3.4.1 SACCH procedures

3GPP44.018GSM/EDGE Radio Resource Control (RRC) protocolMobile radio interface Layer 3 specificationRelease 17TS

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

3.4.1.1 General

In dedicated mode and group transmit mode, the SACCH is used in signalling layer at least for measurement results transmission from the mobile station.

The SACCH has the particularity that continuous transmission must occur in both directions at least on the channel carrying the main signalling link. For that purpose, in the mobile station to network direction, measurement result messages are sent at each possible occasion when nothing else has to be sent (see sub-clause 3.4.1.2). Similarly, SYSTEM INFORMATION TYPE 5, 6 and optionally 5bis and 5ter messages are sent in the network to mobile station direction in UI frames when nothing else has to be sent.

The network may in addition send MEASUREMENT INFORMATION messages on the SACCH, which may order the MS to use the enhanced measurement report.

In a multislot configuration the SYSTEM INFORMATION TYPE 5, 6 and optionally 5bis, 5ter and MEASUREMENT INFORMATION messages shall be sent on the SACCH associated with the channel carrying the main signalling link.

In a multislot configuration the mobile station shall ignore all messages received on the SACCH(s) that are not associated with the channel carrying the main signalling link.

On a VGCS channel, the network may send additional or alternative system information messages for both mobile stations in group transmit mode and those in group receive mode (see sub-clause 3.4.15.2.1).

A mobile station with extended measurement capabilities which receives EXTENDED MEASUREMENT ORDER (EMO) messages on the SACCH, shall perform and report extended measurements, see sub-clause 3.4.1.3.

The SYSTEM INFORMATION TYPE 5bis message shall be sent if and only if the EXT IND bit in the Neighbour Cell Description information element in both the SYSTEM INFORMATION TYPE 5 and TYPE 5bis messages indicates that each information element only carries part of the BA.

A GSM 900 mobile station which only supports the primary GSM band P-GSM 900 (cf. 3GPP TS 45.005) may consider the EXT-IND bit in the Neighbour cell description IE in the SYSTEM INFORMATION TYPE 5 message bit as a spare bit, assume that the information element carries the complete BA, and ignore any SYSTEM INFORMATION TYPE 5bis messages.

NOTE: The network should take into account limitations of certain mobile stations to understand SYSTEM INFORMATION TYPE 5ter and TYPE 5bis messages, the EXT-IND bit in the Neighbour cell description, and formats used in the Neighbour cell description information element and Cell Channel Description information element used in SYSTEM INFORMATION messages, see sub-clause 10.5.2.1b, and sub-clause 10.5.2.22.

Problems occurring in the reception of SACCH frames are interpreted as a loss of communication means and appropriate procedures are then triggered as specified in 3GPP TS 45.008.

3.4.1.2 Measurement Report and Enhanced Measurement Report

When in dedicated mode or group transmit mode, the mobile station regularly sends either MEASUREMENT REPORT or ENHANCED MEASUREMENT REPORT messages to the network. These messages contain measurement results about reception characteristics from the current cell and from neighbour cells. The BA (list) which is the initial basis for the measurements is derived from information received on the BCCH in System Information 2 and optionally 2bis and/or 2ter messages and on the SACCH in System Information 5 and optionally 5bis and/or 5ter messages. MEASUREMENT INFORMATION and SI2quater messages may add information for the GSM Neighbour Cell List and provide 3G Neighbour Cell list and/or E-UTRAN Neighbour Cell list. If System Information 23 message is broadcast in the cell, a mobile station supporting network sharing shall build the 3G Neighbour Cell list and/or E-UTRAN Neighbour Cell list as described in sub-clause 3.4.1.2.1.

The Mobile Station shall use ENHANCED MEASUREMENT REPORT messages instead of MEASUREMENT REPORT messages if that is indicated by the parameter REPORT_TYPE and if at least one BSIC is allocated to each BA (list) frequency. For report with the MEASUREMENT REPORT message, reporting is performed on three separate lists: the BA (list), the 3G Neighbour Cell List (for a multi-RAT MS supporting UTRAN) and the E-UTRAN Neighbour Cell list (for a multi-RAT MS supporting "E-UTRA Measurement and Reporting"). For report with the ENHANCED MEASUREMENT REPORT message, reporting is performed on the Neighbour Cell List (defined in sub-clause 3.4.1.2.1.3) and the E-UTRAN Neighbour Cell list (for a multi-RAT MS supporting "E-UTRA Measurement and Reporting").

The mobile station shall indicate its support for "E-UTRA Measurement and Reporting" in the Mobile Station Classmark 3 IE (see 3GPP TS 24.008).

In addition, the MS with ECSD options implemented shall use fast inband procedure for downlink quality reporting if the use of such procedure has been ordered by the BSC.

When the information is received in more than one message the mobile station shall only combine information relating to the BA (list) from messages received on the same channel and indicating the same value of the BCCH allocation sequence number (BA_IND) without any message indicating a different value of BA_IND received in between. After intracell change of channel (i.e. via ASSIGNMENT COMMAND, DTM ASSIGNMENT COMMAND, or HANDOVER COMMAND message) where the frequency band is not changed (GSM and E-GSM are considered to belong to the same frequency band), the MS may use the BA (list) received on SACCH in system information 5 and optionally 5bis and/or 5ter messages in the previous channel configuration during the time it has not yet received a new list in the new channel. In case the BCCH allocation sequence number (BA_IND) received in the new channel indicates the same value as the one already being used by the mobile station, the mobile station is not required to re-build the BA(list) in the new channel. If neighbour cell information for the serving cell is not available, the mobile station shall indicate this in the MEASUREMENT REPORT message. These measurement results are obtained as specified in 3GPP TS 45.008.

