Backoff based resource access for contend machine type communications in LTE networks

Considering the delay sensitive services in machine type communications (MTC), how to minimize the end-to-end delay is a great challenge to achieve the millisecond time delay requirement in the fifth generation (5G) communication systems. To utilize the radio resources efficiently, the radio resources of cellular networks are partitioned and utilized randomly for MTC devices, known as contention based access (CBA). To solve the delay caused by contention among MTC devices, a novel backoff based resource access (BBRA) scheme is proposed in this paper. In contrast to the existing random resource access schemes, contend MTC devices postpone by a random backoff window before transmission and access to radio resources according to the new transmission request order. Moreover, the backoff probability and expected time delay for a group of MTC devices are also analyzed. Results verify that a significant decrease of 50% on time delay has been achieved for 50 MTC devices by using proposed BBRA scheme in contrast to conventional schemes.