Available Bandwidth Prediction Based QoS Routing For Ad Hoc Networks With Concurrent Medium Access Control

As the important technique of ubiquitious IP networking, ad hoc networks have gainedsignificant attention in the past decade. Medium access control (MAC) protocol defines the mediumaccess mechanisms of nodes, which directly determines the channel resource utilization. Meanwhile,MAC protocol is also an important part of the research in the quality of service (QoS) of wirelessnetworks. Compared with IEEE802.11DCF, concurrent medium access protocols can significantlyimprove the total throughput of network. What remains unaddressed, however, is how to provideeffective QoS guarantees for the multimedia services in ad hoc networks with concurrent mediumaccess control. According to this target, the major contribution of our work is summarized as follows.(1). Based on the study of existing available bandwidth prediction algorithms, we point out theirlimitations. Afterwards, we highlight that obtaining the link available bandwidth is the first step torealize QoS routing by analyzing the routing policy in the current QoS routing protocols. Then, wefocus on the available bandwidth for ad hoc networks with the control gap based concurrent mediumaccess control and propose an accurate available bandwidth prediction algorithm. The proposedalgorithm first demands that the node estimates the available transmission/reception duration bydetecting the signal on the channel. Then, by analyzing the asynchronism of the availabletransmission/reception duration between the sender and recipient, our algorithm yields a preliminaryestimation of link available bandwidth. Finally, our algorithm refines the available bandwidth byperforming the prediction of the failed transmission, where the packet delivery failure probability isderived by discussing the interference from the hidden nodes as well as the parallel datatransmissions.(2). Based on the principle of the above available bandwidth prediction, we propose a QoSrouting protocol that incorporates the distributed link available bandwidth prediction scheme with theaid of the extended Hello packet. Besides, the prediction of bandwidth consumption of flow and theadmission control are also performed in route slection of our proposed routing protocol. Thesimulation results obtained by the QualNet simulator validate that our proposed routing protocol canprovide certain QoS guarantees for the multimedia services in ad hoc networks with concurrentmedium access control.