timer 314

Dear 3G Experts,can any one tell me what is the difference between T314 and T315 in 3G?

hari_22082011-02-10, 01:44 AM

T314 & T315 are guard timers during which the UE keeps the RABs following radio link failure until they expire or the cell update procedure has been completed. During this time, the RNC can try to re-establish the UE so that the user traffic can resume. When T314 and / or T315 expire, the UE releases the associated RABs.

From specs....

t302: Starts at the transmission of CELL/URA UPDATE, and stops at thereception of CELL/URA UPDATE CONFIRM.

T314 expiryUpon expiry of timer T314 the UE shall:1> if timer T302 is running:2> continue awaiting response message from UTRAN.1> if timer T302 is not running and timer T315 is running:2> set IE "T314 expired" in variable RB_TIMER_INDICATOR to TRUE;2> release locally all radio bearers which are associated with any radio access bearers for which in the variableESTABLISHED_RABS the value of the IE "Re-establishment timer" is set to "useT314";2> indicate release of those radio access bearers to upper layers;2> delete all information about those radio access bearers from the variable ESTABLISHED_RABS;2> if all radio access bearers associated with a CN domain are released:3> release the signalling connection for that CN domain;3> remove the signalling connection for that CN domain from the variableESTABLISHED_SIGNALLING_CONNECTIONS;3> indicate release (abort) of the signalling connection to upper layers.1> if timers T302 and T315 are not running:2> clear the variable RB_UPLINK_CIPHERING_ACTIVATION_TIME_INFO;2> clear the variable INTEGRITY_PROTECTION_ACTIVATION_INFO;2> clear the variable PDCP_SN_INFO;2> clear the entry for the CELL UPDATE CONFIRM message in the table "Rejected transactions" in thevariable TRANSACTIONS;2> release all its radio resources;2> indicate release (abort) of the established signalling connections (as stored in the variableESTABLISHED_SIGNALLING_CONNECTIONS) and established radio access bearers (as stored in thevariable ESTABLISHED_RABS) to upper layers;2> clear the variable ESTABLISHED_SIGNALLING_CONNECTIONS;2> clear the variable ESTABLISHED_RABS;2> set the variable CELL_UPDATE_STARTED to FALSE;2> enter idle mode;2> other actions the UE shall perform when entering idle mode from connected mode are specified in subclause8.5.2;2> and the procedure ends.

T315 expiryUpon expiry of timer T315 the UE shall:1> if timer T302 is running:2> continue awaiting response message from UTRAN.1> if timer T302 is not running and timer T314 is running:2> set IE "T315 expired" in variable RB_TIMER_INDICATOR to TRUE;2> release locally all radio bearers which are associated with any radio access bearers for which in the variableESTABLISHED_RABS the value of the IE "Re-establishment timer" is set to "use T315";2> indicate release of those radio access bearers to upper layers;2> delete all information about those radio access bearers from the variable ESTABLISHED_RABS;2> if all radio access bearers associated with a CN domain are released:3> release the signalling connection for that CN domain;

3> remove the signalling connection for that CN domain from the variableESTABLISHED_SIGNALLING_CONNECTIONS;3> indicate release (abort) of the signalling connection to upper layers.1> if timers T302 and T314 are not running:2> clear the variable RB_UPLINK_CIPHERING_ACTIVATION_TIME_INFO;2> clear the variable INTEGRITY_PROTECTION_ACTIVATION_INFO;2> clear the variable PDCP_SN_INFO;2> clear the entry for the CELL UPDATE CONFIRM message in the table "Rejected transactions" in thevariable TRANSACTIONS;2> release all its radio resources;2> indicate release (abort) of the established signalling connections (as stored in the variableESTABLISHED_SIGNALLING_CONNECTIONS) and established radio access bearers (as stored in thevariable ESTABLISHED_RABS) to upper layers;2> clear the variable ESTABLISHED_SIGNALLING_CONNECTIONS;2> clear the variable ESTABLISHED_RABS;2> set the variable CELL_UPDATE_STARTED to FALSE;2> enter idle mode;2> other actions the UE shall perform when entering idle mode from connected mode are specified in subclause8.5.2;2> and the procedure ends.

