Read the paper, which was presented at the 32nd Conference on Communication, Information, and Internet Policy in Washington, DC in September 2004, online at http://research.niftyc.org/Hidden_Interfaces.pdf

From  The Economist article:

Computer chips for  open-spectrum" devices are a closed book

TELECOMMUNICATIONS used to be a closed game, from the copper and fibre that carried the messages, to the phones themselves. Now, openness reigns in the world of wires. Networks must interconnect with those of competitors, and users can plug in their own devices as they will. One result of this openness has been a lot of innovation.

Openness is coming to the wireless world, too. Cheap and powerful devices that use unlicensed and lightly regulated parts of the radio spectrum are proliferating. But there is a problem. Though the spectrum is open, the microprocessor chips that drive the devices which use it are not. The interface informationâ€â€the technical data needed to write software that would allow those chips to be used in novel waysâ€â€is normally kept secret by manufacturers. The result could be a lot less innovation in the open wireless world than in the open wired one.