JP2014011494A - Radio communication device and communication control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio terminal device and a communication control method which can reduce a time required for switching communication systems.SOLUTION: A smart phone 1 comprises: a list acquisition unit 103 which acquires, from a base station of an LTE system, a neighbor list indicating a plurality of base stations existing in a predetermined range from the base station of the LTE system in association with position registration areas of the respective base stations in the predetermined range; and a transition unit 105 which, when the smart phone 1 performs transition from communication by the LTE system to communication by a CDMA system, performs trial communication connection with the CDMA system on the basis of the system time of the LTE system and difference with the system time of the CDMA system, and when the trial fails, searches for a base station of the CDMA system of which position registration area is related to the position registration areas of neighboring base stations included in the neighbor list.

Description

  The present invention relates to a wireless communication apparatus and a communication control method that can communicate with a plurality of communication systems.

  In recent years, as a communication system used by a wireless terminal device such as a cellular phone, there is a communication system using an LTE (Long Term Evolution) system in addition to a circuit switched (CS) system communication system (for example, CDMA).

  However, the wireless terminal device cannot use both the LTE communication system and the CDMA communication system at the same time. For this reason, the mobile phone cannot obtain a CDMA paging channel while using LTE, and cannot know whether there is an incoming call. Therefore, a CS Fallback function that enables notification of an incoming call request from CDMA while using LTE has been defined (for example, see Patent Document 1).

JP 2009-267996 A

  By the way, the base station corresponding to CDMA and the base station corresponding to LTE may have different area ranges (location registration areas) for communicating with the wireless terminal device. Therefore, for example, when the location of the wireless terminal device changes, even if the location registration area corresponding to LTE does not change, the location registration area corresponding to CDMA may change.

  When LTE is used in this state, in order to switch to CDMA, it is necessary to start from a search for a CDMA base station based on, for example, PRL (Preferred Roaming List), which takes time to switch to CDMA. End up.

  An object of this invention is to provide the radio | wireless terminal apparatus and communication control method which can shorten the time concerning switching of a communication system.

  The wireless terminal device according to the present invention is a wireless terminal device capable of communicating in either the first communication system or the second communication system, and when performing communication in the first communication system, prior to the activation of the first communication system. Acquiring a system time of the second communication system in synchronization with the second communication system, and then acquiring a system time of the first communication system in synchronization with the first communication system; A difference calculation unit that calculates a difference between the system time of the first communication system acquired by the acquisition unit and the system time of the second communication system, and a predetermined number from the base station of the first communication system. List acquisition that acquires a neighbor list as information that associates base stations within a range and location registration areas of a plurality of base stations within the predetermined range. The communication connection to the second communication system based on the system time of the first communication system and the difference when the communication from the communication in the first communication system to the communication in the second communication system is performed. A transition unit that tries and searches for a base station in a location registration area of the second communication system related to a location registration area to which a base station within the predetermined range included in the neighbor list belongs if the attempt fails; Is provided.

  Further, in the wireless terminal device according to the present invention, when the transition unit receives a call request during communication in the first communication system, the transition unit performs communication from the communication in the first communication system to the second communication system. It is preferable to shift to communication.

  In the wireless terminal device according to the present invention, when the transition unit receives an incoming call notification from a communication destination base station of the first communication system during communication in the first communication system, the first communication It is preferable to shift from communication in the system to communication in the second communication system.

  The wireless terminal device according to the present invention further includes a storage unit that stores mapping information in which a plurality of location registration areas of the first communication system and a plurality of location registration areas of the second communication system are associated one-to-one. The transition unit identifies a location registration area associated with the base station within the predetermined range based on the neighbor list when the attempt fails, and associates the location registration area with the identified location registration area Preferably, a location registration area of the second communication system is specified based on the mapping information, and a base station in the specified location registration area of the second communication system is searched.

  Moreover, in the radio | wireless terminal apparatus which concerns on this invention, when the said trial fails, the said transition part determines the priority of the location registration area of the said 2nd communication system based on predetermined conditions, The said priority is high In order, it is preferable to search for a base station in the location registration area.

  Further, in the wireless terminal device according to the present invention, when the trial fails, the transition unit acquires information on the electric field strength of the base station within the predetermined range included in the neighbor list, and the acquired electric field It is preferable to determine the priority so that the priority becomes higher in descending order of electric field strength based on the strength information.

  In the wireless terminal device according to the present invention, it is preferable that the first communication system is an LTE communication system and the second communication system is a CDMA communication system.

  The communication control method according to the present invention is a communication control method in which a wireless terminal device capable of communication in either the first communication system or the second communication system controls communication, and when communication is performed in the first communication system, Prior to activation of the first communication system, the system time of the second communication system is acquired in synchronization with the second communication system, and then the system of the first communication system is synchronized with the first communication system. Obtaining a time, calculating a difference between a system time of the first communication system acquired in the acquiring step and a system time of the second communication system, and a base station of the first communication system Information that associates a base station within a predetermined range from the base station and a location registration area of each of a plurality of base stations within the predetermined range And acquiring the neighbor list, and when shifting from communication in the first communication system to communication in the second communication system, based on the system time of the first communication system and the difference (2) A location registration area base of the second communication system related to a location registration area to which a base station within the predetermined range included in the neighbor list belongs when a communication connection to the communication system is attempted and the attempt fails. Searching for a station.

