WLAN CSMA/CA Performance in a Bluetooth Interference Environment
Master's thesis Aug 2001-Mar 2003
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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IEEE 802.11 WLANs and Bluetooth piconets both operate in the 2.4 GHz Industrial Scientific and Medical ISM radio band. When operating in close proximity, these two technologies interfere with each other. Current literature suggests that IEEE 802.11 employing direct sequence spread spectrum technology is more susceptible to this interference than Bluetooth, which uses frequency hopping spread spectrum technology, resulting in reduced throughput. Current research tends to focus on the issue of packet collisions, and not the fact that IEEE 802.11 may also delay its transmissions while the radio channel is occupied by a Bluetooth signal. This research characterizes previously neglected transmission delay effects. Through analytic modeling and simulation, the impact of this interference is determined to identify all facets of the interference issues. Results show that Bluetooth-induced transmission delays improve network performance in many scenarios. When isolating delay effects, the likelihood that WLAN STA signals collide with each other decreases, causing an overall increase in normalized throughput and decrease in expected delay for many network configurations, As wireless communication technologies become an integral part of national defense, it is imperative to understand every performance characteristic. For instance, if the Air Force uses IEEE 802.11 and wants to incorporate a Bluetooth piconet as well, the impact of concurrent operation should be known beforehand. Since IEEE 802,11 and Bluetooth technologies could become vital for the Air Force to maintain its position of air superiority, all the strengths, weaknesses, and limitations of these systems should be understood.
- Radio Communications