QOLSR, QoS routing for ad hoc wireless networks using OLSR

Abstract

SUMMARYThis paper describes a novel quality-of-service (QoS) routing protocol for ad hoc networks based on the OLSR protocol. Our protocol, QOLSR, is designed for wireless networks with stationary or moving nodes, where each node is equipped with 802.11 wireless card. The goal of our protocol is not only to find a route from a source to a destination, but an optimal route that satisfies the end-to-end QoS requirement, often given in terms of bandwidth or delay. We present an analytical model to compute the average delay and permissible throughput on links using the IEEE 802.11 medium access protocol and considering correlations and interferences between nodes. This model takes into account packet's collision probability, node's MAC queuing and service times based on the IEEE 802.11 binary exponential backoff algorithm and the events underneath its operation. Afterwards, our protocol assigns weights to individual links based on the average delay and bandwidth metrics of packets over the link. We present a distributed algorithm for multiple QoS requirements to find the source destination optimal paths in terms of bandwidth and delay using the known partial network topology available on each node. However, these optimal paths in partial network topology are not optimal paths in the whole ad hoc network. We show that this problem is due to the heuristic for the selection of MPRs used in OLSR. We propose innovative heuristics for the selection of MPRs based on QoS measurements that allow QOLSR to find optimal paths on the known partial topology having the same bandwidth performances that those on the whole network. The performance evaluation of our protocol in both static and dynamic ad hoc networks is extensively investigated. Mathematical analysis and simulation results show that the QOLSR protocol yields better performance compared to the best-effort OLSR protocol and significantly improves throughput by using our proposed heuristic.

Wireless Communication Protocols for Distributed Computing Environments

“…There are several basic routing protocols for ad-hoc networks (Badis & Al Agha, 2005;Clausen & Jacquet, 2003;Haas & Pearlman, 2001;Perkins & Royer, 1999); they can be classified into three families:…”

“…The most popular in this class is the OLSR algorithm (Clausen & Jacquet, 2003) and its QoS-aware extension called QOLSR (Badis & Al Agha, 2005), whose aim is to consider the QoS requirements of the different traffic flows for a better routing decision;…”

“…It is well known that reactive protocols require less network traffic than the proactive ones, but the QOLSR principle (Badis & Al Agha, 2005), despite a higher network control traffic with respect to reactive alternatives, can provide the following characteristics:…”

“…The node J, through the advertised list carried on each HELLO message, can also build its 2-hops neighbors set (N 2 J ). According to the QOLSR algorithm (Badis & Al Agha, 2005), every node has to compute its MPR set. The MPR set of the node J (MPR J ) is a subset of N 1 J and it is composed by those network nodes through which is possible to communicate with every element of the N 2 J set relying only on two hops paths.…”

A Survey of QOS Routing Protocols For Mobile Ad Hoc Network

“…Therefore, the source node can get a routing path immediately if it needs one. There are some typical proactive QoS routing protocols such as QOLSR [23] (QoS Optimized Link State Routing) and PLBQR [24] (Predictive Location-Based QoS Routing in Mobile Ad Hoc Networks).…”