KR100659614B1 - ZigBee network device for assigning address to his childrens after constructing cluster-tree structure, address assigning method thereof, and, routing method thereof - Google Patents

Abstract

Disclosed is a method of address allocation in a Zigbee network environment including a plurality of devices. The address allocation method includes (a) connecting a plurality of devices in a cluster-tree structure, and (b) each device belonging to the lowest level to the next highest level of the cluster tree structure, in order from the lowest level to the next highest level, itself. Requesting each of the higher-order devices of an address block of a predetermined size to be used, and (c) each device belonging to the highest level to the next level of the cluster tree structure, in order from the highest level to the next level, Allocating an address block of a size requested by a lower device of the lower device to the lower device. As a result, the entire address can be efficiently used.

ZigBee Network, Cluster-Tree, Address, Device

Description

ZigBee network device for assigning address to his childrens after constructing cluster-tree structure, address assigning method approx, and, routing method kind}

1 is a schematic diagram showing the configuration of a Zigbee network environment in which a cluster-tree structure is assigned an address according to a conventional method;

2 is a flowchart illustrating an address allocation method in a Zigbee network environment according to an embodiment of the present invention;

3 to 6 are schematic diagrams illustrating a ZigBee network environment configuration of an address-allocated cluster-tree structure according to an embodiment of the present invention;

7 is a flowchart illustrating a method of recovering when a connection between devices configuring the Zigbee network environment is lost;

8 is a schematic diagram for explaining a process of recovering when a connection between devices configuring the Zigbee network environment is lost;

9 is a schematic diagram illustrating a ZigBee network environment configuration converted to a mesh structure;

10 is a block diagram showing a configuration of a Zigbee network device according to an embodiment of the present invention;

11 is a flowchart illustrating a routing method of a Zigbee network environment according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawing

110: communication unit 120: control unit

130: address block calculation unit 140: address block allocation unit

150: calculator 160: memory

The present invention relates to a ZigBee network device constituting a ZigBee network environment, an address allocation method in a ZigBee network environment, and a routing method. More specifically, after the cluster tree structure is connected, the present invention sequentially processes the connection order of each subordinate device. The present invention relates to a Zigbee network device constituting a Zigbee network environment for allocating an address, a method for allocating addresses in a Zigbee network environment, and a routing method using the same.

Zigbee can be implemented with lower power than Bluetooth. Wireless communication is suitable for home network based on control and sensor. It costs less than 1/2 of Bluetooth by minimizing the size of software and related components. Technology.

The ZigBee Network Standard Specification v0.85 [1] defines a cluster tree structure that aggregates all devices in a personal area network (PAN). All devices joining the cluster tree structure are assigned an address according to the tree structure. The assigned address will be used in routing in a Zigbee network environment.

For address assignment, the ZigBee coordinator defines two network parameters, Cm and Lm, taking into account the overall size of the network. Cm is the maximum number of devices (hereinafter, referred to as lower devices) that can be connected to each device, and Lm is the maximum level depth of the tree structure.

According to the conventional address assignment method in a Zigbee network environment, an address is assigned to each device. In this case, the Zigbee coordinator allocates an address considering the probability that the lower device of each device will be connected. That is, the Zigbee coordinator assigns the address of the first connected device to s + 1 when its address is s. The address of the second connected device is s + 1 + Cskip _Ls To be assigned. The address of the next connected device is assigned as s + 1 + 2 * Cskip _Ls . That is, the address of the Cmth connected device is s + 1 + (Cm-1) * Cskip _Ls . Here, Cskip _Ls may be represented by the following equation.

In Equation 1, B _L denotes the address size of the entire network, and L s denotes the level number of the Zigbee coordinator having the address s. B _L may be calculated using the following equation using Cm and Lm.

 The ZigBee Coordinator delivers its defined Cm and Lm to each device. Accordingly, each device also assigns an address to its subordinate device in the manner described above.

1 is a schematic diagram showing a conventional Zigbee network environment in which an address is assigned in the above-described manner. According to FIG. 1, device A becomes the final Zigbee coordinator. The address of device A is zero, and Cm and Lm are each defined as four. On the other hand, the lower devices B, C, and D are connected to the device A. According to Equation 2, the total address size B _L usable in the final Zigbee coordinator is calculated to be 341. By performing the calculation according to Equation 1 using this, the final Zigbee coordinator Cskip is calculated to 85. Accordingly, the addresses of the lower devices B, C, and D have an interval of 85 degrees. Specifically, the address of the first connected device B is 1, the address of the second connected device C is 86 and the device D is assigned 171. On the other hand, if Cskip of the devices B, C, and D belonging to the initial level (Ls = 1) is calculated using Equation 2, 21 is obtained. Accordingly, the addresses of the devices E to J belonging to the second level Ls have an interval of 21.

