• Title, Summary, Keyword: Medium Access Control

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The medium access control protocol of virtual token bus network for real time communication (실시간 통신을 위한 가상토큰버스 통신망의 매체접근제어 프로토콜)

  • 정연괘
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.7
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    • pp.76-91
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    • 1996
  • In this paper, we proposed the new medium access control protocol for the virtual token bus netowrk. The network is applied to inter-processor communication network of large capacity digital switching system and digital mobile system with distributed control architecture. in the virtual token bus netowrk, the existing medium access control protocols hav ea switchove rtime overhead when traffic load is light or asymmetric according ot arbitration address of node that has message to send. The proposed protocol optimized average message delay using cyclic bus access chain to exclude switchover time of node that do not have message to send. Therefore it enhanced bus tuilization and average message delay that degrades the performance of real time communication netowrks. It showed that the proposed protocol is more enhacned than virtual token medium access control protocol and virtual token medium access control protocol iwth reservation through performance analysis.

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Performance Evaluation of an Underwater Propagation Delay-Aware Medium Access Control Protocol (수중 전파 지연을 고려한 매체 접근 제어 프로토콜에 대한 성능 평가)

  • Hwang, Ho Young;Kim, Woo-Sik;Lee, Sang-Kug;Cho, Ho-Shin
    • The Journal of the Acoustical Society of Korea
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    • v.34 no.6
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    • pp.463-469
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    • 2015
  • In this paper, we propose an underwater propagation delay-aware medium access control protocol and evaluate the performance of the proposed protocol. In the proposed propagation delay-aware medium access control protocol, a sink node can restore the received RTS frames that are not piled up in a slot time. We analyze and compare the performance of the proposed underwater propagation delay-aware medium access control protocol with that of the conventional medium access control protocol in various environments.

A Medium Access Control Mechanism for Distributed In-band Full-Duplex Wireless Networks

  • Zuo, Haiwei;Sun, Yanjing;Li, Song;Ni, Qiang;Wang, Xiaolin;Zhang, Xiaoguang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.11
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    • pp.5338-5359
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    • 2017
  • In-band full-duplex (IBFD) wireless communication supports symmetric dual transmission between two nodes and asymmetric dual transmission among three nodes, which allows improved throughput for distributed IBFD wireless networks. However, inter-node interference (INI) can affect desired packet reception in the downlink of three-node topology. The current Half-duplex (HD) medium access control (MAC) mechanism RTS/CTS is unable to establish an asymmetric dual link and consequently to suppress INI. In this paper, we propose a medium access control mechanism for use in distributed IBFD wireless networks, FD-DMAC (Full-Duplex Distributed MAC). In this approach, communication nodes only require single channel access to establish symmetric or asymmetric dual link, and we fully consider the two transmission modes of asymmetric dual link. Through FD-DMAC medium access, the neighbors of communication nodes can clearly know network transmission status, which will provide other opportunities of asymmetric IBFD dual communication and solve hidden node problem. Additionally, we leverage FD-DMAC to transmit received power information. This approach can assist communication nodes to adjust transmit powers and suppress INI. Finally, we give a theoretical analysis of network performance using a discrete-time Markov model. The numerical results show that FD-DMAC achieves a significant improvement over RTS/CTS in terms of throughput and delay.

Delay and Channel Utilization Analysis of IEEE 802.12 VG-AnyLAN Medium Access Control under the Homogeneous Traffic Condition (동질 트래픽 조건에서 IEEE 802.12 VG-AnyLAN 매체접근제어의 지연시간과 채널이용율 해석)

  • Joo, Gi-Ho
    • The KIPS Transactions:PartC
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    • v.13C no.5
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    • pp.567-574
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    • 2006
  • VG-AnyLAN is a local area network standard developed by the IEEE 802.12 project. While preserving the frame format of IEEE 802.3, VG-AnyLAN adopts a new medium access control called Demand Priority where transmission requests of stations are arbitrated by a control hub in a round-robin manner. Unlike CSMA/CD which is the medium access control of IEEE 802.3, the Demand Priority, while providing the maximum bound on the packet delay, does not put the limit on the network segment size. In this paper, we analyze the delay and the channel utilization performances of the medium access control of IEEE 802.12 VG-AnyLAN. We develope an analytic model of the system under assumptions that each station generates traffic of the equal priority and that the packets are of fixed length. Using the analytic model, we obtain the recursive expression of the average channel utilization and the average access delay The numerical results obtained via analysis are compared to the simulation results of the system for a partial validation of our analysis.

