JP2015226208A - Communication terminal and transmission path selecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication terminal and a transmission path selecting method that can estimate communication quality and usable band of a network as a single body even under a condition that a partner terminal as a communication destination is absent, thereby selecting an optimum communication transmission path.SOLUTION: A communication terminal is connectable to plural base stations by switching plural communication modes, and has a communication quality measuring unit for measuring communication quality of each of the base stations adaptable to the plural communication modes, a packet generator for generating a predetermined band estimating packet on the basis of the communication quality of each base station, an address converter for converting a transmission destination address of the band estimating packet to a self-address of a communication terminal, a transmitter for transmitting the band estimating packet whose transmission destination address is converted, a receiver for receiving the band estimating packet which is re-directed according to the conversion of the transmission address of the band estimating packet to the self address, and a transmission path selecting unit for selecting a transmission path using a communication mode corresponding to any base station on the basis of the usable band corresponding to the band estimating packet received for each base station.

Description

  The present invention relates to a communication terminal and a transmission path selection method for selecting a transmission path for communication.

  In recent years, for example, a smartphone or tablet terminal has a function of connecting to a plurality of wireless communication broadband networks (hereinafter abbreviated as “wireless network”) and is used for connection to a wireless network (hereinafter referred to as “wireless system”). Communication terminals that automatically select "" by themselves. The communication terminal selects the best wireless method to use for connecting to the wireless network depending on the user's state (eg, moving or stationary, indoor or outdoor) or the type of application in use. Even after connecting to a wireless network, the transmission speed may deteriorate depending on the wireless quality or wireless band of the wireless network to which it is connected.

  Here, as a prior art for calculating an available bandwidth in communication between a transmission-side device and a reception-side device connected to a network, for example, a network bandwidth measurement system disclosed in Patent Document 1 is known.

  In the network bandwidth measurement system disclosed in Patent Document 1, the transmission-side device transmits a plurality of measurement packets whose packet sizes sequentially increase or decrease at a predetermined transmission interval. The receiving side device receives the transmitted measurement packet, measures the measurement packet reception interval, compares the transmission interval when the measurement packet is transmitted with the reception interval when the measurement packet is received, and receives the reception interval and the transmission interval. The available bandwidth is calculated using the measurement packet with the largest packet size among the measurement packets with the same.

JP 2011-142622 A

  However, in the configuration of Patent Document 1, in order to calculate the available bandwidth in communication between the transmission-side device and the reception-side device connected to the network, the transmission-side device that transmits the measurement packet is It becomes necessary, and the usable bandwidth cannot be calculated by the receiving apparatus alone, and the convenience during communication may be deteriorated.

  Therefore, when trying to select the wireless method used for connection to the above-described wireless network using the configuration of Patent Document 1, the communication terminal calculates the available bandwidth by itself in a situation where there is no other terminal as the communication destination. However, there is a problem that it is difficult to select an optimal wireless system.

  In order to solve the above-described conventional problems, the present invention is a communication terminal that estimates the communication quality and available bandwidth of a single network and selects an optimal communication transmission path even in the absence of a communication partner terminal. It is another object of the present invention to provide a transmission path selection method.

  The present invention is a communication terminal that can be connected to a plurality of base stations by switching a plurality of communication schemes, a communication quality measuring unit that measures the communication quality for each base station according to the plurality of communication schemes, Based on the communication quality of each base station measured by the communication quality measurement unit, a packet generation unit that generates a predetermined band estimation packet, and a transmission destination address of the band estimation packet generated by the packet generation unit Is converted to the address of the communication terminal, a transmission unit that transmits the band estimation packet whose transmission destination address is converted by the address conversion unit, and the band estimation transmitted from the transmission unit A receiving unit that receives the packet for bandwidth estimation redirected according to the conversion of the transmission destination address of the packet to the own address; and the receiving unit for each base station A transmission path selection unit that selects a transmission path using the communication method corresponding to any of the base stations based on an available band according to the received band estimation packet. is there.

  The present invention is also a transmission path selection method in a communication terminal that can be connected to a plurality of base stations by switching a plurality of communication methods, and measures the communication quality for each base station according to the plurality of communication methods. A step of generating a predetermined bandwidth estimation packet based on the measured communication quality of each base station, and converting the transmission destination address of the generated bandwidth estimation packet into the own address of the communication terminal Transmitting the band estimation packet in which the transmission destination address is converted, and the band redirected in accordance with the conversion of the transmission destination address of the transmitted band estimation packet into the self address Based on the step of receiving the estimation packet and the available bandwidth according to the bandwidth estimation packet received for each base station, any one of the base stations It has a step of selecting a transmission path using said communication method response, and a transmission path selection method.

  According to the present invention, it is possible to estimate the communication quality and available bandwidth of a network by itself and select an optimum communication transmission path even in a situation where there is no other party as a communication destination.

The block diagram which shows an example of an internal structure of the communication terminal of 1st Embodiment in detail The block diagram which shows an example of the terminal radio | wireless control part of the communication terminal of 1st Embodiment in detail Schematic diagram showing an outline of the operation of the first embodiment Explanatory drawing for demonstrating typically the operation | movement which converts the transmission destination address of the packet for a band measurement in 1st Embodiment. (A) A diagram showing an example of a candidate list of access points related to a WLAN, (B) a diagram showing an example of a candidate list of radio base stations related to LTE, and (C) a diagram showing an example of a priority list A sequence diagram explaining an example of signaling between a communication terminal and a default gateway of a 1st embodiment The block diagram which shows in detail an example of the terminal radio | wireless control part of the communication terminal of the modification of 1st Embodiment The block diagram which shows an example of the terminal radio | wireless control part of the communication terminal of 2nd Embodiment in detail (A) A block diagram showing an example of the internal configuration of the virtual network unit, (B) schematically showing the difference between the estimation of the communication available bandwidth in the first embodiment and the estimation of the communication available bandwidth in the second embodiment. Supplementary explanatory diagram to show, (C) a diagram showing an example of the application information management list The block diagram which shows an example of the terminal radio | wireless control part of the communication terminal of 3rd Embodiment, and the application management part 81 in detail Explanatory diagram of conventional bandwidth estimation method

(Background to the contents of each embodiment)
First, before describing each embodiment of the communication terminal and the transmission path selection method according to the present invention, the process leading to the contents of each embodiment will be described with reference to FIG. FIG. 11 is an explanatory diagram of a conventional band estimation method. FIG. 11 illustrates an example in which communication is performed via the Internet INT between the communication terminal 101 and the counterpart terminal 103 of the communication terminal 101 using, for example, an LTE (Long Term Evolution) wireless method. The wireless system is not limited to LTE, and may be a wireless local area network (HSPA) or WLAN (Local Area Network) such as WLAN.

  In FIG. 11, the conventional bandwidth estimation method includes a bandwidth estimation method (first bandwidth estimation method) between the communication terminal 101 and the counterpart terminal 103, and a bandwidth estimation server provided for communication terminal 101 and bandwidth estimation. And a band estimation method (second band estimation method) with the SVR.

  The communication terminal 101 and the counterpart terminal 103 include a radio base station (eNB) BS10, LTE / HSPA network NW10, default gateway DG10, Internet INT, default gateway DG20, LTE / HSPA network NW20, and LTE compatible with LTE. It is connected via a base station (eNB) BS20.

  The communication terminal 101 and the bandwidth estimation server SVR are connected via the radio base station BS10, the LTE / HSPA network NW10, the default gateway DG10, and the Internet INT.

  As described above, in order to estimate the available bandwidth in both the first bandwidth estimation method and the second bandwidth estimation method, the activated counterpart device (that is, the communication partner terminal 103 or the bandwidth estimation server SVR). However, there is a problem that the use is limited.

  Further, in the second bandwidth estimation method, a packet for requesting bandwidth estimation is transmitted not only from one communication terminal 101 but also from a plurality of communication terminals to the bandwidth estimation server SVR. There is a problem that it is difficult to provide a wide-area service in the server SVR.

