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Energy Aware Error Control in Cooperative Communication in Wireless Sensor Networks
Abstract
Due to small size of sensor nodes deployed in Wireless Sensor Networks
(WSNs), energy utilization is a key issue. Poor channel conditions lead to
retransmissions and hence, result in energy wastage. Error control strategies
are usually utilized to accommodate channel impairments like noise and fading
in order to optimize energy consumption for network lifetime enhancement.
Meanwhile, cooperative communication also emerges to be an appropriate
candidate to combat the effects of channel fading. Energy efficiency of
cooperative scheme when applied with Automatic Repeat Request (ARQ), Hybrid-ARQ
(HARQ) and Forward Error Correction (FEC) is investigated in this work.
Moreover, the expressions for energy efficiency of Direct Transmission, Single
Relay Cooperation and Multi Relay Cooperation are also derived. In all, our
work is focused towards energy optimal communication in WSNs. Our results show
that error control strategies with cooperative schemes can significantly
enhance system performance in form of energy optimization.
... However, the implementation of FEC creates more complexity and in some cases can consume more energy. (Manzoor et al., 2013) HARQ is the conventional combination between ARQ and FEC could reduce the overheads. In HARQ, a transmitter might have FEC encoded packet that can correct errors besides detecting them. ...
The deployment of high densities of node due to the advancement in Wireless Sensor Network (WSN) technology had created the concern regarding the lifetime and error presented in the network. From the previous studies, Hybrid ARQ (HARQ) error control techniques can combat errors and indirectly, can reduce the energy consumption of sensor nodes. Based on the latest previous work, the HARQ algorithm were not able to combat the issue of interference properly. Not to mention, the implementation of Error Correcting Codes (ECC) in the module of HARQ on the unconducive environment will cause additional overhead. Thus,the problem regarding the interference and overhead in WSN becomes our motivation to research HARQ error control protocol with for lifetime maximization and less overhead WSN by implementing along the Kalman Filter algorithm for channel state estimation. This research proposes the low overhead HARQ error control algorithm for lifetime maximization in terms of node densities and packet sizes. This research is expected to show that the proposed HARQ algorithm can lower the overhead and maximize the lifetime of WSN by means of lowering the error rates and interference levels.
... The main purpose of FEC is to encode messages by using an error correction code (ECC). FEC coding techniques are classified as block and convolutional codes [17,18]. The Hamming coding system is a kind of binary block code method used in telecommunications [19]. ...
Many methods have been employed to detect, compare, and correct errors to increase communication reliability and efficiency in wireless sensor networks (WSNs). However, to the best of our knowledge, no existing study has compared the performance of error control codes by using different modulation techniques in a smart grid communication environment when multichannel scheduling is used. This paper presents a detailed performance evaluation and makes a comparison of different modulation techniques, such as frequency shift keying (FSK), differential phase shift keying (DPSK), binary phase shift keying (BPSK), and offset quadrature phase-shift keying (OQPSK), using Hamming codes in a 500-kV line-of-sight substation smart grid environment with multichannel scheduling. A link-quality-aware routing algorithm is used as a routing protocol and a log-normal shadowing channel is employed as a channel model. Simulations are performed in MATLAB and the performance of the Hamming code with various modulation techniques is compared with the results obtained without using any error correction codes for throughput, delay, and bit error rate. The results show that the performance of the Hamming code with OQPSK modulation is better than its performance with other modulation techniques. Moreover, the results show that the performance of Hamming code improves with multichannel scheduling for all modulation techniques.
... This will increase the latency and lengthen the delaythen eventually will use more energy. FEC might not flood the network with retransmission packets or cause irrelevant congestion, however, the usage of FEC creates more complexity in terms of the decoding process and in some cases can also consume more energy [7].Hybrid Automatic Repeat Request (HARQ) were being studied and implemented in order to minimize the overheads of ARQ and FEC. HARQ is the conventional combination of ARQ and FEC. ...
... Therefore, it is important to apply the channel codes to the system to detect and correct the errors and to gain the system's performance [7]. Moreover, the channel coding could also provide the energy efficiency [8] and increase the network's lifetime in the cooperative systems [9]. ...
