Method for actively confirming whether a candidate node is a mesh gate

Abstract

The present invention discloses a method for actively confirming whether a candidate node is a mesh gateway, including: when the current record of the network device indicates that the candidate node is not a mesh gateway, if the network device receives a first notification from the candidate node indicating that the candidate node is a mesh gateway, causing the network device to update the current record and start counting a preset time to confirm that the candidate node is a mesh gateway before the end of the count of the preset time; when the network device does not receive an updated first notification from the candidate node indicating that the candidate node is a mesh gateway before the end of the count of the preset time, causing the network device to send an inquiry packet to the candidate node to confirm whether the candidate node is a mesh gateway; and after the network device sends the inquiry packet, when the network device receives an updated first notification or a first reply packet from the candidate node indicating that the candidate node is a mesh gateway, causing the network device to re-count the preset time and confirm again that the candidate node is a mesh gateway before the end of the count of the preset time.

Description

[0001] This application is a divisional application of the parent application with an application date of March 26, 2019, an application number of 201910233811.9, and an invention title of "Method for Wireless Connection and Actively Confirming Whether a Candidate Node is a Mesh Gateway". Technical Field

[0002] The present invention relates to a mesh network, and in particular to a wireless connection method for a mesh network, a method for actively confirming whether a candidate node is a mesh gateway, and a method for determining a main mesh gateway. Background Art

[0003] The IEEE 802.11s standard specification is used for mesh networking. According to the current IEEE 802.11s standard specification, if a mesh station has the same mesh profile as another mesh station and the basic rates and encryption capabilities of both parties match, these two stations are candidate peers of each other and can be directly interconnected. All mesh stations with the same mesh profile that are directly or indirectly interconnected form a Mesh Basic Service Set (MBSS). In an MBSS, all mesh stations that can directly connect to other non-mesh networks through a Distributed System (DS) are called mesh gates. Other mesh stations in the MBSS can indirectly access network resources outside the MBSS through one or more mesh gates in the MBSS. In this technical field, the aforementioned distributed system is an architecture for interconnecting basic service sets.

[0004] However, according to the current IEEE 802.11s standard specification, two mesh stations can be interconnected as long as they have the same mesh profile. This may allow a group of mesh stations with the same mesh profile to form multiple non-intercommunicating MBSSs through different channels (for example: channels of a wireless local area network, such as the 14 channels in the 2.4 GHz band), and some of these MBSSs may not contain mesh gates, so that these parts of the MBSSs cannot communicate with external networks.

[0005] In addition, according to the current IEEE 802.11s standard specification, a mesh station acting as a mesh gateway in an MBSS advertises itself as the mesh gateway through a broadcast packet. Since the current IEEE 802.11s standard specification lacks a retransmission and acknowledgment mechanism, other mesh stations in the MBSS cannot actively confirm whether this mesh station still acts as the mesh gateway, nor can they actively confirm whether there are other available mesh gateways in the MBSS.

[0006] In addition, when there are multiple mesh gateways in an MBSS that can access the same distributed system, there will be more than one path between this MBSS and this distributed system. Therefore, the network formed by combining this MBSS and this distributed system may generate a path loop, resulting in a network broadcast storm. The IEEE 802.11 standard specification solves the problem of network broadcast storms through the Rapid Spanning Tree Protocol (RSTP). RSTP blocks the critical path that causes the network to form a path loop in the network topology. Not only broadcast and multicast packets cannot be transmitted through this path, but unicast packets also cannot pass through this path. Therefore, the selection of the transmission path of unicast packets is restricted, and even a transmission bottleneck may occur. Summary of the Invention

[0007] An object of the present invention is to provide a wireless connection method, a method for actively confirming whether a candidate node is a mesh gateway, and a method for determining a primary mesh gateway to avoid the problems of the prior art.

