WLAN系统中对抗OBSS问题的MAC层方案设计

发布时间：2018-06-01 13:35

本文选题：无线局域网 + 信道绑定　；参考：《西安电子科技大学》2015年硕士论文

【摘要】：随着新一代无线局域网的发展,具有不同工作频带的基本服务集(Basic Service System,BSS)的重叠现象将变得越来越普遍。在IEEE802.11ac中,主信道不同的相邻BSS可以在各自的主信道上进行控制帧的交互,然后利用静态或动态信道绑定技术绑定可用的子信道进行数据的传输,但是这两种信道绑定机制都会带来次信道上的隐藏终端问题,此时数据的碰撞会导致频谱资源的浪费;另一方面如果相邻的BSS主信道相同时,根据IEEE802.11ac协议,当主信道被占用时,802.11ac的BSS内所有扩展频带必须保持空闲状态,从而导致频谱资源的浪费。因此,在不同协议标准的网络设备共存并相互交叠的密集网络环境下,研究相应的MAC设计方案来提高频谱资源的利用率进而提高系统的吞吐量显得尤为重要。针对主信道不同时对抗重叠基本服务集(Overlap BSS,OBSS)引起的频谱利用率不足问题,本文分析了802.11ac中的拓展连续信道绑定机制,比较分析了静态、动态信道绑定机制的性能,在此基础上针对连续信道绑定机制中出现的次信道隐藏终端问题引出增强型保护机制,最后介绍一种基于增强型保护信道绑定接入机制的介质访问控制层(Medium Access Control,MAC)方案,以解决主信道不同时OBSS引起的频谱利用率不足问题。仿真结果表明,具有增强型保护功能的MAC设计方案可以有效地缓解次信道隐藏终端问题,避免不必要的碰撞,进一步提高网络吞吐量。针对主信道相同时对抗OBSS引起的频谱利用率不足问题,本文首先分析了802.11ac协议下OBSS系统的性能,在此基础上提出了一种基于虚拟主信道的信道接入方案,来优化系统的性能。该方案能够使得802.11ac设备在主信道被占用的情况下在其拓展频带上进行数据传输。仿真结果表明提出的基于虚拟主信道的信道接入方案大大提高了OBSS系统的频谱利用率。
[Abstract]:With the development of the new generation of WLAN, the overlap of basic Service system (BSS) with different operating bands will become more and more common. In IEEE802.11ac, adjacent BSS with different primary channels can interact with control frames on their respective primary channels, and then bind the available subchannels to transmit data using static or dynamic channel binding techniques. However, these two channel binding mechanisms will bring hidden terminal problems on the secondary channel, and the collision of the data will lead to the waste of spectrum resources. On the other hand, if the adjacent BSS primary channel is the same, according to the IEEE802.11ac protocol, When the primary channel is occupied, all the extended frequency bands in the BSS of 802.11ac must remain idle, which leads to the waste of spectrum resources. Therefore, in the dense network environment where the network equipment of different protocol standards coexist and overlap with each other, it is particularly important to study the corresponding MAC design scheme to improve the utilization of spectrum resources and the throughput of the system. In order to solve the problem of insufficient spectrum efficiency caused by overlap BSS), this paper analyzes the extended continuous channel binding mechanism in 802.11ac, and compares the performance of static and dynamic channel binding mechanisms. On the basis of this, the enhanced protection mechanism is introduced in view of the problem of the hidden terminal in the secondary channel in the continuous channel binding mechanism. Finally, a medium Access Control (MAC) scheme based on the enhanced protection channel binding access mechanism is introduced. In order to solve the problem of spectrum utilization caused by OBSS with different primary channels. The simulation results show that the scheme of MAC with enhanced protection can effectively alleviate the problem of hidden terminal in sub-channel, avoid unnecessary collisions, and further improve the throughput of the network. In order to solve the problem of insufficient spectrum utilization caused by OBSS when the primary channel is the same, this paper first analyzes the performance of OBSS system under 802.11ac protocol, and then proposes a channel access scheme based on virtual primary channel to optimize the performance of the system. This scheme enables the 802.11ac device to transmit data over its extended frequency band when the primary channel is occupied. Simulation results show that the proposed channel access scheme based on virtual primary channel greatly improves the spectrum efficiency of OBSS system.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN925.93

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