There are various algorithms used for assigning tasks to heterogeneous processors. We propose an algorithm to assign N tasks to K processors. The motivation of this algorithm is to address the drawback of Minmin+, Max...
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ISBN:
(纸本)9781467377591
There are various algorithms used for assigning tasks to heterogeneous processors. We propose an algorithm to assign N tasks to K processors. The motivation of this algorithm is to address the drawback of Minmin+, Maxmin+, Sufferage+ in solving problems with highly skewed costly distributions. The proposed algorithm is easy to implement and we have illustrated with detailed pseudo codes.
Cloud computing has officially entered the commercial application stage, which puts forward higher requirements on network load balancing. Leveraging effective load distribution and traffic scheduling algorithm to rea...
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ISBN:
(纸本)9781479918928
Cloud computing has officially entered the commercial application stage, which puts forward higher requirements on network load balancing. Leveraging effective load distribution and traffic scheduling algorithm to reasonably allocate the request data between every processing nods to achieve optimal processing capacity of the system is one of the effective ways to improve the utilization of network resources. The unique self-directed learning and reconfiguration capabilities of cognitive network [1] enable the load balancing to become more effective. Based on research of the existing traffic scheduling algorithm, this paper improves the weighted least connections scheduling algorithm, and designs the Adaptive scheduling Algorithm Based on Minimum Traffic (ASAMT). ASAMT conducts the real-time minimum load scheduling to the node service requests and configures the available idle resources in advance to ensure the service QoS requirements. Being adopted for simulation of the traffic scheduling algorithm, OPNET is applied to the cloud computing architecture. Experimental results show that, under the premise of no large network cost, the load condition of this algorithm is better than that of the unmodified weighted least connection scheduling algorithm.
This work presents a multipath multimedia transport protocol (MPMTP), which exploits path diversity over heterogeneous wireless networks. The goal of MPMTP is to provide a seamless high-quality video streaming service...
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ISBN:
(纸本)9781479980895
This work presents a multipath multimedia transport protocol (MPMTP), which exploits path diversity over heterogeneous wireless networks. The goal of MPMTP is to provide a seamless high-quality video streaming service by using multiple wireless networks simultaneously. In MPMTP, systematic Raptor codes are adopted to mitigate video quality degradation caused by wireless channel errors, as well as to alleviate a head-of-line blocking problem in multipath environments, and their encoding parameters such as code rate, symbol size, and the number of source symbols are determined on the fly by considering the wireless channel state, Raptor encoding and decoding complexity, and receiver video buffer occupancy. Furthermore, MPMTP performs packet scheduling considering not only wireless network conditions but also packet payload characteristics for smooth video playback. The proposed MPMTP is fully implemented in a Linux kernel and examined over real wireless network environments.
scheduling algorithm is a hot research topic of real time system. The quality of real-time scheduling algorithm has a direct impact on real-time system's throughput capacity, response time, even on tasks' ...
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scheduling algorithm is a hot research topic of real time system. The quality of real-time scheduling algorithm has a direct impact on real-time system's throughput capacity, response time, even on tasks' scheduling result in required deadline. This paper discusses the features and performance of real-time system. According to system environment, real-time system can be divided into uniprocessor scheduling, centralized multiprocessor scheduling and distributed scheduling. Classic real-time scheduling algorithms RMS, EDF and LLF are discussed in uniprocessor systems. The scheduling thought and strategies are investigated in multiprocessor systems. Distributed real-time scheduling algorithms such as GRMS and DSr are analyzed briefly. Finally, it points out the future direction of real-time scheduling research.
In LTE, resource allocation technique is a non-standardized but an essential process to achieve high data rate and low latency at user end. Any resource allocation technique is incomplete if control channel (PDCCH) re...
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In LTE, resource allocation technique is a non-standardized but an essential process to achieve high data rate and low latency at user end. Any resource allocation technique is incomplete if control channel (PDCCH) resource allocations are not considered in allocation process and only shared data channel (PDSCH) resources are considered. It should be noted that a user would be scheduled or not scheduled is determined from PDCCH resources. Therefore, PDCCH resource allocation is important for scheduling users. In practical scenario, there is constraint in availability of PDCCH resources with respect to number of users demanding resources. So, it is difficult to allocate resources to all users simultaneously. An effective PDCCH resource allocation technique is necessary in order to schedule maximum number of users in limited number of resources. Further, the technique should maintain fairness and throughput of users. The paper discusses different parameters which talks about control channel (PDCCH) scheduler. This paper provides a complete understanding of PDCCH resource allocation technique based on different allocation parameters. Requirement of improvement in PDCCH channel allocation techniques in LTE-Advanced is also discussed in end of the paper.
With the next generation cellular networks making a transition to-wards smaller cells, two-hop OFDMA relay networks have become a dominant, mandatory component in the 4G standards (WiMAX 802.16j, 3GPP LTE-Adv). While ...
