JP2014123850A - Router device and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique enabling a radio terminal to change over an access point without reconnection processing.SOLUTION: A router device (RT1) includes: a LAN communication unit (215) for local radio communication; a mobile communication unit (214) for transferring data received by the local radio communication to an external network; a storage unit (205) for storing terminal information including identification information to identify a radio terminal on the basis of each of one or more radio terminals connected to the router device to perform local radio communication; and when transferring communication with one or more radio terminals to another router device, a control unit (201) for transmitting the terminal information stored in the storage unit to the transfer destination router device.

Description

  The present invention relates to a router device and a program.

  In a wireless LAN, a plurality of networks (BSS: Basic Service Set) managed by one access point (wireless base station) are combined to form one network (ESS: Extended Service Set). The technology to configure is known. A wireless terminal belonging to the ESS can switch an access point to be connected according to a communication state or the like. In order to shorten access point switching time in ESS, the IEEE 802.11r standard (Non-Patent Document 1) specifies that terminal information related to security and QoS is shared in advance between access points.

IEEE802.11r, “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 2: Fast Basic Service Set (BSS).” July 2008.

  In IEEE 802.11r, when a wireless terminal switches a connection destination from one access point to another access point, it is necessary to perform a reassociation process (reconnection process) with the access point after the transition. When the reassociation process is performed, power is consumed in both the wireless terminal and the access point, and resources that can be used in the wireless LAN are also consumed. In view of this, an object of one aspect of the present invention is to provide a technique that enables a wireless terminal to switch access points without performing reconnection processing.

  In view of the above problems, the router device is a first communication means for performing local wireless communication, a second communication means for transferring data received by the local wireless communication to an external network, and the local wireless communication For each of one or more wireless terminals connected to the router device for communication, storage means for storing terminal information including identification information for identifying the wireless terminal; and the one or more wireless terminals When switching communication with a terminal to another router device, there is provided a router device comprising control means for transmitting terminal information stored in the storage means to a switching destination router device The

  The above means provides a technique that allows a wireless terminal to switch access points without performing reconnection processing.

It is a figure explaining an example of the whole composition of one embodiment of the present invention. It is a figure explaining the structural example of the wireless router of one Embodiment of this invention. It is a figure explaining the operation example of the wireless router of one Embodiment of this invention. It is a figure explaining the example of a table which the wireless router of one embodiment of this invention manages. It is a figure explaining an example of the terminal information packet of one embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. Throughout various embodiments, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, each embodiment can be appropriately changed and combined.

  With reference to FIG. 1, an example of the overall configuration of a communication system according to an embodiment of the present invention will be described. FIG. 1 shows a wireless LAN (local area network) 101, a mobile communication network 102, and the Internet 103. The wireless LAN 101 conforms to, for example, IEEE 802.11, and includes three wireless routers RT1 to RT3 and three wireless terminals STA1 to STA3. The wireless router (wireless router device) may be realized by a dedicated device, or may be realized by a computer that supports a plurality of communication technologies and provides a tethering function, such as a PC, a mobile phone, and a smartphone. Each of the wireless routers RT1 to RT3 functions as an access point in the wireless LAN 101, and an ESS is configured by the wireless routers RT1 to RT3. The wireless terminals STA1 to STA3 belong to this ESS. In the example of FIG. 1, the wireless LAN 101 includes three wireless routers RT1 to RT3. However, the present invention can be applied to an ESS including two or more wireless routers. In the example of FIG. 1, the wireless LAN 101 includes three wireless terminals STA1 to STA3. However, the present invention can be applied to any ESS including one or more wireless terminals.

  The wireless routers RT1 to RT3 also function as terminals in the mobile communication network 102 and connect to the mobile communication network 102 via the wireless base station BS. The mobile communication network 102 conforms to a standard such as LTE or 3G and is connected to the Internet 103. Each of the wireless terminals STA1 to STA3 is connected to an external network such as the mobile communication network 102 or the Internet 103 via the wireless routers RT1 to RT3. The wireless routers RT1 to RT3 may comply with any communication standard as long as the wireless terminals STA1 to STA3 can be relayed to an external network. It may be connected to a fixed communication network.

