Performance study of end-to-end traffic-aware routing

There has been a lot research effort on developing reactive routing algorithms for mobile ad hoc networks (MANETs) over the past few years. Most of these algorithms consider finding the shortest path from source to destination in building a route. However, this can lead to some network nodes being more overloaded than the others. In MANETs resources, such as node power and channel bandwidth are often at a premium and, therefore, it is important to optimise their use as much as possible. Consequently, a traffic-aware technique to distribute the load is very desirable in order to make good utilisation of nodes' resources. A number of traffic aware techniques have recently been proposed and can be classified into two categories: end-to-end and on-the-spot. The performance merits of the existing end-to-end traffic aware techniques have been analysed and compared against traditional routing algorithms. There has also been a performance comparison among the existing on-the-spot techniques. However, there has so far been no similar study that evaluates and compares the relative performance merits of end-to-end techniques. In this paper, we describe an extensive performance evaluation of two end-to-end techniques, based on degree of nodal activity and traffic density, using measures based on throughput, end-to-end delay and routing overhead

On the performance of traffic-aware reactive routing in MANETs

Research on mobile ad hoc networks (MANETs) has intensified over recent years, motivated by advances in wireless technology and also by the range of potential applications that might be realised with such infrastructure-less networks. Much work has been devoted to developing reactive routing algorithms for MANETs which generally try to find the shortest path from source to destination. However, this approach can lead to some nodes being loaded much more than others in the network. As resources, such as node power and channel bandwidth, are often at a premium in MANETs, it is important to optimise their usage as far as possible. Incorporating traffic aware techniques into routing protocols in order to distribute load among the network nodes would helps to ensure fair utilisation of nodes' resources, and prevent the creation of congested regions in the network. A number of such traffic aware techniques have been proposed. These can be classified into two main categories, namely end-to-end and on-the-spot, based on the method of establishing and maintaining routes between source and destination. In the first category, end-to-end information is collected along the path with intermediate nodes participating in building routes by adding information about their current load status. However the decision as to which path to select is taken at one of the endpoints. In the second category, the collected information does not have to be passed to an endpoint to make a path selection decision as intermediate nodes can do this job. Consequently, the decision of selecting a path is made locally, generally by intermediate nodes. Existing end-to-end traffic aware techniques use some estimation of the traffic load. For instance, in the traffic density technique, this estimation is based on the status of the MAC layer interface queue, whereas in the degree of nodal activity technique it is based on the number of active flows transiting a node. To date, there has been no performance study that evaluates and compares the relative performance merits of these approaches and, in the first part of this research, we conduct such a comparative study of the traffic density and nodal activity approaches under a variety of network configurations and traffic conditions. The results reveal that each technique has performance advantages under some working environments. However, when the background traffic increases significand, the degree of nodal activity technique demonstrates clear superiority over traffic density. In the second part of this research, we develop and evaluate a new traffic aware technique, referred to here as load density, that can overcome the limitations of the existing techniques. In order to make a good estimation of the load, it may not be sufficient to capture only the number of active paths as in the degree of nodal activity technique or estimate the number of packets at the interface queue over a short period of time as in the traffic density technique. This is due to the lack of accuracy in measuring the real traffic load experienced by the nodes in the network, since these estimations represent only the current traffic, and as a result it might not be sufficient to represent the load experienced by the node over time which has consumed part of its battery and thus reduced its operational lifetime. The new technique attempts to obtain a more accurate picture of traffic by using a combination of the packet length history at the node and the averaged number of packets waiting at node's interface queue. The rationale behind using packets sizes rather than just the number of packets is that it provides a more precise estimation of the volume of traffic forwarded by a given node. Our performance evaluation shows that the new technique makes better decisions than existing ones in route selection as it preferentially selects less frequently used nodes, which indeed improves throughput and end-to-end delay, and distributes load more, while maintaining a low routing overhead. In the final part of this thesis, we conduct a comparative performance study between the end-to-end and on-the-spot approaches to traffic aware routing. To this end, our new load density technique has been adapted to suggest a new "on-the-spot" traffic aware technique. The adaptation is intended to ensure that the comparison between the two approaches is fair and realistic. Our study shows that in most realistic traffic and network scenarios, the end-to-end performs better than the local approach. The analysis also reveals that relying on local decisions might not be always good especially if all the potential paths to a destination pass through nodes with an overload condition in which case an optimal selection of a path may not be feasible. In contrast, there is most often a chance in the end-to-end approach to select the path with lower load

Performance evaluation of a new end-to-end traffic-aware routing in MANETs

There has been a lot of research effort on developing reactive routing algorithms for mobile ad hoc networks (MANETs) over the past few years. Most of these algorithms consider finding the shortest path from source to destination in building a route. However, this can lead to some network nodes being more overloaded than the others. In MANETs resources, such as node power and channel bandwidth are often at a premium and, therefore, it is important to optimise their use as much as possible. Consequently, a traffic-aware technique to distribute the load is very desirable in order to make good utilisation of nodes' resources. Therefore a number of end-to-end traffic aware techniques have been proposed for reactive routing protocols to deal with this challenging issue. In this paper we contribute to this research effort by proposing a new traffic aware technique that can overcome the limitations of the existing methods. Results from an extensive comparative evaluation show that the new technique has superior performance over similar existing end-to-end techniques in terms of the achieved throughput, end-to-end delay and routing overhead

