A method and router for preventing frequent roaming in an 802.11 wireless network

Abstract

This invention provides a method and router for preventing frequent roaming in 802.11 wireless networks, relating to the field of network communication technology. Applied in wireless mesh networks, each access point (AP) periodically measures the signal strength between itself and unassociated stations and quickly and effectively pushes this information to other APs. APs only measure the signal strength of stations already associated with other APs within the mesh network; the number of stations tested is limited, resulting in minimal system overhead. Before deciding whether to allow a station to roam, the associated AP checks for signal strength measurements received from other APs. If no AP with a signal strength better than the roaming threshold is found, the roaming operation is cancelled. The measured signal strength values ​​are broadcast between APs. Therefore, this invention can prevent frequent roaming of stations with minimal system overhead.

Description

Technical Field

[0001] This invention relates to the field of network communication technology, and in particular to a method and router for preventing frequent roaming in an 802.11 wireless network. Background Technology

[0002] IEEE 802.11 is the current standard for wireless local area networks (WLANs). It is a wireless network communication standard defined by the Institute of Electrical and Electronics Engineers (IEEE). An AP (Access Point) is the creator of a wireless network and the central node of the network. A typical home or office wireless router is an AP. A Station device is any terminal device connected to a wireless network (such as a laptop, PDA, or other network-connected user equipment).

[0003] In an 802.11 wireless mesh network environment, whether a station needs to roam depends on the signal strength between the station and its associated access point (AP). When a station wants to roam, it doesn't know if the signal strength between itself and the destination AP is suitable. If the signal strength between the station and its associated AP is below the roaming threshold, the AP will request the station to roam to another AP closer to it. The decision to roam is primarily based on the signal strength between the station and its associated AP. If the signal strength between the station and its associated AP is below a pre-set roaming threshold, the AP sends a roaming command to the station, instructing it to roam to an AP with a stronger signal. If the signal strength between the station and the AP it just roamed to is also below the roaming threshold, the station will have to roam again immediately after completing the roaming operation, resulting in frequent roaming. If the AP site associated with the Station can know in advance whether there is an AP site with a better signal to the Station in the mesh network before instructing the Station to roam, the AP site can know whether to cancel the roaming operation to avoid possible frequent roaming.

[0004] Therefore, it is necessary to provide a method and router for preventing frequent roaming in 802.11 wireless networks to solve the above-mentioned technical problems. Summary of the Invention

[0005] To address one of the aforementioned technical problems, this invention provides a method for preventing frequent roaming in an 802.11 wireless network. This method is deployed in an 802.11 wireless mesh network and establishes a low-overhead and efficient roaming processing flow between each AP site and each Station device in the wireless mesh network, thereby avoiding frequent roaming behavior of the Station devices.

[0006] Station device network access: The station device searches for the AP site with the strongest current receiveable signal strength and establishes an association with it, completing the station device network access and entering the wireless mesh network; the wireless mesh network continuously performs the roaming process;

[0007] Roaming Process: Each AP site in the wireless mesh network periodically performs signal measurements on Station devices that are not currently associated with the AP site. These measurements determine the signal strength between the AP site and the unassociated Station devices. After completing the measurement, the AP site quickly pushes the results to other AP sites in the wireless mesh network. When a Station device needs to roam, the AP site associated with that Station first checks if there is an AP site in the wireless mesh network with a signal strength better than the roaming threshold. If so, it sends a roaming execution command to the requesting Station; otherwise, it sends a roaming cancellation command.

[0008] The specific processing steps in the roaming process include: network association establishment, network signal detection, signal strength query, roaming operation judgment, and roaming operation execution.

[0009] As a further solution, the network association establishment process is performed when the Station device requests access to the wireless mesh network. It uses the 802.11k / v seamless roaming protocol to provide the Station device with information on the AP site with the strongest currently available signal strength, allows the exchange of network information with the Station device, and supports network-assisted roaming functionality. Among these features, the network-assisted roaming functionality allows the Station device to send roaming requests to associated AP sites, ensuring that the Station device can obtain better associated AP sites.

