scholarly journals A Virtual Channels Scheduling Algorithm with Broad Applicability Based on Movable Boundary

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Ye Tian ◽  
Qingfan Li ◽  
Yongxin Feng ◽  
Xiaoling Gao
Keyword(s):  
Time Slot ◽  
Scheduling Algorithm ◽  
Virtual Channel ◽  
Channel Utilization ◽  
Virtual Channels ◽  
Broad Applicability ◽  
Movable Boundary ◽  
Physical Channel ◽  
Utilization Ratio ◽  
Synchronous Time

A virtual channels scheduling algorithm with broad applicability based on movable boundary is proposed. According to the types of date sources, transmission time slots are divided into synchronous ones and asynchronous ones with a movable boundary between them. During the synchronous time slots, the virtual channels are scheduled with a polling algorithm; during the asynchronous time slots, the virtual channels are scheduled with an algorithm based on virtual channel urgency and frame urgency. If there are no valid frames in the corresponding VC at a certain synchronous time slot, a frame of the other synchronous VCs or asynchronous VCs will be transmitted through the physical channel. Only when there are no valid frames in all VCs would an idle frame be generated and transmitted. Experiments show that the proposed algorithm yields much lower scheduling delay and higher channel utilization ratio than those based on unmovable boundary or virtual channel urgency in many kinds of sources. Therefore, broad applicability can be achieved by the proposed algorithm.

scholarly journals Randomized scheduling algorithm for virtual output queuing switch at the presence of non-uniform traffic

2019 ◽  
Vol 8 (1) ◽  
pp. 50
Author(s):  
Ali Ghiasian ◽  
Majid Jamali
Keyword(s):  
Randomized Algorithms ◽  
High Speed ◽  
Time Slot ◽  
Scheduling Algorithm ◽  
Superior Performance ◽  
High Complexity ◽  
Maximum Weight ◽  
Switch Architecture ◽  
Simulation Results ◽  
Maximum Weight Matching

<span>Virtual Output Queuing (VOQ) is a well-known queuing discipline in data switch architecture that eliminates Head Of Line (HOL) blocking issue. In VOQ scheme, for each output port, a separate FIFO is maintained by each input port. Consequently, a scheduling algorithm is required to determine the order of service to virtual queues at each time slot. Maximum Weight Matching (MWM) is a well-known scheduling algorithm that achieves the entire throughput region. Despite of outstanding attainable throughput, high complexity of MWM makes it an impractical algorithm for implementation in high-speed switches. To overcome this challenge, a number of randomized algorithms have been proposed in the literature. But they commonly perform poorly when input traffic does not uniformly select output ports. In this paper, we propose two randomized algorithms that outperform the well-known formerly proposed solutions. We exploit a method to keep a parametric number of heavy edges from the last time matching and mix it by randomly generated matching to produce a new schedule. Simulation results confirm the superior performance of the proposed algorithms.</span>

Research on Resource Scheduling Algorithm Integrating Task Weight and Multi-QoS Constraint

2011 ◽  
Vol 52-54 ◽  
pp. 1125-1130
Author(s):  
Jing Chen ◽  
Ming Xin Liu
Keyword(s):  
Scheduling Algorithm ◽  
Resource Scheduling ◽  
Grid Resource ◽  
Resource Information ◽  
Grid Resource Scheduling ◽  
Utilization Ratio ◽  
Simulation Results ◽  
And Task

To improve the utilization ratio of resources and the complete number of tasks, a kind of a new grid resource scheduling algorithm TWMQC (based on Task Weight and Multi-QoS Constraint) integrating multi-QoS constraint with task weight was proposed. The accomplished process of grid resource scheduling algorithm was transformed multi attribute constraints of resource and task, according to the parametric resource information and task information, classified different task weight sets based on the priority of tasks. Multi-QoS constraints of deadline of gridlets, bandwidth and CPU were defined, and the correlative algorithms were simulated by the GridSim toolkits. The simulation results show that algorithm TWMQC, which integrating multi-QoS constraint and tasks weight is superior in solving such kind of issues by comparing and analyzing the result data.

