CMS provider Gateway.

CMS provider Gateway. The mechanism(s) that supports the C interface and associated protocols between the Alert Gateway and the CMS provider Gateway, and which performs the various functions associated with the authentication, management and dissemination of WEA Alert Messages received from the Alert Gateway.

Source

47 CFR § 10.10

Scoping language

Alert Message. An Alert Message is a message that is intended to provide the recipient information regarding an emergency, and that meets the requirements for transmission by a Participating Commercial Mobile Service Provider under this part.