A cooperative communication system is an effective way to deal with the multipath fading in a wireless channel. However, the data sent from a source to the relay or the destination may experience some losses or corruptions during the transmission, causing error bits. Those errors can degrade the system's performance. In order to detect and correct the errors, it is important to apply a channel coding to the cooperative networks. In this paper, the Hamming Coding for multi-relay cooperative quantize and forward (QF) networks is proposed. The Hamming Codes are the simplest linear codes that can be implemented with low complexity in the proposed networks. The proposed system model is presented with the analytic expressions of the networks. Moreover, the system performance is simulated using the computer simulation in terms of bit error rate (BER). It is shown in the simulation results that the Hamming Code could significantly improve the network's performance when the number of relays is increased. The network's performance is also increased by using high quantization levels in the QF relays. Furthermore, it is found that the performance of the multi-relay QF networks with Hamming Code is better than those of the multi-relay amplify and forward (AF) networks with and without the Hamming Coding. It is concluded that the performance of multi-relay QF network is improved by the use of Hamming Code as well as the advantage of quantization levels.
In the past, PI control algorithm and hysteresis control algorithm are not accurate in islanding detection, which leads to poor control effect. In view of this problem, a single-phase inverter grid connected control method based on wireless sensor network is proposed. According to the wireless sensor network architecture, the current loop closed-loop structure is designed, and the grid connected control model based on wireless sensor network is constructed. Under the support of equivalent diagram, the control target of grid connection is determined and the output current of inverter is adjusted to realize the adjustment of inverter output power. According to the circuit vector diagram of grid connected operation, the current tracking control strategy is designed to determine the vector relationship between the voltage on the inductance of the inverter output side and the feed forward voltage of the grid. The control strategy of the outer and inner loop of the single-phase inverter is corrected by constructing the mathematical model of the controlled object of the single-phase grid connected inverter. The experimental results show that the method has high accuracy, the maximum error of grid connected voltage is 0.14 kV, the maximum grid connected current is 0.11 kA, which is basically in accordance with the actual value, and has good control effect.
Link reliability and transmitted power are two important design constraints in wireless network design. Error control coding (ECC) is a classic approach used to increase link reliability and to lower the required transmitted power. It provides coding gain, resulting in transmitter energy savings at the cost of added decoder power consumption. But the choice of ECC is very critical in the case of wireless sensor network (WSN). Since the WSNs are energy constraint in nature, both the BER and power consumption has to be taken into count. This paper develops a step by step approach in finding suitable error control codes for WSNs. Several simulations are taken considering different error control codes and the result shows that the RS(31,21) fits both in BER and power consumption criteria.
From energy conservation perspective in Wireless Sensor Networks (WSNs), clustering of sensor nodes is a challenging task. Clustering technique in routing protocols play a key role to prolong the stability period and lifetime of the network. In this paper, we propose and evaluate a new routing protocol for WSNs. Our protocol; Divide-and-Rule (DR) is based upon static clustering and dynamic Cluster Head (CH) selection technique. This technique selects fixed number of CHs in each round instead of probabilistic selection of CH. Simulation results show that DR protocol outperform its counterpart routing protocols.
One of the major challenges in design of wireless sensor networks (WSNs) is to reduce energy consumption of sensor nodes to prolong lifetime of finite capacity batteries. In this paper, we propose energy-efficient adaptive scheme for transmission (EAST) in WSNs. EAST is an IEEE 802.15.4 standard compliant. In this scheme, open-looping feedback process is used for temperature-aware link quality estimation and compensation, wherea closed-loop feedback process helps to divide network into three logical regions to minimize overhead of control packets. Threshold on transmitter power loss () and current number of nodes (()) in each region help to adapt transmit power level () according to link quality changes due to temperature variation. Evaluation of the proposed scheme is done by considering
mobile sensor nodes and reference node both static and mobile. Simulation results show that the proposed scheme effectively adapts transmission to changing link quality with less control packets overhead and energy consumption as compared to classical approach with single region in which maximum transmitter assigned to compensate temperature variation.
