TWI701921B - Method for repairing wireless distribution system under software defined networking structure - Google Patents

Abstract

This invention provides a method for repairing wireless distribution system under software defined networking structure, which enables a wireless network base station that suffers the instability or loss of connection of the wired connection between the wireless base station and the switch to access the network by integration and automation of the wireless distribution systems and software defined network, such that users can maintain a good network connection and experience without re-selecting other base station connections.

Description

Method for repairing wireless distributed systems under software-defined network architecture law

The present invention relates to a method for repairing a wireless distributed system, in particular, to a method for repairing a wireless distributed system under a software-defined network architecture.

Traditional network routing protocols are limited by the decentralized management architecture. In traditional networks, to improve this phenomenon, multiple protocols must be applied, and all routers in the network environment must be supported. The layout design is too ideal , There is no room for flexible application.

Software-defined networking (SDN) is an emerging network architecture in recent years. Its concept is to separate the control-plane function from the data-plane function of the network, and to set or obtain switch information through the OpenFlow protocol, which is more flexible than the traditional network architecture.

The routing method of the existing technology previously applied to the ordinary SDN network environment is to create a rule table in the central processing module of the AP, or to add wireless network settings and function information to the OpenFlow protocol, such as China Patent Publication No. CN104602266 A No. and No. The application of CN105430688 No. A directly uses OpenFlow as a channel for transmitting instructions, and does not integrate the characteristics of the wireless network itself. It is not a good design and needs to be improved urgently.

In view of the deviation of the starting point of the above-mentioned conventional methods, the inventor of this case is eager to improve and innovate, and after continuous implementation of prototype systems and in-depth research, finally successfully developed this method for repairing wireless distributed systems based on the SDN environment.

To achieve the foregoing objective, the present invention provides a method for repairing a wireless distributed system under a software-defined network architecture, which includes: receiving control connections from multiple access points from a central controller through a switch; and through the central control The access point (AP) survival detection module of the device sends the basic service setting identifier to each access point to update and store the node information and topology, and then based on the switch and each access point To periodically determine whether each access point is still connected to the central controller; when the control connection between the switch and one of the access points does not exist, it appears When the access point is not connected, based on the node information and the topology stored by the AP survival detection module, the Wireless Distribution System (WDS) switching decision module searches for other most suitable available access points; and The WDS connection module receives the available access point searched by the WDS switching decision module to replace the unconnected access point with the available access point and send a message of success to the central controller.

In the aforementioned method, the step of periodically determining whether each access point is still connected to the central controller includes: periodically determining the control transmitted by each access point Control connection or through the statistics of the control connection recorded by the central controller to determine whether the control connection between each access point and the switch still exists; if so, the central controller records the Control the connection to update the node information and the topology, and synchronize the basic service setting identification code of each access point; and if it does not exist, activate the WDS switching decision module.

In the aforementioned method, the protocol for controlling the connection message is OpenFlow.

In the aforementioned method, the step of searching for other most suitable available access points by the WDS switching decision module includes: obtaining the node information from the AP survival detection module and forming a network topology; obtaining a decision-making judgment target ; Based on the network topology, list all possible alternative access points and simulate the combination of the possible alternative access points to search for the most suitable available access point; determine whether the most suitable available access point is applicable, If it is not applicable, return to the step of obtaining a decision-making judgment target to obtain another decision-making judgment target. If applicable, provide the most suitable setting of the available access point to the WDS connection module.

In the aforementioned method, wherein the decision-making target is a combination of at least one of wireless network quality, available bandwidth, network delay, throughput, system load, user connection information, and control connection statistical parameters.

In the aforementioned method, wherein the step of replacing the unconnected access point with the available access point includes: connecting to the available access point through a wireless distributed system; receiving and analyzing the return from the available access point Information; determine whether the available access point successfully replaces the unconnected access point, if not, return to the step of connecting the available access point through the wireless distributed system, if successful, send a success message to the center Controller.

