Developing regional precise positioning services using the legacy and future GNSS receivers

This paper presents an overview of technical solutions for regional area precise GNSS positioning services such as in Queensland. The research focuses on the technical and business issues that currently constrain GPS-based local area Real Time Kinematic (RTK) precise positioning services so as to operate in future across larger regional areas, and therefore support services in agriculture, mining, utilities, surveying, construction, and others. The paper first outlines an overall technical framework that has been proposed to transition the current RTK services to future larger scale coverage. The framework enables mixed use of different reference GNSS receiver types, dual- or triple-frequency, single or multiple systems, to provide RTK correction services to users equipped with any type of GNSS receivers. Next, data processing algorithms appropriate for triple-frequency GNSS signals are reviewed and some key performance benefits of using triple carrier signals for reliable RTK positioning over long distances are demonstrated. A server-based RTK software platform is being developed to allow for user positioning computations at server nodes instead of on the user's device. An optimal deployment scheme for reference stations across a larger-scale network has been suggested, given restrictions such as inter-station distances, candidates for reference locations, and operational modes. For instance, inter-station distances between triple-frequency receivers can be extended to 150km, which doubles the distance between dual-frequency receivers in the existing RTK network designs.

Validating denial of service vulnerabilities in web services

The loosely-coupled and dynamic nature of web services architectures has many benefits, but also leads to an increased vulnerability to denial of service attacks. While many papers have surveyed and described these vulnerabilities, they are often theoretical and lack experimental data to validate them, and assume an obsolete state of web services technologies. This paper describes experiments involving several denial of service vulnerabilities in well-known web services platforms, including Java Metro, Apache Axis, and Microsoft .NET. The results both confirm and deny the presence of some of the most well-known vulnerabilities in web services technologies. Specifically, major web services platforms appear to cope well with attacks that target memory exhaustion. However, attacks targeting CPU-time exhaustion are still effective, regardless of the victim’s platform.

Marketing VM services to achieve competitive advantage in the Malaysian Construction Sector

Value Management (VM) has been proven to provide a structured framework, together with supporting tools and techniques that facilitate effective decision-making in many types of projects, thus achieving ‘best value’ for clients. It is identified at International level as a natural career progression for the construction service provider and as an opportunity in developing leading-edge skills. The services offered by contractors and consultants in the construction sector have been expanding. In an increasingly competitive and global marketplace, firms are seeking ways to differentiate their services to ever more knowledgeable and demanding clients. The traditional demarcations have given way, and the old definition of what contractors, designers, engineers and quantity surveyors can, and cannot do in terms of their market offering has changed. Project management, design and cost and safety consultancy services, are being delivered by a diverse range of suppliers. Value management services have been developing in various sectors in industry; from manufacturing to the military and now construction. Given the growing evidence that VM has been successful in delivering value-for-money to the client, VM would appear to be gaining some momentum as an essential management tool in the Malaysian construction sector. The recently issued VM Circular 3/2009 by the Economic Planning Unit Malaysia (EPU) possibly marks a new beginning in public sector client acceptance on the strength of VM in construction. This paper therefore attempts to study the prospects of marketing the benefits of VM by construction service providers, and how it may provide an edge in an increasingly competitive Malaysian construction industry.

Efficient algorithm for achieving GWPMM fairness in ATM ABR services

A new explicit rate allocation algorithm is proposed for achieving generic weight-proportional max-min (GWPMM) fairness in asynchronous transfer mode (ATM) available bit rate services. This algorithm scales well with a fixed computational complexity of O(1) and can realise GWPMM fair rate allocation in an ATM network accurately.

Secure tracking for critical applications : communications, GPS and future Galileo services

Tracking/remote monitoring systems using GNSS are a proven method to enhance the safety and security of personnel and vehicles carrying precious or hazardous cargo. While GNSS tracking appears to mitigate some of these threats, if not adequately secured, it can be a double-edged sword allowing adversaries to obtain sensitive shipment and vehicle position data to better coordinate their attacks, and to provide a false sense of security to monitoring centers. Tracking systems must be designed with the ability to perform route-compliance and thwart attacks ranging from low-level attacks such as the cutting of antenna cables to medium and high-level attacks involving radio jamming and signal / data-level simulation, especially where the goods transported have a potentially high value to terrorists. This paper discusses the use of GNSS in critical tracking applications, addressing the mitigation of GNSS security issues, augmentation systems and communication systems in order to provide highly robust and survivable tracking systems.

Secure tracking using trusted GNSS receivers and Galileo authentication services

This paper describes a secure framework for tracking applications that use the Galileo signal authentication services. First a number of limitations that affect the trust of critical tracking applications, even in presence of authenticated GNSS signals, are detailed. Requirements for secure tracking are then introduced; detailing how the integrity characteristics of the Galileo authentication could enhance the security of active tracking applications. This paper concludes with a discussion of our existing tracking technology using a Siemens TC45 GSM/GPRS module and future development utilizing our previously proposed trusted GNSS receiver.