Attachment LightSquared - Comm

This document pretains to SAT-MOD-20101118-00239 for Modification on a Satellite Space Stations filing.

IBFS_SATMOD2010111800239_911516

                                  Federal Communications Commission
                                           Washington, D.C. 20554

                                                  August 10, 2011


    Mr. Jeffrey Carlisle, Executive Vice President
           for Regulatory Affairs and Public Policy
    LightSquared Subsidiary LLC
    10802 Parkridge Boulevard
    Reston, Virginia 20191

    Mr. Charles R. Trimble, Chairman
    U.S. GPS Industry Council
    c/o Raul R. Rodriguez, Esq.
Lerman Senter PLLC
2000 K Street, NW., Suite 600
Washington, DC 20006



                                                              Re: Request for additional information
Gentlemen,

The Commission‘s staff has been reviewing the June 30, 201 1, Final Report of the Working
Group that was formed to study the GPS overload/desensitization issue described in our Order
and Authorization of SAT—MOD—20101118—00239.‘
To better evaluate receiver performance, we seek some additional information, as described
below. Certain information may be kept confidential pursuant to Section 0.459 of our rules upon
your appropriate request for such treatment. We note that the Commission may disclose such
confidential information to other federal agencies under the procedures set forth in Section 0.442
of our rules. We seek the following additional information:

Device Code Key. As discussed in Section 2.6 of the Working Group Report, the results of the
testing were made anonymous via a mechanism that assigned numbers randomly to GPS
receivers in each class. In order to help determine the characteristics of those receivers most—
and least—affected by interference, we wish to identify the receivers associated with each
measurement and therefore request the "device code key," which provides that cross—reference.
If an external antenna was used, please also provide the manufacturer and model number of the
antenna.


Production/sales information. It is unclear to what extent the GPS receivers and devices tested
are current production models, into what market segments those receivers and devices are most
commonly sold, what fraction of a given market segment those devices represent, and their
design lifetimes and typical owner—use lifetimes. This information is important in assessing the
likely impact, if any, of interference on various use cases over time. We therefore request
production and U.S. sales information for each of the devices tested, including (1) the dates of


‘      DA 11—133, "In the Matter of LightSquared Subsidiary LLC, Request for Modification of its Authority for an
       Ancillary Terrestrial Component," Adopted and Released January 26, 2011.


production, (2) the market segment(s) to which the device is targeted or sold, (3) total annual
sales volume and annual sales volume by market segment or estimates thereof, (4) the date on
which full support of the device by the manufacturer ceased (or will cease), (5) estimated time
period after which the device owner would likely replace or discontinue use of the device.

Technical performance data. It is unclear which technical specifications may be limiting the
interference susceptibility of the GPS receivers and devices of various classes. The frequency
response of the first stage of the device often limits its ability to reject energy from emissions
outside the band of interest. We therefore request data showing the frequency response of the
RF front—end (including the antenna system, if commonly integrated or associated with the
receiver or device) to input signals over a frequency range of at least 1,100 to 2,000 MHz, low
noise amplifier gain and the low noise amplifier 1 dB gain compression point. This information
should be provided for each receiver or device tested.

Base Station deployment plan. LightSquared‘s current plan for base station deployment
envisions use only of the lower 10 MHz segment of the downlink band. Because that amount of
spectrum is more limited than initially submitted to the Working Group for study, we request an
updated plan for base station deployment.

The Commussion‘s staff will continue to work with LightSquared and the GPS community to
fully study the potential for overload interference to GPS devices and to identify any measures
necessary to prevent harmful interference to GPS. A full understanding of the technical
performance of receivers and devices as well as of the user segment is important to this effort
and we appreciate the cooperation of LightSquared and the GPS industry in supporting our
review of the compatibility of the two services.

To further assess the interference susceptibility of the various categories of GPS receivers and
devices, we ask that you provide the device code key on or before August 15, 2011. We
recognize that the remaining information may take more time to assemble. We therefore request
that you submit the production/sales information, technical performance data, and base station
deployment plan on or before August 22, 2011. Should you have any questions concerning this
request, please do not hesitate to contact me or Ron Repasi, Deputy Chief of OET.

                                                     Sincerely,
                                                                    j           }




                                                     Julius P. Knapp
                                                     Chief
                                                     Office of Engineering and Technology



cc: Henry Goldberg, Esq.
Counsel for LightSquared Subsidiary, LLC
Goldber%, Godles, Wiener & Wright
1229 19" Street, N. W.
Washington, DC 20036



Document Created: 2011-08-10 14:39:59
Document Modified: 2011-08-10 14:39:59

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