Calypso, which recently was awarded a patent on technology than enables roaming between Wi-Fi and cellular networks, named vendors that it says infringe on the patent: The company said that that patent would have major implications on the way Ericsson, Motorola, and Nokia do business. The press release also said that companies that don't want to license the technology right now but plan eventually to make devices that roam between networks will have to obtain rights from Calypso but doesn't explain why that's so.
I've asked leaders of a few companies such as Radioframe and Bridgeport--both are working on roaming between cellular and Wi-Fi networks--for their take on the Calypso patent and neither was interested in commenting. I had a similar experience when looking for comment on the patent for redirect that Nomadix received recently. However, this story quotes the CTO of Birdstep as saying that its technology, which enables roaming between the networks, doesn't interfere with the Calypso patent. Perhaps that means that companies may be able to get around having to license from Calypso.
On a side note, parts of Calypso's Web site are pretty amusing. On the company history page, I found this statement: "Calypso stunned the telecommunication industry when it introduced the world's first and only mobile video phone…" That's interesting as I'm not sure I recall that happening nor have I heard of any operator selling the product. I wouldn't call that "stunning" the industry.