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Clock synchronization has become essential to modern societies since many critical infrastructures depend on a precise notion of time. This paper analyzes security aspects of high-precision clock synchronization protocols, particularly their alleged protection against delay attacks when clock synchronization traffic is encrypted using standard network security protocols such as IPsec, MACsec, or TLS. We use the Precision Time Protocol (PTP), the most widely used protocol for high-precision clock synchronization, to demonstrate that statistical traffic analysis can identify properties that support selective message delay attacks even for encrypted traffic. We furthermore identify a fundamental conflict in secure clock synchronization between the need of deterministic traffic to improve precision and the need to obfuscate traffic in order to mitigate delay attacks. A theoretical analysis of clock synchronization protocols isolates the characteristics that make these protocols vulnerable to delay attacks and argues that such attacks cannot be prevented entirely but only be mitigated. Knowledge of the underlying communication network in terms of one-way delays and knowledge on physical constraints of these networks can help to compute guaranteed maximum bounds for slave clock offsets. These bounds are essential for detecting delay attacks and minimizing their impact. In the general case, however, the precision that can be guaranteed in adversarial settings is orders of magnitude lower than required for high-precision clock synchronization in critical infrastructures, which, therefore, must not rely on a precise notion of time when using untrusted networks.
Robert Annessi; Joachim Fabini; Felix Iglesias; Tanja Zseby. Encryption is Futile: Delay Attacks on High-Precision Clock Synchronization. 2018, 1 .
AMA StyleRobert Annessi, Joachim Fabini, Felix Iglesias, Tanja Zseby. Encryption is Futile: Delay Attacks on High-Precision Clock Synchronization. . 2018; ():1.
Chicago/Turabian StyleRobert Annessi; Joachim Fabini; Felix Iglesias; Tanja Zseby. 2018. "Encryption is Futile: Delay Attacks on High-Precision Clock Synchronization." , no. : 1.
Group communication facilitates efficient data transmission to numerous receivers by reducing data replication efforts both at the sender and in the network. Group communication is used in today’s communication networks in many ways, such as broadcasting in cellular networks, IP multicast on the network layer, or as application layer multicast. Despite many efforts in providing data origin authentication for specific application areas in group communication, no efficient and secure all-purpose solution has been proposed so far. In this paper, we analyze data origin authentication schemes from 25 years of research. We distinguish three general approaches to address the challenge and assign six conceptually different classes to these three approaches. We show that each class comprises trade-offs from a specific point of view that prevent the class from being generally applicable to group communication. We then propose to add a new class of schemes based on recent high-performance digital signatures. We argue that the high-speed signing approach is secure, resource efficient, and can be applied with acceptable communication overhead. This new class therefore provides a solution that is generally applicable and should be the foundation of future research on data origin authentication for group communication.
Robert Annessi; Tanja Zseby; Joachim Fabini. A New Direction for Research on Data Origin Authentication in Group Communication. Transactions on Petri Nets and Other Models of Concurrency XV 2018, 515 -525.
AMA StyleRobert Annessi, Tanja Zseby, Joachim Fabini. A New Direction for Research on Data Origin Authentication in Group Communication. Transactions on Petri Nets and Other Models of Concurrency XV. 2018; ():515-525.
Chicago/Turabian StyleRobert Annessi; Tanja Zseby; Joachim Fabini. 2018. "A New Direction for Research on Data Origin Authentication in Group Communication." Transactions on Petri Nets and Other Models of Concurrency XV , no. : 515-525.
A. Morton; J. Fabini; N. Elkins; M. Ackermann; V. Hegde. IPv4, IPv6, and IPv4-IPv6 Coexistence: Updates for the IP Performance Metrics (IPPM) Framework. IPv4, IPv6, and IPv4-IPv6 Coexistence: Updates for the IP Performance Metrics (IPPM) Framework 2018, 1 .
AMA StyleA. Morton, J. Fabini, N. Elkins, M. Ackermann, V. Hegde. IPv4, IPv6, and IPv4-IPv6 Coexistence: Updates for the IP Performance Metrics (IPPM) Framework. IPv4, IPv6, and IPv4-IPv6 Coexistence: Updates for the IP Performance Metrics (IPPM) Framework. 2018; ():1.
