JP2010081226A - Mobile station, communication method and communication program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely connect a mobile station to a first wireless base station under environment where a cell of the first wireless base station and a cell of a second wireless base station are overlapped. <P>SOLUTION: As one embodiment, the mobile station is provided with: an automatic connection part which automatically switches a wireless base station to one of a plurality of wireless base stations according to the state of a communication path with each of the plurality of wireless base stations; a connection request acceptance part which accepts a connection request to the first wireless base station during connection with the second wireless base station different from the first wireless base station; a search part which searches for the first wireless base station specified in the connection request when the connection request is accepted by the connection request acceptance part; a first connection destination switching part which switches the connection destination to the first wireless base station discovered by the search part; and an operation stopping part which stops an operation of the automatic connection part when the connection destination is switched to the first wireless base station. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mobile station, a communication control method, and a program.

  The coverage area of a base station in a mobile communication system such as a current mobile phone or PHS extends over a wide area with a radius of several hundreds to several tens of kilometers, and is called a macro cell. In the boundary area between macrocells, indoors of high-rise buildings / housing, underground malls, etc., the radio wave intensity is weak, and a dead area that is difficult to communicate is generated. Conventionally, in order to eliminate this insensitive area, measures such as amplification of transmission power of a base station and installation of a radio relay device (RF repeater) have been taken. On the other hand, in recent years, a method such as a femtocell method has been proposed in which a small base station that can be connected to a commercial broadband line is installed to eliminate a dead area (see, for example, Non-Patent Document 1).

  In the femtocell system, a small base station (femtocell base station) that connects to the mobile phone carrier network via a commercial broadband line used by the user is installed in the home, and a very small coverage area with a radius of several tens of meters It is a method that provides. Since a femtocell base station can be installed in an environment where a broadband line is laid, it is possible to implement insensitive areas such as indoors at low cost. In addition to countermeasures for dead areas, high-speed communication can be realized by monopolizing the radio resources of the femtocell base station with a small number of mobile phones, and part of communication such as e-mail and Internet access can be turned off at the femtocell base station. By controlling the load, there is also an effect of reducing the communication load of the entire network by suppressing the amount of traffic flowing into the mobile phone carrier network. Therefore, in the environment where the femtocell system is introduced, many merits can be obtained by connecting to the femtocell instead of the macrocell.

  On the other hand, handoff control for switching the base station to which the mobile station is connected is realized by control in which the mobile station and the mobile phone carrier network are linked. The trigger for switching is the quality of radio wave propagation between the base station and the mobile station. A method using a degradation scale is common (for example, Patent Document 1). That is, in the conventional cellular phone operator network, which base station the mobile station connects to is determined based on the radio wave propagation environment, and control such as prioritization of the connected base station is not performed. For example, at the position where the macro cell and the femto cell overlap, there is a problem that the communication speed is reduced due to the connection with the macro cell even though the mobile station is located within the femto cell range where high-speed communication is possible. Furthermore, even if it is connected to a femtocell, there is a problem that the communication speed is reduced due to handoff to the macrocell due to fluctuations in the radio wave propagation environment.

In addition, the femtocell system is characterized in that the broadband line used as infrastructure has a higher risk of IP network failure than a highly reliable dedicated line. If an IP network failure occurs on the broadband line, the mobile station connected to the femtocell may lose all communications such as calls, emails, and Internet access.
Femto Forum URL: http://www.femtoforum.org/femto/aboutfemtocells.php JP-A-9-187055

  As described above, in the mobile communication system using the femtocell system, there is a problem that the mobile station cannot be reliably connected to the femtocell that can provide advantages such as high-speed communication. In addition, if an IP network failure occurs on the broadband line used by the femtocell base station as a communication infrastructure, the mobile station connected to the femtocell has a problem that all communications such as calls, mails, and Internet access are interrupted.

  The present invention has been made in consideration of the above circumstances, and in an environment in which a femto cell (cell of a first radio base station) and a macro cell (cell of a second radio base station) overlap each other, the femto cell base Provided are a mobile station, a communication method, and a communication program that enable reliable connection with a station (first radio base station).

