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A large set of valuable applications, ranging from social networking to ambient intelligence, may see their effectiveness and appeal improved when supported by the large‐scale, real‐time tracking of mobile devices, either carried by humans or embedded into vehicles. A centralized approach, where few servers would collect position data and provide them to interested consumers, would hardly cope with the resource demand of the foreseen huge increase of users interested in location‐based services and with the flexibility needs of emerging user‐generated services. The purpose of this paper is to propose a decentralized peer‐to‐peer approach to cope with these requirements, for which positioning information flows directly among mobile devices incurring in limited data exchange.

The authors propose a decentralized peer‐to‐peer approach for which positioning information flows directly among mobile devices incurring limited data exchange. A peer‐to‐peer overlay scheme is introduced called distributed geographic table (DGT), where each participant can effectively retrieve node or resource information (data or service) located near any chosen geographic position. Next, the authors describe a DGT‐based localization protocol that allows each peer to proactively discover and track all peers that are geographically near to itself.

The authors provide a performance analysis of the protocol by simulating several 1,000 users that move across an urban area according to realistic mobility models. The results show that the solution is effective, robust, scalable and highly adaptable to different application scenarios.

The new contributions of this paper are a general framework called DGT, which defines a peer‐to‐peer strategy for mobile node localization, and a particular instance of the DGT that supports applications in which every node requires to be constantly updated about the location of its neighbors.

Routing in ad hoc networks faces significant challenges due to node mobility and dynamic network topology. In this work we propose the use of mobility prediction to reduce the search space required for route discovery. A method of mobility prediction making use of a sectorized cluster structure is described with the proposal of the Prediction based Location Aided Routing (P‐LAR) protocol. Simulation study and analytical results of P‐LAR find it to offer considerable saving in the amount of routing traffic generated during the route discovery phase.

The purpose of this paper is to design an efficient on-demand routing protocol for mobile ad hoc networks (MANETs) which combines greedy forwarding and backtracking.

It uses a hybrid approach. It uses greedy approach to determine a route from source to the destination. If the greedy approach fails, then it uses a backtracking approach. Combining greedy and backtracking approaches results in a more efficient protocol.

A new routing algorithm for MANETs which performs better than some of the existing algorithms.

A major limitation of this work is that the authors did not implement the protocol on a test bed and evaluated the performance. They neither had the infrastructure nor the resources to actually implement the protocol. Instead, like most of the researchers, they evaluated the performance of their protocol based on extensive simulation. The mobility model, the area of deployment and the density of nodes chosen to simulate the protocol are consistent with what many of the other researchers have done. Intuitively, the authors’ protocol, as the performance evaluation indicates, is likely to perform well in small networks.

The authors did not implement the protocol on a test bed to evaluate the performance of the protocol. The authors used simulation to study the performance of their protocol. Their simulation model is similar to many of the research works published in the literature.

To the authors’ knowledge, no other paper has combined the greedy and backtracking approach to design a routing protocols for MANETs.

Localization problem is one of the most important research issues for wireless sensor networks (WSNs). The purpose of this paper is to present a two‐phase localization algorithm for WSNs.

In the first phase, each sensor node obtains its initial position by DV‐hop method. In the second phase, each sensor node gathers the locations and distances to its neighbors, updates and exchanges these location information periodically and then operates the multilateration with different weight values.

The simulation result shows that the average position error of the proposed two‐phase method is less than 20 per cent of the radio range, and the number of sensor nodes which can be located is larger than 70 per cent of total nodes for a network with low density.

The paper presents a weighted multilateration positioning methods for wireless sensor networks.

Security in sensor networks is more important than traditional networks as they are deployed in hostile environments and are more prone to capture. Trusted third party authentication schemes, public‐key systems are not suitable owing to their high resource requirements. Key pre‐distribution was introduced in (3) to solve this problem. Our scheme achieves identical connectivity compared to the random key pre distribution (4) using a less number of preloaded keys in each sensor node. The design of our scheme is motivated by the observation that at present most key pre‐distribution schemes employ random mechanisms which use a large number of keys and are unsuitable for sensor networks. In this paper we extend the deterministic key pre‐distribution scheme proposed by us in our earlier work (1), which is based on assigning keys to sensors by placing them on a grid. This approach has been further modified to use multiple mappings of keys to nodes. In each mapping every node gets distinct set of keys which it shares with different nodes. The key assignment is done such that, there will be keys in common between nodes in different sub‐grids. After randomly being deployed, the nodes discover common keys, authenticate and communicate securely. The analysis and simulation results show that this scheme is able to achieve better security compared to the random schemes.

In a mobile ad hoc network (MANET), design of energy‐efficient routing schemes is essential for prolonging the network lifetime. The purpose of this paper is to show that one way to achieve energy efficiency in routing is to utilize location information, which becomes practical due to the recent increasing availability of low‐cost and reliable positioning devices.

This paper proposes an eight‐direction forwarding virtual grid aided (VGA) routing scheme that uses location information to save energy. As a grid‐based scheme, VGA divides the whole network area into virtual grids.

