JP2006115049A - Method and device for measuring signal strength - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce power consumption when signal strength from a base station device is measured. <P>SOLUTION: A reception part 26 receives a paging signal from a processing part 24. A storage part 32 stores a combination for identifying a base station device before switching at a communication part 22 and information for identifying the base station device after the switching while making those pieces of information correspond to each other. A selection part 34 makes information for identifying the base station device to which a terminal device is currently connected correspond to information for identifying the base station device before the switching, selects the information for identifying the base station device after switching which should correspond to the information for identifying the base station device to which the communication part 22 is currently connected out of the combinations stored in the storage part 32, and outputs the selected information to a correlation part 46. A measurement part 28 calculates the level of a correlation value from the correlation part 26. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a signal strength measurement technique, and more particularly to a signal strength measurement method and device for measuring the strength of signals received from a plurality of base station devices.

A mobile communication system is generally composed of a base station device and a terminal device. A plurality of base station apparatuses are provided, and each base station apparatus forms a cell serving as a service area. The terminal device selects one of a plurality of cells while moving, and is connected to a base station device that forms the selected cell. The operation as described above is also performed in a W-CDMA (Wideband-Code Division Multiple Access) system applied to the third generation mobile phone system. When the terminal device is present in one cell, the terminal device receives information on neighboring cells from the connected base station device. Further, the terminal device measures the strength of the signal from the base station device forming the neighboring cell based on the received information, and determines the base station device to be connected next (see Non-Patent Document 1, for example). ).
Supervised by Keiji Tachikawa, “W-CDMA mobile communication system”, Maruzen Co., Ltd., September 2002, p. 44-45

  Since the terminal device is generally battery-driven, it is important to reduce the power consumption of the terminal device in order to lengthen the driving time. For this reason, the terminal device enters a low power consumption mode when waiting for not performing communication. In the low power consumption mode, the terminal device reduces power consumption by stopping the operation of a circuit necessary for communication. However, even in the low power consumption mode, the terminal device periodically measures the strength of the signal from the base station device forming the neighboring cells in preparation for the start of communication. In this case, if the number of surrounding cells is large, the number of base station apparatuses whose signal strength should be measured increases, and thus power consumption increases.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a signal strength measuring method and device for reducing power consumption when measuring the strength of a signal received from a base station device. .

  In order to solve the above-described problem, a signal strength measurement device according to an aspect of the present invention includes a communication unit connected to at least one base station device while switching a base station device to be connected, and a base before switching in the communication unit. While associating the information for identifying the station device with the information for identifying the base station device after switching, the storage unit for storing the combination and the base station device to which the communication unit is currently connected are identified. Information for identifying the base station device to which the communication unit is currently connected from among the combinations stored in the storage unit by corresponding to the information for identifying the base station device before switching the information for switching A first selection unit that selects information for identifying the base station device after switching to be compatible with the base station device that is currently connected via the communication unit, and becomes a switching candidate. A reception unit that receives information about the base station device, and a second selection that selects information corresponding to the information for identifying the base station device after switching selected by the first selection unit from the information received by the reception unit And a measurement unit that measures the strength of the signal received by the communication unit from the base station apparatus corresponding to the information selected by the second selection unit while using the information selected by the second selection unit. .

  According to this aspect, the information corresponding to the information stored in the storage unit is selected from the information about the base station device that is a candidate for switching, and the signal strength is measured based on the selected information. It is possible to reduce the number of base station devices whose strengths are to be measured, and to reduce power consumption.

  The communication unit may receive a signal spread by a predetermined spreading code from the base station device, and the information received by the receiving unit may include information on the spreading code in the base station device that is a candidate for switching. The measurement unit may measure the strength of the signal received by the communication unit by using the spreading code selected by the second selection unit. In this case, since the spreading code is notified, the process for specifying the spreading code can be omitted, and the signal strength can be measured quickly.

  When the communication unit switches the base station device to be connected according to the signal strength measured by the measurement unit, information for identifying the base station device before switching and the base station device after switching You may further provide the control part which memorize | stores the combination of information in a memory | storage part. In this case, since the result of switching performed in the past is reflected in the selection of the base station device whose signal strength should be measured, the signal strength of the base station device that is likely to be switched can be measured and measured. Even if the number of target base station apparatuses is reduced, a reduction in switching accuracy can be suppressed.

  The control unit, in the combination stored in the storage unit, when there is information for identifying a plurality of base station devices after switching with respect to information for identifying one base station device before switching, The combination may be ordered according to the frequency of switching, and the measurement unit may measure the strength of the signal received by the communication unit according to the order given by the control unit. In this case, since the measurement is performed from the signal strength of the base station apparatus that is likely to be switched, the processing efficiency can be improved.

  The control unit may store the combination in the storage unit for a limited predetermined period. In this case, the storage capacity of the storage unit can be reduced. The control unit preliminarily defines the storage start time and the storage end time as the predetermined period, and the control unit starts the storage when the storage start time comes, and the storage end time If the time comes, the storage may be terminated.

  The “memory start time” and “memory end time” may be defined by the time, but this is defined by combining other parameters that can specify the timing such as year, month, date, day of the week, etc. Also good. For example, when combined with a day of the week, it may be defined as “9:00 am on Monday”.

  Another aspect of the present invention is also a signal strength measuring device. This device includes a communication unit that connects to at least one base station device while switching the base station device to be connected, and a base station that is a candidate for switching from the currently connected base station device via the communication unit. Received by the communication unit from the base station device that is a candidate for switching, based on the reception unit that receives information about the device, the storage unit that stores the information received in the receiving unit, and the information about the base station device that is the candidate for switching A measurement unit for measuring the intensity of the signal to be transmitted. The reception unit and the storage unit operate in a limited predetermined period, and the reception unit corresponds to the base station apparatus to which the information stored in the storage unit is currently connected in a period other than the predetermined period. If the information stored in the storage unit does not correspond to the currently connected base station apparatus, the information received by the operation is output to the measurement unit. If the stored information corresponds to the currently connected base station apparatus in a period other than the period, the information is output to the measurement unit.

  According to this aspect, since the period for storing information in the storage unit is limited, the storage capacity of the storage unit is reduced, and a period in which information is not received occurs, so that power consumption can be reduced.

  Yet another embodiment of the present invention is a signal strength measurement method. This method associates information for identifying a base station apparatus before switching with information for identifying a base station apparatus after switching, and stores a combination of them in advance, and the currently connected base station apparatus When receiving information on a base station device that is a candidate for switching from the station device, the information for identifying the currently connected base station device is associated with the information for identifying the base station device before switching. From the combination, the information for identifying the base station device after switching to be compatible with the currently connected base station device is selected, and the selected base station device after switching is selected from the received information. Information corresponding to the information for identification is selected, and the strength of the signal received from the base station apparatus corresponding to the selected information is measured while using the selected information.

