JP2010147704A - Handover processing method and terminal device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to carry out handover processing while taking into account communication common carrier in a wireless LAN system. <P>SOLUTION: Modulation and demodulation section 22 and others carry out communications with a base station device provided with a service set identifier. A first investigating section 30 investigates a quality of communication. A second investigating section 32 investigates a signal received from another base station device. A selecting section 36 selects one of other base station devices if the investigated quality of communication has been deteriorated worse than a threshold value. The selecting section 36 selects another base station device provided with the same service set identifier as that of a base station device carrying out communications in the modulation and demodulation section 22. A decision section 38 instructs the modulation and demodulation section 22 and others to shift to the selected other base station device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication technique, and more particularly to a handover processing method for executing a handover between a plurality of base station apparatuses and a terminal apparatus using the handover processing method.

A wireless LAN (Local Area Network) system is generally composed of a base station device and a terminal device. The sequence for the terminal device to connect to the base station device is shown as follows, for example. The base station apparatus broadcasts a beacon. After receiving the beacon, the terminal device transmits authentication information to the base station device. This authentication includes, for example, authentication in combination with ESSID (Extended Service Set IDentifier) and WEPKEY (Wired Equivalent Private KEY), EAP (Extensible Authentication Protocol), MD5S (Serial Authentication Protocol), TLS (Tunneled TLS) authentication is used. Next, the terminal device transmits an address acquisition request to the base station device. The base station device assigns an IP address to the terminal device and returns the IP address to the terminal device (see, for example, Patent Document 1).
JP 2008-199137 A

  In recent years, telecommunications carriers have installed a plurality of base station apparatuses, and public wireless LAN services are provided by them. In consideration of the convenience of the user using the terminal device, it is desirable that communication is possible even while moving. Therefore, the terminal device is requested to execute the handover process. The handover process is a process for switching the connection destination from another terminal device connected to a predetermined base station device to another base station device. When there are a plurality of communication carriers, there are base station apparatuses to which the terminal apparatus should not be connected. For this reason, it is necessary to execute the handover process while considering the communication carrier.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a communication technique for executing a handover process in a wireless LAN system while considering a communication carrier.

  In order to solve the above problems, a terminal device according to an aspect of the present invention investigates a communication unit that performs communication with a base station device to which a service set identifier is assigned, and communication quality in the communication unit When the quality of the communication investigated in the 1st investigation part, the 2nd investigation part which investigates the signal received from other base station apparatuses via the communication part, and the 1st investigation part deteriorated from the threshold A selection unit that selects one of the other base station devices that have examined the signal in the second investigation unit, and a control unit that instructs the communication unit to switch to the other base station device selected in the selection unit . The selection unit selects another base station device to which the same service set identifier as that of the base station device performing communication in the communication unit is assigned.

  Another aspect of the present invention is a handover processing method. The method includes performing communication with a base station apparatus to which a service set identifier has been assigned, investigating communication quality, investigating signals received from other base station apparatuses, A step of selecting one of the other base station devices for which a signal has been investigated, and a step of performing a transition to the selected other base station device when the quality of the investigated communication deteriorates below a threshold value; Is provided. The selecting step selects another base station apparatus to which the same service set identifier as that of the base station apparatus performing communication is assigned.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, a handover process can be executed in a wireless LAN system while considering a communication carrier.

  Before describing the present invention in detail, an outline will be described. Embodiments of the present invention relate to a communication system including a plurality of base station apparatuses and terminal apparatuses. Here, the communication system uses a wireless LAN compliant with standards such as IEEE802.11a, b, g, and n, and corresponds to a public wireless LAN service. The terminal device is connected to one of a plurality of base station devices (hereinafter referred to as “movement source base station device”), and the movement source base station device is also connected to a network. As a result, the terminal device performs communication with the network via the source base station device.

  The terminal device moves from a radio zone formed by the source base station device to a radio zone of another base station device (hereinafter referred to as “destination base station device”). At that time, the communication system performs a handover. That is, the terminal device starts communication with the destination base station device after disconnecting communication with the source base station device. As described above, when a plurality of communication carriers are implementing a public wireless LAN service, there are some base station devices that cannot be a destination base station device. That is, base station devices provided by other communication carriers should be excluded from candidates for the movement destination base station device. As described above, in order to realize a smooth handover process in an environment where a plurality of communication carriers provide a public wireless LAN service, the terminal apparatus according to the present embodiment executes the following process.

