Emerging Wireless Standards (pdf)
Transcript of Emerging Wireless Standards (pdf)
http://www.crtwireless.com/EWS_09.htmlAvailable online
Emerging Wireless StandardsWireless Summer SchoolWireless Summer School
June 4, 2008Session C2
1:30‐5:00 PM
James [email protected](540) 230‐6012www crtwireless comwww.crtwireless.com
Presentation Overviewhttp://www.crtwireless.com/EWS_09.htmlAvailable online
Presentation OverviewEmerging Standards(11) Cellular (other than LTE and ( ) (
WiMAX)(10) LTE(11) WiMAX(11) WiMAX(11) 4G(24) WLAN( 8) Interoperability Standards( 8) Interoperability Standards( 9) WPAN(11) Cognitive Radio Standards
http://www.wisoa.net/members_logos/mobile_internet‐big.jpg
(10) Summary and Trends
Break & Poster SessionBreak & Poster Session2:45‐3:30
CellularCellular
(other than LTE and WiMAX)
Cellular OverviewCellular Overview• Two primary competing approaches to 3G
– 3GPP Family• GSM GPRS EDGE WCDMA TD SCDMA
3GPP Declared IP
• GSM, GPRS, EDGE, WCDMA, TD‐SCDMA (WCDMA‐TDD), HSCSD, HSPDA, LTE, LTE Advanced
• Promotional www.gsmworld.com• Standards www.3gpp.org
– 3GPP2 Family• CDMAOne (IS‐95a,b), 1xRTT, 1xEVDO, 1xEVDV, UMB
• Promotional http://www.cdg.orgd d• Standards www.3gpp2.org
– One vision• Voice + high speed data + mobility
– One dominant IP holder (Qualcomm)Oth
3GPP2 Declared IP
• Other– Mobile WiMAX and WiMAX II (802.16m)– Standard http://wirelessman.org/– Promotional http://www.wimaxforum.orgL IP
4 /114
– Lower cost IP• 350 companies own essential IP• http://www.eetimes.eu/design/197007324
Source: “3G Cellular Standards and Patents”, David J. Goodman and Robert A. Meyers
GSM Dominates the LandscapeGSM Dominates the Landscape
http://www.coveragemaps.com/gsmposter_world.htm
• 3GPP (GSM/WCDMA) has most of the market (77% in 2005, 83% in 2006, 86.6% in 2008)– Most of that lead is in GSM3GPP2 ( d 2000) i j 3GPP• 3GPP2 (cdma2000) got a massive jump on 3GPP– 418/431 million of CDMA is 3G (www.cdg.org)– 3GPP2 = 11.4%, 3GPP = 5.6%
• WiMAX just cranking up but will be deploying years ahead of LTEWiMAX just cranking up but will be deploying years ahead of LTE
3GPP Technologies3GPP Technologies
• Generic Access Network (UMA)Supports handoffs between GSM networks
• High Speed Downlink Packet Access – W‐CDMA downlink– Supports handoffs between GSM networks
and 802.11 or Bluetooth networks• Packet Switched Handoffs
– Enables easier handoffs between different 3GPP networks
M lti di B d t/M lti t S i
– W‐CDMA downlink • 8‐10 Mbps (and 20 Mbps for MIMO systems) over
a 5MHz bandwidth–Adaptive Modulation and Coding (AMC), –MIMO (Release 6)–Hybrid ARQ
ll k• Multimedia Broadcast/Multicast Services– Simultaneous broadcast of data streams to
multiple recipients
–All IP core network• (Release 4)• Originally ATM
• High Speed Uplink Packet Access (Enhanced UpLink)
–Similar technologies to HSDPA on uplink–Similar technologies to HSDPA on uplink–AT&T in 350 markets
• http://www.mobileburn.com/news.jsp?Id=4660• Loosely coincides with launch of 3G iPhone
HSPA+“HSPA Evolved”Adds MIMO28/42 Mbps DL12 Mbps YULLatency reduction (2ms on TTI)AT&T upgrade
http://www.informationweek.com/blog/main/archive/2009/05/ 72 b h l j i id 35T02OIs/2009/05/att_says_72mbps.html;jsessionid=35T02OIX4PFBAQSNDLOSKH0CJUNN2JVN
Table from: http://www.umtsworld.com/technology/images/hsdpa.png
TD‐SCDMATD SCDMA• Time Division – Synchronous CDMA
– Synchronized uplink channels aided by joint detectionChina’s 3G technology
• 3GPP
LCR TDD(R4)
LCR TDD(R5)
LCR TDD(R6) MC-CDMA
TDDOFDMA
TDDSC-FDMA
/OFDMA TDD
LTE TDD
LCR TDD(R7)
• 3GPP
LCR TDD(R4)
LCR TDD(R5)
LCR TDD(R6) MC-CDMA
TDDOFDMA
TDDSC-FDMA
/OFDMA TDD
LTE TDD
LCR TDD(R7)
– China’s 3G technology• Core network is almost the same as WCDMA
– Requires mature 2G (GSM) network for implementation
• CCSA
TD-SCDMAN F TD-SCDMA
TD-SCDMAStage III
(R6/R7)
• CCSA
TD-SCDMAN F TD-SCDMA
TD-SCDMAStage III
(R6/R7)
• Part of the 3GPP (3rd Generation Planning Partnership Project)
• Multiple chip rates– LCR: 1.28 Mcps, 1.6 MHz BWHCR: 3 84 Mcps 5 MHz BW
Multi-carrier
TD SCDMA Stage I
(R4 2003/03)
N FrequencyBands Cell
SCStage II(R5) TD-SOFDMA
Current status Short Term Evolution Long Term Evolution
Multi-carrier
TD SCDMA Stage I
(R4 2003/03)
N FrequencyBands Cell
SCStage II(R5) TD-SOFDMA
Current status Short Term Evolution Long Term Evolution
– HCR: 3.84 Mcps, 5 MHz BW• TDD link
– Does not use paired frequency bands• Optimum for symmetric and asymmetric data
servicesb d d h ll fl bl
TD‐SCDMA Multiple Access Options
ZTE Corporation, “3GPP Specification Evolution”2005 20072005 2007
– 1.6 MHz bandwidth allows flexibly spectrum allocation
• Frequency band: – 2010 MHz ‐ 2025 MHz in China (WLL 1900 MHz ‐ 1920 MHz)
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)• Partially motivated by avoiding paying Qualcomm royalties
B. Li, D. Xie, S.Cheng, J. Chen, P. Zhang, W.Zhu, B. Li; “Recent advances on TD‐SCDMA in China,” IEEE Comm. Mag, vol 43, pp 30‐37, Jan 2005
Significant Issues DeployingSignificant Issues Deploying• Standardized in 1999• Was going to roll out in 2004
– http://www.commsdesign.com/news/market
• However, China has made it a point of national pride to have the network running for the 2008 Olympics
– http://www.highbeam.com/doc/1G1‐150687033.html– Is already being tested in 10 cities (includes the Olympic
iti ) b t ti id li t b i d bhttp://www.commsdesign.com/news/market_news/OEG20030102S0009
• Then 2005– http://www.chinadaily.com.cn/english/doc/2004‐06/23/content_341749.htm
• Then 2006
cities) but nationwide licenses may not even be issued by the Olympics
• http://www.thestandard.com.hk/news_detail.asp?pp_cat=1&art_id=54099&sid=15557306&con_type=1
– First commercial trials supposed to begin April 1, 2008• http://www.tdscdma‐
alliance.org/english/news/list.asp?id=4426First public demos in May went badly• Then 2006
– http://www.accessmylibrary.com/premium/0286/0286‐9623636.html
• Then 2007– http://www.theage.com.au/news/Technology/Chi M bil l h 3G bil i
– First public demos in May went badly • http://www.pcworld.com/businesscenter/article/146128/china
_shows_off_olympic_techsort_of.html• China won’t allow 3G or WiMAX until TD‐SCDMA takes off
• Developed a bad reputation– http://homepage.mac.com/dwbmbeijing/iblog/SiHu/C520China‐Mobile‐to‐launch‐3G‐mobile‐services‐
end2007/2007/02/12/1171128898337.html• Now will reportedly issues licenses in 2008
– http://news.zdnet.com/2110‐1035_22‐6207356.html
http://homepage.mac.com/dwbmbeijing/iblog/SiHu/C520534961/E20060302210839/index.html
– Unnamed China Mobile engineer – “you GIVE me a TD‐SCDMA network, and I wouldn't take it.“
– 419,000 Users end of 2008• But 320,000 used it for free in Nov 2008• http://www.marbridgeconsulting.com/marbridgedaily/2009‐01‐
• Delays make Chinese state‐owned service providers unhappy
– Grumblings about forgoing TD‐SCDMA from ChinaMobile (primary deployer)
– http://www.forbes.com/markets/feeds/afx/20
09/article/22889/china_mobile_records_419k_td_scdma_users
Nonetheless, iPhone and Android coming to China apparently with support for TD‐SCDMA
http://www.theregister.co.uk/2009/06/01/chinese_iphone_rumored_for_july/http://www smartbrief com/news/ctia/storyDetails jsp?issueid=71C0
8 /114
p // / / / /06/01/31/afx2489964.html
http://www.smartbrief.com/news/ctia/storyDetails.jsp?issueid=71C09C05‐825C‐40FF‐B9ED‐3AE0CEA92342©id=18BF787F‐8CBC‐4772‐9E89‐C8ABD10C4B1D
3GPP2 Technologies3GPP2 Technologies• cdma2000 1xRTT
Packet switched (always on)• EVDO Rev A
Wide deployment– Packet‐switched (always on)– Maximum of 144kbps
• Typical 40‐60 kbps– 2G / 3G
• 1x EVDO
–Wide deployment• Verizon, Sprint, Kindle best known
–Features• Higher modulation uplink• Multi‐user packets (time‐slots)• Lower Latency– CDMA EVolution Data Only
• Designed to support only data applications– VOIP
• Also known as:– CDMA 1x EV‐DO– CDMA EV‐DO
Lower Latency• Couple new data rates downlink (changed code rate)
• Promotional–http://www.evdoinfo.com
– Can offer data rates of 384kbps ‐ 2.4Mbps• Does not mix voice traffic with data traffic• Changes modulation, # timeslots
• EVDV (Voice + Data)– Dead on arrival
EVDO and HSPA Coverage
– Dead on arrival• http://telephonyonline.com/mag/telecom_evdv_
dead/index.html• Qualcomm halted work on the standard in 2005
– http://news.com.com/Cell+phone+makers+to+adopt+Internet+calling/2100‐7352_3‐5618191 html
9 /114
5618191.html– Slow to field
http://www.verizonwireless.com
EVDO Rev B (TIA‐856 RevB)EVDO Rev B (TIA 856 RevB)
• Adds Multiple carriers – 2xEVDO, 3xEVDO,…U 15 1 25 MH i i hi 20 MH– Up to 15 1.25 MHz carriers within 20 MHz
• Adds support for 64‐QAM modulation• DL 73.5 Mbps • UL 27 Mbps• Dynamic non‐contiguous carrier allocation• Support for single carrier and multiple carrier subscribers• Standardized 2006• Trials mid‐2007 • Software upgrade (at BTS) to Rev A• Commercial deployments?