  Yet another embodiment of the present invention is also a signal strength measurement method. This method accepts information on a base station device that is a candidate for switching from a currently connected base station device during a limited predetermined period, and stores the received information in a memory, based on the received information. Then, measure the strength of the signal received from the base station device that is a candidate for switching, and if the information stored in the memory corresponds to the currently connected base station device in a period other than the predetermined period, Based on the information, the strength of the signal received from the base station device that is a candidate for switching is measured, and the information stored in the memory corresponds to the currently connected base station device in a period other than the predetermined period. If not, it receives information on the base station device that is the candidate for switching from the currently connected base station device, and based on the received information, the candidate for switching The intensity of the signal received from the base station apparatus comprising measuring the.

  Yet another embodiment of the present invention is also a signal strength measurement method. This method includes a step of connecting to at least one base station apparatus while switching the base station apparatus to be connected, information for identifying the base station apparatus before switching, and identifying the base station apparatus after switching While associating the information, a combination of them is stored in the memory, and by switching the information for identifying the currently connected base station apparatus to the information for identifying the base station apparatus before switching, Selecting from the combinations stored in the memory information for identifying the base station apparatus after switching to be associated with the information for identifying the currently connected base station apparatus; and A step of receiving information on a base station device that is a candidate for switching from a base station device that has been switched, and after the selected switching from the received information While using the selected information in the step of selecting information corresponding to the information for identifying the ground station device and the step of selecting the information corresponding to the information for identifying the base station device after the selected switching, Measuring the strength of a signal received from the base station device corresponding to the selected information in the step of selecting information corresponding to the information for identifying the selected base station device after switching. .

  The connecting step receives a signal spread by a predetermined spreading code from the base station apparatus, and the information received in the receiving step includes information relating to the spreading code in the base station apparatus that is a candidate for switching, and the step of measuring May measure the strength of the received signal by using the spreading code selected in the step of selecting information corresponding to the information for identifying the selected base station apparatus after switching. According to the signal strength measured in the measuring step, when the connecting step switches the base station device to be connected, information for identifying the base station device before switching and the base station device after switching are identified. The method may further comprise storing a combination of information for storing in the memory. The step of storing is performed when there is information for identifying a plurality of base station apparatuses after switching with respect to information for identifying one base station apparatus before switching in the combination stored in the memory. The step of ordering and measuring combinations according to the frequency of switching may measure the strength of the received signal according to the order given by the storing step.

  In the storing step, the combination may be stored in the memory for a limited predetermined period. In the storing step, the start time of the storage and the end time of the storage are defined in advance as the predetermined period. The storing step starts the storage when the storage start time is reached, When the end time comes, the storage may be ended. In the step of storing, first information for identifying a base station apparatus to start storing and second information for identifying a base station apparatus to end storing are specified in advance as a predetermined period. The storing step starts storage when the base station apparatus to be switched corresponds to the first information, and ends storage when the base station apparatus to be switched corresponds to the second information. May be.

  Yet another embodiment of the present invention is also a signal strength measurement method. The method includes a step of connecting to at least one base station device while switching a base station device to be connected, and a step of receiving information on a base station device that is a candidate for switching from the currently connected base station device. Storing the received information in a memory, and measuring the intensity of a signal received from the base station apparatus that is a candidate for switching based on information about the base station apparatus that is a candidate for switching. The accepting step and the storing step operate in a limited predetermined period, and the accepting step corresponds to the base station apparatus to which the information stored in the memory is currently connected in a period other than the predetermined period. If the information stored in the memory does not correspond to the currently connected base station apparatus, the information received by the operation is output to the step of measuring, and a period other than the predetermined period If the information stored in the memory corresponds to the currently connected base station apparatus, the information is output to the step of measuring.

  In the accepting step and the storing step, the storage start time and the storage end time are defined in advance as a predetermined period, and the accepting step and the storing step are performed from the storage start time to the end of storage. The operation may be performed up to the predetermined time. In the accepting step and the storing step, as a predetermined period, first information for identifying a base station device to start storing, and second information for identifying a base station device to end storing The step of accepting and storing is a predetermined period from when the base station device to be switched corresponds to the first information to when the base station device to be switched corresponds to the second information. May operate as

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the power consumption at the time of measuring the intensity | strength of the signal received from the base station apparatus can be reduced.

Example 1
Before describing the present invention in detail, an outline will be described. Embodiment 1 of the present invention relates to a terminal apparatus compatible with the W-CDMA system. The plurality of base station apparatuses are arranged in a plane, and each base station apparatus forms a cell. A terminal device owned by a user is connected to one of a plurality of base station devices while moving. At that time, the base station apparatus to be connected is switched. When the terminal device is connected to one base station device, the terminal device receives a paging signal from the base station device. The paging signal includes information related to surrounding base station apparatuses. Here, the information regarding the surrounding base station apparatus includes at least information regarding the spreading code of the surrounding base station apparatus, particularly the scramble code. The spreading code is set for the pilot signal from the base station apparatus, but different spreading codes are set for each base station apparatus.

  The terminal device stores in advance a combination of information for identifying the base station device before switching and information for identifying the base station device after switching. This combination is generated based on the past performance of the terminal device, and can be said to be a movement history of the terminal device. For example, the switching destination from the first base station apparatus is indicated to be the second base station apparatus and the third base station apparatus. When the terminal device receives the information on the above-mentioned neighboring base station devices from the currently connected base station device, the terminal device spreads the base station device to be the base station device after switching based on the combination stored in advance. Select a sign. That is, a base station apparatus having a history of movement in the past is selected from neighboring base station apparatuses. The terminal apparatus measures the strength of the pilot signal from the selected base station apparatus and determines the base station apparatus to switch to.

  FIG. 1 shows a configuration of a communication system 100 according to Embodiment 1 of the present invention. The communication system 100 includes a terminal device 10, a first base station device 12a, a second base station device 12b, a third base station device 12c, a fourth base station device 12d, and a fifth base station device, which are collectively referred to as a base station device 12. 12e, a sixth base station apparatus 12f, a first cell 14a, a second cell 14b, a third cell 14c, a fourth cell 14d, a fifth cell 14e, and a sixth cell 14f, which are collectively referred to as a cell 14.