  The wireless terminal device according to the present invention is a wireless terminal device capable of communicating in both the first communication system and the second communication system, and when the first communication system shifts to the second communication system, Location registration of the second communication system related to a location registration area to which a base station included in base station information associated with a plurality of base stations in one communication system and a location registration area to which each of the plurality of base stations belongs is associated Search for base stations in the area.

  The wireless terminal device according to the present invention is a wireless terminal device capable of communicating in either the first communication system or the second communication system, and is a neighbor list when moving from the first communication system to the second communication system. The base station in the location registration area of the second communication system related to the location registration area to which the base station included in is included is searched.

  ADVANTAGE OF THE INVENTION According to this invention, the time concerning switching of a communication system can be shortened.

FIG. 1 is a perspective view illustrating an appearance of a smartphone according to the embodiment. FIG. 2 is a front view illustrating an appearance of the smartphone according to the embodiment. FIG. 3 is a rear view illustrating an appearance of the smartphone according to the embodiment. FIG. 4 is a block diagram illustrating a configuration of the smartphone according to the embodiment. FIG. 5 is a block diagram illustrating a functional configuration of the controller according to the embodiment. FIG. 6 is a diagram illustrating a neighbor list according to the embodiment. FIG. 7 is a diagram illustrating mapping information according to the embodiment. FIG. 8 is a diagram illustrating an example of performing synchronization with the base station of the CDMA system according to the embodiment. FIG. 9 is a flowchart showing processing at the time of power activation in the smartphone according to the embodiment. FIG. 10 is a flowchart illustrating processing during handoff in the smartphone according to the embodiment. FIG. 11 is a flowchart illustrating processing at the time of outgoing / incoming calls in the smartphone according to the embodiment.

  Embodiments for carrying out the present invention will be described in detail with reference to the drawings. Hereinafter, a smartphone will be described as an example of a wireless terminal device.

  The external appearance of the smartphone 1 according to the embodiment will be described with reference to FIGS. 1 to 3. As shown in FIGS. 1 to 3, the smartphone 1 has a housing 20. The housing 20 includes a front face 1A, a back face 1B, and side faces 1C1 to 1C4. The front face 1 </ b> A is the front of the housing 20. The back face 1 </ b> B is the back surface of the housing 20. The side faces 1C1 to 1C4 are side surfaces that connect the front face 1A and the back face 1B. Hereinafter, the side faces 1C1 to 1C4 may be collectively referred to as the side face 1C without specifying which face.

  The smartphone 1 includes a touch screen display 2, buttons 3A to 3C, an illuminance sensor 4, a proximity sensor 5, a receiver 7, a microphone 8, and a camera 12 on the front face 1A. The smartphone 1 has a camera 13 on the back face 1B. The smartphone 1 has buttons 3D to 3F and an external interface 14 on the side face 1C. Hereinafter, the buttons 3A to 3F may be collectively referred to as the button 3 without specifying which button.

  The touch screen display 2 includes a display 2A and a touch screen 2B. The display 2A includes a display device such as a liquid crystal display (Liquid Crystal Display), an organic EL panel (Organic Electro-Luminescence panel), or an inorganic EL panel (Inorganic Electro-Luminescence panel). The display 2A displays characters, images, symbols, graphics, and the like.

  The touch screen 2B detects contact of a finger, a stylus pen, or the like with respect to the touch screen display 2. The touch screen 2B can detect a position where a plurality of fingers, a stylus pen, or the like is in contact with the touch screen display 2.

  The detection method of the touch screen 2B may be any method such as a capacitance method, a resistive film method, a surface acoustic wave method (or an ultrasonic method), an infrared method, an electromagnetic induction method, and a load detection method. Hereinafter, for the sake of simplicity of explanation, a finger that the touch screen 2B detects contact with the touch screen display 2 or a stylus pen or the like may be simply referred to as a “finger”.

  The smartphone 1 determines the type of gesture based on the contact, contact position, contact time, or number of contacts detected by the touch screen 2B. The gesture is an operation performed on the touch screen display 2. The gesture determined by the smartphone 1 includes touch, long touch, release, swipe, tap, double tap, long tap, drag, flick, pinch in, pinch out, and the like.

  A touch is a gesture in which a finger contacts the touch screen display 2 (for example, a surface). The smartphone 1 determines a gesture in which a finger contacts the touch screen display 2 as a touch. The long touch is a gesture in which a finger contacts the touch screen display 2 for a predetermined time or more. The smartphone 1 determines a gesture in which a finger contacts the touch screen display 2 for a predetermined time or more as a long touch.

