Thinking about Building a
Broadband Wireless Network ?
Now individuals, businesses and local municipalities can launch a Wireless ISP without the
fear, uncertainty or doubt that is usually associated with deploying a new type of technology.
X-LIN’S Solution Wireless ISP provides everything needed to build a profitable high-speed
Internet open access network [with on line billing] anywhere in the world. Whether you need a
system to support 50 customers in a rural environment or thousands of customers in a suburban
or inner city area, X-LIN’S Solution Wireless ISP consulting service provides a complete
business plan, a network design, a training program and even technical support that will enable
even a novice to launch a profitable broadband wireless network for their community.
Broadband Wireless Market Overview
The use of wireless technology for broadband delivery means absolutely nothing to most
customers. Customers care about services that are reliable and affordable, and that offer
excellent value. They care about the responsiveness of their service provider ISP to their needs
and the predictability and controllability of their costs. In a nutshell, customers want excellent
service and no surprises. Customers do not care about how the service is delivered .
X-LIN’S Solution Broadband Wireless technology is a tool, not an end in itself. Wireless has
always been an alternative for high-speed connections, but never has the range of choices been
as great or the rate of innovation as rapid. The X-LIN Solution delves into the world of broadband
wireless fixed wireless connections that deliver data rates from less than T-1 (1.5 Mega bits per
second (Mbps) up to and beyond 108 Mbps. These wireless connections serve the same
function as wired-line or fiber -- interconnecting public and private networks.
Point-to-Point (PtP) Broadband Wireless
RBC Capital Markets estimates that public PtP broadband wireless will generate revenues of
approximately $8.1 billion for calendar year 2007, excluding large OEM companies. This
represents approximately 60% year-over-year growth from 2006. The following bullets highlight
what RBC Capital Markets believes are the drivers for future PtP growth.
• RBC Capital Markets believes there are two primary drivers for PtP broadband
wireless. The first driver is coverage. This continues to be one of the primary
discriminators for operators to capture market share. The second primary driver is
capacity. Capacity is important because of increasing trends of demand for data transfer,
talk-time and mobile data will take hold.
• Base Station growth will be fueled by traditional wireless and new applications such as
2.5G and third-generation (3G) and (4G) wireless. .
• Despite significant build-out of the Internet backbone during the past couple of years that
has made bandwidth available to metropolitan area networks (MANs), RBC Capital
Markets believes that a gap still exists between the MAN and the buildings it
surrounds. With less than 3% of buildings connected to fiber, a significant opportunity
exists to bring bandwidth from the fiber to these buildings with broadband wireless
technology to serve their occupants' growing information demands.
Point-to-Multipoint (PtMP) Broadband Wireless
The following bullets highlight the drivers for future PtMP growth:
• The Strategis group estimates that fixed wireless is expected to grow to more than $13.6
billion of worldwide consumer premise equipment (CPE) product sales by 2007 with
worldwide service revenues mounting to $40 billion.
• Forecasts are more likely to come true once next-generation technologies enabling non-
line-of-site (NLOS) and user installation are available. With NLOS at least 25% more
customers can be served within the same geographical footprint. This could mean the
difference between convincing service providers to put their money into deploying
broadband wireless technology en masse. With the release of high power 2.4Ghz and
5.8Ghz MESH , NLOS has improved dramatically.
Driven by these catalysts, companies positioned with low-cost products that have simple user
installation, low maintenance, and international distribution and support are positioned for growth.
Points to Note:
• The growing Broadband Wireless industry is no different than any other new market. The
early explorers have mapped the terrain, and now the settlers are moving in for growth
• At the end of the day, the ultimate driver for broadband wireless will be the speed and
simplicity the technology provides to connect the world's insatiable appetite for bandwidth
to an efficient fiber-optic network backbone. This applies to next generation mobile
systems as well as fixed broadband wireless network access for businesses and homes
• By Reducing costs and improving non-line-of-site coverage, emerging technologies will
drive point-to-multipoint solutions to mass deployment. Many in the market believe that
low-frequency customer premise equipment costs will be driven to less than $200 in the
next 12 to 24 months . , X-LIN Solution CPE now are less than $200 each.
