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Inleiding Telematica 6 16 mei 2007 Prof. Dr. R.J. Meijer.

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Presentation on theme: "Inleiding Telematica 6 16 mei 2007 Prof. Dr. R.J. Meijer."— Presentation transcript:

1 Inleiding Telematica 6 16 mei 2007 Prof. Dr. R.J. Meijer

2 Organisatorisch l Sheets asap op site –www.science.uva.nl/~rmeijerwww.science.uva.nl/~rmeijer l Graag adres l l l

3 College 6, 24 mrt 2005 Inleiding Geen boek

4 Application Program Interface (API) l Sockets zijn interfaces naar de TCP/IP protocol stacks op een computer l Applicaties worden “op” sockets gebouwd l Maar vrijwel niemand doet dat nu nog l Men gebruikt –Webservers –Applicatie Servers l die een groot (ste) gemene deel van Server ontwikkeling aanbieden TCP IP HTTP Application

5 Groningen 5 TraditionalFuture n Technologies for information exchange n Technologies for the abstraction of individual computers – aka middleware Contemporary n Technologies for information exchange DNA sequencer DB3d Super computer Workstation n Technologies to use the facilities of others Presentation Session Transport Link Data Link Physical Application OSI n Specifications of protocols between computers and/or telecommunication systems Telematics Middleware Application Virtual Computer computer n Technologies for the abstraction of individual computers – aka middleware

6 Groningen 6 Webservices (from Webservice essentials, E.Cerami) Web service Any service available over the Internet That uses a standardized XML messaging system Alternatives XML RPC (remote procedure call) SOAP HTTP Post/Get XML

7 Groningen 7 Aggregation of Teaspoon proxies Web and Grid services are designed to provide on-line services Service oriented architecture Implicit object oriented, component oriented virtualization concept iiiii Teaspoon Software Online internet Computer Program i Proxy of the teaspoon Proxy of the Aggregation Proxy of the teaspoons

8 Groningen 8 Object oriented virtualization … i wireless link computer and sensors i i i i i Teaspoon Software Online internet Step 1: Think and link the things Build in a computer Give that computer control Link the computers (via the Internet) Step 2: Create virtual “agent” for a group of things That offers easy, controlled, service, to many “customers” via the internet “the service of an online resource” Forget about the individual things

9 Groningen 9 … where in the third step the interaction between the resources is coordinated through software, via the internet Caffeine advisor Human caffeine model Billing Software Teaspoon Software Online Telephone Company Step 3: Service integration and creation Software integrates the services and interactions of various resources into a new service

10 Groningen Sensoren (en actuatoren) zullen overal aanwezig zijn. Op dit moment staan vooral de zelforganiserende draadloze (uitstrooibare) senornetwerken in de belangstelling 10

11 SENSORWEB AND SENSOR NETWORKS

12 What is a sensor? Popular Scientist Business A small but very intelligent device that can measure something important Intriguing telecommunication and computing devices that can solve many problems Cheap things for mass market

13 What is a sensor web? Popular Scientist Business A group/swarm of small but very intelligent wireless devices that can measure something important and communicate adhoc with each other and with the sink that connects to the internet xxxxx= buzz word Intriguing telecommunication and computing devices that can solve many problems Cheap things for mass market

14 What is a sensor network? Popular Scientist Business A network and very many sensor webs and several applications at several institutions Intriguing telecommunication and computing devices that can solve many problems Intelligent infrastructures Network/Internet Application

15 Sensor Network Routing Romit Roy Choudhury and Pradeep Kyasanur (Some slides are based on Dr. Nitin Vaidya’s tutorial)

16 A Review of Current Routing Protocols for Ad Hoc Mobile Wireless Networks Elizabeth M Royer, Chai-Keong Toh

17 Mobile Ad Hoc Wireless Networks Unreliable wireless medium Mobile nodes No central authority Traffic patterns application specific Energy constraints More information in MANET Charter

18 Example Ad Hoc Network B A E F H C G I D Nodes have unique identifiers Routing problem – find path between S and D S

19 Classification of routing protocols Table-driven (proactive) – Up-to-date routing information maintained – Routing overhead independent of route usage Source-initiated (demand-driven / reactive) – Routes maintained only for routes in use – Explicit route discovery mechanism Hybrid Protocols – Combination of proactive and reactive

