air-ground radiotelephone service. These systems use far more widely separated ground stations than standard cellular systems. In the 450 MHz band co-channel assignments are at least 497 miles apart and in the 800 MHz band only specific sites were authorized by the FCC. The 450 MHz service is limited to "general aviation" users, usually corporate jets, while the 800 MHz spectrum can be used by airliners as well as for general aviation. The FAA in 14 C.F.R § 91.21 prohibits the use of portable electronic devices, including mobile phones, for all commercial flights and for those private flights being made under instrument flight rules (IFR). It does allow that the airline (or, for privately operated aircraft, the pilot) can make an exception to this rule if the operator deems that device safe. This effectively gives the airline, or the private pilot, the final word as to what devices may safely be used aboard an aircraft as far as the FAA is concerned although the FCC restriction still applies. (Note that for aircraft operated by an airline the pilot is not considered the "operator" and cannot legally allow exceptions to the airline's restrictions although the pilot may dictate additional restrictions.) On February 11, 2014, the House Committee on Transportation and Infrastructure approved the Prohibiting In-Flight Voice Communications on Mobile Wireless Devices Act. The bill would forbid airline passengers from talking on mobile phones during a flight. In September 2014, a bipartisan group of lawmakers opposed the FCC ending the ban on mobile phones aboard, citing safety as one of the main concerns. Regulatory status in Europe In September 2014, the European Aviation Safety Agency removed its ban on mobile phone use during flights. The new guidance allows airlines to permit portable electronic devices to stay switched on, without the need to be in ‘Airplane Mode’. This enables the ability to offer ‘gate-to-gate’ telecommunication or WiFi services. Regulatory status in India On 19 January 2018, the Telecom Regulatory Authority of India (TRAI) permitted the use of mobile phones and internet access through Wi-Fi on-board all flights operating in Indian airspace. However, passengers are only permitted to make mobile phone calls when the aircraft is at an altitude of over . TRAI stated that the height restriction was to ensure "compatibility with terrestrial mobile networks". Future technologies A few U.S. airlines have announced plans to install new technology on aircraft which would allow