Adaptive channel and time allocation for body area networks

Personal health care is a promising application of a body area network (BAN). The BAN for health care application consists of a data collector and multiple wearable sensors that send data to the collector according to a sampling interval determined by the application. The data collector may be any hand-held or portable device such as a mobile phone, a PDA or a wristwatch. An individual user needs a BAN to detect, track or manage his/her health. Multiple BANs for such purpose are likely to appear in a nearby area, especially a place where population density is high. Since multiple BANs must share wireless medium in this scenario, a problem of packet collisions among BANs is unavoidable. To deal with such problem, this study proposes an adaptive scheme to allocate channel and time for coexisting BANs. The proposed scheme distinguishes inter-BAN and intra-BAN communications, and adaptively allocates channel and time according to the current number of BANs that exist in a nearby area. As a salient feature, the proposed scheme allocates time by attempting to satisfy the requirement of sampling interval determined by the application. The evaluation results demonstrate that our scheme achieves much higher packet delivery rate than the existing scheme.