SATNAC 2008 Conference Papers
Work in Progress
Authors: Richard
Barnett (
Abstract: Network
Intrusion Detection is, in a modern network, a useful tool to detect a wide
variety of malicious traffic. The ever present prevalence of scanning activity
on the Internet is fair justification to warrant scan detection as a component
of network intrusion detection. Whilst current systems are able to perform
scan-detection, the methods they use are often flawed and exhibit an inability
to detect scans in an efficient and scalable manner. Existing research by van Riel and Irwin has
illustrated a number of flaws present in the open source systems Snort and Bro.
This paper builds on this by describing current research at
Title: A Probabilistic
Prediction of Packets on a Diversified IP Network
Authors: Christiaan
Brand (
Abstract: As
more households are given broadband access to the Internet, a huge strain is
placed on the underlying IP infrastructure. By being able to predict the packet
types that nodes will send, preference can be given to high priority, latency
sensitive traffic. Various models characterizing packet flow on a network will
be developed and used to predict the packet types to be expected in the
immediate future, as accurately as possible. This will later be used as a
dynamic QoS criteria for assigning bandwidth to specific hosts.
Title: Power Variation and Polarization State
Evolution in a Two Channel WDM System
Authors: Jesman Changundega (
Abstract: We present experimental results that
demonstrate the impact of varying the optical power on the relative angle of
the Stokes vectors in a two channel wavelength division multiplexing
system. The relative orientation of the
output Stokes vectors shows increased evolution with channel power increase as
expected. This rotation has a magnitude that is additionally influenced by the
initial individual and relative orientation of the Stokes vectors.
Title: A Comparison of the Performance and Security of
Free and Open Source Smart Card Offcard APIs
Authors: Albert
Chifura (University of
Abstract: The
increase in internet connectivity has created new avenues for smart cards to be
used as identity tokens in distributed on-line web-services. To make
thispossible, one must be able to read the card and communicate with it using
an application. Off card APIs provide a framework for this by providing
interfaces that can be implemented to enhance the communication. This study
looks at the performance and security comparisons of several free and open
source smart card offcard APIs that are currently in existence.
Title: Optimal Segment Length for Telecommand Data
Link Layer Protocol
Authors: Christian Christelis (
Abstract: The
increase This paper concerns itself with an investigation of optimising data
throughput in space communications using the Telecommand data link layer
protocol. The optimisation problem is seen from the perspective of the data
link layer with payload being supplied by the next higher layer and the unit of
measure used is effective data throughput defined as total payload received
over total data transmitted. The optimisation is done by an on the fly segment
length determination mechanism. The length is determined by the current FER
which is estimated from the frame error history. Initial simulations have shown
that effective data throughput may be vastly improved when using variable
segment length as oppose to fixed segment lengths.
Title: Video on Demand Service for Next Generation
Networks
Authors: Lesang
Dikgole (
Abstract: This paper
discusses the deployment of a Video on Demand (VoD) service for a Next
Generation Network (NGN). VoD is proposed as an effective service thatwill not
only keep Telcos as active players in the telecommunications industry but also
allow them to be instrumental in leveraging television over IP (IPTV) with
satellite television (TV). The paper
discusses various challenges facing the deployment of VoD. Standardization
efforts and future work will be discussed.
Title: Network-Layer Reservation TDM for 802.11
Wireless Mesh Networks
Authors: Kevin
Duff (
Abstract: Wireless
mesh networks (WMNs) are commonly built using 802.11 devices, but the CSMA/CA
MAC in existing 802.11 standards is unsuitable for mesh networking. By performing TDM at the network layer (above
the existing MAC), some of the problems associated with CSMA/CA in mesh
networks can be remedied. This
unconventional approach introduces some new challenges, which are discussed in
this paper.
Title: Testbed Evaluation of QoS Routing Enhancements
for Mobile Ad Hoc Networks
Authors: Melvin
Ferreira (
Abstract:
Title: Developing User Interfaces for Managing Bio-diversity and Human Resource Data in Nature Conservation
Authors: Dominic
Gruijters (
Abstract: CyberTracker
was a successfully implemented ICT4D project implemented in 1996. Current
research is assessing the effectiveness and sustainability of the project to
date. In addition this project aims to assess the effectiveness of a
participatory methodology for designing and implementing user interfaces for
querying data used in nature conservation. Participatory action research
combined with UCD methodologies were utilized to assess current design issues
and develop alternative designs for the user interface. Designs were then
compared in order to ascertain if there is any advantage to using UCD
approaches in the developing world context. The analysis phase of the research
has shown that lack of telecommunications infrastructure hinders the adoption
of technologies for remote users. Computer literacy and user motivation played
major roles in individual adoption and enthusiasm towards technologies. Changes
in software versions proved problematic when users were not consulted in the
upgrade and versioning process. This work in progress discusses technical
issues and reflections on the design methodologies.
