共查询到19条相似文献,搜索用时 46 毫秒
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针对现有太赫兹无线个域网定向MAC协议存在的波束训练开销和入网时延偏大以及Beacon, S-CAP时段时隙利用不足问题,该文提出一种自适应的定向MAC协议——AD-MAC,自适应地在静态场景下采用全网协同波束训练,在动态场景下节点基于历史信息快速回复波束训练帧,同时使用反向监听策略减小同扇区节点的帧碰撞概率,并且通过时隙复用在Beacon和S-CAP时段并行发送控制帧和数据帧。理论分析表明了AD-MAC协议的有效性,仿真结果显示:相较于ENLBT-MAC等典型协议,AD-MAC在静态场景下的波束训练开销和节点平均入网时延分别降低了约21.84%和22.70%,在动态场景下上述二指标则分别减小了约18.7%和13.07%。
相似文献4.
太赫兹无线个域网是一种工作在太赫兹频段的无线个域网,它可克服传统无线个域网宽带容量低、数据时延大及可靠性不高等问题,满足人们对近距离超高速率、高可靠性及低成本无线通信的需求。首先简要介绍了国内外太赫兹MAC协议研究进展;然后阐述了太赫兹无线个域网MAC协议标准化进程,重点分析研究当前研究热点问题;在此基础之上深入探究太赫兹无线个域网MAC协议的未来研究趋势。 相似文献
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无线局域网(WLAN)和无线个域网(WPAN)技术的发展带来的多媒体业务流量的剧增,使无线网络的资源管理、服务质量(QoS)保障等问题日益突出。传统的媒体访问控制(MAC)协议需要重新设计才能对无线网络的QoS问题进行有效地解决。文中研究了IEEEWLAN和WPAN工作组分别于2002年5月和2003年2月提出的IEEE802.11eD3.0和IEEE802.15.3D16两种协议标准的工作机制并对两者的性能作出了比较分析。 相似文献
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针对现有太赫兹无线网络MAC(Medium Access Control)协议中存在的无线局域网场景下原有波束赋形方案不适用、关联请求时段在新入网节点数量受限情况下时隙利用率低,以及网络流量较大时扇区号靠后的节点一直无法获得时隙导致时延陡增的情况,提出了一种适用于无线局域网的高效低时延太赫兹MAC协议(High Efficiency and Low Latency Terahertz MAC,HELL-MAC)。该协议利用中心控制节点与普通节点间的信息交互减少了不必要的波束赋形过程,采用机会性复用关联S-CAP(Sub-channel Access Period)机制提高了时隙利用率,采用公平时隙分配机制提高了时隙分配的公平性,从而减少了波束赋形时间,降低了平均端到端时延,提高了信道利用率。 相似文献
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现有的太赫兹无线个域网双信道介质访问控制(MAC)协议工作在WiFi和太赫兹信道。由于这两种信道的频率相差极大,导致使用全向天线和定向天线的覆盖范围各不相同,这样便会使节点之间的消息传输成功率大大降低,同时也降低了网络整体的吞吐量。另外,在现有的太赫兹无线网络双信道MAC协议中还存在一定的冗余控制开销,这导致了信道利用率低。基于此,文章提出一种太赫兹无线网络中基于中继的高效双信道MAC协议(HE-BRMAC),HE-BRMAC分为中继辅助和自适应减少控制开销机制。通过这两种机制可达到提高消息传输成功率、提升网络整体吞吐量、减少控制开销和提高信道利用率的效果,尤其当节点数较多时,HE-BRMAC的效果更为显著。 相似文献
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为了实现基于太赫兹(THz)技术的超高速无线局域网的组网和通信,提出了一种采用星形网络结构和TDMA-CSMA混合接入机制的太赫兹超高速无线局域网介质访问控制(MAC)接入协议-MAC-T 协议。该接入协议从组网机制、接入机制、参数设置等方面进行了详细的研究设计,从而在理论上保障和促进在太赫兹无线局域网中实现10 Gbps以上的超高速通信。 相似文献
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Due to having a large bandwidth to support Gbps-level data rate, terahertz communication attracts more and more attention in recent years. However, there are few medium access control (MAC) protocols for terahertz ultra-high data-rate wireless networks, which affects the research and application of terahertz communications. To address this problem and to achieve ultra-high data-rate wireless access with terahertz communication, a novel MAC protocol, called medium access control for terahertz communication (MAC-TC), is proposed. Through designing a new channel access scheme, a new superframe structure, and related key parameters, MAC-TC can support a maximum data rate up to 10 Gbit/s even higher. Theoretical analysis and simulation results show that our proposed MAC protocol realizes the function of medium access control and attains a maximum data rate of 18.3 Gbit/s, which is 2 times higher than 5.78 Gbit/s, the theoretical maximum data rate of IEEE 802.15.3c standard. 相似文献
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We introduce AsyMAC, a MAC layer protocol for wireless networks with asymmetric links and study a protocol stack consisting of AsyMAC and the A4LP routing protocol. The two protocols are able to maintain connectivity where the standard IEEE 802.11 MAC protocol coupled with either AODV or OLSR routing protocols may loose connectivity. A comparative study shows that AsyMAC improves on two previously proposed protocols’ accuracy in determining the nodes to be silenced to prevent collisions. 相似文献
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During the past decade, there has been much standardization effort for indoor or shot-range networks, as communication devices
and applications for such networks populate. As a prominent example of these activities, the IEEE 802.15.3 Task Group (TG)
published a standard for high-rate wireless personal area network (HR-WPAN). To support strictly timed multimedia services,
the TG adopts a time-slotted channel access protocol controlled by a central device (DEV). Although the channel time allocation
algorithm plays a key role in deciding the network performance, it remains unspecified in the standard. Therefore, in this
paper, we propose a novel feedback-assisted channel time allocation method for HR-WPAN. After initial channel times are allocated
based on packet inter-arrival time statistics, the allocation is dynamically adjusted by utilizing feedback information from
each DEV. The feedback information includes the buffer status, the packet transmission delay, and the physical transmission
rate. By utilizing this feedback information, the central DEV can allocate sufficient channel time for transmissions of pending
packets from a DEV. Moreover, the allocated channel times can be synchronized to the packet arrival times so that the overall