  A release is a gesture in which a finger leaves the touch screen display 2. The smartphone 1 determines a gesture in which a finger leaves the touch screen display 2 as a release. The swipe is a gesture that moves while the finger is in contact with the touch screen display 2. The smartphone 1 determines a gesture that moves while the finger is in contact with the touch screen display 2 as a swipe.

  A tap is a gesture for releasing following a touch. The smartphone 1 determines a gesture for releasing following a touch as a tap. The double tap is a gesture in which a gesture for releasing following a touch is continued twice. The smartphone 1 determines a gesture in which a gesture for releasing following a touch is continued twice as a double tap.

  A long tap is a gesture for releasing following a long touch. The smartphone 1 determines a gesture for releasing following a long touch as a long tap. The drag is a gesture for performing a swipe from an area where a movable object is displayed. The smartphone 1 determines, as a drag, a gesture for performing a swipe starting from an area where a movable object is displayed.

  The flick is a gesture that is released while the finger moves at high speed in one direction following the touch. The smartphone 1 determines, as a flick, a gesture that is released while the finger moves in one direction at high speed following the touch. Flick: Up flick that moves your finger up the screen, Down flick that moves your finger down the screen, Right flick that moves your finger right in the screen, Left flick that moves your finger left in the screen Etc.

  Pinch-in is a gesture that swipes in a direction in which a plurality of fingers approach each other. The smartphone 1 determines, as a pinch-in, a gesture that swipes in a direction in which a plurality of fingers approach each other. Pinch-out is a gesture that swipes a plurality of fingers away from each other. The smartphone 1 determines a gesture of swiping in a direction in which a plurality of fingers move away from each other as a pinch out.

  The smartphone 1 operates according to these gestures that are determined via the touch screen 2B. Therefore, operability that is intuitive and easy to use for the user is realized. The operation performed by the smartphone 1 according to the determined gesture differs depending on the screen displayed on the touch screen display 2.

  FIG. 4 is a block diagram illustrating the configuration of the smartphone 1. The smartphone 1 includes a touch screen display 2, a button 3, an illuminance sensor 4, a proximity sensor 5, a communication unit 6, a receiver 7, a microphone 8, a storage 9, a controller 10, and cameras 12 and 13. , An external interface 14, an acceleration sensor 15, an orientation sensor 16, and a rotation detection sensor 17.

  As described above, the touch screen display 2 includes the display 2A and the touch screen 2B. The display 2A displays characters, images, symbols, graphics, or the like. The touch screen 2B detects a gesture.

  The button 3 is operated by the user. The button 3 includes buttons 3A to 3F. The controller 10 detects an operation on the button by cooperating with the button 3. The operation on the button is, for example, click, double click, push, and multi-push.

  For example, the buttons 3A to 3C are a home button, a back button, or a menu button. For example, the button 3D is a power on / off button of the smartphone 1. The button 3D may also serve as a sleep / sleep release button. For example, the buttons 3E and 3F are volume buttons.

  The illuminance sensor 4 detects illuminance. For example, the illuminance is light intensity, brightness, luminance, or the like. The illuminance sensor 4 is used for adjusting the luminance of the display 2A, for example.

  The proximity sensor 5 detects the presence of a nearby object without contact. The proximity sensor 5 detects that the touch screen display 2 is brought close to the face, for example.

  The communication unit 6 communicates wirelessly. The communication method performed by the communication unit 6 is a wireless communication standard. For example, wireless communication standards include cellular phone communication standards such as 2G, 3G, and 4G. For example, communication standards for cellular phones include LTE (Long Term Evolution), W-CDMA, CDMA2000, PDC, GSM (registered trademark), PHS (Personal Handy-phone System), and the like. Examples of wireless communication standards include WiMAX (Worldwide Interoperability for Microwave Access) (registered trademark), IEEE 802.11, Bluetooth (registered trademark), IrDA, NFC (Near Field Communication), and the like.

  Here, in this example, the communication unit 6 uses both the CDMA2000_1x (hereinafter referred to as CDMA) system, which is a communication protocol for voice and data communication, and the LTE system, which is a communication protocol mainly used for high-speed data communication. It is possible to communicate with any protocol communication system. The communication unit 6 communicates with the base station using any protocol based on a command from the controller 10. The smartphone 1 prioritizes communication by LTE when performing data communication, and uses communication by CDMA when performing a voice call.

  The receiver 7 outputs the audio signal transmitted from the controller 10 as audio. The microphone 8 converts the voice of the user or the like into a voice signal and transmits it to the controller 10. The smartphone 1 may further include a speaker in addition to the receiver 7. The smartphone 1 may further include a speaker instead of the receiver 7.

  The storage 9 stores programs and data. The storage 9 is also used as a work area for temporarily storing the processing result of the controller 10. The storage 9 may include any storage device such as a semiconductor storage device and a magnetic storage device. The storage 9 may include a plurality of types of storage devices. The storage 9 may include a combination of a portable storage medium such as a memory card and a storage medium reading device.