Chicago/Turabian StyleA. Morton; J. Fabini; N. Elkins; M. Ackermann; V. Hegde. 2018. "IPv4, IPv6, and IPv4-IPv6 Coexistence: Updates for the IP Performance Metrics (IPPM) Framework." IPv4, IPv6, and IPv4-IPv6 Coexistence: Updates for the IP Performance Metrics (IPPM) Framework , no. : 1.
Robert Annessi; Joachim Fabini; Tanja Zseby. To Trust or Not to Trust. Proceedings of the 13th International Conference on Predictive Models and Data Analytics in Software Engineering 2018, 43 .
AMA StyleRobert Annessi, Joachim Fabini, Tanja Zseby. To Trust or Not to Trust. Proceedings of the 13th International Conference on Predictive Models and Data Analytics in Software Engineering. 2018; ():43.
Chicago/Turabian StyleRobert Annessi; Joachim Fabini; Tanja Zseby. 2018. "To Trust or Not to Trust." Proceedings of the 13th International Conference on Predictive Models and Data Analytics in Software Engineering , no. : 43.
Smart power grids require a communication infrastructure to collect sensor data and to send control commands. The common trend for cost reduction influences the architecture, implementation, networking, and operation of smart grid devices. Whereas hardware and software reuse are imperative for vendors to lower device costs, utility companies substantially decrease their operational costs by deploying a homogeneous device base. Thousands of smart meters that feature identical hardware, firmware, and software, are one main prerequisite for automated maintenance, support, and device replacement. However, these cost savings create optimum conditions for malware propagation and infection in the grids’ control networks. In this paper we show how monocultures in device types can lead to critical situations if malware exploits a common vulnerability. Although we assume that classical defensive measures, e.g., firewalls, virtual networks, and intrusion detection, are in place, we argue that new or unpatched vulnerabilities cannot be ruled out and may lead to a very fast distribution of malware in large parts of the smart grids’ control network. Besides showing how fast malware can spread in device monocultures, we also discuss effective defensive measures that can support utility companies in preventing or containing malware distribution. Intelligente Stromnetze benötigen Kommunikationstechnologien, um Sensordaten und Kontrollinformationen zu übertragen. Der modulare Aufbau von Hardware, Firmware und Software sowie deren teilweise Wiederverwendung in verschiedenen Komponenten des Smart Grids ermöglichen eine Senkung der Herstellungs- und Investitionskosten. Je geringer die Anzahl ausgerollter Hardware-, Firmware- und Softwareversionen im Feld ist, desto geringer sind die zu erwartenden Betriebskosten wie etwa für automatisierte Updates, Gerätewartung, Geräteersatz und Schulung. Diese finanziellen Anreize haben eine äußerst homogene Gerätebasis im Smart Grid zur Folge. Das führt zu optimalen Bedingungen für die Ausbreitung von Malware in Smart Grid-Kommunikationsnetzen.
Peter Eder-Neuhauser; Tanja Zseby; Joachim Fabini. Malware propagation in smart grid monocultures. e & i Elektrotechnik und Informationstechnik 2018, 135, 264 -269.
AMA StylePeter Eder-Neuhauser, Tanja Zseby, Joachim Fabini. Malware propagation in smart grid monocultures. e & i Elektrotechnik und Informationstechnik. 2018; 135 (3):264-269.
Chicago/Turabian StylePeter Eder-Neuhauser; Tanja Zseby; Joachim Fabini. 2018. "Malware propagation in smart grid monocultures." e & i Elektrotechnik und Informationstechnik 135, no. 3: 264-269.
