Method for setting up a connection in a synchronous digital telecommunications network and network element

• US 6,714,518 B1
• Filed: 01/19/1999
• Issued: 03/30/2004
• Est. Priority Date: 01/20/1998
• Status: Expired due to Fees

• Current Assignee: Alcatel SA (Nokia Corporation)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Weis, Bernd
• Primary Examiner(s): HO, DUC CHI
• Application Number:
  US09/233,124
• Time in Patent Office: 1,897 Days
• Field of Search: 370/216, 370/227, 370/242, 370/244, 370/248, 370/252, 370/254, 370/256, 370/404, 370/466, 370/539, 370/541, 370/537, 370/223, 370/468, 370/396, 709/220, 709/223, 709/224, 379/219, 379/221.04, 340/3.43
• US Class Current: 370/248
• CPC Class Codes: H04J 2203/0055 Network design, dimensioning, topology or optimisation
• CPC Class Codes: H04J 2203/0067 Resource management and allocation
• CPC Class Codes: H04J 2203/0089 Multiplexing, e.g. coding, scrambling, SONET
• CPC Class Codes: H04J 3/085 for ring networks, e.g. SDH/SONET rings, self-healing rings, meashed SDH/SONET networks
• CPC Class Codes: H04J 3/12 Arrangements providing for calling or supervisory signals
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

A connection is set up between a sending and a selected network element of a digital synchronous telecommunications network without the help of a central management system. The telecommunications network is logically structured based on a hierarchy with at least two multiplex layers based on a protocol that is used in the telecommunications network with each network element being able to access at least a part of the multiplex layers. Using a broadcast that is being sent by the sending network element to all other network elements, possible paths with free transmission capacity are identified between the sending and the selected network element. To this end, first the most suitable multiplex layer for setting up the connection is selected. Then the broadcast is relayed via existing connections of the suitable multiplex layers, which the respective relaying network element can access. Then the connection is set up via one of the identified paths.

Claims

1. A method for setting up a connection between a sending network element and a selected network element of a digital, synchronous telecommunications network wherein possible paths with free transmission capacity between the sending network element and the selected network element are identified using a broadcast that is being sent by the sending network element to all other network elements and whereby the connection is subsequently set up via one of the identified paths said method comprising the steps of:

logically structuring the telecommunications network in at least two multiplex layers based on a hierarchy and in accordance with the protocol used in the telecommunications network with each network element having access to at least one part of the multiplex layers

checking each of the logical multiplex layers to determine which of the multiplex layers is suitable for setting up the connection, and

relaying the broadcasting via existing connections of the suitable multiplex layers to which the respective relaying network element has access.

2. A method in accordance with claim 1 in which the network elements that receive the broadcast check on at least one part of their outputs for the suitable multiplex layers which they can access to see if there is a path with free transmission capacity and only relay the broadcast via such paths.

3. A method in accordance with either claim 1 or 2 in which the broadcast is relayed based on an additional criterion via part of the existing connections of the suitable multiplex layers.

4. A method in accordance with claim 3 in which the additional criterion is a routing table that is stored in the relaying network element.

5. A method in accordance with claim 1 in which connection information is transmitted in the broadcast that discloses which of the multiplex layers is suitable for setting up the connection.

6. A method in accordance with claim 1 in which the process that checks whether a path with free transmission capacity exists is carried out in the reverse order of the hierarchy and in which the checking process per output is interrupted as soon as a path with sufficient free transmission capacity is found.

7. A method in accordance with claim 1 in which each individual network element has a unique address and in which each broadcast contains a list into which the remaining network elements enter their address before they relay the broadcast.

8. A method in accordance with claim 1 in which the network elements that relay the broadcast block the transmission capacity of the outputs in the multiplex level in which they relay the broadcast.

9. A method in accordance with claim 8 in which, following the connection set-up, the selected network element sends a second broadcast to all other network elements and in which the other network elements release the blocked transmission capacity after receiving the second broadcast.

10. A method in accordance with claim 1 in which a cost parameter is calculated based on the free transmission capacity of the respective path and in which the cost parameter is transmitted together with the broadcast.

11. A method in accordance with claim 10 in which the selected network element decides, based on the cost parameter, which of the identified paths is to be used for setting up the connection.

12. A method in accordance with claim 1 in which each broadcast contains a unique transaction number.

13. A method in accordance with claim 10 in which each broadcast contains a unique transaction number and in which a network element that relays a first broadcast stores the unique transaction number and the cost parameter of the first broadcast and in which another broadcast with the same transaction number is relayed only if the cost parameter of the additional broadcast is lower than the cost parameter of the first broadcast and, if this is not the case, in which the additional broadcast is discarded.

14. A method in accordance with claim 1 in which a connection is set up based on a user request.

15. A method in accordance with claim 1 in which a central management system is informed of a newly set up connection.

16. A network element for carrying out a method for setting up a connection between a sending network element and a selected network element of a digital, synchronous telecommunications network wherein possible paths with free transmission capacity between the sending network element and the selected network element are identified using a broadcast that is being sent by the sending network element to all other network elements and whereby the connection is subsequently set up via one of the identified paths, said method comprising the steps of:

logically structuring the telecommunications network in at least two multiplex layers based on a hierarchy and in accordance with the protocol used in the telecommunications network with each network element having access to at least one part of the multiplex layers;

checking each of the logical multiplex layers to determine which of the multiplex layers is suitable for setting up the connection; and

relaying the broadcasting via existing connections of the suitable multiplex layers to which the respective relaying network element has access, said network element comprising;

means for identifying a connection request,

means for checking each of the logical multiplex layers to determine which one of the multiplex layers is suitable for setting up the connection,

means for determining free transmission capacity for existing connections of the suitable multiplex layers,

means for sending the broadcast and

means for relaying a received broadcast.