Minimum Hop Count Research Articles

DV-Hop algorithm for adaptive hop-count improvement and average hop distance optimization

In order to improve the localization accuracy of unknown nodes in DV-Hop algorithm, an improved DV-Hop algorithm combined with adaptive hop count and optimized hop distance was proposed. Our proposed algorithm firstly introduced the concept of the adaptive value for the number of communication radi i. It was used to adaptively select the number of communication radii for beacon nodes and could realize the subdivision of the minimum hop count. Secondly, sensor nodes adaptively set the hop threshold to reduce the calculation. Finally, the calculation method of the average hop distance of beacon nodes was optimized and the error was corrected. The average hop distance of unknown nodes was obtained by the weighted normalization used for the average hop distance of beacon nodes. Simulation results in both random deployment environment of sensor nodes and nonrandom deployment environment of beacon nodes demonstrate that the localization accuracy of our proposed algorithm is significantly better than the DV-Hop algorithm and furthermore has better robustness and adaptability.

An Efficient and Reliable Directed Diffusion Routing Protocol in Wireless Body Area Networks

Wireless body area networks (WBANs) are composed of several tiny sensor devices which are embedded on or implanted in the human body. They are designed to continuously transmit sensed physiological data and act as key infrastructures for remote healthcare monitoring and treatment. Considering the limited power supply, varying link connectivity, and complicated channel environment, the design of routing protocol in WBANs is challenging. The existing algorithms cannot fully satisfy the application requirements. Focusing on lower energy consumption, a directional diffusion routing protocol for WBANs is proposed in this paper. The concept of the gradient is introduced to indicate the direction and the rate of data transmission and the minimum hop count in directed diffusion is used as the criterion for establishing the gradient. Each node is required to maintain the gradient information of its neighbor nodes with the shortest path. Simultaneously, the residual energy is also considered to further improve the performance. The simulation results show that the proposed protocol has significantly lower packet loss rate and power consumption in both static and mobile scenarios. The reliability of the data transmission is improved and the networks life is extended effectively.

Design and analysis of distance error correction–based localization algorithm for wireless sensor networks

AbstractLocalization error is the main criteria to decide the efficiency on any localization approach. In case of range‐free hop‐based localization approaches, position coordinates estimation is done through the common steps like the calculation of the minimum hop count, hop size, and then later on applying the multilateration or least square approach. There are many improvements that have been made in the form of various algorithms through some changes in the common steps for the reduction of localization error. It has been observed that the existing algorithms are still having the highest value of localization error. To overcome the deficiencies in the existing algorithms, a novel distance error correction metric–based approach has been introduced. This paper presents a distance error correction–based algorithm (DEC‐hop) for the hop‐based localization approach for a wireless sensor network. Distance‐based error correction factor that is introduced in this paper further reduces the localization error value to some extent. For measuring the effectiveness and the preciseness of the given approach, it is inspected with other improved algorithms based on DV‐hop. Simulation results have confirmed that the proposed error correction–based algorithm outperforms the other variety of improved hop‐based algorithms. Results are analyzed in terms of various factors like the localization error, accuracy, and error variance against the parameters of interest taken as node amount, anchor ratio, and communication range of the node.

Optimal Routing for Time-Driven EH-WSN under Regular Energy Sources

The recent provision of energy-harvesting capabilities to wireless sensor networks (WSN) has entailed the redefinition of design objectives. Specifically, the traditional goal of maximizing network lifetime has been replaced by optimizing network performance, namely delay and throughput. The present paper contributes to this reformulation by considering the routing problem for the class of time-driven energy-harvesting WSN (EH-WSN) under regular or quasi-periodic energy sources. In particular, this paper shows that the minimum hop count (MHC) criterion maximizes the average duty cycle that can be sustained by nodes in this type of scenarios. This is a primary objective in EH-WSN, since large duty cycles lead to enhanced performance. Based on a previous result, a general expression is first obtained that gives mathematical form to the relationship between duty cycle and traffic load for any node in a time-driven EH-WSN fed by a regular energy source. This expression reveals that the duty cycle achievable by a node decreases as its traffic load increases. Then, it is shown that MHC minimizes the average traffic load over the network, and thus it maximizes the average duty cycle of nodes. This result is numerically validated via simulation by comparison with other well-known routing strategies. Accordingly, this paper suggests assigning top priority to the MHC criterion in the development of routing protocols for time-driven EH-WSN under regular energy sources.

