JP2012227641A - Radio communication device, radio access system selection device, and radio access system selection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a radio communication device capable of selecting a proper radio access network according to a movement state by decreasing suspension of communication.SOLUTION: A radio communication device which is mounted on a movable body, connects with an IP network, and has a plurality of radio devices 37 and 38 corresponding to different access networks respectively comprises: a communication area DB 43 in which information on an usable area for each radio access network is stored; a speed information acquisition part 40 acquiring speed information on the movable body; a location information acquisition part 41 acquiring location information showing a present location of the movable body; and a path switching control part 30 which estimates a moving direction of the movable body on the basis of the speed information, and selects a radio access network to be used for a relay path of communication between an internal network and an external network on the basis of the moving direction, the location information, and the communication area.

Description

  The present invention relates to a radio communication device, a radio access system selection device, and a radio access system selection method.

  In conventional Internet access, TCP (Transmission Control Protocol) is frequently used as a protocol. TCP is a protocol that realizes reliable and efficient communication, and has a confirmation response function in order to realize reliable communication.

  As an upper layer using TCP, HTTP (Hyper Text Transfer Protocol) represented by Web access is becoming the mainstream of Internet access in recent years. Web access is a protocol for acquiring data by accessing the Internet side from an IP (Internet Protocol) node side, and communication is started on the IP node side on which an HTTP client is mounted. The HTTP client is preinstalled in a normal personal computer (PC) generally installed at home or the like. A PC installed in a home or the like can access an Internet server via a broadband router or an optical line.

  In recent years, wireless routers that use a wireless access line to connect a PC or the like to the Internet via a broadband line or an optical line have appeared on the market. When viewed from a PC, the wireless router looks the same as a conventional broadband router, and the PC can communicate within the service area of the wireless access line regardless of location.

  In addition, as a router device for fixed lines, multi-home routers that accommodate two fixed lines, have two IP addresses as routers, and can use both lines simultaneously have appeared (for example, Patent Document 1). The multi-home router is used for the purpose of securing a protection line in preparation for a line failure, load distribution for dividing an access line for each PC, and separating an access between Internet access and an in-house VPN (Virtual Private Network).

  The concept of multihoming is not limited to fixed lines. For example, a wireless router accommodating a plurality of wireless access networks is also being considered, and when a plurality of wireless access lines are not used at the same time, communication is performed on one wireless access line and the use becomes impossible, the other wireless access line is used. It is considered to switch to.

  As a method for switching the radio access line when accommodating a plurality of radio access networks, for example, in Patent Document 1 below, if the mobile terminal is out of the access network used for communication and determines to switch the access line, the transition is made. A technique is disclosed that allows a session to be continued by notifying a server of session information and an IP address before movement through a previous access network.

JP 2004-265354 A

Macnica Networks Corp. , “Multihoming Router LinkProof”, http://www.macnica.net/radware/linkproof.html/

  Some wireless access networks serve a wide area and others serve a limited area. Services that cover a wide area tend to have a relatively narrow communication band, and services that limit an area tend to have a wide communication band. In Japan, the wide area service is a 3G (3rd Generation) mobile phone, and the services that limit the area are WiMAX (Worldwide Interoperability Access), wireless LAN (Local Area Network), DSRC (DedCorate RdCo There is.

  In Europe and the like, there are cases where the wide area service is a GSM (Global System for Mobile Communications) and the area limited service is a 3G area. As described above, the types of wireless access networks that can be used vary depending on the location, and cannot always provide the same communication environment. A wireless access network with a limited service area and a wireless access network with a wide service area are available. Are mixed.

  For the purpose of using different wireless access networks with different service areas, some mobile phones, smartphones, and wireless routers have a function of automatically switching to WiFi when WiFi is detected in the 3G area. However, with this function, since it is not possible to detect that it is out of the WiFi area, there is a problem in that communication is temporarily interrupted if it moves outside the WiFi area during communication.

  In addition, when moving by car, train, or the like, when WiFi is detected by the above function regardless of the movement status, it is automatically switched to WiFi. For this reason, there has been a tendency that problems such as inability to efficiently switch the wireless route depending on the movement situation appear significantly.

  In addition, when communicating with a predetermined access network to be used in advance, for example, even when a broadband wireless access network is available, a narrowband wireless access network is used, and the wireless access network cannot be used efficiently. There was a problem.

