JP4461845B2 - Mobile terminal communication system - Google Patents

Description

The present invention relates to a mobile terminal communication system using a mobile terminal device such as a mobile phone, a PHS, and a PDA having a communication function.

  There is international roaming as a service for using mobile phones overseas. International roaming is a service that enables the service of a contracted telecommunications carrier to be received using the facilities of an overseas partner.

  By the way, when trying to use a mobile terminal device in a wide geographical range by international roaming or the like, the frequency band used for communication may differ in countries and regions. For example, in a communication system called a GSM (Global System for Mobile Communications) network, frequency bands used as carrier waves are divided into 850 MHz, 900 MHz, 1800 MHz, and 1900 MHz depending on the country. Therefore, when using a mobile terminal device with such a communication system in a region different from the country or region where it was last used (hereinafter, abbreviated as appropriate), it is used this time when power is first turned on. It is necessary to select the region and set the frequency of the carrier used on the apparatus side. When such a region input is not performed and the previously used carrier frequency cannot be used, the mobile terminal device searches all frequency bands that may be used, for example, over several hundred carriers, and selects a usable frequency. I am doing so. For this reason, there is a problem that the user cannot start using the mobile terminal device for a relatively long time such as several tens of seconds until the search is completed.

Therefore, a mobile phone that searches for a carrier frequency at high speed has been proposed (see, for example, Patent Document 1). In this proposal, the power distribution of the entire band is measured during the full frequency search, and the search band is limited and ordered.
JP 2003-348648 (paragraph 0024, FIG. 3).

  According to this proposal, it is possible to search for a carrier frequency that can be used in the current location relatively quickly when going to a new area or when the mobile phone is first turned on after purchase. However, in this proposal, as preprocessing for searching, processing for measuring the power distribution of the entire band and processing for limiting and ordering the search bandwidth are performed. Therefore, even if the overall time required for the full frequency search can be reduced, there is no change in forcing the user to wait for a long time to some extent during the full frequency search.

SUMMARY OF THE INVENTION An object of the present invention is to provide a mobile terminal communication system that can reduce the time required to search for a frequency to be used while keeping the case of performing all frequency search to the minimum necessary.

In the present invention , (a) a specific regional frequency is shown as a frequency that is individually arranged at each specified location in a plurality of regions that are geographically spaced from each other and used uniquely when communicating in the corresponding region. An information providing terminal that transmits the specific area frequency information using a common radio frequency that the communication terminal can receive in common in the plurality of areas; and (b) the specific area frequency described above using the common radio frequency. A specific area frequency information receiving means for receiving information, and a frequency specified by the specific area frequency information, when the specific area frequency information receiving means receives the specific area frequency information. First frequency setting means for setting, frequency history storage means for storing each frequency that has been successfully communicated in each area in the past, and the first frequency described above A mobile phone provided with second frequency setting means for changing the setting to each frequency stored in the frequency history storage means until communication succeeds when communication in the area is not successful depending on the frequency setting by the setting means A terminal device is provided in the mobile terminal communication system .

  As described above, according to the present invention, it is possible to save the trouble of performing a full frequency band search by acquiring information related to the frequency band allocated to the mobile terminal device in an area where the mobile terminal device is to be used. Thus, not only can the time required for frequency search be shortened, but the user does not have to select a region where the mobile terminal device is used in advance. For this reason, it is possible to greatly reduce the time from when the portable terminal device is turned on until it is actually usable. In addition, by trying the frequency used in the past before performing the full frequency band search, it is not necessary for the businessmen etc. who are active in several areas to find the frequency once used by the full frequency band search. Communication can be started in a shorter time. For this reason, large-scale equipment is not required.

  Hereinafter, the present invention will be described in detail with reference to examples.

  FIG. 1 shows an outline of a circuit configuration of a mobile phone as a mobile terminal device according to the first embodiment of the present invention. The cellular phone 11 includes a transmission / reception unit 13 connected to an antenna 12, a frequency generator 14 that generates a reference phase frequency used for transmission / reception by the transmission / reception unit 13, and a short-range wireless unit 15 that performs short-range communication wirelessly. And a control unit 16 that controls each unit of the mobile phone 11. The control unit 16 includes a CPU (Central Processing Unit) 21. In addition, a ROM (read only memory) 23 storing a control program (not shown), various temporary data, a short-range wireless unit acquisition information storage area 24, and a previously used frequency storage area are stored in other areas. A random access memory (RAM) 26 in which 25 is arranged is provided.