Novel dynamic source routing protocol (DSR) based on genetic algorithm‐bacterial foraging optimization (GA‐BFO)

SummaryThe goal of mobile ad hoc network (MANET) routing protocol is to establish a correct and effective route with minimal control overhead and bandwidth consumption. Dynamic source routing protocol (DSR) is a simple on‐demand routing protocol designed specifically for MANETs. The choice of routing path only adopts the simplest minimum hop count algorithm, while it did not take the node energy into account. In order to improve the control overhead of the network, we comprehensively consider the node energy information when searching the routes to the destination nodes. We propose a genetic algorithm (GA)‐bacterial foraging optimization algorithm to perform the selection of the optimal routing. After searching out multiple routes to the destination node, the paths are initialized then the GA algorithm is started. This algorithm quickly finds the positions of the maximum probability optimal paths, which are the initial positions of bacteria for the bacteria foraging optimization (BFO) algorithm. Through using the BFO algorithm, it is easy to search out the extreme value and the optimal path in order to compensate for the poor accuracy of GA algorithm. Our proposed optimized strategy improves the routing selection algorithm without change the complexity of DSR and proves the convergence of the algorithm to the global optimal solution. The simulation shows that the proposed algorithm is feasible and applicable and also has better experimental result.

Energy Potent Shortcut Tree Routing in Zigbee Networks

ZigBee is an international standard for low-power and low-data rate WPAN. ZigBee works on IEEE 802.15.4 MAC and physical layers. Its network layer is liable to facilitate routing in networks. To provide a near optimal routing path as well as to balance the load and energy over the nodes, Energy-efficient shortcut tree routing (ESTR) protocol suggested an optimization method with three criteria such as minimum hop-counts, minimum congestion and maximum link quality. This paper proposes an Energy potent shortcut tree routing (EPSTR) that adds one more criterion called minimum failure-transmissions with EPSTR’s criteria. The values for these criteria can be derived from the neighbor table data of a node. Performance evaluation reveals that EPSTR appreciably expands the network lifetime and shows better routing performances compared to ESTR.

Identifying Partitions in Wireless Sensor Network

Wireless sensor networks, consists of a group of tiny nodes, which are powered by small size batteries, which can get failed very easily. The failure of a single node may lead to the failure of an entire network in the following way. If a particular node is unaware of the failed situation of its neighbor node, it simply forwards the packet again and again as it will not receive any acknowledgment. This message passing merely wastes the precious energy of the node, which leads to its failure. This process continues which leads to the failure of the entire network. It is crucial, to identify the node which is failed, as and when it happens and to reconnect the network. In this paper, a hop count based cut detection algorithm is proposed to detect the failure of the nodes and, mobile nodes are used to reconnect the partitioned network. In HCCD at each hop, every node select the node with minimum hop count and maximum link cost, thereby the worst node can be identified as cut node and this cut can be identified before the network actually fails. Experiment results shows that hop count based cut detection outperforms the traditional distributed cut detection algorithm and reconnection using mobile nodes avoids data loss.

Robot Control Strategies for Task Allocation with Connectivity Constraints in Wireless Sensor and Robot Networks

Mobility within Wireless Sensor Networks (WSNs) has been widely considered for data collection tasks, where mobile robots physically collect the data from the sensors and return to the base station. Although this approach has proven to be useful in prolonging the lifetime of these networks, it cannot meet the requirements of real-time data collection tasks. For such tasks, we need to utilize mobile robots to create a connected path from the base station to the event, as well as use in-network forwarding through that path. This will provide a longer lifetime while addressing efficiency and scalability issues because mobile robots have a larger and renewable energy reserve, a longer transmission range, and capacity. One of the fundamental problems is how to coordinate robots to establish a connected path from the event location to the base station. We consider this fundamental problem with two objectives, namely minimizing distance traveled by the robots and minimizing hop count (the number of robots used on paths) under the constraints of satisfying the path and/or network connectivity. After mathematically formulating the underlying problems and discussing their NP-hardness, we propose various heuristic solutions. We then demonstrate the efficacy of our proposed solutions through extensive simulations.

Maximizing the Network Life Time Based on Energy Efficient Routing in Ad Hoc Networks

The maximization of a networks lifetime is an important part of research in the present scenario. In an ad hoc network, the topology of network changes frequently due to the mobility of mobile nodes where the communication is possible without any network infrastructure. Mobile nodes have limited energy resources so that the energy efficient routing should be provided which increases the life time of the network. The existing routing mechanisms do not consider energy of nodes for data transmission. In this paper the data transfer from source to destination is based on the minimum hop count and residual energy of the mobile nodes. The analysis is carried out by using the network simulator. The simulation results shows that the proposed work provides an energy efficient routing in ad hoc networks.

Sigma Routing Metric for RPL Protocol.

