Roundtrip Interaction Delay Analysis of Immersive Communications: A Stochastic Network Calculus Perspective

Terahertz (THz) massive multiple-input multiple-output (MIMO) has recently been expected to address the challenges of extremely high data rates, high reliability and low latency for many future use cases such as immersive communications. This paper investigates the upper bound of the roundtrip interaction delay violation probability (UB-RIDVP) for immersive communications in a THz massive MIMO based communication system through stochastic network calculus (SNC). Specifically, the system design adopts the split rendering introduced in 3GPP TR 26.928, based on which not only the uplink and downlink queuing delays, but also the processing delays at the engine side and the user terminal (UT) side are included in the roundtrip interaction delay of the immersive communications. The traffic arrivals and wireless channels in the uplink and downlink are characterized by carrying out the SNC analysis. We derive the expression of the UB-RIDVP, and solve its parameters through the proposed Solving UB-RIDVP Algorithm. The numerical results show that the theoretical UB-RIDVP can reasonably estimate the trend of its violation probability. When a roundtrip interaction delay bound constraint is given as a performance metric, the proposed analytical approach can be utilized to guide the system design.