Embedded automotive networks combining Power Line and ...

INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

Embedded networks combining Power Line and Wireless communications WSPL2008, Thessaloniki, 2&3/10 / 2008 Fabienne Nouvel, Patrice Maziero IETR, UMR CNRS 6164,INSA of Rennes e.mail : [email protected]

UMR 6164

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INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Summary - Today’s cars : how do they like ? – Today embedded multiplexing and networks – Description of PLC automotive channels – Use of Homeplug V1.0/AV for PLC in vehicles – Wireless solutions : is it possible ? – Conclusion

Fabienne Nouvel – WSPLC2008

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Today’s cars : how many networks ? INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• How do the cars look like ? Networks with various applications

Fabienne Nouvel – WSPLC2008

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Today’s cars : how many networks ? INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• The future applications and needs : high data rate and plug&play systems TV display

Network Network Backbone Backbone

iPOD GPS display

Inter-domain Gateway

Internet access Car Area Network

DVD player

Movie storage

Rear view camera

Fabienne Nouvel – WSPLC2008

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INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Summary - Today’s cars : how do they like ? – Today embedded multiplexing and networks – Description of PLC automotive channels – Use of Homeplug standard for vehicle PLC – Wireless solutions – Conclusion

Fabienne Nouvel – WSPLC2008

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The most representative networks ? INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• 3 most common networks : LIN, CAN, Flexray • Additional networks : MOST, IDB-1394

Fabienne Nouvel – WSPLC2008

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The most representative networks INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• 3 most common networks : LIN, CAN, Flexray

Fabienne Nouvel – WSPLC2008

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The most representative networks INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• LIN (1998) – used by sensors and actuators - Short simple frame – Low cost but low data rate – Number of nodes : 16 slave per master

• Questions vs plug and play nodes: – what happens when a new node is added / suppressed ? – What about the data rate ? Fabienne Nouvel – WSPLC2008

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The most representative networks INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• CAN (1985) – Higher data rate ( > 1 Mbps/s) with short frames (medium complexity) – Implemented for Class B and C – CSMA/CA – masters & masters

• Questions vs plug and play nodes: – CSMA/CA and real time application ? – What ‘s about the data rate for multi-media application ? – Two wires => more complex to route Fabienne Nouvel – WSPLC2008

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The most representative networks INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Flexray (2000) – Highe data rate ( > 10 Mbps/s) with long frames ( more complex) – Implemented on one or two channels – Master – TDMA strategy – static and dynamic time slot

• Questions vs plug and play nodes: – What ‘s about plug and play nodes ? – Two wires => fault tolerance but more complex to route – High cost Fabienne Nouvel – WSPLC2008

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The most representative networks INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• 3 most common networks : LIN, CAN, Flexray

Fabienne Nouvel – WSPLC2008

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The most representative networks INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

9 Advantages – Ability to connect embedded ECU using different data rate – Different fault tolerant – Devices are available

9 Drawbacks – Not convenient for plug and play nodes – Specific additional wires – Power consumption ? Alternative Solutions : Wired/Power line or/and Wireless solutions Fabienne Nouvel – WSPLC2008

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INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Summary - Today’s cars : what, who, how ? – Embedded Solutions – Description of PLC automotive solution – Use of Homeplug standard for vehicle PLC – Wireless solutions – Conclusion

Fabienne Nouvel – WSPLC2008

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PLC automotive channels/wires INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• What is Power Line solution ? ¾ Power and data on the same cable ¾ Preserve the number of wires while increasing the embedded functions ¾ Uses multiplexing techniques : TDMA - CSMA/CD ¾ Modulations : OFDM , widely used for many applications ( xDSL, HomePlug, ..), good efficiency, robust against fadings ¾ High data rate transmission ¾ Standards for domestic applications for indoor access : HomePlug, P1901, HPAV, Panasonic

Fabienne Nouvel – WSPLC2008

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PLC automotive channels/wires INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

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Steps for PLC communications : – Channel measurements – Coupling on DC – Data rate measurements

•

Configuration of measurements ¾ ¾ ¾ ¾ ¾

•

Measurements in the [0-30] MHz band on a Peugeot 407 Different measurement points, in the body area and rear trunck Different cases : car stopped, in motion, ECU ON/OFF, urban & rural trafic Spectrum analyzer connected through a transformer ( DC isolated) Network analyzer

Results in term of ¾ Bandwidth ¾ Noise ( impulsive noise, large and narrow band, background) ¾ Insertion loss ¾ Variation of the channel according the state of ECUs

Fabienne Nouvel – WSPLC2008

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PLC automotive channels/wires INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

