Program insertion in real time IP multicast
US6771644B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 1999 |
| Grant date | Aug 3, 2004 |
| Priority date | — |
| Expiry date | Sep 17, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L12/1895
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Program insertion in real time IP multicast enables the seamless insertion of a secondary program within an IP multicast session of a primary program. A primary content provider transmits its multimedia stream to a first proxy that transmits the data to a destination multicast session. A secondary content provider interested in inserting a program into that destination multicast session sends a request through a second proxy to the first proxy requesting a time slot to insert secondary program. The request includes the duration of the secondary program. The first proxy responds with a time slot or a denial of the request depending if a time slot is available. Assuming an available time slot, at the appropriate time the first proxy transfers control of the destination multicast session to the second proxy which transmits the secondary program. Upon completion of the secondary program the second proxy returns control of the session to the first proxy. All scheduling and control transfer occurs through the development of a new protocol to manage the transfer of control. Smooth transitions occur by manipulation of the RTP header in the packets and the associated RTCP stream.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.