8.3.4 Active set update

25.3313GPPProtocol specificationRadio Resource Control (RRC)Release 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

Figure 8.3.4-1: Active Set Update procedure, successful case

Figure 8.3.4-2: Active Set Update procedure, failure case

8.3.4.1 General

The purpose of the active set update procedure is to update the active set of the connection between the UE and UTRAN. This procedure shall be used in CELL_DCH state. The UE should keep on using the old RLs while configuring the new RLs. Also the UE should keep the transmitter turned on during the procedure. This procedure is only used in FDD mode.

8.3.4.2 Initiation

The procedure is initiated when UTRAN orders a UE in CELL_DCH state, to make the following modifications of the active set of the connection:

a) Radio link addition to the active set;

b) Radio link removal from the active set;

c) Combined radio link addition and removal on the active set;

d) Addition of a radio link to the E-DCH active set;

e) Removal of a radio link from the E-DCH active set.

f) Radio link addition to the secondary E-DCH active set;

g) Radio link removal from the secondary E-DCH active set;

h) Combined radio link addition and removal on the secondary E-DCH active set;

The procedure also allows the addition or removal of a radio link on the downlink frequencies associated with the secondary serving HS-DSCH cells. If the UE is not operating in Dual Cell E-DCH operation, radio links on the downlink frequencies associated with the secondary serving HS-DSCH cells are not part of the active set. Otherwise, radio links on the frequency associated with the first secondary serving HS-DSCH cell, are part of the secondary E-DCH active set.

Additionally, the procedure also allows the update of Target cell preconfiguration information for existing radio link(s).

In case a), c), f) and h), UTRAN should:

1> prepare new additional radio link(s) in the UTRAN prior to the command to the UE.

In case a), b), c), d) and e), UTRAN should:

1> send an ACTIVE SET UPDATE message on downlink DCCH using AM or UM RLC;

1> create active sets that contain at least one common radio link across a DPCH or F-DPCH frame boundary as the result of one or multiple (parallel) active set update procedures.

In case f), g) and h), UTRAN should:

1> send an ACTIVE SET UPDATE message on downlink DCCH using AM or UM RLC;

1> create secondary E-DCH active sets that contain at least one common radio link across a F-DPCH frame boundary as the result of one or multiple (parallel) active set update procedures.

UTRAN should include the following information:

1> IE "Radio Link Addition Information": Downlink DPCH information and other optional parameters relevant for the radio links to be added along with the IE "Primary CPICH info" used for the reference ID to indicate which radio link to add. This IE is needed in cases a) and c) listed above;

1> IEs "Downlink Secondary Cell Info FDD": Downlink optional parameters relevant to the reception of secondary serving HS-DSCH cells;

1> IE "Uplink Secondary Cell Info FDD": Uplink optional parameters relevant to transmission on secondary uplink frequency;

1> IE "Radio Link Removal Information": IE "Primary CPICH info" used for the reference ID to indicate which radio link to remove. This IE is needed in cases b) and c) listed above;

1> IE "Radio link addition information on secondary UL frequency": Downlink F-DPCH information and other optional parameters relevant for the radio links to be added along with the IE "Primary CPICH info" used for the reference ID to indicate which radio link to add on the secondary uplink frequency. This IE is needed in cases f) and h) listed above;

1> IE "Radio link removal information on secondary UL frequency": IE "Primary CPICH info" used for the reference ID to indicate which radio link to remove on the secondary uplink frequency. This IE is needed in cases g) and h) listed above;

1> IE "E-DCH reconfiguration information": IE "Primary CPICH info" used for the reference ID along with the IE "E-HICH information" to indicate which radio link to add to the E-DCH active set. This IE is needed in case d) above, when the RL added to the E-DCH active set is already in the DCH active set;

1> IE "E-DCH reconfiguration information": IE "Primary CPICH info" used for the reference ID along with the IE "E-HICH release indicator" to indicate which radio link to remove from the E-DCH active set. This IE is needed in case e) above, when the RL removed from the E-DCH active set remains in the DCH active set.

NOTE: The UE behaviour is unspecified if SRBs are mapped on E-DCH and the value for the E_DCH_TRANSMISSION variable is changed to FALSE via the Active Set Update procedure; or if SRBs are mapped on HS-DSCH and the value for the HS_DSCH_RECEPTION variable is changed to FALSE via the Active Set Update procedure.

8.3.4.3 Reception of an ACTIVE SET UPDATE message by the UE

Upon reception of an ACTIVE SET UPDATE message the UE shall act upon all received information elements as specified in 8.6, unless specified otherwise in the following.

