JP2015180036A - Communication terminal device and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication terminal device such that direct communication between communication terminals can be stably maintained without increasing traffic between the communication terminal devices.SOLUTION: There is provided a communication terminal device capable of directly communicating with a plurality of other communication terminal devices not through a base station. The communication terminal device includes: reception means of receiving control information for control over the direct communication from the base station; transmission means of transmitting the received control information to other communication terminals; state transmission means of transmitting state information on the communication terminal device to the base station; and notice reception means of receiving notice that an alternative communication terminal is selected by the base station when the alternative communication terminal substituting for the communication terminal device is selected out of one or more communication terminal devices based upon state information transmitted from at least one communication terminal devices present in a communication area of the base station.

Description

  The present invention relates to a communication terminal apparatus capable of direct communication with another communication terminal apparatus without using a base station, and a communication system.

  In recent years, Bluetooth (registered trademark), a wireless communication method in which a plurality of wireless communication terminal devices directly perform wireless communication without going through a wireless base station and an access point, so-called Device-to-Device (D2D) communication, Alternatively, a wireless LAN ad hoc mode is known.

  For example, Japanese Patent Laying-Open No. 2005-295310 (Patent Document 1) discloses a multi-hop wireless communication method in which a plurality of wireless terminals relay and transmit transmission packets based on path information transmitted and received between each other. Has been.

JP 2005-295310 A

  Incidentally, in recent years, it has been studied to realize D2D communication using a wireless communication network provided by a communication carrier. For example, a case is considered in which a wireless terminal existing in a communication area (coverage) of a wireless base station controls the D2D communication between a plurality of other wireless terminals.

  However, in such a case, if the wireless terminal that controls the D2D communication cannot maintain the communication due to a decrease in the remaining battery level, the D2D communication between other wireless terminals is also affected. It will be.

  The present invention has been made to solve the above problems, and can stably maintain direct communication between communication terminal apparatuses without increasing traffic between the communication terminal apparatuses. An object of the present invention is to provide a communication terminal device and a communication system.

  According to an embodiment, a communication terminal device capable of direct communication with a plurality of other communication terminal devices without using a base station is provided. A communication terminal device includes a receiving unit that receives control information for controlling direct communication from a base station, a transmission unit that transmits control information received by the receiving unit to a plurality of other communication terminal devices, and a communication terminal device. Among the one or more communication terminal apparatuses based on the state information transmitted from the one or more communication terminal apparatuses existing in the communication area of the base station and the state transmission means for transmitting the state information indicating the state of When a substitute communication terminal apparatus that transmits control information instead of the communication terminal apparatus is selected by the base station, a notification receiving unit that receives a notification that the alternative communication terminal apparatus has been selected from the base station is provided. The transmission unit stops transmission of control information to a plurality of other communication terminal devices when the notification is received by the notification reception unit.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to maintain stably the direct communication between communication terminal devices, without increasing the traffic between communication terminal devices.

1 is a schematic diagram showing an overall configuration of a communication system according to a first embodiment. FIG. 7 is a sequence diagram showing an operation of the communication system according to the first embodiment. 3 is a block diagram showing a hardware configuration of a communication terminal apparatus according to Embodiment 1. FIG. 3 is a block diagram showing a hardware configuration of a base station according to Embodiment 1. FIG. FIG. 3 is a functional block diagram of a communication terminal apparatus and a base station according to the first embodiment. 6 is a flowchart showing an example of a processing procedure as a communication control device of the communication terminal device according to the first embodiment. FIG. 6 is a functional block diagram of a communication terminal device according to a second embodiment. 6 is a flowchart showing an example of a processing procedure as an alternative communication terminal device of a communication terminal device according to a second embodiment. 10 is a user interface screen according to the second embodiment. 10 is a flowchart showing a modification of the processing procedure as an alternative communication terminal device of the communication terminal device according to the second embodiment. FIG. 11 is a schematic diagram showing an overall configuration of a communication system according to a third embodiment. FIG. 11 is a sequence diagram showing an operation outline of a communication system according to the third embodiment. It is a figure which shows the information table according to Embodiment 3. It is a figure which shows the information table according to Embodiment 3. It is a figure which shows the information table according to Embodiment 3.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated. In the following, a smartphone will be described as a representative example of a “communication terminal device”. However, the communication terminal device may be another information communication device such as a personal computer, PND (Personal Navigation Device), PDA (Personal Data Assistance) or the like.

[Embodiment 1]
<System overview>
(overall structure)
A system overview of communication system 1 according to the first embodiment will be described. FIG. 1 is a schematic diagram showing an overall configuration of a communication system 1 according to the first embodiment.

  Referring to FIG. 1, communication system 1 includes communication terminal apparatuses 10 </ b> A to 10 </ b> D and a base station 20. For ease of explanation, in the following, when a configuration or function common to each of the communication terminal devices 10A to 10D is described, they are also collectively referred to as “communication terminal device 10”.

  For example, the base station 20 performs an operation according to LTE (Long Term Evolution) among radio access technologies (RAT) standardized in 3GPP (Third Generation Partnership Project).

  Communication terminal devices 10A to 10D are UEs (User Equipment) that perform wireless communication according to a radio access technology such as LTE. Further, the communication terminal devices 10A to 10D are configured to be able to communicate with other communication terminal devices via (via) the base station 20, and without (without going through) the base station 20. It is configured to be capable of direct communication (D2D communication) with other communication terminal devices.

  In the present embodiment, communication terminal apparatuses 10A and 10D exist in communication area 200 of base station 20, and can wirelessly communicate with base station 20 using a wireless communication network. On the other hand, since the communication terminal apparatuses 10B and 10C exist outside the communication area 200, they cannot communicate with the base station 20.

  The base station 20 controls direct communication between the communication terminal devices 10A to 10D using a frequency band used in a wireless communication network managed by a communication carrier. Specifically, the base station 20 transmits control information for controlling direct communication between the communication terminal apparatuses 10 </ b> A to 10 </ b> D to the communication terminal apparatus 10 </ b> A existing in the communication area 200 without using the base station 20. .

  The control information includes permission information for permitting direct communication using the wireless communication network, and setting information of a communication environment necessary for the direct communication. For example, the setting information includes radio resource information such as a frequency band allowed for direct communication, and radio field intensity of a radio signal.

