UMTS

1
UMTS

• EPL657
• parts from www.mobinet.gr

2
Intro to UMTS

• 3G systems aim at continuing the already
  successful course of 2G mobile telephony
• As 3G are characterized all standards that are
  under the IMT-2000 umbrella, with most well known
  the UMTS (W-CDMA) standard
• The Universal Mobile Telecommunication System
  (UMTS) is an effort to integrate most of the
  present telecommunication networks, including
  both terrestrial networks and satellite
  constellations

3
UMTS / 3G History and Future Milestones (1/2)

• The Digital Cellular Age
• February 1995 UMTS Task Force established "The
  Road to UMTS" report.
• December 1996 The UMTS Forum established.
  "European" WCDMA standard known as Universal
  Mobile Telecommunications System (UMTS).
• June 1997 UMTS Forum produces first report "A
  regulatory Framework for UMTS".
• October 1997 ERC decided on UMTS core band.
• January 1998 ETSI meeting W-CDMA and TD-CDMA
  proposals combined to UMTS air interface
  specification.
• June 1998 Terrestrial air interface proposals
  (UTRAN, WCDMA(s), CDMA2000(s), EDGE, EP-DECT,
  TD-SCDMA) were handed into ITU-R
• December 1999 in Nice ETSI Standardisation
  finished for UMTS Release 1999 specifications
  both for FDD and TDD (spec version 3.y.z).
• March 2001 in Palm Springs 3GPP approves UMTS
  Release 4 specification

4
UMTS / 3G History and Future Milestones (2/2)

• The High Speed Cellular Age
• October 1, 2001 NTT DoCoMo launched the first
  commercial WCDMA 3G mobile network.
• December 1, 2001 Telenor launched in Norway the
  first commercial UMTS network. UMTS terminals
  were expectedto be available 3Q 2002.
• February 18, 2002 Motorola unveils the companys
  first GSM/GPRS and 3G/UMTS product, the A820.
  Motorola is "introduce a dual-mode enabled UMTS
  mobile phone
• March 2002 (Freeze date) UMTS Release 5 (the
  initial target date was December 2001)
• September 25, 2002 Mobilkom Austria launches
  "Europe's First UMTS-Network
• September 26, 2002 Nokia introduces the "worlds
  first handset 6650 for WCDMA UMTS and GSM
  networks".
• October 3, 2002 Nokia and Vodafone "first VoIP
  call in 3GPP release 4 compliant network that
  transports circuit-switched voice and data calls
  through an IP backbone".
• end 2003/early in 2004 target date for UMTS
  Release 6

5
Why Choose UMTS?

• Main reasons contributing to the success of WCDMA
• Superior voice and data service offering
• Smooth evolution from GSM to WCDMA
• Open standardization process, global standard
• Global markets and economies of scale
• Largest developer base
• Service portability and roaming

6
UMTS Revenue Growth

• The UMTS Forum has predicted that mobile
  operators will earn a total of more than 1
  trillion in customer revenues during the decade
  after full commercial launch

• Building on the enormous success of SMS, MMS has
  so far attracted over 1 million subscribers in
  Europe alone

7
UMTS Characteristics (1/3)

• Universal Mobile Telecommunications System
• exhibits all of GSM Phase 2 systems advantages
• wide-area geographical coverage
• simplified access to packet data networks
• support of QoS mechanisms
• volume-based pricing scheme
• always on connectivity
• will deliver broadband data rates up to 2 Mbps
• will provide global mobile seamless personalized
  multimedia communications

8
UMTS Characteristics (2/3)

• UMTS FDD (Frequency Division Duplex)
• Uplink 1920 - 1975 MHz
• Downlink 2110 - 2165 MHz
• 190 MHz duplex distance
• ? 5MHz (variable) carrier spacing
• 12 bands in Uplink Downlink

9
UMTS Characteristics (3/3)

• UMTS TDD (Time Division Duplex)
• Uplink Downlink 1900 - 1920 MHz and 2020 -
  2025 MHz
• 5 carriers in total, 15 timeslots per frame
• a user may use
• one or several
• timeslots
• a timeslot can
• be assigned to
• either Uplink
• or Downlink

5 Bands used for both Uplink and Downlink
Frequency
5 MHz
10
Cell Breathing

• A MS on the cell edge is transmitting with max
  power
• Another MS becomes active
• Increased interference
• the received signal from the MS on the cell edge
  is too weak!
• Effective cell size decreases with increasing
  number of users
• There is a trade-off between capacity and
  coverage
• Cell size depends on both maximum Tx power and
  number of active users (in the same and other
  cells) which results in cell breathing

