November 2004 doc IEEE 802 11 03xxxr 0

November 2004 doc. : IEEE 802. 11 -03/xxxr 0 Spectrum Agile Radios Kiran Challapali Philips kiran. challapali@philips. com Submission Kiran Challapali, Philips

November 2004 doc. : IEEE 802. 11 -03/xxxr 0 Motivation • Rapid growth of wireless communications over the past several years – Unlicensed (WLAN/WPAN) and licensed (Cellular) bands – Recently, wireless internet access using cellular networks • available in 14 US cities, $80/month, 60 -80 kpbs* – Vast and growing demand for spectrum-based communication links • In some measurements, only about 10% of the allocated spectrum is in use at any given time • Spectrum access and efficiency becoming a critical public policy issue Submission Kiran Challapali, Philips

November 2004 doc. : IEEE 802. 11 -03/xxxr 0 Outline of talk 1. Introduction – – 2. Applications of agile radios – 3. Wireless internet and others FCC policy modernization – Spectrum usage models – Actual spectrum usage (measurements) 4. Spectrum agile radios – 5. 6. 7. Goal of the talk What are Spectrum Agile/Cognitive Radios? Dynamic spectrum management concepts and key considerations Standardization Results Discussions and Summary Submission Kiran Challapali, Philips

November 2004 1. Introduction doc. : IEEE 802. 11 -03/xxxr 0 What are spectrum agile radios? • Cognitive radio – Cognition (Merriam-Webster) • to become acquainted with, to know, to come to know • the act or process of knowing including awareness and judgment – Cognitive radios term originally coined by Joseph Mitola III • Includes learning and reasoning • Spectrum agile radios – Radios that are: • Aware of their environment • Adapt transmission characteristics (based on environment) – Our definition close to FCC’s definition Submission Kiran Challapali, Philips

November 2004 doc. : IEEE 802. 11 -03/xxxr 0 2. Applications Submission Kiran Challapali, Philips

November 2004 Submission 2. Applications doc. : IEEE 802. 11 -03/xxxr 0 Source: Business. Week online Kiran Challapali, Philips

November 2004 2. Applications doc. : IEEE 802. 11 -03/xxxr 0 Remote patient monitoring • Motivation – Healthcare costs are staggering – Aging population, shortage of trained staff in hospitals • Advantages of remote monitoring – Patients spend less time in hospitals, reducing costs – Quality of care improved due to continuous monitoring – Staying at home improves quality of life Submission Kiran Challapali, Philips

2. Applications November 2004 doc. : IEEE 802. 11 -03/xxxr 0 Public safety • Communications failure during 9 -11 • All cellular communications were down for several hours – Cellular networks did not have enough capacity when needed • Public safety communications also failed – Fire and police could not communicate • Public safety under State control (no interoperability) Submission Kiran Challapali, Philips

November 2004 doc. : IEEE 802. 11 -03/xxxr 0 3. FCC policy modernization Submission Kiran Challapali, Philips

November 2004 3. FCC policy modernization • Spectrum reform becoming a global issue Submission doc. : IEEE 802. 11 -03/xxxr 0 Source: FCC Website Kiran Challapali, Philips

November 2004 3. FCC policy modernization doc. : IEEE 802. 11 -03/xxxr 0 FCC’s Spectrum policy task force • Setup by Chairman Powell, headed by Paul Kolozdy • Submitted findings and recommendations Dec. 2002 • Findings – Spectrum access versus scarcity – New methods as a solution to access – Interference tolerance – Need to define rights and responsibilities Submission • Recommendations – Modernizing the regulatory model – Increase access to spectrum – New interference management tech. – Legislative recommendations Kiran Challapali, Philips

3. FCC policy modernization November 2004 doc. : IEEE 802. 11 -03/xxxr 0 Observation • Spectrum usage in NYC during RNC ~ Sept 1 st 2004. – Measurements by Share Spectrum Company • Result: 16 % duty cycle, 30 MHz - 3 GHz, over 24 hours – Actually, even lower (< 10%) occupancies FM TV TV Cell PCS Unlicensed Duty Cycle 1 0 0 Submission 50 0 100 0 1500 Frequency in MHz 200 2500 3000 Source: Shared Spectrum Company 0 Kiran Challapali, Philips

November 2004 3. FCC policy modernization doc. : IEEE 802. 11 -03/xxxr 0 Spectrum usage models Source: Paul Kolodzy @ ISART 2003 Submission Kiran Challapali, Philips

November 2004 3. FCC policy modernization doc. : IEEE 802. 11 -03/xxxr 0 FCC NPRM on Cognitive Radio • Issued on December 30 2003 • Scope – Facilitating Opportunities for Flexible, Efficient, and Reliable Spectrum Use Employing Cognitive Radio Technologies – Authorization and Use of Software Defined Radios • A simpler definition of CR • CR use in four scenarios discussed – Licensee can make more efficient use of their own spectrum – Secondary markets: Based on agreements between licensees and third parties – Co-primaries: Automated frequency coordination – Unlicensed operation: Opportunistic usage (no explicit agreements) Submission Kiran Challapali, Philips