  The terminal device receives beacon signals from other base station devices even when communicating with the source base station device. Further, the terminal device summarizes the relationship between the reception power of the beacon signal and the SSID included in the beacon signal in a table. Apart from this, the terminal apparatus monitors the quality of communication with the source base station apparatus. For example, the terminal device measures the received power of the packet signal from the source base station device. When the communication quality deteriorates, the terminal device refers to the table and selects the destination base station device. Here, the terminal device selects a base station device to which the same SSID as the SSID of the source base station device is assigned among the plurality of base station devices included in the table. The terminal device executes a handover process from the source base station device to the destination base station device.

  FIG. 1 shows a configuration of a communication system 100 according to an embodiment of the present invention. The communication system 100 includes a terminal device 10, a first base station device 12 a, a second base station device 12 b, an N-th base station device 12 n, a network 14, and a server 16. As described above, the terminal device 10 is a wireless device compatible with the wireless LAN system. Since a publicly known technique may be used as the wireless LAN system, description thereof is omitted here. The terminal device 10 also has a data communication function, but may have a call function. Data communication is, for example, transmission / reception of e-mails, browsing of the World Wide Web (WWW), execution of VoIP (Voice over Internet Protocol), and these processes may be performed by the terminal device 10 alone. However, the connection may be made with a personal computer (not shown).

  The base station device 12 is connected to the terminal device 10 by wireless communication at one end and connected to the network 14 by wired communication at the other end. The base station device 12 is connected to the server 16 via the network 14. Here, the first base station apparatus 12a corresponds to the source base station apparatus, and any one of the second base station apparatus 12b to the Nth base station apparatus 12n corresponds to the destination base station apparatus. The terminal device 10 communicates with the server 16 via the first base station device 12a and the network 14.

  The network 14 is connected to the base station apparatus 12 and also to the server 16. For example, the network 14 is configured by an IP (Internet Protocol) network, but is not limited thereto. The network 14 transmits the data received from the server 16 to the base station apparatus 12 and transmits the data received from the base station apparatus 12 to the server 16. The network 14 includes a router (not shown). The server 16 is a server corresponding to a predetermined function, for example, e-mail, WWW, data distribution, and the like, and executes processing in response to a request from the terminal device 10.

  The terminal device 10 receives a beacon signal from another base station device 12 even while communicating with the first base station device 12a. Here, the base station apparatus 12 includes a base station apparatus 12 not shown in FIG. 1, that is, a base station apparatus 12 installed by another communication carrier. Note that the beacon signal is a signal that is periodically broadcast by the base station apparatus 12, and stores information such as the identification number of the base station apparatus and the SSID. The terminal device 10 measures the received power of the beacon signal and extracts the identification number and SSID stored in the beacon signal. Moreover, the terminal device 10 collects combinations of received power, identification numbers, and SSIDs in a table. The terminal device 10 updates the table by appropriately executing such processing.

  The terminal device 10 measures the received power of the packet signal from the first base station device 12a, and compares the received power with a threshold value. When the received power becomes lower than the threshold value, the terminal device 10 selects one base station device 12 as a destination base station device while referring to the table. Here, the terminal device 10 selects the base station device 12 to which the same SSID as the SSID of the first base station device 12a is assigned among the plurality of base station devices 12 stored in the table. When there are a plurality of such base station apparatuses 12, the terminal apparatus 10 selects the base station apparatus 12 corresponding to the maximum received power. If the received power of the base station device 12 is smaller than the received power of the packet signal from the first base station device 12a, the terminal device 10 stops the handover process and establishes communication with the first terminal device 10a. You may decide to continue communication. When the destination base station device is selected, the terminal device 10 disconnects communication with the first base station device 12a and executes connection with the destination base station device, for example, the second base station device 12b.

  After such a handover process is completed, the terminal device 10 performs communication with the server 16 via the second base station device 12b. Immediately after the end, the routing table such as the router included in the network 14 is not updated. Therefore, the packet signal transmitted from the server 16 does not reach the terminal device 10. In order to cope with this, immediately after the termination, the terminal device 10 transmits a packet signal to the server 16 via the second base station device 12b regardless of whether there is data to be transmitted. As a result, the routing table in the network 14 is updated.

