KR20070075097A - Zigbee system - Google Patents

Abstract

A zigbee system is provided to improve data transmission efficiency of a whole network by informing a battery module state through an alarm sound or a light. A zigbee system(100) includes an RFD(Reduced Function Device) module and an FFD(Full Function Device) module. The zigbee system transmits MAC(Media Access Controller) information, network configuration information, and user setting information. The RFD module checks and transmits battery power. The FFD module receives the battery power information from the RFD module and forms a zigbee network. The FFD module checks the battery power and configures power information of nodes. The FFD module displays the configured power information with data transmitted from the RFD module. The FFD module or the RFD module configures and displays the power information.

Description

ZigBee system

FIG. 1 is a diagram illustrating a protocol stack structure illustrating an exemplary data area processed by a Zigbee system according to an embodiment of the present invention. FIG.

2 is a block diagram schematically illustrating the components of a Zigbee module according to an embodiment of the present invention.

3 is a diagram illustrating a network topology formed by a Zigbee system according to an embodiment of the present invention.

4 is a data structure diagram schematically showing the type of data packet processed by the Zigbee module according to an embodiment of the present invention.

5 is a diagram exemplarily illustrating a form in which an FFD module displays power information through an LED according to an embodiment of the present invention;

6 is a diagram illustrating an LED circuit provided by the RFD module according to an embodiment of the present invention for displaying power information.

<Explanation of symbols for main parts of drawing>

100: Zigbee module constituting the Zigbee system

110: antenna 120: RF receiver

130: phase synchronization circuit 140: power control circuit

150: RF transmitter 160: pulse processor

170: control unit 180: switching unit

190: display unit 195: battery

The present invention relates to a Jiesby system and its protocol structure.

Currently, ubiquitous network technology has attracted the attention of many people, ubiquitous network technology means a technology that allows to naturally connect to various networks regardless of time and place.

The ubiquitous network technology can be implemented in various ways using communication technologies such as telematics communication, short-range wireless communication, and mobile communication, and by using this, a natural connection environment is provided in a space such as a car, home, or public place. The utilization of IT information and technology will increase, and the overall IT industry is expected to develop more rapidly.

For example, using ubiquitous network technology, externally located users can control home appliances such as gas valves, lighting fixtures, heating appliances, etc. through mobile communication terminals, check visitors remotely, and receive emergency reports. Etc. services may be provided.

Such ubiquitous network technologies include ZigBee, Bluetooth, and Radio Frequency IDentification (RFID). Among them, interest in ZigBee technology, which is one of the IEEE 802.15.4 standards supporting near field communication, It is concentrated.

ZigBee technology has the following characteristics: First, Bluetooth transmits 720kbps of network access data using Frequency-Hopping Spread Spectrum (when a new slave device is connected, it takes about 3 seconds). ZigBee transfers 128kbps of network access data (which takes about 30 milliseconds when a new slave device is connected), and second, handles a simple communication stack that takes up less than 32KB of memory resources in an 8-bit computing controller. For example, it can be connected quickly and can return to power saving mode after processing a simple stack communication, so that battery life can be maintained for a long time. Fourth, it can configure thousands of clients (tens of thousands of nodes). Through these characteristics, the field of use of Zigbee technology will be gradually expanded in the future.

ZigBee technology can transmit data at speeds of 250Kbps over communication distances of 10m up to 1km, form various network topologies to connect tens of thousands of devices, and consume less power (for reference, AA alkaline batteries) Two can be used for months to years), and individual ZigBee modules can be designed to display the remaining capacity of the battery.

However, it is very difficult for a few administrators to check the battery capacity of many ZigBee modules that make up a complex network, and it is easy to make mistakes such as missing the time to replace the battery even if the management is difficult.

While the Zigbee module consumes very little power, it is also important to know the remaining battery capacity as well as the presence of the modules that make up the entire network.

According to the present invention, the master / slave modules constituting the Zigbee network share power information and display their own power information so that an administrator can easily recognize the power information of each of the plurality of slave modules. It provides a Zigbee system that can provide a unified.

In addition, according to the present invention, in any one master module providing power information of a plurality of slave modules, the Zigbee system facilitates information confirmation and network configuration by providing power information of a corresponding module at the moment of data communication. To provide.

The Zigbee system according to the present invention transmits MAC (Media Access Controller) information, network configuration information and user setting information to configure a Zigbee network, and the RFD (RFD: Reduced Function Device) module for identifying and transmitting battery power ; And an FFD (Full Function Device) module configured to receive battery power information from the RFD modules and configure power information of nodes constituting a Zigbee network.

In addition, the FFD module provided in the ZigBee system according to the present invention comprehends its own battery power and configures power information of the nodes.

In addition, the FFD module provided in the Zigbee system according to the present invention displays the configured power information together with the data transmitted from the corresponding RFD module.