[0008] An embodiment of the wireless connection method of the present invention is executed by a network device in a Mesh Basic Service Set (MBSS), the MBSS includes N mesh gateways, N is a positive integer, and the embodiment includes the following steps: when the network device is not one of the N mesh gateways and is not connected to any of the N mesh gateways, allow the network device to connect to a gate candidate peer in the MBSS, and prohibit the network device from connecting to a non-gate candidate peer in the MBSS, where the gate candidate peer claims that it is one of the N mesh gateways, or claims that it is connected to one of the N mesh gateways, and the non-gate candidate peer does not claim that it is any of the N mesh gateways, nor does it claim that it is connected to any of the N mesh gateways; and when the network device is one of the N mesh gateways or is connected to any of the N mesh gateways, allow the network device to connect to the gate candidate peer, and also allow the network device to connect to the non-gate candidate peer. According to the above, this embodiment ensures that the network device is a mesh gateway or ensures that the network device is directly or indirectly connected to a mesh gateway.

[0009] An embodiment of the method for actively confirming whether a candidate node is a mesh gateway of the present invention is executed by a network device in a Mesh Basic Service Set (MBSS), the MBSS includes the candidate node, and the embodiment includes the following steps: when a current record of the network device indicates that the candidate node is not the mesh gateway, if the network device receives a first notification from the candidate node indicating that the candidate node is the mesh gateway, let the network device update the current record and start counting a preset time to confirm that the candidate node is the mesh gateway before the end of the count of the default time; when the network device does not receive an updated first notification from the candidate node indicating that the candidate node is the mesh gateway before the end of the count of the default time, let the network device send an inquiry packet to the candidate node to confirm whether the candidate node is the mesh gateway; and after the network device sends the inquiry packet, when the network device receives the updated first notification or receives a first reply packet from the candidate node indicating that the candidate node is the mesh gateway, let the network device re-count the default time and confirm again that the candidate node is the mesh gateway before the end of the count of the default time. According to the above, this embodiment ensures that the network device can actively know whether the candidate node is a mesh gateway without passively waiting for the declaration of the candidate node.

[0010] An embodiment of a method for determining a primary mesh gateway in a mesh basic service set (MBSS) of the present invention is performed by a network device in the MBSS, the MBSS including a plurality of mesh gateways. The embodiment includes the following steps: When the network device is not one of the plurality of mesh gateways, causing the network device to receive information of the plurality of mesh gateways, so that the network device processes the information of the plurality of mesh gateways according to a default algorithm to know that one of the plurality of mesh gateways is the primary mesh gateway; When the network device is one of the plurality of mesh gateways and the plurality of mesh gateways includes the network device and M mesh gateways, causing the network device to receive information of the M mesh gateways, so that the network device processes the information of the network device and the information of the M mesh gateways according to the default algorithm to know which one of the plurality of mesh gateways is the primary mesh gateway; and prohibiting mesh gateways other than the primary mesh gateway among the plurality of mesh gateways from sending and receiving a non-unicast packet through a distributed system. According to the above, this embodiment only allows the primary mesh gateway to send and receive a non-unicast packet through the distributed system, thereby avoiding broadcast storms caused by multiple mesh gateways accessing the distributed system.

[0011] Regarding the features, actual operations, and effects of the present invention, preferred embodiments will be described in detail below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 showing an embodiment of the wireless connection method of the present invention;

[0013] Figure 2 showing another embodiment of the wireless connection method of the present invention;

[0014] Figure 3 showing an embodiment of the method for actively confirming whether a candidate node is a mesh gateway of the present invention;

[0015] Figure 4 showing an embodiment of the first / second reply packet;

[0016] Figure 5 showing another embodiment of the method for actively confirming whether a candidate node is a mesh gateway of the present invention;

[0017] Figure 6 showing a finite state machine to present Figure 3 and Figure 5 embodiments of; and

[0018] Figure 7 showing an embodiment of the method for determining a primary mesh gateway in a mesh basic service set of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS ​​​​​​​

[0019] Figure 1 An embodiment of the wireless connection method of the present invention is executed by a network device in a Mesh Basic Service Set (MBSS), where the MBSS includes N mesh gates, and N is a positive integer. Figure 1 The embodiment includes the following steps:

[0020] Step S110: When the network device is not one of the N mesh gates and the network device is not connected (neither directly nor indirectly) to any of the N mesh gates, allow the network device to connect to any gate candidate peer in the MBSS, and prohibit the network device from connecting to any non-gate candidate peer in the MBSS, where each gate candidate peer claims that it is one of the N mesh gates, or claims that it is connected (either directly or indirectly) to one of the N mesh gates, and each non-gate candidate peer does not claim that it is any of the N mesh gates, nor does it claim that it is connected to any of the N mesh gates. It should be noted that in the MBSS, each network device periodically sends beacons to let other devices know whether there are gate candidate peers.

