Zamree Che-Aron

ENFAT-AODV: The fault-tolerant routing protocol for high failure rate Wireless Sensor Networks

As more and more real Wireless Sensor Networks (WSN) applications have been tested and deployed over the last decade, the research community of WSN realizes that several issues need to be revisited from practical angles, such as reliability and availability. Furthermore, fault-tolerance is one of the main issues in WSNs since it becomes critical in real deployed environments where network stability and reduced inaccessibility times are important. Basically, wireless sensor networks suffer from resource limitations, high failure rates and faults caused by the defective nature of wireless communication and the wireless sensor itself. This can lead to situations, where nodes are often interrupted during data transmission and blind spots occur in the network by isolating some of the devices. In this paper, we address the reliability issue by designing an enhanced fault-tolerant mechanism for Ad hoc On-Demand Distance Vector (AODV) routing protocol used in WSN called the ENhancement of FAult-Tolerant AODV (ENFAT-AODV) routing protocol. We design and implement a backup route scheme by creating a backup path for every node in the network. When a node gets failure to deliver the data packet through the main route, it immediately employs the backup route to become a new main path for the next data packet delivery to reduce a number of data packets dropped and to maintain the continuity of data packet transmission in presence of some faults (node or link failures). Furthermore, with high failure rate, this proposed routing protocol improves the throughput and the average End-to-End delay and decrease the control packet load in the network. Consequently, the reliability, availability and maintainability of the network are achieved. The simulation shows that proposed routing scheme is better than the AODV routing.

An enhancement of fault-tolerant routing protocol for Wireless Sensor Network

As more and more real Wireless Sensor Networks (WSN) applications have been tested and deployed over the last decade, the research community of WSN realizes that several issues need to be revisited from practical angles, such as reliability and availability. Furthermore, fault-tolerance is one of the main issues in WSNs since it becomes critical in real deployed environments where network stability and reduced inaccessibility times are important. Basically, wireless sensor networks suffer from resource limitations, high failure rates and faults caused by the defective nature of wireless communication and the wireless sensor itself. This can lead to situations, where nodes are often interrupted during data transmission and blind spots occur in the network by isolating some of the devices. In this paper, we address the reliability issue by designing an enhanced fault-tolerant mechanism for Ad hoc On-Demand Distance Vector (AODV) routing protocol applied in WSN called the ENhanced FAult-Tolerant AODV (ENFAT-AODV) routing protocol. We apply a backup route technique by creating a backup path for every node on a main path of data transmission. When a node gets failure to deliver a data packet through the main path, it immediately utilizes its backup route to become a new main path for the next coming data packet delivery to reduce a number of data packets dropped and to maintain the continuity of data packet transmission in presence of some faults (node or link failures). Furthermore, with increased failure rate, this proposed routing protocol improves the throughput, reduces the average jitter, provides low control overhead and decreases the number of data packets dropped in the network. As a result, the reliability, availability and maintainability of the network are achieved. The simulation results show that our proposed routing protocol is better than the original AODV routing.

The Enhanced Fault-Tolerant AODV Routing Protocol for Wireless Sensor Network

As more and more real Wireless Sensor Networks (WSN) applications have been tested and deployed over the last decade, the research community of WSN realizes that several issues need to be revisited from practical angles, such as reliability and availability. Basically, wireless sensor networks suffer from resource limitations, high failure rates and faults caused by the defective nature of wireless communication and the wireless sensor itself. This can lead to situations, where nodes are often interrupted during data transmission and blind spots occur in the network by isolating some of the devices. In this paper, we address the reliability issue by designing an enhanced fault-tolerant mechanism for Ad hoc On-Demand Distance Vector (AODV) routing protocol used in WSN called the ENhancement of FAult Tolerant (ENFAT) ADOV routing protocol. We design and implement a backup route algorithm by creating a backup path for every node in the network. When a node gets failure to deliver the data packet through the main route, it immediately employs the backup route to become a new main path to reduce a number of data packets dropped and to maintain the continuity of data packet delivery. Moreover, this proposed routing protocol satisfies the tradeoff between the faulttolerance and the low transmission delay. Consequently, the reliability, availability and maintainability of the network are achieved. The simulation shows that proposed routing scheme is better than the AODV routing. Keywords- wireless sensor network

A fault-tolerant multi-path multi-channel routing protocol for Cognitive Radio Ad Hoc Networks

Cognitive Radio (CR) has been proposed as a promising technology to solve the problem of radio spectrum shortage and spectrum underutilization. In Cognitive Radio Ad Hoc Networks (CRAHNs), which operate without centralized infrastructure support, the data routing is one of the most important issues to be taken into account and requires more studies. Moreover, in such networks, a path failure can easily occur during data transmission caused by an activity of licensed users, node mobility, node fault, or link degradation. Also, the network performance is severely degraded due to a large number of path failures. In this paper, the Fault-Tolerant Cognitive Ad hoc Routing Protocol (FTCARP) is proposed to provide fast and efficient route recovery in presence of path failures during data delivery in CRAHNs. In FTCARP, a backup path is immediately utilized in case a failure occurs over a primary transmission route in order to transfer the next coming data packets without severe service disruption. The protocol uses different route recovery mechanism to handle different cause of a path failure. The performance evaluation is conducted through simulation using NS-2 simulator. The protocol performance is benchmarked against the Dual Diversity Cognitive Ad hoc Routing Protocol (D2CARP). The simulation results prove that the FTCARP protocol achieves better performance in terms of average throughput and average end-to-end delay as compared to the D2CARP protocol.

