3GPP is the standardization group for mobile networks and is in existence since 1998. 3GPP specification come in bundles called “Release”.

3rd Generation Partnership Project (3GPP)

3GPP releases are from Release 99 to Release 7.

Release Published Key Architectural Features
Release 99 March 2000 UTRAN, USIM
Release 4 March 2001 MSC Split into MSC server and Media Gateway
Release 5 March 2002 IMS, HSPDA, IP based UTRAN
Release 6 March 2005 I-WLAN, HSUPA, MBMS, IMS
Release 7 Dec 2007 Unified PCC, Direct Tunnel, MIMO, HSPA+, IMS, VCC

The network entities in brief are −

UE User Equipment: the mobile terminal
BTS Base Transceiver Station: the 2G/2,5G radio base station
BSC Base Station Controller: a controlling node in the 2G radio network
NodeB 3G radio base station
RNC network Radio NW controller: controlling and concentrating node in the 3G radio
(G)MSC Nodes (Gateway) Mobile Switching Center: circuit switched core network
S/GGSN Nodes Serving/Gateway GPRS Support Node: packet switched core network
HLR/HSS base Home Location Register / Home Subscription Server: central data
PCRF Policy and Charging Rules Function: a control node for policy management and charging

3rd Generation Partnership Project 2 (3GPP2)

3GPP2 is the corresponding part of 3GPP market. 3GPP2 standards body has also developed a large set of specifications describing own mobile network technology, the current generation being labeled as CDMA2000 ©. 3GPP2 is 3GPP concepts and solutions, but is chosen selectively different. Regarding LTE, there has been a growing interest of 3GPP2 operators in recent years to allow between flexible and efficient. The inheritance 3GPP2 technology includes a component called 1xRTT CS and PS component (EVDO vs eHRPD). 3GPP2 consider their (eHRPD) high-speed packet data network as equivalent to 3GPP old system, the right to transfer procedures optimized specially designed.

Architecture of the 3GPP System

The overall architecture of the 3GPP, evolved system as well as the core and access networks already existing 3GPP defined are called "legacy 3GPP system".

The access networks which are not defined by the 3GPP, but may be used in conjunction with the evolved 3GPP system are called "non-3GPP access networks".

The area of service must be understood as the multitude of IP services, so in general they are represented and implemented by packet data networks (PDN). IP service can simply offer a raw IP connectivity (i.e. allowing an internet connection), providing a connection to a corporate network, or an advanced IP-based control functionality such as telephony and instant messaging via IMS.

It is called "Evolved UTRAN" (EUTRAN). GERAN and UTRAN are the existing radio access networks and are connected to the legacy PS domain.

Evolved Packet Core (EPC) in addition to the basic functions to manage packet routing and forwarding (for the transport of user data) contains all the features necessary to control especially for mobility, session handling, safety and load.

For interworking with legacy CS domain, the CS core network should be considered as well and interfaced with the backend IMS. The dotted arrow indicates an optional interconnection between legacy CS core networks and the new network Evolved Packet Core, the decline in profit to the CS domain for voice services, if necessary.