This paper presents the adaptation of a specific metric for the RPL protocol in the objective function MRHOF. Among the functions standardized by IETF, we find OF0, which is based on the minimum hop count, as well as MRHOF, which is based on the Expected Transmission Count (ETX). However, when the network becomes denser or the number of nodes increases, both OF0 and MRHOF introduce long hops, which can generate a bottleneck that restricts the network. The adaptation is proposed to optimize both OFs through a new routing metric. To solve the above problem, the metrics of the minimum number of hops and the ETX are combined by designing a new routing metric called SIGMA-ETX, in which the best route is calculated using the standard deviation of ETX values between each node, as opposed to working with the ETX average along the route. This method ensures a better routing performance in dense sensor networks. The simulations are done through the Cooja simulator, based on the Contiki operating system. The simulations showed that the proposed optimization outperforms at a high margin in both OF0 and MRHOF, in terms of network latency, packet delivery ratio, lifetime, and power consumption.

An Effective Hybrid Routing Algorithm in WSN: Ant Colony Optimization in combination with Hop Count Minimization.

Low cost, high reliability and easy maintenance are key criteria in the design of routing protocols for wireless sensor networks (WSNs). This paper investigates the existing ant colony optimization (ACO)-based WSN routing algorithms and the minimum hop count WSN routing algorithms by reviewing their strengths and weaknesses. We also consider the critical factors of WSNs, such as energy constraint of sensor nodes, network load balancing and dynamic network topology. Then we propose a hybrid routing algorithm that integrates ACO and a minimum hop count scheme. The proposed algorithm is able to find the optimal routing path with minimal total energy consumption and balanced energy consumption on each node. The algorithm has unique superiority in terms of searching for the optimal path, balancing the network load and the network topology maintenance. The WSN model and the proposed algorithm have been implemented using C++. Extensive simulation experimental results have shown that our algorithm outperforms several other WSN routing algorithms on such aspects that include the rate of convergence, the success rate in searching for global optimal solution, and the network lifetime.

On Finding Minimum and Maximum Path Length in Grid-Based Wireless Networks

In this paper, we obtain the minimum and maximum hop counts between any pair of cells in the 3D gridbased wireless networks. We start by determining the minimum path length between any two points in a 2D grid coordinate system. We establish that the minimum path length is the maximum difference between the corresponding coordinates of the two points. We then extend the result to derive the minimum and maximum hop counts for the 3D grid-based wireless networks. We establish that the maximum path length is the sum of the differences between the corresponding coordinates of the two cells. Whilst the minimum path length depends on the positions of the two cells; it does not exceed the maximum difference between the corresponding coordinates of the two cells.

Efficient Routing by Power Optimization using Minimum Hop Count Routing Protocol in WSN

Efficient Routing by Power Optimization using Minimum Hop Count Routing Protocol in WSN

Effect of Relay-Priority Mechanism on Multi-hop Wireless Sensor Networks

In multi-hop Wireless Sensor Networks (WSN), sensor nodes which cannot communicate directly with the Coordinator Node(CN) can communicate with CN thanks to the other joined sensor nodes. The multi-hop WSN structure is preferred for large-scale WSNs and that consist of multiple sensor and CN.As in the networks sensor node count increase, hop count increase as well. Because of this, end-to-end delay increases. Unless it is taken prevention, end-to-end delays reach a level that negatively effects on network performance in multi-hop WSN. In this study, for multi-hop WSNs, it is aimed to design a new a relay-priority mechanism which will reduce the end-to-end delay. This is a method that will reach the CN with a minimum hop count while joining the node. Thanks to the minimum hop, end-to-end delay is reduced. Performance analysis of this study was done in Riverbed (OPNET) Modeler simulation environment.

Energy Efficient and robust routing with RPAR Protocol in Ad Hoc Networks

In ad hoc network, the topology of network changes frequently due to the mobile nature of nodes where the communication is possible without any fixed network infrastructure. Mobile nodes are battery operated and so energy efficient routing should be provided which increases the network life time. The existing routing mechanisms do not consider both hop count and energy of nodes for data transmission. In this paper we propose a routing mechanism where data transfer from source to destination is based on the minimum hop count and residual energy of mobile nodes. The proposed RPAR protocol shows better performance when compared to existing Energy power aware routing protocol .The analysis is carried out by using network simulator (NS-2), the simulation results shows that the proposed routing mechanism provides energy efficient and reliable routing in ad hoc networks.