  Therefore, in each of the following embodiments, a communication terminal and an example of a transmission path selection method for estimating the communication quality of a network alone and selecting an optimal communication transmission path, even in a situation where there is no counterpart terminal as a communication destination, This will be described with reference to the drawings.

  Embodiments of a communication terminal and a transmission path selection method according to the present invention will be described below with reference to the drawings. The communication terminal of each embodiment can be connected to a plurality of wireless base stations with different communication methods (for example, 3G, LTE, HSPA, WLAN), such as a smartphone, a tablet terminal, an electronic book, a PDA (Personal Digital Assistant), etc. An electronic device having a wireless communication function.

  In addition to the inventions of the device category and the method category, the present invention can also be expressed as a program that causes a communication terminal to execute an instruction that defines the operation of the transmission path selection method or a computer-readable recording medium on which a program is recorded. Is possible.

  The radio base station communicates wirelessly with a communication terminal. For example, if the communication method is LTE, E-UTRAN (Evolved Universal Terrestrial Radio Access Network) Node B: eNB. For example, if the communication method is 3G or HSPA, Node B : NB. The radio base station may be an overhang base station (Remote Radio Head: RRH), a relay device (for example, a repeater or a relay node), a femto base station, or a pico base station.

(First embodiment)
In the first embodiment, the communication terminal 1 supports, for example, communication methods such as the LTE method (or the HSPA method) standardized in 3GPP (The 3rd Generation Partnership Project) and the WLAN method. The communication method can be switched to any one of the communication methods to enable communication with a connection destination base station (including an access point; the same applies hereinafter).

  FIG. 1 is a block diagram illustrating in detail an example of the internal configuration of the communication terminal 1 according to the first embodiment. 1 includes an application group 11, a terminal control unit 13, a tone control unit 15 to which a speaker SP1 is connected, a voice control unit 17 to which a speaker SP2 and a microphone MIC are connected, and a display unit 19. A user interface (UI) unit 21, a terminal radio control unit 23, an LTE / HSPA radio unit 39 to which the transmission antenna Txa1 and the reception antenna Rxa1 are connected, and a WLAN radio to which the transmission antenna Txa2 and the reception antenna Rxa2 are connected Part 41. The transmission antenna Txa1 and the reception antenna Rxa1 may be the same antenna. Similarly, the transmission antenna Txa2 and the reception antenna Rxa2 may be the same antenna.

  The terminal radio control unit 23 includes an optimum radio selection control unit 25, a network control unit 27, a band estimation control unit 29, a packet transmission unit 31, a packet reception unit 33, an LTE / HSPA controller 35, and a WLAN controller 37. It is the structure containing these. Details of the terminal radio control unit 23 will be described later with reference to FIG.

  The application group 11 is one or more applications installed in advance to be executable in the communication terminal 1, and operates according to an operation command of the application generated by the terminal control unit 13 in response to an operation signal from the UI unit 21, for example. In addition, the application group 11 receives data received at the reception antenna Rxa1 or the reception antenna Rxa2 from the terminal radio control unit 23, and operates according to an application operation command generated by the terminal control unit 13. The operation result of the application group 11 is output by the terminal control unit 13 through the tone control unit 15 and the speaker SP1, output through the voice control unit 17 and the speaker SP2, or displayed on the display unit 19.

  The terminal control unit 13 is configured using, for example, a processor, and outputs a control signal (operation command) for controlling the operation of each unit of the communication terminal 1 to each corresponding unit. In the following description, the processor is configured using, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or a DSP (Digital Signal Processor).

  The tone control unit 15 is configured using, for example, a processor, and controls sound output in the speaker SP1 in accordance with a control signal (operation command) from the terminal control unit 13, and for example, a base as an example of a connection destination of the communication terminal 1 When there is an incoming signal from the station, a predetermined ringing tone is output from the speaker SP1. In addition, the tone controller 15 causes the speaker SP1 to output a buzzer sound or an alarm sound in accordance with a control signal from the terminal controller 13.

  The voice control unit 17 is configured using, for example, a processor, and controls voice output from the speaker SP2 and voice collection from the microphone MIC in accordance with a control signal (operation command) from the terminal control unit 13, for example, the communication terminal 1 When there is an incoming signal from a base station as an example of a connection destination, the microphone MIC picks up the user's voice and causes the speaker SP2 to output the voice from the other party.

  The display unit 19 is configured using, for example, an LCD (Liquid Crystal Display) or an organic EL (Electroluminescence), and displays display target data on the screen in accordance with a control signal (operation command) from the terminal control unit 13. For example, when the application of the application group 11 is an application for streaming video, for example, the display unit 19 displays streaming video data.

  The UI unit 21 is a user interface for a user to input an operation on the communication terminal 1, and outputs an operation signal corresponding to the operation content of the user to the terminal control unit 13. For example, when the communication terminal 1 is a smartphone or a tablet terminal, the UI unit 21 is arranged on the display unit 19 and configured using a touch panel that can accept an input operation with a user's finger or stylus pen. Further, for example, when the communication terminal 1 is a mobile phone, the UI unit 21 can be configured using various keys such as a numeric keypad for inputting a telephone number and the like, a telephone key for performing on-hook or off-hook, and a function key. .

  The terminal radio control unit 23 is configured by using, for example, a processor, and mainly performs various operations related to radio communication of the communication terminal 1 (for example, establishment of a network, acquisition of communication quality, estimation of a communication available band, packets according to a communication method Generation, packet transmission / reception, operation control of a communication device provided for each communication method, and selection of an optimal communication transmission path in wireless communication).

  The LTE / HSPA radio unit 39 as an example of the communication quality measuring unit includes one or more base stations (for example, the base station BS1 or the base station shown in FIG. 3) corresponding to the cellular system (for example, LTE or HSPA) as an example of the communication method. This is a device for performing wireless communication with BS2). The LTE / HSPA wireless unit 39 performs wireless communication with each base station in order to perform wireless communication with one or more base stations corresponding to each communication method of LTE or HSPA (for example, reception electric field level). , Noise level, error rate, and so on), and each measurement result is output to the LTE / HSPA controller 35.

  Further, the LTE / HSPA radio unit 39 modulates the band estimation packet (see later) output from the terminal radio control unit 23 or the data transmission packet corresponding to the operation of the application group 11 according to a predetermined modulation scheme. The LTE / HSPA radio unit 39 converts a signal generated by modulation (hereinafter referred to as a “modulated signal”) into a high-frequency signal in a predetermined frequency band and transmits it from the transmission antenna Txa1.

  Furthermore, the LTE / HSPA radio unit 39 receives a high-frequency signal redirected by a default gateway (for example, default gateway DG1 shown in FIG. 3) corresponding to a cellular system (for example, LTE or HSPA) as an example of a communication system by the reception antenna Rxa1. To do. The LTE / HSPA radio unit 39 converts the high-frequency signal into a baseband signal according to the LTE or HSPA communication method, further demodulates the baseband signal, and outputs the received packet to the terminal radio control unit 23.

  The WLAN wireless unit 41 as an example of a communication quality measuring unit wirelessly communicates with one or more access points (for example, the access point AP1 or the access point AP2 shown in FIG. 3) corresponding to the WLAN method as an example of a communication method. It is a device for performing. The WLAN wireless unit 41 measures wireless communication quality with each access point in order to perform wireless communication with one or more access points corresponding to the WLAN communication method, and each measurement result is transmitted to the WLAN controller. To 37.

  Further, the WLAN radio unit 41 modulates the band estimation packet (see later) output from the terminal radio control unit 23 or the data transmission packet corresponding to the operation of the application group 11 according to a predetermined modulation scheme. The WLAN radio unit 41 converts the modulated signal into a high-frequency signal in a predetermined frequency band and transmits it from the transmission antenna Txa2.

