Aspects of UMTS Author: Tassilo Bassermann

6. April 2004UMTS Tassilo Bassermann Outline of report Cellular standards  Evolution of wireless communication systems UMTS Characteristics  Features and services of UMTS UMTS Architecture  Cell Hierarchy  Network Architecture UMTS Technology  Multiplexing

6. April 2004UMTS Tassilo Bassermann Wireless Communication Systems First Generation (1G): Analog Cellular  Transmission of analog voice information  Most prominent technology: AMPS (Advanced Mobile Phone System)  In Germany: A- B- and C-Net (1958, 1972, 1985)  Immense annual growth rates, rising to nearly 20 million subscribers worldwide by 1990

6. April 2004UMTS Tassilo Bassermann Wireless Communication Systems Second Generation (2G):  Development driven by need to improve transmission quality, system capacity and coverage  Introduction of digital technologies (early 90´s)  Services: Domination of speech transmission Demands for fax, SMS, data transmission  Circuit switched networks

6. April 2004UMTS Tassilo Bassermann Wireless Communication Systems Second Generation (2G):  2G Technologies

6. April 2004UMTS Tassilo Bassermann Wireless Communication Systems Transition from 2G to 3G (2.5G):  Intermediate standards to 3G  Motivation: Avoiding costs for new transmission technologies and infrastructure  HSCSD (High Speed Circuit Switched Data)  GPRS (General Packet Radio Service) New Core Network (routing) Importance of IP and internet access

6. April 2004UMTS Tassilo Bassermann Wireless Communication Systems Transition from 2G to 3G (2.5G):  EDGE (Enhanced Data for Global Evolution) GSM/GPRS upgrade (TDMA/FDMA) Modulation Enhancement (8-PSK, Phase Shift Keying) Attractive for operators which cannot afford a licence for the radio spectrum Possible data rate of 384 kbit/s

6. April 2004UMTS Tassilo Bassermann Wireless Communication Systems Third Generation (3G):  Requirements: High data rates Flexible operating environments Spectral efficiency/capacity Multimedia services Packet data network and IP mobility Global roaming Quality of service Interoperability with 2G networks

6. April 2004UMTS Tassilo Bassermann Wireless Communication Systems Third Generation – IMT-2000:  IMT-2000 (International Mobile Telecommunications at 2000 MHz)  A standard created by the ITU (International Telecommunications Union)  Different standards grouped together, to support existing infrastructure

6. April 2004UMTS Tassilo Bassermann Wireless Communication Systems IMT – 2000:

6. April 2004UMTS Tassilo Bassermann UMTS Characteristics UMTS (Universal Mobile Telecommunication Standard):  Defined by Third Generation Partnership Project (3GPP) in 1999  European Version of 3G mobile communication system  Spectrum allocation (Europe):

6. April 2004UMTS Tassilo Bassermann UMTS Characteristics UMTS – Licenses (Germany): OperatorPaired PacketsBil. DMUnpaired PacketsBil. DM E-Plus / Hutchinson 216,4210,0736 Group 3G216,4510,1227 Mannesmann Mobilfunk 216,4710,121 Mobilcom216,3710,121 T-Mobil216,5810,1227 Viag Interkom216,52 SUM1298,8150,561

6. April 2004UMTS Tassilo Bassermann UMTS Characteristics UMTS – Services:  Information (online information)  Education (virtual school)  Entertainment (audio on demand)  Community Services (administration transactions)  Business Information (mobile office)  Communication (video-conference)  Business Services (virtual banking)  Special Services (online support)

6. April 2004UMTS Tassilo Bassermann UMTS Characteristics UMTS – Service Classes:  Conversational (real-time, voice-video, low jitter, low delay)  Streaming (real-time, multimedia, low jitter)  Interactive (limited response time, browsing, database retrieval, low round trip delay time, low BER)  Background (stable transactions, , file transfer, low BER)

6. April 2004UMTS Tassilo Bassermann UMTS Characteristics UMTS Advantages:  Improved capacity (4 to 5 times higher compared with GSM)  Variable bit rate  Quick and secure connection establishment  Breathing cells  Improved signal to noise ratio  Broadband spectrum  Macro diversity

