| 摘要 |
A multi-media interface universally and flexibly supports present (and contemplated) messaging applications including voice mail, facsimile mail, electronic mail, interactive voice response, automated attendant surface services, audio text services, electronic messaging services, radio paging services, speech recognition/speech synthesis, DTMF tone detection, voice recognition, video messaging, video mail, interface of voice and data between the public switched telephone network (PSTN), the packet switched public data network (PSPDN), and mobile/portable telephone subscribers, e.g. cellular telephones and does so at a very high throughput. In order for the host messaging center to provide these services to subscribers communicating over the various communications networks, the multi-media interface makes the necessary protocol conversions for different telecommunications protocols corresponding to various types of telecommunications media (and associated control signalling) which may include, for example, speech in analog form, speech data in pulse code modulated (PCM) form, modem data in PCM digital form, data in analog form modulating sinusoidal carriers, and data in various digital forms associated with a variety of protocol standards. The multi-media interface includes a programmable line interface module and a time slot interchanger switch selectively routes various time slots of information to/from multiple parallel digital signal processors (DSPs), each with its own dual port, high speed RAM. A local central processing unit (CPU) controls and coordinates the line interface, time slot interchanger, and DSPs via a local bus in accordance with the host messaging center. The DSPs are reconfigurable in real time to selectively perform protocol conversions to/from the host's processing and storage format for a wide variety of communications media. Each DSP can simultaneously process up to six digital communications channels so that a large number of multi-media subscribers can be served by the host messaging center in real time. |
