Relay Sensor Research Articles

Achievable Rate of Beamforming Dual-Hop Relay Network With a Jammer and EH Constraint

This paper studies a wireless sensor relay network consist of a source, a jammer, some distribution helping relays, a information decoding (ID) receiver and a Energy harvesting (EH) receiver. In the first time-slot, the source transmits the legitimate signal to the helping relays equipped a single antenna. Meanwhile, the jammer transmits the jamming signal to the relays in order to disturb the communication between the source and the ID receiver. In the second time-slot, the relays forward the sum signal from the source and jammer to the ID receiver employing beamforming. Meanwhile, the EH receiver need to receive the sufficient energy radiated from the relays satisfying the EH constraint to prolong the service life. With the linear beamforming scheme at the relays, this network can be modeled as an equivalent Gaussian arbitrarily varying channel (GAVC). The purpose is to seek the maximal transmission rate under the EH constraint. Since this problem is nonconvex and hard to tackle, we present a second order cone programming (SOCP)-based algorithm to obtain the optimal beamforming vector so as to maximize the transmission rate between the source and ID receiver when perfect channel state information (CSI) is available. In addition, the two important points of the Rate-Energy Region is identified by (SOCP)-based algorithm. Finally, simulations are used to validate the proposed scheme.

Maximizing the lifetime in wireless sensor networks with multiple mobile sinks having nonzero travel times

It is a known phenomenon of the wireless sensor networks that the relay sensors, the sensors neighboring directly to the sinks, spend more energy than the rest of the sensors. This causes premature death of the relay sensors which isolates the sink(s) from the rest of the network. In order to prevent isolation of the sinks due to premature death of the relay sensors, sink mobility is offered as a remedy and that has attracted the interest of many researchers. Mobility of the sinks has been the subject of numerous studies but most of them assume that the mobile sinks travel from one point to another in negligible amount of time. However, harsh and hostile environments in which wireless sensor networks are deployed force the mobility of the sinks to be limited in real applications. Velocity of the mobile sinks for the wireless sensor networks deployed in hostile environments is so slow and consequently considerable sink traveling times occur. In this study, a mathematical model is offered that takes the sink travel times into consideration and the importance of taking sink traveling times into account is illustrated especially for the slow sinks.

Optimal power splitting for MIMO SWIPT relaying systems with direct link in IoT networks

Ultra-high reliability communications are greatly vital for massive user connections and network sensors such as Internet of Things (IoT) devices in the beyond 5th generation (B5G) communication networks. Simultaneous Wireless Information and Power Transfer (SWIPT) has evolved as an efficient strategy through prolonging the battery life by harvesting energy from radio-frequency (RF) signals. Moreover, cooperative relay sensors in IoT network can enhance the network coverage. In this paper, we investigate the multiple-input multiple-output (MIMO) SWIPT relaying systems with direct link, where the relay node splits the received RF signals into two power streams, one for information decoding (ID) and the other for energy harvesting (EH). Under per-antenna power constraints, the relay node forwards the ID signal to the destination. We propose a channel diagonalization scheme based on singular value decomposition (SVD) and eigenvalue decomposition (EVD) to design the precoding matrix of source and the amplifying matrix of relay respectively. Moreover, the closed-form expression of the optimal power splitting (PS) factor diagonal matrix is obtained to maximize the sum-rate of MIMO SWIPT relaying system. Finally, the efficiency of proposed precoding and PS factor design is verified by the presenting numerical results.

Data Forwarding in Wireless Body Area Networks

One of the most crucial application of Wireless Body Area Networks in healthcare applications is the process of monitoring human bodies and gather physiological data. Network performance degradation in the form of energy efficiency and latency are caused because of energy depletions which arises due to limited energy resource availability. The heterogeneity of body sensors will lead to variation in the rate of energy consumption. Based on this, a novel Data Forwarding Strategy is presented in this research work to enhance collaborative WBAN operations, improve network lifetime and restrict energy consumption of the sensors. In this paper, we have contributed towards reducing the size of data to be transmitted by compressed sensing and selection of relay sensor based on sampling frequency, energy levels and sensor importance. Using the proposed methodology, it is possible to improve both reliability and energy-efficiency of WBAN data transmission. moreover, it is also possible to adapt to the changing WBAN topologies when the proposed methodology is used, balancing energy efficiency and consumption.

