• Title/Summary/Keyword: Bandwidth Request

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New Transient Request with Loose Ordering for Token Coherence Protocol (토큰 코히런스 프로토콜을 위한 경서열 트렌지언트 요청 처리 방법)

  • Park, Yun Kyung;Kim, Dae Young
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.10
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    • pp.615-619
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    • 2005
  • Token coherence protocol has many good reasons against snooping/directory-based protocol in terms of latency, bandwidth, and complexity. Token counting easily maintains correctness of the protocol without global ordering of request which is basis of other dominant cache coherence protocols. But this lack of global ordering causes starvation which is not happening in snooping/directory-based protocols. Token coherence protocol solves this problem by providing an emergency mechanism called persistent request. It enforces other processors in the competition (or accessing same shared memory block, to give up their tokens to feed a starving processor. However, as the number of processors grows in a system, the frequency of starvation occurrence increases. In other words, the situation where persistent request occurs becomes too frequent to be emergent. As the frequency of persistent requests increases, not only the cost of each persistent matters since it is based on broadcasting to all processors, but also the increased traffic of persistent requests will saturate the bandwidth of multiprocessor interconnection network. This paper proposes a new request mechanism that defines order of requests to reduce occurrence of persistent requests. This ordering mechanism has been designed to be decentralized since centralized mechanism in both snooping-based protocol and directory-based protocol is one of primary reasons why token coherence protocol has advantage in terms of latency and bandwidth against these two dominant Protocols.

Priority-based Intelligent Uplink Random Access Scheme for Fourth-generation Cellular Systems and Its Standardization (4세대 이동통신시스템을 위한 우선순위 기반 지능적 상향링크 랜덤 접속 방법 및 표준화)

  • Moon, Jung-Min;Lee, Ho-Won;Cho, Dong-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.12B
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    • pp.1623-1635
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    • 2011
  • Fourth-generation (4G) cellular communication systems must provide different quality-of-service (QoS) to users according to the service type, membership class, and usage case of each user. For the purpose of user's QoS differentiation, we propose an enhanced uplink random access scheme for bandwidth request. More specifically, we divide a bandwidth request channel into two parts: One is a primary region and the other is a secondary region. Then, each region has a unique minimum access class that allows only specific users to perform random access through that region. By doing so, we can reduce collision probability and increase the success probability of bandwidth request. From the perspective of standardization, we presented this scheme in the IEEE 802.16m Session #66 held on March 2010. As a result, the concept of the proposed scheme and required messages were defined in the 802.16m standard.

Performance Evaluation of Dynamic Bandwidth Allocation Algorithm for XG-PON with Traffic Monitoring (Traffic Monitoring 방식의 XG-PON 동적대역할당의 성능평가)

  • Han, Man Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.449-450
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    • 2015
  • This paper describes performance evaluation results of a new dynamic bandwidth allocation algorithm for an XG-PON (10-Gbps-capable passive optical network) system without using an explicit request. An ONU (optical network unit) does not send its request to an OLT (optical line termination). The OLT monitors the upstream bandwidth usage of the ONU to estimate the request of the ONU.

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A study on the connection admission control algorithm using dynamic bandwidth allocation in ATM network (ATM 망에서 동적대역폭 할당에 의한 연결수락제어 알고리즘에 관한 연구)

  • 신승호
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.41
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    • pp.51-60
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    • 1997
  • In this paper, A Connection Admission Control(CAC) algorithm by Dynamic Bandwidth Allocation is proposed. The B-ISDN will be required to carry traffic generated by a various traffic sources. These source will have all traffic flow characteristics and quality of services requirements. When a connectionless message with burstiness arrives at a node during a renewal period, CAC will be dynamically determined connection request by using the predetermined connection admission bounds in estimating the number of input arriving cells. The proposed algorithm estimates the available bandwidth by observing cell streams of the aggregate traffic. A connection request is accepted if the available bandwidth is larger than declared peak rate, and otherwise rejected. The proposed CAC scheme is shown to be promising and practically feasible in obtaining efficient transmission of burst traffic with guaranteed quality of services.

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Dynamic Bandwidth Allocation Algorithm of XG-PON using Traffic Monitoring (Traffic Monitoring 방식의 XG-PON 동적대역할당 방법)

  • Hong, Sung Hark;Han, Man Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.705-706
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    • 2014
  • This paper proposes a new dynamic bandwidth allocation algorithm for an XG-PON (10-Gbps-capable passive optical network) system. In the XG-PON system, an ONU (optical network unit) does not explicitly send it request to an OLT (optical line termination). The OLT monitors the upstream bandwidth usage of the ONU to estimate the request of the ONU. Then the OLT performs a dynamic bandwidth allocation process based on the estimated requests.

