Apple has been assigned rights to over 200 patents and pending patent applications by Freescale Semiconductor, the chip design company spun off from Motorola in 2003. Though the exact details of the transaction aren't discernible from the public records, the bulk of the patents appear to be related to wireless communication hardware technology.
Motorola spun its chip design business into a separate unit called Freescale in 1994. In a restructuring effort, Freescale was spun off as its own company in 2003. While responsible for designing many of the PowerPC processors that Apple used until switching to Intel in the middle of the last decade, as well as the radios and signal processors used in Motorola's mobile devices, the company today designs and sells a range of embedded application processors, DSPs, baseband processors, and more.
The list of patents transferred to Apple, reported by Patently O, includes US Patent #5,960,042, "Method in a selective call receiver for synchronizing to a multi-level radio signal," originally assigned to Motorola in 1999 when Freescale was still a subsidiary. It also includes recent patent applications such as US Patent Application #12/981,423, "Channel Sounding Techniques for a Wireless Communication System," filed in December 2010 and published in April 2011. The majority are related to wireless communication, and most seem applicable to iPhone and iPad design.
Patently O noted that the notices filed with the USPTO give Apple an "assignment of assignors interest," which indicates that Apple owns full title to the patents. It is suspected that Apple paid for transfer of the patents outright with cash—Apple has been amassing a huge pile of money over the last decade, and Freescale has been recently mired in debt. Apple may have already been licensing some of the tech described in the patents, and saw buying them outright as a cost-savings measure.
Aside from using the tech in its mobile products, though, Apple could use the patents as additional defense or offense in its growing number of patent battles with competing smartphone makers, including Nokia, Samsung, HTC, and Motorola. It would be ironic if Apple were somehow able to leverage any of these patents against Motorola, but we suspect Moto has some kind of license agreement with Freescale in place.