– Alcatel‐Lucent announced products April 2008http://www cdg org/news/search/2008/04/vendor/040108– http://www.cdg.org/news/search/2008/04/vendor/040108_ven_f.html
– No subscribers listed in 4Q 08 by CDMA Development Group• http://www.cdg.org/worldwide/cdma_world_subscriber.asp
EVDO Rev C (UMB)EVDO Rev C (UMB)• Spec published Sep 24, 2007
h // d / / /200• Killed when Verizon went with
LTE– http://www.cdg.org/news/press/2007/Sep24_07.asp
– 3GPP2 (UMB) beats 3GPP to market again
– Chipsets available nowish
LTE– http://www.phoneplusmag.com/
hotnews/79h20122346.html– Dead on ArrivalChipsets available nowish
• http://www.qualcomm.com/press/releases/2007/070327_complete_solution_ultra.html
• Data rates, mobile with 20 MHz bandwidth
• http://www.abiresearch.com/products/research_brief/Wireless_Infrastructure_Research_Briefs/112
– Qualcomm initially differsbandwidth– DL: 288 Mbps– UL: 75 Mbps
• Key technologiesOFDMA MIMO b f i
– Qualcomm initially differs (ineffectually)
• http://www.fiercebroadbandwireless.com/story/qualcomm‐ceo‐umb‐not‐dead‐yet/2008‐01‐14
– OFDMA, MIMO, beamforming– Flexible spectrum allocation– Enhanced QoS– Support for multiple access
technologies
y
– Qualcomm announced end of UMB work, shift to LTEhttp://www.forbes.com/feeds/afx/2008/11/13/afx5692165.html
technologies– Reduced latency
3GPP2 Statistics3GPP2 Statistics• “More than 301 operators in 108 countries have selected CDMA2000® as their 3G platform ofselected CDMA2000® as their 3G platform of which 280 offer commercial services”
http://www cdg org/technology/3g/resource/cdg markettrendsfacts english pdfhttp://www.cdg.org/technology/3g/resource/cdg_markettrendsfacts_english.pdf
http://www.cdg.org/technology/3g/resource/CDMA450%20Market%20Facts.pdf
IEEE 802.20IEEE 802.20 • Allegations of process abuse brought to a screeching halt when standard suspended in
• Fill performance gap between “high data‐rate, low mobility 802 standards” and “high mobility cellular
k ”g p
September• Project Launched 2004• Looked to be dead in the water
– Flarion leading proposall l d h ld
networks”• From QTDD/QFDD Proposal• OFDMA data channel• CDMA control channel• Bandwidths
– Qualcomm leading vote holder• Turned around when Qualcomm bought Flarion(Aug 05)
– http://www.dailywireless.org/modules.php?name=News&file=article&sid=4532
– 5 MHz – 20 MHz• MIMO
– Single, multiple code word– Pseudo‐ Eigen beamforming
• Space Division Multiple Access• Went to proposal downselection process
– Qualcomm (Flarion) TDD, FDD– ETRI– BEST‐WINE (Kyocera)
R d i D 06
p p– Separate mode from MIMO
• Data Rate 260 Mbps–MIMO, 20 MHz
• Turbo coding• Time‐frequency hopping • Reapproved in Dec 06
• First meeting Jan 2007• Approved June 2008
– http://www.ddj.com/mobile/208403913
• Available:
Time frequency hopping• Supposed to support inter Radio Access Technology handoffs
• Similar to UMB– UMB is effectively an upgrade to MBFDD version– IEEE C802.20‐07/14 Available:
– http://standards.ieee.org/getieee802/802.20.html
• Working on conformance, minimum performance requirements
/
Presentation Overviewhttp://www.crtwireless.com/EWS_09.htmlAvailable online
Presentation OverviewEmerging Standards(11) Cellular (other than LTE and ( ) (
WiMAX)(10) LTE(11) WiMAX(11) WiMAX(11) 4G(24) WLAN( 8) Interoperability Standards( 8) Interoperability Standards( 9) WPAN(11) Cognitive Radio Standards
http://www.wisoa.net/members_logos/mobile_internet‐big.jpg
(10) Summary and Trends
Break & Poster SessionBreak & Poster Session2:45‐3:30
3GPP Long Term Evolution(LTE)
3GPP Long Term Evolution (LTE)3GPP Long Term Evolution (LTE)
• Evolved Universal Terrestrial Radio Access• Downlink: Adaptive multilink OFDM (AML‐
Approximate Deployment ScheduleE‐UTRA Air Interface
Downlink: Adaptive multilink OFDM (AMLOFDM), which means different bandwidths based on demand
– Variable prefix size• 4.7 ms to 16.7 ms• Intent to support up to 120 km cells
C ll d Hi h S d OFDM P k t A HSOPA– Called High Speed OFDM Packet Access or HSOPA• Uplink: SC‐FDMA (more later)• DL 100 Mbps in 20 MHz (5 bps/Hz)• UL 50 Mbps in 20 MHZ (2.5 bps/Hz)• Reduced transition time between states (such as
http://www.motorola.com/staticfiles/Business/Solutions/Industry Solutions/Service Providers/Wireless Operators/LTE/_Document/6993_MotDoc.pdf
(between idle and active states)
• Variable bandwidth allocations: 1.25 MHz, 1.6 MHz, 2.5 MHz, 5 MHz, 10 MHz, 15 MHz and 20 MHz in both the uplink and downlink
• Frequency reuse factor of 1
http://www.3gpp.org/ftp/Specs/html‐info/36‐series.htm
q y– Fractional frequency reuse
• 200 users/cell• Load sharing/policy across radio access technologies
• Support for antenna arrayspp y– Beamforming, MIMO– Space Division Multiple Access http://hgmyung.googlepages.com/scfdma.pdf
LTE NetworkLTE Network• Flat access network
– No central control
– Directly connected via X2 link
– Cooperative resource management
• Evolved Packet Core– All IP Core Network
• All voice is VOIP
– Serving Gateway• Anchor for local mobility between eNodeBs
• Some administrative work for roaming
– Mobility Management Entity• Setup / management of bearer services
• Security
– PDN GatewayIP dd ll i UE
http://hgmyung.googlepages.com/3gppLTE.pdf
HSS• IP address allocation to UE
• QoS Enforcement
– Home Subscriber Server• Hosts user subscription data
PCRF
MME
HSS
PCRFS1‐MME
– PCRF• Sets policy for bearers
UE eNodeBServing Gateway
PDN Gateway
Services / IP Cloiud
S1‐US1‐U
LTE The UMTS Long Term Evolution, S. Sesia, I. Toufik, M. Baker, eds., John Wiley and Sons, 2009
Protocol StackProtocol Stack
• NAS = Non‐access
Control Plane
stratum– Protocols running between core network and UE
• RRC = Radio Resource Controlesou ce o o
• PDCP = Packet Data Convergence Protocol
User Plane
Protocol• RLC =Radio Link Control
http://www.home.agilent.com/agilent/eventDetail.jspx?nid=‐35356.0.08&lc=eng&cc=US&ckey=1381781&id=1381781
Resource ManagementResource Management• Fine grained allocation / scheduling
of subcarriers / timingof subcarriers / timing– Also applies to SCFDMA– Can be based on current fading
conditions• User diversity
• Handoffs– Hard Handoff– Over X1 and over S1
• Multiple levels of packet priorities http://hgmyung.googlepages.com/scfdma.pdf
– QCI = QoS Class Indicatorp g y g g g p g p
B. Furht, S. Ahson, “Long Term Evolution: 3GPP LTE Radio and Cellular Technology” CRC Press, 2009
LTE The UMTS Long Term Evolution, S. Sesia, I. Toufik, M. Baker, eds., John Wiley and Sons, 2009
Single Carrier FDMASingle Carrier FDMA• SC‐FDMA on the uplink
Wh ?• Why?– Gain frequency domain equalization
• Little extra complexity to OFDM• But extra steps to effect SC‐FDMA
– ~2 dB reduction in PAPR• Van Nee and Prasad, OFDM for Wireless
Multimedia Communications, Artech House Publishers, 2000.
– Less power consumption• Better battery life• Better for handsets• Better for handsets
– Less sensitivity to carrier offset– Possibly worse performance in fading channels– Priyanto, B.E.; Codina, H.; Rene, S.;
Sorensen, T.B.; Mogensen, P., “Initial
http://hgmyung.googlepages.com/scfdma.pdf
J Andrews A Ghosh, ; g , ,Performance Evaluation of DFT‐Spread OFDM Based SC‐FDMA for UTRA LTE Uplink,” VTC Spring 2007, pp. 3175 –3179.
J. Andrews, A. Ghosh, R. Muhamed, Fundamentals of WiMAX, Prentice Hall, 2007
More LTE DetailsMore LTE DetailsFrame Structure
• Support for paired / unpaired
http://www.motorola.com/staticfiles/Business/Solutions/Industry Solutions/Service Providers/Wireless
Support for paired / unpaired spectrum
• Multicast / Broadcast Services– Optional now, but expected to
Operators/LTE/_Document/6993_MotDoc.pdf
– Subframes 0,5 must be DL
– Otherwise arbitrary TDD structure
• Other Features
p , pbe supported
• DRX– Aggressive sleep modes guided
b N d B – Interference Mitigation– Extensions
by eNodeB• Latency reduction influenced by
state reduction
UMTS LTE
21 /114http://www.motorola.com/staticfiles/Business/Solutions/Industry Solutions/Service Providers/Wireless Operators/LTE/_Document/6993_MotDoc.pdf
Adrian Scrase, “Overview of the Current Status of 3GPP LTE,” Mobile World Congress, Feb 11‐14, 2008
Deployments• Nokia officially abandoned WiMAX for LTE
// / / / /– http://gigaom.com/2009/03/04/nokia‐plans‐lte‐devices‐for‐2010/
• Japan & China to work on LTE‐flavor– Government level agreement (TD‐SCDMA / LTE?)
– http://tech.yahoo.com/news/afp/20090428/tc_afp/japanchindi l t h l t ladiplomacytechnologytelecom
• First FCC Cert (March 2009)
– LG infrastructure for 1700 AWS
– http://www.engadgetmobile.com/2009/03/18/fcc‐approves‐lte‐gear‐from‐lg‐wimax‐says‐welcome‐to‐the‐party/
h f f• iPhone for LTE for Verizon– http://www.usatoday.com/tech/wireless/phones/2009‐04‐26‐
apple‐verizon‐iphone_N.htm?csp=34
• VodaPhone LTE in German TV Spectrum– http://www.telegeography.com/cu/article.php?article_id=282
96& il h l96&email=html
• LSTI – LTE / SAE Trial Initiative– http://www.lstiforum.org/– Drive industrialization of 3GPP, demonstrate capabilities– Began Interoperability testing May, 09
S. Hattangady, “The promise of 4G LTE (Long‐Term Evolution),” April 2009
S. Hattangady, “The promise of 4G LTE (Long‐Term Evolution),” April 2009
Verizon Open Development for LTE(What Hath Google Wrought?)
• Open platform was a requirement of 700 MHz auctionof 700 MHz auction
• Website:– https://www22.verizon.com/opend
ev/• C‐band LTE spec available
– Issued April 2009– Available to “developers”– Anyone can register as a developerAnyone can register as a developer
• I did! (We’re not building LTE devices)
• LTE Specification Web Conference May 13. Developers, online– wwwverizonwireless‐– www.verizonwireless‐
opendevelopment.com Verizon Wireless, “DEVICE REQUIREMENTS LTE 3GPP BAND 13 NETWORK ACCESS” VERSION 0.9 Issued: April 2009
Potential Snags?Potential Snags?• Concern about VOIP voice quality
– http://www.unstrung.com/document.asp?doc_id=176867
• Backhaul Issues?– HSPA site requires 45 Mbps (3x14.4)
– E1 line is 2‐8Mbps– Circuit switch fallback?• http://www.unstrung.com/document
.asp?doc_id=173090
• IPR Issues?H t 3G i il l
E1 line is 2 8Mbps• http://www.unstrung.com/document
.asp?doc_id=176867
– Could be IP over microwave
M t t th t f b kh l– Hurt 3G, similar players• http://www.unstrung.com/document.asp?doc_id=176867
– Starting to work on patent pooling• Sisvel, VIA Licensing and MPEG LA
– Movement to ethernet for backhaul• “Over half of cellular backhaul
capacity will use Ethernet by the end of 2011”
• http://www instat com/press asp?SkSisvel, VIA Licensing and MPEG LA• Started in 2008• http://www.fiercewireless.com/story/lte‐patent‐pool‐efforts‐heat/2009‐05‐26
– Qualcomm made about $8B in 2008
• http://www.instat.com/press.asp?Sku=IN0904603GW&ID=2533
– Also have to work with security and latency requirements
2008 • LTE Setup more complex (flat, inter‐BS management)
– Automation desired
– http://www unstrung com/document– http://www.unstrung.com/document.asp?doc_id=177252
http://files.shareholder.com/downloads/QCOM/315627873x0x189123/2f1a890f‐ef39‐43f6‐bfd3‐d673c59c16c3/QCOM_stockholder_031108_FINAL.pdf
Presentation Overviewhttp://www.crtwireless.com/EWS_09.htmlAvailable online
Presentation OverviewEmerging Standards(11) Cellular (other than LTE and ( ) (
WiMAX)(10) LTE(11) WiMAX(11) WiMAX(11) 4G(24) WLAN( 8) Interoperability Standards( 8) Interoperability Standards( 9) WPAN(11) Cognitive Radio Standards
http://www.wisoa.net/members_logos/mobile_internet‐big.jpg
(10) Summary and Trends
Break & Poster SessionBreak & Poster Session2:45‐3:30
WiMAXWiMAX
802.16d,e,j
802.16 Family (WiMAX)802.16 Family (WiMAX)802.16 Apr 2002 LOS 10‐66 GHz802 16a Apr 2003 2 11 GH802.16a Apr 2003 2‐11 GHz 802.16c Jan 2003 2‐11 GHz 802.16d Oct 2004 Combined 802.16,a,c802.16e Dec 2005 Mobile WiMAX
Commercialization Roadmap
802.16f Dec 2005 Net Management Database (MIB)
802.16g Spring 2007 Network management plane
802 16h 2009 Li t802.16h 2009 License‐exempt Coexistence
802.16i Fall 2008 Mobile Management Information Base
802 16j 2009 Mobile Multihop Relay802.16j 2009 Mobile Multihop Relay802.16k Aug 2007 Network Management802.16m 2010 4G
WiMAX Forum (2006): Mobile WiMAX – Part I: A Technical Overview and Performance Evaluation.
Available at www.wimaxforum.org
Projections based on data at http://grouper.ieee.org/groups/802/16/published.html
802.16e (Mobile WiMAX, 802.16‐2005)802.16e (Mobile WiMAX, 802.16 2005)
• Ideally 802 16 + mobilityPHY Spec Overview
Ideally, 802.16 + mobility– Really intended for nomadic or low mobility– Not backwards compatible with 802.16‐2004
• http://www.unstrung.com/document.asp // g /p?doc_id=76862
• Direct competitor to 3G, 4G, 802.20 though WiMAX Forum once said otherwise
• Numerous ongoing deployments and working systems, particularly for WiBRO
• PHY– Scalable OFDM + Optional MIMO– Convolutional turbo codes– Optional block turbo codes, LDPC
28 /114WiMAX Forum (2006): Mobile WiMAX – Part I: A Technical Overview and Performance Evaluation. Available at www.wimaxforum.org
Other Mobile WiMAX FeaturesOther Mobile WiMAX Features• Frame‐by‐frame resource allocation • Security
f ff d l d• Hybrid Automatic Repeat Request (HARQ)
• UL and DL Scheduling• Variable QoS
– AES for traffic and control data– EAP– Privacy and Key Management
Protocol Version 2 (PKMv2)Variable QoS• Three handoff methods
– A traditional Hard Handoff (HHO)– Fast Base Station Switching (FBSS)
– 3‐way handshake on handoffs• IP Core Network (supports Voice
Over IP)• Multicast Broadcast Services• A list of reachable base stations is
maintained by mobile and base stations, but base stations discard packets if not the active BS
i i ( HO)
• Multicast Broadcast Services– Like cellular multicast services
• WiBRO– Defines a set of options for
– Macro Diversity (MDHO)• Same list is maintained, but all
base stations in the list can participate in the reception and transmission of packets
pMobile WiMAX for Korean deployment
transmission of packets.
