Wolfgang Leister

Threat Assessment of Wireless Patient Monitoring Systems

We address issues related to threat assessment of mobile patient monitoring systems using a wireless infrastructure including body area biomedical sensor networks. Several user scenarios are presented. Patient sensitive data, mobile and wireless infrastructure, and resource-constraint sensor nodes provide a challenging task of fulfilling some minimum requirements for security, privacy, reliability of the data and availability of the system. We have therefore studied threats associated to both short range and long range mobile wireless communication infrastructures, where requirements for security recommendations for such systems are presented. Emphasis is given on applications that employ a wireless infrastructure, such as biomedical sensor networks. In this work we present an informal threat assessment of mobile patient monitoring systems used with several scenarios.

An architecture for adaptive multimedia streaming to mobile nodes

We describe the ADIMUS architecture which addresses the problem of maintaining the subjective quality of multimedia streaming for a mobile user. In contrast to other works, the entire end-to-end path of the video stream is considered. Adaptation mechanisms for maintaining quality include time-critical handovers, overlay routing and network estimation techniques. Our architecture is built on overlays that provides the necessary functionality for a video streaming service. The paper highlights the key components that ADIMUS advocates to support quality streaming from server to mobile client.

Quality of Service, Adaptation, and Security Provisioning in Wireless Patient Monitoring Systems

Modern patient monitoring systems are designed to put the individual into the centre of the system architecture. In this paradigm, the patient is seen as a source of health-relevant data that are processed and transferred. Patient monitoring systems are used in health care enterprises as well as in paramedic, mobile, and home situations to foster ambient assisted living (AAL) scenarios. There are a multitude of standards and products available to support Quality of Service (QoS) and security goals in patient monitoring systems. Yet, an architecture that supports these goals from data aggregation to data transmission and visualisation for end user has not been developed. Medical data from patient monitoring systems includes sampled values from measurements, sound, images, and video. These data often have a time-aspect where several data streams need to be synchronised. Therefore, rendering data from patient monitoring systems can be considered an advanced form of multimedia data. We propose a framework that will fill this QoS and security gap and provide a solution that allows medical personnel better access to data and more mobility to the patients. The framework is based on MPEG-21 and wireless sensor networks. It allows for end-to-end optimisation and presentation of multimedia sensor data. The framework also addresses the QoS, adaptation and security concerns of handling this data. In Section 2 we present background on patient monitoring systems, their requirements and how we envision communication is handled. We present communication systems in Section 3 and how to treat QoS in Section 4. A short introduction to data streaming, binary XML and how they relate to patient monitoring systems is presented in Section 5. In Section 6we our proposed solution for the framework and present a security analysis of it in Section 7. Finally, we offer our conclusions in Section 8. 36

Use of MPEG-21 for Security and Authentication in Biomedical Sensor Networks

Privacy and security are two major concerns in the ubiquitous deployment of wireless patient monitoring systems. Wireless sensor networks become an integral part of the monitoring process, where wireless sensors can enter or leave the monitoring situation randomly. As a tool to handle threats that may arise by the use of wireless sensors, we propose a new framework using MPEG-21. MPEG-21 is an architecture that can handle end-to-end management of content and network resources. In this paper we evaluate the use of the MPEG-21 architecture in a resource-constraint wireless sensor network, where different threats are evaluated and countermeasures are proposed.

Towards Knowledge Driven Decision Support for Personalized Home-Based Self-Management of Chronic Diseases

The use of ICT technologies to facilitate self-management for patients with chronic diseases attracts increasing attention in smart healthcare. Existing research has mainly focused on sensing and data processing technologies with little work on decision support mechanisms and systems. In this paper, we propose a home-based decision support system based on a wide range of assessment metrics from medical assessment, social and psychological evaluation to behaviour analysis to help self-manage rehabilitation and wellbeing in a personalized manner for different patients. This paper develops semantic models for describing patients, their conditions, medical and behavioural assessments and inference mechanisms for decision recommendations. The research is undertaken in the context of mobile user self-management for Spondyloarthritis (SpA) patients. A case scenario is used to demonstrate the application of the proposed approach, technologies and principles.

Network Selection for Multicast Groups in Heterogeneous Wireless Environments

Coexistence of various wireless access networks and the ability of mobile terminals to switch between them make an optimal selection of serving networks for multicast groups a challenging problem. Since optimal network selection requires large dimensions of data to be collected from several network locations and sent between several network components, the scalability can easily become a bottleneck in large-scale systems. Therefore, reducing data exchange within heterogeneous wireless networks is important. We study the decision-making process and the data that needs to be sent between different network components. We present two decentralized solutions to this problem that operate with reduced sets of information. We define the upper and lower bounds to these solutions and evaluate them in the OMNet++ simulation environment. Both solutions provide a substantial improvement in performance compared to the lower bound.

Analysing Protocol Implementations

Many protocols running over the Internet are neither formalised, nor formally analysed. The amount of documentation for tele- communication protocols used in real-life applications is huge, while the available analysis methods and tools require precise and clear-cut protocol clauses. A manual formalisation of the Session Initiation Protocol (SIP) used in Voice over IP (VoIP) applications is not feasible. Therefore, by combining the information retrieved from the specification documents published by the IETF, and traces of real world SIP traffic we craft a formal specification of the protocol in addition to an implementation of the protocol. In the course of our work we detected several weaknesses, both of SIP call setup and in the Asterisk implementation of the protocol. These weaknesses could be exploited and pose as a threat for authentication and non-repudiation of VoIP calls.

A benchmarking system for multipath overlay multimedia streaming

The rapid growth of the Internet multimedia services brings new challenges to how multimedia streams can be delivered to the users over bandwidth-constraint networks. Different strategies that exploit multipath streaming in order to provide better utilization of the Internet resources have been proposed by the research community. However, there exists no metric that allows us to evaluate how close these strategies are to the optimal resource utilization. This paper proposes a static benchmarking system that models the best possible distribution of streams along multiple paths in an overlay network that is shared by several senders and receivers. We have tested it with several different network topologies, and present the test results in this paper.

Threats identification for the smart Internet of Things in eHealth and adaptive security countermeasures

The Things in the smart Internet of Things (IoT) depend more on self decision making abilities instead of relying on human interventions. In the IoT, static security mechanisms are not well suited to handle all security risks sufficiently. A security mechanism can be considered static if it is developed with fixed security measures whereas an adaptive security mechanism can be considered dynamic if it can continuously monitor, analyse, and reassess a security risk at runtime. Adaptive security mechanisms can be a better choice to secure dynamic and heterogeneous computing systems in the IoT. This paper presents a patient monitoring scenario using the smart IoT and aims at highlighting all important assets, vulnerabilities, and threats that can harm assets and disrupt eHealth systems. We describe adaptive security and introduce a concept of adaptive security countermeasures for the smart IoT in eHealth.

Estimation of Subjective Video Quality as Feedback to Content Providers

Concerning video transmission on the Internet, we present a model for estimating the subjective quality from objective measurements at the transmission receivers and on the network. The model reflects the quality degradation subject to parameters like packet loss ratio and bit rate and is calibrated using the results from subjective quality assessments. Besides the model and the calibration, the main achievement of this paper is the model’s validation by implementation in a monitoring tool. It can be used by content and network providers to help swiftly localise the causes of a possibly poor quality of experience (QoE). It also can help content providers make decisions regarding the adjustment of vital parameters, such as bit rate and other error correction mechanisms.