November 2004 3. FCC policy modernization doc. : IEEE 802. 11 -03/xxxr 0 FCC NPRM on Unlicensed operation in TV Bands • Issued on May 13, 2004 • Scope – Unlicensed operations in the TV Broadcast Bands • New unlicensed devices will not cause interference to – Analog and Digital TV Broadcast stations – LPTV, TV Translator, TV Booster Stations, Auxiliary Operations, and Wireless Microphones – Land Mobile Radio Services (PLMRS and CMRS) • Operation in – Channels 5 to 13 and 21 to 51 (except ch. 37) (76 to 698 MHz) – In addition, Channels 14 to 20 permitted in rural areas Submission Kiran Challapali, Philips

November 2004 3. FCC policy modernization doc. : IEEE 802. 11 -03/xxxr 0 FCC NPRM on Unlicensed operation in TV Bands (Contd. ) • Two types of devices permitted • Personal/portable devices – Peak power 100 m. W – Devices must receive a control signal indicating which channels are vacant • Fixed access devices – Peak power 1 W – Devices must either • Include GPS and means to know which channels are vacant • Professionally installed to operate in vacant channels Submission Kiran Challapali, Philips

November 2004 doc. : IEEE 802. 11 -03/xxxr 0 4. Spectrum agile radios Submission Kiran Challapali, Philips

4. Agile radios November 2004 doc. : IEEE 802. 11 -03/xxxr 0 Key considerations • How to harness spectrum “white spaces”? – Are reliable wireless services without licensed frequency allocation possible? – Can devices automatically find “white spaces”? • How can they avoid harmful interference to licensees? • What if receivers are silent? – How can devices share spectrum efficiently? • How to avoid many competing (interfering) devices in the same band? – What are the hardware/software design challenges? – How to ensure compliance? • FCC currently does not monitor emissions • Solution: Cognitive/Agile Radio technologies – Several approaches to dynamic spectrum sharing Submission Kiran Challapali, Philips

4. Agile radios November 2004 doc. : IEEE 802. 11 -03/xxxr 0 Research directions • Several technical communities answering key questions • Joseph Mitola III • DARPA XG program – For defense needs, architecture based on Policy language • NSF Pro. WIN Ne. TS program – Significant investment on test-beds • Wireless Industry, Standards – IEEE 802. 22 WG – IEEE 802. 16 h SG Submission Kiran Challapali, Philips

November 2004 4. Agile radios doc. : IEEE 802. 11 -03/xxxr 0 Definition of spectrum agile radios • Definition – A new paradigm for wireless communications. – The physical and medium access layers of spectrum agile radios adapt their transmission characteristics to the external radio environment, while retaining the flexibility to react to evolving FCC policies. • Our version of Cognitive Radio, and, Aware/ Adaptive Submission Learning/ Reasoning Kiran Challapali, Philips

November 2004 4. Agile radios doc. : IEEE 802. 11 -03/xxxr 0 Definition of spectrum agile radios spectrum agile radio = flexible re-configurable radio (“quickly adapts transmission characteristics” ) + smart protocols and algorithms (“aware of spectrum usage in vicinity, makes intelligent decisions on that basis, and reacts to evolving FCC policies”) Submission Kiran Challapali, Philips

4. Agile radios November 2004 doc. : IEEE 802. 11 -03/xxxr 0 Opportunity identifier Spectrum agile radio: Key components Policy interaction Opportunity manager Flexible PHY layer Submission Kiran Challapali, Philips

November 2004 4. Agile radios doc. : IEEE 802. 11 -03/xxxr 0 Spectrum agile radio: Key components Submission Kiran Challapali, Philips

November 2004 4. Agile radios doc. : IEEE 802. 11 -03/xxxr 0 Dynamic spectrum sharing concepts • Primary (vertical) sharing – Finding and using spectrum white space • Secondary (horizontal) sharing – Dissimilar networks then sharing the spectrum efficiently Submission Kiran Challapali, Philips

November 2004 4. Agile radios doc. : IEEE 802. 11 -03/xxxr 0 Primary sharing approaches • Self-sensing (or real-time measurements) – Are measurements reliable – Does diversity solve the problem • GPS based location + Retrieval from database – Rely on up-to-date databases (difficult) and Machine readability – Lacks adaptability • Over the air control channel – Cost (infrastructure and receiver) • Professional installation – Lacks adaptability Submission Kiran Challapali, Philips

November 2004 4. Agile radios doc. : IEEE 802. 11 -03/xxxr 0 Secondary sharing approaches • Capacity suffers if no co-ordination at all • Some approaches – Rules based sharing, e. g. Etiquette (Stefan Mangold) • Wi. Fi Co-existence Task Group • Voluntary set of rules, e. g. LBT, max air time, etc. – Explicit coordination • Over the air (separate co-ordination channel) – Rutgers proposal • Via internet (could be broker assisted) • Regional aggregation (statistical multiplexing) – Stevens proposal Submission Kiran Challapali, Philips

