Method and apparatus for multiple media digital communication system
US5995491A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Feb 5, 1997 |
| Grant date | Nov 30, 1999 |
| Priority date | — |
| Expiry date | Feb 5, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M2201/42
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention is embodied in a digital communication system where multiple media data sources are time multiplexed into a packetized data stream, each packet having an assigned priority and the packetized data stream transmitted in substantially the order of assigned priority. At both the transmit side, and the receive side, audio packets are given priority processing over video packets, which in turn have priority over text/graphics data packets. Continuous real time audio playback is maintained at the receiver by delaying the playback of received audio in a first in/first out (FIFO) buffer providing a delay at least equal to the predicted average packet delay for the communication system. Optionally, the average system delay is continuously monitored, and the audio playback delay time is adjusted accordingly. Audio playback is slowed or accelerated in order to shrink or grow the difference in time between the sender and receiver. In another aspect of the invention, a conference of three or more callers is created by broadcasting a common packetized data stream to all conference callers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.