Method for self-constructing a multi-hop structured wireless communication network

Patent metadata

Field	Value
Publication number	US-10652090-B2
Application number	US-201816027027-A
Country	US
Kind code	B2
Filing date	Jul 3, 2018
Priority date	Feb 2, 2018
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

Provided is a method for self-constructing a multi-hop cluster-tree structured wireless communication network performed by a terminal device attempts to join a network includes determining at least one parent candidate device, requesting the determined parent candidate devices a network joining, joining the network as a child device based on a decision whether the requested parent candidate device has an address space available for a main transmission link of the terminal device, determining at least one cluster head as reserved parent candidate devices, requesting the determined reserved parent candidate devices a network joining, joining the network as a reserved child device based on a decision whether the requested reserved parent candidate device has an address space available for a reserved transmission link of the terminal device, and constructing a new main transmission link when the terminal device determines that the main transmission link is in an abnormal condition.

First claim

What is claimed is:

1. A method for self-constructing a multi-hop cluster-tree structured wireless communication network, the method comprising:
determining, by a terminal device that attempts to join a network, at least one parent candidate device that can provide the terminal device a main transmission link;
requesting, by the terminal device, one of the determined parent candidate devices a network joining;
joining, by the terminal device, the network as a child device of the requested parent candidate device based on a decision whether the requested parent candidate device has an address space available for the main transmission link of the terminal device;
determining, by the terminal device, at least one cluster head (CH) other than the parent device as reserved parent candidate devices after receiving a command that requests the terminal device to construct a reserved transmission link, the command being transmitted from a coordinator that manages network operation at a highest priority;
requesting, by the terminal device, one of the determined reserved parent candidate devices a network joining to construct the reserved transmission link;
joining, by the terminal device, the network as a reserved child device of the requested reserved parent candidate device based on a decision whether the requested reserved parent candidate device has an address space available for the reserved transmission link of the terminal device; and
constructing, by the terminal device, a new main transmission link by requesting the reserved parent device to convert the reserved transmission link to the new main transmission link of the terminal device, when the terminal device determines that the main transmission link is in an abnormal condition.

2. The method of claim 1 , wherein the determining of at least one parent candidate device that can construct the main transmission link by the terminal device comprises:
receiving, by the terminal device, a beacon signal that includes information on an available address space and a network depth of corresponding CH, the beacon signal being transmitted from adjacent CHs;
determining, by the terminal device, CHs that have an available address space larger than or equal to an address space required for the construction of the main transmission link of the terminal device and have a transmission link condition better than a predetermined reference level, as a set of parent candidate devices based on the received beacon signal; and
determining, by the terminal device, a parent candidate device in the determined set of parent candidate devices based on the network depth and the transmission link condition of the parent candidate devices.

3. The method of claim 2 , further comprising:
after the terminal device requests the determined parent candidate device a network joining,
receiving, by the terminal device, a ‘network joining permission’ message that includes a ‘joining permission’ or a ‘joining denial’ information, the ‘network joining permission’ message being transmitted from the determined parent candidate device; and
transmitting, by the terminal device, the coordinator via the parent device a ‘network joining completion’ message that includes information on an identification data of the terminal device and the address of the main transmission link, after the terminal device receives a ‘network joining permission’ message that includes a ‘joining permission’ information, the ‘network joining permission’ message being transmitted from the determined parent candidate device.

4. The method of claim 3 , further comprising:
after the terminal device receives a ‘network joining permission’ message that includes a ‘joining denial’ information,
determining, by the terminal device, a parent candidate device in the set of parent candidate devices excluding parent candidate devices that transmitted a ‘network joining permission’ message that includes a ‘joining denial’ information; and
requesting, by the terminal device, the determined parent candidate device a network joining to construct the main transmission link of the terminal device.

5. The method of claim 1 , wherein the determining of at least one CH other than the parent device as reserved parent candidate devices by the terminal device comprises:
receiving, by the terminal device, a beacon signal that includes information on an available address space and a network depth of corresponding CH, the beacon signal being transmitted from adjacent CHs other than the parent device of the terminal device;
determining, by the terminal device, CHs that have an available address space larger than or equal to an address space required for the construction of the reserved transmission link of the terminal device and have a transmission link condition better than a predetermined reference level, as a set of reserved parent candidate devices based on the received beacon signal; and
determining, by the terminal device, a reserved parent candidate device in the determined set of reserved parent candidate devices based on the network depth and the transmission link condition of the reserved parent candidate devices.

6. The method of claim 5 , wherein the address space required for the construction of the reserved transmission link of the terminal device, is larger than or equal to the address space required for the construction of main transmission links of the terminal device and all devices that belong to the cluster network of the terminal device.

7. The method of claim 1 , wherein the constructing the new main transmission link by the terminal device comprises:
requesting, by the terminal device, the reserved parent device to convert the reserved transmission link to the new main transmission link of the terminal device;
after the reserved parent device converts the address space allocated to the reserved transmission link of the terminal device to the address space for the main transmission link of the terminal device and accepts the terminal device as a new child device;
constructing, by the terminal device, the new main transmission link with the new parent device;
determining, by the terminal device, a new reserved parent candidate device; and
joining, by the terminal device, the network as a reserved child device of the new reserved parent device.

8. The method of claim 1 , further comprising:
confirming, by the terminal device, whether a signal transmission/reception with the parent device has been made within a predetermined time; and
when no signal transmission/reception with the parent device has been made within the predetermined time,
transmitting, by the terminal device, the parent device a signal notifying that the main transmission link is in a normal condition.

9. The method of claim 1 , wherein the determining by the terminal device that the main transmission link is in an abnormal condition comprises:
when the terminal device consecutively fails to make communications with the parent device more than a predetermined number of times, the terminal device experiences communication performance with the parent device worse than a predetermined reference level, the terminal device consecutively does not receive a beacon signal transmitted from the parent device more than a predetermined number of times, or the terminal device receives a ‘network re-joining’ command transmitted from the parent device,
determining, by the terminal device, that the main transmission link with the parent device is in an abnormal condition.

10. The method of claim 1 , further comprising:
periodically transmitting, by the terminal device, the reserved parent device a signal notifying that the reserved transmission link is in a norma

Assignees

• Seoul Nat Univ R&Db Foundation

Inventors

• Lee Yong Hwan
• Han Jin Seok
• Bang Jae Seok

Classifications

• H04L12/44

  Star or tree networks · CPC title

• H04L43/0811

  by checking connectivity · CPC title

• H04W40/248 Primary

  Connectivity information update · CPC title

• H04W84/18

  Self-organising networks, e.g. ad-hoc networks or sensor networks · CPC title

• H04W40/32

  for defining a routing cluster membership · CPC title