Patent US4995083A successfully refreshed from Google Patents.
US4995083A
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Method of establishing a radio link in one of a plurality of channels between two radio units
Assignee: GPT Ltd
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Filing: 1989-07-31
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Granted: 1991-02-19
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Expires: 2009-07-31
Abstract
Abstract The method comprises transmitting an initiating signal in the form of a bit pattern as a continuous burst from one radio unit to the other. The pattern incorporates a preamble pattern and a security code having a plurality of bit sequences. Each sequence is transmitted a number of times. The received security code is compared with stored codes in the other unit, and if a matching pair is identified a response signal is transmitted from the other unit to said one unit. The response signal incorporates the preamble pattern for establishing synchronization between the radio units.
Inventors
- 👤 John M. Baker
- 👤 Peter N. Proctor
- 👤 Andrew S. Pearce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:48
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/72; H04M1/725; H04M1/727
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
160 words
A method of establishing synchronization in a digital radio link in one of a plurality of channels between two radio units of a multi-channel communication system, comprising transmitting an initiating signal in the form of a bit pattern as a continuous burst from one radio unit to the other unit, said continuous data stream burst having a timing which is independent of the synchronism achieved, and said other unit temporarily achieving bit synchronism without changing frame synchronism, the bit pattern incorporating a preamble pattern and a security code comprising a plurality of bit sequences, each bit sequence being transmitted a plurality of times in said continuous burst, comparing the received security code with one or more codes stored within said other radio unit, whereupon, if a matching pair of codes is identified, a response signal is transmitted from said other radio unit to said one unit, the response signal incorporating the preamble pattern for establishing synchronisation between the radio units.
Claim 2
Independent Claim
160 words
A method of establishing synchronization in a digital radio link in one of a plurality of channels between two radio units of a multi-channel communication system, comprising transmitting an initiating signal in the form of a bit pattern as a continuous burst from one radio unit to the other unit, said continuous data stream burst having a timing which is independent of the synchronism achieved, and said other unit temporarily achieving bit synchronism without changing frame synchronism, the bit pattern incorporating a preamble pattern and a security code comprising a plurality of bit sequences, each bit sequence being transmitted a plurality of times in said continuous burst, comparing the received security code with one or more codes stored within said other radio unit, whereupon, if a matching pair of codes is identified, a response signal is transmitted from said other radio unit to said one unit, the response signal incorporating the preamble pattern for establishing synchronisation between the radio units.
Claim 3
Dependent Claim
36 words
A method of establishing synchronism in a digital radio link as claimed in claim 1, wherein one radio unity is a portable unit and the other is a fixed unit and together form a cordless telephone.
Claim 4
Dependent Claim
39 words
A method of establishing synchronism in a digital radio link as claimed in claim 2, wherein the portable unit acts as a synchronous slave to the fixed unit, taking timing of transmit and receive frames from the fixed unit.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-18 | 1994-08-20 | 1995-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-18 | 1998-08-20 | 1999-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-18 | 2002-08-20 | 2003-02-19 | $7700.00 | Window Closed / Lapsed |