Cross-layer design for prompt and reliable transmissions over body area networks.

In this paper, we propose a cross-layer design to make ambulatory health monitoring via body area networks (BAN) more reliable and robust. The proposed design builds on our centralized body area network access scheme (CBAS), a receiver-initiated medium access control (MAC) scheme that improves the visibility of a BAN in a coexistent environment, where diverse networks with various physical and MAC protocols share the radio spectrum. The design enhances CBAS by incorporating a network layer scheme that improves the packet delivery ratio (PDR), while minimizing the need for multihop cooperative transmissions; thus, packet delay is less compromised to achieve higher PDRs. The MAC layer provides the network layer with local information about the quality of on-body links to enable the BAN to identify the most reliable links in a distributed manner. Extensive experimental results are presented, which give insights on how the proposed cross-layer design improves PDR and packet delay. Results show the effectiveness of the proposed design which takes advantage of dynamic scheduling and multihop relays as warranted by the link conditions.