I strongly believe, however, that voice over Wi-Fi will become the killer wireless LAN application that we’ve been waiting for. My consulting firm, Wireless-Nets, has seen a widespread trend toward creating voice over Wi-Fi products, and many companies that are deploying wireless LANs also have an eye on voice.

Several Wi-Fi-enabled telephones are on the market now, such as Cisco’s Wireless IP Phone 7920. Traditional wireless LAN infrastructure players, such as Cisco, and startups such as Aruba Networks, have well-designed access points that enhance voice over Wi-Fi connectivity. Non-traditional service providers like Vonage are even offering voice over Wi-Fi service plans for nationwide calling that are much less expensive than cell phones.

The Federal Communications Commission has spoken, ruling a while back that VoIP (voice over IP) services are interstate in nature and not subject to traditional state public utility regulation. For example, Vonage is avoiding the Minnesota Public Utility Commission’s efforts to treat its service as traditional phone company service. While the FCC will further decide what regulations apply to Internet telephony over the next year, it seems at this point that regulation will stay out of the way. 

Some of my clients are currently deploying voice over Wi-Fi solutions, and the majority of the remaining ones are planning to do so in the future. The benefits of voice over Wi-Fi in enterprises yield substantial returns on investment because mobile telephone usage is enabled within facilities and because combining telephone and data networks lowers costs. The returns are just too substantial to resist.

This leads to the bad news. Most existing wireless LANs installations will not adequately support voice over Wi-Fi applications mainly because 802.11 wireless LANs were meant to support data, not voice. Many of these networks definitely don’t meet Cisco’s guidelines for deploying wireless VoIP phones.  

When performing onsite testing, I often find wireless LANs with lots of coverage holes throughout the facility, low signal strength in staircases and hallways where phones will likely operate, sloppy RF channel assignments, and access point handoffs that are too slow. Wi-Fi phone usage on these networks is generally full of crackles and pops, with frequent dropped calls as users roam about the facility. 

Redesigns of existing wireless LAN installations are necessary to offer the optimum blend of antenna types and access point configurations, along with possibly replacing access points with ones that offer faster roaming. Most existing wireless LANs today are 802.11b. Through testing, I’ve found them to only support up to a half dozen simultaneous phones calls. This isn’t good enough for a dense population of phone users who will likely be present even in smaller offices.  

If you’re an enterprise considering the installation of a new wireless LAN, determine early in the project whether you’ll be supporting voice over Wi-Fi now or in the future. Most likely, you’ll be moving in the direction of voice, which will definitely impact your selection of wireless infrastructure. So be sure to review infrastructure designs with an emphasis on meeting requirements for voice.

Jim Geier is the principal of Wireless-Nets Ltd. (www.wireless-nets.com), a consulting firm assisting companies with the implementation of wireless mobile solutions and training. Jim is author of the book “Deploying Voice over Wireless LANs.”