According to the address assignment scheme of FIG. 1, each device in the entire Zigbee network is assigned an address using fixedly fixed Cm and Lm. That is, each device receives Cm and Lm from its upper device, and then assigns an address of its lower device using Equations 1 and 2 described above.

Meanwhile, an end device to which a lower device cannot be connected may be connected to an intermediate level of the Zigbee cluster tree. If an address is assigned to the end device in the same manner, there is a problem in that an address resource is wasted. That is, if E is an end device in Fig. 1, the address blocks {3 to 28} for the lower device of E cannot be used by any device. Therefore, there is a problem that the address is wasted and it cannot be used efficiently.

In addition, when one device is disconnected and then connected again, there is a problem in that there is no recovery algorithm. In particular, when connected to a device different from the previously connected device, there is a problem that a new address for it has to be allocated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to form a cluster-tree structure, and then allocate address blocks of a size requested by lower devices sequentially from devices belonging to the highest level, thereby eliminating address waste. The present invention provides a Zigbee network device, an address allocation method, and a routing method that can be reconnected by using an existing address as it is when a connection fails.

According to an embodiment of the present invention for achieving the above object, the address allocation method in a network environment including a plurality of devices, (a) the plurality of devices are connected in a cluster-tree structure, (b (C) sequentially requesting each of the devices belonging to the lowest level or the next higher level of the cluster tree structure to an upper level device with an address block of a predetermined size to be used by the device, and (c) the cluster tree structure Each device belonging to the highest level or the next lower level sequentially allocates an address block of a size requested by its lower device to the lower device.

In this case, step (c) is performed in such a way that a device belonging to a predetermined level sequentially allocates an address block having a size requested by its lower device in order of connection of each lower device.

Preferably, each device belonging to the highest level to the next lower level is assigned to each of the lower devices and a branch ID sequentially assigned according to the number of lower devices connected to the lower device, a connection order of each of the lower devices. The method may further include storing a routing table in which the address block is recorded.

More preferably, a branch connecting a predetermined first device and the cluster tree structure is disconnected, the first device is connected to a predetermined second device among peripheral devices, and the first device has its own routing. Transmitting the information stored in the table to the second device, the second device assigning a predetermined branch ID to the first device, and then recording the assigned branch ID and the information in its routing table; Receiving the information by each higher level device from the upper level to the highest level of the second device, and each higher level device from the upper level to the highest level of the second device is connected to the received information. After assigning a virtual branch ID to the virtual branch ID and the information in its own routing table The step of the lock may further include.

Also preferably, a predetermined third device of the lower devices of the first device is connected to a predetermined fourth device belonging to the cluster-tree structure, wherein the first device is stored in its own routing table. Transmitting information to the third device, storing, by the third device, first information received from the first device in its routing table, and storing information stored in the routing table of the third device. Transmitting to the fourth device, the fourth device assigning a predetermined branch ID to the third device, and then recording the assigned branch ID and the information in its routing table; Receiving each of the higher level devices from the upper level to the highest level, respectively, and the fourth device; The method may further include recording the virtual branch ID and the information in its own routing table after each upper device from the upper level to the highest level assigns a virtual branch ID to the information.

Or forming a mesh structure by connecting a plurality of devices belonging to the same level on the cluster tree structure, and when another device belonging to the same level is connected, granting a predetermined branch ID to the connected other devices. Receiving information stored in the routing table of the other device, and storing the branch ID assigned to the other device and the information received from the other device in its own routing table.

Preferably, in step (a), each of the plurality of devices sets a predetermined connection level by itself, and the connection request message in which the predetermined fifth device displays each connection class from at least one peripheral device is displayed. Receiving a message; selecting, by the fifth device, a predetermined device according to the connection level indicated in the connection request message; and sending, by the fifth device, a response message to the selected device, It may include the step of being connected.

On the other hand, the routing method according to an embodiment of the present invention, (a) connecting a plurality of devices in a cluster-tree structure, (b) each device belonging to the lowest level or the next higher level of the cluster tree structure, (C) sequentially requesting the size of the address block to be used from its upper device, (c) an address having a size requested by its lower device by each device belonging to the highest level or the lower level of the cluster tree structure; Sequentially assigning blocks to the lower device, (d) each device belonging to the highest level to the next lower level includes a number of lower devices connected to the branch, a branch ID for each of the lower devices, and each lower device Stores a routing table in which the allocated address blocks for And (e) when a predetermined first device belonging to the cluster tree structure receives the predetermined packet, checks the destination address of the packet, and then sends the packet to a predetermined device to which an address block including the destination address is allocated. Routing.