WiMAX SpectrumWiMAX Spectrum• WiMAX Spectrum Alliances• Regulatory DatabaseRegulatory Database
–AT4 Wireless– Launched November 2006–http://www.wimaxforum.org/join/spectrum_demo/
• WiMAX Global Roaming AllianceWiMAX Global Roaming Alliance–Brought together unlicensed providers to promote global roaming
–Now defunct –Will probably come back in some form–http://www.theregister.co.uk/2006/09/29/oz_wi i lli /imax_roaming_alliance/
• WiMAX Spectrum Owners' Alliance–http://www.wisoa.com/–Promotes roaming agreements–Participants:U i d A t li N t k Pl M iti UK
• Recent reports of interference with with C‐B d VSAT
http://www.wimaxforum.org/news/downloads/supercomm_2005/WF_Day_in_a_Life_with_WiMAX_Final.pdf
–Unwired Australia, Network Plus Mauritius, UK Broadband, Irish Broadband, Austar Australia/Liberty Group, Telecom New Zealand, WiMAX Telecom Group, Enertel and Woosh Telecom
• 700 MHz band
Band VSAT– http://www.suirg.org/pdf/SUIRG_WiMaxFieldTestReport.pdf
• Officially declared 3G so 3G spectrum– http://www.wirelessweek.com/WiMAX‐is‐
–http://www.xchangemag.com/articles/501/79h13917183935.html?cntwelcome=1
3G.aspx
Mobile WiMAX DeploymentsMobile WiMAX Deployments• First Mobile WiMAX products certified
April 2008– Now 103 (wimaxforum)
• Mostly 3 5 GHz
802.16d + 802.16e + WiBRO (WiMax Forum)
• Mostly 3.5 GHz, – Already more 802.16e than 802.16d
• Less than 3 million subscribers (3Q08)– ~500,000 on ClearWire– Slightly smaller than largest
Not being adopted by incumbents– Not being adopted by incumbents• April 09 – WiMAX Forum 70% of operators
were greenfield– Success for cellular appears tied to Sprint‐
Nextel / Clearwire effort• Narrow band / high power for private
radio systems (utilities)
All bands
radio systems (utilities)– http://www.wimax.com/commentary/blog/b
log‐2009/may‐2009/introducing‐private‐mobile‐wimax‐0524 http://www.wimaxmaps.org/
3.5 GHz Onlyy
(WiMAX Forum)
Clearwire/SprintClearwire/Sprint • Fixed WiMAX based wireline replacement
Clearwire Coverage
• http://www.clearwireconnections.com/pr/pressreleases/050708.pdf
Merged Company
wireline replacement service to home + portability within coverage area
• 2 Mbps data + voice
• Clearwire + Sprint WiMAX unit– Called Clearwire
• Investors– $3.2 Billion from Google (500 M), Comcast (1 05B) Time Warner (550M) Bright House
S i t
http://www.clearwire.com/
(1.05B), Time‐Warner (550M), Bright House (100M), Trilogy Equity (10M)
– Sprint owns 51%– Clearwire owns 27%– Investors own 22%
N i id fSprint• Mobile WiMAX• Rapid deployment to major cities
– 10,000 sites in preparation– 1750 base stations delivered in 2007, 20,000
• Nationwide focus– 120‐140 million coverage by 2010
• Commercial agreements– Intel will put WiMAX in chipsets
• Had been planning on thatantennas• Incorporated into numerous devices (cameras and televisions)
• Open Network (support Android)• Federal government connectivity via WiMAX
http //www wimaxday net/site/2007/06/05/sprint plans
Had been planning on that– Google services to be carried (and search provider)
– Support Android– Sprint, Comcast, TimeWarner, and Bright House will be wholesale
32 /114
– http://www.wimaxday.net/site/2007/06/05/sprint‐plans‐wimax‐for‐gov%e2%80%99t‐services/
House will be wholesale– Sprint contributes its 2.5 GHz holdings
• Looks like a slow roll out
WiBroWiBro• Korean version of 802.16e
– Phase 1 standardized by TTA of Korea (2004)y– Phase 2 standardized in 2005
• Korean spectrum allocated 2002– 2.3 GHz (100 MHz)H i ti 802 16 /WiB d N 2004• Harmonization 802.16e/WiBro agreed Nov 2004 – Samsung joined WiMAX Forum Dec 2004– May indicate Samsung’s guess on 4G direction
• KT & SK Telecom launched June 30 2006 in Seoul• KT & SK Telecom launched June 30, 2006 in Seoul http://kt.co.kr/kthome/kt_info/pr/news_center/news_view.jsp?page=1&no=397&gubun=1
• Just 200,000 subscriptions since launch (12/08).– Possibly influenced by data‐only – http://www.intomobile.com/2008/12/28/wibro‐voice‐calls‐
coming‐to‐south‐korea‐wimax‐networks‐in‐2009.html
How does WiBRO relate to 802.16e?How does WiBRO relate to 802.16e?
• WiMAX Forum: (http://www.wimaxforum.org/news/press releases/WiBro and Mobile WiMAX Backgrou(http://www.wimaxforum.org/news/press_releases/WiBro_and_Mobile_WiMAX_Backgrounder.pdf)
– “WiBro is the service name for Mobile WiMAX in Korea. WiBro uses the Mobile WiMAX System Profile. The system profile contains a comprehensive list of features that the equipment is required or allowed to support, and, as a result, WiBro offers the same capabilities and features of Mobile WiMAX ”Mobile WiMAX.”
– It’s Mobile WiMAX, just with a different profile (frequency, bandwidth…)• Vendors: WiBRO is compatible with 802.16e, but there’s more to Mobile WiMAX than just
802.16e compatibility and many choices in WiBRO are different from what is mandatory in 802 16e802.16e
– From (http://www.nortel.com/solutions/wimax/collateral/wimax_wibro_white_paper.pdf)• Important implementation differences from Nortel white paper
– Mandatory Handoff • 802 16e = HHO• 802.16e = HHO• WiBRO = FBSS
– HARQ• 80.16e = Chase combine HARQ• WiBRO = Incremental redundancy HARQy
– Likely (though unclear) network layer differences
802.16j Mobile Multi‐hop Relay• Expand coverage, capacity by adding
relay stations
802.16j Mobile Multi hop Relay• Relays controlled from base
stationsrelay stations• Intended for licensed operation• Not intended as a mesh network
– Actually a tree
stations• Fixed Relay
– Permanent installation– Useful for coverage holesN di R l• Support mobile units • Nomadic Relay
– Temporary fixed installation– Extra capacity for special events
(military SDR conferences)• Mobile Relay• Mobile Relay
– Placed on mobile platform to support users on the platform
– Useful for public transport (buses, trains)(buses, trains)
Modified from Fig 1 in IEEE 802.16mmr‐05/032
LTE vs WiMAXLTE vs WiMAX• Technically, very similar• LTE a little later, a little more refined,• Came from different industries
– WiMAX more from the computing industry
– LTE more from the cellular industry– Probably biggest factor in deployment
trends and IP• LTE upgrades, WiMAX deploys new
– Easier spectrum for LTE, More niche markets for WiMAX– More niche markets for WiMAX
• Both seem to be going to more “open” systems
– Development, not so much open‐source• Will WiMAX voice like issues also be• Will WiMAX voice‐like issues also be
experienced in LTE?• Both working towards more
distributed control and more complex topologies
S. Hattangady, “The promise of 4G LTE (Long‐Term Evolution),” April 2009
topologies
Presentation Overviewhttp://www.crtwireless.com/EWS_09.htmlAvailable online
Presentation OverviewEmerging Standards(11) Cellular (other than LTE and ( ) (
WiMAX)(10) LTE(11) WiMAX(11) WiMAX(11) 4G(24) WLAN( 8) Interoperability Standards( 8) Interoperability Standards( 9) WPAN(11) Cognitive Radio Standards
http://www.wisoa.net/members_logos/mobile_internet‐big.jpg
(10) Summary and Trends
Break & Poster SessionBreak & Poster Session2:45‐3:30
4G4G
IMT‐Advanced, 802.16m, LTE‐Advanced
4G (IMT‐Advanced)4G (IMT Advanced)• Been looking towards 4G for a while…
– 1 Gbps
• ITU Requirements (Nov / Dec 2008)
• Report ITU‐R M.2134: “The key features of IMT‐Advanced are:
– a high degree of commonality of ITU Requirements (Nov / Dec 2008)
– Report ITU‐R M.2134: Requirements related to technical performance for IMT Advanced radio interface(s) (2008 ) http://www.itu.int/publ/R‐REP‐M 2134‐2008/en
g g yfunctionality worldwide while retaining the flexibility to support a wide range of services and applications in a cost efficient manner;REP‐M.2134‐2008/en
– Report ITU‐R M.2135: Guidelines for evaluation of radio interface technologies for IMT‐Advanced ( 2008) http://www.itu.int/publ/R‐REP M 2135 2008/en
manner;– compatibility of services within IMT and with fixed networks;
– capability of interworking with other radio access systems;REP‐M.2135‐2008/en y ;
– high‐quality mobile services;– user equipment suitable for worldwide use;
– user‐friendly applications, services y pp ,and equipment;
– worldwide roaming capability;– enhanced peak data rates to support advanced services and applications • (100 Mbit/s for high and 1 Gbit/s for low mobility were established as targets for research)3G Americas, “Defining 4G: Understanding the ITU Process for the Next
Generation of Wireless Technology,” July 2007 Available online: http://3gamericas.com/PDFs/3G_Americas_Defining_4G_WP_July2007.pdf
IMT‐Advanced Requirements (1/2)Report ITU‐R M.2134
• Capacity • Mobility classes are defined:i k /h– Stationary: 0 km/h
– Pedestrian: > 0 km/h to 10 km/h– Vehicular: 10 to 120 km/h– High speed vehicular: 120 to 350
k /h
– In terms of voice channels, actually
km/h
Cell Spectral Efficiency
In terms of voice channels, actually not that impressive
• Assume 10kHz• 1 MHz / 10 kHz = 100 users
• Efficiencies– Peak Link efficiencies
• DL (4x4) 15 bit/s/Hz• UL (2x4) 6.75 bit/s/Hz
Cell‐edge Spectral Efficiency
Tables from: Report ITU‐R M.2134. Available: http://www.itu.int/publ/R‐REP‐M.2134‐2008/en
IMT‐Advanced Requirements (2/2)IMT Advanced Requirements (2/2)
• Handover interruption • Bandwidthsa do e e up o a d d s– 40 MHz
– 100 MHz research target
• Latency – Control (idle to active) =
100 ms
– User (time to move IP packet across link) = 10 ms
Declared Intention to Support IMT‐d dAdvanced
•Several candidates already emerging–LTE‐Advanced–802.16mNTT D C M ’ 5 Gb t t–NTT DoCoMo’s 5 Gbps prototype•http://www.nttdocomo.com/pr/files/20070209_attachment02.pdf
–China’s home grown standardg•http://www.forbes.com/markets/feeds/afx/2007/09/25/afx4151478.html
•Common techniques• Perhaps an impractical
number of antennas for direct
42 /114http://www.nttdocomo.com/pr/files/20070209_attachment01.pdf
Common techniques–OFDMA, MIMO, small cell sizes optimized for low speed, but support for high speed, IP b kb
communication with a handset– 12x 12 MIMO– Large implied bandwidths to
achieve goals – 100 MHzbackbone achieve goals – 100 MHz• Hard to find
802.16m802.16m• TGm System Requirements Document
– http://wirelessman org/tgm/docs/80216• Minimum Peak Rate
– Downlink 6.5 bps/Hz
Requirements
– http://wirelessman.org/tgm/docs/80216m‐07_002r4.pdf
– http://wirelessman.org/tgm/docs/80216m‐07_003.pdf
– http://wirelessman.org/tgm/index.html• Key functionalities to be added (not
p /– Uplink 2.8 bps/Hz
• Latency less than 802.16e• Radio Resource Management
– Reporting, interference management– Multicast broadcast service• Key functionalities to be added (not
defined yet)– Routing – Self Organization – Multi‐Carrier
– “High‐resolution” location determination• Internetworking with:
– 802.11 3GPP, 3GPP2• Coverage optimized for 5 km, functional to 30‐100 kmO i i d f l bili ( 15k h)– Multi‐Radio Coexistence • Optimized for low mobility (<15kph), maintain connection up to 350 kph
• Optimized for contiguous spectrum but support discontiguous
• Reuse/share bandwidth with legacy systemssystems
• Direct migration from 802.16e• Recognition of niche markets:
– “IEEE 802.16m shall be able to support public safety first responders, military and emergency services such as call prioritizationemergency services such as call‐prioritization, pre‐emption, and push‐to‐talk.”
IEEE C802.16m‐07/002r1
TGm TimelinesTGm Timelines• Formal announcement ofannouncement of 802.16m for IMT‐Advanced (Feb 2009)h //– http://www.reuters.com/article/pressRelease/idUS140783+16‐Feb‐2009+BW200902162009+BW20090216
• Mid‐2009 System Description
• Sep 2009 First IMT l
2009‐03‐12
proposal• Final spec – May 2010
LTE‐AdvancedLTE Advanced
• RequirementsRequirements– http://www.3gpp.org/ftp/Specs/html‐/ftp/Specs/htmlinfo/36913.htm
– 3GPP TR 36.9133GPP TR 36.913 V8.0.1 (2009‐03)
• Targeting spec
T. Nakamura “Update of E‐UTRA and IMT Advanced Requirements,” ATIS‐3GPP LTE Conference, January 26, 2009
Targeting spec completion end of 20102010
Requirements q3GPP TR 36.913 V8.0.1
• Available: http://www 3gpp org/ftp/Specs/archi
• Efficiency:DL 30bps/Hhttp://www.3gpp.org/ftp/Specs/archi
ve/36_series/36.913/• Date: March 2009• Peak Data Rate
At l t IMT Ad d
– DL= 30bps/Hz– UL = 15 bps/Hz.
• “Assumption of antenna configuration is 8x8 or less for DL and 4x4 or less for UL”– At least IMT‐Advanced
– Research target• 100 Mbit/s for high
– 1 Gbit/s for low mobility • The system should target a downlink
4x4 or less for UL• Spectrum Flexibility
– 450−470 MHz band, – 698−862 MHz band, – 790−862 MHz bandThe system should target a downlink
peak data rate of 1 Gbps and an uplink peak data rate of 500 Mbps.
– The system should be able to support at least 300 active users without DRX in a 5 MH b d idth Th b f
790 862 MHz band, – 2.3−2.4 GHz band, – 3.4−4.2 GHz band, and– 4.4‐4.99 GHz band
• LatencyMHz bandwidth. The same number of RRC connections with DRX as in Release 8 E‐UTRA and E‐UTRAN (16k) is expected
• Coexistence– With other operators, with other flavors
Latency
p ,of 3GPP, legacy systems
LTE Comparison SummaryLTE Comparison Summary
http://www.atis.org/LTE/documents/IMT‐Advanced%20requirements.pdf
4G Takeaways4G Takeaways• 802.16m, LTE‐Advanced leading candidates
4G d ’t i th b th t h• 4G doesn’t raise the bar that much– Expect very similar to 802.16e, LTE– *Very* aggressive timelines– Then again, LTE = 3.9G
• High data rates ma not be achie ed• High data rates may not be achieved– Mostly due to bandwidth availability concerns (hard to find 100 MHz)– Channel bonding a necessity
• Explicit consideration of modes other than traditional vehicular / pedestrian modes (indoor microcellular)modes (indoor, microcellular)
• Continuing to increase emphasis on interoperability, services, openness• Capacity now measured in VoIP calls• Will the not‐so‐distant standardization impact the deployment of 802.16e / LTE?• Implication of large antenna arrays
– Too large for handhelds (8x8 @ 450 MHz)– Likely need femtocells (relays) to make it work
Presentation Overviewhttp://www.crtwireless.com/EWS_09.htmlAvailable online
Presentation OverviewEmerging Standards(11) Cellular (other than LTE and ( ) (
WiMAX)(10) LTE(11) WiMAX(11) WiMAX(11) 4G(24) WLAN( 8) Interoperability Standards( 8) Interoperability Standards( 9) WPAN(11) Cognitive Radio Standards
http://www.wisoa.net/members_logos/mobile_internet‐big.jpg
(10) Summary and Trends
Break & Poster SessionBreak & Poster Session2:45‐3:30
Wireless LANsWireless LANs
802.11
Jun 1997 802.11 2 Mbps ISM
802.11 Alphabet SoupSep 1999 802.11a 54 Mbps UNIISep 1999 802.11b 11 Mbps ISMOct 2001 802.11d global roamingJun 2003 802.11f interoperability
Past dates are standards approval dates. Future dates from 802.11 working group timelines
Jun 2003 802.11g 54 Mbps ISMOct 2003 802.11h spectrum managementJun 2004 802.11i securityOct 2004 802.11j Japanese spectrum
timelinesLetters are working group (WG) designations.
