7.2 State Description for the VMSC

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

7.2.1 VMSC States

7.2.1.1 IDLE State

In this state, the VMSC location service is inactive for a particular MS. The MS may be known in the VLR (except for a SIMless Emergency call or where the MS record has been canceled or lost in the VLR), but there may not be an active Mobility Management or Radio Resource connection to the MS.

7.2.1.2 LOCATION State

In this state, the VMSC is awaiting a response from either an NSS based SMLC or BSC after requesting the location for a particular MS. In this state, a Radio Resource connection and a Mobility Management connection to the target MS will be active – allowing the SMLC and MS to exchange positioning related messages for mobile based and mobile assisted position methods. For certain position methods (e.g. network based position methods), the SMLC may invoke substates in the VMSC during which other types of association are maintained with the MS (e.g. temporary call establishment). Such substates are defined in later sections for each positioning method. In this state, the VMSC may also transfer positioning related messages between an NSS based SMLC and the target MS and/or between an NSS based SMLC and certain LMUs served by the VMSC.

7.2.2 State Functionality

7.2.2.1 State Transitions

Figure 22: State Transitions in the VMSC

Moving from IDLE to LOCATION state:

After a request has been received to locate a particular MS and the MS subscription options have been verified, a location request is sent to the SMLC or BSC associated with the serving cell of the MS to be located: the VMSC then enters the LOCATION state. Before entering this state, the VMSC must have obtained the current cell ID for the MS and setup a Radio Resource and Mobility Management connection to the MS if none was previously active.

Moving from LOCATION to IDLE state:

After the return of a location estimate result from the SMLC, the VMSC shall reenter IDLE state.

7.2.2.2 LOCATION Timer Function

The VMSC runs a timer while in the LOCATION state to limit the amount of time waiting for a location response from the SMLC or BSC. If the timer expires before such information is received, the VMSC indicates a location failure to the original requesting entity and reenters IDLE state.