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
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.
Digital Hierarchy Two or more signals not generated from the same timing reference but nominally at the same frequency.
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.