JP5953170B2 - Communication method and communication system - Google Patents

Description

  The present invention relates to a communication method and a communication system used in a system including a terminal that can be connected to a mobile network and a wireless LAN, and a base station that provides the mobile network to the terminal.

  With the recent spread of communication networks and information terminals, mobile networks have become widespread, and data communication capacity in mobile networks has increased rapidly. A terminal connected to a mobile network such as a mobile phone or a smartphone can be connected to a core network such as the Internet via a mobile communication carrier base station and an exchange providing mobile phone service. The specifications regarding this mobile network are determined by 3GPP (3rd Generation Partnership Project), OMA (Open Mobile Alliance), etc. (for example, refer nonpatent literature 1 thru | or 6 etc.). 3GPP standardizes specifications for mobile communication systems such as 3G (3rd Generation) and LTE (Long Term Evolution).

  On the other hand, communication networks using wireless LANs are also widespread. This wireless LAN can be connected to a core network by connecting to a wireless LAN access point provided in, for example, a company or a home. At this time, the terminal is connected to the core network via a wireless LAN access point, a router, an exchange of a business operator that provides an Internet connection service, or the like. This wireless LAN is standardized by IEEE 802.11 or the like. In recent years, in particular, game machines and terminals equipped with modules capable of Wi-Fi (wireless fidelity) communication have become widespread.

  Generally, in a mobile network provided by a mobile communication carrier, a wireless communication section from a base station to a terminal is a section where resources are most constrained. Therefore, in the mobile communication carrier, the necessity of traffic offload in this section has been increasing in recent years. Specifically, when a mobile terminal connects to a core network, a mobile communication carrier has proposed a method via a wireless LAN such as Wi-Fi, not via a mobile network.

  Standardization organizations such as 3GPP and OMA have proposed a method using a DM (Device Manegement) function as a method of switching a mobile terminal communication connection from a mobile network to a wireless LAN connection. In this method, an MO (Mobile Object) is downloaded from an operator network ANDSF (Access Network Discovery and Selection Function) to a mobile terminal using the DM function. This MO is an access network selection policy. In accordance with this policy, the mobile terminal selects whether to connect to a base station of a mobile communication carrier that provides 3G, LTE, or the like as a connection destination during communication, or to connect to an access point such as a wireless LAN.

  A case where offloading to a wireless LAN connection using the DM function in the LTE area will be described. First, the control SMS issues an instruction to the mobile terminal to download the MO from the ANDSF. According to this instruction, the mobile terminal downloads the MO according to the ANDSF. Here, DCCH (Dedicated Control Channels) is used for control SMS transmission to the mobile terminal and MO download.

  In general, access class barring is also known in mobile networks of mobile communication carriers. Access class burring is a process of restricting connection of mobile terminals in units of access classes. For example, the access class is defined as shown in FIG. The access classes include access classes “11” to “15” for priority users and access classes “0” to “9” for general users. One of the access classes is set in advance in the SIM (Subscriber Identity Module Card) of each mobile terminal.

  When connection restriction is performed by access class burring in the LTE area, a connection restriction target is randomly selected from access classes “0” to “9” of general users. When the connection restriction target is selected, the connection restriction target is notified to each mobile terminal using the RRC (Radio Resource Control) protocol of BCCH (Broadcasting Control Channels). When the connection restriction target is notified, the mobile terminal in which the access restriction target access class is set is restricted from being connected to the mobile network of the mobile communication carrier for a certain period. In the case of 3G coverage, the same processing is performed by an RNC (Radio Network Controller).

3GPP (The 3rd Generation Partnership Project), “3GPP Specification detail 3GPP TS22.011, 'Service Accessibility'”, [online], June 21, 2012, 3GPP, [search June 25, 2012], Internet < http://www.3gpp.org/ftp/Specs/html-info/22011.htm> 3GPP (The 3rd Generation Partnership Project), "3GPP Specification detail 3GPP TR23.853, 'Operator Policies for IP Interface Selection'", [online], June 21, 2012, 3GPP, [June 25, 2012 search ] Internet <http://www.3gpp.org/ftp/Specs/html-info/23853.htm> 3GPP (The 3rd Generation Partnership Project), "3GPP TS23.855, 'Data Identification in Access Network Discovery and Selection Function'", [online], June 21, 2012, 3GPP, [June 25, 2012 search ] Internet <http://www.3gpp.org/ftp/Specs/html-info/23855.htm> 3GPP (The 3rd Generation Partnership Project), “3GPP TS25.331, 'Radio Resource Control (RRC); Protocol specification'”, [online], June 21, 2012, 3GPP, [June 25, 2012 search ] Internet <http://www.3gpp.org/ftp/Specs/html-info/25331.htm> 3GPP (The 3rd Generation Partnership Project), "3GPP TS36.331, 'Radio Resource Control (RRC); Protocol specification'", [online], June 21, 2012, 3GPP, [June 25, 2012 search ] Internet <http://www.3gpp.org/ftp/Specs/html-info/36331.htm> oma (Open Mobile Alliance), “OMA Device Management V1.2.1”, [online], 2012, oma, [searched on June 25, 2012], Internet <http://www.openmobilealliance.org/technical/ release_program / dm_v1_2.aspx>

  However, the method of switching the connection from the mobile network to the wireless LAN using the MO may not be appropriate. In general, when switching to a wireless LAN is necessary, it is assumed that the load on the base station is high and the resources of the mobile network are tight. However, the above-described conventional method for switching connection to a wireless LAN may further constrain resources.

  Specifically, DCCH is used when downloading control SMS transmission or MO. Since the DCCH is a channel set for each mobile terminal, there is a possibility that the resources of the mobile network will be further tightened. Also, since MO is defined in XML, the size may increase. It may not be appropriate to download the MO while resources are tight as in the prior art.

  Also, DM may be used in a process of presetting MO at a factory or the like before shipping a mobile terminal. In this case, it is necessary to select an environment in which resource compression by DCCH does not become a problem, such as selecting a time and place where resources of the mobile network can be used abundantly.

  As described above, various problems are conceivable regarding the method of switching the connection from the mobile network to the wireless LAN using the MO.

  Accordingly, an object of the present invention is to provide a communication method and a communication system capable of switching the connection of a terminal from a mobile network to a wireless LAN without imposing a load on the mobile network.

