Low-latency multi-hop ad hoc wireless network

• US 20030012168A1
• Filed: 07/03/2002
• Published: 01/16/2003
• Est. Priority Date: 07/03/2001
• Status: Active Grant

• Current Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Original Assignee: Iceberg Intellectual Property Limited
• Inventors: Kaiser, William J., Girod, Lewis D., Elson, Jeremy, Merrill, William, Newberg, Lars Fredric, Schiffer, Brian, Sohrabi, Katayoun
• Granted Patent: US 7,161,926 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: G01D 9/005 Solid-state data loggers
• CPC Class Codes: G01S 5/18 using ultrasonic, sonic, or infrasonic waves
• CPC Class Codes: H04B 7/269 Master/slave synchronisation
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 7/041 using special codes as synchronising signal
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 92/02 Inter-networking arrangements

Abstract

A multi-radio sensor node is provided that includes two or more communication devices. The communication devices include radio frequency (RF) devices like radios. Each communication device supports simultaneous communications among multi-radio sensor nodes of respective independent network clusters. A network structure is provided that includes two or more local network clusters. Each local network cluster includes numerous multi-radio sensor nodes. Each communication device of a multi-radio sensor node supports communication among the multi-radio sensor nodes of a different one of the local network clusters so that simultaneous communications are supported among the multi-radio sensor nodes of the local network clusters. The multi-radio sensor nodes of the local network clusters determine their locations relative to the other multi-radio sensor nodes of the independent network clusters with which they communicate. The location determination includes performing timing synchronization via synchronization signals communicated among the local network clusters, and acoustic signaling.

Claims

1. A network comprising a plurality of local network clusters, wherein each local network cluster includes a plurality of sensor nodes, wherein each of the sensor nodes includes a plurality of communication radios, wherein each of the communication radios supports communication among the sensor nodes of one of the local network clusters so that simultaneous communications are supported among the sensor nodes of the local network clusters.

2. The network of claim 1, wherein each of the sensor nodes further comprise:

at least one time synchronization subsystem that collects timing synchronization information from the plurality of sensor nodes of the local network clusters via synchronization signals communicated among the plurality of sensor nodes of the network clusters; and

at least one acoustic ranging subsystem including two or more microphones and two or more speakers, wherein the acoustic ranging subsystem collects data of acoustic signaling including time-of-flight data to determine a relative location of each sensor node among local network clusters with which the sensor node communicates.

3. The network of claim 1, wherein each of the sensor nodes further comprise a subsystem for providing shared resource access management among two or more applications, wherein the resources include the communication radios, comprising:

a routing module that fuses user space and kernel space of the sensor node; and

a radio driver interface residing in user space of the sensor node, wherein the radio driver interface comprises components including at least one application programming interface and at least one computation component corresponding to each of the communication devices;

wherein the routing module receives radio access requests from the applications and generates and routes calls representative of the received requests to the radio driver interface;

wherein the radio driver interface, upon receipt of the calls, determines radio availability using resource status information received in response to queries transferred among the components;

wherein the radio driver interface generates schedules for granting access to the requested resources in accordance with the status information, and controls access to the radios by the applications in accordance with the generated schedules.

4. The network of claim 1, wherein a first communication radio of a remote sensor node of a first local network cluster communicates among other sensor nodes of the first local network cluster via a first independent channel, and wherein a second communication radio of the remote sensor node communicates among sensor nodes of a second local network cluster via a second independent channel, wherein a link is established among the first and second local network clusters by transferring communication packets between the first and second communication radios, wherein the first and second communication radios support low-latency multi-hop communications among sensor nodes of the first and second local network clusters.

5. The network of claim 1, wherein the communication radios include at least one communication device selected from among radio frequency (RF) devices and radio modems, wherein each communication radio has an assigned radio frequency (RF) address.

6. The network of claim 1, wherein each of the sensor nodes further comprise at least one network discovery and self-assembly module that automatically forms the local network clusters via the plurality of communication radios, wherein the network discovery and self-assembly module determines with which other sensor nodes of the plurality of local network clusters it can communication and, in response, sets a role of the sensor node hosting the network discovery and self-assembly module.

