the new strategy, we study the optimal resource allocation for the weighted sum secrecy rate maximization for IRs by power and subcarrier allocation at the transmitter. The studied problem is shown to be a mixed integer programming problem and thus nonconvex, while we propose an efficient algorithm for solving it based on the Lagrange duality method. To further reduce the computational complexity, we also propose a suboptimal algorithm of lower complexity. The simulation results illustrate the effectiveness of proposed algorithms as compared against other heuristic schemes.

ATS_COMM16_028 - Dynamic Clustering and ON/OFF Strategies for Wireless Small Cell Networks
In this paper, a novel cluster-based approach for maximizing the energy efficiency of wireless small cell networks is proposed. A dynamic mechanism is proposed to locally group coupled small cell base stations (SBSs) into clusters based on location and traffic load. Within each formed cluster, SBSs coordinate their transmission parameters to minimize a cost function, which captures the tradeoffs between energy efficiency and flow level performance, while satisfying their users' quality-of-service requirements. Due to the lack of intercluster communications, clusters compete with one another to improve the overall network's energy efficiency. This intercluster competition is formulated as a noncooperative game between clusters that seek to minimize their respective cost functions. To solve this game, a distributed learning algorithm is proposed using which clusters autonomously choose their optimal transmission strategies based on local information. It is shown that the proposed algorithm converges to a stationary mixed-strategy distribution, which constitutes an epsilon-coarse correlated equilibrium for the studied game. Simulation results show that the proposed approach yields significant performance gains reaching up to 36% of reduced energy expenditures and upto 41% of reduced fractional transfer time compared to conventional approaches.

ATS_COMM16_029 - Cooperative Multicasting in Renewable Energy Enhanced Relay Networks – Expending More Power to Save Energy
Power and on-off control problems are examined for renewable energy enabled base-stations (BSs) and relay nodes (RNs) in cooperative multicast networks. Renewable energy is utilized at BSs and RNs to reduce the overall grid energy cost. By considering a practical energy consumption model and the statistics of the renewable energy arrival, the optimal transmit powers are first determined by minimizing the expected grid energy consumption subject to an average outage probability constraint at MUs. The optimal solution is found via line search in the general case and is obtained in closed-form at high SNR. In addition, an on-off control policy is also proposed to further reduce the basic operational energy costs. The joint on-off and power control problems are solved approximately using two sequential deflation techniques, namely, the subset-search and the convex-relaxation-based approaches. The power control problem is also extended to the multicarrier scenario with unequal transmit powers and is solved using successive convex approximation. Simulations using the photovoltaic energy arrival model are provided to demonstrate the effectiveness of the proposed schemes. The results show that expending more power at RNs allows for more efficient use of renewable energy and, thus, increases energy-savings.

ATS_COMM16_030 - Iterative Distributed Minimum Total MSE Approach for Secure Communications in MIMO Interference Channels
In this paper, we consider the problem of jointly designing transmit precoding (TPC) matrix and receive filter matrix subject to both secrecy and per-transmitter power constraints in the multiple-input multiple-output (MIMO) interference channel, where K legitimate transmitter-receiver pairs communicate in the presence of an external eavesdropper. Explicitly, we jointly design the TPC and receive filter matrices based on the minimum total mean-squared error (MSE) criterion under a given and feasible information-theoretic degrees of freedom. More specifically, we formulate this problem by minimizing the total MSEs of the signals communicated between the legitimate transmitter-receiver pairs, while ensuring that the MSE of the signals decoded by the eavesdropper remains higher than a certain threshold. We demonstrate that the joint design of the TPC and receive filter matrices subject to both secrecy and transmit power constraints can be accomplished by an efficient iterative distributed algorithm. The convergence of the proposed iterative algorithm is characterized as well. Furthermore, the performance of the proposed algorithm, including both its secrecy rate and MSE, is characterized with the aid of numerical results. We demonstrate that the proposed algorithm outperforms the traditional interference alignment algorithm in terms of both the achievable secrecy rate and the MSE. As a benefit, secure communications can be guaranteed by the proposed algorithm for the MIMO interference channel even in the presence of a sophisticated/strong eavesdropper, whose number of antennas is much higher than that of each legitimate transmitter and receiver.

ATS_COMM16_031 - A Novel Coding Scheme for Secure Communications in Distributed RFID Systems
Privacy protection is the primary concern when RFID applications are deployed in our daily lives. Due to the computational power constraints of passive tags, non-encryption-based singulation protocols have been recently developed, in which wireless jamming is used. However, the existing private tag access protocols without shared secrets rely on impractical physical layer assumptions, and thus they are difficult to deploy. To tackle this issue, we first redesign the architecture of RFID system by dividing an RF reader into two different devices, an RF activator and a trusted shield device (TSD). Then, we propose a novel coding scheme, namely Random Flipping Random Jamming (RFRJ), to protect tags' content. Unlike the past work, the proposed singulation protocol utilizes only the physical layer techniques that are already implemented. Analyses and simulation results validate our distributed architecture with the RFRJ coding scheme, which defends tags' privacy against various adversaries including the random guessing attack, correlation attack, ghost-and-leech attack, and eavesdropping.

ATS_COMM16_032 - A Configurable Energy-Efficient Compressed Sensing Architecture with Its Application on Body Sensor Networks
The past decades have witnessed a rapid surge in new sensing and monitoring devices for well-being and healthcare. One key representative in this field is body sensor networks (BSNs). However, with advances in sensing technologies and embedded systems, wireless communication has gradually become one of the dominant energy-consuming sectors in BSN applications. Recently, compressed sensing (CS) has attracted increasing attention in solving this problem due to its enabled sub-Nyquest sampling rate. In this paper, we investigate the quantization effect in CS architecture and argue that the quantization configuration is a critical factor of the energy efficiency for the entire CS architecture. To this end, we present a novel configurable quantized compressed sensing (QCS) architecture, in which the sampling rate and quantization are jointly explored for better energy efficiency. Furthermore, to combat the computational complexity of the configuration procedure, we propose a rapid configuration algorithm, called RapQCS. According to the experiments involving several categories of real biosignals, the proposed configurable QCS architecture can gain more than 66% performance-energy tradeoff than the fixed QCS architecture. Moreover, our proposed RapQCS algorithm can achieve over 150× speedup on average, while decreasing the reconstructed signal fidelity by only 2.32%.

ATS_COMM16_033 - Limited Rate Feedback Scheme for Resource Allocation in Secure Relay-Assisted OFDMA Networks
In this paper, we consider the problem of resource allocation for secure communications in decode-and-forward (DF) relay-assisted orthogonal frequency-division multiple access (OFDMA) networks. In our setting, users want to securely communicate to the base station (BS) with the help of a set of relay stations (RSs) in the presence of multiple eavesdroppers. We assume that all channel state information (CSI) of the legitimate links and only the channel distribution information (CDI) of the eavesdropper links are available. We formulate our problem as an optimization problem whose objective is to maximize the sum secrecy rate of the system subject to individual transmit power constraint for each user and RS. As a first work which considers limited feedback schemes for secure communications in cooperative OFDMA networks, we consider the limited-rate feedback case, where in addition to transmit power and subcarrier assignments, channel quantization should be performed and boundary regions of channels should be computed. We further consider the noisy feedback channel. We solve our problem using the dual Lagrange approach and propose an iterative algorithm whose convergence is analyzed. Using simulations, we evaluate the performance of the proposed scheme in numerous situations.