The increasing power in-feed of Non-Synchronous Renewable Energy Sources (NS-RES) in the grid has raised concerns about the frequency stability. The volatile RES power output and absence of inertia in many types of NS-RES affect the balance between power consumption and production. Therefore, the dynamics of the power grid frequency become more complex. Extreme grid frequency deviations and fast variations can lead to partitioning and load shedding in the case of under-frequency. In the case of over-frequency, it can lead to overloading, voltage collapse and blackouts. The Rate of Change of Frequency (RoCoF) reflects an aspect of the stability status of the grid and therefore its analysis with regard to Non-Synchronous Instant Penetration (NSIP) is of great importance. In this work, two months of high-resolution frequency synchrophasor measurements during 18 January 2018–18 March 2018 recorded in Austria were analyzed to investigate the impact of NS-RES on the frequency. The correlation of RoCoF with the NSIP in Austria and Germany and with the frequency deviation were examined. It was observed that with a maximum NSIP share up to 74% of the total power generation in these two countries, there was no critical increase of RoCoF or abnormal frequency deviation in the power grid.
Evangelia Xypolytou; Wolfgang Gawlik; Tanja Zseby; Joachim Fabini. Impact of Asynchronous Renewable Generation Infeed on Grid Frequency: Analysis Based on Synchrophasor Measurements. Sustainability 2018, 10, 1605 .
AMA StyleEvangelia Xypolytou, Wolfgang Gawlik, Tanja Zseby, Joachim Fabini. Impact of Asynchronous Renewable Generation Infeed on Grid Frequency: Analysis Based on Synchrophasor Measurements. Sustainability. 2018; 10 (5):1605.
Chicago/Turabian StyleEvangelia Xypolytou; Wolfgang Gawlik; Tanja Zseby; Joachim Fabini. 2018. "Impact of Asynchronous Renewable Generation Infeed on Grid Frequency: Analysis Based on Synchrophasor Measurements." Sustainability 10, no. 5: 1605.
Malicious botnets have become a common threat and pervade large parts of the Internet today. Existing surveys and taxonomies focus on botnet topologies, Command and Control (C&C) protocols, and botnet objectives. Building on these research results, network-based detection techniques have been proposed that are capable of detecting known botnets. Methods for botnet establishment and operation have evolved significantly over the past decade resulting in the need for detection methods that are capable of detecting new, previously unknown types of botnets. In this paper we present an in-depth analysis of all network communication aspects in botnet establishment and operation. We examine botnet topology, protocols, and analyze a large set of very different and highly sophisticated existing botnets from a network communication perspective. Based on our analysis, we introduce a novel taxonomy of generalized communication patterns for botnet communication using standardized Unified Modeling Language (UML) sequence diagrams. We furthermore examine data exchange options and investigate the influence of encryption and hiding techniques. Our generalized communication patterns provide a useful basis for the development of sophisticated network-based botnet detection mechanisms and can offer a key component for building protocol- and topology-independent network-based detectors.
Gernot Vormayr; Tanja Zseby; Joachim Fabini. Botnet Communication Patterns. IEEE Communications Surveys & Tutorials 2017, 19, 2768 -2796.
AMA StyleGernot Vormayr, Tanja Zseby, Joachim Fabini. Botnet Communication Patterns. IEEE Communications Surveys & Tutorials. 2017; 19 (4):2768-2796.
Chicago/Turabian StyleGernot Vormayr; Tanja Zseby; Joachim Fabini. 2017. "Botnet Communication Patterns." IEEE Communications Surveys & Tutorials 19, no. 4: 2768-2796.
Reliable and efficient energy supply is based not only on local control but also on remote sensor data and measurements, making communication one of the important components. The increasing threat of possible attacks is the motivation behind the main purpose of the FUSE testbed—an experimental microgrid for smart grid research—to conduct experiments on smart grid security, grid optimization, stabilization and islanding. This work, after providing an insight of the current state of the art concerning research on microgrids, describes the FUSE experimental facility as well as first experiments including partial measurement equipment installation and data collection and analysis.
Evangelia Xypolytou; Joachim Fabini; Wolfgang Gawlik; Tanja Zseby. The FUSE testbed: establishing a microgrid for smart grid security experiments. e & i Elektrotechnik und Informationstechnik 2017, 134, 30 -35.
