AU723224B2

AU723224B2 - Mobile communication system

Info

Publication number: AU723224B2
Application number: AU45141/97A
Authority: AU
Inventors: Tomoya Kaku
Original assignee: NEC Corp
Current assignee: Lenovo Innovations Ltd Hong Kong
Priority date: 1996-11-13
Filing date: 1997-11-12
Publication date: 2000-08-24
Anticipated expiration: 2017-11-12
Also published as: JP2970559B2; JPH10145864A; CA2220739A1; KR19980042512A; AU4514197A

Description

S F Ref: 399399

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

k Name and Address of Applicant: Actual Inventor(s): Address for Service: NEC Corporation 7-1, Shiba Minato-ku Tokyo

JAPAN

Tomoya Kaku Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Mobile Communication System Invention Title: The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845 0a -1- Mobile Communication System BACKGROUND OF THE INVENTION i. FIELD OF THE INVENTION The present invention relates to the inhibition or restriction of use of a mobile communication terminal, such as a pager (a selective call receiver), a portable radio device, a telephone or a cordless telephone, in a mobile communication system wherein radio communication is performed between a base station and such a mobile communication terminal.

2. DESCRIPTION OF THE PRIOR ART :I According to a mobile communication technique whereby radio communication is performed between a mobile communication terminal, such as a pager (a selective call receiver), a portable radio device, a telephone or a cordless telephone, and a base station that provides a communication service for such a mobile communication terminal, a conteeooe: roller for locking operations is provided for the mobile communication terminal, and a control signal can be transmitted from outside to the controller to inhibit or limit the use of the mobile communication terminal. "The restriction of the use" defines that only communication with a specific person a doctor in a hospital) is permitted.

Conventional techniques are disclosed in Japanese

A

-2- Unexamined Patent Publication Nos. Hei 7-245782, Hei 6- 326659 and Sho 64-29031 and Japanese Unexamined Utility Model Publication No. Hei 4-103055.

In Japanese Unexamined Patent Publication No. Hei 7- 245782 is described a mobile radio device that forcibly halts communication at a location where the use of a mobile radio device, such as a portable telephone, should be inhibited, and that changes the operation mode to one for a pager so that calls can be received without disturbing nearby people because of a communication over the telephone.

This mobile radio device will now be explained while referring to Fig. i.

The mobile radio device 71 comprises a pager module 72, S"a power controller 73 and a portable telephone module 74.

15 The power controller 73 includes a mode selective switch 73a, a CPU 73b and a power supply circuit 73c.

oo•• In a mobile radio device 71 in Fig. i, power generated by a power supply circuit 73c is supplied to a pager or to a portable telephone 74 by a switch in a power controller 73. The modes for which the pager 72 and the portable S"telephone 74 are activated are called a pager mode and a portable telephone mode, respectively. The power controller 73 is so set that it selects the portable telephone mode, and supplies power generated by the power supply circuit 73c to the portable telephone 74. As a result, the mobile radio 3 device 71 is set in the portable telephone mode and functions as a portable telephone. When, while waiting for a call, a user passes through a mode switch signal transmitter that is installed at a ticket gate in a station, etc., a mode select receiver 73a in the power controller 73 receives a mode select signal, and a CPU 73b changes the mode of the mobile radio receiver 71 to the pager mode, so that thereafter the mobile radio receiver 71 functions as a pager.

That is, the power generated by the power supply circuit 73c is supplied to the pager 72.

When a call from another user is received while in the pager mode, the caller is notified that the radio device is in the pager mode. Either when a mode select signal is received from the mode select signal transmitter 75 when the 15 user exits through a ticket gate of the station, or when a select switch provided for the key pad of the mobile radio device 71 is manipulated, the mode of the mobile radio device 71 can be changed from the pager mode to the portable telephone mode. Therefore, so long as the radio receiver 71 receives a mode select signal from the mode select trans- *oo mitter 75 when passing through a gate, the mobile radio receiver 71 can be switched from the portable telephone mode to the pager mode, or vice versa, without any action being required of a user.

In Japanese Unexamined Patent Publication No. Hei 6- 4 326659 is described a portable telephone that when lost prevents its unauthorized use and assists in its discovery.