  Further, the WLAN radio unit 41 receives a high-frequency signal redirected by a default gateway (for example, the default gateway DG2 shown in FIG. 3) corresponding to the WLAN system as an example of a communication system at the reception antenna Rxa2. The WLAN wireless unit 41 converts a high-frequency signal corresponding to WLAN as an example of a wireless LAN (WLAN: Wireless Local Area Network) communication method into a baseband signal, and further demodulates the baseband signal to receive a received packet as a terminal. Output to the wireless control unit 23.

  Here, a detailed configuration of the terminal radio control unit 23 will be described with reference to FIG. FIG. 2 is a block diagram illustrating in detail an example of the terminal radio control unit 23 of the communication terminal 1 according to the first embodiment.

  The optimum radio selection control unit 25 controls the selection of the optimum communication transmission path in the radio communication of the communication terminal 1, and includes an optimum radio selection manager 51, a radio available band management unit 53, and a radio quality management unit 55. It is.

  The optimum radio selection manager 51 as an example of the transmission path selection unit refers to the communication quality information held by the radio quality management unit 55, and informs the band estimation manager 61 (to be described later) the communication methods (for example, the communication terminal 1 can be used) Instructs the estimation of the communication available bandwidth in the communication transmission path using LTE or HSPA and WLAN. The optimum wireless selection manager 51 selects an optimum communication transmission path using a communication method based on the estimated value of the communication available band held by the wireless available band management unit 53. The optimum radio selection manager 51 instructs the radio switching unit 65 (to be described later) to switch the communication method necessary for using the selected communication transmission path.

  The wireless available bandwidth management unit 53 is configured by using, for example, a RAM (Random Access Memory), and can be used in communication with each base station obtained for each base station output from the bandwidth estimation manager 61 described later ( (Hereinafter referred to as “communication available bandwidth”).

  The wireless quality management unit 55 is configured using, for example, a RAM, holds information on communication quality in wireless communication using LTE or HSPA output from the LTE / HSPA controller 35 described later, and further, a WiFi controller 37 described later. The communication quality information in the wireless communication using the WLAN output from is held.

  The network control unit 27 manages information related to a communication transmission path for wireless communication using LTE or HSPA in the LTE / HSPA wireless unit 39 and information related to a communication transmission path for wireless communication using WLAN in the WLAN wireless unit 41. In addition, the network control unit 27 controls establishment, maintenance, and blocking of a communication network with each base station to which the LTE / HSPA radio unit 39 or the WLAN radio unit 41 is connected. Further, the network control unit 27 acquires the communication quality information in the communication network with each base station to which the LTE / HSPA radio unit 39 or the WLAN radio unit 41 is connected, by using the LTE / HSPA radio unit 39 or the WLAN radio unit. 41 is instructed.

  The band estimation control unit 29 controls the estimation of the communication available band in the radio communication of the communication terminal 1, and includes a band estimation manager 61, a band estimation unit 63, a radio switching unit 65, and a transmission destination address conversion unit 67. It is a configuration.

  In response to an instruction from the optimum radio selection manager 51, the band estimation manager 61 estimates the communication available band with each base station to which wireless communication is connected using each communication method of LTE, HSPA, and WLAN. The estimator 63 is instructed.

  In response to an instruction from the bandwidth estimation manager 61, the bandwidth estimation unit 63 estimates a communication available bandwidth with each base station to which wireless communication is connected using each communication method of LTE, HSPA, and WLAN. Then, predetermined band estimation data is generated, and further, the packet transmission unit 31 is instructed to generate a band estimation packet including the band estimation data.

  In addition, when the bandwidth estimation unit 63 receives the bandwidth estimation data output from the packet reception unit 33, the bandwidth estimation unit 63 is based on the number of transmissions of the bandwidth estimation packet, the delay time in transmission / reception of the bandwidth estimation packet, and jitter (fluctuation). Then, an estimated value of the communication available bandwidth is calculated according to a known calculation method. Note that the method for calculating the estimated value of the communication available band in the band estimation unit 63 is a known technique, and is also disclosed in, for example, Patent Document 1 described above.

  The radio switching unit 65 switches the communication method in the radio communication for estimating the communication available band or transmitting the data of the application group 11 in accordance with an instruction from the optimum radio selection manager 51 or the band estimation manager 61. For example, when the communication method in the currently used wireless communication is LTE, the wireless switching unit 65 switches the communication method to WLAN.

  The transmission destination address conversion unit 67 as an example of the address conversion unit, when estimating the communication available band based on the instruction from the band estimation manager 61, has the frame structure of the band estimation packet output from the packet transmission unit 31. The address of the destination address is converted into its own address (for example, an IP (Internet Protocol) address or a combination of a MAC (Media Access Control) address and an IP address) and the LTE / HSPA radio unit 39 or The data is output to the WLAN radio unit 41.

  The packet transmission unit 31 as an example of the packet generation unit, in response to an instruction from the band estimation unit 63, sets the band estimation data in order of high wireless communication quality with one or more base stations or access points. A predetermined band estimation packet corresponding to each communication method is generated and output to the transmission destination address conversion unit 67. Details of generation of the band estimation packet, conversion of the destination address, and reception of the band estimation packet will be described later with reference to FIG.

  The packet receiving unit 33 acquires the band estimation packet output from the LTE / HSPA radio unit 39 or the WLAN radio unit 41, extracts the band estimation data from the band estimation packet, and outputs it to the band estimation unit 63.

  The LTE / HSPA controller 35 measures the radio communication quality with one or more base stations to which the LTE / HSPA radio unit 39 is connected in response to an instruction from the network control unit 27 to the LTE / HSPA radio unit 39. Alternatively, the application group 11 is instructed to send and receive data. The LTE / HSPA controller 35 writes the wireless communication quality measurement result with one or more base stations to which the LTE / HSPA wireless unit 39 is connected in the wireless quality management unit 55. In addition, when switching the communication method currently in use to LTE or HSPA, the LTE / HSPA controller 35 switches to an operation according to LTE or HSPA according to an instruction from the radio switching unit 65.

  The WLAN controller 37 measures the wireless communication quality with one or more access points to which the WLAN wireless unit 41 is connected or data in the application group 11 in response to an instruction from the network control unit 27 to the WLAN wireless unit 41. To send and receive. The WLAN controller 37 writes the measurement result of the wireless communication quality with one or more access points to which the WLAN wireless unit 41 is connected in the wireless quality management unit 55. In addition, when the communication method currently in use is switched to WLAN, the WLAN controller 37 switches to an operation corresponding to the WLAN according to an instruction from the wireless switching unit 65.

  FIG. 3 is a schematic diagram showing an outline of the operation of the first embodiment. In FIG. 3, for example, when LTE is used as a communication method, the communication terminal 1 connects to the Internet INT via a base station (eNB) BS1, LTE / HSPA network NW1, and default gateway DG1 corresponding to LTE. For example, when HSPA is used as a communication method, the communication terminal 1 connects to the Internet INT via a base station (NB) BS2, a LTE / HSPA network NW1, and a default gateway DG1 compatible with HSPA.

  Further, when the communication terminal 1 uses both WLAN and HSPA as communication methods, for example, the access point AP1 corresponding to WLAN, the base station (NB) BS2 corresponding to HSPA, the LTE / HSPA network NW1 and the default gateway DG1 Through the Internet INT. For example, when using a WLAN alone as a communication method, the communication terminal 1 connects to the Internet INT via an access point AP2, a WLAN network NW2, and a default gateway DG2 corresponding to the WLAN.

  Further, when the communication terminal 1 selects a communication transmission path using an optimal wireless method, for example, in order to estimate the communication available band of the communication transmission path in the LTE communication network via the base station BS1, a predetermined band An estimation packet is generated and transmitted to the base station BS1. Since the transmission destination address of the bandwidth estimation packet is converted to the address of the communication terminal 1 by the transmission destination address conversion unit 67, the default gateway DG1 redirects the packet (for example, redirect by ICMP (Internet Control Message Protocol) redirect function). And received by the communication terminal 1.

