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The Göttingen Wireless LAN

The Göttingen Wireless LAN. Gerhard Schneider G esellschaft für w issenschaftliche D atenverarbeitung G öttingen and Universität Göttingen. gerhard.schneider@gwdg.de http://www.gwdg.de/~gschnei2. Motivation -1-. The laptop is the (future) working environment (portable!)

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The Göttingen Wireless LAN

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  1. The Göttingen Wireless LAN Gerhard SchneiderGesellschaft für wissenschaftliche Datenverarbeitung Göttingen and Universität Göttingen gerhard.schneider@gwdg.dehttp://www.gwdg.de/~gschnei2

  2. Motivation -1- • The laptop is the (future) working environment (portable!) • And other portable devices • Outside your office everybody tries to keep you away from the Internet • Where do you find the nearest Internet access point? And may you use it? • How many access points do you find in this resort?? • are you allowed to access the Internet in your own company/university everywhere?? • In the meeting room to download your digital information • In other departments to read your mail during session breaks • And even if you could (technically), King SysAdmin happens to be far away • “This is not for everybody”, „you are a security risk“, etc • So one is dreaming of the Internet and its multi media options but even two inches away from a connected computer you are in Network-Never-Never-Land • and in frustration you use your mobile phone • Fact: The internet is at the desk and files/information are available digitally

  3. Motivation -2- • In Göttingen some 4000 dorms are networked, mostly fibre or 100 Mbit/s • Top position in Germany (according to the statistics of the Deutsches Studentenwerk • Makes dormitories very attractive for students • Internet access from the bed, but from nowhere else? • What about private places? • In a library there is almost no possibility to use the own laptop for online research • Use of existing PC for research is no problem • (Göttingen offers several hundred “public” terminals, so there is an option) • transfer of the results to a server • At home download the data onto the private laptop • Which you had with you in the first place • Even when the weather is fine, surfing the net can only be done in your (dark) room. • Bad social image

  4. Motivation -3- • Main problem: Internet access is seen as a local phenomenon, not as a global need. • Personal vision: always online at little cost and with high performance • Also because of my PDA (personal digital assistant) • Current twists to synchronise data are far from optimal • Question: what happens, if you are always online and the tedious search for the net has become history? • Compares with the continous search for food in contrast to always finding a well laid table • Remember the Woody Allen film, where a character is constantly calling the secretary to leave his current phone number? • Now solved by mobile phones... • First experiments in 1995, using proprietary Breezecom technology • Now we have a standard 802.11b – new motivation

  5. 20.4.2000first trial „Göttinger FunkLAN“

  6. Experiences from the trial • A wireless LAN only makes sense, if it is available (almost) everywhere. • Not just in one building, but really everywhere • Everywhere means: global management and global operation • Equal access: all net citizens are equal • In Göttingen, science happens to be everywhere • The scattered buildings scattered over town are a nightmare for networking people, but a dream for the wireless operator • Many points for transmitters at little extra cost • In addition all schools are online via fibre optic or ADSL • So instead of going for a 100% coverage of a few university complex rather go for a (more or less) general coverage of the city • Trick: wireless technology goes in all directions, so a transmitter happens to cover surrounding areas.

  7. University of Göttingen URL: http://www.uni-goettingen.de Max Planck Institute for Aeronomy (in Katlenburg-Lindau, some 30km outside of Göttingen – dark fibre) URL: http://www.mpae.gwdg.de Max Planck Institute for Biophysical Chemistry URL: http://www.mpibpc.gwdg.de Max Planck Institute for fluid Dynamics URL: http://www.gwdg.de/mpisf Institute for the scientific Film URL:http://www.iwf.de Max Planck Institute for Historical Science URL: http://www.geschichte.mpg.de Max Planck Institute for Experimental Medicine URL: http://www.mpiem.gwdg.de GWDG URL: http://www.gwdg.de City of Göttingen (since 3/99 – with the local schools) URL: http://www.goettingen.de URL:http://www.goe.ni.schule.de Primatenzentrum URL:http://www.dpz.de Göttingen’s Data Network for Science and Research The local high speed networt GöNet, started in 1991, connects the following institutions at gigabit speed:

  8. Backbone 1 Gbit/s The first data highway:Gauss-Weber 1833: 1 bit/Sek Today‘s fibre optic backbone: 1.000.000.000 times faster Wireless LAN: currently 11.000.000 times faster LANs in Göttingen • University founded in 1734/37 • Two Campuses and many little buildings scattered all over town. • Observatory of C. F. Gauss • Oldest Institute for Geophysics in the world. • World‘s first data highway

  9. Remarks about the technology • WAVELAN 802.11b • Unrestricted operation in the 2,4 GHz range • “CB-network” with no guarantee for exclusive access/use • Range restricted by law: • short range: 100 mW power • long range: 30mW power • 1/20 bis 1/60 of a mobile phone (900 MHz bzw. 1.800 GHz) • Range up to 300m with normal antennas • Antennas are reasonably invisible (compared with GSM) • Range up to 4km already observed (using special and legal antennas) • Inside of buildings the range is much less • LAN-connection is still required • Up to 11 Mbit/s in one cell • Several cells may cover an area, up to 128 users per cell.