  FIG. 2 shows the configuration of the terminal device 10. The terminal device 10 includes an RF unit 20, a modem unit 22, a processing unit 24, and a control unit 26. The processing unit 24 includes a first survey unit 30, a second survey unit 32, a storage unit 34, a selection unit 36, and a determination unit 38.

  As a reception process, the RF unit 20 performs frequency conversion on the radio frequency packet signal received from the base station apparatus 12 via the antenna, and generates a baseband packet signal. Further, the RF unit 20 outputs a baseband packet signal to the modem unit 22. In general, baseband packet signals are formed by in-phase and quadrature components, so two signal lines should be shown, but here only one signal line is shown for clarity. Shall be shown. The RF unit 20 also includes an LNA (Low Noise Amplifier), a mixer, an AGC, and an A / D conversion unit.

  As a transmission process, the RF unit 20 performs frequency conversion on the baseband packet signal input from the modem unit 22 to generate a radio frequency packet signal. Further, the RF unit 20 transmits a radio frequency packet signal from the antenna. The RF unit 20 also includes a PA (Power Amplifier), a mixer, and a D / A conversion unit.

  The modem unit 22 demodulates the baseband packet signal from the RF unit 20 as a reception process. Further, the modem unit 22 outputs the demodulated result to the processing unit 24. Further, the modem unit 22 modulates the signal from the processing unit 24 as a transmission process. Further, the modem unit 22 outputs the modulated result to the RF unit 20 as a baseband packet signal. When the terminal apparatus 10 supports an OFDM modulation scheme such as the IEEE802.11a and g standards, the modem unit 22 also executes FFT as a reception process and IFFT as a transmission process. When the terminal apparatus 10 supports a spread spectrum method such as the IEEE 802.11b standard, the modem unit 22 also performs despreading as a reception process and also performs spreading as a transmission process. Further, when the terminal apparatus 10 supports a MIMO scheme such as IEEE802.11n, the modem unit 22 also performs adaptive array signal processing as reception processing, and also performs distribution processing into a plurality of streams as transmission processing.

  The processing unit 24 performs digital signal processing on the signal from the modem unit 22 and the signal to the modem unit 22. Here, an example of digital signal processing is encoding of error correction as transmission processing and decoding of error correction as reception processing. The digital signal processing is not limited to this. The processing unit 24 outputs the result of executing digital signal processing on the signal from the modulation / demodulation unit 22 to the outside, and inputs the signal that is the source of the signal to the modulation / demodulation unit 22 from the outside.

  The control unit 26 controls the operation of the terminal device 10. Hereinafter, (1) connection processing, (2) data input / output processing, and (3) handover processing will be described in this order. First, (1) connection processing will be described. The connection process is a process performed to connect to the source base station apparatus before executing communication. The second investigation unit 32 receives a beacon signal received from the base station apparatus 12 (not shown) via the RF unit 20. Moreover, the 2nd investigation part 32 investigates a beacon signal by measuring the reception power of a beacon signal and extracting the identification number and SSID of the base station apparatus 12 stored in the beacon signal. The second investigation unit 32 stores the combination of the identification number, SSID, and received power in the storage unit 34. In addition, the 2nd investigation part 32 memorize | stores a some combination in the memory | storage part 34 by repeatedly performing such a process over a predetermined period.

  FIG. 3 shows the data structure of the table stored in the storage unit 34. As shown, the base station apparatus name column 200, the SSID column 202, and the received power column 204 are shown. The base station apparatus name column 200 indicates the base station apparatus 12 that is the transmission source of the beacon signal, and may be an identification number instead of the name of the base station apparatus 12. Further, the SSID column 202 and the received power column 204 include the SSID and received power corresponding to the name of the base station apparatus 12. Returning to FIG.

  The selection unit 36 selects one base station device 12 as a source base station device from the table stored in the storage unit 34 after the above-described predetermined period has elapsed. Here, the selection unit 36 stores in advance the SSID corresponding to the communication carrier to which the terminal device 10 is permitted to connect. Further, the selection unit 36 selects the base station device 12 to which the SSID is assigned while referring to the storage unit 34. When a plurality of base station devices 12 are selected, the selection unit 36 selects the base station device 12 corresponding to the maximum received power from among them. The selection unit 36 outputs information regarding the selected base station apparatus 12 to the determination unit 38.

