A QoS-oriented distributed routing protocol for hybrid networks

As wireless communication gains popularity, significant research has been devoted to supporting realtime transmission with stringent Quality of Service (QoS) requirements for wireless applications. At the same time, a wireless hybrid network that integrates a mobile wireless ad hoc network (MANET) and a wireless infrastructure network has been proven to be a better alternative for the next generation wireless networks. By directly adopting resource reservation-based QoS routing for MANETs, hybrids networks inherit invalid reservation and race condition problems in MANETs. How to guarantee the QoS in hybrid networks remains as an open problem. In this paper, we propose a QoS-oriented Distributed routing protocol (QOD) to enhance the QoS support capability of hybrid networks. Taking advantage of fewer transmission hops and anycast transmission features of the networks, QOD transforms the packet routing problem to a resource scheduling problem. QOD includes a QoS-guaranteed neighbor selection algorithm to meet the transmission delay requirement, a distributed packet scheduling algorithm to further reduce transmission delay, and mobility-based segment resizing algorithm that adaptively adjusts segment size according to node mobility in order to reduce transmission time. Analytical results show the QOD´s properties of lower transmission delay and dynamism-resilience. Simulation results show that QOD can provide high QoS performance in terms of overhead, transmission delay, dynamism-resilience and scalability compared to a resource reservation-based mechanism.