I arrange and observe EMC/EMI tests on flightdecks as part of the supply of our Electronic Techlogs (which use GSM technology to leave TechLog, etc on ground).
Our systems will not be allowed to even trial if the basic flightdeck test is not successfully completed - and these tests cannot happen without our DDP (Data & Design Performance test) being in place.
Flightdeck tests involve doing transmissions with flightdeck fired-up with engines off, then repeated with all engines on idle.
Results are tested visually (by two engineers) and electronically by a PCMCIA card in the avionics bay. This is then removed and analysed.
Each new aircraft (and variant) that is added to the fleet needs to be tested.
Finally, to emphasise radeng's post, these tests are only valid for that build of computer/phone card combination. It is our responsibility to verify each build of all equipment used. The DDP only covers one type of build; new build = new DDP = new EMI/EMC test.
All tests on all a/c covered (typically 737s and A320s) have been completely clear of any interference - but that's only because of the effort that goes into making sure that's the case!
Many of the electronic equipment allowed on f/decks at the moment don't need to undergo these tests as 'flightbag'solutions are not considered to be an integral part of the operation of a commercial a/c. The TechLog is a vital part of operating procedures, hence different standards of test.
Cello