8.5.5 Actions in "out of service area" and "in service area"

25.3313GPPProtocol specificationRadio Resource Control (RRC)Release 17TS

This subclause specifies the general actions the UE shall perform when it detects "out of service" or "in service" area. The specific UE behaviour when it detects "out of service" or "in service area" and periodical update has been configured by T305 in the IE "UE Timers and constants in connected mode" set to any other value than "infinity" is specified in subclause 8.3.1.

8.5.5.1 Detection of "out of service" area

The UE shall detect "out of service" area as defined in [19].

8.5.5.1.1 Actions following detection of "out of service" area in URA_PCH or CELL_PCH state

If the UE detects the "out of service area" and the UE is in URA_PCH or CELL_PCH state it shall perform the following actions:

1> start timer T316;

1> perform processes described in subclause 7.2.2.

8.5.5.1.2 Actions following detection of "out of service" area in CELL_FACH state

If the UE detects the "out of service area" and the UE is in CELL_FACH state it shall perform the following actions. The UE shall:

1> start timer T317 if not already running;

1> perform processes described in subclause 7.2.2.

8.5.5.1.3 Actions following detection of "out of service" area on transition from CELL_DCH to URA_PCH or CELL_PCH

If the UE detects the "out of service area" on transition from CELL_DCH to URA_PCH or CELL_PCH, it shall perform the following actions:

1> start timer T316;

1> start the timer T305 using its initial value if timer T305 is not running and periodical cell update has been configured by T305 in the IE "UE Timers and constants in connected mode" set to any other value than "infinity";

1> perform processes described in subclause 7.2.2.

8.5.5.1.4 Actions following detection of "out of service" area on transition from CELL_DCH to CELL_FACH

If the UE detects the "out of service area" on transition from CELL_DCH to CELL_FACH, it shall perform the following actions:

1> if the transition is triggered by a reconfiguration procedure:

2> start timer T317;

2> start the timer T305 using its initial value if timer T305 is not running and periodical cell update has been configured by T305 in the IE "UE Timers and constants in connected mode" set to any other value than "infinity";

2> perform processes described in subclause 7.2.2.

1> otherwise:

2> perform processes described in subclause 7.2.2.

8.5.5.2 Detection of "in service" area

When a suitable cell is found based on the description in [4], the UE considers it as having detected "in service area".

8.5.5.2.1 Actions following Re-entry into "in service area" in URA_PCH or CELL_PCH state

If the UE re-enters "in service area" before T316 expiry the UE shall perform the following actions. The UE shall:

1> stop T316;

1> if T307 is active:

2> stop T307.

1> if the UE is in CELL_PCH state and the UE is camped on a cell different from the one where service was lost:

2> for FDD and 1.28 Mcps TDD:

3> clear the variables C_RNTI, H_RNTI and E_RNTI;

3> stop using that C-RNTI, H-RNTI and E_RNTI just cleared from variables C_RNTI, H_RNTI and E_RNTI in MAC.

2> initiate the cell update procedure using the cause "cell-reselection" as specified in subclause 8.3.1.

1> perform processes described in subclause 7.2.2.

8.5.5.2.2 Actions following re-entry into "in service area" in CELL_FACH state

If the UE detects "in service area" before T317 expiry the UE shall perform the following actions. If no cell update procedure or URA update procedure is ongoing, the UE shall:

1> stop T317;

1> if T307 is active:

2> stop T307.

1> initiate the cell update procedure using as cause "Re-entering service area" as specified in subclause 8.3.1;

1> perform processes described in subclause 7.2.2.

If a cell update procedure or URA update procedure is ongoing, the UE shall:

1> stop T317;

1> perform the actions as specified in 8.3.1.

8.5.5.3 T316 expiry

On T316 expiry the UE shall perform the following actions. The UE shall:

1> if "out of service area" is detected:

2> start timer T317;

2> move to CELL_FACH state;

2> perform processes described in subclause 7.2.2.

1> if "in service area" is detected:

2> initiate the cell update procedure using as cause "Re-entering service area" as specified in subclause 8.3.1;

2> perform processes described in subclause 7.2.2.

8.5.5.4 T317 expiry

T317 shall never expire, i.e. all its values shall be assumed to be "infinity".

If T317 is running:

1> the UE behaviour shall be as specified in subclause 7.2.2.2.