Modifying GSM cell phones to function as a transmitter and receiver without a service provider is technically feasible but requires specific hardware and software modifications. Users must utilize tools such as Arduino or Raspberry Pi to facilitate communication between the devices. Additionally, custom firmware may be necessary to bypass standard network protocols. This approach is primarily for experimental purposes and may not comply with legal regulations.
PREREQUISITESElectronics enthusiasts, hobbyists in telecommunications, and developers interested in experimental communication systems.