Interference-Aware Joint Routing and TDMA Link Scheduling for Static Wireless Networks

We study efficient interference-aware joint routing and TDMA link scheduling for a multihop wireless network to maximize its throughput. Efficient link scheduling can greatly reduce the interference effect of close-by transmissions. Unlike the previous studies that often assume a unit disk graph (UDG) model, we assume that different terminals could have different transmission ranges and different interference ranges. In our model, it is also possible that a communication link may not exist due to barriers or is not used by a predetermined routing protocol, while the transmission of a node always result interference to all nonintended receivers within its interference range. Using a mathematical formulation, we develop interference-aware joint routing and synchronized TDMA link schedulings that optimize the networking throughput subject to various constraints. Our linear programming formulation will find a flow routing whose achieved throughput is at least a constant fraction of the optimum, and the achieved fairness is also a constant fraction of the requirement. Then, by assuming known link capacities and link traffic loads, we study link scheduling under the request-to-send and clear-to-send (RTS/CTS) interference model and the protocol interference model (PrIM) with fixed transmission power. For both models, we present both efficient centralized and distributed algorithms that use timeslots within a constant factor of the optimum. We also present efficient distributed algorithms whose performances are still comparable with optimum, but with much less communications. We prove that the timeslots needed by our faster distributed algorithms are only at most O(min(log n, log psi)) for RTS/CTS interference model and PrIM. Our theoretical results are corroborated by extensive simulation studies.