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Region based cooperative routing in underwater wireless sensor networks
Abstract
Cooperative routing is an appealing challenge in underwater wireless sensor networks (UWSNs). In this paper, we propose a region based cooperative routing protocol (RBCRP) for amplify and forward (AF) technique over Rayleigh faded channels in UWSNs. The source node sends the sensed signal to the destination and available relay nodes. At the destination node, bit error rate (BER) is checked on the basis of which, either positive or negative acknowledgement (ACK or NACK) is sent to the source and relay nodes. We also use mobile sinks (MSs) and energy harvesting techniques to further prolong the network lifetime and maximize the throughput. Our derived mathematical equations for the SNR gain and outage probability are verified by simulations. Results show that RBCRP performs better than the existing incremental best relay technique (IBRT) in terms of throughput, network lifetime and outage probability.Cooperative routing is an appealing challenge in underwater wireless sensor networks (UWSNs). In this paper, we propose a region based cooperative routing protocol (RBCRP) for amplify and forward (AF) technique over Rayleigh faded channels in UWSNs. The source node sends the sensed signal to the destination and available relay nodes. At the destination node, bit error rate (BER) is checked on the basis of which, either positive or negative acknowledgement (ACK or NACK) is sent to the source and relay nodes. We also use mobile sinks (MSs) and energy harvesting techniques to further prolong the network lifetime and maximize the throughput. Our derived mathematical equations for the SNR gain and outage probability are verified by simulations. Results show that RBCRP performs better than the existing incremental best relay technique (IBRT) in terms of throughput, network lifetime and outage probability.
... Clustering technique is an appealing choice to construct a UASN and achieve an efficient routing. N. Javaid et al. in [15] proposed a region-based cooperative routing protocol (RBCRP) for AF technique in UASNs, where the clustering technique can convert the global communications into the local communications for saving energy. G. Liu et al. in [16] proposed an improved hierarchical multi-path routing-LEACH (HMR-LEACH) algorithm to optimize the CH selection by multi-hop transmissions. ...
... So, we measure the number of iterations for the K-means based CH selection and Q-learning based clustering algorithms in ECRKQ to analyze the complexity. As shown in Fig. 4, the blue solid line represents the convergence of P i CH as described in Eq. (15), and the four dashed lines represent the Q values (calculated by Eq. (16)) of different clusters under different iterations. We can see that the Q-learning based clustering algorithm can quickly converge after 2 iterations, and K-means based CH selection is converged after 3 iterations, thus demonstrating the low complexity of ECRKQ. ...
... Dr. Chen has authored or coauthored more than 70 peer-reviewed journal/conference papers and holds more than 15 ...
The dynamic topology, narrow transmission bandwidth, and limited energy of sensor nodes in mobile underwater acoustic sensor networks (UASNs) pose challenges to design an efficient and robust network for underwater communications. In this paper, we propose a novel machine learning-based clustering and routing scheme, named energy-efficient clustering and cooperative routing based on improved K-means and Q-learning (ECRKQ), to reduce and balance energy consumption among sensor nodes in a mobile UASN and improve the bandwidth utilization. In the cluster head (CH) selection stage, ECRKQ modifies the K-means algorithm to dynamically select a CH based on the residual energy of the node and the distance from the node to the centroid in a cluster. In the clustering stage, ECRKQ adopts the Q-learning algorithm by incorporating the residual energy of the CH, the energy consumption of data transmission from the node to the CH, and the energy consumption of the data transmission from the CH to the base station into the Q-value function. In the data transmission stage, ECRKQ applies the dynamic coded cooperation (DCC) transmission to improve the bandwidth utilization and the robustness of the underwater communications. In the DCC transmission, cooperative nodes are also dynamically selected based on the residual energy and the energy consumption of transmitting a packet to their destinations. In the simulation, we apply the ocean current drifting model to emulate the position variation of nodes caused by ocean currents in a mobile UASN. The simulation results show that the proposed ECRKQ scheme can achieve more balanced energy consumption among sensor nodes in a mobile UASN than that of the existing scheme.
... An underwater wireless sensor network is a technology that empowers and facilitates the exploration of natural resources in oceanic areas. Underwater sensor systems are a combination of wireless advancements with little micro mechanical sensor innovation having features such as smart identifying, intelligent computing, and communication capabilities [1,2]. Sensors are anchored to the base of sea and are furnished with a drifting buoyant that-can be swelled by strings. ...
... The receiver node's energy utilization E r ð Þ and fusion energy utilization ðE m ) for single bit data are calculated by using Eqs. (2) and (3). ...
... Failure of handling communication creates void messages to assist other nodes in utilizing the error route. Region-Based Cooperative Routing [24] is proposed to enhance the forwarding of the strategy over Rayleigh-fading-channels. The data sender node is expected to send the signal (i.e., sensed) to the receiver node and this is performed to minimize the bit error rate. ...
... Region-Based Cooperative Routing [24] It performs best in throughput, network lifetime and probability. ...
Underwater communication is still carried out using communication cables because of the minimum development that is established in underwater wireless communications. The utilization of wires to make sure the connectivity of sensor nodes that are located at the bottom of the sea is highly expensive. Finding the best route to send the sensed data to the destination in minimum duration has become a primary challenge in underwater wireless sensor networks (UWSN). Feasible routing protocols available for general sensor networks are not feasible for UWSN because of the difficult communication medium. Existing routing protocol face the problem of consuming more energy to deliver the data packet and also due to selecting the unfit route it faces more delay. To overcome the routing challenges present in UWSN, Dolphin Swarm Inspired Protocol (DSIP) is proposed in this paper. DSIP is inspired by the swarming nature of dolphins towards finding their food. Four significant phases involved in DSIP to find the best route in UWSN are searching, calling, reception, and predation. NS3 is used to evaluate the performance of DSIP against previous routing protocols with benchmark metrics namely packet delivery ratio, end-to-end delay, node death rate, and energy consumption. Results indicate that DSIP has consumed 1.43 times less energy than other previous protocols.
... In [17], the authors have deployed two main techniques for energy harvesting. The first technique is energy harvesting based on MFC and the second technique for energy harvesting is based on piezoelectric enabled hydrophones similar to the [16]. ...
... Where P 1 in equations (17)(18)(19) is the power intensity as presented in equation (8), x s is the transmitted data, ℎ 1 and ℎ 2 and ℎ 1 are the underwater channel coefficients from s to R 1 , s to R 2 and s to d respectively. ...
Underwater Sensor Networks (UWSNs) are deployed to monitor various phenomena in marine environment such as pollution control, fuel exploration and underwater seismic activities. Various challenges such as, limited and non-replaceable batteries in sensor nodes, high path loss and high propagation delay exist for UWSNs, to name a few. Successful design deployment of an energy efficient routing scheme is an intense need of the day for successful operation of UWSNs. In this paper we have presented an energy efficient routing protocol by the name of Energy Harvesting Intelligent Relay Selection Protocol (EH-IRSP). The scheme uses task-specific energy harvested relay nodes using piezoelectric technique utilizing dynamic transmission radius incorporated in all sensor nodes. EH-IRSP protocol is compared with existing UWSNs protocols Cooperative UWSN (Co-UWSN) and Energy Harvested Analytical approach towards Reliability with Cooperation for Underwater WSNs (EH-ARCUN). The Co-UWSN focuses on strengthening the sound-to-noise ratio on the minimum distance communication channel in order to reduce the path loss. The EH-ARCUN scheme selects relay nodes based on energy harvesting level in combination with Amplify and Forward (AF) technique. The proposed scheme employs a Euclidean distance between the source-destination and source-relay nodes pairs. Each source node selects the most feasible energy harvested relay node by computing cosine of the angles between itself, relay node, and destination nodes and sends the data using cooperative communication. Based on these computed parameters, each source node adjusts its transmission radius hence conserving energy. Performance parameters for this comparison are based on stability period, packet delivery ratio, end-to-end delay and path loss. Simulation results show enhanced performance of proposed scheme EH-IRSP in contrast to Co-UWSN and EH-ARCUN.
... Regardless of the free space module or multi-path model in UW-ASNs, the amplifier coefficient is defined VOLUME 4, 2016 as a(f ) dsi [37], where a(f ) is the absorption coefficient, d si is the distance between transmitter s and receiver i, d 0 is a reference distance, and f is the frequency of acoustic signal. For frequencies above a few hundred Hz, the factor a(f ) can be expressed empirically using the Thorps formula [38] as shown in Equation 26. ...
... log a(f ) = 0.011f 2 1 + f 2 + 4.4f 2 4100 + f 2 + 2.75f 2 10 5 +0.0003, (26) where a(f ) is given in dB/km and f is in kHz. Upon holding the criteria, only the potential relays response their corresponding sources by transmitting CTS packets. ...
This paper sought to investigate performance of multi-hop underwater acoustic sensor networks (UW-ASNs) when they deploy cooperative routing algorithms combining the cooperative communication and routing methods. Taking into account energy efficiency, the studied schemes are discriminated by different policies of selecting next hop nodes as well as relay nodes of one-hop cooperative communications such that the transmission energy of routing paths is minimized. In order to take full advantage of broadcast nature in wireless communication, we propose to use a node exploited as a joint relay for two-hop cooperative communication. In addition, the unreliable communication of acoustic channels is addressed by incorporated channel-aware mechanism which updates the links by exploiting packet receptions. On the bases of communication, two cooperative routing protocols are developed. Simulation results show that the network employing the proposed schemes achieves an improved performance in terms of energy efficiency, throughput, and end-toend delay as compared to the related works.
... Another study by Javaid et al. [13] proposed a scheme called the Region-Based Cooperative Routing Protocol (RBCRP). In this protocol, amplification and forwarding occur over Rayleigh worn links in UWASNs. ...
... The authors used mobile sinks with energy harvesting to improve the packet delivery ratio and network stability. RBCRP was found to attain enhanced network stability, outage probabilities, and high packet delivery ratios compared with an incremental best relay scheme [13]. ...
In underwater acoustic sensor networks (UWASNs), nodes are either static or dynamic depending upon the network configuration and type of application. Direct or multi-hop transmissions are used to forward data toward the sink. Alternatively, sinks can also be mobile or static, depending on whether the application is real time or passive. The variety of nodes and sink deployments greatly affect the performance of routing protocols. In this chapter, we analyze the effects of node density and scalability on the performance of routing protocols in UWASNs. Two popular UWASNs protocols were selected for this purpose: the depth-based routing protocol (DBR) and energy-efficient depth-based routing protocol (EEDBR). DBR is a non-cluster-based technique that performs routing using only the depth of nodes, whereas EEDBR is a location-free scheme that uses both the depth and the residual energy of nodes to route data. The scalability of node deployment was used to check the efficiency of these schemes in the context of three parameters: packet delivery ratio, end-to-end delay, and path loss.
