11.2.39a MBMS Assignment (Distribution)

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 the PCCCH or on the PACCH from the network to mobile stations in order to assign the radio bearer resources for an MBMS session or to notify the mobile stations that a radio bearer for that MBMS session is not established in the cell.

Message type: MBMS ASSIGNMENT (DISTRIBUTION)

Direction: network to mobile station

Classification: distribution message

Table 11.2.39a.1: MBMS ASSIGNMENT (DISTRIBUTION) information elements

< MBMS Assignment Distribution message content > ::=

< PAGE_MODE : bit (2) >

{ < TMGI : < TMGI struct > >

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

{ 0 — Assignment reject. No point-to-multipoint channel is established for the MBMS session.

< Reject cause: bit (2) >

{ 0 | 1 < Estimated Session Duration : bit (8) > }

| 1 — A point-to-multipoint channel is established for the MBMS session.

< MBMS bearer description : < MBMS bearer description struct > >

< Estimated Session Duration : bit (8) >

< MBMS In-band Signalling Indicator : < MBMS In-band Signalling Indicator IE > >

}

< padding bits >

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

< MBMS bearer description struct > :: =

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

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

< DOWNLINK_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 < TIMESLOT_ALLOCATION_UPLINK_FEEDBACK_CHANNEL : bit (3) > }

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

Table 11.2.39a.2: MBMS ASSIGNMENT (DISTRIBUTION) information element details

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

TMGI
This field contains the Temporary Mobile Group Identity of the MBMS service. 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.

Reject cause (2 bit field)
This field indicates whether the mobile station is allowed to perform further MBMS packet accesses for this MBMS session.

00 No radio bearer established – further MBMS packet accesses allowed for this MBMS session in this cell
01 No radio bearer established – no further MBMS packet accesses allowed for this MBMS session in this cell
10 No radio bearer established – no further MBMS packet accesses allowed for this MBMS session in this Routing Area
11 No radio bearer established – no further MBMS packet accesses allowed for this MBMS session in this PLMN

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

MBMS In-band Signalling Indicator
This information element contains the MBMS In-band Signalling Indicator. This information element is defined in sub-clause 12.45.

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 or, if the PCCCH is not present in the cell, for the CCCH, on which the network sends this message or the IMMEDIATE ASSIGNMENT message including the Multiple Blocks Packet Downlink Assignment construction and the Packet Channel Description IE specifying the PDCH over which this message is sent (see 3GPP TS 44.018), respectively, shall be used. This information element is defined in sub-clause 12.8.

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

MBMS Bearer Identity (1-5 bit field)
This field contains the Bearer identity for the MBMS session. This field is defined in sub-clause 12.34.

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

TIMESLOT_ALLOCATION_UPLINK_FEEDBACK_CHANNEL (3 bit field)
This field, if present, identifies the timeslot where the uplink feedback channel, on which the MBMS DOWNLINK ACK/NACK reports shall be sent, is located.

NPM Transfer Time (5 bit field)

This field is defined in sub-clause 12.45a.