The mobile station as one aspect of the present invention includes an automatic connection unit that automatically switches and connects to one of the plurality of radio base stations according to the state of a communication path with each of the plurality of radio base stations A connection request accepting unit that accepts a connection request to the first radio base station during connection with a second radio base station different from the first radio base station, and the connection request accepting unit by the connection request accepting unit. A search unit that searches for the first radio base station specified in the connection request, and a first connection destination that switches the connection destination to the first radio base station discovered by the search unit A switching unit; and an operation stopping unit that stops the operation of the automatic connection unit when the connection destination is switched to the first radio base station.

The communication method as one aspect of the present invention includes an automatic connection step of automatically switching and connecting to one of the plurality of radio base stations according to the state of a communication path with each of the plurality of radio base stations. A connection request accepting step for accepting a connection request to the first radio base station during connection with a second radio base station different from the first radio base station, and the connection request accepting step by the connection request accepting step. A search step for searching for the first radio base station specified in the connection request, and a first connection destination for switching the connection destination to the first radio base station discovered by the search step A switching step, and an operation stop step of stopping the operation of the automatic connection step when the connection destination is switched to the first radio base station.

The communication program as one aspect of the present invention includes an automatic connection step of automatically switching and connecting to one of the plurality of radio base stations according to a state of a communication path with each of the plurality of radio base stations. A connection request accepting step for accepting a connection request to the first radio base station during connection with a second radio base station different from the first radio base station, and the connection request accepting step by the connection request accepting step. A search step for searching for the first radio base station specified in the connection request, and a first connection destination for switching the connection destination to the first radio base station discovered by the search step A switching step and an operation stop step of stopping the operation of the automatic connection step when the connection destination is switched to the first radio base station are executed by a computer.

  According to the present invention, it is possible to reliably connect to the first radio base station in an environment where the cell of the first radio base station and the cell of the second radio base station overlap.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a configuration example of a communication system according to an embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a mobile phone operator network (external network), and M denotes a radio base station (macrocell base station) connected to the mobile phone operator network 1. The radio base station M corresponds to, for example, the second radio base station of the present invention.

  2 is the Internet (external network), and F is a small wireless base station (femtocell base station) connected to a home network (home network) G laid in the home 3. The small radio base station F is connected to the cellular phone operator network 1 via the Internet 2 via a broadband line (or access line) connected to the ADSL router 4. The small radio base station F corresponds to, for example, the first radio base station of the present invention.

  Reference numerals 5 and 6 are radio links, and H is a mobile station connectable to the radio links 5 and 6. Solid lines and broken lines 5 and 6 indicate connection states between the mobile station H, the radio base station M, and the small radio base station F. A solid line indicates a connected state, and a broken line indicates a disconnected state.

  The mobile station H accesses the cellular phone operator network 1 via the radio base station M, and accesses the cellular phone operator network 1 via the small radio base station F via the home network G and the Internet 2. Further, the mobile station H can access the Internet 2 via the mobile phone carrier network 1 via the wireless base station M, and can also access the home network G. The mobile station H can also access the Internet 2 via the small wireless base station F and the mobile phone operator network 1 according to a tunneling protocol such as VPN.

  Reference numeral 7 denotes an AV device having a communication function, which provides a content download service to the mobile station H. The AV device 7, the ADSL router 4 and the small wireless base station F are connected to a home network (home network) G.

  In FIG. 1, only one radio base station M, one small radio base station F, and one mobile station H are shown. However, a plurality of radio base stations, a plurality of small radio base stations, and a plurality of mobile stations H are shown. There may be mobile stations.

  FIG. 2 shows a configuration example of the mobile station H according to the present embodiment.

  The mobile station H includes an identifier storage unit 10, a connection request reception unit 11, a small radio base station search unit 12, a connection destination switching unit (first connection destination switching unit) 13, and a handoff function invalidation unit (operation (Stop unit) 14, release request accepting unit 15, handoff function enabling unit (operation resuming unit) 16, fault monitoring unit 17, connected radio base station determining unit 18, fault saving unit (second connection) (Destination switching unit) 19, small radio base station re-search unit (re-search unit) 20, fault save release unit (third or fourth connection destination switch unit) 21, fault save state determination unit 23, handoff And a control unit (automatic connection unit) 24. Each element 10-24 may be comprised as hardware, and may be comprised as a software module.