Title: Adaptive Interfaces for Mobile Preference-Based
Searching
Authors: Ryan Hill (
Abstract: Advanced
mobile computing devices are becoming more powerful and available to the public
at affordable prices. These mobile devices are ideal for searching for and
identifying points-of-interest (POIs) Graphical User Interfaces (GUIs) are
becoming increasingly complex as applications continue to add more features and
advanced functionality. Adaptive interfaces have been proposed to address this
issue. The objectives of this paper are to identify potential benefits of
adaptive interfaces and investigate how they can be used to support mobile
preference-based searching.
Title: A Simplified Approach to Application Layer
Service Signalling
Authors: Doron
Horwitz (
Abstract: Current
approaches to service provisioning require that signalling travels between
terminals and the network using call/session signalling through the core
network. This work-in-progress paper discusses future research on simplified,
generic application layer signalling, where terminals communicate directly with
applications in the network, minimizing the message passing required to invoke
and exchange information with a service. This requires the consolidation of
various approaches which use the Parlay interfaces to relocate service
signalling from the call layer into the service layer.
Title: A Comparison of Open
Source Object Oriented Database Products
Authors: Peter
Khayundi (University of
Abstract: Object
oriented databases have been gaining popularity over the years. The reliance on
relational database management systems for data needs has come under threat
from object oriented databases. The ease of use and the advantages that are
offered by object oriented databases over relational databases has made them a
popular choice amongst database administrators. Though object oriented
databases may not, in the long term, replace the more traditional relational
databases, it is hoped that improvements in operations and workings of object
databases will improve their reliability and ability to handle everyday data
needs. This study compares some open source object oriented database products available.
Various standard operations are carried out on each product and the time taken
to complete each operation is calculated.
The results would be of value to practitioners of electronic commerce
who are considering the use of object oriented databases. Keywords : Object
oriented databases, open source.
Title: A Software Agent for Detecting and Correcting Speech Recognition Errors Using a Knowledge Base
Authors: Luis Lopes (
Abstract: Common
speech recognizers based mainly on statistical methods, can produce recognition
errors that result in sentences containing grammar or logical errors. We describe
a software agent that processes the output of a speech recognition engine and
detects syntactic or semantic errors. It also attempts to correct the
recognition error, when the correct word is obvious in the context of the
output sentence, using the information in a common sense knowledge base.
Title: Transmit Antenna Selection in Fading Mobile Telecommunication Systems
Authors: Mzabalazo
Lupupa (
Abstract: The
use of multiple transmitting and receiving antennas in mobile wireless
communication systems plays a great role in improving system performance. But
an increase in the number of antennas used results in an increase in the system
complexity. In this proposal the performance of a mobile wireless communication
system with transmit antenna selection is studied. Antenna selection is applied
so as to reduce the system complexity but still achieving the required goal of
improved system performance. Maximum-ratio combining (MRC) is used at the
receiver end. In this, a single transmit antenna which maximizes the
signal-to-noise ratio (SNR) at the receiver is selected. The number of receiving
antennas will be restricted to two due to the size and power limitations of
hand-held mobile devices. Since much research has been done on system
performance under Rayleigh fading channel, this study will be focusing on
Weibull fading channel. Space-time block (STB) codes will be used due to their
simplicity. Performance parameters that will be studied are the bit-error-rate
(BER), channel capacity and pairwise-error-probability (PEP). The performance
comparison between a full complexity multiple-input multiple-output (MIMO)
system and a transmit antenna selective MIMO system will then be presented.
