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Forty-Forth Quarterly Status Report to Congress Regarding BTOP
NTIA provides quarterly statutory reports to Congress on the Broadband Technology Opportunities Program (BTOP). This report covers activities from October 1 – December 31, 2019.
Forty-Fifth Quarterly Status Report to Congress Regarding BTOP
NTIA provides quarterly statutory reports to Congress on the Broadband Technology Opportunities Program (BTOP
Feasibility of Commercial Wireless Services Sharing with Federal Operations in the 3100-3550 MHz Band
As directed by the MOBILE NOW Act of 2018, the National Telecommunications and Information Administration (NTIA) evaluated the feasibility of allowing commercial wireless services, on both a licensed and unlicensed basis, to share use of the radio frequency spectrum at 3100-3550 MHz, under the assumption of no changes in incumbent operations, except for possibly limiting some use of airborne radar systems over the continental United States.
American Broadband Initiative Progress Report
In February 2019, the American Broadband Initiative (ABI) was launched with the release of the Milestones Report, detailing the Administration’s strategy to drive changes across Federal Agencies to identify and remove barriers to broadband access and leverage public assets and resources to expand our Nation’s broadband infrastructure capacity. The Milestones Report outlined time-framed commitments from Agencies and the three “workstreams” that were created to promote accountability and focus Agencies on the implementation of the ABI’s mission.
Commercial Spectrum Enhancement Act Annual Progress Report for 2019
NTIA submits this report pursuant to Section 207 of the Commercial Spectrum Enhancement Act (CSEA), Title II of Pub. L.
NTIA Appendix to the National Plan on Unlicensed and Licensed by Rule Operations in Furtherance of the Ray Baum's Act
This Appendix was prepared by the National Telecommunications and Information Administration (NTIA), in consultation with the Office of Management and Budget (OMB), and was sent to Congress and shared with the Federal Communication Commission in response to Section 618(d) of the MOBILE NOW Act.
Emission Spectrum Measurements of a 3.5 GHz LTE Hotspot
In response to proposals to introduce new Long Term Evolution (LTE) radio systems into the 3550–3650 MHz (called 3.5 GHz) portion of radio spectrum in the United States, a joint team of National Telecommunications and Information Administration (NTIA) and U.S. Navy electronics engineers performed emission spectrum measurements on a 3.5 GHz (LTE Band 42) wireless access point (WAP), or hotspot. The hotspot was packaged for indoor use but similar systems could be deployed outdoors. The authors measured the hotspot emission spectrum with 110 dB of dynamic range across 1.5 GHz of spectrum (from 2.7 to 4.2 GHz). Other data outputs include: spectra measured with the device tuned to its lowest, highest, and middle available operational frequencies; comparative peak-to-average spectra; and spectra measured when the hotspot was operated with 10, 15, and 50 resource blocks. The emission spectrum is plotted against proposed in band, out-of-band (OOB) and spurious emission limits; the spectrum meets those limits by at least 10 dB at all points. The results presented here may be used in electromagnetic compatibility analyses for future 3.5 GHz spectrum sharing between LTE-based transmitters and incumbent systems such as radar receivers.
