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1、Honggang ZHANG CREATE-NET 12 October, 2005KEYNOTE SPEECH AT ISCIT 2005Fragrant Hill Hotel, Beijing, ChinaCognitive Ultra-Wideband Radio Evolution for Innovative and Dynamic Spectrum Access NetworksBy HONGGANG ZHANGWhat has Happened Recently?Cognitive Radio “A gathering storm” ?Ultra-Wideband (UWB) “
2、Pandoras box” ?“ The Next Horizon” ? Cognitive Radio has been recently hailed to be the “Next Big Thing” in future wireless communications? Uniqueness of Cognitive Radio is its ability to make efficient use of resource-limited spectrum environments, based on automatically adapting to a wireless chan
3、nel and network environment? Cognitive Radio is suitable for radio nodes collaboration to share spectrum and can be applied to realize autonomous, spectrum-agile radios with adaptive wireless networkingWhats Cognitive Radio?IEEE (http:/www.ieeeusa.org/forum/POSITIONS/cognitiveradio.html): “ A Cognit
4、ive Radio is a radio frequency transmitter/receiver that is designed to intelligently detect whether a particular segment of the radio spectrum is currently in use, and to jump into (and out of, as necessary) the temporarily-unused spectrum very rapidly, without interfering with the transmissions of
5、 other authorized users.”? FCC (FCC NPRM, Dec 17, 2003, ET-03-108): “ A cognitive radio (CR) is a radio that can change its transmitter parameters based on interaction with the environment in which it operates. This interaction may involve active negotiation or communications with other spectrum use
6、rs and/or passive sensing and decision making within the radio.”“ Cognitive radio technologies include, among other things, the ability of devices to determine their location, sense spectrum use by neighboring devices, change frequency, adjust output power, and even alter transmission parameters and
7、 characteristics.”Whats Cognitive Radio (cont.)?NTIA definition:?“A radio or system that senses its operational electromagnetic environment and can dynamically and autonomously adjust its radio operating parameters to modify system operation, such as maximize throughput, mitigate interference, facil
8、itate interoperability, access secondary markets.”?Extended definition for science and engineering community:?“Adaptive, multi-dimensionally aware, autonomous radio system that learns from its experiences to reason, plan, and decide future actions to meet user needs Cognition the act or process of k
9、nowing, including awareness, perception, memory, and judgment.”FCC Announcement (ET Docket No. 03-108, Dec. 2003)Bottleneck of Future Wireless Communication?Window of Opportunity? Existing spectrum policy forces spectrum to behave like a fragmented disk? Bandwidth is expensive and good frequencies a
10、re taken? Unlicensed bands biggest innovations in spectrum efficiency? Recent measurements by the FCC in the US show 70% of the allocated spectrum is not utilized ? Time scale of the spectrum occupancy varies from ms to hoursThe Promises of Cognitive Radio? Cognitive Radio can adjust itself to handl
11、e anticipated and unapticipated wireless channels and environments ? Cognitive Radio can detect its environment and learn how to adapt and evolve ? Cognitive Radio requires:? Sensing ? Learnin ? Adaptation? Cognitive Radio can maintain a quality of service (Smart transmitter) as well as reduce inter
12、ference to neighboring radios (Smat receiver)How does a Cognitive Radio Get so Smart?External Intelligence SourcesOrientEstablish Priority PlanNormalRegister to Current TimeGenerate Alternatives (Program Generation) Evaluate AlternativesDecideAlternate ResourcesInitiate Process(es) (Isochronism Is K
13、ey)ActLearnSave Global StatesSet DisplaySend a MessageObserveReceive a MessageRead ButtonsOutside WorldNew StatesThe Cognition CyclePrior StatesPre-processParseImmediate UrgentInfer on Context HierarchyMitola, “Cognitive Radio for Flexible Mobile Multimedia Communications”, IEEE Mobile Multimedia Co
14、nference, 1999, pp3-10The New Philosophy of Wireless World?Are We Ready for Challenging the Gathering Storm - Cognitive Radio? ? Cognitive Radio: ? Is it a coming revolution or storm in wireless world ? Dynamic, open access to spectrum resource (Spectrum freedom) Adaptive spectrum sensing, real-time
15、 spectrum allocation and acquisition Infrastructure-free mesh networks Intelligent radio and Bio-inspired radio ? Do we have any key applications? Dual- , triple-mode mobile phone, Smart Radio (SDR) WiFi, WiMax, WPAN and 3G/B3G coexistence and evolution Cognitive mesh networks (TV band sharing) Cogn
16、itive Ultra-Wideband Radio Bio-communications and bio-networks? How about industry, standardization and regulation procedure? Recent FCC rulemaking (December 2003, April 2004, March 2005) IEEE 802.22 Cognitive Wireless Regional Area Network (WRAN) One small step for IEEE, one giant leap for mankind ?UWB Wireless Technology: “the future is NOW”1.6 1.92.4Bluetooth, 802.11b WLAN Cordless Phones Microwave OvensPCS5802
