• Title, Summary, Keyword: 사용자 스케쥴링

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Grid Scheduling System for Effective Resource Selection in Service-based Grid Computing (서비스 기반 그리드 컴퓨팅에서의 효과적인 자원 선택을 위한 그리드 스케쥴링 시스템)

  • Hahm Jaegyoon;Kwon Oh-Kyoung;Kim Sangwan
    • Proceedings of the Korean Information Science Society Conference
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    • pp.592-594
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    • 2005
  • 그리드 스케쥴링 시스템은 그리드 환경에서 매우 다양하고 많은 자원에 대한 서비스들을 통합하여 사용자에게 일관된 접근 방법을 제공하고, 자원들의 동적인 상태나 자원의 서로 다른 정책 등으로 인해 야기되는 복잡성을 사용자에게 감추어 편리한 자원 사용 환경을 제공해 주게 된다 그리드 스케쥴링 문제에서는 기존의 스케쥴링 문제와는 다른 조건들이 존재하는데 자원에 대한 전적인 권한이 스케쥴러에게 주어지지 않는다는 점과 사용자에게 할당 가능한 자원의 양은 풍부하다는 점 등이다. 본 논문에서는 이러한 필요와 조건 하에 설계되고 구현 된 그리드 스케쥴링 서비스에 대해 다룬다. 본 논문에서 설명하는 그리드 스케쥴링 서비스는 그리드 작업 및 자원 관리 시스템에 자원의 발견, 선택, 예약 기능을 제공하고, GGF의 표준인 OGSI 스펙을 따르는 인터페이스를 제공한다. 특히 사용자의 요구조건과 자원의 정책을 만족하는 자원을 적절히 선택해 줌으로써 작업 실행에 있어서의 자동화를 제공하고, 다양한 어플리케이션에 적합한 자원 선택 알고리즘을 추가할 수 있도록 함으로써 특정 어플리케이션을 위한 최적의 자원을 선택할 수 있게 하였다.

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User Scheduling Algorithm Based on Signal Quality and Inter-User Interference for Outage Minimization in Full-Duplex Cellular Networks (전이중 셀룰라 네트워크에서 아웃티지 최소화를 위한 신호 품질과 사용자간 간섭량 기반의 사용자 스케쥴링 알고리즘)

  • Choi, Hyun-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.11
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    • pp.2576-2583
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    • 2015
  • In a full-duplex (FD) wireless cellular network, uplink (UL) users induce the severe inter-user interference to downlink (DL) users. Therefore, a user scheduling that makes a pair of DL user and UL user to use the same radio resource simultaneously influences the system performances significantly. In this paper, we first formulate an optimization problem for user scheduling to minimize the occurrence of outage, aiming to guarantee the quality of service of users, and then we propose a suboptimal user scheduling algorithm with low complexity. The proposed scheduling algorithm is designed in a way where the DL user with a worse signal quality has a higher priority to choose its UL user that causes less interference. Simulation results show that the FD system using the proposed user scheduling algorithm achieves the optimal performance and significantly decreases the outage probability compared with the conventional half-duplex cellular system.

User Scheduling Algorithm for Cell Capacity Maximization in Full Duplexing Wireless Cellular Networks (전이중 무선 셀룰라 네트워크에서 셀 용량 최대화를 위한 사용자 스케쥴링 방식)

  • Choi, Hyun-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.11
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    • pp.2613-2620
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    • 2014
  • In this paper, we consider a full duplexing (FD) wireless cellular network where a central base station (BS) works in the FD mode while the downlink (DL) and uplink (UL) users work in the time division duplexing (TDD) mode. Since this FD system induces the inter-user interference from UL user to DL user, the main challenge for maximizing the system performances is user scheduling that makes a pair of DL user and UL user to use the same radio resource simultaneously. We formulate an optimization problem for user pairing to maximize the cell capacity and propose a suboptimal user scheduling algorithm with low complexity. This scheduling algorithm is designed in a way where the DL user with a better signal quality has a higher priority to choose its UL user that causes less interference. Simulation results show that the FD system using the proposed user scheduling algorithm achieves the optimal performance and significantly outperforms the conventional TDD system in terms of the cell capacity.