[0021] Step S120: When the network device is one of the N mesh gates or the network device is connected (either directly or indirectly) to any of the N mesh gates, allow the network device to connect to any gate candidate peer, and also allow the network device to connect to any non-gate candidate peer.

[0022] Figure 2 Another embodiment of the wireless connection method of the present invention is shown, where the network device is a wireless network device. Compared with Figure 1 , Figure 2 The embodiment further includes:

[0023] Step S210: In the case where the network device is not one of the N mesh gates and is not connected (neither directly nor indirectly) to any of the N mesh gates, when the network device cannot connect to other devices in the MBSS via a current channel (for example, a channel of a wireless local area network, such as the 14 channels in the 2.4 GHz band) within a predetermined time, let the network device select a channel from M channels or stay on the current channel. More specifically, when M>0, step S210 makes the network device select the channel from the M channels; when M = 0, step S210 makes the network device continue to use the current channel. As described above,Figure 2 Embodiments can, when the network device is unable to communicate (directly or indirectly) with any of the N mesh gateways via the current channel for a long time, cause the network device to attempt to communicate (directly or indirectly) with any of the N mesh gateways via other channels. In a practical operation example, step S210 includes: causing the network device to perform a channel scanning operation to discover the M channels, where information of a candidate node in the MBSS exists in each of the M channels, declaring the candidate node as or connected (directly or indirectly) to one of the N mesh gateways; and causing the network device to select the channel from the M channels according to a default rule (for example: according to the signal strength, signal stability, connection rate, etc.).

[0024] It should be noted that in the foregoing embodiments, to ensure that all devices in the MBSS can be directly or indirectly connected to a mesh gateway, the network device and other devices in the MBSS both execute the wireless communication method; however, this is not a limitation of the implementation of the present invention. It should also be noted that in the foregoing embodiments, the MBSS complies with the current IEEE 802.11s standard specification; however, this is not a limitation of the implementation of the present invention.

[0025] Figure 3 Displays an embodiment of a method for actively confirming whether a candidate node is a mesh gateway according to the present invention. This embodiment is executed by a network device in a mesh basic service set (MBSS), and the MBSS includes the candidate node. Figure 3 The embodiments include the following steps:

[0026] Step S310: When a current record of the network device indicates that the candidate node is not the mesh gateway, if the network device receives a first notification (for example: Figure 6 "GANN of Mesh_A = 1") from the candidate node indicating that the candidate node is the mesh gateway, cause the network device to update the current record and start counting a preset time to confirm that the candidate node is the mesh gateway before the end of the count of the preset time.

[0027] Step S320: When the network device does not receive an updated first notification (for example: Figure 6 "GANN of Mesh_A = 1") from the candidate node indicating that the candidate node is the mesh gateway before the end of the count of the preset time, cause the network device to send an inquiry packet (for example: Figure 6 "Tx PREQ to Mesh_A") to the candidate node to confirm whether the candidate node is the mesh gateway.

[0028] Step S330: After the network device sends the inquiry packet, when the network device receives the first update notification or a first reply packet (e.g., Figure 6 "PREP from Mesh_A = 1") from the candidate node indicating that the candidate node is the mesh gateway, the network device re - counts the preset time and re - confirms that the candidate node is the mesh gateway before the end of the count of the preset time. In a practical operation example, each of the inquiry packet and the first reply packet is a unicast packet. In a practical operation example, the inquiry packet conforms to the specification of the path request packet (PREQ) in the IEEE 802.11s standard specification, and the first reply packet conforms to the specification of the path reply packet (PREP) in the IEEE 802.11s standard specification; for example, as Figure 4 shown, the first reply packet 400 indicates whether the candidate node is the mesh gateway through the value (e.g., 0 or 1) of a bit B0 in a Flags field 410. According to the IEEE 802.11s standard specification, this bit B0 is a reserved bit, and the field 410 includes bits B0 - B7.

