Systems and methods for echo management in conferencing over a network using multiplexed multicast
A system includes participant nodes that unicast a voice stream to a master node and receive a multicast voice stream from the master node. The multicast voice stream may be a mixed voice stream mixing the voice streams of the participants. In this case, each participant performs echo cancellation on the multicast voice stream. Alternatively, the multicast voice stream may be a multiplexed voice stream multiplexing the voice streams of all participants. In this case, each participant de-multiplexes the multicast voice stream and generates a mixed voice stream that does not include that participant. Alternatively, the multicast voice stream received by each participant may be a multiplexed digital voice stream multiplexing multiple mixed streams including one mixed stream that does not include the voice stream of that participant. In this case, each participant de-multiplexes the multicast voice stream to obtain the mixed stream that does not include that participant.
1. A method of voice over Internet protocol (VoIP) conferencing comprising:
transmitting, by a participant node of the VoIP conferencing, an ingress digital voice stream of the participant node to a master node of the VoIP conferencing over a unicast session, wherein the master node includes a multiplexer, wherein the participant node includes a de-multiplexer and a mixer;
receiving, by the participant node, a multiplexed digital voice stream from the master node over a multicast session, wherein the multiplexed digital voice stream is generated by the multiplexer at the master node, wherein the multiplexed digital voice stream includes a plurality of digital voice streams of participants of the VoIP conferencing including the ingress digital voice stream of the participant node;
providing, to the de-multiplexer at the participant node, the multiplexed digital voice stream received from the master node;
de-multiplexing, by the de-multiplexer at the participant node, the multiplexed digital voice stream to obtain the plurality of digital voice streams of the participants of the VoIP conferencing including the ingress digital voice stream of the participant node, wherein the de-multiplexer of the participant node outputs one digital voice stream associated with each one of the participants of the VoIP conferencing;
generating, by the mixer at the participant node, a mixed digital voice stream that includes the plurality of digital voice streams of the VoIP conferencing except for the ingress digital voice stream of the participant node; and
wherein generating the mixed digital voice stream comprises mixing, by the mixer at the participant node, all of the plurality of digital voice streams outputted by the de-multiplexer at the participant node except for the ingress digital voice stream of the participant node.
2. The method of claim 1 , further comprising:
receiving an analog voice stream from a phone card of the participant node; and
converting the analog voice stream into the ingress digital voice stream.
3. The method of claim 2 , wherein the phone card aggregates one or more handsets or one or more subtended phone cards.
4. The method of claim 2 , further comprising:
performing analog echo cancellation on the analog voice stream received from the phone card.
5. The method of claim 2 , further comprising:
converting the mixed digital voice stream into a mixed analog voice stream; and
sending the mixed analog voice stream to the phone card of the participant node.
6. A method of voice over Internet protocol (VoIP) conferencing comprising:
receiving, by a master node of the VoIP conferencing, a plurality of digital voice streams from a plurality of participant nodes of the VoIP conferencing over a plurality of unicast sessions, wherein the master node includes a multiplexer, wherein each of the plurality of participant nodes includes a de-multiplexer and a mixer;
multiplexing, by the multiplexer at the master node, the plurality of digital voice streams and an ingress digital voice stream of the master node to obtain a multiplexed digital voice stream; and
transmitting, by the master node, the multiplexed digital voice stream to the plurality of participant nodes over a multicast session, causing each participant node to:
provide, to the de-multiplexer at that participant node, the multiplexed digital voice stream received from the master node;
de-multiplex, by the de-multiplexer at that participant node, the multiplexed digital voice stream to obtain the plurality of digital voice streams of participants of the VoIP conferencing including the master node and the plurality of participant nodes, wherein the de-multiplexer outputs one digital voice stream for each one of the participants of the VoIP conferencing;
generate, by the mixer at that participant node, a mixed digital voice stream that includes the plurality of digital voice streams of the participants of the VoIP conferencing except for a digital voice stream of that participant node; and
wherein generating the mixed digital voice stream comprises mixing, by the mixer at that participant node, all of the plurality of digital voice streams outputted by the de-multiplexer at that participant node except for the digital voice stream of that participant node.
7. The method of claim 6 , further comprising:
receiving an analog voice stream from a master phone card of the master node; and
converting the analog voice stream into the ingress digital voice stream.
8. The method of claim 7 , wherein the master phone card aggregates one or more handsets or one or more subtended phone cards.
9. The method of claim 7 , further comprising:
performing analog echo cancellation on the analog voice stream received from the master phone card.