20 Classification (cont.) Ad Hoc Routing Protocols Table driven Source-initiated on-demand DSDV WRP AODV DSR TORAABR SSR Reactive Proactive Hybrid ZRP Hybrid OLSR CGSR

21 Table-driven Routing Protocols Each node maintains a routing table – Contains routes to all nodes in the network Changes to network topology is immediately propagated Protocols differ in mechanisms used to propagate topology information

22 Destination Sequenced Distance Vector (DSDV) Based on Bellman-Ford algorithm Enhanced with sequence number to avoid loops – Fresher routes have higher sequence numbers Optimizations added to reduce routing overheads – incremental data exchange, delayed exchange of updates

23 DSDV Example DestinationNextMetricSeq. Nr AA0A-550 BB1B-102 CB2C-588 DB3D-312 A B C D Routing Table of Node A Route information is exchanged periodically

24 Clusterhead Gateway Switch Routing (CGSR) Nodes organized into hierarchy of clusters. Each node has a clusterhead, selected using an election. Nodes send packet through clusterheads. Clusterheads communicate amongst themselves using DSDV. – Two clusters are connected through a gateway node

25 Wireless Routing Protocol (WRP) Maintains multiple tables – Distance, routing, link-cost, etc. Link change messages exchanged only between neighbors Loop freedom using novel algorithm – Uses predecessor hop information

26 Other Table-Driven Protocols Optimized Link State Routing Protocol (OLSR) – RFC 3626 – Optimization of link-state routing to wireless Topology Dissemination Based on Reverse Path Forwarding (TBRPF) - RFC 3684 – Also based on link-state routing

27 Source-Initiated On-Demand Routing Create routes only when needed Routes found using a “route discovery” process Route maintenance procedure used to repair routes

28 Ad Hoc On-Demand Distance Vector Routing (AODV) Now RFC 3561, based on DSDV Destination sequence numbers provide loop freedom Source sends Route Request Packet (RREQ) when a route has to be found Route Reply Packet (RREP) is sent back by destination Route Error messages update routes

29 Robert Meijer, TNO ICT Groningen 4G sensornetwork support telecom infrastructure 29 Shared Resources. It is good practice that sensor networks serve many applications at several institutions. Technical: this enables changes, exploitation: this shares costs Education Pro environment groups Oil company Government Information publishing Processing data to create information Data gathering Research institutes Common infrastructure

30 Groningen NETWERK EN IT WORDEN OBJECTEN! WAT NU ALS DE ICT ZELF EEN RESOURCE IS? 30

31 Nu: Telefonie- en internet infrastructuur: groot complex, statisch. PoP2 IP PAN kabelverdeelkast SAN TAN PoP1 NRC ISP Internet NRC EVKC ADSL DSLAM l 25 EVKC l 2000 NRC l 30 miljoen klanten l werknemers

32 32 Storage Sensor networks will be large and complex too, but are dynamic. E.g. with disasters parts of the networks are destroyed and a immediate addaptation is required Supercomputing Next GNG mobile fixed network nodes - RESEARCH TOPIC

33 Network Element Application NE Application NE Application NC AC Network Element Application NE Application NE Application AC Network Element Network Element AC NC Virtualization of a network in UPVN

34 NE Service Application Component manager IP Router / Forwarding engine Ingress Packet Filter Egress Packet Filter Application Component Collection AC NC Collection Support AC packet injection Network elements are PC’s that run a Free BSD operating system  NE’s expose webservice interfaces  AC’s are SCPed on NE  AC’s communicate with application via a message passing mechanism through NE webservice interface

35 UPVN allows the results of decades of computer science to handle the complexities of application specific networking. 7/26/ Virtualized Network Service Webservices Collection Network Component Collection NE Network Utility Service Token Transaction Uniform Cost Search Topology NC Mathematica

36 Use of Mathematica’s Combinatorica package to interact with real networks 7/26/ Needs["WebServices`"] <

37 demonstratie

38 Als netwerken objecten worden dan Verdwijnt de C uit ICT Telematica wordt Informatica!


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