Partially Overlapped Channel interference measurement implementation and analysis

Abstract

Currently, the widely deployed Wi-Fi devices generally reside in three non-overlapped channels, resulting in severe co-channel interference and performance deterioration. The avoidance of using Partially Overlapped Channels (POC) is mainly because of the complicated interference effects among them, which has not been well studied. In this paper, we build an OpenWrt based Wi-Fi interference measurement system, and focus on analyzing the influence of POC on two typical types of interference: in-range interference and hidden terminal interference. In the 4-AP testbed in an office environment, our experiments demonstrate that the channel separation leads to performance improvement in a non-linear manner. When two APs' channel numbers are separated larger than 4, the transmission rate can be improved by 140% for in-range interference, while the packet loss rate can be reduced by 150% for hidden terminal interference. Moreover, the POC interference measurement in the wild illustrates that hidden terminal interference poses the more negative impact on the transmission rate and the packet loss rate than in-range interference.