Synchronous optical network (SONET) and synchronous digital hierarchy (SDH)
achieve synchronous data transmission over fiber optic networks. SONET is the US
version of the standard published by American National Standard Institute
(ANSI). SDH is the international version of the standard published by ITU.
The first-generation SONET/SDH equipment was added drop multiplexer (ADM)
which was based on the original set of standards. Next generation test equipment
was SONET/SDH switch, with the mechanism of mapping Ethernet on SONET. The third
generation test equipment uses tools like virtual concatenation (VCAT), generic
framing procedure (GFP), and Link capacity adjustment scheme (LCAS). Next
generation SONET/SDH devices are supporting resilient packet ring (RPR) for
scalability, bandwidth efficiency, and class of service support features.
SONET/SDH is preferred more than plesiochronous digital hierarchy (PDH)
because of its compatibility with standard equipment from different vendors.
When sophisticated services with high bandwidth are required, SONET/SDH finds
its importance. SONET/SDH capitalizes the voice transport ability with high
the constantly evolving standards interoperability poses a serious challenge as
compatibility between the equipment and network is required VCAT in next
generation products improves the Ethernet transport efficiency and LCAS can
change the transport bandwidth required. Scalability and interoperability are
the two major challenges to the next-generation SONET/SDH equipments.
The major factors determining market growth of the world SONET/SDH test
equipment market include:
- User demand for Ethernet-based services is the major driver for this
- High bandwidth requirement, along with the integrated product
functionality (generic framing procedures and virtual concatenation) drive
the world SONET/SDH test equipment market.
- Movement towards optical and data convergence is also driving demand for
SONET/SDH test equipment.
- End user spending condenses demand in the SONET/SDH test equipment market.
- There is a slow adoption rate of next generation SONET/SDH test equipment
as users are not willing to let go off their existing equipment and hence
are not upgrading.
- As there is not much technological development, sale in the new test
equipment market is retarded.
The Slow capital expenditure (CAPEX) situation is
dampening demand for SONET/SDH test equipment market.
The complexity of Next generation SONET/SDH test
equipment poses a serious challenge to test vendors.
End user requirements challenging vendors of SONET/SDH
test equipment in terms of product development. Quality of service is also
representing a significant challenge for vendors.
The SONET/SDH market experienced a downward spiral in the last few years.
However, the future looks positive. The price of this equipment is in parity
with asynchronous equipment and is expected to decline further. Next generation
SONET/SDH technologies are main driver for the growth of SONET/SDH test
Prathima Bommakanti, Research Analyst, Frost & Sullivan