(1) The identifier storage unit 10 stores the identifier of the small radio base station F connected to the home network G of the owner of the mobile station. The connection request reception unit 11 receives a connection request with a small radio base station from a user, for example. When the mobile station H is connected to the radio base station M, the small radio base station search unit 12 receives an identifier in the identifier storage unit 10 when the connection request accepting unit 11 accepts a connection request to the small radio base station. Search for a small radio base station that matches. The connection destination switching unit (first connection destination switching unit) 13 switches the connection destination to the small radio base station searched by the small radio base station search unit 12.

(2) The handoff control unit 24 controls handoff execution of the mobile station H. Although details of the handoff will be described later, simply, the mobile station H automatically switches the connection to the base station having the optimum radio wave propagation quality among the surrounding base stations. When the connection destination switching unit 13 switches the connection destination to the small radio base station, the handoff function invalidating unit 14 invalidates the handoff function (stops the operation of the handoff control unit 24).

(3) The cancellation request receiving unit 15 receives a handoff invalidation cancellation request from a user, for example. When the handoff function is invalidated, the handoff function enabling unit 16 validates the handoff function when the cancellation request is accepted by the cancellation request accepting unit 15 (resuming the operation of the handoff control unit 24).

(4) The failure monitoring unit 17 monitors whether there is a communication failure in the broadband line (access line) or the Internet 2 connected to the small radio base station that matches the identifier in the identifier storage unit 10. The connected radio base station determination unit 18 determines whether or not the base station to which the mobile station is currently connected matches the small radio base station of the identifier when the failure monitoring unit 17 detects a communication failure. The failure saving unit 19 switches the connection destination to the radio base station M when the connected radio base station determination unit 18 determines that they match. This saves you from the failure. The failure saving unit 19 includes the second connection destination switching means of the present invention.

(5) When the failure monitoring unit 17 detects that the communication failure has been recovered, the small wireless base station re-search unit 20 re-searches for a small wireless base station that matches the identifier in the identifier storage unit 10. The failure save cancellation unit 21 switches the connection destination again to the small radio base station re-searched by the small radio base station re-search unit 20. As a result, the evacuation from the failure is released. The failure save release unit 21 includes a third connection destination switching unit of the present invention.

(6) The communication destination monitoring unit 22 monitors whether or not the mobile station has started communication. When the communication start is detected, the communication destination monitoring unit 22 determines whether the communication destination is the home network G. When the communication destination monitoring unit 22 determines that the connection destination is the home network G, the failure saving state determination unit 23 determines whether the current state is a failure saving state by the failure saving unit 19. The small radio base station re-search unit 20 re-searches for a small radio base station that matches the identifier in the identifier storage unit 10 when it is determined that the failure has been saved. The failure evacuation cancellation unit 21 switches the connection destination to the found small radio base station. The failure save release unit 21 includes the fourth connection destination switching means of the present invention.

  Hereinafter, the first to sixth operation examples of the operation of the mobile station H will be described in order.

(First operation example)
As an initial state, it is assumed that the user returns home from outside the home with the user's mobile station connected to the radio base station M. In addition, it is assumed that the identifier of the small radio base station F is stored in the identifier storage unit 10 of the mobile station. In this initial state, as shown in FIG. 3, a first operation example is performed when a connection request with the small radio base station F is received and the connection destination is switched from the radio base station M to the small radio base station F. Will be described.

  FIG. 4 is a flowchart for explaining the flow of the first operation example.

First, a connection request with the small radio base station is generated in the mobile station H, and the connection request receiving unit 11 receives this (YES in S10). More specifically, the connection request is determined to occur when one of several predetermined events occurs, and the connection request reception unit 11 detects the occurrence of these events and generates a connection request. Accept. The following are examples of events:
(1) A specific instruction from the user is input to the mobile station H. (2) The mobile station H is connected to a docking station such as a charger. (3) The mobile station H is connected to a wired LAN or wireless LAN. The network I / F is enabled when it is equipped

  For (1) above, for example, when a hardware switch (button) is installed in the main body of the mobile station H and the user presses the button as desired, the event that the button is pressed A method of detection is possible. With regard to (2) above, for example, when the mobile station H is connected to a docking station type charger, a method of detecting that the power state of the mobile station H is energized as an event is possible. With regard to (3) above, for example, a method of detecting as an event that the wired LAN and wireless LAN network I / F has been linked up is possible. In addition, said (1)-(3) is an example, and various events can be considered. In addition, which event is adopted may be determined as appropriate.

