Multihop routing and resource allocation for multimedia applications in dynamic spectrum access networks

In this paper, we propose a distributed routing mechanism in dynamic spectrum access (DSA) networks based on a pricing mechanism, in which each node put prices on their relaying services and adjust the price according to the interference condition and the spectrum availability. The proposed mechanism tries to provide required bandwidth for multimedia transmissions in DSA networks. DSA networks employing cognitive radios enable agile transmissions and provide additional transmission capacity that would otherwise be unavailable. Although the technologies applied in DSA networks provide more information than traditional contention-based networks, conventional resource allocation mechanisms cannot fully use these measurements from the MAC layers to regulate the network. The interference pattern in distributed DSA networks is also not the same as it is in contention-based TDMA networks. Consequently, spectrum allocation mechanisms must cooperate with routing algorithms in order to adapt to the rapidly varying environment of distributed wireless networks. Routing decision is made based on the price offered and price for relaying. Resources are allocated during the routing process according to interference predictions based on spectrum measurements. Simulation results show that the proposed approach increased the throughput of the network by approximately 100% in heavy traffic situation relative to an AODV based direct resource allocation approach.