These messages are sent on the slow ACCH, in unacknowledged mode.

If no other message is scheduled on the SACCH at the instant when a layer 2 frame is due to be sent, then the mobile station shall send a MEASUREMENT REPORT message, an ENHANCED MEASUREMENT REPORT or an extended measurement report message (see sub-clause 3.4.1.3) in that frame. The interval between two successive layer 2 frames containing messages for measurement reporting shall not exceed one layer 2 frame.

3.4.1.2.1 Parameters for Measurements and Reporting

Parameters from the Measurement Information, SI2quater or PSI3quater messages allow an MS to build lists which are used for Measurement reporting, Enhanced Measurement reporting and for CCN mode settings. If the SI23 message is broadcast in the cell and the MS supports network sharing then:

– a multi-RAT MS supporting E-UTRANshall use parameters from the SI23 message instead of parameters from the SI2quater message to build the E-UTRAN Neighbour Cell list.

– a multi-RAT MS supporting UTRAN shall use parameters received in the MEASUREMENT INFORMATION message instead of parameters from the SI2quater message or SI23 message to build the 3G Neighbour Cell list.

A full set of MEASUREMENT INFORMATION messages is defined by a number of different instances indicated by the parameter MI_COUNT. Consistent sets of system information messages are defined in 3GPP TS 44.060. Two different instances of MEASUREMENT INFORMATION (respectively: SI2quater and SI23) messages are two MEASUREMENT INFORMATION (respectively: SI2quater and SI23) messages with different MI_INDEX (respectively: SI2quater_INDEX and SI23_INDEX) parameter values.

In the SI2quater message, the parameters with identical names in the GPRS specific structures (i.e. structures with the prefix GPRS) and in the non-GPRS specific structures (i.e. structures without the prefix GPRS) can have different values. For Measurement reporting and Enhanced Measurement reporting the MS shall ignore the parameters in the GPRS specific structures unless otherwise specified (e.g. sub-clause 3.4.1.2.1.2 and sub-clause 3.4.1.2.1.4). If the SI2quater message is not broadcast or all instances are not yet received or non-GPRS specific parameters in the SI2quater message are omitted, the MS in idle mode or dedicated mode or group transmit mode shall assume the default values defined in 3GPP TS 45.008.

The parameters for Measurements and Reporting received in a MEASUREMENT INFORMATION message shall override the old values.

Upon leaving dedicated mode or group transmit mode and entering idle mode, the MS shall delete the parameters received in all instances of the MEASUREMENT INFORMATION message and read the parameters from the SI2quater message and, for an MS supporting network sharing, the parameters from the SI23 message (if broadcast by the network), or use the parameters which were stored before entering the dedicated mode if they are still valid or assume the default values if the SI2quater message is not broadcast or non-GPRS specific parameters are omitted.

When fast acquisition of system information is not being used in the cell, the following procedures shall apply. The conditions for applying the fast acquisition of system information procedure are described in sub-clause 3.4.1.2.1.11. In Idle mode a multi-RAT MS supporting UTRAN camping on BCCH shall read and decode a consistent set of SI2quater messages to form a 3G Neighbour Cell list (each instance can be used as received). When the 3G_BA_IND parameter is changed in idle mode, the MS shall re-read all instances of the consistent set of SI2quater messages and rebuild the 3G Neighbour Cell list. A multi-RAT MS supporting UTRAN camping on PBCCH shall construct the 3G Neighbour Cell list from PSI3quater messages, see 3GPP TS 44.060. This list (either from SI2quater or from PSI3quater) shall then be used for reporting when the MS enters dedicated mode, until the MS has received a given number of instances of MEASUREMENT INFORMATION messages that contain 3G Neighbour Cell Description. This number of instances is defined by the 3G-WAIT parameter. When the 3G_BA_IND parameter is changed when on SACCH, the MS shall also re-read all instances, rebuild the 3G Neighbour Cell list, and use the new list for reporting based on the parameter 3G-Wait.

When the fast acquisition of system information procedure is being used in the cell, the procedure defined in sub-clause 3.4.1.2.1.11 shall be used.

For the GSM neighbour cell list the MS shall combine the BA (list) received in SI5/SI5bis/SI5ter with the BSIC list received in one or more instances, in ascending order of MI_INDEX, of the MEASUREMENT INFORMATION message with the same BA_IND value as the BA (list). When the BA_IND is changed the MS shall rebuild the combined list (the BSIC list shall also be rebuilt). The GSM neighbour cell list is also defined by the combination of the BA (list) received in SI2/SI2bis/SI2ter and the BSIC list received in one or more instances, in ascending order of SI2quater_INDEX, of the SI2quater message. When the BA_IND is changed the MS shall rebuild the combined list (the BSIC list shall also be rebuilt).

The MS shall combine the BA (list) received in SI5/SI5bis/SI5ter (respectively SI2/SI2bis/SI2ter) messages with the Real Time Differences parameters received in the MEASUREMENT INFORMATION (respectively SI2quater) message with the same BA_IND value as the BA (list). When the BA_IND is changed the MS shall re-read the Real Time Differences parameters in all instances.

The MS shall combine the Neighbour Cell list derived from SI5/SI5bis/SI5ter/MEASUREMENT INFORMATION messages (respectively SI2/SI2bis/SI2ter/SI2quater) with the REP_PRIORITY parameters received in the MEASUREMENT INFORMATION (respectively SI2quater) message with the same BA_IND and 3G_BA_IND values respectively as the Neighbour Cell list. When the BA_IND or 3G_BA_IND are changed the MS shall re-read the REP_PRIORITY parameters in all instances.

