scope:

The present document specifies the methodology for showing conformance to the operational requirements for a GSM onboard aircraft system, which allows communication in the GSM 1800 frequency band and which ensures that mobile terminals will not connect to ground based mobile networks.

The present document further specifies measurement methodologies allowing to define the key RF parameters of the aircraft, which are:

• the aircraft attenuation as observed at the windows;

• the aircraft attenuation in combination of the antenna system as observed at the antenna system feeding point;

• the effective cabin coupling loss within the aircraft cabin.

The present document also provides a way to translate the power level generated by the GSM onboard aircraft system at the antenna system output port to an E.I.R.P. defined outside the aircraft.