JP2011182250A - User equipment, communication system, and communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable efficient transition of a communication network in packet communication and to improve a response to a user in the packet communication. <P>SOLUTION: User equipment communicatable in first and second communication networks includes a determiner for determining whether or not transition to the second communication network is necessary upon packet transmission, and a communication controller for transmitting a radio connection request having a transition unnecessary flag set therein to the first communication network when transition to the second communication network is unnecessary. The determiner may determine the necessity or non-necessity of transition to the second communication network on the basis of at least one of an application type, a data quantity, and the transition unnecessary flag set for incoming notification. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mobile device, a communication system, and a communication method.

  Currently, in a third generation mobile communication system such as UMTS (Universal Mobile Telecommunications System), packet communication of several hundred kbps to several Mbps is possible. On the other hand, LTE (Long Term Evolution), which is being studied by 3GPP (3rd Generation Partnership Project), is a technology that enables high-speed communication of 100 Mbps downlink and 50 Mbps uplink.

  In the UMTS network, circuit switching such as voice and packet switching such as data are provided, and in the LTE network, packet switching such as data is provided. When the mobile device transmits a packet, the mobile device first transmits a wireless connection request to the access network in which the mobile device is located. A message called RRC Connection Request is used for a wireless connection request from the mobile device to the LTE access network or the UMTS access network (see Non-Patent Document 1). When the wireless connection is established, the mobile device transmits a packet transmission request to the core network, and the connection with the core network is established. Thereafter, the packet is transmitted to the server.

TS 25.331

  As described above, when a mobile station located in the UMTS network transmits a packet, first, the mobile station transmits a wireless connection request to a radio network controller (RNC) of the UMTS network. When a wireless connection is established between the mobile device and the RNC in accordance with this wireless connection request, packet communication is performed on the UMTS network. In this case, even if the mobile device can perform high-speed packet communication on the LTE network, communication on the UMTS network is performed unless a transition from RNC to LTE is required.

  In such a case, high-speed packet communication can be performed by shifting the mobile device to the LTE network in response to the wireless connection request. However, there are applications with a small amount of data, such as transmission / reception of mail and transmission / reception of simple information. Even in the case of packet transmission by such an application with a small amount of data, when the transition to the LTE network is made uniformly, a delay in connection time due to detection of a base station, establishment of synchronization, etc. occurs. In addition, a large number of control signals are transmitted and received with the transition to the LTE network. As a result, the response to the user may be delayed. Therefore, in the case of an application with a small amount of data, it is more efficient to continue communication through the UMTS network.

  An object of the present invention is to enable efficient transition of a communication network in packet communication and improve a response to a user in packet communication.

The mobile device of the present invention is
A mobile device capable of communicating with a first communication network and a second communication network,
A determination unit that determines whether or not a transition to the second communication network is necessary when transmitting a packet; and if a transition to the second communication network is unnecessary, a wireless connection request in which a transition unnecessary flag is set is transmitted to the first communication network A communication control unit to transmit;
It is characterized by having.

The communication system of the present invention includes:
A communication system having a mobile station capable of communicating in a first communication network and a second communication network, and a radio network controller,
The mobile device is
A determination unit that determines whether or not a transition to the second communication network is necessary when transmitting a packet; and if a transition to the second communication network is unnecessary, a wireless connection request in which a transition unnecessary flag is set is transmitted to the first communication network A communication control unit to transmit;
Have
The wireless network controller is
A receiving unit that receives a wireless connection request from the mobile device; and a wireless connection establishment unit that establishes a wireless connection with the mobile device in a first communication network when a transition unnecessary flag is set in the wireless connection request;
It is characterized by having.

The communication method of the present invention includes:
A communication method in a mobile device capable of communicating in a first communication network and a second communication network,
A step of determining whether or not a transition to the second communication network is necessary when a packet is transmitted; and if a transition to the second communication network is unnecessary, a wireless connection request in which a transition unnecessary flag is set is transmitted to the first communication network Step to do;
It is characterized by having.

  According to the embodiment of the present invention, an efficient communication network transition in packet communication becomes possible, and the response to the user in packet communication can be improved.