... Many cooperative and localization based protocols are designed for UWSNs [14][15][16]. These protocols need full localization information of each node. ...
... Region-based cooperative protocol is presented in [16], in which the choice of destination and forwarder nodes depends on three parameters: depth, residual energy and SNR. To determine the location of the nodes, instead of GPS, the protocol uses received signal strength indicator (RSSI) with Mote-track technique. ...
Mitigation of channel unfavorable circumstances during data routing in underwater wireless sensor networks (UWSNs) has utmost significance. It guarantees saving packet corruption along unfavorable channels so that vital data is not lost or become meaningless. This paper proposes two routing protocols for UWSNs: localization free energy efficient routing (LFEER) and its improved version, localization free energy efficient cooperative routing (Co-LFEER). The LFEER makes decision of choosing a relay based on its maximum residual energy, number of hops and the bit error rate of the link over which packets are transmitted. These metrics are chosen to save packets from corruption to the maximum limit and maintain stable paths (where nodes do not die soon). Since a single link is used in the LFEER for packets forwarding, the link may become worse with changing circumstances of the channel. To deal with this issue, cooperative routing is added to the LFFER to construct the Co-LFEER protocol, in which some copies of packets are received by destination to decide about packets quality. Converse to some prevalent protocols, both LFEER and Co-LFEER are independent of knowing the sensor nodes’ positions, which increases computational complexity and wasteful utilization of resources. Based on extensive simulations, the proposed schemes are better than Co-DBR in reducing energy utilization and advancing packets to the desired destination.
... With use cases ranging from "smart cities" and "smart environments" (like a "smart home") to environmental monitoring and disaster prevention, intelligent transportation and auxiliary navigation, and even battlefield surveillance, applications built on the Internet of Things have proliferated in recent years (Rani et al. 2017;Yuan et al. 2023). A crucial component of the Internet of Things (IoT), underwater wireless sensor networks (UWSN) are typically a self-organized heterogeneous wireless network made up of a large number of multi-functional underwater micro-sensor nodes coupled by acoustic communication links (Javaid et al. 2017;Guangjie et al. 2012). Nodes, each equipped with unique sensors, work B Jianmei Chen jmchen@czjtu.edu.cn 1 School of Electronic and Electrical Engineering, Cangzhou Jiaotong College, Cangzhou 061100, China together to monitor the underwater environment in real-time. ...
A subset of wireless sensor networks, known as underwater wireless sensor networks (UWSNs), have been established in recent decades at varying depths (the surface, floor, and center of water) and interact with each other via sound waves. High propagation latency, low bandwidth, a high bit error rate, portability, memory, and battery life are some of the obstacles that researchers in this field must contend with when studying these networks. Due to the inherent differences between linking nodes underwater and on land, a new routing algorithm must be introduced for underwater networks. This study presents a CARP-based channel-aware routing algorithm that addresses the latter’s limitations. The proposed system partitions the overall network infrastructure into multiple zones, the administration of which serves to equalize the load on the network’s power supply. A fast and accurate route may be formulated by utilizing the quality information of links and intermediary nodes that have previously successfully transferred data to the chosen destination. Aqua-Sim, a network simulation software based on NS2, is used to run simulations of the proposed solution, and the resulting data is then exported to MATLAB for analysis. The evaluations of the results showed that on average the proposed method has improved 16% energy consumption parameters, 23% successful sending of packets and also 32% end-to-end delay compared to similar methods.
... Decrease the network reliability and maximum Information lost due to packet lost [48] Non-cooperative region region-based protocol, best forwarder node is selected through nodes ID, residual energy and SNR value, used RSSI for localization mote track technique is utilized for path establishment. ...
Wireless Sensor Networks (WSN) are widely used in many applications. However, it still suffering from many issues such as packet loss, idle listening, high delay,
and distance between nodes which all contribute to increase energy consumption and dissipation in WSN. In order to reduce this energy dissipation, this research concentrates on the Hierarchal routing Medium Access Control (MAC) protocols
on how to solve the aforementioned problems. This research proposes the Grid
Mediation Device (GMD) Node to minimize the idle listening of the active duration for each node, the nodes are put to sleep mode for a reasonably long period
of time and they wake up for a short time only to receive data. This behavior
reduces the energy consumption for each sensor while minimizing the delay since
the clusterheads will not wait for the sleeping nodes that have no data to send.
Thereafter, the active clusterheads will be also put in the sleeping mode once they
finish their data transmission. Simulation and mathematical model of the proposed
GMD protocol have confirmed that the proposed GMD can improve the lifetime for all sensor nodes in the network, due to minimizing the idle listening time for
each node. Moreover, adding Multi-levels of grids and Multi-level of MD node to the GMD protocol that will minimize the distance of sending data from each level
cluster grid to another level until reach to the base station instead of sending data
directly from any cluster to the base station, because the path between nodes and
cluster head is not reliable and the nodes are far from each other in different grid. This research leads to reduce packets lost problem as well makes the network more reliable which is another contribution of this study. Lastly, this research adding Fuzzy logic system to the grids to minimize the problem of the distance between
nodes as using three fuzzy logic criteria for each node will lead to choosing the
optimal location and energy for each clusterhead and each node. The three proposed protocols have been compared to the Two-Dimensional Technique Based on
Centre of Gravity and Energy (TDTCGE) protocol which is used two-dimensional technical centers (energy Centres and Gravity Centres) that will help to reduce the energy consumption and distances between nodes. Moreover, some of the proposed
protocol derives better system performance such as end-to-end delay, throughput, lifetime, and energy saving. The Grid Mediation Device (GMD) protocol with
Mathematical model has improved the lifetime around 88% as compared with the
TDTCGE. In addition, The Fuzzy Logic grids (FLG) protocol saves more than
8% energy battery by adding the Fuzzy logic with the three criteria’s (Distance between nodes, distance to the basestation, residual energy) that will minimize theradius competitions between nodes and the clusterhead, and between the nodes and BS by 52% more than TDTCGE protocol. GMD Simulation protocol decreases the mean of delay by 40% because of the sleeping mode, and which node
has data that it has the turn to transmit data only. In addition, Multilevel GMD Proposed protocol reduces the packets lost by 65%. This Research Work improves the lifetime and saving more energy which is also more reliable and efficiency for the wireless sensor network
... The researchers in (Javaid et al., 2017b) divide the network into three equal parts. An effective way to save energy and improve the ratio of transmitted packets is to divide the network. ...
Underwater Wireless Sensor Networks (UWSNs) are the most crucial method for exploring the hidden resources under the water. It enables many underwater applications, such as military, commercial, disaster prevention, ocean sampling, and other emergencies. Data transmission through a single relay node creates a hotspot, which will minimize the network lifetime and reduce the network reliability. Therefore, the cooperative technique is essential for transferring data between the source and the destination. This research proposes an improved version of Reliability and Adaptive Cooperation for Efficient (RACE), a well-known cooperative routing protocol for UWSNs known as RACE-SM. RACE-SM solved the single relay node issues by using the sink mobility scheme. All sensor nodes transfer data directly to the sink node if the sink node is in the communication range. Otherwise, sensor nodes use the cooperative combining strategies scheme to send the data from the source to the destination or sink node. The performance of the proposed method is then compared with the current protocols. The simulation results show that the RACE-SM outperforms in average up to 40.60%, 59%, 278%, and 77% than current protocols in terms of alive nodes, energy consumption, packet delivery ratio (PDR), and end-to-end delay respectively.
... In the region-based cooperative routing protocol (RBCRP) [35], the whole network is divided into four regions. In each region, a mobile sink moves horizontally in the network and collects data from the nodes in its own region. ...
In underwater acoustic sensor networks (UASNs), energy awareness, best path selection, reliability, and scalability are among the key factors that decide information delivery to the sea surface. Existing protocols usually do not combine such performance-affecting factors in information routing. As a result, the performance of such protocols usually deteriorates if multiple performance factors are taken into account. To cope with such performance deterioration, this article proposes two routing protocols for UASNs: energy and path-aware reliable routing (EPRR) and cooperative EPRR (Co-EPRR). Compared with the counterpart systems, the proposed protocols have been designed to deal with the problem of long propagation delays and achieve network reliability. The EPRR scheme uses nodes’ physical distance from the surface with its depth, which minimized the delay of packet transmission. The channel interaction time has been reduced, therefore, reducing unwanted channel effects on the data. Furthermore, the density of the nodes in the upper part of the network prevents data loss and limits the rapid death of the nodes. The second proposed scheme, Co-EPRR, uses the concept of routing information from the source to the destination on multiple paths. In Co-EPRR routing, the destination node can receive more than one copy of the data packet. This reduces unfavorable channel effects during data delivery. Both the schemes show good performance in terms of packet delivery ratio, received packet analysis, and end-to-end delay.
... Region Based Cooperative Routing Protocol (RBCRP) [25] is proposed for amplify and forward over Rayleigh faded channels in UWSNs. In this protocol, source nodes send the sensed data to the sink and available forwarder nodes. ...
It is challenging to propose an efficient routing algorithm for Underwater Wireless Sensor Networks (UWSNs) in terms of packet delivery ratio, end-to-end delay of packet delivery from the source to the destination, and energy consumption. The reasons of that are UWSNs have unique characteristics (e.g. using acoustic channels instead of radio channels for communications), and they have dynamic topology due to the movement of the sensor by the water flow. Depth-Based Routing (DBR) considers one of the well-known algorithms in this context. DBR is a very simple algorithm; however, it is inefficient in terms of packet delivery rate, end-to-end delay, and energy consumption. This study we developed DBR by adding an accelerated routine to it to improve its efficiency, the proposed algorithm; called Accelerated Depth-Based Routing (ADBR). In ADBR, a simple probabilistic mechanism is used to accelerate packet forwarding and provide more multi-path to the destination. In ADBR, each node immediately delivers received packet to the destination with a probability of and follows the DBR routine with a probability of 1 – Pf. The performance of ADBR is evaluated via a set of experiments by using J-SIM simulator. Experimental results indicate the superiority of the ADBR over the DBR algorithm.