  In order to solve the above problem, a first feature of the present invention relates to a communication method used in a communication system including a terminal connectable to a mobile network and a wireless LAN, and a base station that provides the mobile network to the terminal. . That is, in the communication method according to the first aspect of the present invention, when the base station regulates access to the mobile network, the access class to be switched is designated and broadcasted from the mobile network connection to the wireless LAN connection. When the terminal connected to the mobile network receives the switching instruction from the base station, if the access class of the terminal is the switching target access class, the terminal is connected to the wireless LAN and the switching target is transmitted. If it is not the access class, the step of continuing the connection to the mobile network is provided.

  Here, the base station may further include a step of monitoring the load of the base station. In this case, when the load of the base station becomes higher than a predetermined threshold, a step of transmitting an instruction to switch to the wireless LAN connection is executed.

  Further, the communication system may include a subscriber packet switch connected to the base station. In this case, the step of the base station monitoring the load of the base station, and the step of transmitting the load status data of the base station to the subscriber packet switch when the load of the base station becomes higher than a predetermined threshold value; The subscriber packet switch receives the load status data of the base station from the base station connected to the subscriber packet switch; the subscriber packet switch stores the load status data; and the subscriber packet The base station further comprises a step of transmitting an instruction to switch from the mobile network connection to the wireless LAN connection by broadcast when the exchange determines the implementation of access restriction of the mobile network based on the accumulated load state data. When a switching instruction is received from a subscriber packet switch, the mobile network is broadcast. Transmitting a switching instruction from the click connection to the wireless LAN connection.

  Further, the communication system may include a subscriber packet switch connected to the base station, and the subscriber packet switch may transmit a switching instruction. In this case, the base station monitors the load on the base station, and if the load on the base station exceeds a predetermined threshold, sends a notification to that effect to the subscriber packet switch, and the subscriber The packet switch further includes a step of transmitting a switching instruction from the mobile network connection to the wireless LAN connection to the base station. When receiving the switching instruction from the subscriber packet switch, the base station transmits a switching instruction from the mobile network connection to the wireless LAN connection by broadcast.

  The communication system may include a subscriber packet switch connected to the base station. In this case, the subscriber packet switch monitors the load of the subscriber packet switch, and when the load of the subscriber packet switch is higher than a predetermined threshold, the subscriber packet switch The method further includes a step of transmitting an instruction to switch from the network connection to the wireless LAN connection. When receiving the switching instruction from the subscriber packet switch, the base station transmits a switching instruction from the mobile network connection to the wireless LAN connection by broadcast.

  Furthermore, the communication system may include a maintenance terminal. In this case, when the maintenance terminal regulates access to the mobile network, the maintenance terminal further includes a step of transmitting an instruction to switch from the mobile network connection to the wireless LAN connection to the base station. When receiving the switching instruction from the maintenance terminal, the base station transmits a switching instruction from the mobile network connection to the wireless LAN connection by broadcast.

  A second feature of the present invention relates to a communication system including a terminal connectable to a mobile network and a wireless LAN, and a base station that provides the mobile network to the terminal. That is, in the communication system according to the second aspect of the present invention, when the access to the mobile network is restricted, the base station designates the access class to be switched and broadcasts the mobile network connection to the wireless LAN connection. Communication switching notification means for transmitting a switching instruction is provided. When a terminal connected to a mobile network receives a switching instruction from a base station, if the access class of the terminal is the access class to be switched, the terminal is connected to the wireless LAN and is not the access class to be switched And communication switching means for continuing the connection to the mobile network.

  Here, the base station may further include load state monitoring means for monitoring the load of the base station. In this case, the communication switching notification means transmits an instruction to switch to the wireless LAN connection when the load of the base station becomes higher than a predetermined threshold.

  The communication system may include a subscriber packet switch connected to the base station. In this case, the base station transmits the load status data of the base station to the subscriber packet switch when the load of the base station becomes higher than a predetermined threshold and the load status monitoring means for monitoring the load of the base station. Load state notification means. The subscriber packet switch includes a load state receiving unit that receives load state data of the base station from a base station connected to the subscriber packet switch, a load state storage unit that stores load state data, and a stored load state A communication switching notification means for transmitting a switching instruction from a mobile network connection to a wireless LAN connection by broadcast when determining to implement access restriction of the mobile network based on the data is provided. When the communication switching notification means of the base station receives the switching instruction from the subscriber packet switch, it transmits a switching instruction from the mobile network connection to the wireless LAN connection by broadcast.

  Further, the communication system may include a subscriber packet switch connected to the base station, and the subscriber packet switch may transmit a switching instruction. In this case, the base station has a load state monitoring means for monitoring the load of the base station and a load state for transmitting a notification to that effect to the subscriber packet switch when the load of the base station becomes higher than a predetermined threshold A notification means is provided. The subscriber packet switch includes communication switching notification means for transmitting a switching instruction from the mobile network connection to the wireless LAN connection to the base station. When the communication switching notification means of the base station receives the switching instruction from the subscriber packet switch, it transmits a switching instruction from the mobile network connection to the wireless LAN connection by broadcast.

  The communication system may include a subscriber packet switch connected to the base station. In this case, the subscriber packet switch includes means for monitoring the load of the subscriber packet switch, and when the load of the subscriber packet switch is higher than a predetermined threshold, the subscriber packet switch Communication switching notification means for transmitting a switching instruction from network connection to wireless LAN connection is further provided. When receiving the switching instruction from the subscriber packet switch, the base station transmits a switching instruction from the mobile network connection to the wireless LAN connection by broadcast.

  Furthermore, the communication system may include a maintenance terminal. The maintenance terminal further includes communication switching notification means for transmitting a switching instruction from the mobile network connection to the wireless LAN connection to the base station when the access to the mobile network is restricted. When the communication switching notification means of the base station receives the switching instruction from the maintenance terminal, it transmits a switching instruction from the mobile network connection to the wireless LAN connection by broadcast.

  According to the present invention, it is possible to provide a communication method and a communication system capable of switching the connection of a terminal from a mobile network to a wireless LAN without imposing a load on the mobile network.

