JP2006279187A - Mobile terminal and mobile communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of conventional technology that a long time is required from occurrence of a communication request until the establishment of communication since the conventional technology does not search a relay request destination before the communication request comes from a user, requests a relay request destination to relay the communication and establishes the connection. <P>SOLUTION: A mobile terminal has a function of requesting other terminals to relay communication of its own terminal includes: a monitor means having a function of monitoring a communication state with a base station; and a communication relay request means having a function of requesting the other terminals to request communication relay, and a searching means having a function of searching the other terminals starts searching of the other terminals when the mobile terminal discriminates that its own terminal is not present within the communication area of any base station on the basis of a communication state obtained by the monitor means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a mobile terminal and a mobile communication method, and more particularly, to a mobile terminal and a mobile communication method that can communicate even with a mobile terminal (hereinafter simply referred to as a terminal) located outside the communicable range.

Normally, in a mobile communication system such as a mobile phone system, each terminal communicates directly with a base station. Therefore, when a certain terminal is out of the communication range of any base station, the terminal cannot communicate.
For example, the terminal is physically distant from any base station and is outside the communication area. Although the area coverage of typical mobile phone systems in Japan is relatively high and has been increasing gradually, there are still many areas in rural areas and mountainous areas that remain outside the communication area. This is shown in FIG. FIG. 6 shows two base stations (base station A (71) and base station B (74)) and respective communicable areas 72 and 75 for simplicity. The mobile phones 73 and 76 exist in the communication area of either base station, but the mobile phones 77 and 78 are far from any base station, and the place where both mobile phones exist is outside the communication area.
In addition, even when the terminal is near the base station but is located in a place where the electric field strength is locally weak due to the influence of an obstacle (such as a building), the terminal still cannot communicate. Furthermore, even if there is sufficient electric field strength at the start of communication and communication is possible without problems, if the terminal moves during communication and approaches a place where the electric field strength is weak, communication will be interrupted on the way. There is also.

  In order to improve such a problem, some proposals have been made to establish a connection with an appropriate base station by using another terminal as a relay station and substantially expand a communication area. For example, in Patent Document 1, a mobile communication terminal device outside a service area of a radio base station relays communication from itself to another mobile communication terminal device within a communicable range and service area, A technique of performing communication is disclosed. Similar techniques are also disclosed in Patent Documents 2 to 9.

JP 7-162935 A JP 2000-049690 A JP 2001-186076 A JP 2003-179536 A JP 2002-44004 A JP 2004-128847 A Japanese Patent Publication No. 8-84373 Japanese Patent Publication No. 10-336095 Japanese Patent No. 3386030 gazette

  In the prior arts described in Patent Document 1 to Patent Document 9 described above, a relay request destination is searched for the first time after a communication request from a user is generated, a relay request is made to the relay request destination, and a connection is established. Established. For this reason, in these prior arts, there is a problem that it takes a long time to establish communication after a communication request is generated. This problem has prevented the adoption of these technologies in real mobile communication systems.

  In addition, the above-described prior art has a merit that a terminal requesting communication relay can communicate from outside the communication area, but there is a risk of leakage of communication contents at a terminal that accepts communication relay. There is a demerit that there is. On the other hand, a terminal that accepts communication relays has a demerit that hardware resources such as power and CPU power must be provided for communication that has nothing to do with the terminal itself.

  The present invention has been made to solve such problems.

  That is, an object of the present invention is to start communication in a short time after a communication request is generated. Alternatively, an object of the present invention is to balance the right to communicate from outside the communication area and the obligation to provide resources for other terminals. Alternatively, an object of the present invention is to reduce a risk of leakage of communication contents accompanying relay.

  The terminal of the present invention is a terminal having a function of requesting other terminals to relay communication of its own terminal, and has a function of monitoring a communication state with the base station, and communicates with other terminals. Communication relay requesting means having a function of requesting relaying of the base station, and determining that the terminal is not within the communication area of any base station based on the communication state obtained by the monitoring means, Searching for another terminal is started by search means having a function of searching for the other terminal.

  The terminal of the present invention, or moreover, when a plurality of the other terminals are found by the search means, the communication relay request means relays the communication to the terminal having the best communication state with the own terminal among them. It is characterized by requiring. Alternatively, as a result of requesting relay of communication to the terminal having the best communication state with the own terminal by the communication relay requesting means, when connection with any base station cannot be established, the communication relay requesting means It is characterized in that relaying of communication is sequentially requested to the terminals from the second to the predetermined order in order of good communication status with the own terminal.

