Techncial Amendment

0749-EX-ST-2017 Text Documents

The MITRE Corporation

2017-06-07ELS_193245

TECHNICAL EXHIBIT AMENDMENT TO PENDING EXPERIMENTAL FCC Special Temporary Authority (STA) APPLICATION The MITRE Corporation The MITRE Corporation seeks an FCC Special Temporary Authority License to transmit data within the High Frequency (HF) band between 6.4 MHz and 16 MHz from several locations in Alaska from 18 July – 08 August 2017. There are two primary locations from which the test will be executed: 1) Joint Base Elmendorf-Richardson (JBER), Anchorage AK, and 2) Barrow, AK. The JBER primary location has three local sites, only one will be used at any given time/date. Each site will likely be used during the three-week test period, just not simultaneously. The Barrow primary site has four local sites, only one of which will be used at any given time/date as with the JBER locations. As with JBER, each of the local Barrow sites may be used, just not simultaneously. USNORTHCOM is conducting a test between these locations and have asked the MITRE team conducting advanced beyond line of sight (BLOS) High Frequency (HF) communications to be part of the test. As such, we will need transmit authority for those 22 days in those locations. This Exhibit describes the program of research and experimentation proposed, including: description of equipment and theory of operation; the specific objectives sought to be accomplished; and how the program of experimentation has a reasonable promise of contribution to the development, extension, expansion or utilization of the radio art and/or is along lines not already investigated. Research and Experimentation Program Description Assured beyond line-of-sight (BLOS) communications is a challenging problem yet essential for our warfighters. Military and civilian systems rely on a combination of high data rate satellite connectivity as well as low data rate HF Sky Wave communications. While satellite communication provides high data rate connectivity, there are vulnerabilities that include degradation and disruption of service. HF radio communication generally are limited to narrower bandwidths and lower data rates than satellite communications. To ensure critical communications are maintained, we are investigating the capability of higher bandwidth and higher data rate communications in the HF band applying polarization diversity MIMO concepts. Long distance HF communication is accomplished via reflection of HF radio waves off the ionosphere, a variable medium. This introduces challenges that must be overcome to make HF communications more reliable. These include multipath propagation and polarization rotation; both contribute to signal fades. We will demonstrate reliable BLOS HF communications at high data rates. Objectives The MITRE Corporation 202 Burlington Road, Bedford MA 01730

FCC Office of Engineering and Technology (OET) Page 2 The goal is to communicate reliably at a rate of 1-4 bits/Hz/s. We will test several waveforms we have developed ranging from 10 to 400-kHz bandwidth to achieve ~ 256 kbps with forward error correction (FEC) coding. We may test waveforms out to 1 MHz bandwidth. Mitigation of signal fading and improved throughput will be accomplished using polarization diversity techniques and orthogonal coded waveform designs. The research program is planned to include a series of over-the-air (OTA) MIMO demonstrations, each testing new waveforms. We will attempt to test whether we can use both X and O modes to carry independent communications channels and then determine the carrying capability of each at different bandwidths. A stretch goal is to extend to wider bandwidth waveforms, up to 1 MHz. (Researchers’ note: we understand that this wideband waveform may run up against other users and possibly cause interference. We plan to transmit at as low a power as possible and on a not-to-interfere basis. Please see red-highlighted text in Table 1). We will also perform ionospheric sounding for channel characterization and waveform calibration. The requested frequencies and transmission operational parameters are those permitted under Section 90.266 of the Commission’s Rules, Long Distance Communications on Frequencies below 25 MHz and are identified specifically in the FCC’s Electronic Code of Federal Regulations, Title 47 (Telecommunication), Volume 1, Chapter 1, Part 2.106 Table of Frequency Allocations. These frequencies bands requested are designed to avoid the Restricted Bands of Operation outlines in the Electronic Code of Federal Regulations, Title 47 (Telecommunication), Part 15 (Radio Frequency Devices), Subpart C Intentional Radiators. Listed in the following Table 1 are the requested proposed technical parameters for the experimental research program.

