To ameliorate interference between an indoor wireless pico cell system, for example in an aircraft, and public wireless communications systems operating in a surrounding or over-flown area, frequencies of operation of the indoor system are coordinated with those used by the public wireless systems in the surrounding area. The pico cell system operates one type of service on all or a portion of a band used for a different type of service by the public system. In the aircraft example, a pico cell system might support GSM narrowband service and CDMA broadband service. The airborne GSM operations use a portion, e.g. corresponding to a guard band, of CDMA service spectrum in the terrestrial network. The airborne CDMA service uses a band used for GSM service by the terrestrial network. The pico cell system dynamically changes its frequency band(s), as the aircraft flies over different areas.