6 Idle mode tasks

3GPP45.008GSM/EDGE Radio subsystem link controlTS

6.1 Introduction

Whilst in idle mode, an MS shall implement the cell selection and re‑selection procedures described in 3GPP TS 43.022. These procedures make use of measurements and sub‑procedures described in this subclause.

The procedures ensure that the MS is camped on a cell from which it can reliably decode downlink data and with which it has a high probability of communications on the uplink. Once the MS is camped on a cell, access to the network is allowed.

At cell selection, before accessing the network, the MS shall decode all information about dynamic mapping of ARFCN numbers, if used by the network. As an exception, a single access attempt (including repetitions allowed for channel request) is allowed using stored information that has been received from the same PLMN within the last 24 hours. Alternatively a single access attempt is allowed using stored information, received from the same PLMN, without decoding all SI 15 instances if the Dynamic ARFCN Mapping change mark (See 3GPP TS 44.018) in the stored information is equal to that decoded from any of SI 15 instances. The MS shall always use the most recent information about Dynamic ARFCN Mapping. EC-GSM-IoT does not support Dynamic ARFCN Mapping.

This clause makes use of terms defined in 3GPP TS 43.022.

The MS shall not use the discontinuous reception (DRX) mode of operation (i.e. powering itself down when it is not expecting paging messages from the network) while performing the cell selection algorithm defined in 3GPP TS 43.022. However use of powering down is permitted at all other times in idle mode.

For the purpose of cell selection and reselection, the MS shall be capable of detecting and synchronizing to a BCCH carrier and read the (EC-)BCCH data at reference sensitivity level or input level at reference performance, whichever applicable, and reference interference ratios or interference ratios at reference performance, whichever applicable, as specified in 3GPP TS 45.005. An MS in idle mode shall always fulfil the performance requirements specified in 3GPP TS 45.005 at input levels down to the reference sensitivity level and interference ratios down to the reference interference ratio. The allowed error rates (see 3GPP TS 45.005) might impact the cell selection and reselection procedure, e.g. trigger cell reselection. Moreover, one consequence of the allowed error rates is that:

– in the case of no frequency hopping and a TU3 (TU6 for GSM 400, TU3.6 for GSM 700, TU1.5 for DCS 1 800 and PCS 1 900) propagation profile, it can not be expected that an MS will respond to paging unless the interference ratio is 2 dB higher than the specified reference interference ratio for C/Ic and C/Ia; and

– in the case of TU1.2 (no FH) propagation profile (GSM 850, GSM 900, DCS 1800 and PCS 1900) and EC-GSM-IoT, it can not be expected that an MS will respond to paging unless the received signal level is [2] dB higher than the specified input signal level, or the interference ratio is [2] dB higher than the specified cochannel or adjacent channel interference ratio, respectively, at reference performance of EC-CCCH/D for the used Coverage Class.

For the purposes of cell selection and reselection, the MS is required to maintain an average of received signal levels for all monitored frequencies. These quantities termed the "received level averages" (RLA_C), shall be unweighted averages of the received signal levels measured in dBm. The accuracy of the received signal level measurements for idle mode tasks shall be the same as for radio link measurements (see subclause 8.1.2).

As an exception, an EC-GSM-IoT capable MS shall measure RLA_EC as specified in subclause 6.9 when evaluating an EC-GSM-IoT cell for selection and reselection. An EC-GSM-IoT capable MS that also supports GPRS services using GPRS or EGPRS TBFs shall measure RLA_GC as specified in subclause 6.9a when evaluating a non EC-GSM-IoT cell for selection and reselection.

An MS that has enabled PEO or that supports PEO and that is attempting to decode the Base Station Identity Code (BSIC), shall use the 9 bit BSIC consisting of the 6 bit BSIC field transmitted in the SCH and the 3 bit Radio frequency Colour Code (RCC) field transmitted in System Information and AGCH /PCH (see 3GPP TS 44.018 and 3GPP TS 23.003), for later BSIC verification, see sub-clause 7.2.1.

If the MS camps on a GERAN cell as a result of a cell change order from E-UTRAN (see 3GPP TS 36.331) or redirection from E-UTRAN (see 3GPP TS 36.304), and system information for that cell is provided by the network in E-UTRAN, the MS may omit to acquire the system information from the BCCH before establishing a circuit switched connection if the conditions specified in 3GPP TS 44.018 are met.

For the specific case of CS Fallback by cell change order or redirection from E-UTRAN, if the MS camps on a suitable cell whose LAI is different to the one stored in the MS, the MS shall initiate a location updating or a combined routing area updating procedure as specified in 3GPP TS 24.008.

The times given in subclauses 6.2, 6.3 and 6.6 refer to internal processes in the MS required to ensure that the MS camps as quickly as possible to the most appropriate cell.

For the cell selection, the MS shall be able to select the correct (fourth strongest) cell and be able to respond to paging on that cell within 30 seconds of switch on, when the three strongest cells are not suitable. This assumes a valid SIM with PIN disabled and ideal radio conditions. For an MS that supports EC-GSM-IoT, the allowed time is [80] seconds with all four cells in extended coverage, i.e. received levels below the input level for BCCH reference performance (i.e. SDCCH reference performance for a TIGHTER MS for the static channel in Table 1w of 3GPP 45.005) equal to [-110] dBm, but above [-115] dBm. This requirement is not applicable for multi-RAT mobile stations.

NOTE: Priorities between different frequencies or RATs provided to the MS by system information or by dedicated signalling are not used in the cell selection process.

The tolerance on all the timing requirements in clause 6 is ± 10 %, except for PENALTY_TIME where it is ± 2 s.

6.2 Measurements for normal cell selection

The measurements of this clause shall be performed by an MS which has no prior knowledge of which RF channels are BCCH carriers.

The MS shall search all RF channels within its bands of operation, take readings of received RF signal level on each RF channel, and calculate the RLA_C for each. The averaging is based on at least five measurement samples per RF carrier spread over 3 to 5 s, the measurement samples from the different RF carriers being spread evenly during this period.

An EC-GSM-IoT capable MS shall perform EC-GSM-IoT cell selection based on RLA_EC (see subclause 6.9). In case the MS also supports GPRS services using GPRS or EGPRS TBFs, non EC-GSM-IoT cell selection shall be based on RLA_GC (see subclause 6.9a). Therefore, following the RLA_C measurements described above, the MS shall perform a second search of the RF channels within its bands of operation, and measure:

– RLA_EC for the strongest EC-BCCH carrier, out of each RF channel where an EC-SCH is detected.

– RLA_GC for the strongest BCCH carrier on each RF channel where an EC-SCH is not detected, in case the MS supports GPRS or EGPRS TBFs.

The cell selected by an EC-GSM-IoT capable MS as a result of performing the cell selection procedure shall be the suitable cell (see 3GPP TS 43.022 [11]) with the highest measured value (i.e., RLA_EC if the MS does not support GPRS services, highest of RLA_EC and RLA_GC if MS supports GPRS services). When measuring candidate cells during the selection procedure, RLA_EC and RLA_GC measurements may be omitted (and the corresponding cells not considered for cell selection) for those candidate cells for which the measured RLA_C is more than CELL_SELECTION_RLA_MARGIN dB below the measured RLA_EC or RLA_GC of the best candidate cell identified to that point in the cell selection procedure. CELL_SELECTION_ RLA_MARGIN is optionally broadcast in EC SI in cells supporting EC-GSM-IoT, and in SI in cells not supporting EC-GSM-IoT, see 3GPP TS 44.018 [17]. If not broadcast, the default value shall be used (see table 1 in clause 9).

A multi band MS shall search all channels within its bands of operation as specified above. The number of channels searched will be the sum of channels on each band of operation.

BCCH carriers can be identified by, for example, searching for frequency correction bursts. On finding a BCCH carrier, the MS shall attempt to synchronize to it and read the BCCH data.

An EC-GSM-IoT capable MS performing measurements for cell selection on an EC-GSM-IoT capable cell shall search for frequency correction bursts and synchronization bursts carrying EC-SCH when identifying BCCH carriers, see subclause 6.9. Before selecting a BCCH carrier, the MS shall attempt to synchronize to it and read the EC-BCCH data. An EC-GSM-IoT capable MS attempting to synchronize to a BCCH carrier in search for an EC-GSM-IoT cell may assume that the cell is a non EC-GSM-IoT cell if no successful decoding of EC-SCH has been done within 2 s.

The maximum time allowed for synchronization to a BCCH carrier is 0.5 s, and the maximum time allowed to read the BCCH data, when being synchronized to a BCCH carrier, is 1.9 s or equal to the scheduling period for the BCCH data, whichever is greater (see 3GPP TS 45.002). The MS is allowed to camp on a cell and access the cell after decoding all relevant BCCH data.

An EC-GSM-IoT capable MS shall be able to synchronize to the BCCH carrier of an EC-GSM-IoT cell within 2 s at input signal level for reference performance of EC-BCCH. The maximum time allowed to read the EC-BCCH data, when being synchronized to a BCCH carrier of an EC-GSM-IoT cell, is 12 s or equal to the scheduling period for the EC-BCCH data, whichever is greater (see 3GPP TS 45.002 [22]) in ideal radio conditions. The MS is allowed to camp on an EC-GSM-IoT capable cell and access the cell after decoding all relevant EC-BCCH data.

6.3 Measurements for stored list cell selection

The MS may include optional storage of BCCH carrier information when switched off as detailed in 3GPP TS 43.022. For example, the MS may store the BCCH carriers in use by the PLMN selected when it was last active in the network. The BCCH list may include BCCH carriers from more than one band in a multi band operation PLMN. A MS may also store BCCH carriers for more than one PLMN which it has selected previously (e.g. at national borders or when more than one PLMN serves a country), in which case the BCCH carrier lists must be kept quite separate.

A MS supporting EC-GSM-IoT may store a separate list of BCCH carriers configured to carry the EC-BCCH.

The stored BCCH carrier information used by the MS may be derived by a variety of different methods. The MS may use the BA_RANGE information element, which, if transmitted in the channel release message (see 3GPP TS 44.018), indicates ranges of carriers which include the BCCH carriers in use over a wide area or even the whole PLMN. It should be noted that the BA(BCCH) list might only contain carriers in use in the vicinity of the cell on which it was broadcast, and therefore might not be appropriate if the MS is switched off and moved to a new location.

The BA_RANGE information element contains the Number of Ranges parameter (defined as NR) as well as NR sets of parameters RANGEi_LOWER and RANGEi_HIGHER. The MS should interpret these to mean that all the BCCH carriers of the network have ARFCNs in the following ranges:

Range1 = ARFCN(RANGE1_LOWER) to ARFCN(RANGE1_HIGHER);
Range2 = ARFCN(RANGE2_LOWER) to ARFCN(RANGE2_HIGHER);
RangeNR = ARFCN(RANGENR_LOWER) to ARFCN(RANGENR_HIGHER).

If RANGEi_LOWER is greater than RANGEi_HIGHER, the range shall be considered cyclic and encompasses carriers with ARFCN from range RANGEi_LOWER to 1 023 and from 0 to RANGEi_HIGHER. If RANGEi_LOWER equals RANGEi_HIGHER then the range shall only consist of the carrier whose ARFCN is RANGEi_LOWER.

If an MS includes one or more stored BCCH carrier list(s) of the selected PLMN it shall perform the same measurements as in subclause 6.2 except that only the BCCH carriers in the list need to be measured.

NOTE: If the selected PLMN is equal to one of the equivalent PLMNs, then stored list cell selection applies to all equivalent PLMNs.

If stored list cell selection is not successful, then as defined in 3GPP TS 43.022, normal cell selection shall take place. Since information concerning a number of channels is already known to the MS, it may assign high priority to measurements on the strongest carriers from which it has not previously made attempts to obtain BCCH information, and omit repeated measurements on the known ones.

