Capacity Optimization of Spatial Preemptive Scheduling for Joint URLLC-eMBB Traffic in 5G New Radio

Abstract

Ultra-reliable and low-latency communication (URLLC) is envisioned as a primary service class of the fifth generation mobile networks. URLLC applications demand stringent radio latency requirements of 1 millisecond with 99.999% confidence. Obviously, the coexistence of the URLLC services and enhanced mobile broadband (eMBB) applications on the same spectrum imposes a challenging scheduling problem. In this paper, we propose an enhanced spatial preemptive scheduling framework for URLLC-eMBB traffic coexistence. The proposed scheduler ensures an instant and interference-free signal subspace for critical URLLC transmissions, while achieving best-effort eMBB performance. Furthermore, the impacted eMBB capacity is then recovered by limited network-assisted signaling. The performance of the proposed scheduler is evaluateeed by highly detailed system level simulations of the major performance indicators. Compared to the state-of-the-art multi-traffic schedulers from industry and academia, the proposed scheduler meets the stringent URLLC latency requirements, while significantly improving the achievable ergodic capacity.

A new 5G radio evolution towards 5G-Advanced

“…However, FDM has low efficiency and preemption impairs eMBB performance. Thus, URLLC preempts eMBB via spatial opportunity, i.e., projecting eMBB to the orthogonal subspace to ensure URLLC performance [85][86][87][88].…”

A Service-Aware Latency-Relaxed uRLLC Multiplexing Strategy within eMBB Traffic for Hyperloop Communications

“…where α and β are two parameters used to tune the weights of throughput and power consumption with a constraint of (12). Note that constraints (6), (7), and (9) should also be satisfied.…”

“…In terms of scheduling PRBs, the uRLLC traffic punctures those eMBB users' PRBs in the next mini-slot to satisfy the stringent latency requirements. Currently, extensive works have been conducted in this field, typical works like [8][9][10][11][12][13][14]. In [10], Yin et al proposed a new downlink scheduler for uRLLC multiplexing and aimed to maximize eMBB utility while guaranteeing uRLLC constraints.…”

“…The drawback of this method is the time-consuming iteration when searching for the solution. In [12], Esswie and Pedersen proposed an enhanced spatial preemptive scheduler for the joint transmission of uRLLC and eMBB traffics, and it aims to provide the sporadic uRLLC traffic with an interference-free subspace for immediate and secured transmission without queuing. In [13], Alsenwi et al formulated an optimization problem aiming to maximize the eMBB throughput while subject to a uRLLC reliability constraint.…”

Performance Analysis of One-Way Highway Vehicular Networks With Dynamic Multiplexing of eMBB and URLLC Traffics

“…In [19], Esswie et al proposed a novel null-spacebased preemptive scheduling strategy to grant the URLLC traffic with a higher priority while achieve the best possible eMBB data rate. Further, in [20], an enhanced nullspace-based preemptive scheduling strategy was developed with a significantly improved ergodic capacity. In [21], Tang et al considered the incorporations of multiple eMBB and URLLCslices in C-RAN for the maximization of the operator's revenue.…”