Packet mode multimedia conferencing services over an ISDN wide area network

Claim 2

In a system for providing real-time multimedia conferencing services to a dispersed plurality of locations interconnected by a wide area network from multimedia signals consisting of audio, video, and data signals originating at said locations and having properties adapted for said services, said locations employing a quality of service which degrades at least one of said properties, the method comprising in combination the steps of: receiving said multimedia signals from said locations at said wide area network; bridging said multimedia signals in said wide area network, including detecting the degrading of at least said one property in said multimedia signals in said wide area network by estimating a first time period by which a first group of said multimedia signals is expected to be received; determining whether any of said multimedia signals within said first group is absent at the end of said first time period; determining whether any of said multimedia signals received within said first time period belongs to a second group different from said first group; and transmitting said bridged multimedia signals over said wide area network to said plurality of locations.

Claim 3

A method, as claimed in claim 1, wherein said step of receiving comprises the step of receiving said multimedia signals by said wide area network and wherein said wide area network comprises an ISDN network.

Claim 4

A method, as claimed in claim 2, wherein said step of transmitting comprises the step of time division multiplexing said processed multimedia signals for transmission on said ISDN network.

Claim 5

A method, as claimed in claim 1, wherein said step of processing comprises the step of deleting at least some of said multimedia signals belonging to said second group.

Claim 6

A method, as claimed in claim 1, wherein said step of processing comprises the step of storing at least some of said multimedia signals belonging to said second group.

Claim 7

A method, as claimed in claim 1, wherein said step of processing comprises the step of creating one or more dummy groups of multimedia signals for said first group in the event that multimedia signals within said first group are absent.

Claim 8

A method, as claimed in claim 1, wherein said step of processing further comprises the step of synchronizing said multimedia signals.

Claim 9

A method, as claimed in claim 1, wherein said multimedia signals comprise video signals and audio signals and wherein said step of processing comprises the step of synchronizing said video signals and said audio signals.

Claim 10

A method, as claimed in claim 1, wherein said multimedia signals comprise video signals and audio signals and wherein said step of detecting comprises the steps of: estimating a first time period by which a first segment of said audio signals is expected to be received; determining whether any of said audio signals within said first segment is absent at the end of said first time period; increasing said first time period to a second time period in the event any of said audio signals is absent; determining whether any of said audio signals within said segment is absent at the end of said second time period; estimating a third time period by which a first frame of said video signals is expected to be received; determining whether any of said video signals within said first frame is absent at the end of said third time period; increasing said third time period to a fourth time period in the event any of said video signals is absent; and determining whether any of said video signals within said frame is absent at the end of said fourth time period.

Claim 11

A method, as claimed in claim 9, wherein said step of detecting further comprises the steps of: determining whether any of said audio signals received within said first time period belong to a second segment different from said first segment; determining whether any of said video signals received within said third time period belong to a second frame different from said first frame.

Claim 12

A method, as claimed in claim 10, wherein said step of processing comprises the steps of: storing any of said audio signals belonging to said second segment; and storing any of said video signals belonging to said second frame.

Claim 13

A method, as claimed in claim 10, wherein said step of processing comprises the step of deleting at least some of said video signals belonging to said second frame.

Claim 14

A method, as claimed in claim 10, wherein said step of processing further comprises the step of synchronizing said audio signals within said first segment with said video signals within said first frame.

Claim 15

A method, as claimed in claim 1, and further comprising the steps of: receiving said processed multimedia signals at one of said locations over said wide area network; detecting the absence of at least said one property in said multimedia signals at said one location; processing said one location multimedia signals to compensate for the absence of at least said one property; and using said processed one location multimedia signals to create audio visual services at said one location.

Claim 16

A method, as claimed in claim 14, wherein the step of detecting the absence of at least said one property in said one location multimedia signals comprises the steps of: estimating a first time period by which a first group of said one location multimedia signals is expected to be received; determining whether any of said one location multimedia signals within said first group is absent at the end of said first time period; increasing said first time period to a second time period in the event any of said one location multimedia signals is absent; and determining whether any of said one location multimedia signals within said group is absent at the end of said second time period.

Claim 18

A method, as claimed in claim 16, wherein said step of processing said one location multimedia signals comprises the step of deleting at least some of said one location multimedia signals belonging to said second group.

Claim 19

A method, as claimed in claim 16, wherein said step of processing said one location multimedia signals comprises the step of storing at least some of said one location multimedia signals belonging to said second group.

