Based on Synchronous Digital Hierarchy ( SDH ) and Pleisochronous Digital Hierarchy ( PDH ) technology, the transmission infrastructure would also enable the company to enhance the quality of its voice, data and video transmissions.
22.
The Telephone Organization of Thailand _ TOT _ will first try to renegotiate the contracts with the six suppliers for the Synchronous Digital Hierarchy project, the agency's chairman, Mechai Viravaidya, was quoted as saying in reports Thursday.
23.
A few years before a new standard for optical transmission systems called Synchronous Digital Hierarchy ( SDH ) had been developed and ratified as a global standard as a replacement for existing Plesiochronous Digital Hierarchy ( PDH ) equipment.
24.
EoPDH is based on a collection of technologies and standards that allow telecommunications Carriers to make use of their extensive networks of legacy PDH and SONET / SDH ( Synchronous Digital Hierarchy ) equipment to provide new Ethernet services.
25.
Tejas optical netowrking products are based on Dense Wave Division Multiplexing ( DWDM ), Optical Transport Networks ( OTN ), Packet Transport Networks ( PTN ) and Synchronous Digital Hierarchy ( SDH ) or synchronous optical networking ( SONET ) Technology.
26.
Transport networks, the underlying optical fiber-based layer of telecommunications networks, have evolved from DCS ( Digital Cross-connect system )-based mesh architectures in the 1980s, to SONET / SDH ( Synchronous Optical Networking / Synchronous Digital Hierarchy ) ring architectures in the 1990s.
27.
The NDTN is the only major alternative telecommunications backbone in the Philippines, the other being operated by PLDT . The network also includes RCPI's existing Synchronous Digital Hierarchy ( SDH ) microwave network with spur links that also extends from Luzon to Mindanao.
28.
The article talks about optical fibre, the standards for transmission across optical fibre ( Synchronous Optical Networking and Synchronous Digital Hierarchy ), the various standards for digital broadcasts ( ATSC, DVB and ISDB ), the various protocols used in LANs and the Internet, etc.
29.
Backbone transport networks replaced PDH networks with synchronous digital hierarchy ( SDH ) or synchronous optical networking ( SONET ) equipment over the ten years ending around the turn of the millennium ( 2000 ), whose floating payloads relaxed the more stringent timing requirements of PDH network technology.
30.
These resources consisted of a 2, 200, 000 km long nationwide optical network, based on Asynchronous Transfer Mode ( ATM ), Synchronous Digital Hierarchy ( SDH ) and Dense Wavelength Division Multiplexing ( DWDM ) technologies and several submarine cables, in particular with the USA, Japan, Germany and Russia.