ATS_COMM16_034 - Delay and Power Consumption in LTE/LTE-A DRX Mechanism with Mixed Short and Long Cycles
Energy consumption is a major concern in today's wireless communications due to the consensus for a greener world. LTE-Advanced (LTE-A) has been standardized for the fourth-generation mobile communications to meet the growing demands for high-speed wireless communications. However, high-speed signal processing on LTE/LTE-A user equipment (UE) causes excessive power consumption. The discontinuous reception (DRX) mechanism is a critical technique for tackling this issue. Delay constraint and power savings are two contradictory performance metrics associated with the DRX mechanism. Using recursive deduction and Markov model, this paper provides an in-depth analysis on the average delay and average power consumption of the DRX mechanism. Two performance metrics, namely, power-saving factor and relative power saving, are devised to assess the power-saving performance of the DRX mechanism. The accuracy of theoretical analysis is validated by computer simulations using the parameters in compliance with LTE specifications. The performance of the DRX mechanism is governed by a set of parameters that interact with one another in an intricate manner. Therefore, the values of key parameters are tested to assess their impacts on the performance of the DRX mechanism. The results shown in this paper give an insight into the operation and further improvement of the DRX mechanism.

ATS_COMM16_035 - A Simple Recursively Computable Lower Bound on the Noncoherent Capacity of Highly Underspread Fading Channels
Real-world wireless communication channels are typically highly underspread: their coherence time is much greater than their delay spread. In such situations, it is common to assume that, with sufficiently high bandwidth, the capacity without channel state information (CSI) at the receiver (termed the noncoherent channel capacity) is approximately equal to the capacity with perfect CSI at the receiver (termed the coherent channel capacity). In this paper, we propose a lower bound on the noncoherent capacity of highly underspread fading channels, which assumes only that the delay spread and coherence time are known. Furthermore, our lower bound can be calculated recursively, with each increment corresponding to a step increase in bandwidth. These properties, we contend, make our lower bound an excellent candidate as a simple method to verify that the noncoherent capacity is indeed approximately equal to the coherent capacity for typical wireless communication applications. We precede the derivation of the aforementioned lower bound on the information capacity with a rigorous justification of the mathematical representation of the channel. Furthermore, we also provide a numerical example for an actual wireless communication channel and demonstrate that our lower bound does indeed approximately equal the coherent channel capacity.

ATS_COMM16_036 - On the Capacity of the Intensity-Modulation Direct-Detection Optical Broadcast Channel
The capacity of the intensity-modulation direct-detection optical broadcast channel (OBC) is investigated, under both average and peak intensity constraints. An outer bound on the capacity region is derived by adapting Bergmans’ approach to the OBC. Inner bounds are derived by using superposition coding with either truncated-Gaussian (TG) distributions or discrete distributions. While the discrete distribution achieves higher rates, the TG distribution leads to a simpler representation of the achievable rate region. At high signal-to-noise ratio (SNR), it is shown that the TG distribution is nearly optimal. It achieves the symmetric-capacity within a constant gap (independent of SNR), which approaches half a bit as the number of users grows. It also achieves the capacity region within a constant gap. At low SNR, it is shown that on–off keying (OOK) with time-division multiple-access (TDMA) is optimal. This is interesting in practice since both OOK and TDMA have low complexity. At moderate SNR (typically [0,8] dB), a discrete distribution with a small alphabet size achieves fairly good performance.

ATS_COMM16_037 - Optimum Co-Design for Spectrum Sharing Between Matrix Completion Based MIMO Radars and a MIMO Communication System
Spectrum sharing enables radar and communication systems to share the spectrum efficiently by minimizing mutual interference. Recently proposed multiple input multiple output radars based on sparse sensing and matrix completion (MIMOMC), in addition to reducing communication bandwidth and power as compared to MIMO radars, offer a significant advantage for spectrum sharing. The advantage stems from the way the sampling scheme at the radar receivers modulates the interference channel from the communication system transmitters, rendering it symbol dependent and reducing its row space. This makes it easier for the communication system to design its waveforms in an adaptive fashion so that it minimizes the interference to the radar subject to meeting rate and power constraints. Two methods are proposed. First, based on the knowledge of the radar sampling scheme, the communication system transmit covariance matrix is designed to minimize the effective interference power (EIP) to the radar receiver, while maintaining certain average capacity and transmit power for the communication system. Second, a joint design of the communication transmit covariance matrix and the MIMO-MC radar sampling scheme is proposed, which achieves even further EIP reduction.

ATS_COMM16_038 - SLRMA: Sparse Low-Rank Matrix Approximation for Data Compression
Low-rank matrix approximation (LRMA) is a powerful technique for signal processing and pattern analysis. However, its potential for data compression has not yet been fully investigated in the literature. In this paper, we propose sparse lowrank matrix approximation (SLRMA), an effective computational tool for data compression. SLRMA extends the conventional LRMA by exploring both the intra- and inter-coherence of data samples simultaneously. With the aid of prescribed orthogonal transforms (e.g., discrete cosine/wavelet transform and graph transform), SLRMA decomposes a matrix into a product of two smaller matrices, where one matrix is made of extremely sparse and orthogonal column vectors, and the other consists of the transform coefficients. Technically, we formulate SLRMA as a constrained optimization problem, i.e., minimizing the approximation error in the least-squares sense regularized by 0- norm and orthogonality, and solve it using the inexact augmented Lagrangian multiplier method. Through extensive tests on realworld data, such as 2D image sets and 3D dynamic meshes, we observe that (i) SLRMA empirically converges well; (ii) SLRMA can produce approximation error comparable to LRMA but in a much sparse form; (iii) SLRMA-based compression schemes significantly outperform the state-of-the-art in terms of ratedistortion performance.

ATS_COMM16_039 - Gammatone Filter Based on Stochastic Computation
This paper introduces a design of a gammatone filter based on stochastic computation for area-efficient hardware. The gammatone filter well expresses the performance of human auditory peripheral mechanism and has a potential of improving advanced speech communications systems, especially hearing assisting devices and noise robust speech recognition systems. Using stochastic computation, a power-and-area hungry multiplier used in a digital filter is replaced by a simple logic gate, leading to area-efficient hardware. However, a straightforward implementation of the stochastic gammatone filter suffers from significantly low accuracy in computation, which results in a low dynamic range (a ratio of the maximum to minimum magnitude) due to a small value of a filter gain. To improve the computational accuracy, gain-balancing techniques are presented that represent the original gain as the product of multiple larger gains introduced at the second-order sections. As a result, the proposed techniques maintain the original gain of the filter while improving the computational accuracy. The proposed stochastic gammatone filters are designed and evaluated using MATLAB that achieves a high dynamic range of 71.71 dB compared with a low dynamic range of 5.47 dB in the straightforward implementation.

ATS_COMM16_040 - A Scertain Privacy Conservation And Data Security Protection Onboard Small Uas
The potential application areas for small Unmanned Aerial Systems (sUAS) are massive. This paper takes into account the unstoppable trend toward the widespread use of sUAS for a large number of applications and reports on the needed privacy preserving measures and techniques. Specifically, this work researches the prospect of implementing object detection and blurring techniques on the actual sUAS hardware, such that the privacy of sensitive objects captured by the sUAS camera is preserved. The solution approach is to embed FPGA development boards with connected image sensors onboard the sUAS and implement MATLAB image processing algorithms into VHDL/Verilog code. Given the fact that the sUAS may run out of battery or crash during flight, and thus be captured by unauthorized persons, data encryption on the FPGA development boards needs also be studied for security purposes.

ATS_COMM16_041 - Effective Range Doppler Algorithm Simulator Using Vectorization Technique
This paper deals with a new adaption technique for general simulator of using vectorization. This approach is more time effective in comparing with the standard method. In the article, the simulation process of the RDA is analyzed and describes which is widely used for Synthetic Aperture Radar (SAR) imaging techniques. The simulation algorithm uses vectorization which satisfies algorithm performance. There are also depicted all parts of RDA and its results. The echoed signal which was assumed in simulation is described and also its parameters.

