Showing papers on "Dedicated short-range communications published in 2002"

Vehicle control algorithms for cooperative driving with automated vehicles and intervehicle communications

Abstract: Describes the technologies of cooperative driving with automated vehicles and intervehicle communications in the Demo 2000 cooperative driving. Cooperative driving, aiming at the compatibility of safety and efficiency of road traffic, means that automated vehicles drive by forming a flexible platoon over a couple of lanes with a short intervehicle distance while performing lane changing, merging, and leaving the platoon. The vehicles for the demonstration are equipped with automated lateral and longitudinal control functions with localization data by the differential global positioning system (DGPS) and the intervehicle communication function with 5.8-GHz dedicated short range communication (DSRC) designed for the dedicated use in the demonstration. In order to show the feasibility and potential of the technologies, the demonstration was held in November 2000, on a test track with five automated vehicles. The scenario included stop and go, platooning, merging, and obstacle avoidance.

Inter-vehicle communications and their applications to intelligent vehicles: an overview

Abstract: This paper surveys the inter-vehicle communications and the applications to intelligent vehicles. The inter-vehicle communications, defined here as communications among vehicles for ITS applications, are featured by that it can extend the horizon of drivers and on-board sensors. Systems with the inter-vehicle communications are, thus, much beneficial on the road traffic safety and efficiency. One of the earliest studies on the inter-vehicle communications was started in Japan in the early 1980s. In the recent automated platooning and cooperative driving systems, the inter-vehicle communications play an essential role, because they enable vehicles to obtain data difficult or impossible to measure with on-board sensors. The media used in the inter-vehicle communications include infrared, micro wave and millimeter wave, and various kinds of protocol are employed for the experiments. At present there are many technological and non-technological issues for practical use.

Recent advances in ultra wideband communications systems

Abstract: The last compilation of ultra wideband (UWB) communications systems is nearly two years old (see Fontana, R.J., Ultra-Wideband, Short-Pulse Electromagnetics, EuroEM 2000). This paper is intended as an update and illustrates recent trends in UWB communications for multi-user networking applications. More specifically, the paper describes three recent system developments: an ad hoc wireless UWB communications network for tactical voice and high-speed data communications; a long range UWB system for over-the-water and non line-of-sight voice, data and video communications; a wireless UWB communications network for support of both tactical and strategic (long haul) communications.

On the suitability of 802.11a/RA for high-mobility DSRC

Abstract: The 802.11a standard has been considered and applied to DSRC (dedicated short-range communication) in the 5.9 GHz band. Among the parameters of the DSRC are support for data transfers during high-mobility applications. Given that the 802.11a standard was designed for relatively low speed (3 MPH) wireless LAN applications, it is necessary to analyze the suitability of the standard in outdoor high-speed mobility applications. We present an analysis of the error rate of 802.11a in high-speed mobile applications. It is shown that 802.11a/RA communication exhibits high packet error rates and consequently lower channel capacity. An example is submitted and discussed.

Adaptive control method for operating communications environments

Abstract: A method for operating a first communications environment and a communications environment wherein first communications resources for communications according to a first communications standard are used for communications according to a second communications standard and wherein the use of the first communications resources for communications according to the first communications standard is controlled in dependence of communications to be performed according to the second communications standard.

A hierarchical view on modeling the reliability of a DSRC link for ETC applications

Abstract: For electronic payments, the communication link has to be reliable. Dedicated short-range communication (DSRC) is a proposed solution for the automatic debiting of vehicles in an electronic toll collection (ETC) system without disturbing the traffic flow. The requirements on the reliability of such a system are high, which implies that only large-scale simulations with a lot of detail are effective for analyzing occasional errors. In this paper, a hierarchical approach is worked out that allows such simulations of the communication link, with a 80% reduction of the computational effort compared to simulation with full detail.

Network service information providing system and network service information providing apparatus and method and terminal thereof

Abstract: The present invention provides a network service information providing system which allows users to readily know a location and radio transmission parameters for connecting to a narrow-area wireless communications system in a system which contains a mixture of wide-area wireless communications systems and narrow-area wireless communications systems and to set up a new narrow-area wireless communications system which can provide higher communications services without causing degradation in existing communications services in the environment where different wireless communications systems coexist. The user knows his/her own location through a wide-area wireless communications system and sends the location of a narrow-area wireless communications system which he/she wants to connect to, wireless transmission parameters, and other requirements to a wireless area information server. The wireless area information server possesses wireless transmission parameters of narrow-area wireless communications systems and the locations of base stations which provide narrow-area wireless communications services. Upon receiving the requirements from the user, the wireless area information server informs the user of the service area of the narrow-area wireless communications system nearest to the user via the wide-area wireless communications system.

