Topology system of wireless network with dynamic balance

• US 20080225809A1
• Filed: 03/15/2007
• Published: 09/18/2008
• Est. Priority Date: 03/15/2007
• Status: Active Grant

• Current Assignee: Alpha Networks Incorporated
• Original Assignee: Alpha Networks Incorporated
• Inventors: Guo, Ming-Wang
• Granted Patent: US 7,808,959 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 40/246 Connectivity information discovery

Abstract

The present invention is to provide a topology system of wireless network with dynamic balance comprising at least one subsidiary topology system of wireless network each having a plurality of access points and only one access point automatically becomes a root access point which operates on a channel different from others, and dynamically generates an unique derivative group ID different from others as the root access point linked with a wired network; other access points not linked with the wired network join one of subsidiary topology systems of wireless network according to loading and dataflow of the subsidiary topology systems of wireless network, and automatically become either a pure access point or an escape access point, dynamically generate an unique derivative group ID same as those linked with other root access points, and operate on a channel same as those linked with other root access points.

Claims

1. A topology system of wireless network with dynamic balance, comprising:

at least a root access point formed automatically when an initial access point of a topology system of wireless network is linked with a wired network, each of said root access point dynamically generating an unique derivative group ID, operating on its own channel after detection, and periodically declaring its status of existence;

at least a pure access point formed automatically after an initial access point of said topology system of wireless network not linked with said wired network establishing a link with an access point with the minimum loading and dataflow according to the status of existence received of each access point which has established a link, each of said pure access point having a same derivative group ID as the root access point linked with said pure access point does, operating on the same channel as the root access point linked with said pure access point does, and declaring its status of existence periodically; and

said root access points and the back-end pure access points linked therewith respectively forming a subsidiary topology system of wireless network, the access points of the same subsidiary topology system of wireless network transmitting data with the same channel, and different subsidiary topology systems of wireless network being with different channels, so the frames of each pure access point are transmitted to the wired network through the root access points with the same derivative group ID respectively.

2. A topology system of wireless network with dynamic balance of claim 1, wherein a default address group ID is given respectively in advance in each access point of said topology system of wireless network, and each access point which has not established a link or has been disconnected a link will become said initial access point automatically.

3. A topology system of wireless network with dynamic balance of claim 1, further comprising:

at least an escape access point which is an access point of said topology system of wireless network not linked with said wired network, a default address group ID given to said escape access point different from those of the root access points and pure access points of said topology system of wireless network, and said escape access point formed automatically after it establishes a link with a root access point or pure access point with the minimum loading and dataflow according to the status of existence received of each root access point or pure access point, said escape access point dynamically generating the same derivative group ID automatically as the root access point linked with said escape access point does, operating on the same channel as the root access point linked with said escape access point does, and declaring its status of existence periodically.

4. A topology system of wireless network with dynamic balance of claim 3, wherein a probe request frame is broadcasted respectively from each of said access points, and said status of existence is embedded therein.

5. A topology system of wireless network with dynamic balance of claim 4, wherein an information element is respectively appended to each of said probe request frames, and said status of existence is embedded in said probe request frame in the format of said information element, said information element comprising:

an Element ID field for storing an ID of said information element which is different from other used ID;

a Length field for storing the length of said information element, the length from the third byte to the last field of said information element;

a Default Address Group ID field for indicating the group ID that the access point prefers to join by default;

a Current Group ID field for indicating the group ID joined by the access point during operation which enables other access point to determine whether a specific group exists and operates normally, and the ID of said specific group is the derivative group ID of the subsidiary topology system of wireless network which the access point joins;

a Role of AP field which indicates the current role of the access point during operation under the scheme of present invention;

a Sequence field which indicates the sequence number of the latest information element known to show the existence of specific group;

a MACofRootAP field which indicates the MAC address of the root access point of said access point group;

a Hop Count field which indicates the amount of the links of both wireless and wired an access point of the wireless network topology should pass through to link with a wired network, wherein one of the link has to be a wired link while the others are wireless ones; and

a Service Hop Count field which indicates that for the access points not directly linked with a wired network, the service of a specific access point is necessary for said access points to link with the wired network, and the amount of said access points is the service hop count of said specific access point.

