Mobile communication system having pagers for providing two-way data communication between a base station and mobile stations

• US 5,625,885 A
• Filed: 07/18/1994
• Issued: 04/29/1997
• Est. Priority Date: 12/15/1993
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Morita, Osamu, Nakazawa, Isao
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): Nguyen, Lee
• Application Number:
  US08/277,417
• Time in Patent Office: 1,016 Days
• Field of Search: 455/54.1, 455/32.1, 455/33.1, 455/33.3, 455/38.1, 455/38.3, 455/56.1, 455/161.1, 455/227, 455/25, 340/825.44, 340/824.47, 370/95.3, 379/59, 379/63
• US Class Current: 340/7.22
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like

Abstract

A mobile communication system has a base station and a plurality of mobile stations. When a mobile station detects a self station code, it transmits the self station code of the mobile station to the base station by using weak radio waves. The base station performs scanning, using its scanning antenna so as to change the directivity direction, catches the weak radio waves sent from the mobile station, and detects the mobile station code included in the reception signal. Thereby, a requester is told that the call of the mobile station has surely been made. By using the scanning antenna, a notification that the mobile station has surely received the call from the base station is reliably conveyed from the mobile station to the base station by using weak radio waves.

Claims

1. A mobile communication system having a base station and a plurality of mobile stations, comprising:

self station code detecting means, which is installed in each mobile station, for detecting transmission of a self station code from said base station;

self station code transmitting means, which is installed in said mobile station,transmitting the self station code to said base station when said self station code detecting means detects the transmission of the self station code from said base station;

a scanning antenna, which is installed on said base station, and has a directivity, for scanning directivity directions;

mobile station code detecting means, which is installed in said station, for detecting a mobile station code included in reception signals received by said scanning antenna;

an omnidirectional antenna, which is installed on said base station and has no directivity, for transmitting the transmission signal including the mobile station code to all directions;

answer back means, which is installed in said base station, for transmitting the mobile station code detected by said mobile station code detecting means and an answer back signal from said omnidirectional antenna when said mobile station code detecting means detects the mobile station code;

answer back receiving means, which is installed in said mobile station, for receiving the mobile station code for self station and the answer back signal from said answer back means of said base station;

repeatedly executing means, which is installed in said mobile station, for making said self station code transmitting means repeatedly execute the transmission of the self station code to said base station as long as said answer back signal receiving means does not receive the mobile station code and the answer back signal; and

stopping means, which is installed in said mobile station, for stopping the transmission of the self station code to said base station performed by said self station code transmission means by stopping an operation of said repeatedly executing means when said answer back receiving means receives the mobile station code for self station and the answer back signal.

2. A mobile communication system having a base station and a plurality of mobile stations, comprising:

self station code detecting means, which is installed in each mobile station for detecting transmission of a self station code from said base station;

self station code transmitting means, which is installed in said mobile station, for transmitting the self station code to said base station when said self station code detecting means detects the transmission of the self station code from said base station;

a scanning antenna which is installed on said base station, and has a directivity, for scanning directivity directions;

mobile station code detecting means, which is installed in said base station, for detecting a mobile station code included in reception signals received by said scanning antenna;

timing signal transmitting means, which is installed in said base station, for transmitting non-modulated timing signals from said scanning antenna for each of a plurality of divided directivity directions of said scanning antenna;

power value detecting means, which is installed in said mobile station, for receiving the timing signal sent from said timing signal transmitting means of said base station, and detecting power value of the received timing signal; and

transmission control means, which is installed in said mobile station, for operating said self code transmitting means in divided interval of directivity direction of said scanning antenna which transmits said timing signal when the power value detected by said power value detecting means is above a predetermined level.

3. A mobile communication system according to claim 2, further comprising code transmitting means which is installed in said base station, for transmitting, upon receipt of a request for a call of a predetermined mobile station, a code of said predetermined mobile station from an omnidirectional antenna by means of a carrier with the same frequency as that of a carrier of said timing signal in the period of time when said timing signal transmitting means does not transmit timing signals.

4. A mobile communication system having a base station and a plurality of mobile stations, comprising:

self station code detecting means which is installed in each mobile station, for detecting transmission of a self station code from said base station;

self station code transmitting means, which is installed in said mobile station for transmitting the self station code to said base station when said self station code detecting means detects the transmission of the self station code from said base station;

a scanning antenna which is installed on said base station, and has a directivity, for scanning directivity directions; and

mobile station code detecting means, which is installed in said base station, for detecting a mobile station code included in reception signals received by said scanning antenna;

timing word transmitting means, which is installed in said base station, for transmitting a modulated timing word from said scanning antenna for each of a plurality of divided directivity directions of said scanning antenna;

timing word detecting means, which is installed in said mobile station for detecting a timing word by receiving and demodulating the timing word transmitted from said timing word transmitting means of said base station;

transmission control means, which is installed in said mobile station operating, when said timing word detecting means detects a timing word, said self station code transmitting means in the divided time interval of the directivity direction of said scanning antenna which has transmitted said timing word; and

code transmitting means, which is installed in said base station, for transmitting, upon receipt of a request for call of a predetermined mobile station, a code of said predetermined mobile station from an omnidirectional antenna by modulating in the same modulation mode as that of said timing word in the period of time when said timing word transmitting means does not transmit timing words.

