7 Mobile Station requirements

3GPP43.246Multimedia Broadcast/Multicast Service (MBMS) in the GERANRelease 16Stage 2TS

7.1 General requirements

An MBMS capable mobile station shall be able to receive at least one MBMS service. The mobile station shall also be able to receive multiple services if they are transmitted on the same carrier (provided that the MBMS multislot capabilities of the mobile station are not exceeded). The simultaneous reception of multiple services on different carriers shall be dependent upon mobile station capabilities.

A mobile station receiving an MBMS p-t-m transmission shall be in broadcast/multicast receive mode. This state is defined only for the mobile station; from the network’s point of view, the mobile station shall be in packet idle mode. However, if the network has indicated in the assignment message that the mobile station does not need to listen to the (P)CCCH and (P)BCCH in parallel to the MBMS data, and the mobile station has an MS_ID on that MBMS radio bearer, the network needs to keep track of such mobile station listening to that MBMS radio bearer in order to send CS and/or PS paging messages on the PACCH/D.

Unless the network has indicated in the assignment message that the mobile station does not need to listen to the (P)BCCH and (P)CCCH in parallel to the MBMS data, the mobile station shall, in parallel to the MBMS data, read system information for the serving cell from the broadcast control channel and CS and/or PS paging messages from its paging group on the paging channel(s) allocated in the cell. Reading system information and paging messages takes precedence over listening to the MBMS session.

NOTE: In case the network does not provide system information and paging messages on the PACCH, the location of the MBMS bearer with respect to the control channels should be chosen such that it will be possible for the mobile station to read all the PDCHs of the MBMS radio bearer while monitoring the control channels.

A mobile station receiving MBMS shall operate in Network Control mode NC0 (see 3GPP TS 45.008 [9]) even if it had been commanded otherwise by the network. If in GMM-Ready state, the mobile station shall move to NC0 upon the start of the MBMS session. Upon termination of the MBMS session, the mobile station shall revert to the control mode commanded by the network before the start of the MBMS session if the mobile station is still in GMM-Ready state.

7.2 Mobile Station tasks

When in broadcast/multicast receive mode, the requirements for monitoring the received signal level of neighbouring cells shall be the same as those for packet idle mode (see 3GPP TS 45.008 [9]). For the reconfirmation of the BSIC of neighbouring cells, however, the requirements for packet transfer mode shall apply (see 3GPP TS 45.008 [9]).

If the PBCCH is not present in the serving cell, a mobile station in broadcast/multicast receive mode shall not attempt to decode the BCCH data block that contains the parameters affecting cell reselection for non-serving cells that have been provided by the System Information (see 3GPP TS 45.008 [9]). Instead, this information shall be provided by the serving cell either on BCCH or on PACCH.

The behaviour of the MS which does not receive in time or does not receive at all this information is defined in 3GPP TS 43.022 [10].

Mobile stations in broadcast/multicast receive mode shall obey the intra-RAT and inter-RAT cell reselection algorithms defined for the GMM Ready state (see3GPP TS 45.008).

A mobile station in broadcast/multicast receive mode shall be able to respond to a PACKET POLLING REQUEST message as defined in 3GPP TS 44.060 when addressed with its TLLI. It shall also be able to receive a PACKET POWER CONTROL/TIMING ADVANCE message and act accordingly (see 3GPP TS 44.060).

7.3 Multislot capabilities

The multislot capability of an MBMS capable mobile station shall be such that the mobile station is capable of receiving on up to 5 timeslots per frame and the timeslots shall be assigned within a window of maximum size Rx=6.

An MBMS capable mobile station shall be capable of receiving MBMS:

– on up to 4 timeslots simultaneously, if the MS must listen to the (P)BCCH and (P)CCCH in addition to the timeslots assigned for MBMS data transfer; or

– on up to 5 timeslots simultaneously, if PBCCH/PCCCH is mapped on one of the PDCHs assigned to the MBMS session and the number of timeslots assigned to the PCCCH is equal to one; or

– on up to 5 timeslots simultaneously, if the network transmits system information and paging messages on the PACCH of the MBMS radio bearer.

NOTE: The downlink timeslots could be used to receive multiple MBMS sessions in parallel (see subclause 6.4).

If data transfer is with ARQ (see subclause 6.3), the mobile station shall additionally be capable of transmitting on up to two timeslots. The number of timeslots allocated for the reception of MBMS (m) and the number of timeslots allocated for transmission (n) shall be such that the sum of m and n does not exceed 6 (5 in case the mobile station needs to listen to the (P)BCCH and (P)CCCH in addition to the timeslots assigned for MBMS data transfer).

Regardless of the data transfer method, the mobile station shall additionally be capable of reading the (P)BCCH and the (P)CCCH on up to one additional timeslot in those frames where the mobile station is required to read the (packet) broadcast control channel or the (packet) common control channel. The network can however indicate in the assignment message that the mobile station will receive system information and CS and/or PS paging messages on the PACCH/D of the MBMS radio bearer. In that case, the mobile station shall not listen to the (P)BCCH and the (P)CCCH in parallel to the MBMS data (see sub-clause 6.6).

NOTE: This will be possible without interrupting the reception of MBMS only if allowed by the relative location of the (packet) control channels and of the MBMS traffic channel and depending on the number of timeslots allocated to MBMS (see Annex B), unless system information for the serving cell and CS and/or PS paging messages are transferred on the PACCH/D.

If the number of timeslots allocated to the (P)CCCH is higher than one, the number of timeslots on which MBMS can be received may be reduced.

7.4 MBMS notification for mobile stations in dedicated mode or packet transfer mode or dual transfer mode

A mobile station in class A mode of operation which supports the MBMS feature and requires notification of commencing MBMS sessions during dedicated mode operation shall perform the service information sending procedure:

– at the earliest opportunity after the early Classmark sending procedure and any DTM related signalling, if and only if the dedicated mode MBMS notification feature is supported in the cell; or

– if the P-TMSI of the MS is reallocated during the CS connection and the dedicated mode MBMS notification feature is supported in the cell; or

– on the main DCCH of a target cell after successfully completing the handover procedure, if indicated to do so in the HANDOVER COMMAND message and the dedicated mode MBMS notification feature is supported in the target cell.