MOBILE Chapter 1 COMPUTING INTRODUCTION

Distributed Roger Wattenhofer Distributed Mobile Computing Computing Computing Group Summer 2004 Group Summer 2004

Overview A computer in 2010?

• What is it? • Advances in technology • Who needs it? – More computing power in smaller devices • History – Flat, lightweight displays with low power consumption • Future [Der Spiegel] – New user interfaces due to small dimensions – More bandwidth (per second? per space?) – Multiple wireless techniques • Course overview • Technology in the background • Organization of exercises – Device location awareness: computers adapt to their environment • Literature – User location awareness: computers recognize the location of the user and react appropriately (call forwarding) • Thanks to J. Schiller for slides • “Computers” evolve – Small, cheap, portable, replaceable – Integration or disintegration?

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• Aspects of mobility • Vehicles – User mobility: users communicate “anytime, anywhere, with anyone” (example: read/write email on web browser) • Nomadic user – Device portability: devices can be connected anytime, anywhere to the • Smart network • Invisible computing • Wireless vs. mobile Examples • Wearable computing 88Stationary computer 8 9 Notebook in a hotel • Intelligent house or office 9 8 Wireless LANs in historic buildings • Meeting room/conference What is important? 99Personal Digital Assistant (PDA) • Taxi/Police/Fire squad fleet • The demand for mobile communication creates the need for • Service worker integration of wireless networks and existing fixed networks • Lonely wolf – Local area networks: standardization of IEEE 802.11 or HIPERLAN • Disaster relief and Disaster alarm – Wide area networks: GSM and ISDN – Internet: Mobile IP extension of the Internet protocol IP • Games • Military / Security

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Vehicles Vehicles 2

GSM, UMTS GPS

oc h d a

DAB [J. Schiller]

[Der Spiegel]

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• Nomadic user has laptop/palmtop • Connect to network infrequently • Mobile phones get smarter • Interim period operate in disconnected mode • Converge with PDA? [Nokia] • Access her or customer data • Voice calls, video calls (really?) • Consistent database for all agents • Email or instant messaging • Print on local printer (or other service) • Play games – How do we find it? • Up-to-date localized information – Is it safe? –Map – Do we need wires? – Pull: Find the next Pizzeria – Push: “Hey, we have great Pizza!” • Does nomadic user need her own hardware? • Stock/weather/sports info • Read/write email on web browser • Ticketing

• Access data OK too B 1 u •Trade stock 5 i l 0 t B [J. Schiller] •etc. C

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Invisible/ubiquitous/pervasive and wearable computing Intelligent Office and Intelligent House

• Tiny embedded “computers” • Bluetooth replaces cables •Everywhere • Plug and play, without the “plug” • Example: Microsoft’s Doll • Again: Find the local printer

• I refer to my colleagues • House recognizes inhabitant Friedemann Mattern and • House regulates temperature Bernt Schiele and their according to person in a room courses • Trade Shows • Home without cables looks better • LAN in historic buildings [MS] [ABC, Schiele]

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• Share data instantly • Connect • Send a message to someone •Control else in the room •Communicate • Secretly vote on controversial issue • Service Worker • Find person with similar interests • Example: SBB service workers • Broadcast last minute changes have PDA – Map help finding broken signal • Ad-Hoc Network – PDA gives type of signal, so that service person can bring the right tools right away

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Lonely wolf Disaster relief

• We really mean everywhere! • After earthquake, tsunami, volcano, etc: • Cargo’s and yachts • You cannot rely on • Journalists infrastructure but you need to orchestrate disaster relief • Scientists • Early transmission of patient • Travelers data to hospital

• Sometimes cheaper than • Satellite infrastructure? • Ad-Hoc network [Red Cross] • Commercial flop [Motorola]

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• With sensors you might be • Nintendo Gameboy [Advance]: able to alarm early Industry standard mobile • Example: Tsunami game station • Example: Cooling room • Connectable to other • Or simpler: Weather station Gameboys • Can be used as game pad for Nintendo Gamecube • Satellite • Ad-Hoc network • Cybiko [Extreme] is a competitor that has radio capabilities built in [Cybiko] • Second generation already • Also email, chat, etc.

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Military / Security Application Scenarios: Discussion

• Vehicles • From a technology standpoint • Nomadic user this is similar to disaster relief • Smart mobile phone • Invisible computing • Sensoria says “US army is the • Wearable computing best costumer” • Intelligent house or office • Meeting room/conference • Not (important) in this course • Taxi/Police/Fire squad fleet What do you like? • Service worker • Lonely wolf • Disaster relief and Disaster alarm [Der Spiegel] • Games • Military / Security • Anything missing?