  The transmission / reception unit 13 is a circuit part that performs signal processing for communication as a mobile phone. In this embodiment, communication is performed using a W-CDMA (Wideband Code Division Multiple Access) method, but other communication methods may be used. The short-range wireless unit 15 is a device that includes, for example, a non-contact IC (Integrated Circuit) card and performs short-range communication. In the present embodiment, by communicating with a predetermined information providing terminal 28, it is possible to acquire information relating to the area where the mobile phone 11 is currently located. The acquired information is temporarily stored in the short-range wireless unit acquisition information storage area 24 in the RAM 26. The information providing terminal 28 is arranged at a place serving as a window in an area where the use frequency needs to be switched, such as a customs facility when crossing a border at an airport, a port, or a land route.

  By the way, when the user of the mobile phone 11 of the first embodiment goes out to another country where the use frequency is different using the international roaming, the information providing terminal installed in the facility such as the airport that arrived. Find 28. Then, the cellular phone 11 is brought close to the information providing terminal 28, and the short-range radio unit 15 acquires information on the frequency band of the area. The control unit 16 that controls communication between the information providing terminal 28 and the short-range wireless unit 15 stores the information obtained from the information providing terminal 28 in the short-range wireless unit acquisition information storage area 24.

  FIG. 2 shows how information is stored in the short-range radio unit acquisition information storage area and the previous use frequency storage area of the mobile phone of this embodiment. The CPU 21 of the mobile phone 11 determines whether or not information is acquired from the short-range wireless unit 15 (step S101) and whether or not this is normally completed when a call is performed by the user (step S102). Always going. When information is acquired from the short-range wireless unit 15 through the information providing terminal 28 as described above (step S101: Y), the acquired information is overwritten in the short-range wireless unit acquired information storage area 24 (step S103). ). Further, when the call ends normally, that is, when the call ends after being connected to the other party (step S102: Y), the frequency used in the call is overwritten in the previous use frequency storage area 25 (step S102). S104). In this way, the latest information on the user is stored in the short-range radio section acquisition information storage area 24 and the previous use frequency storage area 25.

  FIG. 3 shows the flow of communication processing when the power of the mobile phone of this embodiment is turned on. When the user turns on the mobile phone 11, the CPU 21 in the control unit 16 shown in FIG. 1 reads the short-range wireless unit acquisition information from the short-range wireless unit acquisition information storage area 24 (step S121). It is checked whether or not communication is possible at a frequency (step S122). As a result, if communication is possible (Y), communication of the mobile phone 11 is started using the frequency acquired from the short-range wireless unit acquisition information storage area 24 (step S123). That is, for example, by using the short-range radio unit acquisition information acquired and stored from the short-range radio unit 15 at the destination airport for overseas travel, communication in a new area can be started smoothly.

  On the other hand, if it is determined in step S122 that the short-range wireless part acquisition information acquired from the short-range wireless part acquisition information storage area 24 is not usable (N), it is stored in the previous use frequency storage area 25. The frequency at which the previous communication was normally completed is read (step S124). Then, it is checked whether or not the frequency can be used for the current communication (step S125). If this is available (Y), communication is performed using the frequency stored in the previous use frequency storage area 25 (step S126).

  On the other hand, if it is determined in step S125 that the frequency stored in the previously used frequency storage area 25 cannot be used for communication (N), a search for all frequencies that can be communicated with the mobile phone 11 is performed. If a communicable frequency is found, communication is performed at that frequency (step S127). During this search, the frequencies used in step S122 and step S125 can be excluded in advance. For example, if you drive to another country by car after getting off at the airport, and the latest information is not obtained at the information providing terminal 28 at this time, a call based on the information obtained from the information providing terminal 28 at the airport There is a possibility that not only the frequency used for the call but also the frequency for which the previous call was successfully made in step S125 cannot be used. In such a case, all the candidate frequencies are searched for a successful call.

  Thereafter, the search result is overwritten in the previous use frequency storage area 25. Therefore, as long as the frequency for communication does not move to a different area, communication can be quickly performed using the frequency stored in the previous use frequency storage area 25 in the next call.

