Mobile Communications Summer Term 2002 FU Berlin Computer Science Computer Systems & Telematics Prof. Dr. -Ing. Jochen Schiller http: //www. jochenschiller. de/ schiller@computer. org Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 1
Mobile Communications SS 2002 Chapter 1: Introduction A case for mobility q History of mobile communication q Market q Areas of research q Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 2
Structure and content of the CST lectures Mobile Communications Lab (MCL) Practical assignments for MC, NGI and TM Next Generation Internet (NGI) MPLS, Qo. S, multimedia support, group communication, accounting Wireless transmission, medium access, GSM, 3 G, WLAN, Mobile IP, Ad-hoc-networks, WAP Telematics (TM) Multi processor systems, pipelining, vector processing, interconnections, multithreading Bachelor Master Practical assignments for RS and PEG Microprocessor Lab (MPP) Practical assignments for RO (also RA and TM) Computer Organization (RO) Hardware-Lab (HWP) Networked System Protocols, services, standards, LAN, Internet, TCP/IP, WWW, security, ISDN, management, interworking units Computer Architecture (RA) Semester Mobile Communications (MC) Wireless/ mobile System CPU, RISC/CISC, assembler, I/O, bus, controller, PIO, DMA, interrupt, memory, peripherals Computer Structures (RS) Boolean algebra, combinational and sequential circuits, computer arithmetic, von Neumann machine Physical-Electrical Basics (PEG) Discrete elements, semiconductors, DTL, TTL, CMOS, gates, memory, programmable logic Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 3 Computer Processor Logic Physics
Overview of the lecture q Introduction q l Use-cases, applications l Definition of terms l Challenges, history q l DAB, DVB q l signals, antennas, signal l IEEE 802. 11 a/b/g, . 15, Bluetooth q Media Access l motivation, SDMA, FDMA, TDMA l Ad-hoc networking l Routing q Wireless Telecommunication Systems l GSM, HSCSD, GPRS, DECT, TETRA, UMTS, IMT-2000 q Transport Protocols l Reliable transmission (fixed, Aloha, CSMA, DAMA, PRMA, MACA, collision avoidance, polling), CDMA q Network Protocols l Mobile IP propagation l multiplexing, modulation, spread spectrum, cellular system q Wireless LANs l Basic Technology Wireless Transmission l frequencies & regulations Broadcast Systems l Flow control l Quality of Service q Support for Mobility l File systems, WWW, WAP, i-mode, J 2 ME, . . . Satellite Systems l GEO, LEO, MEO, routing, handover Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 4
Course organization Lecture q Wednesday, 10: 00 -12: 00 h, SR 049, Takustr. 9 Office hours q Prof. J. Schiller: Tuesday, 14: 00 -15: 00 h, room 156, Takustr. 9 News and updates q http: //www. jochenschiller. de/ Literature All slides are available online (and without the slides it is very difficult to follow the lectures. . . )! q The slides will be updated during the course. q This course is based on the book "Mobile Communications", available in English, German, and Finnish from Addison-Wesley. A special price for the German version is offered for participants of the course (20% off). q Exam q At the end of the course, 60 min, only paper&pencil, 40%/points required Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 5
Computers for the next decades? Computers are integrated q small, cheap, portable, replaceable - no more separate devices Technology is in the background computer are aware of their environment and adapt (“location awareness”) q computer recognize the location of the user and react appropriately (e. g. , call forwarding, fax forwarding, “context awareness”)) q Advances in technology q q q more computing power in smaller devices flat, lightweight displays with low power consumption new user interfaces due to small dimensions more bandwidth per cubic meter multiple wireless interfaces: wireless LANs, wireless WANs, regional wireless telecommunication networks etc. („overlay networks“) Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 6
Mobile communication Two aspects of mobility: users communicate (wireless) “anytime, anywhere, with anyone” q device portability: devices can be connected anytime, anywhere to the network q Wireless vs. mobile Examples stationary computer notebook in a hotel wireless LANs in historic buildings Personal Digital Assistant (PDA) The demand for mobile communication creates the need for integration of wireless networks into existing fixed networks: local area networks: standardization of IEEE 802. 11, ETSI (HIPERLAN) q Internet: Mobile IP extension of the internet protocol IP q wide area networks: e. g. , internetworking of GSM and ISDN q
