Programme: MComp Computer Networks and Cyber Security and Advanced Computer Science
Module Code: KF7031
Module Title: Wireless Networks and Security
Distributed on: eLP
Submission Time and Date: To be submitted by 23:59 GMT on May 03, 2021
Page Limit: 7 sides plus a facing page that includes the abstract but excluding the appendix and references. This should be printed on A4 paper and use a font size no smaller than 10
Weighting This coursework accounts for 50% of the total mark for this module
Submission of Assessment
Electronic Management of Assessment (EMA): Please note if your assignment is submitted electronically it will be submitted online via Turnitin by the given deadline. You will find a Turnitin link on the module’s eLP site.
It is your responsibility to ensure that your assignment arrives before the submission deadline stated above. See the University policy on late submission of work.
Title: 802.11 WLAN data throughput and security overheads
Instructions on Assessment:
Your work must be presented in the form of a short technical paper and be no longer than 7 sides plus a facing page that includes the abstract but excluding the appendix and references. This should be printed on A4 paper and use a font size no smaller than 10. A mark penalty of -10%/additional page will be applied for submissions longer than required. For completeness you must include a detailed table of results within an appendix (not included in page count). You may if you wish include further additional material in an appendix, but this will not contribute to the marks and you should not explicitly refer to any appendix to illustrate results etc. You could use an appendix to present a full derivation of formula.
You are to perform a study on data throughput in 802.11 WLAN systems. This will be carried out with wireless security protocols in place and removed. The study will be partially theoretical and partially practical requiring you to build a theoretical model describing data throughput and verify this model through practical experimentation.
802.11 standards are often characterised by channel bit rates, for example 802.11b is usually described as supporting a bit rate of 11Mbps. WLAN users will notice that actual data throughput, as perceived by the clients on a WLAN only approaches half of this value and is sometimes even less. Implementing secure communications on the wireless link will reduce apparent throughput further. Users will sometimes put this lower actual bit rate down to underperforming systems, but this is usually not the case. The lower through put rate is primarily due to the MAC and physical layer overheads in the 802.11 architecture and is therefore intentional. Security protocols place additional overhead on communications and further reduce apparent throughput rates. Communication between a wireless client and an access point is governed by a strict set of protocols that introduces fixed delays in the communication channel. Indeed, the delays do not change significantly despite faster underlying channel bit rates.
You are to examine one of 802.11b, 802.11g or 802.11n standards. You can choose which one you prefer to work with, however you must state clearly in your report which standard you are focussing on. Additionally, you must apply one method of secure wireless communications from WEP, WPA1/2 Personal to understand the overhead incurred in your theoretical modelling.
You will need to do some background research to examine how other authors have developed throughput models. The following two papers are a good start:
• XIAO Yang, IEEE 802.11n: Enhancements for higher throughput in wireless LANs. IEEE Wireless Communications , Dec 2005, pg 82-91.
• XIA0 Yang, ROSDAHL Jon, Throughput and Delay Limits of IEEE 802.11. IEEE Communications Letters Vol 6 No 8 Aug 2002.
Here you need to develop a model to allow you to calculate actual data throughput against underlying data rate. You need to plot this data for a number of packet sizes. Additionally, you need to provide the data in tabular form as part of an excel spreadsheet within the Appendix.
Practical work (or Simulation)
You need to perform a number of experiments to measure actual throughput rates for a system using physical experiments or a network simulator of your choice (OMNET++, MATLAB, OPNET or any other suitable simulator). You are required to measure data throughput using an access point supporting the 802.11 mode (b, g or n) you chose to investigate. For practical experiments, throughput can be measured using JPERF and IPERF traffic generation software or the more sophisticated ZTI traffic generator. Wireless traffic (i.e. traffic through the air between the AP and WNIC) needs to be monitored using Omnipeek or AirPCap on a probe WNIC. For the simulation environment, select appropriate configurations and parameters to obtains the throughput results.
Throughput measurements should be taken for the maximum speed available for your chosen standard. You will need to analyse the data collected carefully and compare your observations with the theoretical predictions you have developed.
Additionally, you need to measure throughput with your chosen security mechanism implemented on the wireless link. You should end up with a set of results, one with security on and one with security off, so you can make clear comparisons of your observations.