Schematic diagram of a communication system according to an embodiment of the present invention (embodiment instructing transition to an LTE network) FIG. 1 is a block diagram of a communication system according to an embodiment of the present invention (an embodiment instructing a transition to an LTE network). FIG. 3 is a sequence diagram of a communication method at the time of outgoing calls according to an embodiment of the present invention (an embodiment instructing a transition to an LTE network). FIG. 7 is a sequence diagram of a communication method at the time of an incoming call according to an embodiment of the present invention (embodiment instructing transition to the LTE network) Schematic diagram of a communication system according to an embodiment of the present invention (modified example for determining whether or not a transition to an LTE network is necessary) FIG. 1 is a block diagram of a communication system according to an embodiment of the present invention. FIG. 9 is a sequence diagram of a communication method at the time of outgoing calls according to an embodiment of the present invention (a modified example for determining whether or not transition to the LTE network is necessary). FIG. 10 is a sequence diagram of a communication method at the time of an incoming call according to an embodiment of the present invention (a modified example for determining whether or not transition to the LTE network is necessary)

  In an embodiment of the present invention, a mobile device that can communicate with a plurality of radio access networks (RATs) to which different radio access technologies are applied is used. For example, the mobile device can communicate with a UMTS network and an LTE network. Hereinafter, embodiments of the present invention will be described using a UMTS network as a low-speed packet communication network and an LTE network as a high-speed packet communication network. However, the present invention is not limited to a CDMA2000 (Code Division Multiple Access 2000) network, GSM (Global The present invention is also applicable to other communication networks such as a System for Mobile Communications (GPS) network and a GPRS (General Packet Radio Service) network.

  In the embodiment of the present invention, when a mobile station located in the UMTS network transmits a packet, first, a radio connection request (RRC Connection Request) is transmitted to a radio network controller (RNC) of the UMTS network. The RNC receives the wireless connection request and determines whether it is packet transmission or voice transmission from the message content of the wireless connection request. When the wireless connection request is a connection request based on packet transmission, the RNC instructs a transition to the LTE network if the LTE network is an area. In this way, even when the mobile device is located in the UMTS network, high-speed packet communication over the LTE network becomes possible.

  However, even when a packet is transmitted by an application with a small amount of data, when the transition to the LTE network is made uniformly, a delay in connection time due to detection of a base station, establishment of synchronization, etc. occurs. In addition, a large number of control signals are transmitted and received with the transition to the LTE network. As a result, the response to the user may be delayed.

  For this reason, the mobile device determines whether or not it is necessary to transition to the LTE network at the time of packet transmission, and when the transition to the LTE network is unnecessary, communication is continued in the UMTS network. Specifically, when a mobile station located in the UMTS network transmits a packet, first, it is determined whether or not it is necessary to transition to the LTE network. For example, in the case of an application with a small amount of data, it is determined that the transition to the LTE network is unnecessary. When the transition to the LTE network is unnecessary, the mobile station sets an LTE transition unnecessary flag indicating that the transition to the LTE network is unnecessary in the wireless connection request, and transmits the wireless connection request to the RNC of the UMTS network. .

  When the LTE transition unnecessary flag is set in the wireless connection request, the RNC of the UMTS network establishes a wireless connection in the UMTS network without instructing a transition to the LTE network. In this way, the mobile device can continue communication over the UMTS network.

  Further, when a mobile station located in the UMTS network determines that a transition to the LTE network is necessary, the mobile station does not set the LTE transition unnecessary flag in the wireless connection request, and sends the wireless connection request to the UMTS network. To the RNC.

  When the LTE transition unnecessary flag is not set in the wireless connection request, the RNC of the UMTS network instructs transition to the LTE network if the LTE network exists. In this way, high-speed packet communication over the LTE network becomes possible.

  Hereinafter, an embodiment in which the RNC of the UMTS network instructs the mobile device to make a transition to the LTE network will be described, and as a modified example, an example will be described in which the mobile device determines whether or not to make a transition to the LTE network when transmitting a packet.

<Overall configuration of communication system>
FIG. 1 shows a schematic diagram of a communication system according to an embodiment of the present invention. The communication system includes a plurality of radio access networks to which different radio access technologies are applied, and a mobile device that can communicate with the plurality of radio access networks.

