JP4806336B2 - Wireless communication terminal and wireless communication method - Google Patents

Description

  The present invention relates to a wireless communication terminal and a wireless communication method used in a mobile communication system that employs communication quality (QoS) guarantees.

  Conventionally, in a mobile communication system using a CDMA system, a plurality of systems are generally adopted and introduced as a data transmission system. For example, in cdma2000, 1xEV-DO Rev. 0 (hereinafter simply referred to as “Rev. 0”), and Rev. 0 1xEV-DO Rev., which is a newer version than 0. A (hereinafter simply referred to as “Rev. A”) is defined.

  Rev. 0 uses a packet switching system, and realizes a data rate of up to 153.6 kbps and up to about 2.4 Mbps in the down direction. Rev. In a radio base station that supports 0, a radio communication terminal that has a good radio wave condition and can be expected to have a high throughput assigns resources in preference to a radio communication terminal that has a bad radio wave condition.

  Rev. A. Rev. 0 is increased, and a maximum data rate of about 1.8 Mbps in the upstream direction and about 3.0 Mbps in the downstream direction is realized. Rev. A. Rev. Compared with 0, it is characterized in that communication quality (QoS) guarantee is adopted in addition to higher data rate.

  Rev. In the wireless base station supporting A, resources are allocated according to the type of application executed by the wireless communication terminal as well as the radio wave state of the wireless communication terminal. Rev. In the radio base station that supports A, the rate of the radio communication performed with the radio communication terminal is kept constant using the rate adjustment buffer.

  For example, when an e-mail application is executed on a wireless communication terminal having a good radio wave condition and a VoIP application is executed on a wireless communication terminal having a bad radio wave condition, Rev. A radio base station that supports A assigns resources in preference to a radio communication terminal with a poor radio wave condition, rather than a radio communication terminal with a good radio wave condition.

On the other hand, a technique has been proposed in which QoS necessary for executing a VoIP application is notified from a calling terminal to a relay device on a transmission path, and the relay device on the transmission path guarantees QoS (see Patent Document 1). .
JP 2003-258879 A

  However, in the mobile communication system as described above, for example, devices such as wireless base stations that support the new method are sequentially installed, so that communication methods that employ QoS guarantees in all communication areas, for example, Rev. mentioned above. The fact is that A is not always supported.

  Therefore, Rev. 0, a wireless communication terminal that performs wireless communication according to 0, Rev. Communication may be performed with a wireless communication terminal that performs wireless communication according to A. In this case, resources allocated for QoS guarantee (for example, the buffer capacity of the rate adjustment buffer of the radio base station) are wasted. As resources are wasted, the number of accommodated terminals using QoS per base station is reduced.

  In view of the above problems, the present invention is a wireless communication system that can avoid wasting resources allocated to guarantee the communication quality of the terminal itself when the communication quality (QoS) of the communication partner terminal is not guaranteed. An object is to provide a communication terminal and a wireless communication method.

  In order to achieve the above object, a first feature of the present invention is that a communication partner terminal (wireless communication terminal 1) and a first base station (wireless base station 3) that is a connection destination base station of the communication partner terminal. A determination unit (QoS determination unit 272) that determines whether or not the communication quality of the first wireless communication executed between them is guaranteed, and when it is determined that the communication quality of the first wireless communication is not guaranteed Without requesting the second base station to guarantee the communication quality of the second wireless communication performed with the second base station (wireless base station 4) that is the base station to which it is connected, the communication partner The gist is that the wireless communication terminal includes a communication control unit (SIP processing unit 274, data communication control unit 275) which controls to start communication with the terminal.

  According to such a feature, if the communication quality (QoS) of the first wireless communication is not guaranteed, the communication control unit can ensure the second wireless communication even if the communication quality of the second wireless communication can be guaranteed. Do not dare to execute communication quality assurance requirements.

  Since the second base station is not requested to guarantee the communication quality of the second wireless communication, the resources of the second base station assigned to guarantee the communication quality of the second wireless communication can be assigned to other wireless communication terminals. . As a result, the number of accommodated terminals using QoS per base station does not decrease.