zhanglw2682011-02-10, 09:22 AM

T314 is used for CS radio link failure, T315 is used for PS radio link failure.

idxtor2012-02-07, 07:15 PM

here is quote from the following document:[Only registered and activated users can see links]

In 3G a new mechanism is available to rescue some dropped calls (both CS and PS) due to RL Failure: Call Reestablishment by Cell Update procedure. Refer to ANNEX I (file:///C:/Documents%20and%20Settings/iivanov/%D0%9C%D0%BE%D0%B8%20%D0%B4%D0%BE%D0%BA%D1%83%D0%BC%D0%B5%D0%BD%D1%82%D1%8B/Downloads/79118694-Optimization-Guidelines-Retain-Ability-NSN-Draft1.doc#_5BANNEX_I:_Call) for further details.

If timer T314 is set higher than 0, Voice calls that suffer from a RL Failure are not considered “dropped” till timer T314 expires and the call could not be reestablished by the Cell Update Procedure.

Similarly, if timer T315 is set higher than 0, PS calls that suffer from a RL Failure are not considered “dropped” till timer T315 expires and the call could not be reestablished by the Cell Update Procedure.

We could say that in both cases, CS and PS, those RL Failures that can be rescued are just system-perceived drops, but not user-perceived drops, as the user does not have to perform any additional manual operations like for example manual re-activation of the PDP context. In reality, during the Cell Update procedure (T314 or T315 seconds), Voice calls will be perceived as “silent” by the user, and PS data sessions may suffer from delays and lower throughputs, but the fact is that the call does not drop, and it is not counted by the RAB releases counters (and therefore, neither as a drop).

In NSN infrastructure, T314=0 is hardcoded, and T315=30 sec (changeable), i.e., this Cell Update mechanism is only available for PS data calls (not for Voice calls).

In terms of Voice Calls, this means that all RL Failures in DL will finally lead to a drop (user and system perceived, and RAB release counters –and drops- increased).In terms of PS Calls, those RL Failures that are rescued will be system but not user-perceived, and the abnormal RAB release counter (=drops) will not be increased.

As some other vendors may have the Cell Update mechanism de-activated for PS, the optimization team should keep in mind these considerations when comparing PS DCR (%) in different vendors: usually worst in those ones with this functionality disabled. Nevertheless, this worst behavior in the KPI usually does not match the user perception (that is typically good) thanks to additional implicit re-establishment mechanisms (Paging/Service Request).

phuvuong_uk

2012-02-09, 02:07 AMCan we set it with NodeB level?

[email protected], 06:35 AM

Dear 3G Experts,can any one tell me what is the difference between T314 and T315 in 3G?

Dear,

These are the UE Timers used during the Cell Update

T314: RRC Connection Re-Establishment Timer used for CS-RAB services.UE starts this timer where there is RL failure and exists till the UE completes the cell update procedure. Once this timer expired then it releases the CS-RAB.

T315: RRC Connection Re-Establishment Timer used for PS-RAB services.UE starts this timer where there is RL failure and exists till the UE completes the cell update procedure. Once this timer expired then it releases the PS-RAB.

Br..Pawan

nkboy92012-02-21, 03:03 AM

t314 for cs domain (or CS RAB)t315 for ps domain (ps rab)

UE Protocol timers, counters, other parameters and default configurationsPosted by: Caterpillar on: September 8, 2010

In: RRC

Leave a Comment

Timers for UETimer Start Stop At expiry

T300 Transmission of RRC CONNECTION REQUEST

Reception of RRC CONNECTION SETUP

Retransmit RRC CONNECTION REQUEST if V300 =< N300, else go to Idle mode

T302 Transmission of CELL UPDATE/URA UPDATE

Reception of CELL UPDATE CONFIRM/URA UPDATE CONFIRM

Retransmit CELL UPDATE/URA UPDATE if V302 =< N302, else, go to Idle mode

T304 Transmission of UE CAPABILITY

Reception of UE CAPABILITY INFORMATION

Retransmit UE CAPABILITY INFORMATION if

Timer Start Stop At expiry

INFORMATION CONFIRM V304 =< N304, else initiate a cell update procedure

T305 Entering CELL_FACH or URA_PCH or CELL_PCH state. Reception of CELL UDPATE CONFIRM/URA UPDATE CONFIRM.

