results into software radios. 13

Another green issue concerns disposable radios. With lower energy consumption, we envision radios with such long operating lives it may be simpler to replace than to recharge them. But if such radios are to be ubiquitous, how can we keep them from adding to our trash? One research effort in the Center for Wireless Sensor Networks at Uppsala University seeks to make radios biodegradable.h

Processors vs. chipsets radios. While this article takes the view that there is a substantial difference between a radio built from programmable components and one built on a highly configurable chipset, I would be remiss if I did not mention an alternative perspective.

There is an argument that fully programmable and chipset radios are not very different. The core observation is that RF signaling and propagation is a mature field. Radio engineers know a lot about RF physics. Many of today’s protocols, especially for the physical layer (frequencies and coding), represent sweet spots for high-quality data channels.

From this perspective, it is perfectly reasonable to assume there is a limited set of reasonable choices for radio communications and entirely plausible that a radio engineer could implement all the reasonable permutations in a chipset. If this assumption holds up, then the difference between chipset radios and radios built from programmable components is practically nil.

Unfortunately, this is a paper argument. No one has attempted to build a sufficiently rich chipset radio, so we do not know if it is possible.

 

Realizing the World of software Radios

Recall that in the PDA scenario described earlier, the PDA downloads the “right” protocols whenever it needs them, but how exactly would that work? How does the PDA’s radio ensure it does not load rogue software that would interfere with, say, a public-safety radio channel? This is an essential research problem relating to both how to exploit the spectrum and how to address regulatory concerns.

Describing radio behavior. Given
h http://www.wisenet.uu.se/
that the central feature of software ra-
dios is their ability to change behavior,
one might imagine a lot of practical
and theoretical work has been done on
how to tell a radio how to behave and
how a radio can describe its own behav-
ior. However, rather stunningly, little
work has targeted this problem.