Priority-Based Random Access control mechanism for M2M communications

When incorporating machine-to-machine (M2M) communications into the Long Term Evolution (LTE) networks, one of the difficult challenges is the Radio Access Network (RAN) overload for massive access attempts. Besides, M2M communications devices can support a broad range of applications with different access requirements. So when dealing with access overload problem, User Equipment (UE) priority should be taken into account. In this paper, we propose a Priority-Based Random Access (PBRA) control mechanism for M2M traffics in LTE. The mechanism can provide priority-based services for different classes of UE by employing preamble split technology and priority-based backoff method. Furthermore, the Access Class Barring (ACB) method is also used to avoid serious RAN overload. The performances obtained by simulations show that the access success probability is high and the mechanism yields satisfactory access delays for all priorities.