Here are some interesting statistics based on a research report
issued by the Cahners In-Stat group in 2001:
More than half of the workforce in the U.S. performs their jobs
remotely, either occasionally or on a full-time basis.
By 2005, the number of remote workers will increase to 60
There are about 3 million remote offices currently. That number is
expected to grow to 5 million by 2005.
ISPs currently deliver services to more than 21 million
telecommuters. By 2005, 35 million remote workers will require Internet
access to connect with employers.
U.S. businesses currently spend about $160 billion on communications
services, which is expected to rise to nearly $260 billion by 2006.
While most of the aforementioned Internet access is expected to
continue through the use of dial-in connections, the availability of
broadband high-speed services, such as DSL and cable, is growing at a
rapid rate and currently serves about 20 percent of the total Internet
subscribers in the U.S.
Wiring these remote offices can be a simple task using off-the-shelf
products; however, when a business permits workers to perform duties at
a remote location, particularly their homes, it assumes a certain level
of liability for the physical facility that houses the equipment,
workers and others using the equipment at the remote location.
Table 1. Typical ratings and designations for low
voltage cabling. Data courtesy of Berk-Tek.
Providing technical support to remote users is more difficult than
simply going down the hall to troubleshoot a problem, sometimes
requiring additional time on the telephone and possibly visits to the
In most cases, cabling a PC to a local LAN or high-speed network
gateway will be done using standard Ethernet cabling. I have dealt with
many of the electrical performance issues related to Ethernet cabling
in this column; however, like all things electronic, performance
increases and new emerging technologies begin to appear, so let's take
a quick look at the current state of transport methods.
Fundamentally, there are three transmission mediums that can be used
for data transmission: electrical, optical and air. Each of these
methods requires a specific component, which carries the signal from
point A to point B.
An electrical connection is the most familiar and popular
transmission method. In the case of network cabling, we are usually
referring to standard unshielded twisted pair (UTP) cable. Shielded
twisted pair (STP) cable is similar to UTP, with the exception that the
conductors are also surrounded by a braided shield. STP cable is used
in areas where external sources of interference, such as high RF or
electrical fields, might couple to the inner pairs and degrade
Current versions of the Ethernet protocol over UTP supports data
throughput of about 1Gb/s, and that is expected to increase to 10Gb/s
in the next two years.
In the context of data communications, optical transmission medium
generally refers to fiber optic cabling, where data is transmitted
through thin strands of plastic or glass fiber material called the
core, which is surrounded by a highly reflective material called the
cladding. This assembly is covered with a protective outer jacket. The
signals sent through fiber cabling originate from a laser light source,
which operates at a specific wavelength.
An interesting fact is that fiber optic cabling has been around
about twice as long as the standard UTP typically associated with the
interconnection of devices on a LAN.
Data transport through the air is possible using one of the many RF
wireless options available for a variety of PC-to-LAN and LAN-to-LAN
interconnections. The adoption of the 802.11x wireless Ethernet
standard, along with the availability of spectrum specifically
allocated for unlicensed RF applications, has created one of the
fastest growing segments of the PC LAN market. The price point for
consumer- and commercial-grade wireless devices is dropping to a point
near that of similar wired equipment. Wireless LANs still lack the data
throughput capabilities of their wired counterpart, typically limited
to about 2Mb/s; however, emerging standards, improvements in technology
and the allocation of new spectrum will ultimately make this the
transport method of choice for most LAN designs. At least one
manufacturer produces a line of point-to-point microwave radios that
permits Ethernet throughput in excess of 100Mb/s.
A relatively new technology that uses high-powered, laser-based
wireless radios is beginning widespread acceptance. These systems
provide bandwidth nearly to that of fiber optic cabling and are limited
only by the requirement that the radios have clear line-of-sight to
Some cable-rating issues
In the U.S., the current National Electric Code (NEC) suggests that
the installation of any permanent cable within commercial and
residential buildings, including those that carry low voltage, have
markings indicating the fire rating of the cable jacket. The NEC
provides guidance in the installation of electrical systems based on
its own testing, and it is generally the reference used by most
electrical code officials.
There are various materials used in the manufacture of metallic and
fiber-based cabling. In the case of a building fire, most of those
materials were capable of supporting and carrying flames across several
rooms or, in many cases, vertically through other floors.
The jackets of cables are manufactured with different materials
based on the type of location (wall, inside conduit), orientation of
run (vertical or horizontal) and where it will be installed. Table 1
describes some typical ratings and designations for low-voltage
Even flame-retardant cabling is capable of supporting a flame under
the right conditions. To prevent those flames from moving into other
rooms or floors, it is important, and required by code, to apply proper
fire-stopping materials to walls and floors that have been penetrated
McNamara, BE Radio's consultant on computer technology, is
president of Applied Wireless Inc., New Market, MD.
All of the Networks articles have been approved by the SBE
Certification Committee as suitable study material that may assist your
preparation for the SBE Certified Broadcast Networking Technologist
exam. Contact the SBE at (317) 846-9000 or go to www.sbe.org for more
information on SBE Certification.