AMA StyleEvangelia Xypolytou, Joachim Fabini, Wolfgang Gawlik, Tanja Zseby. The FUSE testbed: establishing a microgrid for smart grid security experiments. e & i Elektrotechnik und Informationstechnik. 2017; 134 (1):30-35.
Chicago/Turabian StyleEvangelia Xypolytou; Joachim Fabini; Wolfgang Gawlik; Tanja Zseby. 2017. "The FUSE testbed: establishing a microgrid for smart grid security experiments." e & i Elektrotechnik und Informationstechnik 134, no. 1: 30-35.
Modern access network technologies like Long Term Evolution (LTE) and High Speed Packet Access (HSPA) use time-slotting mechanisms to optimize resource sharing and overall network performance. In time-slotted networks, the one-way delay of all packets in a packet stream depends on the absolute point in time when the first packet of the stream is sent. With appropriate feedback signals, applications can exploit this effect to reduce their effective end-to-end delay. Time-critical applications such as real-time sensor data acquisition or voice-over-IP (VoIP) communications can shift their acquisition interval in order to adapt to the network timing. Information about the actual time-slotting periods can be gathered by active network measurements or through implementation of cross-layer information exchange. In this paper, a method is proposed to determine the optimum send time for particular destinations and to support applications in adjusting their send time accordingly. Theoretical findings are supported by the offline analysis of measurement data and by a proof-of-concept implementation that confirms the feasibility and effectiveness of the proposed solution in operational LTE and HSPA networks.
Joachim Fabini; Tanja Zseby; Fabini J.; Zseby T.. The Right Time: Reducing Effective End-to-End Delay in Time-Slotted Packet-Switched Networks. IEEE/ACM Transactions on Networking 2015, 24, 2251 -2263.
AMA StyleJoachim Fabini, Tanja Zseby, Fabini J., Zseby T.. The Right Time: Reducing Effective End-to-End Delay in Time-Slotted Packet-Switched Networks. IEEE/ACM Transactions on Networking. 2015; 24 (4):2251-2263.
Chicago/Turabian StyleJoachim Fabini; Tanja Zseby; Fabini J.; Zseby T.. 2015. "The Right Time: Reducing Effective End-to-End Delay in Time-Slotted Packet-Switched Networks." IEEE/ACM Transactions on Networking 24, no. 4: 2251-2263.
Network access technologies have evolved significantly in the last years. They deploy novel mechanisms like reactive capacity allocation and time-slotted operation to optimize overall network capacity. From a single node's perspective, such optimizations decrease network determinism and measurement repeatability. Evolving application fields like machine to machine (M2M) communications or real-time gaming often have strict real-time requirements to operate correctly. Highly accurate delay measurements are necessary to monitor network compliance with application demands or to detect deviations of normal network behavior, which may be caused by network failures, misconfigurations or attacks. This paper analyzes factors that challenge active delay measurements in modern networks. It introduces the Representative Delay Measurement tool (RDM) that addresses these factors and proposes solutions that conform to requirements of the recently published RFC7312. Delay measurement results acquired using RDM in live networks confirm that advanced measurement methods can significantly improve the quality of measurement samples by isolating systematic network behavior. The resulting high-quality samples are one prerequisite for accurate statistics that support proper operation of subsequent algorithms and applications
Joachim Fabini; Tanja Zseby; Michael Hirschbichler. Representative Delay Measurements (RDM): Facing the Challenge of Modern Networks. Proceedings of the 8th International Conference on Performance Evaluation Methodologies and Tools 2015, 1 .
AMA StyleJoachim Fabini, Tanja Zseby, Michael Hirschbichler. Representative Delay Measurements (RDM): Facing the Challenge of Modern Networks. Proceedings of the 8th International Conference on Performance Evaluation Methodologies and Tools. 2015; ():1.
Chicago/Turabian StyleJoachim Fabini; Tanja Zseby; Michael Hirschbichler. 2015. "Representative Delay Measurements (RDM): Facing the Challenge of Modern Networks." Proceedings of the 8th International Conference on Performance Evaluation Methodologies and Tools , no. : 1.