[0010] As a further solution, a network signal detection phase is periodically initiated in the wireless mesh network, enabling each AP site to know the signal strength value between itself and the corresponding unassociated Station device. The specific steps of the network signal detection phase include: determining the list of Station devices in the network and detecting the signal of the Station devices.

[0011] As a further solution, the steps for determining the list of stations within the network are as follows: Each AP site periodically summarizes the device information of the stations that have established a connection with it; Each AP site broadcasts the device information to each other; All device information is summarized to obtain the list of stations within the network.

[0012] Station device signal detection steps: Read the list of station devices in the network, and each AP site determines the device information one by one according to the list of station devices in the network; each AP site removes the device information of the established associations to obtain the device information of the unassociated station devices; each AP site determines the signal detection target through the device information of the unassociated station devices, and measures the corresponding signal strength value one by one; compile the signal strength values ​​between the station device and each AP site to obtain the signal strength list of the unassociated AP sites corresponding to the station device.

[0013] As a further solution, the signal strength value between the Station device and its corresponding associated AP site is continuously monitored and compared with a preset roaming threshold. If it is lower than the roaming threshold, the Station device sends a roaming request to the associated AP site. After receiving the roaming request, the associated AP site initiates the signal strength query process.

[0014] As a further solution, the signal strength query step is used to check whether there are AP sites in the current wireless mesh network that are better than the roaming threshold. The query is performed through the list of signal strength of unassociated AP sites. The list of signal strength of unassociated AP sites is read, and each signal strength value in the list is compared with the roaming threshold. If it exists, the corresponding unassociated AP site is recorded. If it does not exist, the roaming threshold comparison continues. After completing the roaming threshold comparison for all signal strength values ​​in the list, all unassociated AP sites with signal strength values ​​greater than the roaming threshold are recorded, and the AP site roaming list is obtained.

[0015] As a further solution, the roaming operation judgment step is used to determine whether the requesting roaming station has the network roaming conditions, in order to avoid frequent roaming behavior of the station; it obtains the AP site roaming list and performs roaming operation judgment:

[0016] If the AP site roaming list is empty, then request that the roaming Station device does not meet the network roaming conditions and send a roaming cancellation command;

[0017] If the AP site roaming list exists, request the roaming Station device to have network roaming conditions; record the AP site information corresponding to the current item, and send the roaming execution command;

[0018] The recorded AP site information is sent to the requesting roaming Station via the exchange network information to complete the roaming operation judgment step.

[0019] As a further solution, if there are two or more AP sites in the roaming list, the signal strength values ​​are sorted; the site with the highest signal strength value is selected, and the AP site information of the corresponding AP site is recorded; and a roaming execution command is sent.

[0020] As a further solution, the roaming operation execution process is as follows: The Station device receives roaming execution instructions / roaming cancellation instructions; when a roaming execution instruction is received, it receives AP site information and performs network roaming to complete the switching of associated AP sites; if a roaming cancellation instruction is received, it maintains the network connection with the currently associated AP site and cancels the current roaming request.

[0021] A router, deployed in a wireless mesh network employing 802.11, avoids frequent roaming behavior of station devices in the wireless mesh network by implementing a method for preventing frequent roaming in an 802.11 wireless network as described in any of the preceding claims.

[0022] Compared with related technologies, the method and router for preventing frequent roaming in an 802.11 wireless network provided by this invention have the following beneficial effects:

[0023] This invention is applied in wireless mesh networks. Each access point (AP) periodically measures the signal strength between itself and unassociated stations and quickly and efficiently pushes this data to other APs. APs only measure the signal strength of stations already associated with other APs within the mesh network, limiting the number of stations tested and minimizing system overhead. Before initiating roaming, each associated AP checks the signal strength data received from other APs. If no AP with a signal strength better than the roaming threshold is found, the roaming operation is cancelled. The measured signal strength values ​​are broadcast between APs. Therefore, this invention can avoid frequent roaming of stations with minimal system overhead, demonstrating significant practical and promotional value. Attached Figure Description