  A second feature of the present invention relates to the first feature of the present invention, and is an SMS (registration request message) requesting registration in a call control server (SIP server 7) that performs call control with the communication partner terminal. ) Is received from the second base station (SMS processing unit 271), and the registration request message is executed between the first terminal and the first radio base station. Communication quality information (QoSα) regarding whether or not the communication quality of wireless communication is guaranteed, and the determination unit determines whether or not the communication quality of the first wireless communication is guaranteed based on the communication quality information. The gist is to determine.

  The third feature of the present invention is whether or not the communication quality of the first wireless communication executed between the communication partner terminal and the first base station that is the connection destination base station of the communication partner terminal is guaranteed. The second wireless communication executed between the determining step (step S113) and the second base station that is the connection destination base station when it is determined that the communication quality of the first wireless communication is not guaranteed. A wireless communication method comprising the steps of controlling to start communication with the communication partner terminal without requesting the second base station to guarantee the communication quality of communication (step S115 to step S118). And

  According to a fourth aspect of the present invention, in accordance with the third aspect of the present invention, a registration request message for requesting registration in a call control server that performs call control with the communication partner terminal is sent to the second base station. (Step S108), wherein the registration request message guarantees communication quality of the first wireless communication executed between the communication partner terminal and the first wireless base station. The determination step includes determining whether or not the communication quality of the first wireless communication is guaranteed based on the communication quality information.

  According to the present invention, when the communication quality (QoS) of a communication partner terminal is not guaranteed, it is possible to avoid wasting resources allocated to guarantee the communication quality of the terminal itself and the wireless communication terminal A communication method can be provided.

  Next, an embodiment of the present invention will be described with reference to the drawings. In the description of the drawings in the following embodiments, the same or similar parts are denoted by the same or similar reference numerals.

(1) Overall schematic configuration of mobile communication system:
FIG. 1 shows an overall schematic configuration of a mobile communication system including wireless communication terminals 1 and 2 according to the present embodiment. This mobile communication system is a so-called third generation mobile communication system based on cdma2000.

  The mobile communication system includes radio communication terminals 1 and 2, radio base stations 3 and 4, a packet switching network 5, a circuit switching network 6, a SIP (Session Initiation Protocol) server 7, an SMS (Short Message Service). ) Server 8.

  The wireless communication terminals 1 and 2 are connected to Rev. 0 and Rev. A wireless communication terminal supporting A. The wireless communication terminals 1 and 2 have an IP-based voice call (IP phone) function and an IP-based TV phone (IP-TV phone) function in addition to a circuit-switched voice call function.

  The wireless communication terminal 1 connects to the wireless base station 3 and executes wireless communication with the wireless base station 3. The wireless communication terminal 2 is connected to the wireless base station 4 and performs wireless communication with the wireless base station 4. In the present embodiment, it is assumed that transmission is performed from the wireless communication terminal 1 to the wireless communication terminal 2.

  The radio base station 3 is connected to the Rev. It is a radio base station that supports only 0 and does not have a QoS guarantee function. The radio base station 4 assigns resources to radio communication terminals that have good radio wave conditions and that can be expected to have high throughput, with priority over radio communication terminals that have poor radio wave conditions.

  The radio base station 4 is the Rev. A radio base station that supports A and has a QoS guarantee function. Specifically, when the wireless communication terminal 2 executes a real-time type application, the wireless base station 4 uses the rate adjustment buffer to keep the data rate of wireless communication performed with the wireless communication terminal 1 constant. To maintain.

  Furthermore, the radio base station 4 assigns a band with priority over the radio communication terminal 2 over other radio communication terminals. Specifically, in the downlink direction, the radio base station 4 assigns time slots in preference to the radio communication terminal 2 over other radio communication terminals. In the uplink direction, the radio base station 4 increases the transmission power of the radio communication terminal 2 over other radio communication terminals.

  The packet switching network 5 is a communication network in which communication is performed by packet (IP packet) exchange. In the present embodiment, the packet switching network 5 is configured by the EV-DO network. The packet switching network 5 requires address registration in order to perform call control using SIP (RFC3261 or the like).

  The circuit switching network 6 is a communication network in which communication is performed by circuit switching. In the present embodiment, the circuit switching network 6 is configured by a 1x network. The circuit switching network 6 does not require address registration when the wireless communication terminals 1 and 2 perform communication.

  The SIP server 7 is connected to the packet switching network 5 and the SMS server 8 and executes call control of the wireless communication terminals 1 and 2 according to SIP. Note that the SIP server 7 may be connected to the SMS server 8 via a communication network.

