Dynamic packet relay apparatus and method for sensor network

Patent metadata

Field	Value
Publication number	US-2016277948-A1
Application number	US-201615071721-A
Country	US
Kind code	A1
Filing date	Mar 16, 2016
Priority date	Mar 16, 2015
Publication date	Sep 22, 2016
Grant date	—

Abstract

A dynamic packet relay method of a personal area network (PAN) coordinator in a sensor network includes receiving a Child_Register message that includes information about a device associated with a coordinator and building or updating a network hierarchical structure; monitoring reception of a packet or a beacon from the coordinator and determining whether the coordinator is defective or not; and in response to a determination that the coordinator is defective, changing the current coordinator to one of devices belonging to a PAN as a new coordinator.

First claim

What is claimed is:

1 . A dynamic packet relay method of a personal area network (PAN) coordinator and a device associated with the PAN coordinator in a sensor network, the dynamic packet relay method comprising:
receiving, at the PAN coordinator, a Child_Register message that includes information about a device associated with a coordinator and building or updating a network hierarchical structure; monitoring, at the PAN coordinator, reception of a packet or a beacon from the coordinator and determining whether the coordinator is defective or not; and in response to a determination that the coordinator is defective, changing, at the PAN coordinator, the current coordinator to one of devices belonging to a PAN as a new coordinator.

2 . The dynamic packet relay method of claim 1 , wherein the information about a device includes a media access control (MAC) extended address, a MAC short address, and guaranteed time slot (GTS) information.

3 . The dynamic packet relay method of claim 1 , wherein the network hierarchical structure includes the MAC extended address, the MAC short address and the GTS information, which are device information, and an associated MAC extended address and an associated MAC short address which are information about the coordinator associated with the device.

4 . The dynamic packet relay method of claim 1 , wherein the determining of whether the coordinator is defective or not comprises:
monitoring the reception of a packet or a beacon from the coordinator for a predetermined time period, in response to no beacon or data being received for the predetermined time period, sending an Alive Request message to the coordinator, and in response to no response to the Alive Request message being received from the coordinator, determining that the coordinator is defective.

5 . The dynamic packet relay method of claim 1 , wherein the changing of the current coordinator comprises
broadcasting a Coordinator_Candidate Request message throughout the PAN, receiving a Coordinator_Candidate Response message from all devices belonging to the PAN, is selecting one device with the best communication quality by analyzing the received Coordinator_Candidate Response messages, and sending a Coordinator Request message to the selected device.

6 . The dynamic packet relay method of claim 5 , wherein both the Coordinator_Candidate Request message and the Coordinator Request message contain information about the coordinator and the information about the device associated with the coordinator.

7 . The dynamic packet relay method of claim 5 , further comprising:
receiving, at the device associated with the PAN coordinator, a Coordinator_Candidate Request message from a PAN coordinator, the Coordinator_Candidate Request message containing coordinator information and information about a device associated with a coordinator; sending, from the device associated with the PAN coordinator, a Coordinator_Candidate Response message to the PAN coordinator, wherein the Coordinator_Candidate Response message contains information regarding a packet which has been received during an inactive period, the packet being transmitted to the coordinator from the device associated with the coordinator; and in response to receiving a Coordinator Request message from the PAN coordinator, changing, at the device associated with the PAN coordinator, a mode to serve as a coordinator from a following frame.

8 . The dynamic packet relay method of claim 7 , wherein the sending of the Coordinator_Candidate Response message comprises
comparing a source address in a MAC header of the packet received during the inactive period, with an address of the device associated with the coordinator, and comparing a destination address with an address of the coordinator, calculating both a number of packets with source and destination addresses that match the addresses of the device and the associated coordinator and a value of received signal strength indication (RSSI) during designated frame periods, and creating the Coordinator_Candidate Response message using the calculated values.

9 . A dynamic packet relay method of a coordinator and a device associated with the coordinator in a sensor network, comprising:
sending, at the coordinator, a Child_Register message to a PAN coordinator, the Child Register message containing information about a device associated with the coordinator; receiving, at the coordinator, a packet from the associated device after transmitting a beacon to the device during an inactive period of the PAN coordinator; and transmitting, at the coordinator, the packet to the PAN coordinator during an active period of the PAN coordinator.

10 . The dynamic packet relay method of claim 9 , wherein the Child_Register message is sent to the PAN coordinator each time the information about the associated device is changed.

11 . The dynamic packet relay method of claim 9 , further comprising:
in response to no beacon being received from the coordinator, standing by, at the device associated with the coordinator, for a designated period of time to receive a beacon; in response to receiving a beacon, determining, at the device associated with the coordinator, whether the beacon was sent from the coordinator or another device; and in response to a determination that the beacon was sent from another device, updating, at the device associated with the coordinator, coordinator information based on information about the device.

12 . A dynamic packet relay apparatus of a PAN coordinator comprising:
a relay hierarchy generator configured to receive a Child_Register message that contains information about a device associated with a coordinator, and build or update a network hierarchical structure; a coordinator checker configured to monitor reception of a beacon or data from the coordinator to determine whether the coordinator is defective or not; and a coordinator changer configured to, in response to a determination that the coordinator is defective, change the current coordinator to one of devices belonging to a personal area network as a new coordinator.

13 . The dynamic packet relay apparatus of claim 12 , wherein the coordinator checker comprises
a reception monitor configured to monitor the reception of data or a beacon from the coordinator for a predetermined time period, an alive-request sender configured to send an Alive Request message to the coordinator, and a defect determiner configured to, in response to no response to the Alive Request message being received from the coordinator, determine that the coordinator is defective.

14 . The dynamic packet relay apparatus of claim 12 , wherein the coordinator changer comprises
a candidate requester configured to broadcast a Coordinator_Candidate Request message throughout a PAN, a device selector configured to receive Coordinator_Candidate Response messages from devices in the PAN, and select one device that has the best communication quality, based on the analysis of the received Coordinator_Candidate Response messages, and a change requester configured to send a Coordinator Request message to the selected device.

15 . The dynamic packet relay apparatus of claim 14 , wherein both the Coordinator_Candidate Request message and the Coordinator Request message contain information about the coordinator and the information about the device associated with the coordinator.

16 . The dynamic packet relay apparatus of claim 14 , wherein the device in the PAN comprises
a candidate request receiver configured to receive a Coordina

Assignees

• Electronics & Telecommunications Res Inst

Inventors

• Yeo Geon Min
• Kim Young Ii
• Lee Yong Tae
• Park Dae Geun
• Lim Sun Hwa
• Ryu Won

Classifications

• H04L69/22

  Parsing or analysis of headers · CPC title

• H04W40/248 Primary

  Connectivity information update · CPC title

• H04W4/70

  Services for machine-to-machine communication [M2M] or machine type communication [MTC] · CPC title

• H04W40/22

  using selective relaying for reaching a BTS [Base Transceiver Station] or an access point · CPC title

• H04W88/04

  adapted for relaying to or from another terminal or user · CPC title