241 research outputs found
NETWORK FOR MULTIMEDIA APPLICATION
International audienceFor the last four decades, the number and sophistication of electronic systems in vehicles have shown an exponential increase. One high-growth area is telematics systems-the convergence of mobile telecommunications and information processing in cars (radios, Web browsers, CD/DVD players, telematics, and infotainment systems). There is the need for a high-speed serial interface for future vehicles, able to share audio-video sources between all passengers and able to connect automotive electronic world with consumer electronic world. Different networks are available for multimedia automotive applications. Because of their capabilities IDB-1394b and Most are strong candidate. IDB 1394 is the automotive version of IEEE 1394 version b. It is designed for high-speed multimedia applications that require large amounts of information to be moved quickly in a vehicle. Key features include hot plug capability, compatibility with consumer electronics and the ability to use small, flexible, and inexpensive cables and connectors. Its flexible topology supports both branching and daisy-chaining of nodes. MOST (Media Oriented Systems Transport) is a Multimedia optical fiber system transport that is designed for the automotive environment. This paper presents the main characteristics of these two multimedia protocols. It includes the electrical characteristics, topology, transmission media, software layers⊠It includes as well some examples of applications and platform developmen
Space Shuttle/TDRSS communication and tracking systems analysis
In order to evaluate the technical and operational problem areas and provide a recommendation, the enhancements to the Tracking and Data Delay Satellite System (TDRSS) and Shuttle must be evaluated through simulation and analysis. These enhancement techniques must first be characterized, then modeled mathematically, and finally updated into LinCsim (analytical simulation package). The LinCsim package can then be used as an evaluation tool. Three areas of potential enhancements were identified: shuttle payload accommodations, TDRSS SSA and KSA services, and shuttle tracking system and navigation sensors. Recommendations for each area were discussed
Multimedia Networks: Fundamentals and Future Directions
Multimedia has become an integral part of computing and communications environment, and networks are carrying ever-increasing volume of multimedia information. The main characteristics of multimedia information are high-volume and bursty traffic, with low tolerance to delay and delay variance. The legacy networks (designed in 70s and 80s) are not able to meet these requirements. Enhancements to the older networking technologies have been developed to convert these into multimedia networks. Enhancements to LANs include Switched Ethernet, Isochronous Ethernet, Fast Ethernet, 100VGAnyLAN, FDDI-II, and Synchronous FDDI. WAN options for multimedia networking include digital leased lines and ISDN. The Internet has revolutionized business and personal communications, but falls short of being a genuine multimedia network. To make the Internet capable of carrying multimedia traffic, new protocols such as MBone, ST-II, RTP, and RSVP have been developed. Internet2 is a new initiative that is aimed at overcoming the problems of throughput, delay and jitter encountered on the original Internet. One technology that was developed with multimedia networking as one of its main applications, is the Asynchronous Transfer Mode (ATM) technology. Upcoming Gigabit Ethernet technology will provide a path for upgrading current Ethernet networks into multimedia networks
Centralized vs distributed communication scheme on switched ethernet for embedded military applications
Current military communication network is a generation
old and is no longer effective in meeting the emerging
requirements imposed by the future embedded military applications. Therefore, a new interconnection system is needed to overcome these limitations. Two new communication networks based upon Full Duplex Switched Ethernet are presented herein in this aim. The first one uses a distributed communication scheme where equipments can emit their data simultaneously, which clearly improves systemâs throughput and flexibility. However, migrating all existing applications into a compliant form could be an expensive step. To avoid this process, the second proposal consists in keeping the current centralized communication scheme. Our objective is to assess and compare the real time
guarantees that each proposal can offer. The paper includes the functional description of each proposed communication network and a military avionic application to highlight proposals ability to support the required time constrained communications
Performance analysis of a Master/Slave switched Ethernet for military embedded applications
Current military communication network is a generation
old and is no longer effective in meeting the emerging
requirements imposed by the next generation military embedded applications. A new communication network based upon Full Duplex Switched Ethernet is proposed in this paper to overcome these limitations. To allow existing military subsystems to be easily supported by a Switched Ethernet network, our proposal consists in keeping their current centralized communication scheme by using an optimized master/slave transmission control on Switched Ethernet thanks to the Flexible Time Triggered (FTT) paradigm. Our main objective is to assess the performance
of such a proposal and estimate the quality of service we
can expect in terms of latency. Using the Network Calculus formalism, schedulability analysis are determined. These analysis are illustrated in the case of a realistic military embedded application extracted from a real military aircraft network, to highlight the proposal's ability to support the required time constrained communications
Fault-tolerant communication channel structures
Systems and techniques for implementing fault-tolerant communication channels and features in communication systems. Selected commercial-off-the-shelf devices can be integrated in such systems to reduce the cost
CarRing IV- Real-time Computer Network
Ob in der Automobil-, Avionik- oder Automatisierungstechnik, die Fortschritte in der
Echtzeitkommunikation richten sich auf weitere Verbesserungen bereits existierender
Lösungen. Im Kfz-Bereich fĂŒhren die steigenden Zahlen computerbasierter Systeme,
Anwendungen und AnschlĂŒsse sowie die Verwendung mehrerer proprietĂ€rer Kommunikationsstandards zu einem immer komplexeren Kabelbaum. UrsĂ€chlich hierfĂŒr sind
inkompatible Standards, wodurch nicht nur die Kosten, sondern auch das Gewicht
und damit der Kraftstoffverbrauch negativ beeinflusst werden.
