11.2.24 Packet System Information Type 8

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 optionally sent by the network on the PBCCH and PACCH giving information about Cell Broadcast Channel configuration. 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 PBCCH, see 3GPP TS 05.02.

Message type: PACKET SYSTEM INFORMATION TYPE 8

Direction: network to mobile station

Classification: distribution message

Table 11.2.24.1: PSI8 information elements

< PSI8 message content > ::=

< PAGE_MODE : bit (2) >

< PSI8_CHANGE_MARK : bit (2) >

< PSI8_INDEX : bit (3) >

< PSI8_COUNT : bit (3) >

{ 0 | 1 < CBCH Channel Description : < CBCH Channel Description struct > >}

< padding bits >

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

< CBCH Channel Description struct > ::=

< Channel type and TDMA offset : bit (5) >

< TN : bit (3) >

< Frequency Parameters : < Frequency Parameters IE > > ;

Table 11.2.24.2: PSI8 information element details

PAGE_MODE (2 bit field)
This field is defined in sub-clause 12.20.

PSI8_INDEX (3 bit field) and PSI8_COUNT (3 bit field)
These fields are the binary representation of the PSI index and PSI count parameters associated with the PSI8 messages.

PSI8_CHANGE_MARK (2 bit field)
The PSI8 change mark field is changed each time information has been updated in the PSI8 message. A new value indicates that the mobile station shall re-read the information from the PSI8 message. The coding of this field is network dependent. Range: 0-3.

CBCH Channel Description struct
The CBCH Channel Description provides the description for the CBCH. If the CBCH Channel Description is not available (either as it is not included in any instance of PSI8 or as no PSI8 is broadcast at all), the mobile station can assume that SMSCB is not active in the cell.

Channel type and TDMA offset (5 bit field)
For encoding and description see 3GPP TS 04.18 (‘Channel Description IE’).

TN, Timeslot number(3 bit field)
The TN field is coded as the binary representation of the timeslot number as defined in 3GPP TS 05.02.