Can Smart Radios Save Us from Spectrum Stew?

I’ve been hearing about smart, also known as agile or software-controlled, radios for what seems like 20 years now. The idea is to use software rather than hardware to control transmit and receive frequencies so that a single radio could operate on a broad swatch of spectrum instead of a few narrow bands–and perhaps also use software to control multiple radio protocols. Given the proliferation of frequencies and technologies being used for wireless data, it’s an idea whose time should be now.

Sprint’s wireless broadband announcement today added to an already complex picture. Sprint operates its basic CDMA/EV-DO network nationwide at 1900 MHz and offers WiMAX from Clearwire in selected markets at 2500 MHz. Today it announced that it will begin deploying 4G LTE on its 1900 MHz network and add 800 MHz service as it retires the Nextel network that currently uses that band.

Meanwhile, Verizon wireless runs CDMA/EV-DO at 800 and 1900 MHz and LTE at 700. AT&T offers GSM/HSPA at 850 and 1900 and is deploying LTE in the 700 MHz band.  Just to be different, T-Mobile runs GSM/EDGE at 1900 Mhz and HSPA at 1700 and 2100 Mhz. In case you lost count, that’s four carriers, seven frequency bands, and four fundamentally different radio technologies.

In most of the rest of the world, things are a lot simpler. Most carriers provide GSM and EDGE at 900 and 1800 MHz and HSPA at 2100. 4G plans, however, are literally all over the place.

I’m not sure it’s possible to build a phone that covers all bases with today’s technology, especially given the pressure for ever-thinner handsets. Its Qualcomm dual-mode radio provides CDMA/EV-DO at 800 and 1900 MHz,  GSPA and 850, 900, 1900, and 2100 MHz, and GSM/EDGE at 850, 900, 1800, and 1900 Mhz.  No wonder they left LTE out of this edition.

Unfortunately, smart radios seem to be one of those technologies that always remain a couple of years away from prime time. Given the proliferation of frequencies and technologies, they can’t come too soon.