KR101491151B1 - Zigbee system and formation method of zigbee network - Google Patents

Abstract

A ZigBee system according to an exemplary embodiment of the present invention includes a plurality of routers that constitute a ring network and sequentially transmit token information to transmit its network information; A coordinator for managing the list of routers and for transmitting the ring configuration information to the router to configure the ring network; And an RFD for detecting the strength of a received signal of the network information to select the router in the closest position and configuring a zigbee network according to the network information of the selected router.

According to the embodiment, when a plurality of RFDs and routers transmit and receive a router scan message and a response message in order to configure a ZigBee network, it is unnecessary to repeatedly transmit and receive each message, and duplicate messages can be excluded. Therefore, it is possible to minimize load on each device, network traffic, and data collision phenomenon.

ZigBee Network, Coordinator, Router, RFD, Token, Router Scan Messages

Description

[0001] The present invention relates to a ZigBee system and a ZigBee network,

Embodiments relate to a ZigBee system and a ZigBee network configuration method.

Ubiquitous network technologies include ZigBee, Bluetooth, and Radio Frequency Identification (RFID), among which ZigBee technology, which is one of the IEEE 802.15.4 standards supporting short-range communication, have.

ZigBee technology can transmit data at a speed of about 250 Kbps over a communication distance of 10 m to a maximum of 1 km, can form thousands of network topologies by connecting various devices, and has a small power consumption.

The ZigBee network is composed of a coordinator for managing the network, a full function device (FFD) for performing routing functions of the network, and a reduced function device (RFD) operated as an end device.

Generally, a method of configuring a ZigBee network is as follows.

First, the first RFD transmits the first router scan message in a broadcast manner. At this time, since the first router scan message has no destination address, routers around the first RFD can receive the first router scan message.

Second, the routers receiving the first router scan message configure network information including the channel, PAN ID (Personal Area Network IDentification), and network address of the router, as a first response message, and transmit the first response message to the first RFD .

Third, the first RFD receives a plurality of the first response messages and selects a router that has transmitted the first response message having the highest received signal strength. If the router is selected, the first RFD participates in the network path of the selected router using the network information.

Fourth, the second RFD, the third RFD, ... , And the n-th RFD processes the first to third processes to select routers located closest to each other and configure the ZigBee network.

As such, it is important that the RFD find the router closest to the ZigBee network, each RFD broadcasting a router scan message, and the routers repeated the same response message for each router scan message, i.e., the number of RFDs .

Therefore, the router is subjected to a load on the signal processing. In this process, network traffic increases, and obstacles such as data collision occur. Therefore, there are many difficulties in configuring the ZigBee network.

In the embodiment, when a plurality of RFDs and routers send and receive a router scan message and a response message in order to configure a ZigBee network, the ZigBee network can be configured efficiently by minimizing the failure probability of the scan by reducing the data transmission amount and the signal processing amount ZigBee system and ZigBee network configuration method.

A ZigBee system according to an exemplary embodiment of the present invention includes a plurality of routers that constitute a ring network and sequentially transmit token information to transmit its network information; A coordinator for managing the list of routers and for transmitting the ring configuration information to the router to configure the ring network; And an RFD for detecting the strength of a received signal of the network information to select the router in the closest position and configuring a zigbee network according to the network information of the selected router.

A method of configuring a ZigBee network according to an embodiment includes: operating an n-th router as a start router of a ring network with "n = 1" according to ring configuration information; The nth router broadcasting its network information; Receiving and storing the network information by a plurality of RFDs, and sensing information to generate sensing information; If the next router on the ring network exists, the n-th router transmits token information to the (n + 1) th router; The nth router operates as a preceding router with n = n + 1 according to the ring configuration information and repeats the step of broadcasting the token information or broadcasting the network information, Stopping the repeating operation if there is no following router on the network; And the RFD compares the sensing information to select a router having the largest signal strength, and configuring the router and the ZigBee network.

According to the embodiment, the following effects can be obtained.

First, in order to configure a ZigBee network, when a plurality of RFDs and routers transmit and receive a router scan message and a response message, it is unnecessary to repeatedly transmit and receive each message, and duplicate messages can be excluded.

Secondly, the ZigBee network can be configured by minimizing the load on each device, network traffic, and data collision phenomenon, and the efficiency of the ZigBee network can be maximized.

Third, because the router has network configuration rights, RFD does not need to directly broadcast router scan messages to find routers. Therefore, RFD can operate stably for a long time with minimum power consumption.

A method of configuring a ZigBee system and a ZigBee network according to an embodiment will be described in detail with reference to the accompanying drawings.

In the following description of the embodiments, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention unclear. Accordingly, only the essential components directly related to the technical idea of the present invention will be described .

