Omni-directional antenna supporting simultaneous transmission and reception of multiple radios with narrow frequency separation

• US 8,160,664 B1
• Filed: 12/05/2005
• Issued: 04/17/2012
• Est. Priority Date: 12/05/2005
• Status: Active Grant

• Current Assignee: Fortinet Inc.
• Original Assignee: Meru Networks, Inc. (Fortinet Inc.)
• Inventors: Venugopalachary, Rajendran, Palanisamy, Senthil, Bharghavan, Vaduvur, Sarang, Srinath
• Primary Examiner(s): CAI, WAYNE HUU
• Application Number:
  US11/294,673
• Time in Patent Office: 2,325 Days
• Field of Search: 455/562.1, 455/19, 455/25, 455/63.4, 455/575.7, 455/13.3, 455 82- 83, 455/129, 343/799, 343812-813, 343/827
• US Class Current: 455/575.7
• CPC Class Codes: H04W 28/0226 based on location or mobility handoff or reselection H04W36/00; mobile application services making use of the location of users or terminals H04W4/02
• CPC Class Codes: H04W 28/086 among access entities
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/105 PBS [Private Base Station] network H04W84/12 - H04W84/16 take precedence

Abstract

An omni-directional antenna supporting simultaneous transmission/reception, from the same AP, on multiple frequencies, allowing each AP to communicate using each possible frequency. Each AP multiplexes its outgoing signals onto its transmitting antenna, and de-multiplexes its incoming signals from its receiving antenna. The transmitting and receiving antennae are each substantially located in each other'"'"'s NULL zone (or one is in the NULL zone of the other). The AP can transmit/receive on many distinct frequencies without needing more antennae.

Claims

1. A method, including steps of

substantially simultaneous transmission and reception by substantially co-located multiple radios;

sending signals to a transmission antenna having a relatively small NULL coverage zone;

receiving signals from a reception antenna having a relatively small NULL coverage zone;

wherein

the transmission antenna is disposed parallel to a maximum power reception region of said reception antenna in the NULL coverage zone of the reception antenna, the reception antenna is disposed parallel to a maximum power reception region of said reception antenna in the NULL coverage zone of the transmission antenna, or both; and

the NULL coverage zone of the transmission antenna includes a finite region of substantially zero signal strength at substantially the same polarity as said transmission antenna, the NULL coverage zone of the reception antenna includes a finite region of substantially zero signal strength at substantially the same polarity as said reception antenna, or both;

wherein the transmission antenna further comprises a pair of transmission antennae;

wherein said maximum power transmission regions of said transmission antennas face in substantially 180 degree opposite directions from each other.

2. A method as in claim 1, wherein separate radios are connected to each transmission antenna, thereby co-locating the radios at an access point.

3. A method as in claim 2, further comprising the step of performing a non-spatial handoff between the separate radios.

4. A method as in claim 1, wherein separate channels are connected to each antenna, thereby co-locating channels at an access point.

5. A method as in claim 1, wherein the transmission antenna further comprises a pair of transmission antennae each including a patch transmission element, the reception antenna further comprises a pair or reception antennas each including a patch transmission element, and the transmission patch elements are disposed parallel and adjacent to the reception patch elements.

6. A method as in claim 1, wherein

the transmission antenna is omni-directional and disposed with a transmission power region substantially including a plane,

the reception antenna is unidirectional and disposed with a reception power region substantially including said plane, and

the transmission antenna is disposed within a set of unidirectional reception antenna including the reception antenna substantially surrounding said transmission antenna in said plane.

7. A method as in claim 6, wherein said surrounding set of unidirectional reception antenna form a square.

8. A method as in claim 6, wherein said surrounding set of unidirectional reception antenna form a hexagon.

9. A method as in claim 6, wherein the transmission antenna comprises polar transmitting elements.

10. A method as in claim 9, wherein the reception antenna comprises polar reception elements.

11. A method as in claim 10, wherein the antennae co-locate multiple channels, radios, or channels and radios.

12. A method as in claim 1, wherein the transmission and reception antennae each includes a plurality of patch antennae disposed proximately and each disposed substantially parallel to a transmit/receive axis.

