Roaming management method and program

Abstract

This enables rapid roaming between terminals and access points (APs). [Solution] A roaming management method for when a terminal connecting to an AP moves in an area where a WiFi network formed by multiple APs is configured, wherein when each AP is deployed, an AP list is stored in advance that records the relative positions of the APs, and when a terminal makes its first network connection to an AP, it receives the AP list from the AP it connected to, and when the terminal moves and re-roams with an AP, it refers to the contents recorded in the AP list to narrow down the candidate APs for network connection from among the multiple APs and performs the roaming operation.

Description

[Technical Field]

[0001] The present disclosure relates to a roaming management method and a program. [Background Art]

[0002] In recent years, portable wireless terminals such as tablet terminals that use wireless connection via WiFi (Wireless Fidelity) for connection to a data communication network have been widely used. In a system that assumes a user frequently carries such a terminal, roaming, which is reconnection between the terminal and a plurality of access points (APs), may occur frequently as the terminal moves. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2007-006320 [Summary of Invention] [Problem to be Solved by Invention]

[0004] Generally, when a terminal moves and the radio wave of the AP to which it is originally connected becomes weak, the terminal starts a roaming operation. For wireless terminals, a method is used in which scanning (Probe request / response) is performed for each channel (ch) to find a next AP to connect to, and the optimal AP is selected from among the APs that have returned a Probe response.

[0005] However, for a terminal, time is required for scanning the next AP to connect to and for the operation of selecting the optimal AP from among APs that returned Probe responses, so the overall roaming operation time may become long. In addition, when roaming takes a long time in a terminal, the response becomes slow, which causes a problem of reduced convenience.

[0006] As a typical example, Figure 7 illustrates the roaming operation involved in network connectivity between a terminal and an AP. In this example, terminal CL5 enters roaming mode when it moves and the signal from the AP it was originally connected to weakens. At this time, terminal CL5 performs a scan (probe request) on all channels to confirm the presence of nearby APs.

[0007] Subsequently, terminal CL5 selects the optimal AP based on the Probe response results, sends a unicast Probe request to that AP, and initiates the connection process. As a result, terminal CL5 completes the network connection with the optimal AP.

[0008] Thus, when a terminal searches for an AP, it needs to search all channels. For example, if the terminal and AP are using the 2.4GHz frequency band for communication, the terminal will send Probe requests 13 times, changing channels 1 to 13, and collect Probe responses. Alternatively, if the terminal and AP are using the 5GHz frequency band for communication, the terminal will need to collect data from 21 channels, from 36 to 140.

[0009] Furthermore, the terminal would broadcast probe requests for information gathering to multiple access points (APs), and after selecting an AP, it would send another probe request via unicast. In other words, the terminal was spending time sending and receiving data related to probe requests and responses to APs in two stages.

[0010] The roaming management method described herein aims to enable rapid roaming between terminals and access points (APs). [Means for solving the problem]

[0011] The roaming management method described herein involves multiple access points (APs) having an AP list pre-recorded of the relative positions of the APs when each AP is deployed. When a terminal makes its first network connection to an AP, it receives the AP list from the connected AP. When the terminal moves and re-roams with an AP, it refers to the contents recorded in the AP list to limit the number of APs to candidates for network connection from among the multiple APs and performs the roaming operation.

[0012] Furthermore, the roaming management program according to this disclosure is a roaming management program that is executed when a terminal making a network connection to an AP moves within an area where a WiFi network formed by multiple APs is configured. When multiple APs are deployed, an AP list recording the relative positions of the multiple APs is stored in advance. When the terminal makes its first network connection to an AP, it receives the AP list from the connected AP. When the terminal moves and re-roams with an AP, the terminal refers to the contents recorded in the AP list and performs roaming operations by limiting the number of APs to candidate APs for network connection from among the multiple APs. [Effects of the Invention]

[0013] According to this disclosure, roaming between terminals and APs can be achieved in a short amount of time. [Brief explanation of the drawing]

