The parameters to be indicated, and negotiated, if applicable, during the call set-up shall include:
GERAN Channel coding(s) acceptable (for the call);
maximum number of GERAN TCH/F (that the mobile user can accept);
wanted AIUR (desired rate that the mobile user wants the network to allocate). The wanted AIUR is applicable to NT services only;
indication if the user initiated modification is required, and if so, the network resource needs;
channel coding asymmetry indication.
Some of the parameters are only utilised by GERAN. When UTRAN radio access bearer is allocated the values are ignored.
The GERAN channel coding(s) acceptable shall be indicated by the mobile at call set-up and is not negotiable. It indicates the GERAN channel coding(s) that may be chosen by the network for the call.
The maximum number of GERAN TCH/F shall be indicated at call set-up. It enables the mobile user to limit the number of GERAN TCH/F used and thus to control an essential parameter for charging. It sets the upper limit of number of TCH/F that the network may allocate to the mobile.
The wanted AIUR (applicable to NT services only) indicates the AIUR that the mobile user wants and which the network shall try to reach but which it is not allowed to exceed. The exception where the network is allowed to exceed the wanted AIUR is when the network can achieve the GERAN AIUR with a lower number of TCH/F, e.g. wanted GERAN AIUR indicated by the mobile is 14,4 kbit/s, GERAN channel codings acceptable are both TCH/F9.6 and TCH/F4.8 and maximum number of TCH/F are 3, then the network shall choose 2 x 9,6 over 3 x 4,8 if a channel coding of TCH/F9.6 is available on two TCH/F.
If the user wishes to make use of the user initiated modification procedure, this shall be indicated at the call set-up.
It shall be possible to reserve a different FNUR than the AIUR.
Channel coding asymmetry indication is only applicable to NT calls where the user has indicated acceptance for channel coding(s) based on enhanced modulation. In this case the user may indicate preference for channel coding symmetry, downlink biased channel coding asymmetry, or uplink biased channel coding asymmetry. The channel coding asymmetry indication is only applicable in direction UE to network.
The in-call modification feature shall be supported in case of alternate services.