Energy Efficiency Optimization in SWIPT Enabled WSNs for Smart Agriculture

Smart agriculture is able to optimize the information resources of agriculture, which can improve the quality and productivity of agricultural products. Wireless sensor networks (WSNs) provide smart agriculture with effective solutions for collecting, transmitting, and processing of information. However, the large number of sensor networks consume too much energy that violates the principle of green communication. Simultaneous wireless information and power transfer (SWIPT) technology utilizes radio-frequency signals to transmit information and provide energy to WSNs, which can extend the lifetime of WSNs effectively. In this article, an architecture design of smart agriculture is first proposed by exploiting the SWIPT. Then, an energy efficiency optimization scheme is studied to achieve green communication, in which the subcarriers’ pairing and power allocation are jointly optimized. The process of communication is divided into two phases. Specifically, in the first phase, source sensor sends information to relay sensor and destination sensor. Relay sensor utilizes a part of the subcarriers to receive the information, and utilizes the remaining subcarriers to collect energy. Destination sensor uses all the subcarriers to receive the information. In the second phase, relay sensor utilizes the energy collected in the first phase to forward the information to destination sensor. An effective iterative optimization algorithm is proposed to resolve the proposed optimization problem through Lagrangian dual function. Simulation results validate that the performance of the algorithm can improve energy efficiency of the system effectively.

Monitoring Embedded Flow Networks Using Graph Fourier Transform Enabled Sparse Molecular Relays

Many embedded networks are difficult to monitor, such as water distribution networks (WDNs). A key challenge is how to use minimum sparse sensors to measure contamination and transmit contamination data to a hub for system analysis. Existing approaches deploy sensors using multi-objective optimisation and transmit the data using ground penetrating waves or fixed-line access. Here, for the first time, we introduce a novel molecular communication relay system, which is able to transmit the data report to the hub via the water-flow of WDN itself, and avoids the complex ground penetrating techniques. A water flow data-driven Graph Fourier Transform (GFT) sampling method is designed to inform the invariant orthogonal locations for deploying the molecular relay sensors. Each sensor encodes information via a DNA molecule that enables the common hub to reconstruct the full contamination information. Numerical simulation validates the proposed system, providing a pathway to integrate MC into macro-scale Digital Twin platforms for infrastructure monitoring.

Relay Sensors Selection in Wireless Communication: Bit Error Rate Analysis

Cooperative communication system, which make use of the intermediate relays between the transmitter and the receiver, have been employed as an effective technique to combat the channel fading and to enhance system performance. Cooperative systems have some drawbacks such as high latency and diversity order not guaranteed. To alleviate the negative effects of these factors, relay selection protocol is employed in cooperative communication systems to increase overall cooperative system performance. Relay selection in the cooperative systems enables the source to cooperate with the single relay node rather than multiple relay nodes which guaranteed the diversity order.

Deploy Efficiency Driven k-Barrier Construction Scheme Based on Target Circle in Directional Sensor Network

With the increasing demand for security, building strong barrier coverage in directional sensor networks is important for effectively detecting un-authorized intrusions. In this paper, we propose an efficient scheme to form the strong barrier coverage by adding the mobile nodes one by one into the barrier. We first present the concept of target circle which determines the appropriate residence region and working direction of any candidate node to be added. Then we select the optimal relay sensor to be added into the current barrier based on its input-output ratio (barrier weight) which reflects the extension of barrier coverage. This strategy looses the demand of minimal required sensor nodes (maximal gain of each sensor) or maximal lifetime of one single barrier, leading to an augmentation of sensors to be used. Numerical simulation results show that, compared with the available schemes, the proposed method significantly reduces the minimal deploy density required to establish k-barrier, and increases the total service lifetime with a high deploy efficiency.

