A New Cross-Layer Framework for QoS Multicast Applications in Mobile Ad hoc Networks

摘要

The need to support real-time and multimedia applications in mobile ad hoc networks (MANETs) has increased dramatically over the last few years. There are many challenges in supporting QoS for MANETs. The contribution of this paper is a new framework based on the cross-layer design and integration between a new routing protocol and other components that deal with different types of traffic. We propose a Framework for QoS Multicast (FQM) to support QoS multicast applications for MANETs that is able to support QoS enabled applications. The first component of the framework is a new and efficient routing protocol for finding multiple paths meeting the QoS requirements and for maintaining these paths. Second, cross-layer bandwidth estimation is used to estimate the available bandwidth and support it for other schemes. Third, classifier, shaper, dynamic rate control and priority queue work together to support high priority real-time traffic. We implemented a hybrid scheme that uses unipaths and redundant paths to share the available bandwidth for forwarding data packets. The performance of FQM was studied using the GLOMOSIM simulation environment. Analysis of the simulation results showed the ability of FQM to exploit the available bandwidth efficiently and provide a balance between performance gains and protocol complexity. The results indicated a high packet delivery ratio associated with low control overhead, low average latency and low jitter compared with QAMNet [1]. The FQM framework out-performed QAMNet in most experiments.