• Title/Summary/Keyword: CSMA(Carrier Sense Multiple Access)

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Delay Analysis of Carrier Sense Multiple Access with Collision Resolution

  • Choi, Hyun-Ho;Lee, In-Ho;Lee, Howon
    • Journal of Communications and Networks
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    • v.17 no.3
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    • pp.275-285
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    • 2015
  • To improve the efficiency of carrier sense multiple access (CSMA)-based medium access control (MAC) protocols, CSMA with collision resolution (CSMA/CR) has been proposed. In the CSMA/CR, a transmitting station can detect a collision by employing additional sensing after the start of a data transmission and then resolve the next collision that might occur by broadcasting a jam signal during a collision detection (CD) period. In this paper, we analyze the delay of a CSMA/CR based on a generic p- persistent CSMA model and obtain the minimum achievable delay of the CSMA/CR by finding the optimal length of the CD period according to the number of contending stations. Through this delay analysis, we also investigate the throughput-delay characteristics of the CSMA/CR protocol according to various parameters. Analysis and simulation results show that the CSMA/CR has a considerably lower delay and its throughput-delay characteristic is significantly improved than the conventional CSMA/CA and wireless CSMA/CD protocols.

RawPEACH: Multiband CSMA/CA-Based Cognitive Radio Networks

  • Chong, Jo-Woon;Sung, Young-Chul;Sung, Dan-Keun
    • Journal of Communications and Networks
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    • v.11 no.2
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    • pp.175-186
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    • 2009
  • A new medium access control (MAC) scheme embedding physical channels into multiband carrier sense multiple access/collision avoidance (CSMA/CA) networks is proposed to provide strict quality of service (QoS) guarantee to high priority users. In the proposed scheme, two priority classes of users, primary and secondary users, are supported. For primary users physical channels are provided to ensure strict QoS, whereas secondary users are provided with best-effort service using CSMA/CA modified for multiband operation. The performance of the proposed MAC scheme is investigated using a new multiband CSMA/CA Markov chain model capturing the primary user activity and the operation of secondary users in multiple bands. The throughput of secondary users is obtained as a function of the primary user activity and other CSMA/CA parameters. It is shown that the new MAC scheme yields larger throughput than the conventional single-band CSMA/CA when both schemes use the same bandwidth.

Media Access Scheme for Achieving an Effective Traffic Control Mechanism and Energy Efficiency in Sensor Networks (센서 네트워크에서 효과적인 트래픽 제어 방법과 에너지 효율성을 고려한 Media Access 기법)

  • Min Byung-Ung;Kim Dong-Il
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.6
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    • pp.1060-1064
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    • 2006
  • Data collected by sensors in field are transmitted to the base station gathering all of data. Because sensors have to gather data in surroundings and periodically transmit data to the base station, it makes energy consumed much. In this paper, we mose the scheme that is to avoid traffic congestion with achievement of energy efficiency, so collected data is transmitted efficiently. This is to adjust transmission rate differently in case of increasing or decreasing traffic and minimize the energy consumption with setting ideal options up basic CSMA(Carrier Sense Multiple Access) protocol in each sensor. Through the simulation, we find the ideal CSMA options and apply the proposed scheme of traffic control mechanism to them and analyze them, then show energy efficiency and effective traffic control mechanism.

Dynamic CSMA Protocol Based on the Network Status (네트워크 상태에 따른 동적 CSMA 프로토콜)

  • Lee, Wang-Jong;Rhee, Seung-Hyong
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.7 no.2
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    • pp.70-80
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    • 2008
  • CSMA(Carrier Sense Multiple Access) is a media access control protocol when nodes use a shared channel. To reduce the probability of collision and increase the performance, the station lust checks the state of the channel. In this paper, we study the performance improvement method based on p-persistent strategy. The p-persistent method reduces the chance of collision and improves the efficiency. However, a probability p and the number of station affect the performance. This paper proposes a dynamic CSMA multiple access based on the network status. If the possibility of collision is low, the station increases the probability p to improve the performance. In the opposite case, the station decreases the probability p. Our simulation results show that the proposed scheme outperforms any methods of CSMA multiple access according to the current persistent strategy.

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Media Access Scheme for Achieving an Effective Traffic Control Mechanism and Energy Efficiency in Sensor Networks (센서 네트워크에서 효과적인 트래픽 제어 방법과 에너지 효율성을 고려한 Media Access 기법)

  • Min Byung-Ung;Choi Sam-Gil;Kim Dong-Il
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2006.05a
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    • pp.95-98
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    • 2006
  • Data collected by sensors in field are transmitted to the base station gathering all of data. Because sensors have to gather data in surroundings and periodically transmit data to the base station, it makes energy consumed much. In this paper, we propose the scheme that is to avoid traffic congestion with achievement of energy efficiency, so collected data is transmitted efficiently. This is to adjust transmission rate differently in case of increasing or decreasing traffic and minimize the energy consumption with setting ideal options up basic CSMA(Carrier Sense Multiple Access) protocol in each sensor. Through the simulation, we find the ideal CSMA options and apply the proposed scheme of traffic control mechanism to them, then show energy efficiency and effective traffic control mechanism.

