WO2003001470A1

WO2003001470A1 - Method and system for cartographic information

Info

Publication number: WO2003001470A1
Application number: PCT/FR2002/002196
Authority: WO
Inventors: Thierry Imbert
Original assignee: Ismap
Priority date: 2001-06-25
Filing date: 2002-06-25
Publication date: 2003-01-03
Also published as: FR2826487A1; FR2826487B1

Abstract

The invention relates to a method and a system for cartographic information, comprising at least one server and several mobile radio-communication units. Said server comprises a cartographic database for recording all vectorial grid units and a memory for recording the non-cartographic information. The mobile terminals comprise a memory for recording a sub-set of vectorial grid units and calculation means for the rendition and the manipulation of the geographical map, characterised in that the server also comprises means for receiving and recording geo-localised information, transmitted by a mobile radio communication unit, whereby said mobile radio-communication unit records the geo-localised information locally.

Description

CARTOGRAPHIC INFORMATION METHOD AND SYSTEM

The present invention relates to the field of geographic information systems, and more particularly systems comprising a geographic data server and mobile equipment connected via a network, for example telephone or Internet.

The general principle of such systems is known. Particular embodiments are also known, such as that described in PCT patent WO01 / 28270. This patent describes a system comprising mobile stations each equipped with a means of geographic location. The graphic data is supplied by a server via a communication network, according to the location information acquired by the mobile equipment.

The mobile equipment also comprises storage means for storing geographic related basic data and means for displaying geographic data such as a map. PCT patent WO101370 describes another wireless communication system making it possible to generate cartographic information in a cartographic service and to transmit it to a mobile client. The card is gradually built up on a display unit according to the customer's geographic position and his movement. After a single call to the service server, a map representing an entire geographic area is transmitted in a data stream in the form of small separate map segments. The client decondenses the data stream in real time, extracts the map segments and displays them on the display unit as it receives them. The map database sorts the map segments in a specific order based on the order in which the map segments are to be displayed on the client window. Sorting is based on: customer position, customer movement (direction and speed), and the time (RTT) of a card's transmission.

These different solutions are fixed, insofar as the mobile equipment is passive with regard to the cartographic information delivered by the server.

They do not make it possible to personalize the cartographic information displayed on the mobile equipment according to a user or a community of users. All users of the prior art information systems will receive the same geographic information.

The object of the present invention is to remedy this drawback by proposing an improved solution making it possible to personalize the geographic information, while exploiting a single cartographic or geographic server common to all the users.

To this end, the invention relates, in its most general sense, to a cartographic information system consisting of at least one server and a plurality of mobile radio communication equipment, the server comprising a cartographic database for recording the set of vector tiles and a memory for recording non-cartographic information data, mobile terminals comprising a memory for recording a subset of vector tiles and calculation means for rendering and manipulation of geographic maps, characterized in that the server further comprises means for receiving and recording geolocated information data transmitted by a mobile radiocommunication equipment, said mobile radiocommunication equipment recording the geolocated information data locally.

Advantageously, the memory of the server for recording the non-cartographic information data includes the identification of the community of belonging of the radiocommunication equipment having transmitted the information item under consideration.

According to a variant, the mobile radiocommunication equipment comprises means for establishing a session with the server consisting in identifying the equipment with the server, and means for transmitting to the server a file comprising the non-cartographic information data, the server comprising means for integrating into the memory of non-cartographic information data said information coming from said terminal, associated with the identifier of said terminal.

Advantageously, the server comprises means for selecting the non-cartographic information data as a function of the membership of the identifier of the terminal in a community of terminals.

The invention also relates to a method for communicating cartographic information and non-cartographic information between a server and radiocommunication terminals, characterized in that it comprises the transmission of non-cartographic information by a terminal to the server and recording on the server of said information.

Advantageously, the data transmitted by the terminal is formed by a file comprising a block containing a header determining the nature of said file, an offset block containing the reference coordinates.