Wireless Sensor Networks (WSNs), with growing applications in the environment
which are not within human reach have been addressed tremendously in the recent
past. For optimized working of network many routing algorithms have been
proposed, mainly focusing energy efficiency, network lifetime, clustering
processes. Considering homogeneity of network, we proposed Energy Efficient
Sleep Awake Aware (EESAA) intelligent routing protocol for WSNs. In our
proposed technique we evaluate and enhance certain issues like network
stability, network lifetime and cluster head selection process. Utilizing the
concept of characteristical pairing among sensor nodes energy utilization is
optimized. Simulation results show that our proposed protocolnificantly
improved the
Severe energy constraints and hence the low power communication requirements amplify the significance of the energy efficient and preferably cross-layer error control mechanisms in wireless sensor networks (WSN). In this paper, a cross-layer methodology for the analysis of error control schemes in WSNs is presented such that the effects of multi-hop routing and the broadcast nature of the wireless channel are investigated. More specifically, the cross-layer effects of routing, medium access and physical layers are considered. This analysis enables a comprehensive comparison of forward error correction (FEC) and automatic repeat request (ARQ) in WSNs. FEC schemes improve the error resiliency compared to ARQ. In a multi-hop network, this improvement can be exploited by reducing the transmit power (transmit power control) or by constructing longer hops (hop length extension), which can be achieved through channel-aware routing protocols. The results of our analysis reveal that for certain FEC codes, the hop length extension decreases both the energy consumption and the end-to-end latency subject to a target PER compared to ARQ. Thus, FEC codes can be regarded as an important candidate for delay sensitive traffic in WSNs. On the other hand, transmit power control results in significant savings in energy consumption at the cost of increased latency. Moreover, the cases where ARQ outperforms FEC codes are indicated for various end-to-end distance and target PER values
Several gateway selection schemes have been proposed that select gateway nodes based on single QoS metric, for instance link availability, link capacity etc. or multiple non-QoS metrics, such as the combination of gateway node speed, residual energy, and number of hops, for mobile ad hoc networks (MANETs). Each scheme just focuses to improve only single network performance such as network throughput, packet delivery ratio, end-to-end delay or packet drop ratio. However, none of those schemes improves overall network performance. To improve the overall network performance, it is necessary to select a gateway with stable connection, maximum link capacity and less latency. In this paper, we propose a gateway selection scheme that considers multiple end-to-end QoS parameters such as route availability period, route capacity and route latency, to select a potential gateway node. The precise estimation and propagation of end-to-end QoS metrics are proposed in this paper. We simulate our gateway selection scheme with a simple hybrid gateway discovery algorithm and it shows that our gateway selection scheme improves throughput, packet delivery ratio with less energy consumption per node. Also it improves the end-to-end delay compared to the single QoS gateway selection schemes.
In this paper, we evaluate and analyze the impact of different network loads
and varying no. of nodes on distance vector and link state routing algorithms.
We select three well known proactive protocols; Destination Sequenced Distance
Vector (DSDV) operates on distance vector routing, while Fisheye State Routing
(FSR) and Optimized Link State Routing (OLSR) protocols are based on link state
routing. Further, we evaluate and compare the effects on the performance of
protocols by changing the routing strategies of routing algorithms. We also
enhance selected protocols to achieve high performance. We take throughput,
End-to-End Delay (E2ED) and Normalized Routing Load (NRL) as performance
metrics for evaluation and comparison of chosen protocols both with default and
enhanced versions. Based upon extensive simulations in NS-2, we compare and
discuss performance trade-offs of the protocols, i.e., how a protocol achieves
high packet delivery by paying some cost in the form of increased E2ED and/or
routing overhead. FSR due to scope routing technique performs well in high data
rates, while, OLSR is more scalable in denser networks due to limited
retransmissions through Multi-Point Relays (MPRs).
Energy efficient communication is a key issue in wireless sensor networks. Common belief is that a multi-hop configuration is the only viable energy efficient technique. In this paper we show that the use of forward error correction techniques in combination with ARQ is a promising alternative. Exploiting the asymmetry between lightweight sensor nodes and a more powerful base station even advanced techniques known from cellular networks can be efficiently applied to sensor networks. Our investigations are based on realistic power models and real measurements and, thus, consider all side-effects. This is to the best of our knowledge the first investigation of advanced forward error correction techniques in sensor networks which is based on real experiments.
In wireless sensor networks (WSNs), cooperative communication represents a potential candidate to combat the effects of channel fading by exploiting diversity gain achieved via cooperation among the relays nodes. However, for the energy-constrained WSN, to what extent cooperative communication can save energy consumption for a successful packet transmission is still unknown. Energy efficiency of cooperation and direct transmission schemes inWSN is studied and compared in this paper. The expressions of energy efficiency of the two schemes are derived, respectively. The numerical results reveal that for the small distance separation between the source and destination nodes, the direct transmission scheme is more energy efficient than cooperation and the relay location, packet size, and modulation level have important effects on energy efficiency. At last, energy efficiency maximization for the cooperative communication system is achieved by optimizing both the packet size and modulation level jointly.