The portable telephone comprises: locking means, for inhibiting various operations, such as calling, the reception of calls and the retrieval of memory; input means, for entering data to change the locked state; storage means, for storing the locked state; and control means, for controlling the various individual means. The thus arranged portable telephone can not only receive a telephone number for a regular call, but can also receive a sub-address that accompanies the telephone number, and can control various operations by using the sub-address. In addition, the portable telephone includes display and tone generation S1 means for employing the sub-address to provide various types of displays and to generate sounds. Actually, the lock information and a display are changed upon the receipt of the sub-address during a wait period for the portable telephone.

S"When the portable telephone is stolen or lost and is in the possession of a third party, the locking state is altered by using the sub-address, and the inhibition of the calling process and the reception of calls, and the inhibition of the changing and the retrieval of memory are performed to avoid unauthorized use of the telephone.

Further, a message to contact the owner is shown on the 5 display and an audible signal is produced by tone generation means to assist in the discovery of the portable telephone.

In Japanese Unexamined Patent Publication No. Sho 64- 29031 is provided a radio telephone system, wherein a master device (base station), which is connected to a cable line, is connected to a plurality of mobile radio communication terminals that control calls originated at an arbitrary mobile radio communication terminal.

In the radio telephone system, the master device defines passwords for individual terminals connected thereto by radio. To use the terminal, a user must input a specific password, and if the password does not match the password .oe.ei defined by the parent device, calling is inhibited.

In Japanese Unexamined Utility Model Publication No.

Hei 4-103055 is provided a portable telephone that comprises: a memory, for registering in advance a password that is used to set or release a locking mode for inhibiting all, or a part, of call and call reception operations; a comparator, oooo• S"for comparing a number input for this use with the password o i registered in the memory; a mode selector for setting and releasing the locking mode; and a controller for inhibiting all, or a part, of the call and the call reception operations when the locking mode is set.

This portable telephone can not transmit a call or receive a call so long as the password that is registered in 6 advance is not input, and thus prevents the unauthorized use by a third party.

According to the mobile radio communication technique, a base station performs a call transmission and reception process, a control process, such as the registration of a position, and a communication process for actual user data such as for example speech data relative to all the mobile radio communication terminals that are within a range of a signal emitted by the base station.

However, even when a location where the use of a mobile communication terminal should be limited falls within the range (the reception range) of the signal emitted by the S. base station, it is difficult to inhibit the transmission of a signal.

15 Example locations whereat the use of the mobile communication terminal should be limited are on trains, o.

where problems concerning user manners has arisen; in medical facilities, where there are many delicate medical ooomo S"devices, such as pacemakers, that may be erroneously operated by high frequency signals transmitted by a mobile communication terminal; and in prisons and in police station ooooo cells.

The above described shortcoming arises because the service range of a base station is broader than the range (the limited use range) wherein the use of a mobile communi- 7 cation terminal is to be limited so that the limited use range is situated within the service range.

Among the conventional techniques for limiting or inhibiting the use of a portable communication terminal, the techniques disclosed in Japanese Unexamined Patent Publication Nos. Hei 6-326659 and Sho 64-29031 and in Japanese Unexamined Utility Model Publication No. Hei 4-103055 limit or inhibit the use of the mobile communication terminal.

However, when a matching password is entered, when the inhibition imposed on the operation, or the locking of the operation is released, there is no means available by which to disable the operation.

In Japanese Unexamined Patent Publication No. Hei 7- 245782, when the mobile communication terminal is powered on 15 in the limited use range, it operates in the normal portable telephone mode.

SUMMARY OF THE INVENTION To overcome the above shortcoming, it is an object of the present invention to locally limit or inhibit the use, the transmission and reception of calls, of a mobile communication terminal, such as a pager (a selective calling system), a portable radio device, a telephone or a cordless telephone, in a mobile communication system that permits radio communication between the mobile communication terminal and a base station that supports a communication 8

L

15 f* service for the mobile communication terminal.

According to the present invention, across a radio channel that differs from a radio channel used by a base station, a control signal is transmitted to a mobile communication terminal to inhibit or limit its operation.

Upon receipt of the control signal, the mobile communication terminal inhibits or limits its own use. The radio channel is, for example, a frequency band in an FDMA (Frequency Division Multiple Access), a time slot in a TDMA (Time Division Multiple Access), or a spread code in a CDMA (Code Division Multiple Access).

