Apparatus and method for peer-to-peer link monitoring of a wireless network with centralized control

• US 7,110,366 B2
• Filed: 02/20/2002
• Issued: 09/19/2006
• Est. Priority Date: 08/27/1997
• Status: Expired due to Term

• Current Assignee: Uniloc 2017 LLC (FIG LLC (d/b/a Fortress Investment Group LLC))
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: May, Peter Klaus, Ngo, Chiu, Herrmann, Christoph, Du, Yonggang, Hulyalkar, Samir N.
• Primary Examiner(s): Lee, Andrew C.
• Assistant Examiner(s): Hyun, Soon D.
• Application Number:
  US10/080,184
• Publication Number:
  US 20020085503A1
• Time in Patent Office: 1,672 Days
• Field of Search: 370/252, 370/248, 370/249, 370260-263, 370328-330, 370/255, 370/332, 370/333, 370/338, 370/340, 370/341, 370/347, 370/442, 455/67.11, 455/69, 455/507, 455/508
• US Class Current: 370/252
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 84/08 Trunked mobile radio systems
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

Centrally controlled wireless networks require reliable communications between the central controller and each of the stations within the wireless networks. The structure of a wireless network is often dynamic, or ad-hoc, as stations enter and exit the network, or are physically relocated. The selection of the central controller for the network may also be dynamic, either because the current central controller desires to exit the network, or because the communication between the current central controller and one or more of the stations is poor. This invention discloses a method and apparatus for assessing the quality of the communication paths among all stations in the network. This assessment is useful as a continual monitor of the quality of the network, and can be utilized to select an alternative central control station based upon the quality of communication paths to and from this station. Additionally, the quality assessment can be utilized to establish relay communication paths, as required.

Claims

1. A wireless communications device for communicating in a network comprising a plurality of wireless communication devices, wherein each of the plurality of wireless communication devices comprise a transmitter and a receiver, the wireless communications device comprising:

an identifying device for identifying an identity of the transmitter of a received message; and

a link monitor for measuring quality of the received message, wherein the receiver is for receiving messages intended to be received at one or more of the other wireless communication devices and for receiving a quality factor from at least one other wireless device, and wherein the transmitter is for transmitting a message and for transmitting the quality factor to one of the plurality of wireless devices, the wireless communication device being designatable as a central station in dependence on the measured quality.

2. The wireless communications device of claim 1, wherein the link monitor measures a Signal-to-Noise Ratio (SNR) of a signal associated with the received message.

3. The wireless communications device of claim 1, wherein the link monitor measures a bit error rate associated with the received message.

4. The wireless communications device of claim 1, wherein the link monitor is for determining a relay transmission path for a transmit-receive path between a first one of the plurality of wireless communication devices and a second one of the plurality of wireless communication devices, wherein the relay transmission path relays a message from the first one of said plurality of wireless stations to the second one of said plurality of wireless stations via a third one of said plurality of wireless stations.

5. A communication system comprising:

a plurality of devices, each of the plurality of devices comprising;

a transmitter for transmitting a message; and

a receiver for receiving messages from each other of the devices, determining from the received messages corresponding quality factors of the received messages and determining an identity of the transmitter of the received message, wherein each of the plurality of devices is selectable as a central station in dependence upon the quality factors.

6. The communication system of claim 5, wherein the devices store the transmitter identities along with the corresponding quality factors, and transmit the stored device identities and corresponding quality factors to a selected central station.

7. The communication system of claim 6, wherein the selected central station receives the stored device identities and corresponding quality factors from each of the plurality of devices and selects an alternate central station in dependence upon the received stored device identities and corresponding quality factors.

8. The communication system of claim 5, wherein the system selects relay transmission paths between the devices in dependence upon the quality factors.

9. A wireless communication device for communication within a wireless communication system containing a plurality of other wireless communication devices, said wireless device comprising:

a transmitter for transmitting a message; and

a receiver for receiving messages from the other wireless devices and from the received messages, determining corresponding quality factors of the received messages and determining an identity of the transmitter of the received message, wherein the wireless device is selectable as an alternate central station in dependence upon the quality factors.

10. The wireless communication device of claim 9, wherein the wireless communication device stores the wireless device identities along with the corresponding quality factors, and transmits the stored device identities and corresponding quality factors to a selected central station.

11. The wireless communication device of claim 10, wherein the wireless communication device is configured to receive the device identities and corresponding quality factors from other wireless devices and is configured to select an alternate central station from the other wireless devices in dependence upon the received stored device identities and corresponding quality factors if the wireless device is the selected central station.

