Towards a European Solution for Networked Cars -Integration of Car-to-Car Technology into Cellular Systems for Vehicular Communication in Europe
Yunpeng Zang, Sabine Sories, Bernhard Walke Guido Gehlen Department of Communication Networks Ericsson Research, RWTH Aachen University, Germany Herzogenrath, Germany Geneva, 4-5 March 2009 Outline 2 o Introduction o Car-to-Car Communication for Safety Services o Vehicular Communication with Cellular Systems o C2C vs. Cellular: Competing or Complementary? o A Hybrid Solution o Conclusion
The Fully Networked Car Geneva, 4-5 March 2009 Motivation 3 o Automobile accidents in Europe • 1,300,000 accidents • 40,000 dead persons per year (2005) • 1,700,000 casualties • 160 bn. € economic damage o „eSafety― concept from the European Union • Half number of dead persons until 2010 • Passive safety systems reducing the severity of the accident are not enough • Target is only reachable with active safety systems that completely prevent accidents o Traffic efficiency o Infotainment services for driving comfort
*Photos from EU PReVENT project
The Fully Networked Car Geneva, 4-5 March 2009 Introduction 4 o Spectrum regulation worldwide • 5.9GHz DSRC o Standardization efforts • EU C2C-CC • IEEE WAVE • ITU CALM o Projects • EU projects — CVIS, PReVENT, eSafety, SEVECOM, • German national projects — AKTIV, FleetNet, NOW, SIM-TD
The Fully Networked Car Geneva, 4-5 March 2009 Car-to-Car Communication 5
o Spectrum for ITS in Europe • Aug. 2008 • 30 MHz at 5.9 GHz (5.875GHz – 5.905GHz) o Wireless Access in Vehicular Environments (WAVE) • Physical layer (PHY) — 10MHz channel at 5.9GHz ITS band
— IEEE 802.11p (802.11a, OFDM) IEEE P1609.1 • Medium Access Control (MAC) WAVE Resource Manager — Basic IEEE 802.11 MAC IEEE P1609.2 IEEE P1609.3 Security Services for — CSMA/CA Networking Services Applications and — MAC-X IEEE P1609.4 WAVE Management Messages Management IEEE P1609.4 • Upper layers Entity Multi-channel Operations MLME: (MAC Extension) MAC Layer — IEEE 1609.x Management Entity MLME IEEE 802.11p o Services WAVE MAC PLME: Physical Layer IEEE 802.11p • Wireless local danger warning PLME Management Entity WAVE PHY • Cooperative danger warning • Traffic information dissemination • P2P file sharing
The Fully Networked Car Geneva, 4-5 March 2009 Simulation Study of C2C Communication 6 Performance
o Maneuvering assistance Neighborhood Map Of Host Vehicle • Periodical information Dint exchange among ...... neighboring vehicles ...... • Information update ...... Host frequency 10 Hz Vehicle o Interested metrics ...... • Information Update ...... Interval ...... • Channel Busy Time
Parameter Low Density High Density
Average Inter-vehicle Distance (Dint) 80 m 10 m Average Vehicle Speed 160 km/h 20 km/h Market Penetration Rate 100% 100 % PHY Mode BPSK ½ (3 Mb/s) BPSK ½ (3Mb/s) Hazard Warning Packet Size 100 B 100 B Manoeuvring Message Frequency 10 Hz 10 Hz Warning Message Priority VI (AC2) VI (AC2) Transmit Power Level 20 dBm 20 dBm The Fully Networked Car Geneva, 4-5 March 2009 Performance: Maneuvering Assistance 7 o With 100% penetration rate, WAVE system works well in both low and high density scenarios Low density scenario High density scenario
1 1 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 0.5 0.5 0.4 0.4 0.3 0.3 0.2 0.2 0.1 WAVE Random Start 0.1 WAVE Random Start
WAVE Rebroadcast WAVE Rebroadcast Probability ( Update Interval < x) < Interval Update ( Probability Probability ( Update Interval < x) < Interval Update ( Probability 0 0 0 50 100 150 200 250 300 350 0 50 100 150 200 250 300 350 Update Interval x (ms) Update Interval x (ms)
Update Interval Update Interval Broadcast CBL Broadcast CBL Max Min Mean Standard Max Min Mean Standard Algorithm (%) Algorithm (%) (ms) (ms) (ms) Deviation (ms) (ms) (ms) Deviation WAVE Random WAVE 12 330.5 52.2 104.3 31.6542 35 313.0 53.6 106.5 33.0032 Start Random Start WAVE WAVE 13 209.8 18.1 102.4 23.2994 42 225.5 9.4 84.1 36.8479 Rebroadcast Rebroadcast
The Fully Networked Car Geneva, 4-5 March 2009 Performance: Message Propagation with Low 8 Penetration Rate o With low penetration rate, the vehicular ad-hoc network suffers from fragmented network problem o Message propagation relies on vehicles on the opposite direction o The end-to-end delay depends on the network density and market penetration rate
