Joint Topology-Transparent Scheduling and QoS Routing in Ad Hoc Networks

This paper considers the problem of joint topology-transparent scheduling (TTS) and quality-of-service (QoS) routing in ad hoc networks and presents a joint scheme for the problem. Due to its ability to guarantee single-hop QoS support, TTS is chosen as the underlying medium-access-control (MAC) protocol. By being built on top of TTS, this paper first designs methods for bandwidth estimation and allocation (BWE and BWA, respectively) to provide QoS support without knowledge of slot status information, and then, estimates and allocates nonassigned eligible bandwidth for best effort (BE) flows. With these bandwidth management methods, this paper proposes a QoS routing protocol for a mixture of QoS and BE flows. Idealized simulation results based on the standard radio model, which ignores external sources of radio interference and protocol inefficiencies, reveal that the proposed joint scheme can provide a reduction of at least 93% in QoS violation rates and a reduction of 78%-89% in control overhead compared with the conventional dynamic source routing (DSR)/IEEE 802.11 technique. A comparison with another conventional technique, i.e., DSR/carrier sense multiple access (CSMA), also reveals that the proposed joint scheme can reduce QoS violation rates by at least 93%. In addition, the proposed joint scheme can provide an increase of 31%-104% in aggregate throughput over two representative QoS routing protocols while achieving a reduction of approximately 93% in QoS violation rates. The performance improvement to be achieved under a realistic radio model is yet to be determined.