At long last, there is an 802.11a-capable Wi-Fi phone on the market. An enterprise-class one. And with Wi-Fi Protected Access and WPA2 security, no less.

SpectraLink, the longtime pioneer in local wireless voice capabilities, announced an 802.11a/b/g-capable version of its phones last week. With the company’s NetLink 8000 Series Wireless Telephones, you can get a battery pack for four, six, or eight hours of battery life. The phones weigh less than four ounces.

I’ve long been a fan of 802.11a, particularly for enterprises looking to go whole hog with voice over Wi-Fi. The reason is that the many channels available in 802.11a’ 5GHz range (up to 23) allow for a more flexible “checkerboard” network design.

This means you can create many more overlapping transmission cells while avoiding interference than you can with 802.11b and 802.11g, which operate in the increasingly crowded 2.4GHz range with just three non-overlapping channels. The many available channels used by 802.11a allow you to design for very dense coverage.

Abt Electronics, a large retailer in Glenview, Ill., for example, is running into some interference problems in its 160,000-square-foot showroom, where 250 salespeople all carry 802.11b Avaya-branded SpectraLink Wi-Fi phones.

“We can only have a limited number of access points, because of 802.11b’s three channels,” explains Vince Siragusa, the company’s telecom manager. “So we’re overloading them with too many salesmen. On top of that, manufacturers are coming out with more and more 802.11b type consumer products - wireless speakers, wireless TVs. They’re all causing interference with the phones,” which he says otherwise are “awesome” when there is a clear signal.

Voice traffic, of course, is more sensitive to interference and latency than data. It would be possible, for example, to dedicate some number of 802.11a channels to voice traffic to avoid crosstalk from other traffic types.

SpectraLink’s NetLink 8020 lists for $595. The 8030, with push-to-talk capabilities, costs $675. Battery packs range from $55 to $95.

Joanie Wexler is an independent networking technology writer/editor in Silicon Valley.