What is a Wireless Internet Service Provider ?
A Wireless Internet Service Provider or WISP is a special kind of broadband service provider
that uses a base station antenna to transmit data through the airwaves to a receiving antenna at
a customer's premises. The data transmission works in a similar manner to a satellite dish. The
main difference is that a wireless Internet data antenna sends and receives information from a
local tower or tall structure versus a satellite.
WISPs use designated channels of spectrum to transmit large amounts of data, both upstream
and downstream, over the airwaves. The fact that the service is transported over a wireless
connection is transparent to customers who receive up to 54 Mbps of bandwidth via a regular
Any entrepreneur, ISP or business customer can set up a WISP using X-LIN X-lin Wireless
Networking equipment based on 802.11 standards. While most WISPs use 802.11 technology, a
WISP could also use equipment that’s require them to buy licensed portions of spectrum to
accomplish the same objective. X-LIN offers both such as WiMAX but at the moment WiFi is
leading the technology and pricing developments. Either way, wireless systems have many
advantages over wired systems such as Digital Subscriber Line ( DSL) or cable modems.
Building wireless networks can be a challenge if you don't know how to calculate a Radio
Frequency (RF) link budget or how to use a spectrum analyzer to see what type of RF
environment already exists in a potential service area. X-LIN Solution consultants have built
systems in many different environments that range from very sparsely populated areas with no
RF activity to very dense population centers with many types of RF activity.
To make it easy for customers to deploy these types of systems, X-LIN Solutions has
developed a turnkey or pre-packaged solution for people that don't have time to do the research
or evaluate many different types of wireless networking gear. X-LIN’S leading team of RF , ISP
Security and Internet Protocol (IP) experts put together a complete broadband wireless solution
that takes all the guesswork and headaches out of launching a WISP business.
Turning to X-LIN Solution Consulting for helpful advice on planning, building and launching a
wireless ISP will help you avoid many of the mistakes that are typically made by people with no
RF or IP experience. X-LIN’S Wireless ISP solution and network design provides a well thought
out plan that will allow you to get a system up and running quickly. The first step in any system is
a proposed is a X-LIN Solution Preliminary Design and Risk Application Site Evaluation Contract.
Details involved are discussed near the end of this information package.
In addition to building the system, X-LIN Solution will provide training classes (cost associated)
that will enable you to become a X-LIN WiFi certified RF installer. By the time you finish our
training classes, you will be an expert on installing, troubleshooting and planning for your
networks future growth.
Building a WISP in your neighbourhood, city or town is the quickest and most cost effective
way to get high-speed internet connections for schools, municipal offices, libraries, residents and
While wireless technology may be new to you and your area, there are more than
4,475 operating successfully in the U.S. alone. This group of entrepreneurs is busy showing the
rest of the world that the "broadband wireless" model is an extremely effective way to migrate
customers from old dialup connections to very fast broadband connections without investing
millions of dollars on capital expenditures usually associated with building wired DSL or cable
modem broadband systems.
The best part about a wireless system is the fact that the signal travels through the air, which
means you don't have to worry about running a pair of wires to every single customer.
What Wireless Broadband Technologies Are Available?
"Wireless" products, from remote control cars to cellular telephones, use a form of energy
known as electromagnetic radiation to carry signals. The signals can be the pattern of vibrations
commonly experienced as sound by the human ear. Or they can be the abrupt changes of
frequency or intensity used to encode data signals. Whichever, electromagnetic radiation carries
them through free space. We will get into this in detail in a moment. First, let's describe the four
most common forms of wireless technologies: satellite, microwave, infrared, and radio
Satellite Wireless Communications
Normally, satellite communications are unavailable to small entities for network connectivity.
The cost of leasing a transponder is prohibitive. However, one viable exception is the use of
satellites to connect end-users to the Internet. A couple of companies currently offer high-speed
Internet access to home and business customers through the installation of a small parabolic
antenna (satellite dish).