  The present invention has been made in view of the above, and is capable of reducing communication interruption and selecting an appropriate wireless access network according to a moving situation, a wireless access system selecting device, and a wireless access The purpose is to obtain a system selection method. Moreover, it aims at improving the utilization efficiency of a radio | wireless access network.

  In order to solve the above-described problems and achieve the object, the present invention includes a plurality of wireless processing units mounted on a mobile body, connected to an internal network in the mobile body, and corresponding to different wireless access networks, A wireless communication device that relays communication between the internal network and an external network via the wireless access network, and an area information holding unit that holds communication area information that is information of an available area for each wireless access network; Based on the speed information, a speed information acquisition unit that acquires speed information of the mobile object, a position information acquisition unit that acquires position information indicating a current position of the mobile object, and predicts a moving direction of the mobile object. Used as a relay route for communication between the internal network and the external network based on the moving direction, the position information, and the communication area information. Performing route selection processing for selecting the access network, characterized by comprising a path switching control unit for outputting data received from the internal network to the wireless processing unit corresponding to the selected radio access network, the.

  According to the present invention, it is possible to reduce communication interruption and to select an appropriate radio access network according to a moving situation. In addition, the utilization efficiency of the wireless access network can be improved.

FIG. 1 is a diagram illustrating a configuration example of a communication system according to an embodiment. FIG. 2 is a diagram illustrating an arrangement example of the wireless access network communication area. FIG. 3 is a diagram illustrating a functional configuration example of the wireless access device. FIG. 4 is a diagram illustrating an example of a protocol stack in the communication system according to the embodiment. FIG. 5 is a sequence diagram illustrating an example of an operation flow of the communication system. FIG. 6 is a flowchart illustrating an example of a route selection processing procedure. FIG. 7 is a diagram illustrating a concept of information stored in the communication area DB.

  Embodiments of a radio access system selection device, a communication system, and a radio access system selection method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

  FIG. 1 is a diagram showing a configuration example of a communication system according to the present invention. In the present embodiment, a wireless access device 1 mounted on a vehicle 4 such as an automobile will be described as an example of a wireless communication device according to the present invention. Here, although an example in which the vehicle 4 is an automobile will be described, the mobile body on which the wireless access device 1 is mounted is not limited to an automobile, and may be a train or the like.

  As shown in FIG. 1, the communication system according to the present embodiment includes a wireless access device 1, IP nodes 5-1 and 5-2, wireless access networks 7 and 8, and a server 10 on the Internet 9. Composed. The wireless access device 1 constructs an IP network inside the vehicle 4, and IP nodes 5-1 and 5-2 are connected to the IP network.

  The wireless access device 1 includes a wireless device 2 that performs wireless communication processing using a communication method corresponding to the wireless access network 7 and a wireless device that performs wireless communication processing using a communication method compatible with the wireless access network 8 (wireless processing unit). 3 and a selection control unit (radio access system selection device) 6. The wireless access device 1 is a wireless communication device having a multihoming function, and can simultaneously access the server 10 on the Internet 9 via two wireless access lines.

  FIG. 2 is a diagram illustrating an arrangement example of communication areas of a radio access network. An area 21 of the wireless access network 7 indicates an area that can be wirelessly connected to the wireless access network 7, and an area 20 of the wireless access network 8 indicates an area that can be wirelessly connected to the wireless access network 8. The wireless access network 7 provides a wide area service, and the wireless access network 8 provides a service in a limited area. For example, the vehicle 4 moves in the area 21 of the wireless access network 7 as indicated by an arrow in FIG. 2 and passes through the area 21 of the wireless access network 7.

  FIG. 3 shows a functional configuration example of the wireless access device 1. As illustrated in FIG. 3, the wireless access device 1 includes a path switching control unit 30, IP masquerade units 31 and 34, wireless devices 37 and 38, a TCP proxy processing unit 39, a speed information acquisition unit 40, a position An information acquisition unit 41, a GPS (Global Positioning System) receiver 42, and a communication area database (DB) 43 are provided. The communication area database (DB) 43 is stored in storage means (communication area information holding unit) in the wireless access device 1.

