It's amazed me how many people have asked me about 802.11n support in Vo-Fi handsets. While I'm a strong advocate of Vo-Fi, both for its increased productivity and potential costs savings, Wi-Fi support in this form factor has always lagged behind the laptop modules, PC card, and USB products in terms of security and radio support.

ZyXEL's first Vo-Fi handsets are case in point -- they were released mid 2005 supporting only WEP, even though WPA was announced late 2002. The first 802.11g products were already on the market the early part of 2003, but ZyXEL's handset only supported 802.11b. Fast forward to this year. It was just the first quarter of 2007 when the two leading vendors of enterprise Vo-Fi handsets, Cisco and SpectraLink (now Polycom), introduced their 802.11a/b/g capable handsets. That's a full four years after the IEEE certified 802.11g. I believe that 802.11a support in these Vo-Fi handsets was a little too late in coming. This was their first refresh for both vendors and hindsight being 20/20, they should have spent their development dollars on some other aspect of their phone, or brought an 802.11b/g model
earlier to market. Vo-Fi handset vendors have been betting on the cleaner and more plentiful spectrum available to 802.11a devices, but enterprises were slow to take advantage of dual-band, dual-radio APs, and so few organizations besides higher ed have had a meaningful level of 802.11 usage.

The reality is that development for a ASDs is a different animal than PC cards and USB products. For starters there is form factor, but there's also chipset integration and placement, power consumption, antenna design and placement, and driver design for the handful of embedded and mobile OSes. To complicate things further, volumes are just a fraction of the other product categories.

Software design aspects such as security and driver support should be surmountable challenge through code reuse, but the hardware engineering challenges of multiple radio chains and antennas suggest to me that we'll be fortunate to see even one enterprise-grade 802.11n Vo-Fi handset in 2008.

Even if it was technically possible, a careful evaluation suggests that there's little incentive for either the vendor or enterprise to want such a handset in the short term. For the vendor, there aren't any mobile editions of 802.11n chipsets at this time. This means any product that would come to market at this time would use a larger chip and suffer from poor battery life. For the enterprise, handsets use little bandwidth even though they can use lots of air time. One is better off purchasing new devices and migrating existing ones to 802.11n operating at 5 GHz rather than push the envelope on 802.11n capable Vo-Fi handsets. Let the Vo-Fi handsets use the 802.11b/g radios at 2.4 GHz which will carry less and less traffic while other clients move to 802.11n at 5 GHz. By the time 802.11n at 5 GHz is the norm, mobile-friendly chipsets will be out and vendors can start integrating them into the products.

Don't hold your breath of 802.11n Vo-Fi devices. If Vo-Fi is in your budget today, don't think that FY 2008 will see many related product announcements.

Deploy now, and budget for a refresh three to four years from now. Perhaps by that time you'll be thinking fixed-mobile convergence.