The open-access debate over spectrum

Why not let public safety and commercial operators share the same band?

If you've been following the developments surrounding the upcoming 700-MHz auctions, you've probably heard the term "open access" by now.

Like 4G (which I'll return to shortly), open access is a somewhat imprecise term, but I'm using it here to refer to a network that is capable of supporting multiple classes of service simultaneously via a common set of protocols. With respect to the latter, that would be IP, the only networking protocol that matters anymore. The benefits of the open-access approach are significant and far-reaching, and they have led me to conclude that this is the only way we should be building commercial and public-safety networks going forward.

Why is this important? Well, spectrum is a scarce, expensive commodity thanks to the laws of physics and the auction process that is used to allocate licensed spectrum in most parts of the industrialized world today. The laws of physics are a problem because propagation characteristics vary with frequency -- higher frequencies are more directional and don't usually penetrate buildings very well. This means that only a very limited amount of spectrum is suitable for mobile communications. The auction process makes this limited spectrum expensive, with the auctions cleverly designed to raise the maximum amount of money for the U.S. Treasury.

OK, so spectrum is scarce and expensive and some of the best of this will shortly be going on the block as the FCC starts auctioning the 700-MHz bands. This spectrum is right below the 800-MHz bands used for cellular and public safety, and public safety (along with commercial interests with really, really deep pockets) is going to be a big recipient of spectrum under the proposed rules.

But wait just a minute: Why not build a single, open-access network that can meet the needs of both the commercial world and public safety, simultaneously? That's right, both in one service. Heresy!

Traditionally, blocks of spectrum have been exclusively reserved for public safety because that's historically how it's been done. And the technology of the day -- analog push-to-talk radio -- basically required reserved spectrum. This is wasteful, when you think about it. Much public-safety spectrum is unused much of the time and isn't available to anyone else. But modern digital communications technology, based on IP, allows for prioritizing traffic, at least within a single network. We could thus implement a single network and support multiple services on it, applying quality of service, class of service, security and reliability as appropriate. Prioritizing traffic is the key. When public safety or other high-priority traffic needs service, other users will have to wait, albeit just for a few moments in most cases. This is a much better idea than devoting spectrum to applications which need it only infrequently, making the best use of a scarce and expensive resource, as was noted above. When the public safety guys don't need this spectrum, you and I get to use it.

But there are other benefits. After 9/11, it became clear that we need a single, interoperable wireless public-safety service. Open access could easily fulfill this mission. Subscriber units would be cheaper because the common IP platform would eliminate the need for specialized products working in a large but limited market. Security could be enhanced for all users. All of the services necessary for public-safety needs, like E911 and compliance with the Communications Assistance for Law Enforcement Act CALEA (the lawful intercept of certain traffic), could be easily provisioned in an open-access world. And the fundamental integrity of IP is legendary; it was designed with fault tolerance and survivability in mind, after all.

Putting open access into operation does, however, require a change in thinking on the part of FCC regulators. And, obviously, the incumbent 3G operators probably aren't all that crazy about the idea, since they have a lot of depreciation yet to apply to their infrastructures but still need more spectrum for new customers and new services, particularly broadband data. But even the cellular guys will get to open access eventually, because 4G is the essence of open access -- a single network, based on IP, mobile, broadband, wireless, and with full support for time-bounded services and traffic prioritization.

Wouldn't it be nice, I'm arguing, to get to it sooner rather than later? This is the single most powerful idea currently at work in wireless network strategy, and one that I hope will come to fruition in the not-too-distant future.

Craig J. Mathias is a principal at Farpoint Group, an advisory firm specializing in wireless networking and mobile computing. He can be reached at craig@farpointgroup.com.

Copyright © 2007 IDG Communications, Inc.

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