Ieee 802 22 an introduction to the first wireless standard based on cognitive radios
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IEEE 802.22: An Introduction to the First Wireless Standard based on Cognitive Radios. Carlos Cordeiro , Kiran Challapali , and Dagnachew Birru Philips Research North America/Wireless Communication and Networking Dept., Briarcliff Manor, USA

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Ieee 802 22 an introduction to the first wireless standard based on cognitive radios

IEEE 802.22: An Introduction to the FirstWireless Standard based on Cognitive Radios

Carlos Cordeiro, KiranChallapali, and DagnachewBirru

Philips Research North America/Wireless Communication and Networking Dept., Briarcliff Manor, USA

Email: {Carlos.Cordeiro, Kiran.Challapali, [email protected]

Sai Shankar N

Qualcomm Inc./Standards Engineering Dept., San Diego, USA

Email: [email protected]

指導教授:郭文興

學生: 林祺富


Abstract

Abstract

  • 再2004年10月全世界第一個以CR為基礎的無線空中介面802.22工作組成立了.他的主要發展任務是無線區域網路(WRAN)的PHY和MAC用來分享那些授權者的頻譜並且是在不會影響到原來使用者的權益.本篇只要是在說802.22他的構造,需求,應用和合併的定義.


Ieee 802 22 an introduction to the first wireless standard based on cognitive radios

大綱

  • Abstract

  • Introduction

  • Relatedwork

    A. Applications and Markets

    B. Regulatory Framework

  • The Ieee802.22preliminaries

    A. Topology, Entities and Relationships

    B. Service Capacity

    C. Service Coverage

  • Theieee802.22system

    A. Topology, Entities and Relationships

    B. Service Capacity

    C. Service Coverage


Ieee 802 22 an introduction to the first wireless standard based on cognitive radios

大綱

  • The802.22airinterface

    A. The PHY

    B. The MAC

    B.1 Superframe and Frame Structure

    B.2 Network Entry and Initialization

    B.3 Measurements and Spectrum Management

    B.4 Quiet Periods for Incumbent Sensing

  • Coexistenceinieee802.22

    A. Antennas

    B. Coexistence with TV and Wireless Microphones

    B.1 Sensing Thresholds

    B.2 Calculation of the Keep-Out Region

    B.3 DFS Timing Requirements

    B.4 Wireless Microphone Detection

    B.5 Spectrum Usage Table

    B.6 Out-of-Band Emission Mask

    C. Coexistence with PLMRS/CMRS

    D. Self-Coexistence


Ieee 802 22 an introduction to the first wireless standard based on cognitive radios

大綱

  • CONCLUSIONS

  • REFERENCES


Introduction

Introduction

  • 由於現在無線電被廣泛的使用,使得如何充分的使用頻譜變的格外的重要.感知無線電是目前最有效率利用頻譜的方法.他能感知周圍的環境,主動學習.及時改變調整內部系統的狀態,來適應外部的環境且不影響其他授權的用戶.


Related work

Relatedwork

  • 802.22和802.16之間的不同就是802.22主要是用在偏遠的地區他所涵蓋的範圍比802.16大的多.802.16也沒有對於授權者的保護的技術.


Ieee 802 22 preliminaries

Ieee802.22preliminaries

  • 市場運用:因為農村和偏遠地區地區涵蓋太大且服務困難,所以才需要WRAN.FCC之所以選擇電視頻段是因為該頻段擁有適合偏遠地區傳遞的特性,且用於802.22的設備不需要牌照,可以進一步降低成本.可是這不代表802.22只能用在農村和偏遠地區.還有許多其他地方可利用WRAN.例如—家庭用戶,多聚居單元,小商業用戶和校園.


Ieee 802 22 preliminaries1

Ieee802.22preliminaries

  • Regulatory Framework:在美國無線電主要目標是使用(VHF/UHF)的電視廣播頻段(從2到69).一般來說一個頻道佔用6MHZ,這樣開放的頻譜有3個 (54~72MHZ)(76~88MHZ)(740~806MHZ)FCC也允許無線麥克風在空閑的電視頻段進行通訊.只要不會相互影響就可以.