It is a figure explaining the communication system which concerns on embodiment of this invention. In the communication method which concerns on embodiment of this invention, it is a sequence diagram explaining the process at the time of a base station transmitting a switching instruction | indication. In the communication method which concerns on embodiment of this invention, it is a sequence diagram explaining the process at the time of a subscriber packet switchboard transmitting a switching instruction | indication. FIG. 10 is a sequence diagram illustrating processing when a maintenance terminal transmits a switching instruction in the communication method according to the embodiment of the present invention. It is a functional block diagram of each apparatus of the communication system which concerns on embodiment of this invention. In the communication method which concerns on embodiment of this invention, it is an example in the case of mounting based on SystemInformationBlockType2. In the communication method which concerns on the 1st modification of this invention, it is a sequence diagram explaining the process at the time of a subscriber packet switchboard transmitting a switching instruction | indication. In the communication method which concerns on the 2nd modification of this invention, it is a sequence diagram explaining the process when a subscriber packet switch transmits a switching instruction | indication. It is a figure explaining the access class in general access burring.

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

(Communications system)
As shown in FIG. 1, the communication system 7 according to the embodiment of the present invention includes a first terminal 1a, a second terminal 1b, a third terminal 1c, a fourth terminal 1d, a fifth terminal 1e, A sixth terminal 1f, a first base station 2a, a second base station 2b, a third base station 2c, a first subscriber packet switch 3a, a second subscriber packet switch 3b, a relay packet switch 4, A maintenance terminal 5, a first wireless LAN access point 6a, and a second wireless LAN access point 6b are provided.

  In the embodiment, when the first terminal 1a, the second terminal 1b, the third terminal 1c, the fourth terminal 1d, the fifth terminal 1e, and the sixth terminal 1f are not particularly distinguished, the terminal 1 is simply May be described. Similarly, when the first base station 2a, the second base station 2b, and the third base station 2c are not distinguished, they may be simply referred to as the base station 2. When the first subscriber packet switch 3a and the second subscriber packet switch 3b are not distinguished from each other, they may be simply referred to as the subscriber packet switch 3. When the first wireless LAN access point 6a and the second wireless LAN access point 6bb are not distinguished, they may be simply referred to as the wireless LAN access point 6.

  In the embodiment of the present invention, a method in which the terminal 1 switches the connection from the mobile network to the wireless LAN network based on a request from a device other than the terminal 1 such as the base station 2 will be described. The mobile network is a network provided by a mobile communication carrier, and is standardized by, for example, 3GPP or OMA. By connecting to the base station 2, the terminal 1 can be connected to the core network via an exchange provided by a mobile communication carrier.

  On the other hand, a wireless LAN network is a wireless network provided by a provider who provides an Internet connection service, and is standardized by, for example, IEEE 802.11. By connecting to the wireless LAN access point 6, the terminal 1 can be connected to the core network via an exchange of an operator that provides an Internet connection service.

  In the communication system 7 shown in FIG. 1, a base station 2, a subscriber packet switch 3, a relay packet switch 4 and a maintenance terminal 5 are managed and maintained by a mobile communication carrier operator and provide a mobile network to the terminal 1. The wireless LAN access point 6 provides the terminal 1 with a wireless LAN.

  The base station 2 provides a mobile network to the terminal 1 and relays packets between the terminal 1 and the subscriber packet switch 3. The base station 2 corresponds to eNodeB in LTE, and corresponds to RNC in 3G.

  The subscriber packet switch 3 relays packets between the base station 2 and the relay packet switch 4. The subscriber packet switch 3 corresponds to MME in LTE, and corresponds to SGSN in 3G.

  The relay packet switch 4 relays packets between the subscriber packet switch 3 and the core network.

  The maintenance terminal 5 is a terminal for inputting instructions regarding maintenance of the mobile network, and is operated by an administrator or the like. In the example illustrated in FIG. 1, the case where the maintenance terminal 5 is connected to the relay packet switch 4 will be described, but the present invention is not limited thereto. For example, the maintenance terminal 5 may connect to the subscriber packet switch 3 and input an instruction, or may connect to the base station 2 and input an instruction.

  A wireless LAN access point 6 provides a wireless LAN network. The wireless LAN access point 6 makes a network provided by an Internet connection provider wireless and provides a wireless network such as Wi-Fi.

(Communication method)
In the embodiment of the present invention, the terminal 1 is connected to the mobile network via the base station 2 and switches the connection to the wireless LAN access point 6 in accordance with an instruction from the base station 2 or the like. An example of this processing will be described with reference to FIGS.

  FIG. 2 illustrates an example of processing in which the first base station 2a outputs network connection switching to the first terminal 1a and the second terminal 1b in the communication system 7 illustrated in FIG. When the load on the first base station 2a becomes high, the first base station 2a switches to the connection to the wireless LAN when the terminal 1 is connected to the mobile network via the first base station 2a. Send instructions. Thereby, the load of the 1st base station 2a can be reduced.

  As shown in step S1, the first terminal 1a is connected to the mobile network via the first base station 2a. As shown in step S2, the second terminal 1b is also connected to the mobile network via the first base station 2a.

  In step S3, the first base station 2a determines whether or not a load equal to or higher than the first threshold is detected. Here, the first threshold value is a reference value of a load for switching the terminal 1 connected to the first base station 2a to the wireless LAN in order to reduce the load of the first base station 2a. Here, the first threshold may be the number of traffic processed by the first base station 2a per unit time, may be the amount of data, or may be the CPU usage of the first base station 2a. Or memory usage. The first threshold may be a value obtained by combining these values. As long as the load of the first base station 2a is indexed, the first threshold value may be any numerical value. When the load of the first base station 2a does not exceed the first threshold value, the first base station 2a provides the mobile network to the terminal 1 without performing the connection switching process.

  On the other hand, when the load of the first base station 2a exceeds the first threshold, in step S4, the first base station 2a sends a network connection switching instruction to the terminal 1 connected to the first base station 2a. Send to the broadcast. This network connection switching instruction includes the access class to be switched. In this case, the access class set in the SIM of the first terminal 1a is not the access class to be switched, and the access class set in the SIM of the second terminal 1b is the access class to be switched. explain.

  Here, various implementation examples are conceivable as a method of transmitting a network connection switching instruction by broadcast. For example, based on access burring using an access class, the first base station 2a may set a new parameter for switching the connection to the wireless LAN, and transmit this message on the BCCH.