A Robust On-Demand Routing Protocol for Cognitive Radio Ad Hoc Networks

Cognitive Radio (CR) technology has been introduced to solve the problems of spectrum underutilization and spectrum scarcity caused by improper spectrum management policies. In Cognitive Radio Ad Hoc Networks (CRAHNs), which operate without centralized infrastructure support, data routing encounters various challenges including frequent topology changes, heterogeneous spectrum availability, and intermittent connectivity caused by the activities of Primary Users (PUs). In this paper, a robust on-demand routing protocol for CRAHNs, referred to the Robustness Aware Cognitive Ad-hoc Routing Protocol (RACARP), is proposed with an aim to provide robust paths for data delivery. The Expected Path Delay (EPD) routing metric used for path decision is introduced and applied in the protocol. The metric takes account of the link delay and the effect of packet loss on wireless links. Furthermore, the protocol avoids creating a transmission path that uses PU’s channel in PU regions in order to counteract the impact of PU activities which can simply cause communication interruptions. The protocol also jointly exploits path and spectrum diversity in routing process in order to provide multi-path and multi-channel routes for the purpose of fast route recovery. The performance evaluation is conducted through simulation using NS-2 simulator. The simulation results prove that the RACARP protocol achieves better performance in terms of average throughput and average end-to-end delay as compared to the Dual Diversity Cognitive Ad-hoc Routing Protocol (D2CARP).

Performance analysis of multi-radio routing protocol in cognitive radio ad hoc networks under different path failure rate

In recent years, Cognitive Radio (CR) technology has largely attracted significant studies and research. Cognitive Radio Ad Hoc Network (CRAHN) is an emerging self-organized, multi-hop, wireless network which allows unlicensed users to opportunistically access available licensed spectrum bands for data communication under an intelligent and cautious manner. However, in CRAHNs, a lot of failures can easily occur during data transmission caused by PU (Primary User) activity, topology change, node fault, or link degradation. In this paper, an attempt has been made to evaluate the performance of the Multi-Radio Link-Quality Source Routing (MR-LQSR) protocol in CRAHNs under different path failure rate. In the MR-LQSR protocol, the Weighted Cumulative Expected Transmission Time (WCETT) is used as the routing metric. The simulations are carried out using the NS-2 simulator. The protocol performance is evaluated with respect to performance metrics like average throughput, packet loss, average end-to-end delay and average jitter. From the simulation results, it is observed that the number of path failures depends on the PUs number and mobility rate of SUs (Secondary Users). Moreover, the protocol performance is greatly affected when the path failure rate is high, leading to major service outages.

E-D2CARP: A joint path and spectrum diversity based routing protocol with an optimized path selection for cognitive radio ad hoc networks

Cognitive Radio (CR) is a new paradigm which offers a viable solution to deal with the spectrum shortage problem and enhance the spectrum utilization. In Cognitive Radio Ad Hoc Networks (CRAHNs), data routing is one of the most challenging tasks due to frequent topology changes and intermittent connectivity caused by the activity of Primary Users (PUs). This paper proposes a joint path and spectrum diversity based routing protocol with an optimized path selection for CRAHNs, referred to the Enhanced Dual Diversity Cognitive Ad-hoc Routing Protocol (E-D2CARP). The Expected Path Delay (EPD) routing metric used in the protocol for path decision is also introduced. The protocol utilizes the joint path and spectrum diversity and circumvents the PU regions during path establishment phase in order to make the transmission path less vulnerable to the impact of PU activities and provide efficient route recovery in presence of path failures resulting from PU activities. The performance evaluations are conducted through simulations using the NS-2 simulator. Simulation results obviously demonstrate that the E-D2CARP can achieve better performance in terms of average throughput, packet loss, average end-to-end delay, and average jitter as compared to the recently proposed D2CARP protocol in identical scenarios.

FTCARP: A Fault-Tolerant Routing Protocol for Cognitive Radio Ad Hoc Networks

Cognitive Radio (CR) has been recently proposed as a promising technology to remedy the problems of spectrum scarcity and spectrum underutilization by enabling unlicensed users to opportunistically utilize temporally unused licensed spectrums in a cautious manner. In Cognitive Radio Ad Hoc Networks (CRAHNs), data routing is one of the most challenging tasks since the channel availability and node mobility are unpredictable. Moreover, the network performance is severely degraded due to large numbers of path failures. In this paper, we propose the Fault-Tolerant Cognitive Ad-hoc Routing Protocol (FTCARP) to provide fast and efficient route recovery in presence of path failures during data delivery in CRAHNs. The protocol exploits the joint path and spectrum diversity to offer reliable communication and efficient spectrum usage over the networks. In the proposed protocol, a backup path is utilized in case a failure occurs over a primary transmission route. Different cause of a path failure will be handled by different route recovery mechanism. The protocol performance is compared with that of the Dual Diversity Cognitive Ad-hoc Routing Protocol (D2CARP). The simulation results obviously prove that FTCARP outperforms D2CARP in terms of throughput, packet loss, end-to-end delay and jitter in the high path-failure rate CRAHNs.