A High-Performance Scheduling Algorithm for Buffered Crossbar Switch

2011 ◽  
Vol 268-270 ◽  
pp. 2101-2107
Author(s):  
Mei Yue Yang ◽  
Peng Wang ◽  
Xiang Tao Li ◽  
Sheng Ping Zhu

The limitations in complexity and scalability of current combined input and cross-point queuing switching scheduling policies are first analyzed. To overcome the deficiencies in supporting fair and QOS scheduling, we propose a fair and simple high-performance scheduling algorithm for Combined Input-Cross-point-Queued Switches, which is called Fair Service and Group Smoothed Round Robin (FGSR). The main idea of FGSR is that it first groups flows according to their weight, then decides which group to be scheduled by SRR and finally decides which flow from the selected group to be scheduled. FGSR is based on round robin mechanism, whose complexity is only O(1). FGSR groups and schedules flows according to the weight of flows, thus it has good fairness and can adapt to the need of real-time performance. Theoretical analysis and simulation results show that FGSR exhibits good delay, throughput and anti-burst performance.

2011 ◽  
Vol 474-476 ◽  
pp. 1819-1824
Author(s):  
Peng Wang ◽  
Shu Qiao Chen ◽  
Hong Chao Hu

The limitations in complexities and extensibilities of current scheduling policies based on combined input and cross-point queuing switch (CICQ) are first analyzed. To overcome the deficiencies in supporting fair and QOS scheduling, we propose a fair and simple high-performance multicast scheduling algorithm for Combined Input Crosspoint Queued Switches, which is called multicast Fair Service and Group Smoothed Round Robin (mFGSR). The complexity of the algorithm is onlyO(1).mFGSR groups and schedules flows according to the weight of flows, thus it has good fairness and can adapt to the need of real-time performance. Theorotical analysis and simulation results show that mFGSR exhibits good delay, throughput and anti-burst performance.


2018 ◽  
Vol 17 (05) ◽  
pp. 1399-1427 ◽  
Author(s):  
S. Saroja ◽  
T. Revathi ◽  
Nitin Auluck

This paper proposes a new tri-objective scheduling algorithm called Heterogeneous Reliability-Driven Energy-Efficient Duplication-based (HRDEED) algorithm for heterogeneous multiprocessors. The goal of the algorithm is to minimize the makespan (schedule length) and energy consumption, while maximizing the reliability of the generated schedule. Duplication has been employed in order to minimize the makespan. There is a strong interest among researchers to obtain high-performance schedules that consume less energy. To address this issue, the proposed algorithm incorporates energy consumption as an objective. Moreover, in order to deal with processor and link failures, a system reliability model is proposed. The three objectives, i.e., minimizing the makespan and energy, while maximizing the reliability, have been met by employing a method called Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS). TOPSIS is a popular Multi-Criteria Decision-Making (MCDM) technique that has been employed to rank the generated Pareto optimal schedules. Simulation results demonstrate the capability of the proposed algorithm in generating short, energy-efficient and reliable schedules. Based on simulation results, we observe that HRDEED algorithm demonstrates an improvement in both the energy consumption and reliability, with a reduced makespan. Specifically, it has been shown that the energy consumption can be reduced by 5–47%, and reliability can be improved by 1–5% with a 1–3% increase in makespan.


2019 ◽  
Vol 17 (1) ◽  
pp. 90-98 ◽  
Author(s):  
Uferah Shafi ◽  
Munam Shah ◽  
Abdul Wahid ◽  
Kamran Abbasi ◽  
Qaisar Javaid ◽  
...  