11
WCDMA (1/4)

• Key Features
• Soft Handoff-diversity gain
• Multipath reception - diversity gain by using
  RAKE receivers
• Power Control - solves the near-far problem
• Frequency reuse of 1
• Soft capacity

12
WCDMA (2/4)
13
WCDMA (3/4)
14
WCDMA (4/4)
15
QoS
16
UMTS Network Architecture (1/2)
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UMTS Network Architecture (3/3)
UTRAN is composed of several Radio Network
Subsystems
Every Radio Network Subsystem is composed of a
Radio Network Controller (RNC) and one or more
Node Bs.
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UMTS Network Architecture
19
UMTS Network Architecture (2/2)

• UTRAN is composed of several Radio Network
  Subsystems (RNSs) connected to the Core Network
  through the lu interface.
• Every Radio Network Subsystem is composed of a
• Radio Network Controller (RNC).
• RNSs can be directly interconnected through the
  lur interface (interconnection of the RNCs).
• RNC is responsible for the local handover process
  and the combining/multicasting functions related
  to macro-diversity between different Node-Bs.
• RNC also handles radio resource management (RRM)
  operations.
• one or more Node Bs.
• A Node-B may contain a single BTS or more than
  one (typically 3) controlled by a site
  controller.
• Above entities are responsible for the radio
  resource control of the assigned cells

20
UTRAN

• Base Station
• The main task of Base Station (BS) is to
  establish
• The physical implementation of the Uu interface
  (Communication with the UE) and
• The implementation of Iub interface
  (Communication with the RNC).
• Realization of the Uu interface means that the
  Base Station implements WCDMA radio access
  Physical Channels and transfer information from
  Transport Channels to the Physical Channels based
  on arrangements determined by the RNC
• The term Physical Channels means different kinds
  of bandwidth allocated for different purposes
  over Uu interface.

21
UTRAN

• RNC (Radio Network Controller)
• The Radio Network Controller (RNC) is responsible
  for controlling and managing the multiple base
  stations (Node Bs) including the utilization of
  radio network resources.

22
Core network

• SGSN (Serving GPRS Support Node)
• The SGSN is mainly responsible for Mobility
  Management related issues like Routing Area
  update, location registration, packet paging and
  controlling and security mechanisms related to
  the packet communication
• GGSN
• The GGSN node maintains the connections towards
  other packet switch networks such as the
  internet. The Session Management responsibility
  is also located on the GGSN.

23
Radio Resource Management (1/2)

• Handles QoS provisioning over the wireless
  interface
• Controls cell capacity and interference in order
  to provide an optimal utilization of the wireless
  interface resources.
• Includes Algorithms for Power Control, Handover,
  Packet Scheduling, Call Admission Control and
  Load Control.

24
Radio Resource Management (2/2)

• Power Control
• Ensures that transmission powers are kept at a
  minimum level and that there is adequate signal
  quality and level at the receiving end.
• Packet Scheduling
• Controls the UMTS packet access.
• Call Admission Control
• Decides whether or not a call is allowed to
  generate traffic in the network.
• Load Control
• Ensures system stability and that the network
  does not enter an overload state.
• Handover
• guarantees user mobility in a mobile
  communications network.

25
Services

• In shaping future mobile services, the following
  characteristics should be taken into
  consideration mobility, interactivity,
  convenience, ubiquity, easy access, immediacy,
  personalization, multimedia
• Services for 3G will evolve within 3 different
  areas
• Personal Communication
• Wireless Internet
• Mobile Media (e.g. music,sports, news services)
• Voice traffic will remain the primary business of
  3G mobile networks

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Services
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Global Circulation of Terminals

• The right to carry and use personal terminals,
  global circulation, is very important for many
  users.
• There are very few, if any, technical problems
  with the circulation of GSM terminals.
• The ITU has decided on a regulatory framework for
  global circulation. This should be the basis for
  national rules for 3G

28
Possible Timeline for Transmission Technology
Evolution
29
The Future, as seen in 1998

• The decision of the European Parliament and
  Council of Ministers dated 14 December 1998
  requires that
• Member States take all necessary measures to
  allow the coordinated and progressive
  introduction of UMTS services by 1st January 2002
  at the latest.
• The EU's suggestion is that operators must cover
  80 of the national population by the year 2005.
• 2005 (original target) UMTS service will be world
  wide (?!!!).

30
Current State

• Original launch timescales (2002) specified by
  European governments and EC now under review
• Global economic downturn placed constraints on
  operators financial plans and limited access to
  new capital
• Lack of commercially available WCDMA terminals in
  volume has affected some operators marketing
  plans
• Full interoperability between networks, terminals
  and services not yet guaranteed (compare with
  early days of SMS and MMS)