KR100339240B1 - Deactivating apparatus suitable for use in mobile communication system and method for the same - Google Patents

Abstract

The present invention relates to a call blocking device of a wireless mobile communication system for blocking a call of a wireless terminal in a public place such as a theater or a court, and more particularly, to a call blocking method and device suitable for a CDMA wireless mobile communication system. .

The present invention obtains information of possible neighboring base stations that can be used for call blocking by receiving a control message transmitted from a base station, and measures the signal level of a pilot channel of a neighboring base station from the information to determine the identifier value of the weakest pilot channel among them. By calculating a, and having the same identifier value as the identifier value, and transmits a pilot signal having a signal level higher than the pilot channel of the currently receiving active base station by a predetermined value to induce the blocking target terminal to idle handoff. do. In another important aspect, the present invention further includes the step of transmitting a minimum control message capable of maintaining the handoff state of the blocking target terminals idle idle after transmitting the simulated pilot signal.

Accordingly, the present invention, by optimizing the transmission power of the call blocking device to prevent unnecessary electromagnetic wave transmission, the call blocking is made quickly and surely, the call blocking state is continuously maintained, and the power consumption of the wireless terminal is minimized in the call blocking state. You can do

Description

Deactivating apparatus suitable for use in mobile communication system and method for the same}

The present invention relates to a call blocking device and a method of a wireless mobile communication system for blocking a call of a wireless terminal in a public place such as a theater or a court, and in particular, a call blocking device and method suitable for a CDMA wireless mobile communication system. Is related.

Conventional call blocking devices are disclosed in Korean Patent Application Publication No. 1998-82079 issued November 25, 1998. Although the device is not described in detail, the device unilaterally transmits a strong jammer for blocking in all frequency bands in the control channel, thereby degrading the S / N ratio and blocking the call.

However, the CDMA mobile communication system can receive the desired signal only through a predetermined code, and the external interference and disturbance signals have the characteristic of lowering the interference level in the process of correlating with the given code. It is difficult to block the signal efficiently. Therefore, the call blocker of this type has a disadvantage in that the output power of the jamming device is large and the jamming power level must be adjusted according to the installation location, and the abuse of unnecessary jamming power may adversely affect other communication devices. .

In a more improved form, there is one disclosed in Japanese Patent Laid-Open Publication No. 2000-38 issued on January 15, 2000. This technology generates a simulated channel with a PN offset different from the channel currently being used and no call signal in CDMA, and amplifies and transmits power so that the mobile terminal hands off to this channel. It is to block it. 1 shows a configuration of a call blocking device according to the prior art. The device receives a signal of a pilot channel emitted from a CDMA base station at an antenna, measures a power offset of the PN code for system synchronization at a pilot channel receiver, and a PN offset from a received pilot signal at a pilot channel generator. This other pilot channel is generated, amplified to be greater than the pilot signal power of the base station received by the RF signal uplink frequency converter / power amplifier, frequency converted, and sent out, so that the mobile communication terminal launches the pilot from the call blocking device. Inducing a handoff to the channel prevents a call from the base station.

However, a careful examination of the CDMA handoff process may find that such a prior art has some fatal flaws. In the CDMA scheme, the mobile station is currently busy with a list of active sets associated with the pilot of the base station, such as the forward traffic channel assigned to the mobile station, and a neighbor set that is not present in the active set but may be an active set. Receive from and manage.

The mobile station in call in cell 1 continuously measures the strength of the pilot channel with respect to the pilot channel registered in the neighboring set, and transmits the pilot channel to the base station that transmits this pilot channel when its power is greater than a certain level by the strength of the current pilot channel. The handover intention is transmitted to the base station that was originally busy and the soft handover is performed. When the system synchronization with the base station to be handed over is obtained through the connection with the pilot channel, the system connects to the synchronization channel and synchronizes timing based on information such as the PN offset number, system time, and frequency channel number received from the synchronization channel. Connect to and receive various control messages for paging.