  When the first base station 2a transmits a switching instruction by broadcast, the first terminal 1a receives this notification in step S4a, and the second terminal 1b receives this notification in step S4b. The first terminal 1a and the second terminal 1b individually process the received switching instruction.

  The access class set in the SIM of the first terminal 1a is not the access class to be switched received in step S4a. Accordingly, in step S5, the first terminal 1a determines that the access class is not the switching target. As shown in step S6, the first terminal 1a connects to the mobile network via the first base station 2a without switching the network connection, and continues communication.

  On the other hand, the access class set in the SIM of the second terminal 1b is the access class to be switched received in step S4b. Therefore, when the second terminal 1b determines in step S7 that the access class is the switching target, in step S8, the first wireless LAN access point 6a is changed from the mobile network connection via the first base station 2a. Switch to a wireless LAN connection. Thereafter, as shown in step S9, the second terminal 1b is connected to the first wireless LAN access point 6a via the wireless LAN and starts communication.

  FIG. 3 illustrates an example of processing when it is necessary to reduce the load on the first base station 2a due to maintenance of the first base station 2a or the like.

  As shown in step S11, the first terminal 1a is connected to the mobile network via the first base station 2a. As shown in step S12, the second terminal 1b is also connected to the mobile network via the first base station 2a.

  In step S13, the maintenance terminal 5 transmits a network connection switching instruction to the first base station 2a. This network connection switching instruction includes the access class to be switched. In this case, the access class set in the SIM of the first terminal 1a is not the access class to be switched, and the access class set in the SIM of the second terminal 1b is the access class to be switched. explain. Here, the maintenance terminal 5 may transmit a switching instruction at a timing operated by an administrator or the like, or may transmit a switching instruction according to a predetermined schedule.

  When the first base station 2a receives the switching instruction from the maintenance terminal 5, in step S14, the first base station 2a sends the network connection switching instruction to the terminal 1 connected to the first base station 2a. Send by broadcast.

  The processing from step S15 to step S19 after the first base station 2a broadcasts network connection switching is the same as the example described with reference to FIG.

  Referring to FIG. 4, the connection is switched for terminal 1 connected to base station 2 accommodated in subscriber packet switch 3 as the load on base station 2 accommodated in subscriber packet switch 3 increases. Explain the case. As shown in FIG. 1, the first subscriber packet switch 3a accommodates a first base station 2a and a second base station 2b. The first base station 2a accommodates the first terminal 1a and the second terminal 1b, and the second base station 2b accommodates the third terminal 1c and the fourth terminal 1d. Here, the first terminal 1a and the second terminal 1b are connected to the mobile network via the first base station 2a, and the third terminal 1c and the fourth terminal 1d are connected to the second base station 2b. Connect to the mobile network via. The first terminal 1a and the second terminal 1b are located in the area where the wireless LAN of the first wireless LAN access point is located, and the third terminal 1c and the fourth terminal 1d are the second wireless LAN. It is located in the area where the wireless LAN of the LAN access point is located.

  In step S21, the first base station 2a determines whether or not a load equal to or greater than the second threshold is detected. The second threshold value is a reference value of a load to be dealt with assuming that the load will increase in the future, although the load is lower than the first threshold value described with reference to FIG. If the load on the first base station 2a does not exceed the second threshold, the first base station 2a continues the process of providing the mobile network to the terminal 1.

  On the other hand, when the load of the first base station 2a exceeds the second threshold value, in step S22, the first base station 2a sends the load state data as the current load state to the first subscriber packet switch 3a. Notice. The load state data notified here is, for example, the number of traffics per unit time and the traffic amount, or the CPU usage amount and the memory usage amount of the base station 2, and is data that indexes the load of the base station 2.

  When the first subscriber packet switch 3a receives the load state, it is stored in a memory or the like, and it is determined whether or not access is restricted in step S23. For example, when the load state is similarly notified from other base stations, the first subscriber packet switch 3a itself and the base station 2 accommodated by the first subscriber packet switch 3a may be heavily loaded. There is. Here, the first subscriber packet switch 3a determines whether or not to restrict access based on the load states of the first base station 2a and the second base station 2b.

  Here, various methods can be considered as a method for determining whether to restrict access. For example, the subscriber packet switch 3 may restrict access when receiving load state data from a predetermined number or more of the base stations 2 among the plurality of base stations 2 accommodated in the subscriber packet switch 3. Further, the subscriber packet switch 3 may determine whether or not access is restricted with reference to the past load state data of each base station 2.

  When the access is restricted, the first subscriber packet switch 3a transmits a network connection switching instruction to the first base station 2a and the second base station 2b in step S24. This network connection switching instruction includes the access class to be switched. Here, the access class set in the SIM of the first terminal 1a and the third terminal 1c is the access class to be switched, and the access class set in the SIM of the second terminal 1b and the fourth terminal 1d Is a case where the access class is not the switching target.

  When the first subscriber packet switch 3 a transmits a network connection switching instruction by broadcast, the received base station 2 transmits a network connection switching instruction to the terminal 1. Specifically, in step S25, the first base station 2a transmits a network connection switching instruction by broadcast to the first terminal 1a and the second terminal 1b. In step S26, the second base station 2b transmits a network connection switching instruction by broadcast to the third terminal 1c and the fourth terminal 1d. The first terminal 1a, the second terminal 1b, the third terminal 1c, and the fourth terminal 1d each individually process the received switching instruction.

  The access class set in the SIM of the first terminal 1a is the access class to be switched received in step S25a. Accordingly, when the first terminal 1a determines in step S27 that the access class is a switching target, in step S28, the first wireless LAN access point 6a is connected from the mobile network connection via the first base station 2a. Switch to wireless LAN connection via. Thereafter, the first terminal 1a is connected to the first wireless LAN access point 6a via the wireless LAN and starts communication.

  The access class set in the SIM of the second terminal 1b is not the access class to be switched received in step S25b. Accordingly, in step S29, the second terminal 1b determines that it is not the access class to be switched. Thereafter, the second terminal 1b connects to the mobile network via the first base station 2a and continues communication.

