JPH0738486A - Cellular terminal equipment - Google Patents

Abstract

(57) [Abstract] An object of the present invention is to prevent the clock and the base station information from deviating from the base station even if the standby time is lengthened in order to reduce the power consumption in the cellular terminal device. [Structure] When the standby operation interval is lengthened, the signal from the base station is received at regular intervals for a short period of time to correct the system clock, and the signal from the base station It receives only the time required for signal strength measurement, detects whether or not it has moved between service areas, and updates the base station information.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. Field of Industrial Application Conventional Technology Problems to be Solved by the Invention Means for Solving the Problems (FIG. 1) Action (FIG. 1) Embodiments (FIGS. 1 to 5) Effects of the Invention

[0002]

FIELD OF THE INVENTION The present invention relates to a cellular terminal device,
In particular, the present invention can be applied to a device that waits for a fixed time at a predetermined time interval.

[0003]

2. Description of the Related Art Conventionally, CDMA (code division multip) is used.
In a cellular terminal device used in a le access) cellular telephone system, power consumption is reduced by waiting for a call or instruction from the base station for a certain period of time at a certain time interval and turning off the power of the transceiver device at other times. What is trying to suppress is being considered.

[0004]

By the way, in such a cellular terminal device, the power consumption can be further suppressed by increasing the interval for performing the standby operation and increasing the power-off time. However, in this case, since the signal from the base station is not received for a long time, a system clock shift occurs between the cellular terminal device and the base station, and the signal reception from the base station may fail or may not be expected. There is a possibility that an undesired adjacent signal will be received, or that the base station will transmit a signal when the base station is not in the reception system for the transmission signal from the cellular terminal device.

Further, since the cellular terminal device is generally used while moving, the cellular terminal device may move between cells, that is, the service area of the base station while the signal from the base station is not received. The longer the standby operation, the higher the possibility of moving, and as a result the base station information in the cellular terminal device may differ from that of the base station of the cell in which the cellular terminal device is located. There's a problem.

Therefore, the time interval for performing the standby operation is
There was a restriction that the system clock could not be too long and the base station information should not be too old because the travel distance was too long. On the other hand, if the time interval for performing the standby operation is short, it is necessary to receive for a certain period of time to determine whether there is a call from the base station while in the standby state, so the effect of suppressing power consumption cannot be obtained. I got it.

The present invention has been made in consideration of the above points, and is a cellular terminal in which the system clock and base station information do not deviate from the base station even if the standby time is increased to suppress power consumption. It is intended to propose a device.

[0008]

In order to solve such a problem, according to the present invention, in a cellular terminal device 10 which performs a standby operation for a predetermined time interval at a predetermined time interval, when the standby operation interval is extended, Also,
The system clock is corrected by receiving a signal from the base station 11, 12 or 13 for every short period of time.

Further, according to the present invention, in the cellular terminal device 10 that waits for a fixed time at each predetermined time interval, if the standby operation interval is lengthened, the base station 11, 12 or 13
The signal from is received only for the time required for signal strength measurement,
The base station information is updated by detecting whether the mobile terminal has moved between the service areas 15, 16 or 17.

[0010]

When the standby operation interval is lengthened, the base station 11, for a short period of time at regular time intervals, even when the standby operation is not performed,
The signal from 12 or 13 is received to correct the system clock, or the signal from the base station 11, 12 or 13 is received only for the time required for signal strength measurement, and the service area 15, 16 or 17 is reached. By detecting whether or not the mobile station has been moved and updating the base station information, the base stations 11 and 12 can be updated even if the standby time is increased in order to reduce power consumption.
Alternatively, it is possible to prevent the system clock and the base station information from being shifted from each other.

[0011]

【Example】

An embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the configuration of a CDMA cellular telephone system as a whole, in which base stations 11, 12, and 13 are connected to a control center 14 for a cellular terminal device 10, respectively, and service areas 15 adjacent to each other are provided.
16, 17 are formed. This base station 11, 12, 13
Are connected to the control center 14 through connection lines 18, 19 and 20, respectively, and the control center 14 is connected to a public line 21.

As a result, in the cellular telephone system, when the cellular terminal device 10 exists in the service area 15, 16 or 17, it is connected through other cellular terminal devices existing in the service areas 15 to 17 or public lines. It is designed so that users can freely connect to ordinary telephones and make calls.