However, the prior art scheme generates and transmits an 'arbitrary' pilot channel different from the current pilot channel, so that unnecessary electromagnetic waves can still be avoided due to excessive radio wave transmission, and a pilot channel having an arbitrary PN offset can be avoided. Since it is unlikely that a pilot channel equal to the PN offset of the base station included in the neighbor set of the base station is generated, it is very unlikely that the mobile terminal will be tuned to the simulated pilot channel transmitted by the blocking device. Therefore, there is no guarantee of call blocking. Furthermore, even though the terminal is tuned to the simulated pilot channel, the terminal cannot obtain the control message necessary for the terminal to operate normally in the tuned channel, and thus the terminal enters a system failure state and reestablishes a new pilot channel to recover the communication situation. Attempts to find the network, but there is still the same simulated pilot channel that sends out a lot of power, so it is tuned back to this channel, and this channel tuning and system failure is constantly repeated. There is a problem that the time is greatly reduced.

The present invention is to improve such a problem, it is an object to optimize the transmission power of the call blocking device to prevent the transmission of unnecessary electromagnetic waves.

It is another object of the present invention to keep the call blocking quickly and reliably and to keep the call blocking state continuously.

Furthermore, another object of the present invention is to minimize power consumption of a wireless terminal in a call blocking state.

In addition, an object of the present invention is to provide an economical call blocking device that can effectively cope with a variable environment with a simple configuration.

1 shows a configuration of a call blocking device according to the prior art.

2 is a block diagram showing the configuration of a call blocking device according to a preferred embodiment of the present invention.

FIG. 3 is a more detailed block diagram of the control message generator 220 in FIG. 2.

4 is a flowchart illustrating a call blocking method according to a preferred embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

210: control unit 220: control message generating unit

230: RF transceiver 240: receiver

241: message demodulator 242: correlator

310: message selection unit 320: pilot data storage unit

330: control message storage unit 340: modulation unit

According to an aspect of the present invention for achieving the above object, by measuring the pilot signal level of the current neighboring base stations based on the information on the neighboring base station received from the base station tuned to the installation site from the value to the most call in the normal state Find a pilot signal from a neighboring base station that is less likely, and have the same pilot identification as the pilot signal, but amplify the pilot signal with enough power to allow idle handoff from the currently tuned base station. While transmitting only the minimum power required, the normal channel idle handover (idle handoff, idle handover) of the terminal is performed quickly and securely.

The call blocking device according to the first aspect of the present invention is:

An RF transceiver 230 which receives and demodulates an RF signal and modulates transmission data according to a control signal and transmits the RF data as an RF signal;

A correlator (242) for calculating a power value of a pilot signal received from the signal demodulated by the RF transceiver 230;

A control message generator 220 generating pilot channel data and outputting the pilot channel data to the RF transceiver;

Finding an active pilot channel to which current mobile communication terminals are tuned from the output of the correlator 242 and calculating an active pilot signal value which is a signal strength value; And receiving from the message demodulator 241 a control message sent by the base station associated with the found active pilot channel, extracting pilot channel information on the set of idle handoff base stations therefrom; Receiving power values from the correlator 242 for these pilot channels to find a pilot channel having the weakest signal strength among them; The control message generator 220 controls the pilot channel data corresponding to the pilot channel to be generated, and the RF transmitter / receiver transmits the active pilot signal value that is the power value of the pilot currently tuned to the input pilot channel data. And a control unit 210 controlling to transmit power with a power larger by a predetermined value.

Here, the predetermined value means a value sufficient to determine that handoff should be performed, and is not specifically defined in the standard. Therefore, a simple comparison includes a configuration in which the handoff is performed as long as the strength is stronger than that of the base station currently being received, that is, a predetermined value is extremely close to zero.

The call blocking device according to the second aspect of the present invention includes: generating and transmitting a control message necessary for channel maintenance after handover to a pilot channel to maintain a normal system operation state even after handover to maintain a call blocking state. While it can be surely maintained, it is possible to prevent battery consumption of the terminal due to repeated handover attempts of the terminal, thereby preventing the terminal's waiting time from being excessively shortened.

According to an aspect of the present invention, a call blocking device further includes: a message demodulator 241 for demodulating a control message from a signal demodulated by the RF transceiver, wherein the control message generator 220 is connected to pilot channel data. In addition, after the idle handoff, generate a minimum control message necessary for maintaining the handoff state, and output the RF control unit 230; The control unit 210 may control to transmit the pilot channel data, and then control the control message generator 220 to further transmit a valid control message.

According to the third aspect of the present invention, the call blocking device of the present invention stores such a control message in a state where digital processing including complicated encoding / decoding processing is completed, so that the transmission device can be easily configured.

