Additional STA Information

1161-EX-ST-2014 Text Documents

L-3 Communications

2014-12-19ELS_157106

L3 Communications, CSW
Special Temporary Authorization
File No.: 1161-EX-ST-2014

Application Background:
The purpose of this project is to flight test and experiment with point to point data links for
application to airborne data services.

                                                           Station #3
                                                  Helicopter Satellite Surrogate
                                             Tampa Microwave QBSE LTT-03-W-198R
                                                L-3 CS-W 10 dBi Antenna, 3W PA

                                                                                 Gain = +10 dBi
                                                                                 3 dB BW = 49.1°
                                                                                  RHCP or LHCP


                                                       20.2-21.2 GHz
                                                        943MG1D
         30.0-31.0 GHz                                +14.8 dBW EIRP
           943MG1D
         +50 dBW EIRP



                                                                                30.0-31.0 GHz
                                                                                  943MG1D
                        Gain = +49 dBi                                          +50 dBW EIRP
                        3 dB BW = 0.56°
                         RHCP or LHCP
    Station #1
  Hawkeye III Lite
  GCS-1512A-020                                                                    Gain = +49 dBi
                                                                                   3 dB BW = 0.56°
          Ground Terminals Co-Located                                               RHCP or LHCP
          Latitude     37°29’4.57”N (37.484602N)
                                                                  Station #2
          Longitude    122°8’54.6”W (-122.148501W)              Hawkeye III Lite
                                                                GCS-1512A-020
Figure 1 Concept of Operations

Spectrum Requirements and Test Scheduling:
Up to 2 co-located ground stations will transmit to and receive data from a helicopter operating
no more than 10 km from the ground stations. The helicopter will be acting as a surrogate
Wideband Gapfiller satellite (WGS). Uplink frequency to the helicopter will be 30.0-31.0 GHz


with EIRP limited to +50 dBW. Downlink frequency transmitted from the helicopter will be
20.2-21.2 GHz with an EIRP of +14.8 dBW. In order to minimize potential interference to the
WGS satellite system, the helicopter will be restricted to an area north of the ground stations.
This will prevent the ground stations from radiating in the direction of the satellite constellation
at the equator. Interference to any WGS ground stations that may be in the vicinity, will be
minimized because they are pointed southward towards the equator. WGS terminals receiving
20.2 - 21.2 GHz meets MIL-STD-188-164B. The side-lobe level (SLL) should be G(θ) = -10
dBi for 48° ≤ θ ≤ 180°. As Menlo Park is located at 37.5°N, and our helicopter will fly to the
north over the San Francisco Bay with below 30° elevation from any possible WGS terminals
locations, the aforementioned -10 dBi SLL is the worst case. The interference from our
helicopter to the victim WGS terminal will be -98 dBm in our test geometry of 5 km range,
which translates to -128 dBm/MHz. In comparison, an adjacent satellite causes co-channel
interference to the WGS terminal. An adjacent-satellite carrier is less than -112 dBW/MHz/m2
per MIL-STD-188-164B, which is received by the victim WGS terminal’s side lobe. To match
the interference level of -128 dBm/MHz, a 1.5 dBi side lobe is required. Following MIL-STD-
188-164B SLL limit of G(θ) = 29 – 25 log10(θ) dBi with θ < 20°, its equivalent adjacent
satellite separation is greater than 12°, which is easily met in deployed satellite fleets.

                                                                                                          WGS Satellite
                                                    Minimize interference to WGS Satellite
          Station #3                                Minimal RF Power
                                                    Narrow Beam Antenna
                                                    Test ground antenna faces away from satellite




                                 20.2-21.2 GHz                                    30.0-31.0 GHz


                                                                                                    20.2-21.2 GHz


           30.0-31.0 GHz               Station #2




                                       Station #1                        WGS Ground Station

                                                                         Minimize interference to WGS Ground Station
                                                                         Minimal RF Power
                                                                         Narrow Beam Antenna
                                                                         WGS antenna pointed away from helicopter

Figure 2 Interference Scenario



Location of Testing
The location of the ground stations and aircraft transmission boundary is shown in a Google
Earth map in Figure 3. It is anticipated that the helicopter flight path will be over San Francisco


Bay and directly north of the ground stations indicated by a pin in the figure. Maximum range
will be 10 km. Location of the ground stations are at the pin in the figure and the GPS
coordinates are indicated.




                                   37°29’4.57”N (37.484602N)
                                  122°8’54.6”W (-122.148501W)




                                                               10km radius




                         Figure 3 Ground Station Location and Aircraft Boundary.



Document Created: 2014-12-18 14:39:13
Document Modified: 2014-12-18 14:39:13

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