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完整後設資料紀錄
DC 欄位 | 值 | 語言 |
---|---|---|
dc.contributor.advisor | 周俊廷(Chun-Ting Chou) | |
dc.contributor.author | Shih-Hua Hsiao | en |
dc.contributor.author | 蕭詩樺 | zh_TW |
dc.date.accessioned | 2021-06-15T11:09:56Z | - |
dc.date.available | 2017-02-08 | |
dc.date.copyright | 2017-02-08 | |
dc.date.issued | 2016 | |
dc.date.submitted | 2016-10-06 | |
dc.identifier.citation | [1] “Standard for information technology,” IEEE Std 802.11af-2013, Feb 2013.
[2] A. V. Babu and L. Jacob, “Fairness analysis of ieee 802.11 multirate wirelesslans,” in IEEE Transactions on Vehicular Technology, 2007. [3] Y. Bejerano, H. G. Choi, and S. J. Han, “Fairness analysis of physical layer capture effects in ieee 802.11 networks,” in 13th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt), 2015. [4] A. V. Babu and L. Jacob, “Performance analysis of ieee 802.11 multirate wlans: Time based fairness vs throughput based fairness,” in International Conference on Wireless Networks, Communications and Mobile Computing, 2005. [5] “Standard for information technology,” IEEE Std 802.11g-2013, 2013. [6] I. Tinnirello and S. Choi, “Temporal fairness provisioning in multi-rate contention-based 802.11e wlans,” in Sixth IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks, 2005. [7] Y. Le, L. Ma, W. Cheng, X. Cheng, and B. Chen, “A time fairness-based mac algorithm for throughput maximization in 802.11 networks,” in IEEE TRANSACTIONS ON COMPUTERS, pp. VOL. 64, NO. 1, JANUARY 2013. [8] Y. Weibo, M. Zhichao, N. Dawei, and D. Chao, “Pcap: Proportional channel access probability fairness in multi-rate ieee 802.11 dcf,” in International Conference on Intelligent System Design and Engineering Application, 2012. [9] Y.Wang and B. Bensaou, “Achieving fairness in ieee 802.11 dfwmac with variable packet lengths,” in Global Telecommunications Con, 2001. [10] C. E. Koksal, H. Kassab, and H. Balakrishnan, “An analysis of short-term fairness in wireless media access protocols,” in Proc. of ACM SIGMETRICS, 2000. [11] M. Heusse, F. Rousseau, R. Guillier, and A. Duda, “Idle sense: An optimal access method for high throughput and fairness in rate diverse wireless lans,” in SIGCOMM, pp. pp. 121–132, 2005. [12] X. Tian, X. Chen, T. Ideguchi, and Y. Fang, “Improving throughput and fairness in wlans through dynamically optimizing backoff,” in IEICE Transactions, pp. 88–B(11): 4328–4338, 2005. [13] Q. Yu, Y. Zhuang, and L. Ma, “Dynamic contention window adjustment scheme for improving throughput and fairness in ieee 802.11 wireless lans,” in Globecom 2012 - Wireless Communications Symposium, pp. 5074 – 5080, 2012. [14] X. Zhou, C. Zheng, and X. He, “Adaptive contention window tuning for ieee 802.11,” in 22nd International Conference on Telecommunications, pp. 74 – 79, 2015. [15] L. Luo, M. Gruteser, and H. Liu, “Achieving temporal fairness in multi-rate 802.11 wlans with capture effect,” in IEEE International Conference on Communications, pp. 2496 – 2501, 2008. [16] W. Y. Choi, “Clustering algorithm for hidden node problem in infrastructure mode ieee 802.11 wireless lans,” in Advanced Communication Technology, 2008. ICACT 2008., pp. 1335 – 1338, 2008. [17] S. H. E. M. Najafabadi and C. C. Constantinou, “A game theoretic model for wireless medium access control in the presence of hidden terminals,” in 2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), pp. 1731 – 1736, 2013. [18] Z. Li, S. Nandi, and A. K. Gupta, “Improving fairness in ieee 802.11 using enhanced carrier sensing,” in IEE Proceedings - Communications, pp. 467 – 472, 2004. [19] Z. Li, S. Nandi, and A. K. Gupta, “Ecs: an enhanced carrier sensing mechanism for wireless ad-hoc networks,” in Proceedings of IFIP Networking 2004, Athens, Greece, 2004. | |
dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/48829 | - |
