KR101862392B1 - Apparatus and method for avoiding interference between zigbee channel and wi-fi channel in a single device or a single system - Google Patents

Abstract

An apparatus for avoiding interference between a ZigBee channel and a Wi-Fi channel, the apparatus comprising: an interference determination unit for detecting interference with a ZigBee channel by a Wi-Fi channel used by the apparatus; An overlap detector for detecting information on each of the Wi-Fi channel and the ZigBee channel being used by the apparatus and detecting whether the frequency occupation range of the Wi-Fi channel and the ZigBee channel are overlapped with each other; And a channel changing unit for changing the Wi-Fi channel or the ZigBee channel in use according to a result of the detection. A device for avoiding interference between a ZigBee channel and a Wi-Fi channel is disclosed.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a device or a method for avoiding interference between a ZigBee channel and a Wi-Fi channel in a single device or a single system,

The present invention relates to an apparatus or method for avoiding interference between a ZigBee channel and a Wi-Fi channel, and more particularly, to a method and apparatus for using a ZigBee channel and a Wi-Fi channel in the same / And an apparatus or method for avoiding interference between WiFi channels.

A service for electric power smart grid or remote control is being provided or will be provided using a small network such as a home network. In particular, the power smart grid has been undergoing research and development for efficient use of energy in recent years, and home networks are becoming popular for the efficient use of home appliances in the home.

ZigBee communication, which can configure a network at a relatively low cost due to a low power consumption due to a narrow network range, is used in a home network and the like. The frequency band used by ZigBee is often overlapped with a specification of a wireless LAN referred to as a Wi-Fi, so that there is a high possibility that communications between the two will collide with each other. In recent years, Wi-Fi communication has become popular in offices, homes, public buildings, and the like. Such a collision is a common phenomenon in the current communication environment.

Therefore, it is necessary to develop an algorithm for avoiding communication interference between ZigBee and WiFi, and in particular, a method for controlling mutual interference within a single device or system using both ZigBee and WiFi is required.

An apparatus or method for avoiding possible interference or collision between ZigBee and WiFi communication according to an embodiment of the present invention is proposed.

According to an embodiment of the present invention, a ZigBee channel and a Wi-Fi channel including at least one ZigBee communication chip and at least one Wi-Fi communication chip are used at the same time, and interference between the ZigBee channel and Wi- Is avoided.

The apparatus includes an interference determination unit that detects interference with a zigbee channel by a Wi-Fi channel used by the apparatus; An overlap detector for detecting information on each of the Wi-Fi channel and the ZigBee channel being used by the apparatus and detecting whether the frequency occupation range of the Wi-Fi channel and the ZigBee channel are overlapped with each other; And a channel changing unit for changing the active Wi-Fi channel or the ZigBee channel according to a result of the detection.

In addition, the apparatus may further include a channel information storage unit for storing information on a Wi-Fi channel or a ZigBee channel used by the apparatus.

The interference determining unit may additionally detect an external Wi-Fi channel that interferes with the ZigBee channel being used, and when the frequency occupation range of the Wi-Fi channel and the ZigBee channel in use overlap and change the ZigBee channel, It is further possible to detect whether an external Wi-Fi channel interferes with the changed zigbee channel.

In addition, when the external Wi-Fi channel interferes with the ZigBee channel in use, the channel changing unit may change the ZigBee channel in use to another channel that does not overlap the external Wi-Fi channel or the Wi-Fi channel in use. The channel changing unit may change the channel by identifying the usable Zigbee channel or the Wi-Fi channel using the information. If the frequency occupation range of the Wi-Fi channel and the ZigBee channel in use overlap, the channel changing unit may preferentially change the Wi-Fi channel in use than the ZigBee channel in use.

According to an embodiment of the present invention, interference or collision between the ZigBee band and the Wi-Fi band can be prevented, and communication reliability such as a home network can be ensured. In addition, if ZigBee and WiFi bands are used in a single device or a single system, it is possible to know the ZigBee channel and WiFi channel in use, thus enabling fast interference / collision control.