  In this embodiment, at each time point, only one of the plurality of wireless routers RT1 to RT3 constituting the wireless LAN 101 is in charge of communication with the wireless terminals STA1 to STA3. FIG. 1 shows a situation where only the wireless router RT1 is in charge of communication with the wireless terminals STA1 to STA3, and the other wireless routers RT2 and RT3 are not in charge of communication with the wireless terminals STA1 to STA3. The wireless routers RT2 and RT3 not in charge of communication with the wireless terminals STA1 to STA3 may be in a power saving state as described later. As will be described later, the wireless router in charge of communication with the wireless terminals STA1 to STA3 can be switched as appropriate. A common identifier is assigned to the plurality of wireless routers RT1 to RT3 constituting the wireless LAN 101, and the wireless terminals STA1 to STA3 communicate with the wireless routers RT1 to RT3 using the common identifier.

  As shown in FIG. 1, when the wireless router RT1 is in charge of communication with the wireless terminals STA1 to STA3, the wireless router RT1 notifies the common identifier to the wireless terminals in the coverage. The wireless terminal performs association processing (connection processing) with the wireless router RT1 using the notified common identifier, and connects to the wireless router RT1. In this association process, the wireless router RT1 assigns a unique terminal identifier (for example, AID: Association Identifier) to the wireless terminal in the wireless LAN 101. Since the association process can be performed by a method similar to that of the existing technology, a detailed description thereof will be omitted. Each of the plurality of wireless routers RT1 to RT3 configuring the wireless LAN 101 is assigned not only a common identifier but also a unique identifier unique to the wireless router. This unique identifier can be, for example, the MAC address of the wireless router.

  Next, a detailed configuration example of the wireless router in FIG. 1 will be described with reference to FIG. Since the wireless routers RT1 to RT3 in FIG. 1 may have the same configuration, a configuration example of the wireless router RT1 will be described below as a representative. The wireless router RT1 can include each component shown in FIG. These components may be implemented by hardware according to the characteristics, may be implemented by software, or may be implemented by a combination of hardware and software. The control unit 201 controls the entire operation of the wireless router RT1, and is implemented by a CPU, for example. The timer 202 has a timekeeping function. For example, the timer 202 starts timekeeping in response to an instruction from the control unit 201 and notifies the control unit 201 that a specified period has elapsed. The battery 203 supplies operating power to each component of the wireless router RT1. In the present embodiment, an example in which the wireless router RT1 operates with power supplied from the battery 203 is handled. However, in other embodiments, the wireless router RT1 may include a power adapter instead of or in addition to the battery 203, and can operate with power supplied from a commercial power source.

  The state switching unit 204 switches the state of the wireless router RT1 between a normal state and a power saving state. The normal state is a state in which the wireless router RT1 can perform router processing to be described later. The power saving state is a state in which the power consumption is less than that in the normal state, and can be realized, for example, by stopping the supply of power to some components of the wireless router RT1. For example, the power saving state may be a state where the entire wireless router RT1 is turned off, or a state where only the communication function is stopped.

  The storage unit 205 stores various information used by the wireless router RT1, and includes the unique identifier 206, common identifier 207, terminal information table 208, and router information table 209 shown in FIG. Programs and the like can also be stored. The storage unit 205 is implemented by a combination of, for example, a ROM and a RAM. The unique identifier 206 and the common identifier 207 are different from each other. Each of the unique identifier 206 and the common identifier 207 can be implemented as a pair of BSSID and ESSID. The wireless router RT1 has a multi-SSID function and can have a plurality of sets of BSSIDs and ESSIDs. For example, the wireless router RT1 has a pair of a unique BSSID (for example, XX: XX: XX: XX: XX: X1) and a unique ESSID (for example, abcd) as the unique identifier 206, and a common BSSID ( For example, YY: YY: YY: YY: YY: Y1) and a common ESSID (for example, xyz) are included. The common identifier 207 is an identifier that is used in common by the wireless routers RT1 to RT3 constituting the wireless LAN 101 as described above. Accordingly, the other wireless routers RT2 and RT3 also have a common BSSID (YY: YY: YY: YY: YY: Y1) and a common ESSID (xyz) as a common identifier 207. The common identifier may be manually set individually for each wireless router by the user of the wireless routers RT1 to RT3, or may be automatically set by the wireless routers RT1 to RT3 communicating with each other. The unique identifier 206 is a unique identifier that each of the wireless routers RT1 to RT3 constituting the wireless LAN 101 has as described above. For example, the wireless router RT2 may have a pair of a unique BSSID (XX: XX: XX: XX: XX: X2) and a unique ESSID (abcd) as a unique identifier. In this example, since the unique BSSIDs are different from each other, the unique identifier 206 of the wireless router RT1 and the unique identifier 206 of the wireless router RT2 are different from each other. The unique identifier 206 of the wireless router RT3 is also different from the unique identifier 206 of the wireless routers RT1 and RT2. The wireless routers RT1 to RT3 may use the MAC address assigned to the LAN communication unit 215 as the unique BSSID of the unique identifier 206.