(This requirement is removed from simulation work because OMNeT++ does not provide the security protocol function.)
Before carrying out any throughput measurements you should assess the channel busyness using a Channelizer Pro spectrum analyser. Chose the quietest channel available for your work. You need to comment in your results and discussion section the impact of interference and other Wi-Fi transmissions on the same channel.
Details of the Paper
Although the following link refers to a social sciences research paper, much of the guidance about structure and style is appropriate for your paper, so you might find it helpful to read this:
http://libguides.usc.edu/writingguide (checked 04/12/20)
Mapping to Programme Goals and Objectives
The following Learning outcomes will be addressed in this assignment:
KU1 – Be able to describe, explain critically and analyse wireless data communication technology along with associated security issues.
KU2 – Be able to analyse and model wireless behaviour using appropriate mathematics
IP1 – Critically analyse enterprise requirements for wireless systems
IP2 – Critically analyse 802.11 protocol information
IP3 – Make critical decisions about designing secure wireless networks
Module Specific Assessment Criteria and Rubric
Section Max mark available Comment
Abstract – max 300 words 5 This is the section that will be read the most so it should be a good representation of the whole of your work.
Introduction 10 This introduces your paper and work that you are presenting. You can outline the structure of your paper here too. You do NOT need to provide a background to 802.11 here – focus on the work you have done and its context.
Theoretical throughput development 10 You are expected to provide theoretical underpinning of your throughput model(s), probably based on papers you have read. You should present some modelled data that can be later compared with measured data. The modelling will probably be in two parts, one exploring the impact of MAC layer overheads and the other the impact of security overheads.
Experimental method 10 You need to describe your experimental procedure in sufficient detail someone else could reproduce what you have done. Use diagrams where appropriate.
Results 10 Described your results and observations from your experimental process
Discussion 30 Discuss your observations here, paying particular attention to what you expect to see from your theoretical discussions and how this compares with your observations. Try to explain any differences. Use your observations to explain the differing contributions that each overhead has to the overall throughput rate. You should additionally comment on the robustness of the link security mechanism and compare it with WEP or WPA (depending which you chose) and WPA Enterprise. Please look at the learning outcomes (above) to help guide your discussion.
Conclusion 5 Conclude your experimental observations here
References 5 Appropriate: Quality, quantity, usage
Data recorded in appendix 5 You need to include your data set in the appendix. A tabular presentation is required here.
Presentation 10 Does your paper content flow logically? Is it written clearly? Is it formatted well? Appropriate usage of diagrams?
Mechanism for Handout to Students:
In class notification and via ELP
Date by which Work, Feedback and Marks will be returned to Students:
On or before 20 working days following the submission date (as per University policy)
You are advised to read the guidance for students regarding assessment policies. They are available online here.
Late submission of work
Where coursework is submitted without approval, after the published hand-in deadline, the following penalties will apply.
For coursework submitted up to 1 working day (24 hours) after the published hand-in deadline without approval, 10% of the total marks available for the assessment (i.e.100%) shall be deducted from the assessment mark.
Coursework submitted more than 1 working day (24 hours) after the published hand-in deadline without approval will be regarded as not having been completed. A mark of zero will be awarded for the assessment and the module will be failed, irrespective of the overall module mark.
These provisions apply to all assessments, including those assessed on a Pass/Fail basis.
Word limits and penalties
If the assignment is within +10% of the stated word/page limit no penalty will apply.
The word/page count is to be declared on the front page of your assignment and the assignment cover sheet. The word count does not include:
Students must retain an electronic copy of this assignment (including ALL appendices) and it must be made available within 24hours of them requesting it be submitted.
The Assessment Regulations for Taught Awards (ARTA) contain the Regulations and procedures applying to cheating, plagiarism and other forms of academic misconduct. Refer to the Academic Misconduct Policy (Available through the link above for Assessment Regulations)
You are reminded that plagiarism, collusion and other forms of academic misconduct as referred to in the Academic Misconduct procedure of the assessment regulations are taken very seriously. Assignments in which evidence of plagiarism or other forms of academic misconduct is found may receive a mark of zero.