  The base station apparatus 12 has a wireless communication function at one end and a wired communication function at the other end. The wired communication function of the base station apparatus 12 is connected to a network (not shown), and executes a communication operation with the network. Further, the wireless communication function of the base station device 12 performs a communication operation with the terminal device 10. Here, it is assumed that the wireless communication is compatible with the W-CDMA system. The base station apparatus 12 sets an individual channel for the terminal apparatus 10 in order to execute communication with the terminal apparatus 10. In addition, the base station apparatus 12 transmits a pilot signal and a paging signal so that the terminal apparatus 10 can switch the connection destination to any of the plurality of base station apparatuses 12.

  The pilot signal is a signal for causing the base station apparatus 12 to measure the signal strength, and has a different spreading code, particularly a scramble code, for each base station apparatus 12. Further, the paging signal is a signal for notifying the terminal device 10 of predetermined information, and in particular, here, information of the surrounding base station device 12 is notified. The information on the peripheral base station apparatus 12 includes at least information on the type of spreading code in the pilot signal of the surrounding base station apparatus 12 and the timing difference of the spreading code. The base station apparatus 12 forms a cell 14, and the terminal apparatus 10 can be connected to the base station apparatus 12 that forms the cell 14 in the cell 14. Further, the terminal device 10 can be connected to the plurality of base station devices 12 in the overlapping portion of the plurality of cells 14.

  The terminal device 10 is used by a user and is connected to one of the base station devices 12. The terminal apparatus switches the connection target base station apparatus 12 while moving in the cell 14. The switching is basically performed based on the strength of the pilot signal, and is executed so as to select the base station apparatus 12 corresponding to the pilot signal having a high strength. In the figure, the terminal device 10 moves from the first cell 14a to the second cell 14b. When the terminal device 10 is present in the first cell 14a, the strength of the pilot signal from the first base station device 12a increases in the terminal device 10. As a result, the terminal device 10 selects the first base station device 12a and connects to the first base station device 12a.

  On the other hand, when the terminal device 10 moves and exists in the second cell 14b, the terminal device 10 increases the strength of the pilot signal from the second base station device 12b. As a result, the terminal device 10 selects the second base station device 12b and connects to the second base station device 12b. In addition, the user who owns the terminal device 10 moves between the cells 14, but generally does not move randomly between the cells 14 but tends to move along a route determined to some extent. For example, the first cell 14a, the second cell 14b, and the sixth cell 14f move in this order. Furthermore, in the W-CDMA system, the terminal apparatus 10 performs site diversity. Here, for the sake of clarity of explanation, the terminal apparatus 10 is assumed to be connected to one base station apparatus 12. For application to site diversity, a part described for one base station apparatus 12 may be a plurality of base station apparatuses 12.

  FIG. 2 shows the configuration of the terminal device 10. The terminal device 10 includes an antenna 20, a communication unit 22, a processing unit 24, a reception unit 26, a measurement unit 28, a control unit 30, a storage unit 32, and a selection unit 34. The communication unit 22 includes a radio unit 36, a transmission unit 38, and a reception unit 42, and the reception unit 42 includes a correlation unit 46.

  The communication unit 22 connects to at least one base station apparatus 12 while switching the connection-target base station apparatus 12. As a reception process, the radio unit 36 converts the radio frequency signal received by the antenna 20 into a baseband signal, and outputs the baseband signal to the reception unit 42. Therefore, the radio unit 36 includes a frequency conversion unit, an LNA (Low Noise Amplifier), a quadrature detector, and an AD converter (not shown). On the other hand, as a transmission process, the radio unit 36 converts the baseband signal input from the transmission unit 38 into a radio frequency signal and outputs the signal to the antenna 20. Therefore, the radio unit 36 includes a DA converter, a quadrature modulator, a frequency converter, and a PA (Power Amplifier) (not shown). The radio unit 36 receives from the base station device 12 a signal spread by a predetermined spreading code. The signal includes the above-described dedicated channel signal, paging signal, and pilot signal.

  The transmission unit 38 modulates and spreads data from the processing unit 24. Furthermore, the transmission unit 38 outputs the spread signal to the radio unit 36 as a baseband signal. Here, it is assumed that modulation and spreading conform to the W-CDMA system.

  The receiving unit 42 despreads and demodulates the baseband signal from the radio unit 36. Further, the receiving unit 42 outputs the demodulated signal to the processing unit 24. Here, it is assumed that demodulation and despreading conform to the W-CDMA system. The receiving unit 42 includes a correlation unit 46. The correlation unit 46 is configured by a matched filter or a sliding correlator. Here, the matched filter will be described. A spreading code is set for the tap coefficient of the matched filter. If the spreading code of the signal input to the correlation unit 46 is close to the tap coefficient, the correlation value output from the correlation unit 46 increases. Therefore, using the correlation unit 46, spreading code synchronization, timing synchronization, and signal strength measurement can be performed. Here, it is assumed that the correlation unit 46 is used for signal strength measurement, and synchronization of spreading codes, timing synchronization, and the like can be performed by conventional techniques, and thus description thereof is omitted.

  The processing unit 24 performs predetermined processing on the data input from the receiving unit 42. When a computer (not shown) or the like is connected to the terminal device 10, the processing unit 24 corresponds to an interface with the computer. In particular, here, when a paging signal from the currently connected base station apparatus 12 is input to the processing unit 24, the processing unit 24 outputs the paging signal to the reception unit 26.

  The receiving unit 26 receives a paging signal from the processing unit 24. The paging signal includes information related to neighboring base station apparatuses 12, that is, base station apparatuses 12 that are candidates for switching (hereinafter referred to as "paging information"). The paging information includes information on the spreading code in the base station apparatus 12 that is a candidate for switching, and specifically includes information on the type of spreading code of the base station apparatus 12 and timing error. FIG. 3 shows the data structure of the paging information input to the accepting unit 26. Here, it is assumed that the terminal device 10 to which the terminal device 10 is currently connected is the first terminal device 10a. As the “base station device name”, information on “first base station device” to “Nth base station device” corresponding to the surrounding base station device 12 is included. Information for each base station apparatus is “spread code type” and “timing difference”. The “spread code type” is indicated as “A1” or the like, and the “timing difference” is indicated as “B1” or the like. Note that the paging information may not include the “base station device name” but may include “spread code type” and “timing difference”.

  Here, the spreading code is defined to include a channelization code and a scramble code in the W-CDMA system. In the pilot signal for the terminal device 10 to measure the signal strength, CPICH (Common Pilot Channel) in the W-CDMA system, the scrambling code is defined to be different for each base station device 12. That is, the “spread code type” corresponds to the scramble code type, and the scramble code of the pilot signal is specified by this information. The “timing difference information” is CPICH scramble code timing difference information between the first terminal apparatus 10a and the peripheral terminal apparatus 10. With this information, the terminal device 10 knows the type of scrambling code of the neighboring base station device 12 and the average reception timing of CPICH at the terminal device 10.

