How to Start a Wireless ISP
Part 2: A Tale of Two Spread Spectrum

Adding fixed wireless access at your ISP will free you from more than plain old telephone lines. It allows you to declare that your business is independent of telco tyranny.

by Marlon K. Schafer
Owner of Odessa Office Equipment, KMS Wireless Sales Engineer
[December 8, 2000]

In order to build a business around my fixed wireless Internet service, I needed a plan—so I asked myself a couple of fundamental questions:

• How many customers could I serve in my town?
• How much should I charge for service?
• What would it cost to install customer premise equipment?
• How much would customers be willing to pay for the CPE?

Two trains of thought
In order to answer those questions, I had to settle on which fixed wireless technology I would use. I quickly learned that proprietary or uncommon protocols are of no use when it comes to fixed wireless systems, so there was no way for me to go the "home-brew" route like I had with DSL access.

Basically there are two viable technologies available for setting up a fixed wireless ISP—Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS).

DSSS radios occupy a consistent piece of allocated spectrum constantly. FHSS radios don't always sit on the same exact frequency—it seamlessly skips from band-to-band over a fixed portion of spectrum.

Disputed frequencies
There is an ongoing debate about which spread spectrum technology is better. Both direct sequence and frequency hopping systems have advantages and disadvantages inherent to the equipment used.

FHSS systems are capable of leaping past interference, but at the price of delayed data flow. DSSS technology allows you to program past sources of interference, so the user does not experience delays. But interference can change and you have to re-program around it again in order to maintain speed.

There are many different types of radio frequency interference. Either way, it's important to do some research before you get started to determine which type of 2.4Ghz equipment is already in your area so that you can plan your network around local RF interference.

For the most part, if there are line-of-sight issues impacting your ISPs wireless footprint, then a frequency hopping system would work best for your customers. If there is other RF interference, then you might want to opt for a direct sequence system. It may seem simple enough, but remember—you're wireless ISP business is going to be married to the technology you choose—it would be expensive to change partners halfway through the honeymoon.

Peak performance
No matter which system you choose, it's important to note that your wireless ISP can connect about 100 customers per access point—that's DSLAM or RAS in wire-based ISP-speak—with no noticeable performance hit.

If you plan on servicing a small town like my wireless ISP does, a DSSS solution with three APs should work fine. If you plan on servicing a larger market beyond a 10- to 15-mile radius, you will want to look at a FHSS system. Again, it's important to prepare your business plan for an wireless ISP that's right for your market.

Currently, the 802.11 networking plan is the prevalent standard in the market. I'd recommend that you stick with it because the plan allows quite a bit of flexibility in deploying your wireless systems.

If you are deploying wireless ISP access in rural markets, build your network with high-powered systems and omni directional antennas. If deploying to a metropolitan area, it's best to use low-powered systems with directional antennas.

No matter what, always build the entire wireless installation on the ground first and test it before you hang it in the air! If you have a bad component or flaw in the design the place to find it and fix it is on the ground, not in the air—trust me as the voice of experience on that one.

Radio retrospection
I can tell you that starting a wireless ISP operation is about 50 percent science and 50 percent magic. There is no singular sure-fired system that fits every customer's need. There is no one technology, brand, vendor, or antenna that suits every possible situation.

The key to your success is to try new things—be flexible and experiment. Don't worry if your system doesn't work right the first time, this is a long-term project. Get some equipment, get it in the air, and get yourself some customers.

Once you have debugged your wireless ISP system you'll have no problem selling wire-free connectivity. Your happy and excited customers will take care of that for you! So have no fear, jump on in—the airwaves are fine!

As far as my business plan is concerned, I budgeted for a DSSS system capable of serving 300 customers paying $35 for threshold services. I opted for charging customers a one-time $50 installation fee and a choice of $15 a month rental or $300 purchase of CPE. Yes, that translates to more than $10,000 a month in potential revenue added to my ISP business. That might not seem like much to big city providers, but it's a great time to be in business in my little town.

Right now I provide wireless high-speed access to about 20 customers. As for the local telco ... I hear they have two ADSL customers now. I'm in the drivers seat in this market because my service is twice as fast as DSL access and costs 50 percent less.

Finally—the telco is taking it in the shorts, not the independent ISP operator. Fixed wireless technology could be just what your ISP need's to get your business flying high again.

—End    

Related articles:
	[Dec. 1, 2000]	How to Start a Wireless ISP Part One: Determining Your ISPs Destiny
	[Sept. 25, 2000]	Grassroots Wireless Internet