Entering another state. Transmit CELL UPDATE if T307 is not activated and the UE detects “in service area”. Otherwise, if T307 is not active, start T307.

T307 When the timer T305 has expired and the UE detects “out of service area”.

When the UE detects “in service area”.

Transit to idle mode

T308 Transmission of RRC CONNECTION RELEASE COMPLETE

Not stopped Transmit RRC CONNECTION RELEASE COMPLETE if V308 <=N308, else go to idle mode.

T309 Upon reception of CELL CHANGE ORDER FROM UTRAN message

Successful response to a connection establishment request in the new cell.

Resume the connection to UTRAN

T310 Transmission of PUSCH CAPACITY REQUEST

Reception of PHYSICAL SHARED CHANNEL ALLOCATION

Transmit PUSCH CAPACITY REQUEST if V310 =< N310, else procedure stops.

T311 Reception of PHYSICAL SHARED CHANNEL ALLOCATION message with the CHOICE “PUSCH allocation” set to “PUSCH allocation

Reception of PHYSICAL SHARED CHANNEL ALLOCATION message with CHOICE “PUSCH allocation” set to “PUSCH allocation assignment”.

UE may initiate a PUSCH capacity request procedure.


pending”.T312 When the UE

starts to establish dedicated CH

When the UE detects N312 “in sync” indication from L1.

The criteria for physical channel establishment failure is fulfilled

T313 When the UE detects consecutive N313 “out of sync” indication from L1.

When the UE detects consecutive N315 “in sync” indication from L1.

The criteria for Radio Link failure is fulfilled

T314 When the criteria for radio link failure are fulfilled.The timer is started if radio bearer(s) that are associated with T314 exist of if only RRC connection exists.

When the Cell Update procedure has been completed.

See subclause 8.3.1.13

T315 When the criteria for radio link failure are fulfilled.The timer is started only if radio bearer(s) that are associated with T315 exist.

When the Cell Update procedure has been completed.

See subclause 8.3.1.14

T316 When the UE detects “out of service area” in URA_PCH or CELL_PCH state


Initiate cell update procedure if in service area is detected. Otherwise start timer T317, transit to CELL_FACH state and initiate cell update procedure when the UE detects “in service area”.

T317 When the T316 expires or when in CELL_FACH state, the UE


Transit to idle mode


detects “out of service area”.

Counters for UECounter Reset Incremented When reaching max

valueV300 When initiating

the procedure RRC connection establishment

Upon expiry of T300. When V300 > N300, the UE enters idle mode.

V302 When initiating the procedure Cell update or URA update

Upon expiry of T302 When V302 > N302 the UE enters idle mode.

V304 When sending the first UE CAPABILITY INFORMATION message.

Upon expiry of T304 When V304 > N304 the UE initiates the Cell update procedure

V308 When sending the first RRC CONNECTION RELEASE COMPLETE message in a RRC connection release procedure.

Upon expiry of T308 When V308 > N308 the UE stops re-transmitting the RRC CONNECTION RELEASE COMPLETE message.

V310 When sending the first PUSCH CAPACITY REQUEST message in a PUSCH capacity request procedure

Upon expiry of T310 When V310 > N310 the UE stops re-transmitting the PUSCH CAPACITY REQUEST message.

UE constants and parametersConstant UsageN300 Maximum number of retransmissions of the RRC

CONNECTION REQUEST messageN302 Maximum number of retransmissions of the CELL

UPDATE / URA UPDATE messageN304 Maximum number of retransmissions of the UE

CAPABILITY INFORMATION messageN308 Maximum number of retransmissions of the RRC

Constant UsageCONNECTION RELEASE COMPLETE message

N310 Maximum number of retransmission of the PUSCH CAPACITY REQUEST message

N312 Maximum number of “in sync” received from L1.N313 Maximum number of successive “out of sync” received

from L1.N315 Maximum number of successive “in sync” received from

L1 during T313 is activated.An apparatus and a method are provided for improving user experience in a multi-radio access bearer (multi-RAB) wireless communication system. After a user equipment establishes a circuit-switched communication link and a packet-switched communication link with a core network, it may receive an indication of an error associated with the packet-switched communication link. Here, if the value of a timer such as the RAB re-establishment timer T314 has a predetermined value (e.g., 0), the user equipment may release the packet-switched communication link, and maintain the circuit-switched communication link. The packet-switched communication link may then be re-established. In this fashion, errors that may occur on the data call need not interrupt a voice call.