  The terminal information table 208 holds information related to the wireless terminal connected to the wireless router RT1. The router information table 209 holds information regarding each of the wireless routers RT1 to RT3 constituting the wireless LAN 101. Here, specific examples of the terminal information table 208 and the router information table 209 will be described with reference to FIG. In the example shown in FIG. 4, each piece of information is held in a table format, but any format may be used as long as the information can be held for each wireless terminal or each wireless router. Each entry in the terminal information table 208 in FIG. 4A represents a wireless terminal that is currently connected to the wireless router RT1 (specifically, the association process has been completed). A column 401 represents names of wireless terminals. A column 402 represents a terminal identifier (for example, AID: association ID) uniquely assigned to a wireless terminal by the wireless router RT1. As will be described later, as the terminal identifier, a terminal identifier assigned to the wireless terminal by any of the plurality of wireless routers RT1 to RT3 configuring the wireless LAN 101 is shared by the wireless routers. A column 403 represents the MAC address of the wireless terminal. A column 404 represents a communication rate supported by the wireless terminal. Column 405 represents the IP address assigned to the wireless terminal.

  Each entry in the router information table 209 in FIG. 4B represents a wireless router constituting the wireless LAN 101. The wireless router constituting the wireless LAN 101 includes a wireless router that is not connected to any wireless terminal. For example, information on other wireless routers included in the coverage of the wireless router RT1 is registered in the router information table 209 of the wireless router RT1 by the user. A column 411 represents names of wireless routers. A column 412 represents a unique identifier uniquely assigned to the wireless router RT1. A column 413 represents the order in which the wireless routers are activated. The wireless router with the smaller value is activated with priority. A column 414 indicates the remaining battery level of the wireless router. When the wireless router is supplied with power from a commercial power source, the remaining battery level may be 100% regardless of the actual remaining battery level. The activation order may be updated based on the remaining battery level.

  With reference to FIG. 2 again, other components of the wireless router RT1 will be described. The terminal management unit 210 uses the terminal information table 208 to manage wireless terminals connected to the wireless router RT1. Specifically, the terminal management unit 210 performs association processing with a wireless terminal in the same manner as the existing technology, and when a wireless terminal is connected to the wireless router RT1, information on the wireless terminal is stored in the terminal information table 208. to add. In addition, when the wireless terminal connected to the wireless router RT1 is disconnected, the terminal management unit 210 deletes the information on the wireless terminal from the terminal information table 208. Furthermore, when the terminal management unit 210 receives terminal information from another wireless router, the terminal management unit 210 updates the terminal information table 208 of the storage unit 205 using the information. In addition to the terminal information table 208, the terminal management unit 210 can manage various information related to terminals such as information for connecting the wireless terminals STA1 to STA3 to an external network, such as DNS server information.

  The terminal information extraction unit 211 extracts terminal information from terminal information packets (described later) received from other wireless routers. The terminal information packet generation unit 212 generates a terminal information packet to be transmitted to another router. The packet identification unit 213 identifies whether the packet received by the LAN communication unit 215 is transmitted from a wireless terminal or transmitted from another wireless router, and any one of the constituent elements according to the identification result Forward the packet to

  The mobile communication unit 214 is a network interface for communicating with the radio base station BS of the mobile communication network 102, and may have existing configurations such as a baseband processing unit, an RF unit, and a SIM. The mobile communication unit 214 transfers the packet (data) received from the packet identification unit 213 to the mobile communication network 102. Also, the mobile communication unit 214 transfers the packet received from the mobile communication network 102 to the destination wireless terminals STA1 to STA3 through the LAN communication unit 215.

  The LAN communication unit 215 is a network interface for performing local wireless communication with a wireless terminal or another wireless router, and functions as an access point in the wireless LAN 101. The router management unit 216 uses the router information table 209 to manage the wireless routers that make up the wireless LAN 101. Details of the operation of the router management unit 216 will be described later.

  Next, an operation example of the wireless router according to the present embodiment will be described with reference to FIG. In the following description, the operation of the wireless router RT2 will be mainly described, but the other wireless routers RT1 and RT3 can operate in the same manner. Before the operation of FIG. 4 starts, it is assumed that the wireless LAN 101 is in the connection state shown in FIG. That is, wireless terminals STA1 to STA3 are connected to the wireless router RT1, and no wireless terminals are connected to the wireless routers RT2 and RT3. The wireless routers RT2 and RT3 are both in a power saving state. Each step shown below may be processed by executing a program read from the storage unit 205 by the control unit 201 of the wireless router RT2.