  Then, the communication terminal device 10A transmits the control information received from the base station 20 to the communication terminal devices 10B and 10C that do not exist in the communication area 200. This enables direct communication between the communication terminal devices 10B and 10C. That is, the communication terminal device 10A functions as a communication control device for controlling direct communication between the communication terminal devices 10B and 10C.

  Further, the communication terminal apparatus 10D existing in the communication area 200 periodically transmits state information indicating the state of the own apparatus to the base station 20. Note that the communication terminal apparatus 10 </ b> A may also periodically transmit the state information to the base station 20. The state information includes the remaining battery level and the moving speed of the communication terminal device. Further, communication terminal apparatus 10D (and 10A) may transmit identification information (telephone number, mail address, etc.) of its own terminal to base station 20 together with state information.

  The base station 20 receives state information from one or more communication terminal apparatuses 10 existing in the communication area 200. Then, the base station 20 selects a communication terminal device that functions as a communication control device from the one or more communication terminal devices. Specifically, the base station 20 selects a communication terminal device with the largest remaining battery level as the communication control device among the one or more communication terminal devices. Alternatively, the base station 20 selects the communication terminal device having the slowest moving speed among the one or more communication terminal devices as the communication control device.

  Therefore, in FIG. 1, when the remaining battery level of the communication terminal device 10A functioning as the communication control device has decreased by a certain amount or more, the base station 20 may, for example, replace the remaining battery level with the communication terminal device 10A. The communication terminal device 10D having a large amount is selected as a communication control device. Then, the communication terminal device 10D selected by the base station 20 functions as a communication control device instead of the communication terminal device 10A, and transmits control information to the communication terminal devices 10B and 10C.

  As described above, in the communication system 1, direct communication between the communication terminal devices 10 </ b> A to 10 </ b> D is permitted based on the control information from the base station 20. In the above description, the communication terminal apparatuses 10B and 10C are not present in the communication area 200. However, the communication terminal apparatuses 10B and 10C may be present in the communication area 200.

(Overview of operation)
FIG. 2 is a sequence diagram showing an outline of operation of communication system 1 according to the first embodiment. As described above, it is assumed that the communication terminal devices 10A and 10D existing in the communication area 200 regularly transmit the remaining battery level, the moving speed, and the identification information as the state information.

  Referring to FIG. 2, base station 20 (“base station” in FIG. 2) transmits control information for directly controlling communication via a wireless communication network to communication terminal device 10A (“terminal A” in FIG. ]) (Step S10). 10 A of communication terminal devices will transmit the response with respect to the said reception to the base station 20, if control information is received (step S12).

  The communication terminal device 10A transmits control information to the communication terminal device 10B (“terminal B” in FIG. 2) capable of direct communication (step S14). When receiving the control information, the communication terminal device 10B transmits a response to the reception to the communication terminal device 10A (step S16). The communication terminal device 10A transmits the response received from the communication terminal device 10B to the base station 20 (step S17).

  Further, communication terminal apparatus 10A transmits control information to communication terminal apparatus 10C (“terminal C” in FIG. 2) capable of direct communication (step S18). When receiving the control information, the communication terminal device 10C transmits a response to the reception to the communication terminal device 10A (step S20). The communication terminal device 10A transmits the response received from the communication terminal device 10C to the base station 20 (step S21). Communication terminal device 10A may execute a series of processes in steps S14, S16, and S17 and a series of processes in steps S18, S20, and S21 in parallel.

  When allowing direct communication (D2D communication) between the communication terminal apparatuses 10B and 10C, the base station 20 transmits an instruction to permit the D2D communication to the communication terminal apparatus 10A (step S22). When receiving the permission instruction, communication terminal apparatus 10A notifies communication terminal apparatuses 10B and 10C that D2D communication is permitted (steps S23 and S24).

  In the present embodiment, communication terminal apparatus 10A searches for communication terminal apparatuses 10B and 10C as other communication terminal apparatuses that can directly communicate with the terminal itself. Specifically, communication terminal apparatus 10A directly communicates with communication terminal apparatus 10A based on the radio field intensity of a radio signal transmitted from another communication terminal apparatus or the reach of a radio signal transmitted by communication terminal apparatus 10A. Search for other communication terminal devices capable of communication. For example, the communication terminal apparatus 10A can uniquely identify another communication terminal apparatus based on identification information such as a telephone number and a mail address.

  Then, communication terminal apparatuses 10B and 10C perform transmission / reception of various data (moving images, applications, etc.) by direct communication (D2D communication) not via base station 20 based on the received control information (step S25). Thereby, the direct communication between the communication terminal devices 10B and 10C is established.

  Next, when the communication terminal apparatus 10A determines that the remaining battery level of its own apparatus is less than a predetermined reference value and communication with the communication terminal apparatuses 10B and 10C cannot be continued as a communication control apparatus, The base station 20 is notified that it cannot continue (step S26). Specifically, the communication terminal device 10A notifies the base station 20 that the remaining battery level has been reduced and control information transmission to the communication terminal devices 10B and 10C cannot be continued.

  When receiving the notification from the communication terminal device 10A, the base station 20 selects the communication terminal device 10D from the communication terminal devices existing in the communication area 200 as an alternative communication terminal device for the communication terminal device 10A. The base station 20 notifies the communication terminal apparatus 10A that the communication terminal apparatus 10D has been selected as the communication control apparatus (change of the communication control apparatus) (step S27).

  The base station 20 instructs the communication terminal apparatus 10D to operate as a communication control apparatus (step S28). At this time, the base station 20 transmits control information together with the instruction. Alternatively, the base station 20 may be configured to periodically transmit control information to communication terminal devices existing in the communication area 200.

  Next, when receiving control information from the base station 20, the communication terminal device 10D transmits a response to the reception to the base station 20 (step S29). Communication terminal device 10D transmits control information to communication terminal device 10B capable of direct communication (step S30). When receiving the control information, the communication terminal device 10B transmits a response to the reception to the communication terminal device 10D (step S32). The communication terminal device 10D transmits the response received from the communication terminal device 10B to the base station 20 (step S33).

  Further, the communication terminal device 10D transmits control information to the communication terminal device 10C capable of direct communication (step S34). When receiving the control information, the communication terminal device 10C transmits a response to the reception to the communication terminal device 10D (step S36). The communication terminal device 10D transmits the response received from the communication terminal device 10C to the base station 20 (step S37).

  When allowing direct communication (D2D communication) between the communication terminal apparatuses 10B and 10C, the base station 20 transmits an instruction to permit the D2D communication to the communication terminal apparatus 10D (step S38). When receiving the permission instruction, communication terminal apparatus 10D notifies communication terminal apparatuses 10B and 10C that D2D communication is permitted (steps S39 and S40).