  The programs stored in the storage 9 include an application executed in the foreground or the background and a control program that supports the operation of the application. For example, the application displays a predetermined screen on the display 2A, and causes the controller 10 to execute processing according to the gesture detected by the touch screen 2B. The control program is, for example, an OS. The application and the control program may be installed in the storage 9 via wireless communication by the communication unit 6 or a storage medium.

  The storage 9 stores, for example, a control program 9A, a mail application 9B, a browser application 9C, and setting data 9Z. The mail application 9B provides an electronic mail function for creating, transmitting, receiving, and displaying an electronic mail. The browser application 9C provides a WEB browsing function for displaying a WEB page. The table 9D stores various tables such as a key assignment table. The arrangement pattern database 9E stores arrangement patterns such as icons displayed on the display 2A.

  The setting data 9Z provides various setting functions related to the operation of the smartphone 1. Specifically, the setting data 9Z includes a system time that is used in the communication system and is reference time information notified from the base station. When communication is performed using the LTE communication system as the first communication system, the setting data 9Z includes the system time of the LTE communication system and the system time of the CDMA communication system as the second communication system. The difference between and is stored. In the following description, the LTE communication system is simply referred to as an LTE system, and the CDMA communication system is referred to as a CDMA system.

  The control program 9A provides functions related to various controls for operating the smartphone 1. The control program 9A realizes a call by controlling the communication unit 6, the receiver 7, the microphone 8, and the like, for example. The function provided by the control program 9A includes a function of performing various controls such as changing information displayed on the display 2A according to a gesture detected via the touch screen 2B. Note that the functions provided by the control program 9A may be used in combination with functions provided by other programs such as the mail application 9B.

  The controller 10 is, for example, a CPU (Central Processing Unit). The controller 10 may be an integrated circuit such as a SoC (System-on-a-chip) in which other components such as the communication unit 6 are integrated. The controller 10 controls various operations of the smartphone 1 to realize various functions.

  Specifically, the controller 10 executes instructions included in the program stored in the storage 9 while referring to the data stored in the storage 9 as necessary, and the display 2A, the communication unit 6 and the like. Various functions are realized by controlling. The controller 10 may change the control according to detection results of various detection units such as the touch screen 2B, the button 3, and the acceleration sensor 15.

  For example, by executing the control program 9A, the controller 10 executes various controls such as changing information displayed on the display 2A according to a gesture detected via the touch screen 2B. Detailed functions of the controller 10 will be described later.

  The camera 12 is an in-camera that captures an object facing the front face 1A. The camera 13 is an out camera that captures an object facing the back face 1B.

  The external interface 14 is a terminal to which another device is connected. The external interface 14 may be a general-purpose terminal such as a universal serial bus (USB), a high-definition multimedia interface (HDMI), a light peak (thunderbolt), and an earphone microphone connector. The external interface 14 may be a dedicated terminal such as a dock connector. Devices connected to the external interface 14 include, for example, an external storage, a speaker, and a communication device.

  The acceleration sensor 15 detects the direction and magnitude of acceleration acting on the smartphone 1. The direction sensor 16 detects the direction of geomagnetism. The rotation detection sensor 17 detects the rotation of the smartphone 1. The detection results of the acceleration sensor 15, the orientation sensor 16, and the rotation detection sensor 17 are used in combination in order to detect changes in the position and orientation of the smartphone 1.

  The smartphone 1 configured as described above can reduce the time required for switching the communication system. The configuration will be specifically described below.

  FIG. 5 is a block diagram illustrating a functional configuration of the controller 10. The controller 10 includes a system time acquisition unit 101, a difference calculation unit 102, a list acquisition unit 103, a mapping information acquisition unit 104, and a migration unit 105.

Here, the CS Fallback function is one of incoming call notification services that link the LTE network and the CLMA network in an area where the location registration areas of the LTE network and the CDMA network overlap.
Specifically, the CS Fallback function notifies the smartphone 1 registered in the LTE network of the occurrence of an incoming call in the CDMA network via the LTE network. 6 is a technique for performing voice communication by switching the communication according to 6 to the CDMA network. In this technique, even when an incoming call is originally made in a CDMA network that services a voice call, the network side management device links the CDMA network call area and the LTE network call area. Thereby, the smartphone 1 can operate as if it is registered in both the CDMA network and the LTE network by registering the location in either the CDMA network or the LTE network.

  When communication is performed in the LTE system by the communication unit 6, the system time acquisition unit 101 acquires the system time of the CDMA system in synchronization with the CDMA system before starting the LTE system.

  Specifically, the system time acquisition unit 101 controls the communication unit 6 to synchronize with the CDMA system when the smartphone 1 is powered on, and acquires the system time of the CDMA system via the communication unit 6. To do. In addition, when the LTE system handoff occurs, the system time acquisition unit 101 controls the communication unit 6 to suspend the LTE system, searches for a base station of the CDMA system, and supplements the base of the CDMA system. Synchronize with the station. In this way, the system time acquisition unit 101 acquires the system time of the CDMA system.