Transparent and scalable client-side server selection using netlets

Replication of web content in the Internet has been found to improve service response time, performance and reliability offered by web services. When working with such distributed server systems, the location of servers with respect to client nodes is found to affect service response time perceived by clients in addition to server load conditions. This is due to the characteristics of the network path segments through which client requests get routed. Hence, a number of researchers have advocated making server selection decisions at the client-side of the network. In this paper, we present a transparent approach for client-side server selection in the Internet using Netlet services. Netlets are autonomous, nomadic mobile software components which persist and roam in the network independently, providing predefined network services. In this application, Netlet based services embedded with intelligence to support server selection are deployed by servers close to potential client communities to setup dynamic service decision points within the network. An anycast address is used to identify available distributed decision points in the network. Each service decision point transparently directs client requests to the best performing server based on its in-built intelligence supported by real-time measurements from probes sent by the Netlet to each server. It is shown that the resulting system provides a client-side server selection solution which is server-customisable, scalable and fault transparent

EVEREST IST - 2002 - 00185 : D23 : final report

Deliverable públic del projecte europeu EVERESTThis deliverable constitutes the final report of the project IST-2002-001858 EVEREST. After its successful completion, the project presents this document that firstly summarizes the context, goal and the approach objective of the project. Then it presents a concise summary of the major goals and results, as well as highlights the most valuable lessons derived form the project work. A list of deliverables and publications is included in the annex.Postprint (published version

An Energy Aware and Secure MAC Protocol for Tackling Denial of Sleep Attacks in Wireless Sensor Networks

Wireless sensor networks which form part of the core for the Internet of Things consist of resource constrained sensors that are usually powered by batteries. Therefore, careful energy awareness is essential when working with these devices. Indeed,the introduction of security techniques such as authentication and encryption, to ensure confidentiality and integrity of data, can place higher energy load on the sensors. However, the absence of security protection c ould give room for energy drain attacks such as denial of sleep attacks which have a higher negative impact on the life span ( of the sensors than the presence of security features. This thesis, therefore, focuses on tackling denial of sleep attacks from two perspectives A security perspective and an energy efficiency perspective. The security perspective involves evaluating and ranking a number of security based techniques to curbing denial of sleep attacks. The energy efficiency perspective, on the other hand, involves exploring duty cycling and simulating three Media Access Control ( protocols Sensor MAC, Timeout MAC andTunableMAC under different network sizes and measuring different parameters such as the Received Signal Strength RSSI) and Link Quality Indicator ( Transmit power, throughput and energy efficiency Duty cycling happens to be one of the major techniques for conserving energy in wireless sensor networks and this research aims to answer questions with regards to the effect of duty cycles on the energy efficiency as well as the throughput of three duty cycle protocols Sensor MAC ( Timeout MAC ( and TunableMAC in addition to creating a novel MAC protocol that is also more resilient to denial of sleep a ttacks than existing protocols. The main contributions to knowledge from this thesis are the developed framework used for evaluation of existing denial of sleep attack solutions and the algorithms which fuel the other contribution to knowledge a newly developed protocol tested on the Castalia Simulator on the OMNET++ platform. The new protocol has been compared with existing protocols and has been found to have significant improvement in energy efficiency and also better resilience to denial of sleep at tacks Part of this research has been published Two conference publications in IEEE Explore and one workshop paper

Final report on the evaluation of RRM/CRRM algorithms

Deliverable public del projecte EVERESTThis deliverable provides a definition and a complete evaluation of the RRM/CRRM algorithms selected in D11 and D15, and evolved and refined on an iterative process. The evaluation will be carried out by means of simulations using the simulators provided at D07, and D14.Preprin

M-ATTEMPT: A New Energy-Efficient Routing Protocol for Wireless Body Area Sensor Networks

In this paper, we propose a new routing protocol for heterogeneous Wireless Body Area Sensor Networks (WBASNs); Mobility-supporting Adaptive Threshold-based Thermal-aware Energy-efficientMulti-hop ProTocol (M-ATTEMPT). A prototype is defined for employing heterogeneous sensors on human body. Direct communication is used for real-time traffic (critical data) or on-demand data while Multi-hop communication is used for normal data delivery. One of the prime challenges in WBASNs is sensing of the heat generated by the implanted sensor nodes. The proposed routing algorithm is thermal-aware which senses the link Hot-spot and routes the data away from these links. Continuous mobility of human body causes disconnection between previous established links. So, mobility support and energy-management is introduced to overcome the problem. Linear Programming (LP) model for maximum information extraction and minimum energy consumption is presented in this study. MATLAB simulations of proposed routing algorithm are performed for lifetime and successful packet delivery in comparison with Multi-hop communication. The results show that the proposed routing algorithm has less energy consumption and more reliable as compared to Multi-hop communication.Comment: arXiv admin note: substantial text overlap with arXiv:1208.609