In Search of a Cost-Effective Alternative to Optical Switching

Posted: 12/2003

Perspective:

In Search of a Cost-Effective Alternative to Optical Switching
By Lynne Craver

Industry conversations and trade

publications
are full of laments about the lack of realistic options for cost-efficient
optical switching, particularly in key metro markets. Interconnect costs,
combined with the high price of labor associated with the installation of patch
facilities and completion of the physical cross-connects of a new circuit, have
driven circuit prices to prohibitive levels.

Today, when a new SONET node is installed in a metro location,
the interconnect facilities patch panels and cables and associated
installation labor can add 40 percent to 70 percent to total cost. Moreover, each circuit provisioned through the node adds
another $150 to $300 in operational costs.

In an optimum scenario, physical interconnection of traffic
should occur only where traffic is added to, or dropped from, the service
providers network. In many instances, however, transit traffic on the service
providers network means manually patching facilities each time the traffic
crosses SONET rings. This requires additional capital and can increase
operational costs of the SONET ADM by as much as 50 percent.

From a capacity-planning viewpoint, all SONET ADM terminals at
a given location should, ideally, share one common, dedicated facility for
adding and dropping traffic. This would offer substantial operational and
capital cost savings. However, it would take so long to recover capital outlay
that theres little incentive for the upfront investment needed for
implementation.

IDC market analysis published in December 2002 showed carriers
spent an estimated $158 million in 2002 on metro Ethernet multiservice
provisioning platform (MSPP) equipment. About 66 percent of that figure went
toward the purchase of provisioning systems to perform automated switching.
Clearly, the industry is looking for ways to save money on switching.

Current optical switches cost four to six times more than an
ADM terminal, and the average cost to cross-connect a typical DS3 circuit is
about $400. To recover costs associated with switching, some RBOCs and carriers
with high volumes of circuits (1,000 or more) have installed optical switches at
the edges of their networks, providing reasonable payback on investment. This is
not a viable option, however, for smaller wholesale carriers looking to
integrate the optical switch into their core networks.

For wholesale carriers to recognize the benefits of optical
switching technology, manufacturers must find alternatives that require minimum
initial capital investment. This solution must be embraced in the development of
platforms to be integrated into the wholesale carriers core networks,
ensuring the solution is cost effective for these carriers. Most importantly,
the solution must mitigate operational costs by providing remote, automated
cross connecting of provisioned circuits at traffic locations where several
local SONET rings and long-haul networks interconnect, while reducing capital
costs by providing additional metro overbuild capacity.

The good news today is there is a way to achieve cost
efficiencies through an optical switching solution in metro markets. It is an
alternative that requires minimal initial capital investment. It also provides
additional metro overbuild capacity and reduces operational costs. Most
importantly, it provides remote, automated cross connecting of provisioned
circuits at traffic locations where several local SONET rings and long-haul
networks interconnect, improving services, speed to market and overall network
reliability.

The solution is an Optical Cross Connect (OCC) that
interconnects with the existing remote SONET ADM terminals in such a way that
the headend SONET ADM terminals can be removed after the new OCC solution is
installed. The OCC solution provides for remote provisioning across SONET rings
and acts as the single point for all traffic adds and drops at the installed
node for grooming of metro traffic.

The OCC interconnection is performed via fiber, significantly
reducing cabling requirements by decreasing the cost (and hassle) of maintaining
and scaling cable rack space, tie cables and interconnect facilities. Most importantly, it eliminates the high capital and
operational costs discussed above. Furthermore, the OCC solution terminates and
distributes optical circuits into DS3 increments for handoff to adjacent network
elements (ADMs), eliminating costly build-up of DSX-3 panels, tie cables and
repeaters used to move DS3 connections within the core switching facility. This
OCC solution is a simplified configuration that lowers space, power and
operations requirements for the existing site. Circuit routing via the OCC
solution provides for routine adds, drops and changes to circuits all
without manual intervention. This reduces the chance of circuit outages from
manual misconnections, thereby improving overall service reliability.

The OCC solution delivers the additional benefit of
speed-to-market. Once a circuit is designed and provisioned with an OCC
solution, the entire circuit is complete and ready for traffic activation
rendering intervention from the field unnecessary. The solution also provides
multivendor interoperability because it integrates with all types of legacy
SONET rings to provide seamless provisioning, processing and management
functions.

Short-term expansion of the network is another plus for an OCC
solution. For example: consider a network location where the metro traffic from
5 local SONET rings interconnects with the long-haul network. Implementing an OCC solution in this location would free up
the 5 local SONET terminals and patch facilities, reducing capital expenditures
by as much as $625,000. The OCC solution can be integrated into this scenario
for less than 50 percent of the capital investment required to provide 5
additional SONET ADM terminals and patch facilities.

In summary, OCC solutions must position wholesale carriers to
beat significantly the cost of conventional optical switching solutions,
automate the network, introduce new services, provide speed-to-market and
deliver short-term network extension all at the same time. Whats not to
like about such an alternative?

Lynne Craver is vice president of network engineering and
operations for Progress Telecom. The carriers carrier is evaluating the OCC
solution for integration into its network architecture.