While this type of connectivity provides over 400Kbps download connectivity and 112Kbps
upload.The costs are expensive and based on a daily level of data. Also affected by rain.
Microwave Wireless Communications
The complete electromagnetic spectrum includes many types of wavelengths we've become
very familiar with, at least in name. First among these is visible light. Two other types of
wavelengths, just at either end of the visible spectrum, are infrared and ultraviolet light. These are
the wavelengths that bring us "night vision" technology and tanning booths, respectively. Another
portion of the electromagnetic spectrum we're becoming familiar with are frequencies called
microwaves. These exist below infrared frequencies, but above normal radio frequencies.
Many of the data communications services offered by major telecommunications companies
are supported by microwave technology. While it is a viable alternative even in private
communications, it has two drawbacks. First, microwave communication requires FCC licensing.
Second, the cost of implementing microwave technology (tower/dish infrastructure) is higher than
other options. On the other hand, microwave communication is extremely resistant to interference.
But, because of its cost, it will not be an adequate alternative for many rural community networks.
Infrared Wireless Communications
Computer technology that uses the infrared spectrum is becoming common. For example,
wireless keyboards and receivers are commonly distributed with computers that serve as a base
for home entertainment systems. A receiver is attached to the keyboard connector on the back of
a computer case. An infrared transmitter operating at a proprietary frequency (each wireless
keyboard manufacturer typically uses a different frequency) translates the keystroke coding into
an infrared signal and sends it to the receiver. Also, some computers now come with an infrared
port which allows information from a hand-held or pocket computer to be transmitted to the
There are also network bridges/routers that use the infrared frequencies to transmit data. (For
this manual, infrared communications includes laser technology used for data communications.)
Like microwave technology, infrared provides high-speed connectivity. But infrared
communication solutions are expensive to implement.
In most cases of community infrastructure, radio and microwave equipment will offer the most
effective form of wireless communications. Because of licensing and cost issues, we have chosen
to focus on radio frequency wireless. In the remainder of this document we'll discuss in plain
English the core aspects of using radio frequencies to transmit computer data.
Using Radio Waves to Carry Wireless Data Transmissions
Even though the phrase "RF wireless networking" might seem mysterious, the underlying
technology is very common. It uses radio waves, the same type of energy used to transmit radio
and television broadcasts. Two-way radios and walkie-talkies also use this technology.
The space program utilizes radio waves to control computers onboard space capsules and
probes, and receive signals from other devices. Remember the video broadcasts from the surface
of the moon? The color photographs of the surface of Mars? All of these were translated into
radio waves and transmitted to Earth using radio technology.
Thinking about radio and TV, you can probably already identify some of the components
needed to make RF wireless networking work: a radio transmitter, a radio receiver, an antenna,
and a cable from the antenna to the receiver or transmitter. Add a couple of other components to
protect the equipment—such as lightning arrestors and noise filters—and you've pretty much
listed what you need.
What RF Frequencies Are Available to Build Wireless ISPs ?
Radio Band Plans
For example In order to keep people in the United States from interfering with each other's use
of radio signals, the Federal Communications Commission (FCC) is in charge of assigning small
sections of the radio frequencies to specific uses. These are called licensed frequencies. In order
to broadcast radio signals at these frequencies you must apply to the FCC for a license.
However, to allow use of some of the radio spectrum for small applications that would not
require a license, the FCC has allocated three separate bands of radio frequencies as public
bands. No license is required to use equipment transmitting at these frequencies. These are
called the ISM bands, short for Industrial, Scientific, and Medical bands. Table 10 shows the
frequencies reserved for these bands.There are many more bands available in other parts of the
world. X-LIN Solution has many frequencies available ,900MHz, 2.3GHz, 2.4GHz, 2.5GHz
3.5Ghz, 4.9GHz, 5GHz band and 8.5Ghz along with new WiMAX Frequencies.
Table 10. ISM radio frequency bands.
