摘要:
A packet telephone system which employs a packet network that provides virtual circuits. The packet telephone system employs short packets containing compressed speech. The use of the short packets makes possible compression and decompression times and bounded delays in the virtual circuits which are together short enough to permit toll-quality telephone service. The packet telephone system employs an intelligent network interface unit to interface between the packet network and standard telephone devices. The network interface unit does the speech compression and decompression and also responds to control packets from the packet network. Consequently, many telephone system features can be implemented in the network interface unit instead of in the switches. The network interface unit may also be used to provide data connections to devices attached to it. The combination of virtual circuits, with bounded delays, short packets, rapid compression and decompression, and intelligent network interface units makes it possible to build a telephone system with fewer and cheaper switches and fewer links for a given volume of traffic than heretofore possible and also permits substantial savings in provisioning and maintaining the system.
摘要:
A method and system for combing requests for data bandwidth by a data provider for transmission of data over an asynchronous communication medium is provided. A headend receives one or more bandwidths requests from one or more cable modems via upstream communication. A scheduler then combines one or more bandwidths requests from the same cable modem to create a single data burst bandwidth. The headend then grants the data burst bandwidth to the appropriate cable modem via downstream communication.
摘要:
A cable modem system and method is provided for the transfer and processing of data in accordance with specialized data transfer protocols while utilizing conventional cable modem termination system (CMTS) equipment. A cable modem system in accordance with the invention includes a cable modem that provides for the modification of data packets in accordance with a proprietary protocol and the addressing of the modified data packets to a headend server. The headend server is adapted to reconstruct the data packets for transmission to other local cable modems or to a packet-switched network. In additional embodiments, the CMTS itself rather than a headend server operates to reconstruct the data packets.
摘要:
In a communication system (SYS) in which a packet data transfer is performed between the network side (NS) and the subscriber terminal side (SS) a physical connection (LC) is maintained during the data packet transfer. An active period detector (AP-DET) detects an active period of data packet generation by evaluating the inter-arrival time (TDIFF) between successively arriving data packets (DP). If the inter-arrival time (TDIFF) falls within a predetermined range a physical connection maintaining device (LC-MAIN) maintains the physical connection (LC) even if a transmitter queue (TR-QUE) temporarily becomes empty. Therefore, within the active period (AP) the transmitter (NS-TR; SS-TR) indicates a non-empty queue. The invention finds particular application in the GPRS/(E)GPRS/GSM environment.
摘要:
A data multiplexing network is described which multiplexes a plurality of asynchronous data channels with an asynchronous data stream representing compressed voice signals and/or facsimile signals onto a single synchronous data packet stream. The single synchronous data packet stream is then transmitted by a high speed statistical multiplexer over a composite link to a second site using a modified high-level synchronous data link control protocol with an overlay of a priority statistical multiplexing algorithm. The asynchronous data channels and the compressed voice channel and/or facsimile signals are demultiplexed and reconstructed for sending to other asynchronous computer terminals and to a standard telephone or facsimile analog port at the second site, respectively. PBX trunk interfaces are also provided to allow PBX's to share the composite link between sites.
摘要:
An ATM transmission system which transmits voice data in an asynchronous transfer mode (ATM). It implements compression of a mute section over a channel by detecting the mute section of a call and by physically suppressing its transmission over the channel as an ATM cell. A transmitting side detects the mute section, generates vocal/mute information, and generates a mute start cell and a mute end cell. A receiving side generates a mute section at a fixed interval when receiving the mute start cell, and returns to a normal receiving mode of a speech spurt cell immediately when receiving the mute end cell. The suppression of the mute section makes it possible to reduce the occupied bandwidth, and to increase the channel efficiency.
摘要:
Audio communication apparatus which facilitates reduction of data network traffic. The communication apparatus distinguishes between voice activity and silence or background noise. Upon termination of voice activity the apparatus output the contents of it memory thus far for transmission over the data network. When voice activity is resumed after a period of inactivity, the transmission of voice data is resumed and an indication of the elapsed time between the previous voice samples and the current samples is also transmitted to a receiving terminal to allow correct timing of the output of the resumed transmission of the voice samples.
摘要:
A silence-suppression scheme for a packet voice transmission system (FIG. 1) accurately regenerates the silence signals at the receiving end. The following discipline is implemented at the transmitting end (100): if speech is detected (200), transmit (204) a packet carrying the speech; if silence is detected (200) and the last-transmitted packet carried speech (202), transmit (204) a packet carrying the silence; if silence is detected (200) and the last-transmitted packet carried silence (202), transmit nothing. The following discipline is implemented at the receiving end (101): if a packet is received during a packet time interval (300), output (302) the contents of the packet; if a packet is not received during a packet time interval (300), output (306) again the contents of the last-received packet. Thus, while only one silence-carrying packet is transmitted, the receiver regenerates silence signals for the entire silence interval. Also, no special transmission protocol is required to implement this scheme.
摘要:
The voice over data component of a personal communications system enables the operator to simultaneously transmit voice and data communication to a remote site. This voice over data function dynamically allocates data bandwidth over the telephone line depending on the demands of the voice grade digitized signal. The user may enter voice over data mode from a data transfer mode by lifting the handset of the telephone connected to the modem. The off-hook condition is sensed and software sends a supervisory packet to the remote site to invoke voice-over-data mode. The remote telephone will simulate a ring to alert the remote user, and the local telephone will simulate a ringback to inform the caller that the remote unit is responding.
摘要:
A personal communications system is described which includes components of software and hardware operating in conjunction with a personal computer. The user interface control software operates on a personal computer, preferably within the Microsoft Windows.RTM. environment. The software control system communicates with hardware components linked to the software through the personal computer serial communications port. The hardware components include telephone communication equipment, digital signal processors, and hardware to enable voice, fax and data communication with a remote site connected through a standard telephone line. The functions of the hardware components are controlled by control software operating within the hardware component and from the software components operating within the personal computer. The major functions of the system are a telephone function, a voice mail function, a fax manager function, a multi-media mail function, a show and tell function, a terminal function and an address book function. The telephone function allows the present system to operate, from the users perspective, as a conventional telephone using either hands-free, headset or handset operation. The telephone function is more sophisticated than a standard telephone in that the present system converts the voice into a digital signal which can be processed with echo cancellation, compressed, stored as digital data for later retrieval and transmitted as digital voice data concurrent with the transfer of digital information data.