  The access class set in the SIM of the third terminal 1c is the access class to be switched received in step S26a. Accordingly, when the third terminal 1c determines in step S30 that the access class is the switching target, in step S31, the second wireless LAN access point 6b is connected from the mobile network connection via the second base station 2b. Switch to wireless LAN connection via. Thereafter, the third terminal 1c is connected to the second wireless LAN access point 6b via the wireless LAN and starts communication.

  The access class set in the SIM of the fourth terminal 1d is not the access class to be switched received in step S26b. Accordingly, in step S32, the fourth terminal 1d determines that it is not the access class to be switched. Thereafter, the fourth terminal 1d connects to the mobile network via the second base station 2b and continues communication.

(Each device of the communication system)
With reference to FIG. 5, functional blocks of the terminal 1, the base station 2, the subscriber packet switch 3 and the maintenance terminal 5 will be described.

(Terminal)
The terminal 1 is an information terminal such as a mobile phone, a smartphone, a tablet, and a personal computer, and can be connected to a mobile network and a wireless LAN. The terminal 1 includes a wireless LAN communication unit 11, a mobile network communication unit 12, and a communication switching unit 13.

  The wireless LAN communication means 11 is a communication module for connecting to a wireless LAN access point 6 where the terminal 1 is located, and connecting to a wireless LAN such as Wi-Fi. The wireless LAN communication means 11 communicates with the wireless LAN access point 6 in accordance with the standard of the wireless LAN access point 6 such as IEEE802.11.

  Here, the authentication procedure for connecting to the wireless LAN depends on the service form providing the wireless LAN. For example, when the wireless LAN access point 6 prompts the terminal 1 using the wireless LAN to input a connection confirmation, an SSID, and an authentication key, the wireless LAN communication unit 11 considers these procedures and then uses the wireless LAN access point. Connect to 6.

  The mobile network communication means 12 is a communication module for connecting to the mobile station provided by the mobile communication carrier by connecting to the base station 2 where the terminal 1 is located. The mobile network communication unit 12 communicates with the base station 2 in accordance with a mobile network communication standard such as 3G or LTE.

  The mobile network communication means 12 has a SIM. When connecting to the mobile network, the SIM holds an identification number for identifying the terminal 1 and holds an access class assigned to the terminal 1.

  The communication switching unit 13 switches the connection of the terminal 1 from the mobile network to the wireless LAN, or switches the connection from the wireless LAN to the mobile network. Particularly in the embodiment of the present invention, when the communication switching unit 13 is connected to the mobile network and receives a switching instruction from the base station 2, the access class of the terminal 1 is the access class to be switched. If the access class is connected to the wireless LAN and is not the access class to be switched, the connection to the mobile network is continued.

  When receiving the switching instruction from the base station 2, the communication switching unit 13 acquires the access class to be switched included in the switching instruction and also acquires the access class of the terminal 1 held by the SIM. When the access class of the terminal 1 is the access class to be switched, the communication switching unit 13 disconnects the connection with the mobile network and connects to the wireless LAN according to a predetermined procedure.

(base station)
The base station 2 provides a mobile network to the terminal 1. The base station 2 provides a wireless network to a terminal 1 located in an area covered by the base station 2 in a mobile network provided by a mobile communication carrier. The base station 2 includes a load state monitoring unit 21, a communication switching notification unit 22, and a load state notification unit 23.

  The load state monitoring unit 21 monitors the load on the base station 2. The load state monitoring means 21 is the number of traffics and data processed by the base station 2 per unit time, the CPU usage and memory usage of the base station 2, and the number of terminals 1 located in an area where a mobile network can be provided. Based on the above, the load state obtained by indexing the load of the base station 2 is held as load state data. The method of indexing the load of the base station 2 in the embodiment of the present invention is not limited.

  The load state monitoring unit 21 requests the communication switching notification unit 22 to process when the load state exceeds the first threshold, and requests the load state notification unit 23 to perform processing when the load state exceeds the second threshold. To do. In the embodiment of the present invention, the first threshold value is higher than the second threshold value, indicating that the load on the base station 2 is higher.

  When the load on the base station 2 exceeds the first threshold, the communication switching notification unit 22 regulates access to the mobile network of the terminal 1 connected to the base station 2. In this case, the communication switching notification means 22 designates an access class to be switched and transmits a switching instruction by broadcast. This switching instruction is an instruction for the terminal 1 to switch from the mobile network connection to the wireless LAN connection. The communication switching notification unit 22 may randomly specify an access class to be switched. Further, in the access class shown in FIG. 9, the communication switching notification unit 22 may specify the access class to be switched in order of 0, 1, 2,. There is no limitation on the method for specifying the access class.

  Further, the communication switching notification means 22 notifies the terminal 1 by broadcast of the switching instruction input from the subscriber packet switch 3. When the load on the base station 2 exceeds the second threshold, the base station 2 transmits data on the load on the base station 2 to the subscriber packet switch 3. Thereafter, when the subscriber packet switch 3 restricts access to these base stations based on the load state of the base station 2 connected to the subscriber packet switch 3, the subscriber packet switch 3 A switching instruction is transmitted by broadcast.

  When the base station 2 receives the switching instruction from the subscriber packet switch 3, the base station 2 broadcasts to the terminal 1 connected to the base station 2 and transmits a switching instruction from the mobile network connection to the wireless LAN connection. Here, if the access class to be switched is not specified in the switching instruction transmitted from the subscriber packet switch 3, the base station 2 specifies the access class to be switched and transmits it to the terminal 1 by broadcast. May be.

  In addition, when receiving the switching instruction from the maintenance terminal 5, the communication switching notifying means 22 transmits a switching instruction from the mobile network connection to the wireless LAN connection by broadcasting to the terminal 1 connected to the base station 2. Here, when the access class to be switched is not specified in the switching instruction transmitted from the maintenance terminal 5, the base station 2 may designate the access class to be switched and transmit it to the terminal 1 by broadcast. good.

  Based on the load state monitored by the load state monitoring unit 21, the load state notifying unit 23 transmits the load state data of the base station 2 to the subscriber packet switch when the load of the base station 2 becomes higher than the second threshold value. 3 to send.

(Subscriber packet switch)
The subscriber packet switch 3 accommodates a plurality of base stations 2 and transmits and receives packets. The subscriber packet switch 3 includes a load state receiving unit 31, a load state storage unit 32, and a communication switching notification unit 33.