Relay fusion frames and bridging results for fusion frames

We examine some connections among the original fusion frames, relay operators, relay spaces and so-called relay fusion frames (r-fusion frames). We show that a necessary condition for a setting to be an r-fusion frame is that the initial subspaces can span the whole ambient space. We generalize the notion of redundancy of fusion frames to more general r-fusion frames to explain whether the constructed r-fusion frame is “good” in a specific sense. Also, we demonstrate how model sensor relay networks with the r-fusion frames. Further, we consider certain bridging problem for fusion frames and provide several solutions to this problem. Some sufficient conditions for a fixed fusion frame to have an associated r-fusion frame will be given. We indicate that the process of r-fusion frame model can be implemented in both positive and negative directions, which is consistent with the requirement that subnets have the same type of network topology in practical applications. Moreover, some examples are also given.

A highly sensitive and selective bis(salamo)-type fluorescent chemosensor for identification of Cu2+ and the continuous recognition of S2-, Arginine and Lysine.

A novel bis(salamo)-type chemosensor H3L was synthesized and characterized. It was found that the sensor molecule can selectively recognize Cu2+, and its L-Cu2+ is highly sensitive to the detection of S2- anion, Arginine and Lysine when dissolved in ethanol solvent. The sensor H3L can be used to identify a relay sensor for Cu2+, while the L-Cu2+ recognizes S2- anion, Arginine and Lysine with high selectivity and sensitivity over an acceptable physiological pH range. The detection line of the sensor molecule H3L is 1.02×10-6M, and its binding constant to Cu2+ is 1.54×106M-1. The detection line of L-Cu2+ as a sensor is calculated as 5.57×10-7M, and its binding constants with S2- anion, Arginine and Lysine are 2.80×105M-1, 5.32×106M-1 and 5.94×106M-1, respectively. The crystal structure of the Cu(II) complex [Cu4(L)2(CH3OH)2]·2NO3 with the sensor molecule H3L has been determined by single crystal X-ray crystallography.

Automation Petrol Bunk Management using Postpaid Cards

This paper shows the improvisation of manually operated petrol bunks, as of this process the automated petrol bunks using cloud communications and Arduino along with RFID reader is proposed. Every step is made user friendly,where computerized RFID reader is installed at the bunk and postpaid cards are issued to every person along with vehicle registration certificate.It is that when the user approaches the petrol bunk and swipes the card at the RFID reader, it shows therespective user details. Then, after verifying the details and password is entered just to verify the user and then the required amount of fuel is entered,then the relay sensor gets activated and fuel gets released. When the quantity assigned is filled the filling gets stopped automatically, after this process the message of transaction details is automatically sent to registered mobile number of theuser.

Adaptive cluster-based relay-node placement for disjoint wireless sensor networks

Wireless sensor networks are formed with very small sensor devices with limited energy and short transmission range. Sensors are randomly deployed in remote areas with harsh conditions. Due to this, their distribution are non-uniform. In a hostile environment, the occurring of large scale failure is very often and it creates partitions of different sizes in the network. Restoring the network connectivity is very crucial for network functioning. Typically sensors are static and communication is bi-directional and we need to reconnect the network with the additional relay sensor nodes. After reconnecting the network, overhead on relays is very high and thus it consumes more energy and high computational power. Optimal number of relay nodes required for reconnecting the network is an NP-hard problem. Here, we proposed a new heuristic approach called adaptive Cluster-based Relay Placement Algorithm. Our approach is to reconnecting the networks based on finding the nearest partitions using their centroids. Using the proposed algorithm, relays are placed on the denser part of the partitions and number of required relays are also minimum. It reduces the network recovery time and increases the network lifetime. Through simulation, we show that the proposed algorithm performs better than the existing approaches.