  10. Antenna Pccard for the notebook Access Point (connection to the LAN) Technology (1)

  11. Technology (2) 6 dBi Patch DIR-060-01 5.2 dBi Omni (outdoor) OMN-052-02 21 dBi Solid Dish DIR-210-01 13.5 dBi Yagi DIR-135-01 12 dBi Omni OMN-120-01

  12. Project money from “nds. MWK” and BMBF • This was what we needed to boost our wireless network: € 250.000 • 50% “nds. MWK” = niedersächsisches Ministerium für Wissenschaft und Kunst = Ministry for Research and Arts, Lower SaxonyMinister Thomas Oppermann • 50% BMBF: = Bundesministerium für Bildung und Forschung = Federal Ministry for Education and ResearchMinisterin Edelgard Bulmahn • some 150 Access-Points can be financed • Partly with dual card, i.e. with one access point we can provide service inside and outside of the buildings by suitably placing the antennas • some 250 WaveLAN cards for loan to students • A few laptops for loan, including an iPAQ • Boosts the acceptance of lpatops w.r.t. real computers • Laptops are finally affordable, about €1500 at the food store ALDI • So far good acceptance from everybody • Colleagues showing off the new infrastructure to visitors!

  13. The right antennas… • By use of special antennas larger distances can be covered, provided there is direct (unhampered) visibility • 11 Mbit/s up to 4 km • Blauer Turm as first long range access point, city hall will follow

  14. CZ, 8.2.2001 Security concepts • Access is only granted to cards having a valid identification • Check the MAC-adresse against radius database • Communication between card and access point is encrypted • Generic standard WEP • This appears far from being secure, thus: • No connection between the Wireless LAN backbone and the “normal” network GöNET • Only after logging in at a gateway we grant access to the Internet (VPN-Technology) • Typically used for “external” dial-in • Connection between user and gateway is encrypted using VPN software and its scientifically approved encryption methods

  15. Access to the wireless network • Is this a bottleneck? No! • We can install several gateways • The backbone offers enough capacity to cope with the incoming wireless traffic • We can/could talk about separate user groups/users administration • Faculty gateways  (but better than a separated net) • Advantage: Integration of other user groups into the infrastructure • Get more money to expand the network • Example: companies could also use a relatively wide spread network • Measurement Valley • local Internet provider • City radio – use the GöNET for Internet radio 

  16. Wireless LAN – modes of operation • Central axiom from our point of view:a wireless network is more than a local network • Not an extension of the old idea of a wire based telephone system, but roaming as we know it from the mobile world • At this point many institutions commit their central design error! • Not a centralistic concept, but a concept which scales even for several operators • GWDG-user (science&research), student user, faculty • Target: one wireless network for all scientists and students in Göttingen • „Internet always on“ – well, “almost everywhere • Access is possible everywhere, using the same rules

  17. Wireless LAN – modes of operation Gateway GöNET G-WiN Router Shared 11 Mbit/s

  18. New partners • The local bank (Sparkasse Göttingen) • Transmitters may be placed inside and outside three “crucial” branch offices • Connection to GöNET via dark fibres from the bank network • Easy online banking • Siemens-Fujitsu • 100 high end laptop computers for students sponsored • Model B2175 and model E6560 at €1300 • It pays to be a student  • City of Göttingen • Will grant access to the town hall “skyscraper” • Will donate PCMCIA-WaveLAN-cards to students who take up residence in the city of Göttingen • (rather than stay in their home town – tax reasons) • Suddenly our project is affecting the competition of cities 

  19. Finally a clean desk Future working conditions Voice over IP?

  20. Internet and more • After all, digitised voice is data! • Not really understood in society, parliament, legislation • GWDG is experimenting with Voice over IP • Solution by Siemens: Software running on a PC • VoIP-Gateway to our PABX already installed • Real telephone calls from your PC…. • Including real blue screens • Build your own mobile phone with this?? No, after all: • www.spectralink.com (VoIP-mobile based on 802.11b) • New questions • why DECT???? • If we can scrap the DECT project of the university PABX, we have more money for WaveLAN • why UMTS???? • Compared to the € 50 billion licence fees in Germany, WaveLAN is really cheap • http//www.tagesschau.de/archiv/2001/03/21/sendungen/tt-2230/videos/cebit.ram

  21. Data and “voice” over one wireless network Voice is no longer an expensive special case ) ) ) ) ) ) ) ) WAN ) ) ) ) ) ) ) ) ) ) ) ) PSTN ) ) ) ) Connection to the old world

  22. Summary:wireless vs traditional LAN • Wireless is easy to install • Especially when it comes to respect conservation laws • Wireless is „shared“ media • 802.11b gives at most 11 Mbit/s for all participants in one cell • „good old“ Ethernet in a new box • With all its disadvantages • In Göttingen the wireless LAN is an additional offer for the „roaming user“ • Cabling infrastructure is expanded constantly • Connect remaining sites to GöNET fast • Instant cover of large rooms • library, Café, • No replacement for cabling infrastructurew.r.t. multimedia Library in the Paulinerkirche

  23. Future conferences? Only portable – no – wearable! 900g on belt or arm, 233 MHz, 128 MB RAM, 4,3 GB HDD, 2x PCMCIA, Audio I/O, USB, ext. scanner, ext. keyboard, ext. mini camera

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