Applications I Vehicles q q q transmission of news, road condition, weather, music via DAB personal communication using GSM position via GPS local ad-hoc network with vehicles close-by to prevent accidents, guidance system, redundancy vehicle data (e. g. , from busses, high-speed trains) can be transmitted in advance for maintenance Emergencies early transmission of patient data to the hospital, current status, first diagnosis q replacement of a fixed infrastructure in case of earthquakes, hurricanes, fire etc. q crisis, war, . . . q Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 8
Typical application: road traffic UMTS, WLAN, DAB, GSM, cdma 2000, TETRA, . . . c ad ho Personal Travel Assistant, DAB, PDA, laptop, GSM, UMTS, WLAN, Bluetooth, . . . Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 9
Mobile and wireless services – Always Best Connected LAN, WLAN 780 kbit/s GSM 53 kbit/s Bluetooth 500 kbit/s UMTS, GSM 115 kbit/s LAN 100 Mbit/s, WLAN 54 Mbit/s UMTS, DECT 2 Mbit/s GSM/EDGE 384 kbit/s, WLAN 780 kbit/s UMTS, GSM 384 kbit/s GSM 115 kbit/s, WLAN 11 Mbit/s Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 10
Applications II Travelling salesmen direct access to customer files stored in a central location q consistent databases for all agents q mobile office q Replacement of fixed networks remote sensors, e. g. , weather, earth activities q flexibility for trade shows q LANs in historic buildings q Entertainment, education, . . . outdoor Internet access q intelligent travel guide with up-to-date location dependent information q ad-hoc networks for multi user games q Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ History Info MC SS 02 1. 11
Location dependent services Location aware services q what services, e. g. , printer, fax, phone, server etc. exist in the local environment Follow-on services q automatic call-forwarding, transmission of the actual workspace to the current location Information services „push“: e. g. , current special offers in the supermarket q „pull“: e. g. , where is the Black Forrest Cherry Cake? q Support services q caches, intermediate results, state information etc. „follow“ the mobile device through the fixed network Privacy q who should gain knowledge about the location Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 12
Mobile devices Pager • receive only • tiny displays • simple text messages PDA • simpler graphical displays • character recognition • simplified WWW Laptop • fully functional • standard applications Sensors, embedded controllers Mobile phones • voice, data • simple graphical displays Palmtop • tiny keyboard • simple versions of standard applications performance Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 13
Effects of device portability Power consumption limited computing power, low quality displays, small disks due to limited battery capacity q CPU: power consumption ~ CV 2 f q C: internal capacity, reduced by integration l V: supply voltage, can be reduced to a certain limit l f: clock frequency, can be reduced temporally l Loss of data q higher probability, has to be included in advance into the design (e. g. , defects, theft) Limited user interfaces compromise between size of fingers and portability q integration of character/voice recognition, abstract symbols q Limited memory limited value of mass memories with moving parts q flash-memory or ? as alternative q Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 14
Wireless networks in comparison to fixed networks Higher loss-rates due to interference q emissions of, e. g. , engines, lightning Restrictive regulations of frequencies q frequencies have to be coordinated, useful frequencies are almost all occupied Low transmission rates q local some Mbit/s, regional currently, e. g. , 9. 6 kbit/s with GSM Higher delays, higher jitter q connection setup time with GSM in the second range, several hundred milliseconds for other wireless systems Lower security, simpler active attacking q radio interface accessible for everyone, base station can be simulated, thus attracting calls from mobile phones Always shared medium q secure access mechanisms important Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 15
Early history of wireless communication Many people in history used light for communication heliographs, flags („semaphore“), . . . q 150 BC smoke signals for communication; (Polybius, Greece) q 1794, optical telegraph, Claude Chappe q Here electromagnetic waves are of special importance: q 1831 Faraday demonstrates electromagnetic induction q J. Maxwell (1831 -79): theory of electromagnetic Fields, wave equations (1864) q H. Hertz (1857 -94): demonstrates with an experiment the wave character of electrical transmission through space (1888, in Karlsruhe, Germany, at the location of today’s University of Karlsruhe) Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 16
