During call setup WCS/MSC exchange authentication triplets with HLR-USDS.MAP-D protocol does this.User subscription information is copied to VLR .Radio control points are associated with it to manage user mobility.Note that VLR is nothing but the WCS/MSC .
Hope this answers ,let me know if you want indepth explaination.
During call setup WCS/MSC exchange authentication triplets with HLR-USDS.MAP-D protocol does this.User subscription information is copied to VLR .Radio control points are associated with it to manage user mobility.Note that VLR is nothing but the WCS/MSC .
Hope this answers ,let me know if you want indepth explaination.