11.2.20 Packet System Information Type 3

04.603GPPGeneral Packet Radio Service (GPRS)Mobile Station (MS) - Base Station System (BSS) interfaceRadio Link Control / Medium Access Control (RLC/MAC) protocolRelease 1999TS

This message is sent by the network on the PBCCH or PACCH giving information of the BCCH allocation (BA(GPRS)) in the neighbour cells and cell selection parameters for serving cell and non-serving cells. This message shall not be segmented across more than one RLC/MAC control block by using the procedures specified in sub-clause 9.1.12a. Special requirements for the transmission of this message apply on the PBCCH, see 3GPP TS 05.02.

Message type: PACKET SYSTEM INFORMATION TYPE 3

Direction: network to mobile station

Classification: distribution message

Table 11.2.20.1: PSI3 information elements

< PSI3 message content > ::=

< PAGE_MODE : bit (2) >

< PSI3_CHANGE_MARK : bit (2) >

< PSI3_BIS_COUNT : bit (4) >

< Serving Cell parameters : < Serving Cell params struct > >

< General Cell Selection parameter : < Gen Cell Sel struct > >

< Neighbour Cell parameters : { 1 < Neighbour Cell params struct > } ** 0 >

{ null | 0 bit** = < no string >

| 1 — Release 1998 additions:

< Serving Cell LSA ID information : < LSA ID information struct > >

{ 0 | 1 < LSA Parameters :< LSA Parameters IE >> }

{ null | 0 bit** = < no string >

| 1 — Release 1999 additions:

0 0 The values ’01’, ’10’ and ’11’ were allocated in an earlier version of the protocol

— and shall not be used.

{ 0 | 1 < COMPACT Information : < COMPACT Information struct > > }

0 — The value ‘1’ was used in an earlier version of the protocol and shall not be used.

< padding bits > } }

! < Distribution part error : bit (*) = < no string > > ;

< Serving Cell params struct > ::=

< CELL_BAR_ACCESS_2 : bit >

< EXC_ACC : bit >

< GPRS_RXLEV_ACCESS_MIN : bit (6) >

< GPRS_MS_TXPWR_MAX_CCH : bit (5) >

{ 0 | 1 < HCS Serving Cell parameters : < HCS struct > > }

< MULTIBAND_REPORTING : bit (2) >;

< HCS struct > ::=

< PRIORITY_CLASS : bit (3) >

< HCS_THR : bit (5) > ;

< Gen Cell Sel struct > ::=

< GPRS_CELL_RESELECT_HYSTERESIS : bit (3) >

< C31_HYST : bit (1) >

< C32_QUAL: bit (1) >

< RANDOM_ACCESS_RETRY : bit (1) >

{ 0 | 1 < T_RESEL : bit (3) > }

{ 0 | 1 < RA_RESELECT_HYSTERESIS : bit (3) > } ;

< Neighbour Cell params struct > ::=

< START_FREQUENCY : bit (10) >

< Cell selection params : < Cell Selection struct > >

< NR_OF_REMAINING_CELLS : bit (4) >

< FREQ_DIFF_LENGTH : bit (3) >

{ < FREQUENCY_DIFF : bit (1 + val(FREQ_DIFF_LENGTH)) >

< Cell Selection Params : <Cell Selection struct>> } * (val(NR_OF_REMAINING_CELLS)) ;

< Cell Selection struct > ::=

< BSIC : bit (6) >

< CELL_BAR_ACCESS_2 : bit >

< EXC_ACC : bit >

< SAME_RA_AS_SERVING_CELL : bit (1) >

{ 0 | 1 < GPRS_RXLEV_ACCESS_MIN : bit (6) >

< GPRS_MS_TXPWR_MAX_CCH : bit (5) > }

{ 0 | 1 < GPRS_TEMPORARY_OFFSET : bit (3) >

< GPRS_PENALTY_TIME : bit (5) > }

{ 0 | 1 < GPRS_RESELECT_OFFSET : bit (5) > }

{ 0 | 1 < HCS params : < HCS struct > > }

{ 0 | 1 < SI13 PBCCH Location : < SI13 PBCCH Location struct > > } ;