Wide Area Monitoring Systems (WAMS) improve situational awareness in the electric grid. They support planning and optimizing of grid operations and provide valuable information to prevent critical incidents. Communication demands for WAMS have been elevated by the variety of applications that rely on measurement data from distributed sensors. Besides bounds on tolerated end-to-end latencies for some applications, security is a major concern in todays Wide Area Monitoring Systems. We review recent approaches for WAMS communication and point out security challenges that need to be addressed in future communication solutions for WAMS. Wide Area Monitoring-Systeme (WAMS) formen Netze aus verteilten Sensoren zur Überwachung von intelligenten Stromnetzen (Smart Grids). Sie unterstützen Planung und Optimierung von Prozessen im Elektrizitätsnetz und liefern wertvolle Informationen zur Prävention von kritischen Ereignissen. Viele Anwendungen benötigen aktuelle Messdaten, um auf neue Situationen in intelligenten Stromnetzen reagieren zu können. Damit steigen auch die Kommunikationsanforderungen für Wide Area Monitoring-Systeme. Neben Anforderungen bezüglich der maximal tolerierbaren Ende-zu-Ende-Verzögerungszeiten sind heutzutage vor allem Sicherheitsmechanismen von hoher Bedeutung für Wide Area Monitoring-Systeme. Wir vergleichen verschiedene Ansätze für WAMS-Kommunikation und zeigen, welche Sicherheitsanforderungen in zukünftigen Kommunikationslösungen für WAMS berücksichtigt werden müssen.
Tanja Zseby; Joachim Fabini. Security Challenges for Wide Area Monitoring in Smart Grids. e & i Elektrotechnik und Informationstechnik 2014, 131, 105 -111.
AMA StyleTanja Zseby, Joachim Fabini. Security Challenges for Wide Area Monitoring in Smart Grids. e & i Elektrotechnik und Informationstechnik. 2014; 131 (3):105-111.
Chicago/Turabian StyleTanja Zseby; Joachim Fabini. 2014. "Security Challenges for Wide Area Monitoring in Smart Grids." e & i Elektrotechnik und Informationstechnik 131, no. 3: 105-111.
Synchronized phasor measurements provide the basis for fine-grained wide area power quality monitoring in electric grids. Time-synchronized phasor measurement units (PMUs) are deployed at different locations in the grid and report 10–60 measurements/second to energy management systems or other applications. For control applications it is crucial to receive measurement data as soon as possible after a state change in order to trigger corrective actions in time to prevent incidents in the grid.
Tanja Zseby; Joachim Fabini; Dipika Rani. Synchrophasor communication. e & i Elektrotechnik und Informationstechnik 2013, 131, 8 -13.
AMA StyleTanja Zseby, Joachim Fabini, Dipika Rani. Synchrophasor communication. e & i Elektrotechnik und Informationstechnik. 2013; 131 (1):8-13.
Chicago/Turabian StyleTanja Zseby; Joachim Fabini; Dipika Rani. 2013. "Synchrophasor communication." e & i Elektrotechnik und Informationstechnik 131, no. 1: 8-13.
Last year’s trend to migrate circuit-switched voice networks to packet switched Internet Protocol (IP) based networks has favored wide deployment of Session Initiation Protocol (SIP) based systems and networks. As a reaction to large-scale SIP deployment experiences in the field and the need to implement high availability and reliability within these new networks, the focus of SIP extension standardization has shifted from adding new SIP signaling functionality to operational and maintenance aspects, a particular importance being attributed to overload control. Overload denotes a situation in which the traffic injected into a system exceeds the system’s designed capacity. The authors present a detailed categorization of overload architectures and outline main reasons why SIP-based networks are at high risk to collapse when operating at overload. Using measurements in a real SIP infrastructure this paper compares the performance of two overload protection schemes, namely implicit and explicit overload protection, against the performance of non-protected systems. The measurement results recommend overload protection as a mandatory component of commercial SIP deployments to safeguard operation and prevent system collapse in case of overload.
