JP2014222809A - Radio communication device and control method for collecting radio quality information in radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication device and a control method for collecting radio quality information in a radio communication system that can reduce a waiting time for executing processing using the radio quality information.SOLUTION: A radio communication device (MS) in a radio communication system comprises: a buffer (13) which stores radio quality information of a network (NW); and a load estimation control unit (12) which acquires radio quality information and stores it in the buffer (13), and when a network connection request is generated, estimates a load on a network (NW) on the basis of the stored radio quality information.

Description

  The present invention relates to a radio communication system, and more particularly to a radio communication apparatus and a control method for collecting radio quality information.

  In general, a wireless terminal that is wirelessly connected to a network has a wireless quality measurement function, and wireless quality is measured periodically or according to an arbitrary measurement trigger. The radio quality is measured as a reception quality of a pilot signal (reference signal) or a carrier signal transmitted by the network. For example, RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), RSCP (Reference Signal Code Power), Known are RSSI (Received Signal Strength Indicator), Ec / No (Energy per chip / Noise), and the like (see Non-Patent Document 1). As an example, the measured radio quality information can be used to select a better network (for example, Patent Document 1).

JP 2012-199921 A

3GPP TS 36.214 v10.1.0 (2011-01), Sec. 5.1, pp.7-8

  However, since the wireless quality varies with time due to its nature, it is necessary to continuously measure the wireless quality for a certain long time when the fluctuation is predicted from the tendency of the wireless quality information. For this reason, when a process using wireless quality information is started, execution of the process must be waited until sufficient wireless quality information is acquired. This waiting time is desirably as short as possible from the viewpoint of user convenience.

  Accordingly, an object of the present invention is to provide a wireless communication apparatus and a wireless communication system in a wireless communication system capable of reducing waiting time when executing processing using wireless quality information while executing acquisition of sufficient wireless quality information. It is to provide a collection control method of quality information.

A wireless communication apparatus according to the present invention is a wireless communication apparatus in a wireless communication system, and holds a wireless quality information of a network, acquires the wireless quality information and holds it in the holding means, and a network connection request is received And load estimation control means for estimating the load on the network based on the stored radio quality information when it occurs.
A radio communication system according to the present invention is a radio communication system including a plurality of radio terminals, and at least one of the first radio terminal and the second radio terminal acquires and holds network radio quality information. And when the network connection request is generated, the network load is estimated based on the held wireless quality information.
A radio quality information collection control method according to the present invention is a radio quality information collection control method in a radio communication apparatus in a radio communication system, wherein the measurement means measures the radio quality of the network, and the control means sends a network connection request. In order to estimate the load of the network when it occurs, the wireless quality information of the network is acquired from the measuring means and held.

  ADVANTAGE OF THE INVENTION According to this invention, waiting time at the time of performing the process using radio | wireless quality information can be shortened, performing acquisition of sufficient radio | wireless quality information.

FIG. 1 is a block diagram showing a schematic configuration of a wireless communication apparatus in a wireless communication system according to a first embodiment of the present invention. FIG. 2 is a flowchart showing a radio quality information collection control method according to the first embodiment. FIG. 3A is a schematic diagram showing an example of a radio quality information collection control method in the first embodiment, and FIG. 3B shows a radio quality information collection control method that does not use this embodiment as a comparative example. It is a schematic diagram shown. FIG. 4 is a network diagram showing a schematic configuration of a radio communication system according to the second embodiment of the present invention. FIG. 5 is a block diagram showing a functional configuration of the first mobile station in the second embodiment. FIG. 6 is a block diagram showing a functional configuration of the second mobile station in the second embodiment. FIG. 7 is a communication control sequence diagram in the wireless communication system according to the first embodiment of the present invention. FIG. 8 is a flowchart showing communication control of the first mobile station shown in FIG. FIG. 9 is a flowchart showing communication control of the second mobile station shown in FIG. FIG. 10 is a communication control sequence diagram in the wireless communication system according to the second embodiment of the present invention. FIG. 11 is a flowchart showing communication control of the first mobile station shown in FIG. FIG. 12 is a flowchart showing communication control of the second mobile station shown in FIG. FIG. 13 is a communication control sequence diagram in the wireless communication system according to the third embodiment of the present invention. FIG. 14 is a flowchart showing communication control of the first mobile station shown in FIG. FIG. 15 is a communication control sequence diagram in the wireless communication system according to the fourth embodiment of the present invention. FIG. 16 is a flowchart showing communication control of the first mobile station shown in FIG. FIG. 17 is a flowchart showing communication control of the second mobile station shown in FIG. FIG. 18 is a block diagram showing an example of a wireless communication apparatus according to the first or second embodiment.

  According to the embodiment of the present invention, the wireless quality information of the network is acquired and held under a predetermined condition before the network connection request is generated, and when the network connection request is generated, the stored wireless quality information is stored. Based on this, the network load is estimated. This makes it possible to perform network load estimation using radio quality information with sufficient acquisition time immediately after the request is generated. Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the drawings.

1. 1. First Embodiment 1.1) Configuration As shown in FIG. 1, a radio communication device MS according to a first embodiment of the present invention includes a radio communication unit 11 for communicating with a network NW, and a network that estimates a network load. The load estimation control unit 12, a buffer 13 that holds the measured wireless quality information, and other display functions and input functions (not shown).

  The measurement function provided in the wireless communication unit 11 monitors a pilot signal (reference signal) or a carrier signal from the network NW and periodically measures wireless quality. The network load estimation control unit 12 holds the radio quality information measured by the measurement function in the buffer 13. Furthermore, in response to a network connection request to be described later, the network load estimation control unit 12 executes a load estimation process based on the radio quality information held in the buffer 13.

  The buffer 13 may hold the wireless quality information for a preset period so as to be sequentially updated, or may be held while being sequentially updated for a preset buffer. The amount of the wireless quality information held in the buffer 13 may be as long as the network load can be estimated with sufficient accuracy.