PERFORMANCE ANALYSIS OF DETERMINISTIC ROUTING IN WORMHOLE k-ARY n-CUBES WITH VIRTUAL CHANNELS

2002 ◽  
Vol 03 (01n02) ◽  
pp. 67-83 ◽  
Author(s):  
H. SARBAZI-AZAD ◽  
A. KHONSARI ◽  
M. OULD-KHAOUA
Keyword(s):  
Network Performance ◽  
Operating Conditions ◽  
Analytical Models ◽  
Virtual Channel ◽  
Simple Analytical Model ◽  
Simulation Experiments ◽  
Virtual Channels ◽  
Deterministic Routing ◽  
Proposed Model ◽  
Wormhole Routed

Adding virtual channels to wormhole-routed networks greatly improves performance because they reduce blocking by acting as "bypass" lanes for non-blocked messages. Although several analytical models have been proposed in the literature for k-ary n-cubes with deterministic routing, most of them have not included the effects of virtual channel multiplexing on network performance. This paper proposes a new and simple analytical model to compute message latency in k-ary n-cubes with an arbitrary number of virtual channels. Results from simulation experiments confirm that the proposed model exhibits a good degree of accuracy for various network sizes and under different operating conditions. The proposed model is then used to investigate the relative performance merits of two different organisations of virtual channels.

scholarly journals The Cost of Adaptivity and Virtual Lanes in a Wormhole Router

VLSI Design ◽  
1995 ◽  
Vol 2 (4) ◽  
pp. 315-333 ◽  
Author(s):  
Kazuhiro Aoyama ◽  
Andrew A. Chien
Keyword(s):  
Adaptive Routing ◽  
Cost Effective ◽  
Deadlock Prevention ◽  
Channel Utilization ◽  
Virtual Channels ◽  
Crossbar Switches ◽  
Simulation Results ◽  
Virtual Lane ◽  
The Cost

We examine the cost in router complexity of adaptivity and virtual lanes in wormhole routers, using f-flat adaptive routers (based on a generalization of planar-adaptive routing) which include routers with a range of routing freedom. Our studies show that adaptivity is expensive because it requires additional virtual channels and much larger crossbar switches for both adaptivity and deadlock prevention. Increases of 50 to 100% in channel utilization are required to justify additional degrees of routing freedom.Three internal router architectures for virtual lanes are examined and the fully expanded crossbar is found to be most effective because it gives simplest control and minimal internal blocking. Examining router designs with from 1–16 virtual lanes indicates that 30% improvements in channel utilization are required to justify each additional virtual lane. These studies combined with published simulation results indicate that only modest numbers of virtual lanes are likely to be cost effective.

A Semi-Persistent Scheduling Algorithm for VoIP in LTE-Advanced System

2014 ◽  
Vol 1046 ◽  
pp. 343-347
Author(s):  
Wei Wu ◽  
Jun Sun ◽  
Tong Hui Wu
Keyword(s):  
Source Coding ◽  
Scheduling Algorithm ◽  
System Throughput ◽  
Time Frequency ◽  
Coding Scheme ◽  
Lte Advanced ◽  
Key Technologies ◽  
Utilization Ratio ◽  
Advanced System ◽  
Better Than

The scheduling algorithm is one of the key technologies in LTE-Advanced system. In this paper, a semi-persistent scheduling algorithm designed for the VoIP service in LTE-Advanced system is proposed. The time-frequency resource will be allocated to the users according to the semi-persistent scheduling algorithm based on the gain for each user on the certain RB. By introducing the mechanism and procedure, analyzing the proposed semi-persistent scheduling algorithm combined the source coding (SC) or modulation and coding scheme (MCS) techniques, the superiority of the proposed algorithm is shown. The simulation results indicate that the performance of the proposed semi-persistent scheduling algorithm is better than the traditional algorithms in term of resource utilization ratio, system throughput and scheduling success rate.

Balancing virtual channel utilization for deadlock-free routing in torus networks

2015 ◽  
Vol 71 (8) ◽  
pp. 3094-3115 ◽  
Author(s):  
Zhigang Yu ◽  
Dong Xiang ◽  
Xinyu Wang
Keyword(s):  
Virtual Channel ◽  
Channel Utilization ◽  
Torus Networks
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