While there are still analog alpena voip phone systems in use, it is highly unlikely that the mode of transmission used would be analog as well. Digital telephony or digital phone systems have been around since the 1960s. Phone companies progressed slowly in adopting digital technology. T1 carrier cables were the first notable upgrades, followed by SONET and fiber optic technologies. While most handsets generate analog signals, these are typically converted to digital signals at a relay station and reconverted to analog on the opposite end. New technology has made it possible for calls today to be entirely digital.