8.11 Constrained devices in MSGin5G Service
23.5543GPPApplication architecture for MSGin5G ServiceRelease 18Stage 2TS
8.11.1 General
This clause specifies the procedures for the constrained device UE-2, which does not support an MSGin5G Client to perform registration, to use MSGin5G UE-1 as gateway UE and to send messages and receive messages using MSGin5G UE-1 which is acting as a gateway UE for the UE-2. The communication between MSGin5G UE-1 and UE-2 is over MSGin5G-5 reference point.
NOTE: The procedure in this clause is also applicable to UE-2 that is out of network coverage.
Editor’s note: The API definition for the procedures defined in this clause is FFS.
Editor’s note: Whether the procedures in this clause are applicable to Application Client within MSGin5G UE-1 is FFS.
8.11.2 Constrained device registration to use gateway UE
The signalling flow for registration of Application Client-2 on the UE-2 (which is a Constrained UE) with MSGin5G Client-1 on MSGin5G UE-1 to use it as a gateway UE is illustrated in figure 8.11.2-1.
Pre-conditions:
1. The MSGin5G UE-1 is configured with information to recognize and authorize UE-2.
2. The UE-2 is a Constrained UE and does not have access network connection to connect with the MSGin5G Server.
3. The UE-2 has discovered MSGin5G UE-1 is having connectivity to the MSGin5G Server and offers gateway UE functionality.
4. The UE-2 is using NR-PC5 to communicate with MSGin5G UE-1.
Figure 8.11.2-1: Registration of application client on UE-2 with MSGin5G Client-1 to use gateway UE functionality
1) An Application Client-2 on the UE-2 registers with MSGin5G Client-1 in MSGin5G UE-1 to request MSGin5G Client-1 to act as a gateway UE. The request message includes information elements as specified in Table 8.11.2-1.
Table 8.11.2-1: Information elements for Registration to gateway UE request
|
Information element |
Status |
Description |
|
Layer-2 ID |
M |
Layer-2 identity of UE-2 |
|
Application ID |
M |
Application ID of the application client on UE-2 |
|
Credential information |
M |
UE-2 credential information |
Editor’s note: The security parameters to include in the message between UE-2 and MSGin5G UE-1 are FFS.
2) Upon receiving the request from the Application Client-2, the MSGin5G Client-1 authorizes the Application Client-2 on UE-2 to use gateway functionality and MSGin5G Client-1 stores the mapping between Application ID and Layer-2 ID of the UE-2.
NOTE 1: The MSGin5G Client-1 may reject the request for registration to use gateway UE functionality based on local condition (like available power or connectivity to access network or any other reason outside the scope of 3GPP).
3) The MSGin5G Client-1 sends response to the Application Client-2. The response message includes information elements as specified in Table 8.11.2-2.
Table 8.11.2-2: Information elements for Registration to gateway UE response
|
Information element |
Status |
Description |
|
Result |
M |
Indicates success or failure of the request |
|
Registration ID |
O |
Identifies registration. This IE is included only if Result IE is set to success. |
|
Failure reason |
O |
Indicates failure reason. This IE is included only if Result IE is set to failure. |
NOTE 2: If MSGin5G Client-1 decided to reject the request for registration to use gateway UE functionality or if authorization fails as in step 2), the MSGin5G Client-1 sends a failure response to the Application Client-2. Otherwise, the MSGin5G Client-1 sends a success response to the Application Client-2.
NOTE 3: The MSGin5G Client-1 may act as Gateway UE for multiple Constrained UEs, at the same time.
8.11.3 Constrained device Deregistration from using gateway UE
The signalling flow for deregistration of Application Client-2 on the UE-2 (which is a Constrained UE) with MSGin5G Client-1 to discontinue use of gateway UE functionality is illustrated in figure 8.11.3-1.
Pre-conditions:
1. The UE-2 is a Constrained UE and is successfully registered with MSGin5G UE-1 acting as a gateway UE.
Figure 8.11.3-1: Deregistration of Application Client on UE-2 with MSGin5G Client-1 on MSGin5G UE-1 to discontinue use of gateway UE functionality
1) An Application Client-2 on the UE-2 deregisters with MSGin5G Client-1 in MSGin5G UE-1 to discontinue usage of gateway UE functionality of MSGin5G UE-1. The request message includes information elements as specified in Table 8.11.3-1.
Table 8.11.3-1: Information elements for De-registration to gateway UE request
|
Information element |
Status |
Description |
|
Registration ID |
M |
Identifies the registration |
2) Upon receiving the request from the Application Client-2, the MSGin5G Client-1 removes the mapping between Application ID and Layer-2 ID of the UE-2. The MSGin5G Client-1 sends response to the Application Client-2 on UE-2. The response message includes information elements as specified in Table 8.11.2-2.
8.11.4 Constrained device sending message using Gateway UE
The signalling flow for the Application Client-2 on the UE-2 (which is a Constrained UE) to send message using gateway UE functionality on MSGin5G UE-1 is illustrated in figure 8.11.4-1.
Pre-conditions:
1. The MSGin5G UE-1 is connected to an access network that provides connectivity to the MSGin5G Server.
2. The UE-2 is Constrained UE and is successfully registered with MSGin5G UE-1 acting as a gateway UE.
Figure 8.11.4-1: Application Client-2 on UE-2 sends message using gateway UE functionality on MSGin5G UE-1
1) An Application Client-2 on the UE-2 sends a request to send MSGin5G message to the MSGin5G Client-1. The information elements defined in Table 8.11.4-1 are included in the message.
