introduction - etsn01 advanced...

IntroductionETSN01 Advanced Telecommunications

Emma Fitzgerald2015

Expected outcomes Pre-requisites Course structure Teaching team Assessment General points Socrative A concrete example

Course administration and overview

Expected outcomes

Pre-requisites

Course structure

Teaching team

Assessment

General points

Socrative

A concrete example

Lund University Slide 2 of 18


Components

Two main parts

• Performance models / mechanisms in-depth• Stochastic nature of networks• Queuing theory, Markovian processes, simulations• Understanding the need to analyse and dimensioning

• Systems building• Centrally designed architectures

• Routing and switching functions• Server functions

• Distributed architectures (unplanned)• Medium access control in unlicensed spectrum (WiFi)• Ad hoc and Mesh



Expected outcomes

• In-depth understanding of the design choices in commonnetwork design, where some of the most common standardscome from

• Ability to analyse simple networked systems (nicedistributions) and dimension components such as buffers andlinks

• Ability to implement discrete event simulators and carry outexperiments scientifically (understanding of errors, limitations,etc.)

• Knowledge about most common systems constructs, thetelecom and datacom system models and commonimplementations

• Awareness of current issues and future directions of networkconstructs

The focus is largely on wireless technologies from the systemsperspective



Pre-requisites

In order to be successful in this course, the following skills areassumed:

• Basic course on network protocols and IP systems (must)

• Basic course in statistics / stochastic processes

• Programming (not required but helpful)


Course content and structure

Week Lecture Material Lab1 Introduction, probability review,

simulationCompendium chapters 1 and 2 No lab

2 MAC 1: Reservation schemes,queueing theory

Compendium chapter 3 Lab 1: TDMA

3 Queueing networks, MAC 2:Random access

Compendium chapters 3 and 4,Manitpornsut et al. (2009)

Lab 1: TDMA

4 Modelling, network constructs Kleinrock and Tobagi (1975),Bianchi (2001), Ruhrup (2009),Gupta and Kumar (2000)

Lab 2: CSMA

5 Congestion control and TCP,quality of service

Compendium chapters 5 and6, Floyd and Jacobson (1993),Karn and Partridge (1987), Ja-cobson (1995), RFC 6298, RFC1633, RFC 2475

Lab 2: CSMA

6 Quality of service (cont.), cellu-lar networks

Compendium chapters 6 and 7,RFC 1633, RFC 3031

Lab 3: Queueing disciplines

7 Guest lecture, review Lab 3: Queueing disciplines


Literature

Recommended books (not compulsory for the course!)

• Mobile CommunicationsJochen Schiller, Addisson Wesley,ISBN 0-321-12381-6

• High Speed Networks and Internets: Performance and Qualityof ServiceWilliam Stallings, Prentice HallISBN 0-130-32221-0

• Queueing Systems Volume 1: TheoryLeonard Kleinrock, Wiley InterscienceISBN 978-0-471-49110-1



Teaching team

• Course co-ordinator, lecturerEmma [email protected]:3128 / MAPCI

• TutorAntonio [email protected]:3124b / MAPCI

• ExaminerBjorn [email protected]:3145 / MAPCI

MAPCI: Mobilvagen 10, level 2



Assessment

• Check how well you follow and are able to understand thetutorials and labs

• Take home assignment (literature review, theory, simulationtasks) (2.5 cp)

• Final exam (5 cp)



General points

How to succeed

• Start early, a lost week is hard to make up for

• Get on top of your simulation skills

• As in all large scale systems courses, the material maysometimes seem simple but relationships are sometimes nestedand very complex, dont be fooled!

• The course requires self-study: study the compendium, theextra material and the notes, not just the notes.

• All submitted code and text will be tested for plagiarism.Academic dishonesty is not an option.



Socrative

• In this course we will use Socrative, an interactive learning tool

• When you see this symbol it means there is an activity todo on Socrative

• Go to socrative.com, click on ”Student login” and enter”ETSN01” as the room name

• There will also be an exit quiz at the end of each lecture tocheck what you have learned and how the course is going

• Socrative questions are not part of the assessment: they areonly there to help both you and me!



Socrative Example

Which do you like best?

A Kanelbulle

B Semla

C Wienerbrod

D Lussekatt

E Vaniljbulle



Network Performance Modelling

the art of analysing and understanding your network behaviour



Illustrative example problem

TCP is the most common transport protocol in use

• Designed with many mechanisms to achieve reliability, flowcontrol, congestion control etc.

• Side effects present in any protocol design, in this case:• Bandwidth is round trip time (RTT) and loss constrained

Lets look at it!



TCP bandwidth limitation

• Postulate

BWmax =MSS × C

RTT ×√pC =

√3

2

BW: bandwidth, MSS: maximum segment size, RTT: roundtrip time, p: packet loss probability

• Assume best conditions• No buffer limitation• Only occasional packet loss, probability p• Constant RTT• Link delivers 1/p consecutive packets• Window opens 1/window segments per ack (RTT)


Graphical representation


Why is this a problem?

• Long end-to-end path, maximum segment size (MSS) likely tobe fixed

• We need to control delay and packet loss to help TCP

• Many TCP connections share resources end-to-end

What is causing delay and packet loss? How do we control delayand packet loss? How do we engineer networked systems to meetdemands?



• In the course we will look at• Static dimensioning

• Analytically — queuing theory• Experimentally — simulations

• Dynamic methods• Congestion control protocols (TCP is one example)• Per router congestion control

• Important point: Networks behave stochastically

• Start with Simulation, followed by queuing theory


introduction - etsn01 advanced...

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