  The SMS server 8 is connected to the circuit switching network 6 and the SIP server 7 and transmits an SMS (registration request message) requesting address registration to the SMS server 8 to a wireless communication terminal (for example, the wireless communication terminal 2).

(2) Configuration of wireless communication terminal:
Next, with reference to FIG.2 and FIG.3, the structure of the radio | wireless communication terminals 1 and 2 which concern on this embodiment is demonstrated.

(2.1) Schematic configuration of wireless communication terminal:
FIG. 2 is a functional block configuration diagram of the wireless communication terminal 2. Since the wireless communication terminal 1 has the same configuration as the wireless communication terminal 2, the description of the configuration of the wireless communication terminal 1 is omitted.

  Hereinafter, portions related to the present invention will be mainly described. Therefore, it should be noted that the wireless communication terminal 2 may include a logical block (such as a power supply unit) that is not shown in the drawing or that is not described, which is essential for realizing the function as the device.

  As illustrated in FIG. 2, the wireless communication terminal 2 includes an antenna 21, a wireless communication unit 22, an operation unit 23, a microphone 24, a speaker 25, a display unit 26, a control unit 27, and a storage unit 28.

  The radio communication unit 22 transmits / receives a radio signal according to CDMA to / from the radio base station 4 via the antenna 21. The wireless communication unit 22 has a 1 × wireless communication function for performing wireless communication by a circuit switching method and an EV-DO wireless communication function for performing wireless communication by a packet switching method. In addition, the wireless communication unit 22 performs conversion between the wireless signal and the baseband signal, and transmits and receives the baseband signal to and from the control unit 27.

  The operation unit 23 is configured by a numeric keypad, function keys, and the like, and is an interface used for inputting user operation details.

  The microphone 24 collects sound and inputs a sound signal to the control unit 27 based on the collected sound.

  The speaker 25 outputs sound based on the sound signal acquired from the control unit 27.

  The display unit 26 displays image content received via the wireless communication unit 22 and the control unit 27, and displays operation details (such as input telephone number and address).

  The control unit 27 controls various functions provided in the wireless communication terminal 2. More detailed functional blocks of the control unit 27 will be described later.

  The storage unit 28 stores various information used for control and the like in the wireless communication terminal 2. More detailed functional blocks of the storage unit 28 will be described later.

(2.2) Detailed configuration of control unit and storage unit:
FIG. 3 is a functional block configuration diagram showing detailed configurations of the control unit 27 and the storage unit 28.

  As shown in FIG. 3, the control unit 27 includes an SMS processing unit 271, a QoS determination unit 272, a QoS establishment unit 273, a SIP processing unit 274, and a data communication control unit 275. The storage unit 28 includes a QoS information storage unit 281.

  The SMS processing unit 271 receives an SMS (registration request message) requesting address registration with the SIP server 7 from the SMS server 8 via the radio base station 4. Based on the SMS (registration request message), the SMS processing unit 271 acquires QoS information indicating whether or not QoS is guaranteed for wireless communication executed between the wireless communication terminal 1 and the wireless base station 3 or the type of QoS. The QoS type means, for example, a data rate value.

  The QoS determination unit 272 determines whether or not there is a QoS guarantee for wireless communication performed between the wireless communication terminal 1 and the wireless base station 3 based on the QoS information acquired by the SMS processing unit 271.

  The QoS establishment unit 273 executes a QoS establishment process with the radio base station 4. Further, the QoS establishment unit 273 determines whether or not to request a QoS guarantee from the radio base station 4 according to the determination result of the QoS determination unit 272.

  The SIP processing unit 274 performs call control for performing a voice call or the like with the wireless communication terminal 1 in accordance with SIP. Specifically, the SIP processing unit 274 establishes, manages, and disconnects a session with the wireless communication terminal 1 by transmitting / receiving a SIP message to / from the SIP server 7.

  The data communication control unit 275 executes data communication (packet communication) with the wireless communication terminal 1 in accordance with a predetermined protocol (for example, RTP (Realtime Transport Protocol)).

  The QoS information storage unit 281 stores “NULL” as an initial value, and stores information (ProfileID) indicating the type of QoS when QoS guarantee is established by the QoS establishment unit 273.

(3) Operation of mobile communication system:
Next, operations of the mobile communication system according to the present embodiment described above will be described with reference to FIGS.