History of wireless communication I 1895 Guglielmo Marconi first demonstration of wireless telegraphy (digital!) q long wave transmission, high transmission power necessary (> 200 kw) q 1907 q 1915 1920 Commercial transatlantic connections huge base stations (30 100 m high antennas) Wireless voice transmission New York - San Francisco Discovery of short waves by Marconi reflection at the ionosphere q smaller sender and receiver, possible due to the invention of the vacuum tube (1906, Lee De. Forest and Robert von Lieben) q 1926 q Train-phone on the line Hamburg - Berlin wires parallel to the railroad track Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 17
History of wireless communication II 1928 1933 1958 q 1972 many TV broadcast trials (across Atlantic, color TV, TV news) Frequency modulation (E. H. Armstrong) A-Netz in Germany analog, 160 MHz, connection setup only from the mobile station, no handover, 80% coverage, 1971 11000 customers B-Netz in Germany analog, 160 MHz, connection setup from the fixed network too (but location of the mobile station has to be known) q available also in A, NL and LUX, 1979 13000 customer in D q 1979 1982 q 1983 1984 NMT at 450 MHz (Scandinavian countries) Start of GSM-specification goal: pan-European digital mobile phone system with roaming Start of the American AMPS (Advanced Mobile Phone System, analog) CT-1 standard (Europe) for cordless telephones Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 18
History of wireless communication III 1986 C-Netz in Germany analog voice transmission, 450 MHz, hand-over possible, digital signaling, automatic location of mobile device q Was in use until 2000, services: FAX, modem, X. 25, e-mail, 98% coverage q 1991 Specification of DECT Digital European Cordless Telephone (today: Digital Enhanced Cordless Telecommunications) q 1880 -1900 MHz, ~100 -500 m range, 120 duplex channels, 1. 2 Mbit/s data transmission, voice encryption, authentication, up to several 10000 user/km 2, used in more than 50 countries q 1992 Start of GSM in D as D 1 and D 2, fully digital, 900 MHz, 124 channels q automatic location, hand-over, cellular q roaming in Europe - now worldwide in more than 170 countries q services: data with 9. 6 kbit/s, FAX, voice, . . . q Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 19
History of wireless communication IV 1994 E-Netz in Germany GSM with 1800 MHz, smaller cells q As Eplus in D (1997 98% coverage of the population) q 1996 Hiper. LAN (High Performance Radio Local Area Network) ETSI, standardization of type 1: 5. 15 - 5. 30 GHz, 23. 5 Mbit/s q recommendations for type 2 and 3 (both 5 GHz) and 4 (17 GHz) as wireless ATM-networks (up to 155 Mbit/s) q 1997 Wireless LAN - IEEE 802. 11 IEEE standard, 2. 4 - 2. 5 GHz and infrared, 2 Mbit/s q already many (proprietary) products available in the beginning q 1998 q Specification of GSM successors for UMTS (Universal Mobile Telecommunication System) as European proposals for IMT-2000 Iridium q 66 satellites (+6 spare), 1. 6 GHz to the mobile phone Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 20
History of wireless communication V 1999 Standardization of additional wireless LANs IEEE standard 802. 11 b, 2. 4 -2. 5 GHz, 11 Mbit/s q Bluetooth for piconets, 2. 4 Ghz, <1 Mbit/s q Decision about IMT-2000 q Several “members” of a “family”: UMTS, cdma 2000, DECT, … Start of WAP (Wireless Application Protocol) and i-mode First step towards a unified Internet/mobile communicaiton system q Access to many services via the mobile phone q 2000 GSM with higher data rates HSCSD offers up to 57, 6 kbit/s q First GPRS trials with up to 50 kbit/s (packet oriented!) q UMTS auctions/beauty contests q Hype followed by disillusionment (approx. 50 B$ payed in Germany for 6 UMTS licences!) 2001 Start of 3 G systems q Cdma 2000 in Korea, UMTS in Europe, Foma (almost UMTS) in Japan Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 21
Wireless systems: overview of the development cellular phones 1981: NMT 450 satellites 1983: AMPS 1986: NMT 900 1992: GSM 1994: DCS 1800 analogue 1982: Inmarsat-A 1991: D-AMPS 1984: CT 1 1987: CT 1+ 1989: CT 2 1992: Inmarsat-B Inmarsat-M 1993: PDC 1991: DECT 1998: Iridium 2000: GPRS 199 x: proprietary 1997: IEEE 802. 11 1999: 802. 11 b, Bluetooth 2000: IEEE 802. 11 a 2001: IMT-2000 digital 4 G – fourth generation: when and how? wireless LAN 1980: CT 0 1988: Inmarsat-C 1991: CDMA cordless phones 200? : Fourth Generation (Internet based)
