Nokia unveiled three new Nseries phones today optimized for the North American 3G bands, but as with its domestic launch of the N95, the global handset vendor hasn’t secured a single carrier commitment to carry the devices. By optimizing its latest batch of Symbian gadgets for North America, Nokia is clearly showing its intent to penetrate the highly competitive smartphone market here, but analysts debate the impact Nokia can possibly make by going outside of the traditional sales channels.

Both the N85 and the N79 launched globally today with tri-band HSDPA 3G and quad-band GSM/EDGE radios for worldwide coverage. A North American dual-band 850/1900 HSDPA version of the N96 was also announced today. Now, along with the N95 and recently launched E71, Nokia has five smartphones that can work on US UMTS frequencies, though AT&T and a few regional carriers would be the only operators capable of supporting them.

The Symbian OS-powered line of Nseries phones dominates the global smartphone market, yet the manufacturer still has low penetration in the US, running a distant fifth behind phones powered by competing operating systems from Microsoft, Research in Motion, Palm and now Apple’s iPhone OS. AT&T is the sole carrier to have offered an Nseries device, the N75 in 2006, but the carrier has since dropped it from its catalog.

Avi Greengart, research director for mobile devices at Current Analysis, said that Nokia hasn’t been able to get a carrier distribution for technical, strategic and historical reasons. Until the manufacturer fully embraces CDMA in its higher-end devices, its potential national carrier base is limited to AT&T and T-Mobile, which operate GSM networks in the US. The fact that T-Mobile doesn’t have a fully deployed 3G network – that operates in a different frequency to boot--might make some of these higher-end devices, like the organic-LED-screened N85 and video-centric N96, less compelling than they would be with faster speeds. Greengart also pointed out that AT&T has tried selling an Nseries device, the N75, as well as the Eseries E62 in the past, but the chunky form factor of the N75 was less than ideal, while the E62 lacked both Wi-Fi and 3G.