Figure 1 shows the frequency range of ZigBee and WiFi channels.
2 shows a flowchart of an algorithm that can avoid or prevent interference or collision between a ZigBee and a WiFi in accordance with an embodiment of the present invention.
FIG. 3 illustrates a method for avoiding or preventing interference or collision between a ZigBee and a WiFi according to an embodiment of the present invention.
4 illustrates a method for avoiding or preventing interference or collision between a ZigBee and a WiFi according to an embodiment of the present invention.
FIG. 5 illustrates a block diagram of an apparatus that simultaneously uses a ZigBee channel and a Wi-Fi channel to avoid or prevent interference or collision between a ZigBee and a Wi-Fi according to an embodiment of the present invention.
FIG. 6 illustrates a method for avoiding or preventing interference or collision between a ZigBee and a WiFi according to an embodiment of the present invention.
Fig. 7 shows an application example of an embodiment of the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and should be construed in a sense and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and are not intended to encompass all of the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a ZigBee communication channel and a frequency channel of Wi-Fi communication. Wi-Fi (or IEEE 802.11b) is the most widely used wireless LAN standard recently. It uses 2.4GHz band and uses 14 carriers in total, but 14th carrier is allowed only in Japan. Table 1 below shows the channel, frequency, bandwidth, channel width, overlapping channel relationships, and the like of Wi-Fi. On the other hand, Figure 1 shows only three Wi-Fi frequency channels (Channel 1, Channel 7 and Channel 13), but other channels have been omitted for brevity.

Channel Center Frequency Frequency delta Channel Width Overlaps Channels One 2.412 GHz 5 MHz 2.401-2.423 GHz 2 2 2.417 GHz 5 MHz 2.406-2.428 GHz 1, 3 3 2.422 GHz 5 MHz 2.411-2.433 GHz 2, 4 4 2.427 GHz 5 MHz 2.416-2.438 GHz 3, 5 5 2.432 GHz 5 MHz 2.421-2.443 GHz 4, 6 6 2.437 GHz 5 MHz 2.426-2.448 GHz 5, 7 7 2.442 GHz 5 MHz 2.431-2.453 GHz 6, 8 8 2.447 GHz 5 MHz 2.436-2.458 GHz 7, 9 9 2.452 GHz 5 MHz 2.441-2.463 GHz 8, 10 10 2.457 GHz 5 MHz 2.446-2.468 GHz 9, 11 11 2.462 GHz 5 MHz 2.451-2.473 GHz 10, 12 12 2.467 GHz 5 MHz 2.456-2.478 GHz 1, 13 13 2.472 GHz 5 MHz 2.461-2.483 GHz 12 14 2.484 GHz 5 MHz 2.473-2.495 GHz -

ZigBee covers the 900 MHz band and the 2.4 GHz band, and only 2.4 GHz band can be used in the Republic of Korea. Therefore, channels 1 to 10 in the 900 MHz band are not used, and only channels 11 to 26 in the 2.4 GHz band are used. The bandwidth of each channel is 2 MHz, and detailed information is shown in Table 2 below.

Channel Center Frequency Frequency delta Channel Width Overlaps Channels with Wi-Fi Channels 11 2.405 GHz 2 MHz 2.404-2.406 GHz One 12 2.410 GHz 2 MHz 2.409-2.411 GHz 1, 2 13 2.415 GHz 2 MHz 2.414-2.416 GHz 1, 2, 3 14 2.420 GHz 2 MHz 2.419-2.421 GHz 1, 2, 3, 4 15 2.425 GHz 2 MHz 2.424-2.426 GHz 2, 3, 4, 5 16 2.430 GHz 2 MHz 2.429-2.431 GHz 3, 4, 5, 6 17 2.435 GHz 2 MHz 2.434-2.436 GHz 4, 5, 6, 7 18 2.440 GHz 2 MHz 2.439-2.441 GHz 5, 6, 7, 8 19 2.445 GHz 2 MHz 2.444-2.446 GHz 6, 7, 8, 9 20 2.450 GHz 2 MHz 2.449-2.451 GHz 7, 8, 9, 10 21 2.455 GHz 2 MHz 2.454-2.456 GHz 8, 9, 10, 11 22 2.460 GHz 2 MHz 2.459-2.461 GHz 9, 10, 11, 12 23 2.465 GHz 2 MHz 2.464-2.466 GHz 10, 11, 12, 13 24 2.470 GHz 2 MHz 2.469-2.471 GHz 11, 12, 13, 14 25 2.475 GHz 2 MHz 2.474-2.476 GHz 12, 13, 14 26 2.480 GHz 2 MHz 2.479-2.481 GHz 13, 14

As shown in FIG. 1, ZigBee and Wi-Fi overlap their bandwidths. The overlapping channel numbers are listed in Table 2. Therefore, since the ZigBee signal is relatively small in size (power), it is likely to fail to transmit in case of collision with the Wi-Fi signal, that is, the error rate may be relatively high.

