I found this announcement from Verizon an eye opener.

Patents and the intellectual property they represent come from innovation, and Verizon continues to be an industry leader in this critically important area.

Verizon now owns nearly 2,500 patents in the United States and around the world, and the list continues to grow.  To recognize the groundbreaking work that represents, Verizon recently honored 94 Verizon inventors at a patent awards luncheon.  Since January 2006, 192 patents have been issued to the company - an average of more than 10 new patents each month.

 I have always thought of the carriers as implementers rather than inventors. If a company like Verizon has this many patents how many do the equipment manufactures have. Back in March 2006 Microsoft announced their 5,000th patent.

No wonder the likes of Vonage have a hard time avoiding being sued when implementing anything (Sprint Verizon), unless of course many of these are what the courts may consider to be "obvious".