If you follow the goings-on of wireless LAN start-ups, you've probably noticed a recent rash of top-management changes at many of these companies.Among the changes are new CEOs at wireless switch makers Aruba Wireless Networks, Trapeze Networks and Vivato. Also, an interim "executive chairman" was appointed at wireless gateway company Bluesocket late last year upon the departure of CEO Eric Janszen.The aftertaste of the economic downturn has many enterprises banking even more heavily on vendor viability than in the past. But should you view these changes as signs of doom - or of progress?It depends, says Chris Kozup, program director of technology research services at Meta Group.Young companies all go through an "entrepreneurial and ruthless phase," he says. But as they grow, they need more predictability and accountability for how the business is run."Start-ups can only run off [venture capital] funding for so long before they must become accountable," he says. "So there's a natural point at which transition often takes place."Aruba, for example, brought in Don LeBeau, formerly senior vice president of worldwide sales and operations at Cisco, as CEO early this year. Aruba snagged LeBeau for "his sales muscle and contacts, so we can build a big distribution pipe," says a company spokesman. He dismissed rumors that Aruba has been prepping itself to be bought."We think we can make more money going [IPO] than by being bought," the spokesman says.LeBeau sees value in enabling large-scale wireless deployments in ways that don't disrupt the wired infrastructure."We've learned from our early customers not to try to make a wired network do what it wasn't intended to do," he says. "[It's less disruptive to] use an overlay structure, where there is a services layer in the data center that supplies security, mobility and other services to the wireless network."The long-term viability of Vivato, in particular, and Trapeze "are more questionable," Kozup says.Vivato makes a "big panel" access point and phased-array, omnidirectional antennas for long-range coverage. Most analysts say this architecture is better suited to the public network market.For its part, Trapeze has experienced significant management changes and layoffs - but it has also announced a number of customers. It also offers several identifiable value-adds for enterprises-most notably, its site survey planning tools. One satisfied Trapeze customer that I spoke to last week says the tools allow him to do "in five minutes what took three weeks to do two years ago."There will be more on that installation in another newsletter.