  At this time, the system time acquisition unit 101 calculates the system time of the CDMA system based on the synchronization message on the synchronization (sync) channel notified from the base station of the CDMA system.

  After obtaining the system time of the CDMA system, the difference calculation unit 102 controls the communication unit 6 to start the LTE system and synchronize with the LTE system. Then, the difference calculation unit 102 acquires the system time of the LTE system via the communication unit 6. The difference calculation unit 102 calculates a difference between the system time of the LTE system and the system time of the CDMA system acquired by the system time acquisition unit 101. The difference calculation unit 102 stores the system time of the LTE system and the calculated difference in the storage 9 as part of the setting data 9Z. Thereby, the communication unit 6 maintains the synchronization of the LTE system based on the system time of the LTE system stored in the storage 9.

  The list acquisition unit 103 acquires a neighbor list from the base station of the LTE system via the communication unit 6. The neighbor list is information in which a base station of the LTE system is associated with a location registration area of the LTE system. Specifically, as shown in FIG. 6, the neighbor list associates a base station of the LTE system within a predetermined range from the base station of the LTE system and a location registration area of each of the plurality of base stations within the predetermined range. Information. The list acquisition unit 103 acquires a neighbor list from the connection destination base station via the communication unit 6 at the start of communication by the LTE system. In addition, when a handoff occurs in the LTE system, the list acquisition unit 103 acquires a neighbor list from the base station of the newly connected LTE system via the communication unit 6.

  The mapping information acquisition unit 104 acquires mapping information from the base station of the LTE system via the communication unit 6 at the start of communication by the LTE system or when a handoff occurs. FIG. 7 shows an example of mapping information. As shown in FIG. 7, the mapping information is information that associates the location registration area of the LTE system with the location registration area of the CDMA system. In this mapping information, the location registration area of the LTE system and the location registration area of the CDMA system are associated one-to-one. The mapping information is configured by at least a part of mapping information used in MME (Mobility Management Entity) that manages the base station of the LTE system. The mapping information acquisition unit 104 stores the acquired mapping information in the storage 9.

  When the CS Fallback function notifies the incoming call in the CDMA system during communication in the LTE system, the transition unit 105 controls the communication unit 6 to shift from communication in the LTE system to communication in the CDMA system. . Similarly, the transition unit 105 controls the communication unit 6 and controls the communication unit 6 in the LTE system when receiving a call request from the touch screen display 2 and the button 3 of the smartphone 1 during communication in the LTE system. Transition from communication to communication in a CDMA system.

  In this case, the migration unit 105 calculates the system time of the CDMA system based on the system time and difference of the LTE system stored in the storage 9. The transition unit 105 attempts to synchronize with the base station of the CDMA system by controlling the communication unit 6 based on the calculated system time of the CDMA system.

  When the transition unit 105 succeeds in synchronization with the base station of the CDMA system, the transition unit 105 controls the communication unit 6 to start communication by the CDMA system. Here, the case where the synchronization with the base station of the CDMA system is successful is a case where the communication unit 6 can acquire the overhead message of the paging channel in the CDMA system.

On the other hand, the case where the synchronization with the base station of the CDMA system fails is a case where the communication unit 6 cannot acquire the overhead message of the paging channel in the CDMA system.
Here, an example of performing synchronization with the base station of the CDMA system will be described. FIG. 8 is a diagram illustrating an example in which synchronization with the base station of the CDMA system fails. As shown in FIG. 8, the location registration area TA-1 of the LTE system corresponds to the entire location registration area LA-A of the CDMA system and a part of LA-B. Further, it is assumed that the system time acquired from the location registration area of each CDMA system has a slight deviation.

  For example, as shown in FIG. 8 (a), when communication of the LTE system is started at a position X1 corresponding to the location registration area LA-A of the CDMA system, the controller 10 moves to the base of the location registration area LA-A of the CDMA system. Get the system time from the station. Thereafter, the controller 10 calculates a difference between the system time acquired from the base station in the location registration area TA-1 of the LTE system and the system time from the base station in the location registration area LA-A, and stores the calculated difference in the storage. 9

  Thereafter, as shown in FIG. 8B, the smartphone 1 moves to a position X2 corresponding to the location registration area TA-1 of the LTE system and corresponding to the location registration area LA-B of the CDMA system. . In this case, when an incoming / outgoing call occurs in the smartphone 1, the controller 10 determines whether the system of the CDMA system is based on the difference stored in the storage 9 and the system time acquired from the LTE system location registration area TA-1. Calculate time. The calculated system time of the CDMA system corresponds to the system time of the location registration area LA-A of the CDMA system, and does not correspond to the system time of the location registration area LA-B. For this reason, the smartphone 1 and the base station of the CDMA system fail to synchronize.

