The WRC-15 C-band Debate — a Case of Faulty Assumptions?
By Annette Purves, Principal, Regulatory Affairs
March 13th, 2014 — I don’t know about you, but I feel uneasy whenever I find myself without my smart phone. The access to a map, to email, bank accounts and other applications seems absolutely vital in today’s busy lives. Taking our children to Disney Land last year, my husband and I even had an app that told us the wait times at the various attractions!
Like many of us, I fully appreciate the important and integral role mobile devices have in our lives. So when I initially learned about the International Mobile Telecommunications (IMT) community requesting more spectrum at the upcoming World Radio Communications Conference (WRC-15) in 2015 in Geneva, it seemed to make intuitive sense to me. Mobile usage is up, so that means more spectrum is required, right?
Actually, when you take the time to examine this issue in depth, that assumption is wrong! Such a simplistic conclusion is not supported by the facts. Technology has advanced to the point that more spectrum is not necessarily required to service more mobile users. In addition, much of the research that has been done on this issue to justify more spectrum for mobile devices appears to rely on questionable data.
The following formula was provided to me by an acquaintance in the mobile industry. An engineer would no doubt cringe, but it was very helpful to me in visualizing the issue. The formula is:
capacity = network density x spectrum efficiency x spectrum
Without understanding anything about engineering or mobile technology, you can easily see that the amount of spectrum is just one factor of three in determining overall capacity. Network density and spectrum efficiency are as important (in many cases even more so) in determining capacity than the amount of spectrum itself.
Then there are the assumptions that the IMT spectrum estimates are based on. In a recent article in GigaOm titled Note to the Telecom Industry – Beware of False Models, analyst Tim Farrar raises serious questions that suggest that the ITU usage forecasts greatly overstate future demand – by a factor of at least 200 in the UK and Japan and up to 1200 times in the U.S.!
To cite just one example, Mr. Farrar points out how back in 2007 the ITU modeling predicted that between 760 and 840 MHz would be needed to meet rising mobile traffic demands by 2010. In reality, no country in the world was using more than 400 MHz by 2010.
Fast forward to today, and Verizon’s new LTE network is handling 20 percent of all U.S. mobile data traffic using just 22 MHz of spectrum!
Now the IMT industry is suggesting that up to 1960 MHz of spectrum will be needed for licensed cellular services by 2020 – and that is excluding spectrum for WiFi. This amount of spectrum is more than double the current allocation for mobile services, and at least four times the amount of spectrum deployed in most countries at present. Evidence is accumulating that the kind of massive reallocation required to provide this amount of spectrum for IMT is unnecessary and unwise.
There is still time before WRC-15 for better analysis based on more accurate data. Leading companies and trade associations from the satellite industry have come together to call for better case studies on this issue. For more information on how you can get involved, visit this page on the Intelsat site.
Predictive models are only as good as the assumptions and the data they rely on. Many governments and organizations around the world depend upon reliable satellite communications, and may not have the luxury to have other means to communicate. Before we reallocate critical C-band spectrum from the satellite community, let’s make sure we all are basing the decision on solid statistical grounds and valid assumptions.