Thinking about Building a
                             Broadband Wireless Network ?

   Now individuals, businesses and lo...
capacity. Capacity is important because of increasing trends of demand for data transfer,
        talk-time and mobile dat...
What is a Wireless Internet Service Provider ?

   A Wireless Internet Service Provider or WISP is a special kind of broad...
or evaluate many different types of wireless networking gear. X-LIN’S leading team of RF , ISP
Security and Internet Proto...
Microwave Wireless Communications

  The complete electromagnetic spectrum includes many types of wavelengths we've become...
What RF Frequencies Are Available to Build Wireless ISPs ?

Radio Band Plans

   For example In order to keep people in th...
has been developed over the past fifty years which permits such bandwidth "sharing." This
technology provides a way to spr...


  Notice that the binary string encoding a 0 has t...
Likewise, when a response is sent back to the originating site, the radio transceiver "flips" from
reception mode to trans...
Omni Directional Wireless Antennas

  Omni-directional antennas transmit their energy in a full circle. Spreading the radi...
Data Cables, Lightning Suppression, Tower
            Structures and Other Equipment Needed to Build a WISP

  In addition...
Lightning Suppression Systems

   Lightning Arrestor. Since external antennas are involved, the threat of a lightning stri...
Calculating Overhead and Wireless Data Throughput Rates

 Throughput vs. Data Rates

   A last word regarding wireless con...
In wireless networking, there is even more overhead than encountered in cabled connectivity.
Because a radio is used, a sm...
Steps Needed to Plan and Build a Turnkey
           Broadband Wireless Internet Service Provider Solution ISP

Regardless ...
personal safety in foreign countries and locations along with material storage safety during

Planning for Superior Customer Technical Support
On the customer's side of the network, have trained technical support peo...
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X Lin Building An Isp


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How to start and plan building a Wireless WiFi ISP system , Hotware Taipei

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X Lin Building An Isp

  1. 1. 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 1 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
  2. 2. 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 and expansion. • 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 worldwide. • 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 1 next 12 to 24 months . , X-LIN Solution CPE now are less than $200 each.
  3. 3. 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 Ethernet connection. 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
  4. 4. 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 local businesses. 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 communications. 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. .
  5. 5. 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 desktop computer. 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.
  6. 6. 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
  7. 7. 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 illustrated below.
  8. 8. 0=10010010110 1=01101101001 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.
  9. 9. 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.
  10. 10. 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 to it. 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.
  11. 11. 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 other manufactures.. 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.
  12. 12. 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.
  13. 13. 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.
  14. 14. 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 actual throughput. 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 of light. • 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)
  15. 15. 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. Security Assessment 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
  16. 16. personal safety in foreign countries and locations along with material storage safety during construction. 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 Management systems. 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 classes .. 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.
  17. 17. 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.