7 Technologies to Solve the Spectrum Crisis


Is the sky really falling?

The sky is falling in the mobile broadband world in part because demand appears to be outstripping the supply of spectrum available to provide Facebook or streaming video on our phones and tablets. However, Chicken Littles are ignoring some very promising technological solutions that could help turn the spectrum crunch into a capital spending bonanza by telecommunications companies. Here are seven solutions that can make our airwaves go further. Carriers will still have to figure out how to keep their margins intact as the usages of their spectrum outstrips the current cost models around providing it.

ZTE’s Software Defined Radio: Wednesday the Chinese equipment vendor said it was building a software defined radio, which means that the radio can frequency hop using software since the radio functions aren’t built in hardware. The SDR aspect makes a radio more versatile, and ZTE in its announcement said it will use anti-interference technologies to deliver twice the uplink capacity for future HSPA-plus networks, such as the type of network T-Mobile USA is deploying. Boosting capacity and doubling the amount of data that consumers can send over the same amount of spectrum helps operators deliver more bits over their existing airwaves. A definite win.

Rajant’s Mesh Networking: Rajant is a contractor that has built mesh networks for government customers and oil companies. Its software and gear can be programmed to take advantage of multiple available networks such as Wi-Fi, government bands and cellular signals and it weaves all of that into one unified network offering that can handle rapidly changing conditions on the fly such as a network node failure. The company, which has been around since 2001, is only now trying to market its technology to mobile operators and cable providers, but it does help use all of the available spectrum more efficiently by hopping from a channel with interference to another one seamlessly and by making the network redundant. Today Rajant showed off a portable base station and mesh network designed to be deployed over water, a notoriously difficult spectrum environment.

Carrier Aggregation: Several equipment vendors have shared ways that they can bond a carrier’s disparate chunks of spectrum into a unified block. This renders existing spectrum holdings more productive and may make previously less desirable spectrum a bit better. Plus, adding another chunk of spectrum also adds more capacity to a network.

Wi-Fi: Operators are already using Wi-Fi offload to help shed traffic from their constrained cellular networks, but anything that can make the process seamless and more customer-friendly makes it more likely that consumers will use the less congested option. Forbes reported this wekend that an Israeli startup WeFi is working with U.S. carriers to deliver automatic Wi-Fi offload when customer’s devices are in range.

White Spaces: The effort to promote the idea of White Spaces broadband or Super Wi-Fi has languished with the large manufacturers that championed the effort staying oddly silent now that the FCC has approved it and set up some rules around it. However, having a chunk of unlicensed spectrum in the 700 MHz band is a wonderful opportunity for deploying long-range Wi-Fi style networks that could carry mobile data traffic. Perhaps carriers will operate these Super Wi-Fi hotspots as a means of providing even more offload but still garner a revenue stream, or perhaps municipalities or other organizations will step up.

Pico and Femtocells: Sure, we may have said that femtocells are on a road to nowhere, and with the wrong business model that’s still the case. However, when it comes to reusing spectrum, femtocells and picocells are one of the best options for carriers to improve their actual cellular networks without offloading customers to cheaper Wi-Fi or unlicensed alternatives. One of the things holding deployment back is the business model, but another is how complex it becomes to manage a network after deploying hundreds or thousands of tiny base stations. The network architecture itself must evolve, but vendors are already taking steps to ensure that evolution happens. Now carriers just have to buy into it.

LTE Advanced: For a low-down on how the next iteration of the 4G wireless technology standard will help, check out my detailed post on LTE-Advanced, but the short version is this standard will help cram more bits into each megahertz of spectrum as well as help operators more effectively reuse their spectrum.

Sure, there are plenty of other methods that operators can use to make sure we’re optimizing rather than hoarding our mobile spectrum, but many of those require investment on behalf of the carriers. And with the threat of mobile data use rising while overall average revenue per users drops, carriers may be happier to find faster access to spectrum than to more efficiently use the airwaves they have.

