Universal Mobile
Telecommunication System
Mobile and Satellite
Communications
Jozef Oboňa
UMTS - Introduction
European vision of a third generation
mobile communication system
extension of a second generation
communication system GSM
UMTS – Network Development
two aspects
radio access network
mobile stations, base stations, radio interface
between them
revolutionally new
core network
nodes (also gateways), connecting lines
evolution of the present GSM core network
UMTS – Network Development
core network will be common for GSM
and UMTS
radio access net – independent for GSM
and UMTS
radio access network for UMTS
multimedia applications (needed 2Mbps)
larger bandwidth channels (5MHz)
new access method - CDMA
UMTS – Hierarchical Cell
Structure
UMTS will offer global radio coverage (world-
wide roaming)
URAN
hierarchical way – layers of varying coverage
higher layer – satellites, lower layer – UTRAN
each layer divided into cells
macrocells – land-wide coverage
picocells - buildings
Hierarchical cell structure of UMTS to offer global radio coverage
UMTS – Data Rates
maximum data rate and maximum speed of
user – different for each hierarchical layer
macrolayer – 144 kbps, 500 km/h
microlayer – 384 kbps, 120 km/h
picolayer – 2 Mbps, 10 km/h
possible to trade off BER versus delay
real-time applications – 10-3÷10-7, 20÷300ms
Data rate versus mobility for UMTS in comparison with fixed
network and other mobile communications systems (WLAN
Wireless Local Area Network, MBS Mobile Broadband Systems)
UMTS – Spectrum
UMTS - 1900÷2025 MHz, 2110÷2200 MHz
for satellite service –reserved subband (uplink
1980÷2010 MHz, downlink 2170÷2200 MHz)
terrestrial use into two modes
frequency division duplex
uplink - 1920÷1980 MHz, downlink - 2110÷2170 MHz
time division duplex
uplink and downlink – same frequency, different
timeslots
Spectrum for UMTS:
•1920 MHz - 1980 MHz FDU plink
•2110 MHz - 2170 MHz FDD Downlink
•1900 MHz - 1920 MHz TDD
•2010 MHz - 2025 MHz TDD
•1980 MHz - 2010 MHz MSS (Mobile Satellite Service) Uplink
•2170 MHz - 2200 MHz MSS Downlink
UMTS – Operation Modes
FDD mode – macrocells, microcells
TDD mode – picocells
TDD mode – possible asymmetry of
data transfer between uplink and
downlink
FDD mode – different multiple access
method (Wideband CDMA)
TDD mode – time division CDMA
UMTS – Protocols
UMTS will support realtime services
(multimedia, packet data services)
transport mode in the core network – ATM
(only candidate)
IP – routing packets data in the core network
maybe IP and ATM will be also used in the
radio access network
ETSI defines only framework for the services
completely defined only – speech, fax, SMS
and emergency call
Comparison of transmission times in mobile communication systems
UMTS – Terminal and USIM
card
USIM card – an upgrade of the SIM
card
stores identity of the user, operator,
service provider and user service profile
service profile – subscribed services
(when and where)
USIM – integrated circuit card
UMTS – Terminal and USIM
card
different types of terminals
multi-mode or multi-band handies
notebook-like communicators
UMTS laptos with camera, speaker …
terminals with more than one USIM
one terminal used by several users
UMTS – Coverage
UMTS coverage mobile and fixed line
communication
when user close to the fixed line net –
automatically registered there (fixed line
tariff)
HIPERLAN standard (by ETSI) – offer up to 5
channels 25 Mbps
developed as “wireless LAN”
higher bandwidth, less installation cost ...
UMTS – Links
http://www.nt.tuwien.ac.at/mobile/proj
ects/UMTS/en/
http://www.umtsworld.com/technology/
overview.htm