mobile communications - aminer · pdf filethis course is based on the book "mobile...
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Mobile Communication WS 2005/06
Chair for Computer Networks & InternetWilhelm-Schickard-Institute for Computer ScienceUniversity of Tübingen
Mobile CommunicationsProf. Dr.-Ing. Georg CarleDipl.-Ing. Christian Hoene
Chair for Computer Networks & InternetWilhelm-Schickard-Institute for Computer Science
University of Tübingen
http://net.informatik.uni-tuebingen.de/carle|[email protected]
Winter Term 2005/2006
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Acknowledgements
This course, including the slides, is based on the course on mobile communications of my former colleague, Prof. Dr.-Ing. Jochen Schiller, Free University Berlin, author of the book "Mobile Communications", published by Addison-Wesley.
In case of questions, suggestions or comments to the course material please send e-mails to [email protected]
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Course organization
LectureThursday 15.00-17.00, Sand 1, A301Übung (14-tägig): Wednesday 15-17 Uhr (Auf der Morgenstelle - Gebäude C - 9. Stock - A03)
Questions and Answers / Office hoursProf. Dr. Georg Carle
• After the course• Office hours: Thursday, 11.00 to 12.00, Auf der Morgenstelle 10C9
Dipl.-Ing. Christian Hoene• [email protected]; Auf der Morgenstelle 10C9, Tel. 07071-29-70535
Dipl.-Inf. Andreas Klenk• [email protected]; Auf der Morgenstelle 10C9, Tel. 07071-29-70535
News and updateshttp://net.informatik.uni-tuebingen.de/
LiteratureAll slides are available online (and without the slides it is very difficult to follow the lectures...)! The slides may be updated during the course. This course is based on the book "Mobile Communications”, 2nd edition, by Jochen Schiller, available in English, German, Chinese, and Finnish.
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Georg Carle
1985-1992: Study of Electrical Engineering, University of StuttgartMaster of Science in Digital Systems, Brunel University, London, U.K. (Master Thesis at General Electric Corporation, Hirst Research Centre, London)Research project at Telecom Paris - Ecole Nationale Supérieure des Télécommunications (ENST), Paris
Sept. 1992 - Dec. 1996: Doctoral Degree in Computer Science at University of Karlsruhe in 1996, working as Scientist at Institute of Telematics and Member of Graduiertenkolleg 'Controllability of Complex Systems'
Jan.-Oct. 1997: Postdoctoral Researcher, Institut Eurecom, Sophia Antipolis, France
Oct. 1997-Dec. 2002: Fraunhofer Institut FOKUS (previously: GMD FOKUS): Head of Competence Center Global Networking
Since Dec. 2002: Chair for Computer Networks and Internet, University of Tübingen
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Overview of the lecture
Introduction• Use-cases, applications• Definition of terms• Challenges, history
Wireless Transmission• frequencies & regulations• signals, antennas, signal
propagation• multiplexing, modulation, spread
spectrum, cellular system Media Access
• motivation, SDMA, FDMA, TDMA (fixed, Aloha, CSMA, DAMA, PRMA, MACA, collision avoidance, polling), CDMA
Wireless TelecommunicationSystems
• GSM, HSCSD, GPRS, DECT, TETRA, UMTS, IMT-2000
Satellite Systems• GEO, LEO, MEO, routing, handover
Broadcast Systems• DAB, DVB
Wireless LANs• Basic Technology• IEEE 802.11a/b/g, .15, Bluetooth
Network Protocols• Mobile IP• Ad-hoc networking• Routing
Transport Protocols• Reliable transmission• Flow control• Quality of Service
Support for Mobility• File systems, WWW, WAP, i-mode,
J2ME, ...Outlook
Mobile Communication WS 2005/06
Chair for Computer Networks & InternetWilhelm-Schickard-Institute for Computer ScienceUniversity of Tübingen
Chapter 1:
Introduction
A case for mobility History of mobile communicationMarketAreas of research
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Computers for the next decades?