< SI13 PBCCH Location struct > ::=

{ 0 < SI13_LOCATION : bit (1) >

| 1 < PBCCH_LOCATION : bit (2) >

< PSI1_REPEAT_PERIOD : bit (4) > } ;

< LSA ID information struct > ::=

{ 1 { 0 < LSA_ID : bit (24) >

| 1 < ShortLSA_ID : bit (10) > } } ** 0 ;

< COMPACT Information struct > : :=

<Cell Identification : Cell identification IE>

{ 1 < COMPACT Neighbour Cell params struct > } ** 0 ;

< COMPACT Neighbour Cell params struct > ::=

< START_FREQUENCY : bit (10) >

< COMPACT Cell selection params : < COMPACT Cell Selection struct > >

< NR_OF_REMAINING_CELLS : bit (4) >

< FREQ_DIFF_LENGTH : bit (3) >

{ < FREQUENCY_DIFF : bit (1 + val(FREQ_DIFF_LENGTH)) >

< COMPACT Cell selection params : < COMPACT Cell Selection struct > > }
* (val(NR_OF_REMAINING_CELLS));

< COMPACT Cell Selection struct > ::=

< BSIC : bit (6) >

< CELL_BAR_ACCESS_2 : bit >

< EXC_ACC : bit >

< SAME_RA_AS_SERVING_CELL : bit (1) >

{ 0 | 1 < GPRS_RXLEV_ACCESS_MIN : bit (6) >

< GPRS_MS_TXPWR_MAX_CCH : bit (5) > }

{ 0 | 1 < GPRS_TEMPORARY_OFFSET : bit (3) >

< GPRS_PENALTY_TIME : bit (5) > }

{ 0 | 1 < GPRS_RESELECT_OFFSET : bit (5) > }

{ 0 | 1 < HCS params : < HCS struct > > }

{ 0 | 1 < TIME_GROUP : bit (2) > }

{ 0 | 1 < GUAR_CONSTANT_PWR_BLKS : bit (2) >} ;

Table 11.2.20.2: PSI3 information element details

PAGE_MODE (2 bit field)
This field describes which type of page mode used, i.e. either normal paging, extended paging, paging reorganization or same as before from the previous page mode. The mobile station shall ignore this field if the message is received on the PACCH. Coding of this field is defined in 3GPP TS 04.08

PSI3_CHANGE_MARK (2 bit field)
The PSI3 change mark field is changed each time information has been updated in any of the PSI3, PSI3 bis, PSI3 ter or PSI3 quater messages. A new value indicates that the mobile station shall re-read the information from the PSI3 and all PSI3 bis, PSI3 ter and PSI3 quater messages. The coding of this field is network dependent.
Range: 0-3.

PSI3_BIS_COUNT (4 bit field)
This field is coded as the binary representation of the PSI3 bis index (in the PSI3 bis message) for the last (highest indexed) individual PSI3 bis message.
Range: 0-15.

Serving Cell Parameters:

CELL_BAR_ACCESS_2 (1 bit field)
This field combines the CELL_BAR_ACCESS and CELL_BAR_QUALIFY parameters and indicates the status for cell reselection, see 3GPP TS 05.08:

0 Status for cell reselection is set to normal;
1 Status for cell reselection is set to barred.

EXC_ACC (1 bit field)
EXC_ACC is used by the network to prevent mobiles without exclusive access rights from camping on the cell. The usage of EXC_ ACC is described in 3GPP TS 03.22. The coding of EXC_ ACC is as follows:

0 The cell is not used for SoLSA exclusive access.
1 The cell is used for SoLSA exclusive access.

GPRS_RXLEV_ACCESS_MIN (6 bit field)
The GPRS_RXLEV_ACCESS_MIN field is coded as the binary representation of the ‘RXLEV_ACCESS_MIN’ defined in 3GPP TS 05.08. It is the minimum received level at the mobile station required for access to the system.

