Base Station Subsystem (BSS)

Structure of a GSM network (key elements)

Network SubSystem (NSS)

GPRS Core NetworkMobile Station (MS)

R

Air

(Um)

A-bis

A

Gb

H/E etc

Gr/Gs

Gn

Gi

PSTN

SS7 network

GPRS backbone

IP netwok

Internet

1 2 3

4 5 6

7 8 9

# 0 *

BTS

BTS

BSC

PCU

MSC/VLR

SGSN

GGSN

HLR/AUC

(EIR)

MT/TE

TE

SIM

(UICC)

08-04-2010 GSM structure

upload.wikimedia.org/wikipedia//Gsm_structures.svg 1/1