R. Rajkumar, M. Gagliardi, and L. Sha. The Real-Time Publisher/Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation. In IEEE RTAS, 1995.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....unsubscribe (SubscriberLifeCycle ) 3.2. 2 DistributionTag connector The DistributionTag connector is a multi cast message passing mechanism that allows a group of components (publishers) to advertise messages and other group of components (subscribers) to receive the published messages [5]. There can be one or more publishers and one or more subscribers. The publishers do not need to know the identity of the subscribers and vice versa. When a publisher sends a message, the message is broadcasted to all the registered subscribers. For a given distributionTag connector, their ....

Ragunathan Rajkumar, Michael Gagliardi, and Lui Sha. "The Real-Time Publisher/Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation". Software Engineering Institute, Carnegie Mellon University, 1994

....is amenable to a formal schedulability analysis. The idea of a publish subscribe inter process communication scheme is certainly not new. The scheme used in AVCSS has some di erences with respect to other P S architectures. For instance, it is not a pure P S scheme as the one proposed in [12], where messages are sent only from publishers to subscribers. Instead, the P S of AVCSS maintains the notion of a shared memory, where readers can access variables (atomically) at any time, while at the same time having the possibility to subscribe by setting triggers. Performing the ....

R. Rajkumar, M. Gagliardi, and L. Sha. The real-time publisher/subscriber interprocess communication model for distributed real-time systems: Design and implementation. In IEEE Real-time Technology and Applications Symposium, 1995.

....have evolved. Timely communication is essential to allow applications in these domains to be realized. The real time event based communication paradigm has been recognized as an appropriate high level communication scheme to connect autonomous components in large distributed control systems [6]. The challenge remains to extend real time event based communication to mobile nodes in a dynamic wireless ad hoc network where the assumption of a fixed infrastructure is not applicable. In this paper we discuss the assumptions upon which existing (real time) event based communication models ....

R. Rajkumar and M. Gagliardi, "The Real-Time Publisher/Subscriber Inter-process communication Model for Distributed Real-Time Systems: Design and Implementation". in IEEE Real-time Technology and Applications Symposium, May 1995.

....for a publisher subscriber communication model. Since the publisher subscriber model is extremely attractive for the structuring of object oriented control applications, the OMG specified a CORBA event service [13] according to this model. For the real time domain, several implementations [2][18] of the event service exist, which are often based on TCP IP. Kaiser in [4] and Kim in [7] present possibilities to integrate the CAN Bus into the event service. To use the CAN Bus in Real Time CORBA, a CAN based connection oriented communication model has also to be developed. Kim presents in [7] ....

R. Rajkumar, M. Gagliardi, and L. Sha. The Real-Time Publisher /Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation. In Proceedings of the IEEE Real-time Technology and Applications Symposium, June 1995.

....the QoS of Standard Publisher Subscriber Architectures. If implemented properly, publisher subscriber architectures satisfy many DRE application challenges. However, many implementations of publisher subscriber architectures rely on non standard distribution and infrastructure middleware [6, 7]. Comparatively little research has focused on applying (and potentially augmenting) standard middleware to publisher subscriber architectures to meet the needs of DRE applications. Moreover, research that has focused on this topic [8, 9] has not documented the key patterns and frameworks ....

....can be applied to TAO s Real time Event Service in conjunction with the patterns described in this paper to yield an efficient, predictable, and highly scalable publisher subscriber architecture. CMU Pub Sub. Rajkumar, et al. describe a real time publisher subscriber prototype developed at CMU [6]. Their publisher subscriber model is similar to the CORBA Event Service. An interesting aspect of the CMU model is the separation of priorities for subscription and event transfer so that these activities can be handled by different threads with different priorities. However, the model does not ....

R. Rajkumar, M. Gagliardi, and L. Sha, "The Real-Time Publisher/Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation," in First IEEE Real-Time Technology and Applications Symposium, May 1995.

....use data from sensor proxies to provide higher level views to other application objects. For instance, the aircraft position computed by an I O facade is used by the navigation and weapons release subsystems. The push driven model described above is commonly used in many real time environments [33], such as industrial process control systems and military command control systems. One positive consequence of this push driven model is its efficient and predictable execution of operations. For instance, I O facades only execute when their event dependencies are satisfied, i.e. when they are ....