  Similarly, the communication terminal 1 generates a predetermined bandwidth estimation packet and transmits it to the access point AP2 in order to estimate the communication available bandwidth of the communication transmission path in the WLAN communication network via the access point AP2, for example. Since the transmission destination address of this bandwidth estimation packet is converted to the own address of the communication terminal 1 by the transmission destination address conversion unit 67, it is redirected (for example, redirected by the ICMP redirect function) in the default gateway DG2 and is transmitted in the communication terminal 1. Received.

  Next, details of generation of a bandwidth estimation packet, conversion of a transmission destination address, and reception of a bandwidth estimation packet will be described with reference to FIG. FIG. 4 is an explanatory diagram for schematically explaining the operation of converting the transmission destination address of the bandwidth measurement packet in the first embodiment.

  In FIG. 4, for example, when estimating the communication available bandwidth of the communication transmission path in the WLAN communication network, the transmission destination address conversion unit 67 uses the virtual port number (br0) of the communication terminal 1 in the virtual network technology. IP address or IP address and MAC address are converted.

  As a specific implementation example, the band estimation unit 63 generates predetermined band estimation data ProbeData_A and outputs it to the packet transmission unit 31. In the band estimation data ProbeData_A, dl_src = MAC (br0) indicating that the source MAC address is the MAC address of the communication terminal 1, and dl_dst = indicating that the destination (destination) MAC address is the MAC address of the default gateway. MAC (GW), nw_src = br0 indicating that the source IP address is the IP address of the communication terminal 1, and nw_dst = 0xdeadbeef indicating the destination (destination) IP address are described (designated).

  The packet transmission unit 31 assigns a global IP address assigned to the virtual port number (br0) of the communication terminal 1 to nw_src indicating the transmission source IP address of the band estimation data ProbeData_A, and generates a band estimation packet ProbePacket_A And output to the destination address conversion unit 67.

  The transmission destination address conversion unit 67, when nw_dst indicating the transmission destination (destination) IP address of the bandwidth estimation packet ProbePacketA output from the packet transmission unit 31 is 0xdeadbeef, converts nw_dst to the IP address of nw_src (ie, communication The global IP address assigned to the virtual port number (br0) of the terminal 1, and dl_src indicating the source MAC address is rewritten to the MAC address of the WLAN wireless unit 41 which is the source device for bandwidth estimation. A packet ProbePacket_A ′ is generated. Thereafter, the WLAN radio unit 41 transmits a band estimation packet ProbePacket_A ′ to the default gateway DG2 via the access point AP2 and the WLAN network NW2.

  The bandwidth estimation packet ProbePacket_A ′ is redirected by the default gateway DG2, received by the reception antenna Rxa2 and input to the WLAN radio unit 41 according to nw_dst (= IP (br0)) indicating the transmission destination (destination) IP address. . The WLAN radio unit 41 outputs the input bandwidth estimation packet ProbePacket_A ′ to the packet receiving unit 33. The packet receiving unit 33 extracts predetermined band estimation data ProbeDataA from the band estimation packet ProbePacket_A ′ and outputs it to the band estimation unit 63.

  As shown in FIG. 4, in the estimation of the communication available band, the operation from the generation of the band estimation data ProbeDataA by the band estimation unit 63 to the acquisition of the band estimation data ProbeDataA is repeated a plurality of times. The bandwidth estimation unit 63 calculates the estimated value of the communication available bandwidth according to a known calculation method based on the number of transmissions of the bandwidth estimation packet, the delay time and jitter (fluctuation) in transmission / reception of the bandwidth estimation packet.

  In addition, in FIG. 4, since the estimation of the communication available band which illustrated WLAN as a communication method was explained, the transmission destination address conversion unit 67 converts the transmission destination MAC address, but depending on the communication method (for example, LTE, HSPA). May simply convert the destination (destination) IP address without converting the destination MAC address.

  Next, connection destination candidate lists LST1, LST2 generated for each base station or access point of the connection destination of the communication terminal 1 and the priority list LST3 in which the connection destinations are preferentially rearranged are illustrated in FIG. This will be described with reference to FIGS. 5B and 5C. FIG. 5A shows an example of a candidate list of access points related to WLAN. FIG. 5B is a diagram illustrating an example of a candidate list of radio base stations related to LTE. FIG. 5C is a diagram illustrating an example of a priority list.

  A candidate list LST1 shown in FIG. 5A is a candidate list when the communication method is WLAN, for example, and an ESSID (Extended Service Set) indicating identification information of a communication network via an access point to which the communication terminal 1 is connected. Identifier) and BSSID (Basic Service Set Identifier), and RSSI (Received Signal Strength Indicator) indicating a received electric field level as an example of communication quality information in wireless communication. In the candidate list LST1, a set of ESSID, BSSID, and RSSI is described, for example, in the order in which the communication quality is measured.

  Similarly, candidate list LST2 shown in FIG. 5B is a candidate list when the communication method is LTE, for example, and carrier information indicating identification information of a communication network via a base station to which communication terminal 1 is connected. And an RSRP (Reference Signal Received Power) indicating a received electric field level as an example of communication quality information in wireless communication.

  The priority list LST3 illustrated in FIG. 5C is a list in which the received electric field levels (for example, RSSI and RSRP) are rearranged in the candidate lists LST1 and LST2 illustrated in FIGS. 5A and 5B. For example, in the priority list LST3 shown in FIG. 5C, the communication method is WLAN and ESSID = “*** Z”, BSSID = “*** h”, and RSSI = “− 95 dBm” are obtained. The destination has the highest communication quality.

  In the priority list LST3 shown in FIG. 5C, the connection destination (for example, ESSID) excluded from the communication available band estimation target as “unknown” to indicate the connection destination that the communication terminal 1 has never connected to in the past. = “*** W”, BSSID = “*** D”, and RSSI = “− 92 dBm”).

  In the priority list LST3 shown in FIG. 5C, the LTE base station and the WLAN access point are generated to be the same list, but are generated to be different lists for each communication method. May be.

  Next, an example of signaling between the communication terminal 1 and the default gateway according to the present embodiment will be described in detail with reference to FIG. FIG. 6 is a sequence diagram illustrating an example of signaling between the communication terminal 1 and the default gateway (for example, the default gateway DG1 or the default gateway DG2) according to the first embodiment.

  In FIG. 6, when the optimum radio selection control unit 25 is notified of an event (for example, when the communication terminal 1 is turned on, when a handover occurs, the same applies hereinafter) for starting the communication available band estimation process (S1). The optimal radio selection control unit 25 requests the network control unit 27 to start estimating the communication available bandwidth in order to request a candidate list of connection destinations of the communication terminal 1 (see FIG. 5A or 5B). Instruct (S2).

  The network control unit 27 requests the LTE / HSPA controller 35 and the WLAN controller 37 to perform scanning for obtaining communication quality in wireless communication (S3).

  In response to a request from the network control unit 27, the LTE / HSPA controller 35 and the WLAN controller 37 perform scanning (that is, measurement of communication quality) to obtain communication quality in wireless communication, and the LTE / HSPA wireless unit 39 and WLAN. The wireless unit 41 is started (S4), and a scan response for obtaining communication quality in wireless communication is acquired from the LTE / HSPA wireless unit 39 and the WLAN wireless unit 41 (S5). In addition, the LTE / HSPA controller 35 and the WLAN controller 37 return a scan receipt confirmation (Scan_ack) for the scan request in step S3 to the network control unit 27 including the scan response obtained in step S5 (S6).

  The network control unit 27 extracts a candidate list (see, for example, FIGS. 5A and 5B) from the scan receipt confirmation from the LTE / HSPA controller 35 and the WLAN controller 37, and notifies the optimal radio selection control unit 25 of the candidate list (see FIGS. S7).