The ieee 802 22 system

THE IEEE 802.22 SYSTEM

  • 由於電視頻段並沒有全國統一,所以802.22所推出的標準也必須要適用於各種國家的電視通道.如 6MHZ,7MHZ,8MHZ


The ieee 802 22 system1

THE IEEE 802.22 SYSTEM

  • 拓墣的實體和關聯:

  • 802.22是單點對多點無線傳輸系統P-MP

  • 他透過BS來管理她自己的CELL和有關聯的CPE

  • BS會管理在CELL內的媒體存取,以及向下傳送訊息給cpe而CPE會向上回覆BS訊息

  • Bs會管理distributed sensing,而CPE會在不同的電視頻道去執行分散式的測量.


802 22wran

802.22WRAN的結構圖


The ieee 802 22 system2

THE IEEE 802.22 SYSTEM

  • 服務的容量:

  • 每個CPE最低下載速度為1.5 Mb/s上傳速度為384 kb/s

  • 系統規定了從0.5 bit/(sec/Hz)~5 bit/(sec/Hz)的頻譜利用率,假設平均3bit/sec/Hz將會符合在一個6MHz電視頻道內的所有的PHY18mbps的資料傳輸率


The ieee 802 22 system3

THE IEEE 802.22 SYSTEM

  • 服務的範圍:

  • 802.22WRAN的特色就在他的範圍最高可以達到100公里前提是不考慮功率的問題.

  • 現有的IEEE802標準最高只有33公里4w CPE EIRP(Effective Isotropic Radiated Power)


The ieee 802 22 system4

THE IEEE 802.22 SYSTEM


The ieee 802 22 air interface

THE IEEE 802.22 AIR INTERFACE

  • PHY:

  • 802.22實體層在調變和編碼方面具有高度的擴展性

  • OFDMA可以有效的分配子載波來達到CPE的需求

  • 802.22要只使用一個頻道來達到30KM和19MBPS是困難的,所以要透過頻道的融合來應加頻寬

  • 融合多個通道是理想的情況,可是主要的問題是在於沒有那麼多通道可以使用.

  • 為了避免鄰近高功率TV所產生的干擾,在所需調整的頻道兩旁必須有空的頻道.所以至少要有3個頻道


The ieee 802 22 air interface1

THE IEEE 802.22 AIR INTERFACE


The ieee 802 22 air interface2

THE IEEE 802.22 AIR INTERFACE


The ieee 802 22 air interface3

THE IEEE 802.22 AIR INTERFACE

  • MAC 層:

  • 為了要能夠及時的對外面環境做出回應,802.22的MAC層必需具有高度的動態性能.

  • 頻譜的分布認知和動態管理這些功能是傳統的802.22所沒有具備的功能


The ieee 802 22 air interface4

THE IEEE 802.22 AIR INTERFACE

  • BS會傳送特定的preamble及SCH透過3個鄰近的TV通道用來達到通訊的保護需求,CPE可以同步調整通道並且接收SCH,在超級訊框期間,可以使用multiple channels來傳送較多的MACFRAME,因此能提供更好的系統容量、範圍、多路徑分集及資料傳輸速率


The ieee 802 22 air interface5

THE IEEE 802.22 AIR INTERFACE


The ieee 802 22 air interface6

THE IEEE 802.22 AIR INTERFACE

  • MACFRAME的訊框結構如下圖,包括兩個部分: (downstream, DS) 及 (upstream, US) ,這兩個部分邊界是可掉換的,所以可以很容易控制上傳/下載的容量,DS是由DS PHY PDU組成與共存目的的競爭間隔,US組成則是透過初始化的競爭間隔排程,


The ieee 802 22 air interface7

THE IEEE 802.22 AIR INTERFACE


The ieee 802 22 air interface8

THE IEEE 802.22 AIR INTERFACE

  • Network Entry and Initialization:

  • 在WRAN中802.22中的CPE啟動時,首先必須先建立一個電視頻道的頻譜佔用情況.再把這個訊息傳回去給BS.

  • 在WRAN中802.22沒有預先先偵測頻道.可是他會進行頻道的合併,來提高性能.


