Two-Stage Resource Allocation for Random Access M2M Communications in LTE Network

Deployment of massive machine-to-machine (M2M) user equipments (UEs) in the current cellular network may cause overload in the radio access network (RAN). Access class barring (ACB) is an effective solution for reducing the RAN overload. In this letter, we propose an extended random access (RA) scheme to increase access success probability of M2M UEs by efficient use of available uplink radio resources. The proposed scheme allocates the available radio resources to the access-attempting UEs in two stages. In the first stage, the evolved node B (eNB) grants the available uplink resources to the UEs that have passed the ACB check. Then in the second stage, UEs that did not pass the ACB check utilize the remained unscheduled resources from the first stage. Simulation results show that the proposed scheme increases the number of successful requests and decreases the total service time of a traffic burst.