1.2) Load Estimation Control In FIG. 2, the network load estimation control unit 12 determines whether or not a radio quality information acquisition trigger has occurred (operation S20). Examples of the wireless quality information acquisition trigger include power-on of the wireless communication device MS, screen activation of the display unit, user instruction (operation of a dedicated button or the like), and the like. In any case, an event that occurs simultaneously with or before the network connection request described below may be used as a wireless quality information acquisition trigger.

  When the acquisition trigger for the wireless quality information is generated (operation S20; YES), the network load estimation control unit 12 acquires the wireless quality information from the wireless communication unit 11 and holds it in the buffer 13 (operation S21). As radio quality information, in addition to RSRP, RSRQ, RSCP, RSSI, Ec / No, Ec / Io, and SIR (Signal Interference Ratio), antenna pictogram information displayed on the display unit, in-range / out-of-range information, and the like are used. You can also.

  Subsequently, the network load estimation control unit 12 determines whether or not a network connection request is detected (operation S22). If there is no network connection request (operation S22; NO), the wireless quality information acquisition and holding operation S21 is performed. repeat. The network connection request includes an application that may or may cause communication, such as browser activation, screen activation of a display unit, user instruction (operation of a dedicated button, etc.). Alternatively, power-on of the wireless communication device MS, screen activation of the display unit, and reception of a request message from another terminal can be used as a network connection request.

  Further, the frequency of acquiring the wireless quality information may be a predetermined cycle or the update timing of the wireless quality information. Furthermore, the wireless quality information can be acquired and held only when a predetermined condition is satisfied.

  When a network connection request is detected (operation S22; YES), the network load estimation control unit 12 estimates the network load using the wireless quality information held in the buffer 13 (operation S23). A network load estimation method using the wireless quality information will be described later.

1.3) Effect As shown in FIG. 3A, according to the first embodiment of the present invention, when an information acquisition trigger occurs (S20; YES), acquisition and holding of wireless quality information is started (S21). Then, when there is a network connection request (S22; YES), load estimation is executed using the radio quality information held in the buffer (S23). Therefore, for example, when the user activates the browser, the network load can be estimated using the wireless quality information held in the buffer 13 at that time, and the network selection based on the estimated network load, etc. Can be processed.

  On the other hand, as shown in FIG. 3B, when the load estimation control according to this embodiment is not performed, when there is a network connection request (S1), acquisition of wireless quality information is started from that point. (S2) When the load can be estimated with sufficient accuracy, the load is estimated (S3). Therefore, for example, when the user starts the browser, the wireless quality information is acquired from that point, so that a considerable waiting time is required before actually executing the network load estimation, or insufficient wireless quality information Therefore, the radio load with low accuracy is estimated.

  As is apparent from a comparison between FIG. 3A and FIG. 3B, according to the present embodiment, when the browser is started, the network load can be estimated with sufficient accuracy and the user can be kept waiting. It is possible to perform processing such as network selection.

2. Second Embodiment Next, as a second embodiment of the present invention, a radio communication system in which the radio communication device MS according to the first embodiment described above is applied to a mobile station in a multi-network environment will be described.

2.1) System Configuration As shown in FIG. 4, the wireless communication system according to the present embodiment includes a mobile station 10 that can be wirelessly connected to the mobile network 30 and the wireless LAN 50, and a mobile station 20 that can be wirelessly connected to the mobile network 40. Mobile stations 10 and 20 can communicate with an external network via mobile networks 30 and 40 and a wireless LAN 50, respectively.

  The mobile network 30, the mobile network 40, and the wireless LAN 50 are a cellular network, a public wireless LAN, or the like provided by a communication carrier (mobile operator, wireless service provider). Typically, the mobile network 40 is a network that cannot be directly accessed by the mobile station 10 that can be connected to the mobile network 30 and the wireless LAN 50. For example, when the mobile network 30 and the mobile network 40 are operated by different communication carriers, the mobile station 10 cannot directly access the mobile network 40. If the mobile network operator is an MVNO (Mobile Virtual Network Operator), the mobile station 10 cannot access the mobile network 40 due to restrictions on the service use contract.

  As another example, even when the mobile network 30 and the mobile network 40 are different cellular radio systems operated by the same or different carriers, the support for different radio access technologies or different NAS protocols is generally moved. The mobile station 10 cannot access the mobile network 40 due to technical restrictions. Furthermore, the mobile station 10 cannot directly access the mobile network 40 even when different authentication is required. For example, even in the case of the same carrier, authentication is different because it was a different carrier before. Alternatively, when different authentications are required in different wireless systems, the mobile station 10 cannot directly access the mobile network 40 due to different contracts. Alternatively, even when the mobile station 10 and the mobile station 20 support different frequencies, the mobile station 10 cannot access the mobile network 40 directly.

  The mobile station 10 and the mobile station 20 can communicate with each other wirelessly. For example, the wireless connection between the mobile station 10 and the mobile station 20 can be established by a wireless access technology such as an IEEE 802.11 series-compliant wireless LAN or an IEEE 802.15 series-compliant wireless PAN (eg, Bluetooth (registered trademark)). Further, the mobile station 10 may be a wireless LAN terminal, and the mobile network 30 may be a public wireless LAN.

  The mobile station 20 operates as a bridge / router to transfer the data of the mobile station 10. The wireless connection between the mobile station 20 and the mobile station 10 and the wireless connection between the mobile station 20 and the mobile network 40 can use the same or different wireless access technologies. The mobile station 20 is, for example, a mobile router or a smartphone having a tethering function, and can establish a connection with the mobile network 40 and a connection with the mobile station 10 at the same time. That is, the mobile station 20 as a smart phone having a tethering function establishes a wireless connection with the base station BS of the mobile network 40 by the wireless access technology of the cellular network, and the mobile station 20 as the mobile router can wirelessly use a wireless LAN or a wireless PAN. A wireless connection with the mobile station 10 is established by the access technology.

2.2) Apparatus Configuration Hereinafter, a schematic configuration of the mobile station 10 and the mobile station 20 described above will be described with reference to FIGS. 5 and 6.

