Latency
The time delay between the transmission and reception of data across a network, typically measured in milliseconds. 5G targets sub-1 ms user-plane latency for URLLC.
Latency is delay, and in a mobile network it is the sum of several pieces: time on the air interface, processing in the gNB and core, transport between sites, and the round trip out to wherever the application server lives. People obsess over the radio number, but for a real user the server distance often dominates — which is the whole argument for edge computing.
The headline "sub-1 ms" figure for 5G is a URLLC target for the user-plane radio segment under ideal conditions, not the end-to-end latency you measure pinging a website. Getting there relies on shorter transmission slots (mini-slots), a flatter core, and tight scheduling. For everyday eMBB traffic, single-digit-to-low-tens of milliseconds is more typical, and one-way versus round-trip is a distinction worth nailing down before quoting any number.
Frequently asked questions
- Does 5G actually deliver 1 ms latency in real life?
- Rarely for end-to-end traffic. The 1 ms figure is the URLLC target for the radio user-plane under controlled conditions. What you measure to an internet server includes transport and the distance to that server, which usually pushes real round trips into the tens of milliseconds. The sub-millisecond promise mostly shows up in tightly engineered private or edge deployments.
- What's the difference between latency and jitter?
- Latency is the average delay; jitter is how much that delay varies from packet to packet. A link can have low average latency but high jitter, which wrecks real-time media even when the average looks fine. Voice, gaming, and control loops generally care about bounded jitter as much as low latency.
Related terms
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