Patent EP0859478A2 successfully refreshed from Google Patents.
EP0859478A2
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EP
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Wireless communications systems employing free-space optical communications links
Assignee: AT&T Inc
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Filing: 1997-08-15
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Granted: —
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Expires: 2017-08-15
Abstract
Abstract The cells of a wireless communications system can be subdivided into smaller subcells, in each of which the available radio frequencies can be re-used to allow denser use of the system. To avoid having to run hard-wired communications links to broadcast antennas of the subcells, substantially unguided, free-space, optical communication is used between the antenna that formerly served the cell and the subcell antennas. The existing hard-wired connection from the central antenna to the remainder of the wireless communications system infrastructure continues to be used for communication to and from the cell.
Inventors
- 👤 Christopher L. Rutledge
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 13:59
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/25; H04B10/2575; H04B10/25752; H04B10/07; H04B10/075; H04B10/077; H04B10/0773; H04B10/11; H04B10/112; H04B10/1123; H04B10/1125; H04B2210/00; H04B2210/07; H04B2210/078
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
104 words
A wireless communications system comprising: a plurality of central optical transceivers associated with a cell; a plurality of remote optical transceivers, each of which is associated
with a respective one of a plurality of subcells within said cell; CHARACTERIZED BY: each of said remote optical transceivers being adapted to
communicate with a respective one of said central optical transceivers via substantially
unguided light passing between said remote optical transceiver and the associated central
optical transceiver; and electronic circuitry associated with each of said remote optical
transceivers for converting between radio frequency signals in the associated subcell and
light communicated by said remote optical transceiver.
Claim 2
Dependent Claim
35 words
The apparatus defined in claim 1 further comprising: wireless communications control circuitry remote from said central
and remote optical transceivers; and a communications link between said wireless communications
control circuitry and said central optical transceivers.
Claim 3
Dependent Claim
24 words
The apparatus defined in claim 2 wherein said communication link
comprises optical fiber between said wireless communications control circuitry and said
central optical transceivers.
Claim 4
Dependent Claim
23 words
The apparatus defined in claim 1 wherein light having a unique
wavelength is used for communicating information associated with each of said subcells.
Claim 5
Dependent Claim
37 words
The apparatus defined in claim 1 wherein light having a first unique
wavelength is used for communicating information to each subcell and wherein light
having a second unique wavelength is used for communicating information from each
subcell.
Claim 6
Dependent Claim
33 words
The apparatus defined in claim 5 wherein each of said central optical
transceivers transmits to the associated remote optical transceiver light which includes said
wavelengths used for communication to all of said subcells.
Claim 7
Dependent Claim
35 words
The apparatus defined in claim 6 wherein each of said remote optical
transceivers includes optical filter apparatus for selecting from the wavelengths received by
said transceiver the wavelength used for communication to the associated subcell.
Claim 8
Dependent Claim
15 words
The apparatus defined in claim 7 wherein said optical filter
apparatus comprises Bragg grating apparatus.
Claim 9
Dependent Claim
24 words
The apparatus defined in claim 5 wherein light having a further
unique wavelength is used for communicating control information to all of said subcells.
Claim 10
Dependent Claim
39 words
The apparatus defined in claim 9 wherein each of said central optical
transceivers transmits to the associated remote optical transceiver light which includes said
wavelengths used for communicating said information and said control information to all
of said subcells.
Claim 11
Dependent Claim
51 words
The apparatus defined in claim 10 wherein each of said remote
optical transceivers includes optical filter apparatus for selecting from the wavelengths
received by said transceiver the wavelength used for communicating said information to
the associated subcell and the wavelength used for communicating said control information
to all of said subcells.
Claim 12
Dependent Claim
14 words
The apparatus defined in claim 11 wherein said filter apparatus
comprises Bragg grating apparatus.
Claim 13
Dependent Claim
39 words
The apparatus defined in claim 3 wherein said optical fiber transmits
light from said wireless communications control circuitry to said central optical
transceivers, each of which passes a portion of said light on to the associated remote optical
transceiver.
Claim 14
Dependent Claim
26 words
The apparatus defined in claim 13 wherein said optical fiber
includes erbium doped fiber amplifier apparatus for optically amplifying light being
transmitted via said optical fiber.