5. A mobile communication system having a base station and a plurality of mobile stations, comprising:

self station code detecting means, which is installed in each mobile station, for detecting transmission of a self station code from said base station;

self station code transmitting means, which is installed in said mobile station, for transmitting the self station code to said base station when said self station code detecting means detects the transmission of the self station code from said base station;

a scanning antenna, which is installed on said base station, and has a directivity, for scanning directivity directions; and

mobile station code detecting means, which is installed in said base station, for detecting a mobile station code included in reception signals received by said scanning antenna;

code transmitting means, which is installed in said base station, for transmitting, upon receipt of a request for a call of a predetermined mobile station, a code of said predetermined mobile station from an omnidirectional antenna;

self station code instant transmitting means, which is installed in said mobile station, for transmitting the self station code to said base station as soon as said mobile station receives the self station code transmitted from said base station; and

position detecting means, which is installed in said base station, for detecting the spatial position of said predetermined mobile station on the basis of the time when said code transmitting means transmits the code of said predetermined mobile station, the time when said base station receives the self station code sent from said self station code instant transmitting means of said mobile station, and the directivity direction which said scanning antenna faces when said mobile station code detecting means detects the mobile station code.

6. A mobile communication system having a plurality base station of the same configuration and a plurality of mobile stations, the system comprising:

self station code detecting means, which is installed in each mobile station, for detecting transmission of a self station code from said base station;

self station code transmitting means, which is installed in said mobile station, for transmitting the self station code to said base station when said self station code detecting means detects the transmission of the self station code from said base station;

a scanning antenna, which is installed on said base station, and has a directivity, for scanning directivity directions; and

mobile station code detecting means, which is installed in said base station, for detecting a mobile station code included in reception signals received by said scanning antenna;

a control center for controlling said plurality of base stations;

antenna code transmitting means, which is installed in a respective one of said base stations, for transmitting an antenna code specific to said scanning antenna from said scanning antenna;

antenna code storing means, which is installed in said mobile station, for receiving and storing the antenna code sent from said antenna code transmitting means of said respective base station;

new antenna code transmitting means, which is installed in said mobile station, for comparing the antenna code sent from said antenna code transmitting means of said respective base station with the antenna code stored in said antenna code storing means, and transmitting a new antenna code and the self station code to corresponding base station when the above two antenna codes are different; and

registering means, which is installed in said respective one of said base stations, for registering the new antenna code sent from said new antenna code transmitting means of said mobile station and the mobile station code in said control center as position information indicating the spatial position of said mobile station.

7. A mobile communication system according to claim 6, further comprising control means for controlling said plurality of base stations, which is installed in said control center, wherein said control means, upon receipt of a request for a call of a predetermined mobile station, determines a base station of a zone where said predetermined mobile station is located on the basis of the position information registered by said registering means, and executes the call of said predetermined mobile station by operating said determined base station.

8. A mobile communication system according to claim 7, further comprising:

a mobile station code transmitting scanning antenna, which is installed in said base station, and has a directivity, for scanning the directivity direction, and transmitting the code of a predetemined mobile station requested to call; and

synchronizing means, which is installed in said base station, for synchronizing the directivity direction of said scanning antenna with the directivity direction of said mobile station code transmitting scanning antenna.

9. A mobile communication system having a base station and a plurality of mobile stations, comprising:

self station code detecting means, which is installed in each mobile station, for detecting transmission of a self station code from said base station;

self station code transmitting means, which is installed in said mobile station, for transmitting the self station code to said base station when said self station code detecting means detects the transmission of the self station code from said base station;

a scanning antenna, which is installed on said base station, a directivity, for scanning directivity directions;

mobile station code detecting means, which is installed in said base station, for detecting a mobile station code included in reception signals received by said scanning antenna;

scanning antenna transmission control means, which is installed in said base station, for transmitting the mobile station code from said scanning antenna;

operation control means, which is installed in said base station, for operating said scanning antenna transmission control means for each of a plurality of divided directivity directions of said scanning antenna for the first half period of one unit scanning period of said scanning antenna; and

transmission control means, which is installed in said mobile station, for operating said self station code transmitting means for each of the plurality of divided directive directions of said scanning antenna for the second half period of said unit scanning period.