FIG. 1 is a diagram illustrating a form in which token information is transferred in a ZigBee system according to an embodiment.

1, a ZigBee system according to an embodiment includes a plurality of routers 100, a plurality of Reduced Function Device (E) devices 200, and a coordinator (C) 300).

Hereinafter, the router 100, the RFD 200, and the coordinator 300 will be collectively referred to as a "ZigBee device ".

FIG. 2 is a protocol stack structure diagram exemplarily showing an area of data processed in the router 100 according to the embodiment.

Referring to FIG. 2, the ZigBee protocol stack includes a PHY layer S5, a MAC layer S4, a network / security layer S3, an application framework The PHY layer S5 and the MAC layer S4 correspond to the IEEE standard area and the network layer S3 and the application / The framework layer S2 corresponds to a prescribed area of the ZigBee Alliance, and the application layer S1 corresponds to an application area related to database management and control information generation.

The ZigBee device can function as an RFD, a full function device (FFD), or a coordinator depending on the type of program loaded, that is, the type of program that processes data in the network layer S3 and the framework layer S2.

The FFD performs functions such as network initialization, node management, and node information storage, and can perform communication with other FFDs or RFDs. Also, the FFD that allows the remaining ZigBee devices to configure any one of the three nodes is referred to as a PAN (Personal Area Network) coordinator.

The RFD can not perform a coordinator function and a routing function, and is a ZigBee device operated as an end device. The RFD is a coordinating object and can communicate with an FFD or a coordinator.

Also, an FFD which receives control under the control of the coordinator and processes the routing path to transmit data to the RFD is called a router.

In the ZigBee system according to the embodiment, the router 100 has the configuration authority of the network, and the router 100 configures the ring network and operates sequentially.

The router 100 configures the ring network and uses the token information delivery scheme to operate sequentially.

The coordinator 300 stores and manages a list of the routers 100 and assigns a rank to the routers 100 to generate ring configuration information.

The ring configuration information defines a first router that is the start of the ring network, a transmission order of the token information, and a last router that is an end point of the ring network.

The coordinator 300 may transmit the ring configuration information to the routers 100 registered to the coordinator 300 and the router 100 may configure the ring network by sharing the ring configuration information.

FIG. 3 is a block diagram schematically showing the components of the router 100 according to the embodiment, and FIG. 4 is a data structure diagram schematically showing a form of a data packet processed by the router 100 according to the embodiment.

3, the router 100 includes a first control unit 110, a first storage unit 120, a first MAC processing unit 130, a first RF receiving unit 140, a first RF transmitting unit 150, A first power control circuit 160, a first phase synchronizing circuit 170, and a first antenna 180. [

The first control unit 110 includes a network information processing unit 112 and a token information processing unit 114.

4, a data packet generated by the first controller 110 includes a preamble D1, a Start of Packet Delimiter D2, a PHY header D3, a PHY Service Data Unit (D4) The preamble (or "beacon") may be a series of pulse signals that can be interpreted between ZigBee devices to synchronize transmission timing.

The SPD D2 notifies the relative Zigbee device that the actual packet data has been started and indicates an interpretation point of the PHY header. The PHY header D3 contains analysis information of the PHY layer (physical layer) S5 , And the PSDU (D4) is a section in which application data is loaded together with routing information.

The first controller 110 configures a network topology by performing functions of a software-MAC layer, a function of a network layer S3 and a framework layer S2 (refer to FIG. 2) S1) to manage the database and configure the ZigBee network.

The token information processing unit 114 receives the ring configuration information from the coordinator 300 and records the received ring configuration information in the first storage unit 120. The network information processing unit 114 generates network information, send.

The network information includes at least one of a channel used by the router 100, PAN ID, network ID, device information such as a MAC address, and token delivery information.

The token delivery information is information obtained by the ring configuration information, and means information of a router to which the token information is to be handed over next time.

The network information can be transmitted to all the RFDs 100 in a broadcast manner since there is no destination address.

A protocol defining the transmission standard of the token information is stored in the first storage unit 120. The token information processing unit 114 analyzes the protocol and the ring configuration information and sequentially transmits the token information .

In addition, when the subscription request information requesting the network registration is received from the RFD 200, the first control unit 110 forms the ZigBee network by adding the RFD 200 to the router path.

The ring configuration information, the network information, the token information, and the like may be transmitted and received in the form of a data packet having a structure as shown in FIG. 4, in the period of the PSDU (D4).

The first RF receiving unit 140, the first RF transmitting unit 150, the first phase synchronizing circuit 170 and the first power control circuit 160 process an operation corresponding to the PHY layer S5 The components determine the RF communication structure and the network topology.

