Blue Tooth

This is a wireless technology for exchanging data using short length radio waves.Invented by Erisscon.We can create personal network also using Bluetooth.Blutooth uses a radio technology called frequency hopping spread spectrum.The band used is 2.4 Ghz  short range frequney band which is globally unlicenced.In basic bluetooth the modulation used is GPSK.As this use radio broadcast communication system,they donot have to be in line of sight.