FIG. 2 shows a flowchart of an algorithm that can avoid or prevent interference or collision between a ZigBee and a Wi-Fi band in accordance with an embodiment of the present invention. In an embodiment of the present invention, an apparatus or a system capable of performing both Zigbee communication and Wi-Fi communication is exemplified. The device or system may be an in-home server of a smart grid system or a home appliance control network system, but is not limited thereto. The device or system may prevent or avoid interference or collision between ZigBee and Wi-Fi.

Since the device or the system can use both ZigBee and Wi-Fi communication, it can perform ZigBee communication between various devices in a narrow area and access the Internet or the like directly or via WiFi communication with other systems in the wide area (outside) .

The device or system may transmit ZigBee data (S210). The apparatus or system may transmit ZigBee data and may determine whether interference is present using an interference detection algorithm (S220). The interference detection algorithm may count the number of NACKs by writing NACK (negative acknowledgment) if the apparatus or system transmits a ZigBee packet and does not receive an ACK (acknowledgment) within a predetermined period. If the number of counted NACKs exceeds a predetermined number, then the device or system may determine that there is ZigBee channel interference currently in use. If it is determined that interference does not exist, the apparatus or system can continue the ZigBee communication.

In other words, it is possible to judge whether data transmission / reception through the ZigBee communication is smooth or more precisely, an error occurs in data transmission / reception. If it is determined that interference exists in the current ZigBee channel, the device or system can read information about all the Wi-Fi channels and the ZigBee channel in use (S230). The device or the system can simultaneously perform Wi-Fi communication and ZigBee communication, so that information about the Wi-Fi channel and the ZigBee channel being used can be stored in the memory. In other words, the device or system may know information about the Wi-Fi channel and the ZigBee channel in advance.

For example, the apparatus or system may store information on channel numbers superimposed between the Wi-Fi channel and the ZigBee channel described in Table 2 in a memory. In addition, the device or system can read and know the Wi-Fi channel number and the ZigBee channel number currently in use from the built-in communication chip or other unit.

The device or the system reads the Wi-Fi channel number and the ZigBee channel number currently being used from the built-in memory, a communication chip, or the like, and determines whether the currently used ZigBee channel and the currently used Wi-Fi channel are overlapped (S240). The device or system can determine whether the interference or error of data transmission / reception of the Zigbee communication confirmed or determined in step S220 is caused by overlapping the Wi-Fi channel and the ZigBee channel currently being used. Because ZigBee communication is a low-power, low-rate communication, it is highly likely to be interfered by Wi-Fi channels because Wi-Fi communication and frequency band overlap.

If the Wi-Fi channel and the ZigBee channel overlap with each other, the other ZigBee channel that does not belong to the occupied range (frequency range) of the currently used Wi-Fi channel can be selected and changed to that channel (S250). Searching for other ZigBee channels that are not in the occupied range of the current Wi-Fi channel stores channel information of each currently used channel in the memory or other built-in unit, as described above. can do.

For example, if the device or system currently uses the ZigBee channel 17 and the Wi-Fi channel 5, since the 17th ZigBee channel currently being used and the 5th Wi-Fi channel overlap with each other, You can select other ZigBee channels that do not overlap with Fi channels. The system or apparatus can select, for example, Zigbee channel 20. Once the search or selection of the ZigBee channel is complete, the device or system may change the channel to the selected ZigBee channel.

In addition, information on the usable zigbee channel searched in step S250 may be stored. For example, a usable ZigBee channel number can be stored. When a new ZigBee channel is selected by searching a ZigBee channel, the number (n) of usable ZigBee channels is stored in a memory or the like. When a new ZigBee channel is selected and changed to that channel, And can store the limit value (n-1). The number of such usable ZigBee channels can be stored as the 'available ZigBee channel number' variable.

After the Wi-Fi channel being used and the ZigBee channel are overlapped and the ZigBee channel being used is changed, it is possible to detect whether there is interference due to the external Wi-Fi channel again (S260). Since the ZigBee channel has been changed in step S250, it is possible to detect whether the interference of the Wi-Fi channel that is being used externally affects the changed Zigbee channel. In recent years, a large number of access points (APs) for Wi-Fi access are often activated. In particular, when a home network system is established, the influence of external interference can be ignored because a neighboring Wi- This is not the situation.

