http://www.crtwireless.com/EWS_09.html Available online Emerging Wireless Standards Wireless Summer School Wireless Summer School June 4, 2008 Session C2 1:30‐5:00 PM James Neel [email protected](540) 230‐6012 www crtwireless com www .crtwireless.com
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• Other– Mobile WiMAX and WiMAX II (802.16m)– Standard http://wirelessman.org/– Promotional http://www.wimaxforum.orgL IP
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– 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
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
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
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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
– 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
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
• 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
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
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
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
• 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
– 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
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
• 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)
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
802.11p 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
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
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
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,
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
– 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
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
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
– 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
• 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
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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
• 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
– 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
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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
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
• 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
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)
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
• 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
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
–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
• 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
150 /114
multiple users simultaneously over parallel spatial channels.
J. Andrews, A. Ghosh, R. Muhamed, Fundamentals of WiMAX, Prentice Hall, 2007