• Title/Summary/Keyword: Priority scheduling

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A Cell Scheduling Algorithm based on Multi-Priority in ATM Network (ATM망에서 다중우선순위 기반의 셀 스케줄링 알고리즘)

  • 권재우;구본혁;조태경;최명렬
    • Journal of Korea Multimedia Society
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    • v.4 no.4
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    • pp.339-348
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    • 2001
  • In this paper, a cell scheduling algorithm which can be applied to all of the service class in ATM network is proposed. The proposed algorithm classifies the order of priority in each service class into 4 categories and generates the weight of each class service based on the traffic parameters which are negotiated in connection contract. The proposed algorithm guarantees QoS(Quality of Service) to the traffic which is sensitive to delay carrying out CBR and rt_VBR service. As it effectively manages the connection which has small bandwidth, it minimizes the cell delay in the queue. For verifying the effectiveness of the proposed algorithm the proposed algorithm is simulated with existing cell scheduling algorithm and the result is showed.

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Integrated Packet Scheduling Algorithm for real-time and non-real-time packet service (실시간 및 비실시간 패킷서비스를 위한 통합 패킷 스케줄링)

  • Lee, Eun-Yong;Park, Hyung-Kun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.5
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    • pp.967-973
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    • 2009
  • Recently, as 3rd-generation mobile communication services using high-speed data rate system are widely employed, the demand for a variety of real-time data services such as VoIP service are also increased. Unlike typical data packets, VoIP packets have delay bound and low loss rate requirement. In this paper we propose a new scheduling algorithm that schedule two deferent kinds of packets efficiently, considering the characteristics of VoIP. Basically this algorithm considers both time delay and channel condition and gives priority depending on the time delay. Simulation results show that the proposed algorithm works more efficiently than conventional algorithms.

A Soft Aperiodic Real-Time Task Scheduling Algorithm Supporting Maximum Slack Time (최대여유시간 제공 연성 비주기 실시간 태스크 스케줄링 알고리즘)

  • Im, Deok-Ju;Park, Seong-Han
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.37 no.4
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    • pp.9-15
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    • 2000
  • The purpose of this paper is to minimize the a slack computation time of the scheduling of a soft aperiodic real-time tasks in a fixed priority real-time system. The proposed algorithm reduces the computation overhead at on-line time and supports the maximum slack time assigned for aperiodic real-time tasks. The proposed algorithm has 10~20% more response time for aperiodic real-time tasks than that of Slack Stealing Algorithm that offers optimal response time in fixed priority real-time system. However, the performance of the proposed algorithm is seven times better in a scheduling overhead.

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MPLS-Based IP-QoS Provisioning in 3G GPRS Networks (3G GPRS 망에서 MPLS 기반의 IP-QoS 제공 방안)

  • 이상호;정동수;김영진;박성우
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.7B
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    • pp.653-663
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    • 2002
  • UMTS/GPRS has its own QoS architecture, but additionally needs to support IP-QoS to provide Internet services. This paper describes an IP-QoS provisioning mechanism in the MPLS-based UMTS/GPRS network. We propose a QoS framework that includes the functional architecture of the MPLS-based GPRS networks and the efficient scheduling mechanism based on Diffserv model. The proposed scheduling mechanims is especially focused on the QoS support for real-time services. It also includes a new buffer management scheme that combines the priority queuing and weighted round robin method. The ns-2 simulator has been used to verify the validity of the proposed scheduling method.

Efficient Vehicle-Roadside Data Dissemination Algorithm for the Roadside Safety (도로안전을 위한 효율적인 차량-노변 데이터 배포 알고리즘)

  • Nam, Jaehyun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.1015-1016
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    • 2015
  • VANET is a technology for building a robust ad-hoc network between mobile vehicles as well as, between vehicles and RSU. Vehicles are moving and they only stay in the RSU area for a short time. When the number of requests is increased, an important challenge is to implement a suitable scheduling algorithm which serves as more requests as possible. $D^*S$ algorithm uses a priority weight, DS_Value, for selection of a request to get service. Priority weight is influenced only by deadline and data size parameters. We propose a packet scheduling using multilevel queue and show that using this idea leads to higher service ratio compare to previous algorithms.

