Fixed-mobile convergence (FMC) start-up Agito Networks Monday plans to announce voice-over-Wi-Fi encryption and other features for its RoamAnywhere Mobility Router.

The RoamAnywhere router is customer-premises equipment (CPE) that extends PBX policy and dialing plans across Wi-Fi and cellular networks to smart phones running RoamAnywhere client software. It enables location-based, seamless roaming between both types of wireless networks so that sessions aren’t interrupted when mobile users cross wireless network borders.

A number of companies participate in this market with varying technical approaches. Among those that work with multiple vendors’ PBXs at the back end are Aruba, DiVitas, FirstHand and Siemens. Avaya and Nortel offer FMC capabilities with their own PBXs.

Agito, which also supplies the Wi-Fi-to-cellular signal-handoff component to Cisco’s recently announced Mobility Services Engine, has added a Secure Sockets Layer (SSL) encryption tunnel for voice traffic to the newest version of its gear. Wireless voice conversations without encryption are “bad for compliance with governance mandates such as SOX and HIPAA,” says Pej Roshan, Agito co-founder and VP of marketing.

Chris Nowak, director of IT at fruits and vegetables distributor Anthony Marano, has been testing the new version of RoamAnywhere. Also a Meru Networks WLAN customer, Nowak says the voice encryption capabilities will boost security in the same vein as Meru’s new RF Barrier, which uses a special, outside-mounted antenna to block RF signals from escaping the building and into the clutches of wireless hackers.

“We don’t care if someone knows how many bunches of bananas [a grocer] has ordered” by eavesdropping on a wireless voice call, Nowak explains. “But we do care about the price: that’s proprietary information.”

He thinks wireless voice encryption is more necessary than in wired networks. With physical cabling, someone would have to intercept calls at a termination device or unearth cables to tap in with a sniffing device. “Doing that requires significant effort,” he says. Wireless signals out in the air, of course, are much more accessible.

Agito FMC primary competitor DiVitas currently supports voice-over-Wi-Fi connections without encryption. The company said in an email statement: “Audio streams are not encrypted because current handset CPU hardware doesn’t have sufficient power to encrypt a real-time stream and maintain a high packet data rate required for good voice quality.”

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