KR101021541B1 - Efficient transmitting method of data to end device in zigbee network and device thereof - Google Patents

Abstract

Disclosed are a method and apparatus for efficiently transmitting data to an end device in a Zigbee network. According to an aspect of the present invention, a method of processing data transmission by a node device of a Zigbee network includes an end having a power saving function of periodically turning on or off a power of an RF receiver. Acquiring ZED (Zigbee End Device) information including time information T according to a power saving function from the device; Recognizing a time point at which the RF receiver is powered on using T; And transmitting the data at a time point. According to the present invention, the coordinator or router knows in advance when the RF receiver of the end device is turned on, so that the data can be transmitted when the RF receiver of the end device is turned on without having to receive a request for data from the end device. Compared with the related art, there is an advantage of reducing the traffic of the network.

Zigbee, ZC, ZR, ZED, power, power, saving

Description

Efficient transmitting method of data to end device in zigbee network and device according to the present invention.

The present invention relates to a ZigBee network, and more particularly, to a method and apparatus for efficiently transmitting data to an end device having a power saving function of an RF receiver in a ZigBee network.

Recently, Zigbee networks have been widely used for short-range communication. Zigbee has been recognized for its superiority in communication power compared to other near field communication methods such as Bluetooth, and active research and development has been conducted.

1 is a diagram schematically illustrating a structure of a general Zigbee network.

Referring to FIG. 1, node devices in a Zigbee network include three types of Zigbee Coordinator (ZC), Zigbee Router (ZR), and Zigbee End Device (ZED). This is called a Zigbee Logical Device type.

The main role of ZC (Zigbee Coordinator), which is usually implemented as the root node, is to set up the network to define the main parameters. For example, ZED selects a radio frequency channel to define a unique network identifier. Typically, each node is assigned a unique address by ZC. ZR (Zigbee Router) can be used to extend the range of network communication, so that ZR can act as a relay between devices that are far from each other for direct communication. Zigbee End Device (ZED) is the device located at the far end of the Zigbee network and generally does not participate in routing.

In current ZigBee networks, ZC and ZR have no power saving function that turns off power when not performing any function and must always be powered. On the other hand, in the case of ZED, if the ZED has only a sensing function, power saving is possible because the RF receiver does not always need to be turned on. That is, ZED having a power saving function among ZigBee device types may selectively turn on / off an RF receiver to reduce power consumption. Therefore, ZED can operate longer using a battery than ZC and ZR.

In this case, the ZED must be powered on in order to receive data from ZC or ZR. Accordingly, ZC and ZR wishing to send data to ZED must know whether ZED's RF receiver is currently on.

FIG. 2 is a flowchart schematically illustrating a process of transmitting data to ZED by a conventional ZC, and FIGS. 3 and 4 are diagrams of ZC transmitting data to ZED in a non-beacON mode according to the related art. It is a flow chart showing the process.

ZigBee end device (ZED, 5) has a power saving function to periodically turn on or off the RF receiver, and asks and requests whether ZC has data to be transmitted every time power is turned on.

Looking at the process with reference to Figure 2, ZED (5) is powered on in the power-off state according to the power saving function when the RF receiver is turned on (s10), whether there is data to be transmitted to the ZC (1) Inquiry, if there is data, sends a command request message to the ZC 1 to receive the data transmission request (s12). Of course, if there is a ZR in the network, it is natural that the ZED 5 can also send a command request to the ZR.

Upon receiving the command request, the ZC 1 determines whether there is data to be transmitted (not shown), and if there is data, transmits the data to the ZED 5 (s14). In general, when there is data to be transmitted to the ZED, the ZC 1 holds the corresponding data in its buffer and transmits the pending data to the ZED according to the request of the ZED. Referring to FIG. 3, which shows another embodiment in the non-beacon mode, the ZC recognizes an acknowledgment (ACK) in which a frame pending (FP) sub-field is set to 1 when there is pending data. To ZED (s320), and then transmits data (s330).

