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Method and circuit arrangement for synchronizing frames in multicellular telecommunications systems
Assignee: Alcatel Lucent NV
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Filing: 1996-06-11
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Granted: 1998-09-15
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Expires: 2016-06-11
Abstract
Abstract Telecommunications systems are often built by interconnecting similar subsystems, to enable the adaptation of the systems to different numbers of subscribers. Such a structure must fulfill the requirement that a subscriber with a cordless terminal can move freely within the area served by the telecommunications system without interrupting the call, regardless of which subsystem serves his radio cell at the moment. An uninterrupted hand-off requires the digital information to be frame synchronized. By measuring the time difference (Δt2) between the frame synchronization pulse (FR1) of a subsystem and the frame synchronization pulse (RFR2) which is recovered by an adjacent subsystem, a delay time interval can be calculated, taking the signal propagation time (ΔT) between the subsystems into account, so that any frame offset is equalized. The method can be used for systems which operate according to the DECT standard.
Inventors
- 👤 Heinz Gontsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:52
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/24; H04B7/26; H04B7/2662; H04B7/2671; H04B7/2678; H04J; H04J3/00; H04J3/02; H04J3/06; H04J3/0635; H04J3/0676; H04J3/0682; H04J3/0602
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
185 words
A method of synchronizing frames during digital transmission of information from a first subsystem to a second subsystem in a telecommunications system comprising two or more interconnected subsystems which may be remote from each other, characterized by the following steps: determining, in the first subsystem (1), a second time difference (Δt2) between a frame synchronization pulse (FR1) of the first subsystem (1) and a frame synchronization pulse (FR2) received from the second subsystem (2) and transmitting said second time difference to the second subsystem (2); and determining, in the second subsystem (2), a first time difference (Δt1) between the frame synchronization pulse (FR2) of the second subsystem (2) and the frame synchronization pulse (FR1) received from the first subsystem (1), determining a signal propagation time (ΔT) between the first subsystem (1) and the second subsystem (2) from a sum of the first time difference (Δt1) and the second time difference (Δt2), and subsequently delaying the frame synchronization pulse (FR2) of the second subsystem (2) by a time interval (tv) equal to a difference between the first time difference (Δt1) and the signal propagation time (ΔT).
Claim 2
Independent Claim
185 words
A method of synchronizing frames during digital transmission of information from a first subsystem to a second subsystem in a telecommunications system comprising two or more interconnected subsystems which may be remote from each other, characterized by the following steps: determining, in the first subsystem (1), a second time difference (Δt2) between a frame synchronization pulse (FR1) of the first subsystem (1) and a frame synchronization pulse (FR2) received from the second subsystem (2) and transmitting said second time difference to the second subsystem (2); and determining, in the second subsystem (2), a first time difference (Δt1) between the frame synchronization pulse (FR2) of the second subsystem (2) and the frame synchronization pulse (FR1) received from the first subsystem (1), determining a signal propagation time (ΔT) between the first subsystem (1) and the second subsystem (2) from a sum of the first time difference (Δt1) and the second time difference (Δt2), and subsequently delaying the frame synchronization pulse (FR2) of the second subsystem (2) by a time interval (tv) equal to a difference between the first time difference (Δt1) and the signal propagation time (ΔT).
Claim 3
Dependent Claim
41 words
A method as claimed in claim 1, characterized in that in a telecommunications system comprising a plurality of interconnected subsystems, starting from a master subsystem, making a determination of a time interval for delay step by step from subsystem to subsystem.
Claim 4
Dependent Claim
133 words
A circuit arrangement for carrying out the method according to claim 1, characterized in that, to determine in said first subsystem the first time difference between the frame synchronization pulse (FR1) of the first subsystem and the frame synchronization pulse (RFR2) received from the second subsystem (2), a received clock signal (CL) is applied to an input of a frame aligner (8) which organizes an association between digital information and the clock signal, that an output (RFR) of the frame aligner (8) at which the received frame synchronization pulse is provided is connected to a first input of a comparator (9), and that a signal line carrying the frame synchronization pulse (FR1) of the first subsystem is connected to a second input of the comparator having an output coupled to a microcomputer (6).
Claim 5
Dependent Claim
133 words
A circuit arrangement for carrying out the method according to claim 1, characterized in that, to determine in said second subsystem the second time difference between the frame synchronization pulse (FR2) of the second subsystem and the frame synchronization pulse (RFR1) received from the first subsystem (1), a received clock signal (CL) is applied to an input of a frame aligner (8) which organizes an association between digital information and the clock signal, that an output (RFR) of the frame aligner (8) at which the received frame synchronization pulse is provided, is connected to a first input of a comparator (9), and that a signal line carrying the frame synchronization pulse (FR2) of the second subsystem is connected to a second input of the comparator having an output coupled to a microcomputer (6).
Claim 6
Dependent Claim
22 words
The circuit arrangement of claim 4, further characterized in that said microcomputer (6) has an output connected to a delay circuit (13).
Claim 7
Dependent Claim
40 words
The circuit arrangement of claim 5, characterized in that said output connected to the delay circuit is indicative of the time interval (tv) by which the frame synchronization pulse (FR2) of the second subsystem is delayed by the delay circuit.
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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) | 2001-09-14 | 2002-03-16 | 2002-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-14 | 2006-03-16 | 2006-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-14 | 2010-03-16 | 2010-09-15 | $7700.00 | Window Closed / Lapsed |