6. A topology system of wireless network with dynamic balance of claim 5, wherein said Role of AP field is an information mode field for indicating a role that said access point playing when transmitting said information element.

7. A topology system of wireless network with dynamic balance of claim 5, wherein the value of said Sequence field accumulates that each time the root access point sends a probe request frame with information element, and the access point of the same group takes the maximum value of said field received as the content to be sent.

8. A topology system of wireless network with dynamic balance of claim 5, wherein each root access point writes its MAC address into said MACofRoot field while each pure access point writes the MAC address of the root access point with which it links into said MACofRootAP field.

9. A topology system of wireless network with dynamic balance of claim 5, wherein said information element further comprises a RunOutofVport field for indicating whether an access point may establish a new wireless link or not.

10. A topology system of wireless network with dynamic balance of claim 9, wherein the value of said RunOutofVport field comprising:

a mode that said access point is not permitted to establish a new wireless link with other access point; and

a mode that said access point is permitted to establish a wireless link with other access point, and under said mode, the real time status of network dataflow of said access point must be provided in this field with which other access point may consider when establishing a link with it.

11. A topology system of wireless network with dynamic balance of claim 5, wherein said information element further comprises a Channel field for indicating the operation channel of the group.

12. A topology system of wireless network with dynamic balance of claim 5, wherein said information element further comprises an Escape mode field for indicating whether an access point is permitted to establish a link with another access point with different default address group ID.

13. A topology system of wireless network with dynamic balance of claim 12, wherein the value of said Escape mode field indicates that the access point is under a mode that the escape mode is permitted, the escape mode is not permitted or the escape mode is not permitted for all access points of the same group.

14. A topology system of wireless network with dynamic balance of claim 5, wherein said information element further comprises an Unique Selection Link field for indicating that among all access points within the range of the signal of a specific access point, there exists, only one access point with the smallest Hop Count field.

15. A topology system of wireless network with dynamic balance of claim 5, wherein according to the value of said Role of AP field, the role of each said access point comprises said root access point, said pure access point, said initial access point and an escape access point, and said escape access point indicates that the access point is linked with a wired network through linking with an access point with different default address group ID.

16. A topology system of wireless network with dynamic balance of claim 15, wherein said initial access point automatically detects all the channels to determine whether there exists a topology system of wireless network, and detects all the channels periodically to determine whether there exists a root access point when determined there is no other access point and it is not directly linked with a wired network.

17. A topology system of wireless network with dynamic balance of claim 16, wherein when linked with a wired network, said initial access point changes its status to root access point, and operates on a channel with less interference according to its result of detection of channels used by other root access points.

18. A topology system of wireless network with dynamic balance of claim 17, wherein said root access point periodically determines whether said wired network still exists, and returns to the status of initial access point when it is determined that its link with said wired network is cut for that said root access point is no longer capable of serving the back-end pure access points.

19. A topology system of wireless network with dynamic balance of claim 18, wherein said pure access point has to make sure that the root access point of the wireless topology system operates normally, if the root access point it links with could be constantly detected, the status of being a pure access point indicated by the value of the Role of AP field remains, and under this status, said pure access point may claim the existence of the wireless topology system and serve other access point with link service so as to expand the topology system of wireless network.

20. A topology system of wireless network with dynamic balance of claim 19, wherein when said pure access point is directly linked with a wired network, it will be capable of serving other access point and will return to the initial access point mode for detecting which channel is available so as to choose a proper channel for operation when acting as a root access point.

21. A topology system of wireless network with dynamic balance of claim 5, wherein the value of said Hop Count field comprising:

an optimal hop count which records the minimum value of the hop count among the frames received within the range of the signal when said access point hasn'"'"'t established a link and is under a temporary status; and

a current hop count which records the current hop count when said access point has established a link and is stable.

22. A topology system of wireless network with dynamic balance of claim 5, wherein the value of said Service Hop Count field comprising:

an optimal service hop count which records the optimal service hop count of all access points with optimal hop count when said access point hasn'"'"'t established a link and is under a temporary status; and

a current service hop count which records its current service hop count of said access point when it has established a link and is stable.