Quality-of-Service in BAN: PER Reduction and its Trade-Offs

In ambulatory conditions, body area network (BAN) performances are often impaired due to body obstruction or radio interferences from the surrounding environment. Even in these unfavourable conditions, a Quality-of-service (QoS) layer shall ensure that some critical services are met. The wide variability of BAN applications calls for a flexible QoS layer, which can easily be optimized towards certain application-specific requirements. In this paper we propose a flexible QoS layer for BAN addressing the following services: data consistency (Packet Error Rate –PER-), latency, node lifetime and memory. The QoS layer is evaluated in experimental conditions. Its ability to reduce packet loss (improve data consistency) is demonstrated. The trade-offs with other services (latency, energy consumption) are discussed. A PER reduction of 90% is reported, at the cost of an increased latency (350 ms) and energy consumption (7% increase). PER can be reduced to close to 0% for application in which the latency is left unconstrained. The impact of the memory allocated to QoS layer on the performances is characterized.