The case for addressing the limiting impact of interference on wireless scheduling

Abstract

Co-channel interference is a limiting factor to the predictability and performance of wireless networks, thus interference-oriented scheduling of channel access has become a basic building block of wireless networking. Despite much work in this area, the existing algorithms did not address the limiting impact of interference when optimizing transmission scheduling. Towards understanding the importance of considering the limiting impact of interference, we formulate the concept of interference budget, and we propose the scheduling algorithm iOrder that maximizes the schedulability of future channel access when scheduling concurrent transmissions. When selecting concurrent transmitters for a time slot, more specifically, iOrder tries to maximize the additional interference that can be tolerated by all the receivers while satisfying the application requirement on link reliability. We analyze the approximation ratio of iOrder, and, through extensive simulation and testbed-based measurement, we observe that addressing the limiting impact of interference can improve the performance of existing algorithms by a significant margin, for instance, improving the throughput of the well-known algorithm LQF by a factor up to 2. Thus our study demonstrates the importance of explicitly addressing the limiting impact of interference, which opens up new avenues for future research and for optimizing wireless network performance.