(3.1) Overall operation of mobile communication system:
FIG. 4 is a sequence diagram showing an operation sequence of the entire mobile communication system according to the present embodiment.

  In step S101, the wireless communication terminal 1 sets an initial value “NULL” for the QoS information (QoSα).

  In step S102, the wireless communication terminal 1 accepts a call operation for the wireless communication terminal 2 from the user.

  In step S <b> 103, the wireless communication terminal 1 establishes a connection with the wireless base station 3.

  In step S <b> 104, the wireless communication terminal 1 transmits an “REGISTER” message to the SIP server 7 via the wireless base station 3, thereby performing address registration (login) to the SIP server 7.

  In step S <b> 105, the wireless communication terminal 1 executes a QoS establishment process with the wireless base station 3. When the QoS establishment process is successful, the wireless communication terminal 1 acquires the ProfileID from the wireless base station 3, and sets the acquired ProfileID in the QoS information (QoSα).

  Here, the radio base station 3 is Rev. Since A is not supported, the wireless communication terminal 1 cannot establish a QoS guarantee. For this reason, the initial value “NULL” is maintained in the QoS information (QoSα).

  In step S <b> 106, the wireless communication terminal 1 transmits an “INVITE” message requesting establishment of a session with the wireless communication terminal 2 to the SIP server 7 via the wireless base station 3. In the “INVITE” message, QoS information (QoSα) is described.

  Specifically, QoS information (QoSα) is described in the “INVITE” message in a format according to SDP (Session Description Protocol) (RFC 2327). Alternatively, QoS information (QoSα) is described in a field that defines QoS in IP (Internet Protocol).

  In step S <b> 107, the SIP server 7 transmits an incoming call notification indicating that the wireless communication terminal 2 has received an incoming call to the SMS server 8. In the incoming notification, QoS information (QoSα) in the “INVITE” message received by the SIP server 7 in step S106 is described.

  In step S <b> 108, the SMS server 8 transmits an SMS (registration request message) requesting address registration (login) to the SIP server 7 to the wireless communication terminal 2 via the wireless base station 4.

  In the SMS (registration request message), QoS information (QoSα) in the incoming call notification received by the SMS server 8 in step S107 is described. The wireless communication terminal 2 stores the QoS information (QoSα) in the SMS (registration request message) received in step S108.

  In step S <b> 109, the wireless communication terminal 2 transmits a response message (SMS Ack), which is a permission response to the SMS (registration request message) received in step S <b> 108, to the SMS server 8 via the wireless base station 4.

  In step S <b> 110, the SMS server 8 transmits an incoming call result notification for notifying that the registration request is permitted by the wireless communication terminal 2 to the SIP server 7.

  In step S <b> 111, the wireless communication terminal 2 establishes a connection with the wireless base station 4.

  In step S112, the wireless communication terminal 2 transmits a “REGISTER” message to the SIP server 7 via the wireless base station 4, and performs address registration (login).

  In step S113, the wireless communication terminal 2 determines whether the QoS guarantee of the wireless communication terminal 1 is established. Specifically, the wireless communication terminal 2 determines whether QoS information (QoSα) is described in the SMS (registration request message) received in step S108.

  When the QoS information (QoSα) is described in the SMS (registration request message), the wireless communication terminal 2 determines whether the QoS information (QoSα) is the initial value “NULL”. When the QoS information (QoSα) is not the initial value “NULL”, the wireless communication terminal 2 determines that the QoS guarantee of the wireless communication terminal 1 has been established, and proceeds to the process of step S114.

  In step S114, the wireless communication terminal 2 executes a QoS establishment process with the wireless base station 4. Here, since the QoS guarantee of the wireless communication terminal 1 is not established, the process of step S114 is omitted.

  In step S 115, the SIP server 7 transmits an “INVITE” message to the wireless communication terminal 2 via the wireless base station 4.

  In step S 116, the wireless communication terminal 2 transmits a “200 OK” message to the SIP server 7 via the wireless base station 4 in response to the “INVITE” message received in step S 115.

  In step S 117, the SIP server 7 transmits a “200 OK” message to the wireless communication terminal 1 via the wireless base station 3.

  In step S118, a session is set between the wireless communication terminal 1 and the wireless communication terminal 2, and communication (voice call) is started between the wireless communication terminal 1 and the wireless communication terminal 2.

