Abstract: A map information delivery system, including a navigation apparatus, is capable of preferentially receiving map updating information based on a host vehicle's state. The updating information may be preferentially received based on whether a destination has been set, a location of the updating information relative to an updating position or a destination, and/or the size of the updating information.

Abstract: In a communication system for downloading programs from a center to in-vehicle terminals, a center can check whether downloading has been completed normally or a program is operating normally in an in-vehicle terminal. According to the timing of activating a downloaded program, an in-vehicle terminal checks whether the program is activated to operate normally. The information is transmitted to the center. Based on the information, the center becomes aware of the fact that downloading has been completed without any problem and that the program is operating normally in the in-vehicle terminal.

Abstract: In a communication system for downloading programs from a center to in-vehicle terminals, a center can check whether downloading has been completed normally or a program is operating normally in an in-vehicle terminal. According to the timing of activating a downloaded program, an in-vehicle terminal checks whether the program is activated to operate normally. The information is transmitted to the center. Based on the information, the center becomes aware of the fact that downloading has been completed without any problem and that the program is operating normally in the in-vehicle terminal.

Abstract: In a communication system for downloading programs from a center to in-vehicle terminals, a center can check whether downloading has been completed normally or a program is operating normally in an in-vehicle terminal. According to the timing of activating a downloaded program, an in-vehicle terminal checks whether the program is activated to operate normally. The information is transmitted to the center. Based on the information, the center becomes aware of the fact that downloading has been completed without any problem and that the program is operating normally in the in-vehicle terminal.

Abstract: In a communication system for downloading programs from a center to in-vehicle terminals, a center can check whether downloading has been completed normally or a program is operating normally in an in-vehicle terminal. According to the timing of activating a downloaded program, an in-vehicle terminal checks whether the program is activated to operate normally. The information is transmitted to the center. Based on the information, the center becomes aware of the fact that downloading has been completed without any problem and that the program is operating normally in the in-vehicle terminal.

Abstract: A cache control method is provided which allows a cache state in a proxy server and a client use state to be synchronized and can improve a cache-efficiency regardless of time zones. A cache control method of a proxy server for relaying data between one or more clients connected to one communication network and a data server connected to the other communication network with a white list, includes the steps of determining whether or not a URL requested by a user of the client is registered in a white list, and processing data at the URL to be cached if the URL is registered in the white list.

Abstract: Branch-point image data has coordinates added thereto according to the distance from a branch point such as an intersection. When the vehicle is within a predetermined distance from a branch point on a suggested route, the coordinates of the present position of the vehicle and the coordinates added to the branch-point image data are compared to locate the present position on the image data, and a present-position mark is displayed superimposed on the branch-point image data. The displayed present-position mark moves according to the distance between the vehicle and the branch point.

Abstract: A route search location determining section (12d) of a mobile body (10) decides whether to conduct a route search at the mobile body (10) or to request the route search to an information center (30) based on various conditions such as priorities and how old the map data version is. In this manner, effective search can be conducted using two distinct route searching devices. Also, a current position calculating section (12a) can execute map matching by adding route data obtained from the information center (30) as a map matching candidate.

Abstract: In a communication system for downloading programs from a center to in-vehicle terminals, a center can check whether downloading has been completed normally or a program is operating normally in an in-vehicle terminal. According to the timing of activating a downloaded program, an in-vehicle terminal checks whether the program is activated to operate normally. The information is transmitted to the center. Based on the information, the center becomes aware of the fact that downloading has been completed without any problem and that the program is operating normally in the in-vehicle terminal.

Abstract: A remote navigation device and navigation system which can reduce communications costs by minimizing route guidance data transmitted to an in-vehicle navigation device is configured so that it can obtain guide area information specifying areas where guidance is not needed. When generating route guidance data to be transmitted to an in-vehicle navigation device, the remote navigation device removes the routes which pass through areas where route guidance is not needed, and generates route guidance data for just the other routes. By transmitting only such route guidance data to the in-vehicle navigation device, the amount of transmitted data can be reduced.

Abstract: In a communication system for downloading programs from a center to in-vehicle terminals, a center can check whether downloading has been completed normally or a program is operating normally in an in-vehicle terminal. According to the timing of activating a downloaded program, an in-vehicle terminal checks whether the program is activated to operate normally. The information is transmitted to the center. Based on the information, the center becomes aware of the fact that downloading has been completed without any problem and that the program is operating normally in the in-vehicle terminal.

Abstract: In a communication system for downloading programs from a center to in-vehicle terminals, a center can check whether downloading has been completed normally or a program is operating normally in an in-vehicle terminal. According to the timing of activating a downloaded program, an in-vehicle terminal checks whether the program is activated to operate normally. The information is transmitted to the center. Based on the information, the center becomes aware of the fact that downloading has been completed without any problem and that the program is operating normally in the in-vehicle terminal.

Abstract: A generation section for root guide information 25 retrieves a plurality of information elements from an information data storage section 23 and creates root guide information. Then, a generation part for guide information data blocks 26 reorganizes the root information into a plurality of guide information data blocks including at least one information element from the root guide information. The guide information data blocks generated through reorganizing are sequentially transmitted from a radio communication unit 27 to an in-vehicle device 30. When it becomes impossible to execute route guidance using one type of guide information because of a breakdown in communication or the like, route guidance can still be executed by using guide information already received.

Abstract: In a communication system for downloading programs from a center to in-vehicle terminals, a center can check whether downloading has been completed normally or a program is operating normally in an in-vehicle terminal. According to the timing of activating a downloaded program, an in-vehicle terminal checks whether the program is activated to operate normally. The information is transmitted to the center. Based on the information, the center becomes aware of the fact that downloading has been completed without any problem and that the program is operating normally in the in-vehicle terminal.

Abstract: In a communication system for downloading programs from a center to in-vehicle terminals, a center can check whether downloading has been completed normally or a program is operating normally in an in-vehicle terminal. According to the timing of activating a downloaded program, an in-vehicle terminal checks whether the program is activated to operate normally. The information is transmitted to the center. Based on the information, the center becomes aware of the fact that downloading has been completed without any problem and that the program is operating normally in the in-vehicle terminal.

Abstract: A device searches for an optimum route by estimating traffic information of a link whose traffic information cannot be obtained based on information from another link. Traffic information, such as a degree of congestion of link and a travelling time of link, is obtained by means of a transceiver, a FM antenna, and a receiver, and the optimum route is searched by an ECU for navigation. When there is a second link whose traffic information can not be obtained among links for searching routes, weighting of traffic information of a first link is performed according to a directional difference and a degree of separation (time or distance) between the first link and the second link, and then traffic information of the second link is estimated based on the traffic information weighted. The ECU for navigation searches the optimum route to destination using the traffic information estimated and displays it on a display.

Abstract: An electronic air-fuel mixture control system is adapted to an internal combustion engine to determine an optimum air-fuel ratio in dependence upon renewal of a plurality of learning values related to a plurality of load regions of the engine. The control system is arranged to conduct simultaneous learning of the learning values at a frequency in accordance with lapse of time and to conduct selective learning of the learning values in accordance with change of the load acting on the engine.

Abstract: An electronic air-fuel mixture control system is adapted to an internal combustion engine to determine an optimum air-fuel ratio in dependence upon renewal of plural learning values related to a plurality of load regions of the engine. The control system is arranged to select one of the learning values in accordance with the engine load and to prohibit learning of the selected learning value when a difference between the selected learning value and the adjacent learning value is more than an allowable value determined in consideration with allowable fluctuation of the air-fuel ratio caused by change of the amount of air flowing into the engine.