  When the terminal of the present invention, or in addition, discovers a plurality of the other terminals by the search means, the communication relay request means for relaying communication to the terminal having the best communication state with the base station from among them. It is characterized by requiring. Alternatively, as a result of requesting relay of communication to the terminal having the best communication state with the base station by the communication relay requesting means, when connection with any of the base stations cannot be established, the communication relay requesting means It is characterized in that relaying of communication is sequentially requested to the terminals from the second to the predetermined order in the order of good communication status with the base station.

  The terminal of the present invention is characterized in that the maximum number of terminals involved in communication relay is preset. Alternatively, the maximum number of terminals can be changed. Alternatively, an upper limit is provided for the maximum number of terminals.

  The terminal according to the present invention is characterized in that the predetermined order can be changed. Alternatively, an upper limit is provided in the predetermined order.

  The terminal according to the present invention is characterized in that it further comprises means for switching between enabling and disabling the communication relay request function for the other terminal.

  The terminal of the present invention is characterized in that it further includes a communication relay request accepting unit having a function of accepting a relay of communication requested from a terminal that is a communication relay request source. Alternatively, it further comprises switching means for enabling and disabling the function of accepting a communication relay request from the terminal that is the communication relay request source.

  The terminal of the present invention, or in addition, switching means for enabling / disabling the communication relay request function for the other terminal, and switching between enabling / disabling the function for accepting a communication relay request from the communication relay request source terminal And means. Alternatively, the communication relay request accepting function from the communication relay request source terminal is set to be invalid by the switching means for enabling and disabling the communication relay request accepting function from the communication relay request source terminal. In addition, the communication relay request function for the other terminal cannot be set effectively by the switching means for enabling / disabling the communication relay request function for the other terminal.

  The terminal of the present invention is characterized in that the communication relay request function for the other terminal is effective in the event of a disaster.

  The terminal according to the present invention is characterized in that the function of accepting a communication relay request from the communication relay request source terminal is effective in the event of a disaster.

  The terminal of the present invention is characterized in that the communication relay request function for the other terminal is effective for an emergency call.

  The terminal of the present invention is characterized in that the function of accepting a communication relay request from the communication relay request source terminal is effective for an emergency call.

  The terminal of the present invention is characterized by adopting a Code Division Multiple Access (CDMA) system, Wideband CDMA (W-CDMA) system, or CDMA2000 system as a communication system.

  The terminal of the present invention is characterized in that the communication content is encrypted.

  The terminal of the present invention is a terminal having a function of relaying communication of a communication relay request source terminal, requested by a monitoring means having a function of monitoring a communication state with a base station, and a communication relay request source terminal. A communication relay request accepting unit having a function of accepting relay of communication, and if it is determined that the own terminal is within the communication area of any base station based on the monitoring unit, search for another terminal The search means having a function to start a search for the communication relay request source terminal.

  The mobile terminal of the present invention is a mobile terminal having a function of requesting another terminal to relay communication of its own terminal or a function of accepting relay of communication requested from a terminal that is a communication relay request source, Regardless of whether there is a communication request from the other terminal, it has a function of making a connection for relay with the other terminal or the terminal of the communication relay request source.

  The mobile communication method of the present invention is a mobile communication method for requesting another terminal to relay communication of its own terminal to the other terminal, where the own terminal is one of the base stations based on the communication state with the base station. A determination step for determining whether or not the communication terminal is within a communication area, a search step for searching for another terminal, and a request step for requesting relaying of communication to the other terminal, and the determination step If it is determined that the terminal is not within the communication area of any base station, the search step is started.

According to the present invention, whether or not the mobile phone is within the communication area is monitored, and if it is determined that the mobile phone is out of the communication area, the user can preliminarily become a communication relay request destination even if the user does not attempt to start communication. By searching for the mobile phone and establishing communication with the base station, communication can be started in a short time when the user attempts to start communication. Alternatively, according to the present invention, if the function for accepting communication relay requests from other mobile phones is set to invalid, the communication relay request function for other mobile phones cannot be set to be valid, It can be avoided that a specific terminal does not fulfill the obligation of relaying communication of another mobile phone, and enjoys only the right of having the other mobile phone relay its own communication.
Because of these advantages, this technology can be employed for an actual mobile communication system for the first time.

