Wi-Fi Interference:
3 Things New WISPs Need to Know

Providing Wi-Fi access is sexy—it's a hot topic that has wire-based ISPs taking their tech teams to the sky. But it's not all fun and games when it comes to deploying your first WiPOP. Learn how to get started from a WISP expert operating a successful system in the Chicago area.

by Michael R. Anderson PDQLink Chief Internet Officer [May 2, 2001]

Most wannabe WISPs don't realize that there are many other players out there operating in the same space as their fixed wireless business. Local schools, government agencies, and non-ISP businesses may already be using the same airwaves.

Some newbie WISPs that simply throw their equipment up in the air and expect other operations to contact them if there are any problems could be in for a big surprise. Many of these ad hoc deployments exceed FCC regulations concerning signal strength. Novice WISP operators end up throwing money away because they build a wireless infrastructure with the wrong gear.

These methods of operation are not the proper way to become a successful WISP—they are, however, a good way to rack up legal fees, FCC fines, and make enemies in your market. Wannabe wireless ISPs need to do three things before they deploy their first WiPOP—learn, plan and locate.

Wi-Fi discipline
First, new WISP owners need to learn as much as possible about the equipment being deployed. Each WiPOP is different from the next, every on-site installation is unique, and sources of interference vary. Education, proper planning, and frequency coordination with other wireless operations in your WISPs service area are the building blocks of a truly successful business.

You will need to understand the difference between Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS) systems to determine which method of fixed wireless technology is best for your WiPOP. Knowing which antenna to use for customer premise equipment (CPE) and your WiPOPs tower is imperative. Will a sector antenna work or is an Omni antenna best for your location? Are amplifiers really necessary for your setup?

You will need to be able to answer these questions in order to setup your first WiPOP and get your WISP off the ground. Vendors are a great place to start, but building a real system is different than theory and vendors tend to be a bit self-serving. The ISP-Lists are another valuable asset for learning about Wi-Fi equipment. You may want to check out the ISP-Wireless discussion for specifics. But your best lessons will come in the field—expect to get your hands dirty.

Game plan
Second, new WISP operators need to take the time to build a proper plan for their service area. For example, who else uses the spectrum that you plan to access? Check to see if there is another WISP operating nearby. What equipment do they use? Do they operate a DSSS or FHSS system, over what frequencies and channels?

Before I launched my first WiPOP, I used a mapping application and plotted out all the other operators who used the 2.4GHz spectrum in my service area. I noted their frequency range, as well as what channels they used. In doing so, I could determine what channels they were not using and which direction their signals were sent. That way, I created room to move my WiPOP onto airwaves already shared by others, without disrupting their services or slowing my deployment.

In one instance, another WISP was using Omni antennas in my service area. This created a problem for me, so I asked them if they really needed to use the omni-directional links. As it turned out, they had built a poorly planned system years ago and never bothered to upgrade it as technology improved. I offered to replace their Omni antennas with directional units, so I could deploy my service without interfering with theirs. Remember, interference can go both ways. If another WISP is interfering with your WiPOPs signals, chances are good that you are doing the same thing to their wireless system.

Sure, you're anxious to get things up and running and start tapping into the Wi-Fi dream of providing broadband services without coaxial or copper lines. But taking the time to plan a proper WiPOP deployment means avoiding trial and error testing methods. Specific methods to avoid include:

• Wait and see: Do not deploy Wi-Fi gear and then wait to see if anyone complains about interference from your system. Even if they do express dissatisfaction with your testing methods, these are the same people that could bring down your system while they check one of their network installations. Don't give your WISP a bad reputation by allowing your customers to be disconnected. The time to test a new system is when your current clients are off-line. Wait-and-see testing methods create hours of additional labor and dissatisfied customers—and that's no way to start a successful WISP business.
• Money-taker: Do not throw money at a problem without examining the consequences of your actions. Typically, newbie WISP operators add an amplifier thinking that "more power" will do the trick and correct the problem. This isn't a situation comedy, you're not "Tim Taylor" and this isn't "Tool Time." If you need to improve a link or strengthen a signal, determine what the issue really is. Chances are good, a different antenna or different position will take care of a weak link on your WiPOP. Throwing money away on equipment you don't need is not a good way to start a successful WISP operation.
• Bad neighbor: Don't be out to get your fellow Wi-Fi operators—be a good neighbor. WISP operators that fail to negotiate reasonable settlements of interference issues won't be in business very long. There are rival Wi-Fi providers that could try to put your WISP operation out of business. These are the same players who end up paying piles of money in legal fees, FCC fines, and associated damages.

Quick-witted connections
After you have learned all you can about Wi-Fi equipment and 802.11b standards, built your best-made plans to deploy your first WiPOP, and built a few beta links—you're finally ready for some customers. The final question you must ask yourself, is where are your customers?

Try calling your local school district to see how they are getting their Internet services delivered. Contact the local county government to see if they could benefit from your wireless broadband program. Work with businesses in you service area, speak at a local Jaycees meeting about wireless broadband Internet, go above and beyond the typical sales pitch—and start connecting customers to your WISP today.

In the end, there is much to learn about running a successful WISP. The broadband service arena is there for all those who wish to deploy Wi-Fi systems. It is neither expensive nor difficult to learn. Get out there, make some money, have fun with it, but above all—don't hurt anyone else's business in the process. We can all get along in the 2.4GHz spectrum—our WISP businesses count on it.

—End