[0024] Figure 1 A preferred overall flowchart of a method and router for preventing frequent roaming in an 802.11 wireless network provided in this embodiment of the invention;

[0025] Figure 2 This is a flowchart of the scenario corresponding to the roaming cancellation command provided in an embodiment of the present invention;

[0026] Figure 3 This is a flowchart of the scene corresponding to the roaming execution command provided in an embodiment of the present invention;

[0027] The numbers in the upper left corner of the scene flowchart correspond to the sequence of the scene flow. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] like Figures 1 to 3 As shown, this embodiment provides a method for preventing frequent roaming in an 802.11 wireless network. It is deployed in a wireless mesh network using 802.11 and establishes a low-overhead and efficient roaming processing flow between each AP site and each Station device in the wireless mesh network to avoid frequent roaming behavior of the Station devices.

[0030] Station device network access: The station device searches for the AP site with the strongest current receiveable signal strength and establishes an association with it, completing the station device network access and entering the wireless mesh network; the wireless mesh network continuously performs the roaming process;

[0031] Roaming Process: Each AP site in the wireless mesh network periodically performs signal measurements on Station devices that are not currently associated with the AP site. These measurements determine the signal strength between the AP site and the unassociated Station devices. After completing the measurement, the AP site quickly pushes the results to other AP sites in the wireless mesh network. When a Station device needs to roam, the AP site associated with that Station first checks if there is an AP site in the wireless mesh network with a signal strength better than the roaming threshold. If so, it sends a roaming execution command to the requesting Station; otherwise, it sends a roaming cancellation command.

[0032] The specific processing steps in the roaming process include: network association establishment, network signal detection, signal strength query, roaming operation judgment, and roaming operation execution.

[0033] It's important to note that 802.11i wireless mesh users roam based on the signal strength between the station and its associated access points (APs). As the station moves further away from an AP, the signal strength decreases. When the signal strength falls below a pre-set threshold, the AP will request the station to switch to another AP with a stronger signal. However, the station doesn't know if there are other APs with sufficiently strong signals in the mesh network before roaming. During roaming, the station will choose an AP with a relatively strong signal to associate with. But sometimes, the signal strength of both the station and all APs in the mesh network is weak. This can lead to a situation where the station finds that the signal strength with the newly associated AP is also below the roaming threshold shortly after successfully roaming. The newly associated AP will then quickly initiate another roaming request. This results in the station frequently roaming between different APs, negatively impacting the user experience.

[0034] In this embodiment, each AP site periodically measures the signal strength between itself and unassociated Station devices and quickly and efficiently pushes this information to other AP sites. AP sites only measure the signal strength of Station devices already associated with other AP sites within the same mesh network; the number of Station devices tested is limited, resulting in minimal system overhead. Before deciding to allow a Station device to roam, the associated AP site checks the signal strength information received from other AP sites. If no AP site has a signal strength better than the roaming threshold, the roaming operation is canceled. The push of measured signal strength values ​​({AP site, Station device, RSS1}) between AP sites uses a broadcast method, which is reliable and has low system overhead.

[0035] As a further solution, the network association establishment process is performed when the Station device requests access to the wireless mesh network. It uses the 802.11k / v seamless roaming protocol to provide the Station device with information on the AP site with the strongest currently available signal strength, allows the exchange of network information with the Station device, and supports network-assisted roaming functionality. Among these features, the network-assisted roaming functionality allows the Station device to send roaming requests to associated AP sites, ensuring that the Station device can obtain better associated AP sites.

[0036] It should be noted that in the 802.11k / v seamless roaming protocol, the access point (AP) proactively sends messages to the terminal based on factors such as terminal signal strength and channel load, triggering the terminal to scan and report measurement information. The AP then compares these data and suggests and guides the terminal to roam. Clients supporting 802.11v can also send query messages before roaming to better select reassigned APs. Clients supporting 802.11k only need to probe the corresponding AP site on the specified channel, accelerating roaming and improving channel load.

