Uplink Contention Based Multiple Access for 5G Cellular IoT

This paper introduces novel UL access methods for 5G cellular IoT where devices can directly send a scheduler grant or a small data packet in the contention-based (CB) manner. The novelty of this work is in the combination of medium access control (MAC) contention access with physical layer optimization with new numerology applied to single carrier frequency division multiple access (SC-FDMA) waveforms to remove the need for pre-synchronization of devices on the uplink (UL). An analysis of the new procedures compared with the current LTE random access procedure is provided. The simulation results show that over 50% latency reduction and about 500% capacity increment can be achieved by contention based scheduling request (CB SR) compare to the LTE UL grant via random access. Further, it is shown that CB data is a viable method to transmit small data packets compare to LTE scheduling request via random access followed by scheduled data transmission.