  Next, the small radio base station search unit 12 acquires the small radio base station identifier stored in the identifier storage unit 10 (S11). Here, the small wireless base station identifier can use identification information that can identify each small wireless base station. For example, in the CDMA system, the cell ID included in the signal received by the mobile station H via CPICH (Common Pilot Channel) Can be used.

  Next, the small radio base station search unit 12 searches for neighboring base stations (cell search) (S12), and determines whether a small radio base station matching the small radio base station identifier has been found (S13). ).

  Next, when a small wireless base station is found (YES), the connection destination switching unit 13 switches the connection destination from the wireless base station M to the small wireless base station (S14). That is, the connection with the radio base station M is disconnected and the small radio base station is connected. On the other hand, if it is not found (NO), the connection with the currently connected radio base station M is disconnected (S15). This assumes that the user does not want to connect to the radio base station M when the user is at home (for example, communication via the radio base station M is more expensive than the small radio base station F). Is. However, it is naturally possible to configure to continue the connection with the radio base station M without disconnecting the connection with the radio base station M.

  As described above, the mobile station H can select and connect a specific small radio base station installed in the house.

(Second operation example)
Next, as a second operation example, as shown in FIG. 5, after the process of step S14 shown in the first operation example, the handoff function by the handoff control unit 24 is further invalidated, thereby A case will be described in which a connection with a small radio base station is maintained in a fixed manner regardless of fluctuations.

  Here, the handoff function is a function in which the mobile station H automatically switches the connection to a base station having an optimal radio wave propagation quality among neighboring base stations. Specifically, the mobile station H analyzes the reception level of the control channel received from the surrounding base stations (radio base station and small radio base station), and the radio network control device (in the mobile phone carrier network via the base station ( Not shown). Upon receiving the notification, the radio network controller instructs the mobile station and the base station (the base station currently communicating with the base station having the strongest reception level) to switch to the base station having the strongest reception level. As a result, the mobile station H in which the handoff function is effective operates to automatically switch to a base station having a strong radio wave level at all times. In the second operation example, after the mobile station H switches to a specific small wireless base station connected to the home network G in the first operation example, the handoff function of the handoff control unit 24 is invalidated. Thus, the connection with the small radio base station is fixedly maintained regardless of the fluctuation of the radio propagation environment.

  FIG. 6 is a flowchart for explaining the flow of the second operation example. The difference from the flowchart of FIG. 4 is that S26 is added, and S20 to S25 are the same as S10 to S15 of FIG. Similar to the first operation example, as an initial state, the mobile station H is connected to the radio base station M, and the identifier of the small radio base station F is stored in the identifier storage unit 10 of the mobile station.

  First, a connection request to the small radio base station is generated in the mobile station H, and the connection request receiving unit 11 receives this as a connection request (YES in S20).

  Next, the small radio base station search unit 12 acquires the small radio base station identifier stored in the identifier storage unit 10 (S21), performs a search (cell search) for neighboring base stations (S22), and It is determined whether a small radio base station that matches the station identifier has been found (S23).

  Next, the connection destination switching unit 13 switches the connection destination from the radio base station M to the small radio base station when the small radio base station can be found (YES) (S24). NO) Disconnect from the currently connected radio base station M (S25).

  Next, when the connection destination is switched to the small radio base station in the process of S24, the handoff function invalidating unit 14 invalidates the handoff function of the handoff control unit 24 (S26). That is, the operation of the handoff control unit 24 is stopped.

  From the above, it is possible to realize a method in which the mobile station H is fixedly connected to a small radio base station regardless of changes in the radio propagation environment.