Adaptive and Prioritized Random Access and Resource Allocation Schemes for Dynamic TDMA/TDD Protocols

  • Choi, Hyun-Ho
    • Journal of information and communication convergence engineering
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    • v.15 no.1
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    • pp.28-36
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    • 2017
  • The medium access control (MAC) protocol based on dynamic time division multiple access/time division duplex (TDMA/TDD) is responsible for random access control and radio resource allocation in dynamic traffic environments. These functions of random access and resource allocation are very important to prevent wastage of resources and improve MAC performance according to various network conditions. In this paper, we propose new random access and resource allocation schemes to guarantee quality of service (QoS) and provide priority services in a dynamic TDMA/TDD system. First, for the QoS guarantee, we propose an adaptive random access and resource allocation scheme by introducing an access probability. Second, for providing priority service, we propose a priority-based random access and resource allocation scheme by extending the first adaptive scheme in both a centralized and a distributed manner. The analysis and simulation results show that the proposed MAC protocol outperforms the legacy MAC protocol using a simple binary exponential backoff algorithm, and provides good differential performance according to priorities with respect to the throughput and delay.

A Distributed Medium Access Control Protocol for Cognitive Radio Ad Hoc Networks

  • Joshi, Gyanendra Prasad;Kim, Sung Won;Kim, Changsu;Nam, Seung Yeob
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.1
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    • pp.331-343
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    • 2015
  • We propose a distributed medium access control protocol for cognitive radio networks to opportunistically utilize multiple channels. Under the proposed protocol, cognitive radio nodes forecast and rank channel availability observing primary users' activities on the channels for a period of time by time series analyzing using smoothing models for seasonal data by Winters' method. The proposed approach protects primary users, mitigates channel access delay, and increases network performance. We analyze the optimal time to sense channels to avoid conflict with the primary users. We simulate and compare the proposed protocol with the existing protocol. The results show that the proposed approach utilizes channels more efficiently.

Medium Access Control Protocol for Interconnection Network of Mobile System (이동통신 시스템의 상호연결망을 위한 접근제어 프로토콜)

    • Journal of the Korean Operations Research and Management Science Society
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    • v.24 no.2
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    • pp.95-108
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    • 1999
  • The CDMA mobile system consists of several subsystems and each subsystem has many processing elements that handle voice messages and control messages for performing CDMA call processing functions through CDMA Interconnection Network(CIN). For assuring a high throughput and a short delay in the CIN, an efficient medium access control protocol should be provided. In this paper, we propose a new access control protocol of CIN for providing real time communications in CDMA mobile system. Also, we evaluate the delay performance of the proposed access control protocol and compare it with that of the existing access control protocol. Through a set of numerical examples, we show that our proposed protocol provides a better delay performance than the existing protocol.

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LTE에서의 Medium Access Control 표준기술

  • Song, Pyeong-Jung;Tri, Do Huu;Im, Seon-Bae
    • Information and Communications Magazine
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    • v.25 no.9
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    • pp.32-40
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    • 2008
  • 본고에서는 현재 3GPP (3rd Generation Partner Project)에서 표준화 작업이 마무리중인 LTE (Long Term Evolution) 시스템에서 Medium Access Control의 구조, 절차 및 PDU 포멧 등에 대해 알아본다.

Analysis of Three-Phase Multiple Access with Continual Contention Resolution (TPMA-CCR) for Wireless Multi-Hop Ad Hoc Networks

  • Choi, Yeong-Yoon;Nosratinia, Aria
    • Journal of Communications and Networks
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    • v.13 no.1
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    • pp.43-49
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    • 2011
  • In this paper, a new medium access control (MAC) protocol entitled three-phase multiple access with continual contention resolution (TPMA-CCR) is proposed for wireless multi-hop ad hoc networks. This work is motivated by the previously known three-phase multiple access (TPMA) scheme of Hou and Tsai [2] which is the suitable MAC protocol for clustering multi-hop ad hoc networks owing to its beneficial attributes such as easy collision detectible, anonymous acknowledgment (ACK), and simple signaling format for the broadcast-natured networks. The new TPMA-CCR is designed to let all contending nodes participate in contentions for a medium access more aggressively than the original TPMA and with continual resolving procedures as well. Through the systematical performance analysis of the suggested protocol, it is also shown that the maximum throughput of the new protocol is not only superior to the original TPMA, but also improves on the conventional slotted carrier sense multiple access (CSMA) under certain circumstances. Thus, in terms of performance, TPMA-CCR can provide an attractive alternative to other contention-based MAC protocols for multi-hop ad hoc networks.

Development of a Real-time Communication Service over Random Medium Access Scheme Networks

  • Choo, Young-Yeol;Kwon, Jang-Woo
    • 제어로봇시스템학회:학술대회논문집
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    • pp.350-353
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    • 2004
  • The increasing use of Ethernet-TCP/IP network in industry has led to the growing interest in its reliability in real-time applications such as automated manufacturing systems and process control systems. However, stochastic behavior of its medium access scheme makes it inadequate for time-critical applications. In order to guarantee hard real-time communication service in Ethernet-TCP/IP network, we proposed an algorithm running over TCP/IP protocol stack without modification of protocols. In this paper, we consider communication services guaranteeing deadlines of periodic real-time messages over MAC protocols that have unbounded medium access time. We propose a centralized token scheduling scheme for multiple access networks. The token is used to allow a station to transmit its message during the time amount that is appended to the token. The real-time performance of the proposed algorithm has been described.

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