It\u2019s common for organizations to find the budget to deploy a wireless LAN to support a single, pressing application. However, once the network has been installed, the enterprise tends to find many other uses for its 802.11 infrastructure, and the network may have not been designed properly to support those additional capabilities.For this reason, Tom Hagin, vice president of the wireless business practice at integrator NetXperts, in San Ramon, Calif., advises designing your enterprise WLAN from the outset \u201cfor the worst-case scenario, in terms of coverage, capacity and quality, if you have the budget available.\u201dFor example, when getting started with wireless to support one application, try to predict the workflow of other applications that might get added, he recommends. \u201cThe workflow of an IP phone, for example, is much different than that of a bar code scanner,\u201d he points out.\u201cPhones have specific requirements for RF signal strength,\u201d he says. He says that \u201365dBi antenna signal gain is a good target for voice; \u201357dBi is even better. But \u201390dBi simply can\u2019t support voice, he says.Hagin recounts the circumstances of one customer with a 2.4-GHz Wi-Fi network that wound up with 500 laptops, 500 IP telephones and a capacity bottleneck. \u201cThe 2.4-GHz band [with just three non-interfering channels] prevented us from cramming more [access points]\u00a0in\u201d for additional capacity, Hagin explains.The answer? NetXperts added a 5-GHz radio to every wireless access point - Cisco 1200s, which contain 5-GHz slots for 802.11a radios and 2.4-GHz slots for 802.11b\/g radios. Hagin locked down his customer\u2019s laptops to communicate with the 5-GHz 802.11a network only, and the 802.11b IP phones remained on the 2.4-GHz network.\u201cYou do have to lock down [a device you want to operate exclusively on one frequency] or the software will simply connect to the best available network,\u201d Hagin explains. Locking down his users\u2019 laptops for use only in the 5-GHz band involved simply unchecking the 2.4-GHz option during software configuration, he says.