uRLLC – Ultra-reliable low-latency communications

What is uRLLC?

uRLLC is one of the three fundamental 5G use case categories defined by IMT-2020. It targets applications that simultaneously demand near-zero latency (user-plane target: 1 ms or less one-way) and extreme reliability (99.9999% — or ‘six nines’ — packet success rate). uRLLC represents a paradigm shift: for the first time, wireless networks can support mission-critical real-time control applications.

How Does uRLLC Work?

5G NR enables uRLLC through: mini-slots (as short as 1–2 OFDM symbols, ~0.125–0.25 ms transmission time), configured grants (no scheduling request delay), early HARQ feedback (reducing retransmission delay), frequency-domain resource pre-emption, MEC edge computing (UPF at base station reduces round-trip), network slicing with dedicated resources, and packet duplication over multiple paths for reliability.

Use Cases

Remote robotic surgery (telemedicine), real-time factory floor robot control and motion coordination, autonomous vehicle sensor data exchange (V2X), smart grid substation protection, public safety critical communications (MCPTT), tactile internet and haptic feedback.

3GPP / Standards Reference

3GPP TR 38.824 (uRLLC Study for NR), TS 22.261 (Service Requirements), Release 15 (basic) + Release 16 (enhanced)

Related Terms

eMBB  |  mMTC  |  Latency  |  Network Slicing  |  MEC  |  V2X  |  Private 5G

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