12. A system for assessing the quality of a communications network, said network comprising communication stations comprising means of transmitting and receiving messages, wherein said system comprises:

a means for transmitting a message from a transmitting communication station,

a means for receiving the message at a plurality of receiving communication stations,

and, at each receiving communication station,

a means for identifying the transmitting communication station,

a means for measuring the quality of the received message, and

a means for determining a quality factor associated with the transmitting communication station in dependence upon the measured quality of the received message;

a means for repeating the above steps for other transmitting communication stations, and

a means for having each communication station communicate the quality factors associated with each of said transmitting communication stations to a central station, said central station thereby having a means for assessing the quality of the communication network in dependence upon said quality factors.

13. A system as claimed in claim 12, wherein said means for measuring the quality of the received message comprises a means for measuring a Signal-to-Noise Ratio (SNR) of a signal associated with said received message.

14. A system as claimed in claim 12, wherein said means for measuring the quality of the received message comprises a means for measuring a bit error rate associated with said received message.

15. A system for determining a preferred central controller for a communications network, said communications network comprising communication stations and communication paths between each of said communication stations, one of said communication stations being a current central controller, wherein said system comprises:

a means for transmitting a message from a transmitting communication station,

a means for receiving die message at a plurality of receiving communication stations,

and, at each receiving communication station,

a means for identifying the transmitting communication station,

a means for measuring the quality of the received message, and

a means for determining a quality factor associated with the transmitting communication station in dependence upon the measured quality of the received message; and

,

a means for repeating the above for other transmitting communication stations,

a means for having each communication station communicate the quality factors associated with each of said transmitting communication stations to the current central controller,

at said current central controller thereafter;

a means for assessing the quality of the communication paths in dependence upon said quality factors, and,

a means for determining the preferred central controller in dependence upon the assessed quality of the communication paths.

16. A system as claimed in claim 15, wherein said means for measuring the quality of the received message comprises a means for measuring a Signal-to-Noise Ratio (SNR) of a signal associated with said received message.

17. A system as claimed in claim 15, wherein said means for measuring the quality of the received message comprises a means for measuring a bit error rate associated with said received message.

18. A system for determining a relay pat for a communication path within a communications network, said communications network comprising communication stations and communication paths between each of said communication stations, one of said communication stations being a current central controller, wherein said system comprises:

a means for transmitting a message from a transmitting communication station,

a means for receiving the message at a plurality of receiving communication stations,

and, at each receiving communication station,

a means for identifying the transmitting communication station,

a means for measuring the quality of the received message, and

a means for determining a quality factor associated with the transmitting communication station in dependence upon the measured quality of the received message; and

,

a means for repeating the above steps for other transmitting communication stations,

a means for having each communication station communicate the quality factors associated wit each of said transmitting communication stations to the current central controller,

said current central controller having;

a means for assessing the quality of the communication paths in dependence upon said quality factors, and,

a means for determining the relay pat in dependence upon the assessed quality of the communication paths.

19. A system as claimed in claim 18, wherein said means for measuring the quality of the received message comprises a means for measuring a Signal-to-Noise Ratio (SNR) of a signal associated with said received message.

20. A system as claimed in claim 18, wherein said means for measuring the quality of the received message comprises a means for measuring a bit error rate associated with said received message.

21. A peer-to-peer wireless communication device comprising:

at least one means for transmitting and receiving peer-to-peer communications from and to other wireless communications devices in a network, the communications comprising

a plurality of received messages;

a plurality of received link quality measures;

at least one transmitted message; and

at least one transmitted link quality measure; and

at least one processing means for performing operations, the operations including

identifying respective transmitters of the received messages;

measuring respective link qualities for the received messages;

maintaining data regarding link quality for a plurality of the other devices in the network, responsive to bath measuring link quality and receiving link quality measures; and

enabling the device to convert to a central station, rather than a peer-to-peer station, based on the data and agreement with at least one other device in the network.

22. A system comprising a network of devices as claimed in claim 21, wherein at least one of the devices operations as the central station and the other devices operation as peer-to-peer stations.

23. The device of claim 21, wherein the data comprises link quality information derived from at least one of the received messages that was not addressed to the device.

24. The device, of claim 21, wherein if the device has no message to transmit for a pre-defined period of time, the transmitted message is a dummy or test message.

25. The device of claim 21, wherein the data comprises link quality values relating to communications between first and second ones of the other devices.

26. The device of claim 25, wherein the data is in the form of a matrix having a row and a column for each of the other devices for which the device can maintain link quality values.

27. A system comprising a network of devices as claimed in claim 25 and at least one central station.

28. The system of claim 27, wherein the central station comprises at least one processing means for performing central operations including:

polling the devices to retrieve their data; and

maintaining central data relating to link quality assessments in the network.

29. The system of claim 28, wherein The central operations comprise:

first determining which of the devices has the most optimal set of links to the other devices; and

second determining whether handover of a central station role to another device is desirable.

30. The system of claim 29, wherein the central operations comprise, responsive to the first and second determining, handing over the central station role to that device whose links are most optimal.