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HOME REVIEWS CONTACT ABOUT January 14, 2010
Communication
Requirements for Small Business and Residential Applications
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Before
the Internet revolution, small business and residential applications had only
two wiring systems, the electrical service and the phone service. Phone lines were
the only means available for computer networking and were used for data
transmission. The original networks that were created for computers to share
data simply piggybacked over existing connections and technology. Today, more options are available to meet
networking needs of consumers. The first rule of communications: whatever you
can imagine for the future, and multiply by 100. Who among us in 1990 foresaw the coming
impact of the Internet, or the requirements that HDTV would place on our
communications infrastructure. And given
that technology growth has proven to be exponential, multiply that experience
by 10 for the next 20 years.
When
dealing with the design and construction of a new facility, it is important to
identify needs early in the process. When renovating an existing facility, many
of the same considerations should be addressed, and the task is often more
challenging.
Structured Wire
Structured
wire is a technology of electrical interconnect, and is
rapidly becoming standard in many parts of the
The
Structured Wiring Service Panels for a structured wire installation is a
central panel where services (cable TV, telephone, satellite, internet, etc.)
enter the house. A minimum requirement for each panel is a telephone-connecting
block for terminating the twisted pair, and a passive cable splitter for the
coax. Room should be left in the panel for upgrades.
Although
individual Ethernet and video cables can be used, specifically designed
multimedia cables are becoming standard. A dual cable, for example, consists of
one Ethernet and one video interconnect under a single jacket. Another
composite construction could include 2 Ethernet cables for voice and data and 2
video cables. These multimedia cables speed the installation time because
multiple cables can be pulled at the same time, and it minimizes termination
times since all ends are identifiable.
Ideally,
the wired network has a "home run" configuration: a separate
interconnect for cable TV, phone, and Internet data transmission is made from
the Structured Wiring Service Panel to every point of use.
A good
idea is to include an equipment rack adjacent to the Structured Wiring Service
Panel. Equipment such as a router is
logically located near the service panel.
Structured
Wiring panels are used to provide the miles of cable interconnects required to
distribute Audio, television, security camera video, telephone, and digital
communication applications, and now combines it with multimedia facilities. Structured wiring works well with a wireless
network because administrators can connect wireless access points throughout
the house through an Ethernet connection.
Computer Networks
The
right technology choice is driven by what kind of property is being
serviced. In a good communications
interconnect plan, all interconnects are run to a central location. It may be
OK to run a phone line in series (room to room), but it is not OK for Internet
network cables.
Ø
Technology
changes fast. It was only twenty-five
years ago that Steven Jobs said that no computer would ever need more than 64K
of memory. It is important to future-proof your plans. Fiber-optic solutions seem to be an
unnecessary luxury today, especially with the performance available with high
speed Ethernet. However, the majority of
technology solutions for residential and small business applications are
currently based on Ethernet.
Wireless
networking (WiFi) is another technology that is rapidly impacting computer
networking. Market research firm IDC projects
that the total number of enterprise WiFi access points installed will grow from
1.6 million units in 2006 to 11.5 million units by 2010. Up to 20 users can
connect to a single WLAN access point and receive adequate service. IDC also predicts that Ethernet switch ports,
those predominantly deployed in enterprises, will grow from 172 million units
to 208 million units in the same period.
Ethernet Basics:
Ethernet
is the dominant standard for hardwire data networking. Ethernet hardware is
usually standard in all new computers. If the method for high-speed data (cable
modem, DSL, etc.) is hardwire, then the interface to the computer will usually
be an Ethernet port.
Ethernet
interconnections should not exceed 100 meters, and separate cables are needed
for data and phone. It is possible to run Ethernet in the same jacket as phone,
but it can be unreliable, and is definitely not advisable for High Speed
Ethernet (> 100 Mbps). Use a separate cable, the "home-run"
design, where possible from the network switch to each point of use.
With new
construction, it is also advisable to interconnect buildings with conduit.
Install it in the ground while it's still cheap to do so, and, keep the
ownership rights. This will future-proof the property
for later upgrades.
