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Rapid Wifi signal coverage |
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Close approximation coverage maps for our Access Points (antennas). Keep in mind Wireless Internet service is based on Line of Sight (LOS), so the actual service areas may be slightly different than shown due to the nature of hills, tall trees, and buildings. |
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RaPID WIFI'S WIRELESS FREQUENTLY ASKED QUESTIONS |
INTRODUCTION TO WIRELESS INTERNET
• What
is Wireless Internet Access?
• Why
the 2.4 Ghz Frequency range?
• Who
designed this wireless gear?
• What
is the 802.11 standard?
• What
about all MMDS/LMDS?
• What
about wireless data using cell phones?
• Will
this work with the Palm units?
• How
does this access method compare to Cable?
• How
does this method compare to DSL?
• I
live in a valley. Is there any hope for me?
• Why
aren't the HUGE corporations using this?
THE HARDWARE
• What
are the radios and who makes them?
• How
do I connect to the radio?
• How
do I control the radio?
• Will
radios from different manufacturers work with each other?
• What
are the antennas like and who makes them?
• What
is the power output?
• What
is the power consumption?
• What
are the environmental concerns for using wireless?
• Can
higher gain antennas be used?
• How
many radios can co-exist in one area?
THE SIGNAL
• What
is the current coverage range?
• What
is the power level of 2.4 Ghz?
• What
is FHSS & DSSS?
• What
can I expect for sources of interference?
• Will
this signal interfere with any/one/thing else?
• What
is "clear line of sight"?
• Do
I have to have "line of sight"?
• What
is the fresnel zone?
• Can
this zone be partially blocked?
• What
is the range of the signal?
• Can
the signal be boosted?
• How
secure is the signal?
• I
live in a heavily populated area, how will this affect the signal?
MISCELLANEOUS
• How
does a user interface with Wireless?
• Will
any Ethernet card do?
• Can
I plug in a hub instead of a computer?
• How
may computers can I connect to a wireless radio?
• How
fast will it go?
• Can
I buy a slower/faster connection?
• Can
I buy a guaranteed throughput?
• What
will I need for hardware for a wireless Internet connection?
• How
can I tell if wireless will work for me?
• How
much does the hardware cost?
• Is
wireless as reliable as DSL?
• What
about lightning?
• And
lightning protection?
• Will
it interfere with pacemakers?
• What
Operating Systems is this compatible with?
• Will
I still need my modem?
• Will
I need to keep my second phone line?
• Is
there a limit on the amount of traffic I can send/receive?
• Can
I run servers on this connection?
• How
big are the antenna units?
• Can
I put my antenna in my attic?
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What
is Wireless Internet Access?
Broadband is a term that has suddenly
become the techno buzzword of 1999. It seems as though everyone
has a broadband scheme going. There is high speed access being offered by
cable, telco and wireless in nearly every area of our country, but no one method
has become ubiquitous. Broadband is all the rage and has been the new "buzz-word"
in the industry for a couple of years. There are three major camps in the
wireless game at this time. The Cell guys have their pitifully slow data
rate for use in the wireless PDA and cell phones. The big guys have adopted
the LMDS/MMDS licensed band system that has a 3-5Km range
and uses a higher frequency and sports throughput up to 30mbps. All of
these systems use radios to send packetized data between the distribution
point and a client system. Then there's the unlicensed frequency band that
we're using to deploy wireless Internet to North Whidbey Island.
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Why
the 2.4 Ghz Frequency range?
This frequency range has been set
aside by the FCC, and is generally labeled the ISM band. A few years ago
Apple and several other large corporations requested that the FCC allow
the development of wireless networks within this frequency range. What
we have today is a protocol and system that allows for unlicensed use of
radios within a prescribed power level. The ISM band is populated by Industrial,
Scientific and Medical devices that are all low power devices,
but can interfere with each other.
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Who
designed this wireless gear?