Wireless communications system

Abstract: A wireless communications system for enabling a base station unit and a plurality of customer premises units to wirelessly communicate data at high efficiency by putting communications on standby for each unit of traffic data for which a communications request occurs, and then shifting to communications processing for each unit of traffic data on communication standby and by managing communication standby information including information that distinguishes customer premises units on communication standby with regard to the customer premises units covered by the base station unit. Based on the communication standby information, data traffic channels are allocated to customer premises units on communication standby covered by the base station unit for each unit of traffic data during communication standby. Wireless communication of data is performed between the base station unit and customer premises units using the portion of the data traffic channels allocated to the customer premises units.

Vehicle-mounted apparatus of a dedicated short range communications system

Abstract: A vehicle-mounted apparatus of a dedicated short-range communications system is capable of informing a discount of an amount of toll to a user. The apparatus includes a radio communication part for communicating with road-side radio equipment, an IC card storing therein traffic histories, a control part for processing data received from the radio communication part, an account instruction part for generating an account instruction based on the data from the control part, a discount instruction part for generating a discount instruction based on the data from the control part, a display part and an audio part for informing an account and a discount to the user based on the instruction from the account instruction part and the instruction from the discount instruction part, and a buzzer part for notifying a condition of passage of a vehicle through a toll gate to the user by performing an account or a discount.

Evaluation of information transmission over inter-vehicle communications with simulation studies

Abstract: This paper presents simulation studies on the incident transmission system over the inter-vehicle communications, and investigates the relation between the information transmission over the inter-vehicle communications and the penetration rate of the communication unit. The inter-vehicle communications with the 5.8 GHz DSRC (dedicated short range communications) and a traffic flow based on the time headway on an expressway are modelled for the simulation. The simulation results show that the information relayed via equipped vehicles can be transmitted at the level of the practical use when the penetration rate is over 20%.

A hybrid communication architecture for intelligent shared vehicle systems

Abstract: There has been a large degree of activity in the communications arena of intelligent transportation systems. Various communication linkages are being developed for a variety of ITS applications for different purposes. Shared vehicle systems, as a relatively new transportation paradigm, are very well suited for the application of ITS technology, including advanced communication techniques. In general, a shared vehicle system typically consists of a fleet of vehicles that are used several times each day by different users. They offer the convenience of the private automobile and more flexibility than public transportation alone. There are many potential advantages to shared vehicle systems, including improved transportation efficiency, lower transportation cost, an energy/emission benefit, and increased use of existing transit systems. In this paper, we focus on the application of wireless communications to shared vehicle systems. In particular, we describe the design and development of a unique hybrid data communication architecture for a multiple-station shared vehicle system. This hybrid architecture is composed of vehicle-to-system communications using both DSRC (Dedicated Short Range Communications) and CDPD (Cellular Digital Packet Data) methods. Based on the communication needs within a multiple-station shared vehicle system, the hybrid communication system has been designed and optimized in terms of data packet loss, message latency, and system cost. Several experiments have been carried out, examining these measures of performance.

On-vehicle equipment for dedicated short-range communication in intelligent transport system

Abstract: In an on-vehicle equipment for Dedicated Short-Range Communication (DSRC) in Intelligent Transport System (ITS), a priority sequence for switching local frequencies of f 1 to f 7 in correspondence with types of on-road equipment is previously set, the local frequencies are sequentially outputted at a predetermined cycle in accordance with the priority sequence, a received frequency signal is compared with a selected frequency signal, and when the received frequency signal is the same as the selection frequency signal, the local frequency corresponding to these is determined as a desirable communication frequency, and the communication frequency is fixed as being this local frequency with high efficiency.

Vehicle-mount radio terminal

Abstract: PROBLEM TO BE SOLVED: To communicate a vehicle-mount radio terminal which can switch and use a plurality of radio communication systems, based on the priority of the radio communication system according to the state of its own vehicle SOLUTION: The vehicle-mount radio terminal obtains information of the positional relation between its own vehicle and the covered areas by respective communication systems (ETC, DSRC, 58 GHz wireless LAN) from a car navigation system, and obtains information of the running speed of its own vehicle from a vehicle speed sensor 46 The vehicle-mount radio terminal 10 determines priorities of communication systems to be used on the basis of the obtained information, and carries out communication by switching the communication system based on the priorities COPYRIGHT: (C)2004,JPO

Expanding the wireless universe: EU research on the move

Abstract: This article provides an overview of the activities currently carried out under the IST research program of the European Commission, in the area of mobile and wireless communications and satellite systems. The research orientations specific to wireless communications are described in detail, with reference to the projects active in each area, defining a possible roadmap for the evolution of mobile communications systems beyond UMTS.