2.1) Mobile station 10 (first mobile station)
In FIG. 5, the mobile station 10 is a multi-mode terminal such as a smartphone that supports a plurality of wireless access methods. The radio communication unit 101 of the mobile station 10 has a predetermined radio access scheme (for example, URAN (UMTS Terrestrial Radio Access Network), E-UTRAN (Evolved UTRAN), GERAN (GSM EDGE Radio Access Network), or WiMAX (Worldwide Interoperability for Microwave Access). ) Etc.), it is possible to communicate with the end node via the mobile network 30 by wirelessly connecting to the base station BS of the mobile network 30. It is also possible to communicate with the end node via the wireless LAN 50 by the wireless LAN method. Further, the wireless communication unit 101 can wirelessly connect to the mobile station 20 by the wireless access method such as the wireless LAN or the wireless PAN described above, and can communicate with the end node via the mobile station 20 and the mobile network 40.

  The mobile station 10 further includes a reception data processing unit 102, a data control unit 103, a transmission data processing unit 104, a line control unit 105, and a network estimation unit 106. The reception data processing unit 102 and the transmission data processing unit 104 process data transmitted / received to / from the mobile network 30, the wireless LAN 50, or the mobile station 20 according to control by the line control unit 105, and the data control unit 103 receives the received data. The transmission data processing unit 104 is controlled according to the control.

  The line control unit 105 controls the transmission data processing unit 104 to transmit a network connection request to the mobile station 20 according to the estimated load from the network load estimation control unit 106, and determines whether or not the network connection is received from the mobile station 20. You can save the results. The network load estimation control unit 106 acquires the line quality information of the mobile network 30 and the wireless LAN 50 according to the load estimation control procedure described above, holds it in a buffer (not shown), and estimates the load using a network selection request or the like as a trigger. And outputs the estimation result to the line selection control unit 105.

  Although details will be described in the embodiment, the network load estimation control unit 106 may be omitted from the mobile station 10 when the mobile station 20 has a network load estimation function. In this case, the line selection control unit 105 of the mobile station 10 performs network selection according to an instruction from the mobile station 20.

2.2) Mobile station 20 (second mobile station)
In FIG. 6, the mobile station 20 is a mobile router such as a smartphone or a WiFi router having a tethering function, for example, and can perform transfer control of transmission / reception data between the mobile station 10 and the mobile network 40 or 30. To do. The lower radio link communication unit 201 is wirelessly connected to the mobile station 10 by the wireless access method such as the wireless LAN or the wireless PAN described above, transmits transmission data from the transmission data processing unit 202 to the mobile station 10, and from the mobile station 10 The received data is output to the received data processing unit 203. The upper wireless link communication unit 204 can wirelessly connect to the mobile network 40 by the same or different wireless access method as the mobile station 10 described above. In addition, the mobile network 30 can have a function of acquiring wireless quality information or wirelessly connecting.

  The line selection control unit 205 can control the transmission data processing unit 104 to perform network selection according to the estimated load from the network load estimation control unit 206 and transmit the network selection result to the mobile station 10. The network load estimation control unit 206 acquires the line quality information of the mobile networks 30 and 40 according to the load estimation control procedure described above, holds it in a buffer (not shown), and performs load estimation using a network selection request or the like as a trigger. The estimation result is output to the line selection control unit 205.

  Hereinafter, an example of load estimation control will be described in detail with reference to the drawings, assuming that the mobile stations 10 and 20 in the wireless communication system according to the second embodiment can be connected to two different networks NW1 and NW2, respectively. .

3. First Embodiment As shown in FIG. 7, according to the first embodiment of the present invention, the mobile stations 10 and 20 acquire the radio quality information of the networks NW1 and NW2, respectively, the mobile station 20 performs load estimation, The line selection of the mobile station 10 is executed. First, the mobile station 10 transmits a network connection request including the wireless quality information of the network NW1 acquired by itself to the mobile station 20. Using the network connection request received from the mobile station 10 as a trigger, the mobile station 20 executes load estimation based on the notified wireless quality information of the network NW1 and the wireless quality information of the network NW2 acquired and held by itself. A network selection result based on the estimation result is returned to the mobile station 10. Hereinafter, the operations of the mobile stations 10 and 20 will be described with reference to FIG. 8 and FIG. 9, and the sequence of FIG.

  In FIG. 8, the network load estimation control unit 106 of the mobile station 10 acquires the radio quality information from the radio communication unit 101 after the occurrence of a radio quality information acquisition trigger such as power-on, and holds it in the buffer (operation S311).

  Subsequently, the network load estimation control unit 106 determines whether or not a network connection request is detected (operation S312). If there is no network connection request (operation S312; NO), the wireless quality information acquisition and holding operation S311 is performed. repeat. The network connection request includes an application that may or may cause communication, such as browser activation, screen activation of a display unit, user instruction (operation of a dedicated button, etc.). Alternatively, the power-on of the mobile station 10 or the screen activation of the display unit can be used as a network connection request.

  When the network connection request is detected (operation S312; YES), the line selection control unit 106 controls the transmission data processing unit 104 to put the wireless quality information held in the buffer on the network connection request and to perform the wireless communication unit. 101 is transmitted to the mobile station 20 through 101 (operation S313). When the network selection result corresponding to the network connection request is received from the mobile station 20 (operation S314), the line selection control unit 105 connects to the network NW1 or NW2 according to the notified selection result (operation S315). , S316). When the network NW2 is selected, the mobile station 10 can connect to the network NW2 via the mobile station 20.

  It is also possible for the mobile station 20 to execute network selection of the mobile station 10 without notifying the network selection result. In other words, if the mobile station 10 is set to preferentially select the wireless LAN line with the mobile station 20, the mobile station 20 can automatically connect the network to the mobile station 10 only by turning on / off the wireless LAN function. Can be selected. For example, when the wireless LAN function of the mobile station 20 is turned on, the mobile station 10 preferentially selects the network NW2 (operation S316), and when the wireless LAN function is turned off, the mobile station 10 selects the network NW1. (Operation S315).

  In FIG. 9, the network load estimation control unit 206 of the mobile station 20 acquires the radio quality information from the higher radio link communication unit 204 after the occurrence of the radio quality information acquisition trigger such as power-on, and holds it in the buffer (operation S321). ).

