B.3 Network requirements for supporting MS multislot classes

3GPP45.002GSM/EDGE Multiplexing and multiple access on the radio pathRelease 17TS

The multislot class of the MS will limit the combinations and configurations allowed when supporting multislot communication.

GSM 400 network may support extended cell coverage utilising timing advance values greater than 63. This has an effect that the time for MS to change from RX to TX will be very short for distant MS. It is necessary for the network to decide whether requested or current multislot configuration can be supported by distant MS. If actual TA is great enough it may be necessary for network to downgrade requested resources or it may be necessary for network to downgrade current resources.

It is necessary for the network to decide whether the MS needs to perform adjacent cell power measurement for the type of multislot communication intended and whether the service imposes any other constraints before the full restrictions on TS assignments can be resolved. This is best shown by example:

For a multislot class 5 MS in circuit switched configuration (adjacent cell power measurements required) five basic configurations of channels are possible which can occur in six different positions in the TDMA frame. The service itself may determine that asymmetry must be downlink biased, in which case the last two solutions would not be allowed.

Figure B.1

For a multislot class 13 MS when adjacent cell power measurements are not required and the service does not constrain the transmit and receive timeslots to use the same timeslot number. Many configurations of channels are possible so long as the 5 constraints of the MS are catered for. [Currently services envisaged only allow for the last example here.]

Figure B.2