  The load state receiving means 31 receives the load state data of the base station from the base station 2 connected to the subscriber packet switch 3. In the example shown in FIG. 1, the first subscriber packet switch 3a receives load state data from the first base station 2a and the second base station 2b when the load on each base station 2 becomes high. . The second subscriber packet switch 3b receives load state data from the third base station 2c when the load on the third base station 2c becomes high.

  The load state storage unit 32 stores the load state data received by the load state reception unit 31. At this time, the load state storage unit 32 may store the load state data by associating the identifier or date / time of the base station 2 that is the transmission source of the load state data.

  The communication switching notification unit 33 determines whether or not the mobile network access restriction is necessary based on the load state data stored by the load state storage unit 32. When the access restriction of the mobile network is performed, the communication switching notification unit 33 transmits a switching instruction from the mobile network connection to the wireless LAN connection by broadcast. The switching instruction transmitted by the communication switching notification means 33 is transmitted to the terminal 1 via the base station 2. The first base station 2a and the second base station 2b receive the switching instruction transmitted by broadcast from the first subscriber packet switch 3a. The first base station 2a broadcasts toward the first terminal 1a and the second terminal 1b, and the second base station 2b broadcasts toward the third terminal 1c and the fourth terminal 1d. To do.

  Here, the communication switching notification means 33 may transmit a switching instruction by designating an access class to be switched, or may transmit a switching instruction without designating an access class to be switched. When the access class is not designated by the switching instruction, the base station 2 designates the access class to be switched and broadcasts it to the terminal 1.

(Maintenance terminal)
The maintenance terminal 5 is, for example, a general computer, and includes a communication switching notification unit 51 by executing a predetermined program. The communication switching notification means 51 transmits an instruction to switch from the mobile network connection to the wireless LAN connection to the base station 2 when access to the mobile network is restricted by maintenance work or the like. When it is necessary to reduce the load on the base station 2, the communication switching notification unit 51 transmits a switching instruction for the terminal 1 connected to the base station 2 to the base station 2. When it is necessary to reduce the load on the base station 2 accommodated in the subscriber packet switch 3, the switching of the terminal 1 connected to the base station 2 accommodated in the subscriber packet switch 3 is switched to the subscriber packet switch 3. An instruction may be sent. The maintenance terminal 5 transmits a switching instruction to the base station 2 based on an instruction input from a network administrator or the like.

(Implementation example)
With reference to FIG. 6, an example of implementation of the communication method according to the embodiment of the present invention will be described. The mounting example described here is an example, and the present invention is not limited to this mounting example.

  In the embodiment of the present invention, the base station 2 transmits a switching instruction to the terminal 1 by broadcast, but may transmit it using an access barring technique. Moreover, BCCH can be used as broadcast transmission.

  For example, in order to realize access class burring with BCRC RRC in LTE, System Information Block Type 2 of information elements (Information Elements) of RRC (Radio Resource Control) is used. This SystemInformationBlockType2 is disclosed in Non-Patent Document 5.

  Therefore, in the communication method according to the embodiment of the present invention, notification is made using SystemInformationBlockType2 to which a parameter related to connection switching is added. Specifically, as shown in FIG. 6, a switching instruction notification unit P101 is added to general SystemInformationBlockType2. The access class to be switched is specified by ac-BarringFactor of the switching target specifying unit P102.

  Here, when the terminal 1 receives a message in which the parameter of ac-BarringForTrafficOffload is set to “true”, the terminal 1 obtains the access class specified by ac-BarringFactor and the access class set by its own SIM. Compare. When its own access class is an access class specified by ac-BarringFactor, the terminal 1 disconnects the mobile network connection with the base station 2 and connects to the wireless LAN access point 6 via the wireless LAN.

  Also, 3G can be implemented in the same manner as LTE. Specifically, System Information Block Type 3 of RRC is used in order to realize access class burring with RRC of BCCH in 3G. This SystemInformationBlockType3 is disclosed in Non-Patent Document 4. In the communication method according to the embodiment of the present invention, notification is made using SystemInformationBlockType3 to which parameters related to connection switching are added, as in the case of LTE described with reference to FIG.

  In 3G, traffic relating to data communication in a PS domain out of a CS (Circuit Switched) domain and a PS (Packet Switched) domain is a target of the communication method according to the embodiment of the present invention. In 3G, access restriction control for each domain called DSAC (Domain Specific Access Control) is used. When the packet communication load of the base station 2 increases, the DSAC in which the PS domain is specified is activated. Accordingly, in 3G, a connection switching instruction may be transmitted when a DSAC in which a PS domain is specified is activated. The activation of the DSAC is determined by Domain Specific Access Restriction / Domain Specific Access Restriction Parameters or the like.

  As described above, according to the communication method according to the embodiment of the present invention, when the load on the base station 2 becomes high, the wireless LAN is connected to the terminal 1 of the access class randomly selected from the general user class of the access class. It is possible to transmit a connection switching instruction for urging connection to the network. Since this connection switching instruction can be instructed by broadcasting, it is possible to effectively use the resources of the wireless network between the base station 2 and the terminal 1 as compared with the case of transmitting using a dedicated channel. Further, by adding a parameter for prompting connection switching to the BCCH and transmitting it, the resources of the wireless network can be used more effectively.

  In addition, when connection switching is performed using an individual channel, it is necessary to download the MO. However, the communication method according to the embodiment of the present invention can be notified with a smaller amount of data. In particular, the method of adding a parameter to BCCH is highly effective.

  As described above, the communication method according to the embodiment of the present invention can switch the connection of the terminal 1 from the mobile network to the wireless LAN without placing a load on the mobile network even when the load on the base station 2 is high. it can.

(First modification)
In the embodiment of the present invention, the case where the base station 2 transmits a switching instruction by broadcast to the terminal 1 when the base station 2 detects a load equal to or greater than the first threshold has been described. On the other hand, in the first modification, the base station 2 notifies the subscriber packet switch 3 that a load equal to or higher than the first threshold is detected, and the subscriber packet switch 3 instructs the base station 2 to switch. A case of transmission will be described.