Letters assigned alphabetically as groups created
Sep 2005 802.11e real time QoSMay 2008 802.11k RRM measurementsMay 2008 802.11r fast roamingNov 2008 802.11y US 3.65 GHz
created.
No WG/ WG document
802.11c MAC Bridging work incorporated into 802.1d
Sep 2009 802.11w packet securityNov 2009 802.11n 100 MbpsJan 2010 802.11z Direct Link SetupJun 2010 802.11v network management
p802.11l “typologically unsound”802.11m doc maintenance802.11o “typologically unsound”802 11q too close to 802 1q
Jun 2010 802.11p vehicular (5.9)Sep 2010 802.11u external networksSep 2010 802.11s mesh networksJun 2011 802.11aa Video Transport Streams
802.11q too close to 802.1q802.11x generic 802.11 standard
802.11t (test) was canceled
51 /114
Dec 2012 802.11ac Very High Throughput < 6GHzDec 2012 802.11ad Very High Throughput 60GHz
http://grouper.ieee.org/groups/802/11/Reports/802.11_Timelines.htm
WiFi AllianceWiFi Alliance• Industrial consortium that promotes
802.11 Millions of WiFi Chipset Shipped802.11– www.wi‐fi.org
• Certifies interoperability between vendors’ products
• Certifies consistency with standards
Millions of WiFi Chipset Shipped
• Fills in the gap when 802.11 standards process is too slow (draft n)
• WiFi success owes significant debt to WiFiAlliance
• Line between 802 11 standards community• Line between 802.11 standards community and WiFi Alliance has gotten very blurry
• Certifications– 802.11a/b/g/n WiFi– 802.11e Wireless Multimedia80 . e e ess u t ed a– Draft 2.0 n– EAP (authentication)– (Optional) Wi‐Fi Protected Setup– (Optional) Wi‐Fi Multimedia
(O ti l) WMM P S
Wi‐Fi Alliance, Introducing Wi‐Fi Protected Setup™, January 3, 2007
– (Optional) WMM Power Save – (Optional / Mandatory) Wi‐Fi in handsets
Distributed Coordination Function (DCF)Distributed Coordination Function (DCF)
• Intended to combat “hidden nodes” d d k din an uncoordinated network and
generate fair access to channel•Basic components:
After aitin DIFS after last dete ted–After waiting DIFS after last detected transmission, source sends Request to Send (RTS)
–Destination replies with Clear to Send (if OK)
–Data is then transferred and ACKed–If an error occurs (e.g., collision), then station has to wait for DIFS +
• Network allocation vector– Acts as virtual carrier sense
/then station has to wait for DIFS + random backoff.
• Random backoff grows with # of collisions
– Duration given in RTS/CTS fields
• DIFS = DCF Interframe Space• SIFS = Short Interframe Space
802.11 overhead802.11 overhead
• Significant overhead involved inSignificant overhead involved in 802.11– RTS/CTS/ACK SIFS
– TCP, IP, MAC framing
– Real throughput is rarely come l PHYclose to PHY raw rate
wireless.ictp.trieste.it/school_2002/lectures/ermanno/System_Performance.ppt http://www.cs.tut.fi/kurssit/TLT‐6556/Slides/Lecture4.pdf
802.11n overview802.11n overview•Adds MIMO to WLAN OFDMO t i ith UNII ISM b d•Operate in either UNII or ISM bands
• Status:–In Ballot–But held up by IP battles
Streaming Home Multimedia (HDTV)
• http://arstechnica.com/news.ars/post/20070924‐dark‐australian‐patent‐cloud‐looms‐over‐802‐11n‐spec.html
• CSIRO (http://www.csiro.au/) holds some key IP, hadn’t signed letter of assurance, has history of WiFi lawsuits and sought injunctionshistory of WiFi lawsuits and sought injunctions
– Got bought off
• Last freely available draft–Enhanced Wireless Consortium (merger of TGnSync and WWiSE)
–http://www.enhancedwirelessconsortium.org/home/EWC_PHY_spec_V127.pdf (PHY)
–http://www.enhancedwirelessconsortium.org/home/EWC_MAC_spec_V124.pdf(MAC)
Source: http://www.tgnsync.org/products
(MAC)
802.11n PHY (in 1 slide)802.11n PHY (in 1 slide)•MIMO evolution of 802.11 OFDM PHY
–Up to 4 antennas per devicep p•20 and 40MHz channels
–Fully interoperable with legacy 802.11a/b/g–288 Mbps in 20MHz and 600 Mbps in 40MHz (64 QAM 4 spatial streams 1/2 guard(64 QAM, 4 spatial streams, 1/2 guard interval)
–Claim of 100 Mbps in real throughput
•Optional enhancementsT i b f i i h li ibl–Transmit beamforming with negligible overhead at the client
–Advanced channel coding techniques (RS)–Space Time Block Coding (Alamouti and others)others)
–1/2 guard interval (i.e., 400ns instead of 800 ns)
–7/8 rate coding
http://www.enhancedwirelessconsortium.org/home/EWC_PHY_spec_V127.pdf
802.11n MAC Features802.11n MAC Features• Supports 802.11e (QoS)• Frame aggregation
–Single and multiple destinations• Bi‐directional data flow• Link adaptation with explicit feedbackLink adaptation with explicit feedback and control of channel sounding packets
• Protection mechanisms–For seamless interoperability andcoexistence with legacy devicescoexistence with legacy devices
• Channel management –Including management of 20/40MHzoperating modes
–Channel estimation and feedback B d “802 11 N G i Wi l LAN–Channel estimation and feedback• Power management for MIMO receivers•Data aggregation
Broadcom, “802.11n: Next‐Generation Wireless LAN Technology,” White Paper, April 06
802.11n Certification802.11n Certification• Wi‐Fi Alliance
Certifying to Draft 2 0 while
Key Certification Features
– Certifying to Draft 2.0 while draft is approved
– Certify to Ratified Standard when available
• out of sponsor ballot to final wgballotballot
• Nov 2009– 22 August 2007 ‐ Almost 70
products certified for compliance with Draft 2.0 of the 802 11nthe 802.11n
• http://www.wi‐fiplanet.com/news/article.php/3578886
– Now >500 (lost count)h // f• http://certifications.wi‐fi.org/wbcs_certified_products.php?search=1&advanced=1&lang=en&filter_company_id=&filter_category id &filter subcategory
Wi‐Fi CERTIFIED™ 802.11n draft 2.0: Longer‐Range, Faster‐Throughput, Multimedia‐Grade Wi‐Fi® Networks
y_id=&filter_subcategory=&filter_cid=&date_from=&date_to=&x=30&y=18&selected_certifications%5B%5D=33
802.11p Operation802.11p Operation• “Dedicated Short Range Communications”
(DSRC)d– Started in IEEE 1609, spun into 802.11p
– Aka (WAVE) Wireless Access for Vehicular Environment
• IEEE 802.11a adjusted for low overhead joperations– 54 Mbps, <50 ms latency– 5.850 to 5.925GHz band
• Spectrum divided into 7 bands• Spectrum divided into 7 bands– 178 is control (safety)– 2 edge channels are reserved for future– The rest are service channels (not
l f )application specific)• Mix of roadside‐to‐vehicle and vehicle‐to‐
vehicle communications• Questions on business model
D. Jiang, V. Taliwal, A. Meier, W. Holfelder, R. Herrtwich, “Design of 5.9 ghz dsrc‐based vehicular safety communication,“ IEEE Wireless Comm, Oct 06, pp. 36‐43
Questions on business model– http://www.rita.dot.gov/press_room/press
_releases/index.html
802.11p Applications802.11p Applications
COLLISION COLLISIONCOLLISIONCOLLISION COLLISIONCOLLISION
• Emergency warning system for vehicles C ti Ad ti C i C t l IMMINENT
FRONT
Note 1: The OBU in the vehicle recognizing the threat transmits a WARNING and COLLISION PREPARATION
In-Vehicle Displays and Annunciations
~ ~
IMMINENT
LEFT
IMMINENT
FRONT
IMMINENT
FRONT
Note 1: The OBU in the vehicle recognizing the threat transmits a WARNING and COLLISION PREPARATION
In-Vehicle Displays and Annunciations
~ ~
IMMINENT
LEFT
IMMINENT
LEFT• Cooperative Adaptive Cruise Control • Cooperative Forward Collision Warning
• Intersection collision avoidance MESSAGE with the location address of the threat vehicle.
~ ~~ ~
Note 2: Only the OBU in the threatening vehicle processes the message because only it matches the threat address.
up to 100 m (328 ft)Note 3: COLLISION PREPARATION includes seat belt tightening, side air bag deployment, side bumper expansion etc
MESSAGE with the location address of the threat vehicle.
~ ~~ ~
Note 2: Only the OBU in the threatening vehicle processes the message because only it matches the threat address.
up to 100 m (328 ft)
up to 100 m (328 ft)Note 3: COLLISION PREPARATION includes seat belt tightening, side air bag deployment, side bumper expansion etc
• Approaching emergency vehicle warning (Blue Waves)
• Vehicle safety inspection • Transit or emergency vehicle signal
Traffic Signal
Traffic Signal
OBUs on Control Ch
Radar Threat Identification
expansion, etc.
Car NOT Stopping
Traffic Signal
Traffic Signal
OBUs on Control Ch
Radar Threat Identification
expansion, etc.
Car NOT Stopping
g y gpriority
• Electronic parking payments • Commercial vehicle clearance and safety inspections
From: IEEE 802.11- 04/ 0121r0 Available:http://www.npstc.org/meetings/Cash%20WAVE%20Information%20for%205.9%20GHz%20061404.pdf
y p• In‐vehicle signing • Rollover warning • Probe data collection • Highway rail intersection warning• Highway‐rail intersection warning
802.11r overview802.11r overview• Fast BSS Roaming/Transition within IEEE WLAN networks
– Preserve security with handovers <50msF BSS R i i ibl l i hi i ll d h bili d i• Fast BSS Roaming is possible only within a certain area called the mobility domain (MD), inter‐MD cases are not covered
– Mobility Domain (MD): Set of BSS grouped together with the same 48bit MD Identifier– FT functionality seeks to provide handover performance for RT servicesK I• Key Issues
– Resource Reservations– Security
• Collapsed 5 step process down to 3– Scanning – active or passive for other APs in the area– Authentication with a (one or more) target AP– Re‐association to establish connection at target AP
• Released 2008
http //www cs tut
61 /114
http://www.cs.tut.fi/kurssit/TLT‐6556/Slides/Lecture4.pdf
Reduction in Roaming TimeReduction in Roaming Time
S. Bangolae, C. Bell, E.Qi, “Performance study of fast BSS transition using IEEE 802.11r,” International Conference On Communications And Mobile Computing, 2006
http://www.networkcomputing.com/gallery/2007/0416/0416ttb jh l j i id 0CK4 K 20HC QQS L CKHSCJU 2JV
62 /114
b.jhtml;jsessionid=0CK4ZKR20HC5QQSNDLPCKHSCJUNN2JVN
802.11s• Modify 802.11 MAC to create
dynamic self‐configuring network of access points (AP) called and
802.11s
of access points (AP) called and Extended Service Set (ESS) Mesh
• Automatic topology learning, dynamic path selection
• Single administrator for 802 11i• Single administrator for 802.11i (authentication)
• Support up to 32 AP• Support higher layer connections
IP or Ethernetpp g y
• Allow alternate path selection metrics
• Extend network merely by introducing access point andintroducing access point and configuring SSID
1. http://standards.ieee.org/board/nes/projects/802-11s.pdf
802.11s802.11s• Key Technologies
–Topology Formation• Open 802.11s (Linux)
– http://www.open80211s.org/N WiFi h d– Internetworking
–Routing–Security
• Numerous WiFi mesh products– http://www.cs.wustl.edu/~jain/cse574‐06/ftp/j_jmesh/sld019.htm
Deployment Scenarios
64 /114http://ieee802.org/802_tutorials/nov06/802.11s_Tutorial_r5.pdf
J. Hauser, D. Shyy, M. Green, MCTSSA 802.11s Military Usage Case
Too much 2.4 GHz InterferenceToo much 2.4 GHz Interference• WiFi is very popular ‐> Very crowded
spectrum• Ofcom sponsored study• Ofcom sponsored study
(http://www.ofcom.org.uk/research/technology/research/exempt/wifi/wfiutilisation.pdf)– Generally more interference from other
impolite devices– Cities have more congestion802 11 Ci t d (802 11 08/1440 0)• 802.11a Cisco study (802.11‐08/1440r0)• Expect AP‐AP collisions in urban deployments
802.11‐08/1440r
Mass Consulting Ltd., “Estimating the Utilisation of Key Licence‐Exempt Spectrum Bands,” April 2009. Available online: http://www.ofcom.org.uk/research/technology/research/exempt/wifi/wfiutilisation.pdf
802.11aa802.11aa• Expectation of interference means degradation of performance
• 802.11‐08/0764r1“There are man a s in hich a diodegradation of performance
– Potentially quite bad for video, voice over WiFi
• 802.11aa PAR Goals (doc.: IEEE 802.11‐07/1972r14):
– “There are many ways in which audio video data is streamed over IP networks
– Some methods lend themselves to selective packet discarding, some do notP b bl h b i h i
/ )– “Graceful degradation of audio video streams when there is insufficient channel capacity, by enabling packet discarding without any requirement for deep packet inspection,
– Probably the best pragmatic approach is some simple signalling per UDP packet and let the application decide when it can provide discard hints.”
