Multicast method in zigbee network

• US 20050180447A1
• Filed: 01/26/2005
• Published: 08/18/2005
• Est. Priority Date: 02/12/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd., The Research Foundation of State University of New York
• Original Assignee: City University of New York, Samsung Electronics Co. Ltd.
• Inventors: Liu, Yong, Lee, Myung-jong, Hu, Xu-hui, Lim, Yu-jin, Zhu, Chun-hui
• Granted Patent: US 7,564,786 B2
• Time in Patent Office: Days
• US Class Current: 370/432
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 4/08 User group management
• CPC Class Codes: H04W 40/32 for defining a routing cluster membership
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A method to manage nodes in a ZigBee network. In a ZigBee network including a plurality of nodes, a multicast group is generated including at least two nodes among the plurality of the nodes. A multicast group coordinator (GC) which manages the multicast group is set among the nodes forming the multicast group. The multicast group includes the GC, a multicast group member (GM) requesting to join the multicast group, and/or a multicast router (MR) which links GMs to each other or links the GC and the GC. Accordingly, since the GC manages the multicast group, the load is decreased and the packet data transmission rate is enhanced.

Claims

1. A method of managing a ZigBee network including a plurality of nodes, the method comprising:

generating a multicast group which includes at least two nodes among the plurality of the nodes; and

setting a multicast group coordinator (GC) which manages the multicast group among the at least two nodes forming the multicast group.

2. The method of claim 1, wherein the multicast group comprises at least one of the GC, a multicast group member (GM) requesting to join the multicast group, and a multicast router (MR) which links GMs to each other or links the GC and the GC.

3. The method of claim 2, wherein the GC sets the other nodes of the nodes forming the multicast group as ancestor nodes having a descendant node.

4. The method of claim 2, wherein the nodes forming the multicast group are assigned a multicast group address.

5. The method of claim 2, wherein the ZigBee network comprises a ZigBee coordinator (ZC), and a sub-multicast router (MR′

) which links the ZC and the GC.

6. The method of claim 5, wherein the MR changes its status to a GC if the MR requests to join the multicast group.

7. The method of claim 5, wherein the ZC or the MR′

changes its status to a GC and sends a GC update (GCUD) message indicating the change of the GC to a current GC if the ZC or the MR′

request to join the multicast group.

8. The method of claim 5, wherein a first node which is a non-multicast group member sends a joining request (JREQ) message to a first parent node, which is a parent node of the first node, to request to join the multicast group.

9. The method of claim 8, wherein, if the first parent node receiving the JREQ message is a GM, a MR, a GC, or a MR′

, the first parent node sends a joining reply (JREP) message containing a multicast group address to the first node sending the JREQ message.

10. The method of claim 8, wherein, if the first parent node receiving the JREQ message is a non-multicast group member, the first parent node sends the received JREQ message to a second parent node which is a parent node of the first parent node, sends a JREP message received from the second parent node to the first node, and changes its status into a MR.

11. The method of claim 10, wherein, if a parent node receiving the JREQ message is a ZC, the ZC instructs the first node change its status to a GC.

12. The method of claim 5, wherein, if a GM requesting to leave the multicast group is a leaf node of the multicast group, the GM changes its status to a non-multicast group member, and

if the GM is not the leaf node, the GM changes its status to a MR.

13. The method of claim 12, wherein, if a parent node is a MR and a leaf node of the multicast group due to a child node leaving, the MR leaves the multicast group.

14. The method of claim 12, wherein, if the GC has a child node which is a GM or a MR due to the child node leaving and does not serve as a GM at the same time, the GC gives up its status as the GC.

15. The method of claim 14, wherein the GC sends a GC update (GCUD) message indicating to change the GC into a child node which is a GM or a MR.

16. The method of claim 15, wherein, if a node receiving the GCUD message is a GM, the node changes the GM into a GC, and if the node receiving the GCUD message is a MR, the node counts a number of child nodes which is a MR or a GM.

17. The method of claim 16, wherein, if the number of the child nodes which are the MR or the GM is at least two, the MR receiving the GCUD message changes its status into a GC, and if there is one child node which is the MR or the GM, the MR change the status into a non-multicast group member and sends the GCUD message to the child node.

18. The method of claim 2, wherein the nodes forming the multicast group stores a bitmap which is information relating to nodes forming a multicast group to which the nodes are linked directly.

19. The method of claim 18, wherein the bitmap marks a parent node and a node forming the multicast group among a plurality of child nodes.