  For example, the radio access network includes a UMTS network and an LTE network. The UMTS network includes a UMTS access network and a UMTS core network. In the UMTS network, packet communication of several hundred kbps to several Mbps is possible. The LTE network includes an LTE access network and an LTE core network, and the LTE network can perform packet communication of several tens to several hundreds of Mbps. The UMTS access network includes a device for managing radio resources called RNC and a base station called BTS (Base Transceiver Station). The LTE access network includes a base station called eNB (eNode-B). In the LTE access network, the eNB manages radio resources.

  The mobile device communicates with the server via the UMTS access network and the UMTS core network, or via the LTE access network and the LTE core network. When a mobile device located in the UMTS network transmits a packet to the server, the mobile device transmits a radio connection request (RRC Connection Request) to the RNC of the UMTS access network.

  The RNC of the UMTS access network determines whether it is packet transmission or voice transmission from the message content of the wireless connection request. If the wireless connection request is a connection request by packet transmission, the RNC transmits an LTE transition instruction that instructs a transition to the LTE network if the LTE network exists.

  Upon receiving the LTE transition instruction, the mobile device releases the wireless connection with the UMTS network, detects a base station necessary for communication in the LTE network, establishes synchronization, etc., and wirelessly connects to the eNB of the LTE network Send a request (RRC Connection Request). In this way, the mobile device communicates with the server via the LTE network.

  FIG. 2 shows a block diagram of a communication system according to an embodiment of the present invention. The communication system includes a user equipment (UE) 10, an LTE access network 20, an LTE core network 21, a UMTS access network 30, a UMTS core network 31, a server 401, and an SMS (Short Messaging Service) center. 403.

  The mobile device 10 includes a packet transmission request unit 101, a within-range RAT determination unit 105, an LTE packet communication control unit 107, a UMTS packet communication control unit 109, and an SMS processing unit 111.

  The packet transmission request unit 101 generates a packet transmission request when an application executed on the mobile device 10 needs packet communication.

  The located RAT judging unit 105 judges the radio access network in which the mobile device is located, and transfers the packet transmission request to the LTE packet communication control unit 107 or the UMTS packet communication control unit 109. For example, when the mobile station is in the LTE network, the packet transmission request is transferred to the LTE packet communication control unit 107, and when the mobile station is in the UMTS network, the packet transmission request is transferred to the UMTS packet communication control. The data is transferred to the unit 109.

  When receiving the packet transmission request, the LTE packet communication control unit 107 transmits a wireless connection request to the eNB of the LTE access network to establish a wireless connection. Thereafter, a packet transmission request is transmitted to the exchange of the LTE core network via the LTE access network.

  When receiving the packet transmission request, the UMTS packet communication control unit 109 transmits a wireless connection request to the RNC of the UMTS access network. In the wireless connection request, a packet transmission flag indicating packet transmission is set. According to 3GPP TS 25.311, it is possible to set whether packet transmission or voice transmission is set in the establishment cause of the RRC connection request. In response to the wireless connection request in which the packet transmission flag is set, the UMTS packet communication control unit 109 receives an LTE transition instruction from the RNC. The UMTS packet communication control unit 109 transfers the packet transmission request to the LTE packet communication control unit 107 in accordance with the LTE transition instruction. Thereafter, as described above, the LTE packet communication control unit 107 establishes a wireless connection.

  The SMS processing unit 111 analyzes the SMS incoming notification. The SMS incoming notification is used to indicate that an incoming mail such as a mail addressed to the mobile device 10 has been received on the server 401. In the SMS incoming notification, information indicating to which application on the mobile device 10 the incoming notification has been received is indicated. The SMS processing unit 111 notifies the application on the mobile device 10 that there is an incoming call. Note that SMS is an example of one means of incoming call notification, and other incoming call notification means may be used.

  The LTE access network 20 includes a transmission / reception unit 201 and a wireless connection establishment unit 203. These functional units are mainly implemented in the eNB of the LTE access network.

  The wireless connection request transmitted from the mobile device to the LTE access network is received by the transmission / reception unit 201, and the wireless connection establishment unit 203 establishes the wireless connection.

  The LTE core network 21 connects the LTE access network 20 and an IP (Internet Protocol) network to which the server 401 and the SMS center 403 are connected.