The first RF receiver 140 and the first RF transmitter 150 connected to the first antenna 180 use DSSS (Direct Sequence Spread Spectrum), and in the 2.4 GHz band, O- Offset-Quadrature Phase-Shift Keying (QPSK) modulation and demodulation is used to convert and process RF signals and digital signals.

The first phase synchronization circuit 170 provides an oscillation frequency signal to the first RF receiver 140 and the first RF transmitter 150 and the first power control circuit 160 Determine the strength and adjust the transmission power.

The first MAC (Media Access Controller) processor 130 analyzes the transmitted data frame structure to acknowledge a frame, detects an error (Error Detection (CRC or Checksum), determines whether to retransmit) , And handles packet routing.

5 is a block diagram that schematically illustrates the components of an RFD 200 according to an embodiment.

5, the RFD 200 includes a second control unit 210, a second storage unit 220, a second MAC processing unit 230, a second RF receiving unit 240, a second RF transmitting unit 250, A second power control circuit 260, a second phase synchronization circuit 270, and a second antenna 280. [

The second control unit 210 includes a router selecting unit 212 and a response information processing unit 214. The second RF receiving unit 240 includes a signal strength sensing unit 242. [

The second RF processing unit 230, the second RF receiving unit 240, the second RF transmitting unit 250, the second power control circuit 260, the second phase synchronizing circuit 270, The connection structure and operation of the antenna 280 are similar to those of the components of the router 100 described above, so repeated descriptions will be omitted.

When the network information is sequentially received from the routers 100, the signal strength sensing unit 242 senses the strength of the received signal on the network information and generates sensing information.

For example, the signal strength detection unit 242 may be provided as a logarithmic amplifier, and converts the intermediate frequency signal, which is an analog state, into a DC voltage signal so as to detect a power level.

At this time, the signal strength detection unit 242 can extend the signal sensitivity range of the receivable power level by outputting the intermediate frequency signal as a DC voltage signal proportional to a direct decibel value.

When the sensing information is received from the signal strength sensing unit 242, the router selecting unit 212 converts the sensed information into a comparable digital signal and records the digital signal in the second storage unit 220.

The router selection unit 212 compares the sensed information recorded for each router 100, selects a router determined to have the highest signal strength, generates router selection information, and transmits the router selection information to the response information processing unit 214 .

The response information processing unit 214 records the network information transmitted by the router corresponding to the router selection information in the second storage unit 220.

The network information recorded in the second storage unit 220 is used as network configuration information for the RFD 200 to participate in.

The response information processing unit 214 transmits the subscription request information requesting subscription to the ZigBee network to the router 100 and accesses the ZigBee network when the subscription acceptance information is received from the router 100. [

The subscription request information includes device identification information of a RFD, a network ID, and the like.

After being connected to the ZigBee network, the second control unit 210 performs data communication.

6 is a flowchart illustrating a method of configuring a ZigBee network according to an embodiment.

First, the coordinator 300 generates ring configuration information (S100), and transmits the ring configuration information to the routers 100 (S105).

The router 100 interprets the ring configuration information to determine its own rank on the ring network, and the first router 100 set to the first rank is operated to start the ring network (S110).

The first router 100 generates network information and broadcasts it to an unspecified number of the RFDs 200 (S115).

The RFD 200 stores network information of the first router 100 and generates sensing information by sensing the strength of a received signal. The sensing information is sequentially recorded in the second storage unit 220 (S120).

The first router 100 interprets the ring configuration information to identify the router having the next rank on the ring network, i.e., the second router 100 (YES in S125), generates token information, To the router 100 (S130).

The second router 100 having received the token information takes over the authority of the network configuration (S135), configures and broadcasts its own network information (S115).

Thereafter, all the routers 100 constituting the ring network sequentially receive token information and broadcast their own network information (S115 to S135).

At this time, the RFD 200 records network information of each router 100 and sensing information of received signal strength (S120).

When the broadcast transmissions of all the routers 100 constituting the ring network are completed, the RFDs 200 compare the detected information and select the router 100 determined to be the closest to the router 100 , And records network information of the selected router 100 as network setting information (S140).

The RFD 100 generates subscription request information and transmits the subscription request information to the selected router 100. The selected router 100 transmits the subscription request information to the RFD 100 ), And transmits the registration acceptance information to the registered RFD 100.

The network information processing unit 112 of the router 100 processes the data of the software MAC layer S4, the network layer S3 and the framework layer S2 to determine the network topology, And generates network configuration information. The network configuration information is stored in the first storage unit 120.

Finally, the RFD 200 may establish a ZigBee network by connecting to the router 100 to which the RFD 200 has subscribed, and may perform data communication (S145).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications other than those described above are possible. For example, each component specifically shown in the embodiments of the present invention can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a form in which token information is transferred in a ZigBee system according to an embodiment; FIG.

