Prioritised Dynamic RACH (PD-RACH) Scheme for Delay-Critical MTC Communication

Machine-type communications (MTC) is considered as one of the promising technologies over the next decade and these MTC devices are continuously increasing. When a large number of MTC devices try to access a cellular base station simultaneously using the existing LTE/LTE-A Random Access Channel (RACH), the collision probability among Machine-to-Machine (M2M) and Human-to-Human (H2H) device increases drastically. Thus the performance of RACH degrades sharply which causes significant blocking and huge access delay. Delay-critical applications, cannot therefore be served using the legacy RACH protocol. The present work aims at solving this delay issue for a specific user group by proposing a Prioritised Dynamic Random Access scheme (PD-RACH) that improves the conventional RA procedure in order to minimize the delay and offer priority to the specific user group. Simulation results show that the proposed scheme can significantly reduce the access delay for the priority user group.