Copyright © Philip M. Parker, INSEAD. Terms of Use.

SYNCHRONOUS DIGITAL HIERARCHY

Specialty Definition: SYNCHRONOUS DIGITAL HIERARCHY

Domain	Definition
Computing	Synchronous Digital Hierarchy (SDH) An international digital telecommunications network hierarchy which standardises transmission around the bit rate of 51.84 megabits per second, which is also called STS-1. Multiples of this bit rate comprise higher bit rate streams. Thus STS-3 is 3 times STS-1, STS-12 is 12 times STS-1, and so on. STS-3 is the lowest bit rate expected to carry ATM traffic, and is also referred to as STM-1 (Synchronous Transport Module-Level 1). The SDH specifies how payload data is framed and transported synchronously across optical fibre transmission links without requiring all the links and nodes to have the same synchronized clock for data transmission and recovery (i.e. both the clock frequency and phase are allowed to have variations, or be plesiochronous). SDH offers several advantages over the current multiplexing technology, which is known as Plesiochronous Digital Hierarchy. Where PDH lacks built-in facilities for automatic management and routing, and locks users into proprietary methods, SDH can improve network reliability and performance, offers much greater flexibility and lower operating and maintenance costs, and provides for a faster provision of new services. Under SDH, incoming traffic is synchronized and enhanced with network management bits before being multiplexed into the STM-1 fixed rate frame. The fundamental clock frequency around which the SDH or SONET framing is done is 8 KHz or 125 microseconds. SONET (Synchronous Optical Network) is the American version of SDH. (1995-03-02). Source: The Free On-line Dictionary of Computing.
Post & Telecom	Hierarchy of rates for transmission and multiplexing which offer simplified multiplexing/demultiplexing techniques and easy growth to higher rates in step with the existing multiplexing hierarchies in Europe, North America and Japan. Source: European Union. (references)
Source: compiled by the editor from various references; see credits.

Crosswords: SYNCHRONOUS DIGITAL HIERARCHY

Specialty definitions using "SYNCHRONOUS DIGITAL HIERARCHY": SDH. (references)

Commercial Usage: SYNCHRONOUS DIGITAL HIERARCHY

Domain	Title
Books	Synchronous Digital Hierarchy [DOWNLOAD: ADOBE READER] (reference) (more book examples)
Source: compiled by the editor from various references; see credits.

Non-Fiction Usage: SYNCHRONOUS DIGITAL HIERARCHY

Subject	Topic	Quote
Economic History	Ireland	Synchronous Digital Hierarchy (SDH) technology is increasingly being used in the Irish backbone network infrastructure as it is well-suited to the administration of higher transmission rates and provision of broadband services. (references)
Source: compiled by the editor from ICON Group International, Inc.; see credits.

Expression: SYNCHRONOUS DIGITAL HIERARCHY

Expression using "SYNCHRONOUS DIGITAL HIERARCHY": synchronous digital hierarchy equipment clock. Additional references.
Source: compiled by the editor from various references; see credits.

Frequency of Internet Keywords: SYNCHRONOUS DIGITAL HIERARCHY

The following statistics estimate the number of searches per day across the major English-language search engines as identified by various trade publications. Hyperlinks lead to commercial use of the expression at Amazon.com.

Expression	Frequency per Day
synchronous digital hierarchy	6
Source: compiled by the editor from various references; see credits.

Modern Translation: SYNCHRONOUS DIGITAL HIERARCHY

Language		Translations for "SYNCHRONOUS DIGITAL HIERARCHY"; alternative meanings/domain in parentheses.
Chinese		同步數位階層 (SDH). (various references)

Finnish		synkroninen digitaalinen hierarkia. (various references)

French		SDH, HNS, hierarchie numérique synchrone, hiérarchie numérique synchrone. (various references)

German		Synchrone Digitale Hierarchie, SDH (sorbitol dehydrogenase). (various references)

Pig Latin		ynchronoussay igitalday ierarchyhay

Spanish		reloj de equipo SDH (SDH equipment clock, synchronous digital hierarchy equipment clock). (various references)

Swedish		synkron digital hierarki, SDH. (various references)
Source: compiled by the editor from various translation references.

INDEX

1. Crosswords
2. Usage: Commercial
3. Quotations: Non-fiction
4. Expressions

5. Expressions: Internet
6. Translations: Modern
7. Bibliography

Copyright © Philip M. Parker, INSEAD. Terms of Use.