  The UMTS access network 30 includes a transmission / reception unit 301, a wireless connection establishment unit 303, and an LTE transition instruction unit 305. These functions are mainly implemented in the RNC of the UMTS network.

  The wireless connection request transmitted from the mobile device to the UMTS access network is received by the transmission / reception unit 301. When the packet transmission flag is set in the wireless connection request, the LTE transition instruction unit 305 transmits an LTE transition instruction. If the packet transmission flag is not set in the wireless connection request, the wireless connection establishment unit 303 establishes a wireless connection.

  The UMTS core network 31 connects the UMTS access network 30 with an IP (Internet Protocol) network or the like to which the server 401 and the SMS center 403 are connected.

  The server 401 is a device that processes packet transmission from the mobile device 10. For example, the server 401 receives mail from the mobile device 10 and transfers it to the destination. Also, for example, a contract status confirmation is received from the mobile device 10, the contract status is searched and transmitted to the mobile device 10. Further, the server 401 may prompt the packet transmission from the mobile device 10 by transmitting an incoming notification to the mobile device 10 via the SMS center 403 or the like. For example, the server 401 notifies the mail application of the mobile device 10 that an incoming mail has been received. When the incoming notification is transmitted to the mobile device 10 in the SMS format, the server 401 transmits a packet incoming request to the SMS center 403.

  When the server 401 receives an incoming call, the SMS center 403 receives a packet incoming request from the server 401 and transmits an incoming call notification to the mobile device 10 in the SMS format.

<Sequence diagram of communication method>
3 and 4 are sequence diagrams of the communication method according to the embodiment of the present invention.

  FIG. 3 corresponds to a case where a mobile station located in the UMTS network transmits a packet.

  First, when packet communication is required by an application of a mobile device, a packet transmission request is generated (S111). The packet transmission request is transmitted to the UMTS packet communication control unit 109 of the mobile device (S115).

  In response to the packet transmission request, the UMTS packet communication control unit 109 transmits a wireless connection request to the RNC of the UMTS access network (S117). A packet transmission flag indicating packet transmission is set in the wireless connection request. If the LTE network is an area where the LTE network exists, the RNC transmits an LTE transition instruction for instructing a transition to the LTE network (S119).

  When the UMTS packet communication control unit 109 of the mobile device receives the LTE transition instruction, the wireless connection with the UMTS network is released. Then, the LTE packet communication control unit 107 of the mobile device executes detection of a base station, establishment of synchronization, and the like necessary for communication over the LTE network (S121). The LTE packet communication control unit 107 of the mobile device transmits a wireless connection request to the eNB of the LTE access network (S123), and establishes a wireless connection (S125). Thereafter, the LTE packet communication control unit 107 of the mobile device transmits a packet transmission request to the switch of the LTE core network (S127), and transmits the packet (S129).

  FIG. 4 corresponds to the case where a mobile station located in the UMTS network transmits a packet upon receiving an SMS incoming notification.

  If there is an incoming call for the mobile device on the server, the server sends a packet incoming request to the SMS center (S101). When the SMS center receives the packet incoming request, it generates an incoming call notification SMS (SMS incoming notification) and transmits it to the mobile device (S103). When the mobile device is located in the UMTS network, the SMS incoming notification is notified to the mobile device via the UMTS core network and the UMTS access network.

  When the mobile device confirms the incoming call notification and transmits a packet, the packet is transmitted in the same procedure as in FIG.

<Modification>
Next, the above modification will be described. In this modification, a description will be given of a case where the mobile device determines whether or not a transition to the LTE network is necessary when a packet is transmitted, and when the transition to the LTE network is unnecessary, the communication is continued in the UMTS network.

<Modification: Overall configuration of communication system>
FIG. 5 shows a schematic diagram of a communication system according to this modification. The communication system is configured in the same manner as in FIG.

  When a mobile device located in the UMTS network transmits a packet to the server, the mobile device transmits a radio connection request (RRC Connection Request) to the RNC of the UMTS access network. For example, in the case of an application with a small amount of data, it is determined that the transition to the LTE network is unnecessary, the LTE transition unnecessary flag is set in the wireless connection request, and the wireless connection request is transmitted to the RNC of the UMTS network. On the other hand, if the application has a large amount of data or if the amount of data scheduled to be transmitted / received is large, the LTE transition unnecessary flag is not set.

