CEQMM: a complete and efficient quality of service model for MANETs

This paper specifies CEQMM, a Complete and Efficient Quality of Service (QoS) Model for MANETs which combines the positive aspects of both IntServ and DiffServ. It uses a hybrid per-flow and per-class provisioning scheme. In such a scheme, QoS traffic of highest priority is given per-flow provisioning while other priority QoS classes are given per-class provisioning. To offer this scheme and to ensure that certain packets receive higher priority transmission than other packets, priority classifier, active queue management and packet scheduler are integrated. CEQMM applies the QOLSR protocol to support multiple-metric routing criteria and to respond quickly when changes in topology and/or QoS conditions are detected. Once a path is chosen for one QoS flow, CEQMM performs call admission control (CAC) at each intermediate node. For only QoS flows of highest priority, a node can proceed to soft and later hard bandwidth reservation on links during the CAC process. CEQMM implements congestion avoidance mechanisms to prevent a network from entering the congested state. However, in MANETs, network congestion can still occur frequently under mobility. In order to prevent performance degradation due to mobility-triggered congestion, CEQMM uses a new congestion control scheme. Preliminary simulation results show that CEQMM achieves better performance than the best-effort model