ISatPhone is the latest Inmarsat’s mobile satellite phone service which provides a simple and highly user friendly way of staying in touch. This phone can be used as a satellite phone or a Cell phone. The striking feature of this phone is the dual mode operating system which allows the phone to work in both satellite and GSM network which has made it as one of the popular mobile phones. It renders the possibility of optimizing the usage of the service and GSM networks which depends on the availability and conditions of the operating environment. The phone is indispensable when the location of the operating environment of the phone is changed frequently and where the network access of GSM is limited or no network access. Examples of such places include deserts, sea, countries with poor telecommunication setup or countries which have high mountains. It is used under most advanced communications satellites that support IP data services at broadband speeds and voice simultaneously. The medium which is used to transfer data is a two way satellite transfer system, which renders a very good access to the satellite network where there are limited or no network access which corresponds to additional data and voice services.