Trust-based routing for ad-hoc wireless networks

A mobile ad-hoc network comprises of a number of low power wireless nodes. Each of these participating nodes endeavours to pass packets for other nodes based upon a preagreed protocol. The dynamic source routing (DSR) protocol is one of the most commonly used protocols in ad-hoc wireless networks. In a DSR based network, each transmitted data packet contains the complete list of node addresses that the packet has to traverse in order to reach its final destination. Intermediate nodes blindly forward these packets as per the attached list without taking into consideration the behavioural pattern of the subsequent nodes. In this paper, we present a variant of the DSR protocol in which intermediary nodes act as trust gateways. These gateways take into account the contemporary trust levels of the network nodes and thus facilitate in detecting and evading malicious nodes. With the help of extensive simulations, we demonstrate that the proposed DSR protocol augments the performance of the standard DSR protocol by up to 30% in a network where 40% of the nodes act maliciously. The proposed scheme is also independent of cryptographic mechanisms and does not impose any superfluous conditions upon the network establishment and operation phase.

Wireless Ad Hoc network routing algorithm is one of the core technologies of wireless Ad Hoc networks. Ad Hoc network is dynamic topology on characteristic, mainly reflected on the network node number and node movement, which lead to network topology changes, in order to study the Ad Hoc network size and topology changes influence on packet delivery, time delay and routing control, through experiment it is concluded that, the dynamic source routing protocol is an ideal choice.

We introduce WRP-Lite, which is a table-driven routing protocol that uses non-optimal routes, and compare its performance with the performance of the dynamic source routing (DSR) protocol, which is an on-demand routing protocol for wireless ad-hoc networks. We evaluate the performance of WRP-Lite and DSR for varying degree of mobility and traffic in a 20-node network. The performance parameters are end-to-end delay, control overhead, percentage of packets delivered, and hop distribution. We show that WRP-Lite has much better delay and hop performance while having comparable overhead to DSR.

In mobile ad hoc networks (MANET), links are created and destroyed in an unpredictable way, which makes quite challenging the determination of routes between each pair of nodes. In this paper, we evaluate the performance of the dynamic source routing (DSR) protocol in a multi-services MANET. Simulation results reveal that DSR enables to provide packet delivery ratio higher than 99% for low mobility level and low traffic intensity.

We propose a packet-level model to investigate the impact of channel error on the transmission control protocol (TCP) performance over IEEE-802.11-based multihop wireless networks. A Markov renewal approach is used to analyze the behavior of TCP Reno and TCP Impatient NewReno. Compared to previous work, our main contributions are listed as follows: 1) modeling multiple lossy links, 2) investigating the interactions among TCP, Internet Protocol (IP), and media access control (MAC) protocol layers, specifically the impact of 802.11 MAC protocol and dynamic source routing (DSR) protocol on TCP throughput performance, 3) considering the spatial reuse property of the wireless channel, the model takes into account the different proportions between the interference range and transmission range, and 4) adopting more accurate and realistic analysis to the fast recovery process and showing the dependency of throughput and the risk of experiencing successive fast retransmits and timeouts on the packet error probability. The analytical results are validated against simulation results by using GloMoSim. The results show that the impact of the channel error is reduced significantly due to the packet retransmissions on a per-hop basis and a small bandwidth delay product of ad hoc networks. The TCP throughput always deteriorates less than ~ 10 percent, with a packet error rate ranging from 0 to 0.1. Our model also provides a theoretical basis for designing an optimum long retry limit for IEEE 802.11 in ad hoc networks.

Link state has been the dominating IGP routing technology in IP networks for more than a decade. With the advent of wireless ad-hoc networking, the need for light, efficient and robust routing makes it a good candidate to be also used in this constrained environment. One of the key issue in ad-hoc networking is the lack of bandwidth. Thus, in this paper we examine the overhead due to link state routing in an ad-hoc network. More precisely we study the classic link-state protocol OSPF and OLSR, a link state protocol that was developed specifically for ad-hoc networks. Further, we study how this overhead evolves when the node density increases. The last part of the paper presents directions towards extending OSPF for wireless and ad-hoc networks, which would make it a favorite to seamlessly unify wired and mobile IP networks.

Routing for ad-hoc wireless network is challenging, and there is no single routing strategy to deal with the complex and dynamic nature of the ad-hoc network. Given the availability of the low cost of location-aware devices, geographic forwarding and routing provided opportunity for improving existing ad-hoc routing strategies. In this paper, geographic forwarding strategies and geographic routing protocols are reviewed; challenges of implementing geographic routing in ad-hoc network are identified and discussed. More research effort is called for improving the basic forwarding strategy to increase the efficiency of the geographic routing protocol to provide a practical solution addressing the issues related to routing around local minima.

Enabling transmission over ad-hoc networks is more challenging than over conventional mobile networks because a connection path in an ad-hoc network is highly error-prone and the path can go down frequently. Although it is well-known that wireless channels are time varying because of user mobility and multi-path propagation effects, experiments for various types of channels show that the basic channel parameters can be stable for short time intervals. Therefore, a wireless channel can be adequately represented by a set of stationary channel models. There are number of wireless channel models proposed in literature. For simplicity, we used a two state Markov model known as a Gilbert-Elliot model and then in order to model more appropriately a real communication channel, a three state Markov model is analyzed here. We demonstrate our concept by applying it to the dynamic source routing protocol (DSR). In our proposed modified DSR, both the route discovery and route selection are based on physical layer parameter and the link monitoring function located at each node. Since routing selection based on the link quality is implemented, the minimum transfer delay from source to destination and the maximal throughput may be obtained. Simulation results show that according to the channel quality, the delay and throughput performance show remarkable performance when compared to traditional DSR.

