Transponder systems and methods for radio-over-fiber (ROF) wireless picocellular systems

• US 20080186143A1
• Filed: 02/06/2007
• Published: 08/07/2008
• Est. Priority Date: 02/06/2007
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Cable Systems LLC (Corning Incorporated)
• Inventors: George, Jacob, Sauer, Michael, Kobyakov, Andrey, Hurley, William Carl
• Granted Patent: US 8,111,998 B2
• Time in Patent Office: Days
• US Class Current: 340/10.3
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/10178 including auxiliary means for focusing, repeating or boosting the electromagnetic interrogation field comparable booster antennas integrated on the record carrier itself G06K19/07794
• CPC Class Codes: H04B 10/25756 Bus network topology
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

Transponder systems and methods for radio-over-fiber (RoF) wireless picocellular system are disclosed. One type of transponder system includes a RoF transponder used in combination with at least one radiation-reflector assembly to provide for enhanced antenna directivity of the transponder. Another type of transponder system is a transponder node assembly, wherein two or more transponders are integrated into a single assembly, thereby reducing cost while facilitating RoF wireless picocellular system deployment. Another type of transponder system provides one or more transponders in a RoF wireless picocellular system with radio-frequency identification (RFID) tags, and uses an RFID tag reader to locate and read information from the transponders, as well as to perform transponder mode selection. Another type of transponder system is directed to a tether cable assembly that includes a dispensible/retractable coiled tether cable housed in a protective housing for connecting the tether cable to a transponder.

Claims

1. A transponder system with enhanced antenna directivity, for use in a radio-over-fiber (RoF) wireless picocellular system, comprising:

a transponder having a converter pair unit adapted to convert radio-frequency (RF) electrical signals into optical signals and vice versa, and an antenna system having at least one antenna element operably coupled to the converter pair unit; and

at least one radiation-reflecting member arranged relative to the at least one antenna element so as to provide enhanced antenna directivity as compared to not having the at least one radiation-reflecting member.

2. The transponder system of claim 1, wherein each radiation-reflecting member is part of a radiation-reflector assembly having a support member that supports the radiation-reflecting member, and a mounting member that operably engages the support member.

3. The transponder system of claim 2, wherein the transponder has a housing and wherein the at least one radiation-reflector assembly is mounted to the housing relative to the at least one antenna element.

4. The transponder system of claim 2, wherein the at least one antenna element is incorporated into an optical fiber cable, and wherein the at least one radiation-reflector assembly is attached to the optical fiber cable relative to the at least one antenna element.

5. The transponder system of claim 1, wherein the antenna system includes two or more antenna elements, and wherein a single radiation-reflecting member is arranged relative to the two or more antenna elements.

6. The transponder system of claim 1, wherein the radiation-reflecting element is curved concave-wise relative to the transponder.

7. The transponder system of claim 1, wherein first and second radiation-reflecting members are arranged relative to the at least one antenna element to provide enhanced antenna directivity as compared to arranging a single radiation-reflecting member relative to the at least one antenna element.

8. The transponder system of claim 1, further including an optical fiber cable, wherein the transponder is mounted to the optical fiber cable.

9. The transponder system of claim 1, wherein the antenna system includes a first antenna element adapted to transmit and receive RF radiation in a 5 GHz band having a corresponding center wavelength λ

_RA, and a second antenna element adapted to transmit and receive RF radiation in a 2.4 GHz band having a corresponding center wavelength λ

_RB.

10. The transponder system of claim 9, including first and second radiation reflecting members arranged relative to the first and second antenna elements respectively, at respective distances DA and DB, wherein DA˜

λ

_RA/4 and DB˜

λ

_RB/4.

11. A method of providing enhanced antenna directivity for a radio-over-fiber (RoF) transponder for a wireless picocellular system, the transponder having an antenna system with at least one antenna element, the method comprising:

arranging at least one radiation-reflecting member relative to the at least one antenna element so as to provide enhanced antenna directivity as compared to not having the at least one radiation-reflecting member.

12. The method of claim 11, wherein the transponder includes a housing and wherein at least one antenna element is within a housing, and further including:

mounting the radiation-reflecting member atop the housing relative to the at least one antenna element.

13. The method of claim 12, wherein the at least one antenna element is included within an optical fiber cable, and further including:

mounting the radiation-reflecting member on the optical fiber cable relative to the at least one antenna element.

