This work focuses on the support of applications that must meet temporal QoS constraints. We propose an approach to automatically derive scheduling information from temporal QoS equations expressed at a high level. The application threads are partitioned into finer grain (or elementary) threads to which QoS constraints are applied. The elementary thread decomposition is used to guide the schedu...

This paper develops a framework for statistically guaranteeing end-to-end delay bounds to leaky-bucket-constrained flows transporting real-time traffic in a network of switches using Earliest Deadline First (EDF) packet scheduling and per-hop traffic shaping. We first analyze the delay-bound violation probabilities at an isolated EDF scheduler fed by fluid source processes generating extremal d...

We study a canonical real-time scheduling problem for time-slotted collocated wireless networks serving users with diverse real-time requirements and wireless loss patterns arising from fading. We study two traffic patterns: periodic arrivals with deadline equal to period, and renewal arrivals, in which a new packet from a user arrives when the current one leaves. Wireless channel conditions ar...

The assignment of scheduling parameters under the Earliest Deadline First (EDF) scheduling policy is trivial in single processor systems because deadlines are used directly. However, it is still difficult to find a feasible deadline assignment for EDF distributed systems when the utilization levels of the CPUs and communication networks are pushed near to their limits. Most distributed applicat...

Abstract In this chapter, to improve the schedulability of high-criticality flows when network is running, we present a supply/demand bound function analysis method based on earliest deadline first (EDF) scheduling. addition, our considers both source routing and graph routing. At beginning, in low-criticality mode, applied. When errors or exceptions occur, switches turns guarantee that critica...

This paper examines the relative effectiveness of fixed priority pre-emptive scheduling in a uniprocessor system, compared to an optimal algorithm such as Earliest Deadline First (EDF). The quantitative metric used in this comparison is the processor speedup factor, defined as the factor by which processor speed needs to increase to ensure that any taskset that is schedulable according to an op...

Time constraint is the main factor in real time operating system. Different scheduling algorithm is used to schedule the task. The Earliest Deadline First and Ant Colony Optimization is a dynamic scheduling algorithm used in a real time system and it is most beneficial scheduling algorithm for single processor real-time operating systems when the systems are preemptive and under loaded. The mai...

This paper reports on our on going empirical evalu ation of a two tiered resource allocation scheme assum ing independent jobs that is jobs have no precedence constraints The rst tier extends the temporal density approach load balancing within a time interval while the second tier uses variations of the Earliest Deadline First EDF approach to schedule jobs at a site However job scheduling at si...

Fixed-task-priority (FTP) scheduling and earliest-deadline-first (EDF) scheduling policies are alike in fixing the priority of each job of a task at the time the job is released. This common feature of FTP and EDF scheduling permits a unified analysis of scheduling failures, to derive new sufficient tests for meeting all deadlines of a set of independent sporadic tasks under a global preemptive...

Tasks of an application program of an embedded system are managed by the scheduler of a real-time operating system (RTOS). Most RTOSs adopt just fixed priority scheduling, which is not optimal in all cases. Some applications require earliest deadline first (EDF) scheduling, which is an optimal scheduling algorithm. In order to develop an efficient real-time embedded system, the scheduling algor...