A frequency division multiple access scheme is considered, in which nodes must schedule their transmissions by selecting frequency channels from a limited set in an interference-free fashion. We argue that in order to address the effects of limited frequency resources, such algorithms must be coupled with channel allocation mechanisms for providing conflict free frequency assignments over selected routing paths. To these ends, we propose a set of link metrics for selecting candidate routing paths and a set of heuristics for frequency allocation and evaluate their performance using our detailed simulation model. We outline the trade-offs that arise by the flexibility of wireless nodes to transmit at different power levels and define a framework for formulating the problem of session routing from the perspective of energy expenditure. We propose a set of metrics that associate each link transmission with a cost and consider both the cases of plentiful and limited bandwidth resources, the latter jointly with a set of channel allocation algorithms.
Performance is captured by call blocking probability and average consumed energy.
A detailed simulation model has been developed and used to evaluate the algorithms for a variety of networks. State aggregation is used to solve the problem and accelerate computation by looking for a sub-optimal policy. Preliminary results show that the new method increases the speed of convergence impressively. Aggregation introduces errors inevitably. An adaptive aggregation scheme employing the new computation method is also proposed to reduce the aggregation errors.