Content for  TS 23.433  Word version:  19.3.0

The VAL server sends a Sdd_RegularTransmission request to the SEALDD server, as specified in clause 9.2.2.2. The request includes the identifiers of the application traffic (e.g. VAL service ID, VAL server ID), and optionally, the QoS information for the application traffic, e.g. QoS requirements.

Upon receiving the request, the SEALDD server performs an authorization check. If authorization is successful, the SEALDD server sends a response to the VAL server. The QoS information may be allocated by SEALDD server according to VAL service ID for different service type of application traffic if the QoS information is not provided by VAL server.

The regular data transmission connection is established according to clause 9.2.2.2.

The S-SEALDD server (i.e., SEALDD server#1) can generate the transmission quality measurement report according to the SEALDD enabled transmission quality measurement procedure in clause 9.7.2.1, and detect whether the current transmission quality can satisfy the QoS requirements of VAL application.

The S-SEALDD server subscribes to 5GC for QoS monitoring of the specific UE related to the VAL user, as defined in clause 5.2.6.9 of TS 23.502. If the S-SEALDD server diagnoses that QoS deterioration is caused by N6/SEALDD overload (i.e., based on QoS monitoring between UE and UPF, and the E2E transmission quality measurement). The S-SEALDD server can determine to trigger the data transmission quality guarantee procedure (i.e., switching the connected SEALDD server according to SEALDD service policy) based on the QoS monitoring and E2E transmission quality measurement.

The S-SEALDD server performs target SEALDD server discovery procedure by using EEL, as specified in clause 9.4.

The S-SEALDD server can select the T-SEALDD server (i.e., SEALDD server #2) based on N6 traffic and/or SEALDD server load from performance of the available target SEALDD servers in step 6.

The SEALDD relocation procedure is performed for the switched SEALDD servers and the switched VAL servers, as specified in clause 9.6.2.2. After the SEALDD relocation procedure, the SEALDD client can connect to the selected T-SEALDD server to obtain the data transmission quality guarantee service (i.e. the QoS requirements of VAL application can be satisfied).

A VAL client and server establish a SEALDD connection to transport the application data. As part of the connection establishment, the SEALDD service policy in precondition 1 is shared so that it is available to both the SEALDD client and the SEALDD Server. The SEALDD Server may use the data transmission quality requirements of this policy in conjunction with other local policies pre-provisioned at the SEALDD server. The SEALDD server determines whether to start data transmission quality measurement by itself or by the SEALDD client. As a result, SEALDD measurements (e.g. packet loss rate, latency) are configured either at the SEALDD client as described in clause 9.7.2.3 or at the SEALDD server as described in clause 9.7.2.1 and started accordingly. Then either the SEALDD client or server receives measurement reports.

Based on measurement reports and the SEALDD service policy, depending on the which entity started the measurement, either the SEALDD client or server determines to perform an action so that the data transmission quality requirements of the policy are met.

Specifically, if the measurement was started by the SEALDD client, the SEALDD client triggers the establishment of redundant transmission services. If the measurement was started by the SEALDD server, the SEALDD server triggers the establishment of redundant transmission services by sending a Transmission quality management request to the SEALDD client requesting to establish redundant transmission path.

The SEALDD client uses steps 6 to 9 of the procedure in clause 9.3.2.1 to request the use of redundant transmission service from the SEALDD server. As part of this step, the UE may end the initial PDU session and establish redundant PDU sessions.

The SEALDD client updates the SEALDD connection with the redundant transmission information, i.e., the UE addresses and ports for the redundant PDU sessions, the SEALDD-UU flow identifier, and the application traffic descriptors. The SEALDD client or server also configures the parameters for enabling any necessary SEALDD measurements for the new SEALDD-UU flow.

The SEALDD server may subscribe to receive notifications from the 5G network for user plane measurements (e.g., the network latency requirements specified in TS 28.541), network analytics (as specified in TS 28.104, etc.).

The SEALDD client and server handle data duplication and elimination of application traffic on the redundant SEALDD-UU flows and the necessary measurements are collected by the SEALDD client or server.

A VAL client and server establish a SEALDD regular or redundant connection to transport the application data as described in clause 9.2 or clause 9.3. The connection establishment may be triggered by either SEALDD server or SEALDD client. During the connection establishment, the SEALDD client includes an indication for data transmission adjustment request as part of the connection establishment over SEALDD-UU reference point. In SEALDD-UU connection establishment, the SEALDD client also includes its capability for BAT and periodicity adaptation, or transmission assistance info to the SEALDD server in the connection establishment request (SEALDD client triggered establishment) or response (SEALDD server triggered establishment).

The SEALDD server, based on received data transmission adjustment request from VAL server or SEALDD client, its own capability and/or received capability from SEALDD client for BAT and periodicity adaptation, and its own DL transmission assistance info and/or received transmission assistance info from SEALDD client, subscribes to 5GS AF session with QoS service with capability for BAT adaptation or transmission assistance info as described in clause 4.15.6.6 and 4.16.6.4 of TS 23.502.

The SEALDD server receives BAT offset and optionally a proposed periodicity (which was adjusted in 5GS) in AF session with QoS notification from 5GS.

If the SEALDD client indicated its BAT and periodicity adaptation capability in step 1 during SEALDD connection establishment, the SEALDD server sends UL periodicity and BAT window to the SEALDD client in Transmission quality management request with transmission parameter adjustment action.

The SEALDD client applies UL periodicity and BAT offset for uplink SEALDD data.

The SEALDD server locally applies DL periodicity and BAT offset for downlink SEALDD data.