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Real-time Calculus (RTC) is a non-stochastic queuing theory to the worst-case performance analysis of distributed real-time systems. Workload as well as resources are modelled as piece-wise linear, pseudo-periodic curves and the system under investigation is modelled as a sequence of algebraic operations over these curves. The memory footprint of computed curves increases exponentially with the sequence...
A new routing protocol that adjusts of the necessities of heterogeneous traffic is presented in this paper. The proposed scheme make improvement in TeGAR algorithm. The point of the scheme will be on accomplish low latency, and to fulfill various quality of service (QoS) in different network conditions. To do that, the proposed algorithm exploits multiple nodes' attributes like distance to the Sink,...
This paper studies Trust in real-time distributed database systems. High availability and fault-tolerance are important aspects of these real-time systems and are commonly achieved by replication. Different existing replication techniques are compared in this paper in terms of implementation and limitations. Also, a new replication technique; TIRS; is proposed that relies on Trust when reading or...
The article presents a simulation model of a Time-Triggered Ethernet real-time system. There are two types of traffic (real time traffic and standard traffic) that are used during frame processing in the Time-Triggered Ethernet. The authors considered a static configurable table of unique indexes and a static table of destination addresses when determining the destination address depending on the...
Real-time voice and video streaming applications require a certain Quality of Service (QoS) level for providing user satisfaction. As Wireless Local Area Networks (WLAN's) are not designed for such applications, assessing the communication's QoS level is a challenging task. Sudden Onset Disasters (SODs) poses even a greater challenge as the QoS level must be assessed without generating traffic or...
The next generation of mobile broadband technologies, namely the Fifth Generation (5G), will include an integration of legacy technologies like the Long Term Evolution (LTE), the Worldwide Interoperability for Microwave Access (WìMaX), the Wireless Fidelity (Wi-Fi), etc. However, Quality of Service (QoS) details are not fully defined for the integrated networks, and the subject is left open to be...
This paper proposes a new scheduling scheme which based on user perception, Channel- and QoS-Aware (known as E-MQS scheduler) for real-time traffics in LTE downlink direction. The proposed scheduling scheme is based on the extension of the E-model and the consideration of Maximum Queue Size (MQS) as a an essential factor for the metric. The proposed scheduling scheme is evaluated in LTE heterogeneous...
With advances in the information and communication technology (ICT), connected vehicles are one of the key enablers to unleash intelligent transportation systems (ITS). On the other hand, the envisioned massive number of connected vehicles raises the need for powerful communication and computation capabilities. As an emerging technique, fog computing is expected to be integrated with existing communication...
The controller is a critical piece of the SDN architecture, where it is considered as the mastermind of SDN networks. Thus, its failure will cause a significant portion of the network to fail. Overload is one of the common causes of failure since the controller is frequently invoked by new flows. Even through SDN controllers are often replicated, the significant recovery time can be an overkill for...
Mesh networks provide natural link and node fault tolerance and load balancing characteristics. However, existing solutions for real-time flow allocation seldom utilize those advantages. This paper deals with the real-time flow allocation problem in mesh networks. The objective is to find the suitable path under delay constraint while allowing load balancing. For this purpose, combined online flow...
Delays are often present in embedded and networked control loops and represent one of the main sources of performance limitations. In this paper, we propose two aperiodic control strategies to optimize closed-loop performance in the presence of stochastic delays: (i) a self-triggered strategy, in which the deadline to drop data is decided on-line based on the current state; (ii) an event-driven strategy,...
Hardware in the Loop (HiL) supports development processes in many types of applications. Power electronic systems with switching frequencies up to several kilo hertz constitute some of the most demanding applications for the quantization time of the HiL. The non-avoidable delay forces very short calculation periods which lead to high effort in hardware and software implementation. For PWM based controllers...
When it comes down to public transport systems, delays are a hot topic. For a quantitative conclusion whether a delay is just an incident or happens on a regular basis, we have to believe in the figures published in the annual reports of public transport companies. However, even if some data is available online, it is quite hard to independently examine these numbers without information technologies...
Both traditional wireless sensor networks and novel crowdsensing techniques generate tremendous real- time data, which provides great opportunities for real- time and long-term analytics. However, how to integrate the heterogeneous data sources and create data analytics toolboxes that can be connected together to solve various problems in urban environment remains open problems. As a PhD student,...
Correctly maintained synchronization between devices is very important in deterministic networks like TTEthernet where is used AS6802 standard for this purposes. In this paper is depicted how to calculate number of integration cycles per cluster period depending on accuracy of clocks implemented in network devices. Influence of the number of integration cycles to bandwidth utilization is analyzed...
We present traffic flow and control models for the train dynamics in metro lines. In a first model we introduce the effect of passenger demand on the train dwell times at platforms. We recall that, if this effect is not well controlled, then the traffic is unstable. Then we propose a second traffic control model which deals with this instability, by modifying the control of the train dwell times at...
Abstract-Most practical energy-saving mechanisms for a modem rely on a packet transmission delaying technique where the smartphone attempts to reduce the energy consumption of the modem by delaying transmissions of delay-tolerant packets and piggybacking them onto later packets. However, unconditional packet transmission delaying may lead to unanticipated energy loss at the modem since the exact radio...
Scheduling in queueing networks concerns a scenario where a scheduler, using system backlog information, decides to which processor to route arriving jobs to achieve various objectives. However, in such scenarios, a significant yet inevitable challenge facing the scheduler in practice is its delayed access to such system configuration information. In this paper, we incorporate this crucial delay element...
In real-time embedded systems, periodic messages need to be transmitted at the expected time because of timing sensitive requirements. In this paper, we take advantage of the characteristics of UM-BUS, a novel serial bus with the capability of multi-lane concurrent transmissions, and investigate the scheduling problem to reduce the deviation to the expected completion time of messages. By configuring...
Numerous researchers have studied the contention that arises among tasks running in parallel on a multicore processor. Most of those studies seek to derive a tight and sound upper-bound for the worst-case delay with which a processor resource may serve an incoming request, when its access is arbitrated using time-predictable policies such as round-robin or FIFO. We call this value upper-bound delay...
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