doc IEEE 802 11 090832 r 2 July

  • Slides: 9
Download presentation
doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Enhancement Technology for Vehicular

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Enhancement Technology for Vehicular Communications Date: 2009 -07 -15 Authors: Submission Slide 1 Woong Cho, ETRI

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Vehicular Communications • V

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Vehicular Communications • V 2 V(Vehicle-to-Vehicle) applications: – Vehicle safety via vehicle multi-hop communications • V 2 I(Vehicle-to-Infrastructure) applications: – ITS/Telematics via bi-directional communications • Basic requirements – – – Submission Communication schemes: broadcasting, unicasting Mobility: up to 200 km/h Long packet transmission: ~2 K bytes Packet Latency: 100 msec < Networking: V 2 I, V 2 V Slide 2 Woong Cho, ETRI

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Vehicular Communications Standard •

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Vehicular Communications Standard • WAVE(Wireless Access in Vehicular Environments) – PHY/MAC: 802. 11 p – Upper layers: 1609. x • 802. 11 p – PHY layer(10 MHz Bandwidth) • Uses scaled version of 802. 11 a-20 MHz • Defines sharp spectrum mask in transmission • Defines enhanced channel rejection at the receiver – MAC layer • Uses CSMA/CA of 802. 11 • Uses AIFS(Arbitration Inter. Frame Space) in 802. 11 e for Qo. S supplement Submission Slide 3 Woong Cho, ETRI

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Some Drawbacks of 802.

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Some Drawbacks of 802. 11 p • PHY layer – Channel estimation • Adopts 802. 11 scheme, i. e. , preamble based estimation, without any modification Suitable for short packet transmission Not sufficient for long packet transmission • MAC layer – Collision • Most safety applications use broadcasting As the # of nodes increases, probability of collision increases – Fairness • Unbalanced bandwidth requirements in V 2 I CSMA/CA cannot provide differentiated channel access priority between RSEs and OBUs Submission Slide 4 Woong Cho, ETRI

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Enhancement Technology in PHY

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Enhancement Technology in PHY • Need to guarantee long packet transmission – Modification of channel estimation – Ex) Midamble based channel estimation • 11 -08 -0875 r 1 “Radio Transmission Technology for V 2 V/V 2 I Applications” • 11 -08 -1046 r 0 “Channel Modeling and the Midamble Insertion Effects” Verify the benefit of midamble based system Submission Slide 5 Woong Cho, ETRI

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Enhancement Technology in MAC

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Enhancement Technology in MAC • Provide priority access – Consider TDMA-like system – Ex) Hybrid MAC: TDMA+CSMA/CA • 11 -08 -0875 r 1 “Radio Transmission Technology for V 2 V/V 2 I Applications” • 11 -08 -1273 r 1 “Hybrid MAC for VANET” Hybrid MAC has better throughput than CSMA/CA Submission Slide 6 Woong Cho, ETRI

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Handover Issues • Vehicles

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Handover Issues • Vehicles are move rapidly along roads Handover occurs often, and handover issue becomes more important than 802. 11 When OBU enters new RSE, it takes long channel scanning time to carry out handover • 802. 11 p does not provide a sufficient answer for handover issue • Fast handover scheme in vehicular network is needed to provide continuous communication between RSEs Submission Slide 7 Woong Cho, ETRI

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Next Step in Vehicular

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Next Step in Vehicular Communications • Consider – Modification of PHY • To support long packet transmission Enable to provide various services – Modification of MAC • To provide priority access Solve collision problem and increase throughput – Fast handover • To achieve continuous communication links Provide communication environments with high quality Submission Slide 8 Woong Cho, ETRI

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Straw Poll Q. Should

doc. : IEEE 802. 11 -09/0832 r 2 July 2009 Straw Poll Q. Should IEEE 802. 11 WNG receive further presentations on the topic of enhancement technology for vehicular communications? • Yes : 13 • No : 0 • Abstain : 18 Submission Slide 9 Woong Cho, ETRI