TRANSMISSION POWER CONTROL METHOD AND SYSTEM

• US 20100142425A1
• Filed: 03/26/2009
• Published: 06/10/2010
• Est. Priority Date: 12/10/2008
• Status: Active Grant

• Current Assignee: SerComm Corporation
• Original Assignee: Industrial Technology Research Institute
• Inventors: Chuang, Chun-Chieh, LEE, JIN-SHYAN
• Granted Patent: US 8,218,475 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/322 Power control of broadcast channels
• CPC Class Codes: H04W 52/36 with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 52/54 Signalisation aspects of the TPC commands, e.g. frame structure

Abstract

A transmitting power level control method and system are provided, whereby the power of a terminal device in a wireless sensor network is saved and the lifetime thereof is extended. The control method includes the steps of: (A) broadcasting a plurality of transmitting power level (TPL) messages, each of which represents a respective TPL and the respective TPLs are different from one another, wherein each of the plurality of TPL messages is broadcasted at the respective TPL thereof; and (B) setting a TPL for the terminal device at a minimum one of the TPLs represented by the TPL messages received by the terminal device.

Claims

1. A method of controlling a transmitting power for a terminal device, comprising the steps of:

(A) broadcasting a plurality of transmitting power level (TPL) messages, each of which represents a respective TPL and the respective TPLs are different from one another, wherein each of the plurality of TPL messages is broadcasted at the respective TPL thereof; and

(B) setting a TPL for the terminal device at a minimum one of the TPLs represented by the TPL messages received by the terminal device.

2. The method according to claim 1, wherein the step (B) further comprises a step of:

(B1) storing the received TPL messages in the terminal device.

3. The method according to claim 1, further comprising the steps of:

(C) determining whether the terminal device is communicating with an external information receiving node, and raising the TPL for the terminal device up one level if the terminal device is incapable of communicating with a information receiving node;

(D) detecting whether a specific incident is happening; and

(E) increasing the TPL for the terminal device to a predetermined maximum level thereof and announcing an alarm message if the specific incident is detected by the terminal device.

4. The method according to claim 3, wherein the information receiving node is a cluster head and the step (C) further comprises the steps of:

(C1) transmitting a Hello message at the TPL for the terminal device;

(C2) raising the TPL for the terminal device up one level if the terminal device fails to receive an acknowledge (ACK) message transmitted from the cluster head; and

(C3) repeating the step (C1) and step (C2) until the terminal device receives the ACK message.

5. The method according to claim 3, wherein the step (D) further comprises the steps of:

(D1) transmitting a detecting message by the terminal device;

(D2) receiving the detecting message by the cluster head and transmitting the detecting message via the cluster head to a control center;

(D3) comparing the detecting message with a data in the control center;

(D4) announcing an alarm if the detecting message matches with a feature of the specific incident; and

(D5) storing the detecting message.

6. The method according to claim 3 further comprising the steps of:

(F) determining a packet delivery ratio (PDR) of the terminal device during a predetermined period;

(G) comparing the PDR with a first threshold value and raising the TPL for the terminal device up one level if the PDR is lower than the first threshold value; and

(H) comparing the PDR with a second threshold value and lowering the TPL for the terminal device down one level if the PDR is higher than the second threshold value.

7. The method according to claim 6, wherein the PDR is a ratio of an amount of packets successfully transmitted to the information receiving node by the terminal device to an amount of packets transmitted by the terminal device in a predetermined period, the information receiving node is a cluster head, and the PDR is determined according to an accumulation of acknowledge (ACK) messages received by the terminal device, and the ACK messages are transmitted by the cluster head.

8. The method according to claim 1, wherein the terminal device is one selected from a group consisting of a flame detecting device, a smoke detecting device, a temperature detecting device and a combination thereof.

9. A system for controlling a transmitting power, comprising:

a terminal device transmitting a detecting message and having a transmitting power level (TPL); and

a cluster head receiving the detecting message and broadcasting a plurality of TPL messages, each of which represents a respective TPL and is broadcasted at the respective TPL thereof,

wherein the respective TPLs are different from one another, the terminal device receives the plurality of TPL messages and the TPL for the terminal device is set at a minimum one of the TPLs represented by the received TPL messages.