As shown in FIG. 2, the cellular terminal device 10 includes a receiving unit 102 and a transmitting unit 103 connected to an antenna 101, a power supply 104 for supplying power to each unit, and a control unit 105 for controlling each unit. , A system clock 106 for synchronously operating each unit, a storage device 107, and a speaker 1
08, the operation / display unit 109, and the microphone 110.

First, as a normal operation, while the user does not use the cellular terminal device 10 at all, power is supplied from the power supply 104 to only part of the system clock 106, the storage device 107, the operation / display unit 109 and the control unit 105. As a result, the power consumption is kept to the minimum level at which the user's operation can be accepted and the information necessary for restarting is retained.

When the user waits for a call from the base station 11, 12 or 13, the user operates the operation / display unit 109 to turn on the cellular terminal device 10.
By this operation, the control unit 105 causes the power supply 104 to supply power to the antenna 101, the receiving unit 102, and the speaker 108. Then, the control unit 105 outputs a sound according to the user's operation from the speaker 108, and causes the receiving unit 102 to start reception.

The radio wave from the base station 11, 12 or 13 is
An incoming signal from the antenna 101 is received by the receiving unit 102, such as digital demodulation. The control unit 105 monitors this signal, and if it receives a sufficiently strong signal, it displays the standby state on the operation / display unit 109 and notifies the user. Further, the control unit 105 causes the power supply 104 to supply power to the transmission unit 103, and transmits a signal for position registration of the own station to the base station 11, 12 or 13.

Assuming that the cellular terminal device 10 is now located within the service area 15 of the base station 11 and has transmitted a signal for registering its own position, the base station 11 is in the position of the cellular terminal device 10, that is, the cellular terminal. The device 10 is a base station 11
The information indicating that it is located in the service area 15 is sent to the control center 14 via the connection line 18.

As a result, the control center 14 stores the information, and the cellular terminal device 10 from the public line 21 is stored.
When a call arrives at, the base station 11 transmits a call signal to the cellular terminal device 10. This calling signal enters from the antenna 101 of the cellular terminal device 10 and is processed by the receiving unit 102. The control unit 105 detects an incoming call to its own station, causes the sending unit 103 to send a calling response, and sends it to the operation / display unit 109. The sound is output from the display and the speaker 108 to inform the user that the microphone 11
0 is also supplied with power from the power supply 104 to prepare for a call.

When the user makes a transmission operation from the operation / display unit 109, the control unit 105 causes the transmission unit 103 to operate.
The power supply 104 supplies power to the control unit 105, and the control unit 105 outputs a transmission request signal. The signal is processed by the transmission unit 103 such as digital modulation, and the antenna 101 supplies the base station 11 with the signal.
Sent to. In addition, the power supply 104 to the microphone 110
The power is supplied from the terminal to prepare for a call.

Incoming or outgoing is performed in this way,
After the call line is established, the user's own voice is microphone 11.
Input from 0, speech is encoded by the control unit 105, processing such as digital modulation is performed by the transmission unit 103, and the antenna 1
It is sent from 01. The voice of the other party enters as a radio wave from the antenna 101, undergoes processing such as digital demodulation in the receiving unit 102, is voice-decoded by the control unit 105, and sounds the speaker 108.

During this operation, the base station 1 is receiving during reception.
Based on the signal from 1, the demodulator / decoder 201 corrects the system clock 106 so that the timing continues to be synchronized with the base station 11. Further, since the information of the adjacent base stations 12 and 13 is also transmitted from the base station 11, when receiving the information, the control unit 105 records the information in the storage device 107.

Based on this information, the control unit 105 measures the signal strength from the base station 11 and the adjacent base stations 12 and 13 by the signal detector 202, and the signal from the base station 12 or 13 is detected by the base station 11. Is sufficiently strong, the cellular terminal device 10
Determines that the mobile station has moved to the service area 16 or 17 of the base station 12 or 13, and starts signal reception of the base station 12 or 13 and re-registers the location.

Here, the cellular terminal device 10 performs a slot operation of waiting for a call or an instruction from the base station 11, 12 or 13 for a certain period of time at a certain time interval to suppress power consumption. That is, when performing the slot operation, the cellular terminal device 10 transmits to the base station 11, 12 or 13 a signal notifying the interval for entering the slot operation and the interval for performing the standby operation (hereinafter referred to as the slot cycle).

