Ilja Radusch

sim TD : a car-to-X system architecture for field operational tests [Topics in Automotive Networking]

Car-to-car and car-to-infrastructure communications are considered as a key technology for safe and intelligent mobility in the future. In the German project simTD, car-to-x communication is shifting from a pure research topic toward a first deployment of such a system: the goal of simTD is to test car-to-x applications in a real metropolitan field trial. The simTD scenario includes vehicles, roadside units, and infrastructural facilities for traffic and test management. Besides these domains, several third parties are involved to provide access to additional services. The main communication partners are furthermore distributed over a wide area including highway, suburban, and urban scenarios. As a result, such a system requires a commonly accepted architecture of the individual components and a seamless communication network for reliable and efficient information interchange. In this article we propose the simTD system architecture and the components necessary for successful deployment in the large-scale field trial.

V2X-Based Traffic Congestion Recognition and Avoidance

Vehicular traffic congestion is a global phenomenon that has increased in importance in the last decades and has caused economically and ecologically negative effects. Thus, finding a way to improve traffic efficiency is a high-frequented problem to be solved by scientists and politicians worldwide. One new promising approach is the usage of decentralized wireless vehicle to vehicle communication based on the Vehicle-2-X (V2X) technology. The idea is that vehicles share information about the current local traffic situation and use this information to optimize their routes. In this paper, we introduce a new algorithm that can be used by navigation systems to calculate routes circumnavigating congested roads. For this purpose, each vehicle transmits its average speed of a road segment to vehicles in the neighbourhood. As a result, vehicles receiving this information can recalculate their routes based on the knowledge about the current possible speeds in the road segments of their neighbourhood. To evaluate the improvements that can be achieved by our algorithm, simulations have been done. Our results show that navigation systems using the V2X technology for a more intelligent route calculation can improve the traffic efficiency of future transport systems.

pREST: a REST-based protocol for pervasive systems

The convergence of embedded systems and wireless communication enables interconnection of electronic devices to render control and provide information to the user. Offices, apartments, and public spaces are or in the near future will be able to deliver information and services to their occupants ranging from instant Internet access to configuration and control in a context dependent, personalized way. Despite progressing internetworking and sophistication, we are still dealing with islands of functionality rather than the invisible computer envisioned by Mark Weiser. We believe that the spread and acceptance of smart environments will depend on common standards as well as a simple and flexible way to access data and devices and compose services from existing ones. A good example of such a system is the World Wide Web, whose success is mainly due to the simplicity with which all kinds of content can be published and referenced. We present an access protocol to bring the Webs simplicity and holistic view on data and services to pervasive systems. Our approach is based on the representational state transfer architectural style and emphasizes abstraction of data and services as resources, interoperation via self describing data and service orchestration with loosely typed components. A particular concern is to provide for functionality in the absence of proxy nodes or infrastructure services like directory servers.

Realistic Simulation of V2X Communication Scenarios

Vehicle-2-X (V2X) Communication provides the foundation for new applications that enhance both safety and traffic efficiency. Before V2X applications can be deployed in practice, their in-depth analysis is necessary. For this end, detailed and realistic simulations are essential. Depending on the simulated V2X Communication application, particular simulators have to be coupled. For this purpose, we have developed the V2X Simulation Runtime Infrastructure (VSimRTI) offering the flexibility to combine arbitrary simulators. The VSimRTI is derived from concepts of the High Level Architecture (HLA). It synchronizes the simulators and enables the communication among them. Another feature of our simulation environment is the emulation of the environment of V2X Communication applications in real vehicles. As a result, we can integrate real V2X Communication applications without modifications.

Stochastic Park-and-Charge Balancing for Fully Electric and Plug-in Hybrid Vehicles

Motivated by the need to provide services to alleviate range anxiety of electric vehicles, we consider the problem of balancing charging demand across a network of charging stations. Our objective is to reduce the potential for excessively long queues to build up at some charging stations, although other charging stations are underutilized. A stochastic balancing algorithm is presented to achieve these goals. A further feature of this algorithm is that it is fully decentralized and facilitates a plug-and-play type of behavior. Using our system, the charging stations can join and leave the network without any changes to, or communication with, a centralized infrastructure. Analysis and simulations are presented to illustrate the efficacy of our algorithm.

Cooperative Regulation and Trading of Emissions Using Plug-in Hybrid Vehicles

We present a new approach to regulate traffic-related pollution in urban environments by utilizing hybrid vehicles. To do this, we orchestrate the way that each vehicle in a large fleet combines its two engines based on simple communication signals from a central infrastructure. Our approach can be viewed both as a control algorithm and as an optimization algorithm. The primary goal is to regulate emissions, and we discuss a number of control strategies to achieve this goal. Second, we want to allocate the available pollution budget in a fair way among the participating vehicles; again, we explore several different notions of fairness that can be achieved. The efficacy of our approach is exemplified both by the construction of a proof-of-concept vehicle and by extensive simulations, and is verified by mathematical analysis.

Efficient traffic simulator coupling in a distributed V2X simulation environment

For the simulation of all aspects of V2X Communication scenarios, different simulators have to be combined and an interaction among them at runtime of the simulation has to be enabled. Hence, we have developed the V2X Simulation Runtime Infrastructure (VSimRTI) which couples discrete event-based simulators, e.g. for communication network, traffic, and V2X application simulation. The flexibility of VSimRTI allows us to vary the composition of integrated simulators depending on the specific requirements of a scenario. Moreover, optimistic synchronisation mechanisms enable us to decrease simulation time. In this paper, we combine both traffic simulators VISSIM and SUMO. VISSIM is used to achieve a highly accurate simulation of the most interesting region, whereas the more efficient traffic simulator SUMO simulates surrounding areas. We shall show that this simulator coupling reduces the overall simulation time without any decrease in accuracy. This work has been carried out within the PRE-DRIVE C2X project.

A Novel Approach for Realistic Emulation of Vehicle-2-X Communication Applications

New applications in future intelligent transportation systems are to enhance both safety and traffic efficiency. Wireless vehicular communication is to provide the basis for the new Vehicle-2-X communication applications. However, field tests are necessary to make them usable and validate the improvements that are to be achieved. Since the realization of the field tests is rather complex and expensive, detailed simulations are essential to prepare the tests in the real world and reduce their costs. Currently, software simulators do not support all aspects necessary for a proper validation of Vehicle-2-X applications. In this paper, an integrated software simulation environment that fulfils the special requirements of Vehicle-2-X applications is presented. Furthermore, our testbed architecture that allows simulating Vehicle-2-X communication under real physical conditions is introduced.

Runtime infrastructure for simulating vehicle-2-x communication scenarios

Simulations are essential to evaluate Vehicle-2-X Communication applications and to efficiently prepare their deployment. Accordingly, to enable realistic simulations of Vehicle-2-X Communication applications, different kinds of simulators have to be coupled dynamically. Running coupled simulators synchronously and exchanging simulation data among them is a challenging task. Currently, simulator couplings lack flexibility because they are designed merely for specific simulators. In this work, the runtime infrastructure VSimRTI is presented allowing a flexible combination of time-discrete simulators for Vehicle-2-X simulations. Based on the requirements of a concrete scenario, arbitrary simulators can be plugged onto the VSimRTI and are executed together.

Request-driven Service Provisioning

Heterogeneous smart and mobile devices increasingly form a pervasive computing environment. Service oriented architecture (SOA) provides a unified view on the resources and services of those environments to make them easily available for applications. However, variations in the reliability and the availability of these services result in special requirements for the interactions of service providers and service requesters. In this paper we propose a SOA approach that is based on temporally and spatially uncoupled interactions, and supports a loose coupling in the terminology of exchanged data. For that purpose we define a service model as well as an interaction model for request-driven service provisioning and present an approach for the implementation of these models