Most of Clearwire's (News - Alert) investors are going to cough up more money to go into the North American WiMAX venture. Sprint is going to invest another $1 billion dollars with Comcast, Intel, Time Warner and Bright House Networks coming up with another $500 million – but Google (News - Alert) is going to sit this round out.

Adding up all the numbers, Sprint and its partners will have put in $4.7 billion dollars between this round and the earlier $3.2 billion round which formed the nationwide WiMAX effort 18 months ago The initial Wall Street Journal story also says that Clearwire has been looking for cash from other investors, including Deutsche Telekom (News - Alert), but without success. (Depending on whom you listen to, DT is saving up cash to either buy Sprint outright to get better coverage in North America or to fix the problems with T-Mobile North America).

In addition to raising all this money, Clearwire is also going to do some debt jockeying, retiring $1.4 billion of variable interest rate debt it had with Sprint and Comcast with $1.45 billion in new bonds for a longer term and at a fixed interest rate. When the smoke clears, Clearwire will end up with another $240 million in cash.

What does this all mean? If you want to believe, this is good news.

For Sprint, this investment comes after the company posted a net loss of $478 million in the third quarter and the loss of half a million customers between July and the end of September. But the company has few choices but to support the Clearwire effort since it has already put in its WiMAX (News - Alert) spectrum licenses and other assets into the company in exchange for 51 percent of the stock.

Still, Sprint chose to invest more after an unhappy 3Q earnings announcement, so it is not flinching away from the build out. It and the other investors could have waited another quarter, but everyone seems to feel the time is now to push forward on WiMAX and establish the technology in the market place before LTE (News - Alert) starts showing up in 2010 and 2011.

This move should also be interpreted as Sprint and its investors having faith in the future growth of the U.S. economy. Sprint, Clearwire, and the cable companies are all be selling 4G service in many of the same markets, so they all expect that lots of consumers and businesses will be willing to pay for wireless broadband either as an upgrade to existing services or a substitute for more expensive 3G and/or landline connections.