Spread Spectrum Is Good—But It Doesn’t Obsolete NBC v. US!


This short note addresses a popular misconception—that new technologies such as spread spectrum have eliminated the problem of radio interference. That is false. Spread spectrum is a great technology, but it does not eliminate the problem of interference. Similarly, although some have asserted otherwise, signals below the noise floor can create interference.

We first show that a number of authors have embraced these misconceptions in works addressing public policy. Briefly, a basic argument of these papers is: (1) spread spectrum eliminates the problem of interference; (2) the Supreme Court’s decision in NBC v. US upholding the Communications Act of 1934 depended critically on the perception that radio interference is unavoidable; (3) given (1) the Court’s decision was wrong and must be revisited.

We then provide a nonrigorous (no equations!) explanation of the nature of interference created by spread spectrum signals or by signals below the noise floor. We also offer a few pointers to the technical literature for those who wish to understand these issues in more depth.


Science and Technology Law

Date of this Version

August 2005