  Returning to FIG. The storage unit 32 stores a combination of information for identifying the base station device 12 before switching in the communication unit 22 and information for identifying the base station device 12 after switching. Here, the information for identifying the base station device 12 before switching and the information for identifying the base station device 12 after switching are based on the switching of the base station device 12 made by the terminal device 10 in the past. The generation of these combinations will be described later. In particular, the combination stored in the storage unit 32 corresponds to a movement path having a high frequency among the movement paths of the terminal device 10 in the past. Moreover, the information for identification is information for specifying the base station apparatus 12, for example, an identification number assigned to the base station apparatus 12 or a spreading code assigned to the base station apparatus 12, The format can be arbitrary. Note that the spreading code is a spreading code for the pilot signal. FIG. 4 shows the structure of data stored in the storage unit 32. “Before switching” and “After switching” in the figure correspond to the base station apparatus 12 before switching and the base station apparatus 12 after switching, respectively. This corresponds to the change of the base station device 12 to be connected to the terminal device 10 from the base station device 12 before switching to the base station device 12 after switching due to movement of the terminal device 10.

  As described above, when the terminal device 10 is connected to the first base station device 12a, the paging signal of the first base station device 12a causes the “second base station device” to the “Nth base station” as shown in FIG. "Device" is notified. However, in the past, the terminal device 10 includes the first base station device 12a to the second base station device 12b, the first base station device 12a to the third base station device 12c, and the first base station device 12a to the fourth base station device. When switching to 12d is performed, it can be expected that the switching will be one of these. Therefore, the measurement of the strength of the pilot signal in the terminal device 10 is limited to the second base station device 12b, the third base station device 12c, and the fourth base station device 12d. In FIG. 3, “second base station apparatus” or the like is shown as a storage target, but the storage unit 32 stores an identification number or spreading code corresponding to “second base station apparatus”. Shall. Further, the number of “after switching” base station apparatuses 12 may be limited to a predetermined value. Thereby, the storage capacity of the storage unit 32 can be reduced.

  Returning to FIG. The selection unit 34 stores information in the storage unit 32 by associating information for identifying the base station device 12 to which the terminal device 10 is currently connected with information for identifying the base station device 12 before switching. Among the combinations, the communication unit 22 selects information for identifying the base station device 12 after switching to correspond to the information for identifying the base station device 12 to which the communication unit 22 is currently connected. Therefore, the selection unit 34 receives information for identifying the currently connected base station device 12 from the processing unit 24 via the reception unit 26, that is, the identification number and the spreading code of the first base station device 12a. Yes. For example, when the information for identifying the base station device 12 is the spreading code of the base station device 12, the selection unit 34 selects the first base station device in the “before switching” column stored in the storage unit 32. Search for the 12a spreading code and select if applicable. Further, the spreading code of the base station apparatus 12 “after switching” corresponding to the spreading code of the first base station apparatus 12 a “before switching” is selected. That is, in FIG. 4, the spreading code of the 4th base station apparatus 12d is selected from the 2nd base station apparatus 12b.

  The selection unit 34 selects information corresponding to the information for identifying the base station device 12 after switching selected as described above from the paging information received by the reception unit 26. That is, some information in the paging information is selected. This corresponds to an operation of selecting a base station apparatus 12 with a track record that the terminal apparatus 10 has switched in the past. In FIG. 3, among the “second base station device” to the “Nth base station device”, the spreading code and the timing difference from the “second base station device” to the “fourth base station device” are selected. The selection unit 34 outputs the selected spreading code to the correlation unit 46. The correlation unit 46 sets the spreading code from the selection unit 34 as a tap coefficient, and the correlation unit 46 executes correlation processing according to the timing based on the timing difference from the selection unit 34 and outputs the correlation value to the measurement unit 28. To do. Here, a pilot signal is input to execute the correlation processing.

  The measurement unit 28 calculates the strength of the correlation value from the correlation unit 46. That is, the measurement unit 28 uses the spread code and the timing difference that are information selected by the selection unit 34, and the strength of the pilot signal received from the base station apparatus 12 corresponding to the information selected by the selection unit 34 Measure. When there are a plurality of pieces of information selected by the selection unit 34, spread codes corresponding to the pieces of information are set as tap coefficients of the reception unit 42 at predetermined intervals. As a result, the measurement unit 28 calculates the intensity of the pilot signal corresponding to each of the plurality of pieces of information.

  The control unit 30 determines switching of the base station apparatus 12 to be connected according to the strength of the pilot signal measured by the measurement unit 28. The switching algorithm may be arbitrary. For example, the maximum value of the signal strengths from the second base station device 12b to be connected to the fourth base station device 12d measured by the measurement unit 28 is the current connection. When the signal strength of the first base station apparatus 12a is larger than a value obtained by adding a predetermined value, switching to the base station apparatus 12 corresponding to the maximum value is determined. For example, if the signal strength of the second base station apparatus 12b is high, switching to the second base station apparatus 12b is determined. Note that the switching process of the base station apparatus 12 only needs to be performed in accordance with the prescription in the W-CDMA system, and thus the description thereof is omitted here. The addition of the predetermined value is performed in order to provide hysteresis for switching.

  In addition, when the connection-target base station apparatus 12 is switched according to the strength of the pilot signal measured by the measurement section 28, the control unit 30 and the base station apparatus 12 after switching and the identification number of the switching base station apparatus 12 The combination of identification numbers of the devices 12 is stored in the storage unit 32. In the above-described example, the combination of the first base station apparatus 12a “before switching” and the second base station apparatus 12b “after switching” is stored. In addition, in the combination already stored in the storage unit 32, there is information for identifying a plurality of base station apparatuses 12 after switching with respect to information for identifying one base station apparatus 12 before switching. In some cases, the control unit 30 orders the combinations according to the frequency of switching. The frequency corresponds to the number of switching times.

  In FIG. 4, the second base station device 12b, the third base station device 12c, and the fourth base station device 12d “after switching” are stored for the first base station device 12a “before switching”. Assume that the frequency of switching is “1000 times”, “100 times”, and “10 times” in order. In this way, the control unit 30 arranges the base station apparatuses 12 after switching in order of increasing switching frequency. This can be said to be the order in which the possibility of switching is high. In order to execute the above operation, the storage unit 32 may store the number of times of switching in addition to the information of the base station apparatus 12 “after switching”. At that time, the measurement unit 28 described above measures the strength of the received pilot signal according to the order given by the control unit 30. Therefore, the correlation part 46 sets a spreading code to a tap coefficient according to the said order.

