WIRELESS LOCAL AREA NETWORK PERFORMANCE IN A BLUETOOTH INTERFERENCE ENVIRONMENT

Abstract

Since IEEE 802.11 wireless local area networks (WLANs) and Bluetooth (BT) personal area networks both use the 2.4 GHz Industrial, Scientific, and Medical band, interference can occur when these networks are collocated. A WLAN station's clear channel assessment algorithm will declare a channel busy and induce transmission delays when sufficient energy from a BT signal is received. By assuming the BT's frequency hopped spread spectrum signal will not corrupt the direct sequence spread spectrum WLAN transmission, we isolate and characterize transmission delays due solely to BT interference. We develop expressions for throughput, delay, expected backoff interval, expected number of collisions, and other metrics of interest. In situations where numerous collisions occur between WLAN stations, BT-induced transmission delays reduce the probability of expensive WLAN collisions while increasing overall throughput and decreasing delay. An analytic model is developed to predict interference effects and is verified t...