  Subsequently, the network load estimation control unit 206 determines whether or not a network connection request has been received (operation S322). If there is no network connection request (operation S322; NO), the wireless quality information acquisition and holding operation S321 is performed. repeat. When the network connection request is received (operation S322; YES), the network load estimation control unit 206 is based on the wireless quality information of the network NW1 included in the network connection request and the wireless quality information of the network NW2 acquired and held by itself. Load estimation is executed (operation S323), the line selection control unit 205 selects a network based on the estimation result (operation S324), and the network selection result is transmitted to the mobile station 10 (operation S325). However, as described above, the network selection can be executed only by turning on / off the wireless LAN function without notifying the network selection result.

  As described above, according to the first embodiment of the present invention, the mobile stations 10 and 20 acquire the radio quality information of the networks NW1 and NW2, respectively, and the mobile station 10 notifies the network connection request, whereby the mobile station 20 performs load estimation and line selection. Conversely, when the mobile station 20 notifies the network connection request, the mobile station 10 can execute load estimation and line selection.

In this embodiment, the wireless quality information held in the buffer is transmitted to the mobile station 20 in a network connection request. However, the wireless quality information is transmitted to the mobile station 20 separately from a predetermined period or network connection request. You may send it.

  When the mobile stations 10 and 20 can use GPS information and acceleration sensor information, the wireless station acquires and holds radio quality information when the moving speed of the mobile station is a predetermined value or less, or detects a network selection request. The wireless quality information acquisition is restricted such that the wireless quality information acquired within a predetermined range (for example, within a predetermined radius) from the position is retained, thereby maintaining the reliability of the information and reducing the amount of information. Is possible.

4). Second Embodiment As shown in FIG. 10, according to the second embodiment of the present invention, the mobile stations 10 and 20 acquire the radio quality information of the networks NW1 and NW2, respectively, and the mobile station 10 performs load estimation and performs the line estimation. Make a selection. First, the mobile station 10 transmits a wireless quality information request to the mobile station 20 using its own network connection request as a trigger, and the mobile station 20 transmits the wireless quality information of the network NW2 acquired by the mobile station 20 to the mobile station. 10 is notified. The mobile station 10 performs load estimation based on the radio quality information of the network NW2 received from the mobile station 20 and the radio quality information of the network NW1 acquired and held by the mobile station 20, and the network according to the network selection result based on the estimation result Make a selection. Hereinafter, the operations of the mobile stations 10 and 20 will be described with reference to FIG. 11 and FIG. 12, and the sequence of FIG.

  In FIG. 11, the network load estimation control unit 106 of the mobile station 10 acquires the radio quality information from the radio communication unit 101 after the occurrence of a radio quality information acquisition trigger such as power-on, and holds it in the buffer (operation S411).

  Subsequently, the network load estimation control unit 106 determines whether or not a network connection request has been detected (operation S412). If there is no network connection request (operation S412; NO), the wireless quality information acquisition and holding operation S411 is performed. repeat. The network connection request includes an application that may or may cause communication, such as browser activation, screen activation of a display unit, user instruction (operation of a dedicated button, etc.). Alternatively, the power supply of the mobile station 10, the screen activation of the display unit, the reception of a network connection request from another terminal, etc. can be used as the network connection request.

  When the network connection request is detected (operation S412; YES), the network load estimation control unit 106 determines whether or not the wireless quality information of the valid network NW2 is held in the buffer (operation S413). For example, when the wireless quality information of the network NW2 is received from the mobile station 20, the wireless quality information is stored in the buffer together with the reception time, and the wireless quality information after a predetermined time has been invalidated or discarded to estimate the load. Do not use it. If there is no valid radio quality information in the buffer (operation S413; NO), a radio quality information request is transmitted to the mobile station 20 (operation S414), and a reply from the mobile station 20 is awaited (operation S415).

  When valid wireless quality information exists in the buffer (operation S413; YES) or when wireless quality information of the network NW2 is received from the station 20 (operation S415; YES), the network load estimation control unit 106 receives the received network NW2 Load estimation is performed based on the wireless quality information of the network NW1 and the wireless quality information of the network NW1 acquired and held by itself (operation S416). Based on the estimation result, the line selection control unit 205 selects a network (operation S417), and connects to the network NW1 or NW2 depending on the selection result (operations S418 and S419). When the network NW2 is selected, the mobile station 10 can connect to the network NW2 via the mobile station 20.

  As described above, according to the second embodiment of the present invention, the mobile stations 10 and 20 acquire the radio quality information of the networks NW1 and NW2, respectively, and the mobile station 10 notifies the radio quality information request so that the mobile station 10 The radio quality information of the network NW2 is acquired from the station 20, and load estimation and line selection can be executed. Conversely, when the mobile station 20 makes a request for radio quality information, the mobile station 20 can execute load estimation and channel selection.

  In FIG. 12, the network load estimation control unit 206 of the mobile station 20 acquires the radio quality information from the higher radio link communication unit 204 after the occurrence of the radio quality information acquisition trigger such as power-on, and holds it in the buffer (operation S421). ).

  Subsequently, the network load estimation control unit 206 determines whether or not a wireless quality information request has been received (operation S422). If there is no wireless quality information request (operation S422; NO), acquisition and retention of wireless quality information is performed. The operation S421 is repeated. When the wireless quality information request is received (operation S422; YES), the network load estimation control unit 206 transmits the wireless quality information of the network NW2 acquired and held by itself to the mobile station 10 (operation S423).

As described above, according to the second embodiment of the present invention, the mobile stations 10 and 20 acquire the radio quality information of the networks NW1 and NW2, respectively, and the mobile station 10 transmits the radio quality information request so that the mobile station 10 The wireless quality information of the network NW2 can be acquired from the station 20, and the above-described load estimation and line selection can be executed.

  Similarly to the first embodiment, when the mobile stations 10 and 20 can use GPS information or acceleration sensor information, the wireless quality information when the moving speed of the mobile station is below a predetermined value is acquired and held. Alternatively, the wireless quality information acquisition is restricted such that the wireless quality information acquired within a predetermined range (for example, within a predetermined radius) from the position where the network selection request is detected is held, and the reliability of the information is maintained. At the same time, the amount of information can be reduced.