  When the LTE transition unnecessary flag is set in the wireless connection request, the RNC of the UMTS access network establishes a wireless connection in the UTMS network without instructing a transition to the LTE network. In this way, the mobile device communicates with the server via the UMTS network.

  On the other hand, when the LTE transition unnecessary flag is not set in the wireless connection request, the RNC of the UMTS access network transmits an LTE transition instruction that instructs a transition to the LTE network. Upon receiving the LTE transition instruction, the mobile device releases the wireless connection with the UMTS network, detects a base station necessary for communication in the LTE network, establishes synchronization, etc., and wirelessly connects to the eNB of the LTE network Send a request (RRC Connection Request). In this way, the mobile device communicates with the server via the LTE network.

  FIG. 6 shows a block diagram of a communication system according to this modification. Similar to the communication system of FIG. 2, the communication system includes a user equipment (UE) 10, an LTE access network 20, an LTE core network 21, a UMTS access network 30, a UMTS core network 31, and a server 401. And an SMS (Short Messaging Service) center 403.

  The mobile device further includes an application type / threshold judgment unit 103 in addition to the mobile device 10 of FIG. The application type / threshold determination unit 103, the in-zone RAT determination unit 105, and the SMS processing unit 111 may be collectively configured as a determination unit.

  The packet transmission request unit 101 generates a packet transmission request when an application executed on the mobile device 10 needs packet communication.

  The application type / threshold judgment unit 103 judges whether or not it is necessary to transition to the LTE network based on the application type, the data amount, or the LTE transition unnecessary flag set in the SMS incoming notification. For example, in the case of an application with a small amount of data such as mail transmission / reception, pedometer step transmission, and contract status confirmation, it is determined that transition to the LTE network is unnecessary, and an LTE transition unnecessary flag is set in the packet transmission request. Set. Also, for example, when the amount of data scheduled to be transmitted / received exceeds the threshold, even if the LTE transition unnecessary flag is set based on the application type, it is determined that the transition to the LTE network is necessary, and the LTE transition is unnecessary. Remove the flag. Also, as described below, when the LTE transition unnecessary flag is set in the SMS incoming notification, the LTE transition unnecessary flag may be set in the packet transmission request.

  The located RAT determination unit 105 and the LTE packet communication control unit 107 are configured in the same manner as in FIG.

  When receiving the packet transmission request, the UMTS packet communication control unit 109 transmits a wireless connection request to the RNC of the UMTS access network. When the LTE transition unnecessary flag is set in the packet transmission request, the UMTS packet communication control unit 109 sets the LTE transition unnecessary flag in the wireless connection request. According to 3GPP TS 25.331, a radio access network to which a mobile device can transition can be set in Pre-redirection info of RRC Connection Request. When the LTE transition unnecessary flag is not set in the packet transmission request, for example, the UMTS packet communication control unit 109 may not store the Pre-redirection info so that the RNC cannot request the transition to LTE. When a wireless connection with the UMTS access network is established, the UMTS packet communication control unit 109 transmits a packet transmission request to the exchange of the UMTS core network via the UMTS access network.

  When the LTE transition unnecessary flag is not set in the packet transmission request, the UMTS packet communication control unit 109 does not set the LTE transition unnecessary flag in the wireless connection request. When the LTE transition unnecessary flag is not set in the packet transmission request, for example, the UMTS packet communication control unit 109 may set Support of E-UTRA FDD or Support of E-UTRA TDD in Pre-redirection info. When the UMTS packet communication control unit 109 transmits a wireless connection request without setting the LTE transition unnecessary flag and receives an LTE transition instruction, the UMTS packet communication control unit 109 transfers the packet transmission request to the LTE packet communication control unit 107. Thereafter, as described above, the LTE packet communication control unit 107 establishes a wireless connection.

  The SMS processing unit 111 analyzes the SMS incoming notification. The SMS transition notification flag may be set in the SMS center 403 in the SMS incoming notification as described below. Therefore, the SMS processing unit 111 checks whether or not the LTE transition unnecessary flag is set in the incoming notification. When the LTE transition unnecessary flag is set in the incoming notification, the SMS processing unit 111 may instruct the application type / threshold judging unit 103 to set the LTE transition unnecessary flag.