In addition, the FFD module or the RFD module included in the Zigbee system according to the present invention configures the power information and displays it on the display device.

In addition, the FFD module provided in the Zigbee system according to the present invention compares the power information with the data transmitted from the RFD module to identify the RFD module, and provides a battery replacement time of the RFD module.

In addition, the FFD module or the RFD module included in the Zigbee system according to the present invention delivers the power information together with the data of the physical layer that is exchanged when the Zigbee network is configured.

Hereinafter, a Zigbee system according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram illustrating a protocol stack structure illustrating a data region processed by a Zigbee system according to an embodiment of the present invention.

Referring to FIG. 1, a protocol stack processed by a Zigbee system according to an embodiment of the present invention is largely classified into a physical (HY) layer (SHY), a media access controller (MAC) layer (S4), and a network (network / security). A layer S3, an application framework layer (hereinafter referred to as a "framework layer") (S2) and an application (Profiles / Profiles) layer (S1), wherein the PHY layer (S5) and The MAC layer S4 corresponds to the IEEE standard area, the network layer S3 and the framework layer S2 correspond to the ZigBee Alliance policy area, and the application layer S1 Corresponds to the User defined area.

Each layer of the protocol stack will be described in more detail together with the components of the Zigbee module according to the embodiment of the present invention.

2 is a block diagram schematically showing the components of the Zigbee module 100 according to an embodiment of the present invention.

2, the Zigbee module 100 according to an embodiment of the present invention includes an antenna 110, an RF receiver 120, an RF transmitter 150, a phase locked loop (PLL) 130, and power. The control circuit 140, the pulse processor 160 and the control unit 170 is included.

The RF receiver 120, the RF transmitter 150, the phase synchronization circuit 130, and the power control circuit 140 are components that process operations corresponding to the PHY layer S5 of the Zigbee protocol stack. Determine the network topology.

The RF receiver 120 and the RF transmitter 150 are provided with an amplifier, a filter, etc. to process the frequency signal of the corresponding band, the phase synchronization circuit 130, the RF receiver 120 and the RF transmitter 150 is an intermediate frequency The reference frequency signal is provided to synthesize the signal, and the power control circuit 140 determines the strength of the received signal to adjust the amount of transmission power.

The IEEE 802.15.4 standard defines two types of PHY layers (S5) (2.4 GHz, 866/915 MHz), 16 channels in the 2.4 GHz band, 10 channels in the 902 MHz to 928 MHz band, and 868 MHz to 870 MHz. One channel is allocated to the band.

The RF receiver 120 and the RF transmitter 150 use a Direct Sequence Spread Spectrum (DSSS), and in the 2.4 GHz band, an offset-quad phase phase shift keying (O-QPSK) modulation scheme having a length of 32 PN codes is used. In the case of a band below 1 GHz, a Binary Phase-Shift Keying (BPSK) modulation scheme of 15 PN code length is used.

When the analog signal is processed in this way, the RF receiver 120 and the RF transmitter 150 process digital signals in the baseband region. In the case of the RF receiver 120, the digital signals are synchronized and despreaded. Despreading, demodulation, digital filtering, and the like, and the RF transmitter 150 processes spreading, signal shaping, and the like.

In this case, when the BPSK modulation scheme is used, the baseband processing paths configured by the RF receiver 120 and the RF transmitter 150 may be integrated into one.

When the MAC (Media Access Controller) processing unit 160 finishes the digital processing of the PHY layer S5, the MAC process analyzes the transmitted data frame structure to approve the frame and detects an error (Error Detection; CRC or Checksum). Detects whether to retransmit, and handles packet routing.

That is, the MAC processor 160 is an element for processing an initial hardware network connection, and provides an additional frame structure related to a beacon for time synchronization and a guaranteed time slot (GTS). In addition, the channel access is handled using a carrier sense multiple access with collision avoidance (CSMA-CA) method.

On the other hand, the controller 170 is a function of the remaining MAC layer (referred to as "Software-MAC" corresponding to the hardware-MAC), the function of the network layer (S3), the function of the framework layer (S2) By configuring the network topology, and performs the function of the application layer (S1) to transmit predetermined data and battery power information.

3 is a diagram illustrating a network topology formed by the Zigbee system according to an embodiment of the present invention.

Referring to FIG. 3, three network topologies in which a Zigbee system composed of a plurality of Zigbee modules 100 may be formed by processing a network protocol are illustrated. FIG. 3A illustrates a star. FIG. 3B illustrates a mesh type network, and FIG. 3C illustrates a cluster tree type network.

The star network may operate the Zigbee modules 100 to maintain battery life for a long time, and the mesh network may form one or more data transmission paths in a peer-to-peer form, thus providing high data reliability and access. Has a recognition rate.