By using eight‐direction forwarding, the proposed VGA scheme outperforms the previous four‐direction forwarding geographical adaptive fidelity (GAF) protocol. The proposed VGA scheme is motivated by the fact that, in the GAF protocol, forwarding to the four diagonal neighboring grids cannot be done in one single hop, although most nodes in these grids can hear the signal.

Theoretical analysis shows the eight‐direction forwarding protocol performs better than the four‐direction one unless the forwarding direction has an angle of less than 15^○ with the horizontal or vertical grid axis. Simulation supports the fact that the eight‐direction forwarding VGA scheme has better energy performance than the four‐direction forwarding GAF scheme without sacrificing any routing performance.

Security is one of the major challenges in the design and implementation of protocols for mobile ad hoc networks (MANETs). In such systems, the cooperation between nodes is one of the important principles being followed in the current research works to formulate various security protocols. Many existing works assume that mobile nodes will follow prescribed protocols without deviation. However, this is not always the case, because these networks are subjected to a variety of malicious attacks. Since there are various models of attack, trust routing scheme can guarantee security and trust of the network. The purpose of this paper is to propose a novel trusted routing model for mitigating attacks in MANETs.

The proposed model incorporates the concept of trust into the MANETs and applies grey relational analysis theory combined with fuzzy sets to calculate a node’s trust level based on observations from neighbour nodes’ trust level, these trust levels are then used in the routing decision-making process.

In order to prove the applicability of the proposed solution, extensive experiments were conducted to evaluate the efficiency of the proposed model, aiming at improving the network interaction quality, malicious node mitigation and enhancements of the system’s security.

The proposed solution in this paper is a new approach combining the fundamental basics of fuzzy sets with the grey theory, where establishment of trust relationships among participating nodes is critical in order to enable collaborative optimisation of system metrics. Experimental results indicate that the proposed method is useful for reducing the effects of malicious nodes and for the enhancements of system’s security.

The purpose of this paper is to explore grid‐based routing in wireless sensor networks and to compare the energy available in the network over time for different grid sizes.

The test area is divided into square‐shaped grids of certain length. Energized nodes are placed randomly in the terrain area with the sink node in a fixed position. One node per grid is elected as the leader node based on the highest energy level and the proximity to the centre of the grid. The sink node floods the network to identify a path from sink to source. The path from the sink to the source through the leader nodes are computed using three different methods: shortest path; leader nodes which have the highest energy; and leader nodes based on their received signal strength (RSS) indicator values. After the path is computed, transmission of data is continued until the leader nodes run out of energy. New leader nodes are then elected using the same mechanism to replace the depleted ones.

Identified the optimal grid size to minimize the energy consumption in sensor networks and to extend the network lifetime. Also proposed is a new routing protocol which identifies routes based on energy threshold and RSS threshold.

The use of RSS threshold is identified to be the good metric for path selection in routing the data between source and the sink.

Simulator software and the protocol developed can be used for in optimizing energy efficiency in sensor networks.

This work contributes to the discussion on uniform and non‐uniform grid sizes and emphasizes a new method for reducing the energy consumption by identifying an optimum grid size. It also utilizes bursty data for simulation.

With the rapid growth of wireless sensor networks (WSNs), they have become an integral and substantial part of people's life. As such WSN stands as an assuring outlook, but because of sensor's resource limitations and other prerequisites, optimal dual route discovery becomes an issue of concern. WSN along with central sink node is capable of handling wireless transmission, thus optimizing the network's lifetime by selecting the dual path. The major problem confronted in the application of security mechanisms in WSNs is resolving the issues amid reducing consumption of resources and increases security.

According to the proposed system, two metrics, namely, path length and packets delivery ratio are incorporated for identifying dual routes amid the source and destination. Thereafter by making use of the distance metric, the optimal dual route is chosen and data transmission is carried out amid the nodes. With the usage of the recommended routing protocol high packet delivery ratio is achieved with reduced routing overhead and low average end to end delay. It is clearly portrayed in the simulation output that the proposed on demand dual path routing protocol surpasses the prevailing routing protocol. Moreover, security is achieved make use of in accord the data compression reduces the size of the data. With the help of dual path, mathematical model of Finite Automata Theory is derived to transmit data from source to destination. Finite Automata Theory comprises Deterministic Finite Automata (DFA) that is being utilized for Dual Path Selection. In addition, data transition functions are defined for each input stage. In this proposed work, another mathematical model is 10; introduced to efficiently choose an alternate path between a receiver and transmitter for data transfer with qualified node as relay node using RR Algorithm. It also includes Dynamic Mathematical Model for Node Localization to improve the precision in location estimation using Node Localization Algorithm. As a result a simulator is built and various scenarios are elaborated for comparing the performance of the recommended dual path routing protocol with respect to the prevailing ones.

