6 Compatibility issues

03.673GPPenhanced Multi Level Precedence and Pre-emption service (eMLPP)Stage 2TS

eMLPP cannot be applied with standard Phase 1 or Phase 2 Mobile Stations (non compatible Mobile Stations) with all service aspects. A dedicated Mobile Station (compatible Mobile Station) with eMLPP capability is required.

Specific functions a compatible Mobile Station shall provide are:

– priority selection via MMI for call establishment in case of an eMLPP subscription including priority levels above level 4;

– analysis of the priority level included in a paging message, Call Waiting indication or notification into a voice group call or voice broadcast call, respectively;

– automatic reaction on basis of the analysed priority level in case of an incoming call while in dedicated mode, group transmit mode or group receive mode, respectively, according to the user defined Mobile Station configuration (for each subscribed priority level the user shall be able to configure the Mobile Station for automatic acceptation or indication or rejection of an incoming call);

NOTE: Functions related to notifications are only required for Mobile Stations providing VBS or VGCS functions as defined in GSM 03.69 and GSM 03.68, respectively.

However, if eMLPP is provided in a network, it can be applied to non compatible Mobile Stations in the following way:

– calls of subscribers which have no specific eMLPP subscription shall be treated for resource pre-emption with a default priority level.

This shall also apply independent of the use of compatible or non compatible Mobile Stations;

– calls of eMLPP subscribers which use a non compatible Mobile Station shall be treated for resource pre-emption with the subscriber’s default priority level;

– calls to eMLPP subscribers which use a non compatible Mobile Station shall be indicated to the user by Call Waiting as normal.