Table 8.11.4-1: Information elements for Request to send MSGin5G message
|
Information element |
Status |
Description |
|
Recipient address |
O |
Indicates details of the recipient. This IE is mandatory to initiate Point-to-Point messaging and Point-to-AS messaging (see NOTE). |
|
Recipient Group address |
O |
Indicates target group. This IE is mandatory to initiate Group messaging (see NOTE). |
|
Broadcast Area ID |
O |
The service identifier of the Broadcast Service Area where the message needs to be broadcast. This IE is mandatory in the Broadcast Message and is not present in other message scenarios (see NOTE). |
|
Messaging Topic |
O |
Indicates which Messaging Topic this message is related to. This IE is mandatory for a message distribution based on topic and is not present in other message scenarios (see NOTE). |
|
Application ID |
O |
Identifies the application(s) for which the payload is intended. |
|
Payload |
M |
Payload of the message. MSGin5G Server/Client is unaware of the content. |
|
Delivery status required |
O |
Indicates whether delivery status is required or not. |
|
Priority type |
O |
Application priority level requested for this message as specified in Table 8.3.2-1. |
|
NOTE: Only one occurrence shall be present of any of these IEs. |
||
Editor’s note: If table 8.11.4-1 should be moved to separate clause to be applicable for communication between any Application Client and any MSGin5G Client is FFS.
2) Upon receiving the request from the Application Client-2 in UE-2, the MSGin5G Client-1 constructs the related IEs specified in table 8.3.2-1 and sends an MSGin5G message based on these IEs.
a) if the size of the received message exceeds the maximum allowed packet size, the MSGin5G Client-1 sends the message as specified in clause 8.5;or
b) If the size of the received message does not exceed the maximum allowed packet size, the MSGin5G Client-1 sends the message as specified in clause 8.7.; or
c) If the size of the received message does not exceed the maximum allowed packet size, the MSGin5G Client-1 may apply message aggregation as specified in clause 8.4 before sending the message as specified in clause 8.7
NOTE 1: The MSGin5G Client-1 may also reject the request to send MSGin5G message based on local condition (like available power or connectivity to access network or any other reason outside the scope of 3GPP).
3) The MSGin5G Client-1 sends response to sent MSGin5G message to Application Client-2 on UE-2. The response message includes information elements as specified in Table 8.11.4-2.
Table 8.11.4-2: Information elements for Response to send MSGin5G message
|
Information element |
Status |
Description |
|
Result |
M |
Indicates success or failure of the request |
|
Failure reason |
O |
Indicates failure reason. This IE is included only if Result IE is set to failure. |
NOTE 2: If the MSGin5G Client-1 has decided to reject the request to send the message or the MSGin5G Client-1 received reject response from MSGin5G Server in step 2, the MSGin5G Client-1 sends failure response to the Application Client-2 and stops performing further steps.
4) If delivery status is requested while sending the message in step 1, the MSGin5G Client-1 may receive MSGin5G message delivery status report from the MSGin5G Server.
5) Upon receiving the MSGin5G message delivery status report, the MSGin5G Client-1 sends the message delivery status report to the Application Client-2 on UE-2. The message delivery status report includes information elements as specified in Table 8.11.4-3.
Table 8.11.4-3: Information elements for MSGin5G message delivery status
|
Information element |
Status |
Description |
|
Delivery status |
M |
Indicates delivery status |
8.11.5 Constrained device receiving message via Gateway UE
The signalling flow for Application Client-2 on the UE-2 (which is Constrained UE) to receive a message using gateway UE functionality on MSGin5G UE-1 is illustrated in figure 8.11.5-1.
Pre-conditions:
1. The MSGin5G UE-1 is connected to an access network that provides connectivity to the MSGin5G Server.
2. The UE-2 is Constrained UE and is successfully registered with MSGin5G UE-1 acting as a gateway UE.
Figure 8.11.5-1: UE-2 receives message using gateway UE functionality on MSGin5G UE-1
1) The MSGin5G Client-1 receives either a Group message or a Point-to-Point message or AS-to-Point message as specified in clause 8.2.3 for the Application Client-2 on UE-2 for which the MSGin5G Client-1 is acting as Gateway UE. The MSGin5G Client-1 performs reassembly if the received message is segmented or segregation if the received message is an aggregated message. The MSGin5G Client-1 may also perform segment recovery procedure as specified in clause 8.4.6 to recover missing segments.
2) Upon successfully receiving a message for the Application Client-2 on UE-2, the MSGin5G Client-1 sends message received request to Application Client-2 based on Application ID on the UE-2. The request includes information elements as specified in Table 8.11.5-1.
Table 8.11.5-1: Information elements for Message received request
|
Information element |
Status |
Description |
|
Originator address |
O |
Indicates details of the originator. This IE is mandatory for Point-to-Point messaging and AS-to-Point messaging. |
|
Group Service address |
O |
Indicates group for which the message is received. This IE is mandatory for Group Message. |
|
Messaging Topic |
O |
Indicates the Topic for which the message is received. This IE is mandatory for a Topic Message. |
|
Payload |
M |
Payload of the message. MSGin5G Server/Client is unaware of the content. |
|
Delivery status required |
O |
Indicates whether delivery status is required or not |
|
Priority type |
O |
Application priority level requested for this message as specified in Table 8.3.2-1. |
3) Upon successfully receiving the message, the Application Client-2 on UE-2 sends the message received response to the MSGin5G Client-1.
4) If delivery status is requested in the received message, the Application Client-2 on UE-2 sends message delivery status to the MSGin5G Client-1.
5) Upon receiving the delivery status, the MSGin5G Client-1 sends message delivery status report to the MSGin5G Server.