Thus, the device or system can detect an external Wi-Fi channel using radio wave sensing means or a device having the same function in the Wi-Fi frequency band. Alternatively, the Zigbee communication may be performed after step S250, and the interference or error with respect to the Zigbee communication performed using the interference detection algorithm used in step S220 may be detected.

If it is determined in step S260 that external Wi-Fi interference exists, the channel can be changed to another Zigbee channel among the usable Zigbee channels found in step S250. In this case, it is possible to judge whether all of the available zigbee channels have been searched, selected, or changed in step S270. This determination can be made by detecting whether the value of this variable is 0 or not by using the aforementioned 'available ZigBee channel number' variable. If the value of this variable is not 0, since there is a usable ZigBee channel, it can be changed to a new ZigBee channel by using the previously stored available channel information. Also, in addition to the 'available ZigBee channel number' variable, information on whether or not the usable ZigBee channel that has been judged first can be stored as one variable. As the 'available ZigBee channel number' variable decreases, it is possible to easily identify which zigbee channel is available by storing the channel change history.

If the channel change has been performed for all available ZigBee channels, the device or system may select and change the Wi-Fi channel in use (S280). Since information about the Wi-Fi being used can be grasped, a change to another Wi-Fi channel can be performed similarly to the aforementioned ZigBee channel change.

In this step S280, even if the ZigBee channel is continuously changed, when the external Wi-Fi interference continues to exist, the ZigBee channel is changed to the ZigBee channel overlapping the frequency band of the currently used Wi-Fi channel It may be a preceding procedure. Of course, a ZigBee channel that overlaps the frequency band of the Wi-Fi channel you are currently using may also be interfered with by an external Wi-Fi channel. Step S280 is for avoiding interference by performing channel change to all usable ZigBee channels, that is, for a ZigBee channel occupied by the currently used Wi-Fi channel. Interference avoidance between Wi-Fi channels does not fall within the scope of the present invention, and may be already performed in a Wi-Fi communication standard or a Wi-Fi AP.

When the Wi-Fi channel being used is changed to another Wi-Fi channel, the ZigBee channel to be changed is preferably one of the ZigBee channels superimposed on the frequency band of the Wi-Fi channel that has been used. The flow advances to step S250 to change the channel, and steps S250, S260, S270, and S280 may be repeated. In the case of performing the step S270 after changing the Wi-Fi channel, the usable zigbee channel will be the zigbee channels overlapping the frequency range of the Wi-Fi channel before the change, and in this case, Browsing or selecting any ZigBee channel that does not overlap with a Wi-Fi channel will duplicate what you did earlier. Therefore, it is desirable to newly update and manage information on the above-mentioned usable ZigBee channel.

If it is determined in step S260 that there is no external Wi-Fi interference, the apparatus or the system may proceed to step S210 to perform ZigBee communication again.

If it is determined in step S240 that the Wi-Fi channel and the ZigBee channel are not overlapped with each other, the algorithm may proceed to step S260. If the Wi-Fi channel you are using does not overlap with the ZigBee channel, ZigBee communication may have failed due to external communication interference. Accordingly, the process proceeds to step S260, where it is determined whether interference is caused by external Wi-Fi, and a series of procedures corresponding thereto can be performed. A detailed description thereof will be omitted because it is common to the above.

FIG. 3 illustrates a method for avoiding or preventing interference or collision between ZigBee and Wi-Fi according to an embodiment of the present invention. Figures 3 (a), 3 (b) and 3 (b ') illustrate the use of a frequency carrier in an apparatus or system performing ZigBee communication. A frequency waveform shown in the form of half of an ellipse is displayed on each channel and a solid line rectangle surrounding them indicates that the channel is being used and a dotted rectangle surrounding them indicates that the channel has been changed.

It is also assumed that there are no other signals detected in the Zigbee or Wi-Fi bands other than the waveforms shown in Fig. The waveforms represented by IEEE 802.15.4 and IEEE 802.11b are referred to as ZigBee (hereinafter referred to as "built-in ZigBee") and Wi-Fi (hereinafter referred to as "built-in Wi-Fi") Respectively. For simplicity of explanation, it is assumed that only Wi-Fi channels 1, 7, and 13 exist in FIG.

