A QoS framework to support integrated services in multihop wireless networks with infrastructure support

In this paper, we consider a multihop wireless network with infrastructure support (MWNI) which can be built upon existing IEEE 802.11 based WLANs to extend the coverage and provide more flexibility to adapt to the dynamics of the network. To support integrated services in MWNI, a QoS framework is proposed to achieve the following objectives: (1) allow more real-time flows to be admitted into the network, (2) optimize the performance of best-effort traffic without losing fairness and (3) enhance QoS performance of admitted real-time traffic. There are three main components in our framework to provide corresponding solutions. First, a new QoS routing protocol that discovers global optimized topology based on the network interference modeled by flow contention graph. Second, admission control is performed at the access point (AP) so that a flow will be admitted only if the network has enough bandwidth to support its minimum bandwidth requirement. Third, a two-level hierarchical scheduling algorithm based on weighted fair queueing is implemented at the APs. The efficiency of individual component, as well as the QoS framework is evaluated through simulation studies, and the results show our proposed QoS framework is able to enhance the QoS of real-time traffic and still achieve high network utilization.