System and method for identifying and maintaining reliable infrastructure links using bit error rate data in an ad-hoc communication network
View Patent ↗A system and method for determining the reliability of at least one communication link between nodes in an ad-hoc communication network. The system and method perform the operations of receiving at a first node data sent by a second node over a link from the second node to the first node, determining a bit error rate (BER) at which the first node received the data, and identifying the link from the second node to the first node as being reliable when a value determined based on at least the BER and, more specifically, an aggregate of the BER and BERs of data received by the first node from the second node over a period of time, meets a desired condition. The data sent by the second node can include routing advertisement data indicating at least one node which is a neighboring node of the second node, or can be any suitable regularly expected message. The data also includes an indication as to the reliability of the link from the first node to the second node based on a measure of at least one previous message, for example, the BER or aggregate BER of at least one routing advertisement, that the second node received from the first node.
1. A method for determining the reliability of a bi-directional communication link between nodes in an ad-hoc communication network, comprising:
receiving at a first node data sent by a second node over a link from said second node to said first node, said data sent by said second node including an indication as to the reliability of a link from said first node to the second node based on a measure of at least one previous message that said second node received from said first node;
determining a bit error rate (BER) at which said first node received said data; and
determining that a bi-directional link between said first and second nodes meets a desired criteria when a value determined based on at least said BER meets a desired condition and said indication indicates that the reliability of the link from said first node to said second node is at least at an acceptable level.
2. A method as claimed in claim 1 , wherein:
said value is based on an aggregate of said BER and a plurality of BERs at which a plurality of other data are received by said first node from said second node over said link during a period of time prior to that at which said first node receives said data.
3. A method as claimed in claim 1 , wherein:
said ad-hoc communication network is a multihopping wireless communication network in which said nodes communicate such that each of said nodes including said first and second nodes, is operable as a router to route packets it receives that are destined to a different one of said nodes to that different one of said nodes; and
said data is a routing advertisement transmitted by second node, the routing advertisement includes routing advertisement data indicating at least one node which is a neighboring node of said second node and for which said second node is operable as a router to route packets from said at least one other node destined to another node.
4. A method as claimed in claim 1 , wherein:
said value of said BER meets said desired condition when said value is below a threshold value.
5. A method as claimed in claim 1 , wherein:
said indication is a good link verification bit that is at a first status when said link from said first node to the second node is at least at the acceptable level and is at a second status when said link from said first node to said second node is below the acceptable level.
6. A method as claimed in claim 1 , wherein:
said measure of said previous message is a determination that a BER at which said second node received said at least one previous message meets said desired condition.
7. A method as claimed in claim 1 , further comprising:
controlling said first node to transmit a message including information indicating that said bidirectional link meeting said desired criteria exists.
8. A computer-readable medium of instructions for controlling nodes in an ad-hoc communication network to determine the reliability of a bi-directional communication link between said nodes, comprising:
a first set of instructions, adapted to control a first node to receive data sent by a second node over a link from said second node to said first node, said data sent by said second node including an indication as to the reliability of a link from said first node to the second node based on a measure of at least one previous message that said second node received from said first node;
a second set of instructions, adapted to control said first node to determine a bit error rate (BER) at which said first node received said data; and
a third set of instructions, adapted to control said first node to determine that a bi-directional link between said first and second nodes meets a desired criteria when a value determined based on at least said BER meets a desired condition and said indication indicates that the reliability of the link from said first node to said second node is at least at an acceptable level.
9. A computer readable medium of instructions as claimed in claim 8 , wherein:
said value is based on an aggregate of said BER and a plurality of BERs at which a plurality of other data are received by said first node from said second node over said link during a period of time prior to that at which said first node receives said data.
10. A computer-readable medium of instructions as claimed in claim 8 , wherein:
said ad-hoc communication network is a multihopping wireless communication network in which said nodes communicate such that each of said nodes, including said first and second nodes, is operable as a router to route packets it receives that are destined to a different one of said nodes to that different one of said nodes; and
said data is a routing advertisement transmitted by the second node, the routine advertisement includes routing advertisement data indicating at least one node which is a neighboring node of said second node and for which said second node is operable as a router to route packets from said at least one other node destined to another node.
11. A computer-readable medium of instructions as claimed in claim 8 , wherein:
said value of said BER meets said desired condition when said value is below a threshold value.
12. A computer-readable medium of instructions as claimed in claim 8 , wherein:
said indication is a good link verification bit that is at a first status when said link from said first node to the second node is at least at the acceptable level and is at a second status when said link from said first node to said second node is below the acceptable level.
13. A computer-readable medium of instructions as claimed in claim 8 , wherein:
said measure of said previous message is a determination that a BER at which said second node received said at least one previous message meets said desired condition.
14. A computer-readable medium of instructions as claimed in claim 8 , further comprising:
a fifth set of instructions, adapted to control said first node to transmit a message including information indicating that said bi-directional link meeting said desired criteria exists.
15. A node in an ad-hoc communication network, adapted to determine the reliability of a bi-directional communication link between itself an at least one other node in the ad-hoc communication network, said node comprising:
a receiver, adapted to receive data sent by a second node over a link from said second node to said first node, said data sent by said second node including an indication as to the reliability of a link from said first node to the second node based on a measure of at least one previous message that said second node received from said first node; and
a controller, adapted to determine a bit error rate (BER) at which said first node received said data, and to determine that a bi-directional link between said first and second nodes meets a desired criteria when a value determined based on at least said BER meets a desired condition and said indication indicates that the reliability of the link from said first node to said second node is at least at an acceptable level.
16. A node as claimed in claim 15 , wherein:
said value is based on an aggregate of said BER and a plurality of BERs at which a plurality of other data are received by said first node from said second node over said link during a period of time prior to that at which said first node receives said data.
17. A node as claimed in claim 15 , wherein:
said ad-hoc communication network is a multihopping wireless communication network in which said nodes communicate such that each of said nodes, including said first and second nodes, is operable as a router to route packets it receives that are destined to a different one of said nodes to that different one of said nodes; and
said data is a routing advertent transmitted by the second node, the routing advertisement includes routing advertisement data indicating at least one node which is a neighboring node of said second node and for which said second node is operable as a router to route packets from said at least one other node destined to another node.
18. A node as claimed in claim IS, wherein:
said value of said BER meets said desired condition when said value is below a threshold value.
19. A node as claimed in claim 15 , wherein
said indication is a good link verification bit that is at a first status when said link from said first node to the second node is at least at the acceptable level and is at a second status when said link from said first node to said second node is below the acceptable level.
20. A node as claimed in claim 15 , wherein:
said measure of said previous message is a determination that a BER at which said second node received said at least one previous message meets said desired condition.
21. A node as claimed in claim 15 , wherein:
said controller is further adapted to control said first node to transmit a message including information indicating that said bi-directional link meeting said desired criteria exists.