Stored program control: Difference between revisions

Revision as of 22:42, 26 December 2017

Revision as of 16:48, 30 December 2017

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=== Distributed control ===

Distributed SPC is both more available and more reliable than centralized SPC. The control function are shared by many processors within the exchange. It uses low cost [[microprocessor]]<nowiki/>s. Exchange control may decomposed either horizontally or vertically for distributed processing.<ref>[{{Cite book|url=https://bookswww.googleworldcat.comorg/books?idoclc/29022605|title=ghCiNHzWvL4C&pg=PA96&dqTelecommunication switching systems and networks|last=4Thiagarajan.3+Distributed+SPC&hl|first=en&saViswanathan,|date=X&ei1992|publisher=ToAhT6fJAsHL0QHhr4zVCA&vedPrentice Hall of India Private Ltd|isbn=0CDIQ6AEwAA#v0876927134|___location=onepage&q=4.3%20Distributed%20SPC&f=false]New T WiswanathanDelhi|oclc=29022605}}</ref>

* In vertical decomposition the whole exchange is divided into several blocks and a processor is assigned to each block. This processor performs all tasks related to that specific block. Therefore, the total control system consists of several control units coupled together. For redundancy, processors may be duplicated in each block.

* In horizontal Decomposition each processor performs only one or only some exchange functions.