Method of exchanging messages, sink device and source device

• US 20100315997A1
• Filed: 11/10/2009
• Published: 12/16/2010
• Est. Priority Date: 06/16/2009
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Taek Soo
• Granted Patent: US 8,811,275 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04N 21/43615 Interfacing a Home Network, e.g. for connecting the client to a plurality of peripherals home Audio Video Interoperability [HAVI] data switching networks H04L12/2805
• CPC Class Codes: H04N 21/43637 involving a wireless protocol, e.g. Bluetooth, RF or wireless LAN [IEEE 802.11] arrangements for wireless networking or broadcasting of information in indoor or near-field type systems H04B10/114
• CPC Class Codes: H04N 21/4788 communicating with other users, e.g. chatting arrangements for providing for computer conferences, e.g. chat rooms, to substation in data switching networks H04L12/1813; distributed application using peer-to-peer [P2P] networks H04L67/104
• CPC Class Codes: H04N 21/632 using a connection between clients on a wide area network, e.g. setting up a peer-to-peer communication via Internet for retrieving video segments from the hard-disk of other client devices broadcast-related systems characterised by transmission among terminal devices H04H60/80; distributed application using peer-to-peer [P2P] networks H04L67/104
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A method of exchanging messages for switching of a sink device of a wireless network to a source device comprises receiving audio/video (A/V) data from a first source device; transmitting a first command to a second source device within the wireless network to identify whether the second source device can transmit A/V data; receiving a second command from the first source device, the second command being transmitted from the second source device in response to the first command and including indication information indicating whether the second source device can transmit A/V data; and determining whether to switch to the second source device depending on the indication information included in the second command.

Claims

1. A method of exchanging messages for switching source devices at a sink device in a wireless network to a source device;

the method comprising;

receiving audio/video (A/V) data from a first source device;

transmitting a first command to a second source device within the wireless network to identify whether the second source device can transmit A/V data;

receiving a second command from the first source device, the second command being transmitted from the second source device in response to the first command and including indication information indicating whether the second source device can transmit A/V data; and

determining whether to switch A/V data from the first source device to the second source device depending on the indication information included in the second command.

2. The method of claim 1, wherein if the indication information included in the second command indicates that the second source device does not wish or cannot become an active source device, the sink device receives the A/V data from the first source device.

3. The method of claim 2, wherein the A/V data are received from the first source device by being encapsulated in a first downlink physical data unit (DLPDU).

4. The method of claim 1, wherein the first command is transmitted to the second source device by being encapsulated in an uplink control physical layer data unit (ULCPDU).

5. The method of claim 1, wherein the second command is received from the first source device by being encapsulated in a second DLPDU.

6. The method of claim 3, wherein the first DLPDU is transmitted for a time period including a first time period for which a MAC message and at least one header are transmitted and a second time period for which the A/V data are transmitted.

7. The method of claim 6, wherein an uplink control physical layer data unit (ULCPDU) is transmitted for the first time period.

8. The method of claim 5, wherein the second command is multiplexed with the A/V data transmitted from the first source device and then encapsulated in the second DLPDU.

9. The method of claim 5, wherein the second DLPDU includes a basic header and an extended header, and wherein the second command is encapsulated in the extended header.

10. The method of claim 1, wherein the step of transmitting the first command to the second source device includes:

receiving the first command from an audio video control (AVC) layer in a medium access control (MAC) layer, the first command including a first identifier for identifying a transmitting device, a second identifier for identifying a receiving device, and an action code (Opcode);

configuring a MAC message in the MAC layer and transferring the MAC message to a physical layer, the MAC message including a message preamble, a message type and the first command; and

transmitting an uplink control physical layer data unit (ULCPDU) from the physical layer to the receiving device, the ULCPDU including an uplink control header, the MAC message and audio/video (A/V) data.

11. The method of claim 10, wherein the MAC message is multiplexed with the A/V data to be included in the ULCPDU in the physical layer.