  Then, communication terminal apparatuses 10B and 10C perform transmission / reception of various data through direct communication not via base station 20 based on the received control information (step S41). Thereby, the direct communication between the communication terminal devices 10B and 10C is established.

  In the above sequence, the base station 20 transmits an instruction to permit D2D communication between the communication terminal apparatuses 10B and 10C, but is not limited thereto. For example, the D2D communication permission information may be included in the control information that the base station 20 transmits to the communication terminal device 10A. In this case, the communication terminal device 10A can permit D2D communication between the communication terminal devices 10B and 10C based on the D2D communication permission information included in the received control information. Specifically, communication terminal apparatus 10A transmits control information including D2D communication permission information to communication terminal apparatuses 10B and 10C, respectively, in steps S14 and S18. Therefore, in this case, the processes of steps S17, S21 to S24 and steps S33, S37 to S40 are unnecessary.

<Hardware configuration>
(Communication terminal device 10)
FIG. 3 is a block diagram showing a hardware configuration of communication terminal apparatus 10 according to the first embodiment. Referring to FIG. 3, communication terminal apparatus 10 has a CPU (Central
Processing Unit) 102, memory 104, touch panel 106, display 108, wireless communication unit 110, memory interface (I / F) 114, communication interface (I / F) 116, and GPS (Global Positioning System). A controller 118 and a battery 120 are included.

  The CPU 102 controls the operation of each unit of the communication terminal device 10 by reading and executing the program stored in the memory 104. More specifically, the CPU 102 implements each process (step) of the communication terminal device 10 to be described later by executing the program.

  The memory 104 is realized by a RAM (Random Access Memory), a ROM (Read-Only Memory), a flash memory, or the like. The memory 104 stores a program executed by the CPU 102 or data used by the CPU 102.

  The touch panel 106 is provided on a display 108 having a function as a display unit, and is, for example, a capacitance type. The touch panel 106 detects a touch operation on the touch panel 106 by an external object every predetermined time, and inputs touch coordinates to the CPU 102.

The wireless communication unit 110 connects to a wireless communication network via the communication antenna 112 and transmits and receives signals for wireless communication. Thereby, the communication terminal device 10 is, for example, LTE (Long Term
Evolution) or the like can be used to communicate with other communication terminal devices via the base station 20, and directly communicate with other communication terminal devices without involving the base station 20. Can be executed.

  A memory interface (I / F) 114 reads data from an external storage medium 115. The CPU 102 reads data from the memory 104 and stores the data in an external storage medium 115 via the memory interface 114. The storage medium 115 includes a CD (Compact Disc), a DVD (Digital Versatile Disk), a BD (Blu-ray (registered trademark) Disc), a USB (Universal Serial Bus) memory, an SD (Secure Digital) memory card, and the like. A medium for storing the program in a nonvolatile manner can be mentioned.

  The communication interface (I / F) 116 exchanges various data with an external device, and is realized by an adapter, a connector, or the like. The communication method may be, for example, wireless communication using Bluetooth (registered trademark), wireless LAN (Local Area Network), or wired communication using USB (Universal Serial Bus). .

  The GPS controller 118 receives a GPS signal or a position signal (positioning signal) from the base station, and acquires position information of the communication terminal device 10. The GPS controller 118 inputs the acquired position information of the communication terminal device 10 to the CPU 102.

  The battery 120 is a chargeable / dischargeable power storage element, and typically includes a secondary battery such as a lithium ion battery or a nickel metal hydride battery.

  Communication terminal device 10 may include a button for receiving an instruction from the user, a microphone for receiving an utterance to communication terminal device 10, and a speaker for outputting sound.

(Base station 20)
FIG. 4 is a block diagram showing a hardware configuration of base station 20 according to the first embodiment. Referring to FIG. 4, base station 20 includes, as main components, CPU 202 for executing various processes, memory 204 for storing programs executed by CPU 202, data, and the like, and a wireless communication network. Wireless communication unit 206 for transmitting / receiving various data to / from devices in communication area 200 and communication interface (I / F) 208 for communicating with other base stations.

<Functional configuration>
With reference to FIG. 5, functional configurations of communication terminal apparatus 10 and base station 20 included in communication system 1 will be described. FIG. 5 is a functional block diagram of communication terminal apparatus 10 and base station 20 according to the first embodiment.

(Communication terminal device 10)
Referring to FIG. 5, communication terminal device 10 has, as its main functional configuration, control information receiving unit 150, control information transmitting unit 152, remaining battery level detecting unit 154, speed detecting unit 156, and determining unit 158. And a status transmission unit 160 and a notification reception unit 162. These functions are mainly realized by the CPU 102 of the communication terminal device 10 executing a program stored in the memory 104 and giving a command to the components of the communication terminal device 10. The CPU 102 has a function as a control unit that controls the overall operation of the communication terminal device 10. Note that some or all of these functional configurations may be realized by hardware.

  The control information receiving unit 150 receives control information for controlling direct communication from the base station 20 (control information transmitting unit 250 described later) via the wireless communication unit 110.

  Control information transmitting section 152 transmits the control information received by control information receiving section 150 to a plurality of other communication terminal apparatuses (communication terminal apparatuses 10B and 10C in the present embodiment).

  The remaining battery level detection unit 154 monitors the battery 120 and detects the remaining battery level of the communication terminal device 10.

  The speed detection unit 156 detects the moving speed of the communication terminal device 10 based on the position information acquired via the GPS controller 118. Specifically, the speed detection unit 156 detects the moving speed from the time change of the position of the communication terminal device 10. The speed detection unit 156 may detect the moving speed using a speed sensor or an acceleration sensor (not shown).

  The determination unit 158 determines whether or not transmission of control information by the control information transmission unit 152 can be continued based on a predetermined determination criterion and the state of the communication terminal device 10. In other words, the determination unit 158 determines whether or not the communication terminal device 10 has a margin so that direct communication between a plurality of other communication terminal devices can be controlled as a communication control device.

  Specifically, the determination unit 158 determines that the remaining battery level detected by the remaining battery level detection unit 154 is less than a predetermined reference remaining level (for example, the ratio of the remaining battery level to the fully charged amount is less than 20%). In this case, it is determined that transmission of control information cannot be continued. Alternatively, the determination unit 158 determines that the transmission of the control information cannot be continued when the moving speed detected by the speed detection unit 156 is equal to or higher than a predetermined reference speed (for example, 100 km / h or higher). To do. Note that the reference remaining amount and the reference speed may be appropriately set by a user or the like.