More specifically, a mobile communication system 1 in Fig. 2 comprises: transmission means (a control signal transmitter 2 in Fig. for transmitting a control signal to a mobile communication terminal to inhibit or limit the use of the terminal; and a mobile communication terminal device (a mobile communication terminal 3 in Fig.2), which includes reception means (a receiver 3a in Fig. 2) for receiving a control signal, control means (a controller 3b in Fig. 2) for employing a received control signal to control the use of the mobile communication terminal, and display means (a display device 3c in Fig. 2) for notifying a user of the state of the control means by using a visual display or sound.

In the mobile communication system of the present 0* a* 9 15 4 a invention, across a radio channel that differs from the radio channel employed for a frequency used by a base station that provides a communication service, the transmitter transmits a control signal to the mobile communication terminal to inhibit or limit its operation. The mobile communication terminal, which has been powered on, first receives this control signal. When the operation of the mobile communication terminal has not yet been inhibited or limited even though the control signal has been detected, as in the conventional case, the receiver of the mobile communication terminal is adjusted to a radio channel of the base station that provides a communication service for the performance of transmission and reception.

As a result, the operation of the mobile communication terminal can be locally inhibited or limited even within the transmission range (the service range) of the signal from the base station that provides the communication service for the mobile communication terminal.

When the operation of the mobile communication terminal is halted upon the receipt of the control signal for the inhibition or the limiting of the operation, a user can be notified of the current state audibly or by a visual display.

An identification number is stored in advance in the transmitter and in the mobile communication terminal. When a a a a a control signal that includes the identification number of a specific mobile communication terminal is broadcast by the transmitter, the operation of the mobile communication terminal can be inhibited or limited, or can be restored.

In addition, since the transmitter can vary the power of a transmission signal, the range of a control signal for inhibiting or limiting the operation of a terminal can be changed.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is block diagram illustrating a conventional mobile radio device; Fig. 2 is a block diagram illustrating a mobile communication system according to a first embodiment of the present invention; 15 Fig. 3 is a block diagram illustrating a mobile communication system according to a second embodiment of the present invention; and Fig. 4 is a block diagram illustrating one arrangement of a control signal transmitter in the mobile communication ooooo system of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS o~ooo• The preferred embodiments of the present invention will now be described while referring to the accompanying drawings.

A specific mobile communication system (hereinafter 11 referred to as a "communication system") according to a first embodiment of the present invention will be described while referring to Fig. 2.

As is shown in Fig. 2, a communication system 1 comprises: a control signal generator 2, for generating and transmitting a control signal to a mobile communication terminal 3 to inhibit or limit its operation; and the mobile communication terminal 3 that includes a receiver 3a for receiving a control signal, a controller 3b for employing a received control signal to control the operation of the mobile communication terminal 3, and a display device 3c for notifying a user of the state of the controller 3b. The o communication service is provided for the communication ":'"system 1 by a base station 7.

15 The operations performed in this embodiment will now be explained in detail while referring to Fig. 2.

In Fig. 2, area A, which is enclosed by the broken line, represents the range of a signal emitted by the base station 7 that provides the communication service for the mobile communication terminal, the service area of the base station 7; and area B, which is enclosed by a chained eo o• line, represents the range (the reception enabled range) of a signal generated and transmitted by the control signal generator 2.

An explanation will now be given for the operation 12performed by the control signal generator 2 to inhibit the operation of the mobile communication terminal 3.

The control signal generator 2 transmits a control signal, the contents of which specify that the operation of the mobile communication terminal 3 is to be inhibited. At this time, radio channel Fb, which differs from radio channel Fa that is used by the base station 7, is employed for the transmission of the control signal.

When the mobile communication terminal 3 is powered on, first, the receiver 3a receives a control signal across the radio channel Fb. In this case, assume that the mobile communication terminal 3 is powered on at point c within the area B.

g Upon the receipt of the control signal from the control 15 signal generator 2, the receiver 3a outputs the received data to the controller 3b. Since the control signal ooaw generator 2 has transmitted a control signal that indicates the operation of the mobile communication terminal 3 is to be inhibited, the result obtained by the reception and detection is that "Operation is inhibited." In consonance with this result, the controller 3b halts the operation of .e *e the mobile communication terminal 3, and the display device 3c displays information to the effect that the operation at a current location is inhibited to inform a user of the status of the mobile communication terminal 3.

13 Following this, assume that the mobile communication terminal 3 is powered on at point d outside area B. In the same manner as in the previous case, the mobile communication terminal 3 is powered on and the receiver 3a receives a control signal across the radio channel Fb.

However, since point d is outside the area B of the control signal generator 2, the control signal from the control signal generator 2 is not received. Thus, the control signal is not detected, and the result "No control signal detected" is output to the controller 3b.

