Method and Device for Determining Node Movement

• US 20160165567A1
• Filed: 02/15/2016
• Published: 06/09/2016
• Est. Priority Date: 08/15/2013
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Liu, Pei
• Granted Patent: US 9,603,118 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Embodiments disclose a method and device for determining a node movement. The method includes: when a first node determines that the first node is currently in an abnormal state, broadcasting at least two RSSI request messages, and receiving signal strength measurement values that are returned by a second node and separately obtained by means of measurement for at least two RSSI request messages in the at least two RSSI request messages broadcast by the first node. The method also includes separately calculating at least two path loss values between the first node and the second node according to the at least two received signal strength measurement values; and determining that the first node moves when it is determined that a quantity of second nodes, of which at least two path loss values are all different, is greater than a set threshold.

Claims

1. A method, comprising:

in response to a first node determining that the first node is currently in an abnormal state, broadcasting, by a transmitter, a plurality of received signal strength indication (RSSI) request messages;

receiving, by a receiver of the first node, a plurality of signal strength measurement values that are returned by a plurality of second nodes;

separately calculating, by the first node, a plurality of path loss values between the first node and each of the plurality of second nodes according to signal strength measurement values that are received by the first node from the respective second node of the plurality of second nodes;

determining, by the first node, a quantity of second nodes for which the plurality of path loss values are each different from each other; and

determining, by the first node, that the first node moves in response to determining that the quantity of second nodes is greater than a set threshold.

2. The method according to claim 1, wherein broadcasting the plurality of RSSI request messages comprises:

successively broadcasting a single RSSI request message a plurality of times, wherein the RSSI request message instructs each of the plurality of second nodes that receives the RSSI request message to measure signal strength of the received RSSI request message and return a measurement result.

3. The method according to claim 1, wherein separately calculating the plurality of path loss values between the first node and each of the plurality of second nodes according to signal strength measurement values that are received by the first node from the respective second node of the plurality of second nodes comprises:

calculating one path loss value between the first node and a corresponding second node according to any signal strength measurement value that is received by the first node from the corresponding second node and based on the received signal strength measurement value and a transmit power value of an RSSI request message that corresponds to the signal strength measurement value.

4. The method according to claim 1, wherein determining that the first node moves in response to determining that the quantity of second nodes is greater than a set threshold further comprises:

calculating, by the first node, a ratio of the quantity of second nodes for which the plurality of path loss values are each different from each other to a total quantity of second nodes that for which a signal strength measurement value is received; and

when the ratio is greater than a set threshold, determining that the first node moves.

5. The method according to claim 1, wherein the first node determining that the first node is currently in an abnormal state comprises:

in response to detecting that a preferred parent node of the first node changes, determining that the first node is currently in the abnormal state.

6. The method according to claim 1, wherein the first node determining that the first node is currently in an abnormal state comprises:

in response to detecting that a current rank value changes, determining that the first node is currently in the abnormal state.

7. The method according to claim 1, wherein the first node determining that the first node is currently in an abnormal state comprises:

in response to determining that a parent node set of the first node changes, determining that the first node is currently in the abnormal state.

8. A node device, comprising:

a signal transmitter, configured to broadcast a plurality of received signal strength indication (RSSI) request messages in response to determining that the node device is in an abnormal state; and

a processor, configured to;

receive signal strength measurement values that are returned by a plurality of second nodes, each of the plurality of second nodes separately obtaining signal strength measurements for each of the plurality of RSSI request messages received by the respective second node;

separately calculate a plurality of path loss values between the node device and each of the plurality of second nodes according to signal strength measurement values that are received from the respective second node of the plurality of second nodes;

determine a quantity of second nodes for which the plurality of path loss values are each different from each other; and

determine that the node device moves in response to determining that the quantity of second nodes is greater than a set threshold.

9. The node device according to claim 8, wherein broadcasting a plurality of RSSI request messages comprises:

successively broadcast a single RSSI request message a plurality of times, wherein each RSSI request message instructs a second node of the plurality of second nodes that receives the RSSI request message to measure signal strength of the RSSI request message and return a measurement result.

10. The node device according to claim 8, wherein the processor is further configured to:

calculate one path loss value between the node device and a corresponding second node according to any signal strength measurement value that is received by the node device from the corresponding second node, and based on the signal strength measurement value and a transmit power value of an RSSI request message corresponding to the signal strength measurement value.

11. The node device according to claim 8, wherein the processor is further configured to:

calculate a ratio of the quantity of second nodes for which the plurality of path loss values are each different from each other to a total quantity of second nodes for which signal strength measurement values are received; and

determine that the node device moves in response to determining that the ratio is greater than a set threshold.

12. The node device according to claim 8, wherein the signal transmitter is further configured to:

in response to detecting that a current rank value changes, determine that the node device is currently in the abnormal state.

13. The node device according to claim 8, wherein the signal transmitter is further configured to:

in response to detecting that a parent node set of the node device changes, determine that the node device is currently in the abnormal state.

14. The node device according to claim 8, wherein the signal transmitter is further configured to:

in response to detecting that a preferred parent node of the node device changes, determine that the node device is currently in the abnormal state.