  This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of an arbitrary computer, and in terms of software, it is realized by a program having a reservation management function loaded in memory. The functional block realized by those cooperation is drawn. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  The operation of the communication system 100 configured as above will be described. FIG. 5 is a sequence diagram illustrating a procedure for measuring signal strength in the communication system 100. Here, as described above, it is assumed that the terminal apparatus 10 is connected to the first base station apparatus 12a. The first base station apparatus 12a transmits a paging signal to the terminal apparatus 10 (S10). The terminal device 10 receives the paging signal and acquires the paging information included therein (S12). It is assumed that the paging information includes information for identifying the first base station apparatus 12a to the Nth base station apparatus 12n-1. The terminal apparatus 10 selects a part or all of the base station apparatus 12 included in the paging information while referring to the combinations stored in the storage unit 32 (S14). Here, it is assumed that the second base station apparatus 12b and the third base station apparatus 12c are selected. Therefore, this corresponds to selecting a part of the base station apparatus 12 included in the paging information.

  The first base station apparatus 12a transmits a pilot signal to the terminal apparatus 10 (S16). The terminal device 10 measures the strength of the pilot signal from the first base station device 12a (S18). The second base station apparatus 12b transmits a pilot signal to the terminal apparatus 10 (S20). The terminal device 10 measures the strength of the pilot signal from the second base station device 12b (S22). The third base station apparatus 12c transmits a pilot signal to the terminal apparatus 10 (S24). The terminal device 10 measures the strength of the pilot signal from the third base station device 12c (S26). Through the above processing, the signal strength of a part of the base station apparatus 12 included in the paging information is measured.

  FIG. 6 is a flowchart showing a switching procedure of the base station apparatus 12 in the terminal apparatus 10. If the measurement start timing does not arrive (N in S30), the terminal device 10 does not execute the process until it arrives. This corresponds to a sleep state. When the measurement start timing arrives (Y in S30), the receiving unit 42 receives the paging signal from the connected base station apparatus 12 (S32), and the receiving unit 26 receives the paging information. The selection unit 34 selects the base station apparatus 12 to be measured while referring to the storage unit 32 (S34). The correlation unit 46 sets the spreading code for the connected base station device 12 as a tap coefficient, and the measuring unit 28 measures the strength of the pilot signal from the connected base station device 12 (S36). Further, the correlation unit 46 sets the spreading code for the base station apparatus 12 selected by the selection unit 34 as a tap coefficient, and the measurement unit 28 measures the strength of the pilot signal from the base station apparatus 12 (S38). .

  If the measurement unit 28 does not complete the measurement of the pilot signal strength for the base station apparatus 12 selected by the selection unit 34 (N in S40), the process of step 38 is repeatedly executed. On the other hand, when the measurement of the pilot signal strength for the base station apparatus 12 selected by the selection unit 34 is completed in the measurement unit 28 (Y in S40), the control unit 30 selects the maximum strength (S42). ). The control unit 30 adds a predetermined value to the strength of the pilot signal from the connected base station apparatus 12 to generate a threshold value. The control unit 30 compares the maximum intensity with the threshold value, and if the maximum intensity is greater than the threshold value (Y in S44), determines the switching to the base station apparatus 12 corresponding to the maximum intensity (S46). ). On the other hand, if the maximum intensity is not greater than the threshold value (N in S44), the control unit 30 continues to connect to the currently connected base station apparatus 12. Note that the comparison in step 44 may not be performed after all the signal intensity measurements are completed, but the comparison in step 44 may be performed after the measurement of the intensity of one signal is completed. At that time, if the intensity of one signal becomes larger than the threshold value, the switching of the base station apparatus 12 may be determined. As a result, the number of measurements can be reduced.

  FIG. 7 is a flowchart showing a combination storing procedure in the control unit 30. This corresponds to the processing following the flowchart of FIG. The control unit 30 generates a combination from the spreading code for the base station apparatus 12 before switching and the spreading code for the base station apparatus 12 after switching (S50). The control unit 30 extracts a combination in which the spreading code of the base station apparatus 12 before switching is the same as the current one from the storage unit 32 (S52), and adds the generated combination to the extracted combination (S54). If the generated combination exists in the extracted combination, “1” is added to the number of times of the combination. That is, the switching frequency is counted up.

  As a result of the above processing, if the order of switching frequency corresponding to each of the plurality of combinations is changed (Y in S56), the control unit 30 switches the order of the stored contents of the storage unit 32 (S58). For example, the combination of the base station apparatus 12 “before switching” and the base station apparatus 12 “after switching” is a first base station apparatus 12a and a second base station apparatus 12b, and a first base station apparatus 12a and a third base station. It is assumed that the station apparatus 12c has the switching order in the former. Thereafter, when the switching frequency of the latter increases and becomes greater than that of the former, the control unit 30 causes the storage unit 32 to store the latter so that it is in front. That is, the order of both is switched. On the other hand, if the order of switching frequency corresponding to each of the plurality of combinations is not changed (N in S56), the process is terminated.

  FIGS. 8A and 8B show the effect of reducing power consumption by the terminal device 10. It is assumed that the terminal device 10 performs an operation in the low power consumption mode and periodically receives a signal from the base station device 12 without performing communication. Further, it is assumed that the terminal device 10 is connected to the first terminal device 10a. FIG. 8A shows an operation in a conventional terminal device to be compared with the present embodiment. “P” in the figure indicates that the terminal device 10 is receiving a paging signal. Moreover, the information of the base station apparatus 12 included in the pilot information corresponds to the first base station apparatus 12a to the fourth base station apparatus 12d. “A” in the figure indicates that the terminal apparatus 10 receives a pilot signal from the first base station apparatus 12a, and “B” indicates that the terminal apparatus 10 receives a pilot signal from the second base station apparatus 12b. "C" indicates that the terminal apparatus 10 is receiving a pilot signal from the third base station apparatus 12c, and "D" indicates that the terminal apparatus 10 is the fourth base station. It shows that the pilot signal from the device 12d is received.

  As shown in the figure, the terminal apparatus 10 is periodically activated, performs operations in the order of “P”, “A”, “B”, “C”, and “D”, and a current corresponding thereto flows. Further, power corresponding to the current value is consumed. FIG. 8B shows an operation in the terminal device 10 of the present embodiment. Here, it is assumed that only the switching from the first base station apparatus 12a to the second base station apparatus 12b is stored in the storage unit 32 from the past results, and as a result, the terminal apparatus 10 is “P”, The operation is executed in the order of “A” and “B”. Compared with FIG. 8A, in FIG. 8B, power is not consumed in the periods of “C” and “D”. That is, power consumption is reduced by a value corresponding to this period.

