Some of the major challenges while developing a Wireless Body Area Network (WBAN) related to BCI (Brain Computer Interface) applications is to increase the network lifetime and minimize the power consumption. An energy efficient and transmission reliable Medium Access Control (MAC) protocol can be used to address the above problems by modifying certain control parameters. Past study reveals that there has been no accurate model detailing on the control parameters like delay, minimum energy and throughput for BCI applications. However, there is no mechanism available on the adoption and implementation details of these parameters on multiple transmitters implanted inside the brain. In this thesis, we provide the mechanism for implementing an enhanced MAC protocol for implantable passive UHF-RFID transmitters by modifying the super-frame structure. In-depth analysis of energy consumption of multiple implantable transmitters including the delay constraints and reliable transmission is showcased in this thesis work. Moreover, the performance analysis is provided based on the results obtained using OPNET simulator for CSMA/CA and TDMA based MAC protocols and results of FDMA using MATLAB simulator.