Pure Optical Switching Value Proposition
Introduction
A recent Luxcore White Paper entitled "Evolution
to an All-Optical Wavelength Switch Architecture" identified key differences
between today's first generation architecture, and soon-to-be-released second
and third generation architectures.
In order to quantify some of these benefits we use the same application
example as a basis for comparison.
Application Example
The application we focus on is a single node in a nationwide DWDM network,
located at the junction of three fiber routes (east, west and north).
Each fiber route is equipped to support 80 wavelengths, and the add/drop
requirement is for 80 OC-192 interfaces.
A high level view of the first and third generation equipment required to
address the application example is shown in Figures 2 and 3.
Value Proposition
The value proposition presented in the document compares a current, first
generation OEO-based optical switch with third generation switches
incorporating Luxcore's lambdaxchange all-optical wavelength converter
system, in terms of initial capital costs and expenses over
5 years. Capital cost includes base equipment, installation, and miscellaneous
installation material (cables etc.). Expenses include power and facilities
(floor space, HVAC etc), but not operations and provisioning costs since
these vary significantly between operators.
Floor Space
The electronic switch matrix used in first generation systems does not scale
well. Even in situations with relatively
small wavelength counts, such as the application example used in this
paper, multiple interconnected cores are required to ensure a totally
non-blocking switch. Also, the large number of O-E-O conversions heavily
penalizes the first generation switch in terms of both size and cost. In
order to meet the requirements of the application example the first generation
switch requires 70 bays of equipment vs. 11 bays for third generation
switches incorporating Luxcore's lambdaxchange all-optical wavelength
converter subsystem.
Cabling
The switch matrix and the O-E-O transponders used in the first generation
architecture are typically separate products, even if provided by the
same vendor. As a result, four patch cords are required per wavelength
to interconnect the O-E-O converters with the switch. When applied to
the application example, 966 patch cords are needed for the first generation
switch vs. 6 for third generation solutions utilizing Luxcore's
lambdaxchange all-optical wavelength converter subsystem.
Spares
A set of spares is a must in case of card failure, and because of the
specialized lasers involved, DWDM interface cards are typically the most
expensive spares. The O-E-O transponders used with today's first the generation
switches use a different card for each wavelength, and hence 80 spare
interface cards are required at each switch location. A third generation
switch with Luxcore's lambdaxchange susbsystem uses the same tunable cards for all wavelengths, and hence only
one spare card is required.
Financial Benefits
Taking the three factors listed above into consideration the financial
benefits of third generation switches incorporating Luxcore's
lambdaxchange all-optical wavelength converter subsystem over today's first generation
switches are significant. Capital expenditure drops by as much as 50%,
while ongoing expenses drop by an even more impressive 84%. Taken together
over a 5-year period, the savings are approximately 52%, which can make
a significant difference to a carrier with limited budget in a highly
competitive marketplace.
Other Advantages
In addition to financial benefits, third generation, pure wavelength-routing photonic switches offer
service transparency. As a result, switches utilizing Luxcore's
all-optical wavelength converter subsystem can carry signals of any rate and format including SONET (OC-48, OC-192,
OC-768), Ethernet, ESCON/FICON, Fiber Channel, etc., with no hardware
changes. Existing services can be changed, and new services to be added
to meet end-user demand instantly via a provisioning terminal. The bottom
line is that service velocity can be accelerated from months to minutes,
yielding a significant improvement in customer satisfaction, revenues
and profits.
Value Proposition Assumptions
As with all financial studies, the value proposition presented in this
paper is based on a set of assumptions. To request more detail on these
assumptions, or a customized analysis based on your own network
requirements, please contact:
