Redes Inalámbricas – Tema 1 General concepts

1. Redes Inalámbricas – Tema 1 General concepts An overall view of: Technologies MANETs networks Applications Devices References Acknowledgments Mark Weiser Vint Cerf Jim Kurose, Keith Ross, “Computer Networking: A Top Down Approach Featuring the Internet, 2nd edition. Addison-Wesley, July 2002

2. Redes Inalámbricas – Tema 1 General concepts Technologies

3. Various types of wireless technologies • WiMax • WiFi • Bluetooth • Network telephony. Various generations: • GSM  GPRS, EDGE; • UMTS  HSDPA • LTE • Satellites: • Satellites Geostationary Earth Orbit (GEO) • Example: Inmarsat • Satellites Low-Earth Orbit (LEO) • Example : Iridium (66 satellites) (2.4 Kbps data) • Infrared: IrDA • Ultra-Wide Band (UWB) • RFID • Zigbee • …

4. Personal Area Local Area Wide Area Cellular SystemsGSM, GPRS, EDGEUMTS Wireless LANIEEE 802.11 PAN Bluetooth Wireless Data Networks • Wireless networks are the best option for mobile devices: • Easy installation: no problems with cables • Systems easily expandable according to the needs

5. “HOT SPOTS” Uses of WLANs “CORPORATE CAMPUS” “HOME OFFICE” • COMMON AREAS, • MEETING ROOMS, • LABORATORIES, • TEMPORARY OFFICE • AIRPORTS • HOTELS • CONVENTION CENTER

6. Mobile/Smart HH STB/Media Center PC BT Model UWB Model Photo/Printer Mass Storage Substitute cables Personal ad hoc connectivity HDTV KB, Mouse DVC Voice, Stereo Audio DSC Uses of WPAN

7. Mobility • There are several types of mobility • Physical mobility (of the devices) • off line connectivity: portable • on line connectivity : mobile • Logical mobility: • Of the processes • Of the applications “ubiquitous computing”

8. Mobility and theapplications • Bandwidth variability • Applications should adapt. E.g., a videoconferencing application could vary the image size or its quality when varying the bandwidth. • Disconnection • Allow asynchronous operations, pre-fetching, caching, weak consistency, ... • Security and privacy • The wireless channels are prone to "wiretapping''(snooping) • Who should be given access to the location information? How much accurate should be this information? • Energy management: • stop discs, turn off the screen, standby mode of the CPU, put to sleep the network card, …

9. General view “Mobile ad hoc networking: imperatives and challenges”, ImrichChlamtac, Marco Conti, Jennifer J.-N. Liu, Ad Hoc Networks, Elsevier, 1 (2003).

10. Redes Inalámbricas – Tema 1 General concepts Devices

11. Sensors Mica Hardware Platform: The Mica sensornode (left) with the Mica Weather Board developedfor environmental monitoring applications

12. Mobile devices: PDA and phones

13. Mobile devices: notebooks/laptops

14. Mobile devices: tablet PC

15. Screenfridge More devices (Information/Internet Appliances) Web-enabled toaster+weatherforecaster IP picture frame http://www.ceiva.com/ World’s smallest web server http://www.webservusb.com/

16. More devices (Information/Internet Appliances)

17. Redes Inalámbricas – Tema 1 General concepts MANETs networks

18. Mobile Ad-hoc Networks (MANETs) • Networks formed by mobile wireless nodes. • Do not use any existing infrastructure • There are hybrid solutions known as "mesh networks“ • In a MANET mobility has a crucial importance. • routes vary over time • partitioning

19. Why ad hoc networks? • The ad hoc networks can be deployed in a flexible manner in environments that have no fixed infrastructure • Having a fixed wired infrastructure or access points is not always possible or feasible • It is not economically viable or interesting • It is not practical in temporary environments • It may have been destroyed, for example, due to natural disasters

20. A “clear” example: vehicular networks • About “smart cars” and “smart roads”. On-board systems “talk” with the “road”. • They car offer: • Cooperative driver assistance: • Emergency notification • Overtaking assistance • Obstacle warning • Decentralized floating car data: • Traffic jam monitor • Dynamic navigation • Route weather forecast • User communications and information services: • Hot-spot Internet access • Inter-vehicle chat • Distributed games