6.4 Criteria for cell selection and reselection

6.4.1 C1 path loss criterion

The path loss criterion (see 3GPP TS 43.022 [11]) parameter C1 used for cell selection and reselection by a MS not capable of EC-GSM-IoT is defined as:

C1 = (A ‑ Max(B,0))

The above parameters are defined in table 6.4-1.

Table 6.4-1: C1 parameters

Parameter	Description
A [dB]	RLA_C ‑ RXLEV_ACCESS_MIN
RLA_C [dBm]	Signal level metric as defined in subclause 6.1
RXLEV_ACCESS_MIN [dBm]	Minimum received signal level at the MS required for access to the system.
B [dB]	MS_TXPWR_MAX_CCH + POWER OFFSET – P
MS_TXPWR_MAX_CCH [dBm]	Maximum TX power level an MS may use when accessing the system until otherwise commanded.
POWER OFFSET [dB]	The power offset to be used in conjunction with the MS_TXPWR_MAX_CCH parameter by the class 3 DCS 1 800 MS. In all other cases POWER_OFFSET=0.
P [dBm]	Maximum RF output power of the MS.

For an EC-GSM-IoT capable MS C1 is evaluated in two differenct ways, depending on if the cell supports EC-GSM-IoT or not.

– For an EC-GSM-IoT capable MS evaluating the path loss criterion for an EC-GSM-IoT cell C1 is defined as:

C1_EC = (A_EC ‑ Max(B_EC,0))

The above parameters are defined in table 6.4-2.

Table 6.4-2: C1_EC parameters

Parameter	Description
A_EC [dB]	RLA_EC – EC_RXLEV_ACCESS_MIN, if use of enhanced coverage is not restricted; RLA_EC – min{ (EC_RXLEV_ACCESS_MIN + CE_AUTH_OFFSET), RXLEV_ACCESS_MIN }, if use of enhanced coverage is restricted (see NOTE 2).
RLA_EC [dBm]	Signal level metric as defined in subclause 6.9
EC_RXLEV_ACCESS_MIN [dBm]	Minimum received signal level at the EC-GSM-IoT MS required for access to the EC-GSM-IoT cell.
CE_AUTH_OFFSET [dB]	Offset to be applied, if use of enhanced coverage is restricted (see 3GPP TS 44.018 [17]). If the offset for the serving cell or for a neighbour cell is not broadcasted, the MS shall assume CE_AUTH_OFFSET=0 for the respective cell.
B_EC [dB]	MS_TXPWR_MAX_CCH – P
MS_TXPWR_MAX_CCH [dBm]	Maximum TX power level an EC-GSM-IoT MS may use when accessing the system until otherwise commanded.
P [dBm]	Maximum RF output power of the MS.

NOTE 1: When TX diversity (antenna hopping) is active a MS may underestimate RLA_EC. This can be compensated for by the network in an adjustment of the EC_RXLEV_ACCESS_MIN.

NOTE 2: Use of enhanced coverage may be restricted by the network by having previously signalled that use of enhanced coverage is restricted (see 3GPP TS 24.008 [46]).

– For an EC-GSM-IoT capable MS evaluating the path loss criterion for a cell not supporting EC-GSM-IoT C1 is defined as:

C1_GC = (A_GC ‑ Max(B,0))

The above parameters are defined in table 6.4-3.

Table 6.4-3: C1_GC parameters

Parameter	Description
A_GC [dB]	RLA_GC ‑ RXLEV_ACCESS_MIN
RLA_GC [dBm]	Signal level metric as defined in subclause 6.9a
RXLEV_ACCESS_MIN [dBm]	Minimum received signal level at the MS required for access to the system. NOTE: This refers to the EC-GSM-IoT MS for access to the non EC-GSM-IoT supporting cell.
B [dB]	MS_TXPWR_MAX_CCH + POWER OFFSET – P
MS_TXPWR_MAX_CCH [dBm]	Maximum TX power level an EC-GSM-IoT MS may use when accessing the system until otherwise commanded.
POWER OFFSET [dB]	The power offset to be used in conjunction with the MS_TXPWR_MAX_CCH parameter by the class 3 DCS 1 800 MS. In all other cases POWER_OFFSET=0.
P [dBm]	Maximum RF output power of the MS.

The path loss criterion is satisfied if C1 > 0.

6.4.2 C2 reselection criterion

The reselection criterion C2 is used for cell reselection only and is, for MS that are not EC-GSM-IoT capable, defined by:

For PENALTY_TIME <> 11111:

C2 = C1 + CELL_RESELECT_OFFSET ‑ TEMPORARY_OFFSET * H(PENALTY_TIME ‑ T)

For PENALTY_TIME = 11111:

C2 = C1 ‑ CELL_RESELECT_OFFSET

where the above parameters are defined in table 6.4-4.

Table 6.4-4: C2 parameters

Parameter	Description
H(x)	Equals 0 for serving cells, and non-serving cells when x < 0 Equals 1 for non-serving cells when x  0
T	A timer implemented for each cell in the list of strongest carriers (see subclause 6.6.1). T shall be started from zero at the time the cell is placed by the MS on the list of strongest carriers, except when the previous serving cell is placed on the list of strongest carriers at cell reselection. In this, case, T shall be set to the value of PENALTY_TIME (i.e. expired).
CELL_RESELECT_OFFSET	An offset to the C2 reselection criterion for that cell.
TEMPORARY_OFFSET	A negative offset to C2 for the duration of PENALTY_TIME after the timer T has started for that cell.
PENALTY_TIME	The duration for which TEMPORARY_OFFSET applies The all ones bit pattern on the PENALTY_TIME parameter is reserved to change the sign of CELL_RESELECT_OFFSET and the value of TEMPORARY_OFFSET is ignored as indicated by the equation defining C2.
NOTE: CELL_RESELECT_OFFSET may be used to give different priorities to different bands when multiband operation is used.

CELL_RESELECT_OFFSET, TEMPORARY_OFFSET, PENALTY_TIME and CELL_BAR_QUALIFY (see table 1a) are optionally broadcast on the BCCH of the cell. If the parameters are not broadcast, the default values are CELL_BAR_QUALIFY = 0, and the other parameters shall be set so that C2 = C1.

For an EC-GSM-IoT capable MS, C2 is evaluated in two different ways, depending on if the cell supports EC-GSM-IoT or not.

– For an EC-GSM-IoT capable MS evaluating the cell reselection criterion for a cell capable of EC-GSM-IoT, C2 is defined as:

C2_EC = RLA_EC -Max(B_EC,0) + EC_CELL_RESELECT_OFFSET

The above parameters are defined in table 6.4-5.

Table 6.4-5: C2_EC parameters

Parameter	Description
EC_CELL_RESELECT_OFFSET	EC-GSM-IoT specific version of CELL_RESELECT_OFFSET. In case not broadcast the parameter should be set to 0.

– For an EC-GSM-IoT capable MS evaluating the cell reselection criterion for a cell not supporting EC-GSM-IoT, C2 is defined as:

For PENALTY_TIME <> 11111:

C2_GC = RLA_GC – Max(B,0) + CELL_RESELECT_OFFSET – TEMPORARY_OFFSET * H(PENALTY_TIME ‑ T)

For PENALTY_TIME = 11111:

C2_GC = RLA_GC – Max(B,0) – CELL_RESELECT_OFFSET

The use of C2 is described in 3GPP TS 43.022.

These described parameters are used to ensure that the MS is camped on the cell with which it has the highest probability of successful communication on uplink and downlink.

6.4.3 C4 criteria

The signal strength threshold criterion parameter C4 is used to determine whether prioritised LSA cell reselection shall apply and is defined by:

C4 = A – PRIO_THR

where

A is defined as above and PRIO_THR is the signal threshold for applying LSA reselection. PRIO_THR is broadcast on the BCCH. If the idle mode support is disabled for the LSA (see 3GPP TS 51.011) or if the cell does not belong to any LSA to which the MS is subscribed or if no PRIO_THR parameter is broadcast, PRIO_THR shall be set to .

6.4.4 Disabling of EC operation

In case a MS in EC operation disables EC operation, a cell reselection needs to be performed to ensure that the MS finds a suitable cell for camping. Whenever EC operation is disabled (or enabled) a MS may need to perform a cell update (see 3GPP TS 44.018 [17]).

6.5 Downlink signalling failure

For a MS in idle mode that has not enabled PEO or EC operation, the downlink signalling failure criterion is based on the downlink signalling failure counter DSC. When the MS camps on a cell, DSC shall be initialized to a value equal to the nearest integer to 90/N where N is the BS_PA_MFRMS parameter for that cell (see 3GPP TS 45.002). Thereafter, whenever the MS attempts to decode a message in its paging subchannel; if a message is successfully decoded (BFI = 0) DSC is increased by 1, however never beyond the initial value, otherwise DSC is decreased by 4. When DSC  0, a downlink signalling failure shall be declared.

An MS in packet idle mode or MAC-Idle state that has not enabled PEO or EC operation shall follow the same procedure for DSC management. The counter DSC shall be initialized each time the MS enters packet idle mode or MAC-Idle state, respectively. In case DRX period split is supported, DSC shall be initialized to a value equal to the nearest integer to max(10, 90* N_DRX), where N_DRX is the average number of monitored blocks per multiframe in DRX mode according to its paging group (see 3GPP TS 45.002 [22]). In non-DRX mode, the MS shall only increment/decrement DSC for one block per DRX period according to its paging group. The exact position of these blocks is not essential, only the average rate.

A MS that has enabled PEO with eDRX shall, upon entering packet idle mode, initialize PCH_DSC to the value indicated by the PEO_DSC field of the SI 13 Rest Octets IE (see 3GPP TS 44.018 [17]). Thereafter, if the MS successfully decodes a message in its paging subchannel (i.e. using its nominal paging group) PCH_DSC is incremented by 1, but not beyond the initial value. Otherwise, it shall decrement PCH_DSC by 1 and begin monitoring PCH blocks according to the shortest eDRX cycle value (i.e. eDRX Cycle Value = 0000, see 3GPP TS 45.002 [22]). While monitoring PCH blocks according to the shortest eDRX cycle value the MS shall still monitor PCH paging occasions determined by its negotiated eDRX value. It repeats the process of incrementing/decrementing PCH_DSC based on the outcome of each attempted PCH decoding until it either successfully decodes a PCH/AGCH message at which point it resumes monitoring only PCH blocks corresponding to its negotiated eDRX Cycle Value, or PCH_DSC = 0 at which point a downlink signalling failure shall be declared. A MS that has enabled PEO shall use a non-DRX mode period of zero seconds.

NOTE: The network sends the paging subchannel for a given MS every BS_PA_MFRMS multiframes or, in case DRX period split is supported, every 1/N_DRX multiframes. An exception is the case of a MS that is using eDRX in which case the network sends paging messages using paging sub-channels as described in 3GPP TS 45.002 [22]. The requirement for network transmission on the paging subchannel is specified in 3GPP TS 44.018 [17] or 3GPP TS 44.060 [19]. The MS is required to attempt to decode a message every time its paging subchannel is sent.

For a MS that has enabled EC operation downlink signalling failure is declared if the MS fails to decode EC-SCH within 2.5 seconds during an attempt to synchronize to a cell (i.e. neither DSC nor PEO_DSC are used). A MS that has enabled EC operation shall use a non-DRX mode period of zero seconds.

A downlink signalling failure shall result in the MS performing the cell reselection procedure (i.e. if a better cell is found it is used).