GPRS_MS_TXPWR_MAX_CCH (5 bit field)
The GPRS_MS_TXPWR_MAX_CCH field is coded as the binary representation of the ‘power control level’ in 3GPP TS 05.05 corresponding to the maximum TX power level a mobile station may use when accessing on a packet control channel. This value shall be used by the mobile station according to 3GPP TS 05.08.

HCS struct

If the HCS struct is omitted for the serving cell, HCS is not used and the HCS parameters for the other cells shall be neglected i.e the HCS signal strength threshold shall be set to infinity for all cells. Otherwise PRIORITY_CLASS and HCS_THR are defined. The use of the HCS parameters is defined in 3GPP TS 05.08.

PRIORITY_CLASS (3 bit field)
The PRIORITY_CLASS field contains the binary representation of the HCS priority for the cell.

Bit
3 2 1
0 0 0 Lowest Priority
… …
1 1 1 Highest Priority

HCS_THR (5 bit field)
The HCS_THR is the HCS signal strength threshold

Bit
5 4 3 2 1
0 0 0 0 0 -110 dBm
0 0 0 0 1 -108 dBm
… …
1 1 1 1 1 -48 dBm

MULTIBAND_REPORTING (2 bit field)
Binary encoding of multiband reporting parameter as specified in 3GPP TS 05.08
Range 0-3.

General Cell Selection Parameters

GPRS_CELL_RESELECT_HYSTERESIS (3 bit field)
The GPRS_CELL_RESELECT_HYSTERESIS field indicates the Additional Hysteresis which applies in Ready state for cells in same RA. This field is encoded according to the following table:

Bit
3 2 1
0 0 0 0 dB
0 0 1 2 dB
0 1 0 4 dB
0 1 1 6 dB
1 0 0 8 dB
1 0 1 10 dB
1 1 0 12 dB
1 1 1 14 dB

C31_HYST (1 bit field)
The C31_HYST field indicates if set to 1 that the GPRS_CELL _RESELECT_HYSTERESIS shall be applied to the C31 criterion.

C32_QUAL (1 bit field)
C32_QUAL is a flag indicating an exception rule for GPRS_RESELECT_OFFSET according to 3GPP TS 05.08.

RANDOM_ACCESS_RETRY (1 bit field)
The RANDOM_ACCESS_RETRY field indicates if set to 1 that the mobile station is allowed to try to access another cell if available (see sub-clause 9.4.2).

T_RESEL (3 bit field)
If the mobile station has performed an abnormal release with cell reselection (see sub-clause 9.4.2) from this cell, the mobile station is not allowed to reselect this cell for T_RESEL seconds if another cell is available. The default value of T_RESEL is 5 seconds. If the field is omitted from the message, the default value shall be used by the mobile station.

Bit
3 2 1
0 0 0 5 seconds
0 0 1 10 seconds
0 1 0 15 seconds
0 1 1 20 seconds
1 0 0 30 seconds
1 0 1 60 seconds
1 1 0 120 seconds
1 1 1 300 seconds

RA_RESELECT_HYSTERESIS (3 bit field)
The RA_RESELECT_HYSTERESIS field indicates in both STANDBY and READY state the additional hysteresis which applies when selecting a cell in a new Routing Area. If this field is not present, the default value is GPRS_CELL_RESELECT_HYSTERESIS. This field is encoded according to the following table:

Bit
3 2 1
0 0 0 0 dB
0 0 1 2 dB
0 1 0 4 dB
0 1 1 6 dB
1 0 0 8 dB
1 0 1 10 dB
1 1 0 12 dB
1 1 1 14 dB

Neighbour Cell Parameters

The Neighbour cell parameters are used to specify neighbour cells (BA(GPRS)) and their corresponding cell selection parameters. The Neighbour cell parameters are specified in PSI3 and in at least one instance of PSI3bis. If one instance of PSI3bis is not sufficient to specify the cell selection parameters of all neighbour cells, the remaining neighbour cells are specified in consecutive instances of PSI3bis. If all information fits within the PSI3 message, one instance of PSI3bis without any neighbour cell parameters is broadcast.

