System and method for changing WPAN network channel responding to wireless environment change

1. A system for changing a wireless personal area network (WPAN) channel depending on a change of a wireless environment, the system comprising:

slaves configured to transmit or receive data; and

a master connected to the slaves, and comprising a processor configured to:

obtain communication state information of the slaves,

determine a bad slave ratio which is a ratio of a number of the bad slaves to a number of all of the slaves;

when the bad slave ratio is lower than a preset ratio, select an adjacent channel search slave from among the slaves according to the obtained communication state information of the slaves, and request the selected adjacent channel search slave to scan adjacent channels other than a channel through which the master and the slaves communicate with each other, and

when the bad slave ratio is higher than the preset ratio, change the channel to one of the adjacent channels,

wherein the bad slaves have a packet error ratio (PER) that is higher than a preset PER.

2. The system of claim 1 , wherein the master selects the adjacent channel search slave on the basis of a data reception rate or the number of times of frame reception.

3. The system of claim 2 , wherein the adjacent channel search slave remotely scans adjacent channels other than a channel through which the master and the slaves communicate with each other and obtains energy levels of the adjacent channels.

4. The system of claim 3 , wherein the master changes the channel through which the master and the slaves communicate with each other to a channel having a lowest energy level from among the adjacent channels, if a ratio of a number of slaves having a packet error ratio (PER) higher than a preset PER to a number of all of the slaves is higher than a preset ratio.

5. A master station of a wireless personal area network (WPAN), comprising at least one processor configured to: monitor communication states of slaves, select an adjacent channel search slave, request the selected adjacent channel search slave to scan information of adjacent channels other than a communication channel according to the communication states of the slaves, and change the communication channel on the basis of the information of the adjacent channels scanned by the adjacent channel search slave if a bad slave ratio which is a ratio of a number of bad slaves to a number of all of the slaves is higher than a preset ratio,

wherein the bad slaves have a packet error ratio (PER) that is higher than a preset PER, and

wherein the master station calculates packet error ratios (PERs) of the slaves to count the bad slaves, and, if the bad slave ratio is lower than the preset ratio, selects the adjacent channel search slave for obtaining energy levels of the adjacent channels, wherein the adjacent channel search slave is selected on the basis of data reception rates or the numbers of times of frame reception of the slaves.

6. A method of changing a wireless personal area network (WPAN) channel depending on a change of a wireless environment, the method comprising:

obtaining communication state information of slaves;

detecting bad slaves of which a packet error ratio (PER) is higher than a preset PER;

determining a bad slave ratio which is a ratio of a number of the bad slaves to a number of all of the slaves;

changing a channel through which the master and the slaves communicate with each other if the bad slave ratio is higher than a preset ratio; and

selecting an adjacent channel search slave from among the slaves based on the communication state information and requesting the selected adjacent channel search slave to scan adjacent channels other than the channel, if the bad slave ratio is lower than the preset ratio.

7. The method of claim 6 , wherein the selecting of an adjacent channel search slave comprises selecting the adjacent channel search slave according to data reception rates or the numbers of times of frame reception of the slaves.

8. The method of claim 7 , further comprising remotely scanning, by the adjacent channel search slave, adjacent channels other than a channel through which the master and the slaves communicate with each other and obtaining energy levels of the adjacent channels.

9. The method of claim 8 , wherein the changing of a channel comprises changing the channel through which the master and the slaves communicate with each other to a channel having a lowest energy level from among the adjacent channels, when the bad slave ratio is higher than the preset ratio.