The present invention will be better understood on reading the description of a nonlimiting exemplary embodiment. The system according to the exemplary embodiment described in what follows first comprises a geographic server, comprising a cartographic base in which the vector objects have been divided into 3 classes: - Surfaces (Polygons) - Linear - Points

Points, Linear and Surfaces are pre-classified from the most important (seen from afar) to the least important (seen from near). Similarly for the icon categories, the most important category must appear first. This will display the most important layers first.

Similarly, it is assumed that the display of linear objects will always be done over any surface object. The point objects will be displayed over the lines. Finally the icons will be above all the rest.

It is also important to pre-classify surface type objects by type (Sea under Ground, Ground under Forest, Forest under Lake, etc.).

Any other display order mixture or special case must be managed by the application itself.

The types of the different classes are not always the same (For example, the METRO type will be used only in the Point - Station - and Linear - Lines class.). The coordinates are stored in absolute WGS84, in the form of long integers (WGS * 10 ^Λ 6). Other coordinate systems are however possible.

All the offsets present in the file relate to the beginning of the file, not including the PDB header. This header is kept for Palm compatibility.

For this same reason, the data is aligned on 32Kb pages (No data is "straddling" on two pages).

Any data larger than 1 byte is stored in Motorola format (little endian) [trade name] for optimization on Palm [trade name].

File format

In this file format, the descriptive blocks are linked in a specific order: 1. PDB header, 2. IEVF header then

3. block of Offsets.

The following blocks being pointed from the offset block, their order does not matter. We must therefore not assume any order of sequence.

The encapsulation of the file in PDB is necessary to ensure compatibility with the PALM [trade name].

Other platforms may skip this header as it does not contain any relevant information.

To do this, read the long integer at offset 0x56 of the global file (Motorola format [commercial name]). This value represents the offset at the start of the IEVF data, relative to the start of the file. Thereafter, all offsets will be based on the start of the IEVF data.

The IEVF header is divided into 2 parts: A static part where each element will have the same place from one file to another, and a dynamic part where the data depends on the content of the static part.

Dynamic part

Complete chains:

1 byte: Chain length (not including terminal zero)

X byte: Characters

1 byte: 0, zero terminal

The header part ends here. If the next byte is not aligned to 4, the header will be followed by as many empty bytes as necessary to align.

The size of the header takes these alignment bytes into account, so that you can jump to the next block.

Offsets block The offset block allows you to point any entity in the file directly. Being dynamic itself, applications will have to calculate and keep references to the start of the offsets of a particular entity.

All offsets are long integers (4 Bytes)

Any offset with the value 0 means that the element is not available in the file. Word dictionary The word dictionary is a sequence of words compressed using the Huffman method. Although Huffman encoding is a series of bits, each word is aligned to a full byte. The dictionary can be spread over several 32K pages, but a word will never exceed one page. Lexicographic tree

The lexicographic tree is used to carry out research on PDAs. Its structure is relatively complex, and its usefulness remains confined to PDAs for the moment. Its detailed description will therefore be made later.

bitmaps

Bitmaps are used to store the different navigation bitmaps used on PALM and PocketPC as well as the images of icon categories. Structure:

Abbreviated Size Offset Data

0x0000 1 Type Type of bitmap:

0 = No type (used for icons)

1 = Zoom In

_' 2 = Zoom Out

3 = Arrow Up

at. Vector objects

Vector objects (and icons) have a common substructure for handling names in different languages. This structure will be referred to as the “multi-language chain”:

Points Objects

Linear objects

Objects Surfaces

b. Huffman trees

Huffman trees are not stored as a tree, but as a structure that allows the real tree to be reconstructed.

vs. icons

Cities / CPs are encoded with a special Huffman Tree, unique for all languages, and placed in a unique dictionary as well.

The different information of the Addresses is also encoded with a single Tree, independent of the language. Structure:

d. Knots e. Extra info

Extra info is organized into “chunks”. Each "chunk" is marked with a type and size. This allows the application to process the current chunk, or to ignore it and jump directly to the next one, ignoring its content.

