Bringing Fiber To The Desk

Fiber has already found a firm foothold in the private network backbone and its popularity will grow as more users get connected to networks. Solution providers, especially those in the cabling domain, now need to further position fiber to address the requirements of next-generation high-speed LANs.

In LAN protocols, as Ethernet evolved to higher-speed forms, it addressed the
needs of end-users with a cost-effective reliable solution to their data
networking needs. With the demand for bandwidth increasing, the next step in the
evolution is 10 Gigabit Ethernet, which in turn is moving to fiber-based
networks in the LAN, MAN and WAN.

In the 10 Gbps standard, four optical transceivers were selected: 1310 nm
serial for single-mode fiber, 1550 nm serial for single-mode fiber, 850 nm
serial for laser optimized multimode fiber (referred to as OM3 fiber in
international standards), 1310 nm wide wavelength division multiplexing (WWDM)
for installed multimode fiber and single-mode fiber. More recently, attentions
have turned to 10 Gbps over UTP, a development that clearly has implications for
fiber in the horizontal segment of the infrastructure.

The choice of which fiber optic cabling to install to cost-effectively
support the aforementioned options becomes quite simple:

1) For the lowest cost, fully back wards compatible LAN implementation for
distances up to 300 metres, the OM3 multimode solution is the optimum choice.

2) For LAN, MAN, and WAN implementations with extended distances (any
distance over 300 meters), the single-mode solution is the optimum choice.
Within the MAN and the LAN, the trend is towards single-mode fiber such as new
Low Water Peak (LWP) fiber.

3) The use of the small form factor LC connector gives the lowest loss,
highest density solution.

FUTURE-PROOFING THE BACKBONE

In the campus and riser backbone segment of the private network market,
multimode fiber has clearly long surpassed UTP as the preferred media for LAN
backbones in new installations. With laser optimized OM3 multimode fiber, the
current generation of 100 Mbps backbone technologies can be upgraded to at least
10 Gbps at 300m.

The building backbone network presents the greatest opportunity for fiber in
the private network, and should be the immediate focal point for users.

Enhanced OM3 multimode fiber advantages, such as higher bandwidth capability,
lower loss, faster termination times, and greater density need to be coupled
with apparatus advantages such as those offered by the LC connector system. With
added bandwidth capability being placed in the LAN horizontal, the case for OM3
multimode fiber in the riser makes for an easy choice.

MAKING THE RIGHT CHOICE

UTP is unquestionably the right choice today for traditional voice and data
services in the horizontal. It is the future where the debate lies. High
performance category 5e and 6 UTP provide the lowest initial cost for today’s
Local Area Networks (LANs) up to rates of 1 Gbps. However with the introduction
of Category 6 UTP systems, the capabilities of UTP cabling have increased,
pushing out the move to fiber to the desk (FTTD).

There are two main reasons for the broad acceptance and rapid growth of UTP
as the horizontal media: low initial cost and the ability to deliver higher data
rate LAN services. As speeds increase, copper-based LANs do require more complex
and expensive electronics. This trend, combined with decrease in fiber media and
opto-electronics prices, gives hope to FTTD that the initial price of the two
solutions will converge as data rates increase.

The main potential for use of multimode fiber as a horizontal media is the
need for even higher-bandwidth services and the desire to ‘never’ need to
install cabling again over the life of the building. Fiber’s longer distance
capability also permits cabling architectures that reduce recurring network
operational costs.

Fiber allows a centralized cabling design with a single point of
administration. By collecting all hubs, switches, and routers into one location,
the network requires less active equipment, maintenance and administration
effort.

When making the choice of horizontal media, important issues include: present
and future data speed requirements, upgrade migration strategy, work-group
rearrangement frequency, building ownership and tenancy, remaining building
occupancy, work area environment, horizontal distances, suitability of
telecommunications closets, and long-term and short-term cost sensitivity.

FIBER: HOW CLOSE TO REALITY

As a ubiquitous horizontal media selection for the general business
customer, fiber is still some time away. The fact is that the majority of the
worldwide LAN community is still operating on 10/100 Mbps networks, and the
combined popularity of inexpensive 100BASE-T LAN switching and 1000BASE-T prices
falling rapidly promises to extend the life of UTP in the LAN horizontal for
many years to come.

A pure bandwidth argument for multimode fiber in the horizontal is a very
difficult sell given current bandwidth utilization trends and the significant
price premium for a fiber solution. But while this doesn’t mean that multimode
fiber has no application to the LAN horizontal, it does mean that in the short
term its usage will be limited to specific vertical market implementations with
unique requirements such as very high bandwidth imaging/visualization/simulation
applications, extended distances, secure communications or operation in high
noise environments.

Contrary to the technology-centric view being espoused by some companies in
the industry today, which might lead one to believe that the demand for fiber to
the desktop are just around the corner, the information presented here paints a
much more

realistic view of end-user application demand driving an eventual but gradual
shift from the status quo.

The demand for high performance UTP in the horizontal segment of the private
network will remain strong for at least the next several years, fueled by the
increased popularity of 100 Mbps Ethernet and 1 Gbps Ethernet switching
solutions for workgroup connectivity, while fiber growth will continue to be
strong in the building riser and campus backbone segments.

Prasanna Kumar is Sales Director, Systimax Solutions-India and SAARC, and can
be reached at prasanna@systimax.com