As a result, the base station 11, 12 or 13 makes a call or an instruction to the cellular terminal device 10 only for a certain fixed time at each notified interval (hereinafter, this period is referred to as a slot). In fact, in the case of a CDMA cellular telephone system, this slot is set to 80 [msec].

Upon notifying the base station 11, 12 or 13 of the slot operation, the control unit 105 determines that the sufficiently strong signal currently being received is the signal to be received at the next slot and the storage device 10
7 and the base stations 11 and 12 adjacent to the signal.
Or, after recording the accurate system timing in the memory device 107 for the signal transmitted from the system 13, the system clock 106 and the memory device 10 are stored at times other than the slot.
7. Power is supplied from the power supply 104 to only a part of the operation / display unit 109 and the control unit 105 to suppress power consumption (this period is hereinafter referred to as a power save mode).

Then, the system clock 106 measures the time until preparation for monitoring the next slot. When it is detected that it is time to start the monitor preparation, the control unit 10
Reference numeral 5 causes the power supply 104 to supply power to the antenna 101 and the receiving unit 102, and causes the signal detector 202 to start measuring the signal strength and the correct timing of the signal to be received recorded in the storage device 107.

The system clock 106 includes a receiving section 102.
Of the base station 11, 12 or 13 while the power of the
Since it is not possible to continue synchronizing the timing with the base station 11, 12 or 13 based on the signal from, an error occurs in the output value. When the signal detector 202, which looks for a signal using the value of the system clock 106, measures the exact timing of the indicated signal, it will report a value different from the value recorded in the memory 107.

The control unit 105 calculates the error of the system clock 106 during the slot cycle from the accurate timing of the signal measured by the signal detector 202, and corrects the system clock 106. After the correction of the system clock 106, the control unit 105 instructs the demodulator / decoder 201 to receive the signal in accordance with the accurate timing of the signal measured by the signal detector 202.

The control unit 105 monitors the signal from the receiving unit 102 for the slot time (80 [msec]), and the base station 1
Check if there is a call from 1, 12 or 13. If there is a call, the slot operation is stopped and normal incoming call processing is performed, but when there is no call, the power save mode is resumed until the next slot.

During this slot time (80 [msec]), the adjacent base stations 11 and 1 recorded in the storage device 107 are recorded.
For some of the signals transmitted from 2 or 13,
The signal strength can be measured. As a result, the signal to be received cannot be received, or the adjacent base stations 11 and 1
It is possible to detect that the cellular terminal device 10 has moved to the service area 15, 16 or 17 of another base station 11, 12 or 13 by detecting that the signal strength of 2 or 13 is sufficiently strong. .

As a result of the signal strength measurement, when it is considered that the signal of the base station 12 is sufficiently stronger than the signal of the base station 11 which has been received previously and the cellular terminal device 10 has moved to the service area 16, the control is performed. The unit 105 is the transmission unit 1
Power is supplied from the power supply 104 to 03, and a signal for position registration of the own station is transmitted to the base station 12.

This position registration is sent from the base station 12 to the control center 14 via the connection line 19, so that the control center 14 can grasp the correct position of the cellular terminal device 10. Cellular terminal 10
Notifies the base station 12 of the slot operation to enter the power save mode again.

However, measuring the intensities of all the signals from the adjacent base stations 11, 12 or 13 during a short slot time may not be possible because of insufficient time depending on the number of signals. For this reason, signals that cannot be measured will be measured at the next slot.

Here, in the case of this embodiment, the control unit 105 notifies the base station 11, 12 or 13 that the slot mode operation is to be performed in a long slot cycle. Then, the system clock 106 measures the time until the signal strength measurement timing shorter than the slot cycle. When detecting that the time has come, the control unit 105 causes the power supply 104 to supply power to the antenna 101 and the signal detector 202.
The signal detector 202 is caused to start measuring the signal strength and accurate timing of the signal to be received, which is recorded in the storage device 107.

Similar to the operation during the slot monitor preparation period, the control unit 105 calculates the error of the system clock 106 during the signal intensity measurement period from the accurate timing of the signal measured by the signal detector 202, and Black 1
Correct 06. This makes it possible to prevent signal reception failure or erroneous reception of an adjacent signal due to the slot mode operation in a long slot cycle.

