Mobile service. A radio communication service carried on between mobile stations or receivers and land stations, and by mobile stations communicating among themselves, and includes:
(1) Both one-way and two-way radio communications services;
(2) A mobile service which provides a regularly interacting group of base, mobile, portable, and associated control and relay stations (whether licensed on an individual, cooperative, or multiple basis) for private one-way or two-way land mobile radio communications by eligible users over designated areas of operation; and
(3) Any service for which a license is required in a personal communications service under part 24 of this chapter.
47 CFR § 9.3
Terms with definitions including the (RR) designation are defined in the same way in 2.1 of this chapter and in the Radio Regulations of the International Telecommunication Union.