Method for the discovery of devices connected to an IP network and device to carry out said method

• US 20050220007A1
• Filed: 03/30/2005
• Published: 10/06/2005
• Est. Priority Date: 03/30/2004
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Tang-Talpin, Yan-Mei, Salmon-Legagneur, Charles, Heen, Olivier, Maetz, Yves, Prigent, Nicolas
• Granted Patent: US 7,701,873 B2
• Time in Patent Office: Days
• US Class Current: 370/217
• CPC Class Codes: H04L 12/2803 Home automation networks
• CPC Class Codes: H04L 67/04 specially adapted for terminals or networks with limited capabilities; specially adapted for terminal portability
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/51 Discovery or management thereof, e.g. service location protocol [SLP] or web services
• CPC Class Codes: H04L 67/535 Tracking the activity of the user network monitoring arrangements H04L43/00; recording of computer activity G06F11/34
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

The present invention relates to IP networks and, more particularly, local area networks, for example home networks. It concerns the manner in which devices connected to such networks obtain and update knowledge of the other compatible devices connected to the network. To do this, the invention is based on a finite-state machine, comprising connected, disconnected and standby states. The changes of state take place on receipt of messages, requests or replies from the other devices, or on expiry of timers in the absence of receipt of messages.

Claims

1. Method for the discovery, by a device intended to be connected to an IP network, of devices carrying out said method and connected to said network, comprising the steps of:

the device being considered in a disconnected state, the device sending requests in a repeated and automatic manner on the IP network and

the device switching over to a connected state on receipt by the device of at least one message from a different device.

2. Method according to claim 1, whereby, on receipt of a request originating from said different device, the device sends a reply on the network.

3. Method according to claim 2, whereby the device, being in a connected state, and not receiving a message for a first given period of time, sends a request on the IP network and switches to a message reception standby state.

4. Method according to claim 3, whereby the device, being in a message reception standby state and not receiving a message for a second given period of time, switches to the disconnected state.

5. Method according to claim 4, whereby the device, being in a message reception standby state and receiving a message according to the method, switches to the connected state.

6. Method according claim 1, whereby the device sends a message in a multicast mode to an address and a port, and whereby the device monitors for this address and on this port.

7. Method according to claim 1, whereby the device, being in the message reception standby state and not receiving any messages, repeats for a given number of times the dispatch of the request and the device operates in the message reception standby for the second given period of time (T3) before switching to the disconnected state.

8. Method according to claim 1, whereby the requests sent when the device is in the disconnected state, referred to as first requests, are different from the requests sent when the device is in the connected state and whereby the first reply sent after having switched from the disconnected state is different from the following replies.

9. Method according claim 1, whereby the device signals the arrival of a new device on the network upon receiving a first request or a first reply.

10. Method according to claim 1, whereby the device maintains a list of connected devices.

11. Method according to claim 10, whereby the device compares the replies received in response to a request with the list of devices in order to remove the devices which have not replied from this list.

13. The method of claim 1, wherein said at least one message is a reply message generated in response to said request and a request message from a different device.

12. A device intended to be connected to an IP network comprising:

a means for transmitting requests;

a means for transmitting replies on the IP network,

a means for activating timers, and

a means for switching between a disconnected state a connected state and a standby state depending on at least one of;

a receipt of a request, a receipt of a reply from a different device, and on an expiry of a timer.