System and method for efficiently performing two-way ranging to determine the location of a wireless node in a communications network

• US 6,768,730 B1
• Filed: 10/11/2001
• Issued: 07/27/2004
• Est. Priority Date: 10/11/2001
• Status: Expired due to Term

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: MeshNetworks, Inc. (Motorola Solutions, Inc.)
• Inventors: Whitehill, Eric A.
• Primary Examiner(s): Patel, Ajit
• Assistant Examiner(s): SHAH, CHIRAG G
• Application Number:
  US09/973,799
• Time in Patent Office: 1,020 Days
• Field of Search: 370/348, 370/346, 370/343, 455/434, 455/450, 455/450.2, 455/515
• US Class Current: 370/348
• CPC Class Codes: G01S 13/876 Combination of several spaced transponders or reflectors of known location for determining the position of a receiver G01S13/874 takes precedence
• CPC Class Codes: G01S 5/0284 Relative positioning
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A system and method for reducing the number of transmissions required for a node in a communications network to range other nodes in the network, while also enabling the node to continuously monitor the reservation channel during the ranging process without the use of a second receiver, and to indicate to the ranged node and other nodes in the network that the ranging node and the ranged node are not tuning to a data channel to perform the ranging, to thus enable the node to more efficiently determine its geographic location. The system and method further enables a node in a wireless communications network to minimize the amount of time it is not monitoring the reservation channel while receiving information messages from other nodes in the network.

Claims

1. A communication node, adapted for use in a communications network, comprising:

a transceiver, adapted to transmit and receive messages to and from other nodes in said network over at least one of a plurality of shared data channels, and being tunable to a reservation channel to monitor channel access reservation messages transmitted by said other nodes in said network; and

a controller, adapted to control said transceiver to transmit a range request message to at least one other of said nodes in said network over said reservation channel and to receive a range reply message from said at least one other node over said reservation channel in response to said range request message, to enable said controller to determine a distance of said communication node from said at least one other node based on said range request message and said range reply message, said range request message being configured to indicate to at least said one other node that said transceiver and a transceiver of said one other node are not tuning to a data channel as a result of an exchange of said range request message and said range reply message.

2. A communication node as claimed in claim 1, wherein:

said controller is further adapted to determine said distance by measuring a duration of time that elapses between a first moment when a portion of said range request message is transmitted by said transceiver and a second moment when a portion of said range reply message is received by said transceiver.

3. A communication node as claimed in claim 1, wherein:

said controller is further adapted to control said transceiver to transmit a respective said range request message to each of a plurality of said other nodes in said network over said reservation channel and to receive a respective said range reply message from each of said plurality of other nodes over said reservation channel in response to said respective range request messages, to enable said controller to determine a respective distance of said communication node from each of said other nodes based on said respective range request messages and said respective range reply messages.

4. A communication node as claimed in claim 3, wherein:

said controller is further adapted to determine a geographic location of said communications node based on said respective distances.

5. A communication node as claimed in claim 1, wherein:

said controller is further adapted to control said transceiver to receive an information message that has been transmitted over a data channel by said at least one other node substantially immediately after said at least one other node transmitted said range reply message.

6. A communication node, adapted for use in a communications network, comprising:

a transceiver, adapted to transmit and receive messages to and from other nodes in said network over at least one of a plurality of shared data channels, and being tunable to a reservation channel to monitor channel access reservation messages transmitted by said other nodes in said network; and

a controller, adapted to control said transceiver to transmit a range request message to at least one other of said nodes in said network over said reservation channel, and to receive a range reply message from said at least one other node over said reservation channel and an information message from said at least one other node over a reserved data channel in response to said ranges request message; and

wherein said information message includes at least one of the following;

information presenting the current position of said at least one other node, access codes for a private network in which said at least one other node is operating, regional transmit power or data rate limitations associated with said at least one other node, data rates for routing and neighbor discovery messages relating to said at least one other node, currently accepted priority level at said at least one other node, available bandwidth at said at least one other node, and the suitability of said at least one other node to act as a position reference.

7. A communication node as claimed in claim 6, wherein:

said controller is further adapted to control said transceiver to transmit a respective said range request message to each of a plurality of said other nodes in said network over said reservation channel and to receive a respective said range reply message over said reservation channel and a respective said information message from each of said plurality of other nodes over respective reserved data channels in response to said respective range request messages.

8. A method for controlling a communication node, adapted for use in a communications network, to determine its position relative to at least one of a plurality of other nodes in said network, said other nodes in said network being adapted to communicate with each other over at least one of a plurality of shared data channels and to transmit channel access reservation messages over a reservation channel, the method comprising:

controlling a transceiver of said communication node to transmit a range request message to at least one other of said nodes in said network over said reservation channel and to receive a range reply message from said at least one other node over said reservation channel in response to said range request message, said range request message being configured to indicate to at least said one other node that said transceiver and a transceiver of said one other node are not tuning to a data channel as a result of an exchange of said range request message and said range reply message; and

determining a distance of said communication node from said at least one other node based on said range request message and said range reply message.

9. A method as claimed in claim 8, wherein:

said determining step determines said distance by measuring a duration of time that elapses between a first moment when a portion of said range request message is transmitted by said transceiver and a second moment when a portion of said range reply message is received by said transceiver.

