GERAN stands for GSM EDGE Radio Access Network. It is the term given to the second-generation digital cellular GSM radio access technology, including its evolutions in the form of EDGE (Enhanced Data rates for Global Evolution) and, for most purposes, the General Packet Radio Service (GPRS). GERAN enabled 3G service continuity over the GSM infrastructure by improving speed, latency and mobility experience for data applications. It also introduced a lot more new applications and improved the network efficiency. GERAN includes BTSs and BSCs.
UTRAN, short for UMTS Terrestrial Radio Access Network, is the new generation radio access network within the UMTS architecture. Samilar to GERAN, UTRAN contains the base stations, which are called Node Bs, and Radio Network Controllers (RNC). The RNC provides control functionalities for one or more Node Bs.
UMTS CN (core network) includes network elements within
- legacy GSM: MSC, VLR, HLR, EIR etc.
- GPRS/EDGE: SGSN, GGSN etc.
- IMS core: CBC, CSCF, MRCF, MGCF, SLF, HSS, AS etc.
The following figure shows a brief of the UMTS domains.
