Mobile unit information sharing system

• US 7,181,230 B2
• Filed: 12/16/2004
• Issued: 02/20/2007
• Est. Priority Date: 06/30/2004
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Maeda, Yoshiko, Nonoyama, Yasumasa
• Primary Examiner(s): Eng; George
• Assistant Examiner(s): DOAN, KIET M
• Application Number:
  US11/012,233
• Publication Number:
  US 20060003777A1
• Time in Patent Office: 796 Days
• Field of Search: 455/457, 455/456.1, 455/456.3, 342/357.08, 340988-996
• US Class Current: 455/457
• CPC Class Codes: G01S 5/0072 Transmission between mobile stations, e.g. anti-collision systems

Abstract

A mobile unit information sharing system with which it is possible by wireless communications and without providing a communications control station to share not only voice data but also position information of multiple mobile stations and business information such as images formed in the course of business and instructions and the like. A base station and multiple mobile stations each, by a time-sharing synchronous wireless modem device, acquire position information for themselves and time information via a GPS antenna and transmit their station position information via a wireless installation using a wireless frequency common to all the stations and with timing determined, on the basis of the acquired time information, so that their station position information does not collide with position information transmissions from other stations.

Claims

1. A mobile unit information sharing system including a base station and multiple mobile stations carrying out wireless communications, the base station and each of the mobile stations including:

a wireless installation for wireless communication among the base and mobile stations using a common wireless frequency;

a time-sharing synchronous wireless modem device for receiving self-position information of the respective station through a GPS antenna, transmitting the self-position information to the other stations via the wireless installation, and receiving position information of the other stations from the wireless installation; and

a position information display device for receiving self-position information and other station position information from the time-sharing synchronous wireless modem device and recording the position information received as shared data and displaying the position information on a map, wherein, the time-sharing synchronous wireless modem device comprises

a GPS receiver part for receiving self-position information through the GPS antenna,

a wireless modem part for modulating the self-position information received by the GPS receiver part to a data form used by the wireless installation and demodulating the other station position information received by the wireless installation from the data form used by the wireless installation, and

a first computing part for transmitting the self-position information received from the GPS receiver part and the other station position information demodulated by the wireless modem part to the position information display device and transmitting the self-position information to the other stations via the wireless installation with transmission timing determined so that communication collisions do not occur, each station sharing position information by transmitting and receiving position information to and from the other stations.

2. The mobile unit information sharing system according to claim 1, wherein the position information display device comprises a second computing part for receiving from the first computing part and recording as shared data the self-position information and the other station position information and controlling display of the positions of the stations on a map using map data and the shared data, and a display part for displaying the position information on a map under control of the second computing part.

3. The mobile unit information sharing system according to claim 1, wherein shortest transmission time and basic transmission period to be used in the transmission of the position information are set commonly in the time-sharing synchronous wireless modem devices of the base station and the mobile stations, and the first computing part transmits the self-position information with a transmission period based on the basic transmission period using communication time slot at time intervals having the shortest transmission time.

4. The mobile unit information sharing system according to claim 3, wherein the first computing part can vary the transmission period used in the transmission of the self-position information.

5. The mobile unit information sharing system according to claim 3, wherein, when transmitting high-volume data using the communication time slots, the position information display device divides the high-volume data into data divisions of a size that can be transmitted in the communication time slots, and the first computing part uses empty communication time slots not being used for the transmission of the position information to transmit the data divisions.

6. The mobile unit information sharing system according to claim 5, wherein, when among the high-volume data transmitted in divisions there is a data division that is not received normally by a receiving station, that receiving station uses an empty communication time slot to send to the transmitting station a request for re-transmission of the data division, and the first computing part of the transmitting station re-transmits the data division corresponding to the re-transmission request.

7. The mobile unit information sharing system according to claim 1, wherein the first computing part transmits an activity status of the station, appended to the self-position information.

8. The mobile unit information sharing system according to claim 7, wherein a receiving station receiving the activity status creates an activity history table for each mobile station.

9. The mobile unit information sharing system according to claim 1, wherein the position information display device comprises an input-output part having a user interface and through the first computing part transmits to the other stations object information including position and attribute obtained in the activity of the respective station and input through the input-output part, records the object information as the shared data, and displays symbol information expressing a corresponding object on a map.

10. The mobile unit information sharing system according to claim 9, wherein the object information input through the input-output part is linked to image data corresponding to the object and the object information linked with the image data is transmitted to other stations.

11. The mobile unit information sharing system according to claim 1, including a removable storage medium in the first computing part, wherein the shared data is held in the removable storage medium.

12. The mobile unit information sharing system according to claim 1, wherein the common wireless frequency is used for voice communications, and, when there is voice information to be transmitted to another station, the first computing part transmits the voice information with highest priority.

13. The mobile unit information sharing system according to claim 12, wherein the first computing part transmits the self-position information appended to a trailing end of the voice information.

14. The mobile unit information sharing system according to claim 12, wherein the first computing part encrypts the voice information.

15. The mobile unit information sharing system according to claim 12, wherein the wireless modem part includes switching means for selecting either an analog voice signal or a digital voice signal and, at a station transmitting voice information, the switching means is switched by an operator and, at a receiving station receiving voice information, analog voice signals and digital voice signals are automatically distinguished and the switching means accordingly switched in the wireless modem part.

16. The mobile unit information sharing system according to claim 1, wherein the first computing part encrypts the information to be transmitted and has a changing encryption key used in the encryption.

17. The mobile unit information sharing system according to claim 1, wherein the position information display device of the base station is connected by network to the position information display device of another base station, and, by exchanging of shared data between base stations, position information of the mobile stations is displayed by the position information display device of the other base station.

18. The mobile unit information sharing system according to claim 1, wherein when the first computing part transmits information, the first computing part designates a transmission destination, and the receiving stations choose information to confirm reception.