Convert Timing Advance (TA) values to UE distance from the base station for 4G LTE and 5G NR networks.
4G LTE Timing Advance
Distance (meters)
Distance (km)
Distance (miles)
Round-trip delay (μs)
5G NR Timing Advance
Distance (meters)
Distance (km)
Distance (miles)
NoteN_TA resolution: 0.076 m per unit (independent of SCS)
LTE TA step: 1 TA unit ≈ 78.12 m (max range at TA=1282: ~100 km) 5G NR N_TA step: 1 unit ≈ 0.076 m (max N_TA=3846 for 15 kHz → ~293 m)
Frequently Asked Questions
What is Timing Advance in LTE/5G?
Timing Advance is a mechanism used in LTE and 5G NR to synchronize uplink transmissions from the UE to arrive at the base station at the correct time. Since UEs at different distances have different propagation delays, the eNodeB/gNB instructs each UE to advance its uplink transmission timing to compensate.
How accurate is TA-based distance estimation?
LTE TA gives distance with ~78 m resolution (one TA step), making it useful for rough location estimation. 5G NR N_TA provides much finer resolution (~7.6 cm). However, TA-based ranging only gives the radial distance from the serving cell and cannot determine direction.
What is the maximum cell range detectable by TA?
In LTE, the maximum TA index is 1282, corresponding to approximately 100 km. This aligns with the LTE maximum cell range specification. In 5G NR, the maximum N_TA value is larger, supporting cells up to several hundred km for NTN (satellite) deployments.