6.6 Measurements for Cell Reselection

6.6.0 General

Upon completion of cell selection and when starting the cell reselection tasks, the MS shall synchronize to and read the BCCH information for the 6 strongest non‑serving carriers (in the BA) as quickly as possible within the times specified in subclause 6.6.1. An exception is the case of a MS that has enabled PEO or EC operation in which case the MS shall start the cell reselection task based on the criteria described in sub-clause 6.6.1a. For multi band MSs the strongest non‑serving carriers may belong to different frequency bands. If system information message type 2 ter or 2 quater is used in the serving cell, and the MS has decoded all relevant serving cell BCCH data, except system information message 2 ter and/or 2 quater, then the MS shall start cell reselection measurements based on the known part of the BA, until system information message 2 ter and/or 2 quater is decoded and the full BA can be used.

MSs supporting SoLSA with SoLSA subscription shall perform cell re-selection according to subclause 6.6.3. Other MSs shall perform cell re-selection according to subclause 6.6.2.

MSs supporting other radio access technologies shall also perform measurements according to subclause 6.6.4 and cell-reselection according to subclause 6.6.5 or 6.6.6.

6.6.1 Monitoring of received signal level and BCCH data

6.6.1.1 Applicability

If a MS has enabled PEO or EC operation then while in idle mode it shall monitor the received signal level and BCCH data as described in clause 6.6.1a. Otherwise, whilst in idle mode an MS shall continue to monitor all BCCH carriers as indicated by the BCCH allocation (BA ‑ See table 1). An EC-GSM-IoT capable MS that has not enabled PEO or EC operation (e.g., because it is camping on a cell that does not support EC-GSM-IoT or PEO) shall monitor the received signal level and BCCH data as specified below, except that RLA_C measurements (see subclause 6.6.1.2) shall be replaced by RLA_EC measurements (see subclause 6.9) for neighbour cells supporting EC-GSM-IoT, and by RLA_GC measurements (see subclause 6.9a) for neighbour cells not supporting EC-GSM-IoT, but with requirements on number of samples and averaging periods according to subclause 6.6.1.2.

6.6.1.2 Monitoring of received signal level

A running average of received signal level (RLA_C) in the preceding 5 to:

Max {5 , ((5 * N + 6) DIV 7) * BS_PA_MFRMS / 4}

seconds shall be maintained for each carrier in the BCCH allocation. N is the number of non‑serving cell BCCH carriers in BA and the parameter BS_PA_MFRMS is defined in 3GPP TS 45.002.

The same number of measurement samples shall be taken for all non‑serving cell BCCH carriers of the BA list, and the samples allocated to each carrier shall as far as possible be uniformly distributed over each evaluation period. At least 5 received signal level measurement samples are required per RLA_C value. New sets of RLA_C values shall be calculated as often as possible.

For the serving cell, received signal level measurement samples shall be taken at least for each paging block of the MS. The RLA_C shall be a running average determined using samples collected over a period of 5 s to Max {5s, five consecutive paging blocks of that MS}. The samples shall as far as possible be uniformly distributed over each evaluation period. At least 5 received signal level measurement samples are required per RLA_C value. New RLA_C values shall be calculated as often as possible.

The list of the 6 strongest non‑serving carriers shall be updated at least as often as the duration of the running average defined for measurements on the BCCH allocation and may be updated more frequently.

In order to minimize power consumption, MS that employ DRX (i.e. power down when paging blocks are not due) should monitor the received signal levels of non‑serving cell BCCH carriers during the frames of the paging block that they are required to listen to. The MS shall include the BCCH carrier of the current serving cell (i.e. the cell the MS is camped on) in this measurement routine. Received signal level measurement samples can thus be taken on several non‑serving cell BCCH carriers and on the serving carrier during each paging block.

6.6.1.3 Monitoring of BCCH data and BSIC decoding

The MS shall attempt to decode the full BCCH data of the serving cell at least every 30 seconds or at least as often as possible in the case that system information scheduling period exceeds 30 seconds. As an exception, after the first attempt at cell selection, SI15, if used, shall be decoded at least once every 30 minutes.

If SI13 is broadcast, the MS supporting change mark in SI13 (See 3GPP TS 44.018) is only required to confirm system information on the BCCH of the serving cell if indicated by change mark in SI13.

The MS shall attempt to decode the BCCH data block that contains the parameters affecting cell reselection for each of the 6 strongest non‑serving cell BCCH carriers at least every 5 minutes, if the parameters affecting cell reselection have not been provided by the network in the serving cell.

When the MS recognizes that a new BCCH carrier has become one of the 6 strongest, the BCCH data shall be decoded for the new carrier within 30 seconds, if the information is not already available.

If the network indicates that it supports the SI2n message in the serving cell, the MS in packet transfer mode or broadcast/multicast receive mode shall not interrupt data transfer by attempting to autonomously decode the BCCH data block that contains the parameters affecting cell reselection, from non-serving cells. However, if relevant reselection parameters are not received from the serving cell within 30 seconds after reselecting a new cell, the MS shall revert to autonomous decoding of parameters from non-serving cells.

The MS shall attempt to check the BSIC for each of the 6 strongest non‑serving cell BCCH carriers at least every 30 seconds, to confirm that it is monitoring the same cell. If a change of BSIC is detected then the carrier shall be treated as a new carrier and the BCCH data re-determined.

For an MS supporting network sharing (see 3GPP TS 44.018 [17], 3GPP TS 23.251 [45] and 3GPP TS 24.008 [46]), only cells with allowed BSIC shall be considered for reselection. The allowed BSIC is either a valid BSIC with a permitted NCC part or, for cells in BA(BCCH) where no BSIC is broadcast, a BSIC with a permitted NCC part (see subclause 7.2).

In addition, an MS supporting SoLSA with SoLSA subscription shall attempt to decode BSIC and the BCCH data blocks that contain the parameters affecting SoLSA cell reselection for the 6 strongest carriers, which are included both in the BCCH allocation and in the BA_PREF as received in the latest CHANNEL RELEASE message (see 3GPP TS 44.018). At least one carrier shall be searched every 5 minutes, one after another. In the case the MS has been able to decode the BCCH data blocks, the rules described in subclause 6.6.3 shall be followed.

6.6.1.4 Determination of available PLMNs

When requested by the user, the MS shall determine which PLMNs are available (Manual Mode) or available and allowable (Automatic Mode) (see 3GPP TS 43.022) within 10 seconds (for GSM 450), 10 seconds (for GSM 480), 15 seconds (for GSM 700), 15 seconds (for GSM 850, ER-GSM 900 and GSM 900) or 20 seconds (for DCS 1 800 and PCS 1 900). A multi band MS shall perform the same procedures in all bands of operation within the sum of time constraints in the respective band of operation.

In both cases, this monitoring shall be done so as to minimize interruptions to the monitoring of the PCH.

6.6.1.5 Requirements for synchronization and reading of BCCH data

The maximum time allowed for synchronization to a BCCH carrier is 0,5 s, and the maximum time allowed to read the BCCH data, when being synchronized to a BCCH carrier, is 1,9 s or equal to the scheduling period for the BCCH data, whichever is greater (see 3GPP TS 45.002).

6.6.1a Reduced Monitoring of received signal level and (EC-)BCCH data

6.6.1a.1 General

A MS that has enabled PEO or EC operation shall, while in packet idle mode, support relaxed mobility related procedures, i.e., a reduced monitoring of signal levels and BCCH data (in case of PEO) or EC-BCCH data (in case of EC operation).

6.6.1a.2 Monitoring of the serving cell

The MS shall perform the following tasks for the serving cell:

– BSIC confirmation and evaluation of the applicable C1 criterion (see subclause 6.4.1) for the BCCH carrier of the serving cell shall be performed before each time the paging block is monitored (i.e. eDRX is used) or, if the MS supports EC Paging Indication Channel monitoring and the support of this channel is indicated in EC System Information, before each time the EC-PICH block is monitored, or each uplink transmission. However, these evaluations need not be performed more often than once every 30 seconds. BSIC confirmation is performed on the (EC-)BCCH carrier of the serving cell which may not be the strongest cell when PEO or EC operation is enabled.

– In case of paging block monitoring or, if the MS supports EC Paging Indication Channel monitoring and the support of this channel is indicated in EC System Information, in case of monitoring the EC-PICH block, the MS shall wake up sufficiently in advance so that, in the event that cell reselection becomes necessary, there will be sufficient time to complete the cell reselection prior to the paging block monitoring, or, if the MS supports EC Paging Indication Channel monitoring and the support of this channel is indicated in EC System Information, prior to monitoring the EC-PICH block.

– When evaluating C1, a MS that has enabled PEO shall take received signal level measurement samples over a period of at least 5 seconds to establish a running average RLA_C where the samples shall, as far as possible, be uniformly distributed over each evaluation period and at least 5 received signal level measurement samples are required per RLA_C value. An EC-GSM-IoT capable MS that has enabled EC operation shall calculate RLA_EC as specified in subclause 6.9.

– The MS shall keep track of two C1 values:

– C1_a, the best C1 value experienced in the serving cell since last performing measurements for cell reselection, or, after cell selection, since selecting the serving cell; and

– C1_b, the most recently evaluated C1 (i.e. the current C1 value)

– Upon evaluating C1 it determines if the current C1 value (C1_b) is less than the best C1 value (C1_a) by more than C1_DELTA. C1_DELTA is calculated each time measurements for cell re-selection are performed, see subclause 6.6.1a.4. Measurements for cell re-selection are triggered if the difference is greater than C1_DELTA. After cell selection, C1_DELTA shall be set to the value of the C1_DELTA_MIN parameter sent in SI13 for PEO or in EC SI 3 for EC operation – see 3GPP TS 44.018 [17].

– A MS that has enabled PEO shall read the PEO_BCCH_CHANGE_MARK field when performing the packet access procedure (see 3GPP TS 44.018 [17]). If a change of PEO_BCCH_CHANGE_MARK is detected it shall first read SI13 before proceeding with the packet access procedure. If no change is detected and the time elapsed since it last read SI13 exceeds 24 hours it shall read SI13 before proceeding with the packet access procedure. Otherwise, it proceeds with the packet access procedure without first reading SI13.

– In addition, if the MS supports deferred system information acquisition in PEO, the network provides the PEO Idle Mode Mobility Cell Group definition in SI 13 (see 3GPP TS 44.018 [17]), and the cell it reselects to identifies a cell in the same PEO IMM Cell Group as the last serving cell and no increment of the change mark of the PEO IMM Cell Group compared to the one in the last serving cell is detected, it shall not read BCCH data of that cell prior to monitoring its paging block on PCH. The conditions when to read BCCH data, after cell reselection, in the serving cell are specified in 3GPP TS 44.018 [17]. In case the network does not provide the PEO IMM Cell Group definition in SI 13 (see 3GPP TS 44.018 [17]), the MS does not apply deferred system information acquisition in PEO and performs reading of BCCH data of the serving cell as in normal operation for PEO.

– A MS that has enabled EC operation shall read the EC-BCCH CHANGE MARK field in EC-SCH before proceeding with the packet access procedure (see 3GPP TS 44.018 [17]). If a change of EC-BCCH CHANGE MARK is detected, or if the time elapsed since it last read the complete EC SI message set exceeds 24 hours, the MS shall read EC SI as necessary (see 3GPP TS 44.018 [17]) before proceeding with the packet access procedure. Otherwise, it proceeds with the packet access procedure without first reading EC SI.

– In addition, if the MS supports deferred system information acquisition in EC operation, the network provides the Idle Mode Mobility Cell Group Definition in EC SI (see 3GPP TS 44.018 [17]), and the cell it reselects to identifies a cell in the same IMM Cell Group as the last serving cell and no increment of the change mark of the IMM Cell Group compared to the one in the last serving cell is detected, it shall not read EC-BCCH data of that cell prior to monitoring the paging block (EC-PCH) or the corresponding paging indication block (EC-PICH), if supported by that cell, which it has reselected to. The conditions when to read EC-BCCH data, after cell reselection, in the serving cell are specified in 3GPP TS 44.018 [17]. In case the network does not provide the IMM Cell Group Definition in EC SI (see 3GPP TS 44.018 [17]), the MS does not apply deferred system information acquisition in EC operation and performs reading of EC-BCCH data of the serving cell as in normal EC operation.