13. A method, including steps of

substantially simultaneous transmission and reception by substantially co-located multiple radios;

sending signals to a transmission antenna having a relatively small NULL coverage zone;

receiving signals from a reception antenna having a relatively small NULL coverage zone;

wherein

the transmission antenna is disposed parallel to a maximum power reception region of said reception antenna in the NULL coverage zone of the reception antenna, the reception antenna is disposed parallel to a maximum power reception region of said reception antenna in the NULL coverage zone of the transmission antenna, or both; and

the NULL coverage zone of the transmission antenna includes a finite region of substantially zero signal strength at substantially the same polarity as said transmission antenna, the NULL coverage zone of the reception antenna includes a finite region of substantially zero signal strength at substantially the same polarity as said reception antenna, or both;

wherein the reception antenna further comprises a pair of reception antennae;

wherein said maximum power reception regions of said reception antennas face in substantially 180 degree opposite directions from each other.

14. A method as in claim 13, further comprising the step of detecting collisions and possible collisions between signals on the reception antennae.

15. Apparatus including

a multiplexer coupled to a transmission antenna having a relatively small NULL coverage zone;

a de-multiplexer coupled to a reception antenna having a relatively small NULL coverage zone;

wherein

the transmission antenna is disposed parallel to a maximum power reception region of said reception antenna in the NULL coverage zone of the reception antenna, the reception antenna is disposed parallel to a maximum power transmission region of said transmission antenna in the NULL coverage zone of the transmission antenna, or both; and

the reception antenna'"'"'s NULL coverage zone includes a finite region of substantially zero signal strength at substantially the same polarity as said reception antenna, the transmission antenna'"'"'s NULL coverage zone includes a finite region of substantially zero signal strength at substantially the same polarity as said transmission antenna, or both;

wherein the transmission antenna further comprises a pair of transmission antennas;

wherein said maximum power transmission regions of said transmission antennas face in substantially 180 degree opposite directions from each other.

16. Apparatus as in claim 15, wherein separate radios are connected to each transmission antenna, thereby co-locating the radios at an access point.

17. Apparatus as in claim 16, further comprising the step of performing a non-spatial handoff between the separate radios.

18. Apparatus as in claim 15, wherein separate channels are connected to each antenna, thereby co-locating channels at an access point.

19. Apparatus as in claim 15, wherein

the transmission antenna further comprises a pair of transmission antennas each including a patch transmission element,

the reception antenna further comprises a pair of reception antennas each including a patch transmission element, and

the transmission patch elements are disposed parallel and adjacent to the reception patch elements.

20. Apparatus as in claim 15, wherein

the transmission antenna is omni-directional and disposed with a transmission power region substantially including a plane,

the reception antenna is unidirectional and disposed with a reception power region substantially including said plane, and

wherein the transmission antenna is disposed within a set of unidirectional reception antenna including the reception antenna substantially surrounding said transmission antenna in said plane.

21. Apparatus as in claim 20, wherein said surrounding set of unidirectional reception antenna form a square.

22. Apparatus as in claim 20, wherein said surrounding set of unidirectional reception antenna form a hexagon.

23. Apparatus as in claim 20, wherein the transmission antenna comprises polar transmitting elements.

24. Apparatus as in claim 23, wherein the reception antenna comprises polar reception elements.

25. Apparatus as in claim 24, wherein antennae co-locate multiple channels, radios, or channels and radios.

26. Apparatus as in claim 15, wherein the transmission and reception antennae each includes a plurality of patch antennae disposed proximately and each disposed substantially parallel to a transmit/receive axis.

27. Apparatus including

a multiplexer coupled to a transmission antenna having a relatively small NULL coverage zone;

a de-multiplexer coupled to a reception antenna having a relatively small NULL coverage zone;

wherein

the transmission antenna is disposed parallel to a maximum power reception region of said reception antenna in the NULL coverage zone of the reception antenna, the reception antenna is disposed parallel to a maximum power transmission region of said transmission antenna in the NULL coverage zone of the transmission antenna, or both; and

the reception antenna'"'"'s NULL coverage zone includes a finite region of substantially zero signal strength at substantially the same polarity as said reception antenna, the transmission antenna'"'"'s NULL coverage zone includes a finite region of substantially zero signal strength at substantially the same polarity as said transmission antenna, or both;

wherein the reception antenna further comprises a pair of reception antennas;

wherein said maximum power reception regions of said reception antennas face in substantially 180 degree opposite directions from each other.

28. Apparatus as in claim 27, further comprising a control circuit that detects collisions and possible collisions between signals on the reception antennae.