§  10.510   Call preemption prohibition.

   Devices marketed for public use under part 10 must present an Alert
   Message as soon as they receive it, but may not enable an Alert Message
   to preempt an active voice or data session. If a mobile device receives
   a WEA Alert Message during an active voice or data session, the user
   may be given the option to control how the Alert Message is presented
   on the mobile device with respect to the use of the common vibration
   cadence and audio attention signal.

   [ 81 FR 75726 , Nov. 1, 2016]