Keywords: radar; electromagnetic compatibility (EMC); band sharing; spectrum sharing; out-of-band (OOB) emissions; spectrum measurement; Long Term Evolution (LTE); 3.5 GHz band; LTE band 42; emission limits; resource blocks; spurious emissions; wireless access point (WAP); wireless local area network (WLAN)
Effect of Broadband Radio Service Reallocation on 2900–3100 MHz Band Marine Radars: Front-end Overload
Spectrum reallocations may place broadband radio services (BRS) near spectrum used by 2900–3100 MHz band marine radars. Signals from the BRS base stations can potentially cause the radar front-end to overload and cause interference. This report provides a method that can be used to estimate front-end filter attenuation required at various radar to base station separation distances. The attenuation is the difference between the interfering power at the radar low-noise front-end (LNFE) and the allowable interference power. The BRS signal was emulated with 10 MHz bandwidth Gaussian noise. The allowable interference power IPC is determined from probability of detection measurements with a custom test fixture. Two front-ends were tested. One was an off-the shelf magnetron radar front-end assembly consisting of a circulator, limiter, and low-noise front-end. The other, referred to as the reference front-end, was constructed of discrete components. The reference front-end was tested without the frequency selectivity of the circulator and limiter. Results showed that the allowable interference power is -11.5 and -9 dBm for the reference front-end and magnetron front-end assembly, respectively. Additional front-end filtering is not required for either front-end at distances as close as 400 meters. Distances less than 400 meters were not analyzed due to near-field effects. Gain compression and noise enhancement metrics, which are simpler to measure than performance degradation, were also evaluated to determine if they could reliably predict allowable interference power. Only the noise enhancement metric could reliably predict the performance degradation. This result is important since many front-end overload studies are based on the gain compression point metrics.
Keywords: radar; interference; radio wave propagation; front-end overload; interference protection criteria (IPC); broadband radio service; marine radar; radio spectrum engineering; front-end filter; gain compression; noise enhancement
Effect of Broadband Radio Service Reallocation on 2900–3100 MHz band Marine Radars: Base Station Unwanted Emissions
Spectrum reallocations may place broadband radio services (BRS) near spectrum used by 2900–3100 MHz band marine radars. Signals from the BRS base stations can potentially introduce unwanted emissions in the radar detection bandwidth and cause interference. Interference protection criteria (IPC) are needed to mitigate this effect. The primary IPC of concern are the interference to noise power ratio (INR) and the reliability of the radar link at a specified radar signal to noise power ratio (SNR). Reliability is determined by radio wave propagation path loss variability which increases with distance. Distance separation between base stations and radar for various spurious attenuations were calculated using reliability expressions for short radar to target ranges with constant SNR and for longer radar to target ranges with variable SNR. For a magnetron radar under clutter free conditions, 90 dB of spurious attenuation is needed to obtain 90% radar operational reliability at1.2 km when the INR is -6 dB and the SNR is constant. Reducing the INR to -9 and -12 dB increased the separation distance to 1.7 and 2.7 km, respectively. At longer base station to radar separation distances, variable SNR required less spurious attenuation than constant SNR. Consequently, constant SNR analysis can be considered worst case. Distance and frequency separation were calculated using frequency dependent rejection (FDR). These calculations showed that for constant SNR 92.8 MHz of frequency separation is required to meet the 90% reliability IPC at 1.2 km separation distance when the INR is -6 dB. Only 54.6 MHz frequency separation is needed when the separation distance is increased to 32.8 km.
Keywords: radar; interference; radio wave propagation; frequency dependent rejection; interference protection criteria (IPC); spurious emissions; broadband radio service; marine radar; radio spectrum engineering
Effect of Broadband Radio Service Reallocation on 2900–3100 MHz band Marine Radars: Background
Spectrum reallocations may place broadband radio services (BRS) near spectrum used by 2900–3100 MHz band marine radars. Interference effects from these reallocations include unwanted emissions in the radar detection bandwidth and front-end overload. This report provides background information for subsequent reports that analyze these effects. Interference protection criteria (IPC) are identified, an interference scenario is described, and models for the radar system, BRS system, radar target, and radio wave propagation are presented. The BRS signal is shown to be reasonably emulated by Gaussian noise. A method for determining the aggregate power distribution using a realistic propagation model and Monte Carlo analysis is described. The aggregate power from the base stations was found to be as much as 6 dB more than power from a single base station. Finally a method for incorporating a variable SNR, caused by variable radar to target path loss, into interference analysis is shown.
Keywords: radar; interference; radio wave propagation; front-end overload; unwanted emissions; interference protection criteria (IPC); aggregate power; broadband radio service; marine radar; radio spectrum engineering; signal characterization