03.713GPPFunctional descriptionLocation Services (LCS)Release 1999Stage 2TS
SCCP connection oriented signaling between an SMLC and MSC (NSS based SMLC) or SMLC and BSC (BSS based SMLC) is used to support SMLC signaling to a type A LMU, serving BSC, serving MSC or target MS. Two distinct types of SCCP connection are needed.
7.5.1 SCCP connection for positioning of a target MS
The MSC and BSC set up this connection when they request a location estimate for a target MS. The MSC/BSC sends the BSSMAP-LE Perform Location Request to the SMLC inside an SCCP Connection Request message. Signaling between the SMLC and target MS is then relayed by the serving MSC or BSC between this SCCP connection and the main signaling link to the MS. The same SCCP connection is also used to transfer BSSLAP messages between the SMLC and serving BSC. See figures 25 and 26.
Figure 25: SCCP based signalling for MS positioning with an NSS based SMLC
Figure 26: SCCP based signalling for MS positioning with a BSS based SMLC
7.5.2 SCCP connection to access a type A LMU
The MSC, BSC or SMLC setup this connection to enable LCS messages to be transferred to or from a type A LMU. The MSC, BSC or SMLC sends a BSSMAP-LE LMU Connection Request message inside an SCCP Connection Request message. Signaling is subsequently relayed through the serving MSC and BSC using this SCCP connection as shown in Figures 27 and 28.
Figure 27: SCCP based signalling to access a type A LMU with an NSS based SMLC
Figure 28: SCCP based signalling to access a type A LMU with a BSS based SMLC