According to an aspect of the present invention, a call blocking device includes: a pilot data storage unit (320) for storing a control data generator (220) capable of a pilot data set; A control message storage unit 330 for storing possible control messages; A data selection unit 310 for searching for the pilot data storage unit and the control message storage unit to select corresponding pilot data and control messages under the control of the controller; And a modulator 340 for digitally modulating and outputting the selected data. Characterized in that it comprises a.

On the other hand, in order to block all calls of terminals of various service providers within the call blocking range, all the frequency bands and spreading codes must be blocked. In this case, the transmitter and the receiver become very complicated.

According to the fourth aspect of the present invention, the call blocking device is configured to transmit a specific number of paging channels to be used in a system parameter message to transmit only a specific channel to a terminal, and transmits the same. In addition, it is possible to effectively block terminals of various service providers.

The call blocking device according to the aspect of the present invention is characterized in that the control message generator is configured to designate and store a paging channel (paging channel) to be used by the control message storage unit as a common paging channel.

In addition, if the receiver of the present invention continuously maintains the same channel, different receivers are required for each service provider to prevent information from becoming very complicated. By collecting and storing the contents, the structure of the receiver can be simplified and effectively cope with the variable surrounding environment.

In addition, a call blocking method according to the first aspect of the present invention for achieving the above object is:

In the call blocking method for blocking a call of the mobile communication terminal in a certain local range,

Receiving a control message sent from the base station to obtain information of possible neighbor base stations that can be used for call blocking;

Measuring a signal level of a pilot channel of a neighbor base station from the information to calculate an identifier value of the weakest pilot channel;

Transmitting a pilot signal having a signal level equal to the identifier value and having a signal level higher than a pilot channel of an active base station currently being received, to induce the blocking target terminal to idle handoff;

Characterized in that it comprises a.

In addition, a call blocking method according to a second aspect of the present invention is:

And transmitting the minimum control message capable of maintaining the handoff state by the blocking target terminals that are idle handoff, including the synchronization information and the paging message information.

According to a call blocking method according to a fourth aspect of the present invention, the step of transmitting the control message includes:

A paging channel to be used after handoff may be designated as one paging channel common to all terminals.

Hereinafter, the present invention according to this aspect will be described in detail so that those skilled in the art can easily understand and reproduce the present invention through the preferred embodiments described with reference to the accompanying drawings.

2 is a block diagram showing the configuration of a call blocking device according to a preferred embodiment of the present invention. 4 is a flowchart illustrating a call blocking method according to a preferred embodiment of the present invention.

The present invention is to disable the call of the mobile communication terminal by using the basic features of the CDMA communication method, more specifically, to set up a kind of simulated base station to hand off all the terminals within the call blocking range to the simulated base station. However, although the construction of the actual base station requires a lot of cost, this purpose can be achieved at a much lower cost by including only an essential configuration sufficient to serve as a simulation base station. In the prior art, the possibility of handoff was low by setting this mock base station as a base station with an arbitrary identifier. However, the present invention provides information on adjacent base stations that can handoff from an active base station to which a current connection is established. It is extracted from the control message sent by the base station and then selects the identifier of the best simulated base station that is the least likely to be a handoff target. By sending an appropriate control message to the mobile terminal handoffed to the simulated base station to maintain the connection to the simulated base station even after the handoff once, the call is blocked by blocking the connection to the real active base station to which the actual call message is delivered.

The minimum control message required here is, for example, in the 95B standard, System parameter Message, Access Parameter Message, Neighbor List Message, CDMA channel List Message, Extended System Parameter Message, Global Service Redirection Message, Extended Neighbor List Message, General Neighbor List. This includes Message, General Page Message, TMSI Assignment Message, and Null Message.

