Low-Latency Communications in LTE Using Spatial Diversity and Encoding Redundancy
20 March 2017
Control of data delivery latency in wireless mobile networks is an open problem due to the inherently unreliable and stochastic nature of wireless channels. This paper explores how the current best-effort throughput-oriented wireless services could be evolved into latency-sensitive enablers of new mobile applications such as remote 3D graphical rendering for interactive virtual/augmented-reality overlay. Assuming that the signal propagation delay and achievable throughput meet the basic latency requirements of the user application, we examine the idea of trading excess/federated bandwidth for the elimination of non-negligible data re-ordering delays, caused by temporal transmission failures and buffer overflows. The general system design is based on (i) spatially diverse data delivery over multiple paths with uncorrelated outage likelihoods, and (ii) packet-level forward error correction, creating encoding redundancy for proactive recovery of intolerably delayed data without end-to-end re-transmissions. Performance evaluation and analysis is based on traces of real-life traffic in live carrier-grade LTE networks.