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PDA Pager • simple graphical displays Laptop • Laptop (Linux, Mac, Windows?) 8 • fully functional • receive only • character recognition • Palmtop (Linux, Mac, Windows?) 8 • tiny displays • simplified WWW • standard applications • simple text • PDA/Organizer (Palm, Pocket PC, other?) 8 messages • Mobile phone Sensors, • Satellite phone embedded controllers • Pager

Palmtop • Wireless LAN Card 8 • tiny keyboard Mobile phone • Wireless LAN Base Station (for home networking) • simple versions • voice, data of standard applications • Ethernet Plug in every room (for home networking) • simple text display • Bluetooth • Proprietary device (what kind?)

performance and size for exercises 8

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Effects of device portability Wireless networks in comparison to fixed networks

• Energy consumption • Higher loss-rates due to interference – there is no Moore’s law for batteries or solar cells – emissions of, e.g., engines, lightning – limited computing power, low quality displays, small disks • Restrictive regulations of frequencies – Limited memory (no moving parts) – frequencies have to be coordinated, useful frequencies are almost all – Radio transmission has a high energy consumption occupied – CPU: power consumption ~ CV2f • Low transmission rates • C: total capacitance, reduced by integration – local some Mbit/s, regional currently, e.g., 9.6kbit/s with GSM • V: supply voltage, can be reduced to a certain limit • Higher delays, more jitter • f: clock frequency, can be reduced temporally – connection setup time with GSM in the second range, several hundred • Limited user interfaces milliseconds for other wireless systems, tens of seconds with Bluetooth – compromise between size of fingers and portability • Lower security, simpler active attacking – integration of character/voice recognition, abstract symbols – radio interface accessible for everyone, base station can be simulated, • Loss of data thus attracting calls from mobile phones – higher probability (e.g., defects, theft) • Always shared medium – secure access mechanisms important

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• Many people in history used • 1895: Guglielmo Marconi (1874 – 1937) light for communication – first demonstration of wireless – Heliographs (sun on mirrors), telegraphy (digital!) flags („semaphore“), ... – long wave transmission, high transmission power necessary (> 200kW) – 150 BC: smoke signals for – Nobel Prize in Physics 1909 communication (Polybius, Greece) • 1901: First transatlantic connection – 1794: Optical telegraph by Claude Chappe • 1906 (Xmas): First radio broadcast • 1906: Vacuum tube invented • Electromagnetic waves – By Lee DeForest and Robert von Lieben – 1831: Michael Faraday (and Joseph Henry) • 1907: Commercial transatlantic connections demonstrate electromagnetic induction – huge base stations (30 100m high antennas) – 1864: James Maxwell (1831-79): Theory of electromagnetic fields, wave equations • 1911: First mobile sender – on board of a Zeppelin – 1886: Heinrich Hertz (1857-94): demonstrates with an experiment the wave character • 1915: Wireless voice transmission NY – SF of electrical transmission through space • 1920: First commercial radio station

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History: 1920 – 1945 History: 1945 – 1980

• 1920: Discovery of short waves by Marconi • 1958: German A-Netz – reflection at the ionosphere – Analog, 160MHz, connection setup – smaller sender and receiver only from mobile station, no handover, – Possible with vacuum tube 80% coverage, 16kg, 15k Marks – 1971: 11000 customers • 1926: First phone on a train – Compare with PTT () NATEL: – Hamburg – Berlin 1978 – 1995, maximum capacity – wires parallel to the railroad track 4000, which was reached 1980 [F.Mattern] • 1926: First car radio • 1972: German B-Netz • 1928: First TV broadcast – Analog, 160MHz, connection setup from the fixed network too (but – John L. Baird (1888 – 1946) location of the mobile station has to be known) – Atlantic, color TV – available also in A, NL and LUX, 1979 13000 customer in D – WGY Schenectady – PTT NATEL B: 1984 – 1997, maximum capacity 9000 • 1933: Frequency modulation • 1979: NMT System – Edwin H. Armstrong (1890 – 1954) – 450MHz (Scandinavia)