  In step S301, the state switching unit 204 switches the wireless router RT2 from the power saving state to the normal state. This switching may be performed manually by the user of the wireless router RT2 (for example, the wireless router RT2 may be turned on or the state may be switched through the user interface of the wireless router RT2), or the wireless terminal STA1. -It may be performed by an instruction from the wireless router RT1 in charge of communication with the STA3, or may be performed automatically when a time set in the timer 202 has elapsed.

  Next, in step S <b> 302, the LAN communication unit 215 receives the packet transmitted in the wireless LAN 101 and transfers it to the packet identification unit 213. In step S303, the packet identification unit 213 identifies whether the received packet is transmitted from any of the wireless terminals STA1 to STA3 or transmitted from another wireless router.

  When connecting to the wireless router RT1, the wireless terminals STA1 to STA3 transmit packets with the common identifier notified from the wireless router RT1 as a destination. Therefore, when the destination of the received packet is a common identifier, the packet identification unit 213 determines that the packet is transmitted from any of the wireless terminals STA1 to STA3 (“NO” in S303), and the process is as follows. Proceed to step S304. In this case, since the packet transmitted from any of the wireless terminals STA1 to STA3 should be processed by the wireless router RT1 at this time, the packet identification unit 213 discards the packet in step S304, and the process proceeds to S302. Return.

  On the other hand, the wireless routers RT1 to RT3 communicate with each other using their unique identifiers. Therefore, when the destination of the received packet is its own unique identifier, the packet identification unit 213 determines that the packet is transmitted from any of the wireless routers. In this case, the packet identification unit 213 determines whether the received packet is a terminal information packet.

  The terminal information packet is a packet used when exchanging terminal information between wireless routers. Referring to FIG. 5, an example of terminal information packet 500 transmitted from wireless router RT1 to wireless router RT2 is shown. A field 501 is a destination address of the terminal information packet 500, and in this example, a unique identifier (specifically, a unique BSSID of the unique identifier) of the wireless router RT2 that is the destination is entered. A field 502 is a transmission source address of the terminal information packet 500. In this example, a unique identifier of the wireless router RT1 that is the transmission source is entered. Fields 503 to 505 contain terminal information of the wireless terminals STA1 to STA3 connected to the wireless router RT1. Specific fields 506 to 509 of each terminal information contain information in columns 402 to 405 corresponding to the terminal information table 208 stored in the storage unit 205. Although not shown, the terminal information packet may also include a unique ESSID that is a unique identifier.

  Referring to FIG. 3 again, when the packet identification unit 213 determines that the received packet is a terminal information packet (“YES” in S303), the packet identification unit 213 transfers the packet to the terminal information extraction unit 211. In step S <b> 305, the terminal information extraction unit 211 extracts terminal information from the terminal information packet, and the terminal management unit 210 overwrites the extracted terminal information on the terminal information table 208 of the storage unit 205. As a result, the wireless router RT2 can take over the connection with the wireless terminals STA1 to STA3 from the wireless router RT1. Therefore, the wireless router RT2 performs router processing in S306. The wireless router RT2 may return an acknowledgment (ACK) to the wireless router RT1 that is the transmission source of the terminal information packet. The wireless router RT1 that has transmitted the terminal information packet performs a process of S309 described later and shifts to a power saving state.

  The wireless router RT2 can perform existing router processing as the router processing in S306. For example, the wireless router RT2 transfers packets received by the LAN communication unit 215 from the wireless terminals STA1 to STA3 to the mobile communication network 102 through the mobile communication unit 214. In addition, the wireless router RT2 transfers the packet received from the mobile communication network 102 to the wireless terminals STA1 to STA3 through the LAN communication unit 215. Further, the wireless router RT2 performs association processing in response to a connection request from a new wireless terminal (not shown), and adds the terminal information of the wireless terminal to the terminal information table 208 of the storage unit 205.

  Next, in S307, the state switching unit 204 determines whether the wireless router RT2 satisfies the stop process for stopping the router process in S306. If the stop condition is not satisfied (“NO” in S307), the process returns to S306, and the wireless router RT2 continues the router process. If the stop condition is satisfied (“YES” in S307), the process proceeds to S308. The stop condition may be an instruction from a user of the wireless router RT2 (for example, stop of the power supply of the wireless router RT2 or switching of the state through the user interface), or an instruction from another wireless router It may be that the time set in the timer 202 has elapsed.