The controller 3b assumes that the mobile communication terminal 3 can be operated in the current area, and sets up s e the terminal 3 to receive a signal from the base station 7.

•15 Actually, however, the receiver 3b receives a signal from 15 the base station 7 across radio channel Fa, and thereafter, a normal communication (for example speaking) process is g~e* performed.

e C During the normal communication with the base station 6e S"7, the controller 3b exercises control of the mobile Cegee communication terminal 3 at constant predetermined intervals CeJ to receive any control signals that may be transmitted c0 O0 across radio channel Fb by the control signal generator 2.

Consider a case wherein the mobile communication terminal 3 is moved from point d to point c while the communication for speaking as example with the base station 14 0 0*O6 4*6.

6 15 6@ @6@

C

*66 7 is in progress. When the mobile communication terminal 3 is moved from point d to point c and is in area B, the mobile communication terminal 3 receives a control signal across radio channel Fb from the control signal generator 2.

Since the control signal generator 2 has generated and transmitted a control signal to inhibit the operation of the mobile communication terminal 3, the result obtained by the reception and detection is that "Operation is inhibited." In consonance with this result, the controller 3 halts the operation of the mobile communication terminal 3, and the display device 3c then displays a notice for the user to the effect that "Operation is halted because use is inhibited this location." A mobile communication system (hereinafter referred to as a "communication system") according to a second embodiment of the present invention will now be described while referring to Fig. 3.

A communication system 1 shown in Fig. 3 comprises: a control signal generator 2, which includes a memory device 8a for storing an identification number IDa that is determined in advance, and which transmits a control signal that includes the identification number IDa to a mobile communication terminal 3 to inhibit or limit its operation; and the mobile communication terminal 3, which includes a receiver 3a for receiving a control signal, a memory device 8b for 15 storing an identification number IDb that is determined in advance, a controller 3b that, to control the use of the mobile communication terminal 3, compares the identification number IDa that is included in a received control signal wth the identification number IDb stored in the memory device 8b, and a display device 3c for notifying a user of the state of the controller 3b. Furthermore, an explanation will be given for a case wherein a radio channel used for a control signal is a frequency band.

The operation in this embodiment will now be described in detail while referring to Fig. 3.

Area B, which is enclosed by a chained line, in Fig. 3 reresents the range (the reception range) of a signal emitted by the control signal generator 2. Area A, which is enclosed by the broken line, represents the range of a signal transmitted by the base station 7 that provides a cqmmunication service for the mobile communication terminal 3, the service range of the base station. Area B is 0.

considerably smaller than area A and is completely contained in area A. Point c is in area B (and also in area and point d is in area A but is outside area B.

00 Identification numbers IDa and IDb are respectively stored in the memory device 8a in the control signal generator 2 and in the memory device 8b in the mobile 25 communication terminal 3.

16 The control signal generator 2 transmits a control signal indicating that operation of mobile communication terminals other than a specific mobile communication terminal (in this case, a mobile communication terminal for which the identification number IDa is stored in the memory device 8a) is inhibited. That is, a control signal is transmitted that indicates the operation of a mobile communication terminal having an identification number other than IDa is inhibited. The frequency band used for transmission is Fd, which differs from the frequency band Fc used by the base station 7.

When the mobile communication terminal 3 is powered on, first the receiver 3a receives a control signal across the frequency band Fd. Consider a case where the mobile communication terminal 3 is powered on at point c in area B.

The receiver 3a receives a control signal from the control signal generator 2, and outputs the reception result to the controller 3b. It should be noted that the control signal generator 2 transmits a control signal for the inhibition of the operation of mobile communication termieeo0 9: *nals that have identification numbers other than IDa.

.9 9° The controller 3b compares the identification number S"IDa included in the control signal with the identification number IDb stored in the memory device 8b.

i• Assume that the identification number IDa included in 17 the control signal differs from the identification number IDb stored in the memory device 8b (IDa 0 IDb).

The controller 3b determines that "Operation of the mobile communication terminal 3 is inhibited." In accordance with the result, the controller 3b halts the operation of the mobile communication terminal 3. The display device 3c displays a message to the effect that "Operation of the mobile communication terminal 3 is inhibited at this location" to inform the user of this state.

