"Fixed Wireless"
Broadband Service is often called “Last
Mile” service. It was originally
created to provide digital connections
in situations where digging or hanging
wire was terribly inconvenient or very
costly. Such situations include bridging
signals from one office building to
another in the heart of a city or providing
high-speed digital service to remote
locations not served by cable or telephone
DSL.
Fixed wireless should
not be confused with cellular telephone
service, however the two have some things
in common.
“Last Mile”
service is being used to monitor watersheds,
remote seismograph sensors, provide
high-speed Internet access to entire
communities, and to provide competitive
low-cost high-speed Internet service
to homes and businesses. Aggressive
providers are competing successfully
with the often slower wired services.
Here's how fixed wireless
broadband Internet service works:
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Your Wireless Internet Service
Provider (WISP) has a server farm
or gateway attached to an Internet
carrier. To serve you, the WISP
hooks his server farm or gateway
(A) to high-speed leased lines
or fiber. Somewhere near the target
service area the WISP links his
Access Point (C) radio equipment
to the other end of the transport.
If necessary, the WISP will broadcast
(backhaul) the signal on a “point
to point” tight beam to the
access point (B to C) perhaps
using more than one set of repeater
stations.
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A separate radio (or radios)
at the access point broadcasts a wide-angle
signal which can be picked up by the
customer subscriber units also called
"customer premise equipment"
(think of it as a "wireless modem")
(D). The wireless modem converts the
radio signal to an Ethernet signal which
can be understood by your computer or
network switch. This link(C to D) is
called a “point to multi-point”
system.
When you send something
to the Internet, the process is reversed
(your computer, to the wireless modem,
to the access point, to the WISP gateway,
and finally to the Internet).
It's Fast
Dial-up
at 56Kbps DSL
at 256 Kbps
Broadband at 1.5Mbps
It's Reliable
We can view the entire
process as a chain. Like any chain,
it becomes worthless if one link breaks.
The radios and the gateway require electricity,
if power is interrupted to a radio tower,
the radio won't work. If a tree drops
over a telephone line, that connection
will be broken. If any piece of equipment
fails, the signal will be interrupted
at that point.
Good WISPs are keenly
aware of these problems. They provide
uninterruptable power systems (UPS),
and often generators, for each radio
and computer in their systems. These
devices will power the equipment for
several hours to several weeks depending
upon the size of the UPS. Some radios
are located where no normal power is
available. Those installations gather
solar power (even on cloudy days) during
the day to run the radio and charge
a UPS to run the station at night. Obviously,
an interruption of power is less likely
for those radios (unless someone turns
the sun off). A good WISP also stocks
replacement parts locally for rapid
repairs should a component fail. A smart
WISP also provides more than one route
for his "backhaul" to the
Access Point so should one route fail,
the signal will still get through and
your service will continue without interruption.
Since “last mile”
telephone lines are not involved, such
systems are actually more reliable (similar
to a stationary cellular phone) than
data service that is provided by overhead
wires.
By now, it should have
occurred to you that the real weak spot
is at the client location. The wireless
modem won't work during a power outage
any better than your computer. If you
wish to continue using the service during
a power blackout (or brownout), both
your computer and the wireless modem
should be equipped with an uninterruptable
power supply (UPS). An additional benefit
is that electronic equipment lasts longer
when connected to a good UPS because
it doesn't suffer from power spikes
or brownouts.
If you have converted
your telephone service to VoIP,
your wireless modem should definitely
be equipped with a UPS unless you are
comfortable with a cellular phone for
backup.
It Has a Wide Range
If you have a direct line
of sight to the access point, you might
receive service quite a distance from
it. Some systems will work up to 30
miles and beyond with special antennas
and equipment.
If there are obstructions
in the way, such as trees, you will
need to be much closer. Buildings and
hills provide the most challenging obstruction
to overcome. When in doubt, ask the
WISP to do a site survey of your property
to see if you can receive an adequate
signal. Some WISPs charge for this service.
If you already have equipment that is
compatible with the Access Point, you
can simply try it out to see if you
can receive their signal.
Some WISP's actually use
powerful WiFi (802.11) equipment, the
same signal that you'll find in many
coffee shop and airport hotspots. However,
local interference from in-home wireless
networks, wireless telephone handsets,
the coffee shop next door, and other
gear that use the same frequency (2.4
GHz band) may create interference problems
that can seriously impact WiFi service.
The ability to punch through
trees and bushes is related to the radio
frequency used. Lower frequencies will
penetrate shrubbery and bounce off buildings
more readily than higher frequencies,
while the higher frequencies have a
shorter range at the same power output,
but will carry more data.
A Subscriber Unit must
match the Access Point
There are several equipment
manufacturers making equipment that
broadcast on different frequencies.
Even on the same frequency, the internal
firmware may differ from one brand to
the next. Within the same line of equipment,
the WISP has to “allow” your
particular wireless modem into the system
by programming its internal hardware
identification number into the Access
Point or by using some other arrangement.
You can purchase a wireless
modem from the WISP or possibly from
a 3rd Party
That would be up to the
WISP. In any case, if you purchase a
wireless modem from a 3rd party, there
is no guarantee that it will work with
the Wisp's system -- and you'll probably
have to install and align it yourself.
Even equipment from the same manufacturer
may vary. For instance, Motorola®
sells equipment under their Canopy®
label that may run on one of five different
radio frequency bands. Also, a WISP
may use different equipment in different
areas based upon population densities,
foliage, local interference, and other
considerations.
If you intend to purchase
your own wireless modem, check closely
with the WISP to make sure the equipment
you intend to purchase will work with
their Access Point in your area.
Also make sure you absolutely know how
to aim it properly. If you don't, you
may still get service, but your mis-aligned
antenna will cause many "retries"
which would overload the Access Point,
degrade everyone's service, and your
WISP will not speak kindly to you.
You can do Several Things
with the Service once it's in your Building
or Home
Anything you can do with
any other broadband service.
