11.2.21 Packet System Information Type 3 bis

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 and PACCH giving information of the BCCH allocation in the neighbour cells and cell selection parameters for 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. If not all information fits into one instance of the PSI3bis message, the PSI3bis message can be repeated. Special requirements for the transmission of this message apply on PBCCH, see 3GPP TS 05.02.

Message type: PACKET SYSTEM INFORMATION TYPE 3 BIS

Direction: network to mobile station

Classification: distribution message

Table 11.2.21.1: PSI3 bis information elements

< PSI3 bis message content > ::=

< PAGE_MODE : bit (2) >

< PSI3_CHANGE_MARK : bit (2) >

< PSI3_BIS_INDEX : bit (4) >

< PSI3_BIS_COUNT : bit (4) >

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

< Neighbour Cell parameters 2 : { 1 < Neighbour Cell params 2 struct > } ** 0 >

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

| 1 — Release 1998 additions:

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

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

| 1 — Release 1999 additions:

< COMPACT Neighbour Cell Parameters : { 1 < COMPACT Neighbour Cell params 2 struct > } ** 0 >

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

< padding bits > } } } // — truncation at end of message allowed, bits ‘0’ assumed

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

< 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) > } ;

< HCS struct > ::=

< PRIORITY_CLASS : bit (3) >

< HCS_THR : bit (5) > ;

< Neighbour Cell params 2 struct > ::=

{ 00 — Message escape

{ 1 < NCP2 Repeat struct >

< CELL_PARAMS_POINTER : bit (2) > } ** 0 –Up to four pointers to the ‘Neigbour parameter set

< Neighbour parameter set : < Neighbour parameter set struct > > * (1 + max(val(CELL_PARAMS_POINTER)))

! < Message escape: { 01 | 10 | 11 } bit** = < no string >> } ; — Reserved for future use

< NCP2 Repeat struct > ::=

{ 1 < START_FREQUENCY : bit (10) > — Multiple START FREQ/FREQ DIFF sets may be defined

< NCP2 Property struct >

{ < NR_OF_REMAINING_CELLS : { bit (4) – 0000 } >

< FREQ_DIFF_LENGTH : bit (3) >

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

< NCP2 Property struct > } * (val(NR_OF_REMAINING_CELLS))

< NCP2 Repeat struct > — Repeated recursively

| 0000 } — Break recursion (NR_OF_REMAINING_CELLS == 0)

| 0 } ; — End recursion (no more START_FREQUENCY)

< NCP2 Property struct > ::=

< SAME_RA_AS_SERVING_CELL : bit (1) >

< CELL_BAR_ACCESS_2 : bit >

< BCC : bit (3) > ;

< Neighbour parameter set struct > ::=.

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

< EXC_ACC : bit >

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

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

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

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

{ 0 | 1 < SI13_PBCCH_LOCATION : < SI13_PBCCH_LOCATION struct > > }

< GPRS_TEMPORARY_OFFSET : bit (3) >

< GPRS_PENALTY_TIME : bit (5) >

< GPRS_RESELECT_OFFSET : bit (5) > ;

< COMPACT Neighbour Cell params 2 struct > ::=

{ 00 — Message escape

{ 1 < COMPACT NCP2 Repeat struct >

< CELL_PARAMS_POINTER : bit (2) > } ** 0 — Up to four pointers to the ‘C Neighbour parameter set’

<COMPACT Neighbour parameter set :
<COMPACT Neighbour parameter set struct > > * (1+ max(val(CELL_PARAMS_POINTER)))

! < Message escape: { 01 | 10 | 11 } bit** = < no string >> } ; — Reserved for future use

< COMPACT NCP2 Repeat struct > ::=

{ 1 < START_FREQUENCY : bit (10) > — Multiple START FREQ/FREQ DIFF sets may be defined

< COMPACT NCP2 Property struct >

{ < NR_OF_REMAINING_CELLS : { bit (4) – 0000 } >

< FREQ_DIFF_LENGTH : bit (3) >

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

< COMPACT NCP2 Property struct > } * (val(NR_OF_REMAINING_CELLS))

< COMPACT NCP2 Repeat struct > — Repeated recursively

| 0000 } — Break recursion (NR_OF_REMAINING_CELLS == 0)

| 0 } ; — End recursion (no more START_FREQUENCY)

< COMPACT NCP2 Property struct > ::=

< SAME_RA_AS_SERVING_CELL : bit (1) >

< CELL_BAR_ACCESS_2 : bit >

< BCC : bit (3) >

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

< COMPACT Neighbour parameter set struct > ::=

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

< EXC_ACC : bit >

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

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

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

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

< GPRS_TEMPORARY_OFFSET : bit (3) >

< GPRS_PENALTY_TIME : bit (5) >

< GPRS_RESELECT_OFFSET : bit (5) >

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

Table 11.2.21.2: PSI3 bis information element details

PAGE_MODE (2 bit field)
See description under PSI3.

PSI3_CHANGE_MARK (2 bit field)
See description under PSI3.

PSI3_BIS_INDEX (4 bit field)
The PSI3_BIS_INDEX field is used to distinguish individual PSI3 bis messages containing information about different neighbour cells. The field can take the binary representation of the values 0 to n, where n is the index of the last PSI3 bis message. (PSI3 bis count).

PSI3_BIS_COUNT (4 bit field)

See description under PSI3.

General rules for handling neighbour cell parameter default values

The first neighbour cell defined in the first PSI3bis instance uses as its default parameter values the parameter values defined for the last neighbour cell in PSI3.
The following neighbour cells in PSI3bis use the parameter values of the previous neighbour cell as their default values.

This principle of referring to the previous cell applies independently of the coding used in PSI3bis (Neighbour cell parameters, Neighbour cell parameters 2 and COMPACT Neighbour Cell Parameters).

This principle also applies when going from PSI3bis instance i over to PSI3bis instance i+1.

Neighbour cell params struct
The coding of the Neighbour cell parameters is described under PSI3.

Neighbour cell params 2 struct
This coding may be used if the number of neighbour cells is high and many cells share common parameter values. The structure contains pointers to the list of sets of actual parameters. The coding of actual parameters that are contained in or referenced by the Neighbour Cell params 2 struct is described in PSI3.

COMPACT Neighbour Cell params struct
The coding of the Neighbour cell parameters is the same as the coding of the Neighbour cell params struct 2, except the two additional parameters, TIME_GROUP and GUAR_CONSTANT_PWR_BLKS. The coding of actual parameters that are contained in or referenced by the COMPACT Neighbour Cell params struct is described in PSI3.

The following parameters (CELL_PARAMS_POINTER, BCC and NCC) are not defined in PSI3:

CELL_PARAMS_POINTER (2 bit field)
Pointer to the parameter set valid for a certain cell group (up to four).

BCC (3 bit field)
BTS Colour Code.

Neighbour parameter set struct and COMPACT Neighbour parameter set struct
The actual parameter values for the Neighbour Cell params 2 struct and the COMPACT Neighbour Cell params struct are given is these structures. Default values for absent parameters are defined according to the general rule given above, except:

NCC : bit (3). Network Colour Code. The default value is given by the serving cell.

LSA Parameters IE
The LSA Parameters IE is described under PSI3 and in sub-clause 12.28.