Trade-off Analysis of a MAC Protocol for Wireless e-Emergency Systems

To provide a reliable assistance to patients, emergency and intensive care systems have increased demands for quality of service at different levels, with the MAC layer assuming special relevance. The Low Power Real Time (LPRT) MAC protocol presents suitable characteristics to be deployed in emergency platforms due to its efficient bandwidth allocation, low energy consumption, and bounded latency. Yet, this protocol may still present a significant packet loss ratio in a wireless channel affected by errors. In order to define a MAC protocol more robust to bit error conditions and able to fulfill the required quality of service, solutions based on short size beacons and multiple retransmissions are proposed and tested. Results show that such strategies lead to meaningful improvements regarding packet loss ratio, without compromising significantly the energy consumption.