  In the embodiments so far, the storage unit 32 stores the combination of the base station apparatus 12 before switching and the base station apparatus 12 after switching, thereby shortening the measurement period of the pilot signal strength. If the number of combinations to be stored in the storage unit 32 increases, the storage capacity of the storage unit 32 must be increased. However, the storage capacity of the storage unit 32 provided in the terminal device 10 has a limit. A technique for limiting the number of combinations to be stored in the storage unit 32 will be described below.

  One technique for limiting the number of combinations to be stored in the storage unit 32 is a technique for limiting by time. That is, the control unit 30 stores the combinations in the storage unit 32 during a limited predetermined period. The control unit 30 predefines the storage start time and the storage end time as such a predetermined period. The control unit 30 causes the storage unit 32 to start storing when the storage start time is reached, and ends the storage unit 32 storage when the storage end time is reached. For example, in the control unit 30, if the storage start time is defined as “7 am” and the storage end time is defined as “8 am”, the control unit 30 determines that “7 am” To “8:00 am” and the storage unit 32 stores the combination. Such a setting is made by the user via an interface (not shown).

  FIG. 9 is a flowchart illustrating a storage period determination process performed by the control unit 30. If the start time does not arrive (N in S60), the control unit 30 does not store the combination in the storage unit 32 until it arrives. On the other hand, if the start time arrives (Y in S60), the control unit 30 stores the combination in the storage unit 32 (S62). If the end time has not come (N in S64), the process of step 62 is repeated. On the other hand, if the end time arrives (Y in S64), the control unit 30 ends the combination storage process.

  Another technique for limiting the number of combinations to be stored in the storage unit 32 is a technique for limiting by the connected base station apparatus. The control unit 30 preliminarily defines a first spreading code corresponding to the base station apparatus 12 to start storing and a second spreading code corresponding to the base station apparatus 12 to end storing. When the base station device 12 to be switched corresponds to the first spreading code, the control unit 30 causes the storage unit 32 to start storing, and when the base station device 12 to be switched corresponds to the second spreading code, The storage unit 32 ends the storage. For example, in the control unit 30, the base station device 12 that should start the storage is defined as “base station device 12 installed near home”, and the base station device 12 that should end the storage is “installed near school” If it is prescribed | regulated to the base station apparatus 12 "by which it was prescribed | regulated, the control part 30 will memorize | store a combination in the memory | storage part 32 over the period until a user arrives at a school after leaving a home.

  FIG. 10 is a flowchart showing another process of determining the storage period by the control unit 30. If the base station apparatus 12 corresponding to the start is not connected (N in S70), the control unit 30 does not store the combination in the storage unit 32 until the connection is established. On the other hand, if connected to the base station apparatus 12 corresponding to the start (Y in S70), the control unit 30 stores the combination in the storage unit 32 (S72). If it is not connected to the base station apparatus 12 corresponding to the end (N of S74), the process of step 72 is repeated. On the other hand, if connected to the base station device 12 corresponding to the end (Y in S74), the control unit 30 ends the combination storing process.

  According to the embodiment of the present invention, the information corresponding to the combination stored in the storage unit is selected from the information about the base station device that is a candidate for switching, and the signal strength is measured based on the selected information. Therefore, the number of base station devices whose signal strength should be measured can be reduced, and power consumption can be reduced. In addition, since the combinations stored in the storage unit are based on past results, even if the number of base station devices whose signal strength should be measured is reduced, signals from base station devices that are likely to be switched. Can be measured. In addition, since the power consumption can be reduced, the driving time of the battery can be extended. In addition, since the power consumption can be reduced, the terminal device can be downsized.

  Also, since the spreading code is notified from the base station apparatus, the process for specifying the spreading code can be omitted, and the signal strength can be measured quickly. Also, since the spreading code is notified from the base station apparatus, it is possible to avoid spreading code errors when measuring the signal strength. Moreover, since the process for specifying a spreading code can be omitted, power consumption can be reduced. In addition, since the result of switching in the past is reflected in the selection of the base station device whose signal strength should be measured, the signal strength of the base station device that is highly likely to be switched can be measured. Even if the number of base station apparatuses is reduced, a reduction in switching accuracy can be suppressed. In addition, when there are a plurality of base station apparatuses to be switched, measurement is performed from the signal strength of the base station apparatus that is highly likely to be switched, so that the processing efficiency can be improved.

  In addition, if one base station apparatus performs switching when the switching condition is satisfied, the number of times of measurement can be determined by measuring from the signal strength of the base station apparatus that is likely to be switched. Can be reduced. Further, power consumption can be reduced by reducing the number of times of measurement. Further, the storage capacity of the storage unit can be reduced by limiting the period for storing the combinations in the storage unit. Further, if the predetermined period is limited by the time, the accuracy of the combination stored in the storage unit is increased when a predetermined action is performed at the predetermined time. Moreover, when setting the time, by combining parameters that define other timings, when performing the same action at the same time on another day, the accuracy of the combination stored in the storage unit is increased. In addition, if the predetermined period is limited by the base station device, the combination of the information stored in the storage unit when the behavior starting from the predetermined position and arriving at the predetermined position is periodically executed. Increases accuracy.

(Example 2)
As in the first embodiment, the second embodiment of the present invention relates to a terminal device that supports the W-CDMA system. The terminal apparatus which concerns on Example 2 receives the paging signal from a base station apparatus, and memorize | stores the information regarding the surrounding base station apparatus contained in the paging signal in memory. However, the period for storing in the memory is limited. During the period other than the period, the memory is not stored. Furthermore, if the information stored in the memory corresponds to the currently connected base station apparatus, the information stored in the memory is used without receiving the paging signal. As a result, the amount of information to be stored in the memory can be reduced, and reception of the paging signal may be stopped, so that power consumption can be reduced.

  The communication system 100 according to the second embodiment is of the type shown in FIG. Here, the terminal device 10 receives the paging signal over a predetermined period, and stores the paging information included in the received paging signal. On the other hand, if the stored information corresponds to the connected base station apparatus 12 over a period other than the predetermined period, the terminal apparatus 10 stops receiving the paging signal. Further, the terminal device 10 measures the strength of the pilot signal from the base station device 12 while using the stored information. If the stored information does not correspond to the connected base station apparatus 12, the terminal apparatus 10 receives the paging signal and uses the paging information included in the received paging signal, while the pilot from the base station apparatus 12 is received. Measure the signal strength.