Rapid WiFi is using radio units and antennas made by
BreezeCom. They are an Israeli outfit, originally named LanAir, that designed these
systems for military use in tank-to-tank, and tank-to-HQ, real-time communication
for telemetry and computer communication. These radios communicate within the guidelines
of the 802.11 standard. Each unit is programed to use different
frequency hopping patterns within the 79 frequencies in the spectrum, and to
hop between these frequencies at 10-30 times per second. A client radio picks up
this sequence from the sending unit and they hop in an identical pattern. Individual
packets can be lost or dropped and there is no data loss.
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What
is the 802.11 standard?
802.11 is the wireless Ethernet
standard adopted by the Institute of Electrical and Electronics Engineers, Inc. (IEEE).
This allows a standard Ethernet system to have sections that
are wireless without modifying the standard Ethernet standards or methods.
A short 802.11
General Information page is available here.
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What
about all MMDS/LMDS?
These systems tend to use licensed frequencies,
the drawback being the cost of acquiring licenses. The systems promise to scale
well in densely populated areas, but are very costly to use in a rural
territory. Startup costs for these systems have been said to be in the 6 figure range.
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What
about wireless data using cell phones?
Current cell phone technology operates
at between 9600bps and 19,200bps. It's just too darn slow for today's Internet
uses. So much so that the cell industry is having to make up a whole new
protocol and web server system just to pare down the data into transmittable
size for use on a PDA or the newer cellular phones. Note that you no longer
see the term "cellular" being used by the cell phone industry; it's all PCS this,
and PCS that. Cell phone carriers are trying very hard to establish a foot in
the door of the emerging wireless data market.
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Will
this work with wireless handheld and PDA units?
Not at this time, but it is
possible. While the signal from our access points is based on the 802.11b
protocol, it is encrypted and requires an antenna that can "decode" the
encrypted signal. You could, however, connect a standard 802.11b
consumer-grade access point (like the Linksys WAP-11) to your computer, then
use a consumer-grade 802.11b PCMCIA network card in your PDA to communicate
on the Internet. Your nifty little PDA would work
on our wireless network only with the help of non-encrypted 802.11b wireless
equipment.
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How
does this access method compare to Cable?
It is faster than Cable access,
capable of full T1 speeds in both directions. Easier to upgrade, doesn't
rely on a wiring system with many potential points of failure. Not as proprietary.
Doesn't require a basic service package to obtain. Is available in many
places where Cable data hasn't arrived and isn't likely to.
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How
does this method compare to DSL?
Wireless is much faster, more widely
available in rural areas and is less expensive. DSL is limited to the copper
wire in use by the Telephone company (Telco). Wireless speeds range from 128kps up to 3000kps
(a T1 is 1544kps). DSL services are not currently available in much of rural
Whidbey Island. Even when DSL does arrive, it will not be deployed
outside the zones that are close to the Telco central office (CO). The Telcos
are reluctant to install DSLAMs in rural areas because they are expensive and rural
areas are less populated that urban areas. Wireless will go anywhere
you can create a relay point.
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I
live in a valley. Is there any hope for me?
Perhaps, but unfortunately there
will be places that will be impossible to service with wireless. Being
in a low spot will not help, unless of course you're right next to the
hill where an access point is. We have made a commitment to take the
wireless service wherever there is enough demand to justify the expense
of creating a relay point. If you and 11 other home in your neighborhood
would be willing to subscribe to the service, we'll install an access point
in your area to service you.
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Why
aren't the HUGE corporations using this?
The large players are after large
dollars and that means heading for densely populated areas. In heavily
populated areas there is a much greater chance that this bandwidth would
be saturated, not only by other users, but by lighting and other ISM band
devices. 2.4 Ghz is also unlicensed and would reach a maximum density point
long before they ran out of customers. The 2.4 Ghz is an unlicensed frequency,
so they cannot buy an exclusive right to use it, the way they can with
the LMDS/MMDS bands.
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What
are the radios and who makes them?
The radio units are a little bigger
than a Sony Walkman, and the antennas are about 12-inches square.
There is a variety of manufacturers of wireless Internet equipment.
The BreezeCom units we employ have a rugged case
and are extremely lightweight. The units come with a connection for the
external antenna, and an RJ-45 jack for the CAT5 cable from the network
card in your computer.
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How
do I connect to the radio?