r 2R P( t) 1 etr (2Rvtrtru ) , t u vtr Comm. Range: R=250m
Speed: vtr=85km/h Vehicle density: λtr=29 Vehicle/km
Distance to go: ru=1000m [1] Schoenhof, M., et al, Coupled Vehicle and information flows: Message transport on a dynamic vehicle network, Physica A, Apr., 2006. p73-81
The Fully Networked Car Geneva, 4-5 March 2009 Cooperative Cars – CoCar 9
o German BMBF funded research project • basic research for V2V and V2I communication using cellular mobile communication technologies • Consortium — Ericsson (project leader), Vodafone, Daimler, MAN, Volkswagen o Cellular technologies (GPRS, UMTS, HSPA, LTE) (HSPA = HSDPA+HSUPA) • Sufficient coverage • Increasing data rate and capacity • Improved Latency o Services • Safety • Infotainment
The Fully Networked Car Geneva, 4-5 March 2009 Performance of Cellular System (UMTS) for 10 Vehicular Applications a) Cell_DCH State 100 90 80 70 60 50 40
C.D.F. [%] C.D.F. 30 20 10 0 0 50 100 150 200 c) Cell_FACHDelay [ms]State 100 90 80 70 60 50 40
C.D.F. [%] C.D.F. 30 20 10 o 0 Infrastructure ensures timely message 0 100 200 300 400 500 d) Idle State dissemination throughout large areas 100 Delay [ms] 90 o Broadcast enables efficient message dissemination 80 for many-user scenario 70 60 o End-to-end delays of below 500 ms can be 50 40
achieved using in today’s UMTS networks, but not [%] C.D.F. 30 guaranteed 20 uplink 10 downlink 0 total 0 2000 4000 6000 *) Results from [2] S. Sories, J. Huschke, M.-A. Phan, Delay Performance of Vehicular Safety Delay [ms] Applications in UMTS, 15th World Congress on ITS, New York, 2008 The Fully Networked Car
Geneva, 4-5 March 2009 Cellular System vs. C2C 11
Cellular (UMTS) C2C (WAVE) Infrastructure based system Infrastructure-less system, but some services require infrastructure support Network infrastructure Infrastructure ready No infrastructure ready in Europe
Network coverage range Ad-hoc network with single hop distance of Communication range 300 m-1 km Interference limited system with limited Scalable adaptive ad-hoc network System Capacity resource of each cell Minimum end-to-end delay around 100 ms Minimum end-to-end delay < 100 ms for (HSPA) for local hazard warning service, local hazard warning guaranteed but not guaranteed Processing/network Delay Delay performance of long distance Without supports from roadside communication is independent of infrastructure, the delay performance of penetration rate long distance communication depends on the penetration rate
Licensed spectrum Cost-free spectrum Well developed network reduces the cost Huge investment is expected in deploying Cost of developing and maintaining the and maintaining dedicated roadside infrastructure infrastructure, if there will be any WAVE roadside infrastructure
Centralized Distributed protocol relying on Security and anonymity infrastructure
The Fully Networked Car : Pros Geneva, 4-5 March 2009 : Cons Hybrid Solution with Cellular and C2C 12
o Shared application module
o Parallel WLAN and cellular RNC GGSN TIS communication modules o Infrastructure support from cellular system o Time critical applications through C2C
Memory Vehicle Bus Host vehicle Main speed, UMTS/LTE Processor acceleration, Radio Unit etc. Safety Application WAVE Radio Unit Comm. Logic Human (5.9 GHz) Manager Warning/Info. Machine Host Non-Safety Interface Vehicle Application Position GPS Unit Logic
The Fully Networked Car Geneva, 4-5 March 2009 Conclusion 13 o Car2Car: • With high penetration rate, Car2Car system works well • With low penetration rate, VANET suffers from fragmented network problem o Cellular: • Infrastructure ensures timely message dissemination throughout large areas • Infrastructure already in place • Weak on very time critical safety applications o The hybrid solution combines benefits of both technologies
The Fully Networked Car Geneva, 4-5 March 2009 14
Thanks for your attention! Yunpeng Zang [email protected] Sabine Sories [email protected]
http://www.aktiv-online.org/
The Fully Networked Car Geneva, 4-5 March 2009