[0014] [Figure 1] This diagram shows an example of the processing flow related to this disclosure. [Figure 2] This is a diagram illustrating an example of a WiFi network configuration formed by multiple access points (APs) as described in this disclosure. [Figure 3] This diagram shows a terminal moving within an area where the WiFi network described in this disclosure is configured. [Figure 4] This diagram shows the reception of an AP list from an AP on the terminal related to this disclosure. [Figure 5]FIG. 1 is a diagram illustrating an example of the content described in an AP list according to the present disclosure. [Figure 6] FIG. 2 is a diagram illustrating an example of Probe requests and responses when re-roaming to a neighboring AP according to the AP list according to the present disclosure. [Figure 7] FIG. 3 is a diagram illustrating an example of Probe requests and responses when performing related roaming. DETAILED DESCRIPTION OF EMBODIMENTS

[0015] Embodiment 1 Hereinafter, a roaming management method will be described with reference to the drawings. FIG. 1 is a diagram illustrating an example of a processing flow of the roaming management method.

[0016] Furthermore, FIG. 2 shows an example of a WiFi network configuration formed by a plurality of APs shown in the diagram. More specifically, FIG. 2 is a top view diagram showing a state in which devices operating as four APs are arranged within a predetermined space. The process of the roaming management method shown in FIG. 1 is used in the WiFi network configuration of FIG. 2.

[0017] Here, as shown in FIG. 2, in the WiFi network configuration described below, it is assumed that AP1 to AP4 are arranged in a straight line. More specifically, AP2, AP3, and AP4 are arranged in order in the right direction from AP1 provided at the leftmost position.

[0018] Typically, AP1 to AP4 are devices that transmit and receive Wi-Fi radio waves. Here, each of AP1 to AP4 is a device that provides network connection via Wi-Fi radio waves to terminals capable of Wi-Fi network connection such as personal computers, smartphones, and game consoles, and also provides network connection to the Internet via optical cables or the like, but the present invention is not limited thereto.

[0019] Further, FIG. 3 is a diagram illustrating a state where a terminal CL5 held by a person moves rightward as the person moves, within an area where the WiFi network shown in FIG. 2 is formed. Here, the terminal CL5 is a so-called tablet terminal that establishes a network connection with an AP. Hereinafter, network connection may be simply referred to as connection.

[0020] As shown in FIG. 3, an operation when the terminal CL5 is initially connected to AP2, and then when the person moves rightward together with the terminal CL5 to connect to AP3 arranged adjacent to the right of AP2 will be described.

[0021] Returning to FIG. 1, first, the sequence of the initial connection between the terminal CL5 and AP2 is performed by the same method as the generally performed operation shown in FIG. 7. That is, the terminal CL5 broadcasts a Probe request to all APs, and connects to the AP determined to have the optimal radio wave condition. Accordingly, the terminal CL5 is brought into a state of being connected to AP2 (step S1).

[0022] At this time, the terminal CL5 receives an AP list stored in advance in AP2 (step S2). The AP list includes information on at least the positional relationship between a plurality of APs.

[0023] The terminal CL5 starts a re-roaming operation triggered by the weakening of radio waves from AP2 due to movement (step S3).

[0024] At this time, the terminal CL5 refers to the AP list to set a candidate AP as the next connection destination (step S4). Here, based on the records in the AP list, AP1 and AP3 arranged adjacent to AP2 are extracted.

[0025] The terminal CL5 determines, among the plurality of candidate APs for connection destination, an AP with strong radio waves as the network connection destination, and executes the roaming operation (step S5).

[0026] This allows the CL5 terminal to quickly re-roam with another AP when it moves away from the previously connected AP and the signal weakens, enabling re-roaming.

[0027] Embodiment 2 Next, we will describe an example of the detailed operation of terminal CL5 and AP in relation to the WiFi roaming management method. Here, as in Embodiment 1, as shown in Figure 3, terminal CL5 is initially connected to AP2, and then the detailed operation of connecting to AP3, which is located to the right of AP2, by moving to the right with terminal CL5 will be described.

[0028] First, the initial connection sequence between terminal CL5 and AP2 is performed in the same manner as the commonly performed operation shown in Figure 7. That is, terminal CL5 broadcasts a probe request to all APs and connects to the AP that is determined to have the optimal radio wave conditions. As a result, terminal CL5 is connected to AP2.

[0029] Next, as shown in Figure 4, when terminal CL5 makes its initial connection to AP2, it receives the AP list stored in the connected AP2. Here, we assume that terminal CL5 has made its initial connection to AP2 and has received the AP list file. The AP list is a data file created when APs are deployed, which records the relative positions of multiple APs in advance, and is stored in each AP.

