R-SIMPLE: Reliable Stable Increased-throughput Multi-hop Protocol for Link Efficiency in Wireless Body Area Networks

Wireless Body Area Network (WBAN) has gotten significant attention in the past few years due to the variety of applications that depend on it especially medical applications, and because of the limited energy of sensors, elongating network lifetime became a major target for WBANs. In this paper, a novel design to decrease energy consumption and prolonging network lifetime is submitted by adding smart sleep mode to SIMPLE protocol. We divided sensors types to critical sensors (CS) which relate to the patient's life and any delay in sending data may cause catastrophic consequences to the patient's life, and non-critical sensors (NCS) which can go to sleep according to a specified time table. We suggested a scheduled time report (STR) given by a patient supervisor doctor according to the patient case in order to send data depending on this STR and then go to sleep when no information needs to be transmitted. In our design, we also suggested checking the data by NCS, so if the data measured are above or under critical values specified by the supervisor doctor, the sensor will turn to wake up mode and still transmitting data till the data return to normal state, then it will turn the sensor to scheduled sleep mode (SSM) again. We also suggested the NCS send a receipt acknowledgment request (RAR) after sending data according to the STR in order to make sure the data reach to the sink node (SN) successfully; since missing data for any reason will be a real problem because the data are transmitted only once in each sleeping cycle and the next data will be transmitted after waking up that maybe after a long period of time depending on the STR. Furthermore, as part of the efforts to further improve the network lifetime and quality of service, we enhanced the cost function (CF) of SIMPLE protocol by adding performance factor to SIMPLE cost equitation in order to select the optimal path to transmit the data. The route with the lowest CF will be selected and the data will be transmitted through that route.