Inleiding Telematica6

16 mei 2007

Prof. Dr. R.J. Meijer

Organisatorisch

Sheets asap op site– www.science.uva.nl/~rmeijer

Graag emailadres 0653720517 rmeijer@science.uva.nl

http://gene.science.uva.nl/~bbruin/

College 6, 24 mrt 2005InleidingGeen boek

Application Program Interface (API) Sockets zijn interfaces

naar de TCP/IP protocol stacks op een computer

Applicaties worden “op” sockets gebouwd

Maar vrijwel niemand doet dat nu nog

Men gebruikt – Webservers– Applicatie Servers

die een groot (ste) gemene deel van Server ontwikkeling aanbieden

TCP

IP

HTTP

HTTP

Application

Application

Groningen 5

Traditional Future

Technologies for information exchange

Technologies for the abstraction of individual

computers – aka middleware

Contemporary

Technologies for information exchange

DNA

sequencerDB 3d

Super

computer

Workstation

Technologies to use the facilities of others

Presentation

Session

Transport

Link

Data Link

Physical

Application

OSI

Specifications of protocols between computers and/or

telecommunication systems

Telematics

Middleware

Application

Virtual Computer

computercomputer computer

Technologies for the abstraction of individual

computers – aka middleware

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

XML

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

i

i

i

i

i

Teaspoon Software

Online

internet

Computer Program

i

Proxy of the teaspoon Proxy of the

Aggregation

Proxy of the teaspoons

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

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

Groningen

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

10

SENSORWEB AND SENSOR NETWORKS

What is a sensor?

PopularPopular

ScientistScientist

BusinessBusiness

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

What is a sensor web?

PopularPopular

ScientistScientist

BusinessBusiness

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 Sensor Network Routing

Romit Roy Choudhury and

Pradeep Kyasanur(Some slides are based on Dr. Nitin Vaidya’s tutorial)

CS252/HillLec 8.1

2/14/02

Wireless Sensor Networks

Lecture 8 – CS252

What is a sensor network?

PopularPopular

ScientistScientist

BusinessBusiness

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 Application

Application

Sensor Network Routing

Romit Roy Choudhury and

Pradeep Kyasanur(Some slides are based on Dr. Nitin Vaidya’s tutorial)

A Review of Current Routing Protocols for Ad Hoc Mobile Wireless Networks

Elizabeth M Royer, Chai-Keong Toh

Mobile Ad Hoc Wireless Networks

• Unreliable wireless medium• Mobile nodes• No central authority

• Traffic patterns application specific• Energy constraints

• More information in MANET Charter

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

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

Classification (cont.)

Ad Hoc Routing Protocols

Table driven Source-initiated

on-demand DSDV WRP

AODV DSR TORA ABR

SSR

ReactiveProactive

Hybrid

ZRP

Hybrid

OLSR

CGSR

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

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

DSDV Example

Destination Next Metric Seq. Nr

A A 0 A-550

B B 1 B-102

C B 2 C-588

D B 3 D-312

AB C D

Routing Table of Node A

Route information is exchanged periodically

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

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

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

Source-Initiated On-Demand Routing

• Create routes only when needed

• Routes found using a “route discovery” process

• Route maintenance procedure used to repair routes

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

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

EducationPro environmentgroupsOil company Government

Information publishing

Processing data to create information

Data gathering

Research institutes

Common infrastructure

Groningen

NETWERK EN IT WORDEN OBJECTEN!

WAT NU ALS DE ICT ZELF EEN RESOURCE IS?

30

Nu: Telefonie- en internet infrastructuur: groot complex, statisch. Nu: Telefonie- en internet infrastructuur: groot complex, statisch.

PoP2

IP

PAN

kabelverdeelkast

SANTAN

PoP1

NRCNRC ISP

Internet

NRCNRC

EVKC EVKC

EVKC EVKC

EVKC

ADSLDSLAM 25 EVKC

2000 NRC 30 miljoen klanten 20000 werknemers

32Storage

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

4

3

1

5

2

8

6

10

9

7

11

Supercomputing

Next GNG

mobile fixed

network nodes

- RESEARCH TOPIC

Network

Element

Application

NE

Application

NE

Application

NC

ACNetwork

Element

Application

NE

Application

NE

Application

ACNetwork

Element

Network

Element

AC AC

NC NC NC

Virtualization of a network in UPVN

- 33 -

NE Service

ApplicationComponent

manager

IP Router / Forwarding engine

IngressPacketFilter

EgressPacketFilter

Application Component Collection

ACAC

ACAC

NC

CollectionSupport

AC packet injection AC packet injection

Network elements are PC’s that run a Free BSD operating system

- 34 -

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

UPVN allows the results of decades of computer science to handle the complexities of application specific networking.

04/11/23- 35 -

Virtualized Network Service

Webservices Collection

Network Component Collection

NE NE NE

Network Utility Service

TokenTransactio

n

Uniform

CostSearch

Topology

NC NC NC

Mathematica

Use of Mathematica’s Combinatorica package to interact with real networks

04/11/23- 36 -

Needs["WebServices`"]

<<DiscreteMath`Combinatorica`

<<DiscreteMath`GraphPlot`

Print["The following methods are available from the

NetworkComponent:",InstallService["http://

localhost:3000/network_service/service.wsdl"]];

The following methods are available from the NetworkComponent:

{GetAllLinks,GetAllElements,NetworkTokenTransaction}

Initialisation:

n = GetAllElements[];

e = GetAllLinks[];

nids = Apply[Union,e];

Print["Network elements: ", n];

Print["Number of ports found: ", Length[nids]];

 

Network elements: {bigvirdot,virdot}

 

Number of ports found: 16

NE Discovery:Topology and visualization of the shortest path:

nodePath = ConvertIndicesToNodes[

ShortestPath[ g,

Node2Index[nids,"192.168.3.4"],

Node2Index[nids,"139.63.77.49"]],

nids];

Print["Path: ", nodePath];

If[NetworkTokenTransaction[nodePath, "green"]==True,

Print["Committed"], Print["Transaction failed"]];

 

Path:

{192.168.3.4,192.168.3.1,139.63.77.30,139.63.77.49}

 

Committed

Shortest path, transactions, use of tokens:

demonstratie

Als netwerken objecten worden dan

• Verdwijnt de C uit ICT• Telematica wordt Informatica!