Method for adaptively reassigning addresses of nodes according to changes in volume of wireless network

• US 20060023643A1
• Filed: 07/29/2005
• Published: 02/02/2006
• Est. Priority Date: 07/29/2004
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lim, Yu-jin
• Granted Patent: US 7,715,327 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04L 41/0896 Bandwidth or capacity management, i.e. automatically increasing or decreasing capacities flow or congestion control using dynamic resource allocation, e.g. in-call renegotiation, H04L47/76
• CPC Class Codes: H04L 45/48 Routing tree calculation
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: Y10S 370/913 Wireless or radio

Abstract

A method of adaptively reassigning addresses of nodes according to changes in volume or a wireless network. The method includes receiving, at the node of the wireless network, information according to the changes in volume from a coordinator as a top level of the tree structure, calculating, at the node, a family tree indicating information and a location of the node in the tree structure according to an old logical address of the node and the information, and calculating a new logical address of the node according to the change in volume and the calculated family tree; and transceiving, at the node, a data packet according to the newly calculated logical address. Accordingly, overheads of the whole network for changing addresses may be reduced when changes in volume of the network occur, so that dynamic changes in volume of the network may be rapidly and actively implemented.

Claims

1. A method of adaptively reassigning addresses of nodes according to changes in volume of a tree structure wireless network, comprising:

receiving, at a node of the wireless network, information according to the changes in volume from a coordinator as a top level of the tree structure;

calculating, at the node, a family tree indicating a location of the node in the tree structure according to an old logical address of the node and the information;

calculating a new logical address of the node according to the change in volume and the calculated family tree; and

transceiving, at the node, a data packet according to the newly calculated logical address.

2. The method as recited in claim 1, wherein the information comprises the number of maximum child nodes and the number of maximum levels determined by the change in volume.

3. The method as recited in claim 2, wherein the family tree represents a rank of the node at each level of the tree structure.

4. The method as recited in claim 3, wherein the family tree :

Family.Tree[i] indicates a rank of the node at i^th level of the tree structure, wherein the rank of the node at the i^th level is calculated using equation;

Family.Tree[i];

=|Address/Cskip.old[Li]|
Ancestor.Addr;

=Ancestor.ADDR+Cskip.old[Li]*(Family.Tree[i]−

1)+1
Address;

=Address−

Ancestor.Addr

wherein Address is an old logical address of the node, Cskip.old[Li] is a value calculated according to the number of old maximum child nodes and the number of old maximum levels, and |Address/Cskip.old[Li]| is a minimum value among integers which are equal to or greater than Address/Cskip.old[Li].

5. The method as recited in claim 4, wherein the new logical address is calculated according to the following equation:

$\mathrm{New}.\mathrm{Addr}=\underset{i}{\sum <br><br>}<br><br>\left(\mathrm{Cskip}.\mathrm{new}<br><br>\left[i\right]*\left(\mathrm{Family}.\mathrm{Tree}<br><br>\left[i\right]-1\right)+1\right)$

wherein Cskip.new[i] is a value calculated according to the number of maximum child nodes and the number of maximum levels transmitted from the coordinator.

6. The method as recited in claim 4, wherein Cskip.old[Li] is calculated according to the following equation:

$\begin{array}{c}\mathrm{Bsize}=\frac{1-C_m^{\mathrm{Lm}+1}}{1-C_m}\\ \mathrm{Cskip}=\mathrm{Floor}\left[\frac{\mathrm{Bsize}-\underset{k=0}{\overset{\mathrm{Li}}{\sum <br><br>}}<br><br>{\left(C_m\right)}^k}{{\left(C_m\right)}^{\mathrm{Li}+1}}\right]\end{array}$

wherein Cm denotes the number of maximum child nodes, and Lm denotes the number of maximum levels.

7. The method as recited in claim 1, wherein the node places a mark indicating that the new logical address is used on a predetermined reserved bit of a header portion of the data packet, and transmits the data packet.

8. The method as recited in claim 7, wherein the node transmits the data packet according to the new logical address when the node receives the data packet indicating that the new logical address is used for the predetermined reserved bit.

9. The method as recited in claim 1, further comprising:

calculating a family tree of other nodes included in an address mapping table stored in the node by using the information and thus calculating respective new logical addresses to update the address mapping table.

10. The method as recited in claim 9, wherein the node transceives the data packet according to the address mapping table.

11. The method as recited in claim 1, wherein the node transceives the data packet by using both of the new logical address and the old logical address in combination for a predetermined time.

12. The method as recited in claim 11, wherein the node places a mark on the data packet indicating one of the old logical address and the new logical address is used and transceives the data packet.

13. The method as recited in claim 12, further comprising:

buffering the data packet until the node receives information according to the change in volume from the coordinator when the node receives the data packet indicating that the new logical address is used.

14. The method as recited in claim 13, wherein the data packet is discarded when the node is short of memory.

15. The method as recited in claim 11, wherein the node places a mark indicating that the new logical address is used using a predetermined reserved bit of a header portion of the data packet.

16. The method as recited in claim 15, wherein when the data packet indicating that the new logical address is used on the predetermined reserved bit is received, the data packet is transmitted according to the new logical address.

17. The method as recited in claim 15, wherein when the data packet which does not indicate that the new logical address is used on the predetermined reserved bit is received, the data packet is transmitted according to the old logical address.

18. The method as recited in claim 11, wherein the predetermined time is set according to a time that the information is transmitted from the coordinator to all elements of the wireless network.

19. The method as recited in claim 1, wherein the wireless network is a Zigbee wireless network based on an IEEE 802.15.4 standard.

20. The method as recited in claim 5, wherein Cskip.new[i] is calculated according to the following equation:

$\begin{array}{c}\mathrm{Bsize}=\frac{1-C_m^{\mathrm{Lm}+1}}{1-C_m}\\ \mathrm{Cskip}=\mathrm{Floor}\left[\frac{\mathrm{Bsize}-\underset{k=0}{\overset{\mathrm{Li}}{\sum <br><br>}}<br><br>{\left(C_m\right)}^k}{{\left(C_m\right)}^{\mathrm{Li}+1}}\right]\end{array}$

wherein Cm denotes the number of maximum child nodes, and Lm denotes the number of maximum levels.

21. The method as recited in claim 4, wherein Cskip indicates a size of logical address block for child nodes and wherein parent node'"'"'s Cskip is used in assigning addresses to respective child nodes of the parent node.