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Avoiding WLAN Set-up Headaches (Part II) By Gerry Blackwell Building WLANs that really work may not be as easy as it's cracked up to be, as we started to discover last week in the first part of this two-part primer on design and implementation. In Part I, Jesse Frankel, chief strategy officer and vice president of advanced technology at Akron OH WLAN integrator NeTeam Corp. (www.neteam.com), pointed out some of the wires that all too often trip up first-timers. Readers who took in last week's 802.11 Planet conference in San Jose will also remember Frankel as a panelist in the "Building & Equipping Wireless Networks That Work" session. This week, he takes us through some of the basic step-by-step process of designing and installing a successful WLAN. The first set of steps - and as in most IT- and communications-related projects, it's absolutely crucial - is gathering and analyzing requirements. "You have to make sure that all of the real-life usage requirements are well understood," Frankel says. "One thing we harp on is understanding users' performance expectations. A lot of people may not have a totally realistic idea of what can be achieved. And then we also run into a lot of people who haven't thought about the question at all." This goes back to an example Frankel used last week of a training room where 30 users may all need to connect at once over the WLAN. If the room is only within range of one access point, users will not get the performance they expect. You also have to look at the existing wired infrastructure, he says - assuming the WLAN is an extension of or overlay on an installed wired LAN - and ask what new equipment, if any, and what integration effort will be required to make LAN and WLAN work together seamlessly? Then there are constraints and restrictions related to the physical infrastructure and the environment. What are the building materials and how will that effect propagation if at all? And where is it permissible to install antennas and access points in the facility? "Sometimes there can be aesthetic requirements," Frankel notes. "You don't see it so often in office settings, but if you've got an executive floor, people sometimes don't want antenna masts sticking out through the ceiling, for example." Another set of questions about requirements bears on security issues. In many installations, you may need optimum performance near the perimeter of the coverage area. But without careful design, that can result in coverage extending well beyond the perimeter - up to a half mile outside the building in some cases. "This is something that is generally not well understand," Frankel says. As witness all the stories about hacktivists cruising up to office buildings and easily hacking into the corporate WLANs inside. There are ways to solve such problems using pico-cell architecture, employing low-powered access points. It's even possible to engineer a WLAN that will provide good coverage in one area - a boardroom say - but no coverage at all in an insecure adjacent area such as a lobby. "This phase of the requirements collection and investigation is where a lot of the competency comes into play," Frankel points out. "Much of the effectiveness of [NeTeam's] process is the result of [what we do in] this initial phase." Another aspect of requirements gathering is understanding cost objectives. There are costs outside the price of the access points themselves and the cabling. One important question is how easy or