The UE may:

1> maintain a list of the set of cells to which the UE has Radio Links if the IE "Cell ID" is present.

The UE shall:

1> first add the RLs indicated in the IE "Radio Link Addition Information" which are not yet contained in the UEs active set;

1> remove the RLs indicated in the IE "Radio Link Removal Information". If the UE active set is full or becomes full, an RL, which is included in the IE "Radio Link Removal Information" for removal, shall be removed before adding RL, which is included in the IE "Radio Link Addition Information" for addition;

1> if the IE "Radio Links without DPCH/F-DPCH info" is present:

2> store this IE and indicate to lower layers to start operation with Radio Links without DPCH/F-DPCH.

1> else:

2> perform the physical layer synchronisation procedure B as specified in [29] for the radio links which are not yet contained in the UEs active set.

1> if the IE "E-HICH information" is included:

2> store this E-HICH configuration for the concerning radio link.

1> if the IE "E-HICH information" is included:

2> store this E-RGCH configuration for the concerning radio link, if included.

1> determine the value for the E_DCH_TRANSMISSION variable and take the corresponding actions as described in subclause 8.5.28;

1> stop and reset timer T324 if running;

1> stop monitoring target cell HS-SCCH;

1> if the IE "MAC-es/e reset indicator" is included in the IE "UL 16QAM configuration":

2> reset the MAC-es/e / MAC-is/i entity [15].

1> if the IE "MAC-is/i reset indicator" is included in the IE "UL 64QAM configuration":

2> reset the MAC-is/i entity [15].

1> if both "UL 16QAM configuration" and "UL 64QAM configuration" IEs are included:

2> the UE behaviour is unspecified.

NOTE 1: If the IE "MAC-es/e reset indicator" is not included in the IE "UL 16QAM configuration" and 16QAM operations starts or stops, the UE behaviour is unspecified.

NOTE 1a: If the IE "MAC-is/i reset indicator" is not included in the IE "UL 64QAM configuration" and 64QAM operations starts or stops, the UE behaviour is unspecified.

1> if the IE "UL 16QAM settings" is not included in the IE "16QAM configuration":

2> indicate to lower layers to stop any operation in 16QAM mode.

1> if the IE "UL 64QAM settings" is not included in the IE "UL 64QAM configuration":

2> indicate to lower layers to stop any operation in 64QAM mode.

NOTE 2: If the IE "UL 16QAM configuration" is not included and 16QAM mode operation is currently ongoing, the UE behaviour is unspecified.

NOTE 2a: If the IE "UL 64QAM configuration" is not included and 64QAM mode operation is currently ongoing, the UE behaviour is unspecified.

1> if the IEs "E-TFCI Boost Info" and/or "E-DPDCH power interpolation" are present, act on the received information elements;

1> if the IEs "E-DPCCH/DPCCH power offset" and/or "Reference E-TFCI PO" are included in the IE "E-DCH reconfiguration information same serving cell", act on the received information elements;

NOTE 3: If E-TFCI boost is signalled to the UE and a reference E-TFCI <= E-TFCI Boost is signalled to the UE with a Reference E-TFCI PO of value 30 or 31, the UE behaviour is unspecified.

1> if the IE "Uplink MIMO Info FDD" is present, then act on the received information element as specified in 8.6.6.62;

1> if the IE "Power Control Algorithm 3" is included in the IE "Radio Link Addition Information":

2> if the variable DTX_DRX_STATUS is set to TRUE:

3> set the variable INVALID_CONFIGURATION to TRUE.

2> else:

3> indicate to lower layer to perform Power Control Algorithm 3 on the radio link indicated in this IE, as specified in [29].

NOTE 4: As a result of ACTIVE SET UPDATE message, for those radio links on the same carrier configured with Power Control Algorithm 3, the same power control parameters shall be used; otherwise, the UE behaviour is unspecified.

1> if the radio link currently considered to be the serving HS-DSCH radio link is indicated in the IE "Radio Link Removal Information":

2> no longer consider any radio link as the serving HS-DSCH radio link;

2> determine the value for the HS_DSCH_RECEPTION variable and take the corresponding actions as described in subclause 8.5.25.

1> for each radio link in the IE "Radio Link Addition Information":

2> take the actions related to TARGET_CELL_PRECONFIGURATION variable as described in subclause 8.5.52.

1> if the radio link in the IE "Radio Link Addition Information" is already contained in the UE active set and the IE "Radio Link Addition Information" attempts to reconfigure parameters other than "Target cell preconfiguration information" IE for the radio link:

2> the UE behaviour is unspecified.