  The terminal device 10 according to the second embodiment is of the type shown in FIG. Here, in the reception unit 26 and the storage unit 32, the start time of storage and the end time of storage are defined in advance as predetermined periods. In other words, the reception unit 26 and the storage unit 32 operate for a predetermined period from the start time of storage to the end time of storage. Thus, the predetermined period is limited by the time. The “storage start time” and the “storage end time” are the same as described above, and thus description thereof is omitted. Such control for a predetermined period is performed by the control unit 30. In addition, although the control part 30 performs the process which switches the base station apparatus 12 as Example 1, it abbreviate | omits description here.

  The receiving unit 26 receives a paging signal from the processing unit 24 over a predetermined period. On the other hand, in a period other than the predetermined period, the reception unit 26 does not receive a paging signal from the processing unit 24 under a predetermined condition, and receives a paging signal from the processing unit 24 if the predetermined condition is not met. The predetermined condition will be described later. Here, when the paging signal is not received from the processing unit 24, the terminal device 10 stops receiving the paging signal.

  The storage unit 32 stores the information received by the reception unit 26. Information received in the receiving unit 26 is transmitted to the storage unit 32 through a signal line (not shown). In that case, the memory | storage part 32 performs memory | storage over a predetermined period by control from the control part 30. FIG. If it is not the predetermined period, the storage unit 32 does not execute the storage. Here, the information memorize | stored by the memory | storage part 32 is shown as FIG.

  The selection unit 34 outputs the information received by the reception unit 26 to the correlation unit 46 and the like during a predetermined period. In particular, the selection unit 34 outputs the spread code and the timing difference to the correlation unit 46. On the other hand, in a period other than the predetermined period, the selection unit 34 inputs information for identifying the currently connected base station apparatus 12, for example, a spreading code, from the reception unit 26. If the information corresponding to the currently connected base station apparatus 12 is included with reference to the storage unit 32, the selection unit 34 outputs the information stored in the storage unit 32 to the correlation unit 46 or the like. At that time, the receiving unit 26 stops receiving the paging signal. That is, the fact that information corresponding to the currently connected base station apparatus 12 is included in the storage unit 32 corresponds to the aforementioned “predetermined condition”. On the other hand, referring to the storage unit 32, if the information corresponding to the currently connected base station apparatus 12 is not included, the information received in the reception unit 26 is output to the correlation unit 46 and the like.

  The correlation unit 46 sets the spreading code from the selection unit 34 as a tap coefficient, and the correlation unit 46 executes correlation processing according to the timing based on the timing difference from the selection unit 34 and outputs the correlation value to the measurement unit 28. To do. Here, a pilot signal is input to execute the correlation processing.

  As in the first embodiment, the terminal device 10 corresponds to the first spreading code corresponding to the base station device 12 that should start the storage and the base station device 12 that should end the storage as the predetermined period. The second spreading code may be defined in advance. That is, the predetermined period may be limited by the connected base station apparatus. In this case, the reception unit 26 and the storage unit 32 are configured so that the base station apparatus 12 switched by the communication unit 22 is switched to the second spreading code from the case where the base station apparatus 12 switched by the communication unit 22 corresponds to the first spreading code. Until the case corresponding to is defined as a predetermined period.

  The effect of low power consumption in the terminal device 10 according to the second embodiment is illustrated in FIG. Here, when the reception unit 26 does not receive the paging signal, the operation is not executed during the period “P” in FIG. Therefore, no current flows during the period “P”, and power consumption is reduced.

  According to the embodiment of the present invention, since the period for storing the paging information in the storage unit is limited, the storage capacity of the storage unit can be reduced. In addition, since a period during which paging information is not received also occurs, power consumption can be reduced. Further, if the predetermined period is limited by the time, the accuracy of the paging information stored in the storage unit is increased when a predetermined action is performed at the predetermined time. Further, when setting the time, by combining parameters that define other timings, when performing the same action at the same time on another day, the accuracy of the paging information stored in the storage unit is increased. Further, if the predetermined period is limited by the base station device, the paging information stored in the storage unit is periodically stored when an action starting from the predetermined position and arriving at the predetermined position is executed. The accuracy of.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. is there.

  In the first and second embodiments of the present invention, the communication system 100 is assumed to be a W-CDMA system. However, the present invention is not limited to this. For example, the communication system 100 may be other than W-CDMA. In particular, when the CDMA system is not used, the identification number of the base station apparatus 12 may be used as information for identifying the base station apparatus 12. According to this modification, the present invention can be applied to various communication systems 100. That is, the base station apparatus 12 only has to report information related to neighboring base station apparatuses 12.

  In Embodiments 1 and 2 of the present invention, the base station apparatus 12 uses a paging signal to broadcast information related to the surrounding base station apparatus 12, and the terminal apparatus 10 uses a pilot signal to measure the signal strength. did. However, the present invention is not limited to this. For example, other signals may be used, and signals provided in the applied communication system 100 may be signals having similar functions. According to this modification, the present invention can be applied to various communication systems 100. That is, the base station device 12 may be a signal that can be used for information related to the surrounding base station device 12 or a signal that the terminal device 10 can measure the intensity.

  In the first and second embodiments of the present invention, the period during which the storage unit 32 stores the combination and paging information is limited by the time and the base station apparatus 12. However, the present invention is not limited to this. For example, the terminal device 10 may include a non-contact IC function unit, and may define a predetermined period depending on a position to be recognized by the non-contact IC function unit. That is, in the control unit 30, the receiving unit 26, the storage unit 32, and the like, a non-contact type IC reading device that should start storing and a non-contact type IC reading device that should end storing are defined as predetermined periods. The control unit 30, the reception unit 26, the storage unit 32, and the like start the storage when the non-contact type IC function unit is brought into contact with the non-contact type IC reader to start the storage, and the non-contact type IC function When the unit is brought into contact with the non-contact type IC reader that should end the storage, the storage may be ended. For example, when the terminal device 10 is provided with a non-contact IC reader at the station, the terminal device 10 starts storage from a predetermined station and ends the storage at the predetermined station. According to this modification, an action is periodically performed starting from a position where a predetermined non-contact type IC reader is provided and arriving at a position where the predetermined non-contact type IC reader is provided. In this case, the accuracy of the paging information stored in the storage unit is increased. That is, it is only necessary to limit the execution of storage.

  In the first and second embodiments of the present invention, the period during which the storage unit 32 stores the combination and paging information is limited by the time and the base station apparatus 12. However, the present invention is not limited to this. For example, the terminal device 10 may define a predetermined period by a predetermined action. Here, the predetermined action is activation of a specific application such as an e-mail. That is, the control unit 30, the reception unit 26, the storage unit 32, and the like define the start timing of the predetermined application and the end timing of the predetermined application as the predetermined period. The unit 32 or the like may start storage when it corresponds to the start timing of a predetermined application, and end storage when it corresponds to the end timing of the predetermined application. For example, the terminal device 10 starts storage when starting an e-mail application, and ends storage when ending the e-mail application. According to the present modification, the accuracy of the paging information stored in the storage unit is increased when a predetermined application is periodically started at a predetermined position. That is, it is only necessary to limit the execution of storage.

