The carriers don't want baseband code, they just want finished products to sell.
It's OSS, well tested, secure, and supported. Buy support from me." why won't they go for it. Surely, an OSS solution is cheaper for them than developing an in-house crap solution that I'm sure it is now.
OK, assuming you get a current-generation baseband chip for free (it actually costs a ton of money to develop) with full documentation, you're still talking hundreds of millions to develop that software. GSM (a 2G technology) is complicated. UMTS / HSPA (one of the 3G techs) is an order of magnitude more complex. LTE (4G) is another order of magnitude more complex than 3G. The baseband code, plus all the testing code, plus all the testing required by the FCC, standards bodies and the carriers is a ton of money.
It costs millions to take an existing chipset (which has already been approved), an existing baseband codebase (which has also already been approved for use with that chipset) and put that into a modem and get that approved.
The chip vendors have their own baseband code now, and they are all in fierce competition with each other. They aren't going to just use your code, and they aren't going to let you use their chips either.