Frequency Range Band Description Bandwidth Available
902-928MHz Industrial Band 26.0MHz
2.40-2.4835GHz Scientific Band 83.5MHz
5.725-5.850GHz Medical Band 125.0MHz
Notice that the bandwidth available increases in the higher frequency ranges. These higher
frequencies will support higher data transfer rates. Therefore, many wireless bridge products
being sold today operate in the 2.4GHz and 5.7GHz frequencies. As throughput increases,
computer networking becomes more of a real possibility. And, with more companies producing
RF wireless networking products, prices are continuing to fall, making wireless networking a
viable alternative to land-based lines in many local areas.
What keeps the unlicensed ISM bands from becoming equally overused? There are two
primary differences in how RF wireless networking is implemented that minimize interference and
contention for use of the bandwidth available. The first relates to the method used in transmitting
a data signal over radio waves. The second relates to the type of antennas used to radiate and
receive the radio signals. Let's examine the transmission technology first.
What is Difference Between
Spread Spectrum and Frequency Hopping?
Most communication technologies we are familiar with—radio, television, two-way radios—use
what is called narrowband communications. Each station or channel operates over a very thin
slice of the radio spectrum. Because the station is assigned that particular band, and the FCC
ensures that no other broadcasters in the local area use that same band through licensing, there
is no interference. The range of each station is limited, so the same frequency can be re-used a
great distance away without interference.
Because many devices might use the ISM bands in a local area, additional technology is
required to keep the various signals from interfering with each other. Fortunately, a technology
has been developed over the past fifty years which permits such bandwidth "sharing." This
technology provides a way to spread the radio signal over a wide "spectrum" of radio frequencies,
minimizing the impact of narrowband interference. In most cases, only small parts of the
transmission are corrupted by any interference, and coding techniques allow that data to be
recaptured. This technology is now generally known as spread spectrum.
There are currently two different spreading techniques used. Both use a coded pattern of
communication. A receiving unit is synchronized to use the same pattern and successfully receive
the transmission. Any other radio unit hears the signal as noise because it is not programmed
with the appropriate coding. The two techniques are called frequency hopping spread spectrum
and direct sequence spread spectrum.
Frequency Hopping Technology
Frequency Hopping Spread Spectrum (FHSS). The United States military developed a radio
technology called spread spectrum during the 1950s and 1960s. Obviously, the first concern was
ensuring that radio transmissions were not intercepted. The second concern was to ensure that
guided missile communications were not jammed by enemy radio transmissions.
Though developed and implemented by the U.S. military, the problem was first addressed by
Hedy Lamarr, a famous actress of Austrian descent in the 1930s and 1940s. She and a music
composer, George Antheil, patented the idea in 1940. She was so far ahead of her time in
conceptualizing the idea that she never received any monetary rewards for her patent. The patent
license expired before government and commercial implementation of the concepts occurred.
A communications signal (voice or data) is split into separate parts. Instead of transmitting a
signal continuously over one narrow frequency band, the several parts are transmitted separately
over a wide spectrum of radio frequencies. A defined, but random-appearing pattern of non-
sequential bands is used, with successive parts being transmitted over the next frequency band
in the pattern. On the other end, a receiver is configured to receive the signals in the same
pattern. The radio receiver then reassembles the pieces into the original signal. Since many
distinct patterns can be developed, it is possible to have multiple radios transmitting at the same
time, but never at the same frequency at the same time.
The process of jumping quickly from one frequency to another is called frequency hopping.
And, therefore, the technique is called frequency hopping spread spectrum.
Frequency hopping has two benefits. Electrical noise—random electromagnetic signals which
are not part of any communications signal—will only affect a small part of the signal. Also, the
effects of any other forms of radio communications operating in narrow bands of the spectrum will
be minimized. Any such interference that occurs will result in only a slightly reduced quality of
voice transmission, or a small loss of data. Since data networks acknowledge successful receipt
of data, any missing pieces will trigger a request to transmit the lost data.
Spread Spectrum Technology
Direct Sequence Spread Spectrum (DSSS). Direct sequence spreading is very different from
frequency hopping. Instead of splitting a data signal into pieces, direct sequencing encodes each
data bit into a longer bit string, called a chip. Usually, 11 to 20 bits are used for the chip,
depending on the application. Because the military requires a much higher degree of security, it
generally uses much longer chips—even a long as 1,000 to 10,000 bits! An eleven-bit chip is
Notice that the binary string encoding a 0 has the opposite form as the string encoding a 1—
where a "1" is used in one chip, a zero is used in the other.