• 802.11‐08/0818r0p ,– Increased robustness in overlapping BSS environments, without the requirement for a centralised management entity,
– Intra‐Access Category prioritization of transport streams by modifying EDCA timing
– Managed contention access– Modify framing / coordination function
to reduce contention• Considering
b d / ltransport streams by modifying EDCA timing and parameter selection without any requirement for deep packet inspection,
– Improved link reliability and low jitter characteristics for multicast/broadcast audio video streams,
– broadcast / multicast– Distributed network management– Extending 802.11s mechanisms
,– Interworking with relevant 802.1AVB mechanisms” (Audio / Video Bridging)
802.11ac APAPAP
AP
AP
APAP
AP
AP
AP802.11ac AP
802.11ac• Very High throughput < 6 GHz• Target Application:
i ( d id i
APAPAP
APAP
802.11‐09/0630r1
– Streaming IPTV (and video in general)
– VoIP, smart phones• Requirements (IEEE 802.11‐
/ )
3 million IPTV subscribers in Japan in 3 yrs
08/1285r):– 15 bps/Hz– 500 Mbps / 40 MHz – single link– 1 Gbps / 40 MHz – multi‐station
802.11‐09/0630r1
p /• Key tech appears to be Spatial
Division Multiple Access– And A LOT of antennas
Up to 42.8 bps/Hz with 16 antennas
802.11‐09‐0532‐00‐00ac
802.11‐09/0303r1802.11‐09/0303r1
Move To 60 GHz UnlicensedMove To 60 GHz Unlicensed• 2001, FCC designated 57‐
64 GHz as unlicensed Strong O2 AbsorptionShorter Propagation
64 GHz as unlicensed– Similar around the globe
– Avoid the interference
More bandwidth => More throughput
http://www.gigabeam.com/technology.cfmhttp://www.gigabeam.com/technology.cfm
More antenna gain (same size)Rain Matters
http://wireless.fcc.gov/outreach/2004broadbandforum/comments/YDI benefits60GHz.pdf
802.11ad802.11ad
• Requirements • Known Issuesq– IEEE 802.11‐08/1285r0– > 1 Gbps @ 10 m
– Coexistence with 802.15.3c (60 GHz version)– Seamless handoffs
between 2.4/5 GHz and 60 GHz
version)
• PAR approved Jan 2009– Came from VHT Study yGroup
• 3 Gbps ~ uncompressed 1080p
Others in the marketOthers in the market
• WHDI (Amimon) • WiGig– variant of 802.11– 3Gbps (including
uncompressed 1080p) in a 40MHz @ 5 GHz
– Website: http://wirelessgigabitalliance.org/
– Big players– http://www.whdi.org/Technolo
gy/• WirelessHD (SiBeam)
V i t f 802 15 3
g p y• Atheros, Dell, LG, Samsung,
Microsoft, Nokia, Panasonic– Spec out end of 2010
• http://www.multichannel.com/a– Variant of 802.15.3c– 4 Gbps @ 60 GHz (4 channels)– OFDM + beamforming + (a
bunch of 802.11‐like services)
rticle/277089‐Wireless_HD_Delivery_Race_Heats_Up.php
)– Spec:
http://www.wirelesshd.org/pdfs/WirelessHD_Full_Overview_071009.pdf
http://www.hometheatermag.com/hookmeup/607hook/
• ~ 1 million units 2009, 13 million units 2013p 2013
• http://www.eetimes.com/news/semi/rss/showArticle.jhtml?articleID=217201265&cid=RSSfeed_eetimes_semiRSS
WiFi on the PlaneWiFi on the Plane• Idle hands are a good source of revenue
12 15% of c stomers pa for it on a plane
Aircell Coverage Area
– 12‐15% of customers pay for it on a plane– $7.95 smart phone, – $9.95 normal, < 3 hrs– $12.95 normal > 3 hrs– http://www broadbandreports com/shownews/1http://www.broadbandreports.com/shownews/1215‐Use‐InFlight‐WiFi‐102611
• Boeing / Connexion– Satellite based connection to plane– Launched in 2004, shut down in 2006 – citing no
market– Still provides services to US Gov planes
• http://www.boeing.com/news/releases/2007/q3/070814a_nr.html
– 800 lbs, 2 weeks to install, $1,000,000 / plane • Aircell (GoGo)
http://www.aircell.com/index.php?option=com_content&task=view&id=312&Itemid=1
, , $ , , / p• Row44
– Satellite based (leased from Hughes)– Planned for use by Southwest, Alaska, Norwegian Shuttle
( )– EVDO‐based ground network– 1,000 planes by end of 2009
• Delta, AirTrans. NorthWest, United, American, Air Canada,
• Virgin (28)– 2 nights to install (use in day), 150 pounds– http://www.row44.com/
Virgin (28)– $100,000 / plane, 1 day turnaround
WiFi on Smart PhonesWiFi on Smart Phones
• Statisticshttp://ipod.about.com/od/iphoneinterfacegallery/ig/iPhone‐Gallery‐‐Settings/iPhone‐WiFi‐Settings.htm
– 802.11‐09‐0453r00ac– 2008 ‐ 56 M (~44%)– 2011‐ 300M
2014 520M (90%)– 2014 – 520M (90%) • Cellular Providers Establishing WiFiRelationships for free service
– AT&T + Qwest (May 09)• http://blogs.wsj.com/digits/2009/05/06/qwe
st‐unveils‐wi‐fi‐deal‐with‐att/st unveils wi fi deal with att/– AT&T buys WayPort (Nov 08)
• http://online.wsj.com/article/SB122598801123705301.html
– Verizon with Boingo• http://wifinetnews com/archives/2009/05/v• http://wifinetnews.com/archives/2009/05/v
erizon_broadband_subscribers_get_free_wi‐fi.html
– T‐Mobile• https://content.hotspot.t‐
mobile.com/AssetProcess.asp?asset=com.default.main.001
– Sprint‐Nextel – odd man out??
802.11‐09‐0453r00ac
WiFi in … Bluetooth?WiFi in … Bluetooth?
• Bluetooth 3.0 Highspeed is 802.11nBluetooth 3.0 Highspeed is 802.11n– http://www.wi‐fiplanet.com/news/article.php/3816556
• Some Bluetooth advocates say that this is no yconcession as WiFi is not just 802.11
Presentation Overviewhttp://www.crtwireless.com/EWS_09.htmlAvailable online
Presentation OverviewEmerging Standards(11) Cellular (other than LTE and ( ) (
WiMAX)(10) LTE(11) WiMAX(11) WiMAX(11) 4G(24) WLAN( 8) Interoperability Standards( 8) Interoperability Standards( 9) WPAN(11) Cognitive Radio Standards
http://www.wisoa.net/members_logos/mobile_internet‐big.jpg
(10) Summary and Trends
Break & Poster SessionBreak & Poster Session2:45‐3:30
Interoperability StandardsInteroperability Standards
802.21, UMA/GAN 802.11u Industry Standards
802.21 (Media Independent Handoffs)802.21 (Media Independent Handoffs)• Key Services
– Triggers (state change, predictive, network initiated)– Network Information (services, maps, list of available networks)Network Information (services, maps, list of available networks)– Handover commands (client or network initiated, vertical handoffs)
• Jan 2009: Targeted publication• Follow on (mostly study groups)
b l d d ff ( l d d d– Mobile Broadcast Handoffs (e.g., Digital Video Broadcasting, MediaFLO, Digital Multimedia Broadcast)
– Inter‐network handoff Security– Multi‐radio power
l– Deployment Scenarios, – Emergency Services
http://www.ieee802.org/802_tutorials/july06/802 21‐IEEE‐Tutorial.pptV. Gupta, “IEEE 802.21 MEDIA INDEPENDENT HANDOVER,” IEEE 802.21 session #15 July 17, 2006
•UMA allows to access the mobile voice and data services of the cellular network over adata services of the cellular network over a Wireless LAN
• Subscribers are enabled to roam and handover between cellular networks and wireless networkswireless networks
•Mobile devices access the Core Network through Unlicensed Mobile Access Network (UMAN).
•UMAN has 3 major entities htt // t dUMAN has 3 major entities –Unlicensed wireless network –IP access network –UMA Network controller (UNC)
• UNC authorizes and authenticates the Mobile
http://www.umatoday.com
UNC authorizes and authenticates the Mobile devices for accessing the Core Network
• Part of 3GPP now–Generic Access Network (GAN)
• Products– http://www.umatoday.com/mobileHandsets.php
http://www.umatoday.com
VCCVCC• Addresses shortcomings in UMA’s Voice Call Continuity (VCC)• Status
– Initiated within 3GPP in June 20052006 through requirements has only fully completed the requirements stage– 2006 through requirements, has only fully completed the requirements stage
– 2008 being extended to IMS Service Continuity • Different technologies agree to virtual channel
– Joint control impossible• Some argue inferior to UMAg
– http://www.kineto.com/products/downloads/kineto_wp_UMA_VCC_2007.pdf• Some argue better than UMA
– http://www‐hk.huawei.com/publications/view.do?id=1480&cid=2622&pid=127
http://www.kineto.com/products/downloads/kineto_wp_UMA_VCC_2007.pdf
802.11u (Interworking with External k )Networks)
• Standard out in 2010Standard out in 2010
• Specifically addresses handoffs where user not preauthorized (generally because from another p (g ynetwork)
• Major Topicsj p– Network Selection
– Emergency Call support
– Authorization from Subscriber Network,
– Media Independent Handover Support S ti i f ti d t l f 802 21• Supporting information and control messages of 802.21
Other Cellular + WiFiOther Cellular + WiFi• Seamless Converged Communication Across
Network (SCCAN)– Motorola, Proxim, Avaya – Enterprise solutions– http://www.sccan.org/
• Mobile Integrated Go‐to‐Market Network IP Telephony Experience (Mobile IGNITE)
Mobile IGNITE
p y p ( )– Vendor driven solution– http://www.bridgeport‐
networks.com/partners/mobileignite.html• Wireless Wireline Convergence Working GroupWireless Wireline Convergence Working Group
– Alcatel, Cisco (International Packet Communications Consortium)
– http://www.packetcomm.org/index.shtml• Bottom line• Bottom line
– Even for standard convergence type activities there’s many different emerging standards.
– Need for special radios to navigate standards?
http://www.spectralink.com/products/images/NL‐01.gif
Interoperability SummaryInteroperability Summary• Popularity of WiFi is driving a lot of
integrationintegration– WiFi + Cellular– WiFi + Bluetooth
• Proliferation of standards + lack of silver bullet standard means that
Mobile voice trafficFixed voice traffic
Rapid growth ?
silver bullet standard means that optimal access technology will vary
• Supporting growth in use of VoIP will make networks less dependent on particular access technologies
Fixed voice trafficVoIP traffic
p g• Biggest issues are:
– Getting industries to agree (Herding cats)
– Managing security across
-03-02-01-00-99-98-97-96-95-94-93 -07 e
-92 -04 -05e
-06e
-08 e
Source: Nokia 13.6.2005Technology used to terminate the call
heterogeneous networks– Harmonizing handoff routines
• 802.21 is the standard that ties together the vertical handoff t d dstandards
Other Proprietary StandardsOther Proprietary Standards• Kleer
– http://www.kleer.com• TransferJet (Sony)
– http://www.transferjet.org/en/tj/tj_overviewh l – Proprietary low power RF for audio /
video• En‐Ocean
– http://www.enocean.com/en/
.html–Features
• http://www.sony.net/SonyInfo/News/Press/200801/08‐002E/index.html
• Electric induction field coupling• 3 cm range – Best known as energy scavengers
– Runs a proprietary wireless mesh protocol
• Insteon
• 3 cm range• 4.48 GHz center frequency• 560 Mbps (Max) 375 Mbps (effective)
–Adaptive modulation• “Touch & Get: transfer by touching devices together
– Mixes power line comm with RF comm
– Industry Alliance (15 manufacturers)• http://www.insteon.net/alliance‐
about.html
g• Some registration security
–Demonstrated shortly after announced• http://www.engadget.com/2008/01/06/video‐sonys‐transferjet‐gets‐demonstrated/
– Specification completed about.html• Wireless Valley is a member
– Open source http://www.efundies.com/
p p• http://www.toshiba.co.jp/about/press/2009_05/pr1901.htm?from=RSS_PRESS&uid=20090519‐569e
– 15 members in forum, mostly Japanese
Presentation Overviewhttp://www.crtwireless.com/EWS_09.htmlAvailable online
Presentation OverviewEmerging Standards(11) Cellular (other than LTE and ( ) (
WiMAX)(10) LTE(11) WiMAX(11) WiMAX(11) 4G(24) WLAN( 8) Interoperability Standards( 8) Interoperability Standards( 9) WPAN(11) Cognitive Radio Standards
http://www.wisoa.net/members_logos/mobile_internet‐big.jpg
(10) Summary and Trends
Break & Poster SessionBreak & Poster Session2:45‐3:30
Wireless Personal Area NetworksWireless Personal Area Networks
Industry and Open StandardsIndustry and Open Standards
• Proprietary / Industry802.15 Standards p y / y– Zigbee (on 802.15.4)
• Zigbee Pro
Bl t th ( i i ll )
802.15.1 April 2002 Bluetooth802.15.2 Oct 2003 Coexistence802.15.3 Jun 2003 High data rate802.15.3a UWB (high rate)802.15.3b Doc Maintenance
– Bluetooth (originally)– WiBree– WiMedia
802.15.3c Sep 2009 mm‐wave PHY802.15.4 May 2003 zigbee (PHY/MAC)802.15.4a March 2007 UWB (low rate)802.15.4b Sep 2006 Updates 802.15.4 document802.15.4c Jan 2009 Chinese WPAN PHY
– Z‐Wave– En‐Ocean
802.15.4d Mar 2009 950 MHz in Japan802.15.4e Sep 2010 MAC for 802.15.4c802.15.4f Mar 2011 Active RFID802.15.4g Jun 2011 Low data rate (40 kbps) smart meter802.15.5 Apr 2009 WPAN Mesh
– Insteon– Keer– TransferJet
p802.15.6 >2009 Body Area Networks802.15.7 >2010 Visible LightIGThz Terahertz interest group (300 GHz+)SGRFID RFID Study Group
TransferJet802.15.3a disbanded Jan 2006MBOA technologies became WiMediaHigh speed DS‐UWB basically dead after Freescale pulled out
Emerging 802.15 StandardsEmerging 802.15 Standards• 802.15.4c (China)
–779‐787 MHz band–779‐787 MHz band –Two PHY Modulations: MPSK PHY and O‐QPSK–Considering OFDM, beamforming
• 802.15.4d (Japan)• 802.15.5e MPNC
MPNC802.15.5e–Enhanced MAC for Industrial applications–Modified MAC for 802.15.4c changes
• 802.15.5–Mesh networking
PN 3
PN 2
MPNC
MPCN
MPNC
MPNC
Mesh
• Terahertz study group–300 GHz ‐> 3 THz –http://www.ieee802.org/15/pub/IGthz.html
• TG6 – Body Area Networkshtt // i 802 /15/ b/TG6 ht l
PN 1IEEE P802.15.5™/D0.01, July 2006
–http://www.ieee802.org/15/pub/TG6.html–Just starting
• 802.15.7 Visible Light Interest Group–http://www.ieee802.org/15/pub/IGvlc.html
ZigBeeZigBee
– the software
Standardhttp://www.zigbee.org/en/spec_download/download_request.asp
the software – Network, Security & Application layers– Brand management
• IEEE 802.15.4– “the hardware” – Physical & Media Access Control layers
Security32 / 64 / 128 bit ti
Application
API
ZigBee
Customer
Physical & Media Access Control layers• PHY
– 868MHz/915MHz, 2.4 GHz– Band specific modulations– 20‐250 kbps
• MACMAC
NetworkStar / Mesh / Cluster-Tree
32- / 64- / 128-bit encryption ZigBeeAlliance
• MAC– CSMA‐CA channel access– Support for ad‐hoc networks
• Zigbee Pro (Industrial grade)– Network Scalability
Fragmentation
PHY868MHz / 915MHz / 2.4GHz
MACIEEE
802.15.4
Silicon Stack App – Fragmentation– Frequency Agility– Automated Device Address Management– Group Addressing– Centralized Data Collection– Wireless Commissioning
• Open source implementations• Open‐ZB
h // b /
Source: http://www.zigbee.org/en/resources/
Silicon Stack App
– Wireless Commissioning– http://www.open‐zb.net/• Meshnetics Open‐MAC
– http://www.meshnetics.com/opensource/mac/• SmartGrid
– http://www.zigbeeexpo.com/
WiMediaWiMedia• Industry alliance from MBOA 802.15.3a• Standardized for US in Dec 2005 in ECMA‐
368 and 369
From: http://www.wimedia.org/en/events/documents/02WiMedia_Overview_CES2006.ppt
368 and 369– http://www.ecma‐
international.org/publications/standards/Ecma‐368.htm
– ECMA used specifically to avoid 802 standardization problems
&/or
PAL PAL WiNET
&/or &/or
PAL
IP&/or
PAL PAL WiNET
&/or &/or
PAL
IPIP
standardization problems• PHY
– Multiband OFDM QPSK– 53.3, 80, 106.7, 160, 200, 320, 400, 480
Mbps nominal data ratesR f 10 i d
WiMedia UWB Radio Platform
MAC & Policies
UWB PHY (MB-OFDM)
WiMedia UWB Radio Platform
MAC & Policies
UWB PHY (MB-OFDM)
WiFi802.11
ac/ad will be superior– Range of 10 m indoor
– Data can be interleaved across 3 bands, 7 defined patterns (channels)
– Mandatory support for band group 1 • MAC
• Wireless USB out in Dec 2006–Hub‐spoke model–Mandatory support for band group 1–Mandatory rates of 53.3, 106.7, 200 Mbps– Initial Belkin device didn’t live up to the hype
PAL: Protocol Adaptation LayerPAL: Protocol Adaptation Layerbe superior
– Peer to Peer, Ad‐hoc– AES 128– Support for Dynamic Channel Selection– Ranging via propagation delay
measurements
• http://www.eetimes.com/news/latest/showArticle.jhtml?articleID=196602148
• http://www.usb.org/developers/wusb/wusb_2007_0214.zip
• Bluetooth 3.0 devices in 2008– http://gizmodo.com/gadgets/wireless/nextge
n‐bluetooth‐30‐on‐the‐way‐179684.php• Wireless Firewire and IP also supported over
– Bluetooth‐like information discoveryWireless Firewire and IP also supported over WiMedia standard
From Fig 28:
UWB Now Dead (or on its Deathbed)UWB Now Dead (or on its Deathbed)The Wireless USB crowd is imploding,"
"Those still in existence are hunkering “By 2013, the only UWB solutions still on the market will be proprietary solutions ing
down, and I don't see a lot of traction. They have a lot of competition from 802.11n which is doing a lot of what the WiMedia Alliance promised,"
the market will be proprietary solutions in the industrial/medical segment. All other UWB will be gone by the end of the forecast period" in 2013, he added.”