Relaying Protocols for Wireless Energy Harvesting and Information Processing

Most of the ongoing exploration in wireless relay node networks and data preparing has considered point-to-point correspondence system. In remote helpful or then again sensor organizes, the hand-off or sensor relay node may have restricted battery holds and may need to depend on some outside charging component so as to stay dynamic in the system. Along these lines, vitality reaping in such systems is especially significant as it can empower data handing-off. In this thesis, we are worried about the issue of remote vitality collecting and data preparing in an intensify and-forward (AF) remote agreeable or sensor arrange. We consider the situation that a vitality obliged hand-off relay node harvests vitality from the RF sign communicated by a source node and utilizations that reaped vitality to advance the source signal to a destination node. We consider time switching (TS) and power switch (PS) scheme structures. we propose two transferring conventions: i) TS-based handing-off (TSR) convention and; ii) PS-based handing-off (PSR) convention for discrete data handling and vitality reaping at the vitality compelled wireless relay node. The primary commitments of this thesis are abridged as pursues: • We propose the TSR and the PSR conventions to empower remote vitality reaping and data handling at the vitality obliged transfer in remote AF transferring systems, in light of the TS and PS collector structures. • For the TSR and the PSR conventions, we determine logical articulations for the reachable throughput at the goal. • Comparing the TSR and the PSR conventions, our numerical investigation demonstrates that in postponement restricted transmission mode, the throughput execution of the TSR convention is better than the PSR convention at higher transmission rates, at generally lower signal-to-commotion proportion (SNR), and for lower vitality gathering productivity. • We propose the combination ATPSR system and demonstrate the optimal throughput for that system. • Finally, design and built the hardware circuit and using particle swarm optimization techniques to find the optimal value for the parameters.

Cloning and Functional Analysis of Two Ca2+-Binding Proteins (CaBPs) in Response to Cyantraniliprole Exposure in Bemisia tabaci (Hemiptera: Aleyrodidae)

Ca2+-binding proteins (CaBPs) are widely distributed as Ca2+ sensor relay proteins that regulate various cellular processes, including Ca2+ homeostasis. Diamide insecticides such as cyantraniliprole kill insects by disrupting the Ca2+ homeostasis in muscle cells. However, less attention has been paid to the roles of CaBPs in response to insecticides. In this study, two CaBP genes (BtCaBP1 and BtCaBP2) were identified in the whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), and their functions in response to cyantraniliprole were investigated. After expression of BtCaBP1 and BtCaBP2 in vitro, the results of Ca2+ imaging and cytotoxicity assay revealed that the overexpression of each of the BtCaBPs stabilized Ca2+ concentration in the cytoplasm after exposure to cyantraniliprole and decreased the toxicity of cyantraniliprole against Sf9 cells. However, the knockdown of BtCaBP1 or BtCaBP2 in vivo significantly increased the toxicity of cyantraniliprole to B. tabaci. Taken together, these results provide evidence that BtCaBP1 and BtCaBP2 play a role in response to cyantraniliprole exposure through stabilization of Ca2+ concentration in whiteflies.

A Destination-Aided Wireless Energy Transfer Scheme in Multi-Antenna Relay Sensor Networks

We propose a destination-aided wireless energy transfer scheme in wireless relay sensor networks, where the power of the information collector who has stable power supply is fully exploited. Specifically, a multi-antenna three-node (S, R, D) relay system is considered, where the energy-constrained node R (sensor) assists to forward the message from S (sensor) to D (information collector), and also reports its own sensing information to D. To enhance the amount of scavenged energy at R, the strong energy stream is first transferred by D. The transmitter beamformers, receiver vectors and the relay processing matrix are jointly optimized to maximize the rate of R subject to the required rate of S and the power constraints. To solve this non-convex problem efficiently, these variables are alternatively optimized. Numerical results show that our proposed scheme greatly improves the capacity region, especially when the relay is close to the destination.

Optimal Power Allocation and Relay Location for DF Energy Harvesting Relaying Sensor Networks.

This paper considers a simultaneous wireless information and power transfer (SWIPT) based decode-and-forward (DF) relaying sensor network, where the “save-and-forward” strategy is utilized at the relay sensor node. We investigate a joint power splitting (PS) and relay location (RL) optimization scheme for delay-sensitive transmission mode using the instantaneous channel state information (CSI). In particular, two optimization problems are formulated to minimize the outage probability and maximize the average capacity, respectively. For the two optimization problems, the optimal solutions to the PS ratio and RL are obtained based on the instantaneous CSI. On the basis of optimal solutions, the analytical expressions for outage probability and average capacity are derived, and the corresponding achievable throughputs are obtained. Numerical results verify the correctness of theoretical derivations and validate the advantages of our proposed scheme.

