Method and apparatus for grouping mobile nodes in extended wireless LAN

• US 20060268823A1
• Filed: 05/08/2006
• Published: 11/30/2006
• Est. Priority Date: 05/07/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Cho, Song-yean, Kim, Min-soo
• Granted Patent: US 8,295,254 B2
• Time in Patent Office: Days
• US Class Current: 370/349
• CPC Class Codes: H04W 40/22 using selective relaying for reaching a BTS [Base Transceiver Station] or an access point
• CPC Class Codes: H04W 40/24 Connectivity information management, e.g. connectivity discovery or connectivity update
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/22 with access to wired networks

Abstract

A method and apparatus for grouping wireless access points and re-grouping access points separated from a group in order to construct a clear and efficient transmission connection channel in an extended wireless LAN architecture are provided. Accordingly, a grouped mobile node determines disconnection of a connection channel to the group, and if the connection channel is disconnected, the mobile node searches for a connection channel to the existing group or a new group to re-subscribe thereto, so that all the mobile nodes can always be in a grouped state. As a result, it is possible to prevent broadcast storm in which broadcasted frames are repetitively transmitted along a loop in an extended wireless LAN architecture.

Claims

1. A method of allowing a mobile node subscribing in a predetermined group among a plurality of groups, each group constructed with mobile nodes that intercommunicate and have a function of frame-routing in a wireless network, to re-subscribe to any one of the groups, the method comprising:

determining whether or not a connection channel of the mobile node to the predetermined group is disconnected;

searching other connection channels of the mobile node to the plurality of groups based on a result of the determination; and

setting a connection channel of the mobile node to any one of the plurality of groups based on a result of the searching.

2. The method of claim 1, wherein in the searching the other channels, when the connection channel is determined to be disconnected, a connection channel, which is constructed with mobile nodes subscribing to an arbitrary group managed by a fixed node and through which the mobile node is connected, is searched.

3. The method of claim 1, wherein in the determining disconnection, when a predetermined frame, which is periodically received through a previously-set connection channel from a fixed node managing the predetermined group, is not received for a predetermined time period, the connection channel is determined to be disconnected.

4. The method of claim 1, wherein in the determining disconnection, when a routing path, through which the mobile node is connected to a fixed node managing the predetermined group and which is constructed with the mobile nodes of the predetermined group, is not searched by using a routing protocol, the connection channel is determined to be disconnected.

5. The method of claim 1, wherein in the determining disconnection, when a beacon frame, which a node that is closest to the mobile node in the predetermined group among nodes that construct a connection channel through which the mobile node is connected to a fixed node managing the predetermined group repeatedly transmits to all nodes within a predetermined distance, is not received for a predetermined time period, the connection channel is determined to be disconnected.

6. The method of claim 1, wherein in the determining disconnection, when identification information of fixed nodes recorded in a beacon frame which a node, which is closest to the mobile node in the predetermined group among nodes that construct a connection channel through which the mobile node is connected to a fixed node managing the predetermined group, transmits to all nodes within a predetermined distance is different from identification information of the fixed node managing the predetermined group, the connection channel is determined to be disconnected.

7. The method of claim 1, wherein in the determining disconnection, when a frame which a fixed node managing the predetermined group repeatedly transmits is not received for a predetermined time period, the connection channel is determined to be disconnected.

8. The method of claim 1, wherein in the searching the other channels, a routing path to a fixed node managing the predetermined group is searched using a routing protocol.

9. The method of claim 1, wherein the searching the other channels comprises:

determining whether or not a beacon frame, repetitively transmitted to all nodes within a predetermined distance by another fixed node other than a fixed node in the predetermined group or a mobile node subscribing to a group of another fixed node, is received; and

searching for a routing path to another fixed node using a routing protocol when the beacon frame is determined to be received.

10. A computer readable recording medium having embodied thereon a computer program for executing a method of allowing a mobile node subscribing in a predetermined group among a plurality of groups, each group constructed with mobile nodes that intercommunicate and have a function of frame-routing in a wireless network, to re-subscribe to any one of the groups, the method comprising:

determining whether or not a connection channel of the mobile node to the predetermined group is disconnected;

searching other connection channels of the mobile node to the plurality of groups based on a result of the determination; and

setting a connection channel of the mobile node to any one of the plurality of groups based on a result of the searching.