Title: An Ontology-based Telephony Service for the
Provision of HIV/AIDS Information
Authors: Mathe
Maema (
Abstract: Convergence
of telephony with computer networks has made creation of new and innovative services
an imperative for gaining a competitive edge within the communications
industry. Hence, there has been a substantial effort in ensuring that created
services are deployed in a timely and cost-effective manner. In this paper, we
present work in progess exploring the use of ontologies in adding value to the
process of service creation. The intention is to create a knowledge-oriented
telephony service on iLanga, a converged platform developed at
Title: Developing a Help-Desk System for a
Multi-Purpose ICT Platform in a Marginalised Setting
Authors: Farai
Makombe (University of
Abstract: Attempts
to bridge the digital have led to the deployment of ICT platforms in remote
marginalized rural areas. However, with the increase in the distributionof
information technology platforms, the requirement for end user support within
the rural ICT platform infrastructure has increased. In order to provide
essential, effective and continuous support to such rural environments, which
have few or non existent ICT skilled people, an intelligent help-desk system
need to be developed, implemented and tested. This paper describes conceptual
design of Case Based reasoning methods to develop an intelligent help desk
support system for a geographically distributed multi purpose ICT centre in
Dwesa, a rural remote area in the
Title: Multimedia Session Continuity in the IMS: Investigation and Testbed
Implementation
Authors: Keoikantse
Marungwana (
Abstract: Multimedia
Session Continuity (MMSC) in the IMS provides the ability to maintain
continuity of multimedia sessions during terminal mobility events, and
facilitates session transfer across user terminals. The transfer of a
multimedia IMS session between devices is complicated by the various ways in
which it can be achieved. These include a full transfer of both media and
signaling, full media transfer without transfer of signaling, partial media
transfer in which only one of the media components is transferred to a
different device, e.g. video only transfer. This research aims to investigate,
in a practical IMS testbed implementation, the challenges presented by
multimedia session continuity as a service in the IMS.
Title: The Use of Systems Development Methodologies in the Telecommunication
Industry
Authors: Bruce Mazengera (
Abstract: The
telecommunication industry is widely known as a highly competitive industry,
which also has many challenges to face. In light of these challenges, companies
are charged with the task of continuously adapting to the ever-changing nature
of the industry. It is for this reason that companies operating in the
telecommunication industry strive to identify new and more efficient ways of
realizing an objective in a shorter time period. Therefore this research aims
to identify the systems development methodologies used in the telecommunication
industry, and ascertain whether or not the methodology – or collection thereof
– can be adapted to be more agile, and hence address the issue of quick
but efficient systems development.
Title: Application of Business Intelligence in South African Subsidised Bus
Companies
Authors: Makatleho
Mosebi (University of the
Abstract: The
focus of this research is first of all to determine the extent that business
intelligence (BI) is applied in South African government-subsidised bus
companies. This will be done through a questionnaire survey conducted on a
sample of the bus companies. The current perceptions that bus companies have
towards BI will also be determined through this survey. A second focus of the
research is to determine the feasibility of applying BI principles in a bus
company for the first time. For this purpose a bus company will be selected and
a prototype data warehouse (data mart) will be implemented for the company. A
usability test will be conducted in order to determine how effective and
efficient the data mart can be applied. Based on the analysis of the outcome of
this usability test, it will be possible to determine the value that BI can add
to governmentsubsidised bus ompanies in the country.
Title: Development of Sustainable Mobile Service Contents for a Wireless
Village
Authors: Handsome
Mpofu (University of
Abstract: The
use of
Title: An Analysis Framework for Simulated Video Streaming Networks
Authors: Patrick
Mulumba (
Abstract: Distributed
media streaming has been driven by the combination of improved media
compression techniques and an increase in the availability of bandwidth. This
increase has lead to the development of various streaming frameworks, which
currently provide the majority of the streaming media available throughout the
Internet. This study seeks to analyse a range of existing commercial and
open-source streaming media distribution engines, and will attempt to classify
them in such a way as to define a Common Analysis Framework. The common
framework will be used as the basis for a simulation tool intended to predict
the performance impacts of network configuration changes,new features, and
general scaling. The intention is to validate the theoretical simulation tool
against empirical evidence collected from configuration and engineering
extensions to existing systems. The research will be undertaken using an
experimental Computer Science approach, in which a system is developed or
extended from a hypothesis of possible performance improvements. These
improvements are evaluated for performance and functional viability, before
making successive design changes or extensions based upon the outcome of the
previous iterative design and evaluation steps.
Title: A Mobility Management Framework for the IP Multimedia Subsystem
Authors: Tapfuma
Mvere (
Abstract: Mobility
is a key area of Next Generation Networks. Industry has also seen a
proliferation of multimodal mobile devices capable of handling computationally
intensive multimedia. Given this trend, coupled with the availability of
numerous access technologies it is desirable to allow seamless mid-session
mobility between these access networks. With the IP Multimedia Subsystem (IMS)
touted as the architecture to deliver IP multimedia, we investigate and seek to
implement the current Voice Call Continuity (VCC) specification that will bring
mobility to the IMS platform.
