Letting the Puss in Boots Sweat: Detecting Fake Access Points using Dependency of Clock Skews on Temperature

in Proceedings of the 9th ACM Symposium on Information, Computer and Communications Security (ASIACCS 2014) (2014)

A Cooperative Advanced Driver Assistance System to Mitigate Vehicular Traffic Shock Waves

in IEEE INFOCOM 2014 - IEEE Conference on Computer Communications (2014)

We address the problem of shock wave formation in uncoordinated highway traffic. First, we identify the combination of heavy traffic and small traffic perturbations or unexpected driver actions as the ... [more ▼]

We address the problem of shock wave formation in uncoordinated highway traffic. First, we identify the combination of heavy traffic and small traffic perturbations or unexpected driver actions as the main causes of highway traffic jams. Then we introduce a novel distributed communication protocol that enables us to eliminate upstream shock wave formation even with low system penetration rates. Based on traffic information ahead, we propose a Cooperative Advanced Driver Assistance System (CADAS) that recommends non-intuitive velocity reductions in order to redistribute traffic more uniformly thereby eliminating traffic peaks. Simulation results show that CADAS significantly increases the average velocity and therewith reduces the overall travel time and avoids unnecessary slowdowns. [less ▲]

Solving the FIXML2Code-case Study with HenshinTGG

in Rose, Louis M.; Krause, Christian; Horn, Tassilo (Eds.) Proceedings of the 7th Transformation Tool Contest - part of the Software Technologies: Applications and Foundations (STAF 2014) federation of conferences (2014)

Triple graph grammars (TGGs) provide a formal framework for bidirectional model transformations. As in practice, TGGs are primarily used in pure model-to-model transformation scenarios, tools for text-to ... [more ▼]

Triple graph grammars (TGGs) provide a formal framework for bidirectional model transformations. As in practice, TGGs are primarily used in pure model-to-model transformation scenarios, tools for text-to-model and model-to-text transformations make them also applicable in text-to-text transformation contexts. This paper presents a solution for the text-to-text transformation case study of the Transformation Tool Contest 2014 on translating FIXML (an XML notation for financial transactions) to source code written in Java, C# or C++. The solution uses the HenshinTGG tool for specifying and executing model-to-model transformations based on the formal concept of TGGs as well as the Xtext tool for parsing XML content to yield its abstract syntax tree (text-to-model transformation) and serialising abstract syntax trees to source code (model-to-text transformation). The approach is evaluated concerning a given set of criteria. [less ▲]

A Study of Urban IEEE 802.11 Hotspot Networks: Towards a Community Access Network

in A Study of Urban IEEE 802.11 Hotspot Networks: Towards a Community Access Network (2013, November 13)

With the increasing demand for faster data connectivity, different wireless technologies have been deployed in the last decade, creating a heterogeneous wireless environment. Such wireless diversity is ... [more ▼]

With the increasing demand for faster data connectivity, different wireless technologies have been deployed in the last decade, creating a heterogeneous wireless environment. Such wireless diversity is mainly composed of 2G/3G/4G cellular base stations, IEEE 802.11 hotspots and Community Networks. Previous work suggests that the increasing popularity of IEEE 802.11 networks would mitigate the overloading of current operator-based cellular deployments. However, the unpredictable characteristics of IEEE 802.11 deployments and its loose coupling to cellular architectures limit its user performance in terms of throughput and mobility capacity. In this paper, we describe an evaluation study of a commercial-grade hotspot network in the city of Luxembourg, namely HOTCITY. Through a set of experiments, we provide a characterization of the hotspot network and give a set of performance indicators. Finally, we evaluate hotspot networks' potential to support cellular offloading through the integration of outdoor hotspots and private access points deployed indoors in a single Community Network. [less ▲]

Improving Traffic in Urban Environments applying the Wardrop Equilibrium

in Improving Traffic in Urban Environments applying the Wardrop Equilibrium (2013, October 07)

Over the last few years vehicular traffic density has continuously increased and it is likely that the traffic demand will further increase in the future. In many metropolitan areas the road ... [more ▼]

Over the last few years vehicular traffic density has continuously increased and it is likely that the traffic demand will further increase in the future. In many metropolitan areas the road infrastructure is no longer able to handle the peak traffic demand and the existing road network cannot be easily extended. The best way to improve the traffic situation is to optimise the resources available in the transportation network and to coordinate the traffic demand. The approach that we propose in this paper makes use of a collaborative traffic coordination protocol which collects real-time Floating Car Data (FCD) directly from participating vehicles and suggests dynamic routes in order to minimize travel delay. Information such as speed, position and direction is sent to one or more Traffic Coordination Points (TCPs) where it is aggregated to obtain a global picture of the traffic conditions in real-time. Based on this data, we continuously compute the route that minimizes the travel time to a given destination by applying Wardrop’s first principle of equilibrium. Our results show that, by coordinating the vehicles, we are able to better distribute the overall traffic demand throughout the transportation network, reducing the average travel times and accommodating more vehicles. [less ▲]

