In the morass of wireless goings-on, how can you make sure your investments are sound and future-proof? With new suppliers, architectures and standards continually emerging, it's no wonder a recent Synergy Research Group report cited "buyer confusion" as one of the top reasons enterprise wireless LAN equipment sales were down almost 3% in the third quarter of 2002 - and have fallen nearly 13% year-over-year.The other obstacles, says Synergy, include lingering discomfort with wireless security and, of course, restricted IT spending in general.In particular, enterprises are hung up by the buffet of wireless LAN standards.\u00a0 Understandably, customers want to be sure they install the combination of 802.11a\/b\/g technology that will deliver the greatest return on investment (ROI).There are two basic factors to consider here: 1) making the appropriate mix-and-match technology choices in access points and client adapters and 2) tracking how well the technologies and their various implementations work as advertised.First, let's consider the mix-and match challenge.Some wireless LAN system vendors tell me the trend will be to put dual-mode 802.11a\/b APs in enterprise networks, but that most Wi-Fi hot-spot APs will have 802.11b\/g connections. If you are building an ROI analysis for enterprise LANs that includes traveling users being able to leverage their wireless adapters on the road, this might be a hiccup.Yes, most of the enterprise-class, dual-mode APs on the market will allow you to swap out an 11b (11M bit\/sec) radio for an 11g (54M bit\/sec) radio, once the 802.11g standard gels. And 11g is being crafted to be backward-compatible with 11b (though industry reports last week claimed problems on this score), since they both operate in the 2.4 GHz frequency range.But an 11g-11a mismatch for high-speed networking, while perhaps not a deal-breaker, is another factor to throw into the ROI pot. If the high-speed connections in the client and APs differ, you forfeit the benefits of the higher-speed technology.Put another way, if you install one of today's dual-mode 11a\/b APs, you will likely, at some point, deploy 11a (54M bit\/sec in the 5 GHz range) in your users' adapters. Otherwise, why pay for the 11a radio infrastructure?Now, let's say that your cost justification presumes that traveling users can use their wireless LAN adapters with public Wi-Fi LAN services. If 11g is the prevailing technology in hot spots, but your users' client devices support 11a, you'll hit an ROI bump. Traveling users with 11a\/b cards will fall back to 11b's 11M bit\/sec connectivity (provided the technology works). This stunts, somewhat, the return on your 802.11a technology investment.On the client side, it's looking like you'll have to buy a dual-mode 11a\/b card (or laptop chip architecture) and perhaps an 11g PC Card to hit all the various flavors-unless someone comes out with a tri-mode architecture.