The above-mentioned method for repairing the wireless distributed system under the software-defined network architecture is to integrate the wireless distributed system and the software-defined network, and make the software-defined network The central controller of the road dynamically obtains the required network information for use during repair, and uses the function of the wireless distributed system during repair, so that access points can be connected wirelessly, and at the same time continue to provide users with wireless networks Services to allow users to continue to use the network without disconnection.

The method proposed in the present invention for repairing the wireless distributed system under the software-defined network architecture is based on the centralized management spirit of the software-defined network, and is integrated and automated with the characteristics of the wireless distributed system. The wired connection is unstable or the wireless network base station that has lost the connection can be connected, so that the user does not need to re-select other base station connections to maintain a good network connection and experience. In other words, the present invention allows the user to continuously receive packets without being affected by the network disconnection, and the packets are sent to the user's previously connected access point through another access point, and finally delivered to the user , In this way, users can continue to use the Internet without being affected.

11‧‧‧Access Point/AP

12‧‧‧Control layer

13‧‧‧Controller

14‧‧‧Data layer

21‧‧‧SDN Central Controller

211‧‧‧AP Survival Detection Module

212‧‧‧WDS switching decision module

213‧‧‧WDS connection module

22‧‧‧Switch/Hub

23‧‧‧Access Point/AP

24‧‧‧Terminal device

31~37‧‧‧Step

411~415‧‧‧Step

421~425‧‧‧Step

431~435‧‧‧Step

Figures 1A and 1B are schematic diagrams of the existing network access point architecture and the access point architecture in the software-defined network environment.

Figure 2 is a schematic diagram of the repair mechanism of the wireless distributed system based on the software-defined network of the present invention.

Figure 3 and Figures 4A to 4C are flow charts of the method for repairing a wireless distributed system under a software-defined network architecture according to the present invention.

The present invention is a method for repairing a wireless distributed system under a software-defined network architecture. In a software-defined network (Software Defined Networks, SDN) environment, an access point (AP) is provided through WDS (Wireless Distribution System, WDS) connection allows users to maintain a good network connection and experience without having to re-select other base station connections.

Figures 1A and 1B are schematic diagrams of the existing network AP architecture and the network AP architecture in the SDN environment. In Figure 1A, the control layer 12 of the existing network AP architecture has various access points in a distributed manner. (AP)11 and the data layer 14 do not have the function of centralized control, so the information of each AP 11 cannot be fully grasped. In contrast, the data of the network AP 11 in the SDN environment in Figure 1B The layer 14 architecture has a centralized controller 13, so it can collect information about each AP 11, but the existing AP architecture does not have a mechanism to repair the wireless network in the SDN protocol.

Figure 2 is a diagram of the wireless distributed system architecture of the present invention, which includes an SDN central controller 21, a switch/Hub 22 connected to the SDN central controller 21, and multiple SDN wireless bases wirelessly connected to the switch/Hub 22 An access point (AP) 23, and a mobile terminal device 24 connected to the AP 23.

The central controller 21 includes three operation modules for repairing the wireless network: an AP survival detection module 211, a WDS switching decision module 212, and a WDS connection module 213.

The AP 23 to which the user's mobile terminal device 24 is connected has its back end connected to the switch/Hub 22 to connect to the Internet and be controlled by the central controller 21. Through the method for repairing a wireless distributed system of the present invention, when the AP 23 connected to the mobile terminal device 24 of the user is disconnected from the switch/Hub 22, the central controller 21 transmits the packet through another The AP 23 is transmitted to the AP 23 that the user is currently connected to, and then transmitted to the user, so that the user can continue to use the network service without being affected.

Figure 3 is a flow chart of the method for repairing a wireless distributed system of the present invention.

