mobile communications. introduction a case for mobility – many aspects a case for mobility –...
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Mobile Mobile CommunicationCommunication
ss
IntroductionIntroduction
A case for mobility – many aspectsA case for mobility – many aspects History of mobile communicationHistory of mobile communication MarketMarket Areas of researchAreas of research
Mobile communicationMobile communication Two aspects of mobility:Two aspects of mobility:
user mobilityuser mobility: users communicate (wireless) “anytime, : users communicate (wireless) “anytime, anywhere, with anyone”anywhere, with anyone”
device portabilitydevice portability: devices can be connected anytime, : devices can be connected anytime, anywhere to the networkanywhere to the network
Wireless vs. mobile ExamplesWireless vs. mobile Examples stationary computerstationary computer notebook in a hotelnotebook in a hotel wireless LANs in historic buildingswireless LANs in historic buildings Personal Digital Assistant (PDA)Personal Digital Assistant (PDA)
The demand for mobile communication creates the need for The demand for mobile communication creates the need for integration of wireless networks into existing fixed networks:integration of wireless networks into existing fixed networks: local area networks: standardization of IEEE 802.11, local area networks: standardization of IEEE 802.11,
ETSI (HIPERLAN)ETSI (HIPERLAN) Internet: Mobile IP extension of the internet protocol IPInternet: Mobile IP extension of the internet protocol IP wide area networks: e.g., internetworking of GSM and ISDNwide area networks: e.g., internetworking of GSM and ISDN
Applications Applications
VehiclesVehiclestransmission of news, road condition, weather, music via DABtransmission of news, road condition, weather, music via DABpersonal communication using GSMpersonal communication using GSMposition via GPSposition via GPSlocal ad-hoc network with vehicles close-by to prevent accidents, local ad-hoc network with vehicles close-by to prevent accidents,
guidance system, redundancy guidance system, redundancy vehicle data (e.g., from busses, high-speed trains) can be transmitted vehicle data (e.g., from busses, high-speed trains) can be transmitted
in advance for maintenance in advance for maintenance
EmergenciesEmergenciesearly transmission of patient data to the hospital, current status, first early transmission of patient data to the hospital, current status, first
diagnosisdiagnosisreplacement of a fixed infrastructure in case of earthquakes, replacement of a fixed infrastructure in case of earthquakes,
hurricanes, fire etc.hurricanes, fire etc.crisis, war, ...crisis, war, ...
Typical application: road Typical application: road traffictraffic
ad ho
cUMTS, WLAN,DAB, DVB, GSM, cdma2000, TETRA, ...
Personal Travel Assistant,PDA, Laptop, GSM, UMTS, WLAN, Bluetooth, ...
Mobile and wireless services – Mobile and wireless services – Always Best ConnectedAlways Best Connected
UMTS2 Mbit/s
UMTS, GSM384 kbit/s
LAN100 Mbit/s,WLAN54 Mbit/s
UMTS, GSM115 kbit/s
GSM 115 kbit/s,WLAN 11 Mbit/s
GSM/GPRS 53 kbit/sBluetooth 500 kbit/s
GSM/EDGE 384 kbit/s,DSL/WLAN 3 Mbit/s
DSL/ WLAN3 Mbit/s
Applications Applications Travelling salesmenTravelling salesmen
direct access to customer files stored in a central locationdirect access to customer files stored in a central location consistent databases for all agentsconsistent databases for all agents mobile officemobile office
Replacement of fixed networksReplacement of fixed networks remote sensors, e.g., weather, earth activitiesremote sensors, e.g., weather, earth activities flexibility for trade showsflexibility for trade shows LANs in historic buildingsLANs in historic buildings
Entertainment, education, ...Entertainment, education, ... outdoor Internet access outdoor Internet access intelligent travel guide with up-to-dateintelligent travel guide with up-to-date
location dependent informationlocation dependent information ad-hoc networks forad-hoc networks for
multi user games multi user games
HistoryInfo
Location dependent servicesLocation dependent services Location aware servicesLocation aware services
what services, e.g., printer, fax, phone, server etc. exist in what services, e.g., printer, fax, phone, server etc. exist in the local environmentthe local environment
Follow-on servicesFollow-on services automatic call-forwarding, transmission of the actual automatic call-forwarding, transmission of the actual
workspace to the current locationworkspace to the current location Information servicesInformation services
„„push“: e.g., current special offers in the supermarketpush“: e.g., current special offers in the supermarket „„pull“: e.g., where is the Black Forrest Cherry Cake?pull“: e.g., where is the Black Forrest Cherry Cake?