1. A method of wireless communication operable at a user equipment, comprising: establishing a circuit-switched

communication link with a core network; establishing a packet-switched communication link with the core network;

and receiving an indication of an error associated with the packet-switched communication link, wherein, if a value of

a timer corresponds to a predetermined value, the method further comprises: releasing the packet-switched

communication link; and maintaining the circuit-switched communication link when the packet-switched

communication link is released.

2. The method of claim 1, wherein the releasing of the packet-switched communication link comprises utilizing a

signaling connection release indication procedure.

3. The method of claim 1, further comprising: re-establishing the packet-switched communication link while

maintaining the circuit-switched connection.

4. The method of claim 1, wherein the timer is a timer associated with the circuit-switched communication link.

5. The method of claim 4, wherein the timer is a radio access bearer (RAB) re-establishment timer T314.

6. The method of claim 5, wherein the predetermined value is 0.

7. The method of claim 4, wherein the timer is a radio access bearer (RAB) re-establishment timer T315.

8. The method of claim 7, wherein the predetermined value is 0.

9. The method of claim 1, further comprising comparing the value of the timer with the predetermined value upon the

receiving of the indication of the error associated with the packet-switched communication link.

10. The method of claim 4, further comprising: selecting as the timer a radio access bearer (RAB) re-establishment

timer T314 if the RAB re-establishment timer T314 is configured for the circuit-switched communication link; and

selecting as the timer a RAB re-establishment timer T315 if the RAB re-establishment timer T315 is configured for the

circuit-switched communication link.

11. A user equipment configured for wireless communication, comprising: means for establishing a circuit-switched

communication link with a core network; means for establishing a packet-switched communication link with the core

network; means for receiving an indication of an error associated with the packet-switched communication link; and

means for, if a value of a timer corresponds to a predetermined value, releasing the packet-switched communication

link, and maintaining the circuit-switched communication link when the packet-switched communication link is

released.

12. The user equipment of claim 11, wherein the means for releasing the packet-switched communication link is

configured to utilize a signaling connection release indication procedure.

13. The user equipment of claim 11, further comprising: means for re-establishing the packet-switched

communication link while maintaining the circuit-switched connection.

14. The user equipment of claim 11, wherein the timer is a timer associated with the circuit-switched communication

link.

15. The user equipment of claim 12, wherein the timer is a radio access bearer (RAB) re-establishment timer T314.

16. The user equipment of claim 15, wherein the predetermined value is 0.



19. The user equipment of claim 11, further comprising means for comparing the value of the timer with the

predetermined value upon the receiving of the indication of the error associated with the packet-switched

communication link.

20. The user equipment of claim 14, further comprising: means for selecting as the timer a radio access bearer (RAB)

re-establishment timer T314 if the RAB re-establishment timer T314 is configured for the circuit-switched

communication link; and means for selecting as the timer a RAB re-establishment timer T315 if the RAB re-

establishment timer T315 is configured for the circuit-switched communication link.

21. A user equipment configured for wireless communication, comprising: at least one processor; a communication

interface coupled to the at least one processor; and a memory coupled to the at least one processor, wherein the at

least one processor is configured to: establish a circuit-switched communication link with a core network; establish a

packet-switched communication link with the core network; and receive an indication of an error associated with the

packet-switched communication link, wherein, if a value of a timer corresponds to a predetermined value, the at least

one processor is further configured to: release the packet-switched communication link; and maintain the circuit-

switched communication link when the packet-switched communication link is released.

22. The user equipment of claim 21, wherein the releasing of the packet-switched communication link comprises

utilizing a signaling connection release indication procedure.

23. The user equipment of claim 21, wherein the at least one processor is further configured to: re-establish the

packet-switched communication link while maintaining the circuit-switched connection.

24. The user equipment of claim 21, wherein the timer is a timer associated with the circuit-switched communication

link.





