Ultra-Reliability Connectivity with Redundant D2D Transmission Scheme for Tactile Internet

The Tactile Internet, as a promising communication infrastructure, will be rapidly developed in the 5G era. It supports real-time human-to-machine interactions through delivery of touch and sensation information. The realization of Tactile Internet is associated with the demands of ultra-reliable and ultra-low latency connectivity, which is an important issue needing to be handled. Device-to-device (D2D) communication is a short-distance ultra-low latency transmission mode in 5G, which is capable of D2D edge nodes communicating with each other directly without an infrastructure of access point. In addition, D2D communication can reuse the licensed band resources under the management of the base station. Therefore, to meet the reliability and latency demands, D2D can be advocated as a significant component of the Tactile Internet. This paper focuses on a reliability design of D2D which can support ultra-high reliability and ultra-low latency connectivity in the Tactile Internet. Specifically, we firstly simulate the reliability of D2D communication as a birth and death process. Then, we propose a redundant D2D transmission scheme, which enhances D2D reliability under the conditions of latency and resources. Finally, we design a dynamic programming (DP) algorithm to solve the problem of redundant D2D link selection. Simulation results about the transmission reliability and latency show that our proposed scheme can have better performance than the competing schemes, which can satisfy connectivity requirements of the Tactile Internet.