[0037] As a further solution, a network signal detection phase is periodically initiated in the wireless mesh network, enabling each AP site to know the signal strength value between itself and the corresponding unassociated Station device. The specific steps of the network signal detection phase include: determining the list of Station devices in the network and detecting the signal of the Station devices.

[0038] As a further solution, the steps for determining the list of stations within the network are as follows: Each AP site periodically summarizes the device information of the stations that have established a connection with it; Each AP site broadcasts the device information to each other; All device information is summarized to obtain the list of stations within the network.

[0039] Station device signal detection steps: Read the list of station devices in the network, and each AP site determines the device information one by one according to the list of station devices in the network; each AP site removes the device information of the established associations to obtain the device information of the unassociated station devices; each AP site determines the signal detection target through the device information of the unassociated station devices, and measures the corresponding signal strength value one by one; compile the signal strength values ​​between the station device and each AP site to obtain the signal strength list of the unassociated AP sites corresponding to the station device.

[0040] As a further solution, the signal strength value between the Station device and its corresponding associated AP site is continuously monitored and compared with a preset roaming threshold. If it is lower than the roaming threshold, the Station device sends a roaming request to the associated AP site. After receiving the roaming request, the associated AP site initiates the signal strength query process.

[0041] As a further solution, the signal strength query step is used to check whether there are AP sites in the current wireless mesh network that are better than the roaming threshold. The query is performed through the list of signal strength of unassociated AP sites. The list of signal strength of unassociated AP sites is read, and each signal strength value in the list is compared with the roaming threshold. If it exists, the corresponding unassociated AP site is recorded. If it does not exist, the roaming threshold comparison continues. After completing the roaming threshold comparison for all signal strength values ​​in the list, all unassociated AP sites with signal strength values ​​greater than the roaming threshold are recorded, and the AP site roaming list is obtained.

[0042] As a further solution, the roaming operation judgment step is used to determine whether the requesting roaming station has the network roaming conditions, in order to avoid frequent roaming behavior of the station; it obtains the AP site roaming list and performs roaming operation judgment:

[0043] If the AP site roaming list is empty, then request that the roaming Station device does not meet the network roaming conditions and send a roaming cancellation command;

[0044] If the AP site roaming list exists, request the roaming Station device to have network roaming conditions; record the AP site information corresponding to the current item, and send the roaming execution command;

[0045] The recorded AP site information is sent to the requesting roaming Station via the exchange network information to complete the roaming operation judgment step.

[0046] As a further solution, if there are two or more AP sites in the roaming list, the signal strength values ​​are sorted; the site with the highest signal strength value is selected, and the AP site information of the corresponding AP site is recorded; and a roaming execution command is sent.

[0047] As a further solution, the roaming operation execution process is as follows: The Station device receives roaming execution instructions / roaming cancellation instructions; when a roaming execution instruction is received, it receives AP site information and performs network roaming to complete the switching of associated AP sites; if a roaming cancellation instruction is received, it maintains the network connection with the currently associated AP site and cancels the current roaming request.

[0048] A router, deployed in a wireless mesh network employing 802.11, avoids frequent roaming behavior of station devices in the wireless mesh network by implementing a method for preventing frequent roaming in an 802.11 wireless network as described in any of the preceding claims.

