Method for dynamically optimizing bandwidth allocation in variable bitrate (multi-rate) conferences

• US 7,492,731 B2
• Filed: 09/24/2004
• Issued: 02/17/2009
• Est. Priority Date: 10/02/2003
• Status: Active Grant

• Current Assignee: Avaya Incorporated
• Original Assignee: RADVISION Limited (Avaya Incorporated)
• Inventors: Hagendorf, Pierre
• Primary Examiner(s): Tsang; Fan
• Assistant Examiner(s): TESHALE, AKELAW
• Application Number:
  US10/949,922
• Publication Number:
  US 20060067251A1
• Time in Patent Office: 1,607 Days
• Field of Search: 370260-269, 348 1401- 1416
• US Class Current: 370/262
• CPC Class Codes: H04L 12/1827 Network arrangements for conference optimisation or adaptation
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/25 with rate being modified by the source upon detecting a change of network conditions
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/762 triggered by the network
• CPC Class Codes: H04L 47/765 triggered by the end-points
• CPC Class Codes: H04L 47/801 Real time traffic
• CPC Class Codes: H04L 47/806 Broadcast or multicast traffic
• CPC Class Codes: H04N 21/2385 Channel allocation H04N21/266 takes precedence; Bandwidth allocation H04N21/24 takes precedence ; allocation of channels according to the instantaneous demands of the users in time-division multiplex systems H04J3/1682; admission control, resource allocation in open networks H04L12/5692; arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896; negotiating bandwidth in wireless networks H04W28/16
• CPC Class Codes: H04N 7/152 Multipoint control units therefor

Abstract

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.

Claims

1. A method for dynamically optimizing bandwidth allocation in a variable bitrate conference environment, comprising:

a) providing conference means having two or more outputs, each of which is capable of outputting data at different rates, thereby supporting two or more endpoints which may have different media rates;

b) connecting two or more endpoints to said conference means for participating in said conference;

c) whenever more than one video rate is used by participants in said conference;

i. selecting each set of output rates from all possible combinations of output rates in said conference means, wherein the lowest output rate in each selected set is the entry rate of the endpoint joining said conference at the lowest rate;

ii. for each selected set, determining a Quality Drop Coefficient (QDC) for each endpoint that joins said conference, wherein said 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;

iii. calculating a Quality Drop Value (QDV) for each of said selected sets, wherein, preferably, the set of output rates having the lowest QDV is determined as the optimal video rate set to select;

d) reducing the video rate of all the endpoints having a video rate above the highest optimal video rate to said highest optimal video rate, if required, and reducing the video rate of other endpoints having video rate between two consecutive levels of optimal video rates to the lowest level among said levels; and

e) whenever a change occurs in either the amount of participating endpoints in the conference or in the declared bitrate capability of the participating endpoints, recalculating the video rates of all the outputs.

2. A method according to claim 1, wherein the QDV is calculated starting from the second highest video rate and reduced consecutively to each of the next lower video rates, until a predetermined video rate above the lowest video rate of the endpoints participating in the conference is reached.

3. A method according to claim 1, wherein the QDV is calculated according to each calculated QDC and the number of endpoints suffering from each calculated QDC.