TETRA uses Time Division Multiple Access (TDMA) with four user channels on one radio carrier and 25 kHz spacing between carriers. Both point-to-point and point-to-multipoint transfer can be used. Digital data transmission is also included in the standard though at a low data rate.
The presented principles are directed to an apparatus for monitoring humidity exposure of system components, with the apparatus having sensor modules for collecting environmental data and a monitoring module with a humidity indicator and an electrical monitoring component sealed from the environment that reads a physical change in the humidity indicator to determine the humidity […]
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