Nothing could be easier than setting up a wireless network: You drop by the local big box electronics retailer, buy a $60 wireless router and plug it into any free Ethernet drop in your office. Voila!

Not so fast. "You can set up a wireless network at home like that, but not in the enterprise," Forrester Research analyst Ellen Daley says. "These are networks, they need to be planned and designed. That takes time, but once everything is planned and designed you can set it up in ten minutes."

The ease of deploying wireless is one of the technology's main attractions, but it is in constant tension with both the reality of enterprise networking and the other, more significant benefits of the technology. "Wireless networking has a broad appeal in most industries, but it goes particularly deep in some verticals, like health care, manufacturing and retail," Daley says. "The perceived benefits are improved communication, productivity and accuracy in manufacturing, as well as time-saving."

With the increasing tide of enterprise voice over IP (VoIP), the wireless local area network (WLAN) has acquired even more appeal. It has provided the rationale for those $700 dual-mode voice over WLAN (VoWLAN) phones which, conversely, have justified the investment in Wi-Fi. "In carpeted offices, there's a perception that people are using their cell phones to make business calls while they walk through the halls," Daley says. "Companies have VoIP, and they either have or are thinking about Wi-Fi, so why not combine them? There's a pent-up demand."

In fact, how a company plans to use Wi-Fi will ultimately determine how it will deploy it. And working that out is the first step in a successful deployment. "You have to get your strategy down," Daley says. "How dependent are you going to be on this network? What's you're five-year strategy, and do you want to integrate the WLAN with your wired network? The answer is usually yes."

This is particularly critical when it comes to security, since network integration often implies security and access integration. Consequently, a major question will be whether the WLAN will sit in a DMZ. "Over-air encryption is there, so you don't have to worry about it," Daley says. "But you do have to define how you will do security for the WLAN and for the network as a whole. There are new standards out there, but no one's using them right now, so this is something you have to think about." You also have to think about the physicality of the network. Although WLANs route packets through the air, offices are composed of a lot more than just air. Hallways, cubicles, rooms and the company's geographic location are all variables to be considered in a WLAN deployment.

"You don't always want to have it everywhere, so you have to decide where you do want it," Daley says, pointing out that this first step really isn't all that difficult. "It means importing your office layout into a planning tool to figure out where the walls are and what the RF pattern will be, given the layout."

Most of these tools, like the Cisco Wireless Control System, come as options with enterprise wireless access points (APs). Their propagation databases can be critical to determine the most advantageous AP location, to get maximum coverage with minimum hardware and to ensure that access doesn't spill over into un-welcomed areas.

Coverage patterns are one thing; usage is another. It is absolutely critical, Daley says, to determine how many users will actually use the WLAN. "As more people jump on the network, bandwidth will decrease," she says. "It's sometimes easy to forget that wireless LAN capacity is a function of both distance and bandwidth.

The bottom line is that, while at some level, WLAN deployment is a ten-minute job, doing the job right means taking a bit more time to work out all the variables. In the past, companies typically had no wireless policy, but that's something that Daley says every company should consider before taking the wireless plunge. "There is an education element in all of this, and companies have to take the time to learn about this technology," she says. "Just because you're smart in networking doesn't make you automatically smart in wireless networking."