  The determination unit 38 receives information regarding the selected base station apparatus 12 from the selection unit 36. The determination unit 38 performs connection to the selected base station apparatus 12 via the modem unit 22 and the RF unit 20. Note that the selected base station apparatus 12 corresponds to the first base station apparatus 12a of FIG. Here, a known technique may be used for the connection process. In brief, the determination unit 38 performs an authentication process with the first terminal device 10a. The determination unit 38 transmits an association request frame to the first terminal device 10a. When the determination unit 38 receives an association response frame with the status code “success”, the determination unit 38 interprets that the connection process is successful. On the other hand, when receiving an association response frame whose status code is other than “success”, the determination unit 38 interprets that the connection process has failed.

  Next, (2) data input / output processing will be described. The processing unit 24 outputs the result of the digital signal processing to an unillustrated monitor or speaker as output processing. Further, the processing unit 24 receives an instruction signal from an operation unit (not shown) as input processing, and executes digital signal processing on the data corresponding thereto. Here, the operation unit includes buttons and the like. In addition, when the terminal device 10 is formed so as to be connected to a personal computer, the operation unit may be a keyboard and a mouse provided in the personal computer. As a result, the processing unit 24, the modem unit 22, and the RF unit 20 perform communication with the first base station device 12a to which the SSID corresponding to the communication carrier to which the terminal device 10 is permitted to connect is assigned. To do.

  Next, (3) handover processing will be described. The first examining unit 30 receives the packet signal received by the RF unit 20. The first investigation unit 30 investigates the communication quality by measuring the reception power of the packet signal. The packet signal is transmitted from the first base station apparatus 12a that is the source base station apparatus. The reception power measurement may be performed periodically. The second examining unit 32 investigates the beacon signal received from the other base station apparatus 12 and stores the above-described combination in the storage unit 34 as described above. Here, the 2nd investigation part 32 repeatedly performs said process, without being limited to a predetermined period.

  The selection unit 36 periodically receives received power as communication quality from the first survey unit 30. The selection unit 36 compares the received power with a threshold value, and when the received power is worse than the threshold value, by referring to the table stored in the storage unit 34, the selection unit 36 Select one of the following. The other selected base station apparatus 12 corresponds to the above-mentioned destination base station apparatus, and corresponds to, for example, the second base station apparatus 12b in FIG. Here, the selection unit 36 selects the base station apparatus 12 to which the same SSID as the SSID of the source base station apparatus is assigned.

  When a plurality of base station apparatuses 12 are selected, the selection unit 36 selects the base station apparatus 12 corresponding to the maximum received power from among them. Note that when the received power of the selected base station apparatus 12 is lower than the received power received from the first examining unit 30, the selecting unit 36 determines to cancel the handover process. The selection unit 36 outputs information regarding the selected base station apparatus 12 to the determination unit 38.

  The determination unit 38 receives information regarding the selected base station apparatus 12 from the selection unit 36. The determination unit 38 performs a handover process via the modem unit 22 and the RF unit 20. Specifically, the determination unit 38 disconnects communication with the currently connected first base station apparatus 12a, and then performs connection to the selected base station apparatus 12. Since the connection process is the same as the process described above, a description thereof is omitted here.

  This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of any computer, and in terms of software, it is realized by a program having a communication function loaded in the memory. Describes functional blocks realized by collaboration. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  The operation of the communication system 100 configured as above will be described. FIG. 4 is a flowchart showing a connection procedure in the terminal device 10. Here, it is assumed that the SSID of the predetermined communication carrier is WSV. The 2nd investigation part 32 performs a carrier sense (S10), and acquires SSID and reception power of the other base station apparatus 12 (S12). If the SSID is WSV (Y in S14) and there are two or more base station devices 12 (Y in S16), the selection unit 36 selects the base station device 12 with the maximum received power (S18). On the other hand, if there are not two or more base station apparatuses 12 (N in S16), step 18 is skipped. The determination unit 38 connects to the selected base station apparatus 12 (S20). When the SSID is not WSV (N in S14), the selection unit 36 inquires the user to continue the processing (S22). If the process is to be continued (Y in S24), the process returns to skip 10. If not continued (N in S24), the process is terminated.