Foundation: ITU-R - Recommendations for IMT-2000 M. 687 -2 q IMT-2000 concepts and goals M. 816 -1 q framework for services M. 817 q IMT-2000 network architectures M. 818 -1 q satellites in IMT-2000 M. 819 -2 q IMT-2000 for developing countries M. 1034 -1 q requirements for the radio interface(s) M. 1035 q framework for radio interface(s) and radio sub-system functions M. 1036 q spectrum considerations M. 1078 q security in IMT-2000 M. 1079 q speech/voiceband data performance M. 1167 q framework for satellites M. 1168 q framework for management M. 1223 q evaluation of security mechanisms M. 1224 q vocabulary for IMT-2000 M. 1225 q evaluation of transmission technologies . . . http: //www. itu. int/imt Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 23
Worldwide wireless subscribers (old prediction 1998) 700 600 500 Americas Europe Japan others total 400 300 200 100 0 1996 1997 1998 1999 Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ 2000 MC SS 02 2001 1. 24
Mobile phones per 100 people 1999 Germany Greece Spain Belgium France Netherlands Great Britain Switzerland Ireland Austria Portugal Luxemburg Italy Denmark Norway Sweden Finland 0 10 20 2002: 50 -70% penetration in Western Europe 30 Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ 40 MC SS 02 50 60 1. 25
Worldwide cellular subscriber growth Note that the curve starts to flatten in 2000 Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 26
Cellular subscribers per region (June 2002) Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 27
Mobile statistics snapshot (Sept 2002) Total Global Mobile Users 869 m Total Analogue Users 71 m Total US Mobile users 145 m Total Global GSM users 680 m Total Global CDMA Users 127 m Total TDMA users 84 m Total European users 283 m Total African users 18. 5 m Total 3 G users 130 m Total South African users 13. 2 m European Prepaid Penetration 63% European Mobile Penetration 70. 2% Global Phone Shipments 2001 393 m Global Phone Sales 2 Q 02 96. 7 m http: //www. cellular. co. za/statsmain. htm #1 Mobile Country China (139 m) #1 GSM Country China (99 m) #1 SMS Country Philipines #1 Handset Vendor 2 Q 02 Nokia (37. 2%) #1 Network In Africa Vodacom (6. 6 m) #1 Network In Asia Unicom #1 Network In Japan Do. Co. Mo #1 Network In Europe T-Mobil (22. 3 m) #1 In Infrastructure Ericsson Global monthly SMSs/user 36 SMS Sent Globally 1 Q 02 60 billion SMS sent in UK 6/02 1. 3 billion SMS sent Germany 1 Q 02 5. 7 billion SMS Sent 2001 102. 9 billion GSM Countries on Air 171 GSM Association members 574 Total Cost of 3 G Licenses in Europe 110 bn Euros The figures vary a lot depending on the statistic, creator of the statistic etc. ! Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 28
Areas of research in mobile communication Wireless Communication transmission quality (bandwidth, error rate, delay) q modulation, coding, interference q media access, regulations q. . . q Mobility location dependent services q location transparency q quality of service support (delay, jitter, security) q. . . q Portability power consumption q limited computing power, sizes of display, . . . q usability q. . . q Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 29
Simple reference model used here Application Transport Network Data Link Physical Radio Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ Medium MC SS 02 1. 30
Influence of mobile communication to the layer model Application layer q q q Transport layer q q Network layer q q Data link layer q q Physical layer q q q service location new applications, multimedia adaptive applications congestion and flow control quality of service addressing, routing, device location hand-over authentication media access multiplexing media access control encryption modulation interference attenuation frequency Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 31
Overview of the main chapters Chapter 10: Support for Mobility Chapter 9: Mobile Transport Layer Chapter 8: Mobile Network Layer Chapter 4: Telecommunication Systems Chapter 5: Satellite Systems Chapter 6: Broadcast Systems Chapter 7: Wireless LAN Chapter 3: Medium Access Control Chapter 2: Wireless Transmission Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 32
Overlay Networks - the global goal integration of heterogeneous fixed and mobile networks with varying transmission characteristics regional vertical handover metropolitan area campus-based horizontal handover in-house Prof. Dr. -Ing. Jochen Schiller, http: //www. jochenschiller. de/ MC SS 02 1. 33
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