Transmission of geographic information to mobile devices

• US 6,526,284 B1
• Filed: 02/22/2000
• Issued: 02/25/2003
• Est. Priority Date: 11/10/1999
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Stanford-Clark, Andrew James, Sharp, Christopher Edward
• Primary Examiner(s): Nguyen, Lee
• Application Number:
  US09/510,623
• Time in Patent Office: 1,099 Days
• Field of Search: 455/456, 455/457, 342/450, 342/457, 701/208, 701/209, 701/211, 701/212, 340/990, 340/995, 340/998
• US Class Current: 455/456.6
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G08G 1/0969 having a display in the form of a map

Abstract

Provided is a data transmission method, a communications network, a mobile receiving device and data processing methods for use in broadcast of geographic information to mobile devices. The invention overcomes the problem of lack of currency of static information distribution via CD-ROM, and the problem of the cost of lengthy connections to the Internet which is a requirement of some dynamic solutions. The geographic data which is relevant to a transmitter in the network is broadcast by the transmitter as a plurality of separate data elements which each relate to and include an identification of a specific map segment of a segmented map, such that the data elements can be transmitted independently of each other and the map segment identifier can be used by the receiving device to position the geographic information of each data element within the appropriate map segment. Each data element is retransmitted periodically such that gaps can be filled in and the map can be built up over time even if transmission failures occur during a transmission.

Claims

1. A method of distribution of geographic information to mobile devices via a wireless communications network, the method including:

generating a plurality of data elements comprising containing the geographic information, each data element relating to and including an identifier of a specific single segment of a segmented map, wherein the plurality of data elements comprise a first set of data elements providing low level of detail (LLoD) geographic information and one or more additional sets of data elements providing high level of detail (HLoD) geographic information; and

broadcasting the data elements via the wireless communications network for receipt by the mobile devices, wherein the first set of data elements is broadcast via a first transmission channel and the additional sets of data elements are broadcast via one or more transmission channels separate from the first; and

wherein broadcast of each of the LLoD data elements is repeated more frequently than broadcast of each of the HLoD data elements.

2. A method according to claim 1, wherein said generation of a plurality of data elements comprises accessing geographic information within a database, separating the geographic information into data components which are each related to a single segment of a map, in accordance with a defined map segmentation, and combining one or more of the data components related to a specific map segment with the map identifier of the specific map segment to create a data element.

3. A method according to claim 1, wherein the plurality of data elements are broadcast in a sequence which is repeated periodically.

4. A method according to claim 1, wherein the LLoD data elements have a smaller size than the HLoD data elements.

5. A method according to claim 1, wherein the LLoD data elements contain information relating to respective map segments of a first size and the HLoD data elements contain information relating to map segments of a different size.

6. A method according to claim 1, wherein the data elements are broadcast via a plurality of separate communication channels and information identifying the plurality of separate channels is broadcast via a directory channel.

7. A method according to claim 1, wherein at least some of said data elements include a map segment identifier and a plurality of mutually independent data components.

8. A method according to claim 7 wherein said data elements including a plurality of independent data components include said map segment identifier at both the beginning and end of the data element.

9. A method according to claim 1, including transmitting data elements from a central server computer to a plurality of remote computers and then broadcasting the data elements via a wireless link for receipt by mobile devices local to a respective wireless transmitter, wherein the data broadcast via the wireless link comprises only information which is relevant to the location area of the respective wireless transmitter.

10. A wireless data communications network for transmission of geographic information from a first data processing system to mobile devices, the network comprising:

the first data processing system including means for generating a plurality of data elements to comprise contain the geographic information, each data element relating to and including an identifier of a specific single segment of a segmented map, wherein the plurality of data elements comprise a first set of data elements providing low level of detail (LLoD) geographic information and one or more additional sets of data elements providing high level of detail (HLoD) geographic information and means for distributing the data elements via the network to a plurality of geographically distributed transmitters; and

a plurality of transmitters for broadcasting the data elements via wireless communications for receipt by the mobile devices, wherein the first set of data elements is broadcast via a first transmission channel and the additional sets of data elements are broadcast via one or more transmission channels separate from the first; and

wherein broadcast of each of the LLoD data elements is repeated more frequently than broadcast of each of the HLoD data elements.

11. A wireless data communications network for transmission of geographic information from a first data processing system to mobile devices, the network comprising:

the first data processing system including means for generating a plurality of data elements to contain the geographic information, each data element relating to and including an identifier of a specific single segment of a segmented map, and means for distributing the data elements via the network to a plurality of geographically distributed transmitters; and

a plurality of transmitters for broadcasting the data elements via wireless communications for receipt by the mobile devices;

wherein the first data processing system includes;

a data processing component for separating input geographic information into data components which are each related to a single segment of a map, in accordance with a defined map segmentation, wherein the plurality of data elements comprise a first set of data elements providing a low level of detail (LLoD) geographic information and one or more additional sets of data elements providing a high level of detail (HLoD) geographic information and for combining one or more of the data components related to a specific map segment with an identifier of the specific map segment to create a data element;

wherein the plurality of transmitters broadcast the first set of data elements via a first transmission channel and broadcast the additional sets of data elements via one or more transmission channels separate from the first, the plurality of transmitters broadcasting the first set of data elements more frequently than the additional sets of data elements.

12. A data communication and data processing device including:

a receiver for receiving wireless broadcast transmissions including receiving data elements which each include geographic information related to a specific single segment of a segmented map and each include an identifier of said map segment, the receiver being capable of receiving data elements via a plurality of different communication channels;

a memory for storing a representation of the segmented map;

a processing component implementing functions to process the map segment identifier of a received data element to determine which segment of a map the geographic information included in the data element relates to, and for adding the geographic information of the data element to the respective segment of the segmented map representation within the device and for determining for which map segments one or more broadcast data elements have not been received and for controlling the operation of the receiver to receive on the communication channel or channels relevant to the broadcast data elements which have not been received in priority to other communication channels.

13. A device according to claim 12, wherein the functions implemented by the processing component provide the capability to process a plurality of received data elements which may be received in any order, and to add the geographic information of the received data elements to the respective segments of the segmented map representation to build up a map over time.

14. A device according to claim 13 including a display device for displaying a map representation including the received geographical information, wherein the processing component implements functions for determining for which map segments one or more broadcast data elements have not been received, and for controlling the display device to display said segments for which broadcast data elements have not been received with a visual emphasis which is different from other map segments.