GPS/LSQ Confusion

There is widespread confusion regarding the GPS/LightSquared issue. Many people (some intentionally) confuse two issues:

Q1: Are all existing GNSS receivers LightSquared compatible?

A1: No. We showed that our own GNSS receivers had non-optimal filters to create the best results and were not LightSquared compatible. We designed new filters not only to be LightSquared compatible but also to improve the performance of our GNSS receivers. All GNSS receivers that cannot protect against Light Squared, do not have optimal filter and invite extra noise to the receiver that degrades the GNSS performance, even if LightSquared is not deployed.

Q2: Is technology available today to build Light Squared-compatible GNSS receivers?

A2: Yes. We proved this for the most difficult case of high precision GNSS receivers that: 1) use weaker encrypted P-codes and 2) need clean GNSS signal to mitigate multipath and produce millimeter-level positioning results. We presented technical details in two PNT meetings. We also offered 40 units (off the production line) to organizations like NASA, Air Force (AeroSpace) and some GPS manufacturers (John Deere/Navcom) to test for themselves. Our results were also confirmed by the reputable independent laboratory (Alcatel-Lucent). It is several months that we have been manufacturing and selling LightSquared compatible GNSS receivers with filters that are compatible with LightSquared 10L and 10R signals. Soon we will release for 10H also. Please see details in "All About LightSquared" Section of

The solution for low-precision, C/A code receivers is straightforward and very inexpensive.

There are lots of confusions, wrong conclusions, and misleading reports in the media. They are results of mixing questions 1 and 2. People test old receivers (Question 1) and conclude that technology to build Light Squared-compatible receivers does not exist today (Question 2).

Scientific solutions are not decided by taking votes and counting the opinions of people. They are decided by theoretical and experimental proofs. We did this; and we showed it both in theory and in practice. So far, we have received no objection to all we have demonstrated.

The sad situation is that some people are creating this confusion for personal gains. Bordering on fraud are misleading reports to Government organizations, which deliberately confuse the two issues.

There were also reports and recommendation to US organizations that concluded that technology to make GPS and LightSquared compatible does not exist today. These reports were based on no meaningful scientific research or attempt at research, while those who made the reports and recommendations had access to resources from leading universities, NASA, Air Force, and large GPS manufacturers. Such reports do warrant investigation to find the motivation for writing such misleading reports and recommendations.

All such conclusions have no scientific and technical backing. They have received attention merely by using names of organizations and military generals. Scientific facts are not decided by votes, prominence of names, the number of blogs, and editorials in magazines.

Another question is who should pay for the retrofit of existing bad units in the field? We proposed a plan that makes it win-win for owners of old equipment and for GPS manufacturers who sold them. Please see details in Note that all existing receivers should be replaced soon because they are not able to track modernized signals of GPS, GLONASS, and Galileo.

Retrofit of faulty units should not take many years. Car and electronic manufacturers, who really want to cooperate and to improve, recall millions of faulty cars and instruments and retrofit them in a few months.

To put it bluntly, I also see the signs of some people, including GPS manufacturers, who want to milk LightSquared under the guise of paying for the retrofit of their faulty units.

Other alarming news is that existing military receivers do not have protection even against benign LightSquared signals. I hope some journalists care to investigate the following questions:

  1. How much money was spent to make military receivers jam resistant?
  2. Resistant against what type of jammers were specified and contracted for?
  3. Is it a good strategy to launch million-dollar efforts and ammunitions to eliminate thousand-dollar jammers? Or better to spend few dollars to make military receivers jam resistant — at least against simple signals like LightSquared?
  4. Is the military going to deploy GPS receivers that do not have protections against simple signals like LightSquared to battlefields? Or not deploy them and don't put them at risk until their problems are corrected?

For information regarding spectrum allocation and related issues please see the informative presentation of Professor Michael Marcus, Adjunct professor of Electrical and Computer Engineering of Virginia Tech. To see his PowerPoint presentation, click this link(PDF).

Paying a bit of attention to the facts and to the law one does not see to pound on the table, as it seems to be a fashion these days among countless bloggers and magazine editors.