  FIG. 4 is a view for explaining the principle of synchronous detection in which the detection output is obtained by using the received signals in different frequency bands for each region in the mobile phone of this embodiment. In this embodiment, a received signal subjected to 2PSK (Phase Shift Keying) modulation is detected. When a 2PSK modulated signal is received, the carrier wave is regenerated by doubling the frequency of the received signal input from the antenna 12 (FIG. 1) and removing the noise component with a band pass filter. You may perform operation which returns to a half frequency with the frequency divider circuit which is not shown in figure.

Now, the received signal 41 and S (t), to the carrier frequency and f _c.
At this time, the transmission signal S (t) can be expressed by the following equation (1).
S (t) = cos (2πf _c t + a _i π) (1)
Here, “a _i π” is a modulation component, and “a _i ” has the following relationship with transmission data.
a _i = 0 (when “1” is transmitted)
a _i = 1 (when transmitting “0”)

In the synchronous detection, a reference phase signal 43 having the same frequency component as the transmission signal S (t) shown in the equation (1) is input from the frequency generator 14 shown in FIG. Multiply. Here, the reference phase signal 43 is expressed by the following equation (2).
Reference phase signal 43: cos2πf _c t (2)

The multiplication result 44 of the multiplier 42 can be expanded as the following equation (3) by the trigonometric theorem.
Multiplication result 44: cos (2πf _c t + a _i π) × cos (2πf _c t)
= (Cos (2πf _c t) cosa _i π-sin (2πf _c t) sina _i π) cos (2πf _c t) (3)

Note that “a _i ” is 0 or 1. Then, the second term in the expression (3) becomes “0”.
Further, the following equation (4) is obtained by a trigonometric theorem.
cos ² (2πf _c t) cosa _i π = 1/2 × (cosa _i π + cos (4πf _c t)) (4)

Therefore, by passing the multiplication result 44 of the multiplier 42 through the low-pass filter (LPF) 45, the component obtained by multiplying the carrier frequency of the second term of the equation (4) is deleted, and the modulation component is ignored if the coefficient is ignored. “Cosa _i π” can be extracted. That is, by using the low-pass filter 45 to obtain a DC component as a low-frequency component, the modulation component is extracted and becomes the detection output 46.
Detection output 46: cosa _i π (5)

  Based on the principle described above, the frequency generator 14 generates the same frequency as the frequency used as the carrier wave of the received signal 41 and multiplies it with the received signal 41 to extract the data carried on the carrier wave. Can do. That is, the frequency generator 14 generates a frequency for each region, thereby enabling communication in each region.

  FIG. 5 shows an outline of a circuit configuration of a mobile phone as a mobile terminal device according to the second embodiment of the present invention. In FIG. 5, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. A cellular phone 11A according to the second embodiment includes a transmission / reception unit 13 connected to an antenna 12, a frequency generator 14 that generates a reference phase frequency used for transmission / reception by the transmission / reception unit 13, and a short-distance communication. A wireless unit 15 and a control unit 16A that controls each unit of the mobile phone 11A are provided. A control program (not shown) is stored in the ROM 23A in the control unit 16A, and the position information / frequency correspondence table 22 is arranged in other areas.

  FIG. 6 shows a part of the position information / frequency correspondence table stored in the ROM. The position information / frequency correspondence table 22 is a one-to-one correspondence between position information 31 representing individual areas and frequency bands 32 used in these areas. Here, for example, the position information 31 such as [first position] and [second position] may be represented by a coordinate system such as latitude and longitude, or specific information such as XX lake, XX airport, etc. It may be represented by the name of the place or facility. In the frequency band 32, a unique number (FID: Frequency Identifier) for specifying a frequency to be used is written. For example, [FID: 30, 31] is a frequency band in which the FID is defined as “30” or “31”, and is displayed as corresponding to [first position].

  FIG. 7 shows the flow of communication processing when the power of the mobile phone is turned on in the second embodiment. When the user turns on the mobile phone 11A, the CPU 21 in the control unit 16A shown in FIG. 5 determines whether or not position information exists in the short-range wireless unit acquisition information storage area 24 (step S201). . Such a determination is made, for example, based on whether or not the data stored in the short-range wireless unit acquisition information storage area 24 is “all 0”. In this example, at the time of factory shipment or when a reset button (not shown) is pressed, the data in the short-range wireless unit acquisition information storage area 24 is cleared and becomes “all 0”. On the other hand, when information related to the area where the mobile phone 11A is currently located is acquired from the information providing terminal 28 and stored in the position information / frequency correspondence table 22, the short-range radio unit acquisition information storage area 24 is stored. Is not “all 0”. Therefore, it is possible to check whether or not the position information has already been stored by scanning the data in the short-range wireless unit acquisition information storage area 24 or the data corresponding to the position information in this data. Of course, depending on the mobile phone 11A, when the location information is stored, a flag to that effect may be set.