Image courtesy of Flickr user Alice Popkorn.



“capital spending bonanza by telecommunications companies”

LOLOL that’s rich. As if the telecommunications companies spend a dime of their insane profits on new infrastructure. Here’s how their cycle of fail works:

1. Charge outrageous prices for their services
2. Complain when new technology puts a demand on their network
3. Pocket the money instead of reinvesting it back into their network
4. Charge even higher prices because of the increased demand but limited supply

You’d think at some point that cycle would break and people would get fed up with paying s**t tons of money with little in return, but collectively people are still in the “holy s**t I can browse the web with my phone” aw struck phase, and haven’t yet developed an appetite for doing it fast or without limits. The bar is set low and people don’t know any better, so they’re happy with it.

The telecoms know this, and are purposefully keeping the bar low so they can snort crack off the insane margins. The minute people get a taste for FAST & UNLIMITED mobile broadband, the s**t will hit the fan. But then telecoms will just charge $100/month for data and not give you any cheaper options. Or their cheaper option will still cost a fortune and come with disproportionate restrictions.

We lose either way.

John Burnette

The bad news is spectrum is a finite resource. And while it would be nice to put a pico-cell in every floor of every office building and a cell tower on every street corner the backhaul and related network buildout required to accomplish this is enormously expensive and not a near term solution. Of course, this is on the way for sure and spectrum reuse has to be one of many techniques used to solve the capacity crunch.

However, more efficient use of existing capital deployments is a better near-term solution. There is a great deal of capacity that site idle day-in and day-out that should not be ignored. Network traffic engineers typically take the approach of building enough capacity to meet a ‘peak’ demand given some over-subscription ratio and service level agreement. As a result, there is by definition a great deal of unused capacity during non-peak times. Even in the most congested wireless sectors there is significant idle bandwidth throughout the day (not just middle of night). Of course, these idle times are highly dynamic due to the nature of data networks so you need a technology that can detect network performance in real-time and deliver data during these idle times. Check out http://www.opanga.com. We’ve been doing this for several years now and are working with operators to help them meet their service needs without having to deploy new capital — delivering new services using only idle network capacity.

Steve Crowley

Work toward repurposing spectrum for mobile broadband, using the 500 MHz by 2019 in the National Broadband Plan as a target. In the short term, until spectrum is repurposed, these techniques will help fill the gap. Also, charge the greatest data consumers more; there’s no data explosion a sufficient rate increase won’t quell (but no one wants to go first). If for some reason, the auctions don’t work out as planned, these and other techniques will increase in importance.

Also in the short term, do a spectrum inventory along the lines of Snowe-Kerry, or at least an inventory-lite, that would look at usage the few largest blocks of government spectrum in the mobile broadband range. They may not be the first candidates for repurposing, but in the event of an incentive auction of broadcast spectrum, I’d imagine the reduced risk to bidders from better knowledge of the spectrum landscape would result in higher bids.

Rather than just repack broadcasters, as the FCC wants, look at splitting their cells too. More specifically, cellularization — not using TV broadcast standards, but using the LTE multicast/broadcast standard. The ATSC is about to look at updating the ATSC DTV standard, after 15 years, so this consideration would be timely. One problem the broadcasters have always faced is that they are outspent enormously in R&D. You’re not going to get a group of broadcast engineers together and improve on what 3GPP is doing, but you can get them to take existing 3GPP solutions and create an architecture that I expect would be better suited for the long term than the current one.

Richard Bennett

Cellularization of DTV is an excellent idea that doesn’t get near enough exposure, Steve. That’s a good notion to introduce to our friends on the Hill.