  The optimum radio selection control unit 25 updates the communication quality information (for example, RSSI, RSRP) in the candidate list notified from the network control unit 27 (S8), and further sets the candidate list in a predetermined order ( For example, rearrangement is performed in accordance with the order of communication quality in wireless communication (S9). The optimum radio selection control unit 25 selects a connection destination corresponding to the first row of the priority list LST3, in other words, a connection destination having the highest communication quality, according to the priority list LST3 generated by the rearrangement in step S9. It is determined to start estimation of a communication available band with the selected connection destination base station or access point (S10). The connection destination corresponding to the first row of the priority list LST3 is a connection destination that is most likely to be able to continue stable communication among the connection destination base stations or access points.

  The optimum radio selection control unit 25 requests the network control unit 27 for a connection destination designation type connection for establishing communication with the connection destination after designating the connection destination (for example, an access point) selected in step S10 (see FIG. S11). In response to the request from the optimum radio selection control unit 25, the network control unit 27 requests the WLAN controller 37 to establish communication with the access point as the connection destination selected in step S10 (S12).

  In response to a request from the network control unit 27, the WLAN controller 37 causes the WLAN radio unit 41 to try to establish communication (Connect) to the access point as the connection destination selected in step S10 (S13). If established, the fact that communication has been established (Connected) is acquired from the WLAN radio unit (S14). The WLAN controller 37 notifies the network control unit 27 that communication with the access point as the connection destination selected in Step S10 has been established (Connect_AP1_Linkup) (S15).

  In step S11, the network control unit 27 returns a communication establishment receipt confirmation (connection destination designation type connect_ack) in response to the request from the optimal wireless selection control unit 25 to the optimal wireless selection control unit 25 (S16).

  After obtaining the communication establishment receipt confirmation in S16, the optimum wireless selection control unit 25 sends the start of estimation of the communication available band (band estimation_std) with the connection destination selected in step S10 to the band estimation control unit 29. Instruct (S17).

  The band estimation control unit 29 starts estimating the communication available band with the connection destination selected in step S10 in response to the instruction from the optimum radio selection control unit 25 in step S17 (S18). Specifically, the band estimation control unit 29 generates predetermined band estimation data ProbeData_A (S19), and outputs the band estimation data ProbeData_A to the packet transmission unit 31 (S20).

  The packet transmission unit 31 assigns a global IP address assigned to the virtual port number (br0) of the communication terminal 1 to nw_src indicating the transmission source IP address of the band estimation data ProbeData_A, and generates a band estimation packet ProbePacket_A Then, it is output to the transmission destination address conversion unit 67 (S21, S22).

  When nw_dst indicating the transmission destination (destination) IP address of the bandwidth estimation packet ProbePacketA output from the packet transmission unit 31 is 0xdeadbeef, the bandwidth estimation control unit 29 sets nw_dst to the IP address of the nw_src (ie, the communication terminal (Global IP address assigned to the virtual port number (br0) of 1) (S23), and dl_src indicating the transmission source MAC address is rewritten to the MAC address of the WLAN wireless unit 41 which is the transmission source device. An estimation packet ProbePacket_A ′ is generated and output to the WLAN radio unit 41 (S24).

  The WLAN radio unit 41 transmits a band estimation packet ProbePacket_A ′ to the default gateway DG2 via the access point AP2 and the WLAN network NW2. The bandwidth estimation packet ProbePacket_A ′ is redirected by the default gateway DG2, received by the reception antenna Rxa2 and input to the WLAN radio unit 41 according to nw_dst (= IP (br0)) indicating the transmission destination (destination) IP address. (S25).

  The WLAN radio unit 41 outputs the input bandwidth estimation packet ProbePacket_A ′ to the packet receiving unit 33 (S26). The packet receiving unit 33 extracts predetermined band estimation data ProbeDataA from the band estimation packet ProbePacket_A 'and outputs it to the band estimation control unit 29 (S27). In the estimation of the communication available band with the connection destination selected in step S10, the operation from the generation of the band estimation data ProbeDataA by the band estimation unit 63 to the acquisition of the band estimation data ProbeDataA is performed a plurality of times. Repeated (S28, S29, S30, S31).

  The bandwidth estimation control unit 29, after finishing the transmission / reception of a plurality of bandwidth estimation packets, based on the number of transmissions of the bandwidth estimation packet, the delay time and jitter (fluctuation) in transmission / reception of the bandwidth estimation packet, According to the calculation method, the estimated value of the communication available band is calculated (S32), the estimation of the communication available band is finished (S33), and the estimation of the communication available band with the connection destination selected in step S10 is finished ( (Band estimation_end) is notified to the optimum radio selection control unit 25 (S34). Since the optimum radio selection control unit 25 has finished estimating the communication available bandwidth with the connection destination in the first row of the priority list LST3 generated in step S9, the connection after the second row in the priority list LST3 The estimation of the communication available bandwidth with the destination is continued (S35). In the operations after step S35, the operations from step S11 to step S34 are repeated in the same manner, and thus description thereof is omitted.

  As described above, the communication terminal 1 according to the present embodiment generates a predetermined band estimation packet based on communication quality for each of a plurality of base stations or access points according to a plurality of communication methods (for example, LTE, HSPA, WLAN). Then, the transmission destination address of the bandwidth estimation packet is converted to the own address of the communication terminal 1 and transmitted. The communication terminal 1 receives the bandwidth estimation packet redirected by the default gateway because the transmission destination address has been converted to its own address, and any one of the base stations based on the available bandwidth according to the bandwidth estimation packet Alternatively, a communication transmission path using a communication method corresponding to the access point is selected.

  As a result, the communication terminal 1 can communicate via the base station or access point to which the communication terminal 1 is connected at the time of communication even in the absence of the communication partner terminal or the bandwidth estimation server, which is necessary in the prior art. The communication terminal 1 itself can estimate the communication quality and communication available bandwidth in the communication network, and the optimum communication method for data transmission can be selected from a plurality of communication methods and a plurality of connectable base stations or access points. The used communication transmission path can be selected.

  Further, the communication terminal 1 estimates the communicable bandwidth in the communication network via each base station or access point based on the transmission and reception of a plurality of bandwidth estimation packets, so that, for example, a user who operates the communication terminal 1 A usable bandwidth estimated with high accuracy can be obtained for each base station even when the mobile phone is moving.

  In addition, since the communication terminal 1 generates the band estimation packets in descending order of the communication quality for each measured base station or access point, the communication terminal 1 can estimate the communication band estimation accuracy in the communication network via each base station or access point. Without using the available bandwidth for every connectable base station or access point, for example, using the available communication bandwidth for a given number of base stations or access points. The communication transmission path that has been used can be selected in a short time.

(Modification of the first embodiment)
In the modification of the first embodiment, the communication method that can be used by the communication terminal is single (for example, WLAN). Hereinafter, the configuration of a communication terminal 1A according to a modification of the first embodiment will be described with reference to FIG. FIG. 7 is a block diagram illustrating in detail an example of the terminal radio control unit 23A of the communication terminal 1A according to the modification of the first embodiment. In the description of each part of the terminal radio control unit 23A shown in FIG. 7, the same reference numerals are given to the same contents as those of the parts of the terminal radio control unit 23 shown in FIG. 2, and the description is simplified or omitted. The different contents will be described.

  The terminal radio control unit 23A illustrated in FIG. 7 includes an optimum radio selection control unit 25, a band estimation control unit 29A, a packet transmission unit 31, a packet reception unit 33, and a WLAN controller 37. The terminal radio control unit 23A illustrated in FIG. 7 has a configuration in which the network control unit 27 and the LTE / HSPA controller 35 are omitted from the configuration of the terminal radio control unit 23 illustrated in FIG. Further, the communication terminal 1A according to the modification of the first embodiment has a configuration in which the LTE / HSPA radio unit 39, the transmission antenna Txa1, and the reception antenna Rxa1 are omitted from the configuration of the communication terminal 1 illustrated in FIG.

