QoS-Aware Routing and Admission Control in Shadow-Fading Environments for Multirate MANETs

Providing quality of service (QoS) assurances in a mobile ad hoc network (MANET) is difficult due to node mobility, contention for channel access, a lack of centralized co-ordination, and the unreliable nature of the wireless channel. A QoS-aware routing (QAR) protocol and an admission control (AC) protocol are two of the most important components of a system attempting to provide QoS guarantees in the face of the above mentioned difficulties faced. Many QAR and AC-based solutions have been proposed, but such network layer solutions are often designed and studied with idealized lower layer models in mind. This means that existing solutions are not designed for dealing with practical phenomena such as shadow fading and the link quality-dependent fluctuation of link transmission rates. This paper proposes and evaluates new solutions for improving the performance of QAR and AC protocols in the face of mobility, shadowing, and varying link SINR. It is found that proactively maintaining backup routes for active sessions, adapting transmission rates, and routing around temporarily low-SINR links can noticeably improve the reliability of assured throughput services.