The UMTS Network and Radio Access Technology: Air Interface Techniques for Future Mobile Systems
Jonathan P. Castro
Copyright © 2001 John Wiley & Sons Ltd
Print ISBN 0-471-81375-3 Online ISBN 0-470-84172-9

E
VOLVING
M
OBILE
N
ETWORKS

While the history of mobile communications is long [1–3], and the background of mo
bile networks therebyx is also long, in this chapter we focus on the historic evolution in
terms of network architecture and services starting with 2nd generation (2G) mobile
systems. In particular we consider the development of the architecture of G
lobal Sys-
tems for M
obile Communications (GSM), since it is by far the most widespread mobile
system in the world today. This will provide the basis to cover the introduction of Uni-
versal Mobile Telecommunication Services (UMTS) in relation to its Core Network
(CN) and radio architectures. The latter will in turn serve as the platform to present
UMTS Radio Access Technology, which is one the aims of this book.
1.1 T
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ROWTH OF
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2 The UMTS Network and Radio Access Technology

only in the corporate environment but also in households. Large number of consumers
have embraced the Internet and use it today to access information online, for interactive
business transactions, and e-commerce as well as electronic mail. Figure 1.1 illustrates
the growth in mobile and Internet subscribers.
The success of mobile communications, i.e. the ubiquitous presence it has established
and the emergence of the Internet point towards a tremendous opportunity to offer inte-
grated services through a wireless network.
One of the main market segments for wireless services besides corporate intra-
net/internet access is the consumer sector. The availability of intelligent terminals
1

throughput using the same bandwidth. EDGE in combination with GPRS (E-
GPRS) will deliver single user data rates of over 300 kbits/s.

UMTS as 3rd generation wireless technology utilizes a Wideband CDMA or
TD/CDMA transceiver. Starting with channel bandwidths of 5 MHz it will offer
data rates up to 2 Mbits/s. UMTS will use new spectrum and new radio network
configurations while using the GSM core infrastructure.

_______
1
For example WAP terminals.
2
Including voice or IP as a new trend.
3
In the USA – T1P1, in Japan – ARIB, in Korea – TTA, and in China – CWTS.
Evolving Mobile Networks 3

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4
IS-136 has adopted EDGE as its air-interface expansion.
4 The UMTS Network and Radio Access Technology

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PSTN PTN ISDN 2G 2.5 G 3G
mobile
3G
Internet
New
Telecoms
Computer
Industry
Main
Frames
Desk top
Computing
PC-LAN PC-
Servers
PC-
WAN
Internet / Intranet WWW
Electronic Commerce
Converged
Industry
Media
Industry
Electronic Publication
Interactive Entertainment
New battle
ground
It boils downs to the transformation of the Telecom, Computer and Media Industry,
resulting into the Converged Industry as illustrated in Table 1.1.
Clearly then, UMTS will be part of the convergent Industry with a trend towards multi-
services within integrated infrastructures.

(b) to allow differentiation between service offerings of various serving networks and
home environments;
(c) to provide a wide range of telecommunications services including those provided by
fixed networks and requiring user bit rates of up to 2 Mbits/s as well as services spe-
cial to mobile communications. These services should be supported in residential,
public and office environments and in areas of diverse population densities. These
services are provided with a quality comparable with that provided by fixed net-
works such as ISDN;
(d) to provide services via hand held, portable, vehicular mounted, movable and fixed
terminals (including those which normally operate connected to fixed networks), in
all environments (in different service environments – residential, private domestic
and different radio environments) provided that the terminal has the necessary capa-
bilities;
(e) to provide support of roaming users by enabling users to access services provided by
their home environment in the same way even when roaming.
(f) to provide audio, data, video and particularly multimedia services;
(g) to provide for the flexible introduction of telecommunication services;
(h) to provide the capability to support Universal Personal Telecommunications (UPT);
(i) to provide within the residential environment the capability to enable a pedestrian
user to access all services normally provided by fixed networks;
(j) to provide within the office environment the capability to enable a pedestrian user to
access all services normally provided by PBXs and LANs;
(k) to provide a substitute for fixed networks in areas of diverse population densities, un-
der conditions approved by the appropriate national or regional regulatory authority.