6.6.1a.3 Criteria for triggering measurements for cell re-selection

The MS shall proceed as described in sub-clause 6.6.1a.4 if any of the following criteria are fulfilled:

– Cell selection has been completed and monitoring of non-serving cells for cell reselection has not yet been performed;

– C1 ≤ 0;

– A change in BSIC is detected;

– A downlink signalling failure is declared;

– C1_a – C1_b > C1_DELTA, or

– More than 24 hours have passed since the last evaluation of C1 and C2 of non-serving cells;

– A MS that has enabled PEO or EC operation and supports the MTA procedure receives a paging request message that indicates a positioning event is pending (see 3GPP TS 44.018 and 3GPP TS 43.059) except if a cell re-selection has been performed within the last [60] seconds.

– A MS for which the use of enhanced coverage was previously restricted, receives a paging request message that indicates the removed restriction for use of enhanced coverage (see 3GPP TS 44.018).

The MS need not monitor the BCCH carriers of the non-serving cells as long as none of these criteria are fulfilled.

6.6.1a.4 Monitoring of non-serving cells

When determining if cell reselection is possible the MS shall first evaluate RLA_C, RLA_EC or RLA_GC (whichever is applicable) for all non‑serving BCCH carriers in the BA list and identify the N strongest (where 3 ≤ N ≤ 6 and N is implementation specific) using samples collected over a 5 second period.

In case the MS has enabled PEO and does not support deferred system information acquisition in PEO, and the network does not support transmission of the SI2n message in the serving cell then the MS shall also synchronize to and read the BCCH information for the N strongest non‑serving cell carriers (e.g. to acquire parameters needed for performing C1 and C2 evaluation and to determine if the cell is barred) as quickly as possible before determining if cell reselection is possible.

In case the MS has enabled PEO and supports deferred system information acquisition in PEO, and the network provides the PEO IMM Cell Group definition in SI 13 (see 3GPP TS 44.018 [17]), the MS shall identify non-serving cells based on provided broadcast frequencies assigned to the PEO IMM Cell Group and on BSIC for cells contained in the PEO IMM Cell Group definition. It shall then synchronize to cells with these BCCH frequencies and monitor AGCH/PCH messages, in order to determine if these cells belong to the same PEO IMM Cell Group as the serving cell and if their PEO IMM Change Mark has the same value as in the serving cell (see 3GPP TS 44.018 [17]). For these cells the MS does not need to read BCCH data prior to cell reselection.

In case the MS has enabled EC operation and does not support deferred system information acquisition in EC operation, and the network does not support transmission of cell reselection related parameters in EC SI in the serving cell then the MS shall also synchronize to and read the BCCH information or EC-BCCH information (whichever is applicable) for the N strongest non-serving cell carriers (e.g. to acquire parameters needed for performing C1 and C2 evaluation and to determine if the cell is barred) as quickly as possible before determining if cell reselection is possible.

In case the MS has enabled EC operation and supports deferred system information acquisition in EC operation, and the network provides the IMM Cell Group definition in EC SI (see 3GPP TS 44.018 [17]), the MS shall identify non-serving cells based on provided broadcast frequencies assigned to the IMM Cell Group and on BSIC for cells contained in the IMM Cell Group definition. It shall then synchronize to cells with these BCCH frequencies and read the EC-SCH content in two consecutive EC-SCH messages sent over 8*51-multiframes, starting with 51-multiframe N with N mod 8 = 0, in order to determine if these cells belong to the same IMM Cell Group as the serving cell and if their IMM Change Mark has the same value as in the serving cell (see 3GPP TS 44.018 [17]). For these cells the MS does not need to read EC-BCCH data prior to cell reselection.

For an MS supporting network sharing (see 3GPP TS 44.018 [17], 3GPP TS 23.251 [45] and 3GPP TS 24.008 [46]), only cells with allowed BSIC shall be considered for reselection. The allowed BSIC is a BSIC with a permitted NCC part. The permitted NCCs are defined by the NCC_PERMITTED parameter transmitted in the BCCH data.

The MS then proceeds as described in subclause 6.6.2.

After performing measurements for cell re-selection (regardless of whether a cell re-selection has been performed or not), the MS shall calculate the difference D between the most recent C1 of the serving cell and the most recent C1 of the strongest (in terms of C1) evaluated neighbour cell, and update C1_DELTA as follows:

C1_DELTA = min( max(D,C1_DELTA_MIN) , C1_DELTA_MAX )

If no neighbour cell has been found, C1_DELTA shall be set to C1_DELTA_MAX.

The parameters C1_DELTA_MIN and C1_DELTA_MAX are sent in SI13 for PEO and in EC SI 3 for EC operation – see 3GPP TS 44.018 [17].

6.6.2 Path loss criteria and timings for cell re‑selection

The MS is required to perform the following measurements (see 3GPP TS 43.022 [11]) to ensure that the path loss criterion to the serving cell is acceptable.

At least every 5 s the MS shall calculate the value of C1 and C2 for the serving cell and re‑calculate C1 and C2 values for non serving cells (if necessary). As an exception, a MS that has enabled PEO or EC operation shall only perform the calculations of this subclause under conditions given in subclause 6.6.1a.

The MS shall then check whether:

i) The path loss criterion (C1) for current serving cell falls below zero for a period of 5 seconds. This indicates that the path loss to the cell has become too high.

ii) The calculated value of C2 for a non‑serving suitable cell exceeds the value of C2 for the serving cell for a period of 5 seconds, except;

a) in the case of the new cell being in a different location area or, for a GPRS attached MS, in a different routing area or always for a GPRS attached MS in GMM Ready state (A/Gb mode) or RRC-Cell_Shared state (Iu mode) in which case the C2 value for the new cell shall exceed the C2 value of the serving cell by at least CELL_RESELECT_HYSTERESIS dB as defined by the BCCH data from the current serving cell, for a period of 5 seconds; or

b) in case of a cell reselection occurring within the previous 15 seconds in which case the C2 value for the new cell shall exceed the C2 value of the serving cell by at least 5 dB for a period of 5 seconds.

This indicates that it is a better cell.

If a better cell is available then the MS shall reselect the non-serving suitable cell with the highest C2 value, synchronize to that cell and read the BCCH information sent therein. Cell reselection for any other reason (see 3GPP TS 43.022 [11]) shall take place immediately, but the cell that the MS was camped on shall not be returned to within 5 seconds if another suitable cell can be found. If valid RLA_C, or RLA_EC, or RLA_GC values are not available, the MS shall wait until these values are available and then perform the cell reselection if it is still required. The MS may accelerate the measurement procedure within the requirements in subclause 6.6.1 or in case of PEO or EC operation in subclause 6.6.1a to minimize the cell reselection delay.

If no suitable cell is found within 10 seconds, the cell selection algorithm of 3GPP TS 43.022 shall be performed. Since information concerning a number of channels is already known to the MS, it may assign high priority to measurements on the strongest carriers from which it has not previously made attempts to obtain BCCH information, and omit repeated measurements on the known ones.

6.6.3 Cell reselection algorithm for SoLSA

At least for every new sample or every second, whichever is the greatest, the MS calculate the value of C1, C2 and C4 for the serving cell and the non‑serving cells. The MS shall make a cell reselection if:

i) The path loss criterion parameter (C1) for the serving cell falls below zero for a period of 5 seconds.

ii) A non‑serving suitable cell (see 3GPP TS 43.022 [11]) is evaluated to be better than the serving cell for a period of 5 seconds. The best cell is

– the cell with the highest value of C2 + LSA_OFFSET among those cells that have highest LSA priority among those that fulfil the criteria C4  0, or

– the cell with the highest value of C2 among all cells, if no cell fulfil the criterion C4  0.

LSA_OFFSET is broadcast on BCCH. If no LSA_OFFSET parameter is broadcast, LSA_OFFSET shall be set to 0.

LSA priority is defined by the list of LSAs for the subscriber stored on the SIM (see 3GPP TS 51.011 [34]). LSAs are identified by LSA ID(s), Cell Identity and/or Location Area Identity broadcast on BCCH. Cells not belonging to this list are given LSA priority lower than 0.

When evaluating the best cell, the following hysteresis values shall be subtracted from the C2 value for the neighbour cells:

– if the new cell is in the same location area: 0;

– if the new cell is in a different location area:
CELL_RESELECT_HYSTERESIS, which is broadcast on BCCH of the serving cell.

– in case of a cell reselection occurred within the previous 15 seconds: 5 dB.

Cell reselection for any other reason (see 3GPP TS 43.022 [11]) shall take place immediately, but the cell that the MS was camped on shall not be returned to within 5 seconds if another suitable cell can be found. If valid receive level averages are not available, the MS shall wait until these values are available and then perform the cell reselection if it is still required. The MS may accelerate the measurement procedure within the requirements in subclause 6.6.1 to minimise the cell reselection delay.

If no suitable cell is found within 10 seconds, the cell selection algorithm of 3GPP TS 43.022 [11] shall be performed. Since information concerning a number of channels is already known to the MS, it may assign high priority to measurements on the strongest carriers from which it has not previously made attempts to obtain BCCH information, and omit repeated measurements on the known ones.

6.6.4 Measurements on cells of other radio access technologies

For a multi-RAT MS, cells or frequencies with other radio access technologies (excluding E-UTRA) may be included in 3G Cell Reselection list (see 3GPP TS 44.018 [17]). If cell reselection based on ranking is used, the network controls the measurements for reselection of these cells by the parameter Qsearch_I broadcast on BCCH. Qsearch_I defines a threshold and also indicates whether these measurements shall be performed when RLA_C (see subclause 6.6.1) of the serving cell is below or above the threshold. These measurements may be performed less frequently than measurements of GSM cells as described in subclause 6.6.1, in order to conserve MS power.

For a multi-RAT MS supporting E-UTRA, E-UTRAN frequencies may be included in the E-UTRAN Neighbour Cell list (see 3GPP TS 44.018 [17]). The network controls the measurements for reselection of E-UTRA cells by the parameter THRESH_priority_search broadcast on BCCH. This parameter also controls measurement of inter-RAT cells or frequencies included in the 3G Cell Reselection list when the inter-RAT cell reselection algorithm based on priority information is used (see subclause 6.6.6). The mobile station shall monitor cells of inter-RAT frequencies of higher priority than the serving cell. When RLA_C of the serving cell is below THRESH_priority_search, the mobile station shall monitor cells of inter-RAT frequencies of lower priority than the serving cell. When RLA_C (see subclause 6.6.1) of the serving cell is above the threshold, the mobile station is allowed not to monitor cells of inter-RAT frequencies of lower priority than the serving cell.

The MS shall perform the measurement processes for E-UTRAN and other access technologies in parallel when applicable.

