Journal ArticleDOI
Analyzing TDMA With Slot Skipping
TLDR
A schedulability analysis for TDMA/SS is proposed, assuming knowledge of all message streams in the system, and that each node schedules messages in its output queue according to deadline monotonic, and also presents an algorithm that computes exact queuing times.Abstract:
Distributed real-time systems, such as factory automation systems, require that computer nodes communicate with a known and low bound on the communication delay. This can be achieved with traditional time division multiple access (TDMA). But improved flexibility and simpler upgrades are possible through the use of TDMA with slot-skipping (TDMA/SS), meaning that a slot is skipped whenever it is not used and consequently the slot after the skipped slot starts earlier. We propose a schedulability analysis for TDMA/SS. We assume knowledge of all message streams in the system, and that each node schedules messages in its output queue according to deadline monotonic. Firstly, we present a non-exact (but fast) analysis and then, at the cost of computation time, we also present an algorithm that computes exact queuing times.read more
Citations
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Journal ArticleDOI
Profinet IO IRT Message Scheduling With Temporal Constraints
TL;DR: This paper presents an algorithm that allows one to create a static schedule of the Profinet IO IRT (Isochronous Real Time) communication, which is an industrial Ethernet protocol standardized in IEC 61158, providing comparable results with respect to the resulting schedule makespan.
Proceedings ArticleDOI
Profinet IO IRT Message Scheduling
TL;DR: An algorithm that allows one to create a static schedule of the Profinet IO IRT communication, which is an industrial Ethernet protocol standardised in IEC, is presented, providing comparable results regarding the resulting time schedule length.
Journal ArticleDOI
(m,k)-firm pattern spinning to improve the GTS allocation of periodic messages in IEEE 802.15.4 networks
TL;DR: This paper proposes the use of a dynamic GTS scheduling approach based on the (m,k)-firm task model, to deal with the GTS starvation problem.
Proceedings ArticleDOI
Inter-cell Channel Time-Slot Scheduling for Multichannel Multiradio Cellular Fieldbuses
TL;DR: The equivalence of the three for chained cellular fieldbus topology, a typical topology with broad applications, implies the optimality of greedy scheduling, and the sufficiency and necessity of the schedulability test in the context of chained topology is proved.
References
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Journal ArticleDOI
Scheduling Algorithms for Multiprogramming in a Hard-Real-Time Environment
C. L. Liu,James W. Layland +1 more
TL;DR: The problem of multiprogram scheduling on a single processor is studied from the viewpoint of the characteristics peculiar to the program functions that need guaranteed service and it is shown that an optimum fixed priority scheduler possesses an upper bound to processor utilization.
Book
Scheduling algorithms for multiprogramming in a hard real-time environment
C. L. Liu,James W. Layland +1 more
TL;DR: In this paper, the problem of multiprogram scheduling on a single processor is studied from the viewpoint of the characteristics peculiar to the program functions that need guaranteed service, and it is shown that an optimum fixed priority scheduler possesses an upper bound to processor utilization which may be as low as 70 percent for large task sets.
Journal ArticleDOI
Finding Response Times in a Real-Time System
Mathai Joseph,Paritosh K. Pandya +1 more
Journal ArticleDOI
Controller Area Network (CAN) schedulability analysis: Refuted, revisited and revised
TL;DR: The original schedulability analysis given for CAN messages is flawed and the priority assignment policy, previously claimed to be optimal for CAN, is not in fact optimal and a method of obtaining an optimal priority ordering that is applicable to CAN is cited.
Journal ArticleDOI
TTP/spl minus/a protocol for fault-tolerant real-time systems
Hermann Kopetz,G. Grunsteidl +1 more
TL;DR: The authors describe the architectural assumptions, fault hypothesis, and objectives for the TTP protocol, and discuss TTP characteristics and compare its performance with that of other protocols proposed for control applications.