<P> In the United States, seven frequency bands have been allocated by the Federal Communications Commission for uses that include cordless phones . These are: </P> <Ul> <Li> 1.7 MHz (1.64--1.78 MHz, up to 5 channels, AM). Cordless phones manufactured after October 1, 1984 are not allowed to use this band and were required to use the newer (higher) 43 - 50 MHz frequencies . </Li> <Li> 27 MHz, near the Citizens Band (CB) Radio service with some frequencies being 26.010, 26.050, 26.380 and 26.419 MHz . These were initially paired with the 1.7 MHz frequencies, then, later, with the 49 MHz frequencies . Signals were FM - frequency modulation . </Li> <Li> 43--50 MHz (Base: 43.72--46.97 MHz, Handset: 48.76--49.99 MHz, FM) Allocated in December 1983, and approved for use in mid-1984 for 10 channels . 15 additional channels allocated April 5, 1995 . </Li> <Li> 900 MHz (902--928 MHz, allocated in 1993) </Li> <Li> 1.9 GHz (1880--1900 MHz, used for DECT communications outside the US) </Li> <Li> 1.9 GHz (1920--1930 MHz, developed in 1993 and allocated in October 2005, especially with DECT 6.0) </Li> <Li> 2.4 GHz (2400--2500 MHz, allocated in 1998) </Li> <Li> 5.8 GHz (5725--5875 MHz, allocated in 2003 due to crowding on the 2.4 GHz band) </Li> </Ul> <Li> 1.7 MHz (1.64--1.78 MHz, up to 5 channels, AM). Cordless phones manufactured after October 1, 1984 are not allowed to use this band and were required to use the newer (higher) 43 - 50 MHz frequencies . </Li> <Li> 27 MHz, near the Citizens Band (CB) Radio service with some frequencies being 26.010, 26.050, 26.380 and 26.419 MHz . These were initially paired with the 1.7 MHz frequencies, then, later, with the 49 MHz frequencies . Signals were FM - frequency modulation . </Li>

When did the first cordless phone come out