By measuring the reception intensity of the signal to be received or the signal transmitted from the adjacent base station 11, 12 or 13 recorded in the storage device 107,
Coverage area 15 of another base station 11, 12 or 13;
Movement to 16 or 17 can be determined. During the slot period, the adjacent base station 11, which could not be measured due to lack of time,
The signal strength of the signal from 12 or 13 can also be measured during this period, and the other base station 11, 12 or 1 of the cellular terminal device 10 can be measured.
The movement to the service area 15, 16 or 17 of 3 can be detected quickly.

The signal to be received, which is recorded in the storage device 107 and the correction of the system clock 106, the adjacent base station 1
The strength measurement from 1, 12 or 13 does not require demodulation and decoding of the signal and does not need to wait for the signal transmitted from the base station 11, 12 or 13, so that the slot 80
Compared to [msec], it only needs to receive data for a short time, and the required operation can be performed with low power consumption.

The cellular terminal device 10 has different base stations 11, 1
When it is detected that the mobile station has moved to the service area 15, 16 or 17 of 2 or 13, the transfer destination base station 11, 1
The location registration of the cellular terminal device 10 and the slot operation notification are transmitted to 2 or 13. When not moving, the time until the clock correction / signal strength measurement timing is compared with the time until the next slot monitor preparation period, and the power save mode is entered for the shorter time.

Here, FIG. 3A shows a conventional slot operation, in which the slot cycle is actually shortened, and the system time is corrected before the signal is monitored during the slot. On the other hand, in the slot operation of the embodiment shown in FIG. 3 (B), the slot cycle is lengthened, and power is supplied to the antenna 101 and the signal detector 202 for a shorter time than the slot length during the slot cycle. Power consumption can be suppressed.

This operation is executed according to the slot operation procedure SP0 shown in FIG. That is, when it is determined that the slot operation is to be performed, in step SP1, the control unit 105 transmits the notification of the start of the slot operation and the slot cycle to the base station 11, 12 or 13 and proceeds to step SP2.

At step SP2, the control section 105
The power supply from the power supply unit 104 to the antenna 101, the receiving unit 102, and the transmitting unit 103 is stopped, and the process proceeds to step SP3. In step SP3, the control unit 105 controls the signal being received by the storage device 107 and the adjacent base station 11, 12 or 13
The signal strength of the signal is recorded and the operation proceeds to step SP4.

At step SP4, the control unit 105
The time until the next slot is prepared for monitoring is compared with the time until the clock correction / signal strength measurement timing. If the time until the clock correction / signal strength measurement timing is shorter, the operation proceeds to step SP5 to monitor the next slot. If the time until preparation is shorter, the process proceeds to step SP16.

At step SP5, the control unit 105
The measurement of the time until the clock correction / signal strength measurement timing is started and the operation proceeds to step SP6. In step SP6, the control unit 105 determines whether or not time has elapsed, and if not elapsed, the control unit 105 stays in step SP5, and when it has elapsed, proceeds to step SP7. In step SP7, the control unit 105 determines that the antenna 101 and the signal detector 202
Power supply from the power source 104 to the
Go to.

At step SP8, the control section 105
The signal detector 202 is caused to measure the signal strength and the accurate timing of the previously received signal, and the process proceeds to step SP9.
At step SP9, the control unit 105 determines that the step SP
From the accurate timing measurement result of No. 8, the system clock 106 is corrected, and the process proceeds to step SP10.

At step SP10, the control unit 105
Means that the signal detector 202 is connected to the adjacent base station 11, 12 or 13
The signal intensity from is measured, and the process proceeds to step SP11.
In step SP11, the control unit 105 determines the signal strength of the current base station 11, 12 or 13 and the adjacent base station 1
The signal strengths from 1, 12, or 13 are compared, and if the signal of the adjacent base station 11, 12 or 13 is sufficiently strong, the process proceeds to step SP12, and if not, step S12.
It returns to P2 and enters the power save mode again.

At step SP12, the control unit 105
Starts power supply from the power supply 104 to the demodulator / decoder 201, and the base station 11, 12 or 13 whose signal strength is strong.
Reception of the signal from the base station (that is, the movement destination base station) is started, and the process proceeds to step SP13. In step SP13, the control unit 105 starts power supply from the power supply 104 to the transmission unit 103, and proceeds to step SP14.

At step SP14, the control unit 105
Transmits the position information of the cellular terminal device 10 to the movement-destination base station 11, 12 or 13 and proceeds to step SP15.
In step SP15, the control unit 105 determines whether or not to continue the slot operation. If the slot operation is continued, the process returns to step SP1 to repeat the processing from the slot operation notification to the base station 11, 12 or 13, and if the slot operation is not performed. Return to normal operation.