Central Processing Unit (CPU) is the most significant resource and its scheduling is one of the main functions of an operating system. In timeshared systems, Round Robin (RR) is most widely used scheduling algorithm. The efficiency of RR algorithm is influenced by the quantum time, if quantum is small, there will be overheads of more context switches and if quantum time is large, then given algorithm will perform as First Come First Served (FCFS) in which there is more risk of starvation. In this paper, a new CPU scheduling algorithm is proposed named as Amended Dynamic Round Robin (ADRR) based on CPU burst time. The primary goal of ADRR is to improve the conventional RR scheduling algorithm using the active quantum time notion. Quantum time is cyclically adjusted based on CPU burst time. We evaluate and compare the performance of our proposed ADRR algorithm based on certain parameters such as, waiting time, turnaround time etc. and compare the performance of our proposed algorithm. Our numerical analysis and simulation results in MATLAB reveals that ADRR outperforms other well-known algorithms such as conventional Round Robin, Improved Round Robin (IRR), Optimum Multilevel Dynamic Round Robin (OMDRR) and Priority Based Round Robin (PRR)


2013 ◽  
Vol 347-350 ◽  
pp. 1682-1687
Author(s):  
Jian Bin Xue ◽  
Song Bai Li

SC-FDMA as LTE uplink main technology has been widely studied,at the same time, channel estimation around such technology is becoming hot,In order to research and increase channel estimation accuracy of LTE uplink system,an algorithm based on pilot is proposed in this paper,this algorithms main idea is,by setting a certain bit error rate,choosing some proper data after channel estimation done under R-LS and M-MMSE, combining the chosen data and former block pilot and increasing pilot number to do channel estimation again, system bit error rate and mean square error results can be got by simulation;at last,the theoretical analysis and simulation results show that this algorithm really can make the channel estimation accuracy improved and bit error rate decreased.


2003 ◽  
Vol 04 (02) ◽  
pp. 163-177 ◽  
Author(s):  
Wenjie Li ◽  
Yiping Gong ◽  
Bin Liu

Many researchers have pointed out that using complex scheduling algorithms in input queuing switches with virtual output queuing (VOQ) scheme can achieve 100% throughput. But these algorithms are too complex to be implemented in hardware. In this paper, based on combined input/output queuing (CIOQ) switch fabrics, we propose a simple scheduling algorithm named outlet priority round robin (OPRR). For synthetic workloads we consider, including uniform and bursty traffic models, the performance of OPRR in VOQ mode and single queue mode is evaluated respectively. Through the simulation results we show that 1) OPRR algorithm, coupled with the speedup of 2, can lead to performance very close to output queuing switches, and 2) under the same condition, OPRR algorithm in single queue mode behaves almost identically to VOQ mode. These results are very useful to direct the design and implementation of switch fabrics in core routers.


Author(s):  
Satyasrikanth Palle ◽  
Shivashankar

Objective: The demand for Cellular based multimedia services is growing day by day, in order to fulfill such demand the present day cellular networks needs to be upgraded to support excessive capacity calls along with high data accessibility. Analysis of traffic and huge network size could become very challenging issue for the network operators for scheduling the available bandwidth between different users. In the proposed work a novel QoS Aware Multi Path scheduling algorithm for smooth CAC in wireless mobile networks. The performance of the proposed algorithm is assessed and compared with existing scheduling algorithms. The simulation results show that the proposed algorithm outperforms existing CAC algorithms in terms of throughput and delay. The CAC algorithm with scheduling increases end-to-end throughput and decreases end-to-end delay. Methods: The key idea to implement the proposed research work is to adopt spatial reuse concept of wireless sensor networks to mobile cellular networks. Spatial reusability enhances channel reuse when the node pairs are far away and distant. When Src and node b are communicating with each other, the other nodes in the discovered path should be idle without utilizing the channel. Instead the other nodes are able to communicate parallelly the end-to-end throughput can be improved with acceptable delay. Incorporating link scheduling algorithms to this key concept further enhances the end-to-end throughput with in the turnaround time. So, in this research work we have applied spatial reuse concept along with link scheduling algorithm to enhance end-to-end throughput with in turnaround time. The proposed algorithm not only ensures that a connection gets the required bandwidth at each mobile node on its way by scheduling required slots to meet the QoS requirements. By considering the bandwidth requirement of the mobile connections, the CAC module at the BS not only considers the bandwidth requirement but also conforming the constrains of system dealy and jitter are met. Result: To verify the feasibility and effectiveness of our proposed work, with respect to scheduling the simulation results clearly shows the throughput improvement with Call Admission Control. The number of dropped calls is significantly less and successful calls are more with CAC. The percentage of dropped calls is reduced by 9 % and successful calls are improved by 91%. The simulation is also conducted on time constraint and ratio of dropped calls are shown. The total time taken to forward the packets and the ration of dropped calls is less when compared to non CAC. On a whole the CAC with scheduling algorithms out performs existing scheduling algorithms. Conclusion: In this research work we have proposed a novel QoS aware scheduling algorithm that provides QoS in Wireless Cellular Networks using Call Admission Control (CAC). The simulation results show that the end-to-end throughput has been increased by 91% when CAC is used. The proposed algorithm is also compared with existing link scheduling algorithms. The results reveal that CAC with scheduling algorithm can be used in Mobile Cellular Networks in order to reduce packet drop ratio. The algorithm is also used to send the packets within acceptable delay.


