The purpose of the procedures that are grouped together in this clause is to enable Endpoint B to request location measurement data and/or a location estimate from Endpoint A, and to enable Endpoint A to transfer location measurement data and/or a location estimate to Endpoint B in the absence of a request.
The Location Information Transfer procedure is shown in
Figure 5.3.2-1.
Step 1.
Endpoint B sends a RequestLocationInformation message to Endpoint A to request location information, indicating the type of location information needed and potentially the associated QoS.
Step 2.
Endpoint A sends a ProvideLocationInformation message to Endpoint B to transfer location information. The location information transferred should match or be a subset of the location information requested in step 1 unless Endpoint B explicitly allows additional location information. If step 3 does not occur, this message shall set the endTransaction IE to TRUE.
Step 3.
If requested in step 1, Endpoint A sends additional ProvideLocationInformation messages to Endpoint B to transfer location information. The location information transferred should match or be a subset of the location information requested in step 1 unless Endpoint B explicitly allows additional location information. The last message shall include the endTransaction IE set to TRUE.
The Location Information Delivery procedure allows Endpoint A to provide unsolicited location information to Endpoint B. The procedure is shown in
Figure 5.3.3-1.
Step 1.
Endpoint A sends a ProvideLocationInformation message to Endpoint B to transfer location information. If step 2 does not occur, this message shall set the endTransaction IE to TRUE.
Step 2.
Endpoint A may send one or more additional ProvideLocationInformation messages to Endpoint B containing additional location information data. The last message shall include the endTransaction IE set to TRUE.
When triggered to transmit a
RequestLocationInformation message, Endpoint B shall:
1 >
set the method specific RequestLocationInformation IEs in accordance with the information received from upper layers.
1 >
deliver the message to lower layers for transmission.
Upon receiving a
RequestLocationInformation message, Endpoint A shall:
1 >
if the requested information is compatible with Endpoint A's capabilities and configuration:
2 >
include the requested information in a ProvideLocationInformation message;
2 >
set the SessionID IE in the response message to the same value as the SessionID IE in the received message if received;
2 >
set the SLPP-TransactionID IE in the response to the same value as the SLPP-TransactionID IE in the received message;
2 >
deliver the ProvideLocationInformation message to lower layers for transmission.
1 >
otherwise:
2 >
if one or more positioning methods are included that Endpoint A does not support:
3 >
continue to process the message as if it contained only information for the supported positioning methods;
3 >
handle the signaling content of the unsupported positioning methods by SLPP error detection as in
clause 5.4.3.
When triggered to transmit
ProvideLocationInformation message, Endpoint A shall:
1 >
for each positioning method contained in the message:
2 >
set the corresponding IE to include the available location information;
1 >
deliver the response to lower layers for transmission.