  The band estimation control unit 29A includes a band estimation manager 61, a band estimation unit 63, a radio switching unit 65A, and a transmission destination address conversion unit 67. In response to an instruction from the optimum wireless selection manager 51 or the bandwidth estimation manager 61, the wireless switching unit 65 </ b> A connects a communication method (WLAN) in wireless communication for estimating the communication available bandwidth or transmitting data of the application group 11. Switch (access point). For example, the wireless switching unit 65A switches the current connection destination access point to another access point.

  In the signaling between the communication terminal 1A and the default gateway according to the modification of the first embodiment, the network control unit 27 is omitted from the communication terminal 1A, so the optimum radio selection control unit 25 is the WLAN radio unit 41. The connection destination candidate list is directly requested to the WLAN controller 37, and the candidate list is acquired from the WLAN controller 37. Further, when the communication terminal 1A starts estimating the communication available bandwidth, the communication terminal 1A directly requests the WLAN controller 37 to establish communication with the connection destination access point, and obtains from the WLAN controller 37 that communication has been established. To do. Other operations of the communication terminal 1A are the same as the signaling procedure between the communication terminal 1 and the default gateway shown in FIG.

  As described above, the communication terminal 1A according to the modification of the first embodiment generates a predetermined bandwidth estimation packet based on the communication quality for each of a plurality of access points according to a single communication method (WLAN). The transmission destination address of the bandwidth estimation packet is converted to the address of the communication terminal 1A and transmitted. The communication terminal 1A receives the bandwidth estimation packet redirected by the default gateway because the transmission destination address is converted to its own address, and performs any access based on the communication available bandwidth according to the bandwidth estimation packet. Select a communication transmission path using the communication method corresponding to the point.

  As a result, the communication terminal 1A is a communication network via an access point to which the communication terminal 1A itself connects during communication even in the absence of a communication partner terminal or a bandwidth estimation server, which was necessary in the prior art. The communication terminal 1A itself can estimate the communication quality and the usable bandwidth in the network, and even if there is a single usable communication method, it is possible to select the optimum communication transmission path for data transmission. Further, since the communication terminal 1A has fewer connection destinations for estimating the communication available bandwidth than the communication terminal 1 of the first embodiment, it is possible to shorten the time for selecting the optimum communication transmission path for data transmission. it can.

(Second Embodiment)
In the second embodiment, a communication terminal 1B that uses a virtual network technology for virtually simultaneously connecting communication networks using a plurality of communication methods will be described with reference to FIG. FIG. 8 is a block diagram illustrating in detail an example of the terminal radio control unit 23B of the communication terminal 1B of the second embodiment. In the description of each part of the terminal radio control unit 23B shown in FIG. 8, the same contents as those of the parts of the terminal radio control unit 23 shown in FIG. The different contents will be described.

  The terminal radio control unit 23B illustrated in FIG. 8 includes an optimum radio selection control unit 25, a network control unit 27, a band estimation control unit 29B, a packet transmission unit 31, a packet reception unit 33, and an LTE / HSPA controller 35. The WLAN controller 37 and the virtualization network unit 71 are included.

  The band estimation control unit 29B includes a band estimation manager 61, a band estimation unit 63B, a radio switching unit 65, and a transmission destination address conversion unit 67B.

  The bandwidth estimation unit 63B operates in substantially the same manner as the operation of the bandwidth estimation unit 63 of the first embodiment, but the connection destination of the priority list LST3 (see, for example, FIG. 5C) acquired by the optimum radio selection control unit 25 The same number of band estimation data as the number of are generated and sequentially output to the packet transmission unit 31.

  In addition to the operation of the transmission destination address conversion unit 67 of the first embodiment, the transmission destination address conversion unit 67B performs virtualization in the frame structure of the bandwidth estimation packet according to the connection destination base station or access point. The port number of the network unit 71 is further added and output to the virtualized network unit 71.

  The internal configuration of the virtual network unit 71 will be described with reference to FIG. FIG. 9A is a block diagram illustrating an example of an internal configuration of the virtualization network unit 71. The virtual network unit 71 illustrated in FIG. 9A includes a virtual I / F unit 73, a virtual gateway unit 75, and a routing unit 77.

  The virtual I / F unit 73 removes the field including the port number of the virtual network unit 71 added to the bandwidth estimation packet output from the transmission destination address conversion unit 67B, and the base station set in the virtual gateway unit 75 Alternatively, routing information such as the MAC address, IP address, and port number of the access point is acquired from the virtual gateway unit 75 and output to the routing unit 77.

  In the virtual gateway unit 75, routing information (for example, a MAC address, an IP address, and a port number) of a base station or access point to which the communication terminal 1B is connected is set. Note that the routing information set in the virtual gateway unit 75 may be changed dynamically.

  The routing unit 77 outputs the band estimation packet to the corresponding active communication I / F (that is, the LTE / HSPA radio unit 39 or the WLAN radio unit 41) according to the routing information output from the virtual I / F unit 73. To do.

  Therefore, the virtualization network unit 71 can sequentially estimate the bandwidth estimation packets output from the destination address translation unit 67B even if the destination address translation unit 67B does not designate the LTE / HSPA radio unit 39 or the WLAN radio unit 41. Can be obtained automatically in a short time (see FIG. 9B). FIG. 9B is a supplementary explanatory diagram schematically showing the difference between the estimation of the communication available band in the first embodiment and the estimation of the communication available band in the second embodiment.

  Note that signaling between the communication terminal 1B and the default gateway according to this embodiment conforms to the sequence shown in FIG. As shown in FIG. 9B, in the first embodiment, in the priority list LST3 obtained in step S9 shown in FIG. 6, a connection destination (for example, a WLAN access point) corresponding to the communication available band estimation target ), The estimated value of the communication available band with the next connection destination (for example, an LTE base station) is calculated, and thereafter the remaining connection destinations are similarly calculated. The estimated value of the communication available bandwidth between the two is calculated.

  On the other hand, in the second embodiment, a communication network with each connection destination (for example, a WLAN access point) corresponding to a communication available band estimation target in the priority list LST3 obtained in step S9 shown in FIG. Are virtually simultaneously connected by the virtualized network unit 71, so that each estimated value of the communication available bandwidth between all corresponding connection destinations (for example, LTE base station and WLAN access point) is calculated almost simultaneously. The

  Therefore, as shown in FIG. 9B, in order to simplify the description, when the communication available band estimation targets are one access point and one base station, in the second embodiment, The time EST2 required to calculate the estimated value can be considerably shortened compared to the time EST1 required to calculate the estimated value of the communication available bandwidth in the first embodiment.

  As described above, the communication terminal 1B of the present embodiment can virtually simultaneously connect to a communication network via a plurality of base stations or access points, so that the calculation time required for estimating the communication available bandwidth is greatly increased. Even when a handover occurs due to movement of the communication terminal 1B, it is possible to estimate a wireless available band while continuing communication with a connected base station or access point.

(Third embodiment)
In applications using wireless communication, it is preferable that the communication available bandwidth of the communication transmission path is large, but it is not necessarily preferable, and better delay characteristics and jitter characteristics are preferable than a larger communication available bandwidth There is also a possibility. For example, in an application that plays on-demand video, the size of the available communication bandwidth is preferentially required, but real-time performance is important in a telephone application such as a TV conference system or VoIP (Voice over Internet Protocol). Therefore, a lower delay characteristic is required preferentially.

  In the third embodiment, communication for selecting a communication transmission path in the optimum wireless communication based on information related to a communication available band necessary for the operation of a running application and priority of transmission characteristics at the time of execution of the application. The terminal 1C will be described with reference to FIG. 9C and FIG. FIG. 9C is a diagram showing an example of the application information management list LST4. FIG. 10 is a block diagram illustrating in detail an example of the terminal radio control unit 23C and the application management unit 81 of the communication terminal 1C according to the third embodiment.

  In the description of each part of the terminal radio control unit 23C shown in FIG. 10, the same contents as those of the parts of the terminal radio control unit 23 shown in FIG. The different contents will be described. The communication terminal 1C of the third embodiment has a configuration in which an application management unit 81 is further added to the configuration of the communication terminal 1 shown in FIG.

