Method and system for state-dependent admission control and routing of multi-rate circuit-switched traffic

• US 6,366,559 B1
• Filed: 06/05/1998
• Issued: 04/02/2002
• Est. Priority Date: 06/06/1997
• Status: Expired due to Term

• Current Assignee: Conversant Intellectual Property Management Inc (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Original Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson)
• Inventors: Krishnan, Komandur R., de Bucs, Frank Huebner-Szabo
• Primary Examiner(s): Marcelo, Melvin
• Assistant Examiner(s): TRINH, DUNG N
• Application Number:
  US09/092,732
• Time in Patent Office: 1,397 Days
• Field of Search: 370/230, 370/254, 370/238, 370/351, 370/400, 370/392, 370/389, 709/238, 709/239, 709/241, 709/244
• US Class Current: 370/230
• CPC Class Codes: H04Q 3/66 Traffic distributors

Abstract

A method and system for routing multi-rate traffic in a communications network determines a first expected admission cost difference that corresponds to admission of the traffic onto a single-link route. If the first expected admission cost difference is less than a pre-determined cost threshold, the network routes the traffic through the single-link route. If the first expected admission cost difference is equal to or greater than the cost threshold, the network determines a second set of expected admission cost differences that corresponds to admission of the traffic onto a set of multi-link routes, and selects the multi-link route that has a minimum expected admission cost difference. If the minimum expected admission cost difference is less than the cost threshold, the network routes the traffic through the selected multi-link route. If the minimum expected admission cost difference is equal to or greater than the cost threshold, the network rejects the traffic so that a total traffic loss rate in the network is minimized.

Claims

1. A method for admission control of multi-rate circuit-switched traffic on a candidate link in a communications network comprising a network controller and a plurality of nodes interconnected by one or more links, said method comprising the steps of:

determining at one of the nodes, with respect to a fixed occupancy in the link incident at the one of the nodes, using Markov decision processing, a set of expected admission costs corresponding to a set of occupancies in the link, respectively;

communicating the set of expected admission costs to the network controller;

in response to receiving a call at the one of the nodes, determining in the network controller a difference between the expected admission cost corresponding to the occupancy in the link resulting from admission of the multi-rate traffic onto the link and the expected admission cost corresponding to a current occupancy of the link;

admitting the multi-rate circuit-switched traffic onto the link when the difference is less than a cost threshold; and

rejecting the multi-rate circuit-switched traffic when the difference is equal to or greater than the cost threshold, such that a total traffic loss rate in the link is minimized.

2. A method for admission control and routing multi-rate circuit-switched traffic in a communications network comprising a network controller and nodes interconnected via links, said method comprising the steps of:

determining at one of the nodes, with respect to a fixed occupancy in a single-link route incident at the one of the nodes, using Markov decision processing, a set of expected admission costs corresponding to a set of occupancies in the single-link route, respectively;

communicating the set of expected admission costs to the network controller;

determining in the network controller a difference between the expected admission cost corresponding to the occupancy in the single-link route resulting from admission of the multi-rate traffic onto the single-link route and the expected admission cost corresponding to a current occupancy of the single-link route;

routing the multi-rate circuit-switched traffic through the single-link route when the first expected admission cost differences is less than a cost threshold;

determining at the network controller the expected admission cost differences corresponding to admission of the multi-rate traffic onto each link in each of the multi-link routes;

adding, for each of the multi-link routes, the determined expected admission cost differences for the links in each of the multi-link routes;

determining a further set of expected admission cost differences corresponding to admission of the multi-rate circuit-switched traffic onto a set of multi-link routes in the communications network when the first expected admission cost difference is equal to or greater than the cost threshold;

selecting the multi-link route having a corresponding minimum expected admission cost difference;

routing the multi-rate circuit-switched traffic through the selected multi-link route when the minimum expected admission cost difference is less than the cost threshold; and

rejecting the multi-rate circuit-switched traffic when the minimum expected admission cost difference is equal to or greater than the cost threshold such that a total traffic loss rate in the communications network is minimized.

3. The method of claim 2, wherein said step of determining the further set of expected admission cost differences further comprises the steps of:

determining the expected admission cost differences corresponding to admission of the multi-rate traffic onto each link in each of the multi-link routes; and

adding, for each of the multi-link routes, the determined expected admission cost differences for the links in each of the multi-ink routes.

4. A computer-readable medium containing codes for configuring a switching system to perform a method for admission control of multi-rate circuit-switched traffic on a link in a communications network, said method comprising the steps of:

determining, using a Markov decision process with respect to a fixed occupancy in the link, a set of expected admission costs corresponding to a set of occupancies in the link, respectively;

determining a difference between the expected admission cost corresponding to the occupancy in the link resulting from admission of the multi-rate traffic onto the link and the expected admission cost corresponding to a current occupancy of the link;

admitting the multi-rate circuit-switched traffic onto the link when the difference is less than a cost threshold; and

rejecting the multi-rate circuit-switched traffic when the difference is equal to or greater than the cost threshold, such that a total traffic loss rate in the link is minimized.

5. A computer-readable medium containing codes for configuring a network controller to perform a method for admission control and routing of multi-rate circuit-switched traffic in a communications network comprising nodes, wherein the nodes are interconnected to each other via links, said method comprising the steps of:

determining, using a Markov decision process, a first expected admission cost difference corresponding to admission of the call onto a single-link route in the communications network;

routing the multi-rate circuit-switched traffic through the single-link route when the first expected admission cost difference is less than a cost threshold;

determining a second set of expected admission cost differences corresponding to admission of the multi-rate circuit-switched traffic onto a set of multi-link routes in the communications network when the first expected admission cost difference is equal to or greater than the cost threshold;

selecting the multi-link route having a corresponding minimum expected admission cost difference;

routing the multi-rate circuit-switched traffic through the selected multi-link routes when the minimum expected admission cost difference is less than the cost threshold; and

rejecting the multi-rate circuit-switched traffic when the minimum expected admission cost difference is equal to or greater than the cost threshold, such that a total traffic loss rate in the communications network is minimized.