5. Third Embodiment As shown in FIG. 13, according to the third embodiment of the present invention, one mobile station 10 acquires the radio quality information of the networks NW1 and NW2, and executes load estimation and line selection. That is, the mobile station 10 performs load estimation based on the radio quality information of the networks NW1 and NW2, and performs network selection based on the estimation result. Hereinafter, the operation of the mobile station 10 will be described with reference to FIG. 14, and the sequence of FIG. 13 is also given reference numerals indicating the corresponding operations.

  In FIG. 14, the network load estimation control unit 106 of the mobile station 10 acquires the radio quality information of the networks NW1 and NW2 from the radio communication unit 101 after the occurrence of the radio quality information acquisition trigger such as power-on, and holds it in the buffer. (Operation S511).

  Subsequently, the network load estimation control unit 106 determines whether or not a network connection request is detected (operation S512). If there is no network connection request (operation S512; NO), the wireless quality information acquisition and holding operation S511 is performed. repeat. The network connection request includes an application that may or may cause communication, such as browser activation, screen activation of a display unit, user instruction (operation of a dedicated button, etc.). Alternatively, the power supply of the mobile station 10, the screen activation of the display unit, the reception of a network connection request from another terminal, etc. can be used as the network connection request.

  When a network connection request is detected (operation S512; YES), the network load estimation control unit 106 performs load estimation based on the stored wireless quality information of the networks NW1 and NW2 (operation S513). Based on the estimation result, the line selection control unit 205 selects a network (operation S514), and connects to the network NW1 or NW2 according to the selection result (operations S515 and S516).

  As described above, according to the third embodiment of the present invention, the mobile station 10 can acquire the radio quality information of the networks NW1 and NW2, and the mobile station 10 can execute load estimation and line selection. However, the mobile station 10 has only a function of acquiring the wireless quality with respect to a network (NW2) other than the network NW1 to which the mobile station 10 belongs, and may not have a function of connecting to the other network.

  As in the first embodiment, when the mobile station 10 can use GPS information and acceleration sensor information, the wireless quality information when the moving speed of the mobile station 10 is a predetermined value or less is acquired and held. Alternatively, the wireless quality information acquisition is restricted such that the wireless quality information acquired within a predetermined range (for example, within a predetermined radius) from the position where the network selection request is detected, and the reliability of the information is maintained. It is also possible to reduce the amount of information.

6). Fourth Embodiment As shown in FIG. 15, according to the fourth embodiment of the present invention, one mobile station 20 acquires the radio quality information of the networks NW1 and NW2, performs load estimation, and performs other mobile station 10's. Perform line selection. That is, here, it is assumed that the mobile station 20 functioning as a mobile router can acquire all information necessary for load estimation and network selection. Since the radio quality information acquired at the application level may vary depending on the mobile station and the basic software (OS) used, in this embodiment, one mobile station 20 is used as a dedicated terminal. However, the mobile station 20 does not need to have a function of connecting to a network (NW1) other than the network NW2 to which the mobile station 20 belongs.

  First, the mobile station 20 acquires the radio quality information of each of the networks NW1 and NW2. Subsequently, for example, the mobile station 20 executes load estimation based on the acquired radio quality information using a network connection request received from the mobile station 10 as a trigger, and notifies the mobile station 10 of a network selection result based on the estimation result. To do. Hereinafter, the operations of the mobile stations 10 and 20 will be described with reference to FIG. 16 and FIG. 17, and the sequence of FIG.

  In FIG. 16, the network load estimation control unit 106 of the mobile station 10 determines whether or not a network connection request is detected (operation S611). The network connection request includes an application that may or may cause communication, such as browser activation, screen activation of a display unit, user instruction (operation of a dedicated button, etc.). Alternatively, the power-on of the mobile station 10 or the screen activation of the display unit can be used as a network connection request.

  When the network connection request is detected (operation S611; YES), the line selection control unit 106 controls the transmission data processing unit 104 to transmit the network connection request to the mobile station 20 through the wireless communication unit 101 (operation S612). ). When the network selection result corresponding to the network connection request is received from the mobile station 20 (operation S613), the line selection control unit 105 connects to the network NW1 or NW2 according to the notified selection result (operation S614). , S615). When the network NW2 is selected, the mobile station 10 can connect to the network NW2 via the mobile station 20.

  It is also possible for the mobile station 20 to execute network selection of the mobile station 10 without notifying the network selection result. In other words, if the mobile station 10 is set to preferentially select the wireless LAN line with the mobile station 20, the mobile station 20 can automatically connect the network to the mobile station 10 only by turning on / off the wireless LAN function. Can be selected. For example, when the wireless LAN function of the mobile station 20 is turned on, the mobile station 10 preferentially selects the network NW2 (operation S316), and when the wireless LAN function is turned off, the mobile station 10 selects the network NW1. (Operation S315).

  Further, the mobile station 10 can connect to the network in accordance with the network selection result notification from the mobile station 20 or on / off of the wireless LAN function without transmitting a network connection request.

  In FIG. 17, the network load estimation control unit 206 of the mobile station 20 acquires the radio quality information from the higher radio link communication unit 204 after the occurrence of the radio quality information acquisition trigger such as power-on, and holds it in the buffer (operation S621). ).

  Subsequently, the network load estimation control unit 206 determines whether or not a network connection request is detected (operation S622). If there is no network connection request (operation S622; NO), the wireless quality information acquisition and holding operation S621 is performed. repeat. When there is a network connection request (operation S622; YES), the network load estimation control unit 206 performs load estimation based on the wireless quality information of the networks NW1 and NW2 (operation S623), and based on the estimation result. The line selection control unit 205 selects a network (operation S624), and transmits the network selection result to the mobile station 10 (operation S625).