21. Redes Inalámbricas – Tema 1 General concepts Applications: UBIQUITOUS COMPUTING

22. Ubiquitous Computing • Mark Weiser – The father of “Ubiquitous Computing” (1988) Definitions • Ubiquitous computing is the method of enhancing computer use by making many computers available throughout the physical environment, but making them effectively invisible to the user – Mark Weiser Mark Weiser (1952-1999) was the chief technology officer at Xerox’s Palo Alto Research Center (Parc). He is often referred to as the father of ubiquitous computing. He coined the term in 1988 to describe a future in which invisible computers, embedded in everyday objects, replace PCs. Other research interests included garbage collection, operating systems, and user interface design. He received his MA and PhD in computer and communication science at the University of Michigan, Ann Arbor. After completing his PhD, he joined the computer science department at the University of Maryland, College Park, where he taught for 12 years. He wrote or cowrote over 75 technical publications on such subjects as the psychology of programming, program slicing, operating systems, programming environments, garbage collection, and technological ethics. He was a member of the ACM, IEEE Computer Society, and American Association for the Advancement of Science. Weiser passed away in 1999. Visit www.parc.xerox.com/csl/members/weiser or contact communications@parc.xerox.com for more information about him. Mark Weiser (1952-1999)http://www-sul.stanford.edu/weiser/ M. Weiser, The Computer for the 21st Century Scientific American, 1991

23. Ubiquitous Computing • What Ubiquitous Computing is: • Information technology everywhere • Is a paradigm shift where technology becomes virtuallyinvisible in our lives  “Calm Technology” • It needs • Smart Objects  embedded processors • Wireless Technology to interconnect them • What Ubiquitous Computing is not: • Mobility itself doesn’t lead to UbiComp • Multimedia itself doesn’t lead to UbiComp either • Virtual realityneither Ubiquitous Computing: And old vision

24. The new paradigm • Generic Features • “Invisible” interfaces that provideinteraction between user and application • Awareness of context • Context  information about the environment with which theapplication is associated. • LOCATION and TIME are simple examples of context ! • Capture experience • To capture our day-to-day experience and make it available for future use. • To acquires knowledge from places visited to server future visitors • Research challenges • Multiple streams of information • Their time synchronization • Their correlation and integration

25. More examples at MIT http://ttt.media.mit.edu/

26. Redes Inalámbricas – Tema 1 General concepts Applications: RURAL COMMUNICATIONS

27. Global survey on rural communications • Rural communications on the global agenda • Connecting villages with Information and Communication Technologies (ICT) and establishing community access points • Benefits • E-business and e-commerce could play an important role in enabling local artisans to reach national and international markets Over 40% of the world’s population lives in rural and remote areas of developing countries and have difficult or no access to even basic telecommunications services. Development of telecommunications in rural and remote areas, therefore forms an important mission of the ITU Development sector. Yasuhiko Kawasumi, “Rural communications on the global agenda,” Global Survey on Rural Communications for the ITU-D on Communications for rural and remote areas.

28. Rural populations and their ICT needs • Needs of rural people in connection with e-services • E-health, e-education and e-administration top the list as primary needs • E-business and e-banking also scored highly ITU-D global survey, Doc 111/SG2 For many rural areas, electricity supply is simply non-existent or insufficient Telemedicine Training in Bhutan by Tokai University: Tokai University Institute of Medical Sciences donated the medical equipments with ICT functions and provided the training on the use of equipments. Tokai University Second Opinion center provides the assistance service over the internet when requested by the Bhutanese ends.

29. Optimal Technologies to connect Rural Communities • Question 1: What are the requirements for communications system in rural areas • Implementation should be possible at a low cost in areas where population density is low • The system can be easily installed, even in remote and inaccessible locations • System operation and maintenance may be carried out even where qualified technical personnel are scarce • Implementation should be possible even when basic infrastructure such as mains electricity, running water, paved road networks, etc., are absent • Long life cycles

30. Optimal Technologies to connect Rural Communities • Question 2: What are the choices of technologies for communications in rural areas • Satellite communications system (VSAT) • Terrestrial wireless communications system • Wi-Fi, Wi-Max, 802.16 • Mobile communications system (2G,GSM) • Copper wire including power line • The final report of ITU Focus Group 7 on “New technologies for rural applications” (2001) recommended (WiFi) based on the IEEE 802.11 b/g

31. Optimal Technologies to connect Rural Communities • Question 3: What is the advantage of wireless technologies for communications in rural areas • Provide significant life time cost benefits in rural areas in cases where cable deployment is uneconomic. • Provide easy and speedy installation in harsh terrain and extremely remote areas, smaller investment increments and avoidance of copper cable theft. • Provide lower maintenance cost and greater network flexibilities

32. Optimal Technologies to connect Rural Communities • Question 4: What are the barriers for communications in the environment of rural areas • Scarcity and absence of reliable electricity supply, water, access roads and regular transport • Scarcity of technical personnel • Difficult topographical conditions (lakes, rivers, hills, mountains, or deserts, etc.) • Severe climatic conditions that make critical demands on the equipment. • Low level of economic activity mainly based on agriculture, fishing, handicrafts, etc. • Low per capita income • Underdeveloped social infrastructure (health, education) • Low population density • Low literacy rate

