Closed-loop voice-over-internet-protocol (VOIP) with sender-controlled bandwidth adjustments prior to onset of packet losses
US7668968B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 9, 2002 |
| Grant date | Feb 23, 2010 |
| Priority date | — |
| Expiry date | Aug 13, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L65/752
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A closed-loop voice-over-Internet-Protocol (VoIP) system has a local and a remote VOIP application. Each VOIP application monitors incoming packet arrival times and durations of audio data in the incoming packets to estimate bandwidth. The bandwidth estimates are forwarded to the other VOIP application. The forwarded bandwidth estimates are compared to a sending bandwidth. When the bandwidth estimate is above the sending bandwidth, compression and audio-frame decimation are reduced to improve voice quality. When the bandwidth estimate falls below the sending bandwidth, audio compression and decimation are increased to improve efficiency. Packet size can also be increased. Congestion estimates can also be sent with the audio data, causing packet transmission to pause until congestion ends. Incoming packet latencies are compared to a moving average to determine the congestion estimate, while bandwidth estimates are made by comparing packet audio duration to time between packet arrivals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.