Wireless LAN system and a transmitter-receiver in a wireless LAN system

• US 6,359,873 B1
• Filed: 03/18/1998
• Issued: 03/19/2002
• Est. Priority Date: 08/12/1997
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kobayashi, Naofumi
• Primary Examiner(s): NGO, RICKY QUOC
• Application Number:
  US09/040,426
• Time in Patent Office: 1,462 Days
• Field of Search: 370/338, 370/277, 370/278, 370/280, 370/311, 370/328, 370/329, 370/339, 455/45.1, 455/426, 455/67.1, 455/69
• US Class Current: 370/338
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

In a wireless LAN system chiefly using a millimeter wave, a satellite station is provided with an active phased planar-array antenna, the radiating directivity characteristic of which can be freely changed. When a master station receives a control frame transmitted from the satellite station prior to the commencement of normal communication, the master station transmits a carrier wave. The satellite station determines such a directivity characteristic of an antenna as to receive this carrier wave with the strongest intensity, and fixes the characteristic. Thus, an optimal communication environment can be secured. When the number of errors in a received data frame or the receiving electric field intensity received by the satellite station in normal communication is inferior to a respective predetermined threshold, the deterioration of the communication environment can be coped with by determining again. The power consumption of the master station can be reduced by making the transmitting power of a carrier wave for determining less than the transmitting power at the time of normal communication.

Claims

1. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication;

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna; and

a power feeding power controlling unit adjusting the power feeding power for transmitting a control frame,

when said control frame transmitting unit transmits control frames using one element in said array, the relevant power feeding power controlling unit increases the power feeding power,

wherein said antenna is an active phased planar array antenna,

wherein said control frame transmitting unit transmits a control frame using only one element out of a plurality of elements composing the array of said active phased planar-array antenna.

2. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein said antenna is an active phased planar array antenna,

wherein said antenna directivity characteristic controlling unit determines such a directivity characteristic that said receiving electric field intensity may become a maximum by changing the radiating directivity characteristic of said active phased planar-array antenna on a plane parallel to a plane on which a plurality of elements composing the array of said active phased planar-array antenna are arrayed, and a plane vertical to the relevant parallel plane.

3. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein when in the determination of said directivity characteristic the receiving electric field intensity of said carrier wave does not reach a predetermined minimum value, said antenna directivity characteristic controlling unit determines the relevant directivity characteristic again.

4. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein when in said determination the difference between the maximum value and the minimum value of the receiving electric field intensity of said carrier wave does not exceed a minimum value predetermined for the relevant difference, said antenna directivity characteristic controlling unit determines the relevant directivity characteristic again.

5. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

a an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein when in said determination a ratio of the maximum value to the minimum value of the receiving electric field intensity of said carrier waves “

the maximum/the minimum”

does not exceed a predetermined value, said antenna directivity characteristic controlling unit determines the relevant directivity characteristic again.

6. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein when in said determination a ratio of the minimum value to the maximum value of the receiving electric field intensity of said carrier wave “

the minimum/the maximum”

is the same as or greater than a predetermined value, said antenna directivity characteristic controlling unit determines the relevant directivity characteristic again.

7. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna;

a frame collision detecting unit detecting a collision when a control frame transmitted by its own apparatus collides with a control frame transmitted by another apparatus, or a transmitting and receiving data frame of a backbone local area network or another apparatus, and

after detecting the relevant collision, said control frame transmitting unit transmits a control frame again, and said antenna directivity characteristic controlling unit determines said directivity characteristic again.

8. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna;

a receiving electric field intensity detecting unit detecting the receiving electric field intensity of a data frame received from a communication partner after the transmission and reception of a data frame as communication is started with the partner, and

when the relevant detected receiving electric field intensity becomes less than a predetermined value, said control frame transmitting unit transmits a control frame, and said antenna directivity characteristic controlling unit determines said directivity characteristic.

9. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna;

a frame error detecting/counting unit detecting an error in a data frame received from a communication partner after the transmission and reception of a data frame as communication is started with the partner, and when the number of the relevant error frames exceeds a predetermined number, said control frame transmitting unit transmits a control frame, and said antenna directivity characteristic controlling unit determines said directivity characteristic.

10. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna;

a frame error detecting/counting unit detecting an error in a data frame received from a communication partner after the transmission and reception of a data frame as communication is started with the partner, and

when the number of error frames received consecutively exceeds a predetermined number, said control frame transmitting unit transmits a control frame, and said antenna directivity characteristic controlling unit determines said directivity characteristic.

11. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna;

a frame error detecting/counting unit detecting an error in a data frame received from a communication partner after the transmission and reception of a data frame as communication is started with the partner; and

a timer to be started to operate when the relevant error frame is detected in the first place, and

when a predetermined number of error frames is received within a certain time before the time-out of the timer started to operate at the time of the relevant detection of error frames, said control frame transmitting unit transmits a control frame, and said antenna directivity characteristic controlling unit determines said directivity characteristic.

12. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna;

a frame error detecting/counting unit detecting an error in a data frame received from a communication partner after the transmission and reception of a data frame as communication is started with the partner; and

a timer to be started to operate when the relevant error frame is first detected, and

when the number of error frames received consecutively within a certain time before the timeout of the timer started to operate at the time of the relevant detection of error frames exceeds a predetermined number, said control frame transmitting unit transmits a control frame, and said antenna directivity characteristic controlling unit determines said directivity characteristic.

13. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna;

an electric field intensity detecting unit detecting the electric field intensity of electric waves received from a communication partner, and

when the detected electric field intensity changes discontinuously, said determination by an antenna directivity characteristic controlling unit is stopped, said control frame transmitting unit transmits a control frame, and said antenna directivity characteristic controlling unit determines said directivity characteristic.

14. The transmitter-receiver according to claim 13, wherein time elapsing after said determination is stopped by said antenna directivity characteristic controlling unit is set according to a random back off algorithm.

15. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein said antenna is an active phased planar array antenna,

wherein when in the determination of said directivity characteristic the receiving electric field intensity of said carrier wave does not reach a predetermined minimum value, said antenna directivity characteristic controlling unit determines the relevant directivity characteristic again.

16. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein said antenna is an active phased planar array antenna,

wherein when in said determination the difference between the maximum value and the minimum value of the receiving electric field intensity of said carrier wave does not exceed a minimum value predetermined for the relevant difference, said antenna directivity characteristic controlling unit determines the relevant directivity characteristic again.

17. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein said antenna is an active phased planar array antenna,

wherein when in said determination a ratio of the maximum value to the minimum value of the receiving electric field intensity of said carrier wave “

the maximum/the minimum”

does not exceed a predetermined value, said antenna directivity characteristic controlling unit determines the relevant directivity characteristic again.

18. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication; and

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein said antenna is an active phased planar array antenna,

wherein when in said determination a ratio of the minimum value to the maximum value of the receiving electric field intensity of said carrier wave “

the minimum/the maximum”

is the same as or greater than a predetermined value, said antenna directivity characteristic controlling unit determines the relevant directivity characteristic again.

19. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

a control frame transmitting unit transmitting a control frame to a communication partner prior to the commencement of communication;

an antenna directivity characteristic controlling unit determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein said antenna is an active phased planar array antenna;

a frame collision detecting unit detecting a collision when a control frame transmitted by its own apparatus collides with a control frame transmitted by another apparatus, or a transmitting and receiving data frame of a backbone local area network or another apparatus, and

after detecting the relevant collision, said control frame transmitting unit transmits a control frame again, and said antenna directivity characteristic controlling unit determines said directivity characteristic again.

20. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

control frame transmitting means for transmitting a control frame to a communication partner prior to the commencement of communication; and

antenna directivity characteristic controlling means for determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein said antenna is an active phased planar array antenna,

wherein said antenna directivity characteristic controlling means determines such a directivity characteristic that said receiving electric field intensity may become a maximum by changing the radiating directivity characteristic of said active phased planar-array antenna on a plane parallel to a plane on which a plurality of elements composing the array of said active phased planar-array antenna are arrayed, and a plane vertical to the relevant parallel plane.

21. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

control frame transmitting means for transmitting a control frame to a communication partner prior to the commencement of communication; and

antenna directivity characteristic controlling means for determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein when in the determination of said directivity characteristic the receiving electric field intensity of said carrier wave does not reach a predetermined minimum value, said antenna directivity characteristic controlling means determines the relevant directivity characteristic again.

22. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

control frame transmitting means for transmitting a control frame to a communication partner prior to the commencement of communication; and

antenna directivity characteristic controlling means for determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein when in said determination the difference between the maximum value and the minimum value of the receiving electric field intensity of said carrier wave does not exceed a minimum value predetermined for the relevant difference, said antenna directivity characteristic controlling means determines the relevant directivity characteristic again.

23. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

control frame transmitting means for transmitting a control frame to a communication partner prior to the commencement of communication; and

antenna directivity characteristic controlling means for determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna;

a frame error detecting/counting means for detecting an error in a data frame received from a communication partner after the transmission and reception of a data frame as communication is started with the partner, and when the number of the relevant error frames exceeds a predetermined number, said control frame transmitting means transmits a control frame, and said antenna directivity characteristic controlling means determines said directivity characteristic.

24. A transmitter-receiver for communicating with another party in a wireless local area network system, comprising:

an antenna for dynamically changing a directivity characteristic when receiving electric waves;

control frame transmitting means transmitting a control frame to a communication partner prior to the commencement of communication; and

antenna directivity characteristic controlling means for determining such a directivity characteristic that the receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna;

frame error detecting/counting means for detecting an error in a data frame received from a communication partner after the transmission and reception of a data frame as communication is started with the partner, and

when the number of error frames received consecutively exceeds a predetermined number, said control frame transmitting means transmits a control frame, and said antenna directivity characteristic controlling means determines said directivity characteristic.

25. A method for communicating with another party in a wireless local area network system, comprising:

using an active phased planar array antenna for dynamically changing a directivity characteristic when receiving electric waves;

transmitting a control frame to a communication partner prior to commencement of communication; and

determining such a directivity characteristic that a receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein the determining determines such a directivity characteristic that said receiving electric field intensity may become a maximum by changing the radiating directivity characteristic of said active phased planar-array antenna on a plane parallel to a plane on which a plurality of elements composing the array of said active phased planar-array antenna are arrayed, and a plane vertical to the relevant parallel plane.

26. A method for communicating with another party in a wireless local area network system, comprising:

using an active phased planar array antenna for dynamically changing a directivity characteristic when receiving electric waves;

transmitting a control frame to a communication partner prior to commencement of communication; and

determining such a directivity characteristic that a receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein when in the determining of said directivity characteristic the receiving electric field intensity of said carrier wave does not reach a predetermined minimum value, said determining determines the relevant directivity characteristic again.

27. A method for communicating with another party in a wireless local area network system, comprising:

using an antenna for dynamically changing a directivity characteristic when receiving electric waves;

transmitting a control frame to a communication partner prior to commencement of communication; and

determining such a directivity characteristic that a receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna,

wherein when in said determining the difference between the maximum value and the minimum value of the receiving electric field intensity of said carrier wave does not exceed a minimum value predetermined for the relevant difference, said determining determines the relevant directivity characteristic again.

28. A method for communicating with another party in a wireless local area network system, comprising:

using an antenna for dynamically changing a directivity characteristic when receiving electric waves;

transmitting a control frame to a communication partner prior to commencement of communication; and

determining such a directivity characteristic that a receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna; and

detecting an error in a data frame received from a communication partner after the transmission and reception of a data frame as communication is started with the partner, and when the number of the relevant error frames exceeds a predetermined number, said transmitting transmits a control frame, and said determining determines said directivity characteristic.

29. A method for communicating with another party in a wireless local area network system, comprising:

using an active phased planar array antenna for dynamically changing a directivity characteristic when receiving electric waves;

transmitting a control frame to a communication partner prior to commencement of communication; and

determining such a directivity characteristic that a receiving electric field intensity of a carrier wave transmitted from the communication partner may become a maximum when receiving said control frame by changing the directivity characteristic of said antenna;

detecting an error in a data frame received from a communication partner after the transmission and reception of a data frame as communication is started with the partner, and

when the number of error frames received consecutively exceeds a predetermined number, said transmitting transmits a control frame, and said determining determines said directivity characteristic.