Im ersten Teil der Dissertation wird das Echtzeitprotokoll von CarRing IV (CRIV) vorgestellt. Es bietet isochrone und harte Echtzeitgarantien, ohne dass eine netzwerkweite Synchronisation erforderlich ist. Mit bis zu 16 Knoten pro Ring kann
ein CR-IV-Netz aus bis zu 256 Ringen bestehen, die durch Router miteinander verbunden sind. CR-IV verwendet ein reduziertes OSI-Modell (Schichten 1-3, 7), das
fĂŒr seine Anwendungsbereiche sowohl typisch als auch vorteilhaft ist. AuĂerdem
unterstĂŒtzt es sowohl ereignis- als auch zeitgesteuerte Kommunikationsparadigmen.
Der Transparent-Modus ermöglicht es CR-IV, als Backbone fĂŒr bestehende Netze
zu verwenden, wodurch InkompatibilitÀtsprobleme beseitigt werden und der Wechsel zu einer einheitlicheren Netzlösung erleichtert wird. Mit dieser FunktionalitÀt
können NutzergerĂ€te ĂŒber ein CR-IV-Netz miteinander verbunden werden, ohne dass
der Nutzer eingreifen oder etwas Ă€ndern muss. Durch Multicast unterstĂŒtzt CRIV auch die Emulation von Feldbussen. Der zweite Teil der Dissertation stellt den
anderen wichtigen Aspekt von CR-IV vor. Alle Schichten des OSI-Modells sind in
einem FPGA mit Hardware Description Languages (HDLs) ohne Hard- oder Softprozessoren implementiert. Das Register-Transfer-Level (RTL)-Hardwaredesign von
CR-IV wird mit einem neuen Ansatz erstellt, der am besten als tokenbasierter Datenfluss beschrieben werden kann. Der Ansatz ist sowohl vertikal als auch horizontal
skalierbar. Er verwendet lose gekoppelte Processing Elements (PEs), die stateless arbeiten, sowie Arbiter/Speicherzuordnungspaare. Durch die granulare Kontrolle und
die Aufteilung aller Aspekte einer Lösung eignet sich der Ansatz fĂŒr die Implementierung anderer Software-Level-Lösungen in Hardware.
Viele Testszenarios werden durchgefĂŒhrt, um die in CR-IV erzielten Ergebnisse zu
verdeutlichen und zu ĂŒberprĂŒfen. Diese Szenarien reichen von direkten Leistungsmessungen bis hin zu verhaltensspezifischen Tests. ZusĂ€tzlich wird eine Labor-Demo
erstellt, die grundsÀtzlich auf ein Proof of Concept zielt. Die Demo stellt einen
praktischen Test anstelle szenariospezifischer Tests dar. Alle Testszenarien und die
Labor-Demo werden mit den Prototyp-Boards des Projekts durchgefšuhrt, d.h. es sind
keine Simulationstests. Die Ergebnisse stellen die realistischen Leistungen von CR-IV
mit bis zu 13,61 Gbit/s dar.Whether be it automotive, avionics or automation, advances in their respective real-time communication technology focus on further improving preexisting solutions. For
in-vehicle communication, the ever-increasing number of computer-based systems,
applications and connections as well as the use of multiple proprietary communication
standards results in an increasingly complex wiring harness. This is in-part due to
those standards being incompatible with one another. In addition to cost, this also
impacts weight, which in turn affects fuel consumption.
The work presented in this thesis is in-part theoretical and in-part applied. The
former is represented by a new protocol, while the latter corresponds to the protocolâs
hardware implementation. In the first part of the thesis, the real-time communication protocol of CarRing IV (CR-IV) is presented. It provides isochronous and hard
real-time guarantees without requiring network-wide clock synchronization. With up
to 16 nodes per ring, a CR-IV network can consist of as many as 256 rings interconnected by routers. CR-IV uses a reduced OSI model (layers 1-3, 7), which is both
typical of and preferable for its application areas. Moreover, it supports both event- and time-triggered communication paradigms. The transparent mode feature allows
CR-IV to act as a backbone for existing networks, thereby addressing incompatibility
concerns and easing the transition into a more unified network solution. Using this
feature, user devices can communicate with one another via a CR-IV network without
requiring user interference, or any user device or application changes. Combined with
the protocolâs reliable multicast, the feature extends CR-IVâs capabilities to include
field bus emulation. The second part of the thesis presents the other important aspect
of CR-IV. All of its OSI model layers are implemented in a FPGA using Hardware
Description Languages (HDLs) without relying-on or including any hard or soft processors. CR-IVâs Register-Transfer Level (RTL) hardware design is created using a new
approach that can best be described as token-based data-flow. The approach is both
vertically and horizontally scalable. It uses stateless and loosely coupled Processing
Elements (PEs) as well as arbiter/memory allocation pairs. By having granular control and compartmentalizing every aspect of a solution, the approach lends itself to
being used for implementing other software-level solutions in hardware.
Many test scenarios are conducted to both highlight and examine the results
achieved in CR-IV. Those scenarios range from direct performance measurements to
behavior-specific tests. Moreover, a lab-demo is created that essentially amounts to
a proof of concept. The demo represents a practical test as opposed to a scenariospecific one. Whether be it test scenarios or the lab-demo, all are carried-out using the
projectâs prototype boards, i.e. no simulation tests. The results obtained represent
CR-IVâs real-world realistic outcomes with up to 13.61 Gbps
Spacelab system analysis: A study of the Marshall Avionics System Testbed (MAST)
An analysis of the Marshall Avionics Systems Testbed (MAST) communications requirements is presented. The average offered load for typical nodes is estimated. Suitable local area networks are determined
Spacelab system analysis: A study of communications systems for advanced launch systems
An analysis of the required performance of internal avionics data bases for future launch vehicles is presented. Suitable local area networks that can service these requirements are determined
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