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A Study on the performance improvement of CSMA in the distributed wireless communication network (분산 무선통신망에서 CSMA 성능 개선에 관한 연구)

  • 조병록;최병진;박병철
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.4
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    • pp.605-613
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    • 1994
  • In this paper, we evaluate performance of multiple access for distributed wireless communication network by CSMA protocol. It is envident that the existence of hidden node in an environment degrades the performance of CSMA. In order to improve performance due to the problem of hidden node, the previous paper used random multiple access protocols a as such as ISMA, BTMA, BCMA. In this paper, We propose a protocol that we can improve performance by allowing node to sense the carrier of any other transmission on the channel in the distributed wireless communication networks The probability of transmission success was obtained by steady stats analysis under given assumptions. We confirmed that hidden node problem be virtually elimated by using a new protocol.

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Lower Bound of Partial Packet Recovery (패킷부분재전송기법의 수율 최저 한계)

  • Jeong, Choong-Kyo
    • Journal of Industrial Technology
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    • v.28 no.A
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    • pp.113-117
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    • 2008
  • Wireless carrier sense multiple access (CSMA) systems are widely used but show extremely different transmission efficiency according to the operation environment. Simulation or prototype deployment is needed to see the transmission efficiency of a wireless CSMA system with the partial packet retransmission scheme. The lower bound for the transmission efficiency of such a system is found mathematically in this work. This shows how much the partial packet retransmission scheme improves the transmission efficiency quantitatively. It also shows that the maximum throughput is obtained at higher offered load compared to the conventional CSMA system without the partial packet transmission. The result of this work can be applied to IEEE 802.11 networks or wireless mesh networks.

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Design and Implementation of HomeTDMA: a TDMA Protocol for Home Networks

  • Casaquite, Reizel;Hwang, Won-Joo
    • Journal of Korea Multimedia Society
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    • v.10 no.12
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    • pp.1612-1621
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    • 2007
  • In this paper, we introduced our designed TDMA (Time Division Multiple Access) based MAC (Medium Access Control) protocol for Home Networks called HomeTDMA. We have implemented and tested it in a test bed using crossbow motes and TinyOS. We also have compared HomeTDMA and CSMA (Carrier Sense Multiple Access) in terms of space and time complexity, channel access time, delivery success ratio, and throughput. Based on our results, HomeTDMA has an advantage over CSMA on channel access time, throughput and delivery success ratioIn the case of complexity, HomeTDMA is more complex compared to CSMA. Thus, CSMA is more appropriate in wireless sensor networks (WSNs) where memory, energy, and throughput are important parameters to be considered. However, HomeTDMA has a natural advantage of collision free medium access and is very promising for home networks where a reliable transmission or data transfer and congestion control is highly preferred.

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performance analysis of the CSMA/CA protocol using stop-and-wait ARQ method in iwreless LANs (무선 근거리 통신망에서의 Stop-and-wait ARQ 방식을 사용하는 충돌회피 프로토콜 성능분석)

  • 김재현;이정규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.5
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    • pp.1208-1220
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    • 1996
  • In this paper, the performance of a Carrier Sense Multiple Access/Collision avoidance (CSMA/CA) protocol using stop-and-Wait automatic Repeat reQuest, which is adapted as a draft standard in IEEE 802.11, is analyzed using a mathematical method based on a renewal theory, and simulation checks are performed, which confirm the goodness of our anlysis. In order to anlayze of CSMA/CA, we model that network is composed of finite populationand channel is slotted. And, we consider the CSMA/CA protocol as a hybrid protocol of 1-persistent CSMA and p-persistent CSMA protocol. As resuls of analysis, we have found that the throughput is degraded and packet delay is increased as the number of stations, Acknowledgement (ACK) length and Distributed coordination function Inter Frame Space (DIFS) length are increased.

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Throughput Analysis and Optimization of Distributed Collision Detection Protocols in Dense Wireless Local Area Networks

  • Choi, Hyun-Ho;Lee, Howon;Kim, Sanghoon;Lee, In-Ho
    • Journal of Communications and Networks
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    • v.18 no.3
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    • pp.502-512
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    • 2016
  • The wireless carrier sense multiple access with collision detection (WCSMA/CD) and carrier sense multiple access with collision resolution (CSMA/CR) protocols are considered representative distributed collision detection protocols for fully connected dense wireless local area networks. These protocols identify collisions through additional short-sensing within a collision detection (CD) period after the start of data transmission. In this study, we analyze their throughput numerically and show that the throughput has a trade-off that accords with the length of the CD period. Consequently, we obtain the optimal length of the CD period that maximizes the throughput as a closed-form solution. Analysis and simulation results show that the throughput of distributed collision detection protocols is considerably improved when the optimal CD period is allocated according to the number of stations and the length of the transmitted packet.