Comparative study of access class barring and extended access barring for machine type communications

In this paper, we present a discussion on the congestion control for machine type communications (MTC) in long term evolution (LTE). A huge number of devices and the bursty nature of their packet arrival pattern are two important features of MTC and pose a challenge to the random access procedure of LTE. Access barring which consists of two types, access class barring (ACB) and extended access barring (EAB), is considered to be the potential solution for this issue. In this paper, we first compare both the solutions in the viewpoint of the operating procedure and discuss their key parameters. For ACB, the optimal ACB factor that minimizes the time required for the random access procedure is derived and the approximate analysis of total service time is carried out. Then, through extensive computer simulations, we evaluate and compare the performances of ACB and EAB by considering bursty packet arrivals of the MTC devices.