  With reference to FIG. 7, a communication method according to a first modification of the present invention will be described. FIG. 7 shows that in the communication system 7 shown in FIG. 1, the first subscriber packet switch 3a outputs the switching of the network connection to the first terminal 1a and the second terminal 1b via the first base station 2a. An example of processing to be performed will be described. When the load on the first base station 2a becomes high, the first base station 2a sends a message to that effect to the first subscriber packet switch 3a, and the terminal 1 moves through the first base station 2a. When connected to the network, the first subscriber packet switch 3a transmits an instruction to switch to connection to the wireless LAN. Thereby, the load of the 1st base station 2a can be reduced.

  As shown in step S31, the first terminal 1a is connected to the mobile network via the first base station 2a. As shown in step S32, the second terminal 1b is also connected to the mobile network via the first base station 2a.

  In step S33, the first base station 2a determines whether or not a load equal to or higher than the first threshold is detected. Here, the first threshold value is a reference value of a load for switching the terminal 1 connected to the first base station 2a to the wireless LAN in order to reduce the load of the first base station 2a. When the load of the first base station 2a does not exceed the first threshold, the first base station 2a provides the mobile network to the terminal 1 without performing a process of notifying the first subscriber packet switch 3a. To do.

  On the other hand, when the load of the first base station 2a exceeds the first threshold, in step S34, the first base station 2a informs the first subscriber packet switch 3a that the first threshold has been exceeded. Notice.

  When the first subscriber station 3a is notified from the first base station 2a that the load of the first base station 2a has exceeded the first threshold, the first subscriber station 3a switches to the first base station 2a. Send instructions. This switching instruction is an instruction for switching from the mobile network connection to the wireless LAN connection for the terminal 1 connected to the first base station 2a.

  When the first base station 2a receives the switching instruction from the first subscriber packet switch 3a, the first base station 2a connects the network connection switching instruction to the first base station 2a in step S36. Broadcast to the terminal 1.

  The processes in steps S37 to S41 after the first base station 2a broadcasts the network connection switching are the same as the example described with reference to FIG.

  The processing of each device according to the first modification is partially different from the processing of each device according to the embodiment described with reference to FIG.

  Specifically, when the load of the base station 2 becomes higher than a predetermined threshold, the load state notifying unit 23 of the base station 2 transmits a notification to that effect to the subscriber packet switch 3.

Further, upon receiving notification from the base station 2, the communication switch notification means 33 of the subscriber packet switch 3 transmits an instruction to switch from the mobile network connection to the wireless LAN connection to the base station 2 as described above. In the communication method according to the example, the base station 2 monitors the load, and notifies the higher-order subscriber packet switch 3 when the load exceeds a predetermined threshold, and the subscriber packet switch 3 regulates access. Thereby, the control of the communication system can be concentrated on the base station 2.

(Second modification)
In the embodiment of the present invention, the case where the base station 2 transmits a switching instruction by broadcast to the terminal 1 when the base station 2 detects a load equal to or greater than the first threshold has been described. On the other hand, in the second modification, when the subscriber packet switch 3 detects a load equal to or greater than a predetermined threshold, the subscriber packet switch 3 issues a switching instruction to the base station 2 accommodated in the subscriber packet switch 3. A case of transmission will be described.

  With reference to FIG. 8, a communication method according to a second modification of the present invention will be described. FIG. 8 shows that in the communication system 7 shown in FIG. 1, the first subscriber packet switch 3a outputs the switching of the network connection to the first terminal 1a and the second terminal 1b via the first base station 2a. In addition, an example of processing for outputting network connection switching to the third terminal 1c and the fourth terminal 1d via the second base station 2b will be described. When the load on the first subscriber packet switch 3a becomes high, the terminal 1 is connected to the mobile network via the first base station 2a and the second base station 2b. The first subscriber packet switch 3a transmits an instruction to switch. As a result, the load on the first subscriber packet switch 3a can be reduced.

  The first terminal 1a and the second terminal 2b are connected to the mobile network via the first base station 2a. The third terminal 1c and the fourth terminal 1d are connected to the mobile network via the second base station 2b.

  In step S51, the first subscriber packet switch 3a determines whether a load equal to or greater than a predetermined threshold is detected. Here, the predetermined threshold is a load for switching the terminal 1 connected to the base station 2 accommodated in the first subscriber packet switch 3a to the wireless LAN in order to reduce the load of the first subscriber packet switch 3a. Is the reference value. When the load on the first subscriber packet switch 3a does not exceed a predetermined threshold, the first base station 2a and the second base station 2b provide the mobile network to the terminal 1.

  On the other hand, if the load on the first subscriber packet switch 3a exceeds a predetermined threshold, the first subscriber packet switch 3a transmits a switching instruction to the first base station 2a in step S52a and In S52b, a switching instruction is transmitted to the second base station 2b. This switching instruction is an instruction for switching from the mobile network connection to the wireless LAN connection for the terminal 1 connected to the first base station 2a.

  The processing after step S53 is the same as the processing after step S25 in FIG.

  The processing of each device according to the second modification is partly different from the processing of each device according to the embodiment described with reference to FIG.

  Specifically, the subscriber packet switch 3 includes means for monitoring the load on the subscriber packet switch 3. Further, the communication switching notification means 33 of the subscriber packet switch 3 transmits an instruction to switch from the mobile network connection to the wireless LAN connection to the base station 2 when the load of the subscriber packet switch 3 becomes higher than a predetermined threshold. To do.

  As described above, in the communication method according to the second modification, the subscriber packet switch 3 monitors the load, and when the load exceeds a predetermined threshold, the terminal 1 connected to the base station 2 accommodated in the subscriber packet switch 3. Restrict access to Thereby, for example, it is suitable when a specific subscriber packet switch 3 accommodates many base stations 2 to increase the load. The communication method according to the second modification can reduce the load on the subscriber packet switch 3 by switching the terminal 1 connected to the base station 2 from the mobile network connection to the wireless LAN connection.

(Other embodiments)
As described above, the embodiments of the present invention, the first and second modifications have been described. However, 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.

  For example, the processing order of the communication method according to the embodiment of the present invention described with reference to FIGS. 2 to 4, 7, and 8 is an example, and in any order as long as no contradiction occurs May be.