In Figure 3 (a), the device or system uses an embedded ZigBee channel 11 and built-in Wi-Fi channel 1. The device or system may perform ZigBee communication. After transferring data to another communication device or system using ZigBee communication, the device or system can determine whether the transmitted data is well transmitted to the receiving side using the interference detection algorithm. If the data has been transmitted without error, the device or system may terminate the communication. The method shown in FIG. 2 may be performed for each data transmission, and may be performed at regular intervals.

If the device or system determines that there is interference in the ZigBee communication, the device or system can read all the in-use ZigBee channels in use and the built-in Wi-Fi channel. The device or system stores information about the ZigBee channel and the Wi-Fi channel in a memory or the like as shown in Tables 1 and 2, and thus can acquire channel information currently in use in real time.

Using this information, the device or system can determine whether the frequency bands of the built-in zigbee channel and the built-in Wi-Fi channel overlap. As shown in FIG. 3 (a), since the built-in Wi-Fi channel 1 and the built-in Wi-Fi channel 1 currently in use overlap each other, the device or the system can confirm this. The device or system may then search for or search for a usable ZigBee channel that does not overlap with the built-in Wi-Fi channel in addition to the built-in ZigBee channel 11 that is in use.

However, since the device or system stores the built-in zigbee or Wi-Fi channel information, it can be performed by acquiring and determining the channel information. A usable built-in ZigBee channel in which the frequency bands do not overlap with the built-in Wi-Fi channel will be ZigBee channels 15 to 26 as shown in FIG. 3 (a). The device or system may select one of the available built-in ZigBee channels to perform the channel change. In FIG. 3 (b), the channel is changed by the built-in zigbee channel 15.

On the other hand, when the built-in ZigBee channel and the built-in Wi-Fi channel overlap, you can change the built-in Wi-Fi channel without changing the built-in ZigBee channel. FIG. 3 (b ') shows an example of changing the built-in Wi-Fi channel to Wi-Fi channel 7. By changing the built-in Wi-Fi channel first, the frequency interference avoiding function of the device or system can be improved.

By selectively changing the built-in ZigBee channel or the built-in Wi-Fi channel according to the communication environment, the efficiency or speed of use of communication resources can be ensured. In the flowchart of FIG. 2, the built-in Wi-Fi channel is changed when all the built-in ZigBee channels are changed and the interference does not resolve. However, if the built-in WiBro channel is changed first or the built- The ordering can be changed.

The built-in ZigBee channel or the built-in Wi-Fi channel can be changed to avoid mutual interference, so the method can be terminated.

FIG. 4 illustrates a method for avoiding or preventing interference or collision between ZigBee and Wi-Fi according to an embodiment of the present invention. 4 (a) - (d) illustrate the use of frequency carriers in an apparatus or system that is performing ZigBee communication. 4, it is assumed that no other signal is detected in the Zigbee or Wi-Fi band. The waveforms indicated by IEEE 802.15.4 and IEEE 802.11b are referred to as "built-in ZigBee" and Wi-Fi (hereinafter referred to as "embedded Wi-Fi") used in the device or system . The waveform indicated by IEEE 802.11b (external) represents Wi-Fi (hereinafter referred to as "external Wi-Fi" For simplicity of explanation, it is assumed in FIG. 4 that only Wi-Fi channels 1, 7, and 13 exist.

Referring to FIG. 4 (a), the device or system currently uses ZigBee channel 12 and channels 1 and 13 of the built-in Wi-Fi channels. A rectangle on a channel waveform marked with an ellipse half indicates that the channel is currently in use. The device or system may transmit data using ZigBee communication. Using the interference detection algorithm, the device or system can verify that the ZigBee communication currently in use is being performed well. Since ZigBee channel 12 overlaps with the built-in Wi-Fi channel # 1 frequency band, interference with ZigBee channel may occur, which may cause an error in Zigbee communication.

Since a ZigBee communication error has occurred due to interference with the ZigBee channel, the device or system can read the built-in Wi-Fi channel and the built-in ZigBee channel currently in use to check whether there is a channel whose frequency ranges overlap with each other. As described in connection with FIG. 1, Tables 1 and 2, and FIG. 2, the device or system may be aware of which embedded Wi-Fi channels and built-in ZigBee channels overlap and which channel is currently being used . In the case of FIG. 4, since the built-in ZigBee channel 12 and the built-in Wi-Fi channel 1 are used, it can be confirmed that they are overlapped with each other.

Thus, the device or system can search for or search for available ZigBee channels. Because you are currently using ZigBee channel 12, you can use all but 12, but because there are built-in Wi-Fi channels 1 and 13, built-in Wi-Fi channels 1 and 13 It can be confirmed that the Zigbee channels 15 to 22 are usable Zigbee channels.

