5G NR Timers | T304, T310, T311 timer used in 5G NR
This page covers 5G NR timers which include T304 timer, T310 timer and T311 timer used in 5G NR (New Radio) for various functions. It mentions usage of constants N310 and N311.
| 5G NR Timers | Start | Stop | at Expiry |
|---|---|---|---|
| T304 | Reception of RRCReconfiguration message including reconfigurationWithSync | Successful completion of random access on the corresponding SpCell For T304 of SCG, upon SCG release | For T304 of SCG, inform network about the reconfiguration with sync failure by initiating the SCG failure information procedure as specified in 5.7.3 of TS 38.331 (3GPP). |
| T310 | Upon detecting physical layer problems for the SpCell i.e. upon receiving N310 consecutive out-of-sync indications from lower layers. | Upon receiving N311 consecutive in-sync indications from lower layers for the SpCell, upon receiving RRCReconfiguration with reconfigurationWithSync for that cell group, and upon initiating the connection re-establishment procedure. Upon SCG release, if the T310 is kept in SCG. | If the T310 is kept in MCG: If security is not activated: go to RRC_IDLE else: initiate the connection re-establishment procedure. If the T310 is kept in SCG, Inform E-UTRAN/NR about the SCG radio link failure by initiating the SCG failure information procedure as specified in 5.7.3. |
| T311 | Upon initiating the RRC connection re-establishment procedure | Selection of a suitable NR cell or a cell using another RAT. | Enter RRC_IDLE |
When the 5G NR UE applies zero value for the timer, the timer shall be started and immediately expire unless explicitly stated otherwise.
5G NR constants | N310, N311
Following table mentions usage of constants N310 and N311 in 5G NR system.
• N310: Maximum number of consecutive "out-of-sync" indications for the PCell received from lower layers.
• N311: Maximum number of consecutive "in-sync" indications for the PCell received from lower layers
GSM Timers | WCDMA Timers | LTE Timers
Following links are on useful GSM timers, WCDMA timers and LTE timers other than 5G timers mentioned on this page.
• GSM Timers
• WCDMA Timers
• GSM MS Timers
• GSM BTS Timers
• LTE Timers
5G NR Numerology | 5G NR Terminology
5G NR Control channels | 5G NR Traffic Channels | 5G NR Reference Signals and sequences
5G TECHNOLOGY RELATED LINKS
This 5G tutorial also covers following sub topics on the 5G technology:
5G basic tutorial
5G Frequency Bands
5G millimeter wave tutorial
5G mm wave frame
5G millimeter wave channel sounding
Difference between 4G and 5G
5G testing and test equipments
5G network architecture
5G NR Physical layer
5G NR MAC layer
5G NR RLC layer
5G NR PDCP layer