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Special Issue Advanced Technologies and Solutions toward Ubiquitous Network Society

ABSTRACT

ITS (Intelligent Transportation Systems) SolutionsBy Makoto MAEKAWA*

*Market Development Division / ITS Business Develop-ment Center

Worldwide ITS goals for safety and environment have recently been set to quite a high level, suchas zero fatalities or zero delays. In order to achieve these high level goals, we have to think ITS

with the “ubiquitous” point of view, which aspires that human, road and vehicle are connected to the networkorganically. NEC is now developing ITS solutions not only to support customers in achieving these goals, butalso to bring about a ubiquitous network society.

KEYWORDS ITS, Probe Information System, Car-to-car communication, Fast IP handover, Pedestrian ITS

1. INTRODUCTION

ITS projects to improve safety, transportation effi-ciency, comfort, environment and creating new busi-ness by means of integrating human, road and vehicleutilizing information technology have been conductedin Japan since 1995 by the Japanese Government. Toimprove the environment, there is VICS (Vehicle In-formation Communication System), a system thatgathers traffic condition from roadside sensors, con-verts it to congestion data, transmits it vehicles,where it is displayed on the navigation system screen.VICS infrastructure has been introduced all over Ja-pan, and there are now more than nine million VICSterminals. Drivers can obtain real time congestioninformation and avoid the congested area. ETC (Elec-tronic Toll Collection) has also been introduced onnational highways across the country. There are nowmore than three million ETC terminals in use. ETCcontributes greatly to the reduction of tollgate conges-tion.

From the perspective of safety, “passive safety,”which focuses on safety after the crash, measuressuch as airbags, seat belts and so on have greatlycontributed to the reduction of fatalities. But re-cently, America has introduced a concept called “Vi-sion Zero,” which means zero fatalities and zero de-lays. Europe also has introduced its “e-Safety” con-cept of reducing half the fatalities by 2010. To realizethese safety goals, “active safety”, which focuses onsafety before the crash by gathering crucial informa-tion from surrounding vehicles or from the nearestroadside infrastructure, is essential. In addition, it

would be impossible to achieve the congestion reduc-tion goal only by means of information gathered bythe infrastructure; information from traveling ve-hicles is essential.

To enhance ITS function as described above wouldrequire all cars to be connected to a network; in otherwords, the advent of ubiquitous network society isessential. In a ubiquitous society not only will manythings become more convenient than now, but alsothe value of the network itself will become more valu-able than ever. And this will be the essence of ubiqui-tous network society, and the form of social infra-structure itself will be affected greatly. This paperintroduces some of the NEC’s ubiquitous ITS activi-ties.

2. NEC ACTIVITIES

NEC is developing ITS technologies and applica-tions based on “ubiquitous” point of view. The follow-ing four items are the focal points:

2.1 Probe Information SystemThe Probe Information System is a system that

regards the vehicle as a moving sensor. Vehicles havemore than one hundred twenty (120) sensors includ-ing the results of drivers’ and passengers’ actions liketurning on lights, windshield wipers. The capabilitiesof the system will continually be upgraded as timegoes on.

If such information can be gathered and statisti-cally processed it will be very useful. For example,vehicle speed data can be converted into traffic infor-mation, wiper information can be converted to rain-fall information, and ABS information can be con-verted to road condition information (See Fig. 1).

NEC participated in the Probe Information System

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project led by the Japan Automobile Research Insti-tute from 1999 to 2001. NEC also participated in theInternet ITS project led by the Ministry of Economy,Trade and Industry advised by Professor Murai ofKeio University in 2001. In this project, 1,500 taxiesfunctioned as probe vehicles in the Nagoya area. Fig-ure 2 shows real time traffic conditions gathered fromspeed data from the 1,500 taxies. Compared withVICS, the Probe Information System can provide

more detailed information because on the one handVICS data is gathered through sensors installed onmain thoroughfares whereas on the other hand sen-sor vehicles can send real time information anywhereas long as a cellular phone is activated.

The essence of Probe Information System is to addvalue to the data gathered through network, so in thispoint of view, data mining technology developed byNEC laboratory can be applied in various ways. For

Fig. 1 Probe Information System.

Fig. 2 Traffic congestion information using vehicle velocity.

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example, traveling time from one point to anotherpoint according to time of the day, week, month canbe estimated by mining past probe data.

Also it can be applied to analyze the congestionoccurrence pattern and road expanding plans. Fig-ure 3 shows the result of adapting data mining tech-nology to the estimation of travel time betweenNagoya airport and center of the city of Nagoya. Italso shows that the preciseness has been improved toone digital order. The Probe Information System is astate-of-the-art technology, which realizes manythings that thought to be difficult to achieve and nowis paid attention by all over the world.

2.2 FleetNet — Car-to-Car CommunicationSafe driving can be significantly increased by us-

ing information from other vehicles. Such informationcan be conveyed via direct or indirect car-to-car com-munication, which has increasingly become a subjectfor global research. In this context, NEC Europe Net-work Laboratories has participated in the collabora-tive project FleetNet led by DaimlerChrysler and par-tially funded by the German Ministry of Educationand Research BMBF. NEC was responsible for therouting protocol and chose position-based ad hoc rout-ing as the key technology particularly suited for ahighly dynamic environment.