p ,
Tan Rao, co‐founder of Radiospire
• WiMedia Disbanded
Tan Rao, co founder of Radiospirehttp://www.eetimes.com/news/semi/rss/showArticle.jhtml?articleID=217201265&cid=RSSfeed_eetimes_semiRSS
– March 2009– http://www.phonescoop.com/news/item.php?n=41133
– Sold off IP to Wireless USB, Bluetooth
• Public data: (from wibree.com (no more) and http://www theregister co uk/2006/10/06/wibree analysis/ )http://www.theregister.co.uk/2006/10/06/wibree_analysis/ )– 2.4 GHz ISM band– Range 10 meters– 1 Mbps data rate – Targets low power/low cost market– From
http://www.computerworld.com.au/index.php/id;992123146;fp;4;fpid;18• Up to 8 devices Master/Slave• Turns off frequency hopping• Expects different technology to serve as backbone between masters• Expects to share resources with full Bluetooth
• Many reports mentioned WiBree as a competitor to Bluetoothy p p– Brought into Bluetooth fold as low power alternative– “Bluetooth Low Energy”– https://www.bluetooth.org/About/bluetooth_sig.htm#Bluetooth%20Wirele
ss%20Technology
90 /114
ss%20Technology– Now a competitor to Zigbee
Z‐WaveZ Wave
• Originally Zensys proprietary– http://www.zen‐sys.com/
• Industry standard “Z‐wave”– http://www z‐wave com
Z‐Wave Alliance
http://www.z wave.com
• Low power alternative to Zigbee• PHY
– 9.6 kbps or 40 kbps– GFSK– 100 ft range
• 900 MHz ISM• http://www.z‐wavealliance.com/• http://en wikipedia org/wiki/Z Wave
http://www.z‐wave.com/modules/AboutZ‐Wave/?id=21&chk=4ed024468cb3d7f9095aa54227ea197a
• http://en.wikipedia.org/wiki/Z‐Wave
Other Proprietary StandardsOther Proprietary Standards• Kleer
– http://www.kleer.com• TransferJet (Sony)
– http://www.transferjet.org/en/tj/tj_overviewh l – Proprietary low power RF for audio /
video• En‐Ocean
– http://www.enocean.com/en/
.html–Features
• http://www.sony.net/SonyInfo/News/Press/200801/08‐002E/index.html
• Electric induction field coupling• 3 cm range – Best known as energy scavengers
– Runs a proprietary wireless mesh protocol
• Insteon
• 3 cm range• 4.48 GHz center frequency• 560 Mbps (Max) 375 Mbps (effective)
–Adaptive modulation• “Touch & Get: transfer by touching devices together
– Mixes power line comm with RF comm
– Industry Alliance (15 manufacturers)• http://www.insteon.net/alliance‐
about.html
g• Some registration security
–Demonstrated shortly after announced• http://www.engadget.com/2008/01/06/video‐sonys‐transferjet‐gets‐demonstrated/
– Specification completed about.html• Wireless Valley is a member
– Open source http://www.efundies.com/
p p• http://www.toshiba.co.jp/about/press/2009_05/pr1901.htm?from=RSS_PRESS&uid=20090519‐569e
– 15 members in forum, mostly Japanese
Presentation Overviewhttp://www.crtwireless.com/EWS_09.htmlAvailable online
Presentation OverviewEmerging Standards(11) Cellular (other than LTE and ( ) (
WiMAX)(10) LTE(11) WiMAX(11) WiMAX(11) 4G(24) WLAN( 8) Interoperability Standards( 8) Interoperability Standards( 9) WPAN(11) Cognitive Radio Standards
http://www.wisoa.net/members_logos/mobile_internet‐big.jpg
(10) Summary and Trends
Break & Poster SessionBreak & Poster Session2:45‐3:30
Emerging Cognitive StandardsEmerging Cognitive Standards
Cognitive RadioCognitive Radio
• An approach to wireless engineering pp g gwherein the radio, radio network, or wireless system is endowed with the capacities to:
i l if d i i f i– acquire, classify, and organize information (aware)
– retain information (aware)– apply logic and analysis to informationapply logic and analysis to information
(reason)– make and implement choices (agency)
about operational aspects of the radio, network or wireless system in a mannernetwork, or wireless system in a manner consistent with a purposeful goal (intelligent).
– “Cognitive Radio Definitions and Nomenclature,” Working Document SDRF‐06‐R‐0009‐V0 08Working Document SDRF‐06‐R‐0009‐V0.08
802.11h – Unintentionally Cognitive
• Dynamic Frequency Selection (DFS)
802.11h Unintentionally Cognitive
(DFS)– Avoid radars
• Listens and discontinues use of a channel if a radar is present
– Uniform channel utilization
• Transmit Power Control (TPC)Transmit Power Control (TPC)– Interference reduction
– Range control
P ti S i– Power consumption Savings
– Bounded by local regulatory conditions
802.11y• Ports 802.11a to 3.65 GHz – 3.7 GHz (US Only)
– FCC opened up band in July 2005
802.11y
– Ready 2008• Intended to provide rural broadband access• Incumbents
– Band previously reserved for fixed satellite service (FSS) and radar installations – including offshore
– Must protect 3650 MHz (radar)– Not permitted within 80km of inband government radar– Specialized requirements near Mexico/Canada and other incumbent users
• Leverages other amendments– Adds 5,10 MHz channelization (802.11j)– DFS for signaling for radar avoidance
(802.11h)W ki i h l• Working to improve channel announcement signaling
• Database of existing devices– Access nodes register at
http://wireless fcc gov/uls
97 /114
http://wireless.fcc.gov/uls– Must check for existing devices at same
site
Source: IEEE 802.11‐06/0YYYr0
802.16h802.16h• Draft1 to ballot Oct 06, 67%
approve, resolving pp , gcomments)
• Made it out of group, but not past sponsor ballot
– PAR extended to end of 2009– Going to Draft 9
• Improved Coexistence• Improved Coexistence Mechanisms for License‐Exempt Operation
• Explicitly, a cognitive radio standard
• Incorporates many of the hot d
p ytopics in cognitive radio
– Token based negotiation– Interference avoidance– Network collaboration– RRM databases
• Coexistence with non 802 16h• Coexistence with non 802.16h systems
– Regular quiet times for other systems to transmit
• Strongly suspect not going anywhere From: M. Goldhamer, “Main concepts of IEEE P802.16h / D1,” Document Number: IEEE
C802 16h 06/121 1 N b 13 16 2006y
– Meetings seem sparsely attended
– http://wirelessman.org/le/index.html#09_0004
C802.16h‐06/121r1, November 13‐16, 2006.
IEEE 1900 (SCC 41)IEEE 1900 (SCC 41)• Site: http://www.scc41.org/• 1900.1 – Terminology and Concepts1900.1 Terminology and Concepts• 1900.2 ‐ Recommended Practice for
Interference and Coexistence Analysis – http://crtwireless.com/blog/2008/04/02/1
9002‐approved/• 1900.3 – Conformance Evaluation for SDR
modulesmodules• 1900.4 – Architectural Building Blocks
– network resource managers – device resource managers– the information to be exchanged between
the building blocks sg‐whitespace‐09‐0057g• 1900.4a: Architecture and Interfaces for
Dynamic Spectrum Access Networks in White Space Frequency Bands
• 1900.4.1: Standard for Interfaces and Protocols Enabling Distributed Decision Making forEnabling Distributed Decision Making for Optimized Radio Resource Usage in Heterogeneous Wireless Networks
• 1900.5 – Policy Languages• 1900.6 – Information exchange between
sensors• Demographic trivia
– Majority Japanese– 1900.4 dominated by Europeans
sg‐whitespace‐09‐0057
White SpacesWhite Spaces• Concept:
–Allow unlicensed secondary users into i d TV b d i DSA
• High data rates will not be easy– Channels are only 6 MHzy
unoccupied TV bands via DSA• Initial problems with devices• Approved Nov 2008
– FCC 08‐260A• http://hraunfoss.fcc.gov/edocs_public/attachm
atch/FCC 08 260A1 pdf
Channels are only 6 MHz– High data rates will require channel bonding
• Issues in 802.11n when bonded 40 MHz 802.11n system coexists with 802.11b
– DTV is about 19 Mbps– Large scale MIMO is hard because of long
l hatch/FCC‐08‐260A1.pdf
•Requirement highlights (see Monisha’stalk for more detail)
– Two classes: fixed /portable– Daily geolocation database updates (DTV)
wavelength– “WiFi on Steroids” will mean range, not rate
• Lots of use cases being proposed– Home data (WiFi)– Video distributiony g p ( )
– =Sense for microphones• Licensed and unlicensed• ‐114 dBm• 60s
– Industry to define coexistence protocol
– Mobile DTV rebroadcast– Control apps
• Lots of potential coexisting protocols– 802.22– CogNeAy p
– Industry to define signal for transmitting to allow interferer identification
• Spectrum availability varies widely– Looks like greatest availability for rural
applications
g– Downbanded WiFi
• Easy if only database
applications• Lots of objections from TV broadcasters
and wireless microphone manufacturers / users
Selected White Space PlayersSelected White Space Players• White Space Alliance
– Pushed for opening White Spaces• White Space Database Group
– Goal to quickly turn around database thatPushed for opening White Spaces– Disbanded after decision
• CogNeA– www.cognea.org– Members
• Samsung Phillips HP Motorola Georgia Tech
Goal to quickly turn around database that satisfies FCC specs
– Members include Phillips, Comsearch, Dell, Google Inc., HP, Microsoft Corporation, Motorola Inc., MSTV, and NeuStar and broadcastersG l• Samsung, Phillips, HP, Motorola, Georgia Tech,
ETRI– Focused on low power personal/portable CR
devices, with focus on video• Simple design (OFDM PHY)• Compressed HD Video
C iti f t
– Google: • “We don’t plan to become a database
administrator ourselves, but do want to work with the FCC to make sure that a white spaces database gets up and running. We hope that this will unfold in a matter of months, not years.”