... Also, it suffers from loss of path, increased delay, low network lifetime and high packet loss. Due to these characteristics, the routing path leads to high distractions in the network [7][8][9]. ...
Underwater Wireless Sensor Networks (UWSN) has received more attention in exploring promising technologies for scientific data collection of underwater natural resources with maximum link reliability. For effective communication among the sensor nodes, reliable data delivery based routing protocols have been designed to avoid long-distance communication in large network areas. But the network-based protocols suffer from many constraints like limited distance-dependent bandwidth, defective channels and high delay. Furthermore, the supplied batteries have limited power and also data transmission cannot be exploited in the long-distance network areas due to the harsh underwater environment. Therefore, a clustering-based mobility pattern routing protocol is required to link long-distance communication over depth areas with less consumed energy and less delay. This paper proposed an energy-efficient Distributed Node Clustering Mobility Pattern Routing Protocol (DNC-MPRP) to reach the long-distance depth area for data transmission with less energy consumption and avoid inaccurate routing paths using mobility patterns in UWSN. This approach consists of several phases: network initialization, Cluster Head (CH) formation and data transmission. In DNC-MPRP, the network is partitioned into two dense areas for near and far distance communications. Then the network configuration initializes the rectangle mobility pattern which is used to reach the surface sink with less delay. Next, the CH formation initializes the cluster area in the large and common area to maintain energy in the collected member nodes. Lastly, the data transmission is adopted only when the coverage area is in the transmission range of the network field. Simulation result depicts that the DNC-MPRP approach would be evaluated in terms of Energy Consumption (EC), Packet Delivery Ratio (PDR), End to End Delay (E2ED) and Network Lifetime (NL) based on the variation of nodes, different transmission range, mobile sink, data rate and payload data with high PDR of 95%, high NL of 1200 s, low E2ED of 9.5 s and less EC than existing methods.
... There are several variations of the AF scheme. For example, Javaid [43] proposes RBCRP: a region-based cooperative routing protocol based on the amplify-andforward technique over Rayleigh fading channels in underwater wireless sensor networks. Different from other approaches, they split the UWSN into smaller regions, clustering relays, and source nodes. ...
The novel Underwater Wireless Sensor Network (UWSN) can contribute to monitor and explore aquatic environments. But, communicating in these environments is still hard and has many challenges. For example, optical and electromagnetic waves deteriorate from high-attenuation. Moreover, acoustic communication has a large packet error rate and low throughput. A large number of solutions to improve aquatic communication refers to routing protocols, medium access control protocols, and designing acoustic modems. Cooperative communication explores the broadcast nature of wireless transmission and enhances its performance. However, cooperative communication has not been fully explored in UWSNs. In this work, we present COPPER, a Cooperative Protocol for Pervasive Underwater Acoustic Networks. COPPER considers LLC and MAC sub-layers and operates synchronously or asynchronously over Time Division Multiple Access using a selective repeat ARQ scheme. COPPER exploits the broadcast nature of wireless communication and, sensor nodes that are idle can operate as a relay, enhancing communication by space diversity. Simulation results show that COPPER improves network performance. For example, the network goodput improves by 17% and the packet error rate decreases by 65%.
... The authors in [41] propose the RBCRP protocol in UWSNs. In this protocol, the sender node transmits the data packets to the destination and the relay nodes. ...
Recently, the underwater wireless sensor networks (UWSNs) have been proposed
for the exploration of the aqueous resources and to obtain information about the aquatic
environment. The noise in UWSNs challenges a successful transmission of packets
from a source to the destination. There are many protocols in the literature that
address noise reduction/avoidance during underwater communication. However,
they require localization information of each node that itself is a challenging issue.
This thesis presents a depth and noise-aware routing (DNAR) protocol for UWSNs,
which considers the minimum channel noise and the lowest depth of the sensor
node in order to send the packets reliably from a sender node to a surface sink. In
the DNAR protocol, more energy is assigned to the sensor nodes that have a depth
level ≤ 150m. Therefore, the nodes which are deployed nearby to a surface sink have
more capability of transmission and will not die quickly. Also, the proposed protocol
selects the forwarder candidate that has the lowest depth and minimum channel
noise at the receiver. The proposed scheme requires no geographical information of
the nodes for data routing. The DNAR protocol is validated by Matlab and compared
with the DBR scheme. The simulation demonstrates that the DNAR has better results
in terms of total energy consumption, packet delivery ratio (PDR), and the network
lifetime.
Additionally, in this thesis, a cooperative depth and noise aware routing for
UWSNs is proposed. As compared to the existing cooperative routing protocols,
the CoDNAR protocol selects the destination node based on both the lowest depth
and lowest channel noise. In CoDNAR, a cooperative diversity technique is used
that combat fading and high noise. A Source node uses two paths that forwards
a data packet to the destination node. The one path is directly from a source to
the destination, while the other one is via the relay node(s) to the destination. The
destination node receives multiple copies that combining it by using a maximal ratio
combining technique (MRC). The CoDNAR has the best performance in data delivery
than counterpart techniques, as validated by Matlab simulation.
... Misra et al. (2012) analyzed the jamming characteristics to accurately detect and mitigate jamming in underwater sensor networks. Javaid et al. (2017) addressed the routing technique to maximize the throughput and prolong the network lifetime in underwater sensor networks (UWSNs). In Al-Dharrab et al. (2017), outage probability and signal-to-noise ratio (SNR) performances for underwater acoustic (UWA) channels are investigated to improve the performance of the UWA communications. ...
Cooperation among sensor nodes and the unreliability of acoustic channels are the significant challenges in underwater acoustic sensor networks (UASNs). In UASNs, the unreliability may results in high packet loss due to the high bit-error-rate and packets being dropped due to network congestion. High packet loss decreases the transmission rate in a network. An effective secure transmission mechanism is very much essential among the nodes in UASNs. In this paper, a trust strategy-based dynamic Bayesian game (TSDBG) model is proposed to resolve these problems. In TSDBG, a secure suite is created among the nodes in the network. Trust and Payoff are calculated for each node to evaluate the particular node involved in the packet-dropping and misbehaving activities that occurred during the transmission. Each node updates its trust value using Bayes' rule. Regular nodes are continuously monitored to analyze their neighbor nodes based on trust value. The simulation results reveal that the proposed scheme significantly reduces the packet-dropping attack, misbehaving activities of malicious nodes, propagation delay, and thereby enhancing secure transmission.
... Here, forwarding reduced the unnecessary transmission of the data and hence improved the lifetime of the network. Javaid et al. [23] described about a cooperative routing scheme which uses a region based approach. Since, cooperative routing is a challenging issue in the WSN improves its solution, the performance and lifetime of the network. ...
Many agricultural activities can be highly enhanced by using sensor networks and data mining techniques. One of these activities is the regulation of the quantity of water in cultivated fields. Moreover, wireless sensor network have become a more emerging technology in precision agriculture during the recent years. The important issue in the design of wireless sensor networks is the utilization of energy and to enhance the lifetime of the sensor nodes. In this paper, a new intelligent routing protocol has been proposed to improve the network lifetime and to provide energy efficiency in the routing process which is used to provide data to the irrigation system. This novel intelligent energy efficient routing protocol uses fuzzy rules and the protocol is called as Terrain based Routing using Fuzzy rules for precision agriculture. The fuzzy inference system developed in this work has been used to take decisions for routing. The system has been implemented and compared with two routing algorithms called Region Based Routing and Equalized Cluster Head Election Routing Protocol. The experimental results show that the proposed algorithm performs better than the other existing algorithms.
... However, high energy nodes bear the most data burden. The authors in [26] present a region-based cooperative routing protocol. A sender transmits the packets to the relays and destination. ...
Owing to the harsh and unpredictable behavior of the sea channel, network protocols that combat the undesirable and challenging properties of the channel are of critical significance. Protocols addressing such challenges exist in literature. However, these protocols consume an excessive amount of energy due to redundant packets transmission or have computational complexity by being dependent on the geographical positions of nodes. To address these challenges, this article designs two protocols for underwater wireless sensor networks (UWSNs). The first protocol, depth and noise-aware routing (DNAR), incorporates the extent of link noise in combination with the depth of a node to decide the next information forwarding candidate. However, it sends data over a single link and is, therefore, vulnerable to the harshness of the channel. Therefore, routing in a cooperative fashion is added to it that makes another scheme called cooperative DNAR (Co-DNAR), which uses source-relay-destination triplets in information advancement. This reduces the probability of information corruption that would otherwise be sent over a single source-destination link. Simulations-backed results reveal the superior performance of the proposed schemes over some competitive schemes in consumed energy, packet advancement to destination, and network stability.
... Moreover, it has high end-to-end delay, due to the higher number of hops between source and sink. RBCRP RBCRP [26] is a cooperative routing scheme that works in two phases. During the initial setup phase, nodes discover neighbors (potential forwarders) by broadcasting "hello" packets. ...
Underwater Sensor Networks (UWSN) have attracted huge attention due to their significance in oceanic observation and exploration. They offer a vast number of applications, many of which require routing the sensed data to a centralized location. This makes routing an important part of the design of such applications. In this paper, we present a comprehensive survey of recently proposed routing protocols for UWSNs. We evaluate the proposed schemes through an extensive set of parameters that define the core characteristics of a routing protocol. Moreover, we present a summary of the methods used by each scheme to familiarize readers with the basic operations of the schemes. We also present our view of the strengths and weakness of each scheme. For ease of description, the addressed routing protocols are divided into two categories: localization-based, and localization-free routing schemes. Each of the two categories is further divided into the protocols that consider node mobility, and those that do not. Lastly, we present our view on open research topics.
... Therefore, many of the leading researchers have studied the proposed aggregation methods to improve protocols efficiency of energy for tasks of UWSN node. In data aggregation of UWSN, master nodes (integrator node) aggregate and process data from nearby nodes, and sends the data to Sink [79]. Therefore the major challenge of aggregating data UWSN is minimizing redundant data until the guarantee of accuracy of data. ...