The chip is then used to modulate (change) the signal generated by the radio transmitter,
spreading the signal out over a wide band of frequencies. The receiver uses the same code and
so listens for the unique signature across the frequency spectrum. It then decodes the signal
back to the original data.
This is a simplified explanation of a very technical subject, but hopefully it gives you an idea of
how spread spectrum works. The gist is that spread spectrum technology allows multiple radio
signals to operate in an open, unlicensed band with a minimum of interference. It also provides
security for the transmission.
Using Radio Signals as a Data Transmission Medium
Now that you've become a little more familiar with what radio signals are and how they can be
used in a public band of frequencies without creating general chaos, let's take a look at how
those radio signals are used to create a network transmission medium.
Computer networks use variations in electrical current to transmit data from one computer to
another. While each type of cable (coaxial, thin coaxial, and unshielded twisted pair) has its own
electrical properties, there is a commonality in how the electrical signals are transmitted from one
network card to another using these media. Using a telephone "line," whether analog or digital,
adds a little complexity to the process, but not a lot. However, when using fiber optical cable,
which uses light waves as a medium, and radio signals, which use radio waves as a medium, the
process is a bit more complex.
What is a Microwave Radio Transceiver?
Microwave Radio Transceivers
To create a computer network connection over radio waves, two puzzle pieces are needed.
First, a network device such as a bridge or a router is needed. The network bridge/router handles
the data traffic. It routes the appropriate data signals bound from the computer network in one
building to the network at the other end of the radio connection. Second, a radio transmitter and
receiver, commonly called a transceiver, is required. The radio transceiver handles the radio
signal communications between locations.
The interesting part of this marriage of technologies is that radios have always dealt with
electrical signals. The radio transmitter modulates, or changes, an electrical signal so that its
frequency is raised to one appropriate to radio communications. Then the signal is passed on to a
radio antenna. We'll discuss the work of antennas more in the section "How the Antennas Work."
At the other end of the transmission, the receiving portion of the radio transceiver takes the
radio signal and de-modulates it back to its normal frequency. Then the resulting electrical signal
is passed to the bridge/router side for processing by the network. While the actual process of
modulation/demodulation is technical, the concept of radio transmission is very simple.
Likewise, when a response is sent back to the originating site, the radio transceiver "flips" from
reception mode to transmission mode. The radio transceivers at each end have this characteristic.
Transmit-receive, transmit-receive. They change modes as many as thousands of times per
second. This characteristic leads to a delay in communications called latency. It is idiosyncratic to
radio communications and negatively affects data throughput. See the section "Throughput vs.
Data Rates" below for more information.
How Do Microwave Wireless Antennas Work?
How Wireless Antennas Work
In the middle of the radio transmission/reception process sit two antennas, one at the building
from which the signal is transmitted and one at the building receiving the signal. Of course, it is
possible to have one central location and several remote locations connected to the network. For
discussion's sake, though, let's think of the communication process as a straight line, from one
antenna to the other.
In order to transmit the modulated radio signal, an electrical current passes through the
antenna, inducing a magnetic field, which oscillates at the given frequency. The variations in the
current create slight variations in the radio frequency. These radio waves radiate outward from
the antenna in a "beam" according to the antenna's design.
On the other end, when the radio is in receive mode, the antenna is passive. The
electromagnetic radiation from the originating antenna passes across the receiving antenna. This
creates a magnetic field, which, in turn, induces an electrical current through the antenna. The
current passes through the radio receiver and is demodulated back into an electrical signal with
the same form as the original electrical signal from the first network bridge/router. This electrical
signal passes to the bridge/router portion of the receiving unit as a normal data signal.
As if by magic, a data signal is transferred from one network bridge/router to another without
the necessity or expense of an interconnecting wire. More information about the various antennas
used in wireless networking is presented in the next section.