When the synchronization with the base station of the CDMA system fails, the transition unit 105 controls the communication unit 6 and relates to the location registration area to which the neighboring base station included in the neighbor list acquired by the list acquisition unit 103 belongs. Search for a base station in the location registration area of the CDMA system.
By doing in this way, the smart phone 1 can search a base station about the position registration area of the CDMA system close to the base station adjacent to the base station of the LTE system currently communicating. That is, since the smartphone 1 performs a search in the location registration area of the CDMA system corresponding to the current location, the search can be performed more efficiently than a search based on MRU (Most Recipient Used) or PRL (Preferred Roaming List). it can. Thereby, the smart phone 1 can shorten the time concerning switching of a communication system.

Hereinafter, a process for searching for a base station in the location registration area of the CDMA system will be described more specifically.
First, the transition unit 105 identifies, from the neighbor list acquired by the list acquisition unit 103, a base station within a predetermined range of the LTE system base station that is currently communicating.
Subsequently, the migration unit 105 specifies the location registration area of the CDMA system associated with the location registration area of the LTE system to which the base station within the specified range belongs based on the mapping information stored in the storage 9 To do. Here, the transition unit 105 excludes the location registration area of the LTE system in which the smartphone 1 is currently located from the location registration area of the LTE system included in the mapping information, and then the location registration of the CDMA system. Identify the area. Subsequently, the transition unit 105 controls the communication unit 6 to search for a base station in the specified location registration area of the CDMA system.

  By doing in this way, the smart phone 1 can pinpoint the location registration area of the CDMA system close | similar to the base station adjacent to the base station of the LTE system which is communicating now based on mapping information.

  Further, when synchronization with the base station of the CDMA system fails, the smartphone 1 determines the priority of the location registration area of the CDMA system based on a predetermined condition, and registers the location of the CDMA system in descending order of the priority. You may make it search the base station of an area.

  That is, the transition unit 105 removes the base station corresponding to the location registration area of the LTE system where the smartphone 1 is currently located from the neighbor list, and then transmits from each of the plurality of base stations included in the neighbor list. Get information on the strength (electric field strength) of the radio waves.

  Subsequently, based on the mapping information, the transition unit 105 identifies the location registration area of the CDMA system associated with the location registration area of the LTE system corresponding to the base station having a strong electric field strength, and prioritizes this location registration area. The priority is determined so that the degree becomes higher. Thereby, the priority of the location registration area of the CDMA system corresponding to the base station of the LTE system with the strongest electric field strength is the highest. On the other hand, the priority of the location registration area of the CDMA system corresponding to the base station of the LTE system having the weakest electric field strength is the lowest. Subsequently, the transition unit 105 controls the communication unit 6 to search for a base station of the CDMA system in order from the location registration area of the CDMA system having a high priority.

  By doing in this way, the smart phone 1 can specify the location registration area of the CDMA system considered to be the closest to the base station within the predetermined range from the base station of the LTE system that is currently communicating. Thereby, the smartphone 1 can preferentially search for a base station of the CDMA system close to the current position of the smartphone 1.

  FIG. 9 is a flowchart showing processing at the time of power activation in the smartphone 1 according to the present embodiment. 9 is executed by the controller 10 appropriately controlling the communication unit 6.

  In step S1, when the power of the smartphone 1 is turned on, the controller 10 executes a predetermined activation process and starts a process of capturing a base station and registering a location.

  In step S2, the controller 10 searches for a CDMA system and acquires a pilot channel.

  In step S3, the controller 10 receives the sync channel in code synchronization with the CDMA system, and acquires the system time.

  In step S4, the controller 10 stores the system time of the CDMA system acquired in step S3 in the storage 9.

  In step S5, the controller 10 synchronizes with the CDMA system based on the system time acquired in step S3. The controller 10 acquires peripheral channels and base station positions, and the controller 10 acquires information (frequency channel, PN information, etc.) for establishing communication with the same CDMA system next time. In addition, a paging channel overhead message is received.

  In step S6, the controller 10 suspends the CDMA system in order to activate the LTE system that has priority over the CDMA system.

  In step S7, the controller 10 activates the LTE system and starts the synchronization process.

  In step S8, the controller 10 acquires the system time of the synchronized LTE system.

  In step S9, the controller 10 calculates the difference between the system time of the LTE system acquired in step S8 and the system time of the CDMA system acquired in step S3, and stores the difference in the storage 9.

  In step S10, the controller 10 enters an incoming call waiting state in the LTE system, enables data communication in the LTE, and receives an incoming notification of the CSMA system by the CS Fallback function.

  FIG. 10 is a flowchart showing processing during handoff in the smartphone 1 according to the present embodiment. 10 is executed by the controller 10 appropriately controlling the communication unit 6.

  In step S11, the controller 10 executes a handoff for changing the area of the LTE system based on a change in radio wave condition from the base station.

  In step S <b> 12, the controller 10 acquires the system time of the handoff destination LTE system and stores it in the storage 9. Furthermore, the controller 10 acquires a neighbor list and mapping information from the base station of the LTE system of the handoff destination.

