Presentation on theme: "Wideband HF Channel Availability Working Group San Diego Convention Center San Diego, California THIS INFORMATION IS NOT EXPORT CONTROLLED THIS INFORMATION."— Presentation transcript:
Wideband HF Channel Availability Working Group San Diego Convention Center San Diego, California THIS INFORMATION IS NOT EXPORT CONTROLLED THIS INFORMATION IS APPROVED FOR RELEASE WITHOUT EXPORT RESTRICTIONS IN ACCORDANCE WITH A REVIEW OF THE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS (ITAR), 22CFR 120-130, AND THE EXPORT ADMINISTRATION REGULATIONS (EAR) 15 CFR 730-774.
Agenda Goals (9:00-9:10) Presentation of proposed measurement system (9:10-10:00) Demonstration: Perseus SDR with Clifton Labs Antenna Discussion: Data collection Methodology Discussion: Data Analysis Methodology Discussion: Software and collected data sharing approach Break ( 10:00-10:15) Member Presentations( 10:15-11:00) Thales – Ideas and Considerations for WBHF Channel Availability Measurement Rohde & Schwarz - Necessary Steps - National and International - Towards Harmonized WBHF Test Frequency Licensing FFI measurement plans LT Mehdi DHAKOUANI Break ( 11:00-11:10) Discussion and agreement of Way Forward (11:10-12:00) Modifications to proposed measurement system List of members planning to field a measurement system List of Action Items
From Harris Nordic HF Presentation Inexpensive system could be fielded by a number or countries/ organizations Collected data could be shared among all participants Harris could make available the data collection and data analysis software used for this paper Perhaps under the HFIA a working group could be established to define and agree upon the definition of availability metrics and the interpretation of results August 12-14, 2013
Goals Under the auspices of the HF Industry Association (HFIA), collaboratively field a substantial number of HF wideband channel availability measurement stations in diverse locations worldwide (as far as possible Use common hardware, (SDR and antenna), collection software, and analysis software so that results can be easily and accurately compared between all sites Share the collected data and analysis results among all members of the HFIA Begin testing as soon as possible Present and compare results at next HFIA meeting
Demonstration of the Perseus SDR and Clifton Labs Antenna
Questions, concerns, issues? Perseus http://microtelecom.it/perseus/ http://microtelecom.it/perseus/ Clifton Labs http://www.cliftonlaboratories.com/z1501_active_antenna.htm http://www.cliftonlaboratories.com/z1501_active_antenna.htm Importance of antenna Is Omni directional needed Is a well calibrated antenna needed CL antenna was selected for portability, analysis is based on differences in signal level within each band
Discussion: Data Collection Methodology High Level Overview Set LO to 2.5 to MHz Set pre-selector Set sample-rate= 2 Ms/s Gather USB samples Use a 4096 pt FFT Kaiser Window FFT Bin = 488.28125 Hz Average 488-(1 sec) Store off “middle” 2048 pts representing LO-0.5 MHz to LO+0.5Mhz Increase LO by 1.0 MHz Repeat 2-30MHz in 30 secs Repeat every 60 seconds Collection software created by modifying an example program in the Perseus SDRDK which can be downloaded from the Perseus site Harris can provide the executable
Discussion: Data Collection Methodology Current Output File Format … Data files can be viewed directly or even displayed via MATLAB Questions, concerns, issues?
Discussion: Data Analysis Methodology Each sweep observation file processed in 1 MHz segments Measured RX power divided into 3 kHz bins, sorted and noise floor calculated by summing the 10 lowest values For each 3 kHz bin, if the RX power was 10dB above the noise floor it was considered occupied Each sweep observation file converted to 9334 values, (1,0) indicating if that 3 kHz segment was occupied
Discussion: Data Analysis Methodology If a specific 3 kHz bin was available for 3 observations in a row it was considered available for the current minute - Channel Minute Availability (CMA) This biases the availability to channels that are relatively unused for a few minutes and not experiencing sporadic use or interference (Good for tactical messaging) CMA is a good best case metric which assumes all channels equally available and a low overhead adaptive wideband HF ALE system For each 3 KHz bin, it could have up to 60 available minutes in an hour. For each 1 MHz segment there can be a total of 60*1000000/3000 = 19980 (3 kHz) Results displayed as a normalized CMA ( 0.0 – 1.0) Processing repeated for any bandwidth of interest ( 6-48kHz)
Discussion: Data Analysis Methodology CMA can be displayed as a 24 HR by 28 MHz Grid
Discussion: software and collected data sharing We need a mechanism to support distribution of the data collection software and data analysis software It is desirable to have a common storage area for all data collected. After a modification to the file format and with compression a 24 hr day will result in about 82 MB of data We are investigating whether the HFIA website can provide storage We may need to limit common storage to results and let each individual collector manage their own storage, assuming they would provide raw data upon request Any ideas, comments, concerens?
Discussion and agreement of Way Forward Modifications to proposed measurement system To be filled in in meeting
Discussion and agreement of Way Forward List of members planning to field a measurement system Name / org / location /contact email/ Furman / Harris / Rochester, NY, USA / wfurman@Harris.comwfurman@Harris.com Jodalen / FFI / kjeller, Norway
Discussion and agreement of Way Forward List of Action Items To be filled in at meeting Modify collection software to reduce size of data file ( W.Furman-Harris) Review modified data analysis software ( written in C)
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