System and method for enhancing audio quality for IP based systems using an AMR payload format
US7830920B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 2004 |
| Grant date | Nov 9, 2010 |
| Priority date | — |
| Expiry date | Feb 14, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/70
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method of enhancing audio quality for Internet protocol (IP) based systems using an adaptive multi-rate (AMR) payload format is presented. If a network buffer indicative of network congestion exceeds its threshold a determination is made whether to place a NO DATA frame into the current RTP packet instead of the AMR frame. If network conditions are too congested then a NO DATA frame is placed into the current RTP packet. The process is repeated for each incoming AMR frame. The process first ensures that the AMR coding rate is set to its lowest possible coding rate prior to substituting a AMR frame with a NO DATA frame. The substitution pattern is spread over the entire RTP packet to avoid clusters of NO DATA frames. The process can also single out AMR frames of lower energy value that would be good candidates for substitution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.