[0030] This AP list can be used as a list of potential APs to connect to next when terminal CL5 leaves AP2.

[0031] Here, we will explain the AP list in more detail. Figure 5 is an example of an AP list. The AP list consists of information including the AP name to identify the AP, the MAC address (BSSID) for individual AP identification, the channel used by each AP, the placement order that shows the placement of the APs, and a No. that indicates the roaming order of the APs.

[0032] This AP list is created in advance by the network administrator when arranging each AP device as an element of the WiFi network, and is recorded on each AP.

[0033] Next, referring to Figure 6, we will explain the operation in which terminal CL5 moves away from AP2 and roams to AP3. That is, terminal CL5, which was connected to AP2 and received the AP list, moves to the right as shown in Figure 3, and enters the roaming operation triggered by the weakening of AP2's signal.

[0034] At this time, terminal CL5 performs an AP search based on the AP list it has received and holds from AP2. In this case, the AP list contains the information shown in Figure 5.

[0035] In this AP list, multiple APs are arranged in a single row, and their placement order is listed. The placement order is assigned a number, with AP1 being No. 1, AP2 No. 2, AP3 No. 3, AP4 No. 4, and so on. Therefore, terminal CL5 can consider APs with numbers immediately before and after the number of the currently connected AP as roaming candidates.

[0036] For example, terminal CL5 is currently connected to AP2, which is No. 2, and the APs assigned numbers No. 1 or No. 3 are on either side of it. Therefore, terminal CL5 will perform roaming operations, selecting AP1 (No. 1) and AP3 (No. 3) as the next roaming candidates.

[0037] In other words, terminal CL5 can consider APs assigned numbers immediately before and after the AP it was previously connected to (e.g., No. 1, No. 3) as APs that are close to the previously connected AP (e.g., No. 2), and can perform roaming operations using these as the next roaming candidates.

[0038] In other words, terminal CL5 has narrowed down the potential next connection destination APs to two based on the information listed in the AP list. Therefore, terminal CL5 does not search all channels, but only searches the channels listed in the AP list and can perform roaming operations.

[0039] At this time, the AP list held by terminal CL5 already contains the MAC addresses (BSSIDs) of the candidate APs. Therefore, terminal CL5 can send a Probe request via unicast, not broadcast, to the specified channel. In this case, terminal CL5 sends Probe requests to the two candidate APs, AP1 and AP3.

[0040] Subsequently, terminal CL5 selects the stronger signal from the two probe responses and attempts to connect to that AP. In this case, terminal CL5 can establish a network connection to AP3 because the signal from AP3 is stronger than the signal from AP1.

[0041] In this way, when terminal CL5 moves and re-roams with any AP, it can refer to the information recorded in the AP list to limit the number of APs to which it can connect and perform the roaming operation.

[0042] Typically, terminal CL5 can refer to the contents of the AP list and perform roaming operations by selecting multiple APs adjacent to AP2, to which it was previously connected, as the next connection candidates.

[0043] More specifically, terminal CL5 can connect to AP1 and AP3, two APs positioned on either side of AP2, which it was previously connected to, by sending and receiving information related to probe requests and responses, as potential next connection destinations.

[0044] As a result, while a typical channel scan requires scanning 13 channels for 2.4GHz and 21 channels for 5GHz, the WiFi roaming management method described in this disclosure requires only two channel scans, significantly reducing the number of scans to 2 / 13 or 2 / 21.

[0045] Furthermore, since the MAC address (BSSID) of the next candidate AP to connect to is recorded in the AP list received and held by the AP to which terminal CL5 is connected, the sequence of broadcast probe requests for AP discovery is unnecessary, and this step can be omitted.

[0046] Therefore, the WiFi roaming management method described herein enables the rapid execution of roaming operations between the terminal and the access point due to these two effects.

[0047] A third benefit is that the number of probe requests and probe responses for AP searching can be significantly reduced, which in turn significantly reduces the frequency of radio wave usage by wireless devices involved in roaming. Therefore, wireless devices can be utilized more effectively.