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ISBN:
(纸本)9781450301831
With the next generation cellular networks making a transition to-wards smaller cells, two-hop OFDMA relay networks have become a dominant, mandatory component in the 4G standards (WiMAX 802.16j, 3GPP LTE-Adv). While unicast flows have received reasonable attention in two-hop OFDMA relay networks, not much light has been shed on the design of efficient scheduling algorithms for multicast flows, thereby forming the focus of this work. We show that while relay cooperation is critical for improving multicast performance, it must be carefully balanced with the ability to multiplex multicast sessions and hence maximize aggregate multicast flow. To this end, we highlight strategies that carefully group relays for cooperation to achieve this balance. We then solve the multicast scheduling problem under two OFDMA sub-channelization models. We establish the NP-hardness of the scheduling problem even for the simpler model and provide efficient algorithms with approximation guarantees under both models. Evaluation of the proposed solutions reveals the efficiency of the scheduling algorithms as well as the significant benefits obtained from the multicasting strategy. Copyright 2010 ACM.
To satisfy interaction between users and service providers (SP) in lots of rural areas without enough communication infrastructure, a dedicated return channel for the terrestrial digital TV is demanded. Therefore, we ...
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ISBN:
(纸本)9781479916542
To satisfy interaction between users and service providers (SP) in lots of rural areas without enough communication infrastructure, a dedicated return channel for the terrestrial digital TV is demanded. Therefore, we propose a specification on Dedicated Return Channel (DRC) based on SC-OFDMA technique for future broadcast, and promote it to Advanced Television Systems Committee (ATSC). To efficiently utilize the wireless resources of the uplink channel and support large number of users and wide coverage areas, scheduling among multiple users is the most important part. In this paper, we propose a balanced uplink scheduling (BUS) algorithm in order to meet Quality of service (QoS) requirements of large amount of users and make full use of user diversity, frequency diversity and time diversity at the same time.
In the course of increasing the production flexibility and dynamics, the replacement of wired industrial monitoring and control systems by wireless solutions is ongoing. To offer a similar degree of reliability as wir...
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In the course of increasing the production flexibility and dynamics, the replacement of wired industrial monitoring and control systems by wireless solutions is ongoing. To offer a similar degree of reliability as wired solutions, the IEEE 802.15.4e, targeting factory automation, defines the Time Slotted Channel Hopping (TSCH) mechanism. It appears promising to reach a timely, reliable and energy efficient communication. In particular, the TSCH link allocation mechanism, which cares for transmission scheduling in time and frequency, plays a crucial role. In this paper we model and analyze a network monitoring solution for TSCH-based wireless sensor networks, which supplies the link scheduling algorithm with the necessary information about network health status. For distributing the information, we investigate the piggybacking principle and define a new information container for monitoring purposes in the MAC frame. We show the results of our preliminary evaluation for a centralized and a distributed approach in cluster-tree networks in terms of control plane overhead.
The main idea behind cloud system is to provide the unlimited resources. Existing DawningCloud is an efficient cloud system for scientific communities. It reduced the total resource consumption of cloud resource provi...
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ISBN:
(纸本)9781467377591
The main idea behind cloud system is to provide the unlimited resources. Existing DawningCloud is an efficient cloud system for scientific communities. It reduced the total resource consumption of cloud resource provider and cloud users. However, DawningCloud simply used First Come First Served (FCFS) scheduling Policy and did not investigate the effect of different scheduling techniques on them. Therefore, we are proposing a novel scheduling algorithm, "Priority scheduling based on Users Activities (PS-UA)" to handle the large amount of requests on the existing DawningCloud system. The contribution of this paper is to compare the performance of the existing DawningCloud system with "First Come First Served (FCFS)", "Earlier Account Expire Prioritized with Round Robin (EAEP-RR)" and proposed "Priority scheduling based on Users Activities (PS-UA)" scheduling algorithm. The conclusion of this paper is that existing DawningCloud with EAEP-RR algorithm gives better performance as compared to a FCFS scheduling algorithm. However, existing DawningCloud with proposed PS-UA scheduling algorithm provides less waiting time for resources as compared to FCFS and EAEP-RR. Therefore, we conclude that proposed PS-UA is more efficient than FCFS and EAEP-RR.
Recent advance in distributed scheduling algorithms mainly focuses on designing CSMA-type protocols to achieve maximum network throughput in a fully distributive manner. However, it is inherently difficult for distrib...
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ISBN:
(纸本)9781479935123
Recent advance in distributed scheduling algorithms mainly focuses on designing CSMA-type protocols to achieve maximum network throughput in a fully distributive manner. However, it is inherently difficult for distributed scheduling algorithms to promise high throughput while maintaining low delay. To encounter this, a new scheduling algorithm, namely timely-throughput optimal algorithm, is introduced, which distributively determines the optimal transmission times for network users so that the largest set of traffic rates of network users can be supported, while ensuring timely data delivery within hard deadlines. More specifically, the maximum network capacity region that timely-throughput optimal scheduling algorithms can achieve is first derived, which characterizes the closure of the set of all arrival rate vectors under which there exists an viable scheduling algorithm to guarantee that all network users can meet the delay deadlines. Then, a distributed scheduling algorithm is proposed, which allows every user to make optimal transmission decision locally based on its incoming traffic rate, virtual debts, and previous channel sensing results. Finally, it is proven that the proposed algorithm is timely-throughput optimal in the sense that it can guarantee reliable data delivery before deadlines as long as the incoming traffic rates are within the derived maximum network capacity region.
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