A Cross-layer Qos Mapping Framework For Mobile Ad Hoc Networks

摘要

Research in Quality of Service (QoS) provisioning for wireless ad hoc networks is receiving growing interest due to the rising necessity for supporting multimedia applications in such networks. Quality of Service provisioning is a multilayer problem, where the interaction between protocols at different layers is of paramount importance. In this paper, we are looking at the problem of QoS provisioning from the perspective of three layers - application layer, network layer and medium access control (MAC) layer. Our goal is to design a QoS framework which maps QoS parameters across these three layers of the protocol stack, to support a stronger notion of per-class service guarantees in terms of throughput and delay in ad hoc networks. Further, to cope with network dynamics, MAC layer and network layer are made to adapt their behavior based on both dynamic network conditions and QoS requirements of admitted flows. An MAC layer adaptation takes place in terms of dynamic contention window adjustment per class, whereas a network layer adaptation takes place in the form of rerouting or termination of existing flows. We have proposed a detailed QoS mapping scheme with adaptive protocols, using a TCP/IP protocol suite.