Initiation of routing convergence by a mobile router in a mobile ad hoc network in response to reaching a minimum interval of stable relative proximity between at least one neighbor

• US 8,059,620 B2
• Filed: 07/28/2006
• Issued: 11/15/2011
• Est. Priority Date: 07/28/2006
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Moon, Billy Gayle
• Primary Examiner(s): Ton; Dang
• Assistant Examiner(s): Zhao; Wei
• Application Number:
  US11/494,584
• Publication Number:
  US 20080025270A1
• Time in Patent Office: 1,936 Days
• Field of Search: 370/338, 370/392, 709/241, 709/221, 709/229, 726/22, 726/34
• US Class Current: 370/338
• CPC Class Codes: H04W 40/14 based on stability
• CPC Class Codes: H04W 40/18 based on predicted events

Abstract

Each mobile router in a mobile ad hoc network is configured for measuring a minimum interval of stable relative proximity (SProx_MIN) between at least one neighbor before initiating convergence of a routing protocol. The minimum interval of stable relative proximity requires any variation in relative proximity between at least one neighbor to be stabilized below a prescribed stability threshold (S) for the prescribed minimum interval (SProx_MIN) before initiating convergence of a routing protocol. Hence, mobile routers in a mobile ad hoc network can be configured to avoid prematurely initiating reconvergence according to a routing protocol due to an instability introduced into the network.

Claims

1. A method in a mobile ad hoc router that is within a mobile ad hoc network, the method including:

determining by the mobile ad hoc router a relative proximity of at least one neighboring node relative to the mobile ad hoc router, the relative proximity indicating a relative reliability of a wireless communication link between the mobile ad hoc router and the at least one neighboring node; and

initiating by the mobile ad hoc router a convergence of network routes according to a prescribed routing protocol, that includes the neighboring node, in response to the mobile ad hoc router determining that a determined variation in the relative proximity has reached a prescribed minimum interval of stable relative proximity;

wherein the mobile router determines whether the determined variation in the relative proximity reaches the prescribed minimum interval of stable relative proximity based on;

initiating a stability timer in response to the determined variation in the relative proximity falling below a prescribed stability threshold, and

determining whether the determined variation in the relative proximity remains below the prescribed stability threshold for the prescribed minimum interval according to a prescribed minimum time interval.

2. The method of claim 1, further comprising receiving, by the mobile ad hoc router, a neighbor discovery message including link metrics from the neighboring node, the determining including determining the relative proximity based on the link metrics.

3. The method of claim 2, wherein the relative proximity identifies an aggregate relative proximity of a plurality of mobile ad hoc routers within the mobile ad hoc network including said at least one neighboring node.

4. The method of claim 1, further comprising forwarding information describing the relative proximity to at least another neighboring node.

5. A mobile ad hoc router that is within a mobile ad hoc network, the mobile ad hoc router including:

a routing resource configured for initiating a convergence of network routes according to a prescribed routing protocol in response to an initiation command;

a routing convergence initiation portion configured for determining a relative proximity of at least one neighboring node relative to the mobile ad hoc router, the relative proximity indicating a relative reliability of a wireless communication link between the mobile ad hoc router and the at least one neighboring node, the routing convergence initiation portion configured for outputting the initiation command in response to the routing convergence initiation portion determining that a determined variation in the relative proximity has reached a prescribed minimum interval of stable relative proximity; and

a stability timer, the routing convergence initiation portion configured for determining whether the determined variation in the relative proximity has reached the prescribed minimum interval of stable relative proximity based on;

initiating the stability timer in response to the determined variation in the relative proximity falling below a prescribed stability threshold, and

determining whether the determined variation in the relative proximity remains below the prescribed stability threshold for the prescribed minimum interval according to a prescribed minimum time interval.

6. The mobile ad hoc router of claim 5, further comprising a link management interface configured for receiving a neighbor discovery message including link metrics from the neighboring node, the routing convergence initiation portion configured for determining the relative proximity based on the link metrics.

7. The mobile ad hoc router of claim 6, wherein the relative proximity identifies an aggregate relative proximity of a plurality of mobile ad hoc routers within the mobile ad hoc network including said at least one neighboring node.

8. The mobile ad hoc router of claim 5, wherein the mobile ad hoc router is configured for forwarding information describing the relative proximity to at least another neighboring node.

9. A mobile ad hoc router that is within a mobile ad hoc network, the mobile ad hoc router including:

means for determining a relative proximity of at least one neighboring node relative to the mobile ad hoc router, the relative proximity indicating a relative reliability of a wireless communication link between the mobile ad hoc router and the at least one neighboring node; and

means for initiating a convergence of network routes according to a prescribed routing protocol, that includes the neighboring node, in response to the mobile ad hoc router determining that a determined variation in the relative proximity has reached a prescribed minimum interval of stable relative proximity,

wherein the means for determining is configured for determining whether the determined variation in the relative proximity reaches the prescribed minimum interval of stable relative proximity based on determining the determined variation in the relative proximity, and determining whether the determined variation in the relative proximity has remained below a prescribed stability threshold for the prescribed minimum interval according to a prescribed minimum time interval.

10. The mobile ad hoc router of claim 9, further comprising means for receiving a neighbor discovery message including link metrics from the neighboring node, the means for determining configured for determining the relative proximity based on the link metrics.

11. The mobile ad hoc router of claim 10, wherein the relative proximity identifies an aggregate relative proximity of a plurality of mobile ad hoc routers within the mobile ad hoc network including said at least one neighboring node.

12. The mobile ad hoc router of claim 9, further comprising means for forwarding information describing the relative proximity to at least another neighboring node.