The recent FCC ruling has opened up the possibility of

wireless network deployments over white spaces, i.e., vacant UHF TV

channels. A key requirement for any white space device is that it

must ensure that none of of its transmissions interfere with

incumbents, namely TV transmitters and wireless microphones. For

this purpose, there has been a lot of effort on \emph{spectrum

sensing techniques} that allow white space devices to decide which

parts of the spectrum is currently occupied by primary users. While

potentially feasible, spectrum sensing at the low thresholds

required to protect incumbents is technically challenging. In this

paper, we propose and design an alternative approach to

opportunistic wireless networking in white spaces that does not

require any sensing. Governed by unique system design constraints

characteristic to white space wireless networks, we devise and

develop \system\, a system that combines sophisticated signal

propagation modeling with an efficient content dissemination

mechanism to ensure efficient, scalable, and safe white space

network operation. We compare our results to ground truth spectrum

measurements and present detailed evaluation of our infrastructure

and service.

Publisher  Microsoft Research

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