Publications & Papers

Below are a list of papers I published when reading Software Engineering at Southampton University. They were written as part of my third year project (see Network Management using Abstracted XML Specifications).

Simulation and Implementation of an E-Commerce Communications Infrastructure using XML Specifications

The below paper was written by myself and my project supervisor, and was presented at the BIS 2002 Mobile E-business conference April 2002 in Poznan, Poland. It was submitted as a work in progress, and describes the overall concepts and challenges of my third year project.

Abstract: We report in this paper on a project dealing with the development of an XML-based tool for the management of the communication infrastructure within an e-commerce system. The major aim is to be able to simulate any given infrastructure prior to its implementation in order to detect potential problems early in a cost-effective way. We are focusing mainly on security problems that may arise. From the so tested XML description of the network, the settings of the nodes on the given physical network are generated automatically from the XML. As there are no assumptions made about the underlying network, our approach works for any kind of e-commerce environment, including mobile e-commerce systems.

An XML-based Approach to Modelling and Implementing Firewall Configurations

The below paper was written by myself and my project supervisor, and was presented at the ISSA 2002 Information Security conference July 2002 in Muldersdrift, Gauteng, South Africa.

Abstract: We present in this paper an approach for modelling the security infrastructure of a network using XML. The modelled system can then be validated on the XML level. From validated models, configurations of concrete nodes, such as firewalls, can be generated automatically.

I wrote the following reports as part of my 3rd year project during my Software Engineering degree, more details Network Management using Abstracted XML Specifications.

Network Management using Abstracted XML Specifications

Abstract: Establishing and managing network infrastructures between distributed nodes can be time consuming and risk prone. Such a statement is often re-enforced by the incorporation of new technologies, the merging of existing systems and the rotation of sub-systems. However, the functional requirements of these enterprises remain constant, even though implementation specifics may differ greatly.

The driving force behind this project is to investigate the addition of an extra level of abstraction between the operation and implementation of such nodes within distributed environments. A processing architecture is to be established to enable dynamic configurations of system elements, including support for function calls and external library references within service specifications.

This report details the chosen architecture and the features it provides, along with an overview of the system as a whole. Possible new directions in node configuration are addressed, supported by implemented examples.

In conclusion, this project confirms that such an abstracted approach to system configuration can indeed be achieved, including the ability to dynamically expand to cover new services and implementations. In addition, the integration of simulation modules directly into this project would provide a powerful network validation tool; such research is currently underway.

The following papers, magazine articles and websites have directly referenced projects I've published (such as TMip and XMLNetMan). Note not all of them are in English!

Verified Network Configuration - A TNS Research Project

The Verinec research group at the University of Fribourg, Switzerland, headed by my 3rd year project supervisor at the time, have taken the original ideas presented by my University project to the next level and beyond.

They have produced many papers (include PHD thesis) detailed here on these topics.

An overview of the Verinec research project is given below.

Overview: The Verinec project aims to simplify network configuration. It is based upon an abstract definition of a network and the nodes in that network expressed in XML. Each node consists of its hardware (network interfaces) and a set of services such as DNS server, firewalls, and so on. The abstract configuration is translated automatically into configuration specific to the actual hard- and software used in the network. The simulator part of Verinec allows to check if the configuration will fullfill the desired behaviour prior to really configure the nodes.

Design and Evaluation of iMesh: an Infrastructure-mode Wireless Mesh Network

Abstract: We design and evaluate iMesh, an infrastructure-mode 802.11-based mesh network. Here, 802.11 access points double as routers making the network architecture completely transparent to mobile clients, who view the network as a conventional wireless LAN. Layer-2 handoffs between access points trigger routing activities inside the network, which can be thought of as layer-3 handoffs. We describe the design rationale, and a testbed implementation of iMesh. We present results related to the handoff performance. The results demonstrate excellent handoff performance, the overall latency varying between 50-100ms depending on different layer-2 techniques, even when a fivehop long route update is needed. Various performance measurements also demonstrate the clear superiority of a flat routing scheme relative to a more traditional, mobile IPlike scheme to handle layer-3 handoff.

Performance Optimizations for Deploying VoIP Services in Mesh Networks

Abstract: In the recent past, there has been a tremendous increase in the popularity of VoIP services as a result of huge growth in broadband access. The same VoIP service poses new challenges when deployed over a wireless mesh network while enabling users to make voice calls using WiFi phones. Packet losses and delay due to interference in a multiple hop mesh network with limited capacity can signicantly degrade the end-to-end VoIP call quality. In this work, we discuss the basic requirements for an efcient deployment of VoIP services over a mesh network. We present and evaluate practical optimizing techniques that can enhance the network capacity, maintain the VoIP quality and handle user mobility efciently. Extensive experiments conducted on a real testbed and ns-2 provides insights into the performance issues and demonstrates the level of improvement that can be obtained by the proposed techniques. Specically, we nd that packet aggregation along with header compression can increase the number of supported VoIP calls in a multihop network by 2-3 times. The proposed fast path switching is highly effective in maintaining the VoIP quality. Our fast handoff scheme achieves almost negligible disruption during calls to roaming clients.

Transparent Mobile IP

Abstract: With Mobile IP keeps a laptop's IP address when it enters a new network. Even in the transition from a WLAN into an Ethernet will remain the TCP connections. In TMIP (Transparent Mobile IP) it works even without intervention on the client.

Always connected, Or IP-ROAMING: An Introduction

Abstract: Today's world - a world of mobility. Indeed, for In order to keep abreast of events no longer need to be in one place.

Cross-layer Design for Interference Mitigation and Mobility Support in Wireless Access Networks

Study and analysis aid of an IP System MOBILE Linux

Abstract: This paper presents an introduction to the concept of MOBILE IP, showing the recommendations proposed by IETF to support mobility on the Internet. The main objective of this work is to study and analyze a system MOBILE IP. Then exposed aspects and details of the IP system MOBILE chosen, TMIP. This exposure the detailed parameters set and the operation of the system, pointing its advantages and its problems.