10. The system according to claim 9, further comprising:

a control center connected with the cluster head, storing and processing the detecting message transmitted from the cluster head and controlling the cluster head for broadcasting the plurality of TPL messages; and

an alarm device connected with the control center and the terminal device and announcing an alarm,

wherein the terminal device comprises;

a detecting unit detecting an environmental status;

an information receiving unit receiving the TPL messages broadcasted by the cluster head and an acknowledge (ACK) message transmitted by the cluster head;

a storing unit electrically connected with the information receiving unit and storing the received TPL messages;

a processing unit electrically connected with the information receiving unit and determining the minimum one of the TPLs represented by the received TPL messages;

an information transmitting unit electrically connected with the detecting unit and the processing unit, having a dynamic transmitting power regulator and can transmit a first message at a specific TPL; and

a power source providing power for the terminal device, wherein the processing unit calculates a successful message transmission ratio (SMTR) of a transmission from the information transmitting unit to the cluster head, compares the SMTR with a first threshold value and a second threshold value and adjusts the transmitting power of the information transmitting unit accordingly, and the detecting message is an environmental status message.

11. The system according to claim 10, wherein the power source is a battery, and the first message is one selected from a group consisting of a Hello message, the environmental status message and an alarm message and a combination thereof, the SMTR is a packet delivery ratio (PDR) being a ratio of an amount of packets successfully transmitted by the terminal device toward the cluster head to an amount of packets transmitted by the terminal device in a specific period, the TPL for the terminal device is raised up one level if the PDR is lower than the first threshold value and is lowered down one level if the PDR is higher than the second threshold value, and the alarm message is transmitted at a predetermined maximum TPL for the terminal device by the information transmitting unit.

12. The system according to claim 9, wherein a communication between the terminal device and the cluster head is performed with a communication protocol being one selected from a group consisting of a ZigBee, a Z-Wave, a WiBree, a Bluetooth, an Insteon, a WiFi, a UWB and a combination thereof.

13. The system according to claim 10, wherein a communication between the cluster head and the control center is performed with a communication protocol being one selected from a group consisting of a ZigBee, a Z-Wave, a WiBree, a Bluetooth, an Insteon, a WiFi and a UWB, a power line communication (PLC), an Ethernet and a CAN bus and a combination thereof each of the terminal device, the cluster head and the control center is provided with a unique identification code, and the control center has a data base storing the environmental status message and a reaction corresponding to the environmental status message based on a regulation rule.

14. A method of adjusting a transmitting power for a detecting device, comprising the steps of:

(A) determining a successful message transmission ratio (SMTR) of the detecting device; and

(B) comparing the SMTR with a threshold value, and adjusting a transmitting power level (TPL) of the detecting device according to a comparing result.

15. The method according to claim 14, wherein the step (B) farther comprising the steps of:

(B1) comparing the SMTR with a first threshold value, and raising the TPL of the detecting device up one level if the SMTR is lower than the first threshold value; and

(B2) comparing the SMTR with a second threshold value, and lowering the TPL of the detecting device up one level if the SMTR is higher than the second threshold value.

16. The method according to claim 14 further comprising the steps of:

(C) increasing the TPL of the detecting device to a predetermined maximum level of the detecting device and announcing an alarm message if the detecting device detects a specific incident.

17. The method according to claim 14, wherein the detecting device is one selected from a group consisting of a flame detecting device, a smoke detecting device and a temperature detecting device and a combination thereof, and the specific incident is a fire accident.

18. The method according to claim 14, wherein the detecting device has an information receiving point, the SMTR is a ratio of an amount of messages successfully transmitted by the detecting device toward the information receiving point in one of a specific period and a specific message amount to an amount of messages transmitted by the detecting device.

19. The method according to claim 14, wherein the step (A) further comprises the steps of:

(A1) broadcasting a plurality of messages via the information receiving node, wherein each of the plurality of messages represents a respective TPL and a value of the respective TPL and is broadcasted at the respective TPL thereof;

(A2) setting the TPL for the detecting device at a minimum one of the TPLs represented by the TPL messages received by the detecting device;

(A3) determining whether the detecting device is communicating with the information receiving node; and

(A4) raising the TPL of the detecting device up one level if the detecting device fails to communicate with the information receiving node.

20. The method according to claim 19, wherein the information receiving node is a cluster head, and the step (A3) further comprises the steps of:

(A31) transmitting a Hello message by the detecting device; and

(A32) receiving an acknowledge (ACK) message responding to the Hello message from the cluster head.