The ieee 802 22 air interface9

THE IEEE 802.22 AIR INTERFACE

  • 頻譜的測量和管理:

  • 為了使802.22系統不會對使用者造成干擾,BS要引導CPE在頻道內或是頻道外進行週期性的感知測量

  • In-band必須停止一切的數據的傳送,因為它用的頻道是BS和CPE傳遞訊息的頻道

  • out-of-band則是對於其他的頻道

  • BS在偵測頻譜的使用情況時,如果又遇到了In-band會導致他在感知的時間拉長產生干擾.可是重複的感知活動也不需要每個CPE來進行

  • 802.22 也綜何管理了頻譜的功能,如切換頻道,連結頻道傳輸,終止頻道傳輸.用來保障使用者的權益


The ieee 802 22 air interface10

THE IEEE 802.22 AIR INTERFACE

  • Quiet Periods for Incumbent Sensing:

  • MAC層的穩定周期結構是由Fast Sensing和Fine Sensing 所組成的

  • Fast Sensing:包括一個或多個Fast Sensing來進行,這個階段用快速偵查演算法來進行,執行非常快速且有很高的效率.每個頻道1MS是標準.

  • Fine Sensing:他是出現在Fast Sensing後面,做出更精細的偵測.如果Fast Sensing偵測後發現受干擾的頻道能量低於門檻值, Fine Sensing就不會被執行


The ieee 802 22 air interface11

THE IEEE 802.22 AIR INTERFACE


Vi coexistence in ieee 802 22

VI. COEXISTENCE IN IEEE 802.22

  • 天線:

  • 802.22中每個CPE都需要兩個獨立的天線. directional和omni-directional

  • directional就是工作天線,主要是用於CPE和BS之間的通信,因為它的方向是固定的,所以能量較不易散失也可以降低干擾.

  • omni-directional主要是用於感知和測量.它可以尋找CPE附近所有的使用者用戶訊號,而不是單方向的尋找,所以可以有效的避免衝突.


Coexistence in ieee 802 22

COEXISTENCE IN IEEE 802.22

  • 電視和無線麥克風的共存:

    Sensing Thresholds:BS和CPE利用omni-directional來偵測使用者的門檻值.如果使用者高於門檻值,就會清出一個空的頻道出來.

    (DTV): -116 dBm 在6MHZ頻道

    Analog TV:-94dBM在NTSC中

    Wireless microphones:-107dBM在200KHZ頻道


Coexistence in ieee 802 221

COEXISTENCE IN IEEE 802.22


Coexistence in ieee 802 222

COEXISTENCE IN IEEE 802.22

  • 電視和無線麥克風的共存:

    Wireless Microphone Detection:不同於電視訊號的傳送,因為無線麥克風的功率較低頻寬較小,所以要偵測他是困難的.所以偵測和信標是兩個不能排除的選項.


Coexistence in ieee 802 223

COEXISTENCE IN IEEE 802.22

  • 電視和無線麥克風的共存:

    Spectrum Usage Table:802.22會要求BS建立一個表格,內容可以將頻道分為被佔用,可以用的和禁止使用3種.以方便802.22的感知來控制.


Coexistence in ieee 802 224

COEXISTENCE IN IEEE 802.22


Coexistence in ieee 802 225

COEXISTENCE IN IEEE 802.22

  • Self-Coexistence:

    Self-Coexistence的問題就在於會產生self-interference會使的Self-Coexistence變成毫無價值.

  • 下圖X軸是numberofnetwork隨機挑選放入一個正方形的區域(50*50100*100150*150)Y軸是converge time.


Coexistence in ieee 802 226

COEXISTENCE IN IEEE 802.22


Conclusions

CONCLUSIONS

  • 802.22是全世界第一個air interface和以CR為基礎的協定且操作於電視頻寬.透過頻譜的感知,使用者權益的維護,避免干擾和頻譜的管理等技術來達到有效的合併.

  • 本文提供了一個詳細的802.22WRAN的介紹.包括他的PHY和MAC的起始規格和共存的技術.


References

REFERENCES

  • [1] M. Calabrese and J. Snider, “Up in the Air,” The AtlanticMonthly, New America Foundation, September 2003.

