ALE - Automatic Link Establishment

Updated: 12 September 2005

Automatic Link Establishment (ALE)

There are many good web sites on ALE technology and hot it used. This section of the TSC-60 site will only try to provide an overview and provide links to sites we found very useful.

For more information about ALE and how the HF-80 and later generation HF radios were to be controlled, please go to the NTIA Report on ALE technology. In summary, this site discusses the following:

"High frequency (HF) communications has been an essential part of worldwide information transmission 
since the advent of radio and has advanced nearly in step with information technology.  
Today, advanced thinkers in the field envision HF radio technology as embracing and supporting 
such technological advances as HF e-mail and compressed multimedia voice and data services.  
A guide has long been needed that brings together into one concise user's handbook all 
of the working knowledge of HF Automatic Link Establishment (ALE) radio technology.  
Many publications exist that deal with one or more aspects of this technology - sometimes in great detail.  
This guide, which is general in scope, provides a broad approach.  
It is a tutorial for explaining the basics of this HF ALE technology and for passing along 
working knowledge for hands-on operation of HF ALE systems.  
This guide is the product of many authors who have combined their considerable expertise."

Rockwell-Collins presentation on ALE evolution is here

And if you really need bed time reading material, try reading the MIL-STD document on ALE (188-141). MIL-STD-188-141B or the 188-110B document on HF modems.

To quote the document summary:

"This document contains technical standards and design objectives for medium and high-frequency radio systems. Included are: (1) the basic radio parameters to support both conventional and adaptive radio communications; and (2) technical parameters for automatic link establishment (ALE), linking protection, and other advanced adaptive features and functions."

And the ALE Operations manual for US Forces is here

More ALE data can be found here at the ARRL site at this link

Want to listen to ALE? Go here!

Have lots of spare money, buy one of these to solve your ALE needs: Rockwell-Collins ALE.

The US Homeland Security department - basically the US Customs COTHEN network now uses the current MIL-STD 188-141A protocol. It formally used the FED-STD-1045A ALE protocol, developed by Rockwell Collins (the 309L series, 300 Baud). The FED-STD protocol is Rockwell Collins proprietary and goes by the tradename "Selscan". Selscan is no longer actively used by the COTHEN network. Collins new series, the 309M, uses the 188-141A waveform.

The Rockwell descriiption states: "A Rockwell Collins 309M-1 ALE processor equipped HF communication system provides both enhanced communications reliability and operational simplicity. Compliance with new Automatic Link Establishment (ALE) interoperability standards, combined with over 20 years of prior experience in the development and fielding of HF ALE systems and operator interfaces, make the 309M-1 the best engineered "second generation" ALE control available. The 309M-1 includes a host of ALE features which provide advanced system operational capabilities well beyond those guaranteed by compliance with the requirements of the new ALE standards. The 309M-1 ALE Processor, a user-friendly hardware/software implementation from the original inventors of ALE."

Informal list of ALE users from Ominous-Valve or a backup copy is here. Other utility listening sites for ALE modes include:

Interesting write-up on ALE by the Army in 1990's on ALE.

Recommendation. Test and consider authorization of additional 
antennas, such as Nevus and other minimum footprint, high-gain types, 
which would maximize AE radio capabilities regardless of employment 
scenario. The installation of vehicular whip antennas would also add 
to flexible response capabilities in rapid redeployment situations.

(5) Adaptive controllers.

Observation. The introduction of the Harris RF-7210 Adaptive 
Controller during Operation DESERT SHIELD/STORM offered both 
advantages and disadvantages to the AE communications net.

Discussion. Previously tested for AE during REFORGER 88 and PATRIOT 
SPIRIT 90, the Adaptive Controller provided automated frequency 
evaluation and selection which theoretically ensured the best possible 
communications between linked stations. Although technically 
efficient, even without gain control, the unit operationally isolates 
each user by constantly scanning rather than monitoring a given 
frequency for activity. For those used to monitoring the net in order 
to stay abreast of activity throughout the theater, the new system 
tunes only to a desired location, leaving the rest in silence. This 
method limits the benefits of teamwork when radio sites relay for each 
other if a given station has difficulty transmitting to another. If 
operating more than one net simultaneously, the controller "walks on" 
other stations transmissions when it evaluates their frequency for 
possible use in a subsequent link to another station. Preference for 
or against the system seems to be based more on a preference for 
current knowledge of AE activity among net stations as opposed to 
singular communications that are similar in scope to the use of a 
telephone. Finally, its cube and weight are similar to an RT, adding 
to an already tightly squeezed loadout.

Recommendation. Further testing of adaptive controllers for 
operational feasibility is warranted, and technical improvement before 
procurement is necessary.

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