• 802 Executive Committee Study Group on– Cognitive features• Geolocation, sensing, DFS, TPC
– Publishing through ECMA (TG‐48 TG1)– Target end of 2009
• 802.19 White SpaceC i f 802
802 Executive Committee Study Group on White Spaces
– Assess the impact of the FCC White Space R&O on IEEE 802 activities
– Identify Use Cases of TV White Space Spectrum
– Identify what functions may be common– Coexistence for 802– Scope scaled back to use cases– Follow on from 802 ECSG on WS
• SDRF CRWG– Identifying use cases enabled by more
hi i d CR d b
Identify what functions may be common across 802 technologies
– Begin technical discussion on how to enable coexistence between various 802 technologies in the shared TV white space spectrum
– Prepare a Tutorial for March Plenarysophisticated CR database
• SDRF T&M• Testing procedures / issues for CR
– Make recommendations to 802 EC by March 2009 on next steps
– Transitioned coexistence work to 802.19 (Spring 2009)
802.22802.22• Wireless Regional Area Networks (WRAN)
– First explicit cognitive radio standardp g– Aimed at bringing broadband access in rural and remote areas– Takes advantage of better propagation characteristics at VHF and low‐UHF– Takes advantage of unused TV channels that exist in these sparsely
l t dpopulated areas– Still defining inter‐cell coexistence
• Likely published in 2009S d l hil FCC ttl– Some delay while FCC regs settle
– Many similarities with 802.16• Particularly at PHY
• 802 22 1802.22.1– Enhanced interference protection
• 802.22.2– Best practices for deployment
102 /114
– Best practices for deployment
Features of 802.22Features of 802.22• Data Rates 5 Mbps – 70 Mbps• Point‐to‐multipoint • TDD (mandatory), FDD (ok)
DFS TPC
• 802.16 MAC plus the following–Multiple channel support–Coexistence
I b t• DFS, TPC• Adaptive Modulation
– QPSK, 16, 64‐QAM, Spread QPSK• OFDMA on uplink and downlink• Use multiple contiguous TV channels
• Incumbents• BS synchronization (CBP)• Dynamic resource sharing
–Clustering support–Signal detection/classification routines• Use multiple contiguous TV channels
when available• Fractional channels (adapting around
microphones)• Space Time Block Codes
B F i
–Beacon support• Collaborative sensing
–Quiet periods scheduled by BS–Fall back channels
• Techniques in 802 22 will be extended• Beam Forming– No feedback for TDD (assumes channel
reciprocity)• 802.16‐like ranging
Techniques in 802.22 will be extended to other standards and to other bands around the world
• Security and spectrum sharing among base stations are larger research issues nowissues now
Incumbent or other CR user(except microphone user)
TV incumbent user Microphone userFractional useof TV channel
Other CR user or non-microphone incumbent (regulations permitting)
Incumbent or other CR user(except microphone user)
TV incumbent user Microphone userFractional useof TV channel
Other CR user or non-microphone incumbent (regulations permitting)
Channel BondingFrequency Switching
6 MHz Unused(6 MHz)6 MHz
f
GuardBand
6 MHz Unused(6 MHz)6 MHz
f
GuardBand
Cognitive Radio SummaryCognitive Radio Summary• White space has
i d h• Standards tend to be highly
focused on specific bandsenergized research• But CR is more than just DSA
focused on specific bands– But problems vary greatly by band– Blocks may have to be recombined
• Databases appear popular– Opportunistic spectrum utilization, collaborative radio, link reliability,
pp p p– 802.11y, White space
• DoD still trying to determine how it wants to play in CR y
advanced network structures
• Commercial implementations
p ystandards space– More involved in policy
language
starting to appear– 802.22, 802.11h,y, 802.16h– And may have been around for
a while (cordless phones witha while (cordless phones with DFS)
Presentation Overviewhttp://www.crtwireless.com/EWS_09.htmlAvailable online
Presentation OverviewEmerging Standards(11) Cellular (other than LTE and ( ) (
WiMAX)(10) LTE(11) WiMAX(11) WiMAX(11) 4G(24) WLAN( 8) Interoperability Standards( 8) Interoperability Standards( 9) WPAN(11) Cognitive Radio Standards
http://www.wisoa.net/members_logos/mobile_internet‐big.jpg
(10) Summary and Trends
Break & Poster SessionBreak & Poster Session2:45‐3:30
Summary and Future TrendsSummary and Future Trends
3GPP Will Win the Cellular Market3GPP Will Win the Cellular Market• Virtually all of the cellular incumbents
went with LTEwent with LTE• UMB was stillborn• 802.20 took too long to come out• WiMAX left with mostly greenfield
operators– ClearWire rollout seems slow– Adoption significantly underperforming
estimates• Didn’t say “LTE” will win• Didn t say LTE will win
– HSPA and LTE Advanced may squeeze out LTE
– But IPR issues may be better handled• WiMAX appears to have a future in
http://www.gsacom.com//downloads/charts/GSM_market_share_global.php4
WiMAX appears to have a future in “niche” data markets
– DoD, private radio, cable / DSL replacement
• I’m dubious of the success of 802.16m d d ll l d das an independent cellular standard
http://www.eng.chula.ac.th/files/AttachedFiles/Events/WirelessAcademicDays/3G_Broadband_and_Beyond_082108_Qualcomm.pdf
802.11 is Taking Over the World802.11 is Taking Over the World• It’s everywhere
h ff h b– Not just in the coffee shop, but in the air
– In virtually all smart phones very soon
– In Bluetooth!– The alphabet couldn’t contain it…
• I expect it to “win” everywhere it competesp– White Space (once it enters)– Home video distribution
• 802.11aa, ac, ad
• Seems like a necessity for mass• Seems like a necessity for mass‐market wireless devices
• Success is crowding the spectrum– Moving to other bands
Continuing Proliferation in Number of d dStandards
• Legacy systems not quickly fading and large # of new onesof new ones• AMPS is finally gone
– Dec 2008! ‐ Alltell– http://www.alltel.com/wps/wcm/connect/Per
sonal/home/p/customerservice/annoucements/announcements_analog_sunset_p.html/_ g_ _p
• Cellular may be finally winnowing down– Expect LTE / LTE Advanced
• Different techs solve different• Different techs solve different problems
– Fallback modes• Data over one, voice over another
– Bootstrap whitespace?Bootstrap whitespace?– Backhaul and access different
• Not new conceptually, but roles blur– EVDO for AirCell
Breeding Successful TechnologiesBreeding Successful Technologies
• Mobile WiMAX and 802.11n are MIMO standard, but so will LTEbut so will LTE– Transition of technologies can significantly extend
useful lifetime of deployments• Enhanced EDGE
WC A I O l L ’ k• WCDMA + MIMO may steal LTE’s market– 802.11n predates mobile WiMAX
• Also happening with CR applications– DFS, TPC, databases, ,– Contention Based Protocol?
• IMT‐Advanced solutions should be quite similar to LTE / 802.16e
• Standards can expect to continue to evolve even• Standards can expect to continue to evolve even post‐deployment– Need for SDR
• May make for smoother transition to 4G
110 /114
Erik Dahlman, Hannes Ekström, Anders Furuskär, Ylva Jading, Jonas Karlsson, Magnus Lundevall, Stefan Parkvall, “The 3G Long‐Term Evolution – Radio Interface Concepts and Performance Evaluation,” VTC 06
Ever Increasing Demand for SpectrumEver Increasing Demand for Spectrum
• Successful launch quickly leads to congestionE i i f l i di t ib t d• Emerging issues of overlapping distributed basestations
– Older for 802.11 access nodes– Also coexistence with other
• DSA enabled spectrum access• DSA enabled spectrum access– 802.11y, 802.11h, White Spaces– Spectrum trading (shorter time period)
• http://www.spectrumbridge.com/
• Difficult to find large contiguous bandwidthDifficult to find large contiguous bandwidth– Channel bonding / aggregation– Move up to 60 GHz?
• Flexible multiband devices to find spectrum as neededas needed
– E.g., TV, 2.4, 5, 60• Most high data rates assume large scale
MIMO– But 8x8 may be impractical
http://www.nab.org/AM/Template.cfm?Section=Small_Market_Television_Exchange1&CONTENTID=6489&TEMPLATE=/CM/ContentDisplay.cfm
But 8x8 may be impractical– Movement to higher frequencies
Take Aways (1/2)
• 4G very soon– But should be similar to LTE / 802.16eHi h d i i OFDM A A• High data rate systems migrating to OFDM + Antenna Array Processing PHY– OFDM – WiMedia, 802.11a,g, 802.16, 802.20, 802.22, UMB, LTE
OFDM + MIMO 802 11n 802 16e 802 20 UMB LTE– OFDM + MIMO – 802.11n, 802.16e, 802.20, UMB, LTE– And A LOT of antennas (8x8)
• More responsive/adaptive resource management (early cognitive radio)cognitive radio)– Multiple QoS levels – 802.11e; 802.16e; 802.20; UMB, LTE, EVDO, – Dynamic channel selection – WiMedia; 802.11h,y; 802.16h; 802.22 – Distributed sensing – 802 22Distributed sensing 802.22
• Coexistence given increasing interest– Vertical handoffs – 802.21, 802.11u– Legacy systems – 802 22 802 11h y 802 16hLegacy systems 802.22, 802.11h,y, 802.16h– Overlapping base stations
Take‐Always (2/2)• China pushing own standards
– 802 15 4c TD‐SCDMA TD‐SOFDMA802.15.4c, TD SCDMA, TD SOFDMA
• Emergence of Advanced Networking– 802.11s, 802.15.5, 802.16j, femto cells802.11s, 802.15.5, 802.16j, femto cells
• Convergence on AES for security– 802.11i, WiMedia, Mobile WiMAX, ,
• Convergence on all IP Backbone– Mobile WiMAX, UMB, LTE, ,
– Flatter access networks
– What does this mean for voice?
Cellular Data Rate ComparisonsCellular Data Rate Comparisons
http://www.rysavy.com/Articles/2007_09_Rysavy_3GAmericas.pdfestimated
Useful Websites (News, Promotional, d d )
WLANi fi
3GPP Familywww.gsmworld.com
Forums, Standards)
www.wi‐fi.orgwww.wi‐fiplanet.com/http://grouper.ieee.org/groups/802/11/
802.15bl h
www.gsmworld.comwww.umtsworld.comwww.gsacom.comwww.3gpp.orghttp://www.tdscdma‐forum.org/
3GPP2 Familywww.bluetooth.comhttps://www.bluetooth.org/www.wimedia.orghttp://www.zigbee.org/en/h // bf /
3GPP2 Familywww.cdg.orgwww.3gpp2.org
802.20http://grouper.ieee.org/groups/802/20/
802 21http://www.uwbforum.org/www.wibree.orghttp://www.multibandofdm.org/http://grouper.ieee.org/groups/802/15/
802.21http://www.ieee802.org/21/www.umatechnology.org
802.22http://grouper.ieee.org/groups/802/22/
E2R “Requirements and scenario definition ”802.16www.wimaxforum.orghttp://wimaxxed.comhttp://wimax.com
E2R Requirements and scenario definition, Available online: http://e2r.motlabs.com/Deliverables/E2R_WP4_D4.1_040725.pdf
http://grouper.ieee.org/groups/802/16/
Backup slidesBackup slides
Similar costs breakdowns across techsSimilar costs breakdowns across techs
http://www.eng.chula.ac.th/files/AttachedFiles/Events/WirelessAcademicDays/3G_Broadband_and_Beyond_082108_Qualcomm.pdf
Revenues in BillionsRevenues in Billions
http://www.eng.chula.ac.th/files/AttachedFiles/Events/WirelessAcademicDays/3G_Broadband_and_Beyond_082108_Qualcomm.pdf
P i i l f O th l FPrinciples of Orthogonal Frequency Division Multiplexing and Multiple Input
Multiple Output Communications Systems
Intersymbol InterferenceIntersymbol Interference
• Occurs when symbol period (Ts) is l h h l d l d
10-1BER Floor for various modulations
less than channel delay spread, τ• ISI introduces an error floor to BER
– Limits maximum throughput
+
x
10
BPSK QPSK OQPSK MSK
Modulation
Coherent Detection
• Solutions:– Equalization (high complexity)– Longer symbol periods (generally
l d t t ) ++x
xx
10-2
duci
ble
BER
means lower data rate)
+
+
+
x
x
10-3
Irred
+
10-210-4
10-1 100
QPSK limit
120 /114
10 10 10τT=delay spread
symbol period J. C.‐I. Chuang, "The Effects of Time Delay Spread on Portable Radio Communications Channels with Digital Modulation," IEEE JSAC, June 1987
Multicarrier communications: Longer i d dperiod, same data rate
•Concept:d l d–Divide original data stream at rate R into
L lower rate (R/L) streams on different carriers to increase symbol time
•Long history–KINEPLEX
• 1957 R.R. Mosier & R.G. Clabaugh –ANDEFT
• HF General Dynamics 60’sy–KATHRYN
• HF General Altronics 60’s•Effects
High receiver complexity B/L
( )H f
J. Andrews, A. Ghosh, R. Muhamed, Fundamentals of WiMAX, Prentice Hall, 2007
–High receiver complexity • separate receiver chain per carrier
–Bandwidth due to sidebands–Each subcarrier experiences flat fading
B/L
121 /114
Bc f
B
OFDMOFDM
• Much simpler to create multicarrier transmission using iFFTp g– Information carried in magnitude and phase of each bin
– Then can be recovered by using FFT at receiver
• Ideal inverse Fourier transform of multicarrier would be infinite Magnitude
duration sine waves– Cut at Symbol duration Ts
R t l i d i i
T0T0
– Rectangular windowing causes sinc spectrum in frequency domain with zeros at 1/TsOrthogonal s bcarriers
Frequency
122 /114
– Orthogonal subcarriers
Guard intervals and intersymbol i finterference
Guard interval Guard interval
OFDM Symbol OFDM Symbol OFDM Symbol
• If we space OFDM symbols by gaps at least as
Delay Spread Delay Spread
• If we space OFDM symbols by gaps at least as long as the delay spread, then there will be no intersymbol interferencey
• However, there will still be interference within the symbol (intrasymbol)
123 /114
y ( y )
Equalization and the DFTEqualization and the DFT
• While using longer symbol timing means OFDM can avoid i d ibl till h i t f i i b d firreducible errors, still have interfering energy in band from multipath– Received signal is the (linear) convolution of channel impulse response
with transmitted signalwith transmitted signal
• DFT Circular Convolution Theorem– Circular convolution of two discrete vectors in time domain
*y h x=
Circular convolution of two discrete vectors in time domain
– Is multiplication in the frequency domain
y x h= ∗p q y
• Implication: If we can make the system behave like a circular k k kY X H=
124 /114
p yconvolution, equalization is trivial– complex multiplication per FFT bin at the receiver
Cyclic PrefixCyclic Prefix
• Adding a cyclic prefix g y pat transmitter leads to circular convolution
• Note that misaligned timing still results in a circulara circular convolution, just time shifted
k f h– Makes for phase shifts in FFT bins
– Correct that in a t
125 /114
moment
J. Andrews, A. Ghosh, R. Muhamed, Fundamentals of WiMAX, Prentice Hall, 2007
Comments on Cyclic PrefixComments on Cyclic Prefix• We’re transmitting redundant bits
(no information transfer)J. Andrews, A. Ghosh, R. Muhamed, Fundamentals of WiMAX, Prentice Hall,
– Bandwidth penalty: L / (L + v)– Power penalty: L / (L + v)
• Penalty becomes negligible as Lb l (b h
, ,2007
becomes large (but there are tradeoffs! – more later)
• Power penalty generally more i t t i ti h