  The state transmission unit 160 transmits state information indicating the state of the communication terminal apparatus 10 to the base station 20. Specifically, the state transmitting unit 160 periodically transmits the detected remaining battery level (and moving speed) to the base station 20 as state information. The frequency of transmitting the state information may be determined in advance or may be set by the user. Further, in another aspect, when the determination unit 158 determines that transmission of control information cannot be continued, the state transmission unit 160 further notifies the base station 20 that the transmission cannot be continued.

  The notification receiving unit 162 selects the alternative communication terminal device (communication terminal device 10D in this embodiment) that transmits control information instead of the communication terminal device 10 (in this embodiment, the communication terminal device 10A). A notification to that effect is received from the base station 20 (a notification unit 256 described later).

  When the notification receiving unit 162 receives a notification that an alternative communication terminal device has been selected, the control information transmission unit 152 stops transmission of control information to a plurality of other communication terminal devices.

(Base station 20)
Referring to FIG. 5, base station 20 includes a control information transmission unit 250, a status reception unit 252, a terminal selection unit 254, and a notification unit 256 as its main functional configuration. These functions are mainly realized by the CPU 202 of the base station 20 executing a program stored in the memory 204 and giving a command to the components of the base station 20. Note that some or all of these functional configurations may be realized by hardware.

  The control information transmission unit 250 transmits control information for controlling direct communication to the communication terminal device 10. Note that the control information transmission unit 250 may transmit the control information to all communication terminal devices existing in the communication area 200.

  The state receiving unit 252 receives state information transmitted from the communication terminal device 10 (state transmitting unit 160). Further, the state receiving unit 252 receives the identification information of the communication terminal device 10 transmitted together with (or separately from) the state information, and stores the state information and the identification information in the memory 204 in association with each other. Further, in another aspect, the state receiving unit 252 receives a notification that transmission of control information cannot be continued from the communication terminal device 10 functioning as a communication control device.

  The terminal selection unit 254 selects an alternative communication terminal device from the one or more communication terminal devices based on the state information received from the one or more communication terminal devices existing in the communication area 200. Specifically, the terminal selection unit 254 performs the selection when the state reception unit 252 receives a notification that transmission of control information cannot be continued. The terminal selection unit 254 selects a communication terminal device having the largest remaining battery capacity as the alternative communication terminal device among the one or more communication terminal devices. Or the terminal selection part 254 selects the communication terminal device with the slowest moving speed as an alternative communication terminal device among the one or more communication terminal devices.

  The notification unit 256 notifies the communication terminal device 10 that the alternative communication terminal device has been selected by the terminal selection unit 254. Further, the notification unit 256 instructs the alternative communication terminal device to transmit the control information to a plurality of other communication terminal devices.

<Processing procedure>
FIG. 6 is a flowchart showing an example of a processing procedure of communication terminal apparatus 10 functioning as a communication control apparatus according to the first embodiment. The following steps are realized by the CPU 102 of the communication terminal device 10 executing a program stored in the memory 104.

  Referring to FIG. 6, CPU 102 detects the remaining battery level via battery 120 (step S50). Based on the detected remaining battery level, CPU 102 determines whether its own device can continue communication with communication terminal devices 10B and 10C as a communication control device (step S52). If it is determined that the communication can be continued (YES in step S52), CPU 102 repeats the processing from step S50.

  On the other hand, when it is determined that the communication cannot be continued (NO in step S52), the CPU 102 cannot communicate with the base station 20 via the wireless communication unit 110 because the remaining battery level is low. The base station 20 is notified of this (step S56).

  Next, the CPU 102 determines whether or not a notification that the alternative communication terminal device 10D has been selected as the communication control device (communication control device change notification) has been received from the base station 20 (step S58). If the notification has not been received (NO in step S58), CPU 102 repeats the process of step S58. On the other hand, when the notification is received (YES in step S58), CPU 102 stops transmission of control information to communication terminal apparatuses 10B and 10C, and ends communication as a communication control terminal ( Step S60). Then, the CPU 102 ends the process.

<Effect of Embodiment>
According to the first embodiment, since the state of the communication terminal device functioning as the communication control device can be grasped on the base station side, the communication control device is instructed to perform other communication according to the instruction on the base station side according to the state. It is possible to switch to a terminal device. As a result, direct communication between a plurality of other communication terminal devices controlled by the communication control device can be stably maintained.

  Further, according to the first embodiment, since the communication terminal device does not need to exchange state information with other communication terminal devices, traffic can be reduced accordingly. Furthermore, since it is not necessary to manage the status information of other communication terminal devices, the load is reduced.

[Embodiment 2]
In the first embodiment described above, when the communication terminal apparatus 10D is instructed to operate as a communication control apparatus instead of the communication terminal apparatus 10A from the base station 20 (see step S28 in FIG. 2), the instruction The configuration for starting the operation as the communication control device has been described. In the second embodiment, the communication terminal device 10D determines whether to follow the instruction based on a predetermined determination criterion, and starts operation as a communication control device when it is determined to comply with the instruction. explain.

<Functional configuration>
FIG. 7 is a functional block diagram of communication terminal apparatus 10 according to the second embodiment. Specifically, FIG. 7 shows communication terminal apparatus 10 (selected in this embodiment as communication terminal apparatus 10D) that is instructed to operate as a communication control apparatus (in this embodiment, communication terminal apparatus 10D). The functional block diagram of is shown.

  Referring to FIG. 7, communication terminal apparatus 10 has, as its main functional configuration, control information receiving unit 150, control information transmitting unit 152, remaining battery level detecting unit 154, speed detecting unit 156, and state transmitting unit. 160, an instruction receiving unit 170, and an instruction determining unit 172. These functions are mainly realized by the CPU 102 of the communication terminal device 10 executing a program stored in the memory 104 and giving a command to the components of the communication terminal device 10. Note that some or all of these functional configurations may be realized by hardware.

  The functions of the control information receiving unit 150, the control information transmitting unit 152, the remaining battery level detecting unit 154, the speed detecting unit 156, and the state transmitting unit 160 are the same as those described with reference to FIG. Will not repeat.

