Lookup
Parameters and timers
Plain-English meanings, typical value ranges and the spec to read for each mobility timer and parameter, across 4G, 5G, NTN and IoT.
Checked against the Rel-19 specifications named on each page. Older releases can differ, so confirm against the version you work with.
24 of 24 entries
| Name | Meaning | Values | Spec |
|---|---|---|---|
T304 Timer · UE | Started when reconfigurationWithSync is applied for the cell group. Expiry is a reconfiguration-with-sync failure.Procedure → | NR: 50, 100, 150, 200, 500, 1000, 2000, 10000 ms. LTE: 100, 200, 500, 1000, 2000, 4000, 8000, 10000 ms | TS 38.331 (5.3.5.8.3), TS 36.331 |
T310 Timer · UE | Radio link failure detection timer, started after N310 consecutive out-of-sync indications.Procedure → | NR: 0, 50, 100, 200, 500, 1000, 2000, 4000, 6000 ms | TS 38.331 (5.3.10) |
T311 Timer · UE | Supervises cell selection during RRC re-establishment (5.3.7.6 covers expiry).Procedure → | 1000, 3000, 5000, 10000, 15000, 20000, 30000 ms | TS 38.331 (5.3.7) |
T301 Timer · UE | Supervises the RRC re-establishment request (5.3.7.7 covers expiry).Procedure → | 100, 200, 300, 400, 600, 1000, 1500, 2000 ms | TS 38.331 (5.3.7) |
T300 Timer · UE | Supervises RRC connection establishment (5.3.3.7 covers expiry). | 100, 200, 300, 400, 600, 1000, 1500, 2000 ms | TS 38.331 (5.3.3) |
N310 / N311 Counter · UE | Consecutive out-of-sync (N310) and in-sync (N311) indications that drive T310.Procedure → | N310: n1, n2, n3, n4, n6, n8, n10, n20. N311: n1, n2, n3, n4, n5, n6, n8, n10 | TS 38.331 |
TimeToTrigger Threshold · UE (reportConfig) | Duration the event entering condition must be satisfied before the event is triggered.Procedure → | 0, 40, 64, 80, 100, 128, 160, 256, 320, 480, 512, 640, 1024, 1280, 2560, 5120 ms | TS 38.331 |
Hysteresis Threshold · UE (reportConfig) | Used in the entry and leave conditions of event-triggered reporting. The actual value is the field value times 0.5 dB.Procedure → | Integer 0 to 30 (0 to 15 dB) | TS 38.331 |
T380 Timer · UE | Periodic RNA update timer for a UE in RRC_INACTIVE, configured in suspendConfig.Procedure → | 5, 10, 20, 30, 60, 120, 360, 720 minutes | TS 38.331 (5.3.13.8) |
Srxlev / Squal Threshold · UE | S-criterion for cell selection: Srxlev > 0 and Squal > 0, using Qrxlevmin, Qqualmin, offsets and compensation.Procedure → | Computed by the UE from broadcast parameters | TS 38.304 (5.2.3.2) |
SIntraSearchP / SIntraSearchQ Threshold · Broadcast | If the serving cell satisfies Srxlev > SIntraSearchP and Squal > SIntraSearchQ, intra-frequency measurements follow the relaxed rule in TS 38.304.Procedure → | Broadcast in system information | TS 38.304 (5.2.4.2) |
Treselection Timer · Broadcast | Reselection timer. NR defines TreselectionNR and TreselectionEUTRA, with optional speed-dependent scaling factors.Procedure → | Broadcast in system information | TS 38.304 |
T3510 Timer · UE (5GMM) | 5GMM timer defined in TS 24.501 (see the timer table for its value and use).Procedure → | See TS 24.501 | TS 24.501 |
T3512 Timer · UE (5GMM) | Periodic registration update timer in 5GMM-REGISTERED.Procedure → | Default 54 min (TS 24.501) | TS 24.501 |
T3412 Timer · UE (EMM) | Periodic tracking area update timer. TS 24.301 also defines a T3412 extended value IE.Procedure → | Default 54 min (TS 24.301) | TS 24.301 |
T3430 Timer · UE (EMM) | EMM timer defined in TS 24.301 for the tracking area update request.Procedure → | 15 s | TS 24.301 |
T3324 IoT · UE (EMM) | Timer carried in a T3324 value IE (GPRS timer 2) in the Attach request, Attach accept and Tracking area update accept messages; used with PSM.Procedure → | GPRS timer 2 coding | TS 24.301, TS 23.682 |
eDRX cycle and PTW IoT · UE and network | Extended idle-mode DRX cycle and the Paging Time Window in which the UE monitors paging occasions.Procedure → | Wideband E-UTRAN: 5.12 s up to 2621.44 s. NB-IoT: 2 to 1024 hyper-frames (up to 10485.76 s) | TS 23.682, TS 36.304 |
cellSpecificKoffset NTN · Broadcast (SIB19) | Cell-specific scheduling offset in NTN-Config (cellSpecificKoffset-r17).Procedure → | Integer 1 to 1023 | TS 38.331 |
kmac NTN · Broadcast (SIB19) | NTN-Config field kmac-r17.Procedure → | Integer 1 to 512 | TS 38.331 |
ntn-UlSyncValidityDuration NTN · Broadcast (SIB19) | Duration for which the UE can rely on the NTN uplink synchronisation information. The UE starts T430 with this value from epochTime.Procedure → | 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 120, 180, 240, 900 s | TS 38.331 |
t-Service NTN · Broadcast (SIB19) | When a cell provided via NTN is going to stop serving the area it currently covers. Applies to service link switches in quasi-Earth-fixed cells and to feeder link switches.Procedure → | Integer 0 to 549755813887 | TS 38.331, TS 38.304 |
distanceThresh / referenceLocation NTN · Broadcast (SIB19; SIB31 for LTE IoT-NTN) | Location-based measurement initiation: UEs closer to the reference location than distanceThresh may skip measurements (TS 38.304). movingReferenceLocation is used for Earth-moving cells (Rel-18).Procedure → | distanceThresh: integer 0 to 65525 | TS 38.331, TS 38.304, TS 36.304 |
condEventD1 / condEventT1 / condEventD2 NTN · UE (condTriggerConfig) | Distance-based (D1, D2) and time-based (T1) conditional handover execution conditions.Procedure → | D1 and T1 are -r17; D2 is -r18 | TS 38.331 |