(3.2) Details of QoS establishment process:
Next, the QoS establishment process described above will be described. FIG. 5 is a sequence diagram showing a detailed operation of the wireless communication terminal 1 when the QoS establishment is successful.

  In step S1001, the radio communication terminal 1 specifies at least one Profile ID and requests the radio base station 3 to establish QoS guarantee.

  In step S1002, the radio base station 3 designates one Profile ID and notifies the radio communication terminal 1 of the guaranteed QoS.

  In step S <b> 1003, the wireless communication terminal 1 and the wireless base station 3 validate the QoS guarantee, so that the QoS guarantee is established between the wireless communication terminal 1 and the wireless base station 3.

(4) Action and effect:
As described above, even if the wireless communication terminal 2 can establish QoS guarantee with the wireless base station 4, if the QoS of the wireless communication terminal 1 is not guaranteed, Do not establish QoS guarantees between

  Since the wireless communication terminal 2 does not establish the QoS guarantee with the wireless base station 4, resources allocated to guarantee the QoS of the wireless communication terminal 2 are not wasted. Specifically, the rate adjustment buffer of the radio base station 4 assigned to the radio communication terminal 2 can be assigned to another radio communication terminal.

  Further, in the downlink direction, a time slot that is preferentially assigned to the wireless communication terminal 2 can be assigned to another wireless communication terminal. Furthermore, since it is not necessary to increase the transmission power of the radio communication terminal 1 in the uplink direction, the power consumption of the radio communication terminal 1 can be saved.

  Furthermore, according to the present embodiment, the QoS information (QoSα) of the wireless communication terminal 1 is described in the SMS (registration request message) transmitted by the SMS server 8. The wireless communication terminal 2 determines whether the wireless communication terminal 1 has a QoS guarantee based on the QoS information (QoSα) described in the SMS (registration request message).

  That is, since the sequence according to the existing protocol is used, it is possible to determine whether or not the wireless communication terminal 1 has the QoS guarantee without significantly changing the existing protocol.

[Example of change]
In the above-described embodiment, the configuration in which the wireless communication terminal 1 on the transmission side transmits QoS information (QoSα) has been described. In this modification, a configuration in which the SIP server 7 acquires QoS information (QoSα) without the wireless communication terminal 1 transmitting QoS information (QoSα) will be described. In the present modification example, differences from the above-described embodiment will be described, and redundant description will be omitted.

(1) Configuration of SIP server:
FIG. 6 is a functional block configuration diagram showing the configuration of the SIP server 7 according to this modification.

  As illustrated in FIG. 6, the SIP server 7 includes a SIP processing unit 71, a QoS information acquisition unit 72, an incoming call notification unit 73, and a communication I / F unit 74.

  The SIP processing unit 71 establishes, manages, and disconnects a session between the wireless communication terminal 1 and the wireless communication terminal 2 according to SIP.

  When receiving the “INVITE” message from the wireless communication terminal 1 via the wireless base station 3, the QoS information acquisition unit 72 acquires the QoS information (QoSα) of the wireless communication terminal 1 from the wireless base station 3.

  When receiving an “INVITE” message from the wireless communication terminal 1 via the wireless base station 3, the incoming notification unit 73 sends an incoming notification including the QoS information (QoSα) acquired by the QoS information acquisition unit 72 to the SMS server 8. Send.

  The communication I / F unit 74 functions as an interface with the packet switching network 5 and the SMS server 8.

(2) Operation of mobile communication system:
FIG. 7 is a sequence diagram showing an operation sequence of the entire mobile communication system including the SIP server 7 according to this modification. Here, an operation different from the operation described in FIG. 4 will be mainly described.

  In steps S201 to S206, operations similar to those in steps S101 to S106 in FIG. 4 are executed.

  In step S207, the SIP server 7 requests the wireless base station 3 to notify the QoS information (QoSα) of the wireless communication terminal 1.

  In step S208, the radio base station 3 notifies the QoS information (QoSα) of the radio communication terminal 1 to the SIP server 7.

  In step S209, the SIP server 7 transmits an incoming call notification including the QoS information (QoSα) acquired in step S208 to the SMS server 8.

  In steps S210 to S220, operations similar to those in steps S108 to S118 in FIG. 4 are executed.