29. The user equipment of claim 21, further comprising comparing the value of the timer with the predetermined value

upon the receiving of the indication of the error associated with the packet-switched communication link.

30. The user equipment of claim 24, wherein the at least one processor is further configured to: select as the timer a

radio access bearer (RAB) re-establishment timer T314 if the RAB re-establishment timer T314 is configured for the

circuit-switched communication link; and select as the timer a RAB re-establishment timer T315 if the RAB re-

establishment timer T315 is configured for the circuit-switched communication link.

31. A computer program product operable at a user equipment, comprising: a computer-readable storage medium

comprising: instructions for causing a computer to establish a circuit-switched communication link with a core

network; instructions for causing a computer to establish a packet-switched communication link with the core network;

instructions for causing a computer to receive an indication of an error associated with the packet-switched

communication link; and instructions for causing a computer, if a value of a timer corresponds to a predetermined

value, to release the packet-switched communication link, and to maintain the circuit-switched communication link

when the packet-switched communication link is released.

32. The computer program product of claim 31, wherein the instructions for causing a computer to release of the

packet-switched communication link are configured to utilize a signaling connection release indication procedure.

33. The computer program product of claim 31, wherein the computer-readable storage medium further comprises

instructions for causing a computer to re-establish the packet-switched communication link while maintaining the

circuit-switched connection.

34. The computer program product of claim 31, wherein the timer is a timer associated with the circuit-switched

communication link.

35. The computer program product of claim 34, wherein the timer is a radio access bearer (RAB) re-establishment

timer T314.

36. The computer program product of claim 35, wherein the predetermined value is 0.

37. The computer program product of claim 34, wherein the timer is a radio access bearer (RAB) re-establishment

timer T315.

38. The computer program product of claim 37, wherein the predetermined value is 0.

39. The computer program product of claim 31, wherein the computer-readable storage medium further comprises

instructions for causing a computer to compare the value of the timer with the predetermined value upon the receiving

of the indication of the error associated with the packet-switched communication link.

40. The computer program product of claim 34, wherein the computer-readable storage medium further comprises:

instructions for causing a computer to select as the timer a radio access bearer (RAB) re-establishment timer T314 if

the RAB re-establishment timer T314 is configured for the circuit-switched communication link; and instructions for

causing a computer to select as the timer a RAB re-establishment timer T315 if the RAB re-establishment timer T315

is configured for the circuit-switched communication link.

Description:CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of provisional patent application No. 61/506,329, entitled “SYSTEMS

AND METHODS FOR MAINTAINING A COMMUNICATION LINK”, filed in the United States Patent and Trademark

Office on Jul. 11, 2011, the entire content of which is incorporated herein by reference.

TECHNICAL FIELD

Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to

signaling messages in a multi-RAB wireless communication system capable of a concurrent circuit-switched voice

communication link and packet-switched data communication link.

BACKGROUND

Wireless communication networks are widely deployed to provide various communication services such as telephony,

video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support

communications for multiple users by sharing the available network resources. One example of such a network is the

UMTS Terrestrial Radio Access Network (UTRAN). The UTRAN is the radio access network (RAN) defined as a part

of the Universal Mobile Telecommunications System (UMTS), a third generation (3G) mobile phone technology

supported by the 3rd Generation Partnership Project (3GPP). UMTS, which is the successor to Global System for

Mobile Communications (GSM) technologies, currently supports various air interface standards, such as Wideband-

Code Division Multiple Access (W-CDMA), Time Division-Code Division Multiple Access (TD-CDMA), and Time

Division-Synchronous Code Division Multiple Access (TD-SCDMA). UMTS also supports enhanced 3G data

communications protocols, such as High Speed Packet Access (HSPA), which provides higher data transfer speeds

and capacity to associated UMTS networks.

In a multi-radio access bearer (multi-RAB) system, a mobile user equipment may be capable of maintaining

concurrent communication links over a circuit-switched protocol and a packet-switched protocol. As the demand for

mobile broadband access continues to increase, research and development continue to advance the UMTS

technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the

user experience with mobile communications. In particular, as advancements in communication technology continue

to improve capabilities and data rates for packet-switched data calls, there is a desire to at least maintain, if not

improve, the quality of circuit-switched voice calls.