10. The method of claim 7 , further comprising:
mixing the plurality of digital voice streams into another mixed digital voice stream;
converting the another mixed digital voice stream into a mixed analog voice stream; and sending the mixed analog voice stream to the master phone card of the master node.
11. A participant node for voice over Internet protocol (VoIP) conferencing, comprising:
a transceiver;
a de-multiplexer; and
a mixer,
wherein the transceiver is configured to:
transmit, by the participant node of the VoIP conferencing, an ingress digital voice stream of the participant node to a master node of the VoIP conferencing over a unicast session, wherein the master node includes a multiplexer;
receive, by the participant node, a multiplexed digital voice stream from the master node over a multicast session, wherein the multiplexed digital voice stream is generated by the multiplexer at the master node, wherein the multiplexed digital voice stream includes a plurality of digital voice streams of participants of the VoIP conferencing including the ingress digital voice stream of the participant node; and
provide, to the de-multiplexer at the participant node, the multiplexed digital voice stream received from the master node,
wherein the de-multiplexer is configured to:
de-multiplex, by the participant node, the multiplexed digital voice stream to obtain the plurality of digital voice streams of the participants of the VoIP conferencing including the ingress digital voice stream of the participant node, wherein the de-multiplexer of the participant node outputs one digital voice stream associated with each one of the participants of the VoIP conferencing; and
wherein the mixer is configured to generate, by the participant node, a mixed digital voice stream that includes the plurality of digital voice streams of the participants of the VoIP conferencing except for the ingress digital voice stream of the participant node,
wherein the mixer is further configured to generate the mixed digital voice stream by mixing all of the plurality of digital voice streams outputted by the de-multiplexer at the participant node except for the ingress digital voice stream of the participant node.
12. The participant node of claim 11 , further comprising:
a phone card; and
an analog to digital converter (ADC) configured to:
receive an analog voice stream from the phone card; and
convert the analog voice stream into the ingress digital voice stream.
13. The participant node of claim 12 , wherein the phone card aggregates one or more handsets or one or more subtended phone cards.
14. The participant node of claim 12 , further comprising:
an analog hybrid filtering circuit configured to perform analog echo cancellation on the analog voice stream received from the phone card.
15. The participant node of claim 12 , further comprising:
a digital to analog converter (DAC) configured to convert the mixed digital voice stream into a mixed analog voice stream, wherein the mixed analog voice stream is input to the phone card.
16. A master node for voice over Internet protocol (VoIP) conferencing, comprising:
a transceiver configured to receive, by the master node of the VoIP conferencing, a plurality of digital voice streams from a plurality of participant nodes of the VoIP conferencing over a plurality of unicast sessions, wherein each of the plurality of participant nodes includes a de-multiplexer and a mixer;
a multiplexer configured to multiplex, by the master node, the plurality of digital voice streams and an ingress digital voice stream of the master node to obtain a multiplexed digital voice stream; and
wherein the transceiver is further configured to transmit, by the master node, the multiplexed digital voice stream to the plurality of participant nodes over a multicast session, causing each participant node to:
provide, to the de-multiplexer at that participant node, the multiplexed digital voice stream received from the master node;
de-multiplex, by the de-multiplexer at that participant node, the multiplexed digital voice stream to obtain the plurality of digital voice streams of participants of the VoIP conferencing including the master node and the plurality of participant nodes, wherein the de-multiplexer outputs one digital voice stream for each one of the participants of the VoIP conferencing;
generate, by the mixer at that participant node, a mixed digital voice stream that includes the plurality of digital voice streams of the participants of the VoIP conferencing except for a digital voice stream of that participant node; and
wherein generating the mixed digital voice stream comprises mixing, by the mixer at that participant node, all of the plurality of digital voice streams outputted by the de-multiplexer at that participant node except for the digital voice stream of that participant node.
17. The master node of claim 16 , further comprising:
a master phone card; and
an analog to digital converter (ADC) configured to:
receive an analog voice stream from the master phone card; and
convert the analog voice stream into the ingress digital voice stream.
18. The master node of claim 17 , wherein the master phone card aggregates one or more handsets or one or more subtended phone cards.
19. The master node of claim 17 , further comprising:
an analog hybrid filtering circuit configured to perform analog echo cancellation on the analog voice stream received from the master phone card.
20. The master node of claim 17 , further comprising:
another mixer configured to mix the plurality of digital voice streams into another mixed digital voice stream; and
a digital to analog converter (DAC) configured to convert the another mixed digital voice stream into a mixed analog voice stream, wherein the mixed analog voice stream is input to the master phone card of the master node.