Look at a cross-section of organizations across industries, and you’ll be hard-pressed to find a consistent, common strategy for deploying VoIP over Wi-Fi networks (Vo-Fi).

Plans are all over the map, but if I had to generalize, I’d divvy enterprises up into three camps. Roughly a third of Wi-Fi shops appear to be running Vo-Fi now. Another third say year after year that they plan to deploy Vo-Fi “within 6 to 12 months” – hmm? And still another third haven’t decided if they’ll deploy it at all.

A number of factors are driving these mixed enterprise strategies. Among them:

* Those already using Vo-Fi tend to be in specific industries with very localized mobile voice needs. Take nurses on a single hospital floor. This crowd absolutely requires mobile communication and can probably communicate using a single access point, so inter-AP fast roaming handoff isn’t an issue.

* The status of fast roaming technology, which ensures that voice sessions won’t get dropped as users re-associate to a different AP as they roam, is a mixed bag. Cisco, which makes both WLANs and Wi-Fi handsets, has its own proprietary fast-roaming scheme. If you are using Cisco handsets with a Cisco WLAN, you’re golden. If you are using a Cisco infrastructure with someone else’s handset, you need to make sure your handset provider supports Cisco Compatible Extension software Version 4, which contains the fast roaming mechanism. Polycom (formerly SpectraLink) plans to support CCXv4 in its handsets sometime this year.

Meanwhile, Polycom’s own call admission control and QoS capabilities in its SpectraLink Voice Priority (SVP) server have served niche Vo-Fi implementers wonderfully for years. However, as WLANs continue to grow mainstream, the Wi-Fi community wants fast roaming and QoS to become standard across systems. 802.11r, the fast roaming standard under construction, isn’t due for ratification until next year, with products to follow.

* Finally, there are many ways to skin a mobile voice cat. For example, in-building cellular services with PBX extensions are emerging, and some companies already ingrained in a cellular culture may be anticipating those.

While the many options (and these are just a few) continue to gel, many companies seem to be waiting.

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