When the reception of data from the ZC 1 is completed, the ZED 5 transmits an acknowledgment message (ACK: Acknowledgment) to the ZC 1 (s16 and s340), and turns off the RF receiver according to the power saving function (s18). ).

Referring to FIG. 2 again, when a certain time elapses, the ZED 5 turns on the RF receiver again (s20) and transmits a command request message to the ZC 1 again (s22). If there is no data to be transmitted by the ZC (1) receiving this to inform the ZED (5) (s24). The ZED 5 turns off the RF receiver (s26). Here, referring to FIG. 4 illustrating an embodiment according to the non-beacon mode, the ZC 1 may notify the ZED that there is no data to transmit by setting the FP of the ACK to 0 and sending it to the ZED (s420).

According to the conventional method described with reference to the drawings, the ZED transmits a command request message to the ZC every time the RF receiver is turned off and on. That is, in the related art, ZED should periodically transmit a command request message according to power saving, and likewise, ZC or ZR should periodically receive a command request message from ZED. Therefore, ZC or ZR should receive a request message for data periodically even though there is no data to transmit to ZED. This is because ZC or ZR does not know when the ZED's RF receiver is on. As a result, unnecessary network traffic is increased during transmission and reception between ZC or ZR and ZED, and power consumption of ZED using limited power is increased. This means that inefficient data transmission is performed between ZC or ZR and ZED.

Moreover, if a request sent from the ZED is lost, i.e., if the ZC or ZR does not receive the request sent from the ZED, it must wait more time to transmit the data.

Accordingly, the present invention has been made to solve the above-described problem, the coordinator or the router knows in advance the time point when the RF receiver of the end device is turned on to transmit data at that time, so that the end device periodically Accordingly, the present invention is to provide an efficient data transmission method and apparatus therefor in a ZigBee network that can use a power of an end device more efficiently.

Other objects of the present invention will become more apparent through the preferred embodiments described below.

According to one aspect of the present invention, in a method in which a node device of a Zigbee network handles data transmission, (a) power saving to turn on or off an RF receiver periodically Acquiring ZED (Zigbee End Device) information including time information (T) according to the power saving function from an end device having a function; (b) recognizing a time point at which the RF receiver is powered on using the T; And (c) a data transmission processing method in a ZigBee network including transmitting data at the time point, and a recording medium on which a program for executing the method is recorded.

Wherein step (a) comprises: receiving a data request from the end device; Requesting the ZED information from the end device; And receiving the ZED information from the end device, but the end device may not perform the data request after transmitting the ZED information.

In addition, step (a) may be performed when the end device is initially incorporated into the Zigbee network, or when the end device is assigned an initial address from the Zigbee network.

In addition, the ZED information may include address information of the end device.

In addition, the T is time information that the RF receiver is maintained in a power-off state (OFF), and step (b) recognizes the time when the RF receiver is turned on in the power-off state by counting the T time. can do.

In addition, the step (c), (c1) determining whether there is data to be transmitted to the end device; And (c2) transmitting the data to the end device when there is data to be transmitted to the end device, and notifying the end device that there is no data to transmit when there is no data to be transmitted to the end device. It may include. The step (c1) may determine whether the data to be transmitted is present according to the presence or absence of data buffered in the buffer.

In addition, the node device may be a ZigBee Coordinator or a ZigBee Router.

And a method in which an end device of a Zigbee network having a power saving function of turning on or off a power of an RF receiver to receive data from another node device. Requesting data transmission to the other node device when it is turned on in the off state; Receiving a request for own ZED information from the other node device; And generating ZED information including time information (T) corresponding to the power saving function according to the request of the ZED information, and transmitting the generated ZED information to the other node device. Provided is a method for processing data transmission in a Zigbee network, and a recording medium having recorded thereon a program for executing the method, wherein the data is transmitted from the other node device that recognizes the time when the power is turned on. do.

