Superframe-level time-hopping system with variable contention access period for wireless body area communications

Coexistence of multiple wireless body area networks (WBAN) is a very challenging problem because piconets move frequently and each piconet can have hundreds of sensors. The IEEE 802.15.6 task group is developing a standard based on superframe-level frequency-hopping scheme, which is a good solution to the piconet coexistence problem without requiring coordination between piconets. However, its spectrum efficiency is very low when only a single piconet is operating. In this paper we propose a superframe-level time-hopping scheme with variable contention access period. Compared to the frequency-hopping scheme, the proposed scheme has similar interference mitigation capability, but can achieve significant improvement in energy consumption, latency and spectrum efficiency.