dc.description.abstract | 近年來,物聯網有著顯著的發展,許多新興的應用爆炸性的出現。隨之而來的就是大量頻譜的需求。但以現行頻譜的使用情形來說,免費的頻帶皆已十分的壅擠,需付費使用的頻帶又不是物聯網這種新興小應用可負擔的。好消息是,在甚高頻及特高頻的地方,雖然目前已被授權給電視訊號使用,但實際電視訓好使用的情形卻非常的低。若是能將此頻段拿來再利用,可解決目前頻譜使用不足的問題。
因為在甚高頻及特高頻的特性,使得裝置能傳送的範圍更廣。但隨之而來的是更嚴重的不公平性的問題。這篇論文一開始會先探討這些不公平性產生的原因及做簡單的分析。之後,提出一個新的協定來達到公平性。在這個協定中,不同於原始使用載波偵聽多路存取的方始需要不斷加倍自己的視窗大小,我們提出的協定會選取一個固定大小的視窗。這個固定大小的視窗是每個裝置分散式的算出,不須經由分享器做集中式的運算。因此,每個裝置需由獨自偵測問題的機制。偵測之後,裝置間互相溝通的方式也會在本論文中提出。另一個不同的地方是,在有些情況,就算偵測到通道是用忙碌的,仍然會繼續倒數計數器。在我們的模擬及分析的結果中,不論在什麼樣子的情形,平均而言,幾乎可達百分之九十五的公平性。 | zh_TW |
dc.description.abstract | The explosive growth of Internet of Things (IoT) applications requires many wireless spectrum resources to support connections of billions of sensors and actuators. Unfortunately, the licensed bands such as 2/3/4G networks are very expensive while the unlicensed 2.4GHz/5.8GHz bands are very crowded. The good news is that although many of the licensed bands are already assigned, the actual usage is low, especially in the very-high frequency (VHF) and the ultra-high frequency (UHF) television (TV) bands. In views of this fact, IEEE 802.11af PHY/MAC standard, an emerging technology in the IEEE 802.11 standard family, is developed so that wireless devices can operate in these bands, provided that no harmful interference is caused to the TV broadcasters and the wireless microphones.
Thanks to the low-frequency operation, the IEEE 802.11af protocol has excellent propagation/penetration characteristics and thus, a larger coverage. These characteristics make the IEEE 802.11af standard a valuable solution for various applications, but also cause much serious unfairness problems due to the capture effect, the hidden terminal problem, and designs of IEEE 802.11 MAC protocol. In this thesis, we first evaluate the three unfairness issues in an IEEE 802.11af network, and then propose a distributed-based scheme. In our scheme, every station in a basic service set (BSS) selects a fixed contention window (CW) size rather than doubling it after a failed transmission. Stations choose their CW sizes based on the number of captured and hidden stations. In order to detect the number of captured and hidden stations, some mechanisms are implemented. In addition, rather than freezing the backoff slots when the channel is busy, stations continuously count down the backoff slots. With our design, all stations are guaranteed to successfully transmit the data/control frames with an equal probability. The performance of our solution is evaluated by Opnet-based simulations. Both the analytical and simulation results show that the proposed scheme leads to 95% fairness in terms of the probability of the successful transmissions. | en |
dc.description.provenance | Made available in DSpace on 2021-06-15T11:09:56Z (GMT). No. of bitstreams: 1 ntu-105-R02942046-1.pdf: 9025212 bytes, checksum: dd7bc8345c5be3c16c4424f47d2924f3 (MD5) Previous issue date: 2016 | en |
dc.description.tableofcontents | ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii
LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii CHAPTER 1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Introduction to IEEE 802.11af . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 1.2 The Main Problem and the Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 1.2.1 Problem 1 - The capture effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 1.2.2 Problem 2 - The hidden terminal problem . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.2.3 Problem 3: Reception of an erroneous ACK . . . . . . . . . . . . . . . . . . . . . . . . .12 1.3 Analysis of the unfairness problem in IEEE 802.11af networks . . . . . . . . . . .13 CHAPTER 2 RELATED WORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 2.1 Without the capture effect and the hidden terminal problem . . . . . . . . . . . 18 2.1.1 Achieve the time fairness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 2.1.2 Achieve the short-term fairness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.2 With the capture effect and without the hidden terminal problem . . . . . . . 