Power management method of wireless nodes

• US 7,881,757 B2
• Filed: 11/14/2005
• Issued: 02/01/2011
• Est. Priority Date: 12/21/2004
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Mizuta, Takashi
• Primary Examiner(s): Hu; Jinsong
• Assistant Examiner(s): Figueroa; Marisol
• Application Number:
  US11/792,753
• Publication Number:
  US 20080151801A1
• Time in Patent Office: 1,905 Days
• Field of Search: 455518-522, 455/574, 455/453, 455/41.2
• US Class Current: 455/574
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/46 in multi hop networks, e.g. wireless relay networks
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The invention comprises a step of constructing a plurality of groups using a plurality of wireless nodes during construction of a network; a step of provisionally deciding, from among the wireless nodes in each group, a group master node serving as a group master that communicates with the other nodes in the group and that functions as a communication relay station for communicating with the other groups, with the other nodes in the group serving as slave nodes that are connected under the control of the group master node to perform their respective terminal station operation; a step in which the wireless nodes in each group exchange data with each other at a commencement session and calculate the minimum required transmission power for each other; a step in which the wireless nodes in each group use the calculated minimum required transmission powers to communicate with each other; and a step of, when determining that the time of changing the group master has come, causing one of the slave nodes to take over the group master.

Claims

1. A power management method for managing power consumption of batteries that serve as a power source for wireless nodes in an interactive wireless communication network system including a plurality of wireless nodes, the power management method comprising:

a step of constructing a plurality of groups using a plurality of wireless nodes during construction of a network;

a step of provisionally deciding, from among the wireless nodes in each group, a group master node serving as a group master that communicates with the other wireless nodes in the group and that functions as a communication relay station for communicating with the other groups, with the other wireless nodes in the group serving as slave nodes that are connected under the control of the group master node to perform their respective terminal station operation;

a step in which the wireless nodes in each group exchange data with each other at a commencement session and calculate a minimum required transmission power for each other;

a step in which the wireless nodes in each group use the calculated minimum required transmission powers to communicate with each other;

a step for causing the group master node to monitor volume of communication traffic in communications with the slave nodes in the group; and

a step for causing the slave node having the smallest volume of communication traffic to take over as the group master, when it is determined that the volume of communication traffic of the group master node has reached a pre-set communication traffic volume.

2. A power management method for managing power consumption of batteries that serve as a power source for wireless nodes in an interactive wireless communication network system including a plurality of wireless nodes, the power management method comprising:

a step of constructing a plurality of groups using a plurality of wireless nodes during construction of a network;

a step of provisionally deciding, from among the wireless nodes in each group, a group master node serving as a group master that communicates with the other wireless nodes in the group and that functions as a communication relay station for communicating with the other groups, with the other wireless nodes in the group serving as slave nodes that are connected under the control of the group master node to perform their respective terminal station operation;

a step in which the wireless nodes in each group exchange data with each other at a commencement session and calculate a minimum required transmission power for each other;

a step in which the wireless nodes in each group use the calculated minimum required transmission powers to communicate with each other;

a step for causing the slave nodes to monitor their own communication traffic volumes and report the communication traffic volumes to the group master node;

a step for causing the slave node having the smallest communication traffic volume to take over as the group master, when a prescribed time has passed since a current group master node started as the group master;

a step for causing the group master node to calculate an average communication traffic volume of the wireless nodes in the group and exchange average communication traffic volume information with other group masters;

a step for absorbing and merging a group in which the average communication traffic volume exceeds a pre-set level into an adjacent group having the smallest average communication traffic volume; and

a step for dividing the group, after group absorption and merger, so that each of the divided groups'"'"' average communication traffic volume is equalized.

3. The power management method according to claim 2, further comprising:

a step for causing the group master node to exchange the slave node having the greatest communication traffic volume in the group with the wireless node in the adjacent group having the smallest communication traffic volume.

4. A power management method for managing power consumption of batteries that serve as a power source for wireless nodes in an interactive wireless communication network system including a plurality of wireless nodes, the power management method comprising:

a step of constructing a plurality of groups using a plurality of wireless nodes during construction of a network;

a step of provisionally deciding, from among the wireless nodes in each group, a group master node serving as a group master that communicates with the other wireless nodes in the group and that functions as a communication relay station for communicating with the other groups, with the other wireless nodes in the group serving as slave nodes that are connected under the control of the group master node to perform their respective terminal station operation;

a step in which the wireless nodes in each group exchange data with each other at a commencement session and calculate a minimum required transmission power for each other;

a step in which the wireless nodes in each group use the calculated minimum required transmission powers to communicate with each other;

a step for causing each slave node to monitor its own battery power and report the battery power to the group master node;

a step for causing the slave node having the greatest remaining battery power to take over as the group master, when a prescribed time has passed since a current group master node started as the group master;

a step for causing the group master node to calculate an average remaining battery power of the wireless nodes in the group and exchange average remaining battery power information with other group masters;

a step for absorbing and merging a group in which the average remaining battery power is lower than a pre-set level into an adjacent group having the greatest average remaining battery power; and

a step for dividing the group, after group absorption and merger, so that each of the divided groups'"'"' average remaining battery power is equalized.

5. The power management method according to claim 4, further comprising:

a step for causing the group master node to exchange the slave node having the lowest remaining battery power in the group with the wireless node having the greatest remaining battery power in the adjacent group.

6. The power management method according to claim 4 further comprising:

a step for separating the slave node having the lowest remaining battery power from the group, if the battery power of the slave node having the lowest remaining battery power in the group is lower than a pre-set level.