The device or system that has confirmed the usable ZigBee channel can select the ZigBee channel 17 to perform the channel change. Referring to FIG. 4 (b), it can be confirmed that the channel is changed to the Zigbee channel 17. The apparatus or system that has completed the ZigBee channel change can again perform ZigBee communication. While performing the Zigbee communication again, it is possible to confirm again whether the interference exists in the Zigbee communication through the interference detection algorithm. If it is determined that there is no interference, the transmission of data can be terminated with this.

The device or system can perform a method of avoiding the overlap between the built-in Wi-Fi and built-in zigbee, for example, by checking a zigbee communication error every time a group of data or a certain amount of data is transmitted through the zigbee communication. Alternatively, the device or system may perform a method of avoiding overlap between embedded Wi-Fi and built-in zigbee, for example, by checking for zigbee communication errors once every predetermined period.

In addition, the apparatus or system may determine whether the changed ZigBee channel 17 is interfered with by an external Wi-Fi channel before performing the ZigBee communication again. The built-in ZigBee channel 17 overlaps the frequency domain with the external Wi-Fi channel 7, as shown in FIG. 4 (b). A rectangle marked with a dotted line above the channel waveform indicates that the channel change has been performed with this channel. Of course, interference from external Wi-Fi may not occur if the channel is changed to ZigBee channel 15, 17, 21, or 22 by searching for or using a previously available ZigBee channel.

The device or system may determine that there is interference due to external Wi-Fi because the built-in zigbee channel 17 currently used and the external Wi-Fi channel overlap. Thus, the device or system can again search for or search other available built-in ZigBee channels. As a result of the search or search, due to the detection of an external Wi-Fi channel, the other available built-in ZigBee channels can be 15, 16, 21 or 22. The device or system can be changed by selecting one of the available built-in ZigBee channels again.

However, if for any reason you can not select the built-in ZigBee channel 15, 16, 21, or 22, for example, other Wi-Fi channels in addition to the built-in Wi-Fi channels 1 and 13 and external Wi-Fi channel 7 If so, the device or system will no longer be able to change the built-in ZigBee channel. In this case, the device or system may change the built-in Wi-Fi channel. As shown in FIG. 4 (c), the device or system may change the in-use Wi-Fi channel 13 in use to channel 7. In this case, the modified built-in Wi-Fi channel 7 overlaps with the external Wi-Fi channel, but this is related to the interference between the Wi-Fi channels and does not cause any problem in the present invention.

The device or system may then search for or retrieve an available built-in ZigBee channel. As a result of the search or search, it can be judged that the built-in ZigBee channel 23, 24, 25 or 26 is additionally usable. The device or system can be changed by selecting the built-in zigbee channel as 23. The device or system that changed the built-in ZigBee channel can detect if there is external Wi-Fi interference, and since there is no more external Wi-Fi interference, as shown in Figure 4 (d) ZigBee communication can be resumed.

FIG. 5 illustrates a block diagram of an apparatus that simultaneously uses a ZigBee channel and a Wi-Fi channel to avoid or prevent interference or collision between a ZigBee and a Wi-Fi according to an embodiment of the present invention. The device may be a device that simultaneously uses a ZigBee channel and a Wi-Fi channel with at least one ZigBee communication chip and at least one Wi-Fi communication chip. The apparatus includes an interference determination unit (510) for detecting interference with the built-in Wi-Fi channel using the built-in Wi-Fi channel; Wherein the device reads information on each of the built-in Wi-Fi channels and the built-in zigbee channels being used by the device, and detects whether the frequency occupancy range of the built-in Wi-Fi channel and the built- A detection unit 520; And a channel changing unit 530 for changing the built-in Wi-Fi channel or the built-in ZigBee channel in accordance with a result of the detection.

The interference determining unit 510 can determine whether there is interference on the Zigbee communication or channel in use by using the interference detection algorithm. The interference detection algorithm can detect the communication error by checking the ACK response. The interference determination unit 510 can additionally detect interference caused by an external Wi-Fi channel that interferes with a zigbee channel in use. When the embedded frequency band of the built-in Wi-Fi channel and the built-in zigbee channel is overlapped with the built-in zigbee channel so that the built-in zigbee channel changed by the external Wi-Fi channel is interfered Can be detected.