It is a figure which shows the structure of the communication system which concerns on Example 1 of this invention. It is a figure which shows the structure of the terminal device of FIG. It is a figure which shows the structure of the data input into the reception part of FIG. It is a figure which shows the structure of the data memorize | stored in the memory | storage part of FIG. It is a sequence diagram which shows the measurement procedure of the signal strength in the communication system of FIG. It is a flowchart which shows the switching procedure of the base station apparatus in the terminal device of FIG. It is a flowchart which shows the memory | storage procedure of the combination in the control part of FIG. FIGS. 8A to 8B are diagrams illustrating the effect of reducing power consumption by the terminal device of FIG. It is a flowchart which shows the process of the determination of the storage period by the control part of FIG. It is a flowchart which shows another process of determination of the storage period by the control part of FIG.

Explanation of symbols

  10 terminal devices, 12 base station devices, 14 cells, 20 antennas, 22 communication units, 24 processing units, 26 reception units, 28 measurement units, 30 control units, 32 storage units, 34 selection units, 36 radio units, 38 transmission units 42 receiving unit, 46 correlating unit, 100 communication system.

Claims (12)

A communication unit that connects to at least one base station device while switching the base station device to be connected;
A storage unit for storing a combination of the information for identifying the base station device before switching in the communication unit and the information for identifying the base station device after switching;
By switching the information for identifying the base station apparatus to which the communication unit is currently connected to the information for identifying the base station apparatus before switching, among the combinations stored in the storage unit, A first selection unit for selecting information for identifying a base station device after switching to be associated with information for identifying the base station device to which the communication unit is currently connected;
A receiving unit that receives information on a base station device that is a candidate for switching from the currently connected base station device via the communication unit;
A second selection unit that selects information corresponding to information for identifying the base station device after switching selected in the first selection unit from the information received in the reception unit;
A measurement unit for measuring the strength of a signal received by the communication unit from a base station apparatus corresponding to the information selected by the second selection unit while using the information selected by the second selection unit;
A signal strength measuring device comprising: The communication unit receives a signal spread by a predetermined spreading code from the base station device,
The information received in the reception unit includes information on the spreading code in the base station device that is a candidate for switching,
2. The signal strength measuring apparatus according to claim 1, wherein the measurement unit measures the strength of a signal received by the communication unit by using the spreading code selected by the second selection unit.   According to the signal strength measured by the measurement unit, when the communication unit switches the base station device to be connected, information for identifying the base station device before switching and the base station device after switching are identified. The signal strength measuring device according to claim 1, further comprising a control unit that stores a combination of information for storing in the storage unit. In the combination stored in the storage unit, the control unit has information for identifying a plurality of base station devices after switching with respect to information for identifying one base station device before switching. And order the combinations according to the frequency of switching,
The signal measurement device according to claim 3, wherein the measurement unit measures the intensity of a signal received by the communication unit according to an order given by the control unit.   The signal strength measuring apparatus according to claim 3, wherein the control unit stores the combination in the storage unit for a limited predetermined period. In the control unit, as a predetermined period, the start time of storage and the end time of storage are defined in advance,
6. The signal strength measuring apparatus according to claim 5, wherein the control unit starts storage when the storage start time is reached, and ends storage when the storage end time is reached. The control unit preliminarily defines first information for identifying a base station apparatus to start storing and second information for identifying a base station apparatus to end storing as a predetermined period. And
The control unit starts storage when the base station device switched by the communication unit corresponds to the first information, and when the base station device switched by the communication unit corresponds to the second information, 6. The signal strength measuring apparatus according to claim 5, wherein the storage is terminated. A communication unit that connects to at least one base station device while switching the base station device to be connected;
A receiving unit that receives information on a base station device that is a candidate for switching from the currently connected base station device via the communication unit;
A storage unit for storing information received in the reception unit;
A measurement unit that measures the strength of a signal received by the communication unit from a base station device that is a candidate for switching based on information about the base station device that is a candidate for switching;
The reception unit and the storage unit operate in a limited predetermined period,
If the information stored in the storage unit corresponds to the currently connected base station apparatus in a period other than the predetermined period, the reception unit does not operate and the information stored in the storage unit Is not compatible with the currently connected base station device, outputs the information received by operating to the measurement unit,
If the stored information corresponds to the currently connected base station apparatus in a period other than the predetermined period, the storage unit outputs the information to the measurement unit. apparatus. In the reception unit and the storage unit, a predetermined time is defined in advance as a storage start time and a storage end time,
9. The signal strength measuring apparatus according to claim 8, wherein the reception unit and the storage unit operate as the predetermined period from a storage start time to a storage end time. In the reception unit and the storage unit, as a predetermined period, first information for identifying a base station apparatus that should start storage, and second information for identifying a base station apparatus that should end storage In advance,
The reception unit and the storage unit are configured to perform processing from when the base station device switched by the communication unit corresponds to the first information to when the base station device switched by the communication unit corresponds to the second information. The signal strength measuring device according to claim 8, wherein the signal strength measuring device operates as a predetermined period. While associating the information for identifying the base station device before switching with the information for identifying the base station device after switching, a combination thereof is stored in advance,
When receiving information about a base station device that is a candidate for switching from the currently connected base station device, information for identifying the currently connected base station device is used to identify the base station device before switching. By selecting the information for identifying the base station device after switching to be associated with the currently connected base station device from the combination by making it correspond to the information,
The information corresponding to the information for identifying the selected base station apparatus after switching is selected from the received information, and the received information is received from the base station apparatus corresponding to the selected information while using the selected information. A signal strength measuring method, wherein the signal strength is measured. In a limited period of time, information on the base station device that is a candidate for switching is received from the currently connected base station device, and the received information is stored in the memory, and the switching is performed based on the received information. Measure the strength of the signal received from the candidate base station device,
If the information stored in the memory corresponds to the currently connected base station apparatus in a period other than the predetermined period, the signal received from the base station apparatus that is a candidate for switching is based on the information. Measure the strength,
If the information stored in the memory does not correspond to the currently connected base station apparatus in a period other than the predetermined period, information on the base station apparatus that is a candidate for switching from the currently connected base station apparatus A signal strength measurement method, comprising: receiving and measuring the strength of a signal received from a base station apparatus that is a candidate for switching based on the received information.

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