In step 31, the user connects to the SDN wireless base station AP1; in step 32, according to the AP survival detection module confirmation, the user can connect to the Internet; in step 33, determine whether the connection between AP1 and the switch is Interrupt, if yes, go to step 34, if not, go to step 32; in step 34, AP1 establishes a WDS connection with AP2 through the information provided by the SDN central controller; in step 35, judge AP2 Whether it is disconnected from the switch, if yes, go to step 36, if not, go to step 32; in step 36, AP1 uses the information provided by the SDN central controller to establish a WDS connection with other APs; in step 37 In the process, determine whether the AP and switch connected to AP1 are disconnected. If yes, go to step 36 to confirm whether there are other AP devices that can establish WDS alive, and re-establish the WDS connection based on the decision information. If not, go Go to step 32.

In one embodiment, the AP survival detection module 211 of the central controller 21 is used to collect and detect the connected AP information for the reference of the subsequent WDS switching decision module; the WDS switching decision module 212 serves as a network How to make WDS switching decision when the line connection is interrupted The WDS connection module is used as a reference for the subsequent WDS connection module; the WDS connection module 213 serves as an AP to perform WDS connection with other target APs according to the corresponding decision information after receiving the WDS switching decision module.

As shown in Figure 4A, the AP survival detection module 211, under the SDN architecture, all APs 23 will be connected to the central controller 21 through the switch/Hub 22. After the central controller 21 receives the connection message, Return the Basic Service Set ID (BSSID) belonging to each AP 23 to each AP 23, and according to whether the control connection between the AP 23 and the central controller 21 exists and the control connection statistics Message to determine whether the AP 23 is still connected (alive). When any AP 23 is disconnected from the switch/Hub 22 and needs to establish a WDS connection, the central controller 21 enables the AP 23 to establish a WDS connection from the information provided by it. The steps are as follows: In 411, the AP 23 initiates a control connection to the central controller 21; in step 412, the central controller 21 records the control connection to update the existing node information and form the topology information of the node connection. And send the BSSID to the AP 23; in step 413, the central controller 21 periodically sends the BSSID to the AP 23 to check the control connection, or judge whether the AP 23 is alive according to the recorded control connection; In step 414, whether the central controller 21 receives the message returned by the AP 23 to determine whether the AP is alive, if it is alive, go back to step 412, if not, go to the next step 415; and In step 415, the WDS switching decision module is activated.

The control connection of the AP 23 is used to make the central controller 21 count information, update the topology and synchronize the BSSID information to determine whether the AP 23 is alive, and the connection protocol used is OpenFlow.

As shown in Figure 4B, the WDS switching decision module 212 is activated when any AP is disconnected, and the central controller 21 updates the topology based on the node information stored in the AP survival detection module 211 to determine the WDS connection decision. The decision-making target of the WDS switching decision module 212 includes one or more of the following network parameter combinations: wireless network quality, available bandwidth, network delay, throughput, system load (CPU, memory), user connection Line information and control connection statistical parameters. The steps for executing the WDS switching decision module are as follows: in step 421, the AP survival detection module 211 obtains node information and establishes the overall network topology; in step 422 In step 423, all APs 23 that can be used for replacement are listed, and various combinations of AP 23 that can be used for replacement are simulated for verification, and the most suitable AP 23 is searched for; in step 424, the most suitable AP 23 is determined. Whether the available AP 23 is applicable, if the most suitable available AP 23 cannot be calculated, go back to step 422 to obtain a new decision and judgment target, otherwise go to the next step 425; in step 425, the calculated most suitable available AP 23 The settings of the AP 23 are provided to the WDS connection module 213.

As shown in Fig. 4C, after the judgment of the WDS switching decision module 212, the WDS connection module 213 is used for connection. The execution steps are as follows: In step 431, the available AP 23 from the WDS switching decision module 212 is received. Information; in step 432, connect to the available AP 23 in WDS mode; in step 433, receive and analyze the information returned by the available AP 23; In step 434, it is determined whether the available AP 23 has successfully replaced the non-surviving AP 23. If it is not successful, return to step 432, otherwise proceed to the next step 435; in step 435, send a success message to the central controller twenty one.

