Wireless networks aren't just a convenience anymore; they've become an essential part of business culture. It's nearly impossible to walk into a workplace that doesn't use Wi-Fi in some fashion. For the millions of portable wireless devices--from traditional laptops to smartphones and tablets (including Apple's iDevices and the ever-expanding menagerie of Android-based gear)--that people carry with them today, Wi-Fi is the great connector, providing an industry-standard communication layer for untethered devices.
Making your organization Wi-Fi-friendly is good business. Wireless support can foster goodwill among visitors, enable the workforce to stay connected to the company while on the road, and provide network access in areas that are either too expensive or too inconvenient to reach easily with traditional network cabling. But pulling off a successful Wi-Fi deployment can be tricky. For instance, it may seem like a good idea to buy the lowest-cost access point (AP) and stick it in a corner, but such a minimalist approach is unlikely to yield the results you're looking for.
When Wi-Fi Isn't Enough
Before embarking on a company-wide deployment, you should make sure that Wi-Fi will meet your needs. If you want to give laptops, tablets, and other devices wireless support for Web surfing, Wi-Fi is a great fit. It's also good for asymmetric application access--that is, for situations where users consume bandwidth in just one direction.
The chinks in Wi-Fi's armor become evident, however, if you try to use it with non-Web-based line-of-business applications, such as "fat" client/server applications. Also, software packages that can't deal with occasional communication glitches are less than ideal for Wi-Fi. When I attempted to run a popular small-business accounting package over Wi-Fi, I ran into trouble continually because the software couldn't tolerate occasional momentary lapses in connectivity. Though a Web browser would never even notice such minor issues, applications that send a lot of traffic and can't handle communication errors are poorly suited to Wi-Fi.
Likewise, if you try to stream multimedia content via Wi-Fi, you may encounter difficulties. Depending on your setup and on the quality of your AP, users may be disappointed, especially on densely populated APs. Cheap, low-cost APs typically work fine for a few users, but they can't keep up when you scale to ten or so.
The latest Wi-Fi specification is 802.11n. Like its predecessors 802.11b and 802.11g, 802.11n travels over a 2.4GHz radio signal. The 802.11n spec uses a multiple-antenna system that provides greater range than 802.11g, and it can transfer data at speeds of up to 300 mbps, compared to 802.11g's maximum rate of 54 mbps. And since 802.11n devices are backward-compatible with 802.11b/g devices, there's no reason to look at any APs other than 802.11n devices unless you're bound by a previous purchasing contract.
Location, Location, Location
A successful Wi-Fi installation involves more than just tossing a few APs around and hoping for the best. To start with, you should consider where to place the APs, what the interior walls are composed of, and how many APs need to be installed. Locating the Wi-Fi APs is a critical aspect of the wireless deployment. One option is to use centrally located APs through the floor to provide "inside out" coverage; another is to go "outside in" by placing the APs in corners and along outside offices, with the APs looking in to the user area. If your building setup doesn't permit placing APs in the user space, you can use high-end outdoor APs to "light up" the building from outside the physical walls; this is particularly useful in multiple-tenant situations. Of course, you can always combine approaches to get the exact coverage you need. I've found that, except in the case of floor plans where the center of the building is filled with elevator shafts or other equipment, an inside-out approach provides the best coverage and is easier to deploy.
It may sound obvious, but make sure that you've planned for a sufficient number of APs. I've seen many Wi-Fi installations fail because the company used too few APs to cover the user space, with some overlap. in the open, a typical AP can cover a radius of approximately 300 feet. Indoors, 50 to 100 feet is the usable maximum.
The composition of your walls plays a big role in how far Wi-Fi travels indoors. Wood construction is best; walls attached to steel studs are bad; and concrete walls with steel rebar are the worst. One or two walls can greatly reduce a Wi-Fi signal. And if the path to an AP traverses a wall at an angle, the signal is likely to degrade even more. A number of tools--from handheld scanners to iPhone and Android applications--are available to help admins check wireless signal strength at various points in a building. Use these tools to achieve optimal AP placement.