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A Job Scheduling Scheme based on Analytic Hierarchy Process in Cloud Computing (클라우드 컴퓨팅에서 Analytic hierarchy process를 활용한 작업 스케줄링 기법)

  • Kim, Jeong-Won
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.8
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    • pp.9-15
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    • 2013
  • As the resources of cloud computing are essentially heterogeneous and jobs have various characteristics, resource allocation to jobs is one of important problems. We define this issue as a multi-criteria decision-making problem. This paper proposes a priority-based job scheduling algorithm based on analytic hierarchy process (AHP). On the first step, jobs are classified based on their preferences. On the second step, response time, system utilization, and load becomes decision criteria based on the AHP algorithm. Jobs are allocated to adequate resources through their priorities that are calculated by the AHP algorithm. Through analysis and experiment of the proposed algorithm, we are to confirm that the scheme can schedule jobs as well as utilize its resource efficiently.

A Scheduling Scheme for Conflict Avoidance On-demand Data Broadcast based on Query Priority and Marking (질의 우선순위와 마킹에 기초한 충돌 회피 온디맨드 데이터 방송 스케줄링 기법)

  • Kwon, Hyeokmin
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.21 no.5
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    • pp.61-69
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    • 2021
  • On-demand broadcast is an effective data dissemination technique in mobile computing environments. This paper explores the issues for scheduling multi-data queries in on-demand broadcast environments, and proposes a new broadcast scheduling scheme named CASS. The proposed scheme prioritizes queries by reflecting the characteristics of multi-data queries, and selects the data that has not been broadcast in the query for the longest time as the broadcast data according to the query priority. Simulation is performed to evaluate the performance of CASS. The simulation results show that the proposed scheme outperforms other schemes in terms of the average response time since it can show highly desirable characteristics in the aspects of query data adjacency and data conflict rate.

AUTOSAR : Deadline-Compliant Scheduling Method Applicable to Timing Protection Mechanisms (AUTOSAR:타이밍 보호 메커니즘 적용 가능한 마감시간 준수 스케줄링 방법)

  • Kim, Joo-Man;Kim, Seon-Jong;Kim, Byoung-Chul;Kwon, Hyeog-Soong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.1
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    • pp.103-109
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    • 2019
  • The automotive electronic system should provide a method that can be safely performed by loading a number of application programs having time constraints in several electronic control devices. In this paper, we propose a timing protection mechanism for AUTOSAR, which is a real - time operating system specification for automotive field, in order to observe the deadline of each task when scheduling real - time tasks. We propose a dynamic non-preemption algorithm to guarantee a flexible deadline for fixed priority or dynamic priority tasks, and a location where execution time can be monitored for errors, and suggest ways to implement the AUTOSAR time protection mechanism.

A Priority Time Scheduling Method for Avoiding Gateway Bottleneck in Wireless Mesh Networks (무선 메쉬 네트워크에서 게이트웨이 병목 회피를 위한 우선순위 타임 스케줄링 기법)

  • Ryu, Min Woo;Kim, Dae Young;Cha, Si Ho;Cho, Kuk Hyun
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.5 no.2
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    • pp.101-107
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    • 2009
  • In existing wireless ad-hoc networks, how to distribute network resources fairly between many users to optimize data transmission is an important research subject. However, in wireless mesh networks (WMNs), it is one of the research areas to avoid gateway bottleneck more than the fair network resource sharing. It is because WMN traffic are concentrated on the gateway connected to backhaul. To solve this problem, the paper proposes Weighted Fairness Time-sharing Access (WFTA). The proposed WFTA is a priority time scheduling scheme based on Weighted Fair Queuing (WFQ).

Performance Improvement of Message Transmission over TCN(Train Communication Network) (TCN을 통한 메시지 전송 능력 향상에 관한 연구)

  • Cho Myung-ho;Moon Chong-chun;Park Jaehyun
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.10
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    • pp.720-726
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    • 2004
  • The data transmission over MVB(Multifunction Vehicle Bus) of TCN(Train Communication Network) is divided into the periodic transmission phase and the sporadic transmission phase. TCN standard recommends the event-polling method as the message transfer in the sporadic phase. However, since the event-polling method does not use pre-scheduling to the priority of the messages, it is inefficient for the real-time systems. To schedule message transmission, a master node should know the priority of message to be transmitted by a slave node prior to the sporadic phase, but the existing TCN standard does not support any protocol for this. This paper proposes the slave frame bit-stuffing algorithm, with which a master node gets the necessary information for scheduling and includes the simulation results of the event-polling method and the proposed algorithm.