  The wireless devices 37 and 38 correspond to the wireless devices 2 and 3 shown in FIG. The path switching control unit 30, the IP masquerade units 31, 34, the TCP proxy processing unit 39, the speed information acquisition unit 40, the position information acquisition unit 41, the GPS receiver 42, and the communication area DB 43 are the selection control unit 6 shown in FIG. Configure.

  The TCP proxy processing unit 39 performs a process of once terminating the TCP link on the TCP data from the IP network inside the vehicle 4, and transmits the processed data to the path switching control unit 30. The TCP proxy processing unit 39 performs TCP link termination processing on the data received from the path switching control unit 30 and sends the data to the IP network.

  In the present embodiment, the TCP links of the IP nodes 5-1 and 5-2 inside the vehicle 4 are once terminated, and the TCP link is established with the communication destination via the wireless access network selected after selecting the communication path. In order to establish, a TCP proxy processing unit 39 is provided.

  The route switching control unit 30 receives the current location information of the vehicle 4 from the communication area DB 43 storing communication availability information (communication area information) for each radio access network corresponding to the map information and the GPS receiver 42. A position information acquisition function 41 to be acquired and a speed information acquisition unit 40 for acquiring speed information such as a vehicle speed pulse from an operation control system (not shown) of the vehicle 4 are connected. The GPS receiver 42 acquires its own position information by receiving a signal from a GPS satellite.

  The path switching control unit 30 receives the data received from the TCP proxy processing unit 39 based on the information acquired from the communication area DB 43, the position information acquisition unit 41, and the speed information acquisition unit 40, of the IP masquerade unit 31 or the IP masquerade unit 34. The received data is distributed to either.

  The IP masquerade unit 31 includes an IP address conversion unit 32 and an IP address conversion table 33. The IP masquerade unit 31 converts a local IP address (local address) used in the IP network inside the vehicle 4 into an IP address (address of the radio access network 7) assigned from the radio access network 7, and the local address and radio The correspondence with the address of the access network 7 is recorded in the IP address conversion table 33 as conversion information. Thereafter, based on the conversion information stored in the IP address conversion table 33, conversion of the address IP address of the radio access network 7 of the local address and conversion from the address IP address of the radio access network 7 to the local address are performed.

  The IP address conversion unit 32 is connected to the wireless device 37 and converts the IP address of data received from the wireless access network 7 via the wireless device 37 into a local address based on the conversion information stored in the IP address conversion table 33. To do.

  The IP masquerade unit 34 includes an IP address conversion unit 35 and an IP address conversion table 36. The IP masquerade unit 35 converts a local IP address used in the IP network inside the vehicle 4 into an IP address assigned by the radio access network 8 (address of the radio access network 8). The correspondence with the address is recorded in the IP address conversion table 36 as conversion information. Thereafter, based on the conversion information stored in the IP address conversion table 36, conversion of the address IP address of the radio access network 8 of the local address and conversion from the address IP address of the radio access network 8 to the local address are performed.

  The IP address conversion unit 35 is connected to the wireless device 38 and converts the IP address of data received from the wireless access network 8 via the wireless device 38 into a local address based on the conversion information stored in the IP address conversion table 36. To do.

  FIG. 4 is a diagram illustrating an example of a protocol stack in the communication system according to the present embodiment. In FIG. 4, the radio # 1 indicates a lower layer corresponding to the radio access network 7, and the radio # 2 indicates a lower layer corresponding to the radio access network 8. Ether indicates a lower layer corresponding to Ethernet (registered trademark). APP represents an application layer. The protocol stack in FIG. 4 is an example, and the protocol stack in the communication system is not limited to this.

  As shown in FIG. 4, in the wireless access device 1, the TCP link is once terminated for transmission / reception data between the IP node 5 inside the vehicle 4 and the server 10. In FIG. 4, the IP nodes 5-1 and 5-2 are generalized and described as the IP node 5 without being distinguished. Further, in the wireless access networks 7 and 8, conversion between the wireless # 1, the wireless # 2, and the Ether is performed.

  FIG. 5 is a sequence diagram illustrating an example of an operation flow of the communication system according to the present embodiment. FIG. 6 is a flowchart illustrating an example of a route selection processing procedure of the route switching control unit 30. FIG. 7 is a diagram illustrating a concept of information stored in the communication area DB 43.

  Hereinafter, the operation of the present embodiment will be described with reference to FIGS. In general Internet access, access is started from the IP nodes 5-1 and 5-2 toward the Internet. FIG. 5 assumes that access is started from the IP nodes 5-1 and 5-2 and a TCP link is established from the IP node.

