If there's an obstacle to falling prices, it's standards. Although the VoIP industry has begun to embrace SIP (Session Initiation Protocol, RFC 3261), none of the VoWLAN phones we tested supports SIP. And though SIP-compatible soft phones run on wireless-equipped PDAs, the performance is disappointing. It's not that the products are poorly implemented, but rather that SIP wasn't designed with WLANs in mind, and WLANs weren't designed with voice in mind.
The latter is changing. Meru Networks' new Wireless LAN Solution has low-cost access points that communicate over existing Ethernet infrastructure to the Meru Controller, a services and management appliance.
Airespace, a leading WLAN switch vendor, is emphasizing the voice capabilities of its products, asserting that an increasing percentage of prospective WLAN infrastructure customers require VoWLAN-capable products, even if they don't plan to deploy voice now.
If you believe the market research, in three years VoIP may outsell circuit-switched PBXs. With more capable WLAN infrastructures and more cost-effective VoIP products, it's a good bet that VoWLAN will become a more cost-effective solution.