The MS shall combine the GSM Neighbour Cell list with the CCN_SUPPORTED parameters received in the SI2quater messages with the same BA_IND value as the GSM Neighbour Cell list. When the BA_IND is changed the MS shall re-read the CCN_SUPPORTED parameters in all instances.

If the MP_CHANGE_MARK parameter is changed, the MS shall re-read the Real Time differences, REP_PRIORITY, CCN_SUPPORTED, Measurement Parameters, 3G Measurement Parameters, Serving Cell Priority Parameters Description (SI2quater message only), 3G Priority Parameters Description (SI2quater message only) and 3G Measurement Control Parameters (MEASUREMENT INFORMATION message only) in all instances. The MS shall start using the parameters as soon as they have been received. In the case that not all the parameters have been received in a full set of instances, then the default values shall be used.

If the 3G_BA_IND parameter is changed a multi-RAT MS supporting E-UTRAN shall re-read the E-UTRAN Parameters Description. If SI23 message is broadcast in the cell a multi-RAT MS supporting network sharing shall re-read the Priority and E-UTRAN Parameters Description of the selected PLMN only when the SI 23_3G_BA_IND parameter in the SI23 message is changed. The MS shall start using the parameters as soon as they have been received. In the case that not all the parameters have been received in a full set of instances, then the default values shall be used.

When attempting to decode a consistent set of SI2quater (respectively, a full set of MEASUREMENT INFORMATION) messages, if none of the BA_IND, 3G_BA_IND (for a Multi-RAT MS supporting UTRAN and/or E-UTRAN), and MP_CHANGE_MARK values obtained from the first received SI2quater (respectively MEASUREMENT INFORMATION) message instance has changed since the previous acquisition then the mobile station can consider the parameters from SI2quater (respectively MEASUREMENT INFORMATION) as unchanged and should not decode the other SI2quater (respectively MEASUREMENT INFORMATION) message instances of the set.

When attempting to decode a consistent set of SI23 messages, if none of the SI 23_3G_BA_IND and SI 23_CHANGE_MARK values obtained from the first received SI23 message instance has changed since the previous acquisition then a multi-RAT mobile station supporting network sharing can consider the parameters from SI23 as unchanged and should not decode the other SI23 message instances of the set.

3.4.1.2.1.1 Deriving the 3G Neighbour Cell list from the 3G Neighbour Cell Description sent on BCCH or on SACCH

This applies only to a multi-RAT MS supporting UTRAN. One or more instances of the MEASUREMENT INFORMATION message or SI2quater message may provide 3G Neighbour Cell Description information. This information is used to build the 3G Neighbour Cell list. The 3G Neighbour Cell list may contain up to 96 3G Neighbour Cells and/or UTRAN frequencies for RSSI reporting.

Each 3G Neighbour Cell Description received in the MEASUREMENT INFORMATION message or in the SI2quater message is added to the 3G Neighbour Cell list, starting with the index equal to the parameter Index_Start_3G. If this parameter is not present then the value 0 shall be used.

For each 3G Neighbour Cell Description, the cells / UTRAN frequencies received in SI2quater or MEASUREMENT INFORMATION message are indexed in the following order:

1) UTRAN FDD cells / UTRAN FDD frequencies: FDD ARFCNs are indexed in the order of occurrence in the 3G Neighbour Cell description. For each FDD ARFCN indicating UTRAN FDD cells, the cells are indexed in the order of increasing values of the decoded FDD_CELL_INFORMATION parameters.
2) UTRAN TDD cells / UTRAN TDD frequencies: TDD ARFCNs are indexed in the order of occurrence in the 3G Neighbour Cell description. For each TDD ARFCN indicating UTRAN TDD cells, the cells are indexed in the order of increasing values of the decoded TDD_CELL_INFORMATION parameters.
3) CDMA 2000 cells: the cells are indexed in the order of occurrence in the 3G Neighbour Cell description.

If a 3G Neighbour Cell Description includes non-supported frequencies or Radio Access Technologies, this shall not be considered as an error; indices in the 3G Neighbour Cell list shall be incremented accordingly.

If more than one cell / UTRAN frequency with the same index in the 3G Neighbour Cell list are provided by different instances of 3G Neighbour Cell Descriptions, the cell / UTRAN frequency from the message instance with the highest index shall be used. In case the same 3G Cell / UTRAN frequency occurs more than once in the resulting 3G Neighbour Cell list, each occurrence shall be assigned an index but only the cell / UTRAN frequency with the highest index in the 3G Neighbour Cell list shall be referred to in measurement reports.

For a mobile station indicating support for UTRA Multiple Frequency Band Indicators (MFBI) in the MS Classmark 3 IE (see 3GPP TS 24.008), the network may send different FDD ARFCN values corresponding to different frequency bands but designating the same physical UTRAN frequency in the MEASUREMENT INFORMATION message. The network may also broadcast different FDD ARFCN values corresponding to different frequency bands but designating the same physical UTRAN frequency in the SI2quater message; in such a case, a mobile station supporting UTRA Multiple Frequency Band Indicators (MFBI) shall consider a FDD ARFCN value belonging to frequency band it does not support as a non-supported frequency. When a MEASUREMENT INFORMATION message or a SI2quater message is received by the MFBI capable MS, each occurrence of a FDD ARFCN corresponding to different frequency bands but designating the same physical UTRAN frequency shall be assigned an index in the 3G Neighbour Cell list. However, only the highest index in the list that corresponds to a supported frequency band shall be referred to in measurement reports.