Uplink scheduling scheme based on interference information for TDD cellular networks (TDD 셀룰러 네트워크를 위한 간섭 정보 기반의 상향 링크 스케쥴링 기법)

  • Cho, Moon-Je;Ban, Tae-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.3
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    • pp.537-542
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    • 2017
  • In this paper, we propose a new scheduling scheme to reduce the complexity and overhead in TDD uplink cellular networks. In a TDD network, users can estimate the interference causing to neighboring BSs by measuring the signals transmitted from them. In the existing max SGIR scheduling scheme, each user calculates SGIR and feeds back to BS. Then, the BS selects a user having the largest SGIR value to transmit data. This scheme has a problem that as the number of BSs increases, the number of interference channels to be measured by the users increases, and thus the hardware and algorithm complexity of the user increases. We propose a max SmGIR (Signal-to-max generating interference ratio) scheduling scheme that can reduce the user complexity by predicting the SGIR value based on only the largest interference information. According to computer simulations, the proposed scheme has similar performance to the existing max SGIR scheme despite this low complexity.

A Study on the Uplink SDMA Systems: User Scheduling, Transmit Power Control, and Receive Beamforming (상향링크 공간 분할 다중 접속 시스템에서 사용자 스케쥴링, 송신 전력 제어, 수신 빔포밍에 관하여)

  • Cho, Moon-Je;Ban, Tae-Won;Jung, Bang Chul
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.2
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    • pp.289-294
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    • 2014
  • In this paper, we investigate the user scheduling, transmit beamforming, and receive beamforming of uplink space division multiple access (SDMA) systems where multiple users are allowed to transmit their signal to a base station (BS) using the same frequency band simultaneously. The BS performs a receive beamforming using the predetermined pseudo-random pattern and select users with a specific criterion. Especially, in this paper, we propose the threshold-based transmit power control, in which a user decrease its transmit power according if its generating interference to other users's signal is larger than a predetermined threshold. Assuming that the TDD system is used, the channel state information (CSI) can be obtained at each user from pilot signals from the BS. Simulation results show that the proposed technique significantly outperforms the existing user scheduling algorithms.

Deep Learning Based User Scheduling For Multi-User and Multi-Antenna Networks (다중 사용자 다중 안테나 네트워크를 위한 심화 학습기반 사용자 스케쥴링)

  • Ban, Tae-Won;Lee, Woongsup
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.8
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    • pp.975-980
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    • 2019
  • In this paper, we propose a deep learning-based scheduling scheme for user selection in multi-user multi-antenna networks which is considered one of key technologies for the next generation mobile communication systems. We obtained 90,000 data samples from the conventional optimal scheme to train the proposed neural network and verified the trained neural network to check if the trained neural network is over-fitted. Although the proposed neural network-based scheduling algorithm requires considerable complexity and time for training in the initial stage, it does not cause any extra complexity once it has been trained successfully. On the other hand, the conventional optimal scheme continuously requires the same complexity of computations for every scheduling. According to extensive computer-simulations, the proposed deep learning-based scheduling algorithm yields about 88~96% average sum-rates of the conventional scheme for SNRs lower than 10dB, while it can achieve optimal average sum-rates for SNRs higher than 10dB.