Embodiments of the present invention will be described with reference to the drawings.

Example 1
FIG. 1 is a conceptual diagram showing the internal configuration of a mobile phone according to an embodiment of the present invention. This mobile phone includes an antenna 10, a radio wave transmission / reception unit 11, a field strength monitoring unit 12, a terminal search unit 13, a communication relay request unit 14, a communication relay request acceptance unit 15, a communication relay request valid / invalid switching unit 16, a communication relay request acceptance. The valid / invalid switching unit 17 is configured.

  The radio wave transmission / reception unit 11 is connected to the antenna 10, receives radio waves from the base station or other mobile phone, and transmits radio waves to the base station or other mobile phone. The electric field strength monitoring unit 12 monitors the strength of the electric field input from the radio wave transmission / reception unit 11. The terminal search unit 13 searches for other mobile phones that can request relay based on the electric field strength monitored by the electric field strength monitoring unit 12. The search for another mobile phone by the terminal search unit 13 is performed by detecting the electric field strength emitted by the nearest mobile phone. The communication relay request unit 14 establishes a connection with the mobile phone searched by the terminal search unit 13. The connection establishment by the communication relay request unit 14 establishes a connection between the own terminal and another portable terminal by establishing a similar relationship between the own terminal and the base station. The communication relay request accepting unit 15 is connected to the requesting terminal of the communication relay request according to the communication relay request from the other terminal received by the antenna 10 and the radio wave transmitting / receiving unit 11, and the base station or the further communication relay request destination Establish connections with other terminals. The communication relay request valid / invalid switching unit 16 switches between valid and invalid of the functions of the terminal search unit 13 and the communication relay request unit 14. The user appropriately sets whether to enable or disable this function from the menu screen of the mobile phone. The communication relay request acceptance valid / invalid switching unit 17 switches between valid and invalid of the function of the communication relay request acceptance unit 15. The user can appropriately set whether to enable or disable this function from the menu screen of the mobile phone.

  FIG. 2 is a flowchart illustrating processing when the mobile phone according to the first embodiment makes a request for communication to another mobile phone. In FIG. 2, the radio wave transmission / reception unit 11 receives radio waves from the base station from the antenna 10 (S102). Next, the electric field strength monitoring unit 12 monitors the electric field strength k (i) (S103). Whether the communication is difficult due to weak radio waves is determined by the electric field intensity monitoring unit 12 by comparing the electric field intensity k (i) with a predetermined threshold D (S104). If the radio wave is strong and the electric field strength k (i) ≧ the threshold value D, normal communication is possible (S105). If the radio wave is weak and the electric field strength k (i) <threshold D, the terminal search unit 13 searches for another mobile phone as a partner who requests communication relay (S106). The terminal search unit 13 determines whether or not another mobile phone has been found (S107), and communication cannot be performed if no other mobile phone has been found (S108). If the terminal search unit 13 finds another mobile phone, the communication relay request unit 14 selects another mobile phone that has received the radio wave with the strongest electric field strength as its mobile phone as the relay request destination and establishes a connection. Establish (S109). The communication relay request unit 14 requests the relay request destination to relay communication (S110). At this time, the communication relay request unit 14 determines the order i indicating the number of the mobile phone of the relay request destination from the mobile phone that is the origin of the relay request, and a predetermined maximum involved in the relay. The number n of terminals is notified to the relay request destination (S110). The value of the maximum number of terminals n may be changeable by the user. Here, since an example is described in which the mobile phone is the basis of the relay request, the value of the order i passed to the mobile phone that is the relay request destination is 1. An example (FIG. 3) in which the mobile terminal is requested to relay communication from another terminal and further requests communication from another terminal (FIG. 3) will be described later. In this case, the order i passed from the relay request source is used. It is incremented by 1 and passed to the relay request destination.

  When the communication relay request unit 14 obtains a response indicating that communication is possible from the relay request destination (S111), communication is possible (S112). If the communication relay request unit 14 obtains a reply indicating that communication is not possible (S113), communication is disabled (S114). If no answer is obtained, the communication relay request unit 14 determines whether or not a predetermined time has passed (S115), and communication is disabled if timed out (S116). If it has not yet timed out, the process returns to the determination of whether or not a reply indicating that communication is possible or not is obtained again (S111 and S113).