If a cell / UTRAN frequency is provided for an index higher than 95 in the 3G Neighbour Cell list, this shall not be considered as an error; the cell / UTRAN frequency shall not be included in the 3G Neighbour Cell list.

The MS behaviour is not specified if the number of 3G frequencies or cells exceeds the MS monitoring capabilities as defined in 3GPP TS 45.008.

3.4.1.2.1.1a Deriving the E-UTRAN Neighbour Cell list from the Repeated E-UTRAN Neighbour Cell information sent on BCCH or on SACCH

This applies only to a multi-RAT MS supporting E-UTRAN. One or more instances of the MEASUREMENT INFORMATION message or SI2quater message may provide E-UTRAN Neighbour Cell Description information in one or more instances of the Repeated E-UTRAN Neighbour Cells (respectively for the MEASUREMENT INFORMATION message and if the mobile station and the network supports extended EARFCNs, the Repeated E-UTRAN NC with extended EARFCNs IE). This is used to build the E-UTRAN Neighbour Cell list. The fast acquisition of system information procedure, as defined in subclause 3.4.1.2.1.11, shall be used to acquire E-UTRAN measurement parameters and neighbour cell information from SI2quater and MEASUREMENT INFORMATION.

In the case network sharing is in use in the cell, the SI23 message may provide PLMN specific E-UTRAN frequencies in Priority and E-UTRAN Parameters Description IE; when broadcasted in the cell, a multi-RAT MS supporting network sharing shall use this information to build the E-UTRAN Neighbour Cell list for the selected PLMN. When the SYSTEM INFORMATION TYPE 23 message is not broadcasted in the cell, a mobile station supporting network sharing shall use the information provided within the SYSTEM INFORMATION TYPE 2quater message to build the E-UTRAN NCL (see above); the same requirement applies when the mobile station does not support network sharing.

In the case extended EARFCNs is in use in the cell, the SI2quater message may additionally provide E-UTRAN frequencies within the Extended EARFCNs Description IE. A multi-RAT MS supporting extended EARFCNs but not supporting network sharing shall use this information to build the E-UTRAN Neighbour Cell list; the same requirement applies for a multi-RAT MS supporting network sharing when the SI23 message is not broadcasted in the cell.

The E-UTRAN Neighbour Cell list may contain up to 8 E-UTRAN frequencies. For each E-UTRAN frequency, zero or more E-UTRAN neighbour cells may be specified that are not allowed for cell reselection. The list of not allowed cells is defined in the Not Allowed Cells IEs (alternatively, defined in PLMN-specific Repeated E-UTRAN Not Allowed Cells in the SI23 message).

If a Priority and E-UTRAN Parameters Description includes non-supported frequencies or Radio Access Technologies, this shall not be considered as an error; indices in the Priority and E-UTRAN Parameters Description shall be incremented accordingly.

Each EARFCN in each instance of the Repeated E-UTRAN Neighbour Cells IE (respectively and if the mobile station and the network supports extended EARFCNs, the Repeated E-UTRAN NC with extended EARFCNs IE) is added to the E-UTRAN Neighbour Cell list in the order in which they appear in the IE. Different instances of the Repeated E-UTRAN Neighbour Cells IE shall be evaluated in ascending order of the SI2quater_INDEX (respectively MI_INDEX) of the SI2quater (respectively MEASUREMENT INFORMATION) message that they are received in.

Alternatively, each EARFCN in each instance of the PLMN-specific Repeated E-UTRAN Neighbour Frequency and Priority IE in SYSTEM INFORMATION TYPE 23 message is added to the E-UTRAN Neighbour Cell list in the order in which they appear in the IE. Different instances of the PLMN-specific Repeated E-UTRAN Neighbour Frequency and Priority IE (respectively and if the mobile station and the network supports extended EARFCNs, the Repeated E-UTRAN NC with extended EARFCNs IE) shall be evaluated in ascending order of the SI23_INDEX (respectively MI_INDEX) of the SYSTEM INFORMATION TYPE 23 (respectively MEASUREMENT INFORMATION) message instances that they are received in.

In case the same E-UTRAN frequency occurs more than once in the resulting E-UTRAN Neighbour Cell list, each occurrence shall be assigned an index but only the E-UTRAN frequency with the highest index in the E-UTRAN Neighbour Cell list shall be referred to in measurement reports.

For a mobile station indicating support for E-UTRA Multiple Frequency Band Indicators (MFBI) in the MS Classmark 3 IE (see 3GPP TS 24.008), the network may send different EARFCN values corresponding to different frequency bands but designating the same physical E-UTRAN frequency in the MEASUREMENT INFORMATION message. The network may also broadcast different EARFCN values corresponding to different frequency bands but designating the same physical E-UTRAN frequency in the SI2quater message or SI23 message; in such a case, a mobile station supporting E-UTRA Multiple Frequency Band Indicators (MFBI) shall consider an EARFCN value belonging to frequency band it does not support as a non-supported frequency. When a MEASUREMENT INFORMATION message or a SI2quater message or a SI23 message is received by the MFBI capable MS, each occurrence of an EARFCN corresponding to different frequency bands but designating the same physical E-UTRAN frequency shall be assigned an index in the E-UTRAN Neighbour Cell list. However, only the highest index in the list that corresponds to a supported frequency band shall be referred to in measurement reports.

The mobile station behaviour is not specified if the number of E-UTRAN frequencies exceeds the MS monitoring capabilities as defined in 3GPP TS 45.008.