In addition, the cluster tree-type network can implement the advantages of both networks as a complex form of star and mesh.

In FIG. 3, the Zigbee module denoted by "F" denotes a FFD (Full Function Device) module, and the Zigbee module denoted by "R" denotes an RFD (RFD) Reduced Function Device (RFD) module. ZigBee module indicated by "means a PAN Personal Area Network coordinator module.

The FFD module performs functions such as network initialization, node management, and node information storage among the FFD modules. The FFD module for allowing the remaining Zigbee modules to configure any one of the three networks described above is called a PAN coordinator module.

The FFD module is a module capable of performing a coordinator function, and may configure three types of networks, and may communicate with all of the FFD module or the RFD module. In order to perform the coordinator function, since a relatively large amount of power is consumed, power is usually supplied by wire.

On the other hand, the RFD module is a Zigbee module that does not perform a coordinator function, and is a coordinating target of the FFD module.

That is, the RFD module communicates only with the FFD module and is dedicated to the network function, thereby making it possible to use a stack structure of the smallest size and to save computational / memory resources.

Therefore, since the RFD module finds a PAN coordinator module and transmits data, the RFD module can immediately disconnect the connection and enter a sleep mode, so the power consumption is very low and can be operated for a long time even with battery power.

ZigBee module 100 according to an embodiment of the present invention according to the type of the program that is mounted on the control unit 170, that is, the RFD module according to the type of the program processing data of the network layer (S3), framework layer (S2) May function as an FFD module or a PAN coordinator module, and program codes for processing the network layer S3 and the framework layer S2 may also be affected according to the type of the program processing the data of the application layer S1. Can be.

That is, the configuration of the network, the division of roles of the ZigBee module, and the like differ depending on which network service the ZigBee module 100 provides (how many ZigBee modules transmit what data in which case).

The Zigbee module 100 according to an embodiment of the present invention processes three types of data. First, "periodic data" periodically connects to a network using a beacon and transmits data. The data is processed by the Zigbee module that enters into the saving mode (sleep mode). An example of this is the ZigBee module used in a wireless sensor or meter (meter) system.

Second, "Intermittent data" is an example of a data type for lighting on / off in a home system, for example, the Zigbee module does not handle beacon or sleep mode. If there is a need to transfer data without processing, the connection is processed once.

Third, "repetitive low latency data" is data transmitted using a time slot allocation scheme such as GTS, and is mainly used in a Zigbee module applied to an emergency / security alarm system. In other words, the repetitive wait type data means a data type that requires a fast delivery path as a small packet size.

As described above, the Zigbee module can rapidly form various networks, process various data types in connection with the type of network, and perform various types of operations such as an idle mode, thereby extending battery life. The power management of the Zigbee module is recognized as an important aspect since the power consumption of the Zigbee module varies according to each role, and a large number of Zigbee modules can be applied to the service system.

The control unit of the Zigbee module operated by the RFD module receives the battery power information from the power supply circuit, constructs a packet together with the service data, and transmits the packet to the Zigbee module operated by the FFD.

Here, if the Zigbee module is an FFD module that performs a coordinator function, in particular, if the power is supplied by wire, it will not be necessary to share its battery power information with other Zigbee modules.

4 is a data structure diagram schematically illustrating a form of a data packet processed by a Zigbee module according to an embodiment of the present invention.

Referring to FIG. 4, a data packet processed by a Zigbee module operated as an FFD module or an RFD module includes a preamble (P1), a start of packet delimiter (PD), a PHY header (P3), and a PHY service data unit (PSD). (P5), etc., wherein the preamble (or "beacon" may be used) (P1) means a series of pulse signals that can be interpreted between ZigBee modules to synchronize the transmission timing.

The SPD (P2) informs the counterpart ZigBee module that the actual packet data has begun and indicates an analysis point of the PHY header, and the PHY header P3 contains analysis information of the PHY layer (physical layer) S5. The PSDU P5 includes service data (which is an actual application target) together with routing information.

In this case, the control unit of the RFD module includes the battery power information in the PSDU (P5) packet part and transmits it together, so that the control unit of the FFD module may interpret the information and collect battery power information of each RFD module constituting the network.

That is, the FFD module providing the coordinator function receives the battery power information from another FFD module or RFD module constituting the network node, and identifies the device by analyzing the data packet shown in FIG. 4, and identifies the device to the identified device (node). The power information of each node is configured by matching the battery power information.

At this time, the FFD module that provides the coordinator function can check the battery power of the Zigbee module in real time as soon as another FFD module or RFD module is connected to start data transmission. By displaying the identification information, the operator managing the FFD module providing the coordinator function can easily check the battery remaining capacity of the Zigbee modules constituting each node without having to move to various locations on the network.

