Broadband, narrowband, or both?

A. Michael Noll

Will broadband services win out over narrowband services, or will they both continue to coexist since they seem destined for very different purposes?

The 78-rpm phonograph record did not have the highest quality audio. It evolved into high fidelity, which then evolved into stereo, and ultimately into CD-quality digital audio. Along the way came improvements in the quality of sound but at the expense of ever more bandwidth.

Black-and-white television evolved into color television with greater sensory appeal, but the bandwidth remained the same because of ingenious compromises based on the psychology of human vision. Television then became digital high-definition with increased bandwidth. If television becomes 3D, then even more bandwidth will be required for the stereo pair of images. Increased sensory appeal of television has required increasing bandwidths.

So it would appear that broadband wins out over narrowband in the worlds of audio and video. But the world of interpersonal communication tells a different story.

The telephone was a magnificent invention enabling instant interpersonal telecommunication across the globe. It seemed to be the death of communication by the text of the telegraph--although the telephone required more bandwidth. But then along came textual telecommunication by e-mail, followed by instant messaging and texting--all narrowband services. It seems that interpersonal communication is relatively narrow in its bandwidth.

The purpose of communication is involved in the need for bandwidth, with entertainment requiring more bandwidth than interpersonal communication. Broadband will thus coexist with narrowband services. And, of course, narrowband services can be carried over broadband facilities.

Picturephone-like video telephone services might change that conclusion--but perhaps we humans are basically narrowband when communicating so that we can place all our concentration and attention on the text of what is being communicated.

While narrowband continues to stimulate the imagination versus the vividness of broadband, the reality is that both will continue to serve the diverse needs of the consumer and business user.

A. Michael Noll is Professor Emeritus of Communications at the Annenberg School at the University of Southern California. His 2007 book "The Evolution of Media" explores some the issues presented in this article.