Vehicle to Vehicle Communications and the need for more Wi-Fi spectrum: Can unlicensed devices safely use critical V2V licensed spectrum? Jim Lansford, Ph.D. Fellow, Global Standards Chair, Wi-Fi Alliance Automotive Market Segment Task Group Chair, IEEE 802.11 DSRC Coexistence Tiger Team IEEE ComSoc SCV 11-June-2014
My background Former faculty, University of Colorado at Colorado Springs Former research faculty, Georgia Tech (GT Research Institute) Former CTO, Momentum Microsystems (wireless PAN) Former Wireless Systems Architect, Intel Chair of HomeRF Technical Committee Former VP, Business Development and CTO at Mobilian (Wi-Fi/BT combo) Chair, IEEE 802.19 Coexistence Technical Advisory Group Vice chair, 802.15.2 (802.11-Bluetooth coexistence) Contributor to 802.11g and Bluetooth 1.2 Former CTO at Alereon (UWB chips) Co-chair, 802.15.3a (High speed WPAN) Currently Standards Architect at CSR My role: 802.11 and Wi-Fi Standards, strategy, and related regulatory issues Wi-Fi Alliance: Vice-chair, Long Range Strategy TG and Vice-chair, Wi-Fi SensorNet MTG 802.11: Vice-chair, 802.11 Wireless Next Generation and Chair, DSRC Coexistence Tiger Team Currently adjunct faculty at CU-Boulder (ITP) 2
The automobile is the Fourth Screen WLAN began as a way to connect computers to infrastructure networks Laptops dramatically accelerated the trend almost all laptops now have WLAN The next wave of connectivity was smartphones WLAN is now becoming common in TVs, Blu-Ray players, game decks and other CE equipment The connected car is the next screen Beyond the 4 th screen? No screen at all! (IoT/IoE/M2M) From laptop to smartphone to TV to automobiles the 4 th screen 3
Use Cases for WLAN in IVI Internet connectivity (via in-car modem or tethering) Streaming or Fast content downloading at hotspots (Redbox filling station ) Displays (mirroring, A/V content to other screens) 4
JASPAR Automotive Use cases (WFA) 5
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Wi-Fi is one of many wireless technologies in the Connected Car Wi-Fi (2.4/5GHz) Bluetooth (2.4GHz) GPS (1.575GHz) DSRC (5.9GHz) Cellular (LTE, etc) DSRC will be used for collision avoidance (800/900/1800/1900/2100/2500) NFC (various) Satellite radio (2320-2345/US, DAB 1452-1492) AM/FM broadcast (540-1610kHz, 87.9-107.9) Wireless charging 9
Bandwidth requirements for Wi-Fi Display/Miracast Miracast uses H.264 video codec For standard resolution video: ~5Mbps average, 25Mbps peak For med-high res (720p) video: ~20Mbps average, 100Mbps peak For high res (1080p) video: ~40Mbps average, 200Mbps peak 5GHz needed to support Miracast use cases 40 802.11n can support up to 135Mbps PHY rate (single spatial stream, MCS7, short GI) Miracast uses RTP and UDP for streaming, which can achieve approximately 67% MAC efficiency so about 90Mbps will be available at the top of the stack 40 802.11n very difficult to use in 2.4GHz because of congestion >=80 bandwidth required for higher resolution video and reliability 5GHz bands necessary for Wi-Fi display and video streaming 10
Wireless in Automobiles: A systems approach is needed In-dash head unit Shark fin w/dsrc antenna Consumers will bring smartphones and other devices into the car Wi-Fi and Bluetooth share the 2.4GHz band Wi-Fi and DSRC are in adjacent 5GHz bands Regulatory proposals to allow band sharing Cellular bands are near GPS, Bluetooth, Wi-Fi 800/900/1800/1900/2100/2500 11
Proper coexistence testing is crucial Field testing In-Car Test Lab Theoretical analysis must be followed up with bench and field tests Bench testing 12
Global spectrum availability at 5GHz Band definitions: U-NII-1 U-NII-2 U-NII-2e U-NII-3 U-NII-4 (proposed shared with ITS band) There is no single globally harmonized 5GHz band for 802.11n/ac U-NII-1 is the closest Allowed in US (indoor+outdoor), Japan (indoor) and EU (indoor) no DFS FCC recently allowed U-NII-1 outdoors at up to 1 Watt EIRP Efforts underway to push EU and Japan to follow FCC with U- NII-1 use outdoors 13
