US4775996A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hybrid telephony communication system
Assignee: Nortel Networks Ltd
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Filing: 1987-09-30
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Granted: 1988-10-04
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Expires: 2007-09-30
Abstract
Abstract A wireless telephony system comprising a base station and at least one portable device. The base station employs a ratio frequency (RF) receiver and an optical transmitter. The portable device employs an optical receiver and an RF transmitter.
Inventors
- 👤 Victor F. Emerson
- 👤 Cecil H. Bannister
- 👤 Mahshad Koohgoli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:29
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/72; H04M1/725; H04M1/737
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
105 words
A telephony communications system for providing wireless communications between a base station and a portable device, said telephony communications system comprising: a base station for receiving information from a telephony switching office, said base station having an optical transmitter for transmitting to said portable device information received from said switching office, and a radio frequency receiver for receiving information from said portable device and relaying said information from said portable device to said switching office; at least one portable device for receiving information from said base station in the optical frequency spectrum and for sending information to said base station in the radio frequency spectrum.
Claim 2
Dependent Claim
105 words
A telephony communications system for providing wireless communications between a base station and a portable device, said telephony communications system comprising: a base station for receiving information from a telephony switching office, said base station having an optical transmitter for transmitting to said portable device information received from said switching office, and a radio frequency receiver for receiving information from said portable device and relaying said information from said portable device to said switching office; at least one portable device for receiving information from said base station in the optical frequency spectrum and for sending information to said base station in the radio frequency spectrum.
Claim 3
Dependent Claim
16 words
The telecommunications system of claim 1 wherein said optical frequency spectrum is in the infra-red range.
Claim 4
Dependent Claim
70 words
A base station for use in a wireless telephony communications system that provides wireless communications between said base station and a portable device said base station comprising: interface means for connecting said base station to a telephony switching office; an optical transmitting means for transmitting information received from said switching office; and a radio frequency receiver means for receiving information in the radio frequency spectrum emanating from said portable device.
Claim 5
Dependent Claim
70 words
A base station for use in a wireless telephony communications system that provides wireless communications between said base station and a portable device said base station comprising: interface means for connecting said base station to a telephony switching office; an optical transmitting means for transmitting information received from said switching office; and a radio frequency receiver means for receiving information in the radio frequency spectrum emanating from said portable device.
Claim 6
Dependent Claim
17 words
The base station of claim 3 wherein said optical transmitting means operates in the infra-red frequency spectrum.
Claim 7
Dependent Claim
61 words
A portable device for use in a wireless telephony communications system that provides wireless communications between a base station and said portable device, said portable device comprising: a radio frequency transmitter means for transmitting information from said portable device to said base station; and an optical receiver means for receiving information in the optical frequency spectrum emanating from said base station.
Claim 8
Dependent Claim
61 words
A portable device for use in a wireless telephony communications system that provides wireless communications between a base station and said portable device, said portable device comprising: a radio frequency transmitter means for transmitting information from said portable device to said base station; and an optical receiver means for receiving information in the optical frequency spectrum emanating from said base station.
Claim 9
Dependent Claim
17 words
The portable device of claim 5 wherein said optical receiver means operates in the infra-red frequency spectrum.
References Cited (Backward Citations)
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US4465902A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-04 | 1992-04-04 | 1992-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-04 | 1996-04-04 | 1996-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-04 | 2000-04-04 | 2000-10-04 | $7700.00 | Window Closed / Lapsed |