There is a growing interest in using wireless sensor technologies in various Internet of things scenarios. Considering the huge growth of smart objects and their applications, the need to collect and analyze their product data are becoming one of the main challenges. Sensor nodes are powered by batteries, efficient operations in term of energy are critical. Toward that end, it is desirable for a sensor node to eliminate redundancies in the received data from the neighboring nodes before transferring the final data to the central station. Data aggregation is one of the influential techniques in elimination of data redundancy and improvement of energy efficiency; also it increases the lifespan of Wireless Sensor Networks. In addition, the efficient data aggregation protocol can reduce network traffic. When a specific objective takes place in a specific area, it might be detected by more than one sensor. Considering the main challenges and aspects of data aggregation in wireless sensor networks, a review on different types of data aggregation techniques and protocols are presented in this paper. The ultimate objective of this study is to make the basic foundations to develop new advanced designs based on data integration techniques and clustering that have been proposed so far. Major techniques of data integration in wireless sensor networks covering ground, underground and underwater sensor networks are presented in this paper and the applications, advantages and disadvantages of using each technique are described.
... In [40], [41], the authors addressed the problem of distributed sensors' failure detection in networks through a novel technique based on a gossip algorithm and group testing principles [42]. Likewise, in [43], a distributed fault detection algorithm was proposed for WSNs. Faulty sensor nodes are identified based on comparisons between the neighboring node and dissemination of the decision made at each node. ...
Wireless Sensor Networks (WSNs) are vulnerable to faults because of their deployment in unpredictable and hazardous environments. This makes WSN prone to failure such as software, hardware, and communication failures. Due to the sensor’s limited resources and diverse deployment fields, fault detection in WSNs has become a daunting task. To solve this problem, Support Vector Machine (SVM), Probabilistic Neural Network (PNN), Stochastic Gradient Descent (SGD), Multilayer Perceptron (MLP), Random Forest (RF), and Convolutional Neural Network (CNN) classifiers are used for classification of gain, offset, spike, data loss, out of bounds, and stuck-at faults at the sensor level. Out of six faults, two of them are induced in the datasets, i.e., spike and data loss faults. Likewise, sensors embedded mobile phones are used for the collection of data for some specific task which can effectively save cost and time in Crowd Sensing Network (CSN). The quality of collected data depends on the participation level from all entities of CSN, i.e., service provider, service consumers and data collectors. In comparison with the centralized traditional incentive and reputation mechanisms, we propose a blockchain based incentive and reputation mechanism for CSNs, which mainly consists of three smart contracts. The incentives are used to stimulate the involvement of data collectors and motivate the participants to join the network. Also, the issue of privacy leakage is tackled by using Advanced Encryption Standard (AES128) technique. In addition to that, a reputation system is implemented to
tackle the issues like untrustworthiness, fake reviews, and conflicts among entities. Through registering reviews, the system encourages data utilization by providing correct, consistent and reliable data. Furthermore, the results of first scenario are compared on the basis of their Detection Accuracy (DA), True Positive Rate (TPR), Matthews Correlation Coefficients (MCC), and F1-score. In this thesis, a comparative analysis is performed among the classifiers mentioned previously on real-world datasets and simulations demonstrate that the RF algorithm secures a better rate of fault detection than the rest of the classifiers. Similarly, the second scenario is evaluated through analyzing the gas consumption of all the smart contracts, whereas, the encryption technique is validated through comparing the execution time with base paper technique. Lastly, the reputation system is inspected through analyzing the gas consumption and mining time of input string length.
... This protocol puts extra processing burden on each node for generating neighbouring nodes set. Deficiency of the scheme proposed in [21] lies at relay node which employ processing overhead involving error checking for each received data packet. ...
Underwater sensor networks (UWSNs) are ad-hoc networks which are deployed at rivers, seas and oceans to explore and monitor the phenomena such as pollution control, seismic activities and petroleum mining etc. The sensor nodes of UWSNs have limited charging capabilities. UWSNs networks are generally operated under two deployment mechanisms i.e localization and non-localization based. However, in both the mechanisms, balanced energy utilization is a challenging issue. Inefficient usage of energy significantly affects stability period, packet delivery ratio, end-to-end delay, path loss and throughput of a network. To efficiently utilize and harvest energy, this paper present a novel scheme called EH-ARCUN (Energy Harvesting Analytical approach towards Reliability with Cooperation for UWSNs) based on cooperation with energy harvesting. The scheme employs Amplify-and-Forward (AF) technique at relay nodes for data forwarding and Fixed Combining Ratio (FCR) technique at destination node to select accurate signal. The proposed technique selects relay nodes among its neighbor nodes based on harvested energy level. Most cooperation-based UWSN routing techniques do not exhibit energy harvesting mechanism at the relay nodes. EH-ARCUN deploys piezoelectric energy harvesting at relay nodes to improve the working capabilities of sensors in UWSNs. The proposed scheme is an extension of our previously implemented routing scheme called ARCUN for UWSNs. Performance of the proposed scheme is compared with ARCUN and RACE (Reliability and Adaptive Cooperation for efficient Underwater sensor Networks) schemes in term of stability period, packet delivery ratio, network throughput and path loss. Extensive simulation results show that EH-ARCUN performs better than both previous schemes in terms of the considered parameters.
... In [18], the entire network is split into three equal sub-regions. Division of network is an efficient step towards energy saving and ratio-of-delivered packet (RODP) enhancement. ...
Underwater deployed sensors nodes are energy-constrained. Therefore, energy efficiency becomes crucial in underwater wireless sensor networks (U-WSNs). The adverse channel corrupts the packets and challenges their reliability. To handle these challenges, two routing schemes are introduced in this paper. They are effective energy and reliable delivery (EERD) and cooperative effective energy and reliable delivery (CoEERD). In EERD, the packets follow single-path routing and the best forwarder node is selected using a weight function such that packets are transferred via the reliable paths with low energy usage. Packet transfer via a single route in EERD has, however, compromised reliability as the undersea links bear harshness and unpredictability. Therefore, the CoEERD scheme adds cooperative routing to EERD, in which a relay node is introduced between a source-destination pair. The destination requests the relay when the packets it gets from the source are corrupted beyond a threshold value. Selection of weight function is unique and considers many factors to ensure low energy usage with reliability while considering nodes for data transfer. This also helps in selecting a single relay node rather than many relays in the conventional cooperative routing model. Based on simulation results, the EERD and CoEERD protocols have improved performance in energy usage, reliable packet transfer and delay.
... Recently, UWSNs have emerged as a promising networking technique for various underwater applications. Javaid et al. [30] proposed a region based cooperative routing protocol for amplify and forward technique over Rayleigh faded channels in UWSNs. Rani et al. [31] presented an energy efficient chain based routing protocol for UWSNs. ...
Most existing works on barrier coverage assume that sensors are deployed in a two-dimensional (2D) long thin belt region, where a barrier is a chain of sensors from one end of the region to the other end with overlapping sensing zones of adjacent sensors. However, the 2D assumption cannot cover all application scenarios, e.g., underwater wireless sensor networks, where sensors are finally distributed over three-dimensional (3D) underwater environment. In this paper, we investigate weak k-barrier coverage problem in underwater wireless sensor networks. We first analyse how to determine whether a deployed underwater wireless sensor network provides 3D weak k-barrier coverage, and propose a novel and effective scheme to transform the 3D weak k-barrier coverage problem into 2D complete k-coverage problem, based on which we devise an O(n²) time algorithm for the 3D weak k-barrier decision problem. Furthermore, we propose a parallel movement manner, based on which an effective algorithm called Hungarian Method-based sensor assignment algorithm (HMB-SAA) is proposed for constructing weak k-barrier coverage while minimizing the total movement distance of all sensors in underwater wireless sensor networks. Simulation results validate the correctness of our analysis, and show that the proposed algorithm outperforms the GreedyMatch algorithm. To the best of our knowledge, this is the first result for 3D weak k-barrier coverage problem in underwater wireless sensor networks.
... Likewise in [28,29], authors have worked on void hole avoidance, collision, and reliable data delivery in underwater WSNs. Whereas in [30], the authors have worked on region based routing protocols in underwater WSNs. Their proposed technique is used for forward and amplify technique over Rayleigh faded channels in underwater WSNs. ...
Wireless Sensor Networks (WSNs) are vulnerable to faults because of their deployment in unpredictable and hazardous environments. This makes WSN prone to failures such as software, hardware, and communication failures. Due to the sensor's limited resources and diverse deployment fields, fault detection in WSNs has become a daunting task. To solve this problem, Support Vector Machine (SVM), Convolutional Neural Network (CNN), Stochastic Gradient Descent (SGD), Multilayer Perceptron (MLP), Random Forest (RF), and Probabilistic Neural Network (PNN) classifiers are used for classification of gain, offset, spike, data loss, out of bounds, and stuck-at faults at the sensor level. Out of six faults, two of them are induced in the datasets, i.e., spike and data loss faults. The results are compared on the basis of their Detection Accuracy (DA), True Positive Rate (TPR), Matthews Correlation Coefficients (MCC), and F1-score. In this paper, a comparative analysis is performed among the classifiers mentioned previously on real-world datasets. Simulations show that the RF algorithm secures a better fault detection rate than the rest of the classifiers.
... Gray wolf optimization technique is used to enhance recurrent extreme learning machine for the classification purpose [25]. Authors have used different techniques to analyze the behaviour of large number of sensors in WSNs [26][27][28][29]. ...
Decision fusion is used to fuse classification results and improve the classification accuracy in order to reduce the consumption of energy and bandwidth demand for data transmission. The decentralized classification fusion problem was the reason to use the belief function-based decision fusion approach in Wireless Sensor Networks (WSNs). With the consideration of improving the belief function fusion approach, we have proposed four classification techniques, namely Enhanced K-Nearest Neighbor (EKNN), Enhanced Extreme Learning Machine (EELM), Enhanced Support Vector Machine (ESVM), and Enhanced Recurrent Extreme Learning Machine (ERELM). In addition, WSNs are prone to errors and faults because of their different software, hardware failures, and their deployment in diverse fields. Because of these challenges, efficient fault detection methods must be used to detect faults in a WSN in a timely manner. We have induced four types of faults: offset fault, gain fault, stuck-at fault, and out of bounds fault, and used enhanced classification methods to solve the sensor failure issues. Experimental results show that ERELM gave the first best result for the improvement of the belief function fusion approach. The other three proposed techniques ESVM, EELM, and EKNN provided the second, third, and fourth best results, respectively. The proposed enhanced classifiers are used for fault detection and are evaluated using three performance metrics, i.e., Detection Accuracy (DA), True Positive Rate (TPR), and Error Rate (ER). Simulations show that the proposed methods outperform the existing techniques and give better results for the belief function and fault detection in WSNs.
