Any common carrier network that provides circuit switching among public users. Note: The term is usually applied to public switched telephone networks, but it could be applied more generally to other switched networks, e.g., packet-switched public data networks. 2. A switched network accessible by the public for the purpose of originating and terminating telecommunications messages. 3. Any common carrier switched network, whether by wire or radio, including local exchange carriers, interexchange carriers, and mobile service providers, that use the North American Numbering Plan in connection with the provision of switched services.