NOTE: For efficient coding, cells with common cell selection parameters may be grouped together.

Building of BA(GPRS) is defined in sub-clause 5.6.3.2.

START_FREQUENCY (10 bit field)
The START_FREQUENCY defines the ARFCN for the first carrier in the list (ARFCN(0)). FREQ_DIFF_LENGTH (3 bit field)
This field is required to calculate the number of bits to be used for the FREQUENCY_DIFF field in the current frequency group.

FREQUENCY_DIFF (1+val(FREQ_DIFF_LENGTH) bit field)
Each FREQUENCY_DIFF parameter field specifies the difference in frequency to the next carrier to be defined. The FREQUENCY_DIFF parameter encodes a non negative integer in binary format (W).

Each frequency following the start frequency (ARFCN(0)) and belonging to the Frequency List struct is then calculated by the formula ARFCN(n) = (ARFCN(n-1) + W(n) ) modulus 1024, n=1, . . ., val(NR_OF_REMAINING_CELLS.

General rules for handling neighbour cell parameter default values

The first neighbour cell defined in PSI3 uses as its default parameter values the parameter values defined for the serving cell. The following neighbour cells use the parameter values of the previous neighbour cell as their default values.

Cell Selection params
The first field of the Cell Selection struct, BSIC, defines the BSIC of the cell and then comes the fields CELL_BAR_ACCESS_2, ECX_ACC and SAME_RA_AS_SERVING_CELL. Then follows none, some, or all of the fields GPRS_RXLEV_ACCESS_MIN, GPRS_MS_TXPWR_MAX_CCH, GPRS_TEMPORARY_OFFSET, GPRS_PENALTY_TIME, GPRS_RESELECT_OFFSET , HCS params, SI13_PBCCH_LOCATION, PCCH_TYPE and PSI1_REPEAT_PERIOD. If fields are omitted, the values for these parameters are the same as for the preceding cell unless otherwise specified for the parameter.

BSIC (6 bit field)
The BSIC field is coded as the ‘Base Station Identity Code’ defined in 3GPP TS 03.03. One BSIC for each carrier in BA(GPRS) is defined.

CELL_BAR_ACCESS_2 (1 bit field)
EXC_ACC (1 bit field)
For definition see Serving Cell parameters

SAME_RA_AS_SERVING_CELL (1 bit field)
The same RA as serving cell field contains one bit, set to
0 if the cell is in a Routeing Area different from the serving cell, or
1 if the cell is in the same Routeing Area as the serving cell.

GPRS_TEMPORARY_OFFSET (3 bit field)
The GPRS_TEMPORARY_OFFSET field indicates the negative offset to C32 that the mobile station shall use for duration of GPRS_PENALTY_TIME. It is used by the mobile station as part of its calculation of C32 for the cell reselection process.

Bit
3 2 1
0 0 0 0 dB
0 0 1 10 dB
0 1 0 20 dB
0 1 1 30 dB
1 0 0 40 dB
1 0 1 50 dB
1 1 0 60 dB
1 1 1 infinity

GPRS_PENALTY_TIME (5 bit field)
The GPRS_PENALTY_TIME defines the length of time for which GPRS_TEMPORARY_OFFSET is active.

Bit
5 4 3 2 1
0 0 0 0 0 10 seconds
0 0 0 0 1 20 seconds
. . .
1 1 1 1 1 320 seconds

GPRS_RESELECT_OFFSET (5 bit field)
GPRS_RESELECT_OFFSET is used by the mobile station to apply a positive or negative offset and a hysteresis to the GPRS cell reselection criterion. Default value is 0 dB. If the field is omitted from the message, the default value shall be used by the mobile station.