20. The method of claim 2, wherein a GM receiving a data packet containing a multicast group address sends the data packet to a higher layer only if the data packet is received from a parent node or a child node.

21. The method of claim 2, wherein a GC or a MR′

receiving a data packet containing a multicast group address discards the data packet if the data packet is received from a child node along a multicast cluster tree in the multicast group.

22. The method of claim 2, wherein a node forming the multicast group stores information relating to a delivered data packet.

23. The method of claim 22, wherein the information relating to the delivered data packet comprises a multicast group address, a source address, and a sequence number.

24. The method of claim 2, wherein a node forming the multicast group selects a parent node and a child node for processing a delivered data packet, and sends the data packet together with information relating to the selected parent and child nodes.

25. The method of claim 2, wherein a node forming the multicast group sends a received data packet together with an address of the node transmitting the data packet.

26. The method of claim 2, wherein a node forming the multicast group stores a number of descendant nodes which are a GM or a MR.

27. The method of claim 26, wherein a non-multicast group node requesting to join the multicast group sends a joining request (JREQ) message to a ZigBee (ZC) along the cluster tree.

28. The method of claim 27, wherein the ZC receiving the JREQ message determines a new GC, and sends a GC update (GCUD) message indicating the change of the GC to a current GC and the new GC if the new GC is different from the current GC.

29. The method of claim 27, wherein an intermediate node, which receives a joining reply (JREP) message allowing the joining from the ZC, increases a number of descendant nodes being a GM or a MR by one.

30. The method of claim 26, wherein a GM requesting to leave the multicast group sends a leaving request (LREQ) message to the ZC following the cluster tree.

31. The method of claim 30, wherein the ZC receiving the LREQ message determines a new GC, sends a GCUD message indicating the change of the GC to a current GC and the new GC if the new GC is different from the current GC.

32. The method of claim 30, wherein an intermediate node, which receives a leaving reply (LREP) message allowing the leaving from the ZC, decreases the number of descendant nodes which are a GM or a MR by one.

33. The method of claim 30, wherein the GM requesting to leave the multicast group and receiving a leaving (LREP) message, changes its status into a MR if the number of child nodes which are a GM or a MR is at least one.

34. The method of claim 26, wherein, if there is a data packet to be delivered to the multicast group, the data packet is transmitted to one of a ZigBee coordinator (ZC) or a GC.

35. The method of claim 2, wherein the node forming the multicast group stores a number of child nodes which are a GM or a MR.

36. The method of claim 35, wherein a joining request (JREQ) message received from a node requesting to join the multicast group is transmitted to other nodes until the JREQ message reaches a node forming the multicast group or a ZigBee coordinator (ZC).

37. The method of claim 36, wherein the node forming the multicast group and receiving the JREQ message increases the number of child nodes which are a GM or a MR by one.

38. The method of claim 36, wherein the ZC receiving the JREQ message sends a GC update (GCUD) message indicating the change of the GC to a new GC and a current GC if the new GC is different from the current GC.

39. The method of claim 36, wherein a node receiving a GC update (GCUD) message which is transmitted from the ZC receiving the JREQ message to the GC in sequence, contains an address of a new joining node, and indicates the change of the GC, determines a parent node a new GC if the requesting node is not a descendant node.

40. The method of claim 35, wherein a joining request (JREQ) message from a node requesting to join the multicast group is transmitted until the JREQ message reaches a node forming the multicast group or a ZigBee coordinator (ZC).

41. The method of claim 36, wherein a node transmitting a leaving response (LREP) message in the multicast group decreases the number of child nodes which are a GM or a MR by one.

42. The method of claim 41, wherein a GC, which has one child node which is a GM or a MR and does not serve as a GM due to a node leaving the multicast group, sends a GC update (GCUD) message indicating the change of the GC to the child node.

43. The method of claim 42, wherein, if a MR receiving the GCUD message has at least two child nodes which are a GM or a MR, the MR serves a GC.

44. The method of claim 35, wherein, if there is a data packet to be delivered to the multicast group, the data packet is transmitted to one of a ZigBee coordinator (ZC) or a GC.

45. The method of claim 44, wherein, if there are at least two data packets to be delivered from a source node not being a descendant node of the GC to the multicast group, an ancestor node having the source node and the GC as descendant nodes is determined.

46. The method of claim 45, wherein the source node sends the data packet to the ancestor node.