20880302_ferences__July_2014_FIDE_Laws___FIDE_rule
[0] 3. [USCF rule] USCF rule 20N provides for a time penalty the first time a player's cell phone rings. [FIDE rule] 
The Laws of Chess forbid a player from having a cell phone or other electronic means of communication in the playing venue at all, even if the device is powered off. The penalty is loss of the game, but the rules of a competition may specify a lesser penalty. The arbiter may require the player to allow his clothes, bags, or other items to be inspected in private.
The United States Chess Federation - USCF - FIDE Rule Differences (July 2014 FIDE Laws)
FIDE rule