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Pipelined Dynamic Bandwidth Algorithm for Large-Scale XG-PON (대용량 XG-PON을 위한 Pipeline 방식의 동적대역할당 방법)

  • Lee, Eun Sung;Han, Man Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.693-694
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    • 2014
  • This paper proposes a new pipelined dynamic bandwidth allocation algorithm for XG-PON (10-Gbps-capable passive optical network) passive optical networks) system. The pipelined algorithm is used when a dynamic bandwidth allocation algorithm cannot finished in an unit time. In the proposed mechanism, the request is immediately transferred to each pipeline block to improve performance.

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Video Quality Control Scheme for Efficient Bandwidth Utilization of HTTP Adaptive Streaming in a Multiple-Clients Environment (다중 클라이언트 환경에서 HTTP 적응적 스트리밍의 효율적인 대역폭 활용을 위한 비디오 품질 조절 기법)

  • Kim, Minsu;Kim, Heekwang;Chung, Kwangsue
    • Journal of KIISE
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    • v.45 no.1
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    • pp.86-93
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    • 2018
  • When multiple clients share bandwidth and receive a streaming service, HTTP Adaptive Streaming has a problem in that the bandwidth is measured inaccurately due to the ON-OFF pattern of the segment request. To solve the problem caused by the ON-OFF pattern, the proposed PANDA (Probe AND Adapt) determines the quality of the segment to be requested while increasing the target bandwidth. However, since the target bandwidth is increased by a fixed amount, there is a problem in low bandwidth utilization and a slow response to changes in bandwidth. In this paper, we propose a video quality control scheme that improves the low bandwidth utilization and slow responsiveness of PANDA. The proposed scheme adjusts the amount of increase in the target bandwidth according to the bandwidth utilization after judging the bandwidth utilization by comparing the segment download time and the request interval. Experimental results show that the proposed scheme can fully utilize the bandwidth and can quickly respond to changes in bandwidth.

Novel Bandwidth Scheduling Algorithm for DOCSIS 3.0 Based Multiple Upstream Channels (DOCSIS 3.0 기반의 다중 상향 채널 환경에서 새로운 대역 스케줄링 알고리즘 제안)

  • Jung, Joon-Young;Ahn, Jae-Min
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.11B
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    • pp.1142-1150
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    • 2009
  • In this paper, we propose an novel bandwidth scheduling algorithm for the MAC protocol employed by the Data Over Cable Service Interface Specifications (DOCSIS) 3.0 compliant cable networks. The proposed algorithm statistically improves the chances of request piggybacking to minimize the access delay. It utilizes the piggyback request feature of the segment packets that has been newly specified in DCOSIS 3.0. In DOCSIS 3.0, a bandwidth request can be granted to several upstream channels within an upstream bonding group. The grant on each individual channel is treated as a segment packet. We find the optimal segment placement to minimize the access delay in the proposed algorithm. We also use a self-similar traffic model for simulation and analysis to evaluate the performance of the proposed algorithm.

A Priority based Dynamic Spectrum Allocation Algorithm for Multiple Network Operators Supporting Multiple Service Classes (다중 서비스 클래스를 제공하는 네트워크 운영자를 위한 우선순위 기반의 동적 스펙트럼 할당 알고리즘)

  • Kim, Hoon;Joo, Yang-Ick;Yun, Sang-Boh;Lee, Yeon-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.1A
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    • pp.59-66
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    • 2008
  • This paper presents a spectrum sharing and allocation problem in multiple network operators(NOs). Most of previous works as to dynamic spectrum allocation(DSA) schemes have presented the DSA gain achieved by utilizing the time or regional variations in traffic demand between multi-network operators(NOs). In this paper, we introduce the functionalities required for the entities related with the spectrum sharing and allocation and propose a spectrum allocation algorithm while considering the long-term priority(or fairness) between NOs, the prioritybetween multiple class services, and the urgent bandwidth request. It was shown that the proposed algorithm with priorities between multiple class services could sustain better satisfaction ratio(SR) than the fixed allocation schemes or one without priority under different traffic patterns. Therefore, we conclude that the proposed DSA with priorities between multiple class services and network operators could provide the fairness between service classes of network operators and effective negotiation procedure for urgent bandwidth request by users.

Adaptive Video Watermarking Using Half-cell Motion Vector (반화소 움직임 벡터를 이용한 적응적 비디오워터마킹)

  • Shinn Brian-B.;Kim Min-Yeong;D Khongorzul;Lee In-Sung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.7
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    • pp.1214-1221
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    • 2006
  • Header compression scheme is suggested as a solution to reduce the inefficient overhead of general packet stream data. Especially, it is shown that there are more overhead rate for real-time media stream links such as voice because of its short payload size, and it is possible to get higher bandwidth efficiency using the header compression scheme. There are two kinds of error recovery in header compression such as Periodic Header Refresh(PHR) and Header Request(HR) schemes. In this paper, we analyze the performance of these two compression recovery schemes, and some results such as the overhead rate, bandwidth gain and bandwidth efficiency(BE) are presented.