The overlap detector 520 can detect frequency interference or frequency overlap occurring within the device, and in particular can detect frequency overlap for the device's built-in ZigBee channel and the built-in Wi-Fi channel. The overlap detection unit 520 may store information on the built-in zigbee channel or the built-in Wi-Fi channel, for example, a center frequency and a frequency range for each channel. The overlap detector 520 can determine whether to overlap using this information.

The channel changing unit 530 can change the built-in ZigBee channel or the built-in Wi-Fi channel when the built-in ZigBee channel and the built-in Wi-Fi channel of the device are overlapped. Whether the channel changing unit 530 changes the built-in ZigBee channel or changes the built-in Wi-Fi channel can be determined depending on the communication environment.

In addition, when the external Wi-Fi channel interferes with the built-in zigbee channel currently being used, the channel changing unit 530 does not overlap the active built-in zigbee channel with the external Wi-Fi channel or the built-in Wi- You can change to a different channel. In addition, when there is no longer a ZigBee channel that does not overlap an external Wi-Fi channel or a Wi-Fi channel in use, the channel changing unit 530 can change the built-in Wi-Fi channel in use. When the frequency occupation range of the built-in Wi-Fi channel and the built-in zigbee channel in use is overlapped, the channel changing unit 530 may preferentially change the built-in Wi-Fi channel being used.

The apparatus may further include a channel information storage unit 540 that stores information about the Wi-Fi channel or the ZigBee channel used by the apparatus. The channel information storage unit 540 may also store information on an available built-in zigbee channel or built-in Wi-Fi channel. When the built-in zigbee channel is changed or the built-in Wi-Fi channel is changed, the channel information storage unit 540 stores the changed history to prevent the built-in zigbee channel or the built-in Wi-Fi channel, have.

FIG. 6 illustrates a method for avoiding or preventing interference or collision between ZigBee and Wi-Fi according to an embodiment of the present invention. The method may detect interference with a currently used zigbee channel (S610). Upon detecting the interference with the currently used ZigBee channel, channel information on all the built-in Wi-Fi channels and the built-in ZigBee channel currently being used can be acquired and searched (S620). In operation S630, whether or not the frequency bands of the built-in Wi-Fi channel and the built-in zigbee channel are overlapped can be detected using the channel information. In accordance with the detection result, the built-in Wi-Fi channel or the built-in ZigBee channel can be changed (S640).

When the frequency band of the built-in Wi-Fi channel and the built-in ZigBee channel in use overlap, the method can change the built-in Wi-Fi channel or the built-in ZigBee channel. After changing the built-in Wi-Fi channel or the built-in ZigBee channel, you can detect interference with the changed built-in ZigBee channel. In particular, it is possible to detect interference to the built-in zigbee channel by a Wi-Fi channel used externally. If interference is caused by an external Wi-Fi channel, the method may again search for or search for other available built-in ZigBee channels and change the built-in ZigBee channel accordingly. The built-in ZigBee channel change operation can be performed until interference by an external Wi-Fi channel is eliminated or avoided.

The method can utilize the channel information of the built-in Wi-Fi channel and the built-in ZigBee channel when determining whether to overlap the frequency band of the built-in Wi-Fi channel or the built-in ZigBee channel, or when changing the available built-in ZigBee channel.

An apparatus or method for avoiding overlapping between a Wi-Fi channel and a ZigBee channel according to an embodiment of the present invention, as described above, can be used for a home appliance network or a power smart grid. Figure 7 shows an application according to an embodiment of the present invention.

Figure 7 shows an example of a home network that may be used in the home. The home network communicates with the power meter and includes a server 711 for avoiding interference between the Wi-Fi channel and the ZigBee channel; Each of the household appliances 712, 713, and 714 having the Zigbee communication chips 710-2, 710-3, and 710-4; And a power meter 715 for measuring the power consumption of these. The server 711 and the power meter 715 also have Zigbee communication chips 710-1 and 710-5, respectively.

The server 711 and the power meter 715 can periodically transmit and receive data on the power consumption in the home. The server 711 can receive power charge information by time and usage amount, and can check the power consumption in the home in real time to actively manage the power consumption. For example, when the amount of power used for one hour is larger than the amount of used power patterns in the past, the server 711 may transmit a command for reducing the amount of power consumption to each of the home appliances through the zigbee communication. The refrigerator 712 can raise the refrigeration / freezing temperature, the air conditioner (AC) 714 can control the air volume lightly, and the TV 713 can control the brightness of the screen.