Support servicesSupport services caches, intermediate results, state information etc. „follow“ caches, intermediate results, state information etc. „follow“
the mobile device through the fixed networkthe mobile device through the fixed network PrivacyPrivacy
who should gain knowledge about the locationwho should gain knowledge about the location
Mobile devicesMobile devices
performanceperformance
Pager• receive only• tiny displays• simple text messages
Mobile phones• voice, data• simple graphical displays
PDA• 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
Effects of device portabilityEffects of device portability Power consumptionPower consumption
limited computing power, low quality displays, small disks limited computing power, low quality displays, small disks due to limited battery capacitydue to limited battery capacity
CPU: CPU: power consumption ~ CVpower consumption ~ CV22ff C: internal capacity, reduced by integrationC: internal capacity, reduced by integration V: supply voltage, can be reduced to a certain limitV: supply voltage, can be reduced to a certain limit f: clock frequency, can be reduced temporallyf: clock frequency, can be reduced temporally
Loss of dataLoss of data higher probability, has to be included in advance into the higher probability, has to be included in advance into the
design (e.g., defects, theft)design (e.g., defects, theft) Limited user interfacesLimited user interfaces
compromise between size of fingers and portabilitycompromise between size of fingers and portability integration of character/voice recognition, abstract symbolsintegration of character/voice recognition, abstract symbols
Limited memoryLimited memory limited value of mass memories with moving partslimited value of mass memories with moving parts flash-memory or ? as alternativeflash-memory or ? as alternative
Wireless networks in Wireless networks in comparison to fixed networkscomparison to fixed networks
Restrictive regulations of frequenciesRestrictive regulations of frequencies frequencies have to be coordinated, useful frequencies are almost frequencies have to be coordinated, useful frequencies are almost
all occupiedall occupied Low transmission ratesLow transmission rates
local some Mbit/s, regional currently, e.g., 53kbit/s with GSM/GPRSlocal some Mbit/s, regional currently, e.g., 53kbit/s with GSM/GPRS Higher delays, higher jitterHigher delays, higher jitter
connection setup time with GSM in the second range, several connection setup time with GSM in the second range, several hundred milliseconds for other wireless systemshundred milliseconds for other wireless systems
Higher loss-rates due to interferenceHigher loss-rates due to interference emissions of, e.g., engines, lightningemissions of, e.g., engines, lightning
Lower security, simpler active attackingLower security, simpler active attacking radio interface accessible for everyone, base station can be radio interface accessible for everyone, base station can be
simulated, thus attracting calls from mobile phonessimulated, thus attracting calls from mobile phones Always shared mediumAlways shared medium
secure access mechanisms importantsecure access mechanisms important
Wireless systems: overview of the Wireless systems: overview of the developmentdevelopment
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)
Mobile phones per 100 Mobile phones per 100 people 1999people 1999
0 10 20 30 40 50 60
Finland
Sweden
Norway
Denmark
Italy
Luxemburg
Portugal
Austria
Ireland
Switzerland
Great Britain
Netherlands
France
Belgium
Spain
Greece
Germany
2005: 70-90% penetration in Western Europe
Worldwide cellular subscriber Worldwide cellular subscriber growthgrowth
0
200
400
600
800
1000
1200
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
Su
bsc
rib
ers
[mil
lio
n]
Note that the curve starts to flatten in 2000 – 2004: 1.5 billion users
Cellular subscribers per Cellular subscribers per region (June 2002)region (June 2002)
Asia Pacific; 36,9
Europe; 36,4
Americas (incl. USA/Canada);
22
Africa; 3,1
Middle East; 1,6
2004: 715 million mobile phones delivered
Areas of research in mobile Areas of research in mobile communicationcommunication
Wireless CommunicationWireless Communication transmission quality (bandwidth, error rate, delay)transmission quality (bandwidth, error rate, delay) modulation, coding, interferencemodulation, coding, interference media access, regulationsmedia access, regulations
MobilityMobility location dependent serviceslocation dependent services location transparencylocation transparency quality of service support (delay, jitter, security)quality of service support (delay, jitter, security)
PortabilityPortability power consumptionpower consumption limited computing power, sizes of display, ...limited computing power, sizes of display, ... usabilityusability ......
Simple reference model used Simple reference model used herehere
Application
Transport
Network
Data Link
Physical
Medium
Data Link
Physical
Application
Transport
Network
Data Link
Physical
Data Link
Physical
Network Network
Radio
Influence of mobile Influence of mobile communication to the layer communication to the layer
modelmodelservice locationservice locationnew applications, multimedianew applications, multimediaadaptive applicationsadaptive applicationscongestion and flow controlcongestion and flow controlquality of servicequality of serviceaddressing, routing, addressing, routing,
device locationdevice locationhand-overhand-overauthenticationauthenticationmedia accessmedia accessmultiplexingmultiplexingmedia access controlmedia access controlencryptionencryptionmodulationmodulationinterferenceinterferenceattenuationattenuationfrequencyfrequency
Application layerApplication layer
Transport layerTransport layer
Network layerNetwork layer
Data link layerData link layer
Physical layerPhysical layer
Overview of the main Overview of the main chapterschapters
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
Overlay Networks - the global goalOverlay Networks - the global goal
regional
metropolitan area
campus-based
in-house
verticalhandover
horizontalhandover
integration of heterogeneous fixed andmobile networks with varyingtransmission characteristics