33. El Programa Telecentros • ¿Qué es? • El programa Telecentros se ha dirigido a los municipios de zonas rurales y a núcleos urbanos desfavorecidos, a través de las Diputaciones, Cabildos y Consejos insulares o, en su caso, Comunidades Autónomas uniprovinciales. La actuación tuvo como principal objetivo facilitar el acceso a las nuevas tecnologías tanto a las poblaciones rurales como a los colectivos menos integrados, a fin de lograr su participación efectiva en la Sociedad de la Información. • La actuación tiene como principal objetivo facilitar el acceso a las nuevas tecnologías tanto a las poblaciones rurales como a los colectivos menos integrados, a fin de lograr su participación efectiva en la Sociedad de la Información. • Actuaciones: • Conexiones a Internet de banda ancha en zonas ruralesy urbanas desfavorecidas. • Equipamiento de los Centros de Acceso Público a Internet. • Servicios de instalación, mantenimiento y atención al usuario. • Servicios de control y gestión del Centro. • Portales de servicios a poblaciones rurales. • Servicios de dinamización y formación

34. EU y las redes rurales

35. Mesh Networks • Features • Multi-hop Networks • Automatic organization and maintenance • Support for mobility (clients) • Integration of technology access

36. MIT Roofnet • MIT Roofnet: http://pdos.csail.mit.edu/roofnet/doku.php • Wireless access to the MIT Computer Science Lab • 1,25 squared miles MIT Roofnet: Distribution of nodes and quality of the links

37. guifi.net • PublicWiFinetworkdeployedbasically in Cataluña

38. Otherproposals • Kingsbridge Link • http://www.kblink.co.uk/ • Based on Linksys WRT54g • panOULU • http://www.panoulu.net/ • Finland • Meraki • http://meraki.com/ • San Francisco • Fon • http://www.fon.com/es/

39. Redes Inalámbricas – Tema 1 General concepts Applications: VANETs

40. Motivation • Safetyandtransportefficiency • InEuropearound 40,000 peopledieandmore than 1.5 millionsare injuredeveryyearontheroads • Trafficjamsgenerate a tremendouswasteoftimeandoffuel • Mostoftheseproblemscanbesolvedbyprovidingappropriateinformationtothedriverortothevehicle

41. Passive Approach is not Enough On foggy days What’s in front of that bus ? What’s behind the bend ? On rainy days

42. VehicleCommunication (VC) • VC promisessaferroads, • … more efficient driving,

43. VehicleCommunication (VC) • … more fun, • … and easier maintenance.

44. Lot of Involved Technologies

45. Lot of Involved Parties

46. VANETs vs MANETs • Vehicular ad-hoc network (VANET) are a special case of Mobile ad-hoc networks (MANET) • VANET constrained by • Predefined roads (e.g. one-way and multi-lane) • Vehicle velocities restricted by speed limits • Level of congestion in roads (e.g. urban or suburban) • Traffic control mechanisms (e.g. traffic light) • VANET advantage by • Rechargeable source of energy • Equipped with devices with potentially longer transmission ranges. (e.g. adopt WAVE and WiMAX) • etc.

47. VANETs vs MANETs • RapidTopologyChanges • Highrelativespeedofvehicles => short link life • FrequentFragmentation • Chunks of the net are unable to reach nodes in nearby regions • SmallEffectiveNetworkDiameter • Apathmaycease toexistalmostasquicklyasitwasdiscovered (reactive routing) • LimitedRedundancy • The redundancy in MANETs is critical to providing additional bandwidth • In VANETs the redundancy is limited both in time and in function

48. Redes Inalámbricas – Tema 1General concepts References

49. References • Bibliografía Básica / Basic book • Thebasicreferencebookforthiscourseis "WirelessNetworking in theDevelopingWorld". Thisis a free bookaboutdesigning, implementing, and maintaininglow-costwirelessnetworks. • Referencebooksaboutadvancedtopics: • "WirelessCommunications: Principles and Practice (2nd Edition)", Theodore S. Rappaport, Prentice Hall, January 2002. Availablevia Safari. • "802.11 Wireless Networks: TheDefinitive Guide, SecondEdition", MatthewGast, O'Reilly, April 2005. Availablevia Safari. • "Ad Hoc Mobile Wireless Networks: Protocols and Systems", C. K. Toh, Prentice Hall, 2001. Availablevia Safari. • "Ad Hoc Wireless Networks Architectures and Protocols", C. SivaRamMurthy; B. S. Manoj, Prentice Hall, 2004. Availablevia Safari. • Documentación adicional para matriculados UPV • Disponible en Poliformat

50. IAB 1983 (Internet Architecture Board) 1989 IRTF IETF Internet Society ~1991 Standards en Internet • de-facto standards • “Rough consensus and running code”, D. Clark • Defined in documents called RFCs (Request For Comments) available on line: http://www.rfc-editor.org/ • Phases: Proposed standardsDraft StandardInternet Standard • Before getting to RFC we use Internet-Drafts which are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. • https://datatracker.ietf.org/drafts/