Fig. 2 is a diagram showing a protocol stack structure exemplarily showing an area of data processed in a router according to an embodiment; Fig.

3 is a block diagram schematically illustrating the components of a router according to an embodiment;

FIG. 4 is a data structure diagram schematically showing a form of a data packet processed by a router according to an embodiment; FIG.

5 is a block diagram that schematically illustrates the components of an RFD according to an embodiment;

6 is a flowchart illustrating a method of configuring a ZigBee network according to an embodiment.

Claims (13)

A plurality of routers constituting a ring network and having a network configuration authority; A coordinator for storing and managing a list of the plurality of routers and assigning a ranking to the plurality of routers to generate ring configuration information; And And a plurality of RFDs for establishing a network with any one of the plurality of routers and performing data communication with a router constituting the network, Each of the plurality of routers includes: And transmits the network information of its own to the plurality of RFDs in order in accordance with the assigned rank, and delivers the token information to the router of the next rank as the transmission of the own network information is completed, Wherein each of the plurality of RFDs comprises: Network information sequentially transmitted from the plurality of routers and detection information of the received signal strength are recorded and the detection information corresponding to the plurality of routers is compared to select a router closest to the network information And the network information of the selected router is recorded as network setting information. The method of claim 1, wherein the ring configuration information A first router that is the start of the ring network, a transmission order of the token information, and a last router that is an end point of the ring network. 2. The method of claim 1, wherein each of the plurality of routers A token information processing unit for receiving and storing the ring configuration information and transmitting the token information to a next router of the ring network according to the transmission specification of the token information and the ring configuration information; And And a network information processing unit for generating and transmitting the network information when the first router of the ring network or when the token information is transmitted. The method of claim 1, wherein the plurality of routers And the network information is transmitted in a broadcast manner. The method of claim 1, A PAN ID, a network ID, device information, and token transfer information defining a router to which the token information is to be transmitted next, respectively. The method of claim 1, wherein each of the plurality of RFDs A signal strength detection unit for detecting the strength of the received signal on the network information and generating sensing information; A router selecting unit for converting the sensing information into a comparable digital signal and storing the sensed information, comparing the sensed information stored for each router, selecting a router having the largest signal strength, and generating router selection information; And And a response information processor for storing network information of a router corresponding to the router selection information as network configuration information and transmitting the subscription request information to the router. 7. The method of claim 6, wherein the subscription request information And a network ID of the selected router among the plurality of routers. 7. The method of claim 6, wherein each of the plurality of routers And registers the RFD in which the subscription request information among the plurality of RFDs is transmitted according to the subscription request information in its routing path, and transmits the subscription approval information to the RFD. Quot; n = 1 "in accordance with ring configuration information, and the n-th router is operated as a start router of the ring network; The nth router broadcasting its network information; Receiving and storing the network information by a plurality of RFDs, sensing the strength of the received signal to generate sensing information, If the next router on the ring network exists, the n-th router transmits token information to the (n + 1) th router; The n-th router is operated as a preceding router with "n = n + 1" according to the ring configuration information, and repeating the step of broadcasting the network information or the step of transmitting the token information, Stopping the repeating operation if there is no following router; And Each of the plurality of RFDs compares the sensing information to select a router having the largest signal strength, and configuring the selected router and the ZigBee network, The plurality of routers, The network configuration authority, and thereby, the network information of the user is commonly broadcasted to the plurality of RFDs in the order according to the ring configuration information, Wherein each of the plurality of RFDs comprises: Network information sequentially transmitted from the plurality of routers and detection information of the received signal strength are recorded and the detection information corresponding to the plurality of routers is compared to select a router closest to the network information And the network information of the selected router is recorded as network setting information. 10. The method of claim 9, Wherein before the nth router is operated as a start router of the ring network, And a coordinator for managing the list of the plurality of routers generates the ring configuration information and transmits the ring configuration information to the plurality of routers, respectively. 10. The method of claim 9, wherein the ring configuration information A first router which is the start of the ring network, a transmission order of the token information, and a last router which is an end point of the ring network are defined. 10. The method of claim 9, A PAN ID, a network ID, device information, and token transfer information defining a router to which the token information is to be transmitted next, respectively, which are used by the plurality of routers, respectively. 10. The method of claim 9, wherein configuring the ZigBee network comprises: Each of the plurality of RFDs transmitting subscription request information including at least one of device identification information and network ID to the selected router; Registering, in a routing path, an RFD to which the router having received the subscription request information transmitted the subscription request information, among the plurality of routers, transmits subscription approval information to the registered RFD; And And configuring the ZigBee network by connecting the RFD, which has received the registration acceptance information, to the router.

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