  In S308, the terminal information packet generation unit 212 reads terminal information of the wireless terminal currently connected to the wireless router RT2 from the terminal information table 208, and generates a terminal information packet. Then, the terminal information packet is transmitted to any of the other wireless routers constituting the wireless LAN 101. The wireless router to which the wireless router RT2 should transmit the terminal information packet may be selected in any way. For example, the terminal information packet generation unit 212 transmits the terminal information packet to the wireless router with the highest activation order among the wireless routers managed by the router information table 209. When the confirmation response is returned from the wireless router, the terminal information packet generation unit 212 ends the process of S308. If the confirmation response does not return from the wireless router within a predetermined time, the terminal information packet generator 212 repeats the same processing for the wireless router with the next highest activation order.

  Finally, in step S309, the state switching unit 204 switches the wireless router RT2 from the normal state to the power saving state. As a result, the communication with the wireless terminals STA1 to STA3 performed by the wireless router RT2 so far is taken over by the wireless router that has received the terminal information packet in S308.

  The router information table 209 managed by each wireless router may be manually set and updated by the user, but can also be automated as follows. When a new wireless router is added to the wireless LAN 101, the wireless router broadcasts its own unique identifier and remaining battery capacity. When the router management unit 216 of the wireless router performing the router processing of S306 (that is, the wireless router in charge of communication with the wireless terminals STA1 to STA3 in the wireless LAN 101) receives such a broadcast, Information regarding the new wireless router is added to its own router management table 209. In step S308, the terminal information packet generation unit 212 transmits the information in the current router management table 209 to the destination wireless router together with the terminal information packet. As a result, the destination wireless router can know the information of the wireless router added while it is in the power saving state. Further, when transmitting the information of the router management table 209, the terminal information packet generation unit 212 may update the remaining battery level in the column 414 related to its own wireless router, and update the activation order accordingly.

  In the wireless LAN 101 described above, when the wireless router is switched, the terminal information of the wireless terminal connected to the switching source wireless router at that time is transferred to the switching destination wireless router. In addition, the wireless terminal communicates with the wireless router using a common identifier commonly assigned to all the wireless routers. Therefore, it is not necessary for the wireless terminal to perform a reassociation process when the wireless router is switched. As a result, power consumption is reduced in both the wireless terminal and the wireless router, and wireless resource consumption in the wireless LAN 101 is also reduced. In addition, the power consumption of the wireless router is further reduced by putting the wireless router that is not in charge of communication with the wireless terminal into a power saving state.

  The present invention is effective when, for example, power supply is cut off at an evacuation site at the time of a disaster and both the wireless router and the wireless terminal are driven by a battery. In such an environment, a plurality of devices that can function as a wireless router, such as a smartphone having a tethering function, can be used, and there is a demand for using these wireless routers to connect to an external network such as the Internet for a long time. . According to the present invention, since the power consumption of the wireless router is reduced, such a demand can be realized.

  In the above-described embodiment, the wireless LAN 101 is taken as an example of the local network. However, any network may be used as long as the connection information is managed by the wireless router. In the above-described example, the communication between the wireless routers RT1 to RT3 is performed via the wireless LAN 101. However, this communication may be performed via the mobile communication network 102, Bluetooth (registered trademark) or infrared rays. Other communication techniques such as communication may be used.

101 wireless LAN
102 mobile communication network 103 internet STA1 wireless terminal STA2 wireless terminal STA3 wireless terminal RT1 wireless router RT2 wireless router RT3 wireless router BS wireless base station

Claims (4)

A router device,
First communication means for performing local wireless communication;
Second communication means for transferring data received by the local wireless communication to an external network;
Storage means for storing terminal information including identification information for identifying the wireless terminal for each of one or more wireless terminals connected to the router device to perform the local wireless communication;
Control means for transmitting terminal information stored in the storage means to a switching destination router apparatus when switching communication with the one or more wireless terminals to another router apparatus, Router device. The router device includes a battery for supplying power to the router device,
The router device according to claim 1, wherein the control unit switches the router device to a power saving state after transmitting the terminal information to the switching destination router device. The storage means further stores a unique identifier unique to the router device and a common identifier shared between the switching destination router devices,
The control means notifies the common identifier as an identifier of the router device to a wireless terminal that requests connection to the router device, and assigns identification information for identifying the wireless terminal. The router device according to claim 1 or 2.   The program for functioning a computer as a router apparatus in any one of Claims 1 thru | or 3.