In detail, the RF transceiver 230, the receiver 240, and the control message generator 220 are all controlled by the controller 210. The RF transceiver 230 receives an RF signal transmitted from a neighboring base station from an antenna and outputs I and Q data to the receiver 240. The RF transceiver 230 is similar to the configuration of the RF transceiver of the conventional personal mobile communication, and in the IS-95 scheme, the frequency bandwidth is 1750-1780 MHz from the uplink, that is, the terminal to the base station, that is, from the base station to the terminal. Is designated 1840-1470MHz. The maximum power is determined according to the terminal class. For the current class 3 terminals, minimum -12 dBW and maximum -3 dBW are specified. According to a preferred aspect of the present invention, the receiving unit 240 periodically searches for different channels and frequencies, collects information, stores the contents thereof, and responds quickly when necessary, thereby simplifying the structure and effectively changing the surrounding environment. It is controlled by the control unit 210 to cope. The receiver 240 includes a message demodulator 241 for demodulating various control messages from demodulated digital I and Q data, and a correlator 242 for outputting a power value at a received signal level by inputting a PN code in a pilot channel. do. The correlator 242 outputs an autocorrelation value between two signals. The correlator 242 receives a PN sequence from the controller 210 and outputs a signal strength value of a pilot channel through the correlation value between the sequence and the input pilot signal. do. The correlator 242 measures the signal strength of the pilot channel with respect to the digital I and Q signals demodulated by the RF transceiver 230 to find an active base station having the strongest signal strength (step S400). At this time, the signal strength value of the active base station is stored for later use (step S410).

After acquiring the system synchronization from the pilot channel, the message demodulator 241 changes the Walsh function from 0 to 32 to access the synchronization channel, and then the protocol information, system ID, network ID, and pilot channel PN offset number in the synchronization channel. Obtains long code status, system time and related information, failing channel speed, frequency channel number, etc., and synchronizes long code timing and system timing with base station through designated paging channel. Message) and a specific Station Directed Message. The overhead message includes system parameters, information related to access of the mobile station, base station frequency information, information about neighboring base stations, and the like, and the control unit 210 receives and utilizes information about the neighboring base stations, among others (step S420). ). The controller 210 extracts pilot channel information of the neighbor base station from the received neighbor base station information, outputs a PN offset to the correlator 242, and measures signal strength of the pilot channel. From this information, the controller 210 finds the base station with the lowest signal strength by selecting the lowest base station or the base station with the lowest signal strength among neighboring base stations which can be handed off from the currently connected active base station. The target pilot channel is selected (step S430). The control message generator 220 generates the selected target pilot signal. FIG. 3 is a more detailed block diagram of the control message generator 220 in FIG. 2. The control message generator 220 receives the PN offset of the selected pilot channel from the controller 210, extracts the pilot signal from the pilot data storage 320, and outputs the frequency spread through the modulator 340. (Step S440).

According to a preferred aspect of the present invention, the pilot data is not generated through a complex algorithm, but rather generates and stores appropriate pilot data in advance, and is immediately extracted and used by an index to simplify the configuration of the control message generator 220. Can be.

According to a preferred aspect of the present invention, a call blocking state is maintained by continuously maintaining the handoff state after handoff to the pilot channel by sending an appropriate control message after pilot data transmission. This control message includes synchronization information and paging information. The control message is also stored in advance in the control message storage unit 330 in a state where digital processing is completed in advance according to a preferred aspect of the present invention, and is simply output by addressing and modulated by frequency modulation in the modulator 340. It is output (step S450). Meanwhile, according to an additional aspect of the present invention, the blocking device sets a single paging channel in a control message and sends the paging channel to the terminal so that the terminal receives only a specific paging channel, thereby effectively blocking terminals of various service providers with only one paging channel. The structure of the generator 220 and the RF transceiver 230 can be simplified. The RF transceiver 230 properly modulates, amplifies, and outputs a pilot signal or a control message signal generated by the control message generator 220 under control of the controller 210. The signal strength of the pilot signal of the simulated base station must be sent at a signal strength larger than the signal strength of the currently connected active base station by a predetermined value so that the mobile terminals idle idle with the pilot signal sent from the current active base station. handoff)

As described in detail above, in the CDMA mobile communication system, the present invention uses the idle handoff to an appropriate simulated base station, and it is mistaken that the terminal maintains a connection state with a valid base station. The connection to the channel with no message at all can block the connection with the active base station, thereby effectively blocking the call. According to the configuration of the present invention, by transmitting the pilot signal of the simulated channel at a larger power larger than the signal strength of the received pilot signal by a threshold value for handoff, the unnecessary electromagnetic radiation is minimized to minimize the possibility of electromagnetic interference and the blocking device Can also minimize power consumption. In addition, according to the configuration of the present invention it is possible to further increase the possibility of call blocking due to idle handoff by selecting the simulated pilot channel as a pilot channel of the base station having the minimum signal level among the adjacent base stations. Furthermore, after the handoff, an appropriate control message is sent to maintain the handoff state to ensure that the call blocking state is maintained. In addition, the mobile terminal can prolong the battery life by reducing the power consumption of the mobile terminal by preventing the repetition of pilot tuning and system failure states to find a new valid pilot channel. In addition, the control device or the pilot signal can be stored in a digital processing state in advance to simplify the configuration of the blocking device.

