Link layer adaptation in body area networks: Balancing reliability and longevity

A wireless Body Area Network (BAN) consists of multiple radio-enabled wearable and implantable sensor nodes for use inside or in proximity to the human body. BANs are expected to balance requirement for reliable communication of their nodes with a need for battery energy conservation to ensure their longevity. The main challenge in managing this tradeoff is the inability of interfering BANs to explicitly coordinate their transmissions. This may result in unacceptably high battery energy draining rates to overcome cross-interference by other BANs in the vicinity. Here, we propose a utility-based, link-layer adaptation framework for balancing these tradeoffs for each BAN as well as across different BANs. The framework accounts for the utility of the BANs data rates and penalties associated with high transmission powers. Our analysis indicates that link-layer adaptation is beneficial for mitigating the interference from multiple adjacent BANs. Simulation results support our mathematical framework, indicating a much better spectral efficiency obtainable by using link layer adaptation techniques.