Sprint Nextel (NYSE: S) is betting the house on the first-mover advantage of having a 4G wireless network before everyone else. The network is humming along from coast to coast in partnership with Clearwire (Nasdaq: CLWR), reaching 43 metropolitan areas today, with more to come this year. Verizon (NYSE: VZ) is only testing its 4G network in a handful of markets today, and AT&T (NYSE: T) is even further behind. So it's a shame that Sprint's potential business moat is being bridged by a lack of 4G-capable hardware.

Despite a nationwide marketing campaign, Sprint offers only one 4G-connected handset today: the HTC EVO 4G. That Android-powered smartphone joins its Verizon-bound cousin, the Droid Incredible, in leaning on Samsung for supplying the touchscreen hardware. But Samsung seems to reserve the lion's share of screens for itself these days, leaving but a trickle of supply for HTC and others.

LG Display (NYSE: LPL), Sony (NYSE: SNE), and Toshiba feed touchscreens to Apple (Nasdaq: AAPL) and other mass-market handset makers. Unfortunately, the EVO 4G appears to be handcuffed to Samsung's technology. There are no reports of multi-vendor sourcing for this crucial part. That's why only 300,000 or so EVO 4Gs have left HTC's factories to date, pushing retail availability back to dates unknown and Sprint up the creek without a paddle.

A second 4G phone is coming Sprint's way now, and this one is a Samsung original. That should guarantee steady access to screens, though we're talking chronically volume-limited OLED displays this time. But aside from having 4G radios and a slide-out keyboard, essentially the same model is rolling out to every major network in North America. All told, I don't think that's enough of a difference maker.

Sprint is betting big on the 4G advantage, but the stars are not aligning for huge success here. The network needs to order up 4G handsets from a few more vendors to relieve that choking bottleneck, and make sure that they don't all draw crucial parts from the same single-component manufacturer. That's not easy to do for a company with shrinking annual revenue, negative earnings, and thus a limited budget for marketing and supplier concessions.

Has Sprint fumbled the 4G advantage beyond recovery or is the ball still in play? Discuss in the comments box below.

Fool contributor Anders Bylund holds no position in any of the companies discussed here. Sprint Nextel is a Motley Fool Inside Value recommendation. Apple is a Motley Fool Stock Advisor selection. Try any of our Foolish newsletters today, free for 30 days. You can check out Anders' holdings and a concise bio if you like, and The Motley Fool is investors writing for investors.