  In this operation example, the connection request receiving unit 11 shows the operation when the mobile station H receives a connection request with the small wireless base station while the mobile station H is connected to the wireless base station M. Even when a connection request with a small radio base station is received during connection with the base station, the handoff function invalidating unit 14 may invalidate the handoff function of the handoff control unit 24. Further, when the mobile station H is not connected to either the radio base station or the small radio base station, when the connection request receiving unit 11 receives a connection request with the small radio base station, the processing in steps S21 to S24 and S26 is performed. May be performed.

(Third operation example)
Next, as a third operation example, as shown in FIG. 7, when the handoff function invalidation cancellation request is further generated in the mobile station H from the state in which the handoff function is invalidated in the second operation example. Will be described.

  FIG. 8 is a flowchart for explaining the flow of the third operation example.

First, a handoff invalidation cancellation request is generated in the mobile station H, and the cancellation request reception unit 15 detects this (YES in S30). More specifically, the cancellation request is determined to occur when one of several predetermined events occurs, and the cancellation request reception unit 15 detects the occurrence of these events and Accepted as a release request (S30). The following are examples of events:
(1) A specific instruction from the user is input at the mobile station H. (2) The mobile station H is removed from a docking station such as a charger. (3) The mobile station H is wired or wireless. If the network I / F is installed, the I / F is disabled

  For (1) above, for example, when a hardware switch (button) is installed in the main body of the mobile station H and the user presses the button as desired, the event that the button is pressed A method of detection is possible. With regard to (2) above, for example, when the mobile station H is removed from the docking station type charger, it is possible to detect as an event that the power state of the mobile station H has changed from energized to de-energized. . With regard to (3) above, for example, a method of detecting as an event that a wired LAN and wireless LAN network I / F has been linked down is possible. In addition, said (1)-(3) is an example, and various events can be considered. In addition, which event is adopted may be determined as appropriate.

  Next, the handoff function enabling unit 16 enables the handoff function that has been disabled (S31). That is, the operation of the handoff control unit 24 is resumed.

  As described above, the mobile station H can make a transition from a state where the mobile station H cannot handoff to the macro cell to a state where handoff is possible. This operation example is applied, for example, when maintaining connectivity by handing off to a macro cell when going out of the house.

(Fourth operation example)
Next, as a fourth operation example, as shown in FIG. 9, the handoff function is disabled in the second operation example (that is, the mobile station H accepts a connection request and connects to a small radio base station. Next, a case where an IP network failure occurs on the broadband line after the handoff function is disabled) will be described. When an IP network failure occurs when the handoff function is disabled in this way, the mobile station H is in a state where all communications such as a call, mail, and Internet access are cut off.

  FIG. 10 is a flowchart for explaining the flow of the fourth operation example.

  First, the failure monitoring unit 17 monitors the presence or absence of an IP network failure on the broadband line (S40). Here, as a monitoring method, the mobile station H may periodically check communication with an Internet network server (for example, installed by a mobile phone operator) and detect the presence or absence of communication as the presence or absence of an IP network failure. Alternatively, a method may be used in which a device such as a small wireless base station installed in a home detects an IP network failure by the same method and notifies the mobile station H when it detects the failure. Here, in addition to notifying with a unique control message, the notification method can be notified using an application such as e-mail.

  Next, when an IP network failure is detected (YES), the connected wireless base station determination unit 18 acquires the small wireless base station identifier from the identifier storage unit 10 (S41), and the currently connected small wireless base station It is determined whether the identifier matches (S42).

  Next, when the acquired identifier matches the identifier of the currently connected small wireless base station (YES), the failure saving unit 19 switches the connection destination to the wireless base station M and saves from the failure (S43).

  As described above, the mobile station H can recover from a state in which all communications such as a call, mail, and Internet access are interrupted due to an IP network failure.

(Fifth operation example)
Next, as a fifth operation example, as shown in FIG. 11, the state after step S43 described in the fourth operation example (that is, mobile station H accepts a connection request and connects to a small radio base station. Next, a case will be described where the handoff function is disabled, the IP network failure occurs, and the connection destination is switched to a wireless base station other than the small wireless base station), and the IP network failure on the broadband line is recovered.

  FIG. 12 is a flowchart for explaining the flow of the fifth operation example.

