Collision-Aware Resource Access Scheme for LTE-Based Machine-to-Machine Communications

Long-term evolution (LTE) network is considered as the most promising infrastructure to provide efficient connectivity for a large number of autonomous machine-type communications devices (MTCDs). In order to improve the random access (RA) throughput of massive access machine-to-machine (M2M) communications over LTE networks, we propose a collision-aware resource access (CARA) scheme to reduce the collisions on the granted physical resource blocks (PRBs). In CARA, the evolved Node B exploits early collision detection of preambles at the first message and informs the MTCDs in the corresponding random access response (RAR) message if it can detect the collision successfully. The collided MTCDs then contend for PRBs access using an appropriate probability for efficient use of granted PRBs. Analytical and numerical performance evaluations of the CARA show that the RA throughput can be improved in comparison with the traditional RA procedure.