14. The method of claim 11, including providing a single radiation-reflecting member arranged relative to two or more antenna elements.

15. The method of claim 11, including providing a first antenna element adapted to transmit and receive RF radiation in a 5 GHz band having a corresponding center wavelength λ

_RA, and providing a second antenna element adapted to transmit and receive RF radiation in a 2.4 GHz band having a corresponding center wavelength λ

_RB.

16. The method of claim 15, including arranging first and second radiation reflecting members arranged relative to the first and second antenna elements respectively, at respective distances DA and DB, wherein DA˜

λ

_RA/4 and DB˜

λ

_RB/4.

17. A radiation-reflector assembly for a transponder system for a radio-over-fiber (RoF) wireless picocellular system, comprising:

a radiation-reflecting member adapted to reflect radio-frequency (RF) radiation;

a support member arranged to support the radiation-reflecting member; and

a mounting member arranged to engage the support member so as to support the support member and radiation-reflecting member in a position relative to the antenna system so as to provide enhanced antenna directivity as compared to the absence of the radiation-reflecting member.

18. The assembly of claim 17, wherein the support member is adapted to snap-engage the mounting member.

19. The assembly of claim 17, wherein the mounting member is adapted to be affixed to a transponder housing or to an optical fiber cable.

20. The assembly of claim 17, wherein the support member is a dielectric material.

21. A transponder radio-frequency identification (RFID) system, comprising:

a radio-over-fiber (RoF) transponder adapted to convert radio-frequency (RF) electrical signals to RF optical signals and vice versa;

a RFID tag positioned relative to the transponder and adapted to produce a RFID-tag signal that functions as a ping signal to locate the RFID tag; and

a RFID tag reader adapted to cause the RFID tag to emit the RFID-tag signal and to detect and process the RFID tag signal.

22. The system of claim 21, wherein the RFID-tag signal includes no RFID tag data.

23. The system of claim 21, wherein the RFID-tag signal contains RFID tag data that includes at least one property selected from the group of properties comprising:

a transponder location, GPS coordinates, an installation date, a maintenance history, an operating frequency or frequencies, and a antenna location or locations.

24. The system of claim 21, wherein the RFID tag is electrically connected to the transponder, wherein the RFID tag is adapted to provide an electrical signal to the transponder, wherein the transponder has two or more operational modes, and wherein the transponder is adapted to be responsive to said electrical signal to switch its operation mode.

25. A tether cable assembly for a radio-over-fiber (RoF) wireless picocellular system having an optical fiber cable, comprising:

a tether cable having at least one optical fiber, at least one electrical wire, and proximal and distal ends;

a spool around which the tether cable can be coiled and uncoiled;

a housing surrounding the spool and having a first slot sized to pass the tether cable;

a RoF transponder connected to tether cable proximate end; and

wherein the tether cable distal end is adapted to operably couple to the optical fiber cable.

26. The assembly of claim 25, wherein the RoF transponder resides within the tether cable assembly housing.

27. The assembly of claim 25, wherein the tether cable has an associated minimum bend radius below which causes significant bending loss, and wherein:

when the spool is adapted so that when the tether cable is coiled around the spool, the tether cable does not have a bend with a radius below the minimum bending radius R_C.

28. The assembly of claim 25, further including a locking mechanism adapted to either automatically or manually engage the tether cable so that an amount of tether cable dispensed from the spool remains constant.

29. The assembly of claim 25, wherein the housing includes a second slot sized to pass the tether cable, and wherein the tether cable is coiled around the spool in two different directions so as to allow the tether cable to be dispensed from the spool and through the housing via the first and second slots.

30. A method of storing and/or dispensing a tether cable for a radio-over-fiber (RoF) transponder, comprising:

coiling a tether cable on a spool, wherein the tether cable has a minimum bending radius and includes proximal and distal ends, with the transponder operably coupled to one of the tether cable proximal and distal ends, the tether cable further including at least one optical fiber and at least one wire, and wherein said coiling is performed so that all parts of the tether cable have a bending radius greater than the minimum bending radius;

housing the spool in a protective housing having at least one slot sized to allow the tether cable to pass therethrough to allow the tether cable to be dispensed from or retracted to the spool.