  FIG. 3 is a flowchart showing processing when the mobile phone of the first embodiment is requested to relay communication from another mobile phone. In FIG. 3, first, the communication relay request accepting unit 15 receives a signal requesting relay of communication from another mobile phone from the antenna 10 via the radio wave transmitting / receiving unit 11 (S201). Next, the radio wave transmission / reception unit 11 receives radio waves from the base station from the antenna 10 (S202), and the electric field strength monitoring unit 12 monitors the electric field strength (S203). The electric field strength monitoring unit 12 determines whether communication is difficult because the radio wave is weak by comparing the electric field strength k (i) with a predetermined threshold value D ′ (S204). When the radio wave is strong and the electric field strength k (i) ≧ threshold value D ′, direct communication between the mobile phone and the base station is possible, and the terminal search unit 13 needs to search for further relay request destinations. It means that there is no. That is, since it is determined that communication between the original relay request source and the base station is possible by relaying the mobile phone, the communication relay request accepting unit 15 indicates that the relay is possible. The reply is returned to the relay request source (S205). When the radio wave is weak and the electric field strength k (i) <threshold value D ′, the communication relay request accepting unit 15 performs relaying to determine whether or not the maximum number of terminals involved in relaying has been reached with its own mobile phone. The order i, which is the number of the mobile phone that is received from the requester, counting from the original mobile phone, is compared with the maximum number n of terminals involved in the relay (S206). If the maximum number of terminals has been reached, the communication relay request accepting unit 15 returns a reply indicating that communication is impossible to the relay request source (S207). If the maximum number of terminals has not yet been reached, the terminal search unit 13 searches for another mobile phone that is a partner requesting communication relay (S208). The terminal search unit 13 determines whether or not another mobile phone has been found (S209). If no other mobile phone has been found, the communication relay request accepting unit 15 gives a reply that communication is not possible. Return to the relay request source (S210). If another mobile phone is found, the communication relay requesting unit 14 establishes a connection by selecting the mobile phone that has received the radio wave with the strongest electric field strength as the mobile phone of the first embodiment as a relay request destination ( S211). The communication relay request unit 14 requests the relay request destination to relay communication (S212). At this time, the communication relay requesting unit 14 increments the order i received from the relay request source, which is the order number of the own mobile phone from the original mobile phone, by (i + 1) ( The relay request destination is notified of the rank of the mobile phone of the relay request destination from the original mobile phone and the maximum number n of terminals involved in the relay (S212). When the communication relay request unit 14 receives a response indicating that communication is possible from the relay request destination (S213), the communication relay request accepting unit 15 returns a response indicating that communication is possible to the relay request source. (S214). When the communication relay request unit 14 obtains a reply that communication is not possible (S215), the communication relay request acceptance unit 15 returns a reply that communication is impossible to the relay request source (S216). If no answer is obtained, the communication relay request unit 14 determines whether or not a predetermined time has elapsed (S217), and if it has timed out, the communication relay request accepting unit 15 cannot communicate. Is returned to the relay request source (S218). If it has not yet timed out, the process returns to the determination of whether or not a reply indicating that communication is possible or not is obtained (S213 and S215). The threshold values D and D ′ may be the same value or different values.

  With the above operation, when a user tries to communicate with a mobile phone outside the communication area, a route with the strongest electric field strength is searched from a group of nearby mobile phones, and a connection is established. The same processing is successively performed on the searched mobile phone until communication with the base station can be established via the mobile phone in the communication area of the base station. In this way, communication is possible even with a mobile phone outside the communication area.

  It is desirable that the processing (the flowchart in FIG. 2) when the mobile phone according to the first embodiment requests another mobile phone to perform relaying is repeated at a predetermined time period until a communicable response is obtained. On the other hand, the processing when the mobile phone of the first embodiment is requested to relay communication from another mobile phone (the flowchart in FIG. 3) is performed by the communication relay request acceptance valid / invalid switching unit 17 of the communication relay request acceptance unit 15. When the function is enabled, it is desirable to be in a standby state for receiving a relay request signal (S201 in FIG. 3).