Marco Happenhofer; Joachim Fabini; Christoph Egger; Michael Hirschbichler. An Architectural and Evaluative Review of Implicit and Explicit SIP Overload Handling. Advanced Instrument Engineering 2013, 257 -273.
AMA StyleMarco Happenhofer, Joachim Fabini, Christoph Egger, Michael Hirschbichler. An Architectural and Evaluative Review of Implicit and Explicit SIP Overload Handling. Advanced Instrument Engineering. 2013; ():257-273.
Chicago/Turabian StyleMarco Happenhofer; Joachim Fabini; Christoph Egger; Michael Hirschbichler. 2013. "An Architectural and Evaluative Review of Implicit and Explicit SIP Overload Handling." Advanced Instrument Engineering , no. : 257-273.
The Session Initiation Protocol (SIP) relies on timer-based message retransmission for safeguarding reliable message transfer when deployed on top of the unreliable User Datagram Protocol (UDP) over IP. In this paper we present a detailed impact analysis of SIP timers onto the functionality of a system and its capabilities to recover from overload situations. The results of our event-based SIP simulations demonstrate that message retransmissions originating from a minor short-term overload can force a system into a deterministic congestion collapse when using default SIP timer settings. A recovery from this severe system overload situation is highly difficult or impossible, even if the system load is reduced substantially afterward. Our performance evaluation shows that an increase of timer T1's value significantly enhances the stability, robustness and the ability of systems to handle overload, whereas the resulting increase of response times is relatively small and overall system responsiveness can even improve in some cases. We propose an algorithm for implicit collapse detection as solution for dynamic timer T1 optimization. Based on monitoring of system load and pending transaction counts, our algorithm enables intermediate SIP proxies to detect congestion in a very early phase, allowing them to counteract in time, i.e., to modify timers and reject new system load in order to prevent the system from collapse.
Christoph Egger; Marco Happenhofer; Joachim Fabini; Peter Reichl. Collapse Detection and Avoidance for SIP Architectures. PIK - Praxis der Informationsverarbeitung und Kommunikation 2012, 35, 91 -99.
AMA StyleChristoph Egger, Marco Happenhofer, Joachim Fabini, Peter Reichl. Collapse Detection and Avoidance for SIP Architectures. PIK - Praxis der Informationsverarbeitung und Kommunikation. 2012; 35 (2):91-99.
Chicago/Turabian StyleChristoph Egger; Marco Happenhofer; Joachim Fabini; Peter Reichl. 2012. "Collapse Detection and Avoidance for SIP Architectures." PIK - Praxis der Informationsverarbeitung und Kommunikation 35, no. 2: 91-99.
Novel mobile cellular access network technologies like Long Term Evolution (LTE) promise capacities exceeding the ones of existing 3G networks by at least one order of magnitude. This evolution will enable the deployment of services which, due to their capacity requirements, are currently restricted to fixed access networks. On the other hand, packet-switched-only architectures raise the need for a reliable and accurate management of these high access capacities, particularly service-specific Quality of Service (QoS) enforcement, in order to prioritize real-time (voice) services and safeguard a satisfactory Quality of Experience (QoE) to the user. In this paper we present the concept and architecture of a flow-based QoS enforcement architecture called BIQINI which has been developed at the Telecommunications Research Center Vienna (FTW). It consists of a standard-compliant Policy and Charging Rules Function (PCRF) which is supported by an emulated Policy Enforcement Function (PCEF). Extending the FOKUS OpenSource IMS testbed as well as other session-based signaling frameworks, BIQINI’s emulated enforcement component enables inexpensive but highly realistic tests on real-time voice and -video traffic, supporting impairments like delay, jitter, loss, and link capacity limitation out-of-the-box. In addition, BIQINI can interface with external policy repositories, thus providing a versatile playground for testing rules and policies in an emulated, realistic environment for real media streams.
Christoph Egger; Marco Happenhofer; Joachim Fabini; Peter Reichl. BIQINI – A Flow-Based QoS Enforcement Architecture for NGN Services. Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2011, 46, 653 -667.
