10.7 MC IOPS notification
23.1803GPPMission critical services support in the Isolated Operation for Public Safety (IOPS) mode of operationRelease 17TS
10.7.1 General
In the IOPS mode of operation, it is assumed that the IOPS MC system does not have connectivity to the primary MC system due to the backhaul failure. Therefore, the primary MC system cannot be aware of the initiation of the IOPS operation and the corresponding activation of an IOPS MC connectivity function within the primary MC system coverage.
When an IOPS MC system is active, MC service UEs can move around and may enter and leave the IOPS MC system coverage, i.e. the MC service users may switch from the active IOPS MC connectivity function to the MC service server of the primary MC system, and vice versa.
In order to notify the primary MC service server about the active IOPS MC connectivity function, when MC service users register to the primary MC service server after being recently registered to the IOPS MC connectivity function, the MC service users can provide information to the primary MC service server about the active IOPS MC connectivity function and optionally include associated dynamic information. The primary MC service server uses the provided information to become aware of the active IOPS MC connectivity function.
NOTE: Dynamic information can be, e.g., information about other available MC service users or active MC service groups that the MC service user identified while on the IOPS MC connectivity function. The primary MC service server can use the dynamic information to determine that affiliated MC service users might be registered on the active IOPS MC connectivity function and might not be reachable on the system.
Upon the receipt of the notification, the primary MC service server may notify other MC service users in the proximity of the IOPS MC system coverage about the corresponding active IOPS MC connectivity function. This information can be used by the MC service users to optimize the user experience, e.g. to improve the switching time between systems and to obtain information about the potential availability of other registered MC service users or active MC service groups on the IOPS MC connectivity function.
10.7.2 Information flows
10.7.2.1 MC IOPS notification
Table 10.7.2.1-1 describes the information flow MC IOPS notification from the MC service client to the primary MC service server.
Table 10.7.2.1-1: MC IOPS notification
|
Information element |
Status |
Description |
|
MC service ID |
M |
The identity of the MC service user providing the notification |
|
IOPS MC system information |
M |
Information related to the identified active IOPS MC connectivity function (see NOTE) |
|
List of MC service group IDs |
O |
The list of groups identified by the MC service user as active on the IOPS MC connectivity function |
|
List of MC service IDs |
O |
The list of other users identified by the MC service user as available on the IOPS MC connectivity function |
|
NOTE: The IOPS MC system information consists of the following elements: IOPS PLMN ID, server URI of the IOPS MC connectivity function, and location information (set of coordinates including altitude, longitude and latitude, and time of measurement and optional accuracy) related to the MC service user registration on the IOPS MC connectivity function. |
||
Table 10.7.2.1-2 describes the information flow MC IOPS notification from the primary MC service server to the MC service client.
Table 10.7.2.1-2: MC IOPS notification
|
Information element |
Status |
Description |
|
MC service ID (see NOTE 1) |
M |
The identity of the MC service user receiving the notification |
|
IOPS MC system information |
M |
Information related to the identified active IOPS MC connectivity function (see NOTE 2) |
|
List of MC service group IDs (see NOTE 3) |
O |
The list of MC service groups identified as active on the IOPS MC connectivity function |
|
List of MC service IDs (see NOTE 3) |
O |
The list of MC service users identified as available on the IOPS MC connectivity function |
|
NOTE 1: This information element is not included if the notification is transmitted over MBMS. NOTE 2: The IOPS MC system information consists of the following elements: server URI of the IOPS MC connectivity function, and location information (set of coordinates including altitude, longitude and latitude) where the IOPS MC connectivity function is identified as active. NOTE 3: The MC service server may provide information about identified active MC service groups or available MC service users on the IOPS MC connectivity function. This information is only included if the MC service user receiving the notification is authorized, e.g. if the MC service user is a member of the corresponding MC service groups. This information element is not included if the notification is transmitted over MBMS. |
||
10.7.3 MC IOPS notification procedure
Figure 10.7.3-1 describes the IOPS MC notification procedure when an MC service user has left an active IOPS MC system and enters the primary MC system.
Pre-conditions:
– There is an active IOPS MC connectivity function and the neighbouring cells of the IOPS MC system are part of the primary MC system.
– The MC service user 1 is initially registered to the IOPS MC connectivity function for the support of MC services in the IOPS mode of operation. The MC service user 1 is authorized to provide MC IOPS notifications to the primary MC service server.
– The MC service user 2 is registered to the primary MC service server and is in the proximity of the IOPS MC system coverage.
– MC server users 1 and 2 are members of the same MC service group or are authorized to have a one-to-one MC service communication.
Figure 10.7.3-1: MC IOPS notification procedure
1. An IOPS mode of operation is active and the MC service communication is handled by the IOPS MC connectivity function. The MC service client 1 is registered to the IOPS MC connectivity function.
2. The MC service client 1 moves out of the coverage of the IOPS MC system and registers to the primary MC service server.
3. The MC service client 1 sends a MC IOPS notification to the primary MC service server to provide information about an active IOPS MC connectivity function in the area. This notification includes information about the active IOPS MC connectivity function such as server URI, associated IOPS PLMN ID, and location information. Also, the MC service client 1 may indicate which MC service groups and MC service users were identified as active and available on the IOPS MC connectivity function.
4. The primary MC service server becomes aware of the active IOPS MC connectivity function and can use the received information to determine that affiliated MC service users might be registered on the active IOPS MC connectivity function and might not be reachable on the system. If the primary MC service server determines that the IOPS MC connectivity function is active and identifies that affiliated MC service users are in the proximity of the IOPS MC system, the primary MC service server may notify the corresponding MC service users about the IOPS MC connectivity function.
NOTE 1: The primary MC service server can use received information from different MC IOPS notifications (e.g. location information including the time of measurement) and the information obtained from location information subscriptions (as described in 3GPP TS 23.280 [3]) to determine if the IOPS MC connectivity function might be still active. For instance, if information received from location information subscriptions indicates that MC service users are located within the notified active IOPS MC system coverage, the primary MC service server can determine that the IOPS MC connectivity function is no longer active.
5. If the primary MC service server determines that the IOPS MC connectivity function is active, it sends a MC IOPS notification to the MC service client 2 in proximity of the active IOPS MC system coverage. This information can be used by the MC service user to become aware of the active IOPS MC connectivity function. Hence, the MC service user might decide to not move into the IOPS MC system coverage or to improve the switching time between the systems. Also, the MC service user can be aware of the potential availability of MC service users or active MC service groups on the IOPS MC connectivity function.
NOTE 2: The MC IOPS notification can be sent on an MBMS bearer configured within the proximity of the active IOPS MC system to target multiple MC service users. In this case, information about the active MC service IDs and MC service group IDs is not included in the MC IOPS notification.
Annex A (normative):
Configuration data for the support of MC services in the IOPS mode of operation