Timeline of Evolution
GSM : calls on circuit switching ( CS ) between 2 parties for communication. Dedicated circuits are used for voice and SMS.
GPRS : packet switching (PS) is introduced for data services
UMTS / 3G : network elements begin evolving into PS . No changes to core .
EPC / LTE/VOLTE : No circuit switched domain at all .
IP Multimedia SubSystem was originally meant for evolved UMTS network to provider IP communication to mobile UAs. Today IMS is gaining plenty of attention due to oncoming
More information on IMS and IP Communication go here
What is IMS or IP Multimedia System ?
LTE ( Long Term Evolution )
evolved UMTS terrestrial radio access network (E-UTRAN). With this eco-system Evolved NodeB (eNodeB) is the base station for LTE radio.
What is EPC (Evolved Packet Core ) ?
EPC is a core network architecture framework by 3GPP.
Primarily EPC has 4 sub parts