8 Information storage

23.0673GPPenhanced Multi Level Precedence and Pre-emption service (eMLPP)Release 17Stage 2TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

8.1 Stored in the HLR

Information concerning the maximum priority level which a subscriber is entitled to use at call establishment shall be stored in the HLR.

If the maximum priority level is above level 4, one level shall be indicated as default level. This default level shall be used for mobile originated calls if no priority selection is performed by the user at call establishment.

The default selection can be performed by the subscriber by means of a registration procedure.

NOTE The priority levels in the subscription are related to point-to-point calls. VBS and VGCS calls are treated with the priority level defined in the GCR for a certain group ID in a certain group call area which can be different to the priority levels explicitly defined in the eMLPP subscription. However, these levels are then implicitly defined with the subscribed group IDs.

eMLPP may have the following logical states (refer to 3GPP TS 23.011 for an explanation of the notation):

Provisioning State Registration State Activation State HLR Induction State

(Not Provisioned, Not Registered, Not Active Not Induced)

(Provisioned, Registered, Active and Operative Not Induced)

The HLR shall store the logical state of eMLPP (which shall be one of the valid states listed above) on a per subscriber basis.

8.1.1 State transition model

The following figure shows the successful cases of transition between the applicable logical states of eMLPP. The state changes are caused by actions of the service provider.

Note that error cases are not shown in the diagram as they normally do not cause a state change. Additionally, some successful requests may not cause a state change. Hence they are not shown in the diagram.

Figure 1: State transition model for eMLPP

8.1.2 Transfer of information from HLR to VLR

If the provisioning state for eMLPP is "Provisioned" then, when the subscriber registers on a VLR, the HLR shall send that VLR information about the logical state of eMLPP, the maximum priority level and the default priority level.

If any of the eMLPP subscriber data is changed, the HLR shall send to the VLR the complete eMLPP subscriber data.

8.2 Stored in the VLR

For eMLPP, the VLR shall store the service state information, the maximum priority level a subscriber is entitled to use and the default priority level received from the HLR.

8.3 Stored in the MSC

The network specific service configuration of eMLPP defined by the network operator as specified in 3GPP TS 22.067 shall be stored within each MSC. This includes information on resource pre-emption actions for any given levels of incoming and on-going call priority. An example for a network specific service configuration is given in 3GPP TS 22.067.

8.4 Stored in the SIM

Each compatible Mobile Station shall be aware of the automatic answering actions for any given levels of priority so that when in idle mode or dedicated mode or group receive mode or group transmit mode, it can decide on the necessary reactions to be taken according to the priority information of the incoming call.

For this, the SIM shall store the following data:

Priority level	Subscription available	Automatic answering applies	Fast set-up actions (note)
A	yes/no	yes/no	yes/no
B	yes/no	yes/no	yes/no
0	yes/no	yes/no	yes/no
1	yes/no	yes/no	yes/no
2	yes/no	yes/no	yes/no
3	yes/no	yes/no	yes/no
4	yes/no	—	yes/no

NOTE: Fast set-up actions which shall be performed by the Mobile Stations if indicated in the SIM data are the use of the appropriate establishment cause and the reaction on accelerated establishment procedures allowed by the network (see clause 11.6).

The automatic reaction of the Mobile Station for automatic answering or called party pre-emption shall be predefined by the user via MMI. 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.

In addition, the Mobile Station shall verify a priority level selected by the user at call establishment against the priority levels stored on the SIM and act accordingly as defined in clause 11.5.1.2.

The Mobile Station shall perform automatically the related functions for a fast call set-up if related with a selected priority.

8.5 Stored in the GCR (GSM only)

In the network, specific service configurations for VBS and VGCS calls which are registered in the GCR, a priority level shall be assigned to each voice broadcast call or voice group call configuration, according to 3GPP TS 43.069 and 3GPP TS 43.068, respectively.