  FIG. 5 is a flowchart showing a handover procedure in the terminal device 10. The 2nd investigation part 32 investigates the surrounding base station apparatus 12 (S40). The second investigation unit 32 acquires the SSID and received power of the other base station apparatus 12 (S42). When the received power of the connected base station device 12 acquired by the first investigating unit 30 is smaller than the threshold value (Y in S44), the selection unit 36 has the base station device 12 with the SSID of WSV ( The determination unit 38 instructs the shift (Y in S46) (S48). The modem unit 22 and the RF unit 20 transmit packet signals (S50). If there is an instruction to end (Y of S52), the process ends. On the other hand, when the received power of the connected base station apparatus 12 acquired by the first examining unit 30 is not smaller than the threshold value (N in S44), or the selecting unit 36 has the SSID of WSV. If there is no (N in S46), or if there is no end instruction (N in S52), the process returns to Step 40.

  Next, a modified example will be described. The modification relates to a communication system 100 similar to the embodiment. The terminal device 10 in the modification also selects a base station device to which the same SSID as the SSID of the source base station device is assigned as the destination base station device. The modification differs from the embodiment in the selection process when there are a plurality of base station apparatuses to which the same SSID as the SSID of the source base station apparatus is provided. The terminal device 10 according to the modification holds in advance information related to the installation position for each of the plurality of base station devices. The information regarding the installation position is indicated by, for example, latitude and longitude.

  In addition, the terminal device 10 includes a GPS receiver, and acquires an existing position at a predetermined timing. Furthermore, when the terminal apparatus 10 selects a destination base station apparatus, the terminal apparatus 10 compares the installation position and the existing position with respect to each of the base station apparatuses that are candidates for the destination base station apparatus. The terminal apparatus 10 selects a base station apparatus having an installation position close to the existing position as the movement destination base station apparatus. The communication system 100 according to the modification is of the same type as that in FIG.

  FIG. 6 shows a configuration of the terminal device 10 according to a modification of the present invention. The terminal device 10 includes a GPS receiver 40 in addition to the terminal device 10 shown in FIG. Hereinafter, (3) handover processing will be mainly described, but (1) connection processing may be performed in the same manner. The GPS receiver 40 receives a signal from a GPS satellite (not shown). The GPS receiving unit 40 periodically acquires the location of the terminal device 10 based on the received signal. Since a known technique may be used for positioning the existing position based on the signal from the GPS satellite, the description thereof is omitted here. The existence position is indicated by latitude and longitude. The GPS receiving unit 40 periodically outputs information related to the location to the selection unit 36.

  As in the past, the selection unit 36 refers to the table stored in the storage unit 34 when the received power from the first survey unit 30 has deteriorated below the threshold value, so that other base station devices Select one of twelve. Again, the selection unit 36 selects the base station device 12 to which the same SSID as the SSID of the source base station device is assigned. In addition, when a plurality of base station devices 12 are selected, the selection unit 36 refers to the storage unit 34 to obtain the presence position for each of the plurality of base station devices 12. Again, the location is indicated by the latitude and longitude capital. FIG. 7 shows the data structure of the position information table stored in the storage unit 34. As shown, a base station device name column 200, a latitude column 210, and a longitude column 212 are shown. Here, the latitude and longitude for the base station device 12 indicated in the base station device name column 200 are shown in a latitude column 210 and a longitude column 212, respectively. Returning to FIG.

  The selection unit 36 compares the existence position for each of the plurality of base station apparatuses 12 with the existence position of the terminal apparatus 10, thereby determining the base station apparatus 12 having the nearest position to the existence position of the terminal apparatus 10. select. Specifically, the distance between each base station device 12 and the terminal device 10 is calculated based on the latitude / longitude for each of the plurality of base station devices 12 and the latitude / longitude of the terminal device 10. The selection unit 36 selects the base station apparatus 12 corresponding to the shortest distance. The selection unit 36 outputs information regarding the selected base station apparatus 12 to the determination unit 38.

  According to the embodiment of the present invention, since the base station device to which the same SSID as the source base station device is assigned is selected as the destination base station device, the handover is performed in the wireless LAN system while considering the communication carrier. Processing can be executed. Further, when the presence of surrounding base station apparatuses is investigated in advance and the communication quality deteriorates below the threshold value, the investigation result is used for the handover process, so that the handover process can be executed quickly. If there are multiple base station devices with the same SSID as the source base station device, the base station device closest to the location of the terminal device is selected, so select a base station device installed nearby. it can.