ATS_COMM16_042 - Auto Target Detection of Humanoid and Auto Shooting Using Sniper: A Design Approach
In this paper a new defense mechanism using image processing has been implemented which can acquire targets at long distances with high precision in various weather conditions. The main objective is to make an effective tool for the armed forces which can guard the border areas. The mechanism consists of two modules: targeting unit and firing unit. The targeting unit has a microcontroller along with sensors to detect the presence of humans in the targeted area and processes various atmospheric parameters electronically. LASER pointer is used to determine if the desired target is hit or missed by tracking the path of the bullet and determining the point of intersection with the LASER. The targeting unit has special mechanism which can position the gun automatically once the parameters are obtained.

ATS_COMM16_043 - A System Concept for a 3D Real-Time OFDM MIMO Radar for Flying Platforms
In this paper a new system concept for a low cost, miniaturized and real-time imaging radar system for flying platforms is presented. The proposed solution is based on the MIMO radar architecture, orthogonal signals for simultaneous transmit capabilities and highly integrated SiGe chipsets. Using beamforming techniques at the receiver together with radar processing techniques, a 3D sensing of the range, azimuth, elevation and Doppler information for an arbitrary number of objects can be estimated through a simultaneous transmission and with real-time hardware implementable FFT processing techniques. A top-level system concept and a complete parametrization is proposed for a radar system which is intended for obstacle warning for helicopters and to enhance flight safety in approach, landing and take-off phases of flight even in degraded visual conditions. The full OFDM MIMO Radar system has been implemented and tested in a MATLAB environment and simulation results are here presented. This paper is the first step towards the implementation of a compact and real-time radar system demonstrator.

ATS_COMM16_044 - Onboard Radar Processor Development for Rapid Response to Natural Hazards
The unique capabilities of imaging radar to penetrate cloud cover and collect data in darkness over large areas at high resolution makes it a key information provider for the management and mitigation of natural and human-induced hazards. Researchers have demonstrated the use of UAVSAR data to determine flood extent, forest fire extent, lava flow, and landslide. Data latency of at most 2–3 h is required for the radar data to be of use to the disaster responders. We have developed a UAVSAR on-board processor for real time and autonomous operations that has high fidelity and accuracy to enable timely generation of polarimetric and interferometric data products for rapid response applications. This on-board processor design provides a space-qualification path for technology infusion into future space missions in a high-radiation environment with modest power and weight allocations. The processor employs a hybrid architecture where computations are divided between field-programmable gate arrays, which are better suited to rapid, repetitious computations, and a microprocessor with a floating-point coprocessor that is better suited to the less frequent and irregular computations. Prior to implementing phase preserving processor algorithms in FPGA code, we developed a bit-true processor model in MATLAB that is modularized and parameterized for ease of testing and the ability to tradeoff processor design with performance. The on-board processor has been demonstrated on UAVSAR flights.

ATS_COMM16_045 - Experimental 210GHz tera hertz nonde structive testing foraerospace composite materials
In this paper we proposed a terahertz nondestructive testing method to achieve the image of the aerospace composite materials. We commence in the following manner, using the continuous back wave oscillator (BWO) as the source of terahertz radiation, which the frequency is 210 GHz. By the reflection type imaging testing system, the terahertz probe focus moves from the surface to inside of the concealed composite materials. And the materials are bonded on the two-dimensional scanning translation units towards the focal of the terahertz mirror, which can move in real-time to get the data by the phase-locked amplifier. All the system is controlled by the computer. The interior structure can be tested by the images range from 0.5mm to 1mm resolution. The images are calculated by principal component analysis (PCA) and the least square method(LSM). With the proper math to calculate in Matlab, the structure, the size, position and shape defects such as cracks, inclusions, empty and bubbles in the aerospace insulation composite materials can be tested by the terahertz image system. It is a more convenient and intuitive method of imaging inner aerospace composite material.

Wednesday, June 29, 2016


ARIHANT TECHNO SOLUTIONS

OMNET IEEE PROJECTS - 2016-2017

ATS_OMN16_001 - A Study on Suitable Range of Packetization Interval for Streaming Application over WLAN
Ensuring satisfactory Quality of Service (QoS) is a vital consideration in deploying multimedia streaming service, especially when deploying over wireless network. Selecting suitable parametric values for each streaming parameter is one of a crucial factor. This work is concerned with one of the parameters commonly known as `Packetization Interval' which has direct influences on several critical QoS parameters such as packet loss, packet delay and jitters. The experiment on finding a suitable range of packetization interval had been carried out by means of simulation using INET Framework for OMNeT++. The simulations were carried out based on the basic service set scenario in both no interference and coexistence with background traffics. The result reveals that the commonly recommended default packetization interval of 20 ms. fails to yield satisfactory QoS in many scenarios. The study also indicates that a suitable packetization interval for scenarios under this study or similar ones ought to be set within the range of 40 ms-70 ms. The paper also discusses the findings and applications are suggested.

ATS_OMN16_002 - Multi-agent and Reinforcement Learning Based Code Offloading in Mobile Fog
Fog computing, which performs on network edges, is a front-end distributed computing archetype of centralized cloud computing. Mobile Fog is a special purpose computing prototype, which leverages the mobile computing to deliver seamless and latency-aware mobile services. Offloading computation in mobile Fog is challenging because of the spatiotemporal resource requirements of heterogeneous mobile devices. In this paper, we propose reinforcement learning based code offloading mechanism to ensure low-latency service delivery towards mobile service consumers. We use the distributed reinforcement learning algorithm to offload basic blocks in a decentralized fashion to deploy mobile codes on geographically distributed mobile Fogs. We simulate the proposed prototype using OMNeT++ considering fluctuated resources of mobile Fog and varied service demands of mobile users. The proposed method significantly reduces the execution time and latency of accessing mobile services while ensuring lower energy consumption of mobile devices.

ATS_OMN16_003 - Cyber–Physical Modeling of Distributed Resources for Distribution System Operations
Cosimulation platforms are necessary to study the interactions of complex systems integrated in future smart grids. The Virtual Grid Integration Laboratory (VirGIL) is a modular cosimulation platform designed to study interactions between demand-response (DR) strategies, building comfort, communication networks, and power system operation. This paper presents the coupling of power systems, buildings, communications, and control under a master algorithm. There are two objectives: first, to use a modular architecture for VirGIL, based on the functional mockup interface (FMI), where several different modules can be added, exchanged, and tested; and second, to use a commercial power system simulation platform, familiar to power system operators, such as DIgSILENT PowerFactory. This will help reduce the barriers to the industry for adopting such platforms, investigate and subsequently deploy DR strategies in their daily operation. VirGIL further introduces the integration of the quantized state system (QSS) methods for simulation in this cosimulation platform. Results on how these systems interact using a real network and consumption data are also presented.

ATS_OMN16_004 - New Solution For The Creation Of MANETs Based On Personal Devices
Mobile ad hoc networks (MANETs) enable communication between moving nodes through multi-hop wireless routes. There are protocols with special features that handle both auto-configuration and routing in these networks. Nevertheless, many of these auto-configuration protocols have not been truly implemented and in consequence, only exist a few available solutions for MANETs conformation. This article presents a new solution for this issue, mainly in cases where only personal devices are available. The core of the proposal is a new auto-configuration protocol, which allows dynamic allocation of unique IP addresses and accomplishes effective answers in front of issues like mergers and partitions of networks, and others. Finally, the results of simulations in OMNET++ and of tests of a pilot version based on Android mobile phones are shown.

ATS_OMN16_005 - Integrated Wireless Communication System Using MANET for Remote Pastoral Areas of Tibet
To reduce the network deployment cost and provide voice, message and low rate data services in remote pastoral areas of Tibet effectively, an integrated wireless communication system utilizing MANET (Mobile Ad hoc Network) is proposed. The sparse mobile devices, assisted with the solar-powered multi-functional standing stations mainly on networking maintenance and routing arrangement, self-organize into a MANET. The topology of the standing stations is designed for networking robust and to simplify the routing method and energy strategy. Then in the OMNeT++ (Objective Modular Network Test bed in C++) simulation, the energy consumption is analysis while adjusting routing with the different energy status of the standing stations. The result shows that the standing stations should adjust routing as well as control the mobile devices' activity level according to the energy states of the standing stations and their adjacent mobile devices.