11. An apparatus serving as a mobile node having a function of frame-routing in a wireless network, the apparatus comprising:

a determination unit which determines whether or not to subscribe to a group managed by a fixed node connecting the wireless network with another network different from the wireless network when a frame including identification information of the fixed node is received;

a connection channel setting unit which sets a connection channel to the fixed node based on a determination of the determination unit; and

a transmission unit which transmits the identification information of the mobile node to the fixed node so as to allow the fixed node to register the mobile node as a member of the group.

12. The apparatus of claim 11, further comprising:

a disconnection detection unit which detects whether or not the set connection channel to the fixed node is disconnected; and

a re-subscription connection channel searching unit which searches for a connection channel so as to re-subscribe to the group or another group different from the group when the set connection channel is disconnected,

wherein the connection channel setting unit sets the searched connection channel as a new connection channel to a group that the mobile node subscribes to.

13. A method of allowing a fixed node, connecting a wireless network which includes mobile nodes that intercommunicate and have a function of frame-routing with another network different from the wireless network, to group the mobile nodes, the method comprising:

receiving a frame including identification information of a mobile node from the mobile node which is to subscribe to a group managed by the fixed node; and

registering the mobile node as a group member of the group managed by the fixed node based on the identification information of the mobile node.

14. The method of claim 13, further comprising broadcasting a frame including identification information of the fixed node in order to inform the mobile node of the presence of the fixed node,

wherein the broadcasted frame includes a sequence number having different value according to a time when the fixed node broadcasts the frame as information for determining whether or not the broadcasted frame is redundantly received by a recipient.

15. The method of claim 13, wherein the identification information indicates a MAC address.

16. The method of claim 13, wherein the mobile node is a wireless access point that manages a basic service set (BSS) including at least one mobile station.

17. A computer readable recording medium having embodied thereon a computer program for executing a method of allowing a fixed node, connecting a wireless network which includes mobile nodes that intercommunicate and have a function of frame-routing with another network different from the wireless network, to group the mobile nodes, the method comprising:

receiving a frame including identification information of a mobile node from the mobile node which is to subscribe to a group managed by the fixed node; and

registering the mobile node as a group member of the group managed by the fixed node based on the identification information of the mobile node.

18. An apparatus serving as a fixed node connecting a wireless network, which includes mobile nodes that intercommunicate and have a function of frame-routing, with a network different from the wireless network, the apparatus comprising:

an advertisement frame generation unit which generates a frame including identification information of the fixed node and repetitively broadcasts the frame to the wireless network; and

a group information storage unit which allows a mobile node to subscribe to a group managed by the fixed node by storing identification information of the mobile node transmitted from the mobile node which received the frame.

19. A method of subscribing to a group of mobile nodes that intercommunicate and have a function of frame-routing in a wireless network, the method comprising:

determining whether or not to subscribe to a group managed by a fixed node connecting the wireless network with a network different from the wireless network; and

setting a connection channel to the fixed node if subscription to the group is determined.

20. The method of claim 19, further comprising receiving a frame which includes identification information of the fixed node and which is a frame which the fixed node broadcasts in order to advertise the group,

wherein in the setting the connection channel, a parent node, from which the frame is directly transferred without passing through other nodes, is selected as a first node on a connection channel to the fixed node.

21. The method of claim 20, wherein when there are two or more parent nodes, only one of the parent nodes is selected to construct the connection channel.

22. The method of claim 19,

wherein the frame includes a sequence number having different value according to a time when the fixed node broadcasts the frame as information for determining whether or not the frame is redundantly received, and

wherein the setting the connection channel is performed only if the frame is determined not to be redundantly received based on the sequence number of the received frame.

23. The method of claim 19, wherein the mobile node is a wireless access point that manages a basic service set (BSS) including at least one mobile station.

24. A computer readable recording medium having embodied thereon a computer program for executing the method of subscribing to a group of mobile nodes that intercommunicate and have a function of frame-routing in a wireless network, the method comprising:

determining whether or not to subscribe to a group managed by a fixed node connecting the wireless network with a network different from the wireless network; and

setting a connection channel to the fixed node if subscription to the group is determined.