Introduction to Network Modelling and Simulation

Course 34330 Introduction to Mobile Communication

Lecture 14

October 15, 2010

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Learning objectives and today’s agenda

• After this lecture, you should be able to:

– Discuss the application of computer simulations in relation to communication networks

• Agenda:

– Computer simulation of communication networks – how and why

– Introduction to the simulation exercise

– Introduction to the individual project

Network modelling and simulation

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What is modeling and simulation?

• The imitation (and not a replication!) of a real-life system or subsystem

– Artificially generates the history of a system

• Based on assumptions a model canbe developed, validated and verified

– Model development is an art!

• Questions about the real-life systemscan now be answered by performingexperiments with the model. This is called simulation.

Valid

ation

System

Conceptual

model

Model

implementation

Verification

Valid

atio

n

implementation

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Benefits of simulation

• Predict the behavior of systems

– That do not yet exist

– That are not available for testing

– That are complex

– That are very large

• Event driven simulation

– Ideal for protocol and behavioral modeling

– Shows protocol interactions and application behavior

• Alternatives

– Analytical model

– Measurements

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Why simulate data services in mobile networks?

• Mobile data services must be considered separately from voice services!

– Increased load degrading level of service

– A suite of very differing services

– Satisfactory service level depends on the service

– Bursty services average load not interesting

– Interactive services sensitive to delays

• Network dimensioning impacts service behavior

– Over provisioning is costly

– Under provisioning is costly

• Simulation makes you test drive data services

– Predict behavior

– Dimension correctly - and add capacity at the right time

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Simulation – operator benefits

• What mobile operators want:

– Improve their business

– Rapid solutions to their current operational issues

– Inputs to their strategic planning (e.g., when to migrate to new technologies)

• How can mobile operators improve business?

– Get more subscribers

– Increase the usage of network data services

– Improve QoSEE (end-to-end Quality of Service)

– Reduce costs

– Deploy capacity at the right time

The CommWyse simulation tool

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CommWyse Simulator: IMNS 3000

• Mobile network simulator

• Detailed models of network elements

– Discrete event protocol models (just like the real protocols)

– End-to-end data flows

• Predicts application and network behaviour for a number of different categories of users

Topology

Configuration

Traffic

Mobile network in a box

Network view

User view

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CommWyse simulation tool

Introduction to the lab!

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Lab topics

• GPRS / EDGE

– Comparing GPRS and EDGE performance

– QoS from a users‟ point of view

• UMTS

– dynamic rate adaptation

• HSDPA

– Basic performance compared to UMTS

– Iub dimensioning

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Practical details

• You already got an account to DTU Fotonik‟s databar in building 343 room 105

• 44 participants but only limited number of software licenses Not possible to have the exercise for all students on the same day

– The regular timeslot on 4 Tuesdays have been reserved, i.e., no lectures in these timeslots

– Please show up for the exercise on the assigned day – there might not be an available computer for you on another Tuesday!

• Lab manual will be available from CampusNet no later than October 22

– Please bring it with you to the exercise

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Practical details (2)

• Documentation of exercise in report

– Deadline: November 26 at 12:00

• Choose „Assignments‟ in CampusNet

• Suggested report structure:

– Introduction, e.g., what is simulation and why is it a good idea to use for mobile communication systems.

– GPRS / EDGE simulation setup, results and discussion

– UMTS simulation setup, results and discussion

– HSDPA simulation setup, results and discussion

– Conclusion

• Remember: Simulation report counts for 10% of final grade

Individual project

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Individual project

• As part of the evaluation requirements, you must do an individual project, which counts for 20% of your final grade

• Project: Theoretical analysis of some technology/system/… related to the topics and scope of this course.

• Possible things to include:

– General description/overview of the chosen technology/system/…

– Comparisons with topics from the textbook/lectures (GSM, GPRS, …)

• Pros and cons

– Typical applications and/or usage scenarios

– …

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Individual project (2)

• See a list of possible project topics at:

http://files.fotonik.dtu.dk/larst/34330_Individual_Project.html

• Own idea for topic: OK (if relevant), but it has to be approved

– Send mail to larst@fotonik.dtu.dk with proposal

• Limited number of students per topic

• Individual project – but it‟s OK to discuss your topic with fellow students

• Document with practical details on CampusNet

• Need help? Just ask us

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Individual project (3)

• Typical workflow:

– Selection of a topic

– Gathering relevant material (papers, standards, white-papers, etc.)

– Getting familiar with the material

– Narrowing the scope and making an outline

– Writing the report

• Size of report: Ideally 8 – 12 normalpages

– 1 normalpage ≈ 2400 characters (letters, digits, spaces, …)

• Hand-in of report through CampusNet

– Deadline is December 3 at 15:00 – Absolutely no extension to the deadline will be granted, since we have to read your report before the oral exam

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Concerning plagiarism

• DTU does not tolerate plagiarism!

– Plagiarism: ”… is the unauthorized use or close imitation of the language and thoughts of another author and the representation of them as one's own original work.” Source: Wikipedia

• ”Patchwork” writing (Changing “… system that is …” to “… system, which is …”) is also considered as plagiarism!

• (Suspicion of) plagiarism will be reported. Possible consequences of plagiarism:

– Written warning

– Nullifying the points of this course or even entire semester(s)

– Expulsion

• When you hand-in your report through CampusNet, it will automaticallybe checked by Urkund!

There are absolutely no acceptable excuses for plagiarism, regardless of your prior experience, background, etc.

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References

• Source material must be properly referenced:

– Main text: ”… the thingamajig converter [16] is used to increase …”

– References section: [16] J. Doe, ”A thingamajig converter for mobile phones”, Journal of Fascinating Technical Gadgets and Gizmos, Vol. 32, no. 4, 2005

– See the project information document for more examples on how to reference source material

• Quotations: OK to include a limited number

– Usually no more than 2-3 sentences per quotation

– Must be properly indicated (e.g. italics and quotation signs) and referenced

– Only include quotations when it‟s (very) relevant

Summary

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Summary and next time(s)

• Computer simulation and modelling of mobile communication networks

• Simulation exercise

– Deadline for the report: Nov. 26 at 12:00

• Individual project

– Deadline for the report: Dec. 3 at 15:00

Please notethat the

deadlinesare different!