552 research outputs found
A Structured Hardware/Software Architecture for Embedded Sensor Nodes
Owing to the limited requirement for sensor processing in early networked sensor nodes, embedded software was generally built around the communication stack. Modern sensor nodes have evolved to contain significant on-board functionality in addition to communications, including sensor processing, energy management, actuation and locationing. The embedded software for this functionality, however, is often implemented in the application layer of the communications stack, resulting in an unstructured, top-heavy and complex stack. In this paper, we propose an embedded system architecture to formally specify multiple interfaces on a sensor node. This architecture differs from existing solutions by providing a sensor node with multiple stacks (each stack implements a separate node function), all linked by a shared application layer. This establishes a structured platform for the formal design, specification and implementation of modern sensor and wireless sensor nodes. We describe a practical prototype of an intelligent sensing, energy-aware, sensor node that has been developed using this architecture, implementing stacks for communications, sensing and energy management. The structure and operation of the intelligent sensing and energy management stacks are described in detail. The proposed architecture promotes structured and modular design, allowing for efficient code reuse and being suitable for future generations of sensor nodes featuring interchangeable components
Simulation of Mixed Critical In-vehicular Networks
Future automotive applications ranging from advanced driver assistance to
autonomous driving will largely increase demands on in-vehicular networks. Data
flows of high bandwidth or low latency requirements, but in particular many
additional communication relations will introduce a new level of complexity to
the in-car communication system. It is expected that future communication
backbones which interconnect sensors and actuators with ECU in cars will be
built on Ethernet technologies. However, signalling from different application
domains demands for network services of tailored attributes, including
real-time transmission protocols as defined in the TSN Ethernet extensions.
These QoS constraints will increase network complexity even further.
Event-based simulation is a key technology to master the challenges of an
in-car network design. This chapter introduces the domain-specific aspects and
simulation models for in-vehicular networks and presents an overview of the
car-centric network design process. Starting from a domain specific description
language, we cover the corresponding simulation models with their workflows and
apply our approach to a related case study for an in-car network of a premium
car
Position paper on time and event-triggered communication services in the context of e-manufacturing
Modern factories are complex systems where
advances in networking and information technologies are
opening new ways towards higher efficiency. Such move
is being driven by market rules with ever-increasing
competition levels, in search for faster time-to-market,
improved process yield, non-stop operations, flexible
manufacturing and tighter supply-chain coupling. All
these aims present a common requirement, i.e. a realtime
flow of information, from the plant-floor up to the
management, maintenance, suppliers and clients, to
support accurate monitoring and control of the factory.
This stresses the importance achieved by the communication
infrastructure in modern manufacturing industry.
This paper presents the authors view concerning the
current trends in modern factory communication systems.
It addresses the problems of seamlessly integrating
different information flows with diverse requirements,
mainly in terms of timeliness. In this aspect, the debate
between event-triggered and time-triggered communication
is revisited as well as the joint support for both types
of traffic. Finally, a view of where factory communication
systems are moving to is also presented, showing the
impact of open and widely available technologies.FCT. Comissão Europeia(ARTIST,IST-2001-34820
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