6. April 2004UMTS Tassilo Bassermann UMTS Architecture Cell Hierarchy CellRangeMax. data rateMax. Velocity Macro cell2km144kbit/s500km/h Micro cell1km384kbit/s120km/h Pico cell60m2Mbit/s10km/h

6. April 2004UMTS Tassilo Bassermann UMTS Architecture

6. April 2004UMTS Tassilo Bassermann UMTS Technology UTRAN (UMTS Terrestrial Radio Access Network):  Two essential radio interface models UTRA-FDD (Frequency Division Duplex) UTRA-TDD (Time Division Duplex)

6. April 2004UMTS Tassilo Bassermann UMTS Technology UTRA – FDD:  Paired frequency bands  Two 5 MHz bands, for uplink and downlink  Duplex distance of 190 MHz  Signal spreading (Channelization code)  W-CDMA  Transfer rate of 3.84 million symbols per second (Mcps)  Primary technology for UMTS in Europe

6. April 2004UMTS Tassilo Bassermann UMTS Technology UTRA – TDD:  Unpaired frequency bands  One single 5 MHz band  Usage of time slots Configuration of symmetric services Configuration of asymmetric services Advantage for data transmissions  One frame (10 ms) consists of 15 timeslots  Signal spreading (Channelization code)  W-CDMA combined with TDMA

6. April 2004UMTS Tassilo Bassermann UMTS Technology FDD – TDD:

6. April 2004UMTS Tassilo Bassermann UMTS Technology W-CDMA (Wideband Code Division Multiple Access):  Motivation: Use of Code-Multiplexing to transfer different signals over the same carrier Separation through different code patterns Receiver uses an orthogonal code, to demultiplex the specific signal

6. April 2004UMTS Tassilo Bassermann

6. April 2004UMTS Tassilo Bassermann UMTS Technology W-CDMA:  Method to compare two (orthogonal) codes:

6. April 2004UMTS Tassilo Bassermann UMTS Technology W-CDMA:  Signal coding: Non Return To Zero Transmission Signal bit combined with code pattern (chips) Every bit is substituted with the resulting pattern  Increased data rate  Increased need of bandwidth  Band spreading

6. April 2004UMTS Tassilo Bassermann UMTS Technology W-CDMA:  Usage of constant chip rate 7,68 Mcps = bit rate * spreading factor (downlink) 3,34 Mcps = bit rate * spreading factor (uplink)  FDD spreading factor (4, 8, 16, 32, 64, 128, 256, 512(DL))  TDD spreading factor (1,2,4,8,16)  Possibility to increase signal power of user equipment, through reduction of the bit rate

6. April 2004UMTS Tassilo Bassermann UMTS Technology Bit rate – spreading factor (FDD): Bit rateUplinkDownlink 15kbit/s kbit/s kbit/s kbit/s kbit/s kbit/s kbit/s kbit/sNot possible4

6. April 2004UMTS Tassilo Bassermann UMTS Technology Creation of orthogonal codes (channelization codes, spreading codes):

6. April 2004UMTS Tassilo Bassermann UMTS Technology Channelization code:  Possibility to change data rate every 10 ms  Requirement: Synchronous coded signals Downlink synchronous (station to user equipment) Uplink asynchronous (user equipment to station)  Additional code required  Scrambling code

6. April 2004UMTS Tassilo Bassermann UMTS Technology Scrambling Code:  Synchronous and asynchronous orthogonal codes  Terminal Separation (uplink)  Cell Separation (downlink)  Does not affect bandwidth  Multiplication with spreaded signal is transmitted

6. April 2004UMTS Tassilo Bassermann Conclusion UMTS offers several advantages for operators and users compared with GSM Necessary net coverage achieved (25% of population, Germany) No experience with new technologies / risks Expensive user equipment Attractive competitors (GPRS, EDGE) Cautious operators after immense licence costs UMTS (FOMA) success in Japan (NTT DoCoMo)

6. April 2004UMTS Tassilo Bassermann Sources Riemer, Rudolf. UMTS – A Technical Overview April UMTS. 4 Feb International Engineering Consortium. 6 April UMTS Resources. 8 Feb April G Wireless Standards. March Siemens mobile. 6 April Thomas, Andrew. 3G-Technology Specification April

6. April 2004UMTS Tassilo Bassermann End of Session Thank you for your attention!