Novel routing protocol scheme for real-time applications in mobile Ad Hoc networks

In mobile Ad Hoc networks (MANETs), flooding-based route discovery is usually preferred in order to set up the route with reliability between transmission pair. However, this approach may cause a serious contention in transmission between adjacent nodes and a considerable amount of control packets. In addition, most of Ad Hoc routing protocols establish the route with minimum hop count. Consequently, the performance of Ad Hoc routing protocol is considerably affected by link (or route) duration since the network comprises the nodes with unrestricted mobility and constrained range in transmission. This paper proposes novel routing protocol that aims to (1) minimize routing overhead in route discovery procedure, and (2) guarantee a reliable and fast packet delivery between source and destination, especially in providing real-time applications over MANETs. To achieve this objective, we introduce relay region (RR) within the transmission range of nodes in order to select optimal next relaying nodes for supporting specific application requirements in route discovery procedure. The RR is defined by the limited distance progress in transmission to next relaying node in order to maintain the established route for an arbitrary length of time (i.e., route duration) while meeting packet delivery reliability and delay constraints. In performance evaluation, the simulation results showed that the proposed scheme can significantly improve the performance in comparison with the previous routing algorithms in terms of packet delivery ratio and packet delivery latency, reducing transmission redundancy in route discovery procedure.

An adaptive signal strength based localization approach for wireless sensor networks

In wireless sensor networks (WSNs), frequent update of node location becomes very difficult to estimate while nodes are moving with high speed. In such cases, it is not able to find the location due to excessive overhead. If a sensor node wants to communicate with neighbor node, geographical location of node is required. In hierarchical structure of WSN, it is very difficult to deploy the sensor node in accurate position. In previous schemes, there are several methods which were proposed to achieve location accuracy. However, it suffered from excessive overhead during localization process. In this research work, an adaptive signal strength based localization approach (ASSLA) is proposed for increasing location accuracy with node update method. In this approach, the stable paths are found with the determination of bit error rate, signal strength and packet delivery ratio. Once the paths are found, a cluster is formed with minimal hop count value. Node location update value is estimated using revised vector concept and trilateration method. From the extensive simulation results and analysis using network simulation tool (NS 2.34), the proposed approach ASSLA outperforms than existing schemes in terms of delay, location accuracy, overhead, delivery ratio, location detection efficiency.

Improving the Network Life Time Based on Energy Efficient Routing in Ad Hoc Networks

<p align="justify">The maximization of a networks lifetime is an important part of research in the present scenario. In ad hoc network, the topology of network changes frequently due to the mobility of mobile nodes where the communication is possible without any network infrastructure. Mobile nodes have limited energy resources so that the energy efficient routing should be provided which increases the life time of the network. The existing routing mechanisms do not consider energy of nodes for data transmission. In this paper a novel approach is analyzed to improve the networks lifetime where the data transfer is based on the minimum hop count and residual energy of the mobile nodes. The analysis is carried out by using the network simulator and the simulation results shows that the proposed work provides an energy efficient routing in ad hoc networks. </p>

E3TX: an energy-efficient expected transmission count routing decision strategy for wireless sensor networks

The routing protocol is one of the most important aspects of the wireless sensor network, determining network connectivity, delay, energy balancing, reliability and other factors. Furthermore, a minimum hop-count does not mean minimum delay and energy consumption. To overcome the routing protocol's shortcomings, we proposed an energy-efficient expected transmission count routing decision strategy (E3TX) for wireless sensor networks. E3TX makes use of two physical parameters, received signal strength indicator (RSSI) and battery voltage, to obtain the final decision via our proposed decision strategy. In our strategy, the received signal strength indicator is used to predict the future packet reception rate (PRR), and the battery voltage is used to estimate the residual energy of network nodes to balance their load. In order to estimate the packet reception rate via the received signal strength indicator with greater accuracy, we performed multiple experiments to build the relationship model between RSSI and PRR. In this article, we use NS-2.35 to evaluate and compare the performance of E3TX with AODV, AOMDV and BIETX. Our simulation results show that our proposed E3TX performs well when compared to the previous studies, not only in terms of energy consumption, but also in reliable data transmission and end-to-end delay.

Effective link quality estimation as a means to improved end-to-end packet delivery in high traffic mobile ad hoc networks

Accurate link quality estimation is a fundamental building block in quality aware multi hop routing. In an inherently lossy, unreliable and dynamic medium such as wireless, the task of accurate estimation becomes very challenging. Over the years ETX has been widely used as a reliable link quality estimation metric. However, more recently it has been established that under heavy traffic loads ETX performance gets significantly worse. We examine the ETX metric's behavior in detail with respect to the MAC layer and UDP data; and identify the causes of its unreliability. Motivated by the observations made in our analysis, we present the design and implementation of our link quality measurement metric xDDR – a variation of ETX. This article extends xDDR to support network mobility. Our experiments show that xDDR substantially outperforms minimum hop count, ETX and HETX in terms of end-to-end packet delivery ratio in static as well as mobile scenarios.