Communication route guidance system
First Claim
1. A communication route guidance system wherein an information center transmits route information to a mobile unit for guiding said mobile unit from its current position to a destination, in response to a request from said mobile unit,said information center comprising:
- first communication means for transmitting and receiving data to and from said mobile unit;
first memory means for storing first road data;
first route search means for searching said stored first road data to obtain first route guidance data for guiding said mobile unit from said current position to said destination, each time said information center receives said request from said mobile unit, said current position and said destination being transmitted from said mobile unit through said first communication means; and
data dividing means for dividing said first route guidance data into a plurality of data segments, each data segment being usable in said mobile unit as an independent item of route information providing guidance from a near end of a route segment corresponding to a data segment to the opposite, remote end of the route segment; and
said mobile unit comprising;
second communication means for transmitting and receiving data to and from said information center;
second memory means for storing second road data;
second route search means for searching said second road data to obtain second route guidance data for guiding said mobile unit from said current position to said destination;
third memory means for storing at least one data segment transmitted from said information center through said first and second communication means;
sensor means for detecting whether data communication with said information center through said first and second communication means is available; and
route guidance means for guiding said mobile unit to said destination in accordance with at least one of said second route guidance data and said at least one data segment stored in said third memory means, said route guidance means guiding said mobile unit to said destination in accordance with said second route guidance data when said sensor means detects that data communication between said mobile unit and said information center is not available.
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Accused Products
Abstract
A communication route guidance system provides exchange of data between an information center and each of a plurality of mobile units such as vehicles. The information center has the latest road data and searches it to prepare recommended route guidance data in response to a request from the mobile unit. The reccommended route guidance data is divided into a plurality of data segments, each usable as an independent guidance instruction in the mobile unit. The mobile unit has stored therein road data similar to the road data in the information center and determines if data communication with the information center is available. In a case where the mobile unit can not communicate with the information center, the mobile unit prepares route guidance based on the road data stored in the mobile unit. It thereby becomes possible to guide the user even in the case that the mobile unit can not communicate with the information center. Even in a case where a communication link is disrupted during transmission of route guidance data to the mobile unit, the mobile unit can effectively prepare whole route guidance data in combination with already-received route guidance data and additionally prepared route guidance data by reference to the road data stored in the mobile unit because the already received route guidance data is structured to be usable independently.
132 Citations
22 Claims
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1. A communication route guidance system wherein an information center transmits route information to a mobile unit for guiding said mobile unit from its current position to a destination, in response to a request from said mobile unit,
said information center comprising: -
first communication means for transmitting and receiving data to and from said mobile unit;
first memory means for storing first road data;
first route search means for searching said stored first road data to obtain first route guidance data for guiding said mobile unit from said current position to said destination, each time said information center receives said request from said mobile unit, said current position and said destination being transmitted from said mobile unit through said first communication means; and
data dividing means for dividing said first route guidance data into a plurality of data segments, each data segment being usable in said mobile unit as an independent item of route information providing guidance from a near end of a route segment corresponding to a data segment to the opposite, remote end of the route segment; and
said mobile unit comprising;
second communication means for transmitting and receiving data to and from said information center;
second memory means for storing second road data;
second route search means for searching said second road data to obtain second route guidance data for guiding said mobile unit from said current position to said destination;
third memory means for storing at least one data segment transmitted from said information center through said first and second communication means;
sensor means for detecting whether data communication with said information center through said first and second communication means is available; and
route guidance means for guiding said mobile unit to said destination in accordance with at least one of said second route guidance data and said at least one data segment stored in said third memory means, said route guidance means guiding said mobile unit to said destination in accordance with said second route guidance data when said sensor means detects that data communication between said mobile unit and said information center is not available. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A communication route guidance system wherein an information center transmits route information to a mobile unit for guiding said mobile unit from its current position to a destination, in response to a request from said mobile unit, said information center comprising:
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first communication means for receiving said current position and said destination from said mobile unit and for transmitting data to said mobile unit;
first memory means for storing road data;
route search means for searching said stored road data to obtain route guidance data for guiding said mobile unit from said current position to said destination;
data dividing means for dividing said route guidance data into a plurality of data segments, each data segment being usable in said mobile unit as an independent item of route information providing guidance for said mobile unit from a near end of a route segment corresponding to the data segment to the opposite, remote end of the route segment;
communication area data memory means for storing data identifying, as communication areas, areas in which said mobile unit is able to communicate with said information center through said first communication means; and
transmission route length determining means for determining number of segments in a continuous series of said data segments to be transmitted in a single continuous transmission to said mobile unit, so as to locate a remote end of said continuous series of data segments within one of said communication areas;
said mobile unit comprising;
second communication means for transmitting said current position and said destination to said information center and for receiving said data segments from said information center;
second memory means for storing the received data segments; and
route guidance means for guiding said mobile unit to said destination in accordance with said data segments stored in said second memory means. - View Dependent Claims (8, 9, 10, 11)
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12. A communication route guidance system wherein an information center transmits route information to a mobile unit for guiding said mobile unit from its current position to a destination, in response to a request from said mobile unit,
said information center comprising: -
first communication means for transmitting and receiving data to and from said mobile unit;
first memory means for storing first road data;
first route search means for searching said first road data to obtain first route guidance data for guiding said mobile unit from said current position to said destination, said current position and said destination being transmitted from said mobile unit through said first communication means;
data dividing means for dividing said first route guidance data into a plurality of data segments, each data segment being usable in said mobile unit as an independent item of route information for guiding said mobile unit from one end of a route segment corresponding to the route segment to the other end thereof; and
said mobile unit comprising;
second communication means for transmitting and receiving data to and from said information center;
second memory means for storing second road data;
second route search means for searching said second road data to obtain second route guidance data for guiding said mobile unit from said current position to said destination;
third memory means for storing at least one of said data segments transmitted from said information center through said first and second communication means;
route guidance means for guiding said mobile unit to said destination along a guide route defined by at least one of said second route guidance data and said data segments stored in said third memory means;
first sensor means for detecting whether data communication is available with said information center through said first and second communication means; and
second sensor means for detecting that said mobile unit has strayed from said guide route;
wherein said second route search means conducts a route search, responsive to both detection by said second sensor means that said mobile unit has strayed from said guide route and detection by said first sensor means that data communication between said mobile unit and said information center is unavailable, to obtain restoration route guidance data for guiding said mobile unit to return to said guide route along which said mobile unit had been guided by said route guidance means before said detection by said second sensor means that said mobile unit has strayed from said guide route. - View Dependent Claims (13, 14, 15, 16)
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17. A communication route guidance system wherein an information center transmits route information to a mobile unit for guiding said mobile unit from its current position to a destination, in response to a request from said mobile unit,
said information center comprising: -
first memory means for storing first location data capable of specifying a location by input of at least one of telephone number and address thereof; and
first route search means for searching said first location data to obtain first route guidance data for guiding said mobile unit from said current position;
said mobile unit comprising;
input means for inputting at least one of a telephone number and address for said destination, as destination information;
communication means for transmitting said current position and said destination information to said information center and receiving said first route guidance data from said information center;
second memory means for storing second location data capable of specifying a location by designation of said destination information;
sensor means for detecting whether data communication with said information center is available through said communication means;
second route search means for searching said second location data to obtain second route guidance data for guiding said mobile unit from said current position to said destination, when said sensor means detects that said information input by said input means can not be transmitted to said information center; and
route guidance means for guiding said mobile unit to said destination in accordance with at least one of said first and second route guidance data. - View Dependent Claims (18, 19, 20, 21, 22)
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Specification