You connect your computer to the
unit using a standard Ethernet cable that runs between the radio and the
Ethernet card of your computer. This cable can be up to several hundred
feet long, allowing the radio and antenna to be in one place and the computer
to be where you want it. The antenna connects to the radio with a long
length of coax signal cable.
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How
do I control the radio?
The radio is programmed by Rapid WiFit
and is not programmable by the end user. This helps to ensure the security
of the Wireless network. Rapid WiFi does have the ability to reprogram the
radio units on the fly, to allow for upgrades to the firmware as well as
service adjustments.
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Will
radios from different manufacturers work with each other?
The IEEE 802.11 standards were designed
to, and should, allow manufacturers of wireless Internet
equipment to produce radios that will interoperate with existing manufacturers'
gear. It is up to those manufacturers to fulfill the promise of the 802.11
standards. This scenario is similar to the v.90 modem
rollout, where modems that should have interoperated took a year or more
to actually do just that. One of the reasons we chose the 802.11 standard
was the potential for competition that will drive down the cost for the
end user. We like the idea of consumers having choices.
IEEE
802.11 Working Group is a great place to learn more about the future
of the wireless ethernet standards efforts.
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What
are the antennas like and who makes them?
The antennas range in size from
a 16" long ¾" round pole, to a 24" x 36" grilled directional unit.
The most common antenna used by Rapid WiFi is the 12-inch flat panel.
There are also many other antenna choices within the range of the frequency.
Most of them are very lightweight and are no more difficult to install
that a DishNetwork or DirecTV dish. The cables used for exterior mounting
come in set lengths. The cables are slightly smaller in diameter than TV
coax cable, with the connectors being slightly larger. The cable is fairly
flexible, but should not be bent too sharply.
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What
is the power output?
Through antenna gain, a EIRP 4 watt signal
is as high as the unlicensed use of the band is allowed to go in point to
multipoint environment.
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What
is the power consumption?
The BreezeCom radio unit uses 5
volts at 1.5 amps, and uses a power block that plugs into a standard U.S.
electrical outlet (120 volts AC).
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What
are the environmental concerns for using wireless?
The radio should be protected from
the elements and should be not be used outdoors. It has an operating
temperature range of 32° F to 104° F and a 5% to 95% non-condensing
humidity rane. The antenna should be mounted outside, and has
an operating temperature range of -40° F to 140° F
There have been reports of water intrusion
as a source for weather related problems. This was usually caused by improper connections being
made. Some minor cable problems have also been encountered, but we see
these as inconveniences. Weather does play a small part in signal strength, just as it does with
satellite television. If it's raining heavily, the "rain fade" could cause
insignificant signal loss.
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Can
higher gain antennas be used?
As long as the signal strength does
not exceed 4 Watts EIRP, the end user may use a high gain antenna.
Higher gain antennas are available for use with the BreezeCom radios we use,
but need to be special ordered. Higher gain omnidirectional antennas may
also be used.
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What
the heck is gain, anyway?
Think of a radio signal being a
ball of radio waves being emitted from a single point. By reshaping the
signal you add gain, or power, to the signal strength. In the case of an
omnidirectional antenna, the top and bottom of the ball are squished down
and up to flatten out the signal, creating a doughnut shaped pattern. In
the case on a Uni-Directional antenna, the signal is reshaped by not only
squishing the top and bottom, but by changing the shape as well. Imaging
looking down on the ball and being able to cut into the six o'clock position
and then reshaping it so it looks like a piece of pie with the left edge
at 10 o'clock and the right edge at 2 o'clock. In each case the total power
is compressed into a tighter pattern thus resulting in a gain of the effective
strength of the signal.
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How
many radios can co-exist in one area?
BreezeCom recommends no more than
15 Access Point radios be deployed in such a way that they can see each
other with their antennas. Instances have been reported of hanging antenna
units off the four sides of a large building, thus quadrupling the density.
Clever shielding and creative use of lower powered directional antenna
can increase densities dramatically over larger areas. Using a microcelluar
deployment approach allows for even greater densities to be supported,
facilitating rollouts in even extremely dense areas.
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What
is the current coverage range?
It's hard to give an accurate coverage rangge because wireless Internet
depends on line of sight, but we have created a
coverage map that shows an approximate area of coverage.