  The instruction receiving unit 170 receives from the base station 20 an instruction to transmit control information to a plurality of other communication terminal apparatuses (communication terminal apparatuses 10B and 10C in the present embodiment). That is, the instruction receiving unit 170 from the base station 20 to operate as the communication control apparatus instead of the communication terminal apparatus 10 (in this embodiment, the communication terminal apparatus 10A) currently operating as the communication control apparatus. Instructed.

  Note that the base station 20 sends the transmission instruction to the alternative communication terminal device selected from the one or more communication terminal devices based on the status information received from the one or more communication terminal devices existing in the communication area 200. Send.

  When the instruction receiving unit 170 receives the transmission instruction, the instruction determining unit 172 determines whether to follow the transmission instruction from the base station 20 based on a predetermined determination criterion. Specifically, the instruction determination unit 172 receives an instruction to permit transmission of control information to a plurality of other communication terminal apparatuses from the user of the communication terminal apparatus 10 (communication terminal apparatus 10D in the present embodiment). If it is determined that the transmission instruction is to be followed. The instruction determination unit 172 receives an instruction from the user via the touch panel 106 (or a button, a speaker, or the like).

  In addition, when the remaining battery level detected by the remaining battery level detection unit 154 is less than a predetermined reference remaining level, the instruction determination unit 172 follows the transmission instruction regardless of whether there is a permission instruction from the user. You may decide not to. Alternatively, when the movement speed detected by the speed detection unit 156 is equal to or higher than a predetermined reference speed, the instruction determination unit 172 does not follow the transmission instruction regardless of whether there is a permission instruction from the user. You may judge.

  Control information transmission section 152 transmits control information to a plurality of other communication terminal apparatuses when instruction determination section 172 determines that the transmission instruction is to be followed.

<Processing procedure>
FIG. 8 is a flowchart showing an example of a processing procedure as an alternative communication terminal device of communication terminal device 10 (here, communication terminal device 10D) according to the second embodiment. The following steps are realized by the CPU 102 of the communication terminal device 10 executing a program stored in the memory 104.

  Referring to FIG. 8, CPU 102 determines whether or not an operation instruction as a communication control apparatus has been received from base station 20 (step S70). Here, the operation instruction as the communication control apparatus includes an instruction to transmit control information to the communication terminal apparatuses 10B and 10C. CPU102 repeats the process of step S70, when the said operation instruction is not received (in step S70 NO).

  On the other hand, when CPU 102 receives the operation instruction (hereinafter also simply referred to as “operation instruction”) (YES in step S70), CPU 102 follows the operation instruction to the user of communication terminal device 10D. A user interface screen requesting permission is displayed (step S72).

  FIG. 9 shows user interface screen 500 according to the second embodiment. Referring to FIG. 9, user interface screen 500 includes a word 502 “Do you permit to operate as a communication control device?”, YES button 504, and NO button 506.

  Referring to FIG. 8 again, CPU 102 determines whether to follow the operation instruction based on the input from the user (step S74). Specifically, the CPU 102 determines that the operation instruction is to be followed when an input of the YES button 504 is accepted from the user, and determines that the operation instruction is not obeyed when the input of the NO button 506 is accepted from the user.

  When following the operation instruction (YES in step S74), CPU 102 notifies base station 20 that the operation instruction is to be followed (step S76), and ends the process. In this case, communication terminal apparatus 10D starts transmission of control information to communication terminal apparatuses 10B and 10C as a communication control apparatus (see, for example, step 30 in FIG. 2).

  On the other hand, when CPU 102 does not follow the operation instruction (NO in step S74), CPU 102 notifies base station 20 that the operation instruction is not followed (step S78), and ends the process. In this case, the communication terminal device 10D does not operate as a communication control device and maintains an operation as a normal communication terminal device.

(Modification)
FIG. 10 is a flowchart showing a modified example of the processing procedure as an alternative communication terminal device of communication terminal device 10 (here, communication terminal device 10D) according to the second embodiment.

  Referring to FIG. 10, the process in step S80 is the same as the process in step S70, and therefore detailed description thereof will not be repeated. When receiving an operation instruction as a communication control apparatus from the base station 20 (YES in step S80), the CPU 102 can operate itself (communication terminal apparatus 10D) as a communication control apparatus (follow the operation instruction). It is determined whether or not it is possible (step S81).

  Specifically, when the remaining battery level of the device is equal to or greater than the reference remaining amount, the CPU 102 determines that the device can operate as a communication control device, and the remaining battery level is less than the reference remaining amount. In this case, it is determined that it is impossible to operate as a communication control device. Alternatively, the CPU 102 determines that the device can operate as a communication control device when the movement speed of the own device is less than the reference speed, and as the communication control device when the movement speed is equal to or higher than the reference speed. Judge that it is impossible to operate.

  If it is impossible for the device itself to operate as a communication control device (NO in step S81), the CPU 102 notifies the base station 20 that the operation instruction is not followed (step S88). ), The process is terminated. In this case, the communication terminal device 10D does not operate as a communication control device and maintains an operation as a normal communication terminal device.

  If the device itself is in a state where it can operate as a communication control device (YES in step S81), CPU 102 executes processing in step S82 and subsequent steps. Since the processing of steps S82 to S88 is the same as the processing of steps S72 to S78 in FIG. 8, detailed description thereof will not be repeated.

<Effect of Embodiment>
According to the second embodiment, when receiving an operation instruction as a communication control device from a base station, the communication terminal device confirms with the user whether or not to permit operation as a communication control device. Therefore, it is possible to prevent the communication terminal device from operating as a communication control device without user recognition.

[Embodiment 3]
In the first embodiment described above, the base station 20 (terminal selection unit 254), based on the state information received from one or more communication terminal apparatuses existing in the communication area 200, includes the one or more communication terminal apparatuses. The selection of an alternative communication terminal device to be operated as a communication control device has been described. And base station 20 (terminal selection part 254) is a communication terminal device with the most remaining battery power among the one or more communication terminal devices, or a communication terminal device with the slowest moving speed among the one or more communication terminal devices. The configuration for selecting as an alternative communication terminal device has been described.

  In the third embodiment, another mode of selection method used when the base station 20 selects an alternative communication terminal device will be described.

