Modeling and analysis of two-flow interactions in wireless networks

摘要

Interference plays a complex and often defining role on the overall performance of wireless networks, especially in multi-hop scenarios. Understanding this role is critical for understanding these networks, and in turn for developing effective protocols for them. In the presence of interference, Carrier Sense Multiple Access MAC protocols are known to suffer from the hidden terminal and exposed terminal problems, which can cause poor performance and unfairness. Recent work has shown that depending on the relative location of interfering sources and destinations, several modes of interference exhibiting different behavior, occur. In this paper, we first relax the assumption that the interference range is equal to the reception range. This gives rise to a large number of interference configurations; we develop closed form expressions for their frequency of occurrence. As a result, we discover that the frequency of occurrence of the major modes of interference change significantly from those obtained without relaxing the interference range assumption. More importantly, we show that two previously unknown modes of interactions arise, whose performance differs significantly from the known modes. We develop models for estimating the throughput for the different categories of interaction, and validate them against simulation results. We believe that this analysis represents a further step into the understanding and characterization of the impact of interference from first principles.