In the embodiment of the present invention, the FFD module providing the coordinator function may display the battery power information of the nodes with a display device such as an LED (Light Emitting Diode), and the battery power of a node (Zigbee module) is less than a predetermined value. When lowered, the administrator can easily check the sound by emitting a predetermined speaker sound or emitting a specific color LED such as red.

5 is a diagram exemplarily illustrating a form in which an FFD module displays power information through an LED according to an exemplary embodiment of the present invention.

As illustrated in FIG. 5, when battery power information is transmitted from a Zigbee module constituting a node, the controller 170 of the Zigbee module providing the coordinator function compares the transmitted battery power value with a reference level value to display several LEDs. It is decided whether or not to emit light.

The controller 170 applies a control voltage to the switching element 180 when the number of LEDs to emit light is determined, and the switching element 180 provides power to the corresponding LED 190 according to the control voltage. Emits light.

Therefore, the administrator can estimate the battery power of the Zigbee module which is connected to the Zigbee module providing the coordinator function and transmits the data to the lighted LED 190, and through the alarm information (warning sound or red LED light) as described above. The power situation is easy to recognize without passing the bad ZigBee module.

FIG. 6 is a diagram illustrating an LED circuit provided by an RFD module according to an embodiment of the present invention to display power information.

In addition to the FFD module providing the coordinator function, other FFD modules or RFD modules may also display their own battery power information. In this case, as described above, the plurality of LEDs or one LED may display their battery power information.

For example, if an administrator moves out of the position of the FFD module providing the coordinator function and moves to the RFD module corresponding to a node, the RFD module may indicate that the battery power situation is not good so that the administrator can recognize it. have.

The LED display circuit of the RFD module shown in FIG. 6 is provided with only one LED 190 in order to alert that its battery power situation is not good. The first resistor R1 and the second resistor R2 are When the battery power approaches the lowest value, the power is distributed at a predetermined rate so as to be notified in advance, and the LED 190 emits light in a state slightly higher than the original power value according to the allocated power to provide a warning function.

In addition, the analog-to-digital converter (ADC) 172 included in the controller 170 is connected to the battery 195 to receive power information, and converts it into a digital signal, thereby controlling the controller 170 to digitally present the current battery power situation. Make it recognizable as data.

The controller 170 analyzes the digitalized power information and then converts it into new battery power information (battery power information that can be interpreted as a predetermined level value), and coordinator functions through the pulse processor 160 and the RF transmitter 150. Pass to FFD module that provides.

The present invention has been described above with reference to the preferred embodiments, which are merely examples and are not intended to limit the present invention, and those skilled in the art to which the present invention pertains do not depart from the essential characteristics of the present invention. It will be appreciated that various modifications and applications are not possible that are not illustrated above. For example, each component specifically shown in the embodiment of the present invention can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

According to the ZigBee system according to the present invention, the operator can monitor the battery remaining capacity of the nodes (ZigBee modules) constituting the entire network regardless of where the FFD module or the RFD module is installed, and provides a coordinator function. Through the FFD module, you can check the power status of other FFD modules or RFD modules that are currently connected in real time.

In addition, when the battery replacement situation arrives, the FFD module / RFD module notifies each node or its power state through a beep or light emission, so that the administrator misses the time to replace the battery of each module (as long as the battery life is long). Management is easy to neglect), which improves the data transfer efficiency of the entire network.

Claims (9)

In the configuration of a Zigbee network by transmitting MAC (MAC) information, network configuration information and user setting information, RFD (RFD; Reduced Function Device) module for identifying and transmitting the battery power; And A Zigbee system comprising an FFD (Full Function Device) module configured to receive battery power information from the RFD modules and configure power information of nodes constituting a Zigbee network. The method of claim 1, wherein the FFD module The Zigbee system, characterized in that the power information of the nodes to configure the battery power of its own. The method of claim 1, wherein the FFD module Zigbee system characterized in that for displaying the configured power information with the data transmitted from the corresponding RFD module. The method of claim 1, wherein the FFD module or the RFD module And configuring the power information and displaying the power information on a display device. The method of claim 4, wherein the FFD module or the RFD module Zigbee system, characterized in that for displaying the power information as a light emitting diode (LED). The method of claim 1, wherein the FFD module or the RFD module Zigbee system, characterized in that to provide the power information as alarm data. The method of claim 1, wherein the FFD module And comparing the power information with data transmitted from the corresponding RFD module to identify the corresponding RFD module and providing a battery replacement time of the RFD module. The method of claim 5, wherein the FFD module Zigbee system characterized in that for displaying the power information by distinguishing the color of the LED. The method of claim 5, wherein the FFD module or the RFD module The Zigbee system, characterized in that for transmitting the power information with the data of the physical layer exchanged in the configuration of the Zigbee network.

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