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What
is the power level of 2.4 Ghz?
The FCC limits the signal strength
to an EIRP of 4 watts. At the radio connector the signal is 100mW of power.
(a PC-Card runs at 50 mW) Through the process of antenna gain the signal
is effectively boosted to higher levels, not to exceed the equivalent of
4 watts EIRP.
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What
is FHSS & DSSS?
Frequency Hopping
Spread Spectrum and Direct Sequence Spread
Spectrum is the quick answer. Both operate from 2.400-2.485 Gigahertz,
in what is known as the ISM band. The 802.11 wireless standard covers both DSSS and FHSS,
although not all manufacturers employ or fully adhere to 802.11. Both FHSS
and DSSS use the middle 79 frequencies and must leave the top and bottom
3 alone as a "buffer". The DSSS system utilizes "sets" of frequencies in
a sequential progression and uses "channels" 1,6 and 11. There are 11 channels
available in the spectrum, but each uses frequencies such that only three
channels can coexist and not overlap. To obtain 11Mbps under the 802.11
DS must separate the carrier frequencies of each channel by 30 frequencies
and there are only 79 to go around restricting colo use to 3. DSSS can
sustain throughputs from anywhere from 4.2Mbps and up depending on the
manufacturers claims and methodologies. DSSS can also maintain a higher
throughput over distance than FHSS. DSSS is much more susceptible to detrimental
interference. DSSS can only coexist with 2 other units in RF proximity,
severely limiting its use in a point to multipoint application. A BreezeCom
DS11 WBS can associate with 128 WBC clients, although throughput would
suffer greatly at those densities.
SS was co-invented by Hedy Lamarr in 1942. Some
50 years later, her genius gives us a technology that allows
us to utilize radio frequencies in a much more secure, reliable and efficient
way. FHSS uses 78 frequency hopping patterns employing
all 79 frequencies. This allows for the collocation of 15 FHSS radios in
one location without loss of throughput. FHSS also can overcome moderate
signal interference better than DSSS. FHSS can have packet loss on several
of the frequency hops with no need to retransmit packets. The 802.11 standard
and the FHSS has redundant data built into its methodology that allows
for radio packet loss without the loss of the data being sent and the need
to retransmit that data.
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What
can I expect for sources of interference?
The 2.4 Ghz frequency range is affected
by some industrial lighting devices, some wireless house phones, microwave
ovens, and other radio equipment that uses the 2.4 Ghz range. In rural settings, these
sources of interference are minimal and can be avoided by proper positioning
of the antenna units. In an urban or city environment the sources of interference
could be extremely debilitating.
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Will
this signal interfere with anything or anyone else?
These radios put out a very low
power signal and as such are not likely to interfere with other devices.
Some hospital equipment can be affected by these signals if, and
only if, the unit is used in very close proximity to some devices. Hospitals
are one of the largest users of 2.4 Ghz Wireless LANs.
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What
is "clear line of sight"?
The ability for the antenna units
to see each other without obstruction is clear line of site. For more information
on LOS, please see our Line of Sight page.
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Do
I have to have "line of sight"?
Live by this phrase, but know that
there are no absolutes: "If you can't see it and you can't hit it by throwing
a rock at it, it likely won't work". With that said there are always
exceptions. Reception points within a half mile (give or take) have been
shown to operate without line of site, but these are conditions where the
signal is capable of either penetrating or reflecting. Many factors influence
and affect the radio signal. Building materials such as coated glass and
foil insulation are very good barriers to the signal.
Concrete can be penetrated in close proximity to the antennas. Wooden buildings
can be penetrated. Trees are bad. Trees are mostly water and stop
the signal very effectively, but again, if proximity to the antenna is
close enough, the signal will penetrate some foliage. But, and this can
not be stressed enough, the signal will not penetrate any volume of trees
at distance; distance being defined as more than a 1/2 mile, but again,
it isn't a black and white issue. There are cases where ISPs have literally
burned through trees using amplifiers and highly directional antenna, but
these are exceptions not rules, and they may be overpowering the systems
in order to achieve these penetrations. In some cases, trees can be over
come by using more frequent installations of access points in a microcellular
deployments. Pine trees are easier to penetrate than an oak or maple trees.