  In step S13, the controller 10 once suspends the LTE system in order to acquire the CDMA system.

  In step S14, the controller 10 searches for a CDMA system and acquires a pilot channel. Note that the controller 10 searches by limiting the search target based on the mapping information acquired in step S12.

  In step S15, the controller 10 receives the sync channel in code synchronization with the CDMA system, and acquires the system time.

  In step S16, the controller 10 stores the system time of the CDMA system acquired in step S15 in the storage 9.

  In step S17, the controller 10 synchronizes with the CDMA system based on the system time acquired in step S15, and acquires information (frequency channel, PN information, etc.) for establishing communication with the same CDMA system next time. In addition, a paging channel overhead message is received.

  In step S18, the controller 10 calculates the difference between the system time of the LTE system acquired in step S12 and the system time of the CDMA system acquired in step S15, and stores it in the storage 9.

  In step S19, the controller 10 suspends the CDMA system in order to activate the LTE system suspended in step S13.

  In step S20, the controller 10 activates the LTE system to enter an incoming call waiting state, enables data communication in the LTE system, and receives an incoming call notification in the CDMA system by the CS Fallback function.

  In this process, the system time difference obtained in step S18 may be calculated using the system time acquired after the LTE system is activated in step S20.

  FIG. 11 is a flowchart showing processing at the time of outgoing / incoming calls in the smartphone 1 according to the present embodiment. Note that the processing in FIG. 11 is executed by the controller 10 appropriately controlling the communication unit 6.

  In step S <b> 21, the controller 10 receives an incoming notification message of the CDMA system or accepts an outgoing operation by the CS Fallback function.

  In step S22, after responding to the incoming call notification received in step S21 by the LTE system, the controller 10 activates the CDMA system to start call processing.

  In step S23, the controller 10 calculates the system time of the CDMA system by adding the difference stored in the storage 9 to the system time of the LTE system.

  In step S24, the controller 10 attempts to receive the paging channel in synchronization with the CDMA system using the system time calculated in step S23.

  In step S25, the controller 10 determines whether or not the paging channel overhead message has been received in the CDMA system. If this determination is YES, the controller 10 moves the process to step S26, and if the determination is NO, the controller 10 moves the process to step S27.

  In step S26, the controller 10 shifts to a traffic channel in the CDMA system and executes call processing.

  In step S27, the controller 10 has failed in time synchronization with the CDMA system due to the system time calculated in step S23. Therefore, based on the neighbor list, the controller 10 determines the LTE system within the predetermined range from the base station of the LTE system currently in communication. Measure the field strength of the base station.

  In step S28, the controller 10 determines the priority order of the location registration area to be searched. Specifically, the controller 10 determines the priority of the location registration area of the CDMA system corresponding to the base station within a predetermined range from the base station of the LTE system currently communicating based on the electric field strength measured in step S27. decide.

  In step S29, the controller 10 searches for the base station of the CDMA system in order from the location registration area of the CDMA system related to the LTE system having a higher rank with respect to the location registration area of the CDMA system specified based on the mapping information. Do.

  In step S30, the controller 10 receives the acquired sync channel of the CDMA system and acquires the system time. Then, the controller 10 returns the process to step S24 and tries to receive the paging channel again.

  As described above, according to the present embodiment, the smartphone 1 is configured so that the list acquisition unit 103 causes the base station within the predetermined range of the base station and the location registration areas of the plurality of base stations within the predetermined range from the base station of the LTE system. When the transition unit 105 shifts from communication in the LTE system to communication in the CDMA system, the communication unit tries to connect to the CDMA system based on the system time and the difference in the LTE system. If the trial fails, the base station in the location registration area of the CDMA system related to the location registration area to which the neighboring base station included in the neighbor list belongs is searched.

  By doing in this way, the smart phone 1 can search a base station based on the location registration area of the CDMA system close to the base station adjacent to the base station of the LTE system currently communicating. That is, since the smartphone 1 performs a search in the location registration area of the CDMA system corresponding to the current location, the smartphone 1 can perform a search more efficiently than a search based on MRU or PRL. Thereby, the smart phone 1 can shorten the time concerning switching of a communication system.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to embodiment mentioned above. Further, the effects described in the embodiments of the present invention only list the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the above-described embodiments. Absent.

The configuration of the smartphone 1 shown in FIGS. 4 and 5 is an example, and may be changed as appropriate within a range that does not impair the gist of the present invention.
In the present embodiment, the list acquisition unit 103 acquires the neighbor list from the base station of the connection destination LTE system at the start of communication by the LTE system or when a handoff occurs, but the present invention is not limited to this. For example, the list acquisition unit 103 may acquire a neighbor list from a base station of a connection destination LTE system when shifting from communication in the LTE system to communication in the CDMA system.

  In the present embodiment, the mapping information acquisition unit 104 acquires the mapping information at the start of communication by the LTE system or when a handoff occurs, but the present invention is not limited to this. For example, the mapping information acquisition unit 104 may acquire the mapping information from the base station of the connection destination LTE system when shifting from communication in the LTE system to communication in the CDMA system.