  It goes without saying that the present invention includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 Terminal 2 Base station 3 Subscriber packet switch 4 Relay packet switch 5 Maintenance terminal 6 Wireless LAN access point 7 Communication system 11 Wireless LAN communication means 12 Mobile network communication means 13 Communication switching means 21 Load state monitoring means 22, 33, 51 Communication Switching notification means 23 Load state notification means 31 Load state reception means 32 Load state storage means

Claims (12)

A communication method used in a communication system comprising a terminal connectable to a mobile network and a wireless LAN, and a base station that provides the mobile network to the terminal,
When the base station regulates access to the mobile network, a step of designating an access class to be switched and transmitting an instruction to switch from the mobile network connection to the wireless LAN connection by broadcasting;
When a terminal connected to the mobile network receives a switching instruction from the base station, if the access class of the terminal is a switching target access class, the terminal is connected to a wireless LAN and is not a switching target access class, A communication method comprising the step of continuing the connection to the mobile network. The base station further comprising monitoring a load on the base station;
The communication method according to claim 1, wherein when the load on the base station becomes higher than a predetermined threshold, a step of transmitting an instruction to switch to the wireless LAN connection is executed. The communication system comprises a subscriber packet switch connected to the base station,
The base station monitoring the load of the base station;
When the load of the base station is higher than a predetermined threshold, transmitting the load status data of the base station to a subscriber packet switch;
The subscriber packet switch receives load status data of the base station from a base station connected to the subscriber packet switch;
The subscriber packet switch stores the load status data;
The subscriber packet switch further includes a step of transmitting an instruction to switch from a mobile network connection to a wireless LAN connection by broadcast when the subscriber packet switch determines to implement access restriction of the mobile network based on the accumulated load state data,
2. The communication method according to claim 1, wherein when the base station receives a switching instruction from the subscriber packet switch, the base station transmits a switching instruction from a mobile network connection to a wireless LAN connection by broadcast. The communication system comprises a subscriber packet switch connected to the base station,
The base station monitoring the load of the base station;
If the load on the base station is higher than a predetermined threshold, sending a notification to that effect to the subscriber packet switch;
The subscriber packet switch further comprising a step of transmitting a switching instruction from a mobile network connection to a wireless LAN connection to the base station;
2. The communication method according to claim 1, wherein when the base station receives a switching instruction from the subscriber packet switch, the base station transmits a switching instruction from a mobile network connection to a wireless LAN connection by broadcast. The communication system comprises a subscriber packet switch connected to the base station,
The subscriber packet switch monitoring the load on the subscriber packet switch;
When the load of the subscriber packet switch becomes higher than a predetermined threshold, the subscriber packet switch further comprises a step of transmitting an instruction to switch from a mobile network connection to a wireless LAN connection to the base station,
2. The communication method according to claim 1, wherein when the base station receives a switching instruction from the subscriber packet switch, the base station transmits a switching instruction from a mobile network connection to a wireless LAN connection by broadcast. The communication system includes a maintenance terminal,
When the maintenance terminal regulates access to a mobile network, the maintenance terminal further includes a step of transmitting a switching instruction from a mobile network connection to a wireless LAN connection to the base station,
The communication method according to claim 1, wherein when the base station receives a switching instruction from the maintenance terminal, the base station transmits a switching instruction from a mobile network connection to a wireless LAN connection by broadcast. A communication system comprising a terminal connectable to a mobile network and a wireless LAN, and a base station that provides the mobile network to the terminal,
The base station
When restricting access to a mobile network, the communication switching notification means for specifying an access class to be switched and transmitting a switching instruction from the mobile network connection to the wireless LAN connection by broadcasting is provided.
The terminal
When a terminal connected to the mobile network receives a switching instruction from the base station, if the access class of the terminal is a switching target access class, the terminal is connected to a wireless LAN and is not a switching target access class, A communication system comprising communication switching means for continuing connection to a mobile network. The base station
It further comprises load state monitoring means for monitoring the load of the base station,
The communication system according to claim 7, wherein the communication switching notification unit transmits an instruction to switch to the wireless LAN connection when a load on the base station becomes higher than a predetermined threshold. The communication system comprises a subscriber packet switch connected to the base station,
The base station
Load state monitoring means for monitoring the load of the base station;
When the load of the base station becomes higher than a predetermined threshold, load state notification means for transmitting the load state data of the base station to a subscriber packet switch,
The subscriber packet switch includes a load state receiving means for receiving load state data of the base station from a base station connected to the subscriber packet switch;
Load state storage means for storing the load state data;
A communication switching notification means for transmitting a switching instruction from a mobile network connection to a wireless LAN connection by broadcast when determining to implement access restriction of the mobile network based on the accumulated load state data,
The communication switching notifying means of the base station, when receiving a switching instruction from the subscriber packet switch, transmits a switching instruction from a mobile network connection to a wireless LAN connection by broadcast. Communications system. The communication system comprises a subscriber packet switch connected to the base station,
The base station
Load state monitoring means for monitoring the load of the base station;
When the load of the base station becomes higher than a predetermined threshold, it comprises a load state notification means for transmitting a notification to that effect to the subscriber packet switch,
The subscriber packet switch is
Communication switching notification means for transmitting a switching instruction from mobile network connection to wireless LAN connection to the base station,
The communication switching notifying means of the base station, when receiving a switching instruction from the subscriber packet switch, transmits a switching instruction from a mobile network connection to a wireless LAN connection by broadcast. Communications system. The communication system comprises a subscriber packet switch connected to the base station,
The subscriber packet switch is
Means for monitoring the load on the subscriber packet switch;
A communication switching notification means for transmitting a switching instruction from a mobile network connection to a wireless LAN connection to the base station when the load on the subscriber packet switch becomes higher than a predetermined threshold; Prepared,
The communication switching notifying means of the base station, when receiving a switching instruction from the subscriber packet switch, transmits a switching instruction from a mobile network connection to a wireless LAN connection by broadcast. Communications system. The communication system includes a maintenance terminal,
The maintenance terminal is
When restricting access to a mobile network, the base station further includes a communication switching notification means for transmitting a switching instruction from a mobile network connection to a wireless LAN connection,
8. The communication system according to claim 7, wherein the communication switching notification means of the base station transmits a switching instruction from a mobile network connection to a wireless LAN connection by broadcast when receiving a switching instruction from the maintenance terminal. .

Images