7. A sensor node comprising two or more communication devices, wherein each communication device supports simultaneous communications among sensor nodes of two or more respective independent network clusters, wherein the communication devices include radio frequency (RF) devices.

8. The sensor node of claim 7, further comprising a node interface that provides shared access among communication device drivers of the communication devices, the node interface comprising:

a routing module that fuses kernel space and user space of the sensor node; and

a communication device driver interface that couples to the routing module, wherein the communication device driver interface resides in user space of the sensor node, wherein the communication device driver interface comprises at least one application programming interface and at least one computation component corresponding to each of the communication devices.

9. The sensor node of claim 8, wherein the communication device driver interface:

receives calls representative of communication device requests from the routing module, wherein the routing module generates the calls in response to communication device access requests from applications of the sensor node;

generates queries to determine availability of the requested communication devices;

receives status information in response to the queries;

generates schedules for granting access to the requested communication devices in accordance with the status information; and

provides requesting applications with shared direct access among the requested communication devices in accordance with the generated schedules.

10. The sensor node of claim 7, wherein the sensor node includes an Institute of Electrical and Electronics Engineers (IEEE) 802.11 media access control (MAC) sublayer.

11. The sensor node of claim 7, further comprising at least one ranging component that determines a location of the sensor node relative to sensor nodes of the independent network clusters with which the sensor node communicates.

12. The sensor node of claim 11, wherein the location determination comprises:

receiving timing synchronization information from the sensor nodes of the independent network clusters via synchronization signals communicated among the sensor nodes of the network clusters; and

generating range and angle information to the sensor nodes of the network clusters from time of flight information of acoustic signaling.

13. The sensor node of claim 7, further comprising an acoustic ranging subsystem that uses data of acoustic signaling to determine a location of the sensor node relative to sensor nodes of the independent network clusters with which the sensor node communicates.

14. The sensor node of claim 13, wherein the acoustic ranging subsystem includes two or more microphones and two or more speakers.

16. The method of claim 15, further comprising designating one sensor node of the first network and one sensor node of the second network as base nodes, wherein each of the base nodes:

collects the timing synchronization data and acoustic data of the sensor nodes for which the base coordinated timing synchronization and acoustic ranging;

generates a relative coordinate table for the sensor nodes for which the base node coordinated timing synchronization and acoustic ranging using the collected data; and

transmits the relative coordinate table to a plurality of neighbor sensor nodes.

17. The method of claim 16, wherein each of the sensor nodes of the first and second networks:

receive relative coordinate tables from base nodes with which the sensor nodes communicate;

merge the received relative coordinate tables to form a position table including position information of neighboring sensor nodes.

19. The network of claim 18, wherein the first wireless communication protocol is an Institute of Electrical and Electronics Engineers (IEEE) 802.11a protocol.

20. The network of claim 18, wherein the second wireless communication protocol is an Institute of Electrical and Electronics Engineers (IEEE) 802.11b protocol.

15. A method of forming a sensor network, comprising:

establishing a first communication channel among a first radio of a sensor node and a first network of sensor nodes, wherein the first network includes the sensor node;

establishing a second communication channel among a second radio of the sensor node and a second network of sensor nodes;

supporting simultaneous communication among the sensor nodes of the first and second networks via the first and second communication channels;

receiving timing synchronization data from the sensor nodes of the first and second networks via synchronization signals communicated among the plurality of sensor nodes of the network clusters using the first and second communication channels;

receiving acoustic signaling data including time-of-flight data to determine a relative location of each sensor node of the first and second networks; and

determining a relative location of each node of the first and second network using the timing synchronization data and acoustic signaling data.

18. A network comprising at least one wired network coupled to a plurality of local network clusters via at least one gateway, wherein each local network cluster includes a plurality of sensor nodes, wherein each of the sensor nodes includes at least two communication radios operating under a first wireless communication protocol that supports communications between the sensor nodes and the gateway and supports communications among the sensor nodes of one of the local network clusters so that simultaneous communications are supported among the sensor nodes of the local network clusters, wherein each of the sensor nodes includes at least one communication radio operating under a second wireless communication protocol that supports communications among the sensor nodes and a plurality of portable wireless devices.