5GHz global spectrum at a glance DFS China 5170 5330 5490 5710 5735 5835 5855 5925 US Europe Japan IEEE channel # 20 40 80 160 5170 IEEE channel # 20 40 80 160 36 40 44 48 52 56 60 64 5330 36 40 44 48 52 56 60 64 100 104 108 112 116 120 124 128 132 136 140 5490 100 104 108 112 116 120 124 128 132 136 140 5710 149 153 157 161 165 169 ITS 14
US FCC Changes to U-NII-1 FCC changes in March 2014 U-NII-1 band (5150 to 5250 ) Indoor restriction dropped TX Power limits Indoor: 1W conducted; 4W EIRP Outdoor 250mW conducted; 1W EIRP with antenna restriction U-NII-2 bands (5250 5350 and 5470 5725 ) DFS detection increased to 100% of the bandwidth* Updated the BIN 1 waveform U-NII-3 band (5725 to 5825 ) Extended by 25 (to 5850 ) Change from 15.407 limits to 15.247 limits (1 Watt) All U-NII bands Require manufacturers to improve software security to prevent user modification of regulatory required parameters No requirement to disable devices when modifications are made 15
802.11p/DSRC and U-NII-3/4 band sharing updates (1/3) FCC allocated 75 of spectrum in the 5.9GHz band (5850-5925) for Dedicated Short Range Communications (DSRC) in October 1999 In FCC NPRM 13-22 (13-49), the FCC requested comments on a potential sharing of the DSRC band, to understand if a feasible sharing solution that protects DSRC users could be developed. DSRC would remain as a primary user of the band The new band would be designated U-NII-4 802.11ac could be modified to operate in this new UNII-4 band if approved by the FCC FCC did not specify the framework or etiquette by which band sharing would occur 16
802.11p/DSRC and U-NII-3/4 band sharing updates (2/3) A proposal Add new 10 CCA to 802.11ac Use Carrier Sense of 802.11p preamble, NOT energy detect No Changes to DSRC Similar to 802.11a protection, but 10 CCA Some changes to 802.11ac New CCA for 10 BW not in existing spec DSRC Channels 172 and 178 sensed with CCA other channels TBD CCA for 10 BW exactly the same as 802.11a detection at ½ clock rate IEEE document 13/994r0 suggests a NAV during and for 10 seconds after the last PHY-CCA.indication(BUSY,(DSRC10_CCA)) Other details: CCA level, SIFS, slot times, etc. need to be worked out 802.11p PPDU 17
802.11p/DSRC and U-NII-3/4 band sharing updates (3/3) 5840 5845 5850 5855 5860 5865 5870 5875 5880 5885 5890 5895 5900 5905 5910 5915 5920 5925 Frequency () DSRC Res. DSRC [10 ] Service Chan 172 DSRC [10 ] Service Chan 174 DSRC [10 ] Service Chan 176 DSRC [10 ] Control Chan 178 DSRC [10 ] Service Chan 180 DSRC [10 ] Service Chan 182 DSRC [10 ] Service Chan 184 DSRC Band [10 Channels] DSRC_CCA10: Defers to all BSM traffic in Channel 172 Exp. U-NII-4 [20 ] Center Chan169 Exp. U-NII-4 [40 ] Center Chan 167 Exp. U-NII-4 [20 ] Cente Chan 173 Exp. U-NII-4 [40 ] Center Chan 175 Exp. U-NII-4 [20 ] Center Chan 177 Proposed U-NII-4 Expansion [40 Channels] Exp. U-NII-4 [20 ] Center Chan 181 Proposed U-NII-4 Expansion [20 Channels] U-NII-4 U-NII-4 DSRC_CCA10: Defers to all CCH traffic in Channel 178 Exp. U-NII-4 [80 ] Center Chan 171 Proposed U-NII-4 Expansion [80 Channels] U-NII-4 From 13/541r1 Exp. UNII [160 ] Center Chan 163 Possible CCA Protection? Proposed U-NII-4 Expansion [160 Channels] U-NII-4 5840 5845 5850 5855 5860 5865 5870 5875 5880 5885 5890 5895 5900 5905 5910 5915 5920 5925 Frequency () 18
Conclusion The automobile isn t a giant smartphone Nor is it a small living room Proper analysis, design, and measurements are needed to assure multiple wireless technologies operate properly in the confines of a vehicle Billions of new IoT devices will cause further spectrum congestion Video use cases will accelerate the need for additional spectrum for Wi-Fi Wireless video streaming in cars will become commonplace Most of this will be in the 5GHz band DSRC is adjacent to 802.11ac in U-NII-3 Proposed band sharing between Wi-Fi and DSRC in U-NII-4 will require careful analysis and testing 19
Thank you! 20