... The authors in [32] proposed an algorithm in which the network is split into three small horizontal sectors. Two MSs move in the horizontal orientation, whereas two MSs in the vertical orientation in the network. ...
An efficient algorithm for the persistence operation of data routing is crucial due to the uniqueness and challenges of the aqueous medium of the underwater acoustic wireless sensor networks (UA-WSNs). The existing multi-hop algorithms have a high energy cost, data loss, and less stability due to many forwarders for a single-packet delivery. In order to tackle these constraints and limitations, two algorithms using sink mobility and cooperative technique for UA-WSNs are devised. The first one is sink mobility for reliable and persistence operation (SiM-RPO) in UA-WSNs, and the second is the enhanced version of the SiM-RPO named CoSiM-RPO, which utilizes the cooperative technique for better exchanging of the information and minimizes data loss probability. To cover all of the network through mobile sinks (MSs), the division of the network into small portions is accomplished. The path pattern is determined for MSs in a manner to receive data even from a single node in the network. The MSs pick the data directly from the nodes and check them for the errors. When erroneous data are received at the MS, then the relay cooperates to receive correct data. The proposed algorithm boosts the network lifespan, throughput, delay, and stability more than the existing counterpart schemes.
... In [21], the authors present a new cooperative fashion routing algorithm to reduce the channel effects. The whole network is divided into three equal zones to balance the energy consumption. ...
Symmetry in nodes operation in underwater wireless sensor networks (WSNs) is crucial sothat nodes consume their energy in a balanced fashion. This prevents rapid death of nodes close towater surface and enhances network life span. Symmetry can be achieved by minimizing delay andensuring reliable packets delivery to sea surface. It is because delay minimization and reliability arevery important in underwaterWSNs. Particularly, in dense underworks, packets reliability is of seriousconcernwhen a large number of nodes advance packets. The packets collide and are lost. This inefficientlyconsumes energy and introduces extra delay as the lost packets are usually retransmitted. This is furtherworsened by adaptation of long routes by packets as the network size grows, as this increases the collisionprobability of packets. To cope with these issues, two routing schemes are designed for dense underwaterWSNs in this paper: delay minimization routing (DMR) and cooperative delay minimization routing(CoDMR). In the DMR scheme, the entire network is divided into four equal regions. The minor sinknodes are placed at center of each region, one in each of the four regions. Unlike the conventionalapproach, the placement of minor sink nodes in the network involves timer based operation and isindependent of the geographical knowledge of the position of every minor sink. All nodes havingphysical distance from sink lower than the communication range are able to broadcast packets directlyto the minor sink nodes, otherwise multi-hopping is used. Placement of the minor sinks in the fourregions of the network avoids packets delivery to water surface through long distancemulti-hopping,which minimizes delay and balances energy utilization. However, DMR is vulnerable to informationreliability due to single path routing. For reliability, CoDMR scheme is designed that adds reliabilityto DMR using cooperative routing. In CoDMR, a node having physical distance from the sink greaterthan its communication range, sends the information packets by utilizing cooperation with a singlerelay node. The destination and the relay nodes are chosen by considering the lowest physical distancewith respect to the desired minor sink node. The received packets at the destination node are merged byfixed ratio combining as a diversity technique. The physical distance computation is independent of thegeographical knowledge of nodes, unlike the geographical routing protocols. This makes the proposedschemes computationally efficient. Simulation shows that DMR and CoDMR algorithms outperformthe counterpart algorithms in terms of total energy cost, energy balancing, packet delivery ratio (PDR),latency, energy left in the battery and nodes depleted of battery power.
... In [21], the authors present a new cooperative fashion routing algorithm to reduce the channel effects. The whole network is divided into three equal zones to balance the energy consumption. ...
... Nadeem Javaid et.al [19] proposed a routing protocol where the entire network is divided into distinct regions and cooperative protocol is used for communication where relay nodes amplify the signal and pass to the destination. To reduce the packet drop ration sink nodes are made mobile and they travel in horizontal and vertical direction to cover the entire network. ...
div> The demand for underwater communication is growing at a faster pace since few decades. Maximizing the communication performance and building efficient network architecture for underwater communication is a challenging task. Due to the reduced bandwidth, high error rate, noise, propagation delay, water currents and increased cost in the network topology, the existing communication techniques are not feasible for underwater communication. Research in high speed underwater transmission technology has become a primary need in today’s world. By using underwater acoustic sensor network high transmission distance can be achieved but with lower data rates, high power consumption, larger delays and with higher cost. Underwater Optical Communication can be used to increase data rates and lower delays but it suffers from high attenuation due to which it cannot be used for data transfer over larger distances. Research in the area of hybrid sensor networks is a challenging task and has many open research challenges, which needs to be solved. In this paper we discuss the various architectures of underwater communication. A comparative study is made on different routing protocols and localization algorithms. The challenges faced by acoustic and optical communication are also discussed.
</div
... In [23], the division of the total depth of the network is accomplished into three regions of varying depth. Each region is subdivided into three regions according to the selection of the source, relay and destination nodes. ...
Cooperative routing mitigates the adverse channel effects in the harsh underwater environment
and ensures reliable delivery of packets from the bottom to the surface of water. Cooperative routing is
analogous to sparse recovery in that faded copies of data packets are processed by the destination node to
extract the desired information. However, it usually requires information about the two or three position
coordinates of the nodes. It also requires the synchronization of the source, relay, and destination nodes.
These features make the cooperative routing a challenging task as sensor nodes move with water currents.
Moreover, the data packets are simply discarded if the acceptable threshold is not met at the destination.
This threatens the reliable delivery of data to the final destination. To cope with these challenges, this
paper proposes a cooperative energy-efficient optimal relay selection protocol for underwater wireless
sensor networks. Unlike the existing routing protocols involving cooperation, the proposed scheme combines
location and depth of the sensor nodes to select the destination nodes. Combination of these two parameters
does not involve knowing the position coordinates of the nodes and results in selection of the destination
nodes closest to the water surface. As a result, data packets are less affected by the channel properties.
In addition, a source node chooses a relay node and a destination node. Data packets are sent to the destination
node by the relay node as soon as the relay node receives them. This eliminates the need for synchronization
among the source, relay, and destination nodes. Moreover, the destination node acknowledges the source
node about the successful reception or retransmission of the data packets. This overcomes the packets drop.
Based on simulation results, the proposed scheme is superior in delivering packets to the final destination
than some existing techniques.
Internet of Underwater Things (IoUTs) deals in a resource-constrained environment and has several open issues, challenges, and potential applications in both onshore and offshore fields. The distinctive features of acoustic medium and persistent node mobility have spurred the development of a routing protocol for IoUT that ensures the efficient data transfer at the surface station. The efficient data transfer metrics can be achieved either by the emergence of cluster-based or chain-based routing protocols. This paper provides a simulation-based quantitative analysis of the most recent and prominent cluster-based and chain-based routing protocols for IoUT that are intended to enable the efficient data transfer from source to destination. In this context, we use NS3 to conduct extensive simulations for the quantitative analysis of different routing protocols relating to packet delivery rate, packet drop rate, normalized energy consumption, normalized network lifetime, density of alive nodes, and density of dead nodes. In addition to quantitative analysis, we also provide the performance trade-offs, limitations, and applications for IoUT routing protocols for these two classifications. In last, we also perform quantitative analysis for these two classifications head-to-head. This work aims to provide helpful insights into selecting a suitable protocol for routing applications to meet the various specifications and requirements of IoUT for efficient data dissemination.
Underwater Wireless Sensor Networks (UWSN) have gained more attention from researchers in recent years due to their advancement in marine monitoring, deployment of various applications, and ocean surveillance. The UWSN is an attractive field for both researchers and the industrial side. Due to the harsh underwater environment, own capabilities, and open acoustic channel, it is also vulnerable to malicious attacks and threats. Attackers can easily take advantage of these characteristics to steal the data between the source and destination. Many review articles are addressed some of the security attacks and taxonomy of the Underwater Wireless Sensor Networks. In this study, we have briefly addressed the taxonomy of the UWSNs from the most recent research articles related to the well-known research databases. This paper also discussed the security threats on each layer of the Underwater Wireless sensor networks. This study will help the researchers design the routing protocols to cover the known security threats and help industries manufacture the devices to observe these threats and security issues.
Underwater wireless sensor network is characterized with dynamic network topology owing to node mobility. Frequent changes in position of nodes due to water current cause network partitioning. This often results in frequent network failures and causes void spaces. Frequent network failures lead to unreliable data transmissions where nodes injudiciously drain their power resource. Such a network needs to adapt its network routing in order to diminish the challenges caused by node mobility. A dynamic approach addressing the issues of node mobility will also enhance the network lifetime. Node mobility creates articulation points (AP) in the network topology. AP is similar to bridges in a graph. AP leads to partitioning of the network that only yields failed and unreliable transmission. Cat Swarm Optimization is explored here for detecting a possible partition in the network prior to its occurrence in the seeking mode of the algorithm. In the tracking mode of the algorithm the cat with the closest distance to the predicted AP is selected to move towards the predicted AP in order to avoid the network from partitioning. The proposed approach enhances the network lifetime as it avoids disconnections and failed transmissions. It would conserve energy consumption of nodes by reducing the possibilities of failed and retried transmissions.
Energy limitation is one of the major bottlenecks during the operation of many emerging applications, such as electric vehicles, water and gas meters and a number of sensors used in the context of the Internet of Things and cyber‐physical systems. Energy harvesting techniques have arisen as a promising solution to minimize the energy issues found in these types of application domains. In energy harvesting systems, a critical challenge is the need to use battery models capable of accurately estimating both the input and output power of batteries. This article proposes a temperature‐dependent analytical battery model capable of estimating some output quantities — for example, state of charge, voltage and lifetime — of batteries that use energy harvesting technologies. This model was validated by comparing its analytical results with a dataset called the Randomized Battery Usage Data Set, which is available at the data repository of the National Aeronautics and Space Administration (NASA) website. It is also presented a proof‐of‐concept application, demonstrating that the use of these technologies can serve as an effective means to extend the operating time of batteries, resulting in significant benefits for a number of applications.