When SI23 message is broadcast in the cell and network sharing is supported by the multi-RAT MS, the MS shall read the SI23 message instances of the selected PLMN in order to build the E-UTRAN Neighbour Cell list. When the SI 23_BA_IND parameter is changed in idle mode, the MS shall re-read the SI23 message instances of the selected PLMN and rebuild the E-UTRAN Neighbour Cell list.
The E-UTRAN Neighbour Cell list derived from the SI23 message shall then be used for measurement reporting when the MS enters dedicated mode, until it has received all relevant instances of the MEASUREMENT INFORMATION message.

3.4.1.2.1.1b Deriving the E-UTRAN Neighbour Cell list from the Repeated E-UTRAN Neighbour Cell information sent on BCCH or on SACCH (abnormal cases)

In the case Extended EARFCNs is in use in the cell, the network may broadcast EARFCNs > 65535 within the SI2quater message using the Extended EARFCNs Description IE (see table 10.5.2.33b.2). A mobile station supporting Extended EARFCNs and using the SI2quater message to build its E-UTRAN Neighbour Cell list shall manage each EARFCN value 65535 within the Repeated E-UTRAN Neighbour Cells IE as described within the table 10.5.2.33b.2. In the case no EARFCN corresponding to the n^th EARFCN value 65535 can be found within the Extended EARFCNs Description IE the mobile station shall assume the value 65535 for the n^th EARFCN.

3.4.1.2.1.2 Deriving the GSM Neighbour Cell list from the BSICs and the BA (list)

One or more instances of the Measurement Information message may provide BSIC information. This is used to build the GSM Neighbour Cell list. The GSM Neighbour Cell list may contain up to 96 Neighbour Cells.

The BSICs are associated to the frequencies in the BA (list) with the same BA_IND value. The BSICs may be received before the corresponding BA (list). The first BSIC in each instance applies to the frequency in the BA (list) referenced by the parameter BA_Index_Start_BSIC. For each successive BSIC, one bit indicates if the BSIC applies to the same frequency as the previous BSIC or to the next frequency in the BA (list), as defined in sub-clause 9.1.54, Measurement Information message.

In case the same cell (ARFCN+BSIC) occurs more than once in the resulting GSM Neighbour Cell list, each occurrence shall be assigned an GSM Neighbour Cell list index but only the cell with the highest GSM Neighbour Cell list index shall be used and referred to in measurement reports.

If GPRS BSIC Description is provided in the SI2quater message (see sub-clause 3.4.1.2.1.6), it shall be saved and used by a non-GPRS mobile station as initial BSIC information in connected mode.

3.4.1.2.1.3 Deriving the Neighbour Cell list from the GSM Neighbour Cell list and the 3G Neighbour Cell list

For report with the ENHANCED MEASUREMENT REPORT message, the Neighbour Cell list is the concatenation of the GSM Neighbour Cell list and the 3G Neighbour Cell list (if any). In this concatenation the value of the parameter Absolute_Index_Start_EMR is added to the 3G Neighbour Cell list indices. The Neighbour Cell list may contain up to 96 Neighbour Cells. If the same index occurs for a GSM Cell and a 3G Cell, the GSM Cell shall be used.

NOTE: For report with the MEASUREMENT REPORT message, the concatenated list is not used. Instead, the two lists are used separately, as defined in sub-clause 10.5.2.20, ‘Measurement Results’.

3.4.1.2.1.4 Real Time Differences

One or more instances of the Measurement Information message may provide Real Time Difference information. This is used to build the Real Time Difference list. The mobile station may use Real Time Difference parameters before receiving the BSIC information defined in sub-clause 3.4.1.2. The Real Time Difference list may contain up to 96 Real Time Difference parameters.

The Real Time Difference list is associated with the BA (list) having the same BA_IND value. Each frequency in the BA (list) may be associated to 0, 1 or more Real Time Difference parameters. The Real Time Difference parameters may be received before the corresponding BA (list). The parameter BA_Index_Start_RTD in each structure indicates the index of the frequency in the BA (list) to be taken as a starting reference. A sub-structure is included for each frequency referenced. Each of those sub-structures indicates if 0, 1 or more RTD parameters are present for this frequency. If a frequency in the BA (list) is not provided with Real Time Difference information by any of the message instances with correct BA_IND, it shall be assumed that no information is available for that frequency, see sub-clause 9.1.54 ‘Measurement Information message’. If more than 96 Real Time Difference parameters are provided for the Real Time Difference list, this shall not be considered as an error.

If GPRS Real Time Differences Description is provided in the SI2quater message (see sub-clause 3.4.1.2.1.6), it may also be used by a non-GPRS mobile station in Idle mode.

The MS is not required to take into account more RTDs than cells on the frequency.

3.4.1.2.1.5 Report Priority Description

Report Priority information can be received in one instance of the MEASUREMENT INFORMATION message. The Report Priority information is associated with the Neighbour Cell list (see sub-clause 3.4.1.2.1.3) having the same BA_IND value and 3G_BA_IND value. Each REP_PRIORITY bit of this field relates to indices of the Neighbour Cell list, starting with index 0. The Report Priority information may be received before the corresponding Neighbour Cell list.

Indices exceeding the value 95 shall be ignored. If there are fewer indices than the number of Neighbour Cells, the value 0 shall be assumed for the missing bits.

3.4.1.2.1.6 GPRS Parameters

A set of information may be received in the SI2quater message to be used for GPRS neighbour cell measurement and (NC) Measurement reporting when the cell has no PBCCH allocated, see 3GPP TS 44.060. This information comprises GPRS Report Priority Description, GPRS BSIC Description, GPRS Real Time Differences Description, GPRS Measurement Parameters, GPRS 3G Measurement Parameters, NC Measurement Parameters and GPRS E-UTRAN Measurement Parameters. The use of the parameters is similar to parameters without the term "GPRS".