NOTE 5: To configure or reconfigure the "Target cell preconfiguration information" IE for the radio link already contained in the UE active set, UTRAN should provide the same value of the mandatory IEs in the IE "Radio Link Addition Information" as the one previously configured. Otherwise the UE behaviour is unspecified.

1> if the table "Target cell preconfigurations" in the variable TARGET_CELL_PRECONFIGURATION included the RL indicated in IE "Radio Link Removal Information":

2> clear the entry from the variable TARGET_CELL_PRECONFIGURATION.

1> if the "E-DCH RL Info other cells" in the table "Target cell preconfiguration information" in the variable TARGET_CELL_PRECONFIGURATION included the RL indicated in the IE "Radio Link Removal Information":

2> clear all "E-DCH RL Info other cells" entries in the variable TARGET_CELL_PRECONFIGURATION for the removed RL(s).

1> if the radio link currently considered to be the serving E-DCH radio link is indicated in the IE "Radio Link Removal Information":

2> no longer consider any radio link as the serving E-DCH radio link.

1> if the IE "Uplink Secondary Cell Info FDD" is included; or

1> if the IE "E-DCH reconfiguration information on secondary uplink frequency" is included; or

1> if the IE "Radio link addition information on secondary UL frequency" is included; or

1> if the IE "Radio link removal information on secondary UL frequency" is included:

2> act as specified in 8.3.4.3a.

1> determine the value for the E_DCH_TRANSMISSION variable and take the corresponding actions as described in subclause 8.5.28;

1> if the IE "DPCCH2 info FDD" is present, determine the value for the DPCCH2_TRANSMISSION variable and take the corresponding actions as described in subclause 8.5.83;

1> set the IE "RRC transaction identifier" in the ACTIVE SET UPDATE COMPLETE message to the value of "RRC transaction identifier" in the entry for the ACTIVE SET UPDATE message in the table "Accepted transactions" in the variable TRANSACTIONS; and

1> clear that entry;

1> transmit an ACTIVE SET UPDATE COMPLETE message on the uplink DCCH using AM RLC without waiting for the completion of the Physical Layer synchronisation B, as specified in [29];

1> the procedure ends on the UE side.

8.3.4.3a Handling of ACTIVE SET UPDATE message on secondary uplink frequency (FDD only)

The UE shall:

1> if the IE "Uplink Secondary Cell Info FDD" is included:

2> act as specified in subclause 8.6.6.49.

2> determine the value for the SECONDARY_CELL_E_DCH_TRANSMISSION variable and take the corresponding actions as described in subclause 8.5.58.

1> if the IE "Radio link addition information on secondary UL frequency" or the IE "Radio link removal information on secondary UL frequency" is included:

2> first add the RLs indicated in the IE "Radio link addition information on secondary UL frequency";

2> remove the RLs indicated in the IE "Radio link removal information on secondary UL frequency". If the UE secondary E-DCH active set is full or becomes full, an RL, which is included in the IE "Radio link removal information on secondary UL frequency" for removal, shall be removed before adding RL, which is included in the IE "Radio link addition information on secondary UL frequency" for addition;

2> store this E-HICH configuration for the concerning radio link to be added, if included;

2> store this E-RGCH configuration for the concerning radio link to be added, if included;

2> if the secondary uplink frequency is an activated uplink frequency after the active set update procedure:

3> if the IE "Radio Links without DPCH/F-DPCH indicator" is present:

4> store the IE "F-DPCH frame offset" and ignore all other IEs received in "Downlink F-DPCH info for each RL on secondary UL frequency";

4> indicate to lower layers to start operation with Radio Links without DPCH/F-DPCH.

3> else:

4> perform the physical layer synchronisation procedure B as specified in [29] for the concerning radio link to be added if included.

2> if the IE "Power Control Algorithm 3" is included in the IE "Radio link addition information on secondary UL frequency":

3> if the variable DTX_DRX_STATUS is set to TRUE:

4> set the variable INVALID_CONFIGURATION to TRUE.

3> else:

4> indicate to lower layer to perform Power Control Algorithm 3 on the radio link indicated in this IE, as specified in [29].

NOTE: As a result of ACTIVE SET UPDATE message, for those radio links on the same carrier configured with Power Control Algorithm 3, the same power control parameters shall be used; otherwise, the UE behaviour is unspecified.

1> if the IE "E-DCH reconfiguration information on secondary UL frequency" is included:

2> if the IE "E-DCH RL Info for other cells" is present:

3> if the IE "E-HICH Information" is present:

4> store the E-HICH and E-RGCH information (if present), contained therein, for the indicated radio link.