....Event Channel alleviate the disadvantages of the tightly coupled consumers and suppliers shown in Figure 4. The CORBA Event Service defines supplier, consumer,andevent channel participants so that distributed applications can exchange requests asynchronously via an event based execution model [33]. Suppliers generate events, consumers process events sent by suppliers, and event channels propagate events to consumers on behalf of suppliers. The architecture of our example avionics mission computing application [6] centers on the Publish Subscribe [11] pattern shown in Figure 5. As shown in ....

[Article contains additional citation context not shown here]

R. Rajkumar, M. Gagliardi, and L. Sha, "The Real-Time Publisher/Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation," in First IEEE Real-Time Technology and Applications Symposium, May 1995.

....and operation dispatching. Figure 2 illustrates the primary components in the OMG Reference Model architecture. The ACE ORB (TAO) 10] is a freely available, open source implementation of CORBA. Many distributed applications exchange asynchronous requests using event based execution models [18, 19, 20]. To support these common use cases, the OMG defined a CORBA Event Service component in the CORBA Object Services (COS) layer, as shown in Figure 2. The COS specification [21] presents architectural models and interfaces that factor out common object services, such as persistence [22] security ....

R. Rajkumar, M. Gagliardi, and L. Sha, "The Real-Time Publisher/Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation," in First IEEE Real-Time Technology and Applications Symposium, May 1995.

....and is typically hidden from the application. In this paper, we are associating Q channels with a data event service which applications use for their distributed communications. Our motivation for using event channels in data communications is twofold. First, event and publish subscribe services [6, 16] have become prevalent in distributed applications that range from virtual reality and avionics to support for mobile users [4, 9] Second, recent research contributions have pointed out the applicability of event services for continuous media transfers [2, 11] The event service used to ....

R. Rajkumar, M. Gagliardi, and L. Sha. The Real-Time Publisher /Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation. In Proc. of the 1st IEEE Real-Time Technology and Applications Symposium, May 1995.

....agreement on membership among the communicating processors, and ensures that membership changes resulting from processor joins or departures are atomic and ordered with respect to multicast messages. Both TTP and RTCAST are based on active replication whereas RTPB is a passive scheme. Rajkumar [2, 3] presents a publisher subscriber model for distributed real time systems. It provides a simple user interface for publishing messages on a logical channel , and for subscribing to selected channels as needed by each application. In the absence of faults each message sent by a publisher on a ....

R. Rajkumar et al. The real-time publishersubscriber inter-process communication model for distributed real-time systems: Design and implementation. In Proc. Real-Time Technology and Applications Symposium, pages 66--75, May 1995.

....the table identifying a particular object and subsequent portions identify object states. The least significant portion of the key corresponds to a particular attribute of the object. 2. GCOST Coordination An asynchronous coordination of GCOST entries is achieved using a publisher subscriber [8] interaction pattern built on state based communications. Each insert or update into GCOST results in a call to the Semantic Event Interpreter that associatively publishes the update. The message semantic selector is uniquely generated. Similarly an active listener process monitors message ....

R.Rajkumar, M.Gagliardi and L.Shua "The Real-Time Publisher Subscriber Inter-Process Communication model for Distributed Real-Time Systems," Technical report, SEI, Carnegie Mellon University, 1997.

....of the string sent by the SEM manager. The delimiters described above serves to define each part of the string which in turn serves to index an entry uniquely into the hash table. 6. 3 GCOST Coordination An asynchronous coordination of GCOST entries is achieved using a publisher subscriber [RAJ97] interaction pattern built on state based communications. Each insert or update into GCOST results in a call to the Semantic Event Interpreter that associatively publishes the update. The message semantic selector is uniquely generated. Similarly an active listener process monitors message ....

