NIST Special Database 21old

NIST Automatic Link Establishment (ALE) Degraded Tones Per Fed-STD-1045A

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This set of 12 audio disks and one CD-ROM produced by the National Telecommunications and Information Administration's Institute for Telecommunication Sciences is used to test high frequency (HF) Automatic Link Establishment (ALE) radios. As a follow-up to the ALE Clean Tones CD (NIST Special Database 17), they incorporate signal degradation caused by noise, multipath, and fading using the Watterson channel mode1. With these CDs, users may test HF ALE radio performance under degraded conditions specified in the Federal standard without having to purchase a propagation channel simulator.

The Federal Standards (1045A and 1046/1) for HF ALE radios specify expected linking performance under simulated atmospheric conditions of Gaussian noise, and CCIR Good and Poor channel conditions at various signal-to-noise ratios (SNR).

Both CCIR Good and Poor are invoked at varying Gaussian SNRs. Each of the 12 audio CDs covers one type of atmospheric condition at a given SNR.

Each CD contains 100 simple ALE calls repeated under a specific simulated atmospheric condition. Each call is followed by a non-degraded ALE return to scan. In addition, each CD contains three calibration tracks: a 1000 Hz calibration tone, all 8 ALE Calibration Tones (750-2500 Hz), and a clear channel ALE Allcall.

The CD-ROM contains the contents of the ITS's FTP site, consisting of the ALECALL software, sample profiles, and documentation files, for users who do not have Internet access.

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Price: $50.00

Effective immediately, there will be a minimum $30.00 shipping charge for all international shipments of databases via UPS International. Customer will be responsible for their own duties, tax, and VAT. Contact 301 975 2200 or data [at] nist.gov (data[at]nist[dot]gov) if you have questions.

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