LightSquared vs. Save Our GPS

by Neil Sandler
Publisher, Professional Surveyor Magazine

In some ways, the big debate at this year’s ACSM/Esri Survey Summit between proponents of LightSquared’s nationwide broadband proposal, and the consortium “Save Our GPS,” was like listening to the budget debate going on in Washington.

Both sides presented cases that tugged on our emotions and sounded reasonable, but it doesn’t appear that we as a nation can have it all.

Someone will lose and someone will win.

Rather than attempt to objectively report on what each side said, Professional Surveyor Magazine asked Jeff Carlisle of LightSquared and Pete Large of Trimble and the “Save Our GPS” consortium, to summarize what they took away from the two days of open discourse in San Diego, and what they intended to take back to their respective camps. Here’s what they told us.

Peter Large
Save Our GPS

The Save Our GPS Coalition was grateful for the opportunity to present the facts and supporting data around this issue at the ACSM/ESRI Survey Summit. Many surveyors and GIS professionals have shared their concerns both at the event and through the Coalition website. 

In the time since the conference the FCC has received many letters, including one from officials at the European Commission pointing out that the proposed LightSquared network would interfere not only with GPS but with Galileo receivers on aircraft and  vessels entering the United States as well as with future U.S based GPS/Galileo users, including surveyors. This adds the European Union and European Space Agency to a long list of organizations that have been completely surprised by LightSquared’s announcement last year of a dense terrestrial-only 4G network design and proposal. Not only is GPS and Galileo equipment affected by the new proposal, but so is satellite communications equipment currently used in the MSS band itself. For an organization that claims to have been preparing this for years, LightSquared appears remarkably unprepared itself; not even a single LightSquared terrestrial handset could be produced for the testing and the first cell tower of its kind in this band had to be specially imported for the live sky testing, arriving just days before the tests.

The testing has clearly proven that LightSquared designed and proposed a network that would cause devastating interference to millions of GPS receivers, denying GPS to aircraft over large regions of the United States, to cell phone users making 911 calls, to millions of vehicles and vessels and to the critical high precision users in agriculture, surveying, engineering & construction- including the networks used to monitor dams, levees, earthquake fault zones and volcanoes.

The test report data also shows that operation only in the lower 10MHz channel inflicted harmful interference to over half of all the 100+ GPS devices tested, including all high precision receivers, along with many devices used in cars, trucks, boats and e911 enabled cell phones. The aviation group stated in the report that operation in this lower 10 MHz channel ‘could not be determined definitively’ to be compatible or safe. Despite these facts, data and carefully controlled test results, LightSquared continues to claim that initial operation in this 10 MHz lower channel is a ‘solution’, stating that it solves the problem for ‘99%’ of users – a number which will not be found anywhere in the 1,000 page official report of the Technical Working Group, because neither the data, results or any reasonable engineering assumptions support it. Even if it were the case, the other ‘1%’ represents all the high precision users – billions of dollars of investment and tens of billions of annual benefits to the US economy.

The major survey GPS manufacturers in the Coalition agree that another suggestion raised at the conference - turning off P-Code encryption -would not at all solve the problem for high precision GPS, nor would it solve the problem for all the non-precision GPS receivers found to suffer interference from the lower 10MHz channel which are, in any case, incapable of receiving P-Code.

There remains a very practical and reasonable solution to this problem:
  • LightSquared operates the satellite component of its network in the Mobile Satellite Services band adjacent to GPS allocated for that purpose – providing communications to rural communities, emergency response and industrial users outside of cellular coverage areas and;
  • Deploys the new, dense high-powered ground network in a band where it does not cause harmful interference to either GPS users or to satellite communications in the MSS Band. 
Investigation of this option was excluded from the five month  study, even though 5 of the 6 sub-groups suggested it as a potential solution, as did the independent government NPEF report. LightSquared already has access to other spectrum outside of the MSS band and even more spectrum could be accessed through a variety of available mechanisms. Doing so would avoid all interference to GPS users and would not render a $4Bn investment lost; much of that investment was in the acquisition of a primary satellite communications company and in a new $600m satellite, both of which can of course continue to operate in the MSS band. The proposed terrestrial component is the source of the interference and has yet to be built.

Allowing deployment of this new ground based network in the space based MSS band adjacent to GPS, even in the lower 10MHz channel, will cause harmful interference to many GPS receivers including those used by surveyors. Please reach out to the FCC and your elected members of congress to explain how GPS is important to your work and what the implications and impacts of interference and disruption would be for your organization and for those you serve. Visit for more information. All voices need to be heard on this matter – your voice is important and please don’t leave it to someone else. Act now.
Jeff Carlisle

Dear Neil,

You asked me to write to you about what I learned at the recent Survey Summit in San Diego and the best way forward to resolve GPS interference concerns. I had many conversations with surveyors at the Summit, and listened to the questions that were asked at the panel. I learned about how surveyors use GPS every day as a crucial part of their work, and about how their businesses have become more efficient because of it.

What I did not expect to hear was how important it will be in the future for surveyors to be able to access and share large amounts of data in the field, and how this promised to be the next frontier for efficiency in surveying. It makes sense, though, that surveying will not be different from other professional fields like medicine or finance that rely heavily on the exchange of accurate, timely data. While you and I will have our personal lives made somewhat more convenient by faster upload and download speeds on our personal devices, surveying and many other professions will derive direct productivity gains.

As I asked during the panel discussion, “what kind of broadband future do you want?” It seemed to me that many of the surveyors I talked to would like to have the ability to choose from any number of competitors for their service. As small business owners, they don’t want to continue to pay high rates for inconsistent coverage because they only have a choice of one or two companies.

So where do we go from here? The GPS manufacturers have made a concerted effort to prevent  LightSquared from using its  spectrum for broadband services, even though LightSquared was  authorized to build the network it is building today in 2005. Instead of using those 6 years to design and sell devices that could have  coexisted with this network, they have instead decided to lobby to stop it. The GPS manufacturers want the help of their user communities to do so.

Such an outcome would not just be a defeat for LightSquared, it would be a defeat for American  consumers, and for surveyors. Who knows how many surveying tools and opportunities will be lost in the absence of affordable and reliable wireless broadband?

A better outcome is promised by LightSquared’s proposal. We haven’t asked the GPS manufacturers to shoulder the burden alone. We’ll start service using spectrum as far away as possible from GPS, fund development of resilient precision receivers, and improve and stabilize the provision of augmentation signals to precision receivers. This is a commitment of time and of resources well in excess of $100 million.

But LightSquared can’t do it alone. It will need the help of GPS manufacturers to make this work. And if we get it right together, then the surveying community gets better GPS services, and a better broadband future. So I’d encourage your readers to express their concerns and needs, to make clear that the surveying community wants LightSquared and the GPS manufacturers to work this out, and tell this to both Washington and the manufacturers who hold the key to serving the surveying community’s needs.

Best regards,

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