In this thesis, a suite of schemes is presented to enhance the performance of cooperative communication networks. In particular, techniques to improve the outage probability, end-to-end delay and throughput performances are presented. Firstly, a buffer-aided cooperative communication is studied and analyzed for packet selection and relay selection. A three-node network is considered in the beginning and the phenomenon of packet diversity is taken into consideration to overcome bad channel conditions of the
source to relay (SR) and relay to destination (RD) links. The closed-form expressions for the computation of the outage probability along with the delay, throughput and diversity gain are derived. Then, packet selection is studied along with relay selection for buffer-aided amplify and forward (AF) cooperative relaying networks. The proposed protocol is analyzed for both symmetric and asymmetric channel conditions and buffer size using multiple antennas at relays and compared against the existing buffer-aided schemes.
Markov chain (MC) is used to derive the closed-form expressions for outage probability, diversity gain, delay and throughput.
Next, the performance of SNR based hybrid decode-amplify-forward relaying protocol is observed. When SR link is the strongest, data is transmitted to the selected relay and checked against the predefined threshold at the relay. If it is greater than the threshold, data is decoded and stored in the corresponding buffer. Otherwise, it is amplified and stored in the respective buffer. When RD link is the strongest, data is transmitted to the destination. MC based theoretical framework is used to derive an expression for the outage probability, the average end-to-end delay and throughput. Then, relay selection schemes considering the instantaneous link quality along with buffer status in the relay selection are proposed. A scheme is proposed that simultaneously considers buffer status and link quality. Then, we discuss multiple links with equal weights using a general relay selection factor. It includes the weight of the link as the first metric and the link quality, or priority, as the second metric for different cases of the same weight. The proposed scheme is evaluated for symmetric and asymmetric channel conditions.
Moreover, we propose a specific parameter, termed as the bu�er-limit, which controls the selection of SR or RD links and also have its impact on the average delay and throughput. In this scheme, the outage probability is traded with the average end-to-end queuing delay or the average throughput by adjusting the values of the buffer-limit. The MC based framework is employed to derive the closed-form expressions for the outage probability, average end-to-end queuing delay and the average throughput. The suggested schemes are compared to the existing bufferaided relay selection schemes.
Lastly, we consider the energy constraint cooperative network and propose a generalized approach to study the performance of energy harvesting relaying schemes.
The unified modeling of generalized energy harvesting relaying (GEHR) scheme covers the non-energy harvesting schemes and the well-known energy harvesting schemes, i.e., time switching based relaying (TSR) and power splitting based relaying (PSR). Moreover, the scheme also caters the hybrid of both TSR and PSR schemes. The closed-form expressions for the outage probability and ergodic capacity and average throughput are formulated for non-mixed Rayleigh fading and mixed Rayleigh-Rician fading channels. Each case is analyzed for AF and decode and forward relaying models. Comprehensive Monte-Carlo simulations confirm all theoretical results.
Transmission rate is one of the contributing factors in the performance of Wireless Sensor Networks (WSNs). Congested network causes reduced network time and more packet loss. To address this issue, we have proposed a transmission rate control method. The current node in a WSN adjusts its transmission rate based on the traffic loading information gained from the downstream node. Multi classification is used to control the congestion using Support Vector Machine (SVM). In order to get less miss classification error, Differential Evolution (DE) and Grey Wolf Optimization (GWO) algorithms are used to tune the SVM parameters. The comparative analysis has shown that the proposed approaches DE-SVM and GWO-SVM is more proficient than the other classification techniques in terms of classification error.
Underwater sensor networks are ad hoc networks to monitor different underwater phenomenons such as pollution control, petrol mining, and observation of echo life. For underwater sensor networks to operate for longer duration of time, hoarding energy from background sources is viable option. One such source is harvesting energy from water currents using piezoelectric material embedded in sensor nodes. Piezoelectric materials can produce electricity when pressure is applied on it in the form of oscillating frequency produced by hydrophones. In this paper we have analyzed cooperation-based technique in underwater sensor networks containing sensor nodes which select relay nodes in their immediate vicinity with energy harvesting capabilities. These relay sensor nodes employ technique of amplify and forward (AF). As in current literature, all cooperative-based UWSN routing techniques are without integration of any type of energy harvesting schemes; considering this, we have incorporated piezoelectric energy harvesting mechanism into relay nodes in order to decrease end-to-end delay, increase stability period, and improve packet delivery ratio. As case study, we have selected cooperation-based UWSN protocol ARCUN (Analytical Approach towards Reliability with Cooperation for Underwater WSNs) and integrated piezoelectric energy harvesting scheme with it. We compared our new scheme EH (energy harvested)-ARCUN with ARCUN and RACE (Reliability and Adaptive Cooperation for Efficient Underwater Sensor Networks). Simulation results show improvement of EH-ARCUN over ARCUN and RACE schemes.
It is extremely important to safeguard our harbours from intruders and smugglers who aim to benefit from unlawful activities and cause harm. Theft, terror attacks in commercial boats and cargo ships docked on harbours needs to be prevented. Camera surveillance, radar, satellites images have not been very reliable so far as they fail to work in drastic weather conditions and can be manipulated as well. Underwater Wireless Sensor Network (UWSN) could be installed in both shallow and deep water of the harbour for detecting various types of harbour activities. Ship movements namely heave, sway, surge, yaw, pitch and roll, could be detected and classified using pressure, position and underwater sensors. Such information can help in tracking ship motions, movements, loading and unloading activities. Any unplanned unloading activity can thus be detected and necessary alarms can be raised for ship owners and harbour official's attention. However designing such a network needs one to ensure that the severe energy constraints of the UWSN are well addressed. Bayesian Network based approach is explored in this paper for scheduling the sleep and active cycle of network nodes. Our proposed technique of ship motion monitoring system reduces energy consumption of the network nodes and enhances the network lifetime by balancing network load intelligently. The tracking mechanism proposed here explores the fundamental behaviour of ships motions in waves with reference to translating coordinate system.
Energy saving in wireless sensor networks is a fundamental issue as most sensor nodes are powered by batteries. The deployment of mobile sinks can alleviate the imbalance of energy consumption among sensor nodes, thereby prolonging the network lifetime. In this paper, we study the energy management problem in sensor networks, using multiple mobile sinks. We first formulate the problem as a novel data collection problem and then propose an efficient algorithm for it. The key challenge in the design of the proposed algorithm is how to balance the workload among mobile sinks and the energy consumption among sensor nodes through the control of the movement of mobile sinks. We finally evaluate the performance of the proposed algorithm through experimental simulation. Experimental results show that the proposed algorithm is very promising, which can improve the energy efficiency and the quality of data transmission in the sensor network significantly.
Sink mobility is one of the most effective solutions for improving lifetime and has been widely investigated for the last decade. Algorithms for single-sink mobility are not directly applied to the multiple-sink case due to the latter’s specific challenges. Most of the approaches proposed in the literature use mathematical programming techniques to solve the multiple-sink mobility problem. However, doing so leads to higher complexities when traffic flow information for any possible sink-site combinations is included in the model. In this paper, we propose two algorithms that do not consider all possible sink-site combinations to determine migration points. We first present a centralized movement algorithm that uses an energy-cost matrix for a user-defined threshold number of combinations to coordinate multiple-sink movement. We also give a distributed algorithm that does not use any prior network information and has a low message exchange overhead. Our simulations show that the centralized algorithm gives better network lifetime performance compared to previously proposed MinDiff-RE, random movement, and static-sink algorithms. Our distributed algorithm has a lower network lifetime than centralized algorithms; sinks travel significantly less than in all the other schemes.
Due to increase in its wide range of applications, underwater wireless sensor nodes are gaining importance and there is need to develop reliable underwater sensor networks. Major hindrance to performance of underwater networks is power supply to nodes. The ultimate aim in designing energy harvesters is to provide continuous power supply for node system in adequate environmental energy conditions. To achieve continual, reliable and efficient power supply for underwater sensors, we propose multi source energy harvester system which manages energies from piezoelectric harvesting and microbial fuel cell. Analytical expressions are obtained for proposed system and are validated using extensive simulations.
Recently, energy harvesting (EH) has emerged as a promising way to realize
green communications. In this paper, we investigate the multiuser transmission
network with an EH cooperative relay, where a source transmits independent
information to multiple destinations with the help of an energy constrained
relay. The relay can harvest energy from the radio frequency (RF) signals
transmitted from the source, and it helps the multiuser transmission only by
consuming the harvested energy. By adopting the time switching and the
power-splitting relay receiver architectures, we firstly propose two protocols,
the time-switching cooperative multiuser transmission (TSCMT) protocol and the
power-splitting cooperative multiuser transmission (PSCMT) protocol, to enable
the simultaneous information processing and EH at the relay for the system. To
evaluate the system performance, we theoretically analyze the system outage
probability for the two proposed protocols, and then derive explicit
expressions for each of them, respectively. Moreover, we also discuss the
effects of system configuration parameters, such as the source power and relay
location on the system performance. Numerical results are provided to
demonstrate the accuracy of our analytical results and reveal that compared
with traditional non-cooperative scheme, our proposed protocols are green
solutions to offer reliable communication and lower system outage probability
without consuming additional energy. In particular, for the same transmit power
at the source, the PSCMT protocol is superior to the TSCMT protocol to obtain
lower system outage probability.
In this paper, we discuss a 3-dimensional localization sensor node using EM waves (Electromagnetic waves) with RSSI (Received Signal Strength Indicator). Generally EM waves cannot be used in underwater environment, because the signal is highly attenuated by the water medium according to the distance. Although the signal quickly reduces in underwater, the reducing tendency is very clear and uniform. Hence EM waves have possibility as underwater distance sensors. The authors have verified the possibility by theory and several experiments, and developed calibration methods in case of linear and planer environment. For 3-dimensional localization in underwater, it must be known antenna's radiation pattern property in electric plane(called E-plane). In this paper, we proceed experiments to verify attenuation tendency with z axis movement, PLF (Polarization Loss Factor) and ILF (Inclination Loss Factor) with its theoretical approach.
In this paper, we consider a wireless-powered cooperative communication
network consisting of one hybrid access-point (AP), one source, and one relay.
In contrast to conventional cooperative networks, the source and relay in the
considered network have no embedded energy supply. They need to rely on the
energy harvested from the signals broadcasted by the AP for their cooperative
information transmission. Based on this three-node reference model, we propose
a harvest-then-cooperate (HTC) protocol, in which the source and relay harvest
energy from the AP in the downlink and work cooperatively in the uplink for the
source's information transmission. Considering a delay-limited transmission
mode, the approximate closed-form expression for the average throughput of the
proposed protocol is derived over Rayleigh fading channels. Subsequently, this
analysis is extended to the multi-relay scenario, where the approximate
throughput of the HTC protocol with two popular relay selection schemes is
derived. The asymptotic analyses for the throughput performance of the
considered schemes at high signal-to-noise radio are also provided. All
theoretical results are validated by numerical simulations. The impacts of the
system parameters, such as time allocation, relay number, and relay position,
on the throughput performance are extensively investigated.