  The terminal radio control unit 23C illustrated in FIG. 10 includes an optimum radio selection control unit 25C, a network control unit 27, a band estimation control unit 29B, a packet transmission unit 31, a packet reception unit 33, an LTE / HSPA controller 35, The WLAN controller 37 is included.

  The optimum radio selection control unit 25C includes an optimum radio selection manager 51C, a radio available bandwidth management unit 53, and a radio quality management unit 55.

  The optimum radio selection manager 51C operates in substantially the same manner as the optimum radio selection manager 51 of the first embodiment, but refers to the application information management list LST4 (see FIG. 9C) output from the application management unit 81. Then, based on the estimated value of the communication available band held by the wireless available band management unit 53, the optimum communication transmission path using the communication method is selected.

  The application management unit 81 acquires and manages information related to a running application, and includes an application manager 83, an application required bandwidth management unit 85, and an application monitoring unit 87.

  Based on the monitoring result of the application monitoring unit 87, the application manager 83 acquires the information of the application information management list LST4 related to the running application from the application necessary bandwidth management unit 85 and outputs it to the optimum wireless selection control unit 25C. .

  For each application in the application group 11, the application necessary bandwidth management unit 85 holds an application number, an application information management list LST4 indicating a minimum communication available bandwidth (minimum bandwidth) necessary for the operation of the application, and a priority request. (See FIG. 9C). The priority request is information regarding the priority order that determines which of the delay characteristics, the jitter characteristics, and the communication available bandwidth characteristics should be considered with the highest priority for each application.

  In the application information management list LST4 shown in FIG. 9C, for the application with the application number 3, the minimum bandwidth is 256 k [bps], and it is determined that the characteristic that should be considered most is that the delay is small. . In addition, for an application with an application number of 5, the minimum bandwidth is 1 M [bps], and it is determined that the characteristic that should be considered most is that the communication available bandwidth is large. Similarly, for an application with an application number of 6, the minimum bandwidth is 128 k [bps], and it is determined that the characteristic to be considered most is that the communication available bandwidth is large.

  The application monitoring unit 87 monitors the execution state (for example, start / stop) of the application running on the communication terminal 1C in response to, for example, the user's start operation or automatic start processing, and the monitoring result is constantly or periodically. Output to the application manager 83.

  Note that the signaling between the communication terminal 1C and the default gateway according to the present embodiment conforms to the sequence shown in FIG. 6, but in the communication terminal 1C according to the present embodiment, the optimum radio selection control unit 25C performs the communication available band estimation process. When an event for starting is notified, the application manager 83 of the application management unit 81 is requested for the application information management list LST4 regarding the currently activated (active) application.

  In response to a request from the optimum radio selection control unit 25C, the application manager 83 acquires the application information management list LST4 related to the active application and outputs it to the optimum radio selection control unit 25C. After acquiring the application information management list LST4, the optimum wireless selection control unit 25C performs the operations after step S2 shown in FIG. Further, the optimum radio selection control unit 25C determines that the calculated estimated value of the communication available band is equal to or higher than the communication available band necessary for the operation of the active application, and the communication quality (for example, received electric field level, jitter) is application information. A communication transmission path that satisfies the priority request of the management list LST4 is selected.

  As described above, the communication terminal 1C according to the present embodiment enables communication over the communication available bandwidth necessary for the operation of the application based on the information regarding the communication available bandwidth necessary for the operation of the running application and the priority of the transmission characteristics. A communication transmission path that has a bandwidth and communication quality (for example, received electric field level, jitter) that satisfies the priority order of transmission characteristics can be selected as the optimal communication transmission path for data transmission, thereby reducing traffic increase. Further, it is possible to suppress the occurrence of delay in the operation of the application.

  Although the present embodiment has been described using a configuration in which the application management unit 81 is further added to the terminal radio control unit 23 of the first embodiment, the application management unit 81 is added to the terminal radio control unit 23B of the second embodiment. May be added. In this case, the effects of both the communication terminal 1B of the second embodiment and the communication terminal 1C of the third embodiment can be obtained from the communication terminal.

  Hereinafter, the configuration, operation, and effect of the communication terminal and the transmission path selection method according to the present invention described above will be described.

  One embodiment of the present invention is a communication terminal capable of switching a plurality of communication methods and connecting to a plurality of base stations, and measuring communication quality for each base station according to the plurality of communication methods A packet generation unit that generates a predetermined band estimation packet based on the communication quality of each base station measured by the communication quality measurement unit, and the band estimation packet generated by the packet generation unit An address conversion unit that converts the transmission destination address of the communication terminal into its own address, a transmission unit that transmits the band estimation packet in which the transmission destination address is converted by the address conversion unit, and a transmission unit that is transmitted from the transmission unit. A receiving unit for receiving the band estimation packet redirected in accordance with the conversion of the transmission destination address of the band estimation packet to the own address; and for each base station A transmission path selection unit that selects a transmission path using the communication method corresponding to any one of the base stations, based on an available band corresponding to the band estimation packet received by the reception unit, It is a communication terminal.

  In this configuration, the communication terminal generates a predetermined bandwidth estimation packet based on the communication quality for each of the plurality of base stations according to the plurality of communication methods, and sets the transmission destination address of the bandwidth estimation packet as the communication terminal's own address. Convert to address and send. The communication terminal receives the bandwidth estimation packet redirected as the transmission destination address is converted to its own address, and performs communication corresponding to one of the base stations based on the available bandwidth according to the bandwidth estimation packet. Select the transmission path using the method.

  As a result, the communication terminal can communicate in the communication network via the base station to which the communication terminal itself is connected during communication even in the absence of the communication partner terminal or the bandwidth estimation server, which was necessary in the prior art. Quality and usable bandwidth can be estimated by the communication terminal itself, and it is possible to select a communication transmission path using a communication method optimal for data transmission from a plurality of communication methods and a plurality of connectable base stations. it can.

  In addition, according to an embodiment of the present invention, for each of the base stations, transmission of a plurality of bandwidth estimation packets from the transmission unit and reception of the plurality of bandwidth estimation packets in the reception unit by the redirect are performed. The communication terminal further includes a bandwidth estimation unit that estimates the available bandwidth.

  According to this configuration, the communication terminal estimates a possible bandwidth in the communication network via each base station based on transmission and reception of a plurality of bandwidth estimation packets, so that, for example, a user operating the communication terminal moves In particular, the available bandwidth estimated with high accuracy is obtained for each base station.

  Moreover, one Embodiment of this invention is a communication terminal in which the said packet generation part produces | generates the said packet for band estimation in order with high communication quality for every said base station measured by the said communication quality measurement part.

  According to this configuration, since the communication terminal generates the band estimation packets in descending order of the communication quality for each measured base station, it is possible to improve the estimation accuracy of the possible band in the communication network via each base station. It is possible to select a transmission path using an optimal communication method in a short time without estimating the available bandwidth for every connectable base station, for example, using the available bandwidth for each predetermined number of base stations. it can.

  Moreover, one embodiment of the present invention is a communication terminal further including a virtual network unit that virtually simultaneously connects to the communication networks of the plurality of base stations.

  According to this configuration, the communication terminal can be virtually simultaneously connected to a communication network via a plurality of base stations, so that the estimated time of the available bandwidth can be greatly reduced or a handover has occurred. Even in this case, the available bandwidth can be estimated in a state where communication with the connected base station is continued.

  In addition, an embodiment of the present invention is a communication terminal that can be connected to a plurality of base stations using a single communication method, and measures communication quality for each base station according to the communication method. Based on the communication quality of each base station measured by the measurement unit, the communication quality measurement unit, a packet generation unit that generates a predetermined bandwidth estimation packet, and the bandwidth estimation generated by the packet generation unit An address conversion unit that converts a transmission destination address of the packet into its own address of the communication terminal, a transmission unit that transmits the bandwidth estimation packet whose transmission destination address is converted by the address conversion unit, and a transmission unit that transmits the packet. A receiving unit that receives the band estimation packet redirected in accordance with the conversion of the transmission destination address of the band estimation packet to the own address; A transmission path selection unit that selects a transmission path using the communication method corresponding to any one of the base stations, based on an available band corresponding to the band estimation packet received by the reception unit. It is a terminal.