ATS_OMN16_006 - TCast: A Transitional Region Aware Broadcast Protocol in Variable Wireless Link Qualities 
As Internet-of-Things (IoT) and its applications are increasingly popular, where diverse multi-scale sensors and devices are seamlessly blended for ubiquitous communication infrastructure, broadcast operation still plays an essential role in scalable information dissemination to enhance information accessibility and availability. A unit-disk signal propagation model has been implicitly assumed and extensively applied to prior broadcast protocols, but we need to relax this assumption in reality. In this paper, we propose a transitional region aware broadcast protocol, called TCast, in variable wireless link qualities due to the signal propagation effects and non-uniform radiation pattern from the omni-directional antenna. The TCast is a stateless protocol and consists of two major operations, forwarder search and probabilistic rebroadcast. A sender neither maintains any neighbor information nor searches for a set of forwarders, but broadcasts a set of Beacon packets followed by a single Data packet. The sender repeatedly conducts the broadcast operations depending on the number of rebroadcasted packets overheard. Each receiver independently makes its own rebroadcast decision based on the number of received Beacon packets. A network-level random backoff mechanism is also proposed to avoid any packet contentions and collisions. The transitional region and its corresponding probability of packet reception are further investigated through a simple mathematical analysis. Extensive simulation experiments are also conducted using the OMNeT++, and simulation results indicate that the TCast shows competitive and scalable performance and is deployable in time-varying packet reception rates at receivers.

ATS_OMN16_007 - Combining OpenFabrics Software and Simulation Tools for Modeling InfiniBand-based Interconnection Networks
The design of interconnection networks is becoming extremely important for High-Performance Computing (HPC) systems in the Exascale Era. Design decisions like the selection of the network topology, routing algorithm, fault tolerance and/or congestion control are crucial for the network performance. Besides, the interconnection network designers are also focused on creating middleware layers compatible to different network technologies, which make it possible for these technologies to interoperate. One example is the OpenFabrics Software (OFS) used in HPC for breakthrough applications that require high efficiency computing, wire-speed messaging, microsecond latencies and fast I/O for storage and file systems. OFS is compatible with several HPC interconnect technologies, like InfiniBand, iWarp or RoCE. One challenge in the design of new features for improving the interconnection network performance is to model in specific simulation tools the latency introduced by the OFS modules into the network traffic. In this paper, we present a work-in-progress methodology to combine the OFS middleware with OMNeT++-based simulation tools, so that we can use some of the OFS modules, like OpenSM or ibsim, combined with simulation tools. We also propose a set of tools for analyzing the properties of different network topologies. Future work will consist on modeling other OFS modules functionality in network simulators.

ATS_OMN16_008 - Simulating Search Protocols in Large-Scale Dynamic Networks
Reproducing complex networks with features of real-life networks is exciting and challenging at the same time. Based on the popular Omnet++ discrete event simulator, we introduce Armonia, a framework for modeling massive networks and their dynamic interactions. It includes a collection of topology generators, a set of resource placement and replication modules, a component for specifying resource location strategies, while also offering support for exporting data in order to visualize or analyze with other appropriate tools. Our framework targets search protocols in large-scale dynamic networks. Here, we apply it to simulate various probabilistic flooding strategies, making a comparative study of their performance over different network topologies.

ATS_OMN16_009 - A Variable Speed Limit (VSL) based Model for Advanced Traffic Management through VANETs 
Roads and automobiles have become increasingly important in our day to day lives. To make the roads safer and to enhance the road traffic safety, various technologies have been converged which have become key components of Intelligent Transportation Systems (ITS) network. One of such Technology is "Vehicular Ad hoc Networks" (VANETs) which is a variant of "Mobile Ad hoc Networks" (MANETs) in which automobiles act as mobile nodes and are capable of communicating with one another and hence create a mobile network with a wide range. This paper discusses how to enhance Road Safety and Traffic Management using Variable Speed Limit (VSL) through VANETs. The paper also discusses the limitation of existing system primarily used in India and presents features of VSL systems to overcome the problems faced due to traditional systems. Validation of the paper is done using SUMO Simulator and tools like OMNet++ and Veins.

ATS_OMN16_010 - Analyzing the Energy (Dis-)Proportionality of Scalable Interconnection Networks
Power consumption is one of the most important aspects regarding design and operation of large computing systems, such as High-Performance Computing (HPC) and cloud installations. Various hard constraints exist due to technical, economic and ecological reasons. We will show that interconnection networks contribute substantially to power consumption, even though their peak power rating is low compared to other components. Moreover, networks are still not energy-proportional, opposed to other components such as processors. In fact, network links consume the same amount of energy whether they are in use or not. In this work, we analyze the potential of power savings in high-performance direct interconnection networks. First, by analyzing the power consumption of today's network switches we find that network links contribute most to a switch's power, but they behave differently than other components like processors regarding possible power saving. We extend a OMNeT++ based interconnection network simulator with link power models to asses power savings. Our early experiments, based on traces of the NAMD and Graph500 applications show an immense potential for power saving, as we observe long inactivity periods. However, in order to design effective power saving strategies it is necessary to come to a detailed understanding of different hardware parameters. The transition time, which is the time required to reconfigure a link, could be crucial for most strategies. We see our OMNeT++ based, energy-aware simulator as a first step towards a deeper knowledge regarding such constraints.

Monday, June 27, 2016


ARIHANT TECHNO SOLUTIONS

EMBEDDED IEEE PROJECTS - 2016-2017


ATS_EMB16_001 - Remote monitoring of photovoltaic systems using embedded system clusters
Remote monitoring of photovoltaic systems is critically important for the users. The performance of each component existing in these systems should be observable. In this study, a cheap and easily mountable remote monitoring design for low cost photovoltaic systems located near urban areas is proposed. With this design, it is aimed to transmit collected information at the remote solar energy station with MPI (Message Passing Interface). A design has been done for a remote monitoring of a 1kW photovoltaic system. With this design, panel and battery voltages, temperature and humidity can be observed remotely. An embedded system cluster consisting of single-board computers has been used in the design. This cluster is composed of a center single-board computer and remote node single-board computers as many as the photovoltaic system count. Collected information is broadcasted over internet using the single-board computer at the center.

ATS_EMB16_002 - Wearable Noncontact Armband for Mobile ECG Monitoring System
One of the best ways to obtain health information is from an electrocardiogram (ECG). Through an ECG, characteristics such as patients’ heartbeats, heart conditions, and heart disease can be analyzed. Unfortunately, most available healthcare devices do not provide clinical data such as information regarding patients’ heart activities. Many researchers have tried to solve this problem by inventing wearable heart monitoring systems with a chest strap or wristband, but their performances were not feasible for practical applications. Thus, the aim of this study is to build a new system to monitor heart activity through ECG signals. The proposed system consists of capacitive-coupled electrodes embedded in an armband. It is considered to be a reliable, robust, and low-power-transmission ECG monitoring system. The reliability of this system was achieved by the careful placement of sensors in the armband. Bluetooth low energy (BLE) was used as the protocol for data transmission; this protocol was proposed to develop the low-power-transmission system. For robustness, the proposed system is equipped with analysis capabilities–e.g., real-time heartbeat detection and a filter algorithm to ignore distractions from body movements or noise from the environment.

