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Ideally, clocks in a telecommunications network are synchronous, controlled to run at identical rates, or at the same mean rate with a fixed relative
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to resynchronize periodically. In the teleprinter world, Howard Krum finally came up with a good decoding mechanism for async signals around 1912.
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that must meet the international standards requirement for long term frequency accuracy better than 1 part in 10. To get this performance,
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In telecoms networks two key parameters are used for measurement of synchronisation performance. These parameters are defined by the
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They provide a capability to carry on producing a high quality output even when their input reference is lost, this is referred to as
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Synchronization supply units (SSU) are used to ensure reliable synchronisation distribution. They have a number of key functions:
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Synchronization remained a problem well into the electronic era. The final solution to the synchronization problem came with the
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will occur and degrade performance. Telecommunication networks rely on the use of highly accurate
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They filter the synchronisation signal they receive to remove the higher frequency
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ITU-T Rec. G.811 (09/97) Timing characteristics of primary reference clock | ITU-T
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in practice. In common usage, mesochronous networks are often described as
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displacement, within a specified limited range. However, they may be
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which are distributed network-wide using synchronization links and
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Modern telecommunications networks use highly accurate primary
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Synchronization in communications was a hard problem for
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GR-253 - Synchronous
Optical Network (SONET) | Telcordia
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number of outputs to synchronise other local equipment.
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Synchronization of
Digital Telecommunications Networks
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241:European Telecommunications Standards Institute
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211:They provide distribution by providing a
77:Learn how and when to remove this message
89:Many services running on modern digital
40:This article includes a list of general
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233:International Telecommunication Union
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176:Primary reference clock (PRC)
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156:with a clunky but effective
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252:Maximum time interval error
196:Synchronization supply unit
190:GPS disciplined oscillators
91:telecommunications networks
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144:in the development of the
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331:"Distant Writing – Bain"
111:primary reference clocks
349:Thomas A. Edison Papers
61:more precise citations.
432:Federal Standard 1037C
426:public domain material
235:in its recommendation
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369:US Patent 1286351
300:Plesiochronous system
493:Network architecture
295:Mesochronous network
285:Synchronous network
192:are normally used.
99:telephone exchanges
18:Synchronous network
290:Isochronous signal
488:Data transmission
310:Phase-locked loop
165:phase-locked loop
93:require accurate
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126:mesochronous
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103:synchronized
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447:MIL-STD-188
206:phase noise
146:teleprinter
130:synchronous
59:introducing
477:Categories
355:2024-09-20
316:References
171:Components
42:references
458:. Wiley.
351:, Rutgers
107:bit slips
265:See also
213:scalable
101:are not
67:May 2012
136:History
105:, then
55:improve
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428:from
239:, by
237:G.811
122:phase
460:ISBN
271:PDH
188:or
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