US4979231A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-way radio for use in a communication system
Assignee: Motorola Solutions Inc
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Filing: 1989-01-06
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Granted: 1990-12-18
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Expires: 2009-01-06
Abstract
Abstract A two-way radio includes a receiver having a squelch circuit and a selective calling decoder. A transmitter is connected to an inhibit circuit. The inhibit circuit is responsive to the selective calling decoder for permitting transmission after reception of the radio's ID code. The inhibit circuit inhibits further transmissions if the squelch circuit indicates loss of carrier for more than a predetermined time during receive.
Inventors
- 👤 Brian K. A. Johnson
- 👤 Stelios J. Patsiokas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:44
CPC Classifications
H; H04; H04W; H04W88/00; H04W88/02; H04W88/022; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/44; H04B7/00; H04B7/24
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
92 words
A two-way radio having an address for use in a communication system comprising: receiver means for receiving a carrier signal, address detecting means operatively connected to the receiver means for detecting said address, carrier detection means for detecting presence or absence of said carrier signal: transmitter means, transmit inhibit means for enabling transmission by said transmitter means only in response to detection of said address by said address detecting means and subsequently inhibiting further transmission in absence of detecting said carrier signal by said carrier detection means within a predetermined time interval.
Claim 2
Dependent Claim
92 words
A two-way radio having an address for use in a communication system comprising: receiver means for receiving a carrier signal, address detecting means operatively connected to the receiver means for detecting said address, carrier detection means for detecting presence or absence of said carrier signal: transmitter means, transmit inhibit means for enabling transmission by said transmitter means only in response to detection of said address by said address detecting means and subsequently inhibiting further transmission in absence of detecting said carrier signal by said carrier detection means within a predetermined time interval.
Claim 3
Dependent Claim
32 words
A two-way radio as defined in claim 1, in which: the carrier detection means comprise a squelch circuit having an squelch circuit signal for indicating presence or absence of said carrier signal.
Claim 4
Dependent Claim
31 words
A two-way radio as defined in claim 2, in which: the transmit inhibit means includes a timer means for timing the squelch circuit signal and inhibiting after a predetermined time interval.
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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) | 1993-12-17 | 1994-06-18 | 1994-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-17 | 1998-06-18 | 1998-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-17 | 2002-06-18 | 2002-12-18 | $7700.00 | Window Closed / Lapsed |