In this paper, we propose a cooperative transmission scheme for underwater acoustic sensor networks to enhance the network performance. Relay nodes are exploited as virtual antennas to achieve diversity gains. Based on the distinct characteristics of the underwater channel such as high transmission loss, propagation delay, and ambient noises, the paper presents a distributed cooperative scheme including networking protocols and cooperative transmissions at the physical layer in order to enhance the reliability by providing diversity gains through intermediate relay nodes. Destinations and potential relays are selected from a set of neighbor nodes that utilize distance cost and local measurement of the channel conditions into calculation. The simulation and numerical results show that the proposed scheme outperforms the traditional direct transmission schemes in terms of average energy consumption, packet delivery ratio, and end-to-end delay.
In recent research of wireless communication, the concept of cooperative diversity has been put forward and used widely. A number of transmission schemes designed for radio communications could not be directly applied to underwater network, where channel characteristics are more complicated. In this paper, we consider a situation comparatively closer to the realistic underwater acoustic communication and investigate the relay selection problem. Considering the long propagation delay caused by low speed of sound, we design a cooperative transmission scheme. In this scheme, the network chooses the optimal relay or the suitable number of nodes adapting to the changes of underwater circumstances. Then the signal-to-noise ratio (SNR) is added to the criterion of relay selection to realize a more effective algorithm.
A new method that leads to exact solutions for performance metrics related to the end-to-end signal-to-noise ratio (SNR) of multihop amplify-and-forward (AF) relaying systems is reported. The approach uses a generalized transformed characteristic function (GTCF) to find the exact average symbol error probability, ergodic capacity and outage probability of generic multihop AF relaying systems. The new GTCF method is illustrated by deriving exact solutions for Nakagami-m fading channels.
Cooperative communication has been studied extensively as a promising technique for improving the performance of terrestrial wireless networks. However, in underwater cooperative acoustic networks, long propagation delays and complex acoustic channels make the conventional relay selection schemes designed for terrestrial wireless networks inefficient. In this paper, we develop a new best relay selection criterion, called COoperative Best Relay Assessment (COBRA), for underwater cooperative acoustic networks to minimize the one-way packet transmission time. The new criterion takes into account both the spectral efficiency and the underwater long propagation delay to improve the overall throughput performance of the network with energy constraint. A best relay selection algorithm is also proposed based on COBRA criterion. This algorithm only requires the channel statistical information instead of the instantaneous channel state. Our simulation results show a significant decrease on one-way packet transmission time with COBRA. The throughput and delivery ratio performance improvement further verifies the advantages of our proposed criterion over the conventional channel state based algorithms.
Due to its efficiency, reliability and better channel and resource utilization, cooperative transmission technologies have been attractive options in underwater as well as terrestrial sensor networks. Their performance can be further improved if merged with forward error correction (FEC) techniques. In this paper, we propose and analyze a retransmission protocol named Cooperative-Hybrid Automatic Repeat reQuest (C-HARQ) for underwater acoustic sensor networks, which exploits both the reliability of cooperative ARQ (CARQ) and the efficiency of incremental redundancy-hybrid ARQ (IR-HARQ) using rate-compatible punctured convolution (RCPC) codes. Extensive Monte Carlo simulations are performed to investigate the performance of the protocol, in terms of both throughput and energy efficiency. The results clearly reveal the enhancement in performance achieved by the C-HARQ protocol, which outperforms both CARQ and conventional stop and wait ARQ (S&W ARQ). Further, using computer simulations, optimum values of various network parameters are estimated so as to extract the best performance out of the C-HARQ protocol.
AmbiMax is an energy harvesting circuit and a supercapacitor based energy storage system for wireless sensor nodes (WSN). Previous WSNs attempt to harvest energy from various sources, and some also use supercapacitors instead of batteries to address the battery aging problem. However, they either waste much available energy due to impedance mismatch, or they require active digital control that incurs overhead, or they work with only one specific type of source. AmbiMax addresses these problems by first performing maximum power point tracking (MPPT) autonomously, and then charges supercapacitors at maximum efficiency. Furthermore, AmbiMax is modular and enables composition of multiple energy harvesting sources including solar, wind, thermal, and vibration, each with a different optimal size. Experimental results on a real WSN platform, Eco, show that AmbiMax successfully manages multiple power sources simultaneously and autonomously at several times the efficiency of the current state-of-the-art for WSNs
We propose an efficient cooperative ARQ (Automatic Repeat reQuest) scheme for underwater acoustic communications, in which cooperative nodes are used to provide more reliable alternative paths for a specific source-to-destination connection. Based on the knowledge of inter-node distances, a cooperative region is defined to include all possible candidates for cooperative nodes from a given pair of source-destination nodes. When the destination node receives an erroneous packet, it asks for retransmission from a cooperative node, which is selected in a closest-one-first manner from the nodes in the cooperative region. The selection procedure continues until the retransmission is successful. In this paper, we evaluate the proposed scheme by comparing it with a conventional S&W ARQ in terms of throughput efficiency. Computer simulation results show that the proposed cooperative retransmission scheme can significantly improve the throughput by increasing the probability of successful retransmission.
In this paper, we have studied the energy efficiency of cooperative networks operating in either the fixed Amplifyand- Forward (AF) or the selective Decode-and-Forward (DF) mode. We consider the optimization of the M-ary quadrature amplitude modulation (MQAM) constellation size to minimize the bit energy consumption under given bit error rate (BER) constraints. In the computation of the energy expenditure, the circuit, transmission, and retransmission energies are taken into account. The link reliabilities and retransmission probabilities are determined through the outage probabilities under the Rayleigh fading assumption. Several interesting observations with practical implications are made. It is seen that while large constellations are preferred at small transmission distances, constellation size should be decreased as the distance increases; the cooperative gain is computed to compare direct transmission and cooperative transmission. Comment: Proc. IEEE WCNC2010, Sydney, Australia, April, 2010
This paper describes a systematic approach to building micro-solar power subsystems for wireless sensor network nodes. Our approach composes models of the basic pieces - solar panels, regulators, energy storage elements, and application loads - to appropriately select and size the components. We demonstrate our approach in the context of a microclimate monitoring project through the design of the node, micro-solar subsystem, and network, which is deployed in a challenging, deep forest setting. We evaluate our deployment by analyzing the effects of the range of solar profiles experienced across the network.
Environmental energy is an attractive power source for low power wireless sensor networks. We present Prometheus, a system that intelligently manages energy transfer for perpetual operation without human intervention or servicing. Combining positive attributes of different energy storage elements and leveraging the intelligence of the microprocessor, we introduce an efficient multi-stage energy transfer system that reduces the common limitations of single energy storage systems to achieve near perpetual operation. We present our design choices, tradeoffs, circuit evaluations, performance analysis, and models. We discuss the relationships between system components and identify optimal hardware choices to meet an application's needs. Finally we present our implementation of a real system that uses solar energy to power Berkeley's Telos Mote. Our analysis predicts the system will operate for 43 years under 1% load, 4 years under 10% load, and 1 year under 100% load. Our implementation uses a two stage storage system consisting of supercapacitors (primary buffer) and a lithium rechargeable battery (secondary buffer). The mote has full knowledge of power levels and intelligently manages energy transfer to maximize lifetime.
Design an effective routing protocol in underwater acoustic sensor networks (UASNs) is an important issue. Long propagation time and low DATA rate which are two major concerns for routing protocol design in UASNs will lead to the long end-to-end transmission time. This paper proposes a Self-Adaptive Cooperative Routing Protocol (SACRP) to effectively route collecting DATA to the sink in UASNs. Cooperative transmission in SACRP not only can enhance the link quality (Signal-to-Noise Ratio (SNR)) to improve the network throughput but also can increase the transmission range of a node to reduce the end-to-end transmission time. Some mathematical analyses about cooperative transmission scheme are done to support SACRP protocol in the different DATA size and transmission range as well. Based on the network simulations, the proposed protocol, SACRP, has a significant performance against the related work in average end-to-end delay and packet delivery ratio.
Moving the sink node is an eective solution for improving the lifetime of wireless sensor networks (WSN). Dierent methods in the literature schedule sink movements and determine sink stay points. This paper provides another insight to the sink mobility problem in WSNs by incorporating node-load parameters into a matrix and using this matrix to determine which sink site to visit in each round. We rst present a packet- (trac) load{based sink movement algorithm that relies on the packet distribution of nodes in each sink site for a given topology construction algorithm. We extend this algorithm by considering the distances the packets are transmitted, and in this manner obtain an energy-load{based algorithm. We also provide an integer programming (IP) model to compute optimal results. Our extensive simulations show that our energy- and packet-based algorithms signicantly improve network lifetime compared to keeping the sink static or moving it randomly. Our energy-based algorithm can increase network lifetime by a factor of 2 compared to random movement and by a factor of 5 compared to keeping the sink static. It remains only around 5% behind the optimal solution.
Underwater Wireless Sensor Networks (UWSNs) enable a wide range of aquatic applications. But the underlying physical layer technology makes the development of efficient data collection and routing schemes for UWSNs a challenging issue. It is important for the UWSNs to have maximum possible lifetime, because the recharging or replacement of sensor nodes after deployment is almost impossible. We propose a mobile sink (MS) based model for maximizing network lifetime, considering energy-constrained sensor nodes, location-constrained data collection points, and delay-tolerant applications. Maximum lifetime is achieved by deferring the transmission of data until the MS is at the most favourable location for data transfer, and by solving optimally two joint problems of scheduling and routing. To reduce the complexity of solving the optimization scheme, we propose a simplified model for lifetime maximization. The proposed model is compared with other schemes available in the literature. Keeping the analytical solution as a benchmark, a distributed version of the proposed maximum lifetime routing scheme is implemented in the network simulation platform OMNET++, considering all the peculiarities of the underlying physical layer technology. Both analytical and simulation results show that the proposed model exhibits superior lifetime performance at the cost of increased data collection latency. The comparison of the proposed scheme with other schemes permits us to identify the trade-offs in MS-based lifetime maximization scheme and to select the appropriate model according to application requirements and network constraints.