•Permits low complexity equalization for same data t important in practice where
systems are interference limited • Penalty can be avoided with zero
prefix
rates•Single carrier tap# approximately bandwidth delay product prefix
– Nothing transmitted in guard band (zero prefix)
– Receiver adds tail back to beginning
delay product–MAC
•OFDM, number subcarriers grows with bandwidth delay
126 /114
Receiver adds tail back to beginning of symbol
– Used in WiMedia
grows with bandwidth‐delay product, so
Frequency ErrorsFrequency Errors
• Primary sources ofPrimary sources of frequency errors– Doppler shift
– Clock mismatches
– Phase noise
• Effects– Reduction in amplitude ( i li i )
O. Edfors, M. Sandell, J. van de Beek D. Landström, F. Sjöberg, “An Introduction to Orthogonal Frequency Division Multiplexing,” Sep 98, Available online: (missampling sinc)
– Intercarrier interference
g q y p g, p ,http://epubl.luth.se/avslutade/0347‐0881/96‐16/esb96rc.pdf
127 /114
Effects of Frequency ErrorsEffects of Frequency Errors• Comments
– Impact greater for higher SNR l
Fading ChannelAWGN
signals– Note 5% estimation error can
lead to 5 dB effective degradation at 64‐QAM like g QSNRs
– Big frequency impact is why OFDM was originally for fixed deploymentsdeployments
• Techniques– Data aided– Non data aided
O. Edfors, M. Sandell, J. van de Beek D. Landström, F. Sjöberg, “An Introduction to Orthogonal
Frequency Division Multiplexing,” Sep 98 A il bl liNon data aided
– Cyclic prefix98, Available online:
http://epubl.luth.se/avslutade/0347‐0881/96‐16/esb96rc.pdf
128 /114
Channel EstimationChannel Estimation
• Channel assumed static for duration of symbol, though f / h b d d hfrequency/phase varying over bandwidth
• Solution, embed pilot symbols at regular intervals in the symbol– Used closest pilot– Interpolate
( )H f
129 /114
From IEEE Std 802.16-2004
Peak‐to‐Average Power RatioPeak to Average Power Ratio
• Sum of large number of ( h ) d d
P1dB,out 1dBP1dB,out 1dB
Output Power (dBm)
Output Power (dBm)
(somewhat) independent subcarriers leads to signal distribution that is somewhat Gaussian
11
11
N i FlN i Fl
Fundamen
tal
Fundamen
tal
Fundamen
tal
Gaussian• Implications
– long tails for amplitude distributionPossibly large ratios of peak to power 0
PAPR CDF for Varying # Subcarriers
MDSMDS P1dB,inP1dB,in
Noise FloorNoise Floor
Input Power (dBm)Input Power (dBm)BDRBDR
– Possibly large ratios of peak‐to‐power ratios
• Long tails can drive amplifiers into nonlinear region 10
-2
10-1
100
(a )N=16 (b) N=32 (c) N=64 (d) N=128 (e) N=256 (f) N=1024(a)
nonlinear region– Introduces harmonics and significant
out‐of‐band spectral energy
10-5
10-4
10-3
log(
CD
F)
(f)
(e)
(d) (c)
(b)
130 /1140 2 4 6 8 10 12 14 16
10-6
10
PAPR[dB]
http://www.ee.ccu.edu.tw/~wl/ofdm/class/class ppt/The PAPR problem.pps
Solution TechniquesSolution Techniques
• ClippingSpectral Effects of Windowing and Clipping
– Eliminate signals above a certain level or ratio
• Peak windowingFil k– Filter peaks
• Linear block code– Select only those codewords with
small PAPRsmall PAPR– Can also provide error correction
• Peak CancellationSubtract signals from high peaks
Peak Cancellation, Clipping, PAPR = 4dB
– Subtract signals from high peaks– Need to be similar bandwidth to
limit out‐of‐band interference• Symbol Scrambling
131 /114
Symbol Scrambling
http://www.ee.ccu.edu.tw/~wl/ofdm/class/class ppt/The PAPR problem.pps
Adaptive ModulationAdaptive Modulation
• Different subcarriers ( )H f
B/L
experience different flat fades
d ff
B/L
• Means different SINR• Adapting modulation scheme of each
Bc f
Bscheme of each subcarrier to its SINR allows the system to approach Shannon capacity
132 /114J. Andrews, A. Ghosh, R. Muhamed, Fundamentals of WiMAX, Prentice Hall, 2007
OFDMAOFDMA
• Multiple user access with • Allocation algorithmsOFDM
• Lots of flexibility possible when splitting up OFDM
– Maximum Sum Rate– Proportional fairness– Proportional rates subject to when splitting up OFDM
symbols and frames– Assign different subcarriers to
different users
p jconstraints
– Assign different time slots to different users
– Vary modulation and codingy g– Vary powers– More options available with
antenna arrays
133 /114J. Andrews, A. Ghosh, R. Muhamed, Fundamentals of WiMAX, Prentice Hall, 2007
OFDM SummaryOFDM Summary
• OFDM overcomes even severe intersymbol yinterference through the use of the IFFT and a cyclic prefix.
• Limiting factor is frequency offsetLimiting factor is frequency offset– Correctable via simple algorithm when preambles used
• Two key details of OFDM implementation are h i i d f h ksynchronization and management of the peak‐to‐
average ratio.• OFDMA provides a lot of flexibility to a system’sOFDMA provides a lot of flexibility to a system s resource allocation– Permits exploitation of multi‐user diversity
134 /114
Antenna Array Algorithms and MIMO
Antenna Array PrinciplesAntenna Array Principles•The use of multiple antennas provide two forms of diversity:
Di it i
10
B]–Diversity gain • Exploit multiple independent channels created by multipath diversity
•Works with uncorrelated antennasArray gain
0
5
g E
nvel
opes
[dB
–Array gain•Coherently combine energy from antennas•Works even with perfectly correlated antennas as received SNR increases linearly with the number of receive antennas
0 200 400 600 800 1000-10
-5
Samples
Fadi
ng
receive antennas
• Adding additional transceiver chains is expensive (SWAP and cost), but can provide tremendous (though competing) gainsp ( g p g) g– Increase the system reliability (decrease the bit or packet error rate)– Increase the achievable data rate and hence system capacity– Increase the coverage area
Decrease the required transmit power
136 /114
– Decrease the required transmit power
Receive DiversityReceive Diversity
• Oldest and simplest diversity Selection Diversity
technique• Receiver leverages independence of
fades on antennasfades on antennas– Selection Combining (SC)
• Choose antenna with maximum SINR• Lowest complexity 10
Average SNR Improvementsp y
– Equal Gain Combining (EGC)• Phase align and sum signals across antennas
6
7
8
9
, dB EGC
MRC
– Maximum Ratio Combining (MRC)• Weight signals by SINR• Best performance (system SINR is sum of
t SINR ) 2
3
4
5
6
10 lo
g (<
γ>/Γ
), d
SNR (dB)
SC
137 /114
antenna SINRs)
1 2 3 4 5 6 7 8 9 100
1
2
No. of branches, M
SCMRCEGC
Antennas
Open Loop Transmit Diversity (1/2)Open Loop Transmit Diversity (1/2)• Transmitter sends multiple signals
(possibly copies) TX RX
h1
(p y p )– These interfere at the receiver, but
if coded properly, the receiver can recover the signal
• Simplest implementation is • Receiver Alamouti Operation
TX Encoder
RX Decoderh2
S p es p e e a o sorthogonal space time block codes or Alamouti codes1
p
O SNR 2 1 Al i– Assumes flat constant channel over two symbol periods (may not be true for high mobility)
– Requires channel knowledge at i
• Output SNR 2x1 Alamouti
138 /114
receiver– No change in rate required
1. S. M. Alamouti, “A simple transmit diversity technique for wireless communications,” IEEE Journal on Selected Areas in Communications, vol 16 pp.1451–1458, Oct 1998
Open Loop Transmit Diversity (2/2)Open Loop Transmit Diversity (2/2)
• 2x2 STBC (same transmit A 4x2 Stacked Alamouti System
encoder) SINR
– Note number of h terms maximized when Nt = Nr for a
J. Andrews, A. Ghosh, R. Muhamed, Fundamentals of WiMAX, Prentice Hall, 2007maximized when Nt Nr for a
fixed number of antennas– Also full‐diversity, orthogonal
STBCs exist only for certain
Comparison of STBC and MRC
combinations of Nt and Nr.
• Can also use space‐time trellis codes for added 1‐2 dB, but
139 /114
those have exponential complexity order
Space‐Time Trellis CodingSpace Time Trellis Coding• Convolutional code applied to space and time domain• Each antenna output is mapped into modulation symbolEach antenna output is mapped into modulation symbol• Maximum likelihood sequence estimator ( Viterbi algorithm)
Example) Delay Diversity (by Wittneben [4])Encoder structure for two antennas Generator matrix form
[a1 a2 a3 a4]
QPSK mapping
140 /114
Closed Loop SystemsClosed Loop Systems•Transmit selection diversity
–Antenna(s) chosen which maximizes SINR–Equivalent to receiver selection diversity–Not as good as beamforming–Little bandwidth required–Makes most sense in in deployments withMakes most sense in in deployments with small bandwidths and small delay spreads (low range)
• Linear diversity precoding
J. Andrews, A. Ghosh, R. Muhamed, Fundamentals of WiMAX, Prentice Hall, 2007
y p g–Feedback channel state information to transmit encoder–Transmit encoder then attempts to find encoding matrix which maximizes SNR at the receiver
–Higher SNR than STBC–Higher SNR than STBC
141 /114
–Typically use some sort of codebook to reduce feedback bandwidth
Beamforming SystemsBeamforming SystemsNarrowband adaptive array or linear combiner
1 590
w1x1(t)
x (t)
0.5
1
1.5
30
6090
120
150
interfererw2x2(t)
y(t)
210 330
180 0
desiredsignal
wMxM(t)
• The weight vector is adjusted to improve the reception of some desired signal 210
240270
300
330 signalreception of some desired signal– Angle of arrival
• MUSIC, ESPRIT– Eigenbeamforming
• No physical interpretation, but useful in multipath environment
142 /114
• Minimize some cost function
• Useful for interference rejection, multipath fading mitigation, and increased antenna gain
Adaptive BeamformingAdaptive Beamforming•Narrowband beamforming is equivalent to spatial filtering
–By choosing appropriate sensor coefficients it is possibleBy choosing appropriate sensor coefficients, it is possible to steer the beam in the desired direction
–By varying the sensor coefficients (spatial filter taps) adaptively, the interference is reduced
•Wideband beamforming requires joint space‐time g q j pprocessing
–Phase shift at the antennas is frequency dependent
–Frequency‐dependent response is required (filter)•Common algorithms
–Maximum Signal to Interference and Noise Ratio (MSINR)g ( )–Minimum Mean Squared Error–Least Mean Squares–Minimum Variance Distortionless Response (MVDR)–Recursive Least Squares
143 /114
q–Similar to linear precoding, but may account for interferers
Performance ComparisonPerformance Comparison
• MRT refers to maximum ratio transmission – the choice of antenna weights that maximize 3 dBgreceived SNR
• With optimal eigenbeamformereigenbeamformer, canceling an interferer is equivalent to dropping an antenna elementan antenna element
Modified from: J. Andrews, A. Ghosh, R. Muhamed, Fundamentals of WiMAX, Prentice Hall, 2007
144 /114
Spatial MultiplexingSpatial Multiplexing• In rich scattering environments, independent data signals transmitted
from different antennas can be uniquely decoded to yield an increase infrom different antennas can be uniquely decoded to yield an increase in channel capacity
145 /114
Spatial Multiplexing TechniquesSpatial Multiplexing Techniques•Open loop (Unknown channel)
l k l h d•Closed loop (known channel)
l l–Maximum likelihood• Little additional gain, except at low SNR
–Zero‐forcing• Evaluates pseudo‐inverse of H
–Singular Value Decomposition• Computationally complex• Capacity (assuming waterfilling)
• Can dramatically increase noise power–MMSE
• Minimizes distortion• Like Zero‐forcing at high SNR, but without • For large SNR, capacity grows linearly
ith k f H i t l i {Ng g
the instability at low SNR–BLAST
• Layers & codes transmissions across antennas
with rank of H, approximately min{Nt, Nr}
–Approximations guided by• information capacity, • error probability• Effectively linear receiver with successive
interference cancellation• Receiver iterates through transmission streams using MMSE or ZF
• Works better in lab than real‐world due to
• error probability • detection MSE• received SNR
–Can tradeoff multiplexing for diversity
146 /114
Works better in lab than real world due to high SNR requirement
diversity
Relative Capacity as function of Antenna h iArray Technique
• 19 BS, 3 sectors, spaced 2.8 km, mix of users
• Proportional Fair scheduling
147 /114Source: WiMAX Forum
Correlation/Coupling EffectsCorrelation/Coupling Effects
• Spacing between antennas influence correlation p gand coupling
• Multipath components can act like interference for beamforming which reduces antenna gain
4x4, SNR = 20 dB, 30° AS Beamforming BER
148 /114
http://www.ngwnet.ac.uk/files/wspres/mimo2.thompson.pdf [Ref. D. Figueiredo, WPMC’04]
Diversity vs. BeamformingDiversity vs. BeamformingDiversity Combining
• Combine signals from differentAdaptive beamforming
• Focus the antenna’s gain in the Combine signals from different antenna elements using various algorithms
• Signal from each element is
gdirection of the desired signal– Achieved by manipulating the
weights associated with each elementprocessed separately
• Signals have to be uncorrelated for maximum performanceMiti t f di
element
• Antenna elements have to be separated by λ/2 to attain a certain phase difference in the signals
• Mitigates fading• Increases gain• Can improve polarization match
f
p g– Signals are correlated
• All advantages of diversity combining
• No interference rejection capabilities
• Has interference rejection capabilities– Typically > 20 dB
149 /114
MIMO SummaryMIMO Summary• Spatial diversity offers incredible improvements in reliability, comparable to increasing the transmit power by a factor of 10–100.
• These diversity gains can be attained with multiple receive antennas, multiple transmit antennas, or a combination of both.
• Beamforming techniques are an alternative to directly increase the desired signal energy whiledirectly increase the desired signal energy while suppressing, or nulling, interfering signals.
• In contrast to diversity and beamforming, spatial multiplexing allows multiple data streams to be simultaneously transmitted using sophisticated signal processingsignal processing.
• Since multiple‐antenna techniques require channel knowledge, the MIMO‐OFDM channel can be estimated, and this channel knowledge can be relayed to the transmitter for even larger igains.
• It is possible to switch between diversity and multiplexing modes to find a desirable reliability‐throughput operating point; multiuser MIMO strategies can be harnessed to transmit to
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multiple users simultaneously over parallel spatial channels.
J. Andrews, A. Ghosh, R. Muhamed, Fundamentals of WiMAX, Prentice Hall, 2007