Preferably, the step (e) comprises the steps of: the first device checking the destination address of the packet, and whether the first device belongs to an address block assigned to the lower device of the destination address. Determining, in the case where it is determined to belong to the address block, transmitting the packet to a lower device to which the corresponding address block is allocated, and, if it is determined that the address block does not belong to the address block, the first device sends the packet to a higher device. Transmitting a step.

On the other hand, address allocation method of a device constituting a network environment according to an embodiment of the present invention, (a) at least one sub-device is connected in a cluster-tree structure, (b) from the at least one sub-device Requesting an address block of a predetermined size, (c) combining an address block size requested from each of the at least one lower device, and requesting an address block of a predetermined size to an upper device; and (d) asking the upper device. (B) allocating an address block of a size requested by each of the at least one lower device among the allocated address blocks according to a connection order of the at least one lower device. Steps.

Preferably, if the upper device does not exist, further comprising the step of assigning an address block of the size requested by each of the at least one lower device of the entire address block according to the connection order of the at least one lower device; Can be.

Also preferably, when the lower device does not exist, the method may further include requesting the upper device for an address block having a predetermined size to be used by the lower device.

Meanwhile, according to an embodiment of the present disclosure, a network device belonging to a network environment connected in a cluster-tree structure may include a communication unit connected to a predetermined upper device and at least one lower device on the cluster-tree structure to perform communication; When an address block of a predetermined size is requested from each of the at least one lower device, an address block calculation unit for calculating the size of the address block to be used by combining the sizes of the requested address blocks, and the address block calculation unit A control unit for controlling the communication unit to request an address block of one size from the upper device; and when the address block of the calculated size is allocated from the upper device, each of the at least one lower device according to the connection order thereof. , Request It includes an address block allocation portion for allocating the address of the block size.

Preferably, when the communication unit is not connected to the upper device, it may further include an operation unit for calculating the entire address block using a predetermined network parameter.

More preferably, the address block allocating unit may divide the entire address block calculated by the calculating unit according to the connection order of each of the at least one lower device and allocate the same to each of the at least one lower device.

Preferably, the memory unit may store a routing table in which the number of the at least one lower device, the branch IDs sequentially assigned according to the connection order of the lower devices, and the address blocks allocated to the lower devices are stored. It may further include.

On the other hand, when a predetermined packet is received through the communication unit, the controller checks a destination address of the packet, and then uses a routing table stored in the memory unit to determine a lower device to which the address block including the destination address is allocated. When the lower device is found, the communication unit may be controlled to route the packet to the found lower device.

In this case, if the lower device is not found, the controller may control the communication unit to route the packet to the upper device.

More preferably, when a predetermined first device is connected to the communication unit and information stored in the routing table of the first device is received, the control unit assigns a branch ID to the first device, and then the branch ID and The received information may be recorded in the routing table of the memory unit.

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

2 is a flowchart illustrating an address allocation method in a Zigbee network environment according to an embodiment of the present invention. Referring to FIG. 2, first, as a initialization step, a plurality of devices are connected to each other to form a cluster-tree structure (S210). Specifically, when a connection is initiated in device A, which is the final Zigbee coordinator, the peripheral device transmits an association request message to device A. If the device A wants to be connected with the device that sent the connection request, the device A transmits a response message. Accordingly, the connection between the device A and each device is made. The lower device may be connected in the same manner to each device.

Meanwhile, each device may set a predetermined connection class in consideration of its performance. Specifically, it can be set as a third level that can be connected immediately without reservation, a second level that can be connected after a reservation, a first level that can be reluctantly connected, and a zero level that cannot be connected. When the connection class is set, when the connection request message is transmitted to the peripheral device, the connection class is also transmitted. Accordingly, the device receiving the plurality of connection request messages selects a device having a high connection level from each connection request message and transmits a response message. Accordingly, the connection between the devices can be easily made.

When the cluster tree structure is formed in this manner, each device belonging to the lowest level to the next higher level requests an address block having a predetermined size from its upper device in order from the lowest level to the next higher level (S220). That is, the lower device may be additionally connected to each device in addition to the currently connected lower device. In contrast, each device needs an additional address in addition to its own address. Accordingly, each device belonging to the lowest level notifies its upper device (i.e., the device belonging to the second lowest level) to notify the size of the address block that it needs.

