Basic Mobile networks

Mobile networks comprise:
1.Radio access network
2.Core network and systems
3.Operations support systems
4.Content and applications delivery systems

Radio Access Networks

The radio access networks provide the connectivity from the mobile user equipment UE to the network. They employ transmission links derived on point to point radio or fibre (and in very rare cases satellite) to connect to the radio controllers (BSC Base Sation Controllers for GSM/GPRS/EDGE and RNC Radio Network Controllers for UMTS). The radio controllers in turn connect to the core network.The radio controllers manage the radio resources and schedule the use of the shared channels as well as managing call set up and hand-off of calls and data sessions between base stations. For LTE the functions of the radio controller are by and large delegated to the base station.

Core Network
The core network provides the switching, control and management of the network. It provides core mobile features such as:
Security encryption of call set and and transmission
Equipment identity and management
Call barring and diversion
Location and roaming enablement
Voice switching and trancoding for voice calls to fixed and other mobile networks
Data routing and packet connection to data networks
SMS and MMS service management
Lawful interception capability
Number portability capability
IP Multimedia System IMS

Operations Support Systems
The operations systems support the operation of the mobile network and provide mobile services and operations capability including:
Customer billing and service activation
Over the air management of mobiles
SIM card issue and control
Customer service
Wholesale and reseller billing and control
Prepaid service
Voice Messaging
Video telephony and conferencing
Delivery of content services like streaming video and audio, ringtones
Location based services
Network management, operations and maintenance
Content and Applications