  A Wireless Body Area Network (WBAN) provides health care services. The
performance and utility of WBANs can be degraded due to interference. In this
paper, our contribution for co-channel interference mitigation among coexisting
WBANs is threefold. First, we propose a distributed orthogonal code allocation
scheme, namely, OCAIM, where, each WBAN generates sensor interference lists
(SILs), and then all sensors belonging to these lists are allocated orthogonal
codes. Secondly, we propose a distributed time reference correlation scheme,
namely, DTRC, that is used as a building block of OCAIM. DTRC enables eachWBAN
to generate a virtual time-based pattern to relate the different superframes.
Accordingly, DTRC provides each WBAN with the knowledge about, 1) which
superframes and, 2) which time-slots of those superframes interfere with the
time-slots within its superframe. Thirdly, we further analyze the success and
collision probabilities of frames transmissions when the number of coexisting
WBANs grows. The simulation results demonstrate that OCAIM outperforms other
competing schemes in terms of interference mitigation and power savings.
