| 摘要 |
A mobile subscriber is able to request an outgoing call setup without dialing a Numbering Plan Area (NPA) number. A mobile subscriber specifies a particular NPA number to be used with all subsequently dialed local calls. The user specified NPA number is encapsulated into an Unstructured Supplementary Service Data (USSD) message and transported over to the associated home location register (home HLR). Whenever the mobile station performs a location update, or stores a new NPA number, the home HLR copies the stored NPA number to the serving mobile switching center (MSC). Subsequently, whenever the mobile station originates an outgoing call setup with only a local directory number, the MSC retrieves the copied NPA number and generates a complete B-number by concatenating the retrieved NPA number with the subscriber dialed local directory number. The generated B-number is then utilized to properly process the outgoing call setup. |