  The LTE access network 20, the LTE core network 21, and the SMS core network 31 are configured in the same manner as in FIG.

  Similar to the UMTS access network 30 of FIG. 2, the UMTS access network 30 includes a transmission / reception unit 301, a wireless connection establishment unit 303, and an LTE transition instruction unit 305.

  The wireless connection request transmitted from the mobile device to the UMTS access network is received by the transmission / reception unit 301. When the LTE transition unnecessary flag is set in the wireless connection request, the wireless connection establishment unit 303 establishes a wireless connection. When the LTE transition unnecessary flag is not set in the wireless connection request, the LTE transition instruction unit 305 transmits an LTE transition instruction.

  Since the server 401 understands which application of the mobile device 10 has received an incoming call, based on the application type, the server 401 sets an LTE transition unnecessary flag to a packet incoming request and transmits it to the SMS center 403. For example, in the case of an application with a small amount of data, such as incoming mail, it is determined that there is no need to transition to the LTE network, and an LTE transition unnecessary flag is set in the packet incoming request.

  When the SMS center 403 receives a packet arrival request with the LTE transition unnecessary flag set from the server 401, the SMS center 403 sets the LTE transition unnecessary flag in the SMS incoming notification and transmits the SMS incoming notification to the mobile device 10.

<Modification: Sequence diagram of communication method>
7 and 8 are sequence diagrams of a communication method according to this modification.

  FIG. 7 corresponds to a case where a mobile station located in the UMTS network transmits a packet.

  First, when packet communication is required by an application of a mobile device, a packet transmission request is generated (S211). For example, the mobile device determines whether or not it is necessary to transition to the LTE network based on the application type or the data amount (S213). For example, it is determined that transition to the LTE network is unnecessary in the case of sending / receiving mails, sending pedometer steps, and confirming contract status. In such a case, the LTE transition unnecessary flag is set in the packet transmission request. The packet transmission request is transmitted to the UMTS packet communication control unit 109 of the mobile device (S215).

  In response to the packet transmission request, the UMTS packet communication control unit 109 transmits a wireless connection request to the RNC of the UMTS access network (S217). When the LTE transition unnecessary flag is set in the wireless connection request, the RNC of the UMTS access network establishes the wireless connection without transmitting the LTE transition instruction (S225). Thereafter, the UMTS packet communication control unit 109 of the mobile device transmits a packet transmission request to the exchange of the UMTS core network (S227) and transmits the packet (S229).

  On the other hand, when packet communication is required by an application such as a mobile device browser, a packet transmission request is generated (S311). For example, the mobile device determines whether or not it is necessary to transition to the LTE network based on the application type or the data amount (S313). For example, in the case of transmission / reception of music or moving images, it is determined that a transition to the LTE network is necessary. Also, for example, even when sending / receiving emails, sending pedometer steps, or confirming contract status, if the amount of data scheduled to be sent / received exceeds a threshold, it is necessary to transition to the LTE network. to decide. In such a case, the LTE transition unnecessary flag is not set in the packet transmission request. The packet transmission request is transmitted to the UMTS packet communication control unit 109 of the mobile device (S315).

  In response to the packet transmission request, the UMTS packet communication control unit 109 transmits a wireless connection request to the RNC of the UMTS access network (S317). In the wireless connection request, the LTE transition unnecessary flag is not set, but a packet transmission flag indicating packet transmission is set. If the LTE transition unnecessary flag is not set in the wireless connection request and the packet transmission flag is set, the RNC of the UMTS access network instructs the transition to the LTE network if the LTE network exists. An LTE transition instruction is transmitted (S319).

  When the UMTS packet communication control unit 109 of the mobile device receives the LTE transition instruction, the wireless connection with the UMTS network is released. Then, the LTE packet communication control unit 107 of the mobile device executes detection of a base station necessary for communication on the LTE network, establishment of synchronization, and the like (S321). The LTE packet communication control unit 107 of the mobile device transmits a wireless connection request to the eNB of the LTE access network (S323), and establishes a wireless connection (S325). Thereafter, the LTE packet communication control unit 107 of the mobile device transmits a packet transmission request to the switch of the LTE core network (S327), and transmits the packet (S329).