An energy persistent Range-dependent Regulated Transmission Communication model for vehicular network applications

Multi Point Relays (MPRs) are engaged for supporting road-side communication by sharing traffic information, road conditions and additional notifications. Vehicular Networks (VNs) gather round information from these relay points for ease of information access and monitoring purpose. Managing the operation hours of relay sensors becomes vital as they cannot be frequently recharged but has to meet the vehicle requirements over a protracted time. MPR is a tiny sensor mote with built-in power source that is placed along the roadways for the allotment of useful information. The operation hours of the sensors depends on its battery power for which maintenance is important. To assurance uninterrupted communication and information sharing from MPR sensors, we propose a Range-dependent Regulated Transmission (RRT) with doze formulation. In a RRT, the assortment and power of the sensor nodes are modifiable with respect to vehicular density and type of information. The type of information is pre-informed by the nearest Road-Side Unit (RSU) from which the transmit power level of the MPR is decided. Similarly, the MPRs remain in sleep state when vehicle density is nil. The MPRs switch to operation state when it listens to a Vehicle Request (VR) packet from withers RSU or On-Board unit (OBU). RRT with doze formulation improves the communication time and rate of the road side relay units but adjusting the communication factors with respect to the vehicle requirements.

An energy efficient and secure data forwarding scheme for wireless body sensor network

Monitoring human bodies and collecting physiological information are the major healthcare applications for wireless body area networks (WBANs). Due to the limited energy resource of body sensors, their energy depletions will cause severe network performance degradation such as latency and energy efficiency. To solve this problem existing system introduced an energy-efficient data forwarding strategy (EDFS) to balance sensor energy consumption, improve network lifetime and collaborative operations of heterogeneous WBANs. However, the existing system only considered the energy function for optimal relay sensor node selection, does not considered the delay and hop count of node. Hence in this system, the TOPSIS-based artificial bee colony algorithm (TOPSIS-based ABC) is proposed to select the optimal path for data transmission. In order to reduce the network congestion compressed sensing (CS) is performed. To provide high security for patient related data hybrid RSA and Diffie-Hellman algorithm is used. The proposed methodology is implemented by using NS-2 simulator.

An adaptable CS-based transmission scheme in wireless sensor network

As the essential requirement of wireless sensor network, energy-efficient data transmission has been paying a lot attention. Compressive sensing (CS) has been currently utilised to save consumption of sensors. However, a vital problem still remains unclear that whether the execution costs of sensors employing CS is not worth being considered, motivating us to explore the answer from a point of real deployment platform view. Presenting observations from our operating sensor network with 124 nodes, we verify two important facts: 1) The power costs of measure processing of sensors cannot be negligible as the increasing of samplings; 2) Measurements will constantly change along the routing and force relay sensors to consume more. Based on our findings, we propose an adaptable CS-based transmission scheme, ACS. With our experiments, energy is economised at least 15%. Our work gives a potential guideline for future designs of WSN in practice.

An adaptable CS-based transmission scheme in wireless sensor network

As the essential requirement of wireless sensor network, energy-efficient data transmission has been paying a lot attention. Compressive sensing (CS) has been currently utilised to save consumption of sensors. However, a vital problem still remains unclear that whether the execution costs of sensors employing CS is not worth being considered, motivating us to explore the answer from a point of real deployment platform view. Presenting observations from our operating sensor network with 124 nodes, we verify two important facts: 1) The power costs of measure processing of sensors cannot be negligible as the increasing of samplings; 2) Measurements will constantly change along the routing and force relay sensors to consume more. Based on our findings, we propose an adaptable CS-based transmission scheme, ACS. With our experiments, energy is economised at least 15%. Our work gives a potential guideline for future designs of WSN in practice.