4 may be downloaded from another device through wireless communication by the communication unit 6. 4 may be stored in a storage medium that can be read by a reading device included in the storage 9. 4 is stored in a storage medium such as a CD, a DVD, or a Blu-ray that can be read by a reader connected to the external interface 14. May be.
Each program shown in FIG. 4 may be divided into a plurality of modules or may be combined with other programs.

  Moreover, although the above-mentioned embodiment demonstrated a smart phone as an example of a wireless terminal device, a wireless terminal device is not limited to a smart phone. For example, the wireless terminal device may be a mobile phone, a portable personal computer, a digital camera, a media player, an electronic book reader, a portable electronic device such as a navigator or a game machine, or a communication-dedicated module specialized for a communication function.

1 Smartphone (wireless terminal device)
10 Controller (control unit)
101 System time acquisition unit (acquisition unit)
102 Difference calculation unit 103 List acquisition unit 104 Mapping information acquisition unit 105 Migration unit

Claims (10)

A wireless terminal device capable of communicating in both the first communication system and the second communication system,
When performing communication in the first communication system, prior to starting up the first communication system, the system time of the second communication system is acquired in synchronization with the second communication system, and then the first communication system is acquired. An acquisition unit for acquiring the system time of the first communication system in synchronization with
A difference calculation unit that calculates a difference between the system time of the first communication system acquired by the acquisition unit and the system time of the second communication system;
List acquisition for acquiring a neighbor list as information in which base stations within a predetermined range from the base station and location registration areas of a plurality of base stations within the predetermined range are associated from the base station of the first communication system And
When transitioning from communication in the first communication system to communication in the second communication system, a communication connection to the second communication system is attempted based on the system time and the difference of the first communication system, A transition unit for searching for a base station in the location registration area of the second communication system related to a location registration area to which a base station within the predetermined range included in the neighbor list belongs when the attempt fails;
A wireless terminal device. The transition unit transitions from communication in the first communication system to communication in the second communication system when receiving a call request during communication in the first communication system.
The wireless terminal device according to claim 1. When the transition unit receives an incoming call notification from a communication destination base station of the first communication system during communication in the first communication system, the transition unit performs communication from the communication in the first communication system to the second communication system. Transition to communication,
The wireless terminal device according to claim 1. A storage unit for storing mapping information in which the plurality of location registration areas of the first communication system and the plurality of location registration areas of the second communication system are associated one-to-one;
The migration unit identifies a location registration area associated with the base station within the predetermined range based on the neighbor list when the trial fails, and the second portion associated with the identified location registration area Specifying a location registration area of the communication system based on the mapping information, and searching for a base station in the specified location registration area of the second communication system;
The radio | wireless terminal apparatus of any one of Claim 1 to 3. The transition unit, when the trial fails, determines the priority of the location registration area of the second communication system based on a predetermined condition, and the location registration area of the second communication system in descending order of the priority. Search for base stations,
The radio | wireless terminal apparatus of any one of Claim 1 to 4. The transition unit obtains information on the electric field strength of the base station within the predetermined range included in the neighbor list when the trial fails, and the electric field strength is high based on the obtained electric field strength information. The priority is determined so that the priority becomes higher in order.
The wireless terminal device according to claim 5. The first communication system is an LTE communication system,
The second communication system is a CDMA communication system.
The radio | wireless terminal apparatus of any one of Claim 1 to 6. A communication control method in which a wireless terminal device capable of communication in either the first communication system or the second communication system controls communication,
When performing communication in the first communication system, prior to starting up the first communication system, the system time of the second communication system is acquired in synchronization with the second communication system, and then the first communication system is acquired. Acquiring the system time of the first communication system in synchronization with
Calculating a difference between the system time of the first communication system acquired in the acquiring step and the system time of the second communication system;
Obtaining a neighbor list as information in which base stations within a predetermined range from the base station and location registration areas of a plurality of base stations within the predetermined range are associated from the base station of the first communication system; ,
When transitioning from communication in the first communication system to communication in the second communication system, a communication connection to the second communication system is attempted based on the system time and the difference of the first communication system, Searching for a base station in the location registration area of the second communication system related to a location registration area to which a base station within the predetermined range included in the neighbor list belongs if the trial fails. . A wireless terminal device capable of communicating in both the first communication system and the second communication system,
When transitioning from the first communication system to the second communication system, the base station information in which the plurality of base stations in the first communication system and the location registration areas to which the plurality of base stations belong is associated Searching for a base station in the location registration area of the second communication system related to the location registration area to which the base station belongs.
Wireless terminal device. A wireless terminal device capable of communicating in both the first communication system and the second communication system,
Searching for a base station in the location registration area of the second communication system related to the location registration area to which the base station included in the neighbor list belongs when transitioning from the first communication system to the second communication system;
Wireless terminal device.

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