Test bed

Body area

Engine area

trunck

H Blue wire

I

E

F

lights AR

socket 12 V

Lighter socket

B Alim ECU1

socket12V trunck

ECU1 Alim ECU3 ( Fil bleu)

-

+

Alim ECU2 Blue ( wire)

D ECU3

A

G

ECU2

Fabienne Nouvel – WSPLC2008

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PLC automotive channels INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Results of channel measurements ¾ Linear attenuation ¾ Frequency selective channel Max. attenuation

-0.5 dB / MHz

¾ Variation of the transfer function due to the value of the loads in the vehicle

[500 KHz, 70 MHz] bandwidth Signal attenuation vs frequency : 0.5 dB/MHz

Measurements carried out by TELICE and IETR laboratories

Fabienne Nouvel – WSPLC2008

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PLC automotive channels INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Results of channel measurements : additional results

Channel is not adapted to 50 Ω The length of the wires and loads involve attenuation, non- adaptation, and reflections Fabienne Nouvel – WSPLC2008

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INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Summary - Today’s cars : what, who, how ? – Embedded Solutions – Description of PLC automotive channels – Use of Homeplug standard for vehicle PLC – Wireless solutions – Conclusion

Fabienne Nouvel – WSPLC2008

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Home Plug V1.0 and AV INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

•Homeplug parameters • Standard for indoor PLC communications •14 Mbps data rate – IP applications • Multi-carriers modulation ( OFDM ) • 128 sub carriers / 84 used for data • [0/4 .. 25/30 MHz] bandwidth • DBPSK, QPSK , Robot modulation • Concatenated Viterbi and RS coding • Many products are available based on the Intellon chipset /Spidcom

Fabienne Nouvel – WSPLC2008

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Home Plug V1.0 and AV INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

•Homeplug spectrum over 220 V AC and voltage

128 sub carriers synchro 84 carriers for data

Fabienne Nouvel – WSPLC2008

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Home Plug V1.0 and AV INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

Spidcom SPC200-E • Master/slave • TCP/IP data flow •Bandwidth 2 – 30 MHz, 7 subbands of 4 MHz, notches • Bit coding : BPSK, QPSK, QAM16, according to the SNR • for each sub-band, 128 channels used/not used, FFT 256 •Pilots for channel estimation and synchronisation

Fabienne Nouvel – WSPLC2008

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Home Plug V1.0 and AV INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

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Spectrum analysis => some attenuation

Frequency / MHz

Fabienne Nouvel – WSPLC2008

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Home Plug V1.0 and AV INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

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Data rate measurement ¾ ¾ ¾ ¾

2 laptops connected through the PLC modem Motor ON/OFF, equipments ON/OFF TCP and UDP data flow JPERF and Ixchariot tools ¾ ¾

¾

Jperf : client and host, settings : TCP window, segment size Ixchariot : two clients and a host, settings : TCP/UDP window, segment size

Modems connected on the DC power line through a transformer an filter

Fabienne Nouvel – WSPLC2008

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Home Plug V1.0 and AV INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

¾ Lower data rate when motor is ON and car in motion ¾Up to 8 Mbps ¾Enhancement according to TCP/IP settings 7000 6500 6000 5500 5000

Average Data rate bps/s)

4500 4000 3500 3000

BLUE : motor OFF

2500 2000

Orange : motor ON

1500 1000 500 0 A-B

A-D

A-H

H-B

H-D

Fabienne Nouvel – WSPLC2008

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Other wired solutions INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

Yamar : CAN and power : DCAN250 • • • •

Packet data: 250Kbps, 16 nodes Can interface Modulation DQPSK Collision resolution, coding, power save Packet size: User defined

•

www.yamar.com

HomePLug AV • • •

Homeplug enhancement : higher data rate Bandwidth : [4-30 Mhz], Turbo coding, Tone ordering ( bit loading ) Many products available

Coax solution : expensive Fabienne Nouvel – WSPLC2008

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INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Summary - Today’s cars : what, who, how ? – Embedded Solutions – Description of PLC automotive channels – Use of Homeplug standard for PLC in vehicles – Wireless solutions : that the question – Conclusion

Fabienne Nouvel – WSPLC2008

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Wireless solutions : the usages

INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Advantages ¾ No wires ¾ Easy to install => plug and play application ¾ Easier to replace, to take from one car to an other one

• Many questions ¾ ¾ ¾ ¾ ¾

Which Bandwidth ? Which data rate ? Which solution already in use ? What ‘s about the level ? disturbances What’s about the channel , the antennas ? What’s about body effect ?