3.4.1.2.1.7 The 3G Cell Reselection list

This applies only to a multi-RAT MS. One or more instances of the SI2quater and/or SI2ter messages may provide 3G Cells. If 3G Cells are provided in both of these messages, the union of the cells shall be included in the 3G Cell Reselection list. If network sharing is used in the cell, a mobile station supporting network sharing shall instead use information provided in the SI23 message to build the 3G Cell reselection list. The 3G Cell Reselection list may contain up to 96 3G Cells. 3G Cells not provided explicitly in the SI2ter message or in the SI2quater message (frequencies on their own) are not included in these 96 cells. Up to 8 frequencies on their own, can be added to these 96 cells including when applicable, 3G frequencies broadcast in the SI23 message.

NOTE: Frequencies in the SI2quater message for which the parameter NR_OF_FDD_CELLS or NR_OF_TDD_CELLS is set to 31 are only added to the 3G Cell Reselection list (frequencies on their own). Frequencies for which NR_OF_FDD_CELLS is set to 0 (and FDD_Indic0 is set to 0) are added to the 3G Neighbour Cell list and are only used for RSSI reporting (subject to the restrictions given in 3GPP TS 45.008). Frequencies for which NR_OF_FDD_CELLS is set to a value from 17 to 30 or NR_OF_TDD_CELLS is set to a value of 0 with TDD_indic0 set to 0 or to a value from 21 to 30 are not added to the 3G Cell Reselection list, they are handled as described in sub-clause 10.5.2.33b.

The MS behaviour is not specified if the number of 3G frequencies or cells exceeds the MS monitoring capabilities as defined in 3GPP TS 45.008.

3.4.1.2.1.7a (void)

3.4.1.2.1.7b Closed Subscriber Group Information

This applies only to a multi-RAT MS supporting UTRAN and/or E-UTRAN. One or more instances of the SI2quater message or MEASUREMENT INFORMATION message may provide the E-UTRAN CSG Description IE and/or the 3G CSG Description IE. An MS supporting cell reselection to UTRAN and/or E-UTRAN shall use this information as described in 3GPP TS 45.008.

In the case extended EARFCNs is in use in the cell, the SI2quater message may provide E-UTRAN CSG frequencies within the Extended EARFCNs Description for CSG Cells IE. A multi-RAT MS supporting extended EARFCNs shall use this information as described in 3GPP TS 45.008.

If an MS receives a CSG_PSC_SPLIT IE and/or a CSG_PCI_SPLIT IE it shall store this information and shall consider it as being valid for the specified frequencies for a period of up to 24 hours or until a new CSG_PSC_SPLIT IE and/or a new CSG_PCI_SPLIT IE is received, whichever occurs first.

Any valid "CSG PSC Split Information" received from a UTRAN frequency and stored by the mobile station shall take precedence over the information received from the CSG_PSC_SPLIT IE for that frequency. Any valid "CSG PCI Split Information" received from an E-UTRAN frequency and stored by the mobile station shall take precedence over the information received from the CSG_PCI_SPLIT IE for that frequency.

3.4.1.2.1.7c The 3G Frequency list

The 3G Frequency list consists of the set of UTRAN frequencies contained in the 3G Cell Reselection list (derived from the SI2quater and/or the SI2 ter messages) or in the 3G Neighbour Cell list (derived from the MEASUREMENT INFORMATION message) or, if network sharing is supported in the cell, in the set of UTRAN frequencies contained in the SI23 message. The 3G Frequency list includes all frequencies with cells contained in the 3G Neighbour Cell list and (where applicable) frequencies on their own provided by the SI2quater message and/or the SI2ter message or frequencies provided in the SI23 message.

When multiple cells on the same frequency or multiple references to the same frequency are included in the 3G Neighbour Cell list or 3G Cell Reselection list an index into the 3G Frequency list is allocated for that frequency only the first time it is encountered as outlined below.

Indices for the 3G Frequency list are allocated according to the following steps. When indices are allocated using the 3G Neighbour Cell list derived from the MEASUREMENT INFORMATION message, steps 2 and 3 shall be ignored.

1) Frequencies contained in the 3G Neighbour Cell list are allocated indices that start from 0 and are incremented for each frequency. An index value of 0 refers to the first UTRAN frequency (TDD-ARFCN or FDD-ARFCN) contained in the 3G Neighbour Cell list; an index value of 1 refers to the second frequency contained in the 3G Neighbour Cell list; and so on. Indices to the 3G Frequency list are allocated according to the order in which 3G cells appear in the 3G Neighbour Cell list. An entry in the 3G Neighbour Cell list indicating a frequency for RSSI reporting shall not result in the allocation of an index.

2) UTRAN frequencies on their own provided by the SI2quater message (i.e. frequencies for which the parameter NR_OF_FDD_CELLS or NR_OF_TDD_CELLS is set to 31) are allocated indices that start from 31 and continue in descending order. Indices are first allocated according to increasing order of the SI2quater_INDEX field within a consistent set of SI2quater messages then according to their order of occurrence within the 3G Neighbour Cell description IE for a given SI2quater_INDEX.

3) UTRAN frequencies on their own provided by the SI2ter message are allocated indices that start from (31 – N_UTRAN_OWN_SI2QUATER) and continue in descending order. Indices are first allocated according to increasing order of the SI2ter_INDEX field within a consistent set of SI2ter messages then according to their order of occurrence within the UTRAN FDD Description and/or UTRAN TDD Description IEs for a given SI2ter_INDEX. N_UTRAN_OWN_SI2QUATER is defined as the number of the UTRAN frequencies on their own provided by the SI2quater message.

