With HF radio systems, knowing which is the best channel or frequency to use is difficult for many users. Codan has developed the Codan Automated Link Management (CALM) to remove this problem.
CALM is a new and very advanced feature of the NGT in which the transceiver performs the channel selection operation automatically. With CALM, the process of making a call is as easy as pressing one button. The handset in most ways looks and operates like a mobile phone.
Up until now, FED–STD–1045 ALE has been used to find the best frequency to use when sending a call. The advantages of FED–STD–1045 ALE include:
Automatic channel selection requiring no operator involvement
Voice communications as well as fax, data and email
Compatibility with different manufacturer's ALE system
However, FED–STD–1045 ALE systems also have a number of inherent limitations. These include:
Network time used up with sounding calls
Immediate decay of information
Not a self–managing network
Codan Automated Link Management (CALM) provides a dramatic improvement over conventional ALE systems as It provides all of the benefits of FED–STD–1045 ALE plus the following advantages.
Creates multiple time–stamped entries for each channel/link in the LQA database
Reduces the number of sounding calls
Provides a self–managing network
With the introduction of CALM, it is no longer necessary to reconfigure each NGT station with information about a new NGT transceiver.
Once the new station goes on air with a sounding call, all NGT stations in the network automatically add it to their database. The NGT CALM network is able to upgrade itself, which significantly reduces the network administrator’s workload.
The new station also begins to build its link quality database of each NGT station in the network.
With CALM, you can make selcall, status, message, emergency, phone and GPS calls as ALE calls.
Because signal propagation conditions vary at different times of the day and night, CALM records the time at which a sounding was taken and, with the information received, builds up a profile of the most suitable channels to use at different times. This means that when you make a call at 3pm your transceiver selects a channel based on information received at the same time of day rather than information that could be out of date. It also means that CALM is ready to go the moment your transceiver is switched on.