With all the debate about clearing more spectrum and preparing for the broadcast incentive auctions, one question seems to remain in the background: What happens when existing spectrum is unable to keep pace with the ever-increasing number of Internet-connected devices?
That day will come, perhaps sooner than we think, it has been predicted. Stefan Weitz, the director of search at Microsoft’s Bing, tried to answer the question in an essay published on the website GigaOM.
Weitz noted that most devices and applications today use a single frequency.
“If we were to build mobile apps and devices that were ‘frequency intelligent,’ they could use Wi-Fi (2.4GHz and 5GHz), Bluetooth (2.4GHz) and a variety of cellular network frequencies depending on the carrier, rather than be locked to a single frequency,” he noted. “Software-defined radios could enable future devices to hop across frequencies as environment dictates. Similarly, an app that moves a lot of hi-def video would be self-aware enough to know that it could use the software-defined radio and hop on a frequency that has less contention for bandwidth.”
Weitz cited the example of an app that’s moving simple packets of data without the need for real-time responses. It would say to itself, “Even though there’s some 4G here, I don’t need that. I can use the 3G that’s available here instead.”
Such thinking, Weitz said, would have profound effects on developers building the next-generation of apps.
“In a world with heterogeneous networks, where we are constantly bathed in different radio frequencies with different capabilities, knowing what to use — and when — will ultimately deliver apps that perform better in more scenarios," he said. “Rather than simply accepting a crowded 4G network in downtown San Francisco when uploading your latest cycle ride, developers will need to build both front-end user experiences and also implicit backend network awareness to access the most appropriate network for the use.”
Today, Weitz said, software-defined radios, programming interfaces and wireless protocols that will allow for seamless switching between networks are still being defined for widespread use. But some manufacturers, he noted, are already letting users pick which networks they wish to use to upload photos and videos.
Other innovations with spectrum are on the horizon. "Pico cells" — small base stations that use the same frequencies our devices speak to today — have proven very effective at increasing network capacity in dense usage areas. Used on a large scale, Pico cells could greatly reduce the data throughput burden on a large mobile network since the radios inside our devices could talk to a tower closer to their location.
Bridging techniques are also useful to consider. Personal computers can be turned into access points so others can use a PC’s Internet connection to ride the Net. Much like many people tether their computer to their phone, this solution could allow a host PC to use newly vacated “white space” airwaves (today residing at around 700MHz), while the other devices use a low-power radio on a different frequency to talk to the host.
Trials are already occurring, Weitz said, to see if devices can be made smart enough to “share” federal spectrum beyond 700MHz when those agencies aren’t using it while still giving them priority when they need it. Others are working to use frequencies like those used by cordless phones to create mini-networks among many devices that can work even without any infrastructure in place. Ultimately, these concepts rely on devices working together to balance the load of web requests.
Weitz said the nation needs smarter spectrum allocation and, more importantly, smarter use of it. It should, he advocated, become a critical part of the nation’s dialog on spectrum.
