Interferences
The 2.4GHz frequency band is also used by other applications (e.g microwave ovens, garage door openers). In order to reduce the interference sensitivity, the data is reduced into many small data packets with a duration of at least 625 microseconds (µs). With the help of a 16 bit long checksum the integrity of the packet is checked and if necessary a repeat of the transmission is ordered. In addition the transmission frequency changes 1600 times per second within the frequency band (2.0 to 2.48 GHz). This is called "frequency hopping".