12. The method of claim 10, wherein the MAC message includes a cyclic redundancy check (CRC) code added from the MAC layer to perform an error detection at the receiving device.

13. A sink device receiving A/V data from a first source device in a wireless network, the sink device comprising:

an audio video control (AVC) layer generating a first command including a first identifier for identifying the sink device, a second identifier for identifying a second source device, and an action code Opcode;

a medium access control (MAC) layer generating a MAC message including a message preamble, a message type and the first command transferred from the AVC layer; and

a physical layer generating a first physical layer data unit including an uplink control header, the MAC message and audio/video data and transferring the first physical layer data unit to the second source device, and receiving a second physical layer data unit from the first source device, the second physical layer data unit including a second command being transmitted from the second source device in response to the first command and including indication information indicating whether the second source device can transmit A/V data,

wherein the sink device determines to switch A/V data from the first source device to the second source device depending on the indication information included in the second command.

14. The sink device of claim 13, wherein if the indication information included in the second command indicates that the second source device does not wish or cannot become an active source device, the sink device receives the A/V data from the first source device.

15. The sink device of claim 13, wherein the first physical layer data unit is an uplink control physical layer data unit (ULCPDU).

16. The sink device of claim 13, wherein the second physical layer data unit is a downlink physical data unit (DLPDU).

17. The sink device of claim 16, wherein the DLPDU is transmitted for a time period including a first time period for which the MAC message and at least one header are transmitted and a second time period for which the A/V data are transmitted, and the ULCPDU is transmitted for the first time period for which a part of the DLPDU should be transmitted.

18. The sink device of claim 16, wherein the second command is multiplexed with the A/V data transmitted from the first source device and then encapsulated in the DLPDU.

19. The sink device of claim 17, wherein the at least one header includes a basic header and an extended header, and the second command is encapsulated in the extended header.

20. A sink device for use in a wireless network, the sink device comprising:

a receiving module receiving a broadcasting signal from a first source device;

a decoding module decoding the broadcasting signal received by the receiving module;

a display module displaying contents according to the broadcasting signal decoded by the decoding module;

a network control module generating a first physical layer data unit including a MAC message and transmitting the same to a second source device, the MAC message including the broadcasting signal received by the receiving module and a first command for identifying whether the second source device can transmit A/V data, and receiving a second physical layer data unit including a second command from the first source device and processing the same, the second command being transmitted from the second source device in response to the first command; and

a control module controlling the sink device to switch to the second source device through the second command processed by the network control module, store the broadcasting signal received by the receiving module in a local memory device, or play contents stored in the local memory device.

21. The sink device of claim 20, wherein the second command includes indication information indicating whether the second source device can transmit A/V data.

22. A method of exchanging messages at a first source device for a sink device to switch source devices in a wireless network, the method comprising:

generating a second command including indication information in an AVC layer in response to a first command transmitted from the sink device receiving A/V data from a second source device, the indication information indicating whether the first source device can transmit A/V data;

transferring a MAC message from a MAC layer to a physical layer, the MAC message including a message preamble, a message type and the second command transmitted from the AVC layer; and

transmitting a physical layer data unit from the physical layer to the sink device via the second source device, the physical layer data unit including at least one header, the MAC message, and the A/V data,

wherein the sink device determines to switch to the first source device depending on the indication information included in the second command.

23. A source device receiving a first command from a sink device in a wireless network, the source device comprising:

an AVC layer generating a second command including indication information in response to a first command transmitted from the sink device that receives A/V data from a predetermined source device, the indication information indicating whether the source device can transmit A/V data;

a MAC layer configuring a MAC message and transferring the MAC message to a physical layer, the MAC message including a message preamble, a message type and the second command; and

the physical layer generating a physical layer data unit and transmitting the physical layer data unit to the sink device via the predetermined source device, the physical layer data unit including at least one header, the MAC message, and the A/V data,

wherein the sink device determines to switch to the source device to which the first command is transmitted depending on the indication information included in the second command.