4 ms·

So, it encrypts sms messages and is still in use?

• giantrobot 5y ago
  It doesn't encrypt SMS. It's over the air encryption for packet data (not calls or SMS) like WEP or WPA on WiFi. On GSM networks SMS was transmitted in leftover signaling space on voice circuits.
  • secondcoming 5y ago
    RACH: https://en.m.wikipedia.org/wiki/Random-access_channel https://en.m.wikipedia.org/wiki/Random-access_channel
  • ronsor 5y ago
    IIRC "SMS over GPRS" was an optional extension