A UTRAN capable MS shall be able to identify and select a new best UTRAN cell on a frequency, which is part of the 3G Cell Reselection list, within 30 seconds (in case of cell reselection based on cell ranking) or 25+T_reselection seconds (in case of cell reselection based on priority information, if the UTRAN frequency has lower priority than the serving cell and if RLA_C of the serving cell is below THRESH_priority_search) after it has been activated under the condition that there is only one UTRAN frequency in the list (and no E-UTRAN frequencies in the E-UTRAN Neighbour Cell list) and that no new GSM cells are activated at the same time and under good radio conditions. As an exception, the time is increased to 70+T_reselectionseconds in case of a UTRAN capable MS performing cell reselection based on priority information (see subclause 6.6.6) if the UTRAN frequency has higher priority than the serving cell. A E-UTRAN capable MS shall be able to identify and select a new best E-UTRAN cell on a frequency, which is part of the E-UTRAN Neighbour Cell list, within 25+T_reselection seconds after it has been activated if the frequency has lower priority than the serving cell and if RLA_C of the serving cell is below THRESH_priority_search, or within 70+T_reselection seconds after it has been activated if the frequency has higher priority than the serving cell, under the condition that there is only one E-UTRAN frequency in the list (and no UTRAN frequencies in the 3G Cell Reselection list) and that no new GSM cells are activated at the same time and under good radio conditions. For test purposes the following radio conditions can be used: Serving GSM cell at RXLEV= -70 dBm, with 6 GSM neighbours at RXLEV= -75 dBm. Then either an UTRAN FDD neighbour cell or an UTRAN TDD neighbour cell or an E-UTRAN FDD neighbour cell or an E-UTRAN TDD neighbour cell is switched on. The radio conditions for the UTRAN FDD cell are as follows (see 3GPP TS 25.101 [5] for definitions):

Parameter	Unit	UTRAN FDD Cell
CPICH_Ec/Ior	dB	-10
P-CCPCH_Ec/Ior	dB	-12
SCH_Ec/Ior	dB	-12
PICH_Ec/Ior	dB	-15
DPCH_Ec/Ior	dB	-
OCNS_Ec/Ior	dB	-0.94
	dB	10
	dBm/3.84 MHz	-70
CPICH_Ec/Io	dB	-10.4
CPICH RSCP	dBm	-70
FDD_Qoffset	integer	5 (-12dB)
FDD_Qmin	integer	7 (-12dB)
FDD_Qmin_Offset	integer	0 (0 dB)
FDD_RSCPmin	integer	6 (-102 dBm)
Qsearch_I	integer	7 (search always)
Propagation Condition	AWGN

NOTE: The parameters in the table above are valid only for cell reselection based on cell ranking.

The radio conditions for the UTRAN TDD cell (either 3.84 Mcps TDD option or 1.28 Mcps TDD option) are as follows (see 3GPP TS 25.123 [6] for definitions and for the values of the remaining configuration parameters):

Parameter	Unit	UTRAN TDD Cell (3.84 Mcps option)
Timeslot Number		0	8
P-CCPCH_Ec/Ior	dB	-3
SCH_Ec/Ior	dB	-9	-9
SCH_toffset	integer	0	0
PICH_Ec/Ior	dB		-3
OCNS_Ec/Ior	dB	-3.12	-3.12
PCCPCH RSCP	dBm	-70	-70
TDD_Qoffset	integer	5 (-90dBm)
Qsearch_I	integer	7 (search always)
Propagation Condition	AWGN

NOTE: On timeslot 8 the P-CCPCH is not transmitted; on that timeslot, the P-CCPCH RSCP defines the power level of the beacon channel.

NOTE: The parameters in the table above are valid only for cell reselection based on cell ranking.

Parameter	Unit	UTRAN TDD Cell (1.28 Mcps option)
Timeslot Number		0	DwPTS
P-CCPCH_Ec/Ior	dB	-3
DwPCH_Ec/Ior	dB		0
OCNS_Ec/Ior	dB	-3
P-CCPCH RSCP	dBm	-70
TDD_Qoffset	integer	5 (-90dBm)
Qsearch_I	integer	7 (search always)
Propagation Condition	AWGN

NOTE: The parameters in the table above are valid only for cell reselection based on cell ranking.

The radio conditions for the E-UTRAN FDD cell are as follows (see 3GPP TS 36.101 [37] for definitions):

Parameter	Unit	E-UTRAN FDD Cell
Channel Bandwidth	MHz	10
PSS_RB, SSS_RB, PBCH_RA, PBCH_RB, PCFICH_RA, PHICH_RA, PHICH_RB, PDCCH_RA, PDCCH_RB, PDSCH_RA, PDSCH_RB	dB	0
OCNG_RA (Note 1)	dB	0
OCNG_RB (Note 1)	dB	0
RSRP	dBm/15kHz	-86
Ês/Iot	dB	12
Noc	dBm/15kHz	-98
E-UTRAN_QRXLEVMIN	integer	0 (-140 dBm)
THRESH_priority_search	integer	15 (search always)
T_reselection	integer	0 (5 s)
THRESH_E-UTRAN_high	integer	24 (48 dB)
E-UTRAN_PRIORITY	integer	higher than GERAN_PRIORITY
OCNG pattern	OP.2 FDD (see 3GPP TS 36.133 [39])
MIMO configuration	single transmitter
Propagation Condition	AWGN
NOTE 1: OCNG shall be used such that the E-UTRAN cell is fully allocated and a constant total transmitted power spectral density is achieved for all OFDM symbols.

NOTE: The parameters in the table above are valid if THRESH_E-UTRAN_high_Q is not signalled.

The radio conditions for the E-UTRAN TDD cell are as follows (see 3GPP TS 36.101 [37] for definitions):

Parameter	Unit	E-UTRAN TDD Cell
Channel Bandwidth	MHz	10
PSS_RB, SSS_RB, PBCH_RA, PBCH_RB, PCFICH_RA, PHICH_RA, PHICH_RB, PDCCH_RA, PDCCH_RB, PDSCH_RA, PDSCH_RB	dB	0
OCNG_RA (Note 1)	dB	0
OCNG_RB (Note 1)	dB	0
RSRP	dBm/15kHz	-86
Ês/Iot	dB	12
Noc	dBm/15kHz	-98
E-UTRAN_QRXLEVMIN	integer	0 (-140 dBm)
THRESH_priority_search	integer	15 (search always)
T_reselection	integer	0 (5 s)
THRESH_E-UTRAN_high	integer	24 (48 dB)
E-UTRAN_PRIORITY	integer	higher than GERAN_PRIORITY
OCNG pattern	OP.2 TDD (see 3GPP TS 36.133 [39])
MIMO configuration	single transmitter
Propagation Condition	AWGN
NOTE 1: OCNG shall be used such that the E-UTRAN cell is fully allocated and a constant total transmitted power spectral density is achieved for all OFDM symbols.

NOTE: The parameters in the table above are valid if THRESH_E-UTRAN_high_Q is not signalled.

The allowed time is increased

– by 30 seconds for each additional UTRAN frequency in the 3G Cell Reselection list when the reselection algorithm based on ranking is used, or

– by 30 seconds for each additional UTRAN frequency of lower priority in the 3G Cell Reselection list when the reselection algorithm based on priority information is used or for each additional E-UTRAN frequency of lower priority in the E-UTRAN Neighbour Cell list under the condition that RLA_C of the serving cell is below THRESH_priority_search, or

– by 70 seconds for each additional UTRAN frequency of higher priority in the 3G Cell Reselection list when the reselection algorithm based on priority information is used or for each additional E-UTRAN frequency of higher priority in the E-UTRAN Neighbour Cell list.

However, multiple UTRAN cells on the same frequency in the 3G Cell Reselection list does not increase the allowed time.

NOTE: The requirements above assume that only one of the frequencies in the 3G Cell Reselection list or in the E-UTRAN Neighbour Cell list is switched on.

A multi-RAT MS shall be able to monitor cells from other radio access technologies, divided into (depending on the MS capability):

– UTRAN FDD cells on up to 3 FDD frequencies, with a maximum of 32 cells per frequency; and/or
– UTRAN TDD cells on up to 3 TDD frequencies with a maximum of 32 cells per frequency; and/or
– E-UTRAN FDD cells on up to 3 FDD frequencies; and/or
– E-UTRAN TDD cells on up to 3 TDD frequencies.

The total number of monitored UTRAN cells shall not exceed 64.

An MS supporting E-UTRAN measurements shall be capable of monitoring a minimum total of 7 other RAT carrier frequency layers, comprising of any above defined combination of E-UTRAN FDD, E-UTRAN TDD, UTRAN FDD and UTRAN TDD layers.

The MS shall be capable of performing RSCP and Ec/No measurements of at least 4 best UTRAN cells per UTRAN frequency and RSRP and RSRQ measurements of at least 4 best E-UTRAN cells per E-UTRAN frequency, according to its supported capabilities.

The MS shall attempt to read and store UTRAN predefined configurations using the rules defined in 3GPP TS 25.331 [9] with the following exceptions:

– The MS shall build a list of at most 16 predefined configurations, read from the BCCH of the identified UTRAN cells of equivalent PLMNs.

– After PLMN selection (see 3GPP TS 23.122 [4]), the MS shall delete any old list of predefined configurations and as soon as possible attempt to read the predefined configurations from one identified UTRAN cell of the selected PLMN or of an equivalent PLMN.

– The MS shall attempt to update the list of predefined configurations every 60 minutes.

In case of a conflict with GSM tasks, the GSM tasks take precedence.

NOTE: Instead of reading new predefined configurations from a PLMN, the MS may use previously received predefined configurations for that PLMN according to the rules in 3GPP TS 25.331 [9].

The MS shall report the list of predefined configurations in the UTRAN CLASSMARK CHANGE message (see 3GPP TS 44.018 [17]).

If the MS has no or an empty Permitted CSG list and information about PSC/PCI split information for UTRAN/EUTRAN frequencies is available, the MS shall disable the measurement of the cells on the frequencies with PSC/PCI in the stored range "CSG PSC/PCI Split Information".

If the MS has no or an empty Permitted CSG list and information about dedicated frequencies for UTRAN/EUTRAN is available, the MS shall disable the measurement for cells on dedicated CSG frequencies.

6.6.5 Algorithm for cell re‑selection from GSM to UTRAN based on cell ranking

The algorithm in this subclause shall be used for reselection from GSM to UTRAN if the conditions for the use of the cell reselection algorithm based on priority information (see subclause 6.6.6) are not satisfied.

If the 3G Cell Reselection list includes UTRAN frequencies, the MS shall, at least every 5 s update the value RLA_C for the serving cell and each of the at least 6 strongest non serving GSM cells.

The MS shall then reselect a suitable (see 3GPP TS 25.304 [8]) UTRAN cell if:

– for a TDD cell the measured RSCP value is equal to or greater than TDD_Qoffset for a period of 5 s and

– for an FDD cell the following criteria are all met for a period of 5 s:

1) its measured RSCP value exceeds the value of RLA_C for the serving cell and all of the suitable (see 3GPP TS 43.022 [11]) non-serving GSM cells by the value FDD_Qoffset,

2) its measured Ec/No value is equal or greater than the value FDD_Qmin – FDD_Qmin_Offset, and

3) its measured RSCP value is equal to or greater than FDD_RSCP_threshold.

In case of a cell reselection occurring within the previous 15 seconds, FDD_Qoffset or TDD_Qoffset is increased by 5 dB.

– Ec/No and RSCP are the measured quantities, see subclause 8.1.5.

– FDD_RSCP_threshold equals FDD_RSCPmin – min((P_MAX – 21 dBm), 3 dB) if FDD_RSCPmin is broadcast on the serving cell, else Qrxlevmin + Pcompensation + 10 dB, if these parameters are available, otherwise the default value of FDD_RSCPmin.

– Qrxlevmin is the minimum required RX level in the UTRAN FDD cell (dBm), see 3GPP TS 25.304 [8].

– Pcompensation is max(UE_TXPWR_MAX_RACH – P_MAX, 0) (dB), see 3GPP TS 25.304 [8].

– UE_TXPWR_MAX_RACH is the maximum TX power level an MS may use when accessing the UTRAN FDD cell on RACH (dBm), see 3GPP TS 25.304.

– P_MAX is the maximum RF output power of the MS (dBm) in UTRAN FDD mode, see 3GPP TS 25.304 [8].

– FDD_Qmin, FDD_Qoffset and optionally FDD_RSCPmin and FDD_Qmin_Offset are broadcast on BCCH of the serving cell.

– TDD_Qoffset is broadcast on BCCH of the serving cell.

Note 1: The parameters required to determine if the UTRAN cell is suitable are broadcast on BCCH of the UTRAN cell. An MS may start reselection towards the UTRAN cell before decoding the BCCH of the UTRAN cell, leading to a short interruption of service if the UTRAN cell is not suitable.