In the light of the characteristics of random change that underwater sensor change by time, space and frequency, select the best relay node to improve communication quality and get the diversity gain. A new optimal relay selection method is proposed in this paper, by considering two indexes synthetically that channel gain and underwater acoustic communication long time delay to select the best relay node. Based on the best relay node and minimization of bit error rate to take optimal power allocation of source node and relay node to realize network error rate’s reduction of 1.81 dB so then improve the overall performance of the network.
In underwater acoustic networks, a transmission is done by means of acoustic wave. However, acoustic transmissions suffer long propagation delay and high bit error rate, especially for real time applications. Since speed of sound and underwater noises are varied with water depth, therefore, this paper takes sound speed and underwater noises into account and proposes a channel-aware depth-adaptive routing protocol, named CDRP, for underwater acoustic sensor networks to relief propagation delay and transmission error rate. In CDRP, the source constructs a virtual ideal path to the sink while it has data to send. According to its one-hop neighbor information, the source then chooses one or several proper forwarders to relay the data. Likewise, the forwarders select next forwarders in the same way until the data is sent to the sink. To our best knowledge, CDRP is the first routing protocol considering the effects of underwater noise and sound speed with depth variation. The simulation results show that CDRP has better performance in end-to-end delay and packet delivery ratio.
Recently, Wireless Sensor Networks (WSNs) have attracted lot of attention due to their pervasive nature and their wide deployment in Internet of Things, Cyber Physical Systems, and other emerging areas. The limited energy associated with WSNs is a major bottleneck of WSN technologies. To overcome this major limitation, the design and development of efficient and high performance energy harvesting systems for WSN environments are being explored. We present a comprehensive taxonomy of the various energy harvesting sources that can be used by WSNs. We also discuss various recently proposed energy prediction models that have the potential to maximize the energy harvested in WSNs. Finally, we identify some of the challenges that still need to be addressed to develop cost-effective, efficient, and reliable energy harvesting systems for the WSN environment.
Underwater environment suffers from a number of impairments which effect reliability and integrity of data being transmitted. Cooperative transmission is well known for reliable data transfer. Hence, cooperative routing can be implemented in Underwater Wireless Sensor Networks (UWSNs) in order to reduce the impact of existing link impairments on transmitted data. Cooperative routing involves data transmission via partner node (relay/destination node) towards sink. Selection of partner node for cooperative routing is to be performed on basis of a certain criterion so that effective results can be achieved. In this paper, two different partner node selection criteria are implemented and compared. We consider source node's depth threshold (d th ), potential relay/destination nodes's depth, residual energy and Signal to Noise Ratio (SNR) of the link connecting source node with potential relay/destination node as selection parameters. One criterion considers depth and residual energy while the other also takes link's SNR into account along with depth and residual energy. SNR based criterion is proved to outperform the one involving only depth and residual energy information. Simulation results show that the SNR based criterion achieves better results with respect to stability period and Packet Acceptance Ratio (PAR) along with reduced delay and packet drop.
In this paper, we introduce a comprehensive analysis of the incremental-best-relay cooperative diversity, in which we exploit limited feedback from the destination terminal, e.g., a single bit indicating the success or failure of the direct transmission. If the destination provides a negative acknowledgment via feedback; in this case only, the best relay among M available relays retransmits the source signal in an attempt to exploit spatial diversity by combining the signals received at the destination from the source and the best relay. Furthermore, we study the end-to-end performance of the incremental-best-relay cooperative-diversity networks using decode-and-forward and amplify-and-forward relaying over independent non-identical Rayleigh fading channels. Closed-form expressions for the bit error rate, the outage probability and average channel capacity are determined. Results show that the incremental-best-relay cooperative diversity can achieve the maximum possible diversity order, compared with the regular cooperative-diversity networks, with higher channel utilization. In particular, the incremental-best-relay technique can achieve M+1 diversity order at low signal-to noise ratio (SNR) and considerable virtual array gain at high SNR.
Cooperative relaying has been well appreciated to be a key concept of future wireless systems capable of yielding high network reliability and significant error rate reduction. However, in such paradigm of communication, the total limited power may be wasted without providing minimum performance requirements such as network lifetime if it is not well allocated between the cooperating nodes in an efficient way. In this work, we mainly address the problem of network lifetime limitation in wireless relay communication system by developing optimal power allocation techniques. In the communication scenario, a source sends information to a destination with the help of multiple relay nodes operating in amplify-and-forward relaying protocol. As a parameter of measurement, we particularly address the symbol error rate (SER) performance for MPSK signal using the concept of moment generating function. Due to the complexity of the closed-form SER expression, we then find a tight corresponding lower bound to show useful insights in terms of analysis. Next, we develop a cooperation strategy where only a best relay that maximizes the end-to-end signal-to-noise ratio assists the transmission to further improve the performance of the previous system. In addition, numerical results are presented to validate the theoretical analysis.
We address the outage performance for the opportunistic amplify-and-forward relaying strategies under Nakagami-m fading channels. A closed-form expression for the outage probability is derived. Simulation results verify our theoretical solutions.
This paper studies the newly emerging wireless powered communication network
(WPCN) in which one hybrid access point (H-AP) with constant power supply
coordinates the wireless energy/information transmissions to/from distributed
users that do not have energy sources. A "harvest-then-transmit" protocol is
proposed where all users first harvest the wireless energy broadcast by the
H-AP in the downlink (DL) and then send their independent information to the
H-AP in the uplink (UL) by time-division-multiple-access (TDMA). First, we
study the sum-throughput maximization of all users by jointly optimizing the
time allocation for the DL wireless power transfer versus the users' UL
information transmissions given a total time constraint based on the users' DL
and UL channels as well as their average harvested energy values. By applying
convex optimization techniques, we obtain the closed-form expressions for the
optimal time allocations to maximize the sum-throughput. Our solution reveals
"doubly near-far" phenomenon due to both the DL and UL distance-dependent
signal attenuation, where a far user from the H-AP, which receives less
wireless energy than a nearer user in the DL, has to transmit with more power
in the UL for reliable information transmission. Consequently, the maximum
sum-throughput is achieved by allocating substantially more time to the near
users than the far users, thus resulting in unfair rate allocation among
different users. To overcome this problem, we furthermore propose a new
performance metric so-called common-throughput with the additional constraint
that all users should be allocated with an equal rate regardless of their
distances to the H-AP. We present an efficient algorithm to solve the
common-throughput maximization problem. Simulation results demonstrate the
effectiveness of the common-throughput approach for solving the new doubly
near-far problem in WPCNs.
In cooperative automatic repeat request (C-ARQ) protocols, the retransmission process between a pair of nodes can be assisted by a relay node. We investigate the performance of C-ARQ algorithms in cellular access networks, where the use of relays is a promising strategy for future evolutions. By means of Markov analysis and simulation we show that the implementation of acknowledgment signals from the relays and the retransmission policy at the base station have a notable impact on the throughput of the system.
In this paper, we have studied the energy efficiency of cooperative networks operating in either the fixed Amplify-and-Forward (AF) or the selective Decode-and-Forward (DF) mode. We consider the optimization of the M-ary quadrature amplitude modulation (MQAM) constellation size to minimize the bit energy consumption under given bit error rate (BER) constraints. In the computation of the energy expenditure, the circuit, transmission, and retransmission energies are taken into account. The link reliabilities and retransmission probabilities are determined through the outage probabilities under the Rayleigh fading assumption. Several interesting observations with practical implications are made. For instance, it is seen that while large constellations are preferred at small transmission distances, constellation size should be decreased as the distance increases. Moreover, the cooperative gain is computed to compare direct transmission and cooperative transmission.
In this paper, we present a robust, decentralized approach to RF-based location tracking. Our system, called MoteTrack, is based on low-power radio transceivers coupled with a modest amount of computation and storage capabilities. MoteTrack does not rely upon any back-end server or network infrastructure: the location of each mobile node is computed using a received radio signal strength signature from numerous beacon nodes to a database of signatures that is replicated across the beacon nodes themselves. This design allows the system to function despite significant failures of the radio beacon infrastructure. In our deployment of MoteTrack, consisting of 20 beacon nodes distributed across our Computer Science building, we achieve a 50th
percentile and 80th
percentile location-tracking accuracy of 2 meters and 3 meters respectively. In addition, MoteTrack can tolerate the failure of up to 60% of the beacon nodes without severely degrading accuracy, making the system suitable for deployment in highly volatile conditions. We present a detailed analysis of MoteTrack’s performance under a wide range of conditions, including variance in the number of obstructions, beacon node failure, radio signature perturbations, receiver sensitivity, and beacon node density.
Sustainable operation of battery powered wireless embedded systems (such as sensor nodes) is a key challenge, and considerable research effort has been devoted to energy optimization of such systems. Environmental energy harvesting, in particular solar based, has emerged as a viable technique to supplement battery supplies. However, designing an efficient solar harvesting system to realize the potential benefits of energy harvesting requires an in-depth understanding of several factors. For example, solar energy supply is highly time varying and may not always be sufficient to power the embedded system. Harvesting components, such as solar panels, and energy storage elements, such as batteries or ultracapacitors, have different voltage-current characteristics, which must be matched to each other as well as the energy requirements of the system to maximize harvesting efficiency. Further, battery non-idealities, such as self-discharge and round trip efficiency, directly affect energy usage and storage decisions. The ability of the system to modulate its power consumption by selectively deactivating its sub-components also impacts the overall power management architecture. This paper describes key issues and tradeoffs which arise in the design of solar energy harvesting, wireless embedded systems and presents the design, implementation, and performance evaluation of Heliomote, our prototype that addresses several of these issues. Experimental results demonstrate that Heliomote, which behaves as a plug-in to the Berkeley/Crossbow motes and autonomously manages energy harvesting and storage, enables near-perpetual, harvesting aware operation of the sensor node.
End-to-end performance of two-hop wireless communication systems with nonregenerative relays over flat Rayleigh-fading channels is presented. This is accomplished by deriving and applying some new closed-form expressions for the statistics of the harmonic mean of two independent exponential variates. It is shown that the presented results can either be exact or tight lower bounds on the performance of these systems depending on the choice of the relay gain. More specifically, average bit-error rate expressions for binary differential phase-shift keying, as well as outage probability formulas for noise limited systems are derived. Finally, comparisons between regenerative and nonregenerative systems are presented. Numerical results show that the former systems clearly outperform the latter ones for low average signal-to-noise-ratio (SNR). They also show that the two systems have similar performance at high average SNR.