  First, the failure monitoring unit 17 detects whether or not an IP network failure has been recovered (S50). Here, the detection method may be that the mobile station H periodically confirms communication with the in-home device via the macro cell base station (wireless base station M), and detects the presence or absence of communication as the presence or absence of recovery from the IP network failure. . Alternatively, devices such as small wireless base stations installed in the home regularly check communication with an Internet network server (for example, installed by a mobile phone operator) to monitor IP network failures and recover from IP network failures. Alternatively, a method of notifying the mobile station H when it is detected may be used. Here, in addition to notifying with a unique control message, the notification method can be notified using an application such as e-mail.

  Next, when the IP network failure is recovered (YES), the small radio base station re-search unit 20 acquires the small radio base station identifier stored in the identifier storage unit 10 (S51), and searches for neighboring base stations (cell search). ) Is performed (S52), and it is determined whether a small radio base station matching the small radio base station identifier has been found (S53).

  Next, the failure evacuation canceling unit 21 switches the connection destination to the small radio base station when the small radio base station is found in step S53 (YES), and when it is not found (NO) The connection with the currently connected radio base station is disconnected (S55).

  From the above, it becomes possible for the mobile station H to reconnect to the femtocell (small radio base station cell) as the IP network failure is recovered.

(Sixth operation example)
Next, as a sixth operation example, as shown in FIG. 13, the state after step S43 described in the fourth operation example (that is, mobile station H accepts a connection request and connects to a small radio base station. The handoff function is disabled, the IP network failure occurs, and the connection destination is switched to a wireless base station other than the small wireless base station. The case of starting will be described. In this state, an attempt to start communication with a home device via the wireless base station M causes an IP network failure on the communication path (broadband line or access line) between the wireless base station M and the Internet 2 via the home. Communication cannot be started.

  FIG. 14 is a flowchart for explaining the flow of the sixth operation example.

  First, the communication destination monitoring unit 22 monitors the communication start of the mobile station H (S60), and when the communication start is detected (YES in S60), the communication destination (destination address of the transmission packet) is the home device. It is determined whether or not there is (S61).

  Next, when the communication destination is a home device (YES in S61), the failure saving state determination unit 23 determines whether the mobile station H is currently transitioning to the failure saving state by the failure saving unit 19 ( S62). Here, in the failure saving state, for example, a flag is prepared on the memory of the mobile station H, and when the failure saving unit 19 performs the failure saving process, the flag is turned on (ON), and the failure saving release unit 21 It may be managed by turning off the flag when executing the save release processing.

  Next, the small radio base station re-search unit 20 obtains the small radio base station identifier stored in the identifier storage unit 10 (S63) when it is in the failure saving state (YES in S62), and searches for neighboring base stations. (Cell search) is performed (S64), and it is determined whether or not a small radio base station matching the small radio base station identifier has been found (S65). When the small radio base station is found (YES in S65), the failure save release unit 21 switches the connection destination to the small radio base station (S66).

  As described above, the mobile station H can recover the communication with the home device by reconnecting to the femtocell (the cell of the small radio base station) from the state in which the IP network failure occurs and cannot communicate with the home device.

  As described above, according to the embodiment of the present invention, the mobile station H is reliably connected to the femto cell in an environment where the femto cell (cell of the radio base station M) and the macro cell (cell of the small radio base station F) overlap. As a result, it is possible to reliably connect to a base station having a merit such as high-speed communication.

  Further, according to the embodiment of the present invention, the mobile station H can appropriately switch the connected base station depending on the presence or absence of an IP network failure. As a result, even when an IP network failure occurs, It is possible to avoid the influence of communication interruption.

The figure which shows the structural example of the communication system which concerns on one Embodiment of this invention. The figure which shows the structural example of the mobile station H which concerns on this embodiment. The figure explaining the 1st operation example of a mobile station. The flowchart which shows the flow of the 1st operation example of a mobile station. The figure explaining the 2nd operation example of a mobile station. The flowchart which shows the flow of the 2nd operation example of a mobile station. The figure explaining the 3rd operation example of a mobile station. The flowchart which shows the flow of the 3rd operation example of a mobile station. The figure explaining the 4th operation example of a mobile station. The flowchart which shows the flow of the 4th operation example of a mobile station. The figure explaining the 5th operation example of a mobile station. The flowchart which shows the flow of the 5th operation example of a mobile station. The figure explaining the 6th operation example of a mobile station. The flowchart which shows the flow of the 6th operation example of a mobile station.