Note 2: If FDD_RSCPmin is broadcast, optimum GSM to UTRAN reselection performance is achieved if UTRAN cells at UTRAN coverage border areas are planned for +24 dBm UE power.

Note 3: The parameter TDD_Qoffset is an absolute threshold for reselection towards a target UTRAN TDD cell.

The MS shall store the UTRAN cell RSCP suitability criterion parameters above, whenever decoded from a UTRAN FDD cell, which is not a CSG cell, of a PLMN which is the registered PLMN or is in the stored list of equivalent PLMNs (see 3GPP TS 24.008 [46]) while attempting to camp on the UTRAN FDD cell. The mobile station shall store, along with decoded RSCP suitability parameters, the frequency of the cell from which they were decoded. The most recently stored parameters from a UTRAN FDD cell (other than a CSG cell) of an equivalent PLMN (including the registered PLMN) operating on the same frequency as the candidate cell are valid reselection criteria towards any candidate UTRAN FDD cell evaluated using the algorithm in this sub-clause. This list of parameters shall be cleared after PLMN selection (see 3GPP TS 23.122 [4]).

Cell reselection to UTRAN shall not occur within 5 seconds after the MS has reselected a GSM cell from an UTRAN cell if a suitable GSM cell can be found.

In case of a reselection attempt towards a barred UTRAN cell, the MS shall abandon further reselection attempts towards this UTRAN cell as defined by the T_barred value on the barred UTRAN cell (see 3GPP TS 25.331 [9]).

In case the highest ranked UTRAN cell is not suitable (see 3GPP TS 25.304 [8]) due to being part of the "list of forbidden LAs for roaming" or belonging to a PLMN which is not indicated as being equivalent to the registered PLMN, the MS may abandon further reselection attempts towards this UTRAN cell and all other cells on the same frequency, for a period of up to 20 min. If the MS has to perform cell selection, this limitation shall be removed. If the MS is redirected under GERAN control to a frequency for which the timer is running, any limitation on that frequency shall be removed.

If more than one UTRAN cell fulfils the above criteria, the MS shall select the cell with the greatest RSCP value.

6.6.6 Algorithm for inter-RAT cell re-selection based on priority information

A mobile station supporting E-UTRAN shall support priority based inter-RAT cell re-selection towards all the supported RATs. A mobile station not supporting E-UTRAN and supporting UTRAN and supporting priority based reselection from UTRAN to GERAN (see 3GPP TS 25.306 [47]) shall support priority based inter-RAT cell re-selection towards UTRAN.

The algorithm in this sub-clause shall be used for inter-RAT cell reselection if the following conditions are satisfied:

– the mobile station supports priority based inter-RAT cell re-selection, and

– the mobile station has received the Serving Cell Priority Parameters Description IE (see 3GPP TS 44.018 [17] and 3GPP TS 44.060 [19]) for the serving cell.

If one or both of these conditions are not met, then inter-RAT reselection to E-UTRAN cells is not permitted, and inter-RAT reselection to UTRAN cells shall use the algorithm specified in sub-clause 6.6.5.

The set of valid priorities to be used for this algorithm is specified in 3GPP TS 44.018 [17] and 3GPP TS 44.060 [19] Cells belonging to frequencies for which no valid priority is available or no threshold is provided by the serving cell shall not be considered for measurement and for cell re-selection.

NOTE 1: The network may enable priority based reselection by providing in the serving cell at least the Serving Cell Priority Parameters Description struct and priority information (threshold and priority) for each inter-RAT frequency in the neighbour cell list to which the possibility of reselection by a mobile station using this algorithm is desired (whether or not such cells support priority-based reselection).

NOTE 2: Throughout the specification, the phrase "neighbour cell list" will include also the E-UTRAN Neighbour Cell list where appropriate.

NOTE 3: void

If the 3G Cell Reselection list or the E-UTRAN Neighbour Cell list include frequencies of other radio access technologies, the MS shall, at least every 5 s update the value RLA_C for the serving cell and each of the at least 6 strongest non serving GSM cells.

The MS shall then reselect a suitable (see 3GPP TS 25.304 [8] for UTRAN and 3GPP TS 36.304 [40] for E-UTRAN) cell of another radio access technology if the criteria below are satisfied. S_non-serving_XXX is the measurement quantity of a non-serving inter-RAT cell and XXX indicates the other radio access technology/mode and is defined as follows:

– for a UTRAN cell, is the measured RSCP value for the cell minus UTRAN_QRXLEVMIN for the cell’s frequency;

– for a E-UTRAN cell, is the measured RSRP value for the cell minus E-UTRAN_QRXLEVMIN for the cell’s frequency if THRESH_E-UTRAN_high_Q is not provided; otherwise, if THRESH_E-UTRAN_high_Q is provided, is the measured RSRQ value for the cell minus E-UTRAN_QQUALMIN for the cell’s frequency.

For a GSM cell, S_GSM is defined as the C1 value for the cell (see subclause 6.4);

Cell reselection to a cell of another inter-RAT frequency shall be performed if any of the conditions below (to be evaluated in the order shown) is satisfied:

– The S_non-serving_XXX of one or more cells of a higher priority inter-RAT frequency is greater than THRESH_XXX_high (or, in case of an E-UTRAN target, THRESH_E-UTRAN_high_Q, if provided) during a time interval T_reselection; in that case, the mobile station shall consider the cells for reselection in decreasing order of priority and, for cells of the same priority, in decreasing order of S_non-serving_XXX, and reselect the first cell that satisfies the conditions above;

– The value of S_GSM is lower than THRESH_GSM_low for the serving cell and all measured GSM cells during a time interval T_reselection; in this case, the mobile station shall consider for reselection the inter-RAT cells in the following order, and reselect the first one that satisfies the following criteria:

– cells of a lower priority inter-RAT frequency whose S_non-serving_XXX is greater than THRESH_XXX_low (or, in case of an E-UTRAN target, THRESH_E-UTRAN_low_Q, if provided) during a time interval T_reselection; these cells shall be considered in decreasing order of priority and, for cells of the same priority, in decreasing order of S_non-serving_XXX;

– if no cells satisfy the criterion above, inter-RAT cells for which, during a time interval T_reselection, S_non-serving_XXX is higher than S_GSM for the serving cell by at least a specific hysteresis H_PRIO; these cells shall be considered in decreasing order of S_non-serving_XXX.

A UTRAN FDD cell shall only be reselected if, in addition to the criteria above, its measured Ec/No value is equal to or greater than FDD_Qmin – FDD_Qmin_Offset.

If E-UTRAN_Qmin is provided for a E-UTRAN frequency, a E-UTRAN cell on that frequency shall only be reselected if, in addition to the criteria above, its measured RSRQ value is equal to or greater than E-UTRAN_Qmin.

If THRESH_E-UTRAN_high_Q is provided for a E-UTRAN frequency, and if E-UTRAN_RSRPmin is provided, a E-UTRAN cell on that frequency shall only be reselected if, in addition to the criteria above, its measured RSRP value is equal to or greater than E-UTRAN_RSRPmin. If E-UTRAN_RSRPmin is not provided, the default value shall be used.

If the MS does not support RSRQ based reselection from E-UTRAN (see 3GPP TS 36.304 [40]), cell reselection from GERAN to E-UTRAN shall be based on the RSRP criterion according to the rules above without considering THRESH_E-UTRAN_high_Q (i.e. as in the case when THRESH_E-UTRAN_high_Q is not provided).

E-UTRAN cells which are included in the list of not allowed cells shall not be considered as candidates for cell reselection. If the strongest cells on a E-UTRAN frequency are included in the list of not allowed cells, the mobile station may reselect the strongest valid cell (see subclause 8.4.7) on that frequency.

Cell reselection to a cell of another radio access technology (e.g. UTRAN or E-UTRAN) shall not occur within 5 seconds after the MS has reselected a GSM cell from an inter-RAT cell if a suitable GSM cell can be found.

If a mobile station in camped normally state (see 3GPP TS 43.022 [11]) has valid individual priorities which do not include a priority for the serving cell, the mobile station shall consider the serving cell to have lowest priority (i.e. lower than the eight network configured values).

A mobile station in camped on any cell state (see 3GPP TS 43.022 [11]) shall ignore individual priorities received through dedicated signalling and shall apply priorities received from the system information of the serving cell while attempting to find a suitable cell. If the mobile station supports CS voice services, the MS shall avoid reselecting acceptable (but not suitable) E-UTRA cells regardless of the priorities provided in system information.

NOTE 4: If the MS is camping on an acceptable cell, individual priorities are not discarded until an event leading to their deletion occurs.

In case of a reselection attempt towards a barred UTRAN cell, the MS shall abandon further reselection attempts towards this UTRAN cell as defined by the T_barred value on the barred UTRAN cell (see 3GPP TS 25.331 [9]).

In case of a reselection attempt towards a barred E-UTRAN cell, the MS shall abandon further reselection attempts towards this E-UTRAN cell for a period of up to 20 min.

In case the MS attempts reselection to a UTRAN cell which is not suitable (see 3GPP TS 25.304 [8]) due to being part of the "list of forbidden LAs for roaming" or belonging to a PLMN which is not indicated as being equivalent to the registered PLMN, the MS may abandon further reselection attempts towards this UTRAN cell and all other cells on the same frequency, for a period of up to 20 min. If the MS has to perform cell selection, this limitation shall be removed. If the MS is redirected under GERAN control to a frequency for which the timer is running, any limitation on that frequency shall be removed.

In case the MS attempts reselection to a E-UTRAN cell which is not suitable (see 3GPP TS 36.304 [40]) due to being part of the "list of forbidden tracking areas for roaming" (see 3GPP TS 24.301 [43]), and if the MS has received the PCID to TA Mapping information element (see 3GPP TS 44.018 [17] and 3GPP TS 44.060 [19]) for the frequency of the cell, it shall abandon further reselection attempts towards this E-UTRAN cell and any E-UTRAN cell which is known to belong to the same Tracking Area until the PCID to TA Mapping information changes in the serving cell or until cell reselection occurs. If the mobile station has not received the PCID to TA Mapping information element for the frequency of the cell, the MS may abandon further reselection attempts towards this E-UTRAN cell and all other cells on the same frequency, for a period of up to 20 min. If the MS has to perform cell selection, this limitation shall be removed. If the MS is redirected under GERAN control to a frequency for which the timer is running, any limitation on that frequency shall be removed.

In case the MS attempts reselection to a E-UTRAN cell which is not suitable (see 3GPP TS 36.304 [40]) due to belonging to a PLMN which is not indicated as being equivalent to the registered PLMN, the MS may abandon further reselection attempts towards this E-UTRAN cell and all other cells on the same frequency, for a period of up to 20 min. If the MS has to perform cell selection, this limitation shall be removed. If the MS is redirected under GERAN control to a frequency for which the timer is running, any limitation on that frequency shall be removed.

The MS shall store the UTRAN cell RSCP suitability criterion parameters specified in sub-clause 6.6.5, whenever decoded from a UTRAN FDD cell of a PLMN in the stored list of equivalent PLMNs (see 3GPP TS 24.008 [46]) while attempting to reselect to a UTRAN FDD cell as part of the priority-based reselection algorithm. Stored RSCP suitability criteria shall not be used to evaluate the suitability of a UTRAN cell when evaluating a cell for reselection using the priority-based reselection algorithm.

6.6.7 Cell selection and re-selection to CSG cells and hybrid cells

6.6.7.1 Cell re-selection to CSG cells

If a mobile station is a member of at least one Closed Subscriber Group, i.e. at least one CSG ID and its PLMN ID is included in the MS’s Permitted CSG list, then, in addition to normal cell reselection, the MS shall use an autonomous search function to detect UTRAN and/or E-UTRAN CSG cells. The autonomous search function shall at least detect previously visited allowed CSG cells.

