AWS-3 LTE Impacts on AMT

Summary

This test builds on and extends a previous NASCTN project that measured the out-of-band (OoB) LTE evolved Node B (eNB) and User Equipment AWS-3 emissions into adjacent L and S frequency bands of AMT systems.  While the previous test measured general LTE OoB emissions, this project specifically measures the impact to AMT systems.  Results can be used to improve testing protocols that protect existing federal systems during new cellular deployments.

Description

Designed, demonstrated and validated a test methodology to measure the impacts of newly deployed commercial cellular equipment on existing DoD Test Range systems.  In particular,

• The effects of out-of-band emissions from user equipment deployed in the AWS-3 LTE band (1755MHz - 1780MHz) on the DoD AMT systems in the adjacent L Band (1780Mhz-1850 MHz)
• New coexistence metrics and interference analysis methodologies for multiple waveforms
• A curated set of LTE waveforms for future testing of multiple range environments.

Background:  In 2015, the FCC Auction 97 created the AWS-3 band for commercial mobile broadband usage in the United States, which led to the compressed operations frequency band for DoD test range Aeronautical Mobile Telemetry (AMT) systems.  However, AMT infrastructure remains largely unchanged, and current Inter Range Instrumentation Group (IRIG) Protocols for mitigating interference does not include specifics for new waveforms such as LTE.  In 2017, NASCTN conducted a test campaign for Edwards Air Force Base (EAFB) measuring the out-of-band emissions of commercial LTE smartphones and an evolved node B (eNB) into the newly compressed AMT band.  In 2019, this follow-on project was launched to investigate the potential impacts of LTE adjacent band emissions to the AMT systems.  The in-band and out-of-band LTE uplink emissions are directly injected into an AMT link in a controlled environment to evaluate the impact.

 

Graph of LTE eNB power spectrum, showing LTE and AMT frequency allotments, derived from NASCTN Report 4

Credit: NASCTN

 

Credit: Robert Sullivan

EAFB Telemetry Site

Credit: Duncan McGillivray/NIST

 

 

 

The results of the previous NASCTN project are documented in the completed report which was published simultaneously as NASCTN Report 4, NTIA Technical Report TR-18-528, and NIST Technical Note TN 1980.

 

Framework Stage	Information
Stage 4: Summarize Findings	AWS-3 LTE Impacts on Aeronautical Mobile Telemetry In-Situ Captures of AWS-1 LTE for Aeronautical Mobile Telemetry System Evaluation Laboratory Method for Recording AWS-3 LTE Waveforms Public Briefing
Stage 3: Test Execution	Data - AWS-3 LTE Impacts on Aeronautical Mobile Telemetry Data - Laboratory Methods for Recording AWS-3 LTE Waveforms
Stage 2: Test, Metrology, and Implementation Plan	Advanced Wireless Service 3 (AWS-3) Long-Term Evolution (LTE) Impacts on Aeronautical Mobile Telemetry (AMT) Test and Metrology Draft Test Plan Community Outreach Briefing 9/18/2018 - Adjudicated comment matrix
Stage 1: Proposal Screening	Proposal Submitted by EAFB.  Approved by NASCTN Steering Committee.

 

 

If you have any additional questions, please email nasctn [at] nist.gov.