  FIG. 8 corresponds to a case where a mobile station located in the UMTS network transmits a packet upon receiving an SMS incoming notification.

  When there is an incoming call addressed to the mobile device on the server, the server sends a packet incoming request to the SMS center (S301). For example, in the case of incoming mail, an LTE transition unnecessary flag is set in the packet incoming request. When the SMS center receives a packet incoming request in which the LTE transition unnecessary flag is set, the SMS center sets the LTE transition unnecessary flag in the incoming notification SMS (SMS incoming notification) and transmits it to the mobile device (S303). When the mobile device is located in the UMTS network, the SMS incoming notification is notified to the mobile device via the UMTS core network and the UMTS access network.

  When the mobile device confirms the incoming call notification and performs packet communication, the packet is transmitted in the same procedure as in FIG. In Step 313, the mobile device may determine whether or not it is necessary to transition to the LTE network based on the LTE transition unnecessary flag, application type, or data amount set in the SMS incoming notification. For example, when the LTE transition unnecessary flag is set in the SMS incoming notification, the application type and the data amount may or may not be determined. In this way, the mobile device may set the LTE transition unnecessary flag in the packet transmission request based on at least one of the LTE transition unnecessary flag, the application type, and the data amount.

  In the above embodiment, the mobile device 10 capable of communicating with the LTE network and the UMTS network has been described. However, the concept of the present invention is applicable to any mobile device 10 capable of communicating with a plurality of packet communication networks having different radio access technologies. Is also applicable.

<Effect of Example>
According to the embodiment of the present invention, packet communication is preferentially performed in the LTE network, and high-speed packet communication is possible.

  On the other hand, when the mobile device is located in the UMTS network, communication in the UMTS network can be continued for an application with a small amount of data. For this reason, the delay accompanying the transition to the LTE network can be avoided. Furthermore, the amount of signals accompanying the transition to the LTE network can be reduced.

  In addition, although the application usually has a small amount of data, when the amount of data temporarily increases, high-speed packet communication can be performed by making a transition to the LTE network by comparing the threshold of the amount of data.

DESCRIPTION OF SYMBOLS 101 Packet transmission request part 103 Application classification and threshold value judgment part 105 In-zone RAT judgment part 107 LTE packet communication judgment part 109 UMTS packet communication judgment part 111 SMS processing part 201 Transmission / reception part 203 Wireless connection establishment part 301 Transmission / reception part 303 Wireless connection establishment part 303 305 LTE transition instruction unit 401 server 403 SMS center

Claims (5)

A mobile device capable of communicating with a first communication network and a second communication network,
A determination unit that determines whether or not a transition to the second communication network is necessary when transmitting a packet; and if a transition to the second communication network is unnecessary, a wireless connection request in which a transition unnecessary flag is set is transmitted to the first communication network A communication control unit to transmit;
Mobile machine with.   2. The determination unit according to claim 1, wherein the determination unit determines whether or not a transition to the second communication network is necessary based on at least one of an application type, a data amount, and a transition unnecessary flag set in an incoming call notification. Mobile machine.   The mobile device according to claim 1 or 2, wherein the first communication network is a UMTS network and the second communication network is an LTE network. A communication system having a mobile station capable of communicating in a first communication network and a second communication network, and a radio network controller,
The mobile device is
A determination unit that determines whether or not a transition to the second communication network is necessary when transmitting a packet; and if a transition to the second communication network is unnecessary, a wireless connection request in which a transition unnecessary flag is set is transmitted to the first communication network A communication control unit to transmit;
Have
The wireless network controller is
A receiving unit that receives a wireless connection request from the mobile device; and a wireless connection establishment unit that establishes a wireless connection with the mobile device in a first communication network when a transition unnecessary flag is set in the wireless connection request;
A communication system. A communication method in a mobile device capable of communicating in a first communication network and a second communication network,
A step of determining whether or not a transition to the second communication network is necessary when a packet is transmitted; and if a transition to the second communication network is unnecessary, a wireless connection request in which a transition unnecessary flag is set is transmitted to the first communication network Step to do;
A communication method comprising:

Images