Claim 20

A method, as claimed in claim 15, wherein said step of processing said one location multimedia signals comprises the step of creating one or more dummy groups of multimedia signals for said first group of one location multimedia signals in the event that multimedia signals within said first group of one location multimedia signals is absent.

Claim 21

A method, as claimed in claim 15, wherein said step of processing said one location multimedia signals further comprises the step of synchronizing said one location multimedia signals.

Claim 22

A method, as claimed in claim 1, wherein said locations employ switched local area network hubs and further comprising the steps of: sharing only said switched local area network hubs; and operating said switched local area network hubs within predetermined performance guidelines, whereby superior multimedia conferencing services are provided with guaranteed quality of service parameters.

Claim 23

A method, as claimed in claim 1, wherein said locations employ a mix of shared and switched local area networks, whereby improved multimedia conferencing services are provided with conditional guarantee of quality of service parameters.

Claim 24

The system of claim 1, further including the step of compensating for said degrading of said at least one property whereby the bandwidth required to transmit said multimedia signals between said plurality of locations is reduced.

Claim 25

The system of claim 1, further including: increasing said first time period to a second time period in the event any of said multimedia signals is absent; and determining whether any of said multimedia signals within said group is absent at the end said second time period.

Claim 26

The system of claim 1, further including: processing said multimedia signals to compensate for the absence of at least said one property; and transmitting said bridged, processed multimedia signals over said wide area network to said plurality of locations, whereby the quality of said services at said plurality of locations is improved.

Claim 27

The system of claim 1 including a method for synchronizing said multimedia signals, said signals including audio, video, and data bitstream packets, the method comprising in combination the steps of: generating an audio bitstream packet; generating a video bitstream packet; and clocking said audio and video bitstream packets for synchronizing same to provide an initial time and a final time for each said audio and video bitstream packets, and establishing estimated playout times for said audio and video bitstream packets from said initial and final times.

Claim 28

The method of claim 26, wherein said step of clocking and synchronizing includes the steps of comparing the playout times estimates of said audio and video bitstream packets and attaching a delay to the bitstream packet with the earliest estimated arrival for synchronizing the bitstream packets.

Claim 29

In a system for providing real-time multimedia conferencing services to a dispersed plurality of locations interconnected by a wide area network from multimedia signals, consisting of audio, video, or data signals, originating at said locations and having properties adapted for said services, said locations employing nonguaranteed quality of service packet switched local area networks which degrade at least one of said properties, said method comprising in combination the steps of: receiving said multimedia signals from said local area networks at said wide area network; bridging said multimedia signals in said wide area network; detecting the absence of at least said one property in said multimedia signals in said wide area network; processing said multimedia signals to compensate for the absence of at least said one property; and transmitting said bridged, processed multimedia signals over said wide area network to said plurality of locations, whereby the quality of said services at said plurality of locations is improved and the bandwidth to transmit said multimedia signals between said plurality of locations is reduced; said step of detecting comprising the steps of estimating a first time period by which a first group of said multimedia signals is expected to be received; determining whether any of said multimedia signals within said first group is absent at the end of said first time period; increasing said first time period to a second time period in the event any of said multimedia signals is absent; determining whether any of said multimedia signals within said group is absent at the end said second time period; and determining whether any of said multimedia signals received within said first time period belong to a second group different from said first group.

Claim 30

In a system for providing real-time multimedia conferencing services to a dispersed plurality of locations interconnected by a wide area network from multimedia signals, consisting of audio, video, or data signals, originating at said locations and having properties adapted for said services, said locations employing nonguaranteed quality of service packet switched local area networks which degrade at least one of said properties, said method comprising in combination the steps of: receiving said multimedia signals from said local area networks at said wide area network; bridging said multimedia signals in said wide area network; detecting the absence of at least said one property in said multimedia signals in said wide area network; processing said multimedia signals to compensate for the absence of at least said one property; and transmitting said bridged, processed multimedia signals over said wide area network to said plurality of locations, whereby the quality of said services at said plurality of locations is improved and the bandwidth to transmit said multimedia signals between said plurality of locations is reduced; said step of detecting comprising the steps of estimating a first time period by which a first group of said multimedia signals is expected to be received; determining whether any of said multimedia signals within said first group is absent at the end of said first time period; increasing said first time period to a second time period in the event any of said multimedia signals is absent; determining whether any of said multimedia signals within said group is absent at the end said second time period; and determining whether any of said multimedia signals received within said first time period belong to a second group different from said first group.