AMA StyleChristoph Egger, Marco Happenhofer, Joachim Fabini, Peter Reichl. BIQINI – A Flow-Based QoS Enforcement Architecture for NGN Services. Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering. 2011; 46 ():653-667.
Chicago/Turabian StyleChristoph Egger; Marco Happenhofer; Joachim Fabini; Peter Reichl. 2011. "BIQINI – A Flow-Based QoS Enforcement Architecture for NGN Services." Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 46, no. : 653-667.
Simulation Notes Europe SNE 20(1), 2010, 16-20DOI: 10.11128/sne.20.tn.09962
Lukas Wallentin; Marco Happenhofer; Christoph Egger; Joachim Fabini. XML Meets Simulation: Concepts and Architecture of the IBKSim Network Simulator. SNE Simulation Notes Europe 2010, 20, 16 -20.
AMA StyleLukas Wallentin, Marco Happenhofer, Christoph Egger, Joachim Fabini. XML Meets Simulation: Concepts and Architecture of the IBKSim Network Simulator. SNE Simulation Notes Europe. 2010; 20 (1):16-20.
Chicago/Turabian StyleLukas Wallentin; Marco Happenhofer; Christoph Egger; Joachim Fabini. 2010. "XML Meets Simulation: Concepts and Architecture of the IBKSim Network Simulator." SNE Simulation Notes Europe 20, no. 1: 16-20.
The delay experienced by mobile applications in HSPA networks depends to a large extent on highly dynamical global context like, e.g., cell load or algorithms and thresholds governing radio resource scheduling, and on local context like, e.g., user-generated load or load history. These complex uncertainty factors are outside of an application’s sphere of influence and result in applications perceiving HSPA link behavior as non-deterministic and non-reproducible. This paper analyzes accurate round-trip and one-way delay measurement results for three public HSPA networks to demonstrate the high degree of network non-determinism which mobile applications are likely to encounter in practice, particularly significant payload-dependence and halved delay on slightly increased user-generated link load. We argue that current HSPA radio link schedulers, relying on instantaneous user load as decision criterion for channel capacity allocation, neglect real-time application requirements. Cross-layer optimization is one solution which enables deterministic scheduler decisions based on application requirements.
Joachim Fabini; Wolfgang Karner; Lukas Wallentin; Thomas Baumgartner. The Illusion of Being Deterministic – Application-Level Considerations on Delay in 3G HSPA Networks. Computer Vision 2009, 5550, 301 -312.
AMA StyleJoachim Fabini, Wolfgang Karner, Lukas Wallentin, Thomas Baumgartner. The Illusion of Being Deterministic – Application-Level Considerations on Delay in 3G HSPA Networks. Computer Vision. 2009; 5550 ():301-312.
Chicago/Turabian StyleJoachim Fabini; Wolfgang Karner; Lukas Wallentin; Thomas Baumgartner. 2009. "The Illusion of Being Deterministic – Application-Level Considerations on Delay in 3G HSPA Networks." Computer Vision 5550, no. : 301-312.
Joachim Fabini; Peter Reichl; Christoph Egger; Marco Happenhofer; Michael Hirschbichler; Lukas Wallentin. Generic Access Network Emulation for NGN Testbeds. Proceedings of the 4th International ICST Conference on Testbeds and Research Infrastructures for the Development of Networks and Communities 2008, 1 .
AMA StyleJoachim Fabini, Peter Reichl, Christoph Egger, Marco Happenhofer, Michael Hirschbichler, Lukas Wallentin. Generic Access Network Emulation for NGN Testbeds. Proceedings of the 4th International ICST Conference on Testbeds and Research Infrastructures for the Development of Networks and Communities. 2008; ():1.
Chicago/Turabian StyleJoachim Fabini; Peter Reichl; Christoph Egger; Marco Happenhofer; Michael Hirschbichler; Lukas Wallentin. 2008. "Generic Access Network Emulation for NGN Testbeds." Proceedings of the 4th International ICST Conference on Testbeds and Research Infrastructures for the Development of Networks and Communities , no. : 1.