Wireless LAN frame collision control using collision type information

With the increase of wireless local area networks (WLAN) using the IEEE 802.11 standard, the interference between WLAN devices has become a significant problem. The IEEE802.11 standard includes a carrier-sense and collision avoidance mechanism, but it is not able to avoid some causes of collisions, including coincidental choice of identical random backoff count, or interfering transmission power below the carrier-sense threshold. It also does not distinguish the cause of frame loss at a receiver, and executes the same control countermeasures regardless of the cause of frame loss. We propose that identifying collision type by detecting and analyzing frame collision events is useful for WLAN managers and controllers to select appropriate countermeasures to reduce collisions. In particular, we consider the classification of collision type based on temporal features of received signal power. We present examples that show the relation between collision cause and collision type, and the feasibility of reducing collisions by changing transmissions parameters according to the collision type.