(3) Action / effect:
According to this modified example, since the SIP server 7 acquires the QoS information (QoSα) of the wireless communication terminal 1 from the wireless base station 3, the wireless communication terminal 1 describes the QoS information (QoSα) in the “INVITE” message. There is no need. Therefore, it is not necessary to change the configuration of the wireless communication terminal 1 on the transmission side. A normal wireless communication terminal supporting A can be used as the wireless communication terminal 1 on the transmission side.

[Other Embodiments]
Although the present invention has been described by using the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the embodiment shown in FIGS. 1 and 3, both the radio communication terminal 1 and the radio communication terminal 2 are both Rev. A and Rev. 0, but the wireless communication terminal 1 does not necessarily have Rev. A may not be supported. At least one of the wireless communication terminal 1 and the wireless base station 3 is connected to Rev. If it does not support A, Rev. This is because wireless communication according to 0 is performed.

  In the above-described embodiment, the Profile ID is transmitted as the QoS information to the wireless communication terminal 2 on the incoming side. However, the present invention is not limited to the case of transmitting the Profile ID, and information indicating whether or not QoS is guaranteed may be transmitted.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

It is a figure which shows the whole schematic structure of the mobile communication system which concerns on embodiment of this invention. It is a functional block block diagram which shows the structure of the radio | wireless communication terminal which concerns on embodiment of this invention. It is a functional block block diagram which shows the detailed structure of the control part of FIG. 2, and a memory | storage part. It is a sequence diagram which shows the operation | movement sequence of the whole mobile communication system which concerns on embodiment of this invention. It is a sequence diagram which shows the QoS establishment process sequence performed between the radio | wireless communication terminal and radio | wireless base station which concern on embodiment of this invention. It is a functional block block diagram which shows the structure of the SIP server (call control server) which concerns on the example of a change of embodiment of this invention. It is a sequence diagram which shows the operation | movement sequence of the whole mobile communication system which concerns on the example of a change of embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2 ... Wireless communication terminal, 3, 4 ... Wireless base station, 5 ... Packet switching network, 6 ... Circuit switching network, 7 ... SIP server, 8 ... SMS server, 21 ... Antenna, 22 ... Wireless communication part, 23 ... Operation unit, 24 ... microphone, 25 ... speaker, 26 ... display unit, 27 ... control unit, 28 ... storage unit, 71 ... SIP processing unit, 72 ... QoS information acquisition unit, 73 ... incoming call notification unit, 74 ... communication I / F part, 271 ... SMS processing part, 272 ... QoS determination part, 273 ... QoS establishment part, 274 ... SIP processing part, 275 ... data communication control part, 281 ... QoS information storage part

Claims (4)

A determination unit that determines whether or not the communication quality of the first wireless communication executed between the communication partner terminal and the first base station that is a connection destination base station of the communication partner terminal is guaranteed;
When it is determined that the communication quality of the first wireless communication is not guaranteed, the communication quality of the second wireless communication executed with the second base station that is the connection destination base station is guaranteed. A wireless communication terminal comprising: a communication control unit that controls to start communication with the communication partner terminal without requesting the two base stations. A reception unit that receives from the second base station a registration request message for requesting registration to a call control server that performs call control with the communication counterpart terminal;
The registration request message includes communication quality information regarding whether or not the communication quality of the first wireless communication executed between the communication partner terminal and the first wireless base station is guaranteed,
The wireless communication terminal according to claim 1, wherein the determination unit determines whether communication quality of the first wireless communication is guaranteed based on the communication quality information. Determining whether or not the communication quality of the first wireless communication executed between the communication partner terminal and the first base station which is a connection destination base station of the communication partner terminal is guaranteed;
When it is determined that the communication quality of the first wireless communication is not guaranteed, the communication quality of the second wireless communication executed with the second base station that is the connection destination base station is guaranteed. And a step of controlling to start communication with the communication partner terminal without requesting the base station. Receiving a registration request message for requesting registration to a call control server that performs call control with the communication partner terminal from the second base station;
The registration request message includes communication quality information regarding whether or not the communication quality of the first wireless communication executed between the communication partner terminal and the first wireless base station is guaranteed,
The wireless communication method according to claim 3, wherein in the determining step, it is determined whether or not the communication quality of the first wireless communication is guaranteed based on the communication quality information.