A QoS enabled MAC protocol for multi-hop ad hoc wireless networks

Abstract

In this paper, a medium access control (MAC) technique for multi-hop wireless networks with Quality of Service (QoS) assurance is introduced. The proposed protocol deals with most of the Hidden Node problems in multi-hop environment and also provides service differentiation for various types of traffic: real-time constant bit rate (CBR) traffic, real-time variable bit rate (VBR) traffic, and non-real-time datagram traffic, by guaranteeing bounded delay for real-time traffic, at the same time avoiding lockout of datagram traffic. It uses a distributed mechanism of scheduling and making reservation of the channel access for real-time sessions. Transmissions of datagram or starting packet of new real-time sessions are granted only after checking the reservation such that they do not affect the scheduled ongoing real-time sessions. The protocol has been implemented and tested using VINT Network Simulator 2 (NS2). The performance evaluation and comparison confirm the improved QoS features and multimedia support compared to various existing QoS enabled MAC protocols.