3.4.1.2.1.8 CCN Support description

The SI2quater message may also contain information, the CCN Support description, to be used when CCN is enabled in the serving cell, see 3GPP TS 44.060. This CCN Support description is associated with the GSM Neighbour Cell list (see 3.4.1.2.1.2) having the same BA_IND value. Each CCN_SUPPORTED bit of this field relates to indices of the GSM Neighbour Cell list, starting with index 0. The CCN Support description may be received before the corresponding GSM Neighbour Cell list.

Indices exceeding the value 95 or the number of cells in the GSM Neighbour Cell List shall be ignored. If there are fewer indices than the number of cells in the GSM Neighbour Cell List, the value 0 shall be assumed for the missing bits.

When this information is not present but CCN is enabled in the serving cell, the mobile station shall assume that CCN is enabled towards all neighbour cells.

3.4.1.2.1.9 3G_CCN_ACTIVE Description

The SI2quater message may also contain the 3G_CCN_ACTIVE parameter in order to indicate whether the MS shall perform the CCN procedures in the serving cell when re-selecting to a 3G neighbour cell, see 3GPP TS 44.060.

The 3G_CCN_ACTIVE parameter indicates if CCN is activated in serving cell towards all 3G neighbour cells.

3.4.1.2.1.9a E-UTRAN_CCN_ACTIVE Description

The SI2quater message may also contain the E-UTRAN_CCN_ACTIVE parameter in order to indicate whether the MS shall perform the CCN procedures in the serving cell when re-selecting to an E-UTRAN neighbour cell, see 3GPP TS 44.060.

The E-UTRAN_CCN_ACTIVE parameter indicates if CCN is activated in the serving cell towards all E-UTRAN neighbour cells.

3.4.1.2.1.10 GSM Neighbour Cell Selection parameters

The SI2n message contains cell reselection parameters for the GSM neighbouring cells. These GSM Neighbour Cell Selection parameters are associated with the GSM Neighbour Cell list (see 3.4.1.2.1.2) having the same BA_IND value. For the application of this information, see 3GPP TS 45.008.

The GSM Neighbour Cell Selection parameters may be received before the corresponding GSM Neighbour Cell list.

3.4.1.2.1.11 Fast Acquisition of System Information

For a multi-RAT MS, the fast acquisition of system information procedure shall be applied to UTRAN if the 3G Priority Parameters Description IE is present in the SI2quater message or 3G Supplementary Parameters Description IE is present in the MEASUREMENT INFORMATION message. The procedure shall apply to E-UTRAN if the E-UTRAN Parameters Description IE is present in the SI2quater or MEASUREMENT INFORMATION messages.

The network shall ensure that UTRAN (respectively E-UTRAN) neighbour cell list, UTRAN (respectively E-UTRAN) measurement parameters and UTRAN (respectively E-UTRAN) priority information are contained in consecutive instances of SI2quater message and that, immediately following this information, 3G CSG Description (respectively E-UTRAN CSG Description) parameters are contained in consecutive instances of the message together forming a UTRAN information set (respectively E-UTRAN information set). Similarly, in the case of MEASUREMENT INFORMATION messages, the network shall ensure that UTRAN (respectively E-UTRAN) neighbour cell list and UTRAN (respectively E-UTRAN) measurement parameters are contained in consecutive instances of the message and that, immediately following this information, 3G CSG Description (respectively E-UTRAN CSG Description) parameters are contained in consecutive instances of the message together forming a UTRAN information set (respectively E-UTRAN information set).

The UTRAN_Start (respectively E-UTRAN_Start) bit and the UTRAN_Stop (respectively E-UTRAN_Stop) bit shall be set as specified below:

– The first instance of the SI2quater or MEASUREMENT INFORMATION message containing UTRAN (respectively E-UTRAN) neighbour cell list and/or UTRAN (respectively E-UTRAN) measurement parameters and/or UTRAN (respectively E-UTRAN) priority information shall have the UTRAN_Start (respectively E-UTRAN_Start) bit set to value ‘1’. The last instance of the SI2quater or MEASUREMENT INFORMATION message containing UTRAN (respectively E-UTRAN) neighbour cell list and/or UTRAN (respectively E-UTRAN) measurement parameters and/or UTRAN (respectively E-UTRAN) priority information shall have the UTRAN_Stop (respectively E-UTRAN_Stop) bit set to value ‘1’.; or

– Alternatively, if all instances of the SI2quater or MEASUREMENT INFORMATION message contain UTRAN (respectively E-UTRAN) neighbour cell list and/or UTRAN (respectively E-UTRAN) measurement parameters and/or UTRAN (respectively E-UTRAN) priority information, the network may instead set UTRAN_Start (respectively E-UTRAN_Start) bit and UTRAN_Stop (respectively E-UTRAN_Stop) bit to ‘0’ in every instance containing these bits.

Not including or not setting of UTRAN_Start (respectively E-UTRAN_Start) bit and/or UTRAN_Stop (respectively E-UTRAN_Stop) bit according to the above is considered as an abnormal case in which the mobile station’s behaviour is implementation specific.

The network shall ensure that the Serving cell priority parameters are included in at least one instance of the SI2quater message containing the UTRAN (respectively E-UTRAN) neighbour cell list, measurement parameters, or priority information. If the network repeats the Serving cell priority parameters within a consistent set of messages, then the network shall ensure that same set of Serving cell priority parameters are included in all repeated instances.

