Medium Access Control Protocols for Brain Computer Interface Applications

Overview Of Existing Mac Protocols

For BCI Applications, in order to increase the throughput, decrease the collisions between transmitter nodes, and decrease the end to end delay, many experiments and models have been investigated.

Hybrid technique has been explored to combine different existing MAC protocols. In our previous work we have designed many models such as TDMA+CSMA, TDMA+FDMA, FDMA+CSMA, and FDMA+TDMA+CSMA. The previous studies showed that the collision avoidance mechanism is not suitable for large scale networks, this state’s that CSMA is not efficient for large scale BCI applications. Also, the throughput is very low. TDMA has been investigated to overcome the CSMA issues due to the collisions of packet and large energy consumption during channel sensing, but we faced fixed time allocation issues caused by TDMA in the beacon message. To overcome TDMA and CSMA alone issues and decrease the lag time between different signals we have examined different hybrid MAC protocols. FDMA+TDMA+CSMA shows promising results for medium scale BCI applications. We have analyzed the network behavior using nine transmitters transmitting the data with Different frequencies at different time for three receivers. It is like following FDMA and TDMA in CSMA protocol. The transmitters are organized in cluster design as three clusters, each cluster uses different frequencies and time. Frequencies used here are 908MHz, 912MHz and 915MHz. Different time for each cluster and for each three nodes.

The results of all the scenarios in terms of traffic sent, traffic received, data dropped, and delay has been considered and we can say that, FDMATDMA+CSMA is good option for working in medium scale brain space.