[0029] Figure 5 Shows another embodiment of the method for actively confirming whether a candidate node is a mesh gateway according to the present invention. Compared with Figure 3 , Figure 5 the embodiment further includes:

[0030] Step S510: When the current record of the network device indicates that the candidate node is the mesh gateway, if the network device receives a second notification (e.g., Figure 6 "GANN of Mesh_A = 0") from the candidate node indicating that the candidate node is not the mesh gateway, the network device updates the current record to confirm that the candidate node is not the mesh gateway.

[0031] Step S520: After the network device sends the inquiry packet, when the network device receives a second reply packet (e.g., Figure 6"(PREP from Mesh_A = 0)" indicates that the candidate node is not the mesh gateway, or in the case of not receiving the first update notice and the second notice, neither the first reply packet nor the second reply packet is received within another preset time (e.g., the aforementioned preset time), and the network device updates the current record to confirm that the candidate node is not the mesh gateway. In a practical operation example, each of the inquiry packet, the first reply packet, and the second reply packet is a unicast packet. In a practical operation example, each of the first reply packet and the second reply packet complies with the IEEE 802.11s standard specification for a path reply packet; for example, the first reply packet indicates that the candidate node is the mesh gateway through a first value (e.g., 1) of a bit in the flag field of the path reply packet, and the second reply packet (e.g., Figure 4 packet 400) indicates that the candidate node is not the mesh gateway through a second value (e.g., 0) of this bit, and this bit is a reserved bit according to the IEEE 802.11s standard specification.

[0032] Figure 3 and Figure 5 The embodiments of can be represented by Figure 6 a finite state machine. Figure 6 The finite state machine of includes three states, namely "the network device determines that the candidate node is not a mesh gateway", "the network device determines that the candidate node is a mesh gateway", and "the network device actively inquires whether the candidate node is a mesh gateway"; the paths between the three states represent state changes, and the arrow directions of the paths represent how the states change; the descriptions of the annotations of each path are shown in Table 1 below. In these annotations, non-bold words represent the conditions for state changes, and bold words represent the actions to be performed when the conditions are met.

[0033] Table 1

[0034]

[0035]

[0036] Figure 7 An embodiment showing a method for determining a primary mesh gate in a mesh basic service set (MBSS) of the present invention is executed by a network device in the MBSS, and the MBSS includes multiple mesh gateways. Figure 7 The embodiment of includes the following steps:

[0037] Step S710: When the network device is not one of the multiple mesh gateways, the network device is made to receive information of the multiple mesh gateways, so that the network device processes the information of the multiple mesh gateways according to a preset algorithm to know that one of the multiple mesh gateways is the main mesh gateway. In a practical operation example, step S710 makes the network device receive the information of the multiple mesh gateways periodically / aperiodically to know whether there is a new main mesh gateway.

[0038] Step S720: When the network device is one of the multiple mesh gateways and the multiple mesh gateways include the network device and M mesh gateways, the network device is made to receive the information of the M mesh gateways, so that the network device processes the information of the network device and the information of the M mesh gateways according to the preset algorithm to know which one of the multiple mesh gateways is the main mesh gateway. In a practical operation example, step S710 makes the network device send the information of the network device to the M mesh gateways periodically / aperiodically, and makes the network device receive the information of the M mesh gateways periodically / aperiodically, so that when at least one of the information of the network device and the information of the M mesh gateways changes, the network device processes the information of the network device, the information of the M mesh gateways, and the preset algorithm again to know which one of the multiple mesh gateways is the main mesh gateway. In a practical operation example, the preset algorithm gives priority to the stability of transmitting broadcast and multicast packets through a distributed system to determine the main mesh gateway; for example, when one of the multiple mesh gateways is connected to a distributed system via Ethernet, and other mesh gateways are connected to the distributed system via wireless network, according to the preset algorithm, the mesh gateway connected to the distributed system via Ethernet will be the main mesh gateway. In a practical operation example, when the transmission conditions of the multiple mesh gateways are the same, the mesh gateway with the smallest Media Access Control (MAC) address among the multiple mesh gateways is the main mesh gateway.

