URLLC

Ultra-Reliable Low-Latency Communications

Services

Introduced in Rel-15

5G service category for mission-critical applications requiring extreme reliability and low latency.

Description

Ultra-Reliable Low-Latency Communications (URLLC) is one of the three main 5G service categories, targeting applications requiring very high reliability (99.999%+) and very low latency (1 ms or less).

URLLC enables applications like factory automation, remote surgery, autonomous vehicles, and smart grid control. It requires innovations across the entire system from air interface to core network.

Purpose & Motivation

URLLC was introduced to:

- Enable mission-critical industrial applications - Support real-time control systems - Provide deterministic latency for automation - Enable new use cases like remote surgery

Key Features

  • 1 ms user plane latency target
  • 99.999% reliability
  • Mini-slot transmission
  • Grant-free (configured grant) UL
  • PDCP duplication
  • Preemption indicators

Evolution Across Releases

Rel-15Initial

Initial URLLC with mini-slot, grant-free transmission

Enhanced URLLC (eURLLC) with higher reliability, TSN integration

Further latency reduction, improved reliability

Defining Specifications

SpecificationTitle
NR Physical Channels and Modulation
NR Physical Layer Procedures for Data
5G System Architecture