58 In 1994, when the Commission initially established that definition of “public switched network,” cellular telephone (i.e., mobile voice) service was the major mobile service; mobile broadband did not yet exist. Noting that the “purpose of the public switched network is to allow the public to send or receive messages to or from anywhere in the nation,” the Commission observed that the NANP fulfilled that purpose by providing users with “ubiquitous access” to all other users. Id. at 1436–37 ¶¶ 59–60; see 2015 Open Internet Order, 30 FCC Rcd. at 5779 ¶ 391. Because mobile voice users could interconnect with the public switched network as then defined (the network of ten-digit telephone numbers), mobile voice was classified as a “commercial”—as opposed to “private”— “mobile service.” 1994 Order, 9 FCC Rcd. at 1454–55 ¶ 102. It therefore was subject to common carrier treatment. In 2007, the Commission first classified the thenemerging platform of mobile broadband. The Commission determined that mobile broadband users could not interconnect with the public switched network—defined at the time as the telephone network—because mobile broadband uses IP addresses, not telephone numbers. See 2015 Open Internet Order, 30 FCC Rcd. at 5784 ¶ 397; 2007 Wireless Order, 22 FCC Rcd. at 5917–18 ¶ 45. Mobile broadband thus was not considered an “interconnected service” (or, therefore, a commercial mobile service), i.e., a “service that is interconnected with the public switched network” as that term was then “defined by . . . the Commission.” 47 U.S.C. § 332(d)(2). Presumably in light of mobile broadband’s “nascent” status at the time, 2007 Wireless Order, 22 FCC Rcd. at 5922 ¶ 59, the Commission gave no evident consideration to expanding its definition of the “public switched network” so as to encompass IP addresses in addition to telephone numbers.