A distributed MAC scheme to avoid collisions among multiple wireless personal area networks

Wireless personal area network (WPAN) technology will be used for cable replacement in connecting various devices and sensors carried by a person for health monitoring. With the increasing need, every person will eventually have a WPAN and each WPAN is an autonomous entity. When two WPANs come into the radio range of each other, a collision occurs and network performance is affected. To manage the impact, the WPAN collision must be detected early and resolved quickly. This paper assumes the use of IEEE 802.15.4 WPAN. Then, we propose a MAC scheme, called Inter-Network Collision Avoidance (INCA) to detect and avoid WPAN collision accurately in a distributed manner. The proposed INCA scheme does not require any central coordinator for transmission scheduling. Instead, INCA successively separates each pair of colliding WPANs after identifying which portion of an active period suffers from the collision. We have evaluated the proposed scheme through extensive simulations. Evaluation results confirm that WPAN collisions can be effectively resolved leading to a significantly higher normalized throughput. Specifically, the probability of suffering from zero normalized throughput can be reduced from about 40% to less than 1%.