Author(s):  
Ge Weiqing ◽  
Cui Yanru

Background: In order to make up for the shortcomings of the traditional algorithm, Min-Min and Max-Min algorithm are combined on the basis of the traditional genetic algorithm. Methods: In this paper, a new cloud computing task scheduling algorithm is proposed, which introduces Min-Min and Max-Min algorithm to generate initialization population, and selects task completion time and load balancing as double fitness functions, which improves the quality of initialization population, algorithm search ability and convergence speed. Results: The simulation results show that the algorithm is superior to the traditional genetic algorithm and is an effective cloud computing task scheduling algorithm. Conclusion: Finally, this paper proposes the possibility of the fusion of the two quadratively improved algorithms and completes the preliminary fusion of the algorithm, but the simulation results of the new algorithm are not ideal and need to be further studied.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1400
Author(s):  
Muhammad Adnan ◽  
Jawaid Iqbal ◽  
Abdul Waheed ◽  
Noor Ul Amin ◽  
Mahdi Zareei ◽  
...  

Modern vehicles are equipped with various sensors, onboard units, and devices such as Application Unit (AU) that support routing and communication. In VANETs, traffic management and Quality of Service (QoS) are the main research dimensions to be considered while designing VANETs architectures. To cope with the issues of QoS faced by the VANETs, we design an efficient SDN-based architecture where we focus on the QoS of VANETs. In this paper, QoS is achieved by a priority-based scheduling algorithm in which we prioritize traffic flow messages in the safety queue and non-safety queue. In the safety queue, the messages are prioritized based on deadline and size using the New Deadline and Size of data method (NDS) with constrained location and deadline. In contrast, the non-safety queue is prioritized based on First Come First Serve (FCFS) method. For the simulation of our proposed scheduling algorithm, we use a well-known cloud computing framework CloudSim toolkit. The simulation results of safety messages show better performance than non-safety messages in terms of execution time.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2715
Author(s):  
Ruth Yadira Vidana Morales ◽  
Susana Ortega Cisneros ◽  
Jose Rodrigo Camacho Perez ◽  
Federico Sandoval Ibarra ◽  
Ricardo Casas Carrillo

This work illustrates the analysis of Film Bulk Acoustic Resonators (FBAR) using 3D Finite Element (FEM) simulations with the software OnScale in order to predict and improve resonator performance and quality before manufacturing. This kind of analysis minimizes manufacturing cycles by reducing design time with 3D simulations running on High-Performance Computing (HPC) cloud services. It also enables the identification of manufacturing effects on device performance. The simulation results are compared and validated with a manufactured FBAR device, previously reported, to further highlight the usefulness and advantages of the 3D simulations-based design process. In the 3D simulation results, some analysis challenges, like boundary condition definitions, mesh tuning, loss source tracing, and device quality estimations, were studied. Hence, it is possible to highlight that modern FEM solvers, like OnScale enable unprecedented FBAR analysis and design optimization.


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