Communications: electrical – Vehicle position indication
Reexamination Certificate
1999-10-13
2002-03-19
Hofsass, Jeffrey (Department: 2736)
Communications: electrical
Vehicle position indication
C340S905000
Reexamination Certificate
active
06359571
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a broadcasting type information providing system which permits an information collecting device mounted on a moving body to obtain information stored in an information providing center via a communication line and a broadcasting line, and to the information collecting device mounted on a moving body, in particular, a travel environment information collecting device which efficiently transmits travel environment information such as traffic jam to a predetermined station such as an information providing center.
2. Conventional Art
A device which provides a variety of information to a moving body or vehicle so as to enhance comfort and safety in the moving vehicle is now being developed. A typical device of such devices is a car navigation system which calculates the shortest route to a destination by making use of such as map information and guidance information stored in the moving vehicle and navigates the same with such as a displayed map and voices. In such car navigation system, the map information and guidance information are stored in a large capacity memory medium such as CD-ROM and DVD. Although the information volume stored in such memory medium is enormous, the information is static one so that a dynamic information such as vacancy information in a parking lot, road traffic jam information and road condition information including an obstacle on the road at a desired moment can not be provided to a driver.
On one hand, recently a moving body communication device such as a portable phone and PHS is rapidly spreading, and a broad communication network including moving bodies is being established.
In one of already established examples of such system which permits to provide such dynamic information, an information service center is provided, and a user accesses the information service center via such as a portable phone or PHS installed in the moving body and obtains desired information via a communication line. The obtained information is displayed as image information on a display provided in a navigation device or is transferred to a driver via a voice synthesizer.
Although through the use of the above referred to moving body communication device the dynamic information can be provided to a user in a moving body as has been explained above, there arose the following problems.
Firstly, the capacity of the communication line is small. The digital data transferring speed for the portable phone and PHS which is now reduced into practice is from 9.6 KBPS to 32 KBPS, therefore, when communicating image information, it takes about 10 sec. for transmitting one screen image which deteriorates the response characteristic.
Secondly, a cost incurred for the communication is high. Further, since the communication cost is proportional to the communication time, when communicating image information, the communication time prolongs as has been explained above to increase the communication cost.
Thirdly, communication quality during moving is poor. This is caused by such as fading generated in the communication path, and the communication speed decreases in proportion to increase of bit error rate in the communication line and in the worst case the communication will be interrupted.
As a method of resolving the above problems, a method is studied in which dynamic information is transferred to a driver via a digital broadcasting line having a further higher quality as disclosed in Christer Grewin, “Audio Quality vs. Data Services—a Possible Conflict?” (Third International Symposium on Digital Audio Broadcasting, Jun. 4-5 1996. Montreux Switzerland). Although the digital broadcasting line is limited to a unidirectional data transmission from the side of a broadcasting station to a user, the digital broadcasting line has a communication capacity of several MBPS with regard to an audio line and of several tens MBPS with regard to animating image. Further, in order to apply a technology such as image compression the communication capacity is designed to meet the worst case.
Further, when the data compression rate is high, namely, such as when monotonous images continue and when static images are transmitted, the compression rate is inherently heightened, and a band which is not used for general broadcasting is generated in the communication band. Therefore, if the communication information from the information service center to the moving body is superposed on the empty band and a broadcast receiving device installed at the side of the moving body separates the communication information, information can be obtained via the communication line having a high speed and stability.
Further, as a system which provides dynamic information, a system is already in use in which a traffic stream volume is measured by making use of such as cameras, ultrasonic wave sensors and photo sensors disposed along roads to discriminate between traffic jamming and non-traffic jamming based on the measured volume, and the traffic information is provided to a moving body via a communication path including FM multiplex channel broadcasting and radio wave, photo beacon. Further, another system is also practically used in which a plurality of photo beacons which enable bidirectional communication are disposed along roads and traffic jamming information is collected by measuring travel time of a moving body between the beacons disposed at the road side.
These systems collect traffic information in real time by making use of a variety of information collecting devices such as cameras, ultrasonic sensors and photo beacons disposed at the sides of roads.
Further, a still further system is disclosed in JP-A-5-151496 (1993) in which a moving body communication is used and traffic information collected by the moving body itself is transmitted to the side of an information providing center, and the information providing center determines traffic information such as traffic jam by collecting these respective traffic information.
In a moving body communication device, a specific cell where the moving body exists now is judged, and a communication is performed via a base station installed in the specific cell. In order to judge a specific cell where the moving body exists, periodical communication is performed between the terminal side of the moving body communication device and the base station side, and the specific cell where the terminal exists is judged.
On the other hand, even when information is transmitted via a broadcasting station, there is a problem that it has to be judged whether a moving body which receives information exists in a service area of the broadcasting station, and information has to be provided to the moving body from the broadcasting station of which service area covers the position where the moving body exists now.
Further, when obtaining information via broadcasting, there is another problem that waiting time until answer information is transmitted tends to be prolonged in comparison with when a bidirectional communication is used. This is because that an instance sometimes happens which requires a waiting time when superposing the answer information on general information, and because of existence of other users the broadcasting line sometimes becomes crowded.
Still further, with regard to the broadcasting receiving device, except when a user is receiving the broadcasting, the power source therefor is turned off. Accordingly, there arises further problem that it is necessary to turn on and off the power source by a proper measure depending on necessity.
With regard to the above explained method in which the traffic information is collected by making use of such as photo beacons, since it is necessary to dispose sensors along the road sides, an enormous number of ultrasonic wave sensors and photo sensors is necessitated depending on number of roads which incurs substantial investment cost. Further, with the ultrasonic wave sensors and the photo sensors, basically only information is obtained with regard to v
Endo Yoshinori
Fujiwara Toshio
Hiroshige Hideo
Hondo Ichiro
Kurata Ke'nichirou
Crowell & Moring LLP
Hitachi , Ltd.
Hofsass Jeffrey
LandOfFree
Broadcasting type information providing system and travel... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Broadcasting type information providing system and travel..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Broadcasting type information providing system and travel... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2883166