3> if the IE "E-RGCH release indicator" is present:

4> delete the stored E-RGCH configuration for the indicated radio link.

2> if the IE "E-DCH RL Info for new secondary serving E-DCH cell" is present:

3> consider the radio link identified by the IE "Primary CPICH info" in the first IE "Downlink secondary cell info FDD" as the secondary serving E-DCH radio link, and no longer consider any other radio link as secondary serving E-DCH radio link except when Serving E-DCH cell decoupling is configured.

3> store the E-HICH and E-RGCH information (if present), contained therein, for the new secondary serving E-DCH radio link;

3> if the IE "E-RGCH release indicator" is present:

4> delete the stored E-RGCH configuration for the new secondary serving E-DCH radio link.

3> store the newly received E-AGCH configuration for the new secondary serving E-DCH radio link;

3> if the old secondary serving E-DCH cell remains in the secondary E-DCH active set after the active set update, or if the new secondary serving E-DCH cell was already in the secondary E-DCH active set prior to the active set update:

4> keep the current activation status of the secondary uplink frequency and take the corresponding actions as described in subclause 8.5.58.

3> otherwise:

4> consider the secondary uplink frequency as not activated and take the corresponding actions as described in subclause 8.5.58.

NOTE: UTRAN should configure the same value of IE "F-DPCH frame offset" for the serving E-DCH radio link and the secondary serving E-DCH radio link, otherwise the UE behaviour is unspecified.

8.3.4.4 Unsupported configuration in the UE

If UTRAN instructs the UE to use a configuration that it does not support, the UE shall:

1> keep the active set as it was before the ACTIVE SET UPDATE message was received;

1> transmit an ACTIVE SET UPDATE FAILURE message on the DCCH using AM RLC;

1> set the IE "RRC transaction identifier" in the ACTIVE SET UPDATE FAILURE message to the value of "RRC transaction identifier" in the entry for the ACTIVE SET UPDATE message in the table "Accepted transactions" in the variable TRANSACTIONS; and

1> clear that entry;

1> set the IE "failure cause" to "configuration unsupported";

1> when the ACTIVE SET UPDATE FAILURE message has been submitted to lower layers for transmission:

2> the procedure ends on the UE side.

8.3.4.5 Invalid configuration

If any of the following conditions are valid:

– a radio link indicated by the IE "Downlink DPCH info for each RL" in the IE "Radio link addition information" has a different spreading factor than the spreading factor for the radio links in the active set that will be established at the time indicated by the IE "Activation time"; and/or

– a radio link in the IE "Radio link addition information" is also present in the IE "Radio Link Removal Information"; and/or

– a radio link in the IE "Radio link addition information on secondary UL frequency" is also present in the IE "Radio link removal information on secondary UL frequency"; and/or

– the IE "Radio Link Removal Information" contains all the radio links which are part of or will be part of the active set at the time indicated by the IE "Activation time"; and/or

– the IE "Radio link removal information on secondary UL frequency" contains all the radio links which are part of or will be part of the secondary E-DCH active set at the time indicated by the IE "Activation time"; and/or

– the IE "TX Diversity Mode" is not set to "none" and it indicates a diversity mode that is different from the one currently used (<STTD> or <closed loop mode1>) in all or part of the active set; and/or

– the IE "TX Diversity Mode" is set to "closed loop mode1" and there are two configured uplink frequencies; and/or

– a radio link indicated by the IE "Radio Link Removal Information" does not exist in the active set; and/or

– a radio link indicated by the IE "Radio link removal information on secondary UL frequency" does not exist in the secondary E-DCH active set; and/or

– after the removal of all radio links indicated by the IE "Radio Link Removal Information" and the addition of all radio links indicated by the IE "Radio Link Addition Information" the active set would contain more than the maximum allowed number of radio links; and/or

– after the removal of all radio links indicated by the IE "Radio link removal information on secondary UL frequency" and the addition of all radio links indicated by the IE "Radio link addition information on secondary UL frequency" the secondary E-DCH active set would contain more than the maximum allowed number of radio links; and/or

– after the addition of all radio links indicated by the IE "Radio Link Addition Information" the active set would contain radio links indicated by the IE "Downlink DPCH info for each RL" and radio links indicated by the IE "Downlink F-DPCH info for each RL"; and/or

– after the addition of all radio links, the active set would contain a radio link configured with the IE "Downlink DPCH info for each RL" and the RL would be included in the table "Target cell preconfigurations" in the variable TARGET_CELL_PRECONFIGURATION; and/or