  When the TCP proxy processing unit 39 of the wireless access device 1 receives the TCP link establishment message (TCP Syn) transmitted from the IP node 5-1 and addressed to the server 10 (step S1), the path switching selection control unit 30 To the TCP Syn message. The route switching selection control unit 30 performs route selection processing with the TCP Syn message as a trigger (step S2). In FIG. 5, for simplification of the drawing, the TCP Proxy processing unit 39 is abbreviated as TCP Proxy 39, the route switching selection control unit 30 is selected as the selection control unit 30, and the IP masquerade units 31 and 34 are abbreviated as the NAPT units 31 and 34, respectively. ing. The route selection process in the route switching selection control unit 30 will be described later. Here, it is assumed that the route switching selection control unit 30 selects the wireless access network 7 by route selection processing.

  The TCP proxy processing unit 39 once terminates the TCP link and transmits a TCP Syn Ack, which is a response to the TCP Syn message, to the IP node 5-1 (step S3). The IP node 5-1 that has received TCP Syn Ack transmits Ack (step S4). Through the above processing, a TCP link is established between the IP node 5-1 and the TCP proxy processing unit 39, and data transmission / reception is performed between the IP node 5-1 and the TCP proxy processing unit 39 (step S5). ). The TCP proxy processing unit 39 holds data received from the IP node 5-1 until the establishment of a TCP link with the server 10 described later, and transmits the data held after the TCP link with the server 10 is established. To do.

  Note that the TCP proxy processing unit 39 may hold a message (TCP Syn or the like) received from the IP node 5-1 for establishing the TCP link until the TCP link is established with the server 10. The route switching selection control unit 30 may hold it. When the TCP proxy processing unit 39 holds a message for establishing a TCP link, the path switching selection control unit 30 notifies the TCP proxy processing unit 39 of the end of the path selection end process. When the route switching selection control unit 30 holds a message for establishing a TCP link, the message for establishing a TCP link received from the TCP proxy processing unit 39 is held until the route selection end processing is completed. In addition, as soon as the route selection end process is completed, the message is transferred based on the selection result. Here, it is assumed that the TCP proxy processing unit 39 holds a message for establishing a TCP link for completing the route selection process.

  On the other hand, when the route selection processing by the route switching selection control unit 30 is completed, the TCP Proxy processing unit 39 transmits a TCP Link establishment message (TCP Syn) to the route switching selection control unit 30, and the route switching selection control unit 30 Based on the selection result of the route selection process (selecting the wireless access network 7), the message is transmitted to the server 10 via the wireless access network 7 (step S6). Specifically, the path switching selection control unit 30 outputs the message to the IP masquerade unit 31. The IP masquerade unit 31 converts the local address of the IP node 5-1 in the message into an address assigned by the wireless access network 7, and transmits the address-converted message to the wireless device 37. The wireless device 37 transmits the message to the wireless access network 7, and the wireless access network 7 transfers this message to the server 10.

  When the server 10 receives the TCP Syn, the server 10 transmits a TCP Syn Ack as a response to the node 5-1, and this message is sent to the TCP Proxy processing unit via the wireless access network 7, the wireless device 37, and the IP masquerade unit 31. Arrive at 39 (step S7). Specifically, the wireless device 37 performs a predetermined reception process on the TCP Syn Ack received from the wireless access network 7 and then transmits it to the IP masquerade unit 31. The IP masquerade unit 31 converts the address assigned by the wireless access network 7 in the TCP Syn Ack into a local address of the IP node 5-1 and transmits it to the route switching selection control unit 30. The path switching selection control unit 30 transmits the received TCP Syn Ack to the TCP Proxy processing unit 39.

  When receiving the TCP Syn Ack, the TCP proxy processing unit 39 transmits the Ack to the server 10 (step S8). This Ack is transferred through the same route as the TCP Syn transfer in Step 6. Through the above processing, a TCP link is established between the TCP Proxy processing unit 39 and the server 10, and data is transmitted / received (step S9).

  Through these processes, TCp links are established between the IP node 5-1 and the TCP proxy processing unit 39, and between the TCP proxy processing unit 39 and the server 10, respectively. Thereafter, the IP node 5-1 is connected to the TCP proxy. Data can be transmitted / received to / from the server 10 via the processing unit 39, the route switching selection control unit 30, the IP masquerade unit 31, the wireless device 37, and the wireless access network 7.

