Choosing a WLAN for your SMB: A primer

This tip originally appeared on SearchSMB.com. For more IT articles and tips specific to small and midsized businesses, visit SearchSMB.com.

Wireless LANs (WLAN) are quickly becoming the standard connectivity for anyone who owns a mobile computer. It is almost synonymous with LANs for all businesses.

Choosing the right WLAN for your small or midsized business (SMB) can be a daunting task. The rise of the IEEE 802.11 standard and the Wi-Fi interoperability specification based on it has led to an enormous range of products that can address essentially any enterprise LAN application -- including the rapidly emerging Voice over Internet Protocol space. Never fear; all you need is a basic understanding of the various architectural choices available and you'll be on the air in no time.

If you run a very small business, then almost any access point (AP) will do. An AP is the bridge between wireless (and often mobile) users and the rest of your network infrastructure. APs are often integrated into wireless routers, which plug directly into a broadband connection; a standalone AP can be used if you already have a router.

Wireless routers are readily available at computer and consumer-electronics stores; almost any model and brand will do. While .11g alone is fine, we generally recommend, however, that SMBs buy so-called "triple-mode" routers including 802.11a, b, and g. This will yield the best performance and capacity, even for small enterprises. Note that these products are mostly residential-class products, but will work fine in small firms -- they're easy to set up and require little ongoing management.

Larger firms need enterprise-class APs with network management and power over Ethernet (PoE) support. They must also consider two key variables in selecting their WLAN solution: coverage and capacity. WLANs are by their very nature "microcellular." This means that a given user's connection can be handed off among APs as the user physically roams throughout a building or campus. Thus, a potentially large number of APs may be required -- and the specific number in each case depends upon how large an area is to be covered, and the user traffic demands in each part of the building.

For example, applications requiring very limited throughput, like the bar-code scanning typical of warehouse operations, could probably live with each AP covering up to 50,000 square feet or so. Those with typical office workers who are e-mailing, Web browsing and sharing applications, might demand as little as 5,000 square feet per AP. Adding VoIP over Wi-Fi (or VoFi) might decrease this to as little as 3,000 square feet.

That's a lot of APs to configure and manage. So, the approach we recommend for most SMBs is to use a wireless switch and "thin" (not requiring individual configuration or management) APs.

A wireless switch looks a lot like a traditional Ethernet switch but connects only to (typically thin) APs over Cat 5 (or better) wiring, and provides PoE to the APs. These APs can even be plugged into existing network wiring to save on installation expense. The switch provides all required configuration, security, management and control. So, instead of having to deal with a sea of APs, all that's needed is a few settings on the switch itself (via the usual Web-page interface), and the enterprise is up and running.

Most wireless switches are designed for larger enterprises, but there's at least one that is designed with SMBs in mind, and we expect this category to grow dramatically as new WLAN-switch chips cut costs and complexity for system builders. Expect to see a huge range of inexpensive WLAN switches next year, along with the next big trend -- unified switches.

Eventually, it won't be necessary to think of wired and wireless LANs as separate and distinct. Rather, they'll be integrated and managed as a single network. With wireless becoming the default, that's exactly what most SMBs are going to need.

Some WLAN offerings:

Residential/SOHO Routers
Belkin
D-Link
Linksys
SMC
Trendware

Wireless Switches
3Com
Aruba
Cisco
Meru
Symbol Technologies
Trapeze

Craig J. Mathias is the founder of the Farpoint Group, an advisory firm specializing in wireless communications and mobile computing.