plesiochronous


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plesiochronous

(communications)
Nearly synchronised, a term describing a communication system where transmitted signals have the same nominal digital rate but are synchronised on different clocks.

According to ITU-T standards, corresponding signals are plesiochronous if their significant instants occur at nominally the same rate, with any variation in rate being constrained within specified limits.

plesiochronous

A transmission where the sending and receiving devices are synchronized but set to different clocks. Although the bits may not arrive in the same time slot as they were sent, as long as they arrive within a certain, defined range, the transmission is said to be plesiochronous (almost synchronous).
References in periodicals archive ?
This contract is a service contract for all services and supplies, including travel expenses for maintaining the PDH-type digital data network (Plesiochronous digital hierarchy) in good working order.
According to ITU standards for telecommunications (ITUT), two signals are plesiochronous if they have the same nominal rate, with any variation in rate being constrained within specified limits.
Historically, this problem has been addressed in a brute-force manner by deploying multiple types of elements including multi-service provisioning platforms (MSPP), Ethernet over Plesiochronous Digital Hierarchy (EoPDH) termination boxes, Ethernet switches and DCS platforms.
The company said that the new capabilities enable the product to address the growing market for delivering IP and Ethernet services over copper PDH (Plesiochronous Digital Hierarchy -- DS1, DS3, E1 and E3) access networks.
Over the years there has been an evolution in the backbone networks from analogue to digital transmission, from Plesiochronous Digital Hierarchy (PDH) to Synchronous Digital Hierarchy (SDH) and recently from SDH to SDH upon Wavelength Division Multiplexing (WDM).
* Transmitter features differential CML outputs with no rise time control, fully programmable 4-tap transmitter pre-emphasis, adjustable output drive levels to minimize power and crosstalk and configurable Tx CDR to allow tracking of plesiochronous data sources
For the project, Alcatel will provide its synchronous digital hierarchy (SDH) data-aware Optical Multi-Service Node (OMSN) systems equipped with Integrated Service Adaptors (ISA), as well as low-to-medium urban microwave radio equipment based on Plesiochronous Digital Hierarchy, (PDH) technology.
The Swedish radio-based infrastructure solutions supplier Allgon AB said today (27 March) that it had signed a supply agreement for Plesiochronous Digital Hierarchy (PDH) Microwave equipment with Marconi Communications GmbH.
PDH Plesiochronous Digital Hierarchy Two or more signals not generated from the same timing reference but nominally at the same frequency.
Tenders are invited for iarnrd ireann currently operates a legacy transmission network using now obsolete ericsson synchronous digital hierarchy (sdh) technology and nokia plesiochronous digital hierarchy (pdh) technology.
It will also provide radio delay technology for wide area transport, based on the Synchronous Digital Hierarchy (SDH) and Plesiochronous Digital Hierarchy (PDH) standards.
The Norwegian communication equipment supplier Nera ASA has signed an agreement to license PDH (Plesiochronous Digital Hierarchy) radio transmission technology from Finland's Nokia.