摘要：Machine-to-machine (M2M) communication is considered as one of the key enablers for providing of advanced services and applications. Since M2M features a massive number of user equipment (UE) pieces, one of the key issues is the radio access network (RAN) overload problem for massive connections in M2M communications. In order to improve the number of successful accesses (i.e., the M2M UE pieces that successfully transmit data packets) for M2M communications in the current long term evolution (LTE) systems, we propose a new hybrid protocol for random access (RA) and data transmission based on two-phase access class barring (ACB) mechanisms. Furthermore, the joint optimization algorithm of the two-phase ACB factors and the number of resource blocks (RBs) allocated for RA and data transmission is designed to maximize the number of successful accesses. Finally, simulation results demonstrate that our scheme can significantly improve the number of successful accesses and achieve performance improvement in reducing the grant time.