ATS_EMB16_003 - UR-SolarCap: An Open Source Intelligent Auto-Wakeup Solar Energy Harvesting System for Supercapacitor Based Energy Buffering
Energy harvesting systems that couple solar panels with supercapacitor buffers offer an attractive option for powering computational systems deployed in “field settings,” where power infrastructure is inaccessible. Supercapacitors offer a particularly compelling advantage over electrochemical batteries for such settings because of their ability to survive many more charge-discharge cycles. We share UR-SolarCap – a versatile open source design for such a harvesting system that targets embedded system applications requiring power in the 1–10 W range. Our system is designed for high efficiency and controllability and, importantly, supports auto-wakeup from a state of complete energy depletion. This paper summarizes our design methodology, and the rationale behind our design and configuration decisions. Results from the operation and testing of a system realized with our design demonstrate: (a) an achievable harvester efficiency of 85%, (b) the ability to maintain sustained operation over a two week period when the solar panel and buffer are sized appropriately, and (c) a robust auto-wakeup functionality that resumes system operation upon availability of harvestable energy after a period in which the system has been forced into a dormant state because of a lack of usable energy. To facilitate the use of the system by researchers exploring embedded system applications in environments that lack a power infrastructure, our designs are available for download as an archive containing design schematics, PCB files, firmware code, and a component list for assembly of the system. Additionally, a limited number of pre-assembled kits are available upon request.

ATS_EMB16_004 - Real-time patient health monitoring and alarming using wireless-sensor-network
The main objective of this research is design and realization of real-time monitoring and alarming system for patient health, especially for patients suffering from diseases during their normal life. The proposed system has an embedded microcontroller connected to a set of medical sensors (related to the patient case) and a wireless communication module (Bluetooth). Each patient is considered as a node in a wireless sensor network and connected to a central node installed at the medical center through an internet connection. The embedded microcontroller checks if the patient health status is going well or not by analyzing the scanned medical signals. If the analysis results are abnormal, the embedded unit uses the patient's phone to transmit these signals directly to the medical center. In this case, the doctor will send medical advice to the patient to save his/her life. The implemented prototype has been tested and calibrated with standard devices. The experimental results confirm the effectiveness of the proposed system that is accurate in scanning, clear in monitoring, intelligent in decision making, reliable in communication, and cheap (about 100 US$).

ATS_EMB16_005 - Assessment of Robotic Picking Operations Using a 6 Axis Force/Torque Sensor
This letter presents a novel architecture for evaluating the success of picking operations that are executed by industrial robots. It is formed by a cascade of machine learning algorithms (kNN and SVM) and uses information obtained by a 6 axis force/torque sensor and, if available, information from the built-in sensors of the robotic gripper. Beyond measuring the success or failure of the entire operation, this architecture makes it possible to detect in real-time when an object is slipping during the picking. Therefore, force and torque signatures are collected during the picking movement of the robot, which is decomposed into five different stages that allows to characterize distinct levels of success over time. Several trials were performed using an industrial robot with two different grippers for picking a long and flexible object. The experiments demonstrate the reliability of the proposed approach under different picking scenarios since, it obtained a testing performance (in terms of accuracy) up to 99.5% of successful identification of the result of the picking operations, considering an universe of 400 attempts.

ATS_EMB16_006 - Evaluating User Gestures in Rehabilitation from Electromyographic Signals
One of the strategies being used over the last years to increase the user commitment and motivation on rehabilitation systems is the use of virtual reality (VR) environments. In addition to contributing to motivation, these systems can simulate real life activities and provide means to measure and evaluate user performance. The use of natural interaction devices originally conceived to the game market allowed the development of low-cost and minimally invasive systems. With the advent of interaction devices based on electromyography, the electromyographic signals of the user can also be used on the natural interaction process. This work has as goal to verify if, by using a evaluation model, is possible to evaluate user performance in real time through gesture recognition by means of an electromyography device attached to a rehabilitation system.

ATS_EMB16_007 - Implementation of ZigBee-VLC system to support light control network configuration
In this paper, ZigBee-VLC Transmitter and Receiver are designed, implemented and tested. By utilizing the ZigBee-VLC Transmitter and Receiver, commissioning procedures for light control network configuration are simplified and commissioning time is drastically reduced. With this configuration, lighting control network configured to use a maximum of 216 lighting is possible. As a result of this research, the transmitter is complete with ZigBee-VLC features implemented in the Single MCU without rising production costs and the 1-board solution receiver including a ZigBee and VLC functions are implemented. In addition, as a result of the test work using the light control app, dramatically shortening commissioning time, easy lighting control is possible was confirmed.

ATS_EMB16_008 - Coexistence of ZigBee-Based WBAN and WiFi for Health Telemonitoring Systems
The development of telemonitoring via wireless body area networks (WBANs) is an evolving direction in personalized medicine and home-based mobile health. A WBAN consists of small, intelligent medical sensors which collect physiological parameters such as electrocardiogram, electroencephalography, and blood pressure. The recorded physiological signals are sent to a coordinator via wireless technologies, and are then transmitted to a healthcare monitoring center. One of the most widely used wireless technologies in WBANs is ZigBee because it is targeted at applications that require a low data rate and long battery life. However, ZigBee-based WBANs face severe interference problems in the presence of WiFi networks. This problem is caused by the fact that most ZigBee channels overlap with WiFi channels, severely affecting the ability of healthcare monitoring systems to guarantee reliable delivery of physiological signals. To solve this problem, we have developed an algorithm that controls the load in WiFi networks to guarantee the delay requirement for physiological signals, especially for emergency messages, in environments with coexistence of ZigBee-based WBAN and WiFi. Since WiFi applications generate traffic with different delay requirements, we focus only on WiFi traffic that does not have stringent timing requirements. In this paper, therefore, we propose an adaptive load control algorithm for ZigBee-based WBAN/WiFi coexistence environments, with the aim of guaranteeing that the delay experienced by ZigBee sensors does not exceed a maximally tolerable period of time. Simulation results show that our proposed algorithm guarantees the delay performance of ZigBee-based WBANs by mitigating the effects of WiFi interference in various scenarios.

ATS_EMB16_009 - ZigBee network system for observing operating activities of work vehicles
Observing activities of working vehicles on a work site, such as a factory, is important in regard to managing the lifetime of vehicles and achieving high operational availability. However, it is a problem that an administrator cannot completely grasp the activities of a working vehicle. Existing systems cannot cover a large area, particularly in an indoor environment. A system is proposed for monitoring operating activities of working vehicles, regardless of whether they are operating indoors or outdoors. The system calculates the activity rate of a vehicle by analyzing the topology of a network configured by the wireless technology ZigBee. In addition, it was experimentally verified that network topology and RSSI can be used to estimate activities of working vehicles.

ATS_EMB16_010 - The Design of Building Fire Monitoring System Based on ZigBee-WiFi Networks
With the rapid development of wireless communication technology, people's life has undergone great changes. In recent years, the comfort and safety of the building environment have become a universal concern. However, building fire is the greatest threat to building safety. In consideration of the current issues on building security, the design applies the important part, the wireless sensor network technology to building fire safety monitoring system and establishes the wireless sensor network by using ZigBee technology and ZigBee-WiFi gateway which transforms ZigBee network into WiFi network, In addition, taking advantage of the ZigBee wireless sensor network locates a fire place so that the fire information is uploaded to the handheld terminal and the building security personnel work out the retreat and rescue plan in time. This paper provides a new solution for building fire monitoring system.

ATS_EMB16_011 - A low complex spread spectrum scheme for ZigBee based smart home networks
One of the biggest challenges that consumers and service providers have is connecting a wide range of consumer electronics in a smart home environment. Resource planning and bandwidth allocation for these networks in the license free Industrial Scientific Medical (ISM) frequency band can not be guaranteed. In this paper, we propose improvements for ZigBee physical layer in order to cope with coexistence issue. A detailed MATLAB/Simulink simulator is developed to achieve our objective. In order to balance the trade-off between multipath effects and receiver complexity, the spreading gain of the conventional Direct Sequence Spread Spectrum (DSSS) scheme is limited to 9dB. Unfortunately, this reduces the interference suppression capability of spread spectrum schemes. Here, we propose a low complex spread spectrum scheme for the ZigBee physical layer. The proposed scheme is shown to be robust against multipath fading and interference with a low complexity.