Automated Source Code Extension for Debugging of OpenFlow based Networks

in Proc. 9th International Conference on Network and Service Management (CNSM) (2013, October)

Software-Defined Networks using OpenFlow have to provide a reliable way to to detect network faults in operational environments. Since the functionality of such networks is mainly based on the installed ... [more ▼]

Software-Defined Networks using OpenFlow have to provide a reliable way to to detect network faults in operational environments. Since the functionality of such networks is mainly based on the installed software, tools are required in order to determine software bugs. Moreover, network debugging might be necessary in order to detect faults that occurred on the network devices. To determine such activities, existing controller programs must be extended with the relevant functionality. In this paper we propose a framework that can modify controller programs transparently by using graph transformation, making possible online fault management through logging of network parameters in a NoSQL database. Latter acts as a storage system for flow entries and respective parameters, that can be leveraged to detect network anomalies or to perform forensic analysis. [less ▲]

Driver Behavior Profiling using Smartphones

in Driver Behavior Profiling using Smartphones (2013, October)

The proliferation of smartphones and mobile devices embedding different types of sensors sets up a prodigious and distributed sensing platform. In particular, in the last years there has been an ... [more ▼]

The proliferation of smartphones and mobile devices embedding different types of sensors sets up a prodigious and distributed sensing platform. In particular, in the last years there has been an increasing necessity to monitor drivers to identify bad driving habits in order to optimize fuel consumption, to reduce CO2 emissions or, indeed, to design new reliable and fair pricing schemes for the insurance market. In this paper, we analyze the driver sensing capacity of smartphones. We propose a mobile tool that makes use of the most common sensors embedded in current smartphones and implement a Fuzzy Inference System that scores the overall driving behavior by combining different fuzzy sensing data. [less ▲]

Identifying abnormal pattern in cellular communication flows

in Proceedings of IPTComm 2013 (2013, October)

Analyzing communication flows on the network can help to improve the overall quality it provides to its users and allow the operators to detect abnormal patterns and react accordingly. In this paper we ... [more ▼]

Analyzing communication flows on the network can help to improve the overall quality it provides to its users and allow the operators to detect abnormal patterns and react accordingly. In this paper we consider the analysis of large volumes of cellular communications records. We propose a method that detects abnormal communications events covering call data record volumes, comprising a country-level data set. We detect patterns by calculating a weighted average using a sliding window with a fixed period and correlate the results with actual events happening at that time. We are able to successfully detect several events using a data set provided by a mobile phone operator, and suggest examples of future usage of the outcome such as real time pattern detection and possible visualisation for mobile phone operators. [less ▲]

Path Extension Analysis of Peer-to-Peer Communications in 6LoWPAN/RPL Sensor Networks

in Abstract book of 21st International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems, MASCOTS’13 (2013)

Researchers and manufacturers are currently putting a lot of efforts to design, improve and deploy the Internet of Things, involving a significant number of constrained and low cost embedded devices ... [more ▼]

Researchers and manufacturers are currently putting a lot of efforts to design, improve and deploy the Internet of Things, involving a significant number of constrained and low cost embedded devices deployed in large scales with low power consumption, low bandwidth and limited communication range. For instance we can easily build a network composed by multiple sensors distributed in a building in order to monitor temperature in different offices. This kind of architecture is generally centralized as all sensors are mainly programmed to periodically transmit their data to the sink. The specific IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) had been designed in order to enable such communications. Support for point-to-point traffic is also available. In fact new applications may also consider peer-to-peer communications between any nodes of the network. In that case, RPL is not optimal as data packets are forwarded in respect with longer paths with larger metrics. In this paper we propose to study the effectiveness of RPL compared to a shortest path algorithm such like the Dijkstra's algorithm. We suggest to analyze peer-to-peer communications inside random wireless sensor network topologies with size limited to 250 nodes, corresponding to a reasonable cluster size. We have built a particular simulation environment named Network Analysis and Routing eVALuation (NARVAL). This toolbox permits to generate random topologies in order to study the impact of routing algorithms on the effectiveness of communication protocols. In our work, we first generated many random network topologies where we selected a sink node. We built the Destination Oriented Directed Acyclic Graph (DODAG) from the chosen sink in respect with the RPL algorithm. We finally performed all paths between each couple of two distinct sensor nodes and compared them to the corresponding shortest paths obtained by the Dijkstra's algorithm. This approach permits to retrieve some statistics on the path extension between RPL and the Dijkstra's algorithm. We also analyzed the impact of the sink position and the network size on this path extension. [less ▲]

On the Evaluation of Make-Before-Break Handovers in Urban WiFi Networks for Moving Vehicles

Scientific Conference (2013, February)