  In the above description of the operation, an example in which the wireless access network 7 is selected is shown. However, there is a case where the wireless access network 8 is routed depending on the result of the route selection process. In this case, the TCP proxy processing unit 39 A TCP link is established with the server 10 via the route switching selection control unit 30, the IP masquerade unit 34, the wireless device 38, and the wireless access network 8.

  The upper side of the sequence diagram of FIG. 5 (up to step S9) corresponds to the operation when the vehicle 4 is not in the area 21 of the radio access network 7 and is not close to the area 20 of the radio access network 8. Here, it is assumed that the vehicle 4 moves within the area 21 of the radio access network 7 and passes through the area 20 of the radio access network 8 that overlaps with the area 21 of the radio access network 7 as shown in FIG.

  The lower side of FIG. 5 (after step S10) shows a sequence when the vehicle 4 is expected to move into the area 20 of the radio access network 8 within a predetermined time. In this state, when the IP node 5-2 transmits a TCP link establishment message (step S10), the TCP proxy processing unit 39 once terminates the TCP link and transmits a TCP Syn Ack (step S12). The IP node 5-2 transmits Ack (step S13). Then, a TCP link is established between the node 5-2 and the TCP proxy processing unit 39, and data is transmitted and received (step S14).

  The TCP proxy processing unit 39 notifies the route switching selection control unit 30 of a TCP link establishment message, and the route switching selection control unit 30 performs route selection processing (step S11). In this case, as described above, it is assumed that the wireless access network 8 is selected as a route because the mobile device moves into the area 20 of the wireless access network 8 within a predetermined time. The route switching selection control unit 30 selects the wireless access network 8 but is not an area where the wireless access network 8 can be used at that time, so the TCP proxy processing unit 39 is instructed to temporarily store data, and wireless access is performed. Wait until the vehicle 4 enters the area 20 of the net 8.

  Here, it is assumed that a connection confirmation inquiry message is transmitted to the wireless access network 8 as to whether or not the wireless access network 8 has entered the area 20, and the path switching selection control unit 30 generates a connection confirmation inquiry message. Then, the data is transmitted to the wireless access network 8 via the IP masquerade unit 34 and the wireless device 38 (step S15). This message is transmitted periodically, for example. When the path switching selection control unit 30 receives a response to the connection confirmation inquiry message (step S16), it determines that the route switching selection control unit 30 has entered the area 20 of the wireless access network 8, and stores it in the TCP proxy processing unit 39. Instruct to output a TCP link establishment message (TCP Syn). Based on the route selection result, the route switching selection control unit 30 transmits the TCP Syn received from the TCP proxy processing unit 39 to the server 10 via the IP masquerade unit 34, the wireless device 38, and the wireless access network 8 (step S17). .

  When receiving the TCP Syn, the server 10 transmits a TCP Syn Ack (step S18). This TCP Syn Ack arrives at the TCP Proxy processing unit 39 via the wireless access network 8, the wireless device 38 and the IP masquerade unit 34. When receiving the TCP Syn Ack, the TCP proxy processing unit 39 transmits Ack to the server 10 (step S19). Thereafter, the TCP proxy processing unit 39 transmits the retained data to the server 10 (step S20), and communication is performed between the IP node 5-2 and the server 10 via the wireless access network 8.

  Next, route selection processing performed by the route switching selection control unit 30 will be described. When TCP Syn is received, the route selection process is started. As shown in FIG. 6, the route switching selection control unit 30 first measures the current vehicle position (the current position of the vehicle 4) (step S31). Specifically, the route switching selection control unit 30 requests the position information acquisition unit 41 to acquire the current vehicle position. Based on the GPS information acquired by the position information acquisition unit 41 from the GPS receiver 42, The current position of the vehicle 4 is calculated. This calculation method is the same as the method in which normal car navigation calculates a position based on GPS information. Then, the route switching selection control unit 30 acquires the current vehicle position information from the position information acquisition unit 41 as a calculation result.