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• 1982: Start of GSM-specification (Groupe spéciale mobile) • 1992/3: Start of GSM “D-Netz”/“NATEL D” – goal: pan-European digital mobile phone system with roaming – 900MHz, 124 channels • 1984: CT-1 standard for cordless telephones – automatic location, hand-over, cellular • 1986: German C-Netz – roaming in Europe – analog voice transmission, 450MHz, hand-over possible, digital – now worldwide in more than 130 countries signaling, automatic location of mobile device – services: data with 9.6kbit/s, FAX, voice, ... – still in use today, services: FAX, modem, X.25, e-mail, 98% coverage • 1994/5: GSM with 1800MHz – American AMPS: 1983 – today – smaller cells – PTT NATEL C: 1986 – 1999 – supported by • 1991: DECT many countries – Digital European Cordless Telephone. Today: “Enhanced” –SMS – 1880-1900MHz, ~100-500m range, 120 duplex channels, 1.2Mbit/s – Multiband data transmission, voice encryption, authentication, up to several phones 10000 users/km2, used in more than 40 countries

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History: 1995 – today Wireless systems: overview of the development

• 1996: HiperLAN cordless cellular phones satellites wireless LAN – High Performance Radio Local Area Network phones 1980: – Products? 1981: CT0 NMT 450 1982: 1983: Inmarsat-A • 1997: Wireless LAN AMPS 1984: CT1 – IEEE 802.11 1986: NMT 900 1987: – 2.4 – 2.5 GHz and infrared, 2Mbit/s 1988: CT1+ Inmarsat-C 1989: – already many products (with proprietary extensions) CT 2 1991: 1991: 1991: 1992: CDMA D-AMPS 1992: DECT 199x: Inmarsat-B GSM 1993: proprietary Inmarsat-M • 1998: Specification of GSM successors PDC 1994: 1997: – GPRS is packet oriented IEEE 802.11 DCS 1800 1998: Iridium 1999: – UMTS is European proposal for IMT-2000 802.11b, Bluetooth

2000: 2000: GPRS IEEE 802.11a analogue 2001: • 1998: Iridium IMT-2000 digital – 66 satellites (+6 spare) 200?: Fourth Generation – 1.6GHz to the mobile phone (Internet based)

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• M.687-2 • Mobile Phones • M.1078 – IMT-2000 concepts and goals – security in IMT-2000 – Switzerland February 2002: More mobile phones than fixnet phones • M.816-1 • M.1079 – Worldwide: More mobile phones than Internet connections – framework for services – speech/voiceband data performance – SMS: “More net profit with SMS than with voice” • M.817 • M.1167 • Laptops – IMT-2000 network architectures – framework for satellites • M.818-1 – Switzerland 2001: For the first year less computers sold, but more mobile • M.1168 – satellites in IMT-2000 computers; private households buy 18% more laptops than the previous year. – framework for management • M.819-2 • M.1223 – IMT-2000 for developing countries – evaluation of security mechanisms • M.1034-1 Desktop • M.1224 800 – requirements for the radio interface(s) Mobile – vocabulary for IMT-2000 700 • M.1035 • M.1225 600 – framework for radio interface(s) and 500 radio sub-system functions – evaluation of transmission technologies 400 • M.1036 •etc. 300 200 – spectrum considerations • www.itu.int/imt 100 0 [R.Weiss] 1996 1997 `998 `999 2000 2001

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Mobile phones worldwide Mobile phones Top 12 [crt.dk] [crt.dk]

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Simple reference model Course overview: Networking Bottom – Up Approach

– service location • Application layer – new applications, multimedia – adaptive applications – congestion and flow control • Transport layer – quality of service – addressing, routing, • Network layer device location – hand-over Application Application – authentication Transport Transport • Data link layer – media access – multiplexing Network Network Network Network – media access control Data Link Data Link Data Link Data Link – encryption • Physical layer – modulation Physical Physical Physical Physical – interference [Tanenbaum/Schiller] – attenuation Radio Medium – frequency

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LF Systems FT TA RA SH CS RR LIR

