Telephone (D-network) mobile subscriber to mobile subscriber - GF82.70-P-0003-05C
Mobile subscribers (A) and (B) have logged into the D-network outside of the reception range of their (home) mobile switching center (MSC).
They are then logged into the best located base transceiver station (BTS) and base station controller (BSC) in the closest (external) mobile switching center (MSC) and are registered in the home location register (HLR) there. The (external) mobile switching centers (MSC) automatically connect to the responsible (home) mobile switching center (MSC) (MSC, A is not shown) and inform them of the momentary location of the subscriber. The location of the corresponding mobile subscriber is then registered in both (home) mobile switching centers. If a mobile subscriber (A) wants to complete a call to mobile subscriber (B) he/she enters his/her number.
This number allows determination of the location of mobile subscriber (B) by his (home) mobile switching center (MSC, B). With the information on the location, the system then transmits the call from mobile subscriber (A) to mobile subscriber (B) via the best communication path. During a call the system automatically continues to search for the best communication option to minimize transmission losses.
The communication path is therefore subdivided into the radio telephone network path:
- Mobile telephone
- Base transceiver station (BTS)
- Base station controller (BSC)
- Mobile switching center (MSC)
- Mobile service switching center (MSC-B)