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.