In telecommunication, a wireless phone, cellular mobile or cell phone (in the United States), also called a mobile phone in other English speaking countries, is a mobile communications system that uses a combination of radio wave transmission and conventional telephone switching to permit telephone communication to and from mobile users within a specified area.
The term does not comprise the so-called portable phone or cordless phone, which is associated with a fixed telephone landline and can only be operated close to (less than 100 metres of) its base station, such as in and around the house. The term cell phone applies specifically to mobile phones which use a cellular network; satellite phones are also mobile phones, but not cellular.
Inmarsats use a completely different system. Basically, the satellite simply retransmits whatever signals it receives. The mobile stations actually log into a ground station. More information is available at INMARSAT.
Note: In cellular mobile systems, large geographical areas are segmented into many smaller areas, i.e., cells, each of which has its own radio transmitters and receivers and a single controller interconnected with the public switched telephone network. Synonyms cellular phone, mobile phone, cellular radio, cellular telephone.
Source: from Federal Standard 1037C