<System overview>
(overall structure)
FIG. 11 is a schematic diagram showing an overall configuration of a communication system 1A according to the third embodiment. Communication system 1 according to the first embodiment has only one communication terminal device (communication terminal device 10D) in communication area 200 (not a plurality) other than communication terminal device 10A operating as a communication control device. It also included existing configurations. However, in the communication system 1A according to the third embodiment, in addition to the communication terminal device 10A operating as the communication control device, at least a plurality of communication terminal devices (communication terminal devices 10D and 10D) in the communication area 200 (not one) 10E). Therefore, the communication system 1A in FIG. 11 has a communication terminal device 10E added to the communication system 1 in FIG. The communication terminal device 10E has the same function and configuration as the communication terminal devices 10A to 10D.

(Overview of operation)
FIG. 12 is a sequence diagram showing an outline of operation of communication system 1A according to the third embodiment. In addition, it is assumed that the communication terminal devices 10A, 10D, and 10E existing in the communication area 200 regularly transmit state information.

  Referring to FIG. 12, the processing in steps S10 to S26 is the same as that described in FIG. 2, and therefore detailed description thereof will not be repeated.

  When the base station 20 receives a notification from the communication terminal device 10A that communication with the communication terminal devices 10B and 10C cannot be continued (step S26), the base station 20 operates as a communication control device instead of the communication terminal device 10A. Processing for selecting an alternative communication terminal device is executed (step S26A). In the example of FIG. 12, the base station 20 selects an alternative communication terminal device from the communication terminal devices 10D and 10E existing in the communication area 200, in addition to the communication terminal device 10A. A specific selection method will be described later. Here, it is assumed that the base station 20 selects the communication terminal device 10D as an alternative communication terminal device.

  Since the processing in steps S27 to S41 is the same as that described in FIG. 2, detailed description thereof will not be repeated.

<Selection method>
Next, an alternative communication terminal apparatus selection method for the base station 20 will be described. The following contents are mainly realized by the function of the terminal selection unit 254 of the base station 20. It is assumed that communication terminal apparatuses 10D and 10E transmit the remaining battery level, movement speed, and position information of the own apparatus to base station 20 as state information.

(Part 1)
FIG. 13 shows information table 600 according to the third embodiment. Referring to FIG. 13, information table 600 includes battery remaining amount, moving speed, and relative position information for each of communication terminal apparatuses 10D and 10E. These three pieces of information are used as indices when the base station 20 (terminal selection unit 254) selects an alternative communication terminal device.

  The relative position is information indicating a relative position with respect to a communication terminal device (in this embodiment, communication terminal device 10B or 10C) that performs D2D communication. The base station 20 calculates the relative position based on the position information transmitted from the communication terminal apparatus 10D (and 10E) and the position information of the communication terminal apparatus 10B.

  When the communication terminal device 10B exists in the communication area 200, the base station 20 acquires the position information directly from the communication terminal device 10B. On the other hand, when the communication terminal device 10B exists outside the communication area 200, the base station 20 uses, for example, the location information of the communication terminal device 10B via the communication terminal device 10A operating as the communication control device. To get.

  In the example of FIG. 13, the communication terminal device 10D is present at a position 10 km away from the communication terminal device 10B, and the communication terminal device 10E is present at a position 5 km away from the communication terminal device 10B. ing. Note that the relative position may be a relative position with respect to the communication terminal apparatus 10C instead of the communication terminal apparatus 10B.

  The information table 600 includes reference information corresponding to each remaining battery level, moving speed, and relative position. Specifically, the reference information corresponding to the remaining battery level is information indicating a criterion “the remaining battery level is 50% or more”. The reference information corresponding to the moving speed is information indicating a reference that “the moving speed is within 10 km / h”. The reference information corresponding to the relative position is information indicating a reference of “within 15 km from the communication terminal device that performs D2D communication”.

  For each of two or more communication terminal devices (here, communication terminal devices 10D and 10E) existing in communication area 200, terminal selection unit 254 includes the remaining battery level, movement speed, and relative position of the communication terminal device. The number of information satisfying the corresponding standard (the number of sufficiency) is calculated. Specifically, in communication terminal device 10D, terminal selection unit 254 calculates the sufficiency number as three because all the information on the remaining battery level, the moving speed, and the relative position satisfy the corresponding standards. Moreover, in the communication terminal device 10E, the terminal selection unit 254 calculates the number of suffices as two because the remaining battery level and the relative position satisfy the corresponding standards (the moving speed does not satisfy the reference).

  And the terminal selection part 254 selects communication terminal device 10D with many fulfillment numbers among communication terminal device 10D and 10E as an alternative communication terminal device.

  When there is a communication terminal device that is a candidate for an alternative communication terminal device other than the communication terminal devices 10D and 10E, the terminal selection unit 254 selects the communication terminal device with the most sufficient number as the alternative communication terminal device.

  Further, in the above, when any of the two or more communication terminal devices existing in the communication area 200 has a sufficient number (for example, one) or less, the terminal selection unit 254 selects an alternative communication terminal device. You may not.

(Part 2)
FIG. 14 shows information table 700 according to the third embodiment. Referring to FIG. 14, information table 700 includes a remaining battery level, a moving speed, and a relative position for each of communication terminal apparatuses 10D and 10E. Also, different priorities are set for these three pieces of information. In the example of FIG. 14, priority levels “high”, “medium”, and “low” are set for the remaining battery level, the moving speed, and the relative position, respectively.

  The terminal selection unit 254 uses the highest priority information (here, the remaining battery level) in each of two or more communication terminal devices (here, the communication terminal devices 10D and 10E) existing in the communication area of the base station. Based on this, an alternative communication terminal device is selected from the two or more communication terminal devices. Specifically, since the remaining battery level (80%) of the communication terminal device 10D is greater than the remaining battery level (50%) of the communication terminal device 10E, the terminal selection unit 254 replaces the communication terminal device 10D. Select as communication terminal device.

  When the moving speed is set as the highest priority information, the moving speed (0 km / h) of the communication terminal device 10D is more than the moving speed (20 km / h) of the communication terminal device 10E. Since it is small, the terminal selection part 254 selects communication terminal device 10D as an alternative communication terminal device. When the relative position is set as the highest priority information, the communication terminal device 10E is located closer to the communication terminal device that performs D2D communication than the communication terminal device 10D. Therefore, the terminal selection unit 254 selects the communication terminal device 10E as an alternative communication terminal device.

  Note that the terminal selection unit 254 may select an alternative communication terminal device by comparing information on the remaining battery level, the moving speed, and the relative position in order of priority. In the example of FIG. 14, the remaining battery level, the moving speed, and the relative position are set in descending order of priority. Therefore, terminal selection unit 254 first compares the remaining battery levels of both communication terminal apparatuses 10D and 10E. When both the remaining battery levels are equal, the terminal selection unit 254 compares the moving speeds of the communication terminal devices 10D and 10E. When both moving speeds are equal, the terminal selection unit 254 compares the relative positions of the communication terminal devices 10D and 10E. When both relative positions are equivalent, the terminal selection part 254 selects either one at random, for example.

