An Improved LTE RACH Protocol for M2M Applications

Machine-to-machine (M2M) communications allow multiple devices to communicate directly without human intervention. There will be a huge number of devices in the M2M communications which results in enormous congestion in the current Random Access Channel (RACH) of LTE based cellular systems. This paper presents a protocol for improving the performance of the LTE RACH for M2M applications. This protocol, the Distributed Queuing Access for LTE (DQAL), is based on the Distributed Queuing (DQ) algorithm. One of the benefits of using that algorithm is minimizing the collision in the access phase for the M2M communications. The reduction in the collision will turn in enhancing both the access success probability and the access delay for M2M devices (MDs). Furthermore, the protocol is designed to guarantee that the normal User Equipment (UE) device can access the system using the traditional RACH procedures without any modification. This will assure a seamless implementation of the proposed protocol over the existing LTE cellular systems. The simulation results show how the access delay obtained by the proposed DQAL protocol outperforms the Extended Access Baring (EAB) which is the baseline solution recommended by the 3 GPP for M2M communication.