sdh and sonet markets replace PDH technology
sdh and sonet markets replace PDH technology
Synchronous Digital Hierarchy (sdh) and its North American counterpart, Synchronous Optical Network (sonet), are edging out Plesiochronous Digital Hierarchy (pdh) as the dominant transmission technology worldwide, according to a study by Burlington, MA-based consultants Ovum Inc. The report, sdh: the Worldwide Market, says an increased demand for bandwidth in networks is driving the deployment of sdh technology.
With the sdh/sonet market growing, the report predicts that product prices will fall over the next five years due to the following trends:
new higher-speed products such as stm-
64/oc-192 (10-Gbit/sec) systems and wavelength-division multiplexing (wdm) equipment,
development of low-cost equipment for the
access network spurred by extending sdh/sonet services to end-users,
development of add/drop multiplexers, the
deployment of flexible ring architectures with fast traffic protection schemes, and use of digital crossconnects for fully meshed architectures in core networks,
development of standardized network
management interfaces for multivendor environments.
The combined market for sdh and sonet equipment in 1997 reached more than $6.7 billion, with the North American sonet market snagging $3.6 billion of the total, according to the report. Findings indicate that the largest market for sdh equipment in 1997 was western Europe, but sales of sdh equipment are growing fastest in the Asia-Pacific and central and eastern Europe. Revenues are expected to peak at $9.9 billion in 2001 but decline to $9.2 billion in 2003.
The report predicts the decline will result from a combination of price reductions, a decrease in network expansion in some developing regions, and the increased use of wdm. The report indicates the solutions will coexist in future networks rather than compete with sdh and sonet.
"It is also vital for vendors and operators to recognize that wdm will extend beyond long-distance, high-capacity links to the core," indicates the report. "wdm will lead to the creation of a new optical network layer, where individual wavelengths of light are routed through the network. Tomorrow`s transport networks will be a hybrid of sdh technology and optical networking using wdm."
The report recommends that sdh/sonet networks be flexible, since future networks will incorporate a variety of standards, protocols, and technologies. "There will be no single architectural solution for all applications; instead, a range of interfaces between IP [Internet protocol], atm [Asynchronous Transfer Mode], sdh, and optical network layers will coexist," it says.
Although there has been increased sdh/sonet deployment, the report lists a number of unresolved issues in the market, including interoperability among network management systems from different vendors, finding an efficient way to bring sdh to the end-user, and the fluid evolution of broadband transport networks.
For more information about the report, contact Ovum Inc. at 1 New England Executive Park, Burlington, MA, 01803, or call (781) 272-6414. u