[0048] Although the present disclosure has been described above with reference to embodiments, the present disclosure is not limited to the embodiments described above. Various modifications to the structure and details of the present disclosure can be made as understandable to those skilled in the art within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0049] In the above explanation, the AP list primarily records the relationship between each AP and other APs, such as being the leftmost, to the left of other APs, or to the right of other APs, but it is not limited to this. For example, the AP list may also record information such as the location of the AP within a predetermined area where the APs are located, or the relative distance between APs, and terminal CL5 may use this information to determine the next candidate AP to connect to.

[0050] Furthermore, while the above explanation assumes that the next connection destination will be one of two APs adjacent to the currently connected AP, based on the information recorded in the AP list, this is not limited to this, and three or more APs may be considered as candidates.

[0051] Furthermore, while the above explanation assumes that AP1 and AP3 are the connection candidates, terminal CL5 may also include AP2, which it was previously connected to, as a connection candidate. In this case, if the signal strength of AP1 or AP3 is weaker than that of AP2, terminal CL5 can reconnect to AP2.

[0052] Furthermore, the above explanation assumes that multiple APs are arranged in a single line in a predetermined direction, as shown in Figures 2 and 3, but this is not limited to this configuration. For example, multiple APs may be arranged not only in the left-right direction as in Figure 3, but also in the up-down direction (for example, the depth direction within the area). In this case, the area shown in Figure 3 can be divided into sections in the up-down, left-right, and right directions, and the AP list can record which section within the area each AP is located in. Then, terminal CL5 can perform processing such as considering APs located in adjacent areas as candidates for the area of ​​the currently connected AP.

[0053] Similarly, the locations of multiple APs recorded in the AP list are not limited to two-dimensional information but may also be three-dimensional information. In this case, for example, terminal CL5 can search for multiple APs that are located close to AP2, which it was previously connected to, in a three-dimensional spatial relationship.

[0054] The above explanation assumed that each AP arranged in a line in one direction is assigned a No., and that APs that are close together are assigned the No. with the closest number. However, this can be adopted even when APs are not arranged in a line in one direction. In other words, even if multiple APs are not arranged in a line in one direction, adjacent APs are assigned the No. with the closest number. This allows terminal CL5 to efficiently set candidate APs for the next connection destination by referring to the assigned No.

[0055] Furthermore, when terminal CL5 newly connects to an AP, the timing of receiving the AP list from that AP can be the same as when the connection with the AP is established, but it is not limited to this timing. For example, it is also possible to configure the AP to send the AP list to terminal CL5 after a predetermined time has elapsed since the connection between terminal CL5 and the designated AP was established.

[0056] Each drawing is merely illustrative to illustrate one or more embodiments. Each drawing may be associated with one or more other embodiments rather than with only one specific embodiment. As those skilled in the art will understand, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings, for example, to create embodiments not explicitly shown or described. Not all features or steps shown in any one drawing to illustrate an exemplary embodiment are necessarily required, and some features or steps may be omitted. The order of steps shown in any of the drawings may be changed as appropriate.

