Video conferencing over public network

• US 20050259601A1
• Filed: 05/18/2005
• Published: 11/24/2005
• Est. Priority Date: 05/19/2004
• Status: Abandoned Application

• Current Assignee: Surf Communications Solutions
• Original Assignee: Surf Communication Solutions Limited
• Inventors: Rosenberg, Ofer, Fisher, Abraham
• Application Number:
  US11/131,868
• Publication Number:
  US 20050259601A1
• Time in Patent Office: Days
• US Class Current: 370/260
• CPC Class Codes: H04L 65/103 in the network
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/1106 Call signalling protocols; H.323 and related
• CPC Class Codes: H04L 65/403 Arrangements for multi-party communication, e.g. for conferences data switching systems for conference H04L12/18; arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities H04M3/56; television conferencing systems H04N7/15
• CPC Class Codes: H04L 65/4038 with floor control
• CPC Class Codes: H04L 65/765 intermediate
• CPC Class Codes: H04N 21/6131 involving transmission via a mobile phone network wireless downlink channel access H04W74/006
• CPC Class Codes: H04N 21/64322 IP
• CPC Class Codes: H04N 21/64707 for transferring content from a first network to a second network, e.g. between IP and wireless
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

A method of handling video signals by a gateway. The method includes receiving by a gateway between a land cellular network and a public switched telephone network, video signals of a real time session, from an end unit, reducing the rate of the video signals, by the gateway and transmitting the rate reduced video signals onto a channel passing through a public switched telephone network.

Claims

1. A method of handling video signals by a gateway, comprising:

receiving, by a gateway between a land cellular network and a public switched telephone network, video signals of a real time session, from an end unit;

reducing the rate of the video signals, by the gateway; and

transmitting the rate reduced video signals onto a channel passing through a public switched telephone network.

2. A method according to claim 1, wherein the received video signals are compressed by the end unit.

3. A method according to claim 1, wherein the received video signals have a bit rate greater than 46 Kbits per second.

4. A method according to claim 1, wherein the received video signals have a bit rate of about 64 Kbits per second.

5. A method according to claim 1, wherein the received video signals have a bit rate which can fit on the nominal bit rate of the public switched telephone network.

6. A method according to claim 1, wherein the end unit comprises a mobile unit.

7. A method according to claim 1, wherein the received video signals are in accordance with the 3G-324M standard.

8. A method according to claim 1, wherein reducing the rate of the video signals comprises dropping signal portions of the received video signals.

9. A method according to claim 1, wherein transmitting the rate reduced signals comprises transmitting over a channel suffering from at least one of digital attenuation pads, robbed bits and PCM clock skew.

10. A method according to claim 1, wherein reducing the rate of the video signals comprises compressing headers of packets of the video signals.

11. A method according to claim 1, wherein the received signals are in accordance with a standard format and the rate reduced signals are also according to the standard format.

12. A method according to claim 1, wherein the received signals are in accordance with a standard format and the rate reduced signals are not according to the standard format.

13. A method according to claim 1, wherein transmitting the rate reduced signals onto the channel comprises transmitting over a voice band modem connection.

14. A method according to claim 13, wherein transmitting the rate reduced signals comprises transmitting over an all digital modem connection over a PCM channel.

15. A method according to claim 1, wherein transmitting the rate reduced signals comprises transmitting over a non-dedicated channel of the public switched telephone network.

16. A method of handling video signals by a gateway, comprising:

receiving, by a gateway between a land cellular network and a public switched telephone network, video signals having a bit rate greater than 42 Kbps for both upstream and downstream transmissions; and

transmitting the video signals onto a modem connection passing through an all digital PCM link of a public switched telephone network.

17. A method according to claim 16, wherein the received video signals have a bit rate greater than 48 Kbps.

18. A method according to claim 16, comprising reducing the rate of the received video signals before transmitting the video signals on the modem connection.

19. A method according to claim 16, wherein transmitting the video signals onto a modem connection comprises transmitting on a V.91 modem connection.

20. A gateway to a public switched telephone network for video signals, comprising:

a video interface, for receiving video signals of a real time session;

a rate adaptation unit adapted to reduce the rate of the video signals received by the video interface; and

a PSTN interface for transmitting the reduced rate video signals onto a channel passing through a public switched telephone network PSTN.

21. A gateway according to claim 20, wherein the video interface is adapted to receive signals of the real time session at a rate greater than 33.6 Kbps in at least the upstream or downstream direction.

22. A gateway according to claim 20, wherein the video interface is adapted to receive signals in accordance with the 3G-324M standard.

23. A gateway according to claim 20, wherein the rate adaptation unit is adapted to drop video frames of the session.

24. A gateway according to claim 20, wherein the rate adaptation unit is adapted to increase the rate of video conferencing signals received through the PSTN interface and passed through the video interface.

25. A gateway according to claim 20, wherein the PSTN interface comprises a VBM modem.

26. A gateway according to claim 20, wherein the PSTN interface comprises an all-digital modem.

27. A gateway according to claim 20, wherein the video interface comprises an interface to a land cellular network.

28. A gateway according to claim 20, wherein the video interface comprises an interface to a private network.

29. A gateway according to claim 20, wherein the video interface is adapted to receive signals from a circuit switched emulated network.

30. A gateway according to claim 20, wherein the video interface is adapted to receive signals having a signal rate 1-20% greater than the actual capacity of the channel passing on the PSTN.

31. A gateway to a public switched telephone network for video signals, comprising:

a video interface, for receiving video signals of a real time session, at a rate greater than 42 Kbps;

a modem adapted to establish an all-digital connection over a PCM link of a public switched telephone network; and

a PSTN interface for transmitting the received video signals over the all-digital connection established by the modem.

32. A gateway according to claim 31, wherein the video interface receives signals at a rate greater than 48 Kbps.