FCC Office of Engineering and Technology (OET) Page 3 Crossed Dipole (Signal) Transmit Antenna Transmitter Site Locations Transmitter Site #1 Joint Base Elmendorf, Anchorage AK (National Guard Building) 61.180316 N, 149.423848 W Crossed Dipole Antenna Radiation Center: 5.9 m AGL Crossed Dipole (signal) Transmit Antenna Azimuth Orientation: omnidirectional Crossed Dipole (signal) Transmit Antenna Vertical Plane Orientation: 90 degrees (120 Deg beamwidth) Transmitter Site #2 Joint Base Elmendorf, Anchorage AK (JBER MRC Location) 61.256995 N, 149.750704 W Antenna Configuration same as Transmitter Site # 1 Transmitter Site #3 Joint Base Elmendorf, Anchorage AK (ALCOM J6 Alternate Facility) 61.247025 N, 149.811503 W Antenna Configuration same as Transmitter Site # 1 Transmitter Site #4 Barrow, AK (Top of the World Inn) 71.175100 N, 156.461830 W Antenna Configuration same as Transmitter Site # 1 Transmitter Site #5 Barrow, AK (High School Football Field) 71.105458 N, 156.394730 W Antenna Configuration same as Transmitter Site # 1 Transmitter Site #6 Barrow, AK (East Barrow Location) 71.200530 N, 156.383467 W Antenna Configuration same as Transmitter Site # 1 Transmitter Site #7 Barrow, AK (Barrow Airport) 71.164436 N, 156.471237 W Antenna Configuration same as Transmitter Site # 1 6400.0 - 8250.0, 8970.0 - 9995.0, 10005.0 - 11275.0, 11400.0 - 12200.0, 13500.0 - 14990.0, 15010.0 - Requested Frequency ranges (kHz) 16000.0 Maximum Transmit Power 200 Watts (average varies between 20 and 200 Watts) Transmitter Ettus USRP N210 Software Defined Radio Transmitting Antenna MITRE-built Crossed-Dipole (see Figure 1) Broadband bow-tie shaped, inverted vee-dipoles with resistive loading Small Footprint (< 20 meter diameter) Dipoles are arranged orthogonally on mast to produce x-,y- polarizations 1 MHz (typically vary from 50 kHz up to 400 kHz) ** 1 MHz is a stretch goal and will be done on a Maximum Occupied Bandwidth not-to-intefere basis. Most work will be done around 100-300 kHz. Most of the experiment will be conducted during the daylight hours, some portion may run up to 24 Maximum Transmit Time Duration (Duty) hours. Duty cycle will be up to 100% during the 22 day period. Table 1. Proposed Experimental Crossed-Dipole Transmission Parameters The MITRE-developed Crossed-Dipole antenna configuration and dimensions are shown in Figure 1 below.

FCC Office of Engineering and Technology (OET) Page 4 Figure 1. Model Crossed Dipole Antenna (< 20m diameter) The system supports two orthogonal polarizations: two inverted vee-dipoles (x-, y-polarized). The antenna elements are well matched over 6.4-16 MHz to 50 ohms and offset to avoid mutual coupling effects. The antennas exhibit omnidirectional antenna patterns with an antenna gain of 2 dBi between 6.4 and 16 MHz. The system is simple, low-cost and MITRE-fabricated, - assembled, and –setup. While MITRE fabricated the antennas, and designed the transmit and receive systems, some of the equipment was purchased from commercial vendors. Table 2 shows a list of the commercially purchased equipment that will be used during the experiment(s). Table 2. Commercially purchased transmission equipment list. Transmitting Equipment Manufacturer Model Number No. of Units Experimental (Y/N) Ettus USRP N210 4 (2 sites x 2 radios) N AR Modular RF Amplifiers KMA2040M22 4 (2 sites x 2 radios) N Research and Experimentation Contribution to the Development of the Radio Art Assured beyond line-of-sight communications is a challenging problem yet essential for certain types of communication. Fortunately, HF technology is uniquely suited to address this problem, applying new techniques and understanding of the ionosphere. With HF, BLOS communications is achievable without the use of satellites or pseudo-lites. The traditionally low data rates can be improved upon as well. In today's economic climate, HF is very affordable, with a well- established commercial market.

FCC Office of Engineering and Technology (OET) Page 5 MITRE's work will demonstrate a new approach to addressing critical communications capability shortfalls through the application of polarization diversity and advanced orthogonal coding designs. If there are any technical questions with the proposed application, please contact one of the undersigned. Maureen Scheible The MITRE Corporation 202 Burlington Road Bedford MA 01730 June 6, 2017 Eliot Lebsack The MITRE Corporation 202 Burlington Road Bedford, MA 01730 June 6, 2017


Document Created: 2017-06-07 16:38:40
Document Modified: 2017-06-07 16:38:40
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