Get started !
online LTE test
online C test

Updated or New
5G NR Data Rate calculator New
5G NR TBS calculator New
5G NR UE Registration New
Python programming
C++ programming
MIMO for 3GPP Developer - 2
Uplink power control
MIMO for 3GPP Developer
NR ARFCN and GSCN
5GS Interfaces



About
Feedback
Information Theory
Modulation
Multiple Access
OSI Model
Data Link layer
SS7
Word about ATM
GSM
GPRS
UMTS
WiMAX
LTE
CV2X
5G
Standard Reference
Reference books
Resources on Web
Miscellaneous
Mind Map
Magic MSC tool
Bar graph tool
C programming
C++ programming
Perl resources
Python programming
Javascript/HTML
MATLAB
ASCII table
Project Management

another knowledge site

3GPP Modem
Simulator


Sparkle At Office comic strip

UMTS (Network architecture) - 3

Network architecture [Under UMTS]
» Network architecture - 23.002 «
» QoS architecture - 23.107 «

GSM stream of wireless standards started by ETSI always tried to maintain as much backward compatibility as would be possible. This has helped both new and existing network operators. In addition to international nature of standardisation, backward compatibility is another possible reason for popularity that 3GPP standards have received and continues to receive.

Below diagram show logical domains of UMTS network.

UTRAN (UMTS Terrestrial Access Network) consists of Node Bs connected RNCs (Radio Network Controller). Node B can be considered as UMTS counterpart of GSM BTS and RNC as similar to BSC.

Core network consists of MSC/VLR/GMSC for CS operations, SGSN/GGSN for PS operations, and other GSM elements like HLR, AuC, EIR etc. Yes, UMTS distinguish between CS and PS operations. Services which require CS operations like voice call, video telephony will be sent over CS network elements and PS based services like internet access will be over PS network elements. This mean RNC will be connected to both MSC/VLR and SGSN as shown in R99 based UMTS architecture below:

As can be seen GSM/GPRS interfaces are reused in core network. TRAU (not shown) will be located at MSC location. Note that MSC and SGSN need to support new Iu interfaces with RNC. Also, there is (open) interface between RNCs to handle handover without much of involvement from core network elements. This is an important step as core network become more independent of actual radio technology being used.

A RNC and its connected Node Bs collectively known as RNS (Radio Network Subsystem). In GSM A-bis interface (between BTS and BSC) was not defined thoroughly (or openly), eventually there being proprietary solutions. This is not the case with Iub interface between Node B and RNC.

Below is UMTS QoS architecture diagram showing how UMTS tries to achieve end-to-end service.

In next article, we will have a look at Rel 5 architecture.

References: UMTS by Sanchez and Thioune, and WCDMA for UMTS by Holma and Toskala.

Copyright © Samir Amberkar 2010§ §

Introduction « UMTS Index » R5 core network