This paper proposes an improved random access (RA) procedure for machine to machine (M2M) communications. The proposed RA procedure makes evolved nodeB (eNB) detect if a preamble is selected by multiple user equipments (UEs) in the first step. To avoid false detection, an extended guard band is provided in PRACH. Based on the improved RA procedure, theoretical analysis on the probability of preamble collision and the number of successful access are addressed. In the simulation, the simulation of the probability of false detection with different number of bits of UE ID, the number of successful access and the impact of preamble collision are presented. Simulation results show that the new RA procedure outperforms traditional RA procedure on both probability of preamble collision and the number of successful access.
['Ningbo Zhang']
An improved random access procedure for M2M communications