Reliability and fault-tolerance: The actual motive in utilizing the approach of multipath routing in sensor network was to offer path resilience in case of a node or link failures thus ascertaining reliable transmission of data. Usually in a fault tolerant domain, when the sensor node is unable to forward the data packets to the sink, alternative paths can be utilized for recovering its data packets during the failure of any link/node. Load balancing: Load balancing involves equalizing energy consumption of all the existing nodes, thereby degrading them together. Load balancing via clustering improves network scalability. The network's lifetime as well as reliability can be extended if varied energy level's nodes exist in sensor node. Quality of service (QoS): Improvement backing of quality of service with respect to the data delivery ratio, network throughput and end-to-end latency stands very significant in building multipath routing protocols for various network types. Reduced delay: There is a reduced delay in multipath routing since the backup routes are determined at the time of route discovery. Bandwidth aggregation: By dividing the data toward the same destination into multiple streams (by routing all to a separate path) can aggregate the effective bandwidth. The benefit being that, in case a node possesses many links with low bandwidth, it can acquire a bandwidth which is more compared to the individual link.

Few more new algorithms can be used to compare the QoS parameters.

Proposed mechanism with feedback ascertains improvised delivery ratio compared to the single path protocol since in case of link failure, the protocol has alternative route. In case there are 50 nodes in the network, the detection mechanism yields packet delivery of 95% and in case there are 100 nodes, the packet delivery is lowered to 89%. It is observed that the packet rate in the network is more for small node range. When the node count is 200, the packet ratio is low, which is lowered to 85%. With a node count of 400, the curve depicts the value of 87%. Hence, even with a decrease in value, it is superior than the existing protocols. The average end-to-end delay represents the transmission delay of the data packets that have been successfully delivered as depicted in Figure 6 and Table 3. The recommended system presents the queue as well as the propagation delay from the source to destination. The figure depicts that when compared to the single path protocol, the end-to-end delay can be reduced via route switching. End-to-end delay signifies the time acquired for the delay in the receival of the the retransmitted packet by each node. The comparison reveals that the delay was lower compared to the existing ones in the WSN. Proposed protocol aids in reducing consumption of energy in transmitter, receiver and various sensors. Comparative analysis of energy consumptions of the sensor in regard to the recommended system must exhibit reduced energy than the prevailing systems.

On demand dual path routing protocol. Hence it is verified that the on demand routing protocol comprises DFA algorithms determines dual path. Here mathematical model for routing between two nodes with relay node is derived using RR algorithm to determine alternate path and thus reduce energy consumption. Another dynamic mathematical model for node localization is derived using localization algorithm. For transmitting data with a secure and promising QoS in the WSNs, the routing optimization technique has been introduced. The simulation software environment follows the DFA. The simulation yields in improvised performance with respect to packet delivery ratio, throughput, average end-to-end delay and routing overhead. So, it is proved that the DFA possesses the capability of optimizing the routing algorithms which facilitates the multimedia applications over WSNs.

Load balancing is an effective enhancement to the proposed routing protocol, and the basic idea is to share traffic load among cluster members to reduce the dropping probability due to queue overflow at some nodes. This paper aims to propose a novel hierarchical approach called distributed energy efficient adaptive clustering protocol (DEACP) with data gathering, load-balancing and self-adaptation for wireless sensor network (WSN). The authors have proposed DEACP approach to reach the following objectives: reduce the overall network energy consumption, balance the energy consumption among the sensors and extend the lifetime of the network, the clustering must be completely distributed, the clustering should be efficient in complexity of message and time, the cluster-heads should be well-distributed across the network, the load balancing should be done well and the clustered WSN should be fully connected. Simulations show that DEACP clusters have good performance characteristics.

A WSN consists of large number of wireless capable sensor devices working collaboratively to achieve a common objective. One or more sinks [or base stations (BS)] which collect data from all sensor devices. These sinks are the interface through which the WSN interacts with the outside world. Challenges in WSN arise in implementation of several services, and there are so many controllable and uncontrollable parameters (Chirihane, 2015) by which the implementation of WSN is affected, e.g. energy conservation. Clustering is an efficient way to reduce energy consumption and extend the life time of the network, by performing data aggregation and fusion to reduce the number of transmitted messages to the BS (Chirihane, 2015). Nodes of the network are organized into the clusters to process and forwarding the information, while lower energy nodes can be used to sense the target, and DEACP makes no assumptions on the size and the density of the network. The number of levels depends on the cluster range and the minimum energy path to the head. The proposed protocol reduces the number of dead nodes and the energy consumption, to extend the network lifetime. The rest of the paper is organized as follows: An overview of related work is given in Section 2. In Section 3, the authors propose an energy efficient level-based clustering routing protocol (DEACP). Simulations and results of experiments are discussed in Section 4. In Section 5, the authors conclude the work presented in this paper and the scope of further extension of this work.

The authors have proposed the DEACP approach to reach the following objectives: reduce the overall network energy consumption, balance the energy consumption among the sensors and extend the lifetime of the network, the clustering must be completely distributed, the clustering should be efficient in complexity of message and time, the cluster-heads should be well-distributed across the network, the load balancing should be done well, the clustered WSN should be fully connected. Simulations show that DEACP clusters have good performance characteristics.