Pool resource management based on early collision detection in random access of massive MTC over LTE

Abstract

Collision in Random Access (RA) procedure of Long-Term Evolution (LTE) networks is the main problem in supporting massive Machine-Type Communications (MTC). Current solutions for resolving MTC Devices (MTCDs) collisions in the LTE incur additional overhead to existing MTCDs which may not be efficient for cost-effective MTCDs. Also, the lack of proper Physical Resource Blocks (PRBs) management scheme may waste a large number of PRBs and leads to poor RA performance upon massive access of MTCDs. To this end, a simple PRBs management scheme based on the early preamble collision detection is proposed in this paper to improve the RA throughput of massive MTC. By exploiting the pool of RA resources and upon collision detection, a proper number of PRBs is granted to each collided preamble by estimating the number of collided MTCDs. To sustain the number of consumed PRBs around a certain threshold, the number of contending MTCDs is regulated using an appropriate Access Class Barring (ACB) factor. Simulation results show that the RA throughput and average RA delay can be improved using the proposed solution compared to the previous schemes; while the expected number of consumed PRBs in each RA procedure is sustained below a certain threshold.