11.2.42 Packet MBMS Announcement

3GPP44.060General Packet Radio Service (GPRS)Mobile Station (MS) - Base Station System (BSS) interfaceRadio Link Control / Medium Access Control (RLC/MAC) protocolRelease 17TS

This message is sent on PACCH by the network to notify all MBMS mobile stations listening to that PDCH that an MBMS Service Session is commencing or an ongoing MBMS Broadcast Service Session with an updated MBMS service area list is available.

Message type: PACKET MBMS ANNOUNCEMENT

Direction: network to mobile station

Classification: distribution message

Table 11.2.42.1: PACKET MBMS ANNOUNCEMENT information elements

< PACKET MBMS ANNOUNCEMENT message content > ::=

< PAGE_MODE : bit (2) >

< TMGI : < TMGI IE > >

{ 0 | 1 < MBMS Session Identity : bit (8) > }

{ 0 — counting is off

{ 0 | 1 < MBMS p-t-m channel description : < MBMS p-t-m channel description struct > > }

| 1 — counting is on

{ 0 | 1 < MPRACH description : < MPRACH description struct > > }

}

{ 0 | 1 < RESTRICTION_TIMER : bit (4) > }

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

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

< MBMS p-t-m channel description struct > :: =

< Estimated Session Duration : bit (8) >

{ 0 | 1 < MBMS Radio Bearer Starting Time : bit (16) > }

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

< DL_TIMESLOT_ALLOCATION : bit (8) >

< Length of MBMS Bearer Identity : bit (3) >

< MBMS Bearer Identity : bit (val (Length of MBMS Bearer Identity)) >

{ 0 | 1 < EGPRS Window Size : < EGPRS Window Size IE >> }

{ 0 | 1 < NPM Transfer Time : bit (5) > };

< MPRACH description struct > :: =

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

< MPRACH_TIMESLOT : bit (3) >

< USF : bit (3) >

{ 0 — no MPRACH access parameters present

| 1 — MPRACH access parameters present

< MPRACH Control Parameters : < MPRACH Control Parameters IE > > } ;

Table 11.2.42.2: PACKET MBMS ANNOUNCEMENT information element details

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

TMGI IE
This field contains the Temporary Mobile Group Identity of the MBMS service that the MBMS Notification concerns. This field is encoded as defined in sub-clause 12.33.

MBMS Session Identity (8 bit field)
This field contains the MBMS Session Identity of the concerned MBMS session (see TS 23.003).

Estimated Session Duration (8 bit field)
This field contains an estimation of the session (remaining) duration for the concerned MBMS session. This information element is defined in sub-clause 12.44.

MBMS Radio Bearer Starting Time (16 bit field)
This field contains a starting time that indicates the frame number from which the data transfer on the assigned MBMS radio bearer may start. The MBMS Radio Bearer Starting Time is encoded as the value part of the type 3 information element Starting Time in 3GPP TS 44.018.

Frequency Parameters
If this information element is not present, the same frequency as for the PCCCH shall be used. This information element is defined in sub-clause 12.8.

DL_TIMESLOT_ALLOCATION (8 bit field)
This field is defined in sub-clause 12.18.

MBMS Bearer Identity (1-5 bit field)
This field assigns a TFI value, or a subset of a TFI value, which identifies the MBMS radio bearer that is described. In case only a subset of a TFI value is assigned for the MBMS radio bearer, that subset corresponds to the most significant bit(s) of the TFI field.

EGPRS Window Size
This information element is defined in sub-clause 12.5.2.

MPRACH_TIMESLOT (3 bit field)
This field identifies the timeslot number of the PDCH where the MPRACH is located.

USF (3 bit field)
This field identifies the USF value that identifies the MPRACH on the defined PDCH.

MPRACH Control Parameters
This information element, if present, defines the access control parameters to be used on the MPRACH. This information element is defined in sub-clause 12.41.

RESTRICTION_TIMER
This field indicates the maximum reaction time to the PACKET MBMS ANNOUNCEMENT message in seconds for mobile station, before the information contained in the PACKET MBMS ANNOUNCEMENT message expires.

Bit
4 3 2 1
0 0 0 0 10
0 0 0 1 20
0 0 1 0 30
…
1 1 1 0 150
1 1 1 1 160

NPM Transfer Time (5 bit field)

This field is defined in sub-clause 12.45a.