In addition, the server 711 may include a Wi-Fi communication chip 720 to transmit the power consumption / power charge information to a user located outside the home via Wi-Fi. In addition, the user may transmit commands to control the respective home appliances from the outside to the server 711. [

Meanwhile, in such a network, the server 711 can simultaneously perform Wi-Fi communication and ZigBee communication, and thus can perform a method for avoiding overlap between the built-in Wi-Fi channel and the built-in ZigBee channel. The server 711 can confirm whether the Zigbee communication is performed smoothly or by performing an ACK / NACK response. If a transmission / reception failure due to interference due to another channel or the like occurs in the Zigbee communication, the server 711 may first check the frequency band that it is using.

The server 711 can store information on the built-in Wi-Fi channel and the built-in ZigBee channel currently in use in a memory or the like, and can use this information to determine whether the built-in Wi-Fi channel and the built- have. In other words, it can be confirmed whether the communication through the ZigBee channel used by the built-in Wi-Fi channel is interfered with. If the built-in Wi-Fi channel and the built-in ZigBee channel overlap each other, you can change either channel. The server 711 can resume the Zigbee communication after changing the channel.

In addition, the server 711 can detect the interference caused by the Wi-Fi used in the outside before resuming the Zigbee communication. Interference with the ZigBee channel in the home network by the external Wi-Fi channel can be detected by detecting the radio wave of the Wi-Fi frequency band in the area where the home network is installed. Upon detecting interference with ZigBee communication by external Wi-Fi, the server 711 can again perform channel change to another usable ZigBee channel and change the built-in Wi-Fi channel as needed.

The present specification does not exemplify all of the examples in which an apparatus or method for avoiding interference between the built-in ZigBee channel and the built-in Wi-Fi channel according to the embodiment of the present invention is applied. The home network shown in FIG. 7 can be constructed and applied to not only an example of a smart grid but also a large building energy management system, a water management system, and a personal healthcare system through a home network.

Having described the embodiments of the present invention above, those of ordinary skill in the art will recognize that these embodiments are illustrative rather than limiting, and that various modifications, additions and substitutions are possible, without departing from the scope or spirit of the invention Variations, and modifications may be made without departing from the scope of the present invention.

510: interference determination unit 520: superposition detection unit
530: Channel changing unit 540: Channel information storing unit
711: Server 712: Refrigerator
713: TV 714: Air conditioner
715: Power meter

Claims (7)

A device for simultaneously using a ZigBee channel and a Wi-Fi channel having at least one ZigBee communication chip and at least one Wi-Fi communication chip, and avoiding interference between the ZigBee channel and the Wi-
An interference determination unit for detecting interference with a Zigbee channel by a Wi-Fi channel used by the apparatus;
An overlap detector for detecting information on each of the Wi-Fi channel and the ZigBee channel being used by the apparatus and detecting whether the frequency occupation range of the Wi-Fi channel and the ZigBee channel are overlapped with each other;
A channel changing unit for changing the Wi-Fi channel or the ZigBee channel in use according to a result of the detection; And
And a channel information storage unit for storing information on a Wi-Fi channel or a ZigBee channel used by the apparatus,
Wherein the channel change unit selects another ZigBee channel that does not belong to the occupied range of the WiFi channel currently being used and changes the channel to the ZigBee channel when the WiFi channel and the ZigBee channel overlap,
Wherein the channel information storage unit stores a value obtained by subtracting 1 from the number of existing usable ZigBee channels as an 'available ZigBee channel number' variable, thereby avoiding interference between the ZigBee channel and the Wi-Fi channel.
delete The apparatus of claim 1, wherein the interference determination unit further detects an external Wi-Fi channel that interferes with the zigbee channel being used, wherein the interference determination unit interferes with the interference between the zigbee channel and the Wi-Fi channel.
The method according to claim 1,
Wherein the interference determination unit further detects whether an external Wi-Fi channel interferes with the changed ZigBee channel when the frequency occupation range of the Wi-Fi channel and the ZigBee channel being used overlap and the ZigBee channel is changed, Apparatus for avoiding interference.
The method of claim 3 or 4, wherein, when the external Wi-Fi channel interferes with the active ZigBee channel, the channel changing unit overlaps the active ZigBee channel with the external Wi-Fi channel or the active Wi- A device that avoids interference between a ZigBee channel and a WiFi channel, changing to a different channel.
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