Priority-based Scheduling Methods for Real-time Tasks of Massively Multiplayer On-line Game Systems (대규모 다중사용자용 온라인 게임 시스템의 실시간 태스크를 위한우선순위 스케쥴링 기법)

  • Kim, Jinhwan
    • Journal of Korea Multimedia Society
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    • v.16 no.4
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    • pp.493-501
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    • 2013
  • A key challenge in massively multiplayer on-line game(MMOG) systems is providing real-time response latencies to the large number of concurrent game players. MMOG systems are a kind of soft real-time systems because requests from many players should be responded within specified time constraints. Client events have different timeliness and consistency requirements according to their nature in the game world. These requirements lead to tasks with different priorities on CPU processing. In order to meet their timing constraints, we propose priority scheduling methods that attempt to allocate preferentially more CPU bandwidth to serve an task with the higher priority level in the presence of transient overloading. The proposed scheduling methods are capable of enhancing real-time performance of MMOG system by maximizing the number of tasks with higher priority completed successfully within their deadlines while minimizing total average latency of tasks finished after given deadlines. The performance of these scheduling methods is evaluated through extensive simulation experiments.

A Threshold-Based Distributed User Scheduling with Transmit Power Control for Uplink Multi-Cell Networks (다중 셀 상향링크 네트워크에서 송신전력제어를 이용한 임계값 기반 분산 사용자 스케쥴링)

  • Cho, Moon-Je;Ban, Tae-Won;Jung, Bang Chul
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.11
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    • pp.2607-2612
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    • 2014
  • In this paper, we propose a distributed user scheduling with transmit power control based on the amount of interference inflicted to other BSs in multi-cell uplink networks. Assuming that the channel reciprocity time-division duplexing(TDD) system is used, the channel state information (CSI) can be obtained at each user from pilot signals from other BSs. The amount of generating interference to other BSs will be calculated at each user. Especially, in this paper, we propose the threshold-based transmit power control, in which a user decrease its transmit power if its generating interference to other BSs is larger than a predetermined threshold. Simulation results show that the proposed technique significantly outperforms the existing user scheduling algorithms.

Joint User Scheduling and Power Control Considering Both Signal and Interference for Multi-Cell Networks (다중 셀 상향링크 네트워크에서 신호와 간섭을 동시에 고려하는 전력 제어 및 사용자 스케쥴링)

  • Cho, Moon-Je;Jung, Bang Chul;Ban, Tae-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.3
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    • pp.477-483
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    • 2016
  • In this paper, we propose a distributed user scheduling with interference-aware power control (IAPC) to maximize signal to generating interference plus noise ratio (SGINR) in uplink multi-cell networks. Assuming that the channel reciprocity time-division duplexing (TDD) system is used, the channel state information (CSI) can be obtained at each user from pilot signals from other BSs. In the proposed scheduling, to be specific, each user reduces the transmit power if its generating interference to other BSs is larger than a predetermined threshold. Each BS selects the user with the largest SGINR among users. Simulation results show that the proposed technique significantly outperforms the existing user scheduling algorithms. It is worth noting that the proposed technique operates with distributed manner without information exchange among cells. Hence, it can be easily applied to the practical wireless systems like 3GPP LTE without significant modifications of the specification.

A User Scheduling with Interference-Aware Power Control for Multi-Cell MIMO Networks (다중안테나 다중셀 네트워크에서 간섭인지 기반 전력제어 기술을 이용한 사용자 스케쥴링)

  • Cho, Moon-Je;Ban, Tae-Won;Jung, Bang Chul
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.5
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    • pp.1063-1070
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    • 2015
  • In this paper, we propose a distributed user scheduling with transmit power control based on the amount of generating interference to other base stations (BSs) in multi-cell multi-input multi-output (MIMO) networks. Assuming that the time-division duplexing (TDD) system is used, the interference channel from users to other cell BSs is obtained at each user. In the proposed scheduling, each user first generates a transmit beamforming vector by using singular value decompositon (SVD) over MIMO channels and reduces the transmit power if its generating interference to other BSs is larger than a predetermined threshold. Each BS selects the user with the largest effective channel gains among users, which reflects the adjusted power of users. Simulation results show that the proposed technique significantly outperforms the existing user scheduling algorithms.