NOTE 1: The autonomous search function is implementation dependent and controls when and/or where to search for allowed CSG cells.

NOTE 1a: (void).

NOTE 2: (void).

NOTE 3: (void).

If the strongest cell (see 3GPP TS 25.304 [8] and 3GPP TS 36.304 [40] for the definition of the strongest cell) which the MS has detected on a UTRAN or E-UTRAN frequency during a time interval T_reselection is a suitable CSG cell (see 3GPP TS 25.304 [8] and 3GPP TS 36.304 [40] for suitability criteria for UTRAN and E-UTRAN CSG cells respectively), the MS shall reselect to this cell irrespective of the cell reselection rules applicable for the cell on which the MS is currently camped.

The following requirements are valid for reselection to allowed CSG cells previously visited by the MS when the radio configuration parameters, including the carrier frequency and PSC/PCI (whichever and if it is applicable) of the CSG cell, non CSG cell and other neighbour cells, are unchanged from the most recent previous visit. The autonomous search and cell re-selection to a previously visited allowed CSG cell shall meet the performance requirements defined as follows:

– the MS shall perform search and re-selection to a previously visited allowed UTRAN FDD CSG cell, that has met the CSG cell re-selection criterion defined above, within 6 minutes in the radio conditions specified for an UTRAN FDD CSG cell in 3GPP TS 36.133 [39] in terms of parameters for CSG inter-RAT UTRAN FDD reselection; UARFCN and PSC shall be unchanged from the most recent previous visit of the UTRAN FDD CSG cell; Serving GSM cell at RXLEV= -70 dBm, with 6 GSM neighbours at RXLEV= -75 dBm;

– the MS shall perform search and re-selection to a previously visited allowed E-UTRAN CSG cell, that has met the CSG cell re-selection criterion defined above, within 6 minutes in the radio conditions specified for an E-UTRAN CSG cell in 3GPP TS 25.133 [7] in terms of parameters for CSG inter-RAT E-UTRA reselection; E-UARFCN and PCI shall be unchanged from the most recent previous visit of the E-UTRAN CSG cell; Serving GSM cell at RXLEV= -70 dBm, with 6 GSM neighbours at RXLEV= -75 dBm.

NOTE 4: The above performance requirements are minimum requirements defined to ensure the testability of autonomous CSG search.

The MS shall disable the autonomous search function for CSG cells if the MS has no Permitted CSG list or the MS’s Permitted CSG list is empty.

When the MS has no or an empty Permitted CSG list, and the MS has stored "CSG PSC Split Information" or "CSG PCI Split Information", the MS shall ignore for measurement and cell re-selection cells known to be CSG cells, i.e.:

– cells on a UTRAN frequency with PSC in the stored range "CSG PSC Split Information" for that frequency (see 3GPP TS 25.331 [9]);

– cells on an E-UTRAN frequency with PCI in the stored range "CSG PCI Split Information" for that frequency (see 3GPP TS 36.331 [41]).

In addition, when the MS has no or an empty Permitted CSG list, the MS may ignore for measurement and cell re-selection cells known to be CSG cells according to implementation specific means on a frequency for which no "CSG PCI Split Information" or "CSG PSC Split Information" is stored.

The network may provide information about dedicated UTRAN CSG frequencies and/or dedicated E-UTRAN CSG frequencies. In this case, the MS may use the autonomous search function only on these dedicated frequencies and on the other frequencies listed in the system information. When the MS has no or an empty Permitted CSG list, the MS shall ignore those frequencies for measurement and cell re-selection.

A mobile station which has a Permitted CSG list which is not empty shall not use stored RSCP parameters to evaluate a candidate UTRAN FDD CSG cell for reselection, unless those (stored) parameters were obtained from a CSG cell with the same physical layer identifiers (frequency and PSC).

The mobile station which has a Permitted CSG list which is not empty may store the UTRAN cell RSCP suitability criterion parameters from a UTRAN FDD CSG cell; in this case, these stored parameters shall be stored separately from parameters stored as specified in sub-clauses 6.6.5 and 6.6.6 and may only be used subsequently to evaluate a candidate CSG cell with the same physical layer identifiers.

6.6.7.1a Cell re-selection to hybrid cells

If a mobile station is a member of at least one Closed Subscriber Group then, in addition to normal cell reselection, the MS shall use an autonomous search function to detect hybrid cells. The autonomous search function shall at least detect previously visited hybrid cells whose CSG IDs are included in the Permitted CSG list of the MS.

NOTE: The autonomous search for hybrid cells does not imply that the MS needs to constantly check the CSG IDs of all cells it sees, and the impact on battery consumption should be minimised.

If a neighbour cell has been detected as a hybrid cell and the CSG ID of the hybrid cell is included in the Permitted CSG list of the MS, reselection to that cell shall follow the rules for CSG cells in subclause 6.6.7.1. Otherwise normal cell reselection rules (see subclause 6.6.5 and 6.6.6) shall apply.

6.6.7.2 Manual CSG ID selection

If NAS requests AS to search for available CSG IDs, the MS shall perform the search and report the results to NAS as described in 3GPP TS 25.304 [8] for UTRAN and as described in 3GPP TS 36.304 [40] for E-UTRAN.

If a CSG ID is manually selected by NAS, the MS shall behave as specified in 3GPP TS 25.304 [8] or in 3GPP TS 36.304 [40], depending on the RAT type of the selected CSG cell.

6.7 Release of TCH, SDCCH and DBPSCH

6.7.1 Normal case

In A/Gb mode, when the MS releases all TCHs or SDCCH and returns to idle mode, packet idle mode or MAC-Idle state, it shall, as quickly as possible, camp on the cell whose channel has just been released. Similarly in Iu mode, when the MS releases all DBPSCHs and returns to MAC-Idle state, it shall, as quickly as possible, camp on the cell whose channel has just been released. However, in both modes (A/Gb mode or Iu mode), if the CHANNEL RELEASE message contains a "cell selection indicator after release of all TCH and SDCCH" or "Individual priorities" (see TS 44.018), the MS shall as quickly as possible camp on an indicated GSM, UTRAN or E-UTRAN cell that has been identified by the CHANNEL RELEASE message. If UTRAN or E-UTRAN frequency only is indicated the MS shall as quickly as possible camp on a suitable cell of this frequency.

In case the "cell selection indicator after release of all TCHs and SDCCH" or "Individual priorities" is not present, then if the full (P)BCCH data for that cell was not decoded in the preceding 30s, the MS shall attempt to decode the full (P)BCCH data. Until the MS has decoded the (P)BCCH data required for determining the paging group, it shall also monitor all paging blocks on timeslot 0 of the BCCH carrier or, for GPRS if PCCCH exists and for Iu mode, on the PDCH indicated on BCCH for possible paging messages that might address it. If the MS receives a page before having decoded the full (P)BCCH data for the cell, the MS shall store the page and respond once the relevant (P)BCCH data has been decoded, provided that the cell is not barred and the MS’s access class is allowed. Reception of full BCCH(BA) information is not required before responding to the page.

If the CHANNEL RELEASE does not contain a "cell selection indicator after release of all TCH and SDCCH" or "Individual priorities", and the MS has the knowledge that the cell whose channel is being released is not suitable (see 3GPP TS 43.022 [11]), the MS is allowed to camp on any suitable cell.

If the CHANNEL RELEASE contains a "cell selection indicator after release of all TCH and SDCCH" or "Individual priorities" and

– the MS cannot find a suitable cell from the indicated ones within 10 s, or

– none of the indicated cells are suitable,

the MS is allowed to camp on any suitable cell.

NOTE: The received signal level measurements on surrounding cells made during the last 5 seconds on the TCH or SDCCH in A/Gb mode, or on the DBPSCH in Iu mode, may be averaged and used, where possible, to speed up the process. However, it should be noted that the received signal level monitoring while on the TCH or SDCCH in A/Gb mode, or on the DBPSCH in Iu mode, is on carriers in BA (SACCH), while the carriers to be monitored for cell reselection are in BA (BCCH) or BA (GPRS).

After decoding the relevant (P)BCCH data the MS shall perform cell reselection as specified in 3GPP TS 43.022 [11].

6.7.2 Call re‑establishment

In the event of a radio link failure, call re‑establishment may be attempted on a GSM cell (according to the procedure in 3GPP TS 44.018 [17]). The MS shall perform the following algorithm to determine which cell to use for the call re‑establishment attempt.

i) The received signal level measurement samples taken on the carriers indicated in the BA (SACCH) received on the serving cell and on the serving cell BCCH carrier in the last 5 seconds shall be averaged, and the carrier with the highest average received signal level with a permitted NCC as indicated on the SACCH of the serving cell (see subclause 7.2) shall be taken.

ii) On this carrier the MS shall attempt to decode the BCCH data block containing the parameters affecting cell selection.

iii) If the cell is suitable (see 3GPP TS 43.022 [11]) and call re‑establishment is allowed, call re‑establishment shall be attempted on this cell.

iv) If the MS is unable to decode the BCCH data block or if the conditions in iii) are not met, the carrier with the next highest average received signal level with a permitted NCC shall be taken, and the MS shall repeat steps ii) and iii) above.

v) If the cells with the 6 strongest average received signal level values with a permitted NCC have been tried but cannot be used, the call re‑establishment attempt shall be abandoned, and the algorithm of subclause 6.7.1 shall be performed.

The MS is under no circumstances allowed to access a cell to attempt call re‑establishment later than 20 seconds after the detection within the MS of the radio link failure causing the call re‑establishment attempt. In the case where the 20 seconds elapses without a successful call re‑establishment the call re‑establishment attempt shall be abandoned, and the algorithm of subclause 6.7.1 shall be performed.

Call re‑establishment shall not be applied for voice group calls.

6.8 Abnormal cases and emergency calls

When in the limited service state (see 3GPP TS 43.022 [11]) the aim is to gain normal service rapidly and the following tasks shall be performed, depending on the conditions, as given in the table below:

a) The MS shall monitor the received signal level of all RF channels within its bands of operation, and search for a BCCH carrier which has C1 > 0 and which is not barred. When such a carrier is found, the MS shall camp on that cell, irrespective of the PLMN identity.

b) The MS shall search the strongest RF channels to determine which PLMNs are available (Manual Mode) or available and allowable (Automatic Mode). This information shall be processed according to the PLMN selection algorithm defined in 3GPP TS 43.022 [11].

c) The MS shall perform cell reselection at least among the cells of the PLMN of the cell on which the MS has camped, according to the algorithm of 3GPP TS 43.022 [11], except that a zero value of CELL_RESELECT_HYSTERESIS shall be used.

	Condition		Tasks to be performed as a minimum:
SIM Present	Other	MS camped on a cell	a)	b)	c)
X	X	No	Yes	No	No
No	X	Yes	No	No	Yes
Yes	"IMSI Unknown", "illegal MS"	Yes	No	No	Yes
Yes	No suitable cell of selected PLMN or "PLMN not allowed"	Yes	No	Yes	Yes
NOTE: X = "Don’t care state".

In this state, the only services available to the mobile station are:

i) the establishment of emergency calls (which may only be made if task c) was being performed).

ii) the reception of warning notifications in the conditions where the mobile station is able to receive paging as specified in 3GPP TS 23.122 [4].

Powering down of the MS is permitted.

6.9 RLA_EC signal level and SLA measurements

6.9.1 General

For purposes of cell selection, cell reselection, coverage class selection and for deriving the C value in packet idle mode (see subclause 10.2.3.1.1), a MS that has enabled EC operation or that supports EC-GSM-IoT and is attempting to select an EC-GSM-IoT capable cell shall measure received signal level. In addition, for purposes of downlink coverage class selection, a MS that has enabled EC operation shall, if so indicated by the DL_CC_Selection parameter (see 3GPP TS 44.018 [17]), measure signal-to-interference-and-noise ratio (SINR).