Authors: Zenzo Ncube (
Abstract: A lot of research has been done to
analyse the relationships between telecommunication technology proliferation
and other social, economic and telecommunication indicators such as Gross
Domestic Product per Capita (GDPC), Financial Freedom,
etc. According to some researchers, there is a need to carry out a reassessment
of the connection between telecommunications, economic growth and other
factors. In our research we are empirically investigating the factors affecting
telecommunication technology proliferation using international comparisons. The
methodology that is employed to make these comparisons is Linear Response
Surface Analysis (LRSA) based on multiple regression analyses Some of the relationships
investigated are aimed at empirically testing the perception that mobile phone
technology can help developing countries to overcome the lack of fixed line
infrastructure (Substitution effect). A dimension that is also explored in this
work concerns the overall ability of a country to access and use new ICT
methodologies. The index that measures this (DAI), launched in 2003 by the
Market, Economics and Finance Unit of the ITU, is considered as a response
variable and factors influencing this DAI in 160 countries are investigated.
Title: An Intelligent Wireless Forensic Model (IWFM) for Moving Devices between
Wireless Networks
Authors: Sipho
Ngobeni (Meraka Institute), Hein Venter (
Abstract: There
are currently many different types of wireless crime investigation tools
designed for different purposes in order to track down intruders of wireless
crime, like Intrusion Detection Systems (IDSs), Wlan-Jack, HotSpotter, Monkey
Jack, TULP 2G, MOBILedit! Forensic, and Cell Seizure [1, 2]. These tools were
designed for different purposes, but their main objective was to minimize
wireless crime, however these tools have their own challenges. The main
challenge about these tools is that they were not designed for digital forensic
purposes and none of them indicate the movement of devices between wireless
networks during digital forensic investigations therefore the acquired electronic
evidence by these tools can not be used in a court of law for prosecution of
the wireless perpetrators. The essence of this study is to develop an
Intelligent Wireless Forensic Model (IWFM) for acquiring data for forensic
purposes in the event that a device has moved from one wireless network to
another.
Authors: Rehoboam Radzokota (
Abstract: In
this article we discuss the effect of ill conditioning on a spatially multiplexed
channel in a MIMO OFDM system. It is shown that the ill conditioned spatially
multiplexed channels degrade the performance of detectors. The two detectors
considered in this paper are zero forcing (ZF) and minimum mean square error
(MMSE) detector. The performance is
measured by the symbol error rate (SER) performance.I.Ill conditioning
can be brought by fading correlation and rice component this makes decoding difficult.
Authors: Memory
Ranga (University of
Abstract: In
this paper we discuss robustness and effectiveness issues in wireless
telecommunication networks, particularly rural networks, with the view of
planning work to increase the availability of the wireless network deployed in
the rural community of
Authors: Mfundo
Scott (University of
Abstract: In
developing nations and governments the judiciary system is catching up with
societal and technological evolution as a component of building a knowledge
society, so the need for an e-Judiciary system is of great importance. The
benefits of Information and Communication Technology (ICT) are numerous and
almost all segments of human activity benefit from it. This paper describes an
e-Judiciary platform for a marginalized rural community. It presents the
preliminary stage of the development of a robust e-Judiciary software
framework. This platform is for the Dwesa – Cwebe, a rural community in
the Eastern Cape Province of South Africa.
Title: Intelligent User
Interface in a Service Oriented Architecture Environment
Authors: Emile Senga (
Abstract: Many
enterprises seeking to open their legacy systems and share information are
turning to service oriented architectures for their applications. The promise
of flexibility, loose coupling of components and reusability are driving this
change. User interfaces designed for use in SOA systems are lacking in their
presentation of information to users in an efficient and effective manner. This
paper proposes an approach that would allow interfaces to be composed as
services as well as make use of intelligence providing services to infer how
best to present their information to users in the user interface.