  Even when a network connection request is not transmitted from the mobile station 10, the mobile station 20 compares the load estimated values of the networks NW1 and NW2 to notify the network selection result or turn on / off the wireless LAN function. The network selection may be controlled. In particular, when the mobile station 10 is connected to the mobile station 20 at the time of tethering, the network selection of the mobile station 10 is controlled by turning on / off the wireless LAN function of the mobile station 20 as described above. Therefore, there is an advantage that it is not necessary to provide the mobile station 10 with a special radio quality information acquisition function or network selection function.

  In addition, when the mobile station 20 can use GPS information or acceleration sensor information, the wireless quality information when the moving speed of the mobile station is equal to or lower than a predetermined value is acquired and held, or the position where the network selection request is detected It is possible to limit the acquisition of wireless quality information, such as holding wireless quality information acquired within a predetermined range (for example, within a predetermined radius), to maintain the reliability of information and reduce the amount of information is there.

7). Other Embodiments In the first embodiment described above, radio quality information is notified from the mobile station 10 to the mobile station 20 using a network selection request, but the mobile station 10 is also provided with a network load estimation function. Can also notify the other mobile station 20 of the network load estimated by the mobile station 10. Similarly, in the second embodiment, when the mobile station 20 is provided with the network load estimation function when the wireless quality information is notified from the mobile station 20 to the mobile station 10 by the wireless quality information notification, the mobile station 20 It is also possible to notify the other mobile station 10 of the network load estimated in (1).

8). Configuration Example of Mobile Station The control operation of the above-described wireless communication devices (mobile stations 10 and 20) can also be realized by executing a program on a processor (computer) mounted on each mobile station. In the embodiment described above, the measurement function for periodically measuring the radio quality by monitoring the pilot signal (reference signal) or carrier signal from the network NW is at the hardware layer level, and the network load estimation control function is as follows. Implemented at the application layer level. Hereinafter, a software implementation example will be briefly described.

  As shown in FIG. 18, the wireless communication apparatus includes a cellular wireless transceiver 111, a wireless LAN transceiver 112, and a baseband processor 113. Further, a microphone 115, a speaker 116, a touch panel 117, and a display 118 are included as specific examples of the input device and the output device. The application processor 114 executes a system software program (OS (Operating System)), a load estimation control application, a line control application, and various application programs (for example, a web browser and a mailer) read from the nonvolatile storage unit 119. By implementing various functions.

  For example, the load estimation control function described above is realized by the application processor 114 executing the load estimation control application, and the line control function is realized by executing the line control application. Further, another nonvolatile storage unit 120 stores radio quality information acquired from the cellular radio transceiver 111.

9. Load Estimation Next, an example of a network load estimation method used in each of the above-described embodiments and examples will be described. This network load estimation method is described in a patent application filed by the present applicant (application number: Japanese Patent Application No. 2012-267717, application date: December 6, 2012), but the present invention is not limited thereto. However, the load estimation function may be executed based on the acquired wireless quality information.

  The network load can be estimated based on a quality index that does not depend on the communication load of the network and a quality index that depends on the communication load of the network. Next, the case of WCDMA (Wideband Code Division Multiple Access) and LTE (Long Term Evolution) will be exemplified to specifically describe the load estimation method in the network load estimation control unit 12.

9.1) Load estimation (LTE)
Hereinafter, a case where the network load u (resource usage rate) is estimated using RSRP as the first quality index independent of the network communication load and RSRQ as the second quality index dependent on the network communication load will be described.

  When an OFDMA (Orthogonal Frequency Division Multiple Access) resource block configuration is used, RSSI and quality indicators RSRP and RSRQ are defined as follows (see Non-Patent Document 1).

RSSI: Received signal power of an OFDM symbol in which the reference signal RS is multiplexed. Therefore, it depends on the network communication load.
RSRP: received signal power of a cell-specific reference signal (CRS) per resource element. Therefore, it does not depend on the network communication load.
RSRQ: number of resource blocks (RB) × RSRP / RSSI. Since RSSI depends on network communication load, RSRQ also depends on network communication load.

  Assuming that the transmission power is the same for all subcarriers in the OFDM symbol, and the transmission signals of each cell are uncorrelated with each other, RSSI can be expressed by the following equation (1).

ここで、ＮはＲＢ数、Ｋはセル数、ｐ_ｋは第ｋセルのＲＳＲＰ、ｕ_ｋは第ｋセルのリソース使用率（ネットワーク負荷）、Noiseは１ＲＢ当たりの雑音電力である。式（１）における２ｐ_ｋは、２つのＣＲＳのＲＳＲＰを、１０ｐ_ｋｕ_ｋはＣＲＳ以外の１０サブキャリアにおけるリソース使用率を考慮したＲＳＲＰをそれぞれ示す。なお、ＣＲＳ以外の１０サブキャリアはデータ信号や制御信号に割り当てられ、発生したトラフィック量によって使用するサブキャリア数が変化する。

Here, N RB number, K is the number of cells, _{p k} is RSRP of the k cell, _{u k} is the resource utilization of the k cell (network load), Noise is the noise power per 1 RB. In equation (1), 2p _k represents RSRP of two CRSs, and 10p _k u _k represents RSRP in consideration of resource usage rates in 10 subcarriers other than CRS. Note that 10 subcarriers other than CRS are allocated to data signals and control signals, and the number of subcarriers used varies depending on the amount of traffic generated.

  The above equation (1) is transformed into the following equation (2),

さらに、全セルでリソース使用率ｕ_ｋが同一（＝ｕ）であると仮定すると、次式（３）を得る。

Furthermore, the resource utilization u _k in all the cells is assumed to be identical (= u), we obtain the following expression (3).

式（３）をｕについて解き、上述したＲＳＲＱの定義式q_k=Nxp_k/RSSIを利用して書き直すと、リソース使用率ｕは次のように表すことができる。

When the equation (3) is solved for u and rewritten using the RSRQ definition equation q _k = Nxp _k / RSSI described above, the resource usage rate u can be expressed as follows.