R.Rajkumar, M.Gagliardi and L.Shua "The Real-Time Publisher Subscriber InterProcess Communication model for Distributed Real-Time Systems," SEI, Carneige Mellon

....the table identifying a particular object and subsequent portions identify object states. The least significant portion of the key corresponds to a particular attribute of the object. 2. GCOST Coordination An asynchronous coordination of GCOST entries is achieved using a publisher subscriber [8] interaction pattern built on state based communications. Each insert or update into GCOST results in a call to the SII that associatively publishes the update. The message semantic selector is uniquely generated. Similarly an active listener process monitors message selectors and subscribes to ....

R.Rajkumar, M.Gagliardi and L.Shua "The Real-Time Publisher Subscriber Inter-Process Communication model for Distributed Real-Time Systems," Technical report, SMI, Carnegie Mellon University, 1997.

....different channel classes are mapped to the mechanisms necessary to implement the model on the CAN Bus. 1 Introduction The publisher subscriber (P S) model has been recognized as an appropriate high level communication scheme to connect autonomous components in large distributed control systems [21], 20] Particularly, P S supports autonomy of components by an asynchronous notification mechanism omitting any implicit control transfer coupled with the exchange of information. This is in contrast to other high level interaction models as remote procedure calls or remote invocations which ....

R. Rajkumar, M. Gagliardi, and L. Sha. The real-time publisher/subscriber inter-process communication model for distributed real-time systems: Design and implementation. In IEEE Real-time Technology and Applications Symposium, June 1995.

....down processing on a mobile device. You can also observe that at some frequencies the energy consumption rises. We disregard this behavior in this paper, but point out that others (e.g. in [9] have investigated this issue. Solution Approach. Event services or publish subscribe mechanisms [2, 4, 7, 16] are increasingly being deployed in applications that range from remote sensing, to multimedia and video streaming [1, 10] to transactional systems [3] We adopt this approach to enable per frame power management for multimedia applications. That is, video or audio frames are distributed as data ....

R. Rajkumar, M. Gagliardi, and L. Sha. The Real-Time Publisher/Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation. In Proc. of the 1st IEEE Real-Time Technology and Applications Symposium, May 1995.

....manage the quality of service experienced by end users. Further, the Q fabric mechanism is implemented as a kernel level service, which enables QoS management at higher levels of predictability and performance than possible with the user level counterparts developed in our past work and elsewhere [7, 12, 14]. The remainder of this section describes the QoS management model used in our work. Event based communications. The Q fabric s operation is based on the exchange of events, which trigger the execution of some action (e.g. monitoring, adaptation, etc. Event exchange is anonymous, so that local ....

R. Rajkumar, M. Gagliardi, and L. Sha. The Real-Time Publisher/Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation. In Proc. of the 1st IEEE Real-Time Technology and Applications Symposium, May 1995.

No context found.

R. Rajkumar, M. Gagliardi, and L. Sha. The Real-Time Publisher/Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation. In IEEE RTAS, 1995.

No context found.

R. Rajkumar and M. Gagliardi, "The Real-Time Publisher/Subscriber Inter-process communication Model for Distributed Real-Time Systems: Design and Implementation". in IEEE Real-time Technology and Applications Symposium, May 1995.

No context found.

R. Rajkumar and M. Gagliardi, "The Real-Time Publisher/Subscriber Inter-process communication Model for Distributed Real-Time Systems: Design and Implementation". in IEEE Real-time Technology and Applications Symposium, May 1995.

No context found.

R. Rajkumar, M. Gagliardi, and L. Sha, "The Real-Time Publisher/Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation," in Proceedings of the IEEE Real-time Technology and Applications Symposium, 1995.

No context found.

R. Rajkumar, M. Gagliardi, and L. Sha, "The real-time publisher /subscriber inter-process communication model for distributed realtime systems: Design and implementation," in IEEE Real-time Technology and Applications Symposium, 1995.

No context found.

R. Rajkumar, M. Gagliardi, and L. Sha. The Real-Time Publisher/Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation. In IEEE RTAS, 1995.

No context found.

R. Rajkumar, M. Gagliardi, and L. Sha, "The Real-Time Publisher/Subscriber Inter-Process Communication Model for Distributed Real-Time Systems: Design and Implementation," in First IEEE Real-Time Technology and Applications Symposium, May 1995.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC