PAT meaning in Telecommunication ?

In electrical safety testing, portable appliance testing (PAT, PAT inspection or redundantly as PAT testing) is a process in the United Kingdom, the Republic of Ireland, New Zealand and Australia by which electrical appliances are routinely checked for safety. The formal term for the process is "in-service inspection & testing of electrical equipment". Testing involves a visual inspection of the equipment and any flexible cables for good condition, and also where required, verification of earthing (grounding) continuity, and a test of the soundness of insulation between the current carrying parts, and any exposed metal that may be touched. The formal limits for pass/fail of these electrical tests vary somewhat depending on the category of equipment being tested.

Other countries have similar procedures, for example, testing of equipment according to DGUV Vorschrift 3 in Germany.