Throwing spectrum at the problem is the lazy solution. Its a bit like hoarding. There’s a finite amount of spectrum and the most useful bits of it for this purpose are already in use. Granted, there is new whitespace thanks to TV consolidation and that should be used (and cooperatively shared, not sold to some greedy corporation that may not even use it). The danger you run into when you start talking about “we desperately need more spectrum!!!!” is that you get congresspeople who think they can be a hero by stealing the spectrum from the poor and giving it to the rich. There are already bills floating around to steal an insignificant amount of spectrum from people who use it heavily for things like public safety and developing NEW technologies. With this mentality we’ve already seen cell phone companies buying up spectrum to keep others from having it and then never once using it.

There’s plenty of spectrum already but its being used inefficiently on several levels. The most obvious is that cells are too large. (i.e., cell towers are spaced too far apart) The single most effective, and most expensive, way to improve capacity is to make the cells smaller and lower power. Take a high-rise as an example. A traditional cell will cover a square mile of a city or a few blocks or whatever. Some might even cover a building. But they really need to cover each floor of each building. That requires installing something like femtocells at each corner of each floor of each building and using the right kind of antennas to direct the signal to only cover that one floor. Not impossible. Not even especially difficult. But it costs money and takes time. And you need to future-proof something like that as much as is possible because you don’t want to have to do it again for a while.

Richard Bennett

Nice comprehensive list. All seven (4 or 5 after combining duplicates) range from marginal to dubious, so it’ clear that more spectrum is the best, and probably only, way to go.


I have to agree and disagree. The “technologies” discussed are indeed dubious when applied to the issue of wireless capacity. I read Stacey’s previous article on LTE and found it lacking and confusing. The biggest confusion is carried over here: that between speed and capacity. LTE promises faster speeds and reliability but will only marginally increase network capacity. It’s also important to note that in many tests, like those done by Consumer Reports, LTE has performed significantly worse than 3G. LTE has a ways to go before it even delivers on its speed promise.

More spectrum simply isn’t a solution. Every frequency is currently claimed by someone and no amount will satisfy the demand which ironically will increase in pace as carriers promote byte hungry services to match the hypothetical speed limits.

There are basically two known solutions to the problem of wireless network capacity. The first is simple free market economics: the price of a finite resource will rise until demand matches supply. Caps, price hikes in disguise, are the first indications markets are adjusting.

The second solution are smaller cells. This is not femtocells, which were nothing more than carriers trying to get their customers to pay to plug coverage holes. Instead, this is a realization that smaller more numerous cells have more network capacity, usually much more, than larger less numerous cells covering the same area. Recently I’ve seen some very interesting technology coming out of universities that exploit this very simple idea. It will be interesting to see if carriers are up to the challenge as well.

Stacey Higginbotham

Ray, my understanding is that LTE significantly increases capacity over HSPA technologies. For example this NSN paper offers 5-0 percent more bits per hertz as a metric, although I have heard different amounts as well (http://www.nokiasiemensnetworks.com/sites/default/files/document/Mobile_broadband_A4_26041.pdf) Yes that also also boosts speed (s especially since many operators are deploying LTE in larger spectrum blocks) but I’m talking about cramming more bits per hertz, which affects both speed and capacity. Does that help?

Stacey Higginbotham

Richard, I’m not saying we’ll never need more spectrum, however we haven’t reached the limit yet of how carriers can most efficiently use their licensed and the existing unlicensed networks. And honestly I think Wi-Fi or other unlicensed bands can offer much greater efficiency, although the burden of dealing with interference issues then rests on the end consumer. That’s not ideal, so finding a mix is what the FCC needs to do.

Richard Bennett

One thing that should be clear is that we’re going to need to pull every trick out of the book to meet the demand for wireless capacity, on the efficiency side, the overall supply side, and on the demand side.

There’s no way that unlicensed can ever come close to the efficiency of licensed spectrum. The technical problem is the high overhead of coordinating access among a group of potential accessors. Licensed can use a master scheduler to ensure very close to 100% utilization, but unlicensed has to use contention protocols that have at best about 30% efficiency under load.

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