Bit
5 4 3 2 1
0 0 0 0 0 -52 dB
0 0 0 0 1 -48 dB

0 1 0 1 0 -12 dB
0 1 0 1 1 -10 dB

1 0 1 1 0 +12 dB
1 0 1 1 1 +16 dB

1 1 1 1 1 +48 dB

SI13_PBCCH_LOCATION construction

The optional SI13_PBCCH_LOCATION struct may either indicate the position of the SI13 message or a PBCCH position. If not included, SI3 and SI4 in the neighbour cell indicates if the neighbour cell supports GPRS.

SI13_LOCATION (1 bit field)
The SI13_LOCATION field, if present, indicates the logical channel where the SYSTEM INFORMATION TYPE 13 is broadcast (see 3GPP TS 05.02).

0 SYSTEM INFORMATION TYPE 13 message is sent on BCCH norm
1 SYSTEM INFORMATION TYPE 13 message is sent on BCCH ext

PBCCH_LOCATION (2 bit field)
The PBCCH_LOCATION field, if present, indicates the location of the PBCCH on the BCCH carrier (see 3GPP TS 05.02).

bit
2 1
0 0 PBCCH on TN 1 of BCCH carrier
0 1 PBCCH on TN 2 of BCCH carrier
1 0 PBCCH on TN 3 of BCCH carrier
1 1 PBCCH on TN 4 of BCCH carrier

PSI1_REPEAT_PERIOD (4 bit field)
The PSI1_REPEAT_PERIOD field indicates the PSI repeat period. The field is coded according to the following table:

Bit
4 3 2 1
0 0 0 0 PSI1 repeat period = 1
0 0 0 1 PSI1 repeat period = 2

1 1 1 1 PSI1 repeat period = 16

LSA Parameters IE
The LSA Parameters IE contains a list of LSA_ID(s) corresponding to the entries in the Neighbour Cell Parameters. Some entries in LSA parameters may be empty. The entries in the LSA Parameters IE are listed in the same order as in the Neighbour Cell Parameters and the number of entries (nr_of_frequencies_or_cells) should be the same. In case there are too few entries in the LSA Parameters IE, empty entries shall be added at the end. In case there are too many entries in the LSA parameters, the last shall be discarded. The ‘LSA parameters IE’ is defined in sub-clause 12.28.

LSA_ID (24 bit field)
The purpose of the LSA_ID field is to identify a LSA. The LSA ID value field is coded as specified in 3GPP TS 03.03.

Short LSA_ID (10 bit field)
The purpose of the Short LSA_ID field is to identify a LSA. The LSA ID defined by the Short LSA_ID is a LSA_ID as specified in 3GPP TS 03.03 with bit 0 set to "0" bit 1 to 10 set to the value of the Short LSA_ID field (LSB in bit 1, MSB in bit 10) and bit 11 to 23 set to "0".

TIME_GROUP (2 bit field)
The TIME_GROUP defines which time group (see 3GPP TS 05.02) the cell belongs to

bit
2 1
0 0 Time Group 0
0 1 Time Group 1
1 0 Time Group 2
1 1 Time Group 3

GUAR_CONSTANT_PWR_BLKS (2 bit field)
This field indicates the guaranteed number of constant power blocks in the neighbour cell. These are the blocks that the MS can use to perform neighbour cell measurements (see 3GPP TS 05.08). Note that there may be more CPBCCH blocks or allowed paging blocks in the neighbour cell than what is indicated in this field, but never less.

bit
2 1 Blocks at constant power
0 0 4
0 1 5
1 0 6
1 1 12 (i.e. BS_PAG_BLKS_RES = 0 in that cell)

Cell Identification
This information element is defined in sub-clause 12.23.