  That both battery remaining amounts are equal includes that these differences are within a predetermined remaining amount range (such as less than 1%). Both movement speeds being equal include that these differences are within a predetermined movement speed (such as less than 1 km / h). Both relative positions being equal includes that the distance between both positions is within a predetermined distance range (10 m or the like).

  Further, the terminal selection unit 254 may execute the selection methods (part 1) and (part 2) in combination. For example, when the communication terminal devices 10D and 10E have the same number of suffices, the terminal selection unit 254 cannot select an alternative communication terminal device using the selection method (part 1). Therefore, if the terminal selection unit 254 uses the selection method (part 1) and determines that the number of fulfillment of each of the two or more communication terminal devices is the same, the terminal selection unit 254 uses the selection method (part 2), An alternative communication terminal device may be selected from the two or more communication terminal devices based on information having the highest priority in each of the two or more communication terminal devices.

(Part 3)
FIG. 15 shows information table 800 according to the third embodiment. Referring to FIG. 15, information table 800 shows remaining battery level, moving speed and relative position for each of communication terminal apparatuses 10D and 10E, and reference information corresponding to each remaining battery level, moving speed and relative position. Including. In addition, priority levels “high”, “medium”, and “low” are set for the remaining battery level, the moving speed, and the relative position, respectively. Furthermore, the points are weighted according to the priority, and are 3 points, 2 points, and 1 point in descending order of priority.

  The terminal selection unit 254 determines, for each of the communication terminal devices 10D and 10E, whether each of the remaining battery level, the moving speed, and the relative position in the communication terminal device satisfies a corresponding standard. Specifically, terminal selection unit 254 determines in communication terminal device 10D that all the information on the remaining battery level, the moving speed, and the relative position satisfy the corresponding standards. In addition, in communication terminal device 10E, terminal selection unit 254 determines that the remaining battery level and the relative position satisfy corresponding standards.

  Next, the terminal selection unit 254 determines the communication terminal devices 10D and 10E based on the respective remaining battery levels, movement speeds, and relative positions that satisfy the corresponding criteria in the communication terminal devices 10D and 10E. An alternative communication terminal device is selected from the list. Specifically, for the communication terminal device 10D, the terminal selection unit 254 has a score “3” corresponding to the priority of the remaining battery level, a score “2” corresponding to the priority of the moving speed, and the relative position. A total value “6” obtained by adding the score “1” corresponding to the priority is calculated. For the communication terminal device 10E, the terminal selection unit 254 adds a total value “4” obtained by adding the score “3” corresponding to the priority of the remaining battery level and the score “1” corresponding to the priority of the relative position. calculate.

  And the terminal selection part 254 selects communication terminal device 10D with the said total value large among communication terminal devices 10D and 10E as an alternative communication terminal device.

  Note that the points need only be weighted according to the priority, and may be 1 point, 2 points, or 3 points in order of increasing priority. In this case, the terminal selection unit 254 selects a communication terminal device having a small total value as an alternative communication terminal device.

<Others>
The state information only needs to include at least one of the battery remaining amount, the moving speed, and the relative position. That is, the state information may be configured to include only one piece of information (for example, remaining battery level) or to include two pieces of information (for example, remaining battery level and moving speed). In this case, the base station 20 uses the one or two pieces of information to select an alternative communication terminal apparatus by the selection method as described above.

  In the above, when the base station 20 instructs the communication terminal apparatus 10D to operate as a communication control apparatus (step S28 in FIG. 12), the base station 20 receives a notification that the operation instruction is not followed from the communication terminal apparatus 10D. Sometimes (see step S78 in FIG. 8), the communication terminal device 10E may be selected. Alternatively, the base station 20 may cancel the change of the communication control device itself when the selection conditions described above are not met.

<Effect of Embodiment>
According to Embodiment 3, the base station uses the information on at least two of the battery remaining amount, the moving speed, and the relative position to select an alternative communication terminal device from among a plurality of communication terminal devices existing in the communication area. select. Therefore, the base station can select a suitable alternative communication terminal device comprehensively.

[Other embodiments]
In the embodiment described above, a case where a communication terminal device functioning as a communication control device notifies the base station that transmission of control information to another communication terminal device as a communication control device cannot be continued is described. However, it is not limited to this. For example, only the state information may be transmitted from the communication terminal device, and it may be determined whether or not the base station can continue.

  In this case, the base station determines that the transmission of the control information cannot be continued when the remaining battery level transmitted from the communication terminal apparatus is less than a predetermined reference remaining level. Alternatively, the base station determines that the transmission of the control information cannot be continued when the moving speed transmitted from the communication terminal apparatus is equal to or higher than a predetermined reference speed. Then, the base station selects an alternative communication terminal device from one or more communication terminal devices existing in the communication area.

  Moreover, although embodiment mentioned above demonstrated the case where a communication terminal device detected the moving speed of an own apparatus, it is not restricted to this. For example, the base station may detect the moving speed of the communication terminal device based on position information transmitted from the communication terminal device.

  Moreover, in embodiment mentioned above, although the battery remaining amount, the moving speed, and the positional information were mentioned as a specific example of status information, information other than these may be included. For example, the state information may include terminal performance information including communication performance information and hardware performance information of the communication terminal device. The communication performance information is, for example, information indicating an LTE category, and the hardware performance information is, for example, information indicating CPU performance (clock frequency, number of cores, etc.). In this case, the base station selects a communication terminal device with higher communication performance (LTE category is higher) as an alternative communication terminal device, and has higher hardware performance (high CPU performance). The alternative communication terminal device is selected with priority.

  It is also possible to provide a program that causes a computer to function and execute control as described in the above flowchart. Such a program is recorded on a non-temporary computer-readable recording medium such as a flexible disk attached to the computer, a CD-ROM (Compact Disk Read Only Memory), a ROM, a RAM, and a memory card as a program product. It can also be provided. Alternatively, the program can be provided by being recorded on a recording medium such as a hard disk built in the computer. A program can also be provided by downloading via a network.