Meanwhile, the device notified of the address block size determines whether it belongs to its highest level (S230), and if it does not belong to the highest level, it notifies the upper level device of its own address block size (S240). ). In this case, the size of the combination of the size requested by the subordinate device and the address block size required by the subordinate device is notified. In this way, the device of each level requests the address block size required by the upper level, so that the final ZigBee coordinator belonging to the highest level can know the size of the address block required in each branch.

The final Zigbee coordinator allocates an address block of the requested size for each branch (S250). In this case, the allocation is sequentially performed according to the connection order of the lower devices corresponding to each branch. Each lower device does not belong to the lowest level (S260), and reassigns its assigned address block to its lower device (S270). In this case, its lower device sequentially allocates an address block of the size requested. Accordingly, an address can be allocated to each device belonging to the lowest level. As a result, each device creates a routing table, that is, an adaptive robust tree table (ARTT) using an address assigned to the device, and then performs a routing operation accordingly. Detailed description thereof will be described later.

3 to 6 are schematic diagrams illustrating a ZigBee network environment configuration of a cluster-tree structure in which an address is assigned according to an address allocation method according to an embodiment of the present invention.

First, FIG. 3 illustrates an initialization step in which a plurality of devices form a cluster tree structure. Each device can be connected to another device using its MAC address. Device A, the final Zigbee coordinator belonging to the top level of the cluster tree structure, is connected to two subordinate devices, respectively. The connection between each level is called a branch. That is, device A has two branches each connected to device B and device J belonging to the second highest level. In FIG. 3, the numbers in [] around each device mean the total number of lower devices in each branch. That is, the total number of lower devices belonging to the first branch of device A is 8 and the total number of lower devices belonging to the second branch is 6.

4 is a schematic diagram illustrating a process of notifying the upper level device of the size of an address block required by the lowest level device from its lowest device. According to FIG. 4, devices F, M, and N belonging to the lowest level each request address blocks having sizes 3, 2, and 1 to their upper devices, respectively. That is, in the case of the device F, the upper device E is requested two more addresses for the lower device that can be connected in addition to the one to be used by the upper device E. On the other hand, the device N requests only one address to use. The size of such an address block may vary depending on the performance of each device. That is, in the case of a device without a routing function, it is preferable to request only one address because the lower device cannot be connected. Alternatively, the size of the address block can be set differently according to the power capacity of each device. In other words, when using a battery power source rather than an outlet power source, the available power capacity is limited so that a large number of sub-devices cannot be connected. Therefore, in this case, the size of the address block is set small. On the other hand, in the case of an outlet power source, a relatively large number of addresses (ie, large address blocks) may be requested.

The upper devices request the address block for their upper device by adding the size of the address block to be used separately, in addition to the size requested by the lower device. In this way, an address block is requested up to device A belonging to the highest level. That is, the device A can know that the size of the address block to be used in the first branch is 18 and the size of the address block to be used in the second branch is 16.

5 is a schematic diagram illustrating a process of allocating an address block having a predetermined size according to a request of a lower device. According to FIG. 5, the device A allocates an address block according to a connection order of its lower devices. That is, if device B is connected first, it allocates address blocks [1 to 18] which are located after address 0 of device A itself. Device B uses its first address, 1, as its address. Then, address blocks [2 to 11] and [12 to 17] are allocated to their lower devices C and H according to their connection order. Since address B allocated to device B is [1 to 18], address 18 remains. The remaining address is an additionally allocated address in preparation for a later connectable device. On the other hand, devices C and H also allocate address blocks of their requested sizes to their lower devices. In this way, an address is allocated up to the device belonging to the lowest level.

Similarly, [19 ~ 36] is allocated to device J belonging to the second branch. The device J allocates the allocated address block to its lower device again according to the connection order. On the other hand, according to Figure 5, the entire address block that can be used by the device A is the same as [0 ~ 40]. Therefore, device A can use the addresses [37 to 40] even after address assignment. The remaining address is to prepare for a spare lower device to be connected later.

6 is a schematic diagram showing a cluster tree structure including each device finally assigned an address. According to Figure 6, the addresses assigned to the devices A, B, C, D, E, F, G, H, I, J, K, L, M, N, O are 0, 1, 2, 3, 4, respectively. , 5, 9, 12, 13, 19, 20, 21, 22, 24, 26.