What is the Difference Between an
Omni Directional and a Directional Sector Antenna?
Different Types of Wireless Antennas
Because the radio equipment used in wireless networking must by law be very low-powered to
minimize interference with other devices, the antennas required are much more focused than
those used in radio or television applications. The amount of focus they use in transmitting a
signal, and their corresponding ability to "pick out" specific radio signals is called gain. The gain is
measured in decibels, abbreviated dB.
Sector Wireless Antennas
There are two major categories of antennas: directional and omni-directional. Directional
antennas focus their energy in tight, narrow beams. When receiving signals, directional antennas
do not "see" any signals coming from outside the "beam" on which they are focused. This
eliminates a great deal of potential interference from other radio sources and contributes to the
ability of multiple wireless communications systems to coexist with a minimum of interference.
Omni Directional Wireless Antennas
Omni-directional antennas transmit their energy in a full circle. Spreading the radio signal over
such a large area reduces the energy in the signal. This severely restricts the distance the signal
can be transmitted and received effectively. Therefore, transmissions via an omni-directional
antenna do not travel as far before being degraded as do those from directional antennas.
(However, amplifiers are available for both types of antennas to lengthen the transmit distance.)
X-LIN solution devices have built in amplifiers tuned for maxium through-put , examples below
These characteristics make each type of antenna optimal in different situations. For those
networks involving more than two buildings, called multi-point connections, an omni-directional
antenna at the central site will be most cost-effective. A directional antenna is installed at each
remote site, aimed back at the central site omni-directional antenna. Since the omni-directional
antenna transmits in all directions, every remote antenna can pick up its signal and transmit back
Some examples of antennas and CPE with yagie directional antennas below
Both types of antennas are available with various levels of gain. X-LIN Solution design team
will provide a guide which shows some common antenna types, their gain, the maximum distance
over which they are effective, and their approximate cost.
Data Cables, Lightning Suppression, Tower
Structures and Other Equipment Needed to Build a WISP
In addition to the wireless bridge and antenna, there are a few more items required to make a
functional wireless network connections. In the course of specifying a system, some are easy to
overlook. Below X-LIN Fighter CPE with built in lighting protection.
Wireless Equipment Feature Sets
Feature Sets. Some manufacturers sell their wireless bridges in separate units. In such
instances, the physical radio/bridge unit has a base cost. Software features, such as individual
protocol routing and encryption, are sold as a separate unit. However, X-LIN units are a Total
Solution Design and have complete assembly..
Coaxial Cabling Systems
External Cables. For all wireless installations there must be a cable which connects the
antenna to the radio in the wireless bridge. All X-LIN Solution devices are outdoor rated and have
operating temperatures from -35C to 70C , thus we keep the cable length to 1 Meter between
Antenna and Device.
Power over Ethernet Cabling. X-LIN Solution uses power over Ethernet which can carry both
power and a Ethernet signal to the radio and antenna. This option will save you a lot of money on
buying long runs of coaxial cable and isn't as susceptible to signal loss on long cable runs as are
Internal Data Cables. A network data cable is required to connect the wireless bridge to your
internal network (to a hub, switch, or repeater). This cable is generally the responsibility of the
individual entity. If the wireless bridge is a significant distance from the network equipment,
installation of this cable may require a cable installer. In this case, be sure to discuss the cable
run with your wireless installer when the system is being specified.
Lightning Suppression Systems
Lightning Arrestor. Since external antennas are involved, the threat of a lightning strike can be
very real. Make sure that proper measures are implemented to minimize the risk of lightning
strikes. X-LIN Solution include an optional device called a lightning arrestor. It is normally
installed between the antenna and the bridge. Also make sure the antenna is properly grounded.
Mast Poles or Cell Towers for Wireless Antennas
Mast or Tower. When it is not possible to obtain a clear line-of-sight between the two antennas
involved in a wireless connection, a mast or radio tower may provide additional height for the
antenna, clearing obstacles such as trees or buildings which lie in the path of the radio signal.