10. A method as claimed in claim 8, wherein:

said controlling step controls said transceiver to transmit a respective said range request message to each of a plurality of said other nodes in said network over said reservation channel and to receive a respective said range reply message from each of said plurality of other nodes over said reservation channel in response to said respective range request messages; and

said determining step determines a respective distance of said communication node from each of said other nodes based on said respective range request messages and said respective range reply messages.

11. A method as claimed in claim 10, further comprising:

determining a geographic location of said communications node based on said respective distances.

12. A method as claimed in claim 8, further comprising:

controlling said transceiver to receive an information message that has been transmitted over a data channel by said at least one other node substantially immediately after said at least one other node transmitted said range reply message.

13. A method for controlling a communication node, adapted for use in a communications network, to receive an information message from at least one of a plurality of other nodes in said network, said other nodes in said network being adapted to communicate with each other over at least one of a plurality of shared data channels and to transmit channel access reservation messages over a reservation channel, the method comprising:

controlling a transceiver of said communication node to transmit a range request message to at least one other of said nodes in said network over said reservation channel; and

controlling said transceiver to receive a range reply message over said reservation channel and an information message from said at least one other node over a reserved data channel in response to said range request message; and

wherein said information message includes at least one of the following;

information representing the current position of said at least one other node, access codes for a private network in which said at least one other node is operating, regional transmit power or data rate limitations associated with said at least one other node, data rates for routing and neighbor discovery messages relating to said at least one other node, currently accepted priority level at said at least one other node, available bandwidth at said at least one other node, and the suitability of said at least one other node to act as a position reference.

14. A method as claimed in claim 13, further comprising:

controlling said transceiver to transmit a respective said range request message to each of a plurality of said other nodes in said network over said reservation channel and to receive a respective said range reply message over said reservation channel and a respective said information message from each of said plurality of other nodes over respective reserved data channels in response to said respective range request messages.

15. A computer readable medium of instructions for controlling a communication node, adapted for use in a communications network, to determine its position relative to at least one of a plurality of other nodes in said network, said other nodes in said network being adapted to communicate with each other over at least one of a plurality of shared data channels and to transmit channel access reservation messages over a reservation channel, the computer readable medium of instructions comprising:

first set of instructions, adapted to control a transceiver of said communication node to transmit a range request message to at least one other of said nodes in said network over said reservation channel and to receive a range reply message from said at least one other node over said reservation channel in response to said range request message, said range request message being configured to indicate to at least said one other node that said transceiver and a transceiver of said one other node are not tuning to a data channel as a result of an exchange of said range request message and said range reply message; and

a second set of instructions, adapted to control said communication node to determine a distance of said communication node from said at least one other node based on said range request message and said range reply message.

16. A computer readable medium of instructions as claimed in claim 15, wherein:

said second set of instructions is adapted to control said communication node to determine said distance by measuring a duration of time that elapses between a first moment when a portion of said range request message is transmitted by said transceiver and a second moment when a portion of said range reply message is received by said transceiver.

17. A computer readable medium of instructions as claimed in claim 15, wherein:

said first set of instructions is adapted to control said transceiver to transmit a respective said range request message to each of a plurality of said other nodes in said network over said reservation channel and to receive a respective said range reply message from each of said plurality of other nodes over said reservation channel in response to said respective range request messages; and

said second set of instructions is adapted to control said communication node to determine its respective distance from each of said other nodes based on said respective range request messages and said respective range reply messages.

18. A computer readable medium of instructions as claimed in claim 17, further comprising:

a third set of instructions, adapted to control said communication node to determine its geographic location based on said respective distances.

19. A computer readable medium of instructions as claimed in claim 15, further comprising:

a fourth set of instructions, adapted to control said transceiver to receive an information message that has been transmitted over a data channel by said at least one other node substantially immediately after said at least one other node transmitted said range reply message.

20. A computer readable medium of instructions for controlling a communication node, adapted for use in a communications network, to receive an information message from at least one of a plurality of other nodes in said network, said other nodes in said network being adapted to communicate with each other over at least one of a plurality of shared data channels and to transmit channel access reservation messages over a reservation channel, the computer readable medium of instructions comprising:

a first set of instructions, adapted to control a transceiver of said communication node to transmit a range request message to at least one other of said nodes in said network over said reservation channel; and

a second set of instructions, adapted to control said transceiver to receive a range reply message over said reservation channel and an information message from said at least one other node over a reserved data channel in response to said range request message; and

wherein said information message includes at least one of the following;

information representing the current position of said at least one other node, access codes for a private network in which said at least one other node is operating, regional transmit power or data rate limitations associated with said at least one other node, data rates for routing and neighbor discovery messages relating to said at least one other node, currently accepted priority level at said at least one other node, available bandwidth at said at least one other node, and the suitability of said at least one other node to act as a position reference.

21. A computer readable medium of instructions as claimed in claim 20, wherein:

said first set of instructions is further adapted to control said transceiver to transmit a respective said range request message to each of a plurality of said other nodes in said network over said reservation channel; and

said second set of instructions is further adapted to control said transceiver to receive a respective said range reply message over said reservation channel and a respective said information message from each of said plurality of other nodes over respective reserved data channels in response to said respective range request messages.