Dynamic RLC mode based upon link adaptation to reduce latency and improve throughput in cellular networks

Abstract

Latency is key in today cellular networks. The latest 3GPP Release 14 includes a future work item to shorten the Transmission Time Interval of LTE networks from 1ms to 0.5ms in order to lower the overall system latency. Towards achieving such goal, this paper proposes a mechanism to reduce the latency of mobile cellular systems, while improving the throughput, by leveraging the benefits of the two modalities of operation of the Radio Link Control (RLC) protocol, namely Unacknowledgment Mode (UM) and Acknowledgment Mode (AM). By analyzing and comparing the performance of RLC in UM and AM in the presence of difference network conditions, a novel mechanism is proposed which introduces an adaptive RLC mode which dynamically alternates between UM and AM according to the real-time analysis of radio conditions. The mechanism aims to improve system latency, reduce processing power and improve throughput by enabling UM, while, on the other hand, increase data reliability when radio conditions degrade by activating AM. This approach minimizes the system delay by reducing layer 2 overhead and complexity whilst maintaining data reliability.