Retrofit Strategies
for Computer Networks
There
are two common methods for retrofitting buildings: Wireless and Ethernet. Wireless has the apparent advantage a less
expensive and easier to implement infrastructure, especially for retrofits. However, this is not always the case. Today, the answer is probably a combination
of both systems. At points of use that
are obvious and static, for example the home office, an Ethernet connection is
appropriate. Overlaying this system with
a wireless (WiFi) network provides improved flexibility.
Wireless:
Wireless
networks (802.11) can be a good choice for communication retrofits for small
projects. WiFi operates on radio frequencies (RF) and was developed for
wireless digital communication between personal computers and consumer
electronic devices. Most new computers
include built-in WiFi support. Wireless
Ethernet has applications including large buildings. Wireless access within
common areas of a property, such as a pool area, can be an elegant solution.
Wireless also is an excellent choice where it is difficult to run additional
wire.
Hardwire:
In some
situations, rewiring can make more sense. For larger projects, a hard wire
approach is more reliable, and in the end, cheaper. Wireless looks good "on paper", but
in a large building, universal connectivity is difficult. The average cost to rewire with Ethernet
cable is about $300 per point of use in large buildings. Having infrastructure
in place for future expansion may justify the expense of rewiring.
Environmental
issues must be considered when rewiring. Issues such as asbestos and lead-paint
abatement are examples. There are those applications where rewiring is not an
option because of construction constraints, unless exterior conduit is used,
and esthetics often preclude this option.
Once the
wiring is installed, implementing the network is straightforward using standard
Ethernet hub or switch equipment.
Remember that there is a 100-meter distance limitation with Ethernet. In
large projects, locating Ethernet switches in each building or on each floor of
a high rise resolves the issue.
Fiber Optic vs. Ethernet
Fiber is
probably not the solution to deploy today given Ethernet's ability to handle
high-speed communication over the short distances typical of large
buildings. But remember Steven Jobs (see
above): it is difficult to anticipate the future. Fiber optic cables are used instead of
traditional copper cables because this technique offers more capacity and is
less susceptible to electrical interference. Fiber optic is becoming more
common as a way to provide very high speed Internet service (100 Mbps and
higher).
Uncompressed HDTV
This is
an interesting problem. If one want to
distribute uncompressed video, say from the output of a satellite or cable
receiver, then the bandwidth requirements are significant. The alternative would be to distribute the
compressed signal, and install a receiver (with decompressions) at each point
of use. The simple answer is to not decompress
until point of use. The alternative is
to distribute uncompressed HDTV video, which is an intense signal (the last
option, to recompress the signal, is a challenge which we won't tackle today). If you are in the first camp, read on,
otherwise you can skip forward to the next section.
Today's
video installations grow ever more complex, with
source components positioned a good distance away from the display. The
distance is the biggest factor in determining which technology to use. There are two choices, Copper or Fiber Optic.
An
uncompressed digital video signal is a challenge. HDMI and DVI is the best
choice for transporting uncompressed digital HDTV. Cable lengths in excess of 75 feet can cause
problems,
The bandwidth of Ethernet is less than 0.6
Gbps, and this is much lower than uncompressed video data (1.65 Gbps), it is
easy to understand why fiber optic is better when it comes to high bandwidth
digital signal transfer for long cable runs.
Typically, 1080p signal would mean 1920 x 1080 pixels at 60 Hz.
Interconnect
reliability over time should also be considered. The optical conversion
electronics should last at least 80,000 hrs of continuous operation. Fiber
optic cables are also immune to electrical interference such as RFI. With Fiber Optic Conversion technology, there
is zero impedance (zero loss during transmission).
High
quality interconnect is an investment. As digital video technology improves,
you may be upgrading your DVD player or TV and it is important to make sure your interconnects do not become obsolete. Utilize a
technology good to at least 1080p at 60 Frames/Second. Fiber Optics may be more
expensive, but the price differential may be worth consideration for
future-proofing your system now.
Summary
The goal
is to deliver a cost-effective, future-proof deployment. Inexpensive computing, the Internet, and
digital communications are transforming the global economy. Twenty years of stunningly rapid advances in
technology have brought computing into businesses and homes in ways that were
recently barely imagined.