CHANNEL SWITCHING METHOD, CHANNEL SWITCHING DEVICE, AND CHANNEL SWITCHING SYSTEM

• US 20110239262A1
• Filed: 06/10/2011
• Published: 09/29/2011
• Est. Priority Date: 12/12/2008
• Status: Abandoned Application

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Qin, Xia, Yang, Peilin, Li, Jun
• Application Number:
  US13/158,217
• Publication Number:
  US 20110239262A1
• Time in Patent Office: Days
• US Class Current: 725/109
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04N 21/26616 for merging a unicast channel into a multicast channel, e.g. in a VOD application, when a client served by unicast channel catches up a multicast channel to save bandwidth data multicast over packet-switching network H04L12/18
• CPC Class Codes: H04N 21/4384 involving operations to reduce the access time, e.g. fast-tuning for reducing channel switching latency
• CPC Class Codes: H04N 21/6405 Multicasting data broadcast and multicast in packet switching networks H04L12/18
• CPC Class Codes: H04N 21/6408 Unicasting

Abstract

A channel switching method, a channel switching device, and a channel switching system are provided. The method includes that: a network buffer apparatus determines whether a buffered video stream burst in unicast is synchronous with a channel video stream pushed by a network node to a client in multicast; notifies the client of sending a request for joining a multicast group, so as to implement fast channel switching; and dynamically adjusts the speed of pushing the video stream in unicast, so that the number of concurrent connections of the client and the channel switching efficiency are increased, and the deployment and operation cost of an Internet Protocol Television (IPTV) system is decreased. In this case, the channel switching scheme achieves universality and expandability, and the level of user experience is improved.

Claims

1. A channel switching method, comprising:

buffering a video stream of a channel;

receiving a channel switching request for switching to a second channel sent by a client;

pushing a buffered video stream of the second channel to the client according to the channel switching request; and

determining whether the pushed buffered video stream is synchronous with a video stream of the second channel, and if the pushed buffered video stream is synchronous with the video stream of the second channel, sending a notification message to the client to notify the client of sending a request for joining a multicast group of the second channel.

2. The method according to claim 1, wherein the notification message carries any one or a combination of multicast group address information of the second channel, time information for joining the second channel, and time information for requesting stopping pushing the video stream.

3. The method according to claim 1, wherein before the sending the notification message to the client, the method further comprises:

decreasing a sending speed of pushing the buffered video stream of the second channel to the client.

4. The method according to claim 1, further comprising:

notifying the client of sending a request for stopping pushing the video stream; and

after receiving the message of stopping sending the buffered video stream returned by the client, stopping pushing the buffered video stream to the client.

5. The method according to claim 4, wherein the message of stopping sending the buffered video stream returned by the client carries information capable of confirming a packet not sent between a multicast video stream of the second channel and the buffered video stream of the second channel received by the client.

6. The method according to claim 1, wherein after the buffering the video stream of the channel, the method further comprises:

marking a starting location of a video frame capable of being independently decoded by the client in a buffer.

7. The method according to claim 1, wherein before the pushing the buffered video stream of the second channel to the client, the method further comprises:

determining whether a next video frame capable of being independently decoded by the client arrives, and if the next video frame capable of being independently decoded by the client arrives, directly notifying the client of joining the multicast group.

8. The method according to claim 1, wherein the pushing the buffered video stream of the second channel to the client comprises:

pushing the buffered video stream to the client in unicast.

9. The method according to claim 1, wherein the pushing the buffered video stream of the second channel to the client further comprises:

dynamically adjusting a sending speed of pushing the buffered video stream to the client according to feedback of the client.

10. A channel switching device, comprising:

a buffering module, configured to buffer a video stream of a channel;

a receiving module, configured to receive a channel switching request for switching to a second channel sent by a client;

a pushing module, configured to push a buffered video stream of the second channel to the client according to the channel switching request sent by the receiving module;

a first determination module, configured to determine whether the buffered video stream pushed by the pushing module is synchronous with a video stream of the second channel; and

a first notification module, configured to send a notification message to the client to notify the client of sending a request for joining a multicast group of the second channel when the determination module determines that the pushed buffered video stream is synchronous with the video stream of the second channel.

11. The device according to claim 10, wherein the notification message carries any one or a combination of multicast group address information of the second channel, time information for joining the second channel, and time information for requesting stopping pushing the video stream.

12. The device according to claim 10, further comprising:

a second notification module, configured to notify the client of sending a request for stopping pushing the video stream; and

a first processing module, configured to stop pushing the buffered video stream to the client after the second notification module receives the request for stopping sending the buffered video stream returned by the client, wherein the message of stopping sending the buffered video stream returned by the client carries information capable of confirming a packet not sent between a multicast video stream of the second channel and the buffered video stream of the second channel received by the client.

13. The device according to claim 12, further comprising:

a speed decreasing module, configured to decrease a sending speed of pushing the buffered video stream of the second channel to the client before the client is notified of sending the request for stopping pushing the video stream.

14. The device according to claim 10, further comprising:

a marking module, configured to set a packet mark for the video stream buffered by the buffering module, to mark a starting location of a video frame capable of being independently decoded by the client in a buffer.

15. The device according to claim 10, further comprising:

a second determination module, configured to determine whether a next video frame capable of being independently decoded by the client arrives, and send a determination result to a second processing module for processing; and

the second processing module, configured to directly notify the client of joining the multicast group if the second determination module determines that the next buffered video stream capable of being independently decoded by the client is about to arrive, and send the channel switching request received by the receiving module to the pushing module if the second determination module determines that the next buffered video stream capable of being independently decoded by the client is not about to arrive.

16. The device according to claim 10, further comprising:

a speed adjustment module, configured to dynamically adjust a sending speed of pushing the buffered video stream to the client according to feedback of the client.

17. A channel switching system, comprising:

a network buffer apparatus, configured to buffer a video stream of a channel;

receive a channel switching request for switching to a second channel sent by a client;

push a buffered video stream of the second channel to the client according to the channel switching request; and

determine whether the pushed buffered video stream is synchronous with a video stream of the second channel, and send a notification message to the client to notify the client of sending a request for joining a multicast group of the second channel if the pushed buffered video stream is synchronous with the video stream of the second channel;

a client, configured to send the channel switching request to the network buffer apparatus, receive the buffered video stream pushed by the network buffer apparatus, and send the request for joining the multicast group of the second channel to a network node according to a notification from the network buffer apparatus to request joining the multicast group; and

the network node, configured to send the video stream of the second channel to the client according to the request for joining the multicast group sent by the client.