Fabienne Nouvel – WSPLC2008

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Wireless possible solutions

INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Focus on 3 potential solutions in the 2.4 GHz band : Bluetooth, Wifi, ZigBee Protocole

Zigbee

Bluetooth

Wi-Fi

Wireless USB

IEEE /Modulation

802.15.4 2.4 Ghz et 800 MHz DSSS

UWB- MBOFDM and DS

802.15.1 2.4 Ghz OFDM

802.11a/b/g 2.4 Ghz - OFDM

Architecture

Master/slave and master

Master/slave and master

Ad-hoc and infra

Master/slave and master

Media access

CSMA/CA

CSMA/CA

CSMA/CA

TDMA

Nodes number

65 000+

7

32

127

Data rate

250 Kbps

1 Mbps

11-54-108 Mbps

55 à 480 Mbps

Distance/power

100 m

10-100 m

300 m

10 m Fabienne Nouvel – WSPLC2008

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First Step : Channel measurements INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

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Configuration of measurements ¾ Measurements in the [2.3-2.5] GHz band on the same car ¾ Different points : body area and rear trunck ¾ Different cases : car stopped, in motion, ECU ON/OFF, urban and rural trafic ¾ Network analyzer and Spectrum analyzer connected to the antennas

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Results in terms of ¾ ¾ ¾ ¾

Bandwidth Noise (radio, GSM, UMTS, WLAN, …) Insertion loss No Variation of the channel according the state of ECUs H E1

F

E2

A

Fabienne Nouvel – WSPLC2008

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Channel measurements INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Results of channel measurements in the 2.4 Ghz band : car stops Transfert Channel for different cases 2400 0

2410

2420

2430

2440

2450

2460

2470

2480

2490

2500

-10

-20

dBm

-30 AE1 AE2 AF AH

-40

-50

-60

-70

-80

-90 f (MHz) Fabienne Nouvel – WSPLC2008

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Channel measurements INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Results of channel measurements in the 2.4 Ghz band : car driving Transfert Channel when the car is in motion 2400 0

2410

2420

2430

2440

2450

2460

2470

2480

2490

2500

-10

-20

dBm

Stop – OFF

STOP- Motor ON

-30

Driving Breaking / Driving Equipment

-40

-50

-60 f (MHz)

Fabienne Nouvel – WSPLC2008

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Second step : Configuration for data rate INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

802.11g / infrastructure configuration Dungle USB D-Link DWL-G132 802.11b/g Routing node WiFi BeWan (802.11g)

WiFi

Antenna 2,4GHz

PC1 : Server

Routing node BeWan PC2 : Client

Data rate measurement

Spectrum analyser

Fabienne Nouvel – WSPLC2008

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Data rate measurements INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

802.11g / infrastructure configuration

I

H

E

F

Jperf_D-Link Data rate for 4 configurations

A

D

13000 12000 11000

¾Up to 12 Mbps

10000

Data rate Kbps)

9000 8000 AH

7000

AD AE

6000

AH_haut

5000 4000 3000

¾Enhancement according to TCP/IP settings ¾Antenna position is important

2000 1000 0 Stopped

Motor on

In motion

motion equipements ON

Motion+breaking

Fabienne Nouvel – WSPLC2008

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Wireless solutions INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Additionnal studies ¾ Comparison with PLC : ¾ Frame structure, modulation technique, coding ¾ noise, data rate

¾ Tests with other wireless systems : wireless usb, additionnal nodes ¾ Switch between PLC and Wireless ¾ ¾ ¾ ¾

=> Reconfigurable node => redundancy => when do the ECU switch => frame compatible with the 2 systems

¾ EMC measurements, power limitation ¾ Choice of the antenna : small, easy to install

Fabienne Nouvel – WSPLC2008

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Power Lines and wireless communications : it can be possible

INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

• Conclusion

¾ Todays embedded solutions allow middle data rates ¾ PLC and wireless can allow higher data rate and plug &play ¾ OFDM modulation for both ¾ Improvement : coupling techniques, power, bandwidth ¾ Additionnal measurements : wireless systems, additional nodes This work was supported in part by the ANR contract, CIFAER Project, in cooperation between two manufacturers, ATMEL, GEENSYS, and two universities, IRISA and IREENA. It has been done within the cluster ‘Pôle Automobile Haut de Gamme’. Fabienne Nouvel – WSPLC2008

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INSTITUT D’ÉLECTRONIQUE ET DE TÉLÉCOMMUNICATIONS DE RENNES

Embedded networks for automotive : Power Line and Wireless communications WSPL2008, Greece, 2&3/10 / 2008

Questions ?

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