Method for determining connection topology of home network

• US 20060274673A1
• Filed: 05/31/2006
• Published: 12/07/2006
• Est. Priority Date: 06/01/2005
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Fleury, Jean-Francois, Henry, Jean-Baptiste, Burdin, Nicolas
• Granted Patent: US 7,907,547 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04L 12/2803 Home automation networks
• CPC Class Codes: H04L 12/2807 Exchanging configuration information on appliance services in a home automation network arrangements for maintenance or administration involving network analysis for automatically determining the actual topology of a network H04L41/12; hardware or software tools for network management using graphical user interfaces H04L41/22; address allocation H04L61/50
• CPC Class Codes: H04L 12/2821 Avoiding conflicts related to the use of home appliances cryptographic protocols H04L9/00; protocols for network security H04L63/00
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/26 Route discovery packet

Abstract

A method is provided in order to determine connection topology of a home network. The main idea of the present invention is to send out a topology determination message on each link of the network, wherein the topology determination message is constituted of two consecutive packets, first one being a broadcast packet with a predetermined payload that identifies it as a topology determination packet, and second one being a unicast packet with the same content and a non-existent destination MAC address. If a node receives both the broadcast and unicast packet from a sending node, the sending node is determined to be on the same physical link with said receiving node and the MAC address of the sending node is added into a local link nodes list of said receiving node, otherwise if said receiving node receives only the broadcast packet from the sending node, the send node is determined not to be on the same physical link with said receiving node.

Claims

1. A method for determining connection topology of a home network, which is constituted by a plurality of nodes organized around multiple hubs and switches, comprising steps of:

transmitting a topology determination message in a random sequence one by one by the plurality of nodes;

determining the connection topology of all the nodes one by one upon reception of the topology determination message;

generating and updating lists of local nodes of all the nodes;

wherein

said topology determination message includes two consecutive packets, first one being a broadcast packet with a predeterimined payload identifying it as a topology determination packet, and second one being a unicast packet with the same content and a non-existent destination MAC address.

2. The method as claimed in claim 1, wherein the connection topology of all the nodes are determined upon reception of the topology determination message based on following rules:

i) if a node receives both of the broadcast packet and the unicast packet from a sending node, the sending node is determined to be on the same physical link with said receiving node;

ii) if said receiving node receives only the broadcast packet, the sending node is determined not to be on the same physical link with said receiving node.

3. The method as claimed in claim 2, wherein, the list of local node of the receiving node is generated and updated by adding the MAC address of the sending node into the list, when the sending node is determined to be on the same physical link with said receiving node.

4. The method as claimed in claim 1, wherein a first timer (T₀) with a fixed time delay defining the whole duration of the process is provided.

5. The method as claimed in claim 4, wherein a second timer (T₁) is provided, which is a random bounded time delay defining a time period between the beginning of the process and the starting of the transmitting of the topology determination message.

6. The method as claimed in claim 5, wherein the maximum length of the second timer (T₁) is less than the length of the first timer (T₀).

7. The method as claimed in claim 5, wherein a third timer (T₂) is automatically triggered each time said receiving node receives the broadcast packet from the sending node in order to define a duration intended to wait for the unicast packet.

8. The method as claimed in claim 7, wherein the third timer (T₂) is less than the second timer (T₁), and preferably less than a centisecond.

9. The method as claimed in claim 8, wherein the second timer (T₁) is restarted with a new random bounded delay (T₁′

), which is expired before the expiration of the first timer (T₀), if a collision of the topology determination message is detected.