This paper examines error-control coding (ECC) use in wireless sensor networks (WSN), to determine the energy efficiency of specific ECC implementations in WSN. ECC provides coding gain, resulting in transmitter energy savings, at the cost of added decoder power consumption. This paper derives an expression for the critical distance dCR, the distance at which the decoder's energy consumption per bit equals the transmit energy savings per bit due to coding gain, compared to uncoded. Results for several decoder implementations, both analog and digital, are presented for dCR in different environments over a wide frequency range. In free space, dCR is very large at lower frequencies, suitable only for widely spaced outdoor sensors. In crowded environments and office buildings, dCR drops significantly, to 3m or greater at 10 GHz. Interference is not considered; it would lower dCR. Analog decoders are shown to be the most energy-efficient de coders in this study.
Retransmission has been adopted as one of the most popular schemes for improving transmission reliability in wireless sensor networks. Many previous works have been done on reliable transmission issues in experimental ways, however, there still lack of analytical techniques to evaluate these solutions . Based on the traffic model, service model and energy model, we propose an analytical method to analyze the delay and energy metrics of two categories of retransmission schemes: hop-by- hop retransmission (HBH) and end-to-end retransmission (ETE). With the experiment results, the maximum packet transfer delay and energy efficiency of these two scheme are compared in severa l scenarios. Moreover, the analytical results of transfer delay are validated through simulations. Our experiments demonstrate that HBH has less energy consumption at the cost of lager transfer delay compared with ETE. With the same target success probability, ETE is superior on the delay metric for low bit-error- rate (BER) cases, while HBH is superior for high BER cases. I. I NTRODUCTION network calculus are validated by simulations of realistic WSN deployment scenarios. In this paper, we also use network calculus theory for analyzing the maximum transfer delay of retransmission schemes. Many previous works have been done on reliable transport issues in experimental ways, however, there still lack of analyt- ical techniques to evaluate different reliable transport s olutions. In (9), Liu et al. analyze the roles of packet retransmission and erasure coding in the reliable transport of WSNs by establishing the probability models. In this paper, we propose analytical techniques to evaluate retransmission schemes in WSNs. We first introduce the traffic model, service model and energy model. Based on these models and network calculus, we analytically evaluate the maximum packet transfer delay and energy efficiency of two basic types of retransmission schemes, which are hop-by-hop retransmission and end-to- end retransmission. From the experiment results, the maxi- mum delay and energy consumption of these two schemes are compared in several scenarios. Moreover, the analytical maximum delay is compared with the simulation results. With our method, appropriate retransmission scheme can be chosen based on different requirements and constraints. To the best of our knowledge, this is the first work that analytically studi es the transmission delay of reliable data transport schemes i n sensor networks.
Cluster based routing technique is most popular routing technique in Wireless Sensor Networks (WSNs). Due to varying need of WSN applications efficient energy utilization in routing protocols is still a potential area of research. In this research work we introduced a new energy efficient cluster based routing technique. In this technique we tried to overcome the problem of coverage hole and energy hole. In our technique we controlled these problems by introducing density controlled uniform distribution of nodes and fixing optimum number of Cluster Heads (CHs) in each round. Finally we verified our technique by experimental results of MATLAB simulations.
Wireless Sensor Networks (WSN) are usually a set of battery-supplied small devices. One of the main challenges in deploying WSN is to improve energy-efficiency and lifetime of the nodes while keeping communication reliability. Transmissions over the wireless channel may experience many impairments, like random noise and fading, increasing the bit error rate at reception, causing several retransmissions, and consuming extra energy from the node. In order to minimize the harmful effects of the radio channel, error control strategies using packet retransmission and error correcting codes are commonly utilized. In this work we investigate the trade-off between transmission and processing energy consumption in a sensor node employing convolutional codes. Through this study we can identify and select the appropriate complexity of the error control code to be used in each sensor node, in order to maximize the network lifetime.
Wireless Multi-hop Networks (WMhNs) provide users with the facility to
communicate while moving with whatever the node speed, the node density
and the number of traffic flows they want, without any unwanted delay
and/or disruption. This paper contributes Linear Programming models
(LP_models) for WMhNs. In WMhNs, different routing protocols are used to
facilitate users demand(s). To practically examine constraints of
respective LP_models over different routing techniques, we select three
proactive routing protocols; Destination Sequence Distance Vector
(DSDV), Fish-eye State Routing (FSR) and Optimized Link State Routing
(OLSR). These protocols are simulated in two important scenarios
regarding to user demands; mobilities and different network flows. To
evaluate the performance, we further relate the protocols strategy
effects on respective constraints in selected network scenarios.