transmission delay is reduced. To cope with time-varying wireless channels, a dynamic rate selection algorithm assisted by
physical layer information is proposed in this paper. Performance evaluation is carried out through extensive simulations,
from which significant performance enhancements are observed. 相似文献
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Selfish MAC layer misbehavior in wireless networks 总被引:4,自引:0,他引:4
Wireless medium access control (MAC) protocols such as IEEE 802.11 use distributed contention resolution mechanisms for sharing the wireless channel. In this environment, selfish hosts that fail to adhere to the MAC protocol may obtain an unfair throughput share. For example, IEEE 802.11 requires hosts competing for access to the channel to wait for a "backoff" interval, randomly selected from a specified range/before initiating a transmission. Selfish hosts may wait for smaller backoff intervals than well-behaved hosts, thereby obtaining an unfair advantage. We present modifications to the IEEE 802.11 protocol to simplify detection of such selfish hosts and analyze the optimality of the chosen strategy. We also present a penalty scheme for punishing selfish misbehavior. We develop two misbehavior models to capture the behavior of misbehaving hosts. Simulation results under these misbehavior models indicate that our detection and penalty schemes are successful in handling MAC layer misbehavior. 相似文献
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JIANG Fan FAN Jiu-lun CHANG Zhi-xian School of Communications Information Engineering Xi'an University of Posts Telecommunications Xi'an China 《中国邮电高校学报(英文版)》2011,(5):7-14
A novel network protocol,enhanced cooperative medium access control(ECoop MAC),is present in this article.Its function is to guarantee the quality of service(QoS)in wireless local area networks.For the sake of supporting different application scenarios,two proposed schemes,namely E-scheme I for lower priority traffic and E-scheme II for higher priority traffic can be adopted independently or in combination.ECoop MAC takes into account request failure problems,and utilizes cooperative protocol information to boost the system performance as well as to effectively cut control packets overhead.Simulation results show that the proposed algorithm can not only improve network throughput,but also lead to reduced network delays for individual packets. 相似文献
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High-rate wireless personal area networks 总被引:5,自引:0,他引:5
《Communications Magazine, IEEE》2001,39(12):96-102
This article presents an overview of high-rate wireless personal area networks, its targeted applications, and a technical overview of medium access control and physical layers, and system performance. The high-rate WPANs operate in the unlicensed 2.4 GHz band at data rates up to 55 Mb/s that are commensurate with distribution of high-definition video and high-fidelity audio. An industry effort to create a MAC and PHY layer standard specification for high-rate WPANs has been ongoing in the IEEE 802.15.3 High Rate WPAN Task Group 相似文献
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An efficient packet sensing MAC protocol for wireless networks 总被引:4,自引:0,他引:4
The Group Allocation Multiple Access with Packet-Sensing (GAMA-PS) protocol for scheduling real-time and datagram traffic
in a wireless LAN is specified and analyzed. By maintaining a dynamically-sized cycle that changes in length depending on
the amount of network traffic, GAMA-PS is able to efficiently control channel access while ensuring that there are no collisions
of data packets. Each cycle contains a contention period and a group-transmission period; a station with data to send competes
for membership in the “transmission group” by using packet sensing to successfully complete an RTS/CTS message exchange during
the contention period. Once a station is a member of the transmission group, it is able to transmit a collision-free data
packet during each cycle; as long as a station has data to send, it maintains its position in the group.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Angelos Antonopoulos Christos Verikoukis Charalabos Skianis Ozgur B. Akan 《Ad hoc Networks》2013,11(1):190-200
In this paper we introduce a network coding-aided energy efficient Medium Access Control (MAC) protocol that coordinates the transmissions among a set of relay nodes which act as helpers in cooperative Automatic Repeat reQuest-based (ARQ-based) wireless networks. Applying network coding techniques, we achieve to increase the energy efficiency of the network without compromising the system performance in terms of Quality of Service. Our proposed solution is evaluated by both analytical and simulation results. 相似文献