Installations performed during winter months may stop functioning during
the spring when tree begin to leaf.
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What
is the fresnel zone?
The fresnel zone is a conical shaped
area extending out from an antenna in the direction the signal is traveling.
Think of it as a megaphone. The fresnel zone for antennas one mile apart,
has a radius of 27' in the middle where the two cones are as large as they
get. Fresnel zones are discussed further on our Line of Sight
page.
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Can
this zone be partially blocked?
Yes. But the more blockage/distance
there is, the less signal is received. Theoretically, one application running
at 5 miles, where the lower portion of the zone is significantly blocked
by trees, could manage to keep a low level signal.
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What
is the range of the signal?
Servicing customers from an omnidirectional
antenna can be supported up to 10 miles out with the use of an amplifier at
the both the client and the access point. Unamplified omnidirectional antenna
can service out to 5 miles. Panel antennas, like we use at Rapid WiFi, can
generally be thought of as doing the above without the amplification, and can
increase the range ability. All of the above is conditional on the LOS qualities
of each link.
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Can
the signal be boosted?
Yes! Amplifiers can be used. The same FCC
regulation applies that you cannot exceed the 4 watts EIRP. An omnidirectional
antenna with 100' of cable can be used with a 500mW amp and not exceed the
power restriction. Amplifiers can significantly improve signal quality, but
line of sight is still required.
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How
secure is the signal?
If it's secure enough for the Israeli Military,
we think it's secure enough for Internet. The nature of FHSS makes it very difficult
to intercept. The hopping sequence could be observed but only in the case of one unit
transmitting as an access point without other units in proximity. As soon as more than
one unit is in use, it becomes exponentially more difficult to isolate
one signal. A community string is used to allow only approved radios clients
to associate with an Access Point. Encryption is also used to further secure
the signal at the radio level. In addition, more robust encryption boxes can
be positioned at each end of the link to further protect the signal.
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I
live in a heavily populated area, how will this affect the signal?
As was mentioned in various places
in the FAQ, the higher the density of population, the more likely other
devices will cause detrimental interference. In point-to-multipoint applications
this interference will be much more of a problem in densely populated areas.
In point-to-point application, the directional antennas will greatly reduce
the likelihood of interference being noticeable. The largest source of
interference in the city/urban environment would most likely be lighting
systems and other ISM band communication devices.
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How
do I interface with Wireless?
Your computer needs an Ethernet
card and a CAT5 Ethernet cable to connect to the radio. Rapid WiFi uses
Linksys DSL/Cable routers to act as a firewall and DHCP server for your computer.
Your computer will be configured as if it was using a direct Ethernet connection to a LAN
with Internet access.
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Will
any Ethernet card do?
Any standard 10BaseT Ethernet card
will work fine. 10Base2 network cards are coax-based, and will not work.
Your network card should be configured and working properly under your
computer's operating system (Windows, Linux, Macintosh, etc.).
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Can
I plug in a hub instead of a computer?
The radio needs to terminate to a device
with a valid MAC address. If your hub is network addressable, you should be able
to connect it to the radio. Since Rapid WiFi uses Linksys DSL/Cable routers
you will be able to plug a "dumb" hub into the radio to allow all computers on
your local LAN to access the wireless Internet.
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How
may computers can a client radio support?
Rapid WiFi uses the single client radio to provide you
with wireless Internet. But since Rapid WiFi uses the Linksys DSL/Cable routes, you
can provide access to 253 computers with the use of a hub connected to the Linksys' 10/100
port. The wireless link is much more flexible than a standard leased line.
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How
fast will it go?
This is very dependent on the strength
of the signal. The lowest throughput we have seen is 500kbps and the radios
support up to 3.0mbps throughput. The wireless link is faster than cable and DSL
(leased lines)
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Can
I buy a slower/faster connection through Wireless?
Yes. The BreezeAccess system
allows for Committed Information Rate (CIR) and Maximum Information
Rate (MIR).
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Can
I buy a guaranteed throughput?