7. A power management method for managing power consumption of batteries that serve as a power source for wireless nodes in an interactive wireless communication network system including a plurality of wireless nodes, the power management method comprising:

a step of constructing a plurality of groups using a plurality of wireless nodes during construction of a network;

a step of provisionally deciding, from among the wireless nodes in each group, a group master node serving as a group master that communicates with the other wireless nodes in the group and that functions as a communication relay station for communicating with the other groups, with the other wireless nodes in the group serving as slave nodes that are connected under the control of the group master node to perform their respective terminal station operation;

a step in which the wireless nodes in each group exchange data with each other at a commencement session and calculate a minimum required transmission power for each other;

a step in which the wireless nodes in each group use the calculated minimum required transmission powers to communicate with each other;

a step for causing the group master node to monitor a retransmission frequency occurring in communications with each slave node;

a step for causing the slave node having the lowest retransmission frequency to take over as the group master, when a prescribed time has passed since a current group master node started as the group master;

a step for causing the group master node to calculate an average retransmission frequency occurring in communications with each wireless node in the group and to exchange average retransmission frequency information with other group masters;

a step for absorbing and merging a group in which the average retransmission frequency exceeds a pre-set level into an adjacent group having the lowest average retransmission frequency; and

a step for dividing the group, after group absorption and merger, so that each of the divided groups'"'"' average retransmission frequency is equalized.

8. The power management method according to claim 7, further comprising:

a step for causing the group master node to exchange the slave node having the greatest retransmission frequency in the group with the wireless node in the adjacent group having the lowest retransmission frequency.

9. The power management method according to claim 7, further comprising:

a step for separating the slave node having the greatest retransmission frequency from the group, when the retransmission frequency of the slave node having the greatest retransmission frequency in the group exceeds a pre-set level.

10. A power management method for managing power consumption of batteries that serve as a power source for wireless nodes in an interactive wireless communication network system including a plurality of wireless nodes, the power management method comprising:

a step of constructing a plurality of groups using a plurality of wireless nodes during construction of a network;

a step of provisionally deciding, from among the wireless nodes in each group, a group master node serving as a group master that communicates with the other wireless nodes in the group and that functions as a communication relay station for communicating with the other groups, with the other wireless nodes in the group serving as slave nodes that are connected under the control of the group master node to perform their respective terminal station operation;

a step in which the wireless nodes in each group exchange data with each other at a commencement session and calculate a minimum required transmission power for each other;

a step in which the wireless nodes in each group use the calculated minimum required transmission powers to communicate with each other;

a step for causing the group master node to monitor a bit error rate occurring in communications with each slave node;

a step for causing the slave node having the lowest bit error rate to take over as the group master, when a prescribed time has passed since a current group master node started as the group master;

a step for causing the group master node to calculate an average bit error rate occurring in communications with each wireless node in the group and to exchange average bit error rate information with other group masters;

a step for absorbing and merging a group in which the average bit error rate exceeds a pre-set level into an adjacent group having the lowest average bit error rate; and

a step for dividing the group, after group absorption and merger, so that each of the divided groups'"'"' average bit error rate is equalized.

11. The power management method according to claim 10, further comprising:

a step for causing the group master node to exchange the slave node having the greatest bit error rate in the group with the wireless node in the adjacent group having the lowest bit error rate.

12. The power management method according to claim 10, further comprising:

a step for separating the slave node having the greatest bit error rate from the group, when the bit error rate of the slave node having the greatest bit error rate in the group exceeds a pre-set value.

13. A power management device for managing power consumption of a batteries serving as a power source for wireless nodes in an interactive wireless communication network system including a plurality of wireless nodes, the power management device comprising:

a group creation unit causing a wireless node to belong to any one of a plurality of groups comprising a plurality of wireless nodes formed at a time of network creation and communicate with other wireless nodes in the group, and in a case where in its own group there is no group master node for performing the role of a group master that serves as a communication relay station for communicating with the other wireless nodes in the group, to serve as a provisional group master node, and in a case where there is a group master in its own group, to serve as a slave node connected under the group master node and operate as a terminal station;

a master unit operation unit for, in the case where the wireless node serves as the group master node, communicating with the other slave nodes in the group, serving as a communication relay station for communicating with the other groups, and monitoring volume of communication traffic in communications with the slave nodes in the group;

a rotation controller for, in the case where the wireless node serves as the group master node, determining at prescribed intervals whether a time for group master rotation has come, and performing a rotation request for group master role rotation to the slave node having the smallest volume of communication traffic, when it is determined that the volume of communication traffic of the group master node has reached a pre-set communication traffic volume; and

a slave unit operation unit for, in the case where the wireless node serves as a slave node, transmitting, to the group master of its own group, information necessary for determining whether the time for group master rotation has come, and for receiving a rotation request from the group master node and shifting operation to the master unit operation unit.

14. A non-transitory computer-readable recording medium on which a program for is recorded, the program for managing power consumption of batteries that serve as a power source for wireless nodes in an interactive wireless communication network system comprising a plurality of wireless nodes, the program causing a computer to execute steps comprising:

a step of using a plurality of wireless nodes to construct a plurality of groups during construction of a network;

a step of provisionally deciding, from among the wireless nodes in each group, a group master node serving as a group master that communicates with the other wireless nodes in the group and that functions as a communication relay station for communicating with the other groups, with the other wireless nodes in the group serving as slave nodes that are connected under the control of the group master node to perform their respective terminal station operation;

a step in which the wireless nodes in each group exchange data with each other at a commencement session and calculate a minimum required transmission power for each other;

a step in which the wireless nodes in each group use the calculated minimum required transmission powers to communicate with each other;

a step for causing the group master node to monitor volume of communication traffic in communications with the slave nodes in the group; and

a step for causing the slave node having the smallest volume of communication traffic to take over as the group master, when it is determined that the volume of communication traffic of the group master node has reached a pre-set communication traffic volume.