  When the position information is stored in the short-range wireless unit acquisition information storage area 24 (step S201: Y), the position information is converted into a frequency from the position information / frequency correspondence table 22 shown in FIG. 6 (step S201). S202). Then, it is checked whether or not communication is possible at that frequency (step S203). As a result, if communication is possible (Y), communication of the mobile phone 11A is started using the frequency (step S204). That is, for example, by using the location information in the short-range radio section acquisition information acquired and stored from the short-range radio section 15 at the destination airport for overseas travel, communication in a new area can be started smoothly. Can do.

  On the other hand, if it is determined in step S201 that the position information is not stored in the short-range wireless unit acquisition information storage area 24 (N), the previous normal communication stored in the previous use frequency storage area 25 is communicated. The frequency at which the process is completed is read (step S205). Then, it is checked whether or not the frequency can be used for the current communication (step S206). If this is available (Y), communication is performed using the frequency stored in the previous use frequency storage area 25 (step S207). Even when it is determined in step S203 that the converted frequency cannot be used (N), the same processing is performed from step S205.

  By the way, if it is determined in step S206 that the frequency stored in the previous use frequency storage area 25 cannot be used for communication (N), a search for all frequencies that can be communicated with the mobile phone 11A is performed. If a communicable frequency is found, communication is performed at that frequency (step S208). At the time of this search, the frequencies used in step S203 and step S206 can be excluded in advance.

  FIG. 8 shows an outline of a circuit configuration of a mobile phone as a mobile terminal device according to the third embodiment of the present invention. In FIG. 8, the same parts as those in FIG. The cellular phone 11B of the third embodiment includes a transmission / reception unit 13 connected to an antenna 12, a frequency generator 14 that generates a reference phase frequency used by the transmission / reception unit 13 for transmission and reception, and control of each unit of the cellular phone 11B. The control part 16B which performs is provided. In addition to the CPU 21, a ROM 23 storing a control program and a RAM 26B for temporarily storing various data are arranged in the control unit 16B. The RAM 26B is a non-volatile memory that stores, in a list format, the frequency used in the previous use frequency storage area 25 that stores the frequency when the call ended normally last time, and the frequencies that have been searched so far as frequencies that can be communicated. All-frequency search list storage area 51 composed of memory.

  FIG. 9 shows the flow of communication processing when the mobile phone is turned on in the third embodiment. When the user turns on the cellular phone 11B, the CPU 21 in the control unit 16B shown in FIG. 8 reads the frequency at which the previous communication was normally completed, which is stored in the previous use frequency storage area 25. (Step S221). Then, it is checked whether or not the frequency can be used for the current communication (step S222). If this is usable (Y), communication is performed using the frequency stored in the previous use frequency storage area 25 (step S223).

  On the other hand, if it is determined in step S222 that the previously used frequency cannot be used this time (N), the list is displayed when the all frequency search is performed before being stored in the all frequency search list storage area 51. A frequency other than the previously used frequency is read out from the increased frequency (step S224). Then, it is checked whether or not the frequency in this can be used this time (step S225). When there are a plurality of target frequencies, it is also effective to check whether the frequency can be used in order from the latest added to the list or to check in order of frequency of use.

  If it is found that communication is possible at any of the frequencies stored in all frequency search list storage area 51 (step S225: Y), communication is performed using a frequency that has been determined to allow communication (step S225: Y). Step S226). On the other hand, when all the frequencies stored in all frequency search list storage area 51 cannot be used for communication (including when no frequency is stored in all frequency search list storage area 51) (step S225: N) A full frequency search is performed (step S227). Then, as a result, frequencies that can be communicated are added to all frequency search list storage area 51 in a list format (step S228). Communication is performed using the frequency (step S229). Since all frequency search list storage area 51 is constituted by a non-volatile memory, the contents are retained even if the mobile phone 11B is turned off. Therefore, it is possible to quickly start communication in an area where the user has visited in the past.

  In each of the embodiments described above, the case where communication is performed using a mobile phone has been described. However, a PHS (Personal Handy-phone System), a PDA (Personal Digital Assistant) having a communication function, or a notebook type having a communication function. The present invention can be similarly applied to other portable terminal devices such as personal computers.