  FIG. 4 shows a conceptual diagram when the mobile phone outside the communication area is able to reach the base station only by relaying by one mobile phone in the first embodiment. In this case, since the primary relay terminal 53 requested to be relayed by the mobile phone 54 outside the communication area is in the communication area 52 of a certain base station 51, the primary relay terminal 53 cannot search for another mobile phone any more. Without establishing a connection with the base station 51, the mobile phone 54 outside the communication area can start communication.

  FIG. 5 shows a conceptual diagram when two mobile phones can reach the base station by relaying. In this case, since the primary relay terminal 64 requested by the mobile phone 65 outside the communication area is not in the communication area of any base station, another mobile phone is searched for and the secondary relay terminal 63 is found. In this case, since the secondary relay terminal 63 is in the communication area 62 of a certain base station 61, the secondary relay terminal 63 does not look for another mobile phone any more and connects to the base station 61. And the mobile phone 65 outside the communication area can start communication.

  In the mobile phone according to the first embodiment, whether or not the mobile phone is within the communication area is monitored, and if it is determined that the mobile phone is outside the communication area, the communication is performed in advance without the user trying to start communication. It searches for other mobile phones as relay request destinations and establishes communication with the base station. As a result, in the first embodiment, when the user tries to start communication, the communication can be started in a short time.

  In the first embodiment, as a criterion for selecting one relay request destination from a plurality of nearby cellular phones discovered by the terminal search unit 13, by using the field strength of the radio wave reaching the cellular phone as a criterion. It is configured so that a connection can be established reliably.

  In the first embodiment, by setting the maximum number of terminals n involved in relay in advance, the search is repeated infinitely, and the power and hardware resources of other mobile phones / own mobile phones are wasted. It is configured so that there is nothing. Furthermore, if this value can be changed by user settings, (1) even if it takes some time to establish a connection, (2) even if a connection is to be established. If it takes a long time, the user can select the case where he wants to give up. Furthermore, by setting an upper limit for the value that can be set by the user, it is possible to avoid a large amount of power and hardware resources of another mobile phone being used for communication of a specific user.

  In the first embodiment, communication based on the CDMA system is performed. Since communication based on the spread spectrum system represented by the CDMA system has high secrecy, there is no concern that the communication contents leak from the relay terminal, and there is an effect that high security is maintained. Even if it is not a spread spectrum system, high security is similarly maintained by encrypting communication.

  In the first embodiment, the communication relay request valid / invalid switching unit 16 is configured to be able to select the validity or invalidity of a function for requesting another mobile phone to relay communication. As a result, there is an advantage that the user can take advantage of the advantage of being able to communicate from outside the communication area and the disadvantage that there is a risk of leakage of communication contents from the terminal that has accepted the communication relay request. In the first embodiment, switching between valid and invalid by the communication relay request valid / invalid switching unit 16 is appropriately performed by the user from the menu screen of the mobile phone, but is performed by a contract between the user and the carrier of the mobile phone. The aspect of, is also possible.

  In the first embodiment, the communication relay request acceptance valid / invalid switching unit 17 is configured to be able to select the validity or invalidity of the function for accepting the relay of communication requested from another mobile phone. As a result, for mobile phones that are required to relay communications, hardware resources such as power and CPU power of the mobile phone must be provided for communication that has nothing to do with the mobile phone. Can be avoided. In the first embodiment, switching between valid and invalid by the communication relay request acceptance valid / invalid switching unit 17 is appropriately performed by the user from the menu screen of the cellular phone. However, according to the contract between the user and the cellular phone carrier. A mode of performing is also conceivable.

  Furthermore, if the function for accepting communication relay requests from other mobile phones is set to be invalid, the specific terminal will not be able to enable the communication relay request function for other mobile phones. It is possible to avoid enjoying only the right of relaying communication of other mobile phones to other mobile phones without fulfilling the obligation of relaying communication of other mobile phones.

  In the first embodiment, the communication relay request function or the communication relay request acceptance function or both of them are used only in case of a disaster and for emergency calls such as 110 or 119 in Japan regardless of the user setting. By making it effective, the public nature of radio waves and communication systems can be secured.

