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