As shown in Fig. 4, FleetNet regards car-to-carand car-to-roadside communication as within thesame framework with the following four types of com-

munication:

1) Car-to-car direct communication2) Car-to-car communication via relaying by interme-

diate cars3) Car to stationary FleetNet gateway4) Car-to-Internet via stationary FleetNet gateway

Applications for these communication types are,for example, cooperative driver assistance, decentral-ized probe car, user communication and informationservices.

The core of this system is position-based routing.To avoid accidents or crashes, FleetNet cars sendemergency warnings to cars in the rear based on theirposition, a technique called “geocast.” Packets areforwarded via the reachable car that is nearest thetarget area or car. This allows for a rapidly changingcar and thus network topology, because cars are con-stantly updated about the current position of reach-able (neighbour) cars by regular beacons. This makesposition-based routing an appropriate choice for in-ter-vehicular communication. Simulation results inFig. 5 show that position-based approach has betterpacket delivery rates than conventional ad-hoc com-munication methods.

The results of the FleetNet project will be taken upby a new collaborative research project called NoW(Network on Wheels), which has new partners, suchas BMW and Volkswagen. The goal is to advance

Fig. 3 Estimation of travel time.

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towards the product stage with focus on testing andenhancing robustness under real-world conditionsand a strong emphasis on security and dependability.

2.3 Fast IP HandoverThe most popular communication media for mov-

ing vehicle is currently the cellular telephone, butthere is a strong demand for higher speed communi-cation media. It is possible to realize fast communica-tion if wireless LAN can communicate seamlessly. Todownload high volume contents like moving picturesor music while moving fast on a train or on a car,handover among wireless LAN technology is essen-tial. Fast IP Handover technology realizes handoverat the IP layer. Since handover is accomplished at theIP layer, it can be applied to any communicationmedia, even a new wireless technology can be applied.

To communicate seamlessly over a quite long dis-tance (more than 100km), we have applied a hierar-chy structure for the routers. Thanks to this hierar-chy structure, it is not necessary to register the carposition information with all the routers. That is tosay we can localize and minimize the update of rout-ing information table, thus we can realize the Fast IPHandover. Also by sending the information to thenext spot where the vehicle is supposed to pass, wecan prevent packet loss. Figure 6 shows the mecha-nism of the Fast IP Handover.

We have made an experiment to evaluate the FastIP Handover at Japan Automobile Research Institutein September 2003. In this experiment we sent inter-active moving picture between the test vehicle andthe backyard system, while driving at 330km/h with-out missing a frame. Figure 7 shows the experimentoverview. After releasing the result of this experi-ment, we have received many responses from railroad

Fig. 5 Packet delivery ratio.

Fig. 4 FleetNet: Inter-vehicle communications platform.

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Fig. 6 Overview of IP hand-over technology.

companies and car companies.

2.4 Pedestrian ITSIn order to support pedestrians by providing route

guidance and peripheral information, it is very impor-tant to allow them to obtain positional information.

GPS-based positional information acquisitionsystems currently in common use have some prob-lems regarding positional accuracy and speed. Theycannot provide correct information for users at side-walks between tall buildings, in underground shop-ping mall, or inside structures where large numbers

Fig. 7 Overview of the field test system.

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* * * * * * * * * * * * * * *

Received July 27, 2004

*Names of companies and products introduced in thispaper are trademarks or registered trademarks of eachcompany.

of people are walking around because multi-pathtransmissions from GPS satellites cause errors inaccuracy and shields make it difficult to receive radiowaves.

For solving these problems, we have employedwireless communication technologies for relativelyshort ranges as shown in Fig. 8 to allow pedestrianshaving portable terminals to communicate withwireless communication devices transmitting posi-tional information installed in roads, undergroundshopping areas, and the inside of buildings (we callthese devices wireless information markers). As soonas connections are established in communication ar-eas, this new system can provide the portableterminal’s position to support the pedestrians. In-stalling the wireless information markers in appro-priate places can solve the positioning accuracy and

Fig. 8 Configuration of pedestrian ITS.

Makoto MAEKAWA received his B.E. andM.E. degrees from Tokyo Institute of Technol-ogy in 1977 and 1979, respectively. He joinedNEC Corporation in 1979, and he is now ChiefManager of Market Development Division andalso head of ITS Business Development Cen-ter.

place-dependent positioning difficulty encountered inthe conventional system.

In addition to positional information, a variety ofother information can be received from wireless infor-mation markers, thereby increasing the range of ser-vices.

This system can cope with problems in conven-tional GPS and can be used as public infrastructureand as an advertising media for commercial facilitiesto enhance convenience for pedestrians.

3. CONCLUSION

The advent of ubiquitous network society is not faroff, and we are heading toward to it in gradually butsurely. ITS can play a large role in ubiquitous net-work society, and will contribute greatly to enhancingsafety, environment and comfort. NEC will keep pro-viding solutions for the ubiquitous ITS.