SW Theory RIB TIM MIB JCT SS7 STA PTP SDT PSK NSS IMSI RFC PCH CSD VCC PTM NMT COA PCM CDM GMM SAAL GFSK WTLS CLMS MTSA RAND UMTS DAMA M-NNI MATM MSDU T-SAP BSSAP PDTCH BLIRCS EMAS-E D-AMPS WMLScript ISI RL CC CU FW AIB URI SIM PLL UIM JDC RTT DSL FSK LBR V+D CTS SFD TLLI PPP BCA GTP PHS UBR DNS XOR PMA SDM MOT GWL WSP WAP MMF MNC EIRP WRC AESA CEPT CATV EMAS CSMA TCH/F HCSAP DPCCH M-PNNI IMT-MC ATM-CL GSM TD-CDMA CSMA/CD PTP-CLNS SCPAS-TP How do I route WAP How can we LI TI FR VC DH Cnf MN Loc FIC CIF HIB RIP AID IWF RTT AFS SAP TFO ESS SCF EHF FEC ASA ACT How does my PAD VDB RAS SDP UDP TMN HEO GEO BLIR WML ISDN in a mobile ad- HTTP BPSK EDTV HDLC DVTR PACS SDMA AGCH IMT-FT PRACH HMQoS CORBA access a shared TCH/FS TR-SAP TC-HMPDU HO-HMPDU wireless LAN hoc network? WML and channel? SI LA TV SS UP HP LM CD UN BLI GR ILR EIT MH

NIT card work? TLS LLC BTS RAL HLR TPC VBR IMEI VHE PCS CCF DVD HBR CDV DCA GAP ARQ IETF MSC WAE DDIB PNNI CIDR DTIM MSIN Assoc DTMF CDPD AMPS Codec MPEG WPAN M-QoS B-ISDN HCQoS WMLscript

WP-CDMA Orthogonal Satellites PI FA UE DS FM PLI HM TIB NIB CGI MCI VLR QoS ASP NFS SFN RLC TDD LMP ACK WIM DCS ATM GPS COS CPM PMD ANSI WAN WMT codes SwMI USIM TFTS WTAI ITU-T DECT SATM FCCH BCCH SGSN ARQN NMAS Bluetooth OFDM MHEG IMT-TC CAMEL VBR-nrt HCPDU SDCCH SCDMA TCH/HS Optimal IP IN ID SA RA GP MT NNI IMT AAL PSF SHF FCA VAD WLL FDD DCF TCH OSS SCH PDU RAN DSR BCH RNS BMP SIFS MSC PIFS WTP MAC OMC UWC GSM SCPS AMES WLAN M-UNI DCCH GGSN EDGE SMRIB BSSGP FACCH LAPDm IMT-SC PSPDN UTRAN HCSDU Frequency GERAN GERAN W-CTRL W-CDMA AK-HCPDU DT-HCPDU Allocation T IS LS TE PS CT PC SN CN CN TM DC PM ISL AM KID SIG OSI ISM Req TOS DAB PCS RSA XML RSS AUS DVB BSC RTR MUL PDO SMS GRE ETSI RRM ROM HDTV UTRA USSD QPSK SEQN DHCP CCCH MSRN GMSC COMS DVB-S COFDM FPLMTS DFWMAC

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Course overview: Hands-On Exercises Course overview: Lectures and Exercises

Introduction • We build a wireless LAN based ad-hoc network Hard- and Software Tests Physical and Link Layer – We start with the “hello world” equivalent "Hello World" Media Access Control – Neighbor detection Theory: Codes/MAC [Ostern] – Chat application Neighbor Detection – Multihop routing Wireless LAN Instant Messenger – Multihop project Ad-Hoc & Sensor Networks – Emulator software Topology Detection Geometric Routing – Grading! Multihop Routing 1 Clustering Multihop Routing 2 Topology Control • Supported by Theory: Ad-Hoc Networks [Pfingsten] – paper exercises Multihop Project 1 Mobile IP and TCP Multihop Project 2 GSM Multihop Project 3 Mobile Web

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• Maximum possible spectrum of systems and theory • Jochen Schiller – Mobile Communications / Mobilkommunikation • New area, more open than closed questions • Ivan Stojmeniovic – Handbook of Wireless Networks and Mobile • Lecture and exercises are hard to synchronize Computing • Andrew Tanenbaum – Computer Networks, plus other books • http://distcomp.ethz.ch/mobicomp • Hermann Rohling – Einführung in die Informations– und Codierungstheorie • James D. Solomon – Mobile IP, the Internet unplugged • Charles E. Perkins – Ad-hoc networking

• Plus tons of other books on specialized topics • Papers, papers, papers, …

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Famous last words

“Mobile wireless computers are like mobile pipeless bathrooms – portapotties. They will be common on vehicles, and at construction sites, and rock concerts. My advice is to wire up your home and stay there.”

Bob Metcalfe, 1995 (Ethernet inventor)

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