Example 2
In the mobile phone according to the first embodiment, the terminal can be used regardless of whether the mobile phone is based on the mobile phone (FIG. 2) or when relaying is requested from another mobile phone (FIG. 3). When the search unit 13 finds a plurality of mobile phones in the vicinity, the communication relay request unit 14 selects a mobile phone that has received the radio wave with the strongest electric field strength from the mobile phone, and sets the communication relay request unit 14 establishes a connection with the mobile phone (S109 and S211), and requests the mobile phone to relay (S110 and S212). However, when such a relay terminal search algorithm is used, a mobile phone in which radio waves reach the mobile phone with the strongest electric field strength is not necessarily physically close to the base station. Therefore, even if communication is finally possible, there is a fear that the processing shown in FIG. 2 and FIG. Alternatively, there is a fear that power and hardware resources are consumed in vain. In addition, depending on the value of the maximum number of terminals n involved in relaying, although it should be possible to reach the base station if a proper route is originally selected, it is not possible to reach any base station and communication is impossible. There is a fear of becoming.

  Therefore, in the mobile phone according to the second embodiment which is another embodiment of the present invention, when the terminal search unit 13 can find a plurality of mobile phones in the vicinity, the communication relay request unit 14 selects the base station from among them. The mobile phone receiving the radio wave with the strongest electric field strength is selected as the relay request destination, the communication relay request unit 14 establishes a connection with the mobile phone (S109 and S211), and relays to the mobile phone. Request (S110 and S212). 1 to 5 for explaining the first embodiment can also be applied to the mobile phone of the second embodiment.

  The processing performed by the mobile phone according to the second embodiment is different from the processing performed by the mobile phone according to the first embodiment. When the terminal search unit 13 finds a plurality of mobile phones, the communication relay request unit 14 performs relaying. As a mobile phone that establishes a connection to make a request (S109 and S211), the communication relay request unit 14 uses the radio wave from the base station most, not the mobile phone that has received the radio wave with the strongest electric field strength. The choice is to select a mobile phone receiving with strong electric field strength. For this purpose, first, the communication relay request unit 14 once establishes a connection with some or all of the plurality of mobile phones discovered in the vicinity by the terminal search unit 13, and the strength of each mobile phone is Ask if the station is receiving radio waves. The communication relay requesting unit 14 selects a mobile phone that receives the radio wave from the base station with the strongest electric field strength as a relay request destination with reference to the answer from each mobile phone to the inquiry.

  A mobile phone that receives radio waves from the base station with the strongest electric field strength is likely to be close to the physical distance from the base station. By repeating the above, it is possible to gradually approach the base station, and there is a high probability of finally reaching the base station.

Example 3
In the first embodiment, if the base station cannot be reached within the range of the maximum number n of terminals involved in relaying, communication is disabled there. On the other hand, in the mobile phone of the third embodiment which is another embodiment of the present invention, when the terminal search unit 13 can find a plurality of mobile phones in the vicinity, the communication is not disabled and a communication relay request is made. The unit 14 sequentially selects a mobile phone that has received radio waves with the second strongest electric field strength from the mobile phone, and the communication relay request unit 14 establishes a connection with the mobile phone (S109 and S211). ), The mobile phone is requested to relay (S110 and S212). As a result, there is a possibility that the mobile phone that has received the radio wave with the strongest electric field strength reaches the base station even when the tip of the mobile phone is a dead end.

  Here, it is desirable to set in advance how many mobile phones with the highest electric field strength are tried. Accordingly, it is possible to prevent the search from being repeated indefinitely when there are innumerable mobile phones in the vicinity, such as during a congestion. It is desirable that the limit of how many mobile phones with the highest electric field strength can be tried can be changed by user settings.

  In the third embodiment, when the mobile station reaches the base station by selecting the terminal having the strongest electric field intensity that reaches the mobile phone, a relay request to the terminal having the second or higher electric field intensity that reaches the mobile phone is made. By trying, it is possible to avoid a situation in which communication cannot be performed without reaching any base station even though it should be possible to reach the base station if the route is properly selected.

Example 4
In the first embodiment, the mobile phone 54 (FIG. 4) outside the communication area requests the nearby mobile phone 53 (FIG. 4) to relay, and finally connects to the base station 51 (FIG. 4). Established. In contrast, in the fourth embodiment, the mobile phone 53 (FIG. 4) in the communication area searches for the mobile phone 54 (FIG. 4) in the vicinity and outside the communication area in advance to search for the base station 51 (FIG. 4). By establishing the relay, the connection between the mobile phone 54 (FIG. 4) outside the communication area and the base station 51 (FIG. 4) is established. Therefore, when the user of the mobile phone 54 (FIG. 4) outside the communication area tries to start communication, communication can be performed immediately.

