An analysis of the Received Signal Strength accuracy in 802.11a networks using Atheros chipsets: A solution towards self configuration

Self-Configuration Frameworks for 802.11 Wireless Mesh Networks mainly use measured Received Signal Strength values to mitigate interferences such as Adjacent Channel Interference and Inter Channel Interference by applying interference and capacity aware channel assignment algorithms and radio configuration techniques. For such tasks accurate Received Signal Strength values are essential with a granularity of less than 1 dB. This paper investigates the poor accuracy of Received Signal Strength values reported by Atheros chipsets and develops a Slope-Intercept approach to provide accurate Received Signal Strength values over various transmission power settings. In addition this work also investigates the mechanism by which ambient noise can enable the Ambient Noise Immunity feature implemented in Atheros chipsets and in the Linux Multiband Atheros Driver for Wireless Fidelity which negatively affects the reported Received Signal Strength and Noise Floor.