Abstract
When the M2M devices communicate and share data with each other within a group or cluster without any direct human intervention, it is called inter-M2M communications. For this purpose, there is a critical need of an energy efficient scalable medium access control (MAC) protocol to facilitate a large number of M2M devices to access the channel. To accomplish this task, contention or reservation-based MAC protocols can be used, but with numerous M2M devices, adaptability, scalability, and energy efficiency become bottlenecks. Therefore, in this paper, we propose a novel hybrid-MAC protocol, which primarily consists of a contention interval (CI), and a data transmission interval (DTI). During CI, all the active M2M devices contend for the channel access. After contention, the successful devices win time-slots in DTI. The M2M devices are enabled with multiple beam antenna array MAC (MBAA-MAC) protocol, and share data with each other within each time-slot during DTI. Simulation results show considerable per time-slot throughput and energy consumption improvement as compared to IEEE 802.11 MAC protocol enabled M2M devices.