A research on bus information service system using DSRC

Abstract: Advanced Public Transportation Systems (APTS) are required to collect traffic information dynamically and provide real-time information for travelers and traffic management departments. DSRC is a short-range communication system that is applied specifically in the field of transportation. It can be used for identification and location of vehicles. The concept of the Bus Information Service (BIS) system using DSRC is proposed in this paper, and the system architecture, patterns of operation, and information service available are discussed. The establishment of this system will provide an open platform for public transportation management, and offer a practical information service for both travelers and bus dispatching companies.

Communications device, address modification device, communications method and communications control program

Abstract: On receipt of communications data from a client with an address modified by the relay device, the source address modification unit of a server (communications device) modifies the source address of data in response to the communications data to the source address registered in a source address modification database. Thus, response data can be directly transmitted to the client without going through the relay device and a communications route can be shortened accordingly.

Providing network service information in a system including wide- and narrow-area wireless communication systems

Abstract: The present invention provides a network service information providing system which allows users to readily know a location and radio transmission parameters for connecting to a narrow-area wireless communications system in a system which contains a mixture of wide-area wireless communications systems and narrow-area wireless communications systems and to set up a new narrow-area wireless communications system which can provide higher communications services without causing degradation in existing communications services in the environment where different wireless communications systems coexist. The user knows his/her own location through a wide-area wireless communications system and sends the location of a narrow-area wireless communications system which he/she wants to connect to, wireless transmission parameters, and other requirements to a wireless area information server. The wireless area information server possesses wireless transmission parameters of narrow-area wireless communications systems and the locations of base stations which provide narrow-area wireless communications services. Upon receiving the requirements from the user, the wireless area information server informs the user of the service area of the narrow-area wireless communications system nearest to the user via the wide-area wireless communications system.

Roadside radio communication system

Abstract: PROBLEM TO BE SOLVED: To provide a road side radio communication system solving problems of unnecessary radio wave generated by reflecting the radio wave irradiated from an antenna of a roadside radio device to adjacent buildings, installations, road surfaces, and ceilings and erroneous communication of an on-vehicle device outside a prescribed communication range in road-vehicle communications of DSRC(dedicated short range communications) system. SOLUTION: The road side radio device 68 of the DSRC system including an antenna 23 for forming a new erroneous communication preventing electric field 24 covering over an unnecessary radio wave region 26 leaking the unnecessary radio wave by using a feature that the on-vehicle device 28 of the DSRC system does not communicate with radio waves of different frequency channels and radio waves of the same frequency channel with the strength of the synchronized radio wave or less as long as the electric field strength in an electric field range already establishing synchronization is stabilized at a sufficient strength for holding synchronization.

Base station communication equipment, mobile station communication equipment and communication equipment between vehicles on road

Abstract: PROBLEM TO BE SOLVED: To provide communication equipment between vehicles on a road which has high transmission efficiency by selecting an optimum transmitting speed and an optimum modulation method while following the large temporal change of the communication environment of a mobile station in a dedicated short range communication (DSRC) system. SOLUTION: This communication equipment between vehicles on a road (base station communication equipment 11, mobile station communication equipment) measures a radio wave propagation situation and changes modulation and demodulation systems and signal transmitting speeds on the basis of measurement results even during communication. This enables the communication equipment between vehicles on the road with high transmission efficiency to select an optimum transmitting speed and an optimum modulation method while following the large temporal of change the communication environment of the mobile station. COPYRIGHT: (C)2004,JPO

Toll collection apparatus using dedicated short range communication

Abstract: PURPOSE: An electronic toll calculation(ETC) system using DSRC(Dedicated Short Range Communication) is provided, to allow the toll of a car passing through a toll road to be collected automatically without stopping the car. CONSTITUTION: The electronic toll calculation system comprises a car sensor(130) for sensing the kind of entering cars; first and second DSRC base stations(120, 150) for communicating with an ETC terminal equipped in the entering car when the car enters; a central processor(190) which stores the information comprising the user's identification number, the car information, the remainder and the kind of a car received from the first DSRC base station into an internal memory device, calculates the toll from the user's identification number received from the second DSRC base station and collects the toll; and guide displayers(110, 140) for displaying the remainder and whether or not the card is out of order when a car enters.

