摘要:
A system and method for extending the time period at which a response signal can be received before a time-out occurs without altering the length of the time-out period defined in any transmission protocol, ensuring that the two faxes communicate using one of a predefined, e.g., standard, set of transmission protocols, and/or ensuring that the two faxes communicate using one of a predefined set of signal modulation techniques. The present invention receives signals transmitted from a local fax and transmits these signals to a remote fax. Similarly, the present invention receives signals transmitted from the remote fax and transmits these signals to the local fax. The present invention examines the contents of the signals and can modify the signal transmitted to the local fax in order to ensure that the two faxes communicate using a transmission protocol that is supported by the present invention and to ensure that the two faxes communicate using a signal modulation technique that is supported by the present invention.
摘要:
A system and method for extending the time period at which a facsimile response signal can be received before a time-out occurs without altering the underlying transmission protocol. The disclosed system and method determines a response time before which a response signal must be received by a transmitting facsimile station in order to avoid a time-out event. Before the response time arrives, the disclosed system and method generates and transmits a delay signal to the transmitting facsimile station which does not substantively interfere with ongoing communications. Instead, the delay signal causes the transmitting facsimile station to tickle an internal time-out counter which results in an extension of the response signal delay tolerance. Delay signal frames can be transmitted repeatedly to accommodate any desired time-out period.
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.
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 calling station sends to a called station a call request package including the address of the called station and the information digitizing rate of the calling station. The packet may also include the address of the calling station. The called station selects the lower of the information digitizing rates of the calling and called stations or the information digitizing rates of both stations if such rates are the same. The called station sends to the calling station a call request response package including the selected information digitizing rate. The call request response packet may include the addresses of the calling and called stations. The calling station selects the lower of the information digitizing rates of the calling and called stations or the information digitizing rates of both stations if both rates are the same. The information digitizing rates of the calling and called stations may be the voice digitizing rates of both stations. When the calling station selects the information digitizing rate, the calling and called stations send and receive information packets at such information digitizing rates.