ATS_EMB16_012 - Interference-Mitigated ZigBee-Based Advanced Metering Infrastructure
An interference-mitigated ZigBee-based advanced metering infrastructure (AMI) solution, namely IMM2ZM, has been developed for high-traffics smart metering (SM). The IMM2ZM incorporates multiradios multichannels network architecture and features an interference mitigation design by using multiobjective optimization. To evaluate the performance of the network due to interference, the channel-swapping time (Tcs) has been investigated. Analysis shows that when the sensitivity (PRχ) is less than -12 dBm, Tcs increases tremendously. Evaluation shows that there are significant improvements in the performance of the application-layer transmission rate (σ) and the average delay (D). The improvement figures are σ > ~300% and D > 70% in a 10-floor building, σ > ~280 % and D > 65% in a 20-floor building, and σ > ~270% and D > 56% in a 30-floor building. Further analysis reveals that IMM2ZM results in typically less than 0.43 s delay for a 30-floor building under interference. This performance fulfills the latency requirement of less than 0.5 s for SMs in the USA (Magazine of Department of Energy Communications, USA, 2010). The IMM2ZM provides a high-traffics interference-mitigated ZigBee AMI solution.

ATS_EMB16_013 - Energy-saving IAQ monitoring ZigBee network using VIKOR decision making method
Indoor Air Quality (IAQ) is an urgent topic nowadays. It is concluded that 90% of human's life is spent indoor. However, it is commonly known that materials used in construction or furniture is often detected to release Volatile organic compounds (VOC) which affect IAQ significantly and lead to dizziness, respiratory irritation, fatigue, asthma and allergic airway disease and even cancer. As a result, IAQ monitoring system assists of improving IAQ, and wireless sensor network is an efficient method for building up the system network. In this paper, a new ZigBee network for IAQ monitoring system is designed. A Multi-criteria decision-making method VIKOR is used to figure out the best parameters of the MAC layer and CSMA/CA mechanism under this environment. The network designed can achieve 35% improvement of energy saving without affecting the latency and throughput performance compared with the commonly-used TOPSIS method.

ATS_EMB16_014 - A Mobile ZigBee Module in a Traffic Control System
Time is of the essence when ambulances are utilized to save people's lives, but when an ambulance needs to pass through a junction, its speed often must be reduced due to traffic. This complicates situations when the patient in the ambulance needs urgent treatment that can be administered only at a hospital. Due to the unavailability of advanced medical procedures in an ambulance, there is the possibility for patients to suffer a loss of life.

ATS_EMB16_015 - Configurable ZigBee-based control system for people with multiple disabilities in smart homes
Nowadays, home appliances manufacturers are increasingly relying on wireless sensor network and single chip embedded technologies to build smart environment. Many existing systems are already in the market, however, they were designed without envisioning the need of residents with special needs. This work presents a framework that enables the integration and control of devices within a smart home environment for residents with disabilities. The framework supports the integration of multiple control devices for different residents with different disabilities. Moreover, the work addresses the safety of the users by providing warnings and notifications in case of an emergency. A prototype was designed, implemented and tested.

ATS_EMB16_016 - Self-configuration and smart binding control on IoT applications
The rapid development of wireless communication technology facilitates the realization of the Internet-of-Things (IoT). Automatic configuration and smart connection system have become relative important issue in accordance with extensive applications of IoT, and the energy saving concepts. Therefore, this work presents the integration of ???Automatic Configuration and Wisdom Connection System??? with Wireless Sensor Networks (WSN), IoT and ZigBee technology, to actualize automatic configuration based on a received signal strength indicator (Received Signal Strength Indicator, RSSI), lighting auto-configuration area, regional allocation, and sub-areas. The proposed ???Automatic Configuration and Wisdom Connection System??? automatically configures different lightings to the same position within in the range ???3dBm when the RSSI value varies only slightly. The system is configured to the same lighting site within the experimental environment when the sub-area range set ???3dBm. This study presents a significant contribution to new configuration of objects in Things (Web of Objects), context awareness control, and optimization of network control platform.

ATS_EMB16_017 - Accurate Wireless Sensor Localization Technique Based on Hybrid PSO-ANN Algorithm for Indoor and Outdoor Track Cycling
This paper aims to determine the distance between the mobile sensor node (i.e., bicycle) and the anchor node (i.e., coach) in outdoor and indoor environments. Two approaches were considered to estimate such a distance. The first approach was based on the traditional channel propagation model that used the log-normal shadowing model (LNSM), while the second approach was based on a proposed hybrid particle swarm optimization-artificial neural network (PSO-ANN) algorithm to improve the distance estimation accuracy of the mobile node. The first method estimated the distance according to the LNSM and the measured received signal strength indicator (RSSI) of the anchor node, which in turn used the ZigBee wireless protocol. The LNSM parameters were measured based on the RSSI measurements in both outdoor and indoor environments. A feed-forward neural network type and the Levenberg-Marquardt training algorithm were used to estimate the distance between the mobile node and the coach. The hybrid PSO-ANN algorithm significantly improved the distance estimation accuracy more than the traditional LNSM method without additional components. The hybrid PSO-ANN algorithm achieved a mean absolute error of 0.022 and 0.208 m for outdoor and indoor environments, respectively. The effect of anchor node density on localization accuracy was also investigated in the indoor environment.

ATS_EMB16_018 - Design and Evaluation of an Open-Source Wireless Mesh Networking Module for Environmental Monitoring
Wireless mesh networking extends the communication range among cooperating multiple low-power wireless radio transceivers and is useful for collecting data from sensors widely distributed over a large area. By integrating an off-the-shelf wireless design, such as the XBee module, development of sensor systems with mesh networking capability can be accelerated. This study introduces an open-source wireless mesh network (WMN) module, which integrates the functions of network discovery, automatic routing control, and transmission scheduling. In addition, this design is open source in order to promote the use of wireless mesh networking for environmental monitoring applications. Testing of the design and the proposed networking module is reported. The proposed wireless mesh networking module was evaluated and compared with XBee. The average package delivery ratio and standard deviation of the proposed WMN module and the XBee are 94.09%, 91.19%, 5.14%, and 10.25%, respectively, in a 20 node experiment. The proposed system was demonstrated to have the advantages of low-cost combined with high reliability and performance, and can aid scientists in implementing monitoring applications without the complications of complex wireless networking issues.

ATS_EMB16_019 - A smart helmet for air quality and hazardous event detection for the mining industry
A smart helmet has been developed that is able to detect of hazardous events in the mines industry. In the development of helmet, we have considered the three main types of hazard such as air quality, helmet removal, and collision (miners are struck by an object). The first is the concentration level of the hazardous gases such as CO, SO2, NO2, and particulate matter. The second hazardous event was classified as a miner removing the mining helmet off their head. An IR sensor was developed unsuccessfully but an off-the shelf IR sensor was then used to successfully determine when the helmet is on the miner's head. The third hazardous event is defined as an event where miners are struck by an object against the head with a force exceeding a value of 1000 on the HIC (Head Injury Criteria). An accelerometer was used to measure the acceleration of the head and the HIC was calculated in software. The layout of the visualisation software was completed, however the implementation was unsuccessful. Tests were successfully done to calibrate the accelerometer. PCB's that were designed and made included a breakout board and a prototype board. A whole software implementation was done based on Contiki operating system in order to do the control of the measuring of sensors and of calculations done with the measured values. This paper presents the undertaken design detailing solutions to issues raised in previous research.

