Nokia has taken 450 of the patents that it holds and sold them off to another firm called Sisvel. The patents that were sold have to do with wireless and video technology. Sisvel is an Italian patent licensing firm. It's more than a little interesting that at a time when many other tech firms are buying patents, Nokia is selling.
The patents in the sale cover things like GSM, 3G and LTE mobile devices. The video patents have to do with encoding optimization. Nokia gets to keep the license to use the tech as part of the sale. The 450 patents sold off are only 1/60th of its patent portfolio of pending and granted patents. Out of those 450 patents, 350 of them are considered essential and are assumed to be used by other firms.
This raises the question of why sell the patents. The easy guess is that Nokia is hard up for money in the face of very hard competition and sagging sales of its devices globally. Sisvel is using the patents to deepen its pool of patents for LTE technology.