  The program may be a program module that is provided as a part of an operating system (OS) of a computer and that calls necessary modules in a predetermined arrangement at a predetermined timing to execute processing. In that case, the program itself does not include the module, and the process is executed in cooperation with the OS. A program that does not include such a module can also be included in the program according to the present embodiment.

  Further, the program according to the present embodiment may be provided by being incorporated in a part of another program. Even in this case, the program itself does not include the module included in the other program, and the process is executed in cooperation with the other program. A program incorporated in such another program can also be included in the program according to the present embodiment.

  The configuration illustrated as the above-described embodiment is an example of the configuration of the present invention, and can be combined with another known technique, and a part of the configuration is omitted without departing from the gist of the present invention. It is also possible to change the configuration.

  In the above-described embodiment, the processing and configuration described in the other embodiments may be adopted as appropriate.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1, 1A communication system, 10 communication terminal device, 20 base station, 102, 202 CPU, 104, 204 memory, 106 touch panel, 108 display, 110, 206 wireless communication unit, 112 communication antenna, 114 memory interface, 115 storage medium, 118 GPS controller, 120 battery, 150 control information reception unit, 152,250 control information transmission unit, 154 remaining battery level detection unit, 156 speed detection unit, 158 judgment unit, 160 status transmission unit, 162 notification reception unit, 170 instruction reception Unit, 172 instruction determination unit, 200 communication area, 252 status reception unit, 254 terminal selection unit, 256 notification unit.

Claims (10)

A communication terminal device capable of direct communication without using a base station with a plurality of other communication terminal devices,
Receiving means for receiving control information for controlling the direct communication from the base station;
Transmitting means for transmitting the control information received by the receiving means to the plurality of other communication terminal devices;
Status transmitting means for transmitting status information indicating the status of the communication terminal device to the base station;
Based on the state information transmitted from one or more communication terminal devices existing in the communication area of the base station, the control information is transmitted instead of the communication terminal device from the one or more communication terminal devices. A notification receiving means for receiving, from the base station, a notification that the alternative communication terminal apparatus has been selected when an alternative communication terminal apparatus is selected by the base station;
The transmission means is a communication terminal apparatus that stops transmission of the control information to the plurality of other communication terminal apparatuses when the notification is received by the notification reception means. Based on a predetermined criterion and state information of the communication terminal device, further comprising a determination means for determining whether or not the transmission of the control information by the transmission means can be continued;
The communication terminal apparatus according to claim 1, wherein the state transmission unit further notifies the base station that the transmission cannot be continued when the transmission of the control information by the transmission unit is not continued. The state information includes a remaining battery level of the communication terminal device,
The communication terminal device
The battery further comprises a remaining amount detecting means for detecting the remaining battery level,
The said judgment means judges that transmission of the said control information by the said transmission means cannot be continued, when the detected remaining battery level becomes less than the predetermined reference | standard remaining charge. Communication terminal device. The state information includes a moving speed of the communication terminal device,
The communication terminal device
It further comprises speed detecting means for detecting the moving speed,
The communication according to claim 2, wherein the determination unit determines that the transmission of the control information by the transmission unit cannot be continued when the detected moving speed is equal to or higher than a predetermined reference speed. Terminal device. A communication system,
A base station,
A communication terminal device capable of direct communication with a plurality of other communication terminal devices without using the base station,
The communication terminal device
Receiving means for receiving control information for controlling the direct communication from the base station;
Transmitting means for transmitting the control information received by the receiving means to the plurality of other communication terminal devices;
State transmitting means for transmitting state information indicating the state of the communication terminal device to the base station,
The base station
Information transmitting means for transmitting the control information to the communication terminal device;
Status receiving means for receiving the status information transmitted from the communication terminal device;
An alternative of transmitting the control information instead of the communication terminal device from the one or more communication terminal devices based on the state information received from the one or more communication terminal devices existing in the communication area of the base station Terminal selection means for selecting a communication terminal device;
Notification means for notifying the communication terminal apparatus that the alternative communication terminal apparatus has been selected by the terminal selection means,
The communication terminal device
A notification receiving means for receiving a notification that the alternative communication terminal device is selected;
The transmission unit is a communication system in which transmission of the control information to the plurality of other communication terminal devices is stopped when the notification is received by the notification reception unit. The number of the one or more communication terminal devices is two or more,
The status information includes at least one information of a remaining battery level, a moving speed, and position information of the communication terminal device,
The base station
Storage means for storing corresponding criteria for each of the at least one piece of information;
The terminal selection means includes
For each of two or more communication terminal devices existing in the communication area of the base station, calculate the number of information satisfying the corresponding criterion among the at least one information in the communication terminal device,
The communication system according to claim 5, wherein a communication terminal device having the largest calculated number is selected as the alternative communication terminal device among the two or more communication terminal devices. The number of the one or more communication terminal devices is two or more,
The status information includes at least one information of a remaining battery level, a moving speed, and position information of the communication terminal device,
Each of the at least one information has a different priority,
The terminal selection means is configured to use the two or more communication terminal apparatuses based on information having the highest priority among the at least one information in each of two or more communication terminal apparatuses existing in a communication area of the base station. The communication system according to claim 5, wherein the alternative communication terminal device is selected from the list. The number of the one or more communication terminal devices is two or more,
The status information includes at least one information of a remaining battery level, a moving speed, and position information of the communication terminal device,
Each of the at least one information has a different priority,
The base station
Storage means for storing corresponding criteria for each of the at least one piece of information;
The terminal selection means includes
For each of two or more communication terminal devices existing in the communication area of the base station, determine whether each of the at least one information in the communication terminal device satisfies the corresponding criterion,
The alternative communication terminal device is selected from the two or more communication terminal devices based on each priority of the at least one information that satisfies the corresponding criterion in each of the two or more communication terminal devices. The communication system according to claim 5. A communication terminal device capable of direct communication without using a base station with a plurality of other communication terminal devices,
Receiving means for receiving control information for controlling the direct communication from the base station;
An instruction receiving means for receiving, from the base station, an instruction to transmit the control information to the other communication terminal devices;
Instruction determining means for determining whether or not to follow the transmission instruction by the base station based on a predetermined determination criterion when the transmission instruction is received;
A communication terminal apparatus comprising: a transmission means for transmitting the control information to the plurality of other communication terminal apparatuses when the instruction determination means determines that the transmission instruction is followed.   The instruction determination unit determines to follow the transmission instruction when an instruction to permit transmission of the control information to the plurality of other communication terminal apparatuses is received from a user of the communication terminal apparatus. The communication terminal device according to 1.

Images