Ultra-Reliable Communication for Services with Heterogeneous Latency Requirements

Ultra-reliable communication (URC) is often studied with very strict and homogeneous latency requirements, commonly referred to as ultra-reliable low-latency communication (URLLC). However, in many scenarios the tolerated latencies may vary across users, and treating all users equally may lead to unnecessary over-provisioning of resources. In this paper, we study URC with orthogonal and non-orthogonal access in uplink scenarios where users have heterogeneous latency requirements. Users with strict latency requirements are given resources that are localized in time, while users with less strict latency are given resources that are spread across time and with intermediate feedback. We show that exploiting differences in the tolerated latency can lead to both a significant increase in reliability, and to more efficient use of resources.