Computers are integratedsmall, cheap, portable, replaceable - no more separate devices
Technology is in the backgroundcomputer are aware of their environment and adapt (“location awareness”)computer recognize the location of the user and react appropriately (e.g., call forwarding, fax forwarding, “context awareness”))this and related functionality is summarized under “ambient intelligence”
Advances in technologymore computing power in smaller devicesflat, lightweight displays with low power consumptionnew user interfaces due to small dimensionsmore bandwidth per cubic metermultiple wireless interfaces: wireless LANs, wireless WANs, regional wireless telecommunication networks etc. („overlay networks“)
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Mobile communication
Two aspects of mobility:user mobility: users communicate (wireless) “anytime, anywhere, with anyone”device portability: devices can be connected anytime, anywhere to the network
Wireless vs. mobile Examplesstationary computernotebook in a hotelwireless LANs in historic buildingsPersonal 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)Internet: Mobile IP extension of the internet protocol IPwide area networks: e.g., internetworking of GSM and ISDN
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Applications I
Vehiclestransmission of news, road condition, weather, music via DABpersonal communication using GSMposition via GPSlocal 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
Emergenciesearly transmission of patient data tothe hospital, current status, first diagnosisreplacement of a fixed infrastructure in case of earthquakes, hurricanes, fire etc.crisis, war, ...
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Typical application: road traffic
ad ho
cUMTS, WLAN,DAB, GSM, cdma2000, TETRA, ...
Personal Travel Assistant,PDA, Laptop, GSM, UMTS, WLAN, Bluetooth, ...
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Mobile and wireless services –Always Best Connected
UMTS2 Mbit/s
UMTS, GSM384 kbit/s
LAN100 Mbit/s,WLAN54 Mbit/s
UMTS, GSM115 kbit/s
GSM 115 kbit/s,WLAN 108 Mbit/s
GSM/GPRS 53 kbit/sBluetooth 500 kbit/s
GSM/EDGE 384 kbit/s,DSL/WLAN 3 Mbit/s
DSL/ WLAN3 Mbit/s
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Applications II
Traveling salesmendirect access to customer files stored in a central locationconsistent databases for all agentsmobile office
Replacement of fixed networksremote sensors, e.g., weather, earth activitiesflexibility for trade showsLANs in historic buildings
Entertainment, education, ...outdoor Internet access intelligent travel guide with up-to-datelocation dependent informationad-hoc networks formulti user games
HistoryInfo
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Location dependent services
Location aware serviceswhat services, e.g., printer, fax, phone, server etc. exist in the local environment
Follow-on servicesautomatic call-forwarding, transmission of the actual workspace to the current location
Information services„push“: e.g., current special offers in the supermarket„pull“: e.g., where is the Black Forrest Cherry Cake?
Support servicescaches, intermediate results, state information etc. „follow“ the mobile device through the fixed network
Privacywho should gain knowledge about the location
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Mobile devices
performanceperformance
Pager• receive only• tiny displays• simple text
messages
Mobile phones• voice, data• simple graphical displays
PDA• simpler graphical displays• character recognition• simplified WWW
Palmtop• tiny keyboard• simple versions
of standard applications
Laptop/Notebook• fully functional• standard applications
Sensors,embeddedcontrollers
www.scatterweb.net
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Effects of device portability
Power consumptionlimited computing power, low quality displays, small disks due to limited battery capacityCPU: power consumption ~ CV2f
• C: internal capacity, reduced by integration• V: supply voltage, can be reduced to a certain limit• f: clock frequency, can be reduced temporally
Loss of datahigher probability, has to be included in advance into the design (e.g., defects, theft)
Limited user interfacescompromise between size of fingers and portabilityintegration of character/voice recognition, abstract symbols
Limited memorylimited value of mass memories with moving partsflash-memory or harddisc as alternative
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Wireless networks in comparison to fixed networks
Higher loss-rates due to interferenceemissions of, e.g., engines, lightning
Restrictive regulations of frequenciesfrequencies have to be coordinated, useful frequencies are almost all occupied
Low transmission rateslocal some Mbit/s, regional currently, e.g.,53kbit/s with GSM/GPRS
Higher delays, higher jitterconnection setup time with GSM in the second range, several hundred milliseconds for other wireless systems