In short, the switching mechanism of the existing wireless network base station is not implemented under the SDN architecture, it is impossible to select the appropriate wireless network base station to obtain the wireless network signal, and it is impossible to achieve load balancing to properly distribute the network. Resources are given to users, and users cannot get a better network experience. Because SDN can obtain the entire network status and node information, and form a topology, it can better cope with various changes in the network. With SDN technology Gradually mature and widely used, using SDN's repair mechanism in wireless networks has the following advantages:

1. The present invention uses the AP survival detection module for survival detection, and the detection period and sensitivity can be adjusted quickly according to requirements.

2. The present invention uses the WDS switching decision module to decide the switching information, which can provide optimal decision-making and continuously introduce new decision-making methods.

The above detailed description is a specific description of a feasible embodiment of the present invention, but this embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification without departing from the technical spirit of the present invention shall be included in In the scope of the patent in this case.

To sum up, this case is not only innovative in terms of technical ideas, but also has the above-mentioned multiple functions that are not available in conventional traditional methods. It has fully met the requirements of novel and progressive statutory invention patents. I file an application in accordance with the law. Approval of this invention patent application to encourage invention, so that it is convenient.

21‧‧‧SDN Central Controller

211‧‧‧AP Survival Detection Module

212‧‧‧WDS switching decision module

213‧‧‧WDS connection module

22‧‧‧Switch/Hub

23‧‧‧Access Point/AP

24‧‧‧Terminal device

Claims (5)

A method for repairing a wireless distributed system under a software-defined network architecture includes: receiving control connections from multiple access points from a central controller through a switch; and through the access point of the central controller. , AP) Survival detection module, send basic service setting identification code to each access point to update and store node information and topology, and then based on the control connection between the switch and each access point, cycle To determine whether each access point is still connected to the central controller; when the control connection between the switch and one of the access points does not exist and an unconnected access point appears, according to The node information and the topology stored in the AP survival detection module are searched for by the Wireless Distribution System (WDS) switching decision module for other most suitable available access points; and the WDS connection module receives the The available access point searched by the WDS switching decision module, the WDS connection module establishes a WDS connection between the unconnected access point and the available access point, and transmits the WDS connection A message of success or failure is sent to the central controller; wherein, when the WDS connection is established between the unconnected access point and the available access point, the WDS connection module first connects to the Available access point to receive and analyze the information returned by the available access point, and then determine whether the available access point is successful in establishing the WDS connection with the unconnected access point. If not, then The WDS connection module connects to the available access point through the wireless distributed system again, and if it succeeds, the WDS connection module sends a successful message of the WDS connection to the central controller. For the method described in claim 1, wherein the step of periodically determining whether each access point is still connected to the central controller includes: periodically determining whether each access point transmits the Control connection or through the statistics of the control connection recorded by the central controller, determine whether the control connection between each access point and the switch still exists; if so, the central controller records the Control the connection to update the node information and the topology, and synchronize the basic service setting identification code of each access point; and if it does not exist, activate the WDS switching decision module. For the method described in item 1 of the scope of patent application, wherein the protocol for controlling the connection message is OpenFlow. For the method described in item 1 of the scope of patent application, the step of searching for other most suitable available access points by the WDS switching decision module includes: obtaining the node information from the AP survival detection module and forming a network topology Park; obtain the decision-making judgment target; list all possible alternative access points based on the network topology and simulate the combination of the possible alternative access points to search for the most suitable available access point; determine the most suitable available Whether the access point is applicable, if not, return to the step of obtaining a decision-making judgment target to obtain another decision-making judgment target, if applicable, provide the most suitable setting of the available access point to the WDS connection module. Such as the method described in item 4 of the scope of patent application, wherein the decision-making target is wireless network quality, available bandwidth, network delay, throughput, system load, user connection information, and control connection statistical parameters A combination of at least one of them.

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