In my company, mobiles have to be switched off or on "silent" during meetings.
There are occasions when calls are extremely urgent, but these are the exception. I think it is incredibly rude to go into a meeting with a mobile switched on and to take calls, particularly without saying that the person is expecting an urgent call during the meeting. I feel the same about mobile phones at lunch and dinner tables! But then, I also think that many people these days simply don't know how to behave.
I'm getting old

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R.