Structure:

There is no type defined yet. To see as needed. Each type value defined must remain so for life, to avoid any interpretation error between old and new versions of maps or applications. Calculation of CRCs

The CRCs are each coded on 2 bytes, Motorola format.

The first Word represents the sum of all the Words in the IEVF file (Not including the PDB header). If the file size is odd, the last byte is ignored. The second Word represents the Exclusive Or of all the Words in the IEVF files, to which the first Word in Exclusive Or is also applied. This makes the two calculations independent, but the two CRCs united. Again, if the file size is odd, the last byte is ignored.

Attention: When checking the CRCs, the locations of the CRCs must be 0! Type of card and contact details

The "Type" byte of the header is composed as follows:

5 bits: Card type (City, country, lounge, etc.)

3 bits: Coordinate type (WGS84, Metric, etc.) The values of the card type are: 0: Slab

1: Country

2: Region

3: City

4: Living room (Intra-built) There remain 27 undefined values.

The values of the coordinate type are: 0: WGS84 * 10 ^Λ 6 There are 7 undefined values remaining.

Claims

1 - Cartographic information system consisting of at least one server and a plurality of mobile radio communications equipment, the server comprising a cartographic database for recording all the vector slabs and a memory for recording non-cartographic information data, the mobile terminals comprising a memory for recording a subset of vector slabs and calculation means for rendering and manipulating geographical maps, characterized in that the server also comprises means for receiving and recording geolocated information data transmitted by a mobile radiocommunication equipment, said mobile radiocommunication equipment recording the geolocated information data locally.

2 - Cartographic information system according to claim 1, characterized in that the server memory for recording non-cartographic information data includes the identification of the community of belonging of the radiocommunication equipment having transmitted the information given.

3 - cartographic information system according to claim 2, characterized in that the mobile radiocommunication equipment comprises means for establishing a session with the server consisting in identifying the equipment with the server, and means for transmitting a file to the server comprising the non-cartographic information data, the server comprising means for integrating into the memory of non-cartographic information data said information coming from said terminal, associated with the identifier of said terminal. 4 - Cartographic information system according to claim 2 or 3, characterized in that the server comprises means for selecting the non-cartographic information data as a function of the membership of the identifier of the terminal in a community of terminals.

5 - Method for communicating cartographic information and non-cartographic information between a server and radiocommunication terminals, characterized in that it comprises the transmission of non-cartographic information by a terminal to the server and of recording on the server said information.

6 - Communication method according to claim

5, characterized in that the data transmitted by the terminal are formed by a file comprising a block containing a header determining the nature of said file, and at least one offset block containing the reference coordinates.

7 - Communication method according to claim 5 or 6, characterized in that the transmitted data are organized to present a first PDB header block, a second IEVF header block, then at least one offset block, the blocks following being pointed from the offset block.

8 - Communication method according to claim 7, characterized in that the IEVF header block comprises a static part where each element will have the same place from one file to another, and a dynamic part where the data depends on the content of the static part.

9 - A communication method according to any one of the preceding claims 5 to 8, characterized in that the offset block includes at least one decompression shaft

Huffman for the dictionary of vector objects or the dictionary of icons or the dictionary of cities or keywords.

10 - A communication method according to claim 9, characterized in that the Huffman decompression tree is stored in the form of a tree reconstruction structure.

11 - A communication method according to any one of claims 5 to 10, characterized in that the vector objects have been divided into 3 classes, polygons, linear and points.

12 - A communication method according to claim 11, characterized in that the Points, Linear and Surfaces are pre-classified from the most important (seen from afar) to the least important (seen from near).

13 - A communication method according to claim 11, characterized in that for the categories of icons, the most important category must appear first.

14 - A communication method according to claim 11, characterized in that the display of linear objects is always done over any surface object and in that the point objects will be displayed over the linear, the icons being displayed above all else.

15 - Communication method according to claim 11, characterized in that the objects of type surfaces are classified by type (Sea under Ground, Ground under Forest, Forest under Lake, etc.).