摘要:
A system and method for transmitting aural signals across a wide area network (WAN) from a local phone coupled to a computer, e.g., a PC-phone, to a remote phone coupled to a KTS, PBX, or PSTN, for example. This capability is provided by the gateway unit of the present invention. The system of the present invention is quickly installed in a server or a personal computer coupled to a local area network. The system is connected to one or more of a PSTN, a private branch exchange, a key telephone system, a telephone, a facsimile machine, and a modem. In the case of voice transmission, a gateway unit translates received telephony signal into a format that is compatible with the telephone system or equipment connected thereto. The present invention can provide a voice quality that approaches, equals, or exceeds the voice quality of conventional telephone switched networks. This high voice quality is achieved by utilizing a high quality voice digitization algorithm on both the PC-phone and the gateway, by ensuring a low maximum network delay between the PC-phone and the gateway, by permitting a dynamic compensation for variations in network delay, and by utilizing a forward error correction technique for transmission over WANs that can recreate lost or delayed signals in a manner that recreates the signal so the lost signal is typically not detectable by a user.
摘要:
A system and method for transparently transmitting aural signals across a wide area network (WAN). The system of present invention is connected to one or more of a private branch exchange, a key telephone system, a telephone, a facsimile machine, and a modem, for example. In the case of voice transmission, a user places a telephone call using the same procedure that is used when placing a telephone call over a conventional public switched network. The aural signals are translated into a format that is compatible with the local area network (LAN) and the translated signals are transmitted to a router or a switch that connects the LAN to the WAN. The data is transmitted across the WAN to a router or switch coupled to a second LAN. The data is then sent to a destination central site unit or PC which translates the signal into a format that is compatible with the telephone system connected thereto. The present invention provides a voice quality that approaches, equals, or exceeds the voice quality of conventional telephone switched networks. This high voice quality is achieved by utilizing a high quality voice digitization algorithm, by ensuring a low maximum network delay, by dynamically compensating for variations in network delay, and by using a forward error correction technique that can recreate lost or delayed signals in a manner that recreates the signal so the lost signal is typically not detectable by a user.