Wearable sensors inWireless Body Area Networks (WBANs) provide health and
physical activity monitoring. Modern communication systems have extended this
monitoring remotely. In this survey, various types of wearable sensors
discussed, their medical applications like ECG, EEG, blood pressure, detection
of blood glucose level, pulse rate, respiration rate and non medical
applications like daily exercise monitoring and motion detection of different
body parts. Different types of noise removing filters also discussed at the end
that are helpful in to remove noise from ECG signals. Main purpose of this
survey is to provide a platform for researchers in wearable sensors for WBANs.
In this paper, we present a comprehensive study of Medium Access Control
(MAC) protocols developed for Wireless Body Area Networks (WBANs). In WBANs,
small batteryoperated on-body or implanted biomedical sensor nodes are used to
monitor physiological signs such as temperature, blood pressure,
ElectroCardioGram (ECG), ElectroEncephaloGraphy (EEG) etc. We discuss design
requirements for WBANs with major sources of energy dissipation. Then, we
further investigate the existing designed protocols for WBANs with focus on
their strengths and weaknesses. Paper ends up with concluding remarks and open
research issues for future work.
One of the major issues in Wireless Body Area Sensor Networks (WBASNs) is
efficient localization. There are various techniques for indoor and outdoor
environments to locate a person. This study evaluating and compares performance
of optimization schemes in indoor environments for optimal placement of
wireless sensors, where patients can perform their daily activities. In indoor
environments, the performance comparison between Distance Vector-Hop algorithm,
Ring Overlapping Based on Comparison Received Signal Strength Indicator
(ROCRSSI), Particle filtering and Kalman filtering based location tracking
techniques, in terms of localization accuracy is estimated. Results show that
particle filtering outperforms all. GPS and several techniques based on
GSMlocation tracking schemes are proposed for outdoor environments. Hidden
Markov GSM based location tracking scheme efficiently performs among all, in
terms of location accuracy and computational overheads.
In a relay enhanced system the classical HARQ schemes should be adapted to exploit the better channel conditions of the relay in comparison to the direct link. In particular, we need to decide which node (either the source or one of the relays) should retransmit and how many resources have to be spent to avoid further retransmissions. This adaptation should be optimized with respect to the trade-off between Frame Error Rate (FER) and the required resources. We propose an approach based on accumulated Mutual Information (MI) for relay networks applying different relay functions. We consider several memoryless relay functions without channel decoding aiming for simple and cheap relays. Beside the well-known Amplify-Forward (AF) and Detect-Forward (DetF) schemes, we also consider a soft-information relaying function called Estimate-Forward (EF) as this provides higher Mutual Information than AF and DetF. We show that our proposed HARQ retransmission scheme can improve the throughput significantly, especially if EF is applied at the relay.
In this paper, we identify and analyze the requirements to design a new
routing link metric for wireless multihop networks. Considering these
requirements, when a link metric is proposed, then both the design and
implementation of the link metric with a routing protocol become easy.
Secondly, the underlying network issues can easily be tackled. Thirdly, an
appreciable performance of the network is guaranteed. Along with the existing
implementation of three link metrics Expected Transmission Count (ETX), Minimum
Delay (MD), and Minimum Loss (ML), we implement inverse ETX; invETX with
Optimized Link State Routing (OLSR) using NS-2.34. The simulation results show
that how the computational burden of a metric degrades the performance of the
respective protocol and how a metric has to trade-off between different
performance parameters.
In this paper, we propose a new quality link metric, interference and bandwidth adjusted ETX (IBETX) for wireless multi-hop networks. As MAC layer affects the link performance and consequently the route quality, the metric therefore, tackles the issue by achieving twofold MAC-awareness. Firstly, interference is calculated using cross-layered approach by sending probes to MAC layer. Secondly, the nominal bit rate information is provided to all nodes in the same contention domain by considering the bandwidth sharing mechanism of 802.11. Like ETX, our metric also calculates link delivery ratios that directly affect throughput and selects those routes that bypass dense regions in the network. Simulation results by NS-2 show that IBETX gives 19% higher throughput than ETX and 10% higher than Expected Throughput (ETP). Our metric also succeeds to reduce average end-to-end delay up to 16% less than Expected Link Performance (ELP) and 24% less than ETX.
Hybrid ARQ transmission schemes combine the conventional ARQ with forward error correction. Incremental redundancy hybrid ARQ schemes adapt their error correcting code redundancy to varying channel gains, and thus achieve better throughput performance than ordinary ARQ, particularly over wireless channels with fluctuating channel conditions. Consequently, the scheme has been adopted by a number of standards for mobile phone networks. We provide a brief survey of theory and state of the art of hybrid ARQ, and present some possible future directions keeping in mind practical considerations.