  In the fourth embodiment, the mobile phone 54 (FIG. 4) outside the communication area can efficiently find the mobile phone of the relay request destination for relaying its own communication. Further, when the mobile phone 54 (FIG. 4) outside the communication area tries to start communication, communication can be performed immediately.

  In the embodiment described so far, the example in which the present invention is applied to the mobile phone has been described. However, the application of the present invention is not limited to this. The present invention is applicable not only to mobile phones but also to mobile communication systems composed of mobile phones, car phones, mobile terminals, mobile terminals, mobile terminals, etc. can do.

  When two or more nearby mobile phones are found, the criteria for selecting an appropriate one of them are the two types described in the above embodiment (the radio waves reach the mobile phone with the strongest electric field strength) It is not limited to selecting a terminal and selecting a terminal that receives radio waves from the base station with the strongest electric field strength). For example, it is involved in relaying based on a predetermined evaluation function from the electric field strength of radio waves that reach the mobile phone from each terminal in the vicinity and the electric field strength of radio waves from the base station that each nearby terminal receives. It can also be said that the number of terminals is relatively small, and the one that is assumed to have a relatively reliable connection with the base station is selected.

  In the first embodiment, the CDMA method is adopted as the spread spectrum method, but other methods such as the W-CDMA method or the CDMA2000 method can be adopted without any problem.

  In the above-described embodiment, an example in which various determinations are made based on the electric field strength is shown. However, as a criterion for judging the communication state, various things such as a bit error rate can be considered in addition to the electric field intensity.

It is a conceptual diagram which shows the internal structure of the mobile telephone which is one Example of this invention. It is a flowchart which shows the process performed when the mobile telephone which is one Example of this invention requests | requires the relay of communication to other mobile telephones. It is a flowchart which shows the process performed when the mobile telephone which is one Example of this invention is requested | required of relay from another mobile telephone. In the mobile communication system which is an example which implemented this invention, it is a conceptual diagram which shows the mode of communication of a terminal and a base station when one terminal can reach to a base station only by relaying. In the mobile communication system which is an example which implemented this invention, it is a conceptual diagram which shows the mode of communication of a terminal and a base station when two terminals can relay and reach | attain to a base station. It is a conceptual diagram which shows the mode of communication of the mobile communication system by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Antenna 11 Radio wave transmission / reception part 12 Electric field strength monitoring part 13 Terminal search part 14 Communication relay request part 15 Communication relay request acceptance part 16 Communication relay request valid / invalid switching part 17 Communication relay request acceptance valid / invalid switching part 51 Base station 52 Base station Communication area 53 Mobile phone 54 in base station communication area Mobile phone 61 outside communication area Base station 62 Base station communication area 63 Mobile phone in base station communication area 64 Mobile phone outside communication area 65 Mobile phone outside communication area Mobile phone 71 Base station A
72 Communication area of base station A 73 Mobile phone 74 in communication area of base station A Base station B
75 Communication area 76 of base station B Cellular phone 77 in communication area of base station B Cellular phone 78 outside communication area Cellular phone outside communication area

Claims (24)