  • [2] Federal Communications Commission (FCC), “SpectrumPolicy Task Force,” ET Docket no. 02-135, November 15,2002.

  • [3] P. Kolodzy, “Spectrum Policy Task Force: Findings andRecommendations,” in International Symposium onAdvanced Radio Technologies (ISART), March 2003.

  • [4] M. McHenry, “Report on Spectrum OccupancyMeasurements,” Shared SpectrumCompany,http://www.sharedspectrum.com/?section=nsf_summary.

  • [5] J. Mitola et al., “Cognitive Radios: Making SoftwareRadios more Personal,” IEEE Personal Communications,vol. 6, no. 4, August 1999.

  • [6] J. Mitola, “Cognitive radio: An integrated agentarchitecture for software defined radio,” PhD Dissertation,Royal Inst. Technol. (KTH), Stockholm, Sweden, 2000.


References1

REFERENCES

  • [7] S. Haykin, “Cognitive Radio: Brain-Empowered WirelessCommunications,” in IEEE JSAC, vol. 23, no. 2, February2005.

  • [8] DARPA ATO, Next Generation (XG) Program,http://www.darpa.mil/ato/programs/xg/.

  • [9] Federal Communications Commission (FCC), “Notice ofProposed Rule Making,” ET Docket no. 04-113, May 25,2004.

  • [10] IEEE 802.22 Working Group on Wireless Regional AreaNetworks, http://www.ieee802.org/22/.

  • [11] ITU’s New Broadband Statistics,http://www.itu.int/osg/spu/newslog/ITUs+New+Broadband+Statistics+For+1+January+2005.aspx, January 1, 2005.

  • [12] Federal Communications Commission (FCC), “Report andOrder AND Memorandum Opinion and Order,” ET Docketno. 05-56, March 16, 2005.

  • [13] Business Week, “Commentary: Behind in Broadband,”BusinessWeek Online Magazine, September 6, 2004.


References2

REFERENCES

  • [14] Federal Communications Commission (FCC), “Report andOrder,” ET Docket no. 05-57, March 11, 2005.

  • [15] K. Challapali, D. Birru, and S. Mangold, “Spectrum AgileRadio for Broadband Applications,” EE Times In-Focus,August 23, 2004.

  • [16] IEEE 802.16 Working Group on Broadband WirelessAccess, http://www.ieee802.org/16/.

  • [17] K. Challapali, S. Mangold, and Z. Zhong, “Spectrum AgileRadio: Detecting Spectrum Opportunities,” in ISART,Boulder, CO, March 2004.

  • [18] S. Mangold, Z. Zhong, K. Challapali, and C-T. Chou,“Spectrum Agile Radio: Radio Resource Measurements forOpportunistic Spectrum Usage,” in IEEE Globecom, 2004.

  • [19] K. Challapali, “Spectrum Agile Radios: Real-timeMeasurements,” in Cognitive Radio Conference,Washington DC, October 2004.

  • [20] A. Sahai, N. Hoven, and R. Tandra, “Some fundamentallimits on cognitive radio,” Allerton Conference onCommunication, Control, and Computing, October 2004.


References3

REFERENCES

  • [21] D. Agrawal and Q-A. Zeng, Introduction to Wireless andMobile Systems, Brooks/Cole Publishing, 432 pages, ISBN0534-40851-6, August 2002.

  • [22] H. Gossain, C. Cordeiro, T. Joshi, and D. Agrawal, “Cross-Layer Directional Antenna MAC and Routing Protocols forWireless Ad Hoc Networks,” in Wiley WirelessCommunications and Mobile Computing (WCMC) Journal,Special Issue on Ad Hoc Wireless Networks, to Appear.

  • [23] Federal Communications Commission (FCC), “Revision ofParts 2 and 15 of the Commissions Rules to PermitUnlicensed National Information Infrastructure (U-NII)Devices in the 5GHz Band,” ET Docket no. 03-122,November 18, 2003.

  • [24] G. Chouinard, “WRAN Reference Model,” IEEE 802.22,

    http://www.ieee802.org/22/, May 2005.


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