Method and system for operating stations in a cooperative station network

• US 9,642,093 B2
• Filed: 03/18/2013
• Issued: 05/02/2017
• Est. Priority Date: 09/24/2012
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Festag, Andreas, Egea-Lpez, Esteban, Alcaraz Espin, Juan Jose, Vales-Alonso, Javier, Garcia-Haro, Joan
• Primary Examiner(s): BLANTON, JOHN D
• Application Number:
  US14/430,234
• Publication Number:
  US 20150230188A1
• Time in Patent Office: 1,506 Days
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/243 taking into account interferences
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 52/246 where the output power of a terminal is based on a path parameter calculated in said terminal
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A method for operating a plurality of stations in a cooperative station network, wherein each of the stations transmits signals and receives signals from other stations, includes determining a path loss between at least two of the stations. A carrier sense range for signals of a first station of the stations is determined based on the path loss and received power of signals from the other stations. A load on a dedicated signal exchange channel is determined based on the determined carrier sense range. A maximum output power for the first station is determined based on the determined load. The first station is operated by adjusting the output power of the first station to be, at least on average below the determined maximum output power for the first station.

Claims

1. A method for operating a plurality of stations in a cooperative station network, wherein each of the stations transmits signals and receives signals from other stations, comprising:

determining a path loss between at least two of the stations;

determining a carrier sense range for signals of a first station of the stations based on the path loss and received power of signals from the other stations, wherein the carrier sense range is a transmission range at which a signal can be detected;

determining a load on a dedicated signal exchange channel based on the determined carrier sense range;

determining a maximum output power for the first station based on the determined load; and

operating the first station by adjusting the output power of the first station to be, at least on average below the determined maximum output power for the first station,

wherein the carrier sense range is an average carrier sense range that is calculated using a probability that a receive power at a distance from a transmitter is above a sensitivity of a receiver, and

wherein the probability that the receive power at a distance from a transmitter is above a sensitivity of a receiver is calculated using the formula;

2. The method according to claim 1, wherein, for determining the path loss, a one slope path loss model is used, which is based on wavelength of the signals, distance to the other stations, or a path loss exponent.

3. The method according to claim 1, wherein for determining the path loss, a fading intensity is determined, modeled by a shape parameter.

4. The method according to claim 1, wherein the received power is determined based on a Gamma-distribution with a shape parameter or a sensitivity of the receiving station.

5. The method according to claim 1, wherein neighbor station information is used to determine the channel load.

6. The method of claim 5, wherein the neighbor station information includes one or more of a signal sending rate, a signal size, and a station density.

7. The method according to claim 6, wherein the station density is estimated based on a number of neighbor stations in the carrier sense range.

8. The method according to claim 7, wherein the station density is estimated based on an interference range between the stations or hidden station collisions.

9. The method according to claim 7, wherein, for each of the stations, a neighbor station table is created and updated to comprise collected information included in the signals from the neighbor stations.

10. The method according to claim 9, wherein entries of a neighbor station table are removed after a predetermined time-period.

11. The method according to claim 6, wherein the station density is determined based on a measured channel business time and based on data rate, signal rate and signal size of the signals received from the other stations.

12. The method according to claim 6, wherein an interference range is used, based on interferences or the channel load being above a certain threshold, to correct the station density.

13. The method according to claim 12, wherein, for determining the station density, the carrier sense range is estimated by average transmit power used by neighbor stations.

14. The method according to claim 1, wherein, for determining the received power, a Nakagami-m model is used.

15. The method according to claim 1, wherein a margin is added to the determined maximum output power.

16. The method according to claim 1, wherein the signals are beacon signals.

17. The method of claim 1, wherein the average carrier sense range is calculated using the formula:

18. A system for operating a cooperative station network, wherein each of a plurality of stations transmits signals and receives signals from other stations, comprising:

a pass loss device operable to determine a path loss between at least two stations;

a range device operable to determine a carrier sense range for signals of a first station of the stations based on the path loss and received power of signals from the other stations, wherein the carrier sense range is a transmission range at which a signal can be detected;

a load device operable to determine a load on a dedicated signal exchange channel based on the determined carrier sense range;

a power determining device operable to determine a maximum output power for the station based on the determined load; and

an operating device operable to adjust the output power of the station to be below the maximum output power for the first station,

wherein the carrier sense range is an average carrier sense range that is calculated using a probability that a receive power at a distance from a transmitter is above a sensitivity of a receiver, and

wherein the probability that the receive power at a distance from a transmitter is above a sensitivity of a receiver is calculated using the formula;

19. The system of claim 18, wherein the average carrier sense range is calculated using the formula:

20. A method for operating a plurality of stations in a cooperative station network, wherein each of the stations transmits signals and receives signals from other stations, comprising:

determining a path loss between at least two of the stations;

determining a carrier sense range for signals of a first station of the stations based on the path loss and received power of signals from the other stations, wherein the carrier sense range is a transmission range at which a signal can be detected;

determining a load on a dedicated signal exchange channel based on the determined carrier sense range;

determining a maximum output power for the first station based on the determined load; and

operating the first station by adjusting the output power of the first station to be, at least on average below the determined maximum output power for the first station,

wherein the carrier sense range is an average carrier sense range that is calculated using a probability that a receive power at a distance from a transmitter is above a sensitivity of a receiver, and

wherein the average carrier sense range is calculated using the formula;

21. A system for operating a cooperative station network, wherein each of a plurality of stations transmits signals and receives signals from other stations, comprising:

a pass loss device operable to determine a path loss between at least two stations;

a range device operable to determine a carrier sense range for signals of a first station of the stations based on the path loss and received power of signals from the other stations, wherein the carrier sense range is a transmission range at which a signal can be detected;

a load device operable to determine a load on a dedicated signal exchange channel based on the determined carrier sense range;

a power determining device operable to determine a maximum output power for the station based on the determined load; and

an operating device operable to adjust the output power of the station to be below the maximum output power for the first station,

wherein the carrier sense range is an average carrier sense range that is calculated using a probability that a receive power at a distance from a transmitter is above a sensitivity of a receiver, and

wherein the average carrier sense range is calculated using the formula;