Title: Comparative Analysis of Media Pipeline Plug-in Architectures
Authors: Veronica Sentongo (Council for Scientific and Industrial
Research), Anthony Chan (
Abstract: The
future of Next Generation Networks relies heavily on the effective operation of
real-time applications. Media pipeline plug-in architectures have been
introduced to provide the efficiency and improvements that these wireless applications
require. The pipeline architectures exist for the efficient capture and
processing of multimedia streams into a format suitable for transmission in the
context of real-time processing. Numerous media pipeline plug-in architectures
exist for streaming audio and video applications. However, this research paper
is a comparative analysis of only three of these architectures: GStreamer,
Microsoft DirectShow and RealNetworks Helix. The project investigates the
feasibility of implementing these architectures in
Title: An Open Service Delivery Platform for Adding Value to Softswitch-Based
Telephony Environments
Authors: Mosiuoa Tsietsi (
Abstract: Softswitches
have played a crucial role in next generation networks (NGNs) not only as the
primary agents responsible for controlling the data and media paths between
endpoints, but also as hosts of telephony applications such as billing and
legal intercept. Even though very useful and flexible application interfaces
have been used to program these softswitches, there is much benefit that can be derived from decoupling the
application layer from the switching core. NGN architectures such as the IP
Multimedia Subsystem (IMS) have borrowed the concept of an application server
from the IT domain in order to deliver enhanced services to the network. This paper
describes an initial investigation into the development of a service delivery
platform (SDP) based on the JAIN Service Logic and Execution Environment
(JSLEE) industry standard, to provide advanced services that can be deployed
over a telephony environment called iLanga, which is based on the open source
software PBX named Asterisk.
Title: Determination of Network Delays for Networked
Control Systems using Network Calculus
Authors: Frans-Willem
Vermaak (
Abstract: This
paper presents work in progress for research on Networked Control Systems
(NCS). NCS occur when a data network is included in the control loop of a
control system. The prominent effect of including a network in a control loop
is the network delay that is added to the loop. Various methodologies have been
developed to attempt dealing with this added delay. In this report network
calculus is investigated and considered as a possibility to determine bounds on
such network delays. Network calculus is a suitable method to determine network
delays in certain networks and some of the fundamentals of network calculus are
covered in the report.
Title: Magnetic Inductive Power Transfer for Wireless Sensor Networks
Authors: Nico Vorster (
Abstract: This
paper discusses the use of magnetic inductive techniques to recharge wireless
sensor nodes. An overview of the
existing literature on magnetic inductive coupling between coils is given. The coupling coefficient of a non-resonant
solenoidal coil link is determined, and it is shown that non-resonant coupling
is not a viable option. A hybrid type
coil is presented, and it is shown that the hybrid coil's coupling coefficient
for similar parameters is higher than that of a solenoidal coil.
Title: Using Decoys to Prevent Attacks on IPTV Systems in the IP Multimedia
Subsystem
Authors: Phillippa
Wilson (
Abstract: Multimedia
web servers are vulnerable to attack due to their large storage capabilities.
The IP Multimedia Subsystem (IMS) is also vulnerable due to its high-speed
links. Furthermore, it is difficult to detect malicious traffic in such
networks. As a result, IMS-based IPTV systems are targets. Currently, there are
no standardised security techniques to secure IPTV web servers. This
Work-in-Progress paper discusses the current techniques used to secure
web-based systems and networks, such as intrusion detection systems (IDS),
firewalls and decoys. The framework proposed in this paper uses the honeynet to
detect malicious traffic and secure IPTV systems.
Title: Wireless Sensor Networks in Power Supply Grids
Authors: Venita
Wolmarans (
Abstract: The
integration of wireless sensor networks into power distribution grids creates
the potential to efficiently regulate and manage energy resources. The
automation of electric systems is an important function for electricity supply
companies and reduces operating cost and increases efficiency. The applications
created by wireless sensor networks are wide-ranging and beneficial for both
utility companies and power consumers. There are many issues that have to be
dealt with concerning the integration of wireless sensor networks into the
power distribution grid and these issues have to be addressed in an
application-specific manner.
Title: Kiara: An Open Source SIP System to Support
Deaf Telephony
Authors: Long Yi (
Abstract: This
paper describes Kiara, an open source SIP-based communication system that
provides the building blocks to enable Deaf relay services. We have implemented
a prototype that provides real-time text, voice and video to a variety of end
user devices over a variety of networks. The work-in-progress concerns the
addition of relay services for the Deaf.
Authors: Tapiwa Zvenyika (
Abstract: This
research paper focuses on the progress in the construction of a finite grammar
for enhancing the language model for the Northern Sotho speech recognizer. This
automatic speech recognizer will play an important role in enabling a
human-computer interface technology suited for domain-specific user
applications. To enable this process, we collect nearly all possible speech
utterances that can exist in a specific domain and construct a finite grammar
suitable to cover most common utterance instances in that domain before testing
the speech recognizer performance with that finite grammar. In this project we
restrict our grammar to the birth, death and marriage registration systems
domain of the Department of Home Affairs where queries are posed by applicants
wishing to register birth, death or marriage events with appropriate responses
telephonically provided by the system. This system approximates to an IVR system
focused on a specific domain of information retrieval for event registration in
Northern Sotho.