[0049] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preventing frequent roaming in an 802.11 wireless network, the method comprising: Deployed in a wireless mesh network using 802.11, and establish a low-overhead and efficient roaming process between each AP site and each Station device in the wireless mesh network to avoid frequent roaming behavior of Station devices; Station device network access: The station device searches for the AP site with the strongest current receiveable signal strength and establishes an association with it, completing the station device network access and entering the wireless mesh network; the wireless mesh network continuously performs the roaming process; Roaming Process: Each AP site in the wireless mesh network periodically performs signal measurements on Station devices that are not currently associated with the AP site. These measurements determine the signal strength between the AP site and the unassociated Station devices. After completing the measurement, the AP site quickly pushes the results to other AP sites in the wireless mesh network. When a Station device needs to roam, the AP site associated with that Station first checks if there is an AP site in the wireless mesh network with a signal strength better than the roaming threshold. If so, it sends a roaming execution command to the requesting Station; otherwise, it sends a roaming cancellation command. The specific processing steps of the roaming process include: network association establishment, network signal detection, signal strength query, roaming operation judgment, and roaming operation execution. The network association establishment process is performed when the Station device requests access to the wireless mesh network. It uses the 802.11k / v seamless roaming protocol to provide the Station device with information on the AP site with the strongest currently available signal strength, allows the exchange of network information with the Station device, and supports network-assisted roaming functionality. The network-assisted roaming functionality allows the Station device to send roaming requests to associated AP sites, ensuring that the Station device can obtain better associated AP sites. The specific steps in the network signal detection process include: determining the list of stations within the network and detecting station signals. The steps for determining the list of stations within the network are as follows: each AP site periodically summarizes the device information of the stations associated with it; each AP site broadcasts the device information to each other; and all device information is summarized to obtain the list of stations within the network. Station device signal detection steps: Read the list of station devices in the network, and each AP site determines the device information one by one according to the list of station devices in the network; each AP site removes the device information of the already associated devices to obtain the device information of the unassociated station devices; each AP site determines the signal detection target through the device information of the unassociated station devices and measures the corresponding signal strength value one by one; compile the signal strength values ​​between the station device and each AP site to obtain the signal strength list of the unassociated AP sites corresponding to the station device; The signal strength query step is used to check whether there are AP sites in the current wireless mesh network with a signal strength better than the roaming threshold. The query is performed using a list of unassociated AP sites' signal strengths. The list of unassociated AP sites' signal strengths is read, and each signal strength value in the list is compared with the roaming threshold. If a site exists, the corresponding unassociated AP site is recorded. If no site exists, the roaming threshold comparison continues. After completing the roaming threshold comparison for all signal strength values ​​in the list, all unassociated AP sites with signal strength values ​​greater than the roaming threshold are recorded, resulting in the AP site roaming list. If there are two or more AP sites in the roaming list, the signal strength values ​​are sorted. The site with the highest signal strength value is selected, and the corresponding AP site information is recorded. Finally, a roaming execution command is sent.

2. The method for preventing frequent roaming in an 802.11 wireless network according to claim 1, characterized in that, In a wireless mesh network, a network signal detection process is initiated periodically so that each access point (AP) can know the signal strength between itself and the corresponding station device that has not yet established a connection.

3. The method for preventing frequent roaming in an 802.11 wireless network according to claim 1, characterized in that, The system continuously monitors the signal strength between the Station device and its corresponding associated AP site and compares it with a preset roaming threshold. If the signal strength is lower than the roaming threshold, the Station device sends a roaming request to the associated AP site. Upon receiving the roaming request, the associated AP site initiates a signal strength query process.

4. The method for preventing frequent roaming in an 802.11 wireless network according to claim 1, characterized in that, The roaming operation judgment step is used to determine whether the requesting roaming station has the network roaming conditions, in order to avoid frequent roaming behavior of the station; it obtains the AP site roaming list and performs roaming operation judgment: If the AP site roaming list is empty, then request that the roaming Station device does not meet the network roaming conditions and send a roaming cancellation command; If the AP site roaming list exists, request the roaming Station device to have network roaming conditions; record the AP site information corresponding to the current item, and send the roaming execution command; The recorded AP site information is sent to the requesting roaming Station via the exchange network information to complete the roaming operation judgment step.

5. A method for preventing frequent roaming in an 802.11 wireless network according to claim 1, characterized in that, Roaming operation execution phase: The Station device receives roaming execution instructions / roaming cancellation instructions; when a roaming execution instruction is received, it receives AP site information and performs network roaming to complete the switching of associated AP sites; if a roaming cancellation instruction is received, it maintains the network connection with the currently associated AP site and cancels the current roaming request.

6. A router, characterized in that, Deployed in a wireless mesh network using 802.11, and by implementing a method for preventing frequent roaming in an 802.11 wireless network as described in any one of claims 1 to 5, frequent roaming behavior of Station devices in the wireless mesh network is avoided.

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