  The route switching selection control unit 30 acquires communication area information around the vehicle 4 from the communication area DB 43 based on the acquired current vehicle position information (step S32). With the periphery, for example, communication area information of a rectangular area including an area with a radius of 10 km centered on the current position of the vehicle 4 is acquired. In the communication area DB 43, the map information is divided into meshes, and communication enable / disable information of each wireless access network such as the wireless access network 7 and the wireless access network 8 is stored for each mesh. Assume that the mesh stored in the communication area DB 43 is, for example, a 500 m square mesh. In this case, a rectangular area including an area with a radius of 10 km around the current position of the vehicle 4 is 40 × 40, and the communication area information is 40 × 40 information.

  FIG. 7 shows the information stored in the communication area DB 43 in different colors for easy understanding. In FIG. 7, an area communicable with the radio access network 7 is shown as an area 51 without hatching, and an area communicable with the radio access network 8 is shown as an area 50 hatched. The current position 52 indicates the current position of the vehicle 4, and the predicted movement direction 53 indicates the assumed movement direction of the vehicle 4. Moreover, the mesh shown with the dotted line of FIG. 7 has shown the mesh by which information is stored in communication area DB43. FIG. 7 shows a concept, and the size of each mesh, the size of the vehicle 4 and the like do not represent the actual size or the like. In the communication area DB 43, information indicating whether or not the area is actually communicable with each wireless access network is stored for each mesh. In FIG. 7, an area where communication is possible for both the radio access network 7 and the radio access network 8 is illustrated as an area of the radio access network 8.

  The route switching selection control unit 30 calculates in which mesh the vehicle current position is located in the acquired peripheral communication area information (step S33). Then, based on the communication area information, it is determined whether or not a plurality of wireless access networks can be used within the mesh where the vehicle current position is located (step S34).

  When it is determined that a plurality of wireless access networks can be used (Yes in step S34), the route switching selection control unit 30 acquires the speed of the host vehicle from the speed information acquisition unit 40, and based on the acquired speed and speed history. Then, an average speed, which is an average value for a fixed time from the past to the present, is calculated (step S35). Here, it is assumed that the plurality of access networks shown in FIG. 2 are in both areas of the radio access network 7 and the radio access network 8 (that is, in both areas 20 of the radio access network 8). It is assumed that the speed information acquisition unit 40 measures the speed of the host vehicle at regular intervals based on, for example, vehicle speed pulses and holds these measurement results for a certain past time.

  The route switching selection control unit 30 predicts the moving direction based on the calculated average speed (step S36). For example, the average from the past 30 minutes to the present is obtained as the average speed, and the moving direction is predicted as proceeding northeast from the direction of the average speed. The movement direction may be a rough movement direction. For example, the direction of movement changes frequently because it bends frequently in the city center or the like, but it is only necessary to be able to determine whether or not the city center is moving toward the suburbs on average.

  The route switching selection control unit 30 determines whether the connection priority of the wireless access network 7 and the wireless access network 8 is a wireless access network (in this case, wireless access network) based on the communication area information, the average speed, and the prediction result of the moving direction. The time until the vehicle 4 exits from within the area 20 of the wireless access network 8 (assuming that the network 8 has a higher connection priority) is calculated (step S37). It is assumed that the path switching selection control unit 30 holds the relationship of connection priority with each wireless access network. Alternatively, the communication area information DB 43 may hold the priority of the radio access network together with the available radio access network. The route switching selection control unit 30 determines whether or not the calculated time is shorter than a predetermined set time (step S38). When the calculated time is shorter than the predetermined set time (Yes in step S38), the route switching selection control unit 30 determines that there is a high possibility of exiting from the area 20 of the wireless access network 8 during communication, and the route selection result. The wireless access network 7 is selected (step S39), and the process is terminated.

  If the calculated time is equal to or longer than the predetermined set time (No in step S38), the possibility of leaving the area 20 of the radio access network 8 during communication is low, so the radio access network 8 is selected as a route selection result (step S40). ), The process is terminated.

  On the other hand, if it is determined in step S34 that a plurality of wireless access networks are not available, the path switching selection control unit 30 calculates the average speed in the same manner as in step S35 (step S41). Then, the path switching selection control unit 30 predicts the moving direction based on the average speed as in step S36 (step S42).

  Next, the route switching selection control unit 30 calculates the time until entering the area 20 of the radio access network 8 based on the communication area information, the average speed, and the movement direction prediction result (step S43). Here, the time until entering the area 20 of the wireless access network 8 is calculated, but generally there is an access network other than the wireless access network that can be used at the current position in the communication area information. In addition, when the access network has a higher connection priority, the time required to enter the access network may be calculated.

