7.10 Common Procedures supporting Interaction between Peer SMLCs

03.713GPPFunctional descriptionLocation Services (LCS)Release 1999Stage 2TS

7.10.1 Information Transfer between Peer SMLCs

Figure 49 illustrates LCS information transfer between peer SMLCs where, in this scenario, one SMLC is NSS based and the other BSS based. It is assumed that while the NSS based SMLC has SS7 links to an STP, the BSS based SMLC does not.

FigureĀ 49: Information Transfer between an NSS based and a BSS based SMLC

1) When the NSS based SMLC has LCS information to send to another SMLC, it transmits a BSSMAP-LE Connectionless Information message containing an embedded SMLCPP message and the LAC/CI cell address identifying the other SMLC. If an SMLCPP message is too large to fit in a single BSSMAP-LE Connectionless Information message, it may be segmented and transferred inside a sequence of BSSMAP-LE messages. The BSSMAP-LE message is transferred inside an SCCP Unitdata message. The message is routed to an SS7 signaling point code associated with the LAC/CI address. In this scenario, the signaling point code is that for the MSC connected to the BSC for the BSS based SMLC.

2) The MSC forwards the BSSMAP message or a message segment to the BSC associated with the LAC/CI address received in step 1.

3) The BSC transfers the BSSMAP-LE message or a message segment to the SMLC. The BSC recognizes the SMLC as the final destination due to the presence of the embedded SMLCPP message.

4) When the BSS based SMLC has positioning information to return to the NSS based SMLC, it passes this to its associated BSC in a BSSMAP-LE Connectionless message contained in an SCCP Unitdata message. The BSSMAP-LE message contains an embedded SMLCPP message and the LAC/CI address identifying the other SMLC. If an SMLCPP message is too large to fit in a single BSSMAP-LE message, it may be segmented and transferred inside a sequence of BSSMAP-LE messages.

5) The serving BSC forwards the BSSMAP message or a message segment to its MSC.

6) The MSC forwards the BSSMAP-LE message or a message segment directly to the NSS based SMLC in an SCCP Unitdata message. The message is routed to an SS7 signaling point code associated with the LAC/CI address in the BSSMAP-LE message. In this scenario, the signaling point code is that for the NSS based SMLC.