A QoS-Aware Medium Access Control Protocol for Real Time Traffic in Ad Hoc Networks

The advances in wireless communications and growth of real-time applications have necessitated the development of wireless networks that can support high Quality of Service (QoS). Unfortunately, support for real time traffic in such networks is still in its infancy. In this paper, we introduce a new MAC protocol, called Multi-rate Multi-hop QoS-aware MAC Protocol (MMMP) for Ad hoc networks that concurrently address several MAC layer QoS issues. MMMP is a reservation based asynchronous scheme that provides QoS guarantees for real time traffic by providing service differentiation for various multi-rate real-time traffic (both real time constant bit rate traffic and real time variable bit rate traffic) and guaranteeing a bounded end-to-end delay for the same while still catering to the throughput requirements of non real time traffic. In addition, bandwidth preservation is administered via a feature called 'Smart Drop'. Simulation results on the Qualnet simulator indicate that MMMP outperforms IEEE 802.11 on all performance measures and can efficiently handle a large range of traffic intensity. It also outperforms other similar state of the art MAC protocols.