Here, the ZED information may be generated and transmitted to the other node device to include its own address information.

According to another aspect of the present invention, a node device for transmitting data from a ZigBee network to an end device, the node device having a power saving function for periodically turning on or off the power of the RF receiver. A communication module for transmitting a ZED information request message to the end device to obtain Zigbee End Device (ZED) information including time information (T) according to the power saving function from an end device; A storage module for storing the obtained ZED information; And a control module for recognizing a time point when the power of the RF receiver is turned on by using the T of the ZED information to transmit data to the end device through the communication module. Node devices are provided.

According to the present invention, the coordinator or router knows in advance when the RF receiver of the end device is turned on, so that the data can be transmitted when the RF receiver of the end device is turned on without having to receive a request for data from the end device. Compared with the related art, there is an advantage of reducing the traffic of the network.

In addition, according to the present invention, the end device does not need to transmit a data request message to the coordinator or the router from time to time, so that the end device using the limited power can use the power more efficiently.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and in describing the present invention with reference to the accompanying drawings, the same or corresponding elements are denoted by the same reference numerals regardless of the reference numerals, and duplicates thereof. The description will be omitted.

FIG. 5 is a flowchart illustrating a data transmission process in a Zigbee coordinator according to an embodiment of the present invention, and FIG. 6 is a flowchart illustrating a data transmission process between a ZED and a ZC according to an embodiment of the present invention.

Prior to describing the data transmission method of the present invention with reference to the drawings, the following embodiments will be described taking the data transmission between the coordinator and the end device as an example, but the router (router) and It will be apparent to those skilled in the art through the following description that data transmission between end devices can be performed in the same manner.

First, referring to FIG. 5, when a ZigBee coordinator (ZC) of a ZigBee network receives a command request (ie, a data request) from a ZigBee end device (ZED) (s510), it requests the ZED address information and power. Acquire ZED information about saving period information (ie, time period when the RF receiver is turned off and on, time information when the RF receiver is turned off, or time information on when the RF receiver is turned on). (s520). Referring to FIG. 6, the ZC may request ZED information by transmitting a ZED_INFO.REQUEST message to ZED.

Here, in the present embodiment, a case in which ZC receives a command request from the first ZED is obtained as an example, but this is only one embodiment. Of course, it is obvious that the ZED information may be acquired at another time. Do. For example, a time point when the first ZED joins the network, a time point when the ZC assigns an address to the ZED, and the like may be used. Hereinafter, for convenience of description, as in the present embodiment, a ZC acquires ZED information when receiving an initial data request as an example.

Referring back to FIG. 5, the ZC determines whether there is data to be transmitted to the ZED (s530), if present, transmits the data to the ZED (s540), or if there is no data to be transmitted, ZED. Notified by (s545). For example, if there is data to be transmitted to ZED, ZC first buffers and stores the data in a buffer. As a result, ZC can recognize that data to be transmitted exists when data exists in the buffer.

The ZC counts the power saving time of the ZED to recognize the time when the ZED RF receiver is turned off and off using the acquired ZED information of the ZED (s550).

Subsequently, the ZC recognizes the time when the RF receiver of the ZED is turned off and then turned on again according to the power saving function by the counting, and then proceeds to step s530 again.

Therefore, according to this embodiment, the ZC acquires a time period according to the power saving of the ZED from the initial ZED, so that it is not necessary to receive a request for data from the ZED every time data is transmitted. That is, the ZC can recognize the time that the RF receiver of the ZED is turned on, and can notify the ZED that data is transmitted or no data is transmitted every corresponding time.

In summary, after ZED and ZC form a network topology, ZC acquires information about the time (hereinafter, T) that the RF receiver according to ZED's power saving function remains off. .