November 2004 doc. : IEEE 802. 11 -03/xxxr 0 5. IEEE Standards Submission Kiran Challapali, Philips

November 2004 doc. : IEEE 802. 11 -03/xxxr 0 IEEE Standardization • IEEE 802. 22 – A new Working Group formed in IEEE – Regional Area Network TV Band Specification • includes mechanisms to protect incumbent licensees from harmful interference. • Specifically, • SCOPE: This standard specifies the air interface, including the medium access control layer (MAC) and physical layer (PHY), of fixed point-tomultipoint regional area networks operating in the VHF/UHF TV broadcast bands between 54 MHz and 862 MHz. • PURPOSE: This standard is intended to enable deployment of interoperable 802 multivendor regional area network products, to facilitate competition in broadband access by providing alternatives to wireline broadband access and extending the deployability of such systems into diverse geographic areas, including sparsely populated rural areas, while preventing harmful interference to incumbent licensed services in the TV broadcast bands. Submission Kiran Challapali, Philips

November 2004 doc. : IEEE 802. 11 -03/xxxr 0 IEEE Standardization • IEEE 802. 16 – A new Task Group h proposed – PAR and 5 Criteria drafted – Will likely be voted on in November (this) meeting • SCOPE (DRAFT): This amendment specifies improved mechanisms, as policies and medium access control enhancements, to enable coexistence among license-exempt systems based on IEEE Standard 802. 16 and to facilitate the coexistence of such systems with primary users. Submission Kiran Challapali, Philips

November 2004 doc. : IEEE 802. 11 -03/xxxr 0 6. Results Submission Kiran Challapali, Philips

6. Results November 2004 doc. : IEEE 802. 11 -03/xxxr 0 802. 11 k medium sensing time histogram • With 802. 11 k, stations can report new measurement results • After sensing, results are reported with standardized frames • Histogram helps identifying opportunities Author: Stefan Mangold/Zhun Zhong Submission Kiran Challapali, Philips

6. Results November 2004 doc. : IEEE 802. 11 -03/xxxr 0 heavily used Examples … no opportunity licensed spectrum, used with deterministic pattern opportunity unlicensed (4 channels) Author: Stefan Mangold/Zhun Zhong Submission Kiran Challapali, Philips

6. Results November 2004 doc. : IEEE 802. 11 -03/xxxr 0 802. 11 k MSTH measurement results • Simulation of high channel load (many stations) Author: Stefan Mangold/Zhun Zhong Submission Kiran Challapali, Philips

6. Results November 2004 doc. : IEEE 802. 11 -03/xxxr 0 Spectrum agile radio: cyclic spectrum for analog TV Submission Kiran Challapali, Philips

6. Results November 2004 doc. : IEEE 802. 11 -03/xxxr 0 Spectrum agile radio: Cyclic correlation for digital TV Submission Kiran Challapali, Philips

November 2004 Submission doc. : IEEE 802. 11 -03/xxxr 0 Kiran Challapali, Philips

6. Results November 2004 doc. : IEEE 802. 11 -03/xxxr 0 Further reading … [1] [2] [3] [4] [5] MANGOLD, S. AND CHALLAPALI, K. (2003) Coexistence of Wireless Networks in Unlicensed Frequency Bands. Wireless World Research Forum #9 Zurich Switzerland July 2003. CHALLAPALI, K. AND MANGOLD, S. AND ZHONG, Z. (2004) Spectrum Agile Radio: Detecting Spectrum Opportunities. International Symposium on Advanced Radio Technologies 2004 Boulder Colorado USA, Mar 2004. CHALLAPALI, K. AND BIRRU, D. AND MANGOLD, S. (2004) Spectrum Agile Radio for Broadband Applications. EETimes In Focus Article Aug 23. MANGOLD, S. AND ZHONG, Z. AND CHALLAPALI, K. (2004) Spectrum Agile Radio: Radio Resource Measurements for Opportunistic Spectrum Usage. IEEE Globecom 2004 Dallas TX, USA, Nov 2004. MANGOLD, S. AND ZHONG, Z. AND HIERTZ, G. AND WALKE, B. (2004) IEEE 802. 11 e/802. 11 k Wireless LAN - Spectrum Awareness for Distributed Resource Sharing. Special Issue on Emerging WLAN Technologies and Applications. Wireless Communications and Mobile Computing. New York USA: John Wiley & Sons. Submission Kiran Challapali, Philips

November 2004 doc. : IEEE 802. 11 -03/xxxr 0 7. Summary • A new paradigm for wireless communications – Harness unused spectrum, thereby, – Enable many new applications • Substantial interest in many technical communities Submission Kiran Challapali, Philips