Claim 15
Dependent Claim
32 words
The apparatus defined in claim 3 wherein said optical fiber transmits
to said wireless communications control circuitry light received by each of said central
optical transceivers from the associated remote optical transceiver.
Claim 16
Dependent Claim
57 words
The apparatus defined in claim 15 wherein each of said remote
optical transceivers transmits light of a unique wavelength to the associated central optical
transceiver, and wherein said apparatus further comprises optical coupler apparatus for
combining, for application to said optical fiber, the light received by all of said central
optical transceivers from said remote optical transceivers.
Claim 17
Dependent Claim
37 words
The apparatus defined in claim 15 wherein said optical fiber
includes erbium doped fiber amplifier apparatus for optically amplifying light being
transmitted via said optical fiber from said central optical transducers to said wireless
communications control circuitry.
Claim 18
Dependent Claim
92 words
A wireless communication method comprising: (a) communicating information between a communication
network and a central location; CHARACTERIZED BY: (b) communicating at least some of said information between
said central location and each of a plurality of remote locations via substantially unguided
light passing between said central location and each of said remote locations; and (c) communicating at least some of said information between
each of said remote locations and wireless communication devices in the vicinity of said
remote location via radio signals broadcast between said remote location and said wireless
communication devices.
Claim 19
Dependent Claim
21 words
The method defined in claim 18 wherein said communicating
between said communication network and said central location is via optical
communication.
Claim 20
Dependent Claim
23 words
The method defined in claim 19 wherein said optical communication
is guided via optical fiber between said communication network and said central location.
Claim 21
Dependent Claim
19 words
The method defined in claim 18 wherein said communicating
between said communication network and said central location is bi-directional.
Claim 22
Dependent Claim
21 words
The method defined in claim 18 wherein said communicating
between said central location and each of said remote locations is bi-directional.
Claim 23
Dependent Claim
20 words
The method defined in claim 18 wherein said communicating
between said remote locations and said wireless communication devices is bi-directional.
Claim 24
Dependent Claim
15 words
The method defined in claim 18 wherein said information includes
message information and control information.
Claim 25
Dependent Claim
36 words
The method defined in claim 24 wherein said control information
includes radio frequency assignment information for controlling selection of radio
frequencies to be used for said communicating between said remote locations and said
wireless communication devices.
Claim 26
Dependent Claim
32 words
The method defined in claim 19 wherein said communicating
between said communication network and said central location is bi-directional, and
wherein light of different wavelengths is used for communicating in each direction.
Claim 27
Dependent Claim
18 words
The method defined in claim 21 wherein light of different
wavelengths is used for communicating in each direction.
Claim 28
Dependent Claim
40 words
The method defined in claim 26 wherein said information includes
message information and control information, and wherein light of different wavelengths is
used for communicating said message information and said control information from said
communication network to said central location.
Claim 29
Dependent Claim
40 words
The method defined in claim 27 wherein said information includes
message information and control information, and wherein light of different wavelengths is
used for communicating said message information and said control information from said
central location to said remote locations.
Claim 30
Dependent Claim
54 words
The method defined in claim 28 wherein said message information
includes a plurality of message portions, each of which is for use at a respective one of said
remote locations, and wherein light of a different wavelength is used for communicating
each of said message portions from said communication network to said central location.
Claim 31
Dependent Claim
54 words
The method defined in claim 29 wherein said message information
includes a plurality of message portions, each of which is for use at a respective one of said
remote locations, and wherein light of a different wavelength is used for communicating
each of said message portions from said central location to said remote locations.
Claim 32
Dependent Claim
22 words
The method defined in claim 31 wherein said central location
communicates all of said message portions to all of said remote locations.
Claim 33
Dependent Claim
48 words
The method defined in claim 32 further comprising: filtering at each of said remote locations to select the wavelength
used for the message portion for use at that remote location and to reject the wavelengths
used for the message portions for use at others of said remote locations.
Claim 34
Dependent Claim
26 words
The method defined in claim 22 wherein light of a different
wavelength is used for communicating from each of said remote locations to said central
location.
References Cited (Backward Citations)
No citation records indexed.
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