We propose a distributed and adaptive topology management algorithm, called PATM (Priority-based Adaptive Topology Management), that constructs and maintains a connected backbone topology based on a minimal dominating set of the network. PATM provides a succinct presentation of the network topology to routing protocols, and therefore reduces the control overhead in routing updates. Two optimizations are proposed to further reduce the topological information exchanges among the nodes by piggybacking topology updates in packets transmitted by each node, and adaptively adjusting the topology update intervals. The efficiency of the algorithm is validated by simulations based on DSR (Dynamic Source Routing) protocol. The simulation results demonstrate that PATM not only significantly reduces the routing control overhead, but also substantially improves the network data forwarding performance.

The rapid advances in the wireless communication industry have paved the way for the enhancement of wireless mobile ad-hoc networks (MANETs) to support various domains including civilian environments, emergency operations, and military affairs. Source routing in MANETs is subject to some issues such as changes in the network topology, which lead to frequent link breakages that may increase the requests of route discoveries. Thus, this paper aims to enhance on-demand source routing protocols by proposing two mechanisms, a zone-based route discovery mechanism (ZRDM) and a link failure prediction mechanism (LFPM). ZRDM aims to control the flooding of route requests, and LFPM aims to avoid route breakages caused by node mobility. The performance of the proposed mechanisms was evaluated using network simulator 3 in terms of normalized routing load, average end-to-end delay, and packet delivery ratio. The experimental results showed that the proposed mechanisms outperform well-known mechanisms such as the dynamic source routing (DSR) protocol, reliable DSR, and zone-based DSR and segment-based DSR.

Power-aware routing has proven to be effective in maximizing the life time of ad-hoc networks. However, all the previous research focused on the power-aware routing algorithms in a cooperative network, where all the nodes honestly report battery usage. However, selfish nodes in ad-hoc networks have incentives to misreport lower residual energy to maximize their own usage. In this paper, we first show that it is a dominant strategy for a selfish node to report lower residual energy in a power-aware ad-hoc network, which diminishes the benefits of power-aware routing algorithms. We then propose a novel power-aware reputation system (PARS), to stimulate cooperation on power-aware routing in ad-hoc networks. Analysis and simulation results show that PARS is effective in supporting power-aware routing in selfish ad-hoc networks.

Ad hoc networks are useful for providing communication support where no fixed infrastructure exists or the deployment of a fixed infrastructure is not economically profitable, and movement of communicating parties are allowed. Due to the dynamic topology, developing better routing protocol became a challenging task. The Dynamic Source Routing (DSR) protocol is a simple and efficient routing protocol designed specifically for use in multi-hop wireless ad hoc networks of mobile nodes. Multi-path routing protocol is one of the approaches used to have less overhead, better bandwidth cost by distributing the load among a set of paths . However, due to interfering in the channels of the paths, multi-path increases the end to end delay and do not work well in highly congested networks. In this paper we propose a congestion aware multi-path Dynamic Source Routing Protocol. we generate a set of disjoint multi-paths and handle the problem of end to end delay using the correlation factor measurement. A set of path selection criteria have been used to improve the end to end delay. The simulation experiments are conducted using ns-2 network simulator. We will compare the performance of the suggested algorithm to the performance of the conventional Dynamic Source Routing Protocol (DSR).

Ad Hoc network is one of the popular wireless multi-hop networks. Nodes or Users in Ad Hoc network can move randomly and freely to maintain communication without the control of the fixed infrastructure. Due to the limited transmission power and wireless coverage of the terminal, if two terminals that are beyond their respective transmission radius need communicate, they must use other intermediate or relay nodes for packet forwarding, so that a wireless Ad Hoc network is formed among these nodes. In this paper, the current state-of-the-art multipath routing protocols for Ad Hoc networks are reviewed. Particularly, the pros and cons of them are analyzed. Finally, they are summarized and compared.

Power consumption is a crucial design concern in mobile ad‐hoc networks (MANETs), since the nodes are powered by batteries with limited battery power, whereas the existing dynamic source routing (DSR) protocol does not take the battery power limitation of the MANET nodes into account. The mobile hosts in MANETs are constrained by the battery power for their operation. Hence, the battery power of a node is a precious resource that must be used efficiently in order to avoid early termination of a node or a network. In the MANET, power is one of the major issues, since the devices have limited battery power to execute the tasks. This study proposes a new scheme called efficient power routing DSR (EPRDSR) to improve the existing on‐demand routing protocols by introducing a power efficient scheme in the whole MANET. In the route discovery, the EPRDSR selects the bandwidth and the power constraints are built into the DSR route discovery mechanism. Hence, it enhances the network lifetime and delays the repair and reconstruction of the route. The main goal of EPRDSR is not only to extend the lifetime of each node, but also to prolong the lifetime of each connection.

To choose more stable route in Ad Hoc network, it integrated the link stability arithmetic and the principle of the least hop number in route discovery, and proposed link stability Dynamic Source Routing protocol. This protocol chooses route with high link stability, and decreases the number of route interrupted, which results in lower packet loss rate and improves the performance of the network. It obtains all messages needed to control this arithmetic from packets transmitted between nodes. The simulation shows it is a simple and high efficient routing protocol.