NOTE: If the network indicates by the DL_CC_Selection parameter to measure SINR (for interference limited scenarios in extended coverage), it should not have configured EC-PICH, i.e. it should not indicate EC paging indication channel support in EC SI (see 3GPP TS 44.018 [17]).

These measurements are specified in the following subclauses.

6.9.2 Physical parameters

The RMS received wanted signal level at the receiver input shall be estimated by the MS on bursts of the FCCH and/or EC-SCH channels. The estimated received wanted signal level shall exclude contributions from other sources such as interference and noise.

In addition, if SINR is to be measured, wanted signal level and interference plus noise level shall be measured by the MS on the same bursts.

NOTE: The interference plus noise level can for instance be calculated by subtracting the received wanted signal level from the received total signal level.

During the estimation, the MS shall attempt to synchronize to the cell, decode the EC-SCH and decode the 9 bit BSIC value sent as part of the EC-SCH payload space.

6.9.3 Statistical parameter

The estimated parameter (RLA_EC) shall be the linear average of at least 10 received wanted signal level measurements during at least 5 s, expressed in dBm.

If SINR is to be measured, the parameter SLA shall be calculated as

SLA = RLA_EC – INA

where INA is the linear average of the interference plus noise measurements on the same bursts on which RLA_EC was based, expressed in dBm.

The RLA_EC and SLA estimates are valid only if at least one successful decoding of EC-SCH and verification of BSIC has occurred during this time.

The RLA_EC for the serving cell shall also be used as the C value in packet idle mode (see subclause 10.2.3.1.1).

6.9.4 Accuracy requirements

RLA_EC shall be measured for received wanted signal levels in the full range of -122 dBm to ‑48 dBm with an absolute accuracy of ±3 dB under both normal and extreme conditions.

If the received signal wanted level falls below -122 dBm, then the measured level shall be within the range allowed for the absolute accuracy specified above. In case the upper limit of this range is below -122 dBm, then the upper limit shall be considered as equal to -122 dBm.

The relative accuracy shall be as specified in subclause 8.1.2.

The received wanted signal level values above refer to the received wanted signal level excluding contributions from interference and noise.

SLA shall be measured for SINR levels in the range of -7 dB to 27 dB for received wanted signal levels in the range of -122 dBm to -48 dBm and interference plus noise levels in the range of -115 dBm to -48 dBm with an absolute accuracy of ±3 dB under both normal and extreme conditions.

If the SINR falls below -7 dB or rises above 27 dB, the measured SLA shall be below -4 dB and above 24 dB, respectively.

For test purposes the following radio conditions can be used: BT_Threshold_DL = 8 dB, CC2_Range_DL = 6 dB, CC3_Range_DL = 6 dB. Serving GSM cell at RXLEV= -70 dBm with two non-serving cells acting as co-channel interferers both at -84 dBm, at -78 dBm, at -72 dBm, or at -66 dBm, for the MS to select CC1, CC2, CC3 or CC4, respectively.

6.9.5 Void

6.9a RLA_GC signal level measurements

6.9a.1 General

For purposes of cell selection and cell reselection a MS capable of EC-GSM-IoT shall when applicable (see sub-clause 6.4) measure received signal level as specified in this subclause.

6.9a.2 Physical parameter

The R.M.S received signal level at the receiver input shall be estimated by the MS on bursts transmitted on TN0 on the BCCH carrier.

6.9a.3 Statistical parameter

The estimated parameter (RLA_GC) shall be the linear average of at least 10 received signal level measurements during at least 5 s, expressed in dBm.

6.9a.4 Accuracy requirements

The accuracy defined in subclause 8.1.2 for RXLEV shall apply.

6.10 Coverage class selection for EC-GSM-IoT

6.10.1 General

A MS that has enabled EC operation shall, before each time the paging block is monitored or, if the MS supports EC Paging Indication Channel monitoring and the support of this channel is indicated in EC System Information, before each time the EC-PICH block is monitored, or before each uplink transmission, estimate the uplink CC (coverage class) and the downlink CC, unless the MS has done these estimations within the last 30 seconds.

6.10.2 Downlink coverage class selection

The MS shall select the downlink CC based on either RLA_EC or SLA, as indicated by the DL_CC_Selection parameter sent in EC SI 2 (see 3GPP TS 44.018 [17]), according to table 6.10.2-1 and indicate it to the network in the EC Packet Channel Request message (see 3GPP TS 44.018 [17]). The network shall apply the indicated downlink CC on EC-AGCH.

Table 6.10.2-1: Downlink CC selection

Downlink CC	Upper limit of RLA_EC or SLA	Lower limit of RLA_EC or SLA
CC1	–	BT_Threshold_DL
CC2	BT_Threshold_DL	BT_Threshold_DL – CC2_Range_DL
CC3	BT_Threshold_DL – CC2_Range_DL	BT_Threshold_DL – CC2_Range_DL – CC3_Range_DL
CC4	BT_Threshold_DL – CC2_Range_DL – CC3_Range_DL	– (see note)
NOTE: There is no explicit lower limit for selection of downlink CC4 but the C1 criterion (see subclause 6.4.1) will trigger a cell re-selection if RLA_EC ≤ EC_RXLEV_ACCESS_MIN + Max(MS_TXPWR_MAX_CCH – MSPWR,0), which implicitly sets a lower limit if CC selection is based on RLA_EC.

BT_Threshold_DL indicates the RLA_EC (in dBm) or SLA (in dB) below which blind physical layer transmissions are used on EC-AGCH. CC2_Range_DL and CC3_Range_DL indicate the RLA_EC range (in dB) of downlink CC2 and CC3, respectively.

BT_Threshold_DL and EC_RXLEV_ACCESS_MIN are broadcast in EC SI 2 (see 3GPP TS 44.018 [17]).

CC2_Range_DL and CC3_Range_DL are optionally broadcast in EC SI 2. If either of CC2_Range_DL and CC3_Range_DL is not broadcast, its value shall be set to 0 and the corresponding downlink CC is not supported by the network.

If RLA_EC or SLA (whichever is applicable) is on the limit between two CC, the MS shall select the higher CC.

In case downlink CC1 is selected, the MS shall further indicate in the EC Packet Channel Request message (see 3GPP TS 44.018 [17]) the margin of the measured RLA_EC (or SLA) relative to BT_Threshold_DL. The parameter DL_Signal_Strength_Step_Size broadcast in EC SI 2 (see 3GPP TS 44.018 [17]) is used to quantize the margin to report in the EC Packet Channel Request message. The maximum margin that can be reported is dependent on the number of Coverage Classes supported in the cell, and whether or not the access is initiated on RACH or EC-RACH, see 3GPP TS 44.018 [17].

NOTE: When TX diversity (antenna hopping) is active a MS may underestimate RLA_EC. This can be compensated for by the NW in an adjustment of the BT_Threshold_DL.

6.10.3 Uplink coverage class selection

The MS shall select the uplink CC to use on (EC-)RACH according to table 6.10.3-1, based on the uplink received signal strength, estimated as

BS_RX_PWR = RLA_EC + min(MSPWR, MS_TXPWR_MAX_CCH) – BSPWR.

MSPWR is the nominal maximum output power of the MS. MS_TXPWR_MAX_CCH is the maximum TX power level an MS is allowed to use when accessing the system. BSPWR is the output power of the BTS used on FCCH and EC-SCH. MS_TXPWR_MAX_CCH and BSPWR are broadcast in EC SI 2 (see 3GPP TS 44.018 [17]).

Table 6.10.3-1: Uplink CC selection

Uplink CC	Upper limit of BS_RX_PWR	Lower limit of BS_RX_PWR
1	–	BT_Threshold_UL
2	BT_Threshold_UL	BT_Threshold_UL – CC2_Range_UL
3	BT_Threshold_UL – CC2_Range_UL	BT_Threshold_UL – CC2_Range_UL – CC3_Range_UL
4	BT_Threshold_UL – CC2_Range_UL – CC3_Range_UL	BT_Threshold_UL – CC2_Range_UL – CC3_Range_UL- CC4_Range_UL (see NOTE 1)
5	BT_Threshold_UL – CC2_Range_UL – CC3_Range_UL- CC4_Range_UL	(see NOTE 2)
NOTE1: In case CC4_Range_UL is not broadcast, there is no explicit lower limit for selection of uplink CC4 but the C1 criterion (see subclause 6.4.1) will trigger a cell re-selection. NOTE 2: In case CC4_Range_UL is broadcast and the MS supports uplink CC5 (see 3GPP TS 24.008), there is no explicit lower limit for selection of uplink CC5 but the C1 criterion (see subclause 6.4.1) will trigger a cell re-selection.

BT_Threshold_UL indicates the BS_RX_PWR (in dBm) below which blind physical layer transmissions are used on EC-RACH. CC2_Range_UL, CC3_Range_UL and CC4_Range_UL indicate the BS_RX_PWR range (in dB) of uplink CC2, CC3 and CC4, respectively. BT_Threshold_UL is broadcast in EC SI 2 while CC2_Range_UL, CC3_Range_UL and CC4_Range_UL are optionally broadcast in EC SI 2 (see 3GPP TS 44.018 [17]). If either of CC2_Range_UL and CC3_Range_UL is not present, its value shall be set to 0 and the corresponding uplink CC is not used. If CC4_Range_UL is not present the uplink coverage class CC5 is not used, whilst CC4 shall be considered being supported by the network. If CC4_Range_UL is present and the MS does not support uplink CC5 (see 3GPP TS 24.008), it shall ignore the CC4_Range_UL parameter. If BS_RX_PWR is on the limit between two CC, the MS shall select the higher CC.

NOTE: The maximum BTS output power (BSPWR), EC_RXLEV_ACCESS_MIN (see table 6.4-2) and MS_TXPWR_MAX_CCH (see table 6.4-2) will together define the lowest signal level possible to estimate on the UL (BS_RX_PWR). Hence, by appropriate settings of BT_Threshold_UL, CC2_Range_UL, CC3_Range_UL and CC4_Range_UL, the set of uplink Coverage Classes possible to select by the MS can be restricted.

6.10.4 Coverage class adaptation for EC-CCCH

If CC adaptation on EC-RACH and EC-AGCH is allowed (as indicated by the CC_Access_Adaptation parameter broadcast in EC SI 2, see 3GPP TS 44.018 [17]), the MS shall gradually increase its CC as described in 3GPP TS 44.018 [17] and use it as its selected uplink or downlink CC.

6.10.5 Downlink coverage class update

For the purpose of paging block monitoring on EC-PCH or, if the MS supports EC Paging Indication Channel monitoring and the support of this channel is indicated in EC System Information, for the purpose of paging indication monitoring on EC-PICH, the MS shall keep the network informed about the selected downlink CC (see subclause 6.10.2). The MS shall indicate the selected downlink CC using the Selected DL Coverage Class field in the EC Packet Channel Request message. This shall be done in advance of the next occurrence of the paging group of the MS or, if the MS supports EC Paging Indication Channel monitoring and the support of this channel is indicated in EC System Information, in advance of the EC-PICH block corresponding to the paging block for the next occurrence of the paging group of the MS, and at least if any of the following conditions are fulfilled:

– the selected downlink CC is higher than the last downlink CC communicated to the network;

– the selected downlink CC is CC1 and the last downlink CC communicated to the network is CC4; or

– the MS has completed an uplink data transfer in a cell not supporting EC-GSM-IoT since the last time it communicated a downlink CC to the network.

A downlink CC is considered to be communicated to the network at successful contention resolution (see 3GPP TS 44.018) following a system access triggered by an EC PACKET CHANNEL REQUEST. The communicated downlink CC is the ‘Used DL Coverage Class’ if the EC IMMEDIATE ASSIGNMENT type 2 message is used, or, is CC1 if the EC IMMEDIATE ASSIGNMENT type 1 is used.

The network shall apply the indicated downlink CC on EC-PCH messages sent to that MS.