On the other hand, in step SP16, the control unit 105
Start measuring the time to prepare for the next slot monitor,
Go to step SP17. In step SP17, the control unit 105 determines whether or not time has elapsed, and if not, it stays in step SP5, and when it has elapsed, proceeds to step SP18.

At step SP18, the cellular terminal device 10 operates in a normal slot, that is, corrects the system clock, measures the signal strength, and waits for a call from the base station 11, 12 or 13. If no call reception or movement of the service area 15, 16 or 17 is detected during this operation, the process returns to step SP2 to enter the power save mode.

According to the above configuration, in the reception performed at regular time intervals without waiting, it is not judged whether or not there is a call, so that the receiving time can be shortened as compared with the case of waiting. Therefore, it is possible to realize a cellular terminal device that can suppress power consumption and prevent deviation of system clocks and aging of base station information as compared with a case where standby operation is performed at similar intervals.

In the above-mentioned embodiment, the case where the accurate measurement of the signal is measured at every signal strength measurement timing to detect the error of the system clock and immediately correct the system clock will be described. However, the error of the detected system clock is accumulated without correcting the system clock at each signal strength measurement timing,
If it is necessary to accurately match the system clock later, the system clocks may be collectively corrected. In this way, the activation time at each signal strength measurement timing is further shortened, and the power consumption can be further reduced.

Further, in the above-mentioned embodiment, the case where the signal strength from the adjacent base station is measured at the timing of the slot and signal strength measurement is described, but the strength of the signal from the other non-adjacent base stations is also measured. You may.

By connecting a positioning device or the like, estimating a service area having a high possibility of movement from the position information of the cellular terminal device, the position information of the base station, and the like, and frequently measuring only the signal of the base station. Alternatively, the movement of the cellular terminal device may be effectively detected in a shorter time than the slot time.

Further, in the above-mentioned embodiment, the signal strength measurement interval is constant, but the signal strength measurement interval, that is, the service area movement inspection interval is variable in consideration of the interval between adjacent signals and the user's moving speed. You may

[0057]

As described above, in the present invention, when the standby operation interval is lengthened, a signal from the base station is received for a short period of time at regular intervals even during no standby, and the system clock is received. Power consumption by correcting the signal from the base station or receiving the signal from the base station for the time required to measure the signal strength to detect whether or not the mobile station has moved between service areas and updating the base station information. Therefore, it is possible to realize a cellular terminal device that can prevent a system clock and a base station information from being shifted from the base station even if the standby time is increased.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a cellular telephone system in which a cellular terminal device according to the present invention is used.

FIG. 2 is a block diagram showing an embodiment of a cellular terminal device according to the present invention.

FIG. 3 is a timing chart for explaining the comparison between the present invention and the conventional slot operation.

FIG. 4 is a flow chart showing a slot operation procedure according to the present invention.

5 is a flow chart showing a slot operation procedure similar to FIG.

[Explanation of symbols]

10 ... Cellular terminal device, 11-13 ... Base station, 14
...... Control center, 15-17 ... Service area, 18-20 ... Connection line, 21 ... Public line, 1
01 ... antenna, 102 ... reception part, 103 ... transmission part, 104 ... power supply, 105 ... control part, 106 ... system clock, 107 ... storage device, 108 ... speaker, 109 ... operation / Display, 110 ... Microphone, 2
01 ... Demodulator / decoder, 202 ... Signal detector.

Claims (3)

[Claims] 1. In a cellular terminal device that waits for a fixed time at a predetermined time interval, if the standby operation interval is lengthened, a signal from a base station is sent for a short time at a fixed time even when the standby operation is not performed. A cellular terminal device characterized by receiving and correcting a system clock. 2. A cellular terminal device that waits for a fixed time at predetermined time intervals, and measures the signal strength of a signal from a base station at fixed intervals even if the standby operation interval is not increased. The cellular terminal device is characterized in that it receives only for a necessary time to detect whether it has moved between service areas and updates the base station information. 3. Even while not waiting, the signal from the base station is received at regular intervals for a short period of time to detect the error of the system clock, accumulate the error, and accumulate the error. The cellular terminal device according to claim 1, wherein the system clock is corrected by using an error.