* Dual-mode hits the big-time
Osaka Gas, of Osaka, Japan, has purchased 6,000 NEC N900iL dual-mode handsets supporting both 3G and voice-over-Wi-Fi (Vo-Fi) connections. Osaka employees intend to use Wi-Fi services on-site and NTT DoCoMo cellular services outdoors from the same device.
Wi-Fi switch start-up Meru Networks landed the Wi-Fi component of the installation, which involves blanketing the utility company’s 50 offices in Japan with its 802.11 access points and controllers. A Fujitsu Session Initiation Protocol (SIP) server provides presence management capabilities and calling features, which work with the SIP-standard calling features in the DoCoMo-supplied handsets.
The deployment is under way and should be completed by year-end, according to Toshi Kibe, president and CEO of Nissho Electronics U.S.A., a distributor and integrator that was involved in helping Osaka Gas with its dual-mode evaluation, selection and installation.
The availability of dual-mode devices has been gathering steam this year. The devices have the potential to support single-number communications across both cellular and Wi-Fi networks. Users can make calls on the corporate calling plan when they are local and cellular calls when they’re not.
Kibe said Osaka will be running voice traffic on 802.11b channels and data on 802.11a channels from a common access point, primarily because “there are still no Vo-Fi handsets supporting 802.11a.”
802.11a, however, could be beneficial to voice, because its 5-GHz spectrum currently is less prone to interference than the crowded 2.4-GHz spectrum. It also supports many more channels for varying network design to further avoid interference.
Kibe said aside from Meru’s ability to support the greatest number of concurrent users per AP (14 to 15, depending on conditions), the call admission control (CAC) and call-balancing features of Meru’s recently announced Voice Services Module were “very important” to Meru winning the Osaka deal.
“The CAC feature returns a busy signal to a new caller if an AP is full so that the additional call won’t degrade the quality of all other calls,” he explained. “Call balancing moves users to less loaded APs to avoid busy signals.”