Referring to FIG. 6 illustrating a data transmission process between ZED and ZC, the end device 30 (ZED) sends a command request message to the coordinator 10 to request data when the RF receiver is turned on (s610). , ZC) (S612).

The coordinator 10 sends a response message (ACK) to the end device 30 (s614), and immediately sends a ZED_INFO.REQUEST message to the end device 30 to request the ZED information (s616). The ZED information may be address information of the end device 30 and information about "T", which is time information when the RF receiver according to the power saving function is kept off.

Accordingly, in response to the request of the ZED information, the end device 30 transmits the ZED information including its address and the information about the T to the coordinator 10 in a ZED_INFO.REPLY message (s618). In step S620, the RF receiver is turned off.

The coordinator 10 counts T which is information on a time period in which the power of the RF receiver is turned on / off according to the power saving function of the RF receiver of the end device 30 from the time point at which the ZED information is received (s622). In operation S624, the ZED information is stored.

When the coordinator 10 completes counting for T time, the coordinator 10 recognizes that the power of the RF receiver of the end device 30 is turned on (s626) and transmits data when there is data to be transmitted (s628). That is, the coordinator 10 does not receive a separate data request from the end device 30, and transmits data to be transmitted immediately upon recognizing that the RF receiver of the end device 30 is turned on.

As described above, the coordinator 10 counts T time again after transmitting the data (s634 and s646).

If the transmission of the data fails (s638), the coordinator 10 retransmits the data (s640), and the end device 30 keeps the RF receiver in the ON state until the data is received from the coordinator 10. .

In addition, if there is no data to transmit, the coordinator 10 notifies that there is no data to transmit by transmitting a No data announce command message to the end device 30 (S650). The end device 30 then transmits an ACK to the coordinator 10 as a response signal (s652) and turns off the RF receiver.

Tables 1 to 9 below show tables added to the ZigBee Application Support (APS) layer of the ZigBee specification according to an embodiment of the present invention.

Table 1 above shows primitives added to the APS layer. APSME-ZED INFO. REQUEST serves to request ZED information by ZC or ZR, and APSME-ZED INFO. Conform informs upper layer about the result of request. In addition, APSME-ZED INFO. Indication is obtained from ZC or ZR by ZED INFO. Called from a lower layer when a REQUEST is received. APSME-ZED INFO. Response is ZED INFO. It serves to give a response to ZC or ZR asking for REQUEST.

Table 2 above shows the format of the device type sub-field of 1 byte length added to check the Zigbee device type in the extended header sub-frame ( format), and Table 3 shows a sub-field of the device type of the extended header subframe of Table 2.

Table 4 shows the frame format of the command request. ZED informs ZC or ZR that its RF receiver is turned on, and ZED INFO. Request the REQUEST command. The APS command identifier field has a length of 1 byte to distinguish APS commands, and the address field has a length of 2 bytes to indicate the address of the ZED. The RF receiver status field has a length of 1 byte to indicate the ON or OFF state of the ZED RF receiver. If the ZED RF receiver status field is 0x01, it indicates that the RE receiver of ZED is ON, whereas if the ZED RF receiver status field is 0x00, it indicates that the RF receiver is OFF.

Table 5 shows ZED INFO. Represents a REQUEST / REPLY frame. The ZED address field is reserved for the address of the ZED to which ZC or ZR wants to transmit data, and the ZED RF receiver ON time period field is reserved for the length of 4 bytes for the time period during which the ZED RF receiver is turned on. The Status field indicates success or rejection.

Table 6 shows the additional contents of the APS® Information Base (APSIB). The APSIB consists of the attributes required for managing the APS layer of the device. MAX ZED INFO. The default value of TABLE SIZE is specified as 1 and ZED ADDR. The default value of LIST is specified as null.

Table 7 is a ZED information table generated from ZC or ZR. The ZED information table is the MAX ZED INFO. Up to TABLE SIZE can be created.