Following this, when the identification number IDa included in the control signal matches the identification number IDb stored in the memory device 8b (IDa IDb), the controller 3c determines that "Operation is permitted." In accordance with this result, the controller 3c assumes the mobile communication terminal 3 is in an area where it can be used, and enables the reception by the mobile communicaoooee tion terminal 3 of signals from the base station 7.

Actually, the receiver 3a receives signals from the base station 7 across frequency band Fc. A normal communication (speaking) process is thereafter performed.

During the normal communication (speaking) with the base station 7, the controller 3b exercises control at constant predetermined intervals to receive any signals oooe• transmitted across a frequency band Fd. A control signal indicating "Operation is enabled" is consistently received oo..oi 18 in area B.

Assume a case where the mobile communication terminal 3 is shifted out of the area B while the communication (speaking) with the base station 7 is in progress, and enters a range (area C, which is enclosed by the chain double-dashed line) where the operation of the mobile communication terminal 3 is inhibited.

It should be noted that in area C a control signal generator 2' transmits a control signal granting operating permission only to a mobile communication terminal for which an identification number IDc is stored in the memory device 8c (IDc 0 IDb).

The mobile communication terminal 3 then receives a control signal across frequency band Fc from the control signal generator 2' Since the control signal generator 2' has transmitted o 3 a control signal granting operating permission only for a mobile communication terminal that has the identification number IDc, the receiver 3a of the mobile communication terminal 3 obtains the reception and detection result "Operation is inhibited." In accordance with this result, go the controller 3b halts the operation of the mobile communi- S"cation terminal 3, and the display device 3c displays the e ooo• message "Operation is halted because the use at this S.i 25 location is inhibited" to inform the user of the status of 9 19 the mobile communication terminal 3.

In the second embodiment, a frequency band different from that used by the base station has been employed for transmission of a control signal. But instead of the frequency band, a time slot or a spread code can be used.

Specifically, it is apparent that so long as there is a usable radio channel in addition to a radio channel that is used by the base station for normal communication, that radio channel can be used for transmission of a control signal concerning the operation of a mobile communication terminal.

Another arrangement for the control signal generator 2 is shown in Fig. 4.

The control signal generator 2 in Fig. 4 includes a variable transmission power output device 9 for varying a power value for transmission of a control signal, and a dial (level) 10 is provided outside the control signal generator 2 to operate the variable transmission power output device 9. A user manipulates the dial 10 to vary the power of a control signal that is output by the control signal generator 2.

With this arrangement, the range spanned by a control S"signal, the size of area B in Figs. 2 and 3, can be 4**SSS changed as desired.

25 Therefore, the range wherein the operation of the 5So555 20 mobile communication terminal 3 should be inhibited or limited can be changed.

According to the first effect obtained by the mobile communication system of the present invention, the control signal generator 2 transmits a control signal, which specifies that the operation of the mobile communication terminal 3 will be inhibited or limited, across the radio channel Fb, which differs from the radio channel Fa used by the base station 7. When the mobile communication terminal 3 is powered on, first the receiver 3a receives the control signal and transmits the received data to the controller 3 for evaluation, so that the operation of the mobile communication terminal 3 can be inhibited or limited.

As a result, it is possible to inhibit or limit the operation of the mobile communication terminal in a specific area (area B or area C in Figs. 2 and 3) within the range of the control signal emitted by the control signal generator 2.

Furthermore, a control signal is received at predetermined time intervals even after normal communication for speaking as an example has been permitted. Therefore, when the mobile communication terminal is moved to a location S"where its operation is inhibited or limited, the operation of the mobile communication terminal can be inhibited or S: 25 limited.

C C 21 As is shown in Fig. 3, the memory device 8a in which the identification number IDa is stored, and the memory device 8b in which the identification number IDb is stored are respectively provided for the control signal generator 2 and the mobile communication terminal 3. When a control signal including the identification number IDa is transmitted by the control signal generator 2, the operation of a specific mobile communication terminal can be inhibited or limited.

In addition, as is shown in Fig.4, the variable transmission power output device 9 is included in the control signal generator 2, and the dial (level) 10 is provided outside the control signal gyenerator 2 for operating the variable transmission power output device 9. With this arrangement, the range within which the inhibiting or the limiting of the operation of the mobile communication terminal can be varied.

S

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Claims

8. A mobile communication system substantially as described herein with reference to the accompanying drawings 2 to 4. DATED this ELEVENTH day of NOVEMBER 1997 NEC Corporation Patent Attorneys for the Applicant SPRUSON FERGUSON o* VSG:5086U