  Then, the path switching selection control unit 30 determines whether or not the time calculated in step S43 is shorter than a predetermined set value (step S44). This predetermined set value may be different from the predetermined set value used in the determination in step S38 or may be the same.

  When the calculated time is shorter than the predetermined set value (step S44 Yes), the route switching selection control unit 30 determines that there is a high possibility that the user will soon enter the area 20 of the wireless access network 8, and the wireless access is performed as the route selection result. After selecting the network 8 and waiting for a certain time (for example, a time obtained by adding a predetermined margin time to the time calculated in step S43), a connection confirmation inquiry is performed to the radio access network 8 (step S45). Then, the path switching selection control unit 30 determines whether or not the connection has been confirmed by the connection confirmation inquiry (step S46), and when the connection has been confirmed (step S46 Yes), the process proceeds to step S40).

  If the connection cannot be confirmed due to the connection confirmation inquiry (No in step S46), the process proceeds to step S39. If the connection cannot be confirmed by the connection confirmation inquiry (No in step S46), the connection confirmation inquiry is further transmitted a predetermined number of times after a predetermined time, and the connection confirmation can be confirmed by the connection confirmation inquiry during that time. In this case, the process may proceed to step S40, and in the meantime, the process may proceed to step S39 when the connection confirmation cannot be confirmed by the connection confirmation inquiry.

  In the above processing, the case where all the wireless access networks are not used is not described. However, for example, it is determined in step S34 whether all the wireless access networks are usable, and all the wireless access networks are used. If it is determined that communication is not possible, the IP node 5 may be notified that communication is not possible, or the process may return to step S31 and wait until the wireless access network becomes available by movement. When waiting until the wireless access network becomes available or when it is not available even after waiting for a certain period of time, the IP node 5 may be notified that communication is not possible.

  Further, FIG. 3 shows an example in which the communication area DB 43 is held in the wireless access device 1, but a server on the Internet is held instead of the communication area DB 43, and the wireless access device 1 communicates from there. You may make it acquire area information. The wireless access device 1 includes a temporary storage unit (communication area information holding unit) that holds the acquired communication area information, and performs the above-described operation using the communication area information held in the storage unit. It may be.

  In the present embodiment, the wireless access network 8 having a narrow communication area has a higher data transfer rate than the wireless access network 7 having a wide communication area, so that the wireless access network 8 is selected with priority. However, the present invention is not limited to this, and the wireless access network may be selected using other priorities.

  In the present embodiment, the communication area DB 43 stores information on the wireless access network that can be used in each mesh for each mesh. However, the configuration of the communication area DB 43 is not limited to this, and the wireless access network is not limited to this. Any information configuration may be used as long as an area that can be used for each network can be grasped.

As described above, in the present embodiment, the route switching selection control unit 30 is based on the communication area DB 43 storing the wireless access network that can be used for each mesh, the current position, and the predicted moving direction. The wireless access network to be used is selected. Therefore, communication interruptions can be reduced, and an appropriate radio access network can be selected according to the movement status. In addition, the utilization efficiency of the radio access network can be improved.

  In addition, in this embodiment, it has communication area information, has a function of predicting the arrival time to the communication area by detecting the moving speed information and moving direction, and the TCP from the IP node 5 mounted in the moving body. The session start request is temporarily suspended, and the TCP session is started via the selected radio access network when entering the communicable area. Therefore, the utilization efficiency of the radio access network can be improved.

  With the configuration as described above, Internet access optimized for the communication area of the wireless access network accompanying the movement of the vehicle 4 can be realized. Specific effects include an improvement in total throughput, a reduction in communication cost, and an improvement in communication response.

