Presentation is loading. Please wait.

Presentation is loading. Please wait.

Redes Inalámbricas – Tema 1 General concepts

Similar presentations

Presentation on theme: "Redes Inalámbricas – Tema 1 General concepts"— Presentation transcript:

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

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 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 Local Area Personal Area Wide Area Wireless LAN IEEE PAN Bluetooth Cellular Systems GSM, GPRS, EDGE UMTS


6 Personal ad hoc connectivity
4/11/2017 9:23 AM Uses of WPAN DSC HDTV STB/Media Center PC Photo/Printer Mobile/Smart HH Mass Storage Substitute cables Personal ad hoc connectivity KB, Mouse DVC Voice, Stereo Audio BT Model UWB Model © 2006 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION. 6

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 the applications
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”, Imrich Chlamtac, Marco Conti, Jennifer J.-N. Liu, Ad Hoc Networks, Elsevier, 1 (2003).

10 Redes Inalámbricas – Tema 1 General concepts

11 Sensors Mica Hardware Platform: The Mica sensor node (left) with the Mica Weather Board developed for environmental monitoring applications

12 Mobile devices: PDA and phones

13 Mobile devices: notebooks/laptops

14 Mobile devices : tablet PC
Prototype w/full Windows for 2002

15 More devices (Information/Internet Appliances)
Web-enabled toaster+weather forecaster IP picture frame World’s smallest web server Screenfridge

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

22 Ubiquitous Computing Mark Weiser Definitions – 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 ( ) 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 Visit or contact for more information about him. Mark 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 virtually invisible 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 reality neither Ubiquitous Computing: And old vision

24 The new paradigm Generic Features
“Invisible” interfaces that provide interaction between user and application Awareness of context Context  information about the environment with which the application 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

26 Redes Inalámbricas – Tema 1 General concepts

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, 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 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 rurales y 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: Distribution of nodes and quality of the links
Wireless access to the MIT Computer Science Lab 1,25 squared miles MIT Roofnet: Distribution of nodes and quality of the links

37 Public WiFi network deployed basically in Cataluña

38 Other proposals Kingsbridge Link panOULU Meraki Fon
Based on Linksys WRT54g panOULU Finland Meraki San Francisco Fon

39 Redes Inalámbricas – Tema 1 General concepts
Applications: VANETs

40 Motivation Safety and transport efficiency
In Europe around 40,000 people die and more than 1.5 millions are injured every year on the roads Traffic jams generate a tremendous waste of time and of fuel Most of these problems can be solved by providing appropriate information to the driver or to the vehicle

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 Vehicle Communication (VC)
VC promises safer roads, … more efficient driving,

43 Vehicle Communication (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. Vehicular ad-hoc network (stand for VANET) is a special case of mobile ad-hoc networks.

47 VANETs vs MANETs Rapid Topology Changes Frequent Fragmentation
High relative speed of vehicles => short link life Frequent Fragmentation Chunks of the net are unable to reach nodes in nearby regions Small Effective Network Diameter A path may cease to exist almost as quickly as it was discovered (reactive routing) Limited Redundancy 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 1 General concepts

49 References Bibliografía Básica / Basic book
The basic reference book for this course is "Wireless Networking in the Developing World". This is a free book about designing, implementing, and maintaining low-cost wireless networks. Reference books about advanced topics: "Wireless Communications: Principles and Practice (2nd Edition)", Theodore S. Rappaport, Prentice Hall, January Available via Safari. " Wireless Networks: The Definitive Guide, Second Edition", Matthew Gast, O'Reilly, April Available via Safari. "Ad Hoc Mobile Wireless Networks: Protocols and Systems", C. K. Toh, Prentice Hall, Available via Safari. "Ad Hoc Wireless Networks Architectures and Protocols", C. Siva Ram Murthy; B. S. Manoj, Prentice Hall, Available via Safari. Documentación adicional para matriculados UPV Disponible en Poliformat

50 (Internet Architecture Board)
Standards en Internet de-facto standards “Rough consensus and running code”, D. Clark Defined in documents called RFCs (Request For Comments) available on line: 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. (Internet Architecture Board) IAB IRTF IETF 1983 1989 Internet Society ~1991

51 Where to find up-to-date research references
Journals and Magazines: IEEE Network Magazine IEEE Communications Magazine IEEE Wireless Communications Magazine IEEE Pervasive Computing IEEE/ACM Transactions on Networking (TON) IEEE Transactions on Mobile Computing IEEE Journal on Selected Areas of Communications (JSAC) Conferences: MOBICOM, MOBIHOC, PIMRC, MWCN... ICC, ISCC, ICCN GLOBECOM INFOCOM SIGCOMM WWW Web pages of research groups Google…

Download ppt "Redes Inalámbricas – Tema 1 General concepts"

Similar presentations

Ads by Google