Frame-Level Integrated Transmission for Extended Reality over 5G and Beyond

Extended reality (XR) is one of the most important media applications enabled by 5G and beyond. Providing XR services over 5G networks is very challenging due to high requirements in terms of data rate, reliability, and latency. Different from eMBB and URLLC services, XR has a unique characteristic that each XR video frame can be segmented into several correlated packets. Any one of the packets loss would result in frame decoding error, and thus bad quality of experience. In this paper, we investigate such characteristic of frame-level integrity and propose a new concept called frame-level integrated transmission. Unlike conventional wireless communication with the goal of transmitting one packet successfully, the proposed frame-level integrated transmission takes “multiple packets belonging to one video frame” as an “entity”. Specifically, we formulate a resource allocation problem by considering the frame-level integrity to maximize the number of satisfied UEs under the data rate, reliability, and latency requirements for each UE. This problem is highly challenging due to the discontinuous and non-convex objective function and intractable reliability constraint. We propose to solve it approximately by jointly considering the user admission control and a frame-level integrated transmission problem to maximize the total number of frames that are successfully transmitted, which is efficiently solved via smooth function approximation and convex-concave procedure. Simulation results demonstrate the superiority of the proposed frame-level integrated transmission scheme, which can achieve much better performance than the conventional proportional fairness scheduler in terms of various performance metrics.