A mobile terminal having a function of requesting other terminals to relay communication of its own terminal,
Monitoring means having a function of monitoring the communication state with the base station;
A communication relay requesting means having a function of requesting other terminals to relay communication;
When it is determined that the own terminal is not in the communication area of any base station based on the communication state obtained by the monitoring means, search means for starting a search for other terminals,
A mobile terminal characterized by comprising: The mobile terminal according to claim 1, wherein
A mobile terminal characterized in that, when a plurality of other terminals are found by the search means, a relay of communication is requested by the communication relay request means to a terminal having the best communication state with the own terminal among them. . The mobile terminal according to claim 2, wherein
As a result of requesting the relay of communication to the terminal having the best communication state with the own terminal by the communication relay requesting means, when the connection with any base station cannot be established, the communication relay requesting means A mobile terminal characterized by sequentially requesting relaying of communication to terminals from the second to a predetermined rank in order of good communication status. The mobile terminal according to claim 1, wherein
A mobile terminal characterized in that, when a plurality of other terminals are found by the search means, a communication relay request means is requested to relay a communication to a terminal having the best communication state with a base station among them. . The mobile terminal according to claim 4, wherein
As a result of requesting communication relay to the terminal having the best communication state with the base station by the communication relay requesting means, when connection with any base station cannot be established, the communication relay requesting means A mobile terminal characterized by sequentially requesting relaying of communication to terminals from the second to a predetermined rank in order of good communication status. The mobile terminal according to any one of claims 1 to 5, wherein
A mobile terminal characterized in that the maximum number of terminals involved in communication relay is preset. The mobile terminal according to claim 6, wherein
The mobile terminal characterized in that the maximum number of terminals can be changed. The mobile terminal according to claim 7, wherein
A mobile terminal characterized in that an upper limit is provided for a change target of the maximum number of terminals. The mobile terminal according to claim 3 or 5, wherein:
The mobile terminal characterized in that the predetermined order can be changed. The mobile terminal according to claim 9, wherein
A mobile terminal characterized in that an upper limit is provided for the change target of the predetermined order. The mobile terminal according to any one of claims 1 to 10, wherein
A mobile terminal comprising switching means for enabling and disabling a communication relay request function for the other terminal. The mobile terminal according to any one of claims 1 to 10, wherein
A mobile terminal comprising: a communication relay request accepting unit having a function of accepting a relay of a communication requested from a communication relay request source terminal. The mobile terminal according to claim 12, wherein
A mobile terminal comprising switching means for enabling / disabling a function for accepting a communication relay request from the terminal that is the communication relay request source. The mobile terminal according to claim 13, wherein
A mobile terminal comprising switching means for enabling / disabling a function for accepting a communication relay request from the terminal that is the communication relay request source. The mobile terminal according to claim 14, wherein
When the communication relay request accepting function from the communication relay request source terminal is set to invalid by the switching means between the communication relay request accepting function valid and invalid from the communication relay request source terminal,
A mobile terminal characterized in that the communication relay request function for the other terminal cannot be effectively set by means of switching between valid and invalid of the communication relay request function for the other terminal. The mobile terminal according to any one of claims 11, 14, 15, or 16,
A mobile terminal characterized in that a communication relay request function for the other terminal becomes effective at the time of a disaster. The mobile terminal according to any one of claims 13, 14, 15, or 16,
A mobile terminal characterized in that a function of accepting a communication relay request from the communication relay request source terminal becomes effective in a disaster. The mobile terminal according to any one of claims 11, 14, or 15,
A mobile terminal characterized in that a communication relay request function for the other terminal is effective for an emergency call. The mobile terminal according to any one of claims 13, 14, or 15,
For an emergency call, a mobile terminal characterized in that a function for accepting a communication relay request from the communication relay request source terminal is enabled. 20. The mobile terminal according to claim 1, wherein a code division multiple access (CDMA) system, a wideband CDMA (W-CDMA) system, or a CDMA2000 system is adopted as a communication system. A mobile terminal characterized by that. The mobile terminal according to any one of claims 1 to 21, wherein the communication content is encrypted. A mobile terminal having a function of relaying communication of a communication relay request source terminal,
Monitoring means having a function of monitoring the communication state with the base station;
A communication relay request accepting unit having a function of accepting a relay of communication requested from the terminal requesting communication relay, and
When it is determined that the terminal is within the communication area of any base station based on the monitoring means, the search means having a function of searching for another terminal starts to search for the terminal of the communication relay request source. Feature mobile terminal. A mobile terminal having a function of requesting another terminal to relay communication of its own terminal, or a function of accepting relay of communication requested from a terminal of a communication relay request source,
A mobile terminal having a function of making a connection for relay with the other terminal or the terminal of the communication relay request source regardless of the presence or absence of a communication request from a user. In the mobile terminal, a mobile communication method for requesting other terminals to relay communication of the own terminal,
A determination step of determining whether or not the own terminal is in the communication area of any base station based on a communication state with the base station;
A search step for searching for other terminals;
A requesting step for requesting relay of communication to another terminal, and
The mobile communication method according to claim 1, wherein when the determination step determines that the terminal is not within the communication area of any base station, the search step is started.

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