Multiple clock rate teleconferencing network
First Claim
1. For use with a communication network in which a plurality of node sites communicate with each other by way of a hub site, wherein a respective node site transmits and receives communication signals at a clock frequency that differs from the clock frequencies at which other node sites of the network transmit and receive communication signals, an apparatus for use at said hub site for enabling said plurality of node sites to simultaneously communicate with each other at their respectively different clock frequencies, via said hub site, comprising:
- a time division multiplex communication bus having a first portion which accommodates video data signals and a second portion accommodates portion which accommodates audio data signals;
a plurality of node interface units, each of which is associated with a respective node site and is coupled to receive incoming audio and video communication signals being transmitted from its associated node site at its respective clock frequency and to transmit outgoing audio and video communication signals to its associated node site at its respective clock frequency, and is coupled to said time division multiplex communication bus for interfacing video data signals with the first portion of said time division multiplex communication bus and audio data signals with said second portion of said time division multiplex communication bus; and
an audio combining unit having a plurality of audio data processing channels respectively associated with the plurality of node sites of said network, each audio data processing channel being coupled to said second portion of said time division multiplex communication bus and combining audio data signals from node sites other than that with which that channel is associated and forwarding combined audio data signals via the second portion of said time division multiplex communication bus to its associated node interface unit.
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Accused Products
Abstract
A hub-resident data switching apparatus for a multinode teleconferencing network enables plural node sites, operating at differing clock rates, to communicate with each other asynchronously and simultaneously. The switching apparatus includes an internal TDM bus to which plural node interface units, an audio combiner unit and a timing and control unit are coupled. Each node interface unit is associated with a respective node and is operative to receive and forward communication signals with respect to its node at the clock rate of the service used by that node. The hub'"'"'s TDM bus includes a video/PC file bus and an audio/command bus and operates at a clock rate that is a multiple of the number of nodes in the network times the highest clock frequency of any node in the network divided by the bit width of the TDM bus. Each unit interfaces with the TDM bus by way of a pipeline bus interface unit. The audio combiner unit outputs digitized `combined audio` signal packets onto the audio bus for transmission to its associated node. The output section of the audio combiner unit includes an audio packet input buffer whose contents are processed in dependence upon the occupancy status of each audio packet input buffer in the combiner. As long as there is sufficient audio data stored in one or more buffers to ensure effectively continuous audio processing, audio data is processed and forwarded for transmission. If the audio packet input buffers have very little or no audio data, then processing is delayed.
143 Citations
35 Claims
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1. For use with a communication network in which a plurality of node sites communicate with each other by way of a hub site, wherein a respective node site transmits and receives communication signals at a clock frequency that differs from the clock frequencies at which other node sites of the network transmit and receive communication signals, an apparatus for use at said hub site for enabling said plurality of node sites to simultaneously communicate with each other at their respectively different clock frequencies, via said hub site, comprising:
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a time division multiplex communication bus having a first portion which accommodates video data signals and a second portion accommodates portion which accommodates audio data signals; a plurality of node interface units, each of which is associated with a respective node site and is coupled to receive incoming audio and video communication signals being transmitted from its associated node site at its respective clock frequency and to transmit outgoing audio and video communication signals to its associated node site at its respective clock frequency, and is coupled to said time division multiplex communication bus for interfacing video data signals with the first portion of said time division multiplex communication bus and audio data signals with said second portion of said time division multiplex communication bus; and an audio combining unit having a plurality of audio data processing channels respectively associated with the plurality of node sites of said network, each audio data processing channel being coupled to said second portion of said time division multiplex communication bus and combining audio data signals from node sites other than that with which that channel is associated and forwarding combined audio data signals via the second portion of said time division multiplex communication bus to its associated node interface unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. For use with a telecommunication network in which a plurality of teleconferencing node sites may simultaneously communicate with each other by way of a hub site, wherein a respective node site transmits and receives telecommunication signals at a clock frequency that differs from the clock frequencies at which other node sites of the network transmit and receive telecommunication signals, an apparatus, located at said hub site, for enabling said plurality of node sites to simultaneously exchange telecommunication signals with each other at their respectively different clock frequencies comprising:
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a time division multiplex telecommunication pipeline bus having a video/data file portion which accommodates video and data file signals and an audio/command portion which accommodates audio and command signals; a plurality of node interface units, each of which is associated with a respective node site and is coupled to receive incoming telecommunication signals being transmitted from its associated node site at its respective clock frequency and to transmit outgoing telecommunication signal to its associated node site at its respective clock frequency, and is coupled to said time division multiplex telecommunication pipeline bus for interfacing video/data file signals with the first portion of said time division multiplex telecommunication pipeline bus and audio/command signals with said second portion of said time division multiplex telecommunication pipeline bus; and an audio combining unit having a plurality of audio signal processing channels respectively associated with the plurality of node sites of said network, each audio signal processing channel being coupled to said second portion of said time division multiplex telecommunication pipeline bus and combining audio signals from node sites other than that with which that channel is associated and forwarding combined audio signals via the second portion of said time division multiplex telecommunication pipeline bus to its associated node interface unit. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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Specification