Masts are generally mounted on the roof and may be 10-50 feet in height. If a mast is used in
your implementation, be sure it is tied down properly to minimize the risk of wind damage
Radio towers are generally independent structures erected to raise antennas when extended
distances are desired. They may also be required when tall buildings (larger than three stories) or
topographical features lie directly in the path of the radio signal between two antennas. Towers
can be erected at heights of 50 feet and higher. Obviously, depending on the application, the cost
of erecting tall towers can be prohibitive.
Calculating Overhead and Wireless Data Throughput Rates
Throughput vs. Data Rates
A last word regarding wireless connectivity is appropriate. earlier I listed the theoretical
download times of a Tom Clancy novel using various connection types. These are theoretical
because real network transmission involves some "overhead," or additional information sent to
aid in delivery of the actual data.
On a network, data is divided into pieces and packaged for transmission over the network.
Called packets, these pieces all have additional information attached to them. Think of the
attached information as an "address label" for the packet. At minimum, the "label" has the
address of its destination on the network and that of its sending computer. It also has a sequence
number so that the packets can be reassembled in proper order.
Because of this added information, the data transfer rate associated with any medium refers to
the maximum amount of total data transmitted per second, including "address labels." The actual
content transmitted is less.
In wireless networking, there is even more overhead than encountered in cabled connectivity.
Because a radio is used, a small slice of time is used to switch from transmit to receive mode.
Other internal functions required to receive data signals from the bridge and alter them to work
over a radio connection consume more slices of time. Since time lost equals data throughput lost,
a radio connection generally is not as efficient as a direct-cabled connection.
Two specifications are normally provided for wireless bridges. The term data rate is normally
used to specify the theoretical bit transfer rate of a particular implementation of radio frequency
transmission. Throughput specifies the maximum amount of data that can be pushed across the
link. Some spreading technologies are more effective than others, so the throughput will vary.
As a rule of thumb, you can take the data rate and divide it in half to obtain an estimate of
Summary of How RF Works and
Its Network of Wireless Elements
In this section we discussed the technical aspects of radio frequency wireless network
connectivity and the different elements needed to send and receives signals through the airwaves.
Here are some of the points we made:
• Radio waves are like light waves—they are electromagnetic energy traveling at the speed
• Frequency equals the number of waves that pass a specific point in one second. The
measure of frequency is hertz.
• There are three license-free radio frequency bands used in radio frequency wireless
networking. These are called the ISM bands (Industrial, Scientific, and Medical).
• Spread spectrum transmission enables multiple wireless transmissions over the same
frequency bands without interference.
• The two spread spectrum techniques are called frequency hopping spread spectrum and
direct sequence spread spectrum.
• There are several components required to implement an RF wireless network link:
o Wireless bridges
o Optional software feature sets Management , Billing and customer interface.
o Antennas, directional and omni-directional (for multi-point connections)
o External cables
o Lightning arrestors
o Masts or Towers
o Data cable (from bridge to network hub)
Steps Needed to Plan and Build a Turnkey
Broadband Wireless Internet Service Provider Solution ISP
Regardless of what consultant or system integrator you are using to build your system, they
should include the following check list of procedures to provide a solid foundation for your
wireless network's architecture. These steps should be taken whether it consists of one outdoor
Wi-Fi Hotspot serving 50 customers or a huge municipal MESH network serving many square
miles of a city and hundreds of thousands of customers.
X-LIN Solution Preliminary Design and Risk Application Site Evaluation Contract should be
considered to fully evaluate the application in question.
Each wireless network should require the following list of activities be performed before, during
and after a network is constructed:
Physical Site Survey
A physical site survey involves driving around in potential coverage areas and scanning the
buildings, water towers, grain silos and other tall structures for existing wireless antennas. This
step will give you a good idea of where existing wireless equipment is located and what slice of
wireless spectrum they are using to deliver service. It should also give you a list of potential sites
to be considered for building out your own wireless antenna cell sites.
HQ –NOC Center Location
X-LIN NOC design team will design a system for the approved safe location approved by the
Security Division. Our design team is made up of senior IT employees who worked and designed
the 3 largest ISP in Canada.