  In the first embodiment, the mobile phone 11 acquires information necessary for a call such as the current frequency band from the information providing terminal 28. However, the present invention is not limited to this. For example, when the non-contact IC that constitutes the short-range radio unit 15 is used as an electronic ticket by incorporating it into an air ticket or a train ticket that travels between countries, the destination and the area to be connected at the time of check-in are selected. The information indicating the date and time may be taken into the non-contact IC. Similarly, at the time of check-out, information necessary for a call such as a frequency band of the country or region may be captured.

  Further, in the control shown in FIG. 3 of the first embodiment, unlike the control shown in FIG. 7 of the second embodiment, the short-range wireless unit acquisition information is suddenly read from the short-range wireless unit acquisition information storage area 24. (Step S121), it is determined whether or not communication is possible at that frequency (Step S122). In many cases, the use of the mobile phone 11 increases the state in which information is stored in the short-range wireless unit acquisition information storage area 24, so that it is not necessary to check whether location information is stored. This is because. However, instead of performing such processing, as shown in FIG. 7, first, it may be checked whether or not position information is stored in the short-range wireless unit acquisition information storage area 24.

  In addition, depending on the mobile phone, storage date and time of information stored in the short-range radio unit acquisition information storage area 24 and storage of information regarding the frequency at which communication was normally completed stored in the previous use frequency storage area 25 are stored. Times may be compared to check whether the frequency can be used based on the newer information. As a result, it is possible to prevent the frequency selection from being reversed by adopting the older information.

It is a block diagram showing the outline | summary of the circuit structure of the mobile telephone in 1st Example of this invention. It is a flowchart showing the mode of the storage control of the short distance radio | wireless part acquisition information storage area of the 1st Example, and the last use frequency storage area. It is the flowchart which showed the communication process when the power supply of the mobile telephone of a 1st Example is turned on. It is explanatory drawing which showed the principle of the synchronous detection which obtains a detection output using the received signal of a different frequency band for every area in a 1st Example. It is a block diagram showing the outline | summary of the circuit structure of the mobile telephone in 2nd Example of this invention. It is explanatory drawing which showed a part of positional information and frequency correspondence table stored in ROM in the 2nd Example. It is a flowchart of a communication process when the power supply of a mobile telephone is turned on in 2nd Example. It is a block diagram showing the outline | summary of the circuit structure of the mobile telephone in the 3rd Example of this invention. It is a flowchart of a communication process when the power supply of a mobile telephone is turned on in a 3rd Example.

Explanation of symbols

11, 11A, 11B Mobile phone 13 Transmission / reception unit 14 Frequency generator 15 Short-range radio unit 16, 16A, 16B Control unit 22 Position information / frequency correspondence table 23, 23A ROM
24 Short-range wireless unit acquisition information storage area 25 Previous use frequency storage area 26, 26B RAM
28 Information providing terminal 51 All frequency search list storage area

Claims (4)

Communicating specific regional frequency information that represents a specific regional frequency as a frequency that is individually placed at each specified location in multiple regions that are geographically distant from each other and used independently when communicating in that region. An information providing terminal that transmits using a common radio frequency that the terminal can receive in common in the plurality of regions;
The specific area frequency information receiving means for receiving the specific area frequency information using the common radio frequency, and when the specific area frequency information receiving means receives the specific area frequency information, the frequency for communication in the area is The first frequency setting means for setting the frequency specified by the specific area frequency information, the frequency history storage means for storing each frequency successfully communicated in each area in the past, and the frequency by the first frequency setting means Mobile terminal device comprising second frequency setting means for changing the settings to the respective frequencies stored in the frequency history storage means until communication succeeds when communication in the area is not successful depending on the setting of
And a portable terminal communication system. When the mobile terminal device does not succeed in communication in the area depending on the setting of the second frequency setting means, the mobile terminal device performs communication in the area for all frequencies that may be used in the plurality of areas. The mobile terminal communication system according to claim 1, further comprising third frequency setting means for attempting to set a frequency for use. The mobile terminal communication system according to claim 1, wherein the information providing terminal transmits the specific area frequency information by short-range wireless communication that communicates with a mobile terminal device at a short distance. The mobile terminal communication system according to claim 1, wherein the information providing terminal includes a table that stores the plurality of areas and the specific area frequency in association with each other.

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