[0057] Some or all of the above embodiments may also be described as follows, but are not limited to the following: (Note 1) Multiple APs have a pre-recorded AP list that records the relative positions of each AP when they are placed. The device is, When the initial network connection is established to the aforementioned AP, the AP list is received from the connected AP. When the terminal moves and re-roams with an AP, it refers to the contents recorded in the AP list and performs roaming by limiting the number of APs to a network connection candidate AP from among multiple APs. Roaming management methods. (Note 2) The aforementioned AP list is It includes records of at least the AP name, the MAC address for AP identification, the channel used by each AP, the placement order that indicates the AP's location, and a No. indicating the AP's roaming order. The roaming management method described in Appendix 1. (Note 3) The aforementioned terminal is By referring to the contents listed in the aforementioned AP list, probe requests, probe responses, and information related to the probe responses are sent and received via unicast to a limited number of network connection candidate APs. Roaming management method as described in Appendix 2. (Note 4) The aforementioned AP list includes: As a number indicating the roaming order of the APs, for each of the multiple APs, numbers are assigned to APs that are close to each other. The aforementioned terminal is Refer to the assigned number and configure the candidate AP for the next network connection destination. Roaming management method as described in Appendix 3. (Note 5) The aforementioned terminal is For the specified channel recorded in the AP list, Probe requests, Probe responses, and information related to Probe responses are sent and received. Roaming management method as described in Appendix 4. (Note 6) The aforementioned terminal is For the multiple network connection candidates APs set as the next network connection candidates, a roaming connection operation is performed with the AP with the strongest signal. Roaming management method as described in Appendix 5. (Note 7) The aforementioned terminal is By referring to the contents listed in the aforementioned AP list, the system will perform roaming operations by selecting multiple APs adjacent to the AP that was previously connected to the network as candidates for the next network connection. The roaming management method described in Appendix 6. (Note 8) The aforementioned terminal is The roaming operation is performed with the AP itself, which was previously connected to the network, included as the next network connection candidate. The roaming management method described in Appendix 7. (Note 9) The aforementioned AP list is Assuming that the aforementioned multiple APs are arranged in a single line, the order in which the APs are arranged is described. The roaming management method described in Appendix 6. (Note 10) A roaming management program that is executed when a terminal connecting to an AP moves within an area where a WiFi network formed by multiple APs is configured, When deploying multiple APs, an AP list is saved in advance, which records the relative positions of the multiple APs. When the terminal makes its first network connection to an AP, it receives the AP list from the connected AP. When the terminal moves and reroams with an AP, The aforementioned terminal, By referring to the contents recorded in the aforementioned AP list, the system narrows down the network connection candidates from multiple APs and performs roaming operations. Roaming management program.

[0058] Some or all of the elements described in Appendices 2 through 9 that are dependent on Appendice 1 may also be dependent on Appendice 10 in the same manner as those described in Appendices 2 through 9. Some or all of the elements described in any appendice may apply to various hardware, software, recording means, systems, and methods for recording software. [Explanation of symbols]

[0059] CL5 terminal

Claims

1. Multiple APs have a pre-recorded AP list that records the relative positions of each AP when they are placed. The device is, When the initial network connection is made to the aforementioned AP, the AP list is received from the connected AP. When the terminal moves and re-roams with an AP, it refers to the contents recorded in the AP list and performs roaming by limiting the number of APs to a network connection candidate AP from among multiple APs. Roaming management methods.

2. The aforementioned AP list is It includes at least the AP name, the MAC address for AP identification, the channel used by each AP, the placement order that indicates the AP's location, and a number indicating the AP's roaming order. The roaming management method according to claim 1.

3. The aforementioned terminal is Referencing the contents listed in the aforementioned AP list, Probe requests, Probe responses, and information related to Probe responses are sent and received via unicast to a limited number of network connection candidate APs. The roaming management method according to claim 2.

4. The aforementioned AP list includes: As a number indicating the roaming order of the APs, the APs are assigned numbers that are close to each other. The aforementioned terminal is Refer to the assigned number and configure the candidate AP for the next network connection destination. The roaming management method according to claim 3.

5. The aforementioned terminal is For the specified channel recorded in the AP list, Probe requests, Probe responses, and information related to Probe responses are sent and received. The roaming management method according to claim 4.

6. The aforementioned terminal is For the multiple network connection candidates APs set as the next network connection candidates, a roaming connection operation is performed with the AP with the strongest signal. The roaming management method according to claim 5.

7. The aforementioned terminal is By referring to the contents listed in the aforementioned AP list, the system will perform roaming operations by selecting multiple APs adjacent to the AP that was previously connected to the network as candidates for the next network connection. The roaming management method according to claim 6.

8. The aforementioned terminal is The roaming operation is performed with the AP itself, which was previously connected to the network, included as the next network connection candidate. The roaming management method according to claim 7.

9. The aforementioned AP list is Assuming that the aforementioned multiple APs are arranged in a single line, the order in which the APs are arranged is described. The roaming management method according to claim 6.

10. A roaming management program that is executed when a terminal connecting to an AP moves within an area where a Wi-Fi network formed by multiple APs is configured, When deploying multiple APs, an AP list is saved in advance, which records the relative positions of the multiple APs. When the terminal makes its first connection to an AP, it receives the AP list from the connected AP. When the terminal moves and reroams with an AP, The aforementioned terminal, By referring to the contents recorded in the aforementioned AP list, the system narrows down the number of APs to select candidate APs for connection and performs roaming operations. Roaming management program.

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