Lower security, simpler active attackingradio interface accessible for everyone, base station can be simulated, thus attracting calls from mobile phones
Always shared mediumsecure access mechanisms important
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Early history of wireless communication
Many people in history used light for communicationheliographs, flags („semaphore“), ...150 BC smoke signals for communication;(Polybius, Greece)1794, optical telegraph, Claude Chappe
Here electromagnetic waves are of special importance:
1831 Faraday demonstrates electromagnetic inductionJ. Maxwell (1831-79): theory of electromagnetic Fields, wave equations (1864)H. Hertz (1857-94): demonstrateswith an experiment the wave character of electrical transmission through space(1888, in Karlsruhe, Germany, at the location of today’s University of Karlsruhe)
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History of wireless communication I
1896 Guglielmo Marconifirst demonstration of wireless telegraphy (digital!)long wave transmission, high transmission power necessary (> 200kw)
1907 Commercial transatlantic connectionshuge base stations (30x 100m high antennas)
1915 Wireless voice transmission New York - San Francisco1920 Discovery of short waves by Marconi
reflection at the ionospheresmaller sender and receiver, possible due to the invention of the vacuum tube (1906, Lee DeForest and Robert von Lieben)
1926 Train-phone on the line Hamburg - Berlinwires parallel to the railroad track
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History of wireless communication II
1928 many TV broadcast trials (across Atlantic, color TV, TV news)1933 Frequency modulation (E. H. Armstrong)1958 “A-Netz” in Germany
analog, 160MHz, connection setup only from the mobile station, no handover, 80% coverage, 1971 11000 customers
1972 “B-Netz” in Germanyanalog, 160MHz, connection setup from the fixed network too (butlocation of the mobile station has to be known)available also in A, NL and LUX, 1979 13000 customer in D
1979 NMT at 450MHz (Scandinavian countries)1982 Start of GSM-specification
goal: pan-European digital mobile phone system with roaming1983 Start of the American AMPS (Advanced Mobile Phone
System, analog) 1984 CT-1 standard (Europe) for cordless telephones
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History of wireless communication III
1986 “C-Netz” in Germanyanalog voice transmission, 450MHz, hand-over possible, digital signaling, automatic location of mobile deviceWas in use until 2000, services: FAX, modem, X.25, e-mail, 98% coverage
1991 Specification of DECTDigital European Cordless Telephone (today: Digital Enhanced Cordless Telecommunications)1880-1900MHz, ~100-500m range, 120 duplex channels, 1.2Mbit/s data transmission, voice encryption, authentication, up to several 10000 user/km2, used in more than 50 countries
1992 Start of GSMin D as D1 and D2, fully digital, 900MHz, 124 channelsautomatic location, hand-over, cellularroaming in Europe - now worldwide in more than 200 countriesservices: data with 9.6kbit/s, FAX, voice, ...
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History of wireless communication IV
1994 E-Netz in GermanyGSM with 1800MHz, smaller cellsAs Eplus in D (1997 98% coverage of the population)
1996 HiperLAN (High Performance Radio Local Area Network)ETSI, standardization of type 1: 5.15 - 5.30GHz, 23.5Mbit/srecommendations for type 2 and 3 (both 5GHz) and 4 (17GHz) as wireless ATM-networks (up to 155Mbit/s)
1997 Wireless LAN - IEEE802.11IEEE standard, 2.4 - 2.5GHz and infrared, 2Mbit/salready many (proprietary) products available in the beginning
1998 Specification of GSM successorsfor UMTS (Universal Mobile Telecommunication System) as Europeanproposals for IMT-2000
Iridium66 satellites (+6 spare), 1.6GHz to the mobile phone
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History of wireless communication V
1999 Standardization of additional wireless LANsIEEE standard 802.11b, 2.4-2.5GHz, 11Mbit/sBluetooth for piconets, 2.4Ghz, <1Mbit/s
Decision about IMT-2000Several “members” of a “family”: UMTS, cdma2000, DECT, …
Start of WAP (Wireless Application Protocol) and i-modeFirst step towards a unified Internet/mobile communicaiton systemAccess to many services via the mobile phone
2000 GSM with higher data ratesHSCSD offers up to 57,6kbit/sFirst GPRS trials with up to 50 kbit/s (packet oriented!)
UMTS auctions/beauty contestsHype followed by disillusionment (approx. 50 B$ payed in Germany for 6 UMTS licenses !)
2001 Start of 3G systemsCdma2000 in Korea, UMTS in Europe, Foma (almost UMTS) in Japan
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Wireless systems: overview of the development
cellular phones satellites wireless LANcordlessphones
1992:GSM
1994:DCS 1800
2001:IMT-2000
1987:CT1+
1982:Inmarsat-A
1992:Inmarsat-BInmarsat-M
1998:Iridium
1989:CT 2
1991:DECT 199x:
proprietary
1997:IEEE 802.11
1999:802.11b, Bluetooth
1988:Inmarsat-C
analogue
digital
1991:D-AMPS
1991:CDMA
1981:NMT 450
1986:NMT 900
1980:CT0
1984:CT1
1983:AMPS
1993:PDC
4G – fourth generation: when and how?