Yes. On a point-to-point connection
we can work with a customer to guarantee throughput. This would require
a higher setup fee, similar to a leased line setup fee, but the recurring
fees would still be less than a leased line.
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What
will I need for hardware for a wireless Internet connection?
You will need a receive radio, the antenna and the cable running to it,
a network-capable computer, a CAT5 network cable, and a Linksys DSL/Cable router. Oh,
and electricity at the radio site will really help. We also highly recommend
that battery backup and surge devices be used with all computers and their
various connections.
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How
can I tell if wireless will work for me?
A site survey will need to be
performed for almost all potential customers to evaluate the ability to
use wireless where you are. If you know where our antennas are, and you
can see one, then you should be able to get a working signal. A site survey
must be done prior to installing any wireless hardware.
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How
much does the hardware cost?
A single computer installation would
run about $1200 for everything, if you had to buy the equipment. Since Rapid WiFi
is "leasing" you the equipment, much like the cable company "rents" you their converter
boxes, you won't have to pay $1200. Setup is $75, installation is $100 for a standard
antenna installation, and the monthly fees range from about $50 to $100 or higher, depending
on the data rate you desire.
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Is
wireless as reliable as DSL?
We have found that it is more reliable
than the Telco systems we are currently used to. We have no first hand information
on the reliability of Cable Internet, but we've heard that as more and more
subscribers jump on Cable Internet, it becomes slower and slower. Since it is a
wired system, it is subject to those types of problems.
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What
about lightning?
This is probably the most significant
threat to you and your wireless gear. Although it is just as likely to affect a
cable or DSL connection as well. The antenna has a grounding screw on it,
and it must be grounded to a 4-foot ground rod or cold water pipe.
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And
lightning protection?
Lightning arrestors are available
for the external antenna units. Further measures are recommended to protect
your entire system(s). A surge arrestor is available for the Ethernet connections,
as well as power, and the phone connections. We highly recommend that be used,
in addition to a battery backup for the power pack on the radios and the
computer.
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Will
it interfere with pacemakers?
It is suggested that people with
pacemakers not be in the immediate path of the signal. This means closer
than a few feet from the antenna. These units are less likely to cause a problem than a
microwave oven.
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What
Operating Systems is this compatible with?
Any Internet/Networkable computer
can use wireless Internet. Rapid WiFi will still apply the OS limitations it has in place
for any new customer; a Pentium-class 266 MHz computer with Windows 95/98/ME/NT/2000/XP or PowerPC
Macintosh with MacOS 7.6.x or greater, and a minimum of 16 MB of RAM, and a 10BaseT
network card propery configured and working properly under your computer's operatin system.
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Will
I still need my modem?
All wireless customers will be given
a dialup account to use as a backup in the unlikely event their wireless link stops
functioning. This dialup account is not meant to be used as a primary access
method, nor should it be shared or used in combination with a working wireless
access system. Wireless customers who abuse their dialup access while a
wireless customer will be charged for a standard dialup account in addition
to any wireless charges.
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Will
I need to keep my second phone line?
It's entirely up to you. But remember that you will have
a dialup connection available in the unlikely event the wireless link goes down,
so be sure to account for that potential need.
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Is
there a limit on the amount of traffic I can send/receive?
No, but we always watch bandwidth usage very closely. We want
everyone to have the speed of wireless available to them. Those that misuse this availability
of speed will face additional charges or possible termination of service. We have found that
the average user doesn't really need all that much bandwidth to do what they want.
What they will love is the speed at which the webpages load when connected via wireless.
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Can
I run servers on this connection?
Absolutely not! The running of
servers of any kind (such as FTP, Web, Mail, Napster-like peer-to-peer
file sharing, etc.) is strictly prohibited
with Rapid WiFi's wireless access plan. If it's discovered that subscribers are
running servers on their wireless link, they will be subject to immediate termination.
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How
big are the antenna units?
The antenna is about 12-inches square.
The mounting process in very similar to a TV antenna or a DishTV/DirectTV
dish.
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Can
I put my antenna in my attic?
Most likely the answer is, no. If
you are very close to a broadcast point and your attic is uninsulated,
you might be able to get away with it, but even then, any blockage to the
line of site will have a negative effect on the signal.
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