Practical issues of implementing a hybrid multi-NIC wireless mesh-network

Testbeds are a powerful tool to study wireless mesh and sensor networks as close as possible to real world application scenarios. In contrast to simulation or analytical approaches these installations face various kinds of environment parameters. Challenges related to the shared physical medium, operating system, and used hardware components do arise. In this technical report about the work-in-progress Distributed Embedded Systems testbed of 100 routers deployed at the Freie Universität Berlin we focis on the software architecture and give and introduction to the network protocol stack of the Linux kernel. Furthermore, we discuss our first experiences with a pilot network setup, the encountered problems and the achieved solutions. This writing continues our first publication and builds upon the discussed overall testbed architecture, our experiment methodology, and aspired research objectives

Integration of Legacy Appliances into Home Energy Management Systems

The progressive installation of renewable energy sources requires the coordination of energy consuming devices. At consumer level, this coordination can be done by a home energy management system (HEMS). Interoperability issues need to be solved among smart appliances as well as between smart and non-smart, i.e., legacy devices. We expect current standardization efforts to soon provide technologies to design smart appliances in order to cope with the current interoperability issues. Nevertheless, common electrical devices affect energy consumption significantly and therefore deserve consideration within energy management applications. This paper discusses the integration of smart and legacy devices into a generic system architecture and, subsequently, elaborates the requirements and components which are necessary to realize such an architecture including an application of load detection for the identification of running loads and their integration into existing HEM systems. We assess the feasibility of such an approach with a case study based on a measurement campaign on real households. We show how the information of detected appliances can be extracted in order to create device profiles allowing for their integration and management within a HEMS

The Media Layers of the OSI (Open Systems Interconnection) Reference Model: A Tutorial

The Media Layers of the open systems interconnection (OSI) reference model convert bits to packets. It is a very important aspect of network communication and consists of various networking protocols. At the lowest level the physical layer deals with Media, Signal and Binary Transmission of Bits. Then there is the Data Link layer which deals with media access control (MAC) and logical link control (LLC) Physical Addressing of Frames, for example Ethernet. Finally, there is the Network layer which deals with Path Determination and IP Logical addressing of Packets. This article gives a review of these Media Layers and will contribute to adding knowledge for a networking novice while consolidating concepts for an experienced professional or academic

Incident Analysis & Digital Forensics in SCADA and Industrial Control Systems

SCADA and industrial control systems have been traditionally isolated in physically protected environments. However, developments such as standardisation of data exchange protocols and increased use of IP, emerging wireless sensor networks and machine-to-machine communication mean that in the near future related threat vectors will require consideration too outside the scope of traditional SCADA security and incident response. In the light of the significance of SCADA for the resilience of critical infrastructures and the related targeted incidents against them (e.g. the development of stuxnet), cyber security and digital forensics emerge as priority areas. In this paper we focus on the latter, exploring the current capability of SCADA operators to analyse security incidents and develop situational awareness based on a robust digital evidence perspective. We look at the logging capabilities of a typical SCADA architecture and the analytical techniques and investigative tools that may help develop forensic readiness to the level of the current threat environment requirements. We also provide recommendations for data capture and retention

Challenges Using the Linux Network Stack for Real-Time Communication

Starting in the early 2000s, human-in-the-loop (HITL) simulation groups at NASA and the Air Force Research Lab began using the Linux network stack for some real-time communication. More recently, SpaceX has adopted Ethernet as the primary bus technology for its Falcon launch vehicles and Dragon capsules. As the Linux network stack makes its way from ground facilities to flight critical systems, it is necessary to recognize that the network stack is optimized for communication over the open Internet, which cannot provide latency guarantees. The Internet protocols and their implementation in the Linux network stack contain numerous design decisions that favor throughput over determinism and latency. These decisions often require workarounds in the application or customization of the stack to maintain a high probability of low latency on closed networks, especially if the network must be fault tolerant to single event upsets

Investigating the Cybersecurity of Smart Grids Based on Cyber-Physical Twin Approach

While the increasing penetration of information and communication technology into distribution grid brings numerous benefits, it also opens up a new threat landscape, particularly through cyberattacks. To provide a basis for countermeasures against such threats, this paper addresses the investigation of the impact and manifestations of cyberattacks on smart grids by replicating the power grid in a secure, isolated, and controlled laboratory environment as a cyber-physical twin. Currently, detecting intrusions by unauthorized third parties into the central monitoring and control system of grid operators, especially attacks within the grid perimeter, is a major challenge. The development and validation of methods to detect and prevent coordinated and timed attacks on electric power systems depends not only on the availability and quality of data from such attack scenarios, but also on suitable realistic investigation environments. However, to create a comprehensive investigation environment, a realistic representation of the study object is required to thoroughly investigate critical cyberattacks on grid operations and evaluate their impact on the power grid using real data. In this paper, we demonstrate our cyber-physical twin approach using a microgrid in the context of a cyberattack case study.Comment: IEEE International Conference on Communications, Control, and Computing Technologies for Smart Grids (SmartGridComm) 202

Investigation of thermal regimes of lakes used for water supply and examination of drinking water system in Kotzebue, Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2012Many villages in Arctic Alaska rely on lakes for water supply, such as the Alaskan City of Kotzebue, and these lakes may be sensitive to climate variability and change, particularly thermal regimes and corresponding effects on water quality. Thus, I initiated a study of water supply lakes in Kotzebue to collect data for developing a model to hindcast summer thermal regimes. Surface (Tws) and bed (Twb) temperature data collected from two water supply lakes and two control lakes from June 22nd-August 28th 2011 showed a similar pattern in relation to air temperature (Ta) and solar radiation with more frequent stratification in the deeper lakes. The average Tws for all lakes during this period was 14.5°C, which was 3.4°C higher than Ta for the same period. I modeled Tws from 1985 to 2010 using Ta, and theoretical clear-sky solar radiation (TCSR) to analyze interannual variability, trends, and provide a baseline dataset. Similar to patterns in Ta for this period, I found no trend in mean Tws for the main lake used for water supply (Devil's Lake), but considerable variation ranging from 12.2°C in 2000 to 19.2°C in 2004. My analysis suggests that 44% of years during this 25 year period maximum daily Tws surpassed 20°C for at least one day. This hindcasted dataset can provide water supply managers in Kotzebue and other Arctic villages with a record of past conditions and a model for how lakes may respond to future climate change and variability that could impact water quality

The Design Fabrication and Flight Testing of an Academic Research Platform for High Resolution Terrain Imaging

This thesis addresses the design, construction, and flight testing of an Unmanned Aircraft System (UAS) created to serve as a testbed for Intelligence, Surveillance, and Reconnaissance (ISR) research topics that require the rapid acquisition and processing of high resolution aerial imagery and are to be performed by academic research institutions. An analysis of the requirements of various ISR research applications and the practical limitations of academic research yields a consolidated set of requirements by which the UAS is designed. An iterative design process is used to transition from these requirements to cycles of component selection, systems integration, flight tests, diagnostics, and subsystem redesign. The resulting UAS is designed as an academic research platform to support a variety of ISR research applications ranging from human machine interaction with UAS technology to orthorectified mosaic imaging. The lessons learned are provided to enable future researchers to create similar systems