  In addition, since the base station apparatus installed in the vicinity is selected, the communication quality can be improved. In addition, since the packet signal to the predetermined communication device is transmitted via the post-movement base station device after the migration to the destination base station device, the routing table can be changed quickly. In addition, since the routing table is quickly changed, occurrence of erroneous transmission of packet signals after handover can be reduced. In addition, since the occurrence of erroneous transmission of packet signals after handover is reduced, handover processing can be executed at high speed.

  In the above, this invention was demonstrated based on the Example. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

  In the embodiment of the present invention, the first examining unit 30 measures received power as communication quality. However, the present invention is not limited to this. For example, the first examining unit 30 may measure an error rate or EVM (Error Vector Magnitude) as communication quality. At that time, it is said that the communication quality deteriorates as the error rate deteriorates, and the communication quality deteriorates as the EVM increases. According to this modification, the degree of freedom for the communication quality measuring means can be improved.

  In the embodiment of the present invention, the selection unit 36 stores the SSID corresponding to the communication carrier to which the terminal device 10 is permitted to connect. However, the present invention is not limited to this. For example, when roaming is permitted with another communication carrier, the selection unit 36 may store an SSID corresponding to the other communication carrier. According to the present modification, the area where the public wireless LAN service can be corrected can be expanded while selecting the usable base station apparatus 12.

  In the modification of this invention, the memory | storage part 34 has memorize | stored the positional information on the base station apparatus 12 previously. However, the present invention is not limited to this. For example, the beacon signal from the terminal device 10 may include position information of the base station device 12. According to this modification, the storage capacity of the storage unit 34 can be reduced, and a change in the installation position of the base station apparatus 12 can be easily handled.

It is a figure which shows the structure of the communication system which concerns on the Example of this invention. It is a figure which shows the structure of the terminal device of FIG. It is a figure which shows the data structure of the table memorize | stored in the memory | storage part of FIG. It is a flowchart which shows the connection procedure in the terminal device of FIG. It is a flowchart which shows the handover procedure in the terminal device of FIG. It is a figure which shows the structure of the terminal device which concerns on the modification of this invention. It is a figure which shows the data structure of the table of the positional information memorize | stored in the memory | storage part of FIG.

Explanation of symbols

  10 terminal devices, 12 base station devices, 14 networks, 16 servers, 20 RF units, 22 modulation / demodulation units, 24 processing units, 26 control units, 28, 30 first survey units, 32 second survey units, 34 storage units, 36 A selection unit, 38 determination unit, 40 GPS reception unit, 100 communication system.

Claims (4)

A communication unit that performs communication with a base station device to which a service set identifier is assigned;
A first investigation unit that investigates communication quality in the communication unit;
A second investigation unit that examines signals received from other base station devices via the communication unit;
A selection unit that selects one of the other base station devices that have investigated the signal in the second survey unit when the quality of the communication surveyed in the first survey unit is worse than a threshold;
A control unit that instructs the communication unit to shift to another base station device selected by the selection unit;
The said selection part selects the other base station apparatus provided with the same service set identifier as the base station apparatus which is performing communication in the said communication part, The terminal device characterized by the above-mentioned. A first acquisition unit for acquiring the location of the terminal device;
A second acquisition unit that acquires an existing position of another base station device that has investigated the signal in the second investigation unit;
Among the other base station devices to which the same service set identifier as that of the base station device performing communication in the communication unit is assigned, the selection unit acquires the presence position acquired in the second acquisition unit, The terminal device according to claim 1, wherein another base station device close to the location acquired by the first acquisition unit is selected.   The said communication part transmits the signal to a predetermined | prescribed communication apparatus via the said other base station apparatus, after transfering to the other base station apparatus selected in the said selection part. The terminal device according to 2. Performing communication with a base station apparatus to which a service set identifier is assigned;
Investigating communication quality;
Investigating signals received from other base station devices;
Selecting one of the other base station devices that investigated the signal when the quality of the investigated communication deteriorated below the threshold;
Performing a transition to another selected base station device,
The handover processing method characterized in that the selecting step selects another base station apparatus to which the same service set identifier as that of the base station apparatus that is performing communication is assigned.

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