Home of RF and Wireless Vendors and Resources

One Stop For Your RF and Wireless Need

UE WCDMA/UMTS Timers


This tutorial section on UMTS basics covers following sub topics:
Main Page  Architecture  Stack  channel types  Bands  UARFCN  Frame  Timers 


This page covers timers used in 3G/WCDMA/UMTS compatible UE which include T300,T302,T304,T305,T307,T308,T309,T310,T311,T312,T313,T314,T315 and T316 timers.


WCDMA/UMTS Timer Function when Start/Stop/at expiry
T300 >>Starts at the transmission of RRC CONNECTION REQ
>>Stops at the receipt of RRC Connection setup
>> At expiry, re-transmits RRC CONNECTION REQ if V300<=N300, ELSE go to IDLE Mode
T302 >> Starts at the transmission of Cell Update or URA Update
>> Stops at the receipt of Cell Update Confirm or URA Update Confrim
>> At expiry, re-transmits Cell Update/URA Update if V302<= N302 Else goto IDLE Mode
T304 >> Starts at the transmission of UE Capability Info
>> Stops at the receipt of UE capability Information Confirm
>> At Expiry, re-transmits UE capability information if V304<=N304, Else initiate a Cell Update proc
T305 >> Starts upon entering CELL_FACH/URA_PCH/CELL_PCH state. OR upon receipt of CELL Update Confirm/URA Update Confirm
>> Stops upon entering another state
>> At expiry, transmits CELL Update if T307 is not activated and UE detects "In Service Area" Otherwise If T307 is not active, initiate starting of timer T307
T307 >>Starts when timer T305 has been expired and UE detects the " Out of Service Area"
>>Stops when UE detects "In Service Area"
>>At Expiry it transit to the IDLE MODE
T308 >> Starts at the transmission of RRC Connection Release Complete
>> Not Stopped
>> At Expiry,transmits RRC connection Release Complete IF V308<=N308 ELSE GOTO IDLE MODE
T309 >>Starts upon receipt of Cell Change Order from UTRAN message
>> Stops upon successful response to a CONNECTION ESTABLISHMENT REQUEST in a new CELL
>> At Expiry, resumes the Connection to UTRAN network
T310 >> Starts upon transmission of PUSCH Capacity Request message
>> Stops upon receipt of Physical Shared Channel Allocation
>> At expiry transmits PUSCH Capacity Request if V310 <= N310 ELSE stops the procedure
T311 >> Starts upon reception of Physical Shared Channel Allocation ( When "PUSCH ALLOCATION" set to "PUSCH ALLOCATION pending")
>> Stops upon receipt of Physical Shared Channel Allocation ( When "PUSCH allocation" set to "PUSCH allocation assignment")
>> At Expiry, UE initiate a PUSCH CAPACITY REQUEST procedure
T312 >>Starts When UE starts to establish dedicated channel mode
>>Stops When UE detects N312 "in sync" indication from Layer-1(PHY)
>>Timer expires when criteria for physical channel establishment failure is fulfilled
T313 >>Timer Starts when UE detects consecutive N313 "out of sync" indication from Layer-1(PHY)
>> Stops when UE detects consecutive N315 "in sync" indication from Layer-1(PHY)
>> Timer expires when the criteria for Radio Link failure is fulfilled
T314 >>Starts after the criteria for radio link failure have been fulfilled, and if radio bearers associated with T314 exists.
>>Stops when the cell update procedure completes
>>REFER 8.3.1.13 in 3GPP TS 25.331 Specification
T315 >>Starts after the criteria for radio link failure have been fulfilled, and if radio bearers associated with T315 exists.
>> Stops when the cell update procedure completes
>> REFER 8.3.1.14 in 3GPP TS 25.331 Specification
T316 >>Starts when UE detects "out of service area" in the URA_PCH or CELL_PCH state
>>Stops when UE detects "in service area"
>>At expiry,initiates cell update procedure if "in service area" is detected, OTHERWISE starts timer T317,
transit to CELL_FACH state and initiate cell update procedure when the UE detects "in service area"
T317 >> Starts when timer T316 expires OR when in CELL_FACH state, UE detects "out of service area"
>> Stops when UE detects "in service area"
>> At Expiry, transits to IDLE MODE

V300,V302,V304,V308 abd V310 are counters used in UE.
N300,N302,N304,N308,N310,N312,N313 and N315 are constants used in UE.
For information refer 3GPP TS 25.331 Specification .

Useful WCDMA/UMTS Links

• UMTS TUTORIAL
• CDMA Tutorial
• TD-SCDMA Tutorial
• UMTS Frequency bands and UARFCN
• UMTS Multiple Access types
• UMTS Frame structure
• UMTS Network Architecture
• UMTS Protocol Stack
• UMTS Logical, Transport and physical channels
• UMTS Spreading,scrambling and modulation

RF and Wireless Terminologies


Share this page

Translate this page