| 摘要 |
In a messaging system such as a voice message system, message retrieval is restricted to authorised users by the need to dial a PIN following the telephone number for access to the system. For environments in which no post dial signalling is available, such as when pulse dialling is used, the system recognises a specific prefix to the number being dialled, and allows reception of additional dialled digits, which constitute the PIN, before generation of a "dialled digits complete" signal. The received PIN associated with the user's number is then compared with data held in a store (20), and message retrieval is enabled only if the comparison is positive. A facility may be provided for users to change their PINs. The additional digits may instead be used for transmission to called parties, the digits signifying corresponding standard phrases. <IMAGE> |