ATS_EMB16_020 - Low-Power Wearable ECG Monitoring System for Multiple-Patient Remote Monitoring
Many devices and solutions for remote electrocardiogram (ECG) monitoring have been proposed in the literature. These solutions typically have a large marginal cost per added sensor and are not seamlessly integrated with other smart home solutions. Here, we propose an ECG remote monitoring system that is dedicated to non-technical users in need of long-term health monitoring in residential environments and is integrated in a broader Internet-of-Things (IoT) infrastructure. Our prototype consists of a complete vertical solution with a series of advantages with respect to the state of the art, considering both the prototypes with integrated front end and prototypes realized with off-the-shelf components: 1) ECG prototype sensors with record-low energy per effective number of quantized levels; 2) an architecture providing low marginal cost per added sensor/user; and 3) the possibility of seamless integration with other smart home systems through a single IoT infrastructure.

ATS_EMB16_021 - Development of a distributed disaster data and human life sign probe system
This paper deals with a novel sensor network system designed for gathering disaster information including physical environmental information and potential signals of survivers. The system consists of numerous sensor probes and a central database server. The sensor probes organize their own ZigBee network, which is managed by the central database server. The server is connected to the Internet to be able to provide total disaster information worldwide. In this paper, the authors introduce their development and show some basic performance test to verify its potential usability.

ATS_EMB16_022 - Characterization of RSS variability for biobot localization using 802.15.4 Radios
A cyber-physically organized swarm of insect biobots or biological robots can aid first responders in search-and-rescue scenarios after natural disasters or earthquakes by establishing an under-rubble sensor network. In such a network, the nodes are represented by the insect biobots equipped with electronic backpacks utilizing a system-on-chip. This application requires effective real-time localization of the mobile sensor nodes. Radio signal strength (RSS) is a measurement of the received signal power, and can be used in estimating the distance between two nodes, which then can help localize the biobotic sensor nodes in the future. This paper investigates RSS variability and its suitability for biobotic localization.

ATS_EMB16_023 - Evaluation of Ultrasound-Based Sensor to Monitor Respiratory and Nonrespiratory Movement and Timing in Infants
Goal: To describe and validate a noncontacting sensor that used reflected ultrasound to separately monitor respiratory, nonrespiratory, and caretaker movements of infants. Methods: An in-phase and quadrature (I & Q) detection scheme provided adequate bandwidth, in conjunction with postdetection filtering, to separate the three types of movement. The respiratory output was validated by comparing it to the electrical activity of the diaphragm (Edi) obtained from an infant ventilator in 11 infants. The nonrespiratory movement output was compared to movement detected by miniature accelerometers attached to the wrists, ankles, and heads of seven additional infants. Caretaker movement was compared to visual observations annotated in the recordings. Results: The respiratory rate determined by the sensor was equivalent to that from the Edi signal. The sensor could detect the onset of inspiration significantly earlier than the Edi signal (23+/-69 ms). Nonrespiratory movement was identified with an agreement of 0.9 with the accelerometers. It potentially interfered with the respiratory output an average of 4.7+/-4.5% and 14.9+/15% of the time in infants not requiring or on ventilatory support, respectively. Caretaker movements were identified with 98% sensitivity and specificity. The sensor outputs were independent of body coverings or position. Conclusion: This single, noncontacting sensor can independently quantify these three types of movement. Significance: It is feasible to use the sensor as trigger for synchronizing mechanical ventilators to spontaneous breathing, to quantify overall movement, to determine sleep state, to detect seizures, and to document the amount and effects of caretaker activity in infants.

ATS_EMB16_024 - Smart real-time healthcare monitoring and tracking system using GSM/GPS technologies
Health monitoring systems have rapidly evolved recently, and smart systems have been proposed to monitor patient current health conditions, in our proposed and implemented system, we focus on monitoring the patient's blood pressure, and his body temperature. Based on last decade statistics of medical records, death rates due to hypertensive heart disease, shows that the blood pressure is a crucial risk factor for atherosclerosis and ischemic heart diseases; thus, preventive measures should be taken against high blood pressure which provide the ability to track, trace and save patient's life at appropriate time is an essential need for mankind. Nowadays, Globalization demands Smart cities, which involves many attributes and services, such as government services, Intelligent Transportation Systems (ITS), energy, health care, water and waste. This paper proposes a system architecture for smart healthcare based on GSM and GPS technologies. The objective of this work is providing an effective application for Real Time Health Monitoring and Tracking. The system will track, trace, monitor patients and facilitate taking care of their health; so efficient medical services could be provided at appropriate time. By Using specific sensors, the data will be captured and compared with a configurable threshold via microcontroller which is defined by a specialized doctor who follows the patient; in any case of emergency a short message service (SMS) will be sent to the Doctor's mobile number along with the measured values through GSM module. furthermore, the GPS provides the position information of the monitored person who is under surveillance all the time. Moreover, the paper demonstrates the feasibility of realizing a complete end-to-end smart health system responding to the real health system design requirements by taking in consideration wider vital human health parameters such as respiration rate, nerves signs ... etc. The system will be able to bridge the gap between pat- ents - in dramatic health change occasions- and health entities who response and take actions in real time fashion.

ATS_EMB16_025 - Indoor Blind Localization of Smartphones by Means of Sensor Data Fusion
Locating the nodes in wireless sensor networks (WSNs) is currently a very active area of research due to their increasing number of potential applications. Wireless networks composed of smartphones have gained particular interest, mainly due to the high availability of such devices. This paper presents a novel algorithm for blind localization of commercial off-the-shelf smartphones in a WSN. The algorithm uses acoustic signals and inertial sensors to estimate the sensor positions simultaneously. Estimates of range and direction-of-arrival (DOA) locally obtained in each node are combined with a maximum likelihood estimator. A tailored optimization algorithm is also proposed to solve the DOA uncertainty problem. Our proposal obtains low localization errors without considering any reference node nor any prior synchronization between nodes.

ATS_EMB16_026 - Low-Overhead and High-Precision Prediction Model for Content-Based Sensor Search in the Internet of Things
A growing number of Internet-connected sensors have already promoted the advance of sensor search service. Accessing all available objects to find the sought sensor results in huge communication overhead, thus a low-overhead and high-precision prediction model (LHPM) is proposed to improve the sensor search efficiency. We design the approximation method to lower the reporting energy cost. Then a multistep prediction method is proposed to accurately estimate the sensor state. Furthermore, a sensor ranking method is presented to assess the matching probabilities of sensors, so as to effectively reduce the communication overhead of the search process. Simulation results demonstrate the validity of the proposed prediction model in the area of content-based sensor search.

ATS_EMB16_027 - Preprocessing Design in Pyroelectric Infrared Sensor-Based Human-Tracking System: On Sensor Selection and Calibration
This paper presents an information-gain-based sensor selection approach as well as a sensor sensing probability model-based calibration process for multihuman tracking in distributed binary pyroelectric infrared sensor networks. This research includes three contributions: 1) choose the subset of sensors that can maximize the mutual information between sensors and targets; 2) find the sensor sensing probability model to represent the sensing space for sensor calibration; and 3) provide a factor graph-based message passing scheme for distributed tracking. Our approach can find the solution for sensor selection to optimize the performance of tracking. The sensing probability model is efficiently optimized through the calibration process in order to update the parameters of sensor positions and rotations. An application for mobile calibration and tracking is developed. Simulation and experimental results are provided to validate the proposed framework.

ATS_EMB16_028 - Lightweight Mashup Middleware for Coal Mine Safety Monitoring and Control Automation
Recently, the frequent coal mine safety accidents have caused serious casualties and huge economic losses. It is urgent for the global mining industry to increase operational efficiency and improve overall mining safety. This paper proposes a lightweight mashup middleware to achieve remote monitoring and control automation of underground physical sensor devices. First, the cluster tree based on ZigBee Wireless Sensor Network (WSN) is deployed in an underground coal mine, and propose an Open Service Gateway initiative (OSGi)-based uniform devices access framework. Then, propose a uniform message space and data distribution model, and also, a lightweight services mashup approach is implemented. With the help of visualization technology, the graphical user interface of different underground physical sensor devices could be created, which allows the sensors to combine with other resources easily. Besides, four types of coal mine safety monitoring and control automation scenarios are illustrated, and the performance has also been measured and analyzed. It has been proved that our lightweight mashup middleware can reduce the costs efficiently to create coal mine safety monitoring and control automation applications.