– the IE "Downlink information per radio link list on secondary UL frequency" is present in the IE "Uplink Secondary Cell Info FDD" in the received message; and/or

– the IE "Radio link addition information on secondary UL frequency" or the IE "Radio link removal information on secondary UL frequency" is included while the secondary E-DCH active set prior to the reception of the message do not contain any radio link; and/or

– the variable INVALID_CONFIGURATION is set to TRUE:

the UE shall:

1> keep the active set as it was before the ACTIVE SET UPDATE message was received;

1> transmit an ACTIVE SET UPDATE FAILURE message on the DCCH using AM RLC;

1> clear that entry;

1> set the IE "failure cause" to "Invalid configuration";

1> When the ACTIVE SET UPDATE FAILURE message has been submitted to lower layers for transmission:

2> the procedure ends on the UE side.

If the following condition is valid:

– the active set update procedure results in active sets that do not contain at least one common radio link before and after a DPCH or F-DPCH frame boundary:

the UE behaviour is not specified.

8.3.4.5a Void

8.3.4.5b Incompatible simultaneous reconfiguration

If the variable ORDERED_RECONFIGURATION is set to TRUE, the UE may:

1> if the activation time for the procedure that has set variable ORDERED_RECONFIGURATION and the activation time for the Active Set Update procedure are within a time window of 5 frames:

2> transmit an ACTIVE SET UPDATE FAILURE message on the uplink DCCH using AM RLC;

2> set the IE "RRC transaction identifier" in the ACTIVE SET UPDATE FAILURE message to the value of "RRC transaction identifier" in the entry for the ACTIVE SET UPDATE message in the table "Accepted transactions" in the variable TRANSACTIONS; and

2> clear that entry;

2> set the IE "failure cause" to the cause value "incompatible simultaneous reconfiguration";

2> when the ACTIVE SET UPDATE FAILURE message has been delivered to lower layers for transmission:

3> continue with any ongoing processes and procedures as if the ACTIVE SET UPDATE message has not been received.

3> and the procedure ends.

8.3.4.6 Reception of the ACTIVE SET UPDATE COMPLETE message by the UTRAN

When the UTRAN has received the ACTIVE SET UPDATE COMPLETE message,

1> the UTRAN may remove radio link(s) that are indicated to remove to the UE in case b), c), g) and h); and

1> the procedure ends on the UTRAN side.

8.3.4.7 Reception of the ACTIVE SET UPDATE FAILURE message by the UTRAN

When the UTRAN has received the ACTIVE SET UPDATE FAILURE message, the UTRAN may delete radio links that were included in the IE "Radio Link Addition Information" and the IE "Radio link addition information on secondary UL frequency" for addition. The procedure ends on the UTRAN side.

8.3.4.8 Invalid ACTIVE SET UPDATE message

If the ACTIVE SET UPDATE message contains a protocol error causing the variable PROTOCOL_ERROR_REJECT to be set to TRUE according to clause 9, the UE shall perform procedure specific error handling as follows. The UE shall:

1> transmit a ACTIVE SET UPDATE FAILURE message on the uplink DCCH using AM RLC;

1> set the IE "RRC transaction identifier" in the ACTIVE SET UPDATE FAILURE message to the value of "RRC transaction identifier" in the entry for the ACTIVE SET UPDATE message in the table "Rejected transactions" in the variable TRANSACTIONS; and

1> clear that entry;

1> set the IE "failure cause" to the cause value "protocol error";

1> include the IE "Protocol error information" with contents set to the value of the variable PROTOCOL_ERROR_INFORMATION;

1> when the ACTIVE SET UPDATE FAILURE message has been delivered to lower layers for transmission:

2> continue with any ongoing processes and procedures as if the invalid ACTIVE SET UPDATE message has not been received;

2> and the procedure ends.

8.3.4.9 Reception of an ACTIVE SET UPDATE message in wrong state

If the UE is in another state than CELL_DCH state upon reception of the ACTIVE SET UPDATE message, the UE shall perform procedure specific error handling as follows. The UE shall:

1> transmit a ACTIVE SET UPDATE FAILURE message on the uplink DCCH using AM RLC;

1> clear that entry;

1> set the IE "failure cause" to the cause value "protocol error";

1> include the IE "Protocol error information" with the IE "Protocol error cause" set to "Message not compatible with receiver state";

1> when the ACTIVE SET UPDATE FAILURE message has been delivered to lower layers for transmission:

2> continue with any ongoing processes and procedures as if the ACTIVE SET UPDATE message has not been received;

2> and the procedure ends.