Wireless Site Survey
Once you have eliminated cell sites with existing wireless equipment and found several potential
spots with good elevated positions near large groups of customers, it is time to conduct a wireless
site survey with a spectrum analyzer to see what levels of radio noise are in the area. Sites
should be scanned for 900MHz, 2.4GHz and 5GHz. If new public frequencies are available, these
should be scanned as well. In addition to raw frequencies, WiMAX coverage for future
deployment if feasible you should scan for polarization. The noise levels on vertical polarization
might be very saturated, while horizontal polarization might be completely open.
Planning Wireless Cell Sites
Other decisions that need to be made are how big will your cell coverage areas need to be and
how many simultaneous customers should be allowed to logon to the network at the same time
per AP device, X-LIN devices are based on 125 clients per AP and 225 for each MESH device. .
Planning also requires that WISPs contact potential site owners to see what type of requirements
need to be met before equipment can be installed such as wind and insurance.
X-LIN security assessment team is made of retired senior officials from the Canadian RCMP. This
service provides a detailed service manual required to obtain a ISP rating for commercial services
such as banks and other sensitive intuitions. A employee hiring and screening process is also
covered to insure proper procedures in email server authorizations by personal, email tap
procedures required by international agencies for terror threats .Internal password authorization
allocation for management systems and servers, VOIP wire tap procedures and warrant handling ,
HQ site evaluation for safety, redundancy for email servers (3 months) . Construction phase and
personal safety in foreign countries and locations along with material storage safety during
Contracting Space on Existing Cell Towers
If large cell towers are already built and have space available for your equipment, you should
check on the pricing. In most cases, cell phone towers will be too expensive for beginner Wireless
ISPs, but it is worth a couple of phone calls to check it out.
Assessing Broadband Demand in Target Coverage Area
Once you have selected your wireless cell sites, preferably near large groups of potential
customers, you should verify broadband demand exists before making capital investments. This
is where the 5GHz backhauls will be used to the HQ center containing the Fibre and
Before building out a 1000 home neighbourhood, conduct a door-hanger marketing campaign
that tells potential customers that if 100 customers sign up for service, your company will have
enough business to build a wireless broadband network. You might even offer a discount to the
first 100 customers that sign up.
Make sure you provide a way to sign up for service, such as a phone number, website site or
email address. If you get 200 responses, you are sitting on a gold mine. If you get one phone call,
you should think twice.
Building a Business Plan
If you get a good customer response to your survey, you are ready to put all of your facts and
figures into a written business plan. The plan should cover cell sizes, customer penetration goals,
marketing costs, equipment costs and personnel costs related the construction and daily
operations of the network.
Building a Marketing Plan
Most people don't plan properly for the marketing portion of their business model. You should
always plan on doing advertising , direct mail, and public relations campaigns to make sure
customers are aware that high-speed Internet service is available in their area.
Wireless Training for Proper Engineering Principles
Before attempting to build a wireless network, X-LIN suggests staff to take some training
Planning for Proactive Network Management
Making sure that your network is available to all customers at all times is mission critical. Before
selling service, X-LIN Management systems are pre tested, X-LIN project management team
provide a stress test it to make sure that everything is working properly. Once the network is
operational, the system provides proactive 24x7 network management that continually scans the
system for equipment that is becoming congested or has failed completely. Our system always
tries to stay one step ahead of the customer. If there is a problem, be prepared to let customers
know why and when the network will be up and running. Our redirect screens allow for instant
information to clients via internet if there is a international connection problem , and thus saves on
call center activity.
Planning for Superior Customer Technical Support
On the customer's side of the network, have trained technical support people waiting solve their
problems as quickly as possible. Remember, once you touch a user's computer, they will always
assume that your network is what caused it to crash. Make sure that you have clear
documentation that shows where your network support ends and where they can go to get
support for their computer and software applications.
Advanced Wireless ISP Training Workshop
Advanced Workshops are two-day classes that cover the same text book and class binder
notes, but also add very important real world, hand-on training and exercises that teach you many
important steps and processes for performing WISP installations correctly the first time.