[0039] Step S730: Prohibit the mesh gateways other than the main mesh gateway among the multiple mesh gateways from sending and receiving a non-unicast packet through a distributed system (DS). In a practical operation example, the main mesh gateway is allowed to send and receive non-unicast packets and unicast packets through the distributed system; other mesh gateways are prohibited from sending and receiving non-unicast packets through the distributed system, but are allowed to send and receive unicast packets through the distributed system. In a practical operation example, the non-unicast packet is a broadcast packet or a multicast packet.

[0040] Please note that, on the premise that implementation is possible, those with ordinary knowledge in the technical field may selectively implement some or all of the technical features in any of the foregoing embodiments, or selectively implement the combination of some or all of the technical features in multiple foregoing embodiments (for example: Figure 5 The combination with the Figure 7 embodiment), thereby increasing the flexibility during the implementation of the present invention. Another thing to note is that, on the premise that implementation is possible, there is no order restriction for the steps of each method of the present invention. Also note that each method of the present invention may be in the form of a software and / or firmware, and is executed / implemented by a known or self-developed network device.

[0041] To sum up, the wireless connection method of the present invention can ensure that a network device is a mesh gateway or ensure that the network device is directly or indirectly connected to a mesh gateway; the method of actively confirming whether a candidate node is a mesh gateway of the present invention can ensure that a network device actively knows whether the candidate node is a mesh gateway without having to passively wait for the declaration of the candidate node; the method of determining a primary mesh gateway in a mesh basic service set of the present invention can avoid the broadcast storm caused by multiple mesh gateways accessing a distributed system.

[0042] Although the embodiments of the present invention are as described above, these embodiments are not used to limit the present invention. Those with ordinary knowledge in the technical field can make changes to the technical features of the present invention according to the explicit or implicit content of the present invention. All such changes may fall within the scope of patent protection sought by the present invention. In other words, the scope of patent protection of the present invention shall be subject to what is defined by the scope of the claims in this specification.

[0043]

Symbol Explanation

[0044] Steps S110 to S120

[0045] Step S210

[0046] Steps S310 to S330

[0047] Packet 400

[0048] Flag field (Flags) 410

[0049] Bits B0 to B7

[0050] Steps S510 to S520

[0051] Steps S710 to S730

Claims

1. A method for actively confirming whether a candidate node is a mesh gateway, which is executed by a network device in a mesh basic service set that includes the candidate node. The method includes: When a current record of the network device indicates that the candidate node is not the mesh gateway, if the network device receives a first notification from the candidate node indicating that the candidate node is the mesh gateway, the network device updates the current record and starts counting a preset time to confirm that the candidate node is the mesh gateway before the end of the count of the preset time; When the network device does not receive an updated first notification from the candidate node indicating that the candidate node is the mesh gateway before the end of the count of the preset time, the network device sends an inquiry packet to the candidate node to confirm whether the candidate node is the mesh gateway; And After the network device sends the inquiry packet, when the network device receives the updated first notification or a first reply packet from the candidate node indicating that the candidate node is the mesh gateway, the network device recounts the preset time and again confirms that the candidate node is the mesh gateway before the end of the count of the preset time.

2. The method according to claim 1, further including: When the current record of the network device indicates that the candidate node is the mesh gateway, if the network device receives a second notification from the candidate node indicating that the candidate node is not the mesh gateway, the network device updates the current record to confirm that the candidate node is not the mesh gateway; and After the network device sends the inquiry packet, when the network device receives a second reply packet from the candidate node indicating that the candidate node is not the mesh gateway, or does not receive any of the first reply packet and the second reply packet within another preset time without receiving the updated first notification and the second notification, the network device updates the current record to confirm that the candidate node is not the mesh gateway.

3. The method according to claim 2, wherein each of the inquiry packet, the first reply packet, and the second reply packet is a unicast packet.

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