ここで、ｑ_ｋは第ｋセルのＲＳＲＱ（q_k=Nxp_k/RSSI)である。ｐ_ｌ／ｑ_ｌの添え字ｌはセルを示すＫ以下の任意の値であるが、ＲＳＲＰ、ＲＳＲＱの値が大きいセルを用いることが好ましい。

Here, q _k is the RSRQ (q _k = Nxp _k / RSSI) of the _k -th cell. The subscript _l of p _l / q _l is an arbitrary value equal to or less than K indicating a cell, but it is preferable to use a cell having a large RSRP or RSRQ value.

  As shown in Equation (4), the resource usage rate u, which is the network load, is obtained by using the first quality index RSRP that does not depend on the network communication load and the second quality index RSRQ that depends on the network communication load. Can do. Here, the case where the number of transmission antennas is 1 has been described as an example, but the present invention can be applied to a case where there are a plurality of transmission antennas by changing the coefficient of Equation (4).

9.2) Load estimation (in case of WCDMA)
Next, a case where the network load u (average simultaneous multiple users) is estimated using RSCP as the first quality index that does not depend on the network communication load and Ec / No as the second quality index that depends on the network communication load. explain.

  The common pilot channel CPICH (Common Pilot channel) of cell #k and transmission signals of users # 1 to #x are CDM multiplexed, and other cell signals and noise signals are added and received by the radio communication terminal.

  Such RSSI in WCDMA and quality indexes RSCP and Ec / No are defined as follows (see Non-Patent Document 1).

RSSI: In-band received signal power.
RSCP: Common pilot channel (CPICH) received signal power.
Ec / No: Ratio of RSCP to RSSI (Ec / No = RSCP / RSSI).

  Assuming that the transmission powers of the CPICH and the user signal are the same, and the transmission signals are uncorrelated with each other, the RSSI can be expressed by the following equation (5).

ここで、Ｋはセル数、ｐ_ｋは第ｋセルのＲＳＣＰ、ｕ_ｋは第ｋセルの平均同時多重ユーザ数（ネットワーク負荷）、Noiseは帯域内の雑音電力である。

Here, K is the number of cells, the p _k RSCP of the k cell, is u _k mean simultaneous multiple number of users of the k cell (network load), Noise is the noise power within the band.

  The above equation (5) is transformed into the following equation (6),

さらに、全セルで平均同時多重ユーザ数ｕ_ｋが同一（＝ｕ）であると仮定すると、次式（７）を得る。

Furthermore, the average simultaneous multiple number of users u _k in all the cells is assumed to be identical (= u), we obtain the following expression (7).

式（７）をｕについて解き、上述したＥｃ／Ｎｏの定義式Ec/No=p_k/RSSIを利用して書き直すと、平均同時多重ユーザ数ｕは次のように表すことができる。

Solving equation (7) for u, rewritten using the definition expression Ec / No = p _k / RSSI above the Ec / No, the average simultaneous multiple number of users u can be expressed as follows.

ここで、Ｅｃ／Ｎｏ（ｌ）は第ｌセルのＥｃ／Ｎｏである。添え字ｌは任意の値であるが、ＲＳＣＰ、Ｅｃ／Ｎｏの値が大きいセルを用いることが好ましい。

Here, Ec / No (l) is Ec / No of the l-th cell. The subscript l is an arbitrary value, but it is preferable to use a cell having a large value of RSCP and Ec / No.

  As shown in the above equation (8), by using the first quality index RSCP that does not depend on the network communication load and the second quality index Ec / No that depends on the network communication load, the average simultaneous multiple users that are the network load u can be determined.

9.3) Load estimation (other examples)
In addition to the above-described LTE and WCDMA, Ec, Ec / lo, and Pilot Strength can be used as quality indicators in the case of cdma2000, and Preamble RSSI and CINR are used as quality indicators in the case of WiMAX. it can.

  The present invention is applicable to a mobile communication system using a mobile router or a smartphone having a tethering function.

10 Mobile station (first mobile station)
11 wireless communication unit 12 network load estimation control unit 13 buffer 20 mobile station (second mobile station)
30 Mobile network 40 Mobile network 50 Wireless LAN
Reference Signs List 101 wireless communication unit 102 received data processing unit 103 data control unit 104 transmission data processing unit 105 line selection control unit 106 network load estimation control unit 201 lower radio link communication unit 202 transmission data processing unit 203 received data processing unit 204 upper radio link communication Unit 205 line selection control unit 206 network load estimation control unit

Claims (40)