Table 8 shows an extended frame control field in an acknowledgment (ACK) frame. A ZED RF receiver status sub-field with a length of 2 bits is added to indicate the ON / OFF status of the ZED RF receiver in the ACK. If the ZED RF receiver status subfield is 01, it indicates that the ZED RF receiver is ON. If the ZED RF receiver status subfield is 00, it indicates that the ZED RF receiver is OFF.

Table 9 shows the No data announce command frame transmitted to the ZED to notify the ZED when there is no data to be sent to the ZED.

Hereinafter, a configuration of a Zigbee coordinator and a Zigbee end device according to a method of performing data transmission after acquiring ZED information in advance as described above will be described.

7 is a block diagram showing the configuration of a Zigbee coordinator according to an embodiment of the present invention, Figure 8 is a block diagram showing the configuration of a Zigbee end device according to an embodiment of the present invention.

In the following description of the configuration and function of the coordinator 10 and the end device 30, the method for processing data transmission has been described in detail above, and thus redundant description will be omitted.

Referring first to FIG. 7, the coordinator 10 includes a communication module 110, a storage module 120, and a control module 130, wherein the storage module 120 includes a memory 112 and a buffer 114. The control module 130 may include a time counting unit 132, a transmission control unit 134, and a main control unit 136.

The communication module 110 is for transmitting and receiving data with other devices (eg, ZR, ZED, etc.) of the Zigbee network, which will be apparent to those skilled in the art, and thus detailed description thereof will be omitted.

The buffer 114 of the storage module 120 is for buffering data to be transmitted to the ZED, and the memory 112 includes a ZED including an address of a corresponding ZED obtained from the ZED, time period information according to a power saving function, and the like. It is for storing information.

The control module 130 acquires the ZED information from the ZED, checks the time when the RF receiver of the ZED is turned on using the corresponding time period information (for example, "T", which is the time information as described above), and the corresponding time. It transmits the data to be transmitted to the ZED through the communication module 110 or to inform that there is no data.

The time counting unit 132 of the control module 130 functions to count the time T for keeping the ZED RF receiver in the OFF state as described above in order to recognize the state in which the ZED RF receiver is in the ON state.

The transmission controller 134 of the control module 130 controls the communication module 110 to transmit data to the ZED. For example, as shown in FIG. 6, when the transmission of the data to be transmitted has failed, the transmission control unit 134 may recognize the message and retransmit the corresponding data.

The main controller 136 of the control module 130 determines whether there is data to be transmitted to the ZED, and based on the determination result, to inform the ZED that there is no data to be transmitted or transmitted.

Referring to FIG. 8 showing the configuration of the end device 30, the end device 30 according to the present embodiment includes a main body 210 and an RF receiver 220, the main body 210 is ZED information The generator 212, the message transmitter 214, and the RF receiver controller 216 may be included.

The ZED information generation unit 212 of the main body 210 functions to generate the ZED information as described above, which is information about itself to be transmitted to the coordinator 10, and the generated ZED information is the message transmission unit 214. It is transmitted to the coordinator 10 through. For example, the ZED information generation unit 212 generates ZED information including address information allocated from a Zigbee network and time information T for turning off an RF receiver according to a power saving function.

In addition, the main body 210 may further include a request message generator (not shown) for generating a command request since the main body 210 may perform an initial data request (ie, transmit a command request) before providing the ZED information. Of course, the command request may be transmitted to the coordinator 10 through the message transmitter 214.

The RF receiver controller 216 of the main body 210 performs a power saving function, thereby managing the power of the RF receiver 220. That is, the RF receiver controller 216 controls the RF receiver 220 to be turned on or off according to the power saving function, and in particular, to be turned on after the RF receiver 220 is turned off for the time T as described above. It may further include a counting unit (not shown) for counting the T time.

In this embodiment, the RF receiver controller 216 is included in the main body 210 as an example, but the RF receiver controller 216 for controlling the power saving function in the RF receiver 220 itself and the counting described above. An additional may be included.