Claims (10)

In the call blocking device of the mobile communication system: An RF transceiver for receiving and demodulating an RF signal and modulating the transmission data according to a control signal and transmitting the RF signal as an RF signal; A correlator for calculating a power value of a pilot signal received from the signal demodulated by the RF transceiver; A control message generator for generating pilot channel data and outputting the pilot channel data to the RF transceiver; Finding an active pilot channel to which current mobile communication terminals are tuned from an output of the correlator and calculating an active pilot signal value that is a signal strength value; And receiving, from the message demodulator, a control message sent by the base station associated with the found active pilot channel and extracting information of pilot channels for the set of idle handoff base stations therefrom; Receiving power values from the correlator for these pilot channels and finding a pilot channel having the weakest signal strength among them; Control the control message generator to generate pilot channel data corresponding to this pilot channel, and cause the RF transceiver to be more than a predetermined value than the active pilot signal value, which is a power value of a pilot currently tuned to the input pilot channel data. A control unit controlling to transmit at a high power; Call blocking device comprising a. In the call blocking device of claim 1: The call blocking device further includes: a message demodulation unit for demodulating a control message from the signal demodulated by the RF transceiver; The control message generator adds to the pilot channel data to generate a minimum control message necessary for maintaining the handoff state after idle handoff, and outputs it to the RF transceiver; And the control unit: controls to send pilot channel data, and then controls the control message generator to send a valid control message additionally. In the call blocking device of claim 1 or 2: The control message generator: A pilot data storage unit for storing possible pilot data sets; A control message storage unit for storing possible control messages; A data selection unit searching for the pilot data storage unit and the control message storage unit to select corresponding pilot data and control messages under the control of the controller; And A modulator for digitally modulating and outputting the selected data; Call blocking device of a mobile communication system comprising a. In the call blocking device of claim 3: The control message storage unit of the control message generator: And a paging channel to be used as a common paging channel and configured to store the paging channel to be used. In the call blocking method for blocking a call of the mobile communication terminal in a certain local range, Receiving a control message sent from the base station to obtain information of possible neighbor base stations that can be used for call blocking; Calculating a signal level of a pilot channel of a neighbor base station from the information and calculating an identifier value of the weakest pilot channel among them; Transmitting a pilot signal having a signal level equal to the identifier value and having a signal level higher than a pilot channel of an active base station currently being received, to induce the blocking target terminal to idle handoff; Call blocking method of a mobile communication system comprising a. The method of claim 5, wherein the call blocking method comprises: And transmitting at least a control message capable of maintaining the handoff state by the idle target off-blocking terminals, including the synchronization information and the paging message information. The method of claim 5, 6, wherein the transmitting of the control message comprises: A method of blocking a call in a mobile communication system, characterized in that a paging channel to be used after handoff is designated as one paging channel common to all terminals. In the call blocking method for blocking a call of the mobile communication terminal in a certain local range, 1) measuring the signal strength of a pilot channel to find an active base station with which mobile communication terminals within the predetermined local range communicate; 2) storing the signal strength of the pilot channel of the active base station; 3) receiving a control message sent from the active base station and extracting neighbor base station information that can be handed off from the active base station therefrom; 4) measuring a pilot signal strength of a pilot channel of the neighbor base stations and obtaining a pilot channel identifier value of the neighbor base station having the least possibility of call in the normal state from the value; 5) transmitting a pilot signal having a power equal to a predetermined value greater than a signal strength value of a pilot channel of an active base station stored in step 2) with the same pilot identifier value obtained in step 4); Call blocking method of a mobile communication system comprising a. The method of claim 8, wherein the call blocking method comprises: And transmitting at least a control message capable of maintaining the handoff state by the idle target off-blocking terminals, including the synchronization information and the paging message information. The method of claim 8, 9, wherein the transmitting of the control message comprises: A method of blocking a call in a mobile communication system, characterized in that a paging channel to be used after handoff is designated as one paging channel common to all terminals.