Sprint Nextel (S), already counting the billions in cash to come in to its treasury once its deal with SoftBank is finalized, had been flirting with the idea of stealing MetroPCS (TMUS 0.57%) out from under T-Mobile USA and its German sugar daddy Deutsche Telekom. But the No. 3 U.S. wireless carrier has decided instead to hook up with its longtime WiMAX network partner and erstwhile 4G LTE wholesaler, Clearwire (NASDAQ: CLWR), in a deal worth $2.1 billion, according to Sprint's filing with the SEC.

For those who follow the telecom world, the nuptials of Sprint and Clearwire will remove one of the more interesting (and sometimes entertaining) story lines in in our narrow universe.

A bad romance
The relationship Sprint has had with Clearwire has sometimes seemed like a movie plot involving star-crossed lovers who just can't seem to make their relationship work, but one that neither can quit.

Clearwire itself was formed in a joint venture with Sprint, Google (GOOGL 0.55%), Intel (INTC 0.64%), Comcast (CMCSA -0.37%), and Time Warner Cable (NYSE: TWC).

The new company was supposed to build a state-of-the-art high-speed mobile network to leapfrog Sprint into the 4G era before Verizon (VZ -0.53%) and AT&T (T 1.88%) could get their faster networks into high gear.

Seemed like the right move... at the time
It would have been a good idea except the 4G technology chosen was WiMAX, which was faster than what was available at the time, but not anywhere near as fast as LTE, the technology that came in right on WiMAX's heels.

So all Sprint got for the bragging rights of being the first with 4G-ish capability was a soon-to-be-obsolete network. The other Clearwire investors jumped off the Clearwire bandwagon at a fraction of the price they paid to buy in.

Sprint, too, had been playing with the idea of letting its commitment to Clearwire just run its contractual course and create a 4G LTE network on its own. As Clearwire's financial picture became bleaker, Sprint even got rid of enough Clearwire voting shares to give it slightly less than 50% control of Clearwire to lessen any liability in case the company went bankrupt.

Sprint had also been hedging its 4G LTE bet by signing on with LightSquared, the privately funded company with the hybrid satellite-ground station LTE networking plans. That scheme was eventually nixed by the Federal Communications Commission due to GPS interference problems.

But Clearwire still had something keeping Sprint from just running off: the spectrum bought with the billions from the original investment. Sprint's queasiness about losing that invaluable resource may have played into what happened next.

High noon
In mid-November of last year, Clearwire CEO Erik Prusch told The Wall Street Journal his company just might decide not to make its $237 million interest payment on the $4 billion it owed.

"It would be a significant drain of our cash, so we have to evaluate everything in terms of our decision of where we're going," Prusch told the Journal.

Some analysts thought this was a ploy to push Sprint into committing itself further to Clearwire's survival -- or to attract another suitor.

If it was a ploy, it worked. Just hours before the interest payment deadline of Dec. 1, 2011, Sprint agreed to a deal with Clearwire to provide it funding totaling $1.6 billion, and to continue with WiMAX through 2013.

Clearwire paid its bill. Crisis averted.

Back to the present
The SoftBank deal changed everything. In October, immediately after accepting the Japanese company's offer, Sprint filed with the SEC its intent to buy a controlling interest in Clearwire. According to sources speaking to The Wall Street Journal at the time, SoftBank wanted to make sure Sprint would have control of Clearwire.

That increasing of its voting rights in Clearwire may have been seen as the first step in Sprint's taking total control of Clearwire and all its assets but for the distraction caused by the T-Mobile deal with MetroPCS.

So now there are many happier Clearwire shareholders, and one very happy investor who bought 28,000 call options last July. Each of those options cost $0.15 and give the buyer the right to purchase one Clearwire share for $2.00 before the option expires on Dec. 21. As of this writing, Clearwire shares are up over 14% to $3.15.