  In this configuration, the communication terminal generates a predetermined bandwidth estimation packet based on the communication quality for each of a plurality of base stations according to a single communication method, and sets the transmission destination address of the bandwidth estimation packet to the communication terminal. Convert it to its own address and send it. The communication terminal receives the bandwidth estimation packet redirected as the transmission destination address is converted to its own address, and performs communication corresponding to one of the base stations based on the available bandwidth according to the bandwidth estimation packet. Select the transmission path using the method.

  As a result, the communication terminal can communicate in the communication network via the base station to which the communication terminal itself is connected during communication even in the absence of the communication partner terminal or the bandwidth estimation server, which was necessary in the prior art. The quality and usable bandwidth can be estimated by the communication terminal itself, and even if there is a single usable communication method, it is possible to select the optimum communication transmission path for data transmission.

  In addition, an embodiment of the present invention further includes an application management unit that holds information about a bandwidth necessary for operation of a running application and a priority of transmission characteristics, and the transmission path selection unit includes the application The communication terminal selects the transmission path that has the available bandwidth that is equal to or greater than the bandwidth required for the operation of the transmission quality and that satisfies the communication quality priority order of the transmission characteristics.

  According to this configuration, the communication terminal sets a communication available bandwidth that is equal to or higher than the communication available bandwidth necessary for the operation of the application based on the information on the communication available bandwidth necessary for the operation of the running application and the priority of the transmission characteristics. And communication quality (for example, received electric field level, jitter) that satisfies the priority of transmission characteristics can be selected as the optimal communication transmission path for data transmission, and delays can be prevented in application operations. can do.

One embodiment of the present invention is a transmission path selection method in a communication terminal that can be connected to a plurality of base stations by switching a plurality of communication methods,
Measuring communication quality for each of the base stations according to the plurality of communication methods;
Generating a predetermined band estimation packet based on the measured communication quality of each base station;
Converting the transmission destination address of the generated bandwidth estimation packet to the own address of the communication terminal;
Transmitting the bandwidth estimation packet in which the transmission destination address is converted;
Receiving the band estimation packet redirected according to the conversion of the transmission destination address of the transmitted band estimation packet to the self address;
Selecting a transmission line using the communication method corresponding to any one of the base stations based on an available band corresponding to the band estimation packet received for each base station. It is a selection method.

  In this configuration, the communication terminal generates a predetermined bandwidth estimation packet based on the communication quality for each of the plurality of base stations according to the plurality of communication methods, and sets the transmission destination address of the bandwidth estimation packet as the communication terminal's own address. Convert to address and send. The communication terminal receives the bandwidth estimation packet redirected as the transmission destination address is converted to its own address, and performs communication corresponding to one of the base stations based on the available bandwidth according to the bandwidth estimation packet. Select the transmission path using the method.

  As a result, the communication terminal can communicate in the communication network via the base station to which the communication terminal itself is connected during communication even in the absence of the communication partner terminal or the bandwidth estimation server, which was necessary in the prior art. Quality and usable bandwidth can be estimated by the communication terminal itself, and it is possible to select a communication transmission path using a communication method optimal for data transmission from a plurality of communication methods and a plurality of connectable base stations. it can.

  While various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  INDUSTRIAL APPLICABILITY The present invention is useful as a communication terminal and a transmission path selection method for estimating the communication quality and available bandwidth of a network by itself and selecting an optimal communication transmission path even in the absence of a communication partner terminal. As the terminal, for example, a smartphone or a tablet terminal can be considered.

1, 1A, 1B, 1C Communication terminal 11 Application group 13 Terminal control unit 15 Tone control unit 17 Voice control unit 19 Display unit 21 UI unit 23 Terminal radio control unit 25 Optimal radio selection control unit 27 Network control unit 29 Band estimation control unit 31 Packet transmission unit 33 Packet reception unit 35 LTE / HSPA controller 37 WLAN controller 39 LTE / HSPA radio unit 41 WLAN radio unit 51 Optimal radio selection manager 53 Wireless available band management unit 55 Radio quality management unit 61 Band estimation manager 63 Band estimation unit 65 Wireless switching unit 67 Destination address conversion unit 71 Virtualized network unit 73 Virtual I / F unit 75 Virtual gateway unit 77 Routing unit 81 Application management unit 83 Application manager 85 Application required bandwidth management unit 87 Application monitoring unit

Claims (7)

A communication terminal that can connect to a plurality of base stations by switching a plurality of communication methods,
A communication quality measuring unit that measures communication quality for each base station according to the plurality of communication methods;
Based on the communication quality of each base station measured by the communication quality measurement unit, a packet generation unit that generates a predetermined bandwidth estimation packet;
An address conversion unit that converts a transmission destination address of the bandwidth estimation packet generated by the packet generation unit into a self-address of the communication terminal;
A transmission unit for transmitting the band estimation packet whose transmission destination address is converted by the address conversion unit;
A receiving unit that receives the band estimation packet redirected according to the conversion of the transmission destination address of the band estimation packet transmitted from the transmission unit to the own address;
A transmission path selection unit that selects a transmission path using the communication method corresponding to any one of the base stations based on an available band corresponding to the band estimation packet received by the reception unit for each base station And comprising
Communication terminal. The wireless communication device according to claim 1,
Bands for estimating the available band based on transmission of a plurality of band estimation packets from the transmission unit and reception of the plurality of band estimation packets in the reception unit by the redirection for each base station An estimator,
Communication terminal. The communication terminal according to claim 1,
The packet generator is
In order from the highest communication quality for each base station measured by the communication quality measurement unit, the bandwidth estimation packet is generated.
Communication terminal. The communication terminal according to claim 1,
A virtual network unit that virtually simultaneously connects to the communication networks of the plurality of base stations,
Communication terminal. A communication terminal that can be connected to a plurality of base stations using a single communication method,
A communication quality measuring unit that measures the communication quality of each base station according to the communication method;
Based on the communication quality of each base station measured by the communication quality measurement unit, a packet generation unit that generates a predetermined bandwidth estimation packet;
An address conversion unit that converts a transmission destination address of the bandwidth estimation packet generated by the packet generation unit into a self-address of the communication terminal;
A transmission unit for transmitting the band estimation packet whose transmission destination address is converted by the address conversion unit;
A receiving unit that receives the band estimation packet redirected according to the conversion of the transmission destination address of the band estimation packet transmitted from the transmission unit to the own address;
A transmission path selection unit that selects a transmission path using the communication method corresponding to any one of the base stations based on an available band corresponding to the band estimation packet received by the reception unit for each base station And comprising
Communication terminal. The communication terminal according to claim 1 or 4,
An application management unit that retains information related to the bandwidth necessary for the operation of the running application and the priority of transmission characteristics;
The transmission path selection unit
Selecting the transmission path having the available bandwidth that is equal to or higher than the bandwidth necessary for the operation of the application, and the communication quality satisfying the priority of the transmission characteristics;
Communication terminal. A transmission path selection method in a communication terminal capable of switching a plurality of communication methods and connecting to a plurality of base stations,
Measuring communication quality for each of the base stations according to the plurality of communication methods;
Generating a predetermined band estimation packet based on the measured communication quality of each base station;
Converting the transmission destination address of the generated bandwidth estimation packet to the own address of the communication terminal;
Transmitting the bandwidth estimation packet in which the transmission destination address is converted;
Receiving the band estimation packet redirected according to the conversion of the transmission destination address of the transmitted band estimation packet to the self address;
Selecting a transmission path using the communication method corresponding to any one of the base stations based on an available band corresponding to the band estimation packet received for each base station. Selection method.

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