21 2.3 Without the capture effect and with the hidden terminal problem . . . . . . . 21 2.4 The solution of the problem of the reception of an erroneous ACK . . . . . . . 22 CHAPTER 3 SIMPLE NON FROZEN-BASEDMECHANISM (SNFBM) . . . . . . . . . . . . .24 3.1 The first step of SNFBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 3.1.1 Case1: station A captures station B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 3.1.2 Case2: station A and station B do not capture each other . . . . . . . . . . . . . 28 3.1.3 Case3: station B captures station A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 3.2 The second step of SNFBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 CHAPTER 4 NON FROZEN-BASED MECHANISM (NFBM) . . . . . . . . . . . . . . . . . . . .35 4.1 The first step of NFBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 4.1.1 Case1: station B is outside the sensing range station A . . . . . . . . . . . . . . . .40 4.1.2 Case2: station B is inside the decoding range to station A . . . . . . . . . . . . . 41 4.1.3 Case3: station B is inside the sensing range but outside the decoding range of station A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 4.2 The second step of NFBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 4.2.1 Case1: station A captures station B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44 4.2.2 Case2: station A and station B do not capture each other . . . . . . . . . . . . 44 4.2.3 Case3: station B captures station A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45 4.2.4 Miss detection and false alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 4.3 The third step of NFBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 4.4 The fourth step of NFBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 CHAPTER 5 SIMULATION RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 5.1 STC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 5.1.1 Only the capture e↵ect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73 5.1.2 Only the hidden terminal problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 5.1.3 Both the capture effect and the hidden terminal problem . . . . . . . . . . . . . . .78 5.1.4 A solution of using a constant CW size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 5.2 The convergence time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 CHAPTER 6 MORE DISCUSSION ABOUT FAIRNESS AND NFBM . . . . . . . . . . . . . . . . . 83 6.1 Analyze and solve the unfairness due to different data rate . . . . . . . . . . . . . . . .83 6.2 Analyze and solve the unfairness due to different time interval after RTS frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84 6.3 Make sure that every station can successfully decode the CTS frames . . . . . . . 86 6.4 Adjust the backoff timer if some stations enable the RTS/CTS mechanism while some are not . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 6.5 Simulation results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 CHAPTER 7 CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91 | |
dc.language.iso | en | |
dc.title | 在IEEE802.11af 網路中公平存取通道之協定設計 | zh_TW |
dc.title | A Fair Channel Access Protocol for IEEE 802.11af | en |
dc.type | Thesis | |
dc.date.schoolyear | 105-1 | |
dc.description.degree | 碩士 | |
dc.contributor.oralexamcommittee | 馮輝文(Huei-Wen Ferng),謝宏昀(Hung-Yun Hsieh),魏宏宇(Hung-Yu Wei) | |
dc.subject.keyword | 公平性,通道存取,隱藏節點問題,截獲效應, | zh_TW |
dc.subject.keyword | IEEE802.11af,fairness,channel access,hidden terminal problem,capture effect,EIFS, | en |
dc.relation.page | 93 | |
dc.identifier.doi | 10.6342/NTU201603644 | |
dc.rights.note | 有償授權 | |
dc.date.accepted | 2016-10-07 | |
dc.contributor.author-college | 電機資訊學院 | zh_TW |
dc.contributor.author-dept | 電信工程學研究所 | zh_TW |
顯示於系所單位: | 電信工程學研究所 |
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