Overlapping Impacts and Resource Coordination for High-density Wireless Communication

A high-density wireless environment could not avoid cell/BSS (Basic Service Set) overlapping, which may cause Co-channel interference. Such interference makes it difficult to support QoS. It is desirable that BSSs can share a single frequency channel without interference and at the same time, QoS is supported. Additional functionalities particularly in MAC layer are required to achieve interference-free for a business- sound wireless deployment. In this paper, we present a detailed analysis on OBSS interference, caused by overlapping, in relation to MAC functions and propose a resources coordination scheme to support OBSS co-existence and QoS, based on the context of 802.11 WiFi as an example. The uplink and downlink transmission are separated into two periods. The grouping assignments using coloring theory are carried out based on the topology to divide BSSs into groups and time span to avoid downlink collision.