The method of the present invention as described above may be implemented in a program and stored in a computer-readable recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.).

In addition, preferred embodiments of the present invention described above are disclosed for the purpose of illustration, those skilled in the art will be able to various modifications, changes, additions within the spirit and scope of the present invention, such modifications, Modifications and additions should be considered to be within the scope of the following claims.

1 schematically illustrates the structure of a typical Zigbee network.

2 is a flowchart schematically illustrating a process of transmitting data to a ZED by a conventional ZC.

3 and 4 are flowcharts illustrating a process in which ZC transmits data to ZED in a non-beacON mode according to the prior art.

5 is a flowchart illustrating a data transmission process in a Zigbee coordinator according to an embodiment of the present invention.

6 is a flowchart illustrating a data transmission process between ZED and ZC according to an embodiment of the present invention.

7 is a block diagram showing the configuration of a Zigbee coordinator according to an embodiment of the present invention.

8 is a block diagram showing a configuration of a Zigbee end device according to an embodiment of the present invention.

Claims (12)

In a method in which a node device of a Zigbee network handles the transmission of data, (a) ZED (Zigbee) including time information (T) according to the power saving function from an end device having a power saving function for periodically turning on or off an RF receiver; End Device) information; (b) recognizing a time point at which the RF receiver is powered on using the T; And (c) transmitting data at said time, The step (a) includes receiving and requesting ZED information from the end device after receiving a data request from the end device, And the end device does not perform the data request after transmitting the ZED information. delete The method of claim 1, wherein step (a) comprises: And at the time when the end device first joins the Zigbee network, or when the end device receives an initial address from the Zigbee network. The method of claim 1, And the ZED information includes address information of the end device. The method of claim 1, The T is time information for which the RF receiver is maintained in an off state, and the step (b) recognizes a time point at which the RF receiver is turned off by counting the T time. A method of processing data transmission in a Zigbee network. The method of claim 1, wherein step (c) comprises: (c1) determining whether there is data to be transmitted to the end device; And (c2) if there is data to be transmitted to the end device, transmitting the data to the end device; and if there is no data to be transmitted to the end device, informing the end device that there is no data to transmit. And a data transmission processing method in a Zigbee network. The method of claim 6, The step (c1) is a method for processing data transmission in a ZigBee network, characterized in that the presence of the data to be buffered in the buffer to determine whether the data exists. The method of claim 1, And the node device is a Zigbee coordinator or a Zigbee router. A method of receiving data from another node device by an end device of a Zigbee network having a power saving function of powering an RF receiver on or off, Requesting data transmission to the other node device when the RF receiver is turned on in a power-off state; Receiving a request for own ZED information from the other node device; And Generating ZED information including time information T corresponding to the power saving function according to the request of the ZED information, and transmitting the generated ZED information to the other node device, The T node receives data at the time point from the other node device that recognizes a time point when the RF receiver is powered on, and includes ZED information including time information corresponding to the power saving function. And a data transmission request is not performed to the other node device after the transmission to the other node device. The method of claim 9, And generating the ZED information to include its address information and transmitting the generated ZED information to the other node device. A recording medium in which a program of instructions for performing the method of any one of claims 1 and 3 to 10 is recorded and a program readable by a digital information processing apparatus is recorded. A node device for transmitting data from a Zigbee network to an end device, Zigbee End Device (ZED) including time information (T) according to the power saving function from an end device having a power saving function for periodically turning the RF receiver on or off. A communication module for sending a ZED information request message to the end device to obtain information; A storage module for storing the obtained ZED information; And In order to transmit data to the end device through the communication module, using the T of the ZED information includes a control module for recognizing the time when the power of the RF receiver (ON), The communication module requests ZED information from the end device after receiving the data request from the end device, and the end device does not perform the data request after transmitting the ZED information. Node devices.

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