Method for dynamically optimizing bandwidth allocation in variable bitrate (multi-rate) conferences
Method for dynamically optimizing bandwidth allocation in a variable bitrate conference environment. Conference means with two or more outputs are provided, where each one can output data at different rates, in order to support two or more endpoints which may have different media rates. Two or more endpoints are connected to these conference means for participating in the conference. Whenever more than one video rate is used by participants during the conference, each set of output rates is selected from all possible combinations of output rates in the conference means, wherein the lowest output rate in each selected set is the entry rate of the endpoint joining the conference at the lowest rate. A Quality Drop Coefficient (QDC) for each endpoint that joins the conference is determined for each selected set, wherein the QDC is computed according to the endpoint entry rate and the highest rate, among the output rates of each selected set, that is lower or equal to said endpoints' entry rate. A Quality Drop Value (QDV) is calculated for each of the selected sets, wherein, preferably, the set of output rates with the lowest QDV is determined as the optimal video rate set to select. The video rate of all the endpoints having a video rate above the highest optimal video rate is reduced to the highest optimal video rate, if required, and the video rate of other endpoints having video rate between two consecutive levels of optimal video rates is reduced to the lowest level among said levels. Whenever a change occurs in either the amount of participating endpoints in the conference or in the declared bit rate capability of the participating endpoints, the video rates of all the outputs are recalculated.
1. A method of allocating conference resources on a conference system, said method comprising:
dynamically calculating for multiple participants of a given conference, by a controller of said system, a quality drop coefficient (QDC) for possible resource allocations of said system for said given conference, wherein said QDC for a given participant for a given resource allocation represents a quality of service said participant would experience in said given conference if said given resource allocation is implemented in said given conference and, wherein said QDC is calculated by said controller separately for each participant in said conference and is computed according to a second highest video rate between said multiple participants;
dynamically calculating, by said controller, for said possible resource allocations a quality drop value (QDV), which QDV for a given resource allocation represents a weighted aggregation of said calculated QDC's for said given resource allocation;
dynamically selecting, by said controller from said possible resource allocations said resource allocation with said lowest calculated QDV; and
implementing, by said system, said selected resource allocation, by, via said controller, one of sending said selected resource allocation for each participant to said each participant and commanding said participant associated with said selected resource allocation to limit the output of said associated participant.
2. The method according to claim 1 , wherein said QDV calculation includes consideration of a conferencing resource allocation priority.
3. The method according to claim 2 , wherein said resource allocation priority is to minimize image quality degradation for one or more of said multiple participants.
4. The method according to claim 1 , wherein said calculated QDC for each resource allocation is represented in a table.
5. The method according to claim 2 , wherein said resource allocation priority is to maximize service fees from participants.
6. The method according to claim 5 , wherein maximizing service fees comprises compliance with at least one Service Level Agreement requirement.
7. The method according to claim 1 , further comprising performing said steps of said method of claim 1 again upon a participant leaving said conference, wherein said process of performing the steps again comprises accounting for a maximum conference rate, a minimum conference rate, and an adjustment conference rate.
8. The method according to claim 1 , further comprising performing said steps of said method of claim 1 again upon a new participant entering said conference, wherein said process of performing the steps again comprises accounting for a maximum conference rate, a minimum conference rate, and an adjustment conference rate.
9. The method according to claim 1 , further comprising performing said steps of said method of claim 1 again upon a capability of a conference participant changing.
10. A multi-participant conferencing system comprising:
conferencing resources; and
a control unit for:
(1) dynamically calculating for multiple participants of a given conference a quality drop coefficient (QDC) for possible resource allocations of said conferencing resources for said given conference, wherein said QDC for a given participant for a given resource allocation represents a quality of service said participant would experience in said given conference if said given resource allocation is implemented in said given conference and wherein said QDC is calculated by said control unit separately for each participant in said conference and is computed according to a second highest video rate between said multiple participants;
(2) dynamically calculating for said possible resource allocations a quality drop value (QDV), which QDV for a given resource allocation represents a weighted aggregation of said calculated QDC's for said given resource allocation;
(3) dynamically selecting from said possible resource allocations said resource allocation with said lowest calculated QDV; and
(4) providing to said participants said conferencing resources according to said selected resource allocation by one of sending said selected resource allocation for each participant to said each participant, and commanding said participant associated with said selected resource allocation to limit the output of said associated participant.
11. The system according to claim 10 , wherein said QDV calculation includes consideration of a conferencing resource allocation priority.
12. The system according to claim 11 , wherein said resource allocation priority is to minimize image quality degradation for one or more of said multiple participants.
13. The system according to claim 10 , wherein said calculated QDC for each resource allocation is represented in a table functionally associated with said control unit.
14. The system according to claim 11 , wherein said resource allocation priority is to maximize service fees from participants.
15. The system according to claim 14 , wherein maximizing service fees comprises compliance with at least one Service Level Agreement requirement.
16. The system according to claim 10 , wherein upon a participant leaving a conference, said control unit recalculates said QDV for each possible resource allocation and accordingly reselects said resource allocation with said lowest calculated QDV, wherein said recalculating comprises accounting for a maximum conference rate, a minimum conference rate, and an adjustment conference rate.
17. The system according to claim 10 , wherein upon a participant entering a conference, said control unit recalculates said QDV for each possible resource allocation and accordingly reselects said resource allocation with said lowest calculated QDV, wherein said recalculating comprises accounting for a maximum conference rate, a minimum conference rate, and an adjustment conference rate.
18. The system according to claim 10 , wherein upon a capability of a conference participant changing, said control unit recalculates said QDV for each possible resource allocation and accordingly reselects said resource allocation with said lowest calculated QDV.
19. A machine-readable non-transitory storage medium comprising instructions which, when executed, cause a conference system to:
upon a participant entering or leaving a given conference:
(1) dynamically calculate for multiple participants of said given conference a quality drop coefficient (QDC) for possible resource allocations of said system for said given conference, wherein said QDC for a given participant for a given resource allocation represents a quality of service said participant would experience in said given conference if said given resource allocation is implemented in said given conference and wherein said QDC is calculated by said system separately for each participant in said conference and is computed according to a second highest video rate between said multiple participants;
(2) dynamically calculate for said possible resource allocations a quality drop value (QDV), which QDV for a given resource allocation represents a weighted aggregation of said calculated QDC's for said given resource allocation;
(3) dynamically select from said possible resource allocations said resource allocation with said lowest calculated QDV; and
(4) implement said selected resource allocation by one of to send said selected resource allocation for each participant to said each participant, and to command said participant associated with said selected resource allocation to limit the output of said associated participant.
20. The machine-readable storage medium according to claim 19 , wherein said QDV calculation includes consideration of a conferencing resource allocation priority.