Getting Started

You have to begin somewhere, and you begin by thinking about your requirements and making certain decisions. What follows is a list of some of the facts you will need to gather and decisions you will need to make. This is not a linear list. Some of the decisions interact with others.

• Where will people be accessing the network?

• How many people will be accessing the network?

• What technology should I use?

• What sort of area do I need to cover?

• Can I get by with one access point or will I need multiple access points?

• If I need more than one access point, how can I arrange multiple access points to provide full-speed coverage of my target area?

In the rest of this chapter I'll talk about these points in more detail. Before I do, however, I'd like to briefly discuss product vendors and prices.

I didn't include 'decide how much you want to spend' in the design process decisions list for a number of reasons. For small offices and home offices, Wi-Fi gear has mostly become a commodity, in that Wi-Fi products deliver a standard service (802.11b wireless connectivity) that doesn't vary much among products and vendors. Spending more won't get you 'better' Wi-Fi. Comparison shopping can save you money, and I encourage you to shop aggressively. What the goods go for is what you'll have to spend. For a home network consisting of a wireless residential gateway and three client adapters, you should plan on spending $300 to $350. If you can get the goods for less than that, it's gravy. I'm writing this book in 2003 so figure each year thereafter the price will drop until it reaches the $100 to $150 range-maybe even lower.

On the other hand, if you spend any amount of time cruising online catalogs, you'll notice that there is often a huge spread in prices for what seems to be equivalent Wi-Fi hardware. This is especially true of access points. Admittedly, the spread has come down as the Wi-Fi idea has become more 'mainstream' and thus more price-competitive, but some product lines are consistently more expensive than others. The Cisco Aironet 350 access point, for example, sells for between $500 and $600, whereas the Linksys WAP-11 runs for about $110, sometimes less on sale. Both are Wi-Fi-compliant access points. Why should one cost so much more?

Cisco designs their products for a particular market: Large corporate shops that need to integrate Wi-Fi with very large, very fast, and highly protected networks. Cisco has thus 'filled the holes' in the Wi-Fi standard with proprietary technology that plays to the high-end corporate market. Their access points have a lot more muscle in certain areas like virtual private networks, 802.1X authentication frameworks, and other things that home office and small office networks don't need and in most cases can't even use.

The point I'm making is that more really can be better - if you need the 'more' that a high-end product offers. If you can't use 802.1X integration, it's wasted. As you design your Wi-Fi network, be realistic about your needs, and don't buy features that you can't put to work.

Sketching Network Usage Patterns

Your physical location is a given: You have a house or an office to equip with a Wi-Fi network. A good first step is to determine where people will be establishing wireless connections to the network. If you have a scale drawing of your home or office, it's a good idea to make a copy and mark where network access will be required.

There are two different kinds of client connections to an access point: Fixed and roaming. Fixed connections are easy to spot: People in your home or office have desks at which they work, and their desktop computers can be equipped with Wi-Fi client adapters to let them connect.

Roaming access is less well defined. At home, I use my laptop in three places: On the dining room table, on the coffee table in the living room, and out in the garage where I have my workshop. Anywhere you may need a 'work surface' is a likely candidate, as is your 'easy chair' where you read.

In an office, your conference rooms will be the #1 roaming destinations, followed by the break rooms. Staffers sometimes bring their laptops into one another's offices, but if a desktop machine is already connected in an office, a laptop will usually be able to connect as well. If you have a warehouse or mailroom, you may need to think a little harder about whether those areas (which can be substantial) need Wi-Fi coverage.

In a home network, the number of people connecting will usually be small and isn't generally an issue. In an office 'cube farm,' however, you may have enough people in a small area to overload a single access point and drag throughput down to dialup levels. All clients connecting through an access point share that access point's throughput on an equal basis. Get more than five people on a Wi-Fi access point, and if they all use the connection simultaneously the connection will slow down significantly.

Once you know how much area your prospective network has to cover and how many people the network must serve, you can begin making decisions about what technology to choose.

To start designing your network, I suggest you get out a piece of paper and draw out your home or office configuration. In this drawing indicate where your computers are currently located and the areas where you may be working (assuming that you have one or more laptops). Try to mark your fixed and roaming connections on your drawing; that is, indicate which locations have desktop machines that don't move around, and which (like the kitchen table) might be popular laptop hangouts. Also indicate where your access point might be (hint: Where's your broadband Internet connection?) and be mindful of the distance from your access point to your fixed and roaming connections.