Novel BER improvement method for OFDM simulcast road vehicle communication system

Abstract: When road to vehicle communication (RVC) is applied to an intelligent transport system (ITS), we sometimes need a larger or more complicated shaped radio zone than the usual dedicated short range communication (DSRC) system. One solution for extending the zone is to place another transmitter that sends the identical data to the original one. The OFDM capability of combining a number of delayed signals from each transmitter enables to adopt the same carrier frequency for every transmitter. However, in the overlap of two radio zones in such a single frequency system, the received power at a vehicle could drop sharply due to the interference of direct waves resulting in the occurrence of severe transmission errors. We propose a technique to control the constellation of each subcarrier to avoid this problem. We show, by computer simulations, that this technique is effective.

Impact of Security/AAA on Intelligent Transport Systems

Abstract: On-demand type DSRC (Dedicated Short Range Communication) system is one of the future target RVC (Road-to-Vehicle Communication) system in ITS (Intelligent Transport Systems). This paper investigates the permissible range of contents download volume focusing on the duration time of vehicle passage thought a spot and the download time of contents in addition to authentication process time. It is clarified that the most priority technical issue is the realization of the real-time characteristics in the On-demand type DSRC system.

5.8 An Automatic Customs Gate System by the AVI/AEIAutomatic Vehicle Identification/Automatic Equipment Identification Using the Active DSRCDedicated Short Range System of 5.8 GHz

Abstract: PURPOSE: A gate management system for identifying a vehicle and a cargo by using a DSRC(Dedicated Short-Range Communications) network is provided to manage automatically a gate by tracking a position of a vehicle and a position of a cargo. CONSTITUTION: A vehicle terminal(100) is formed with a card input portion(104) for reading information of a driver and a license number of a vehicle from a smart card(102), an antenna for receiving radio signals from a wireless communication device(290), and a screen(103) for displaying stop position information within a container terminal. The wireless communication device(290) is connected with a gate fixing device(200). The gate fixing device(200) is located between the wireless communication device(290) and a main computer(300) of a management center. The gate fixing device(200) extracts vehicle information from the wireless communication device(290), transmits the vehicle information to the main computer of the parking lot management center(300), and converts the stop position information received from the main computer.

Wireless communication operation apparatus for dedicated short range communication system

Abstract: PURPOSE: A system for operating a radio communication network in a DSRC(Dedicated Short Range Communication) system is provided to connect between a DSRC base station and a server by wireless using a mobile communication network. CONSTITUTION: A system for operating a radio communication network in a DSRC system consists of a mobile terminal(120), a DSRC server(170), a base station(130), a base station controller(140), a mobile switching center(150), and a heterogeneous network access part(160). The mobile terminal(120) is installed in a DSRC base station(110) in order to execute short range communication with a vehicle terminal. The DSRC server(170) collects and analyzes the transmission information of the DSRC base station(110) and transmits this analyzed information to the DSRC base station(110). The base station(130) is for wireless communication with the mobile terminal(120). The base station controller(140) controls data transmission and reception with the base station(130). The mobile switching center(150) controls data transmission and reception with the base station controller(140). The heterogeneous network access part(160) executes data format conversion for data transmission and reception between the mobile switching center(150) and the DSRC server(170).

Wireless electronic toll collection system

Abstract: PURPOSE: A wireless automatic electronic toll collection(ETC) system using DSRC(Dedicated Short Range Communication) is provided, to allow the building of the ETC system to be constructed easily, to reduce the management cost of a parking lot and to improve the convenience of usage of a parking lot. CONSTITUTION: The wireless automatic ETC system comprises an ETC terminal; a first DSRC base station(101); a sensor for sensing the kind of entering cars(102); a first driver guide display(104); a central process server(111); a second driver guide display(112); a passing car sensor(103); a second DSRC base station(113); an apparatus for disclosing the illegal cars; a crossing gate(115); and an applicant client(121). The ETC system comprises a first pico net for transmitting the information for collecting toll by bluetooth protocol; a second pico net for controlling the display of toll information and the picture-taking by bluetooth protocol; a third pico net(120) for receiving and transmitting the system application information by bluetooth protocol; and a toll calculation server(12) which is connected with the second and third pico nets.

Dedicated short range communication (dsrc) for advanced cruise-assist highway systems (ahs)

Abstract: The road to vehicle communication (RVC) system used with Advanced Cruise-Assist Highway Systems (AHS) is known as Dedicated Short Range Communication (DSRC), which is a domestic standard specification developed for intelligent transport systems (ITS) in Japan. DSRC provides AHS with effective information services for the purpose of immediate driving assistance, and additionally provides a reference position for information services. AHS services require maintaining the strict safety of systems, and DSRC must also convey AHS information without fail to the vehicle. However, DSRC has erroneous data reception problems (reference position deviation, transmission of data to vehicles that are not service recipients, etc.) that are ascribable to radio wave propagation range. This paper will describe the overview of DSRC for use with AHS and the results of evaluation tests on DSRC problems, together with the countermeasures taken.