DESCRIPTION OF SYMBOLS 1 Radio access apparatus 2,3,37,38 Radio apparatus 4 Vehicle 5,5-1,5-2 IP node 6 Selection control part 7,8 Radio access network 9 Internet 10 Server 20 Area of radio access network 8 21 Radio access Network 7 area 30 Route switching control unit 31, 34 IP masquerade unit 32, 35 IP address conversion unit 33, 36 IP address conversion table 39 TCP Proxy processing unit 40 Speed information acquisition unit 41 Position information acquisition unit 42 GPS receiver 43 Communication Area DB
50, 51 Area 52 Current position 53 Predicted movement direction

Claims (9)

Mounted on a mobile unit, connected to an internal network in the mobile unit, provided with a plurality of radio processing units respectively corresponding to different radio access networks, and relaying communication between the internal network and an external network via the radio access network A wireless communication device,
An area information holding unit for holding communication area information which is information of an available area for each wireless access network;
A speed information acquisition unit for acquiring speed information of the moving body;
A position information acquisition unit that acquires position information indicating a current position of the mobile body;
A radio access network that predicts a moving direction of the moving body based on the speed information and is used as a relay path for communication between the internal network and the external network based on the moving direction, the position information, and the communication area information. A path switching control unit that performs a path selection process for selecting and outputting data received from the internal network to the radio processing unit corresponding to the selected radio access network;
A wireless communication apparatus comprising:   The path switching control unit performs the path selection process when there is a connection request from the internal network to the external network. In the path selection process, a predetermined setting is performed based on the moving direction and the position information. A radio access network that obtains a predicted position of the mobile body after time and is used as the relay path based on a radio access network that can be used at the current position of the mobile body and a radio access network that can be used at the predicted position The wireless communication device according to claim 1, wherein the wireless communication device is selected.   The path switching control unit preferentially selects a radio access network having a high data transfer rate when two or more radio access networks are available at the current position of the mobile body. Item 2. The wireless communication device according to Item 1. The plurality of radio access networks include a first radio access network having a wide communication area and a second radio access network having a narrow communication area and a data transfer rate higher than that of the first radio access network. Including
When the second radio access network is not available at the current position of the mobile body and the second radio access network is available at the predicted position, the path switching control unit 4. The second radio access network is selected as a radio access network to be used, and a connection start with the second radio access network is instructed after waiting for the predetermined set time or longer. Wireless communication device. The plurality of radio access networks include a first radio access network having a wide communication area and a second radio access network having a narrow communication area and a data transfer rate higher than that of the first radio access network. Including
The path switching control unit can use the first and second radio access networks at the current position of the mobile body, and the second radio access network is not available at the predicted position. 4. The wireless communication apparatus according to claim 3, wherein when one wireless access network is available, the first wireless access network is selected as a wireless access network used as the relay route.   The path switching control unit can use the first and second radio access networks at the current position of the mobile body, and when the second radio access network is available at the predicted position, 6. The wireless communication apparatus according to claim 5, wherein the second wireless access network is selected as a wireless access network used as a relay path. The communication area information stores availability information indicating whether or not each radio access network can be used for each mesh area obtained by dividing the map into a mesh.
The route switching control unit performs the route selection process based on the availability information corresponding to the mesh region including the current position of the moving body. The wireless communication device according to one. The radio connected to a plurality of radio apparatuses respectively corresponding to different radio access networks, mounted on a mobile body, connected to an internal network in the mobile body, and used as a relay path for relaying communication between the internal network and an external network A wireless access system selection device for selecting an access network,
An area information holding unit for holding communication area information which is information of an available area for each wireless access network;
A speed information acquisition unit for acquiring speed information of the moving body;
A position information acquisition unit that acquires position information indicating a current position of the mobile body;
A radio access network that predicts a moving direction of the moving body based on the speed information and is used as a relay path for communication between the internal network and the external network based on the moving direction, the position information, and the communication area information. A path switching control unit that outputs data received from the internal network to the wireless device corresponding to the selected wireless access network;
A wireless access system selection device comprising: A plurality of wireless processing units mounted on a mobile body, connected to an internal network in the mobile body, and corresponding to different radio access networks, respectively, communicate between nodes in the internal network and external networks via the radio access network A wireless access system selection method in a wireless communication device that relays
An area information holding step for holding communication area information which is information of an available area for each wireless access network;
A speed information acquisition step of acquiring speed information of the moving body;
A position information acquisition step of acquiring position information indicating a current position of the mobile body;
A radio access network that predicts a moving direction of the moving body based on the speed information and is used as a relay path for communication between the internal network and the external network based on the moving direction, the position information, and the communication area information. A path switching control step of performing a path selection process for selecting and outputting data received from the internal network to the radio processing unit corresponding to the selected radio access network;
A wireless access system selection method comprising:

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