Explanation of symbols

H: Mobile station
M: Radio base station
F: small wireless base station 1: mobile phone operator network 2: Internet 4: ADSL router 7: AV device 10: identifier storage unit 11: connection request receiving unit 12: small wireless base station searching unit 13: connection destination switching unit ( First connection destination switching unit)
14: Handoff function invalidation part (operation stop part)
15: Connection release request receiving unit 16: Handoff function enabling unit (operation resuming unit)
17: Failure monitoring unit 18: Connected radio base station determination unit 19: Failure saving unit (second connection destination switching unit)
20: Small radio base station re-search unit (re-search unit)
21: Failure save release unit (third or fourth connection destination switching unit)
22: Communication destination monitoring unit 23: Failure save state determination unit 24: Handoff control unit (automatic connection unit)

Claims (7)

An automatic connection unit that automatically switches to and connects to one of the plurality of radio base stations according to the state of the communication path with each of the plurality of radio base stations;
A connection request accepting unit that accepts a connection request to the first radio base station during connection with a second radio base station different from the first radio base station;
A search unit that searches for the first radio base station specified in the connection request when the connection request is received by the connection request reception unit;
A first connection destination switching unit that switches a connection destination to the first radio base station discovered by the search unit;
An operation stop unit that stops the operation of the automatic connection unit when the connection destination is switched to the first radio base station;
Mobile station equipped with. A release request accepting unit for accepting a request for releasing the operation stop of the automatic connection unit;
The mobile station according to claim 1, further comprising: an operation resuming unit that resumes the operation of the automatic connection unit when the release request is received. A failure monitoring unit that monitors the presence or absence of communication failure in the network to which the first wireless base station is connected;
A second connection for switching the connection destination to the second radio base station when a communication failure is detected in the connection destination network of the first radio base station during the connection with the first radio base station; The mobile station according to claim 1, further comprising: a destination switching unit. A re-search unit for re-searching the first radio base station when the failure monitoring unit detects that the communication fault has been recovered after the connection destination is switched to the second radio base station; ,
The mobile station according to claim 3, further comprising: a third connection destination switching unit that switches a connection destination to the first radio base station discovered by the re-search unit. A communication destination monitoring unit, a re-search unit, and a fourth connection destination switching unit;
The first radio base station is disposed in a home network connected to an external network via a predetermined access line,
The failure monitoring unit monitors the presence or absence of a communication failure of the predetermined access line or external network as a connection destination network of the first radio base station,
The communication destination monitoring unit identifies a destination network by monitoring a destination address of a transmission packet,
The re-search unit re-searches the first radio base station when it is detected that the communication destination is the home network after the connection destination is switched to the second radio base station,
The mobile station according to claim 3, wherein the fourth connection destination switching unit switches the connection destination to the first radio base station discovered by the re-search unit. An automatic connection step of automatically switching and connecting to one of the plurality of radio base stations according to the state of the communication path with each of the plurality of radio base stations;
A connection request receiving step for receiving a connection request to the first radio base station during connection with a second radio base station different from the first radio base station;
A search step of searching for the first radio base station specified in the connection request when the connection request is received by the connection request reception step;
A first connection destination switching step of switching a connection destination to the first radio base station discovered by the search step;
An operation stop step of stopping the operation of the automatic connection step when the connection destination is switched to the first radio base station;
A communication method comprising: An automatic connection step of automatically switching and connecting to one of the plurality of radio base stations according to the state of the communication path with each of the plurality of radio base stations;
A connection request receiving step for receiving a connection request to the first radio base station during connection with a second radio base station different from the first radio base station;
A search step of searching for the first radio base station specified in the connection request when the connection request is received by the connection request reception step;
A first connection destination switching step of switching a connection destination to the first radio base station discovered by the search step;
An operation stop step of stopping the operation of the automatic connection step when the connection destination is switched to the first radio base station;
A communication program for causing a computer to execute.

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