ATS_EMB16_029 - Improving the Locating Precision of an Active WIFI RFID System to Obtain Traceability of Patients in a Hospital
It is a challenge to integrate RFID technology into the healthcare sector to increase security by obtaining traceability of patients during their hospital stay. In this case, RFID provides arange of technical architectures for implementing an RFID system. The installation or use of the WIFI network available in a hospital is a possible element in system design since a priori with a correct configuration of RFID components, excellent results in location accuracy can be obtained over other architectures available in the market. The accuracy of RFID Aeroscout WIFI system can be improved with the installation of exciters. These are components that assist the localisation engine in calculating the location of an active RFID tag WIFI. The precision offered by the localisation engine depends on multiple configurable parameters set by the engineers responsible for the design and development of an active RFID WIFI system.

ATS_EMB16_030 - Joint access point and user localization using unlabeled WiFi RSS data
This paper investigates the problem of joint estimation of a pedestrian user path and the available WiFi access point locations. The observations are limited to unlabeled WiFi received signal strength (RSS) values. The problem is formed as a partially observable Markov decision process and RSS gradients are integrated to estimate and update the user locations along the path. The RSS data is modeled as a Gaussian process and gradient vectors are updated for each step based on the motion dynamics. Realistic assumptions and constraints are introduced to model the user's movement and reduce the computational complexity.

ATS_EMB16_031 - Water Level Meter for Alerting Population about Floods
The most important thing immediately before, during and after a disaster occurs is the dissemination of information, a deployment of devices enabled by IoT (Internet of Things) could bring benefits in terms of giving to people information opportunely for making decisions in face of this disaster. In this paper, we present a sensor to measure water level in rivers, lakes, lagoons and streams. For such purpose and to prove our concept, we designed a pilot project through a micro-model that is constructed with a water level measurement sensor based on a simple open circuit that closes when in contact with water and experimentally tested into a water container under a controlled environment. This micro-model is performed on the basis of a programmable electronic board (Netduino Plus 2), an electronic circuit connected to electrical resistances that are located at a specific height, within a water container, when the water level rises and reaches the resistors, varies the impedance, this shows the actual water level and so on for different heights. The information from water level sensor is transmitted via WiFi to a laptop, then this information is also seen in smartphones, where users can see the water level in rivers. Finally, the micro-model is tested by experimental tests under a controlled environment and satisfactory results are obtained.

ATS_EMB16_032 - Brain-controlled devices: the perception-action closed loop
     Future neuroprosthetics will be tightly coupled with the user in such a way that the resulting system can replace and restore impaired upper limb functions because controlled by the same neural signals than their natural counterparts. However, robust and natural interaction of subjects with sophisticated prostheses over long periods of time remains a major challenge. To tackle this challenge we can get inspiration from natural motor control, where goal-directed behavior is dynamically modulated by perceptual feedback resulting from executed actions. Current brain-computer interfaces (BCI) partly emulate human motor control as they decode cortical correlates of movement parameters -from onset of a movement to directions to instantaneous velocity- in order to generate the sequence of movements for the neuroprosthesis. A closer look, though, shows that motor control results from the combined activity of the cerebral cortex, subcortical areas and spinal cord. This hierarchical organization supports the hypothesis that complex behaviours can be controlled using the low-dimensional output of a BCI in conjunction with intelligent devices in charge to perform low-level commands. A further component that will facilitate intuitive and natural control of motor neuroprosthetics is the incorporation of rich multimodal feedback and neural correlates of perceptual cognitive processes resulting from this feedback. As in natural motor control, these sources of information can dynamically modulate interaction.

ATS_EMB16_033 - Experimental investigation of remote control via Android smart phone of arduino-based automated irrigation system using moisture sensor
     Climate change because of the greenhouse effect has been authenticated. Fallouts like the 2015 Chennai floods suggest techniques like precision agriculture that includes automation in the irrigation system are important. This paper suggests an economical and easy-to-use arduino-based automated irrigation system that utilizes the Android smart phone for remote control. The system design includes a soil moisture sensor that provides a voltage signal proportional to the moisture content in the soil which is compared with a predetermined threshold value obtained by sampling of various soils and specific crops. The outcome of the comparison is that appropriate data are fed to the arduino uno processor. The arduino is linked wirelessly via the HC-05 module to an Android smart phone. The data received by the Android smart phone from the arduino is displayed on the User Interface (UI) (S2 terminal application). The UI in the Android smart phone allows the user easy remote control of the irrigation drive system that involves switching, on and off, of the drive motor by the arduino, wired to its controller, based on commands from the android smart phone. Studies conducted on a laboratory prototype suggest that the design is viable and can be easily adopted for real time application.

ATS_EMB16_034 - MAGIC: Model-Based Actuation for Ground Irrigation Control
     Lawns make up the largest irrigated crop by surface area in North America, and carries with it a demand for over 9 billion gallons of freshwater each day. Despite recent developments in irrigation control and sprinkler technology, state-of-the-art irrigation systems do nothing to compensate for areas of turf with heterogeneous water needs. In this work, we overcome the physical limitations of the traditional irrigation system with the development of a sprinkler node that can sense the local soil moisture, communicate wirelessly, and actuate its own sprinkler based on a centrally- computed schedule. A model is then developed to compute moisture movement from runoff, absorption, and diffusion. Integrated with an optimization framework, optimal valve scheduling can be found for each node in the space. In a turf area covering over 10,000ft2, two separate deployments spanning a total of 7 weeks show that MAGIC can reduce water consumption by 23.4% over traditional campus scheduling, and by 12.3% over state-of-the- art evapotranspiration systems, while substantially improving conditions for plant health. In addition to environmental, social, and health benefits, MAGIC is shown to return its investment in 16-18 months based on water consumption alone.

ATS_EMB16_035 - Potential for improving green roof performance through artificial irrigation
     Historically extensive green roofs were designed for natural precipitation with a plant selection focusing on hardy succulents such as sedums that can survive harsh, water stressed conditions. Although this seems a convenient solution to establish and maintain a green roof system, at a much broader level this does not optimize the functions and performance of the green roof. In this paper the influence of irrigation on green roof functions and performance is presented for an extensive green roof by an extensive literature study. Green roof energy saving potential under Sri Lankan climatic conditions is significant. The average water retention of green roof substrate under different climatic zone conditions in Sri Lankan context is simulated with hypothetical twelve extensive green roof types. Results justify the artificial irrigation requirement and provide key directions to develop water balance model considering locational factors to maintain set soil moisture target.

ATS_EMB16_036 - Dual Sink Efficient Balanced Energy Technique for Underwater Acoustic Sensor Networks
     Underwater Acoustic Sensor Networks are considered to provide efficient monitoring tasks in aquatic environment but due to limited battery resource of sensor nodes, network lifetime collapses. Energy balancing is the major issue in low network lifetime. High energy consumption creates energy holes and ultimately leads to shorter network lifetime. Therefore, energy consumption must be balanced to increase network life time. To overcome these concerns a technique should be designed that minimizes the energy consumption and prolong network lifetime. This paper presents a Dual Sink Efficient and Balanced Energy consumption Technique (DSEBET) for UASNs. DSEBET overcomes the problem of limited network lifetime and high energy consumption over long distance. Dual sinks underwater model is established. DSEBET first establishes links between nodes on the basis of their optimum distance value and then picks relay nodes on the basis of their minimum distance "Nj" value for the transmission of data. In the data transmission phase every nodes have equal energy levels numbers (ELNs). Long distance nodes from one sink will share their data to other sink if come in range of sink otherwise they will establish a multi hop path for transmission of data to the respective sink.