The network may repeat a UTRAN information set or an E-UTRAN information set within a consistent set of messages, provided that the information contained in all repeated information sets is the same. On BCCH, the MS needs only receive and decode the information in a single information set.

In idle mode or packet idle mode a multi-RAT MS supporting UTRAN and camping on BCCH shall read and decode all instances of SI2quater messages containing the UTRAN information set. When the 3G_BA_IND parameter is changed in idle mode or packet idle mode, the MS shall acquire the new UTRAN information set and rebuild the 3G Neighbour Cell list. The 3G Neighbour Cell list derived from SI2quater shall then be used for reporting when the MS enters dedicated mode, until it has received all instances of MEASUREMENT INFORMATION messages containing the UTRAN information set. In this case, the newly constructed 3G Neighbour Cell list shall be used. When the 3G_BA_IND parameter is changed when on SACCH, the MS shall also re-read all the instances of MEASUREMENT INFORMATION messages containing the new UTRAN information set, rebuild the 3G Neighbour Cell list, and use the new list for reporting.

In idle mode or packet idle mode a multi-RAT MS supporting E-UTRAN and camping on BCCH shall read and decode all instances of SI2quater messages containing the E-UTRAN information set. When the 3G_BA_IND parameter is changed in idle mode or packet idle mode, the MS shall acquire the new E-UTRAN information set and rebuild the E-UTRAN Neighbour Cell list. The E-UTRAN Neighbour Cell list shall then be used for reporting when the MS enters dedicated mode, until it has received all instances of MEASUREMENT INFORMATION messages containing the E-UTRAN information set. In this case, the newly constructed E-UTRAN Neighbour Cell list shall be used. When the 3G_BA_IND parameter is changed when on SACCH, the MS shall also re-read all the instances of MEASUREMENT INFORMATION messages containing the new E-UTRAN information set, rebuild the E-UTRAN Neighbour Cell list, and use the new list for reporting.

3.4.1.2.1.12 Reporting of CSG Cells and Hybrid Cells

A multi-RAT mobile station in dedicated mode or dual transfer mode may report a UTRAN CSG cell or hybrid cell if:

– the mobile station has received the UTRAN CSG Cells Reporting Description IE from the network in the SI2quater or MEASUREMENT INFORMATION message; and

– the mobile station has determined that it is allowed to access the CSG cell or hybrid cell, i.e. the CSG ID and the PLMN ID of the CSG cell or hybrid cell matches both a CSG ID and an associated PLMN ID stored in the mobile station’s CSG Whitelist (see 3GPP TS 23.122) and the PLMN ID of the CSG cell or hybrid cell matches:

– RPLMN ID or a PLMN ID in the EPLMN list and

– in dedicated mode after handover, the PLMN ID received in the System Information Type 6 message;

– in dual transfer mode, the RPLMN ID or a PLMN ID in the EPLMN list received during the latest registration or registration update with CS domain.

Further conditions and measurement reporting restrictions are specified in 3GPP TS 45.008.

The mobile station shall not report UTRAN CSG cells if it receives a MEASUREMENT INFORMATION message that does not include the UTRAN CSG Cells Reporting Description IE.

A mobile station shall report a detected UTRAN CSG cell, or hybrid cell which meets all the conditions and measurement reporting restrictions applicable to CSG cells, by including the UTRAN_CSG_Measurement_Report IE in the Measurement Results IE when reporting with the MEASUREMENT REPORT message or by including the UTRAN CSG Measurement Report IE in the ENHANCED MEASUREMENT REPORT message.

A hybrid cell which does not meet all the conditions and measurement reporting restrictions applicable to CSG cells shall be reported according to the rules for reporting non-CSG cells.

NOTE: The autonomous search function used to detect a CSG cell and determine whether a detected cell is a hybrid cell or not is implementation dependent and no performance requirements apply for this function while the mobile station is in dedicated or dual transfer mode.

3.4.1.3 Extended measurement report $(MAFA)$

Only applicable to mobile stations which support extended measurement.

When in dedicated mode or group transmit mode, a mobile station may receive an EXTENDED MEASUREMENT ORDER message, from the network. As defined in 3GPP TS 45.008, the mobile station shall then perform measurements on the frequencies specified by this EXTENDED MEASUREMENT ORDER message for one reporting period. The mobile station shall thereafter send an EXTENDED MEASUREMENT REPORT message. This message contains the measurement results as defined in 3GPP TS 45.008.

If the mobile station has not started to send its EXTENDED MEASUREMENT REPORT message within 10 seconds after the reception of the EXTENDED MEASUREMENT ORDER message, no EXTENDED MEASUREMENT REPORT message shall be sent. The mobile station shall after a successful channel change abort any pending measurements or reporting related to an EXTENDED MEASUREMENT ORDER message received on the old channel.

If a mobile station receives an EXTENDED MEASUREMENT ORDER message indicating the same value of the sequence code as an EXTENDED MEASUREMENT ORDER message received earlier on the same channel without having received any EXTENDED MEASUREMENT ORDER message indicating a different value of the sequence code in between, that EXTENDED MEASUREMENT ORDER message shall be ignored. If the mobile station, before the reporting related to an EXTENDED MEASUREMENT ORDER message has started, receives a new EXTENDED MEASUREMENT ORDER message with a different value of the sequence code, any pending measurements or reporting related to the earlier EXTENDED MEASUREMENT ORDER message shall be aborted and the new message treated.

The EXTENDED MEASUREMENT ORDER message and the EXTENDED MEASUREMENT REPORT message are sent on the SACCH, in unacknowledged mode.