2000:GPRS
2000:IEEE 802.11a
200?:Fourth Generation(Internet based)
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Foundation: ITU-R - Recommendations for IMT-2000
M.687-2IMT-2000 concepts and goals
M.816-1framework for services
M.817IMT-2000 network architectures
M.818-1satellites in IMT-2000
M.819-2IMT-2000 for developing countries
M.1034-1 requirements for the radio interface(s)
M.1035framework for radio interface(s) and radio sub-system functions
M.1036spectrum considerations
M.1078security in IMT-2000
M.1079speech/voiceband data performance
M.1167framework for satellites
M.1168framework for management
M.1223evaluation of security mechanisms
M.1224vocabulary for IMT-2000
M.1225evaluation of transmission technologies
. . .
http://www.itu.int/imt
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Worldwide wireless subscribers (old prediction 1998)
0
100
200
300
400
500
600
700
1996 1997 1998 1999 2000 2001
AmericasEuropeJapanotherstotal
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Mobile phones per 100 people 1999
0 10 20 30 40 50 60
FinlandSwedenNorway
DenmarkItaly
LuxemburgPortugal
AustriaIreland
SwitzerlandGreat BritainNetherlands
FranceBelgium
SpainGreece
Germany
2002: 50-70% penetration in Western Europe
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Worldwide cellular subscriber growth
0
200
400
600
800
1000
1200
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
Sub
scri
bers
[mill
ion]
Note that the curve starts to flatten in 2000
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Cellular subscribers per region (June 2002)
Asia Pacific; 36,9
Europe; 36,4
Americas (incl. USA/Canada);
22
Africa; 3,1
Middle East; 1,6
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Mobile statistics snapshot (09/2002 / 12/2004)
Total Global Mobile Users 869m Total Analogue Users 71m Total US Mobile users 145m Total Global GSM users 680m Total Global CDMA Users 127m Total TDMA users 84m Total European users 283m Total African users 18.5m Total 3G users 130m Total South African users 13.2m European Prepaid Penetration 63% European Mobile Penetration 70.2% Global Phone Shipments 2001 393m Global Phone Sales 2Q02 96.7m
http://www.cellular.co.za/stats/stats-main.htm
#1 Mobile Country China (139M / 300m) #1 GSM Country China (99m) #1 SMS Country Philipines#1 Handset Vendor 2Q02 Nokia (37.2%) #1 Network In Africa Vodacom (6.6m) #1 Network In Asia Unicom (153m)#1 Network In Japan DoCoMo#1 Network In Europe T-Mobile (22m / 28m) #1 In Infrastructure Ericsson
SMS Sent Globally 1Q02 60T / 135bnSMS sent in UK 6/02 1.3T / 2.1bnSMS sent Germany 1Q02 5.7TGSM Countries on Air 171 / 210GSM Association members 574 / 839Total Cost of 3G Licenses in Europe 110T €SMS/month/user 36
The figures vary a lot depending on the statistic, creator of the statistic etc.!
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Areas of research in mobile communication
Wireless Communicationtransmission quality (bandwidth, error rate, delay)modulation, coding, interferencemedia access, regulations...
Mobilitylocation dependent serviceslocation transparencyquality of service support (delay, jitter, security)...
Portabilitypower consumptionlimited computing power, sizes of display, ...usability...
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Simple reference model used here
Application
Transport
Network
Data Link
Physical
Medium
Data Link
Physical
Application
Transport
Network
Data Link
Physical
Data Link
Physical
Network Network
Radio
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Influence of mobile communication to the layer model
service locationnew applications, multimediaadaptive applicationscongestion and flow controlquality of serviceaddressing, routing, device locationhand-overauthenticationmedia accessmultiplexingmedia access controlencryptionmodulationinterferenceattenuationfrequency
Application layer
Transport layer
Network layer
Data link layer
Physical layer
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Overview of the main chapters
Chapter 2: Wireless Transmission
Chapter 3: Medium Access Control
Chapter 4: Telecommunication
Systems
Chapter 5: Satellite Systems
Chapter 6: Broadcast Systems
Chapter 7: Wireless
LAN
Chapter 8: Mobile Network Layer
Chapter 9: Mobile Transport Layer
Chapter 10: Support for Mobility
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Overlay Networks - the global goal
regional
metropolitan area
campus-based
in-house
verticalhandover
horizontalhandover
integration of heterogeneous fixed andmobile networks with varyingtransmission characteristics