A wireless communication device in a wireless communication system,
Holding means for holding network wireless quality information;
Load estimation control means for acquiring the wireless quality information and holding it in the holding means, and estimating a load on the network based on the held radio quality information when a network connection request is generated;
A wireless communication apparatus comprising:   The wireless communication apparatus according to claim 1, wherein the load estimation control unit acquires the wireless quality information using an event that occurs before the network connection request as an information acquisition trigger, and stores the wireless quality information in the storage unit.   The wireless communication apparatus according to claim 1, wherein the load estimation control unit acquires the wireless quality information at a predetermined cycle or update timing.   The load estimation control unit acquires radio quality information of another network from another radio communication device of the radio communication system and holds the information in the holding unit, and the hold is performed when the network connection request is generated. The wireless communication apparatus according to claim 1, wherein loads on the network and the other network are estimated based on wireless quality information.   5. The apparatus according to claim 4, further comprising network selection means for selecting a network to be connected from the network and the other network based on the load of the network and the other network estimated by the load estimation control means. A wireless communication device according to 1.   The load estimation control unit estimates the load of the network and the other network in response to a network selection request from the other wireless communication device, and the network selection unit determines the load based on the estimated load. 6. The wireless communication apparatus according to claim 5, wherein a network to which another wireless communication apparatus is to be connected is selected.   The load estimation control unit acquires the radio quality information of each of a plurality of networks and holds the information in the holding unit. When the network connection request is generated, the load estimation control unit stores each radio network information based on the held radio quality information. The wireless communication apparatus according to claim 1, wherein each of the loads is estimated.   The wireless communication apparatus according to claim 6, further comprising a network selection unit that selects a network to be connected from the plurality of networks based on a load of each network estimated by the load estimation control unit.   The wireless communication apparatus according to claim 1, wherein the load estimation control unit acquires only wireless quality information that satisfies a predetermined condition.   The load estimation control means obtains information related to at least one of a position and a moving speed of the wireless communication apparatus in addition to the wireless quality information, and determines whether or not the information satisfies the predetermined condition. The wireless communication apparatus according to claim 9.   The wireless communication apparatus according to claim 1, wherein the load estimation control unit retains the wireless quality information for a predetermined period and invalidates the predetermined period.   The wireless communication apparatus includes a hardware layer and an application layer, the wireless quality information measurement unit is mounted on the hardware layer, and the holding unit and the load estimation control unit are mounted on the application layer. The wireless communication apparatus according to claim 1. A wireless communication system including a plurality of wireless terminals,
At least one of the first wireless terminal and the second wireless terminal acquires the wireless quality information of the network and holds it in the holding means, and when the network connection request is generated, the held wireless quality information is stored in the held wireless quality information. A wireless communication system characterized by estimating a load on the network based on the network.   14. The wireless communication system according to claim 13, wherein the wireless quality information is acquired by using an event that occurs before the network connection request as an information acquisition trigger, and is held in the holding unit.   15. The wireless communication system according to claim 13, wherein the wireless quality information is acquired at a predetermined cycle or update timing.   The first wireless terminal is connectable to a first network, the second wireless terminal is connectable to a second network, and the first wireless terminal and the second wireless terminal are connected If possible, the first wireless terminal or the second wireless terminal can determine whether the first network and the second wireless terminal are based on wireless quality information of the first network and the second network. The wireless communication system according to any one of claims 13 to 15, wherein each of the network loads is estimated. The second wireless terminal notifies a network selection request to the first wireless terminal;
The first wireless terminal selects a network to be connected to the second wireless terminal based on estimated loads of the first network and the second network. The wireless communication system according to 1.   When the network connection request is generated, the second wireless terminal selects a network to be connected based on the estimated load of the first network and the estimated load of the second network. The wireless communication system according to claim 16.   The said 2nd radio | wireless terminal estimates the load of the said 1st network based on the radio | wireless quality information of the said 1st network acquired from the said 1st radio | wireless terminal. Wireless communication system.   The first wireless terminal or the second wireless terminal can acquire the wireless quality information of the first network and the second network, and the first network and the second network that are acquired and held. The wireless communication system according to any one of claims 13 to 15, wherein a load on each of the first network and the second network is estimated based on wireless quality information of the network.   The first wireless terminal or the second wireless terminal selects a network to be connected based on estimated loads of the first network and the second network. The wireless communication system according to 1.   The first wireless terminal selects a network to which the second wireless terminal is connected based on estimated loads of the first network and the second network, respectively. The wireless communication system according to 1.   23. The wireless communication system according to claim 22, wherein the second wireless terminal notifies the network selection request to the first wireless terminal.   The wireless communication system according to any one of claims 13 to 23, wherein the wireless terminal acquires only wireless quality information satisfying a predetermined condition.   The wireless terminal acquires, in addition to the wireless quality information, information related to at least one of a position and a moving speed of the wireless terminal, and determines whether the information satisfies the predetermined condition. Item 25. The wireless communication system according to Item 24.   The wireless communication system according to any one of claims 13 to 25, wherein the wireless terminal retains the wireless quality information for a predetermined period and invalidates the wireless terminal after the predetermined period has elapsed.   The wireless terminal comprises a hardware layer and an application layer, the wireless quality information measuring means is mounted on the hardware layer, and the holding means and the load estimation control means are mounted on the application layer, respectively. A wireless communication system according to any one of claims 13 to 26. A wireless quality information collection control method in a wireless communication device in a wireless communication system, comprising:
Measuring means measure the wireless quality of the network,
The control means acquires and holds the wireless quality information of the network from the measurement means in order to estimate the load on the network when a network connection request occurs.
A method for collecting and controlling radio quality information.   The radio quality information collection control method according to claim 28, wherein the control means acquires and holds the radio quality information using an event occurring before the network connection request as an information acquisition trigger.   30. The radio quality information collection control method according to claim 28 or 29, wherein the control means acquires the radio quality information at a predetermined cycle or update timing.   The control means acquires and holds radio quality information of another network from another radio communication device of the radio communication system, and when the network connection request occurs, based on the held radio quality information The radio quality information collection control method according to any one of claims 28 to 30, wherein the loads of the network and the other network are respectively estimated.   32. The radio quality information collection control method according to claim 28, wherein the control unit acquires only radio quality information satisfying a predetermined condition.   In addition to the wireless quality information, the control unit acquires information on at least one of a position and a moving speed of the wireless communication device, and determines whether the information satisfies the predetermined condition. The radio quality information collection control method according to claim 32.   34. The radio quality information collection control method according to claim 28, wherein the control means retains the radio quality information for a predetermined period and invalidates the radio quality information after the predetermined period elapses.   35. The method according to claim 28, wherein the measurement unit measures the radio quality information in the hardware layer in the background, and the control unit acquires and holds the radio quality information in the application layer. The method for collecting and controlling radio quality information according to item 1. A communication control method in a wireless communication system including a plurality of wireless terminals,
The first wireless terminal acquires the wireless quality information of the network and holds it in the holding means, and when the network connection request is generated, the load of the network is estimated based on the held wireless quality information. Communication control method.   37. The communication control method according to claim 36, wherein the wireless quality information is acquired by using an event that occurs before the network connection request as an information acquisition trigger, and is held in the holding unit.   38. The communication control method according to claim 36 or 37, wherein the wireless quality information is acquired at a predetermined cycle or update timing.   The first wireless terminal is connectable to a first network, the second wireless terminal is connectable to a second network, and the first wireless terminal and the second wireless terminal are connected If possible, the first wireless terminal estimates the load of the first network and the second network based on the wireless quality information of the first network and the second network, respectively. The communication control method according to any one of claims 36 to 38, wherein: The second wireless terminal notifies a network selection request to the first wireless terminal;
When the first wireless terminal receives the network selection request, the first wireless terminal selects a network to which the second wireless terminal is to be connected based on the estimated loads of the first network and the second network. 40. The communication control method according to claim 39.

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