1. Computer Networks Group Universität Paderborn Computer Networks Chapter 0: Overview & Formalities Holger Karl

2. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities2 Overview Who are we? Research and teaching at Fachgebiet Rechnernetze The topic of Communication Networks Formalities Resources Exams

3. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities3 Who are we Fachgebiet Rechnernetze Prof. Dr. Holger Karl hkarl@ieee.org oder holger.karl@upb.de P 1.7.01.5 Mittwoch, 11:00 – 12:00 hkarl@ieee.orgholger.karl@upb.de Mitarbeiter: Christian Dannewitz Web page: http://wwwcs.uni-paderborn.de/cs/ag-karl/http://wwwcs.uni-paderborn.de/cs/ag-karl/

4. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities4 Introduction of communication technologies – Internet Internet today: About 600 million users estimated Shortest introduction time of any communication technology 1922 1950 1982 1994 110 100 90 80 70 60 50 40 30 20 10 0 Zahl der angeschlossenen Haushalte in den Vereinigten Staaten (in Millionen) Internet/Online Radio Fernsehen Kabelfernsehen (Quelle: Bertelsmann)

5. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities5 A paradigm shift – from voice to data Source: Alcatel Telecommunication Review, 1998 Machine-to- machine communication difficult to estimate, but will grow considerably in the future

6. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities6 Mobile and Wireless Communication: Always Best Connected UMTS, DECT 2 Mbit/s UMTS, GSM 384 kbit/s LAN 100 Mbit/s, WLAN 54 Mbit/s UMTS, GSM 115 kbit/s GSM 115 kbit/s, WLAN 11 Mbit/s GSM 57 kbit/s Bluetooth 500 kbit/s GSM 384 kbit/s, WLAN 780 kbit/s LAN, WLAN 780 kbit/s Wireless, low-rate control networks

7. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities7 The future of telecommunication systems ad hoc Personal Travel Assistant, DAB, PDA, Laptop, GSM, UMTS, WLAN, Bluetooth, IrDA, Intelligent Roadside by sensor networks... UMTS, WLAN, DAB, GSM, TETRA,...

8. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities8 Communication/information is serious business Quelle: L.A. Nefiodow: Der fünfte Kontratieff 0 10 20 30 40 50 60 70 80 180018501900195020002050 Landwirtschaft Produktion Dienstleistungen Informationen Agrar- zeitalter Industrie- zeitalter Infor- mations- zeitalter Erwerbspersonen, Anteil in %

9. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities9 A bit of communication history YearInnovationIssue 1840Morse TelegraphElectrical exchange of data over larger distances 1861Telephone (Reiss)One-way voice communication over larger distances 1870Telephone (Bell)Bi-directional voice communication patented 1887Electromagnetic waves (Hertz) Wireless communication possible 1892Rotary dialerAutomation of telephone switching 1923Radio broadcastFirst electronic mass communication 1929Coax cablePaves the way to higher data rates 1964Communication satellitesWorld-wide communication 1966Optical fiberLeap forward in possible data rates 1984De-regulation (US)End of state monopolies in telecommunication 1997Wavelength division multiplexing Optical fibers can carry up to tera bits per second (1 tera = 10^12) Source: Schiller, Telematik, FU Berlin, 2003

10. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities10 Main research topics In general: architectures and protocols of communication systems Structure, design, performance evaluation, implementation, … For all types of communication: computer networks, voice communication, data & multimedia content More specifically Future mobile and wireless communication What comes after GSM, UMTS, WLAN? Buzzwords: anybody, anytime, anywhere Cross-layer optimization Try to improve system by using all available sources of information Technical communication Wireless sensor (& actuator) networks Tiny devices to measure and control environment

11. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities11 Main teaching topics – FG Rechnernetze Research topics are reflected in setup of courses Basic education in a broad range of communication topics Visible focus on mobile and wireless communication Currently planned structure: KMS Rechnernetze Mobil- kommunikation Ad hoc/Sensor- netze Leistungsbewertung/ Simulation Advanced Internet Seminar Projektgruppe IV V VII VIII

12. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities12 Topic of Computer Networks Ever wondered what really happened after Typing http://www.uni-paderborn.de into a Web browser?http://www.uni-paderborn.de Making a phone call? How does data get from one device to another? Basic abstractions have been treated in KMS What happens behind the scene and on the wire? Communication systems enable this transport of data What are the necessary ingredients for such systems? Typical components? Are there any basic mechanisms to put such components together? To organize their working together? How can we cope with size, complexity, failures, user demands, … in such systems?

13. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities13 Topic of Computer Networks This lecture is about basic architecture and protocol mechanisms Attempts to give an overview of all important components Essentially, a round-up of all layers of ISO/OSI model For both data communication and voice / telecommunication It is NOT about specific technical solutions It is NOT about mobile and wireless communication Covered in Mobile Communication, this semester and follow-up lectures Requires Computer Networks as pre-requisite It is NOT about distributed systems Rather, builds the foundation for them to work

14. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities14 Formalities – Resources Slides are/will be available on the web site There will be NO script Secondary literature is necessary To give due credit where credit is due: Some of the material on these slides (text, pictures, graphs, pictograms, etc.) is used from lectures given by Profs. Krüger, Juling, Zitterbart, Schiller, Carle at the universities Karlsruhe, Braunschweig, Kiel, FU Berlin, Tübingen Other parts are based on material available via the Internet, company presentations, and similar sources In particular, Tanenbaums and Peterson/Davies books online material Many thanks to everybody who contributed here and has graciously agreed to make their material available

15. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities15 Formalities – Book recommendation Basic textbook for this class: A. Tanenbaum, Computer Networks, 4th edition, Prentice- Hall Classic textbook, excellent tutorial style, if occasionally a bit lengthy Do NOT use an earlier edition; they are partially outdated Do NOT use a translation Good command of English is necessary anyway

16. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities16 Secondary book recommendations Another excellent book: William Stallings, Data and Computer Communications, 7th Edition, Prentice Hall A bit more technical, less chatty than Tanenbaum

17. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities17 Secondary book recommendations L. L. Peterson & B. S. Davie, Computer Networks – A Systems Approach, 2003, 3rd edition, Morgan Kaufman Rather technical approach, quickly gets down to how to build it questions Maybe a bit quick on the beginner, though J. F. Kurose & K. W. Ross, Computer Networking: A Top-Down Approach Featuring the Internet, 2004, 3rd edition, Addison Wesley Motivates why communication systems are built in a certain fashion by starting out from the applications that they should support

18. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities18 Further book recommendations F. Halsall: Data Communications, Computer Networks and OSI. Addison-Wesley, 4. Auflage, 1997 Similar to Tanenbaum, more details, particularly good for lower-layer questions Unfortunately, no longer updated S. Keshav: An Engineering Approach to Computer Networking. Addison-Wesley, 1999 Excellent book for fundamental treatments, some good theory chapters Also explains why some design choices are made Unfortunately, also a bit outdated

19. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities19 Further book recommendations W.R. Stevens: TCP/IP Illustrated, Vol. 1- 3, 1994, Addison-Wesley If you want to know everything about TCP/IP J. Schiller, Mobile communication, 2 nd edition, 2003, Addison Wesley Details on mobile communication

20. WS 05/06, v 1.1Computer Networks - Ch. 0: Overview and Formalities20 Formalities – Exam There will be a written exam Unless number of participants is too small, then oral examination Date, place, details to be announced Closed book, no additional material Both lecture and exercise material are relevant for the exam