Each device assigns a branch ID to each lower device connected to the device, and prepares and stores a routing table that records the allocated address blocks for the branch. Accordingly, the routing operation can be performed after the address assignment. Specifically, the routing table stored in the device A may be represented by the following table.

Branch ID First address Last address One One 18 2 19 36

According to Table 1, branch IDs sequentially assigned according to the connection order of the lower devices, first addresses and last addresses of address blocks allocated to each branch are recorded in the routing table. Accordingly, it can be seen that branch 1 of device A is assigned an address between [1-18] and branch 2 [19-36].

As another example, the routing table stored in the device H may be stored as follows.

Branch ID First address Last address One 13 15

Although not shown in Tables 1 and 2, the total number of branches can also be added to the routing table.

FIG. 7 is a flowchart illustrating an address allocation method when a device is disconnected and then recovered after disconnection between devices in an Zigbee network environment in which an address is allocated as shown in FIGS. 3 to 6. According to FIG. 7, after a connection state of a predetermined first device belonging to a Zigbee network environment of a cluster tree structure is disconnected (S310), and connected to a second device belonging to a predetermined level of the cluster tree structure (S320), the first device The master transmits the address block information used by the second device to the second device (S340).

In this case, if it is assumed that the device to which the first device was previously connected is not the second device, the second device grants a new branch ID to the branch to which the first device is connected (S350). Accordingly, the first address, the last address, and the assigned branch ID are recorded in the routing table using the address block information transmitted from the first device (S350). If the device to which the first device was previously connected is the second device, since the second device does not need to receive information from the first device separately, the second device uses the information previously stored in its routing table.

Meanwhile, when a connection failure of the first device occurs, the lower device of the first device may be directly connected to the cluster tree structure. Accordingly, when the third device, which is a lower device of the first device, is connected to the second device (S330), the level rank between the first device and the third device is changed. That is, the first device operates as a lower device of the third device. In this case, the first device transmits the address block information used by the first device to the third device (S360). The third device assigns a new branch ID to the first device, and then, among the address blocks received from the first device, retains the remaining address block information (ie, the first and last address) and the branch ID except for the address block used by the third device. It is stored in the routing table (S360).

Next, the third device transmits the information received from the first device to the second device (S370). After assigning a new branch ID to the third device, the second device records the received branch information in its routing table together with the received information (S350).

On the other hand, if the second device is not the top device (S380), the second device transmits the information received from the first device to its own upper device (S390). In this case, the upper device receiving the information does not have a new branch connected to itself, and thus, gives a virtual branch ID to the received information. Then, the virtual branch ID and the received information (that is, the first address and the last address) are recorded in its routing table (S390). In this way, it updates its routing table up to the final ZigBee coordinator. As a result, each device in the Zigbee network environment can recover the connection while maintaining the existing address.

FIG. 8 is a schematic diagram for explaining the method of FIG. 7 more efficiently. According to FIG. 8, the connection between the device J and the device K is broken. In this case, the device K attempts to connect by sending a connection request message to the peripheral device.

First, a case in which device K is connected to device H will be described as an example. The device K transmits the address block information [20 to 36] used by the device K to the device H. Device H assigns a new branch ID with device K and writes the received information to the routing table. Accordingly, Table 2 is updated as follows.

Branch ID First address Last address One 13 15 2 20 36

Next, the device H transmits the information received from the device K to the device B, which is its upper device. Device B assigns a virtual branch ID to the received information and stores it in the routing table. The routing table for device B is shown in the table below.

Branch ID First address Last address One 2 11 2 12 17 -2 20 36

In Table 4, the virtual branch ID is indicated by attaching a negative sign to the existing branch ID. That is, the virtual branch ID -2 indicates that a new device is connected at a lower level of the second branch.

The device B transmits the information received from the device H to device A, which is its upper device. Since the device A receives information through the first branch, the virtual branch ID -1 is assigned to the received information, and the information is recorded in its own routing table.

On the other hand, when the device J, which is conventionally connected to the device K, is disconnected from the device K, it needs to update its routing table to perform a normal routing operation. In other words, it should be noted that device K is no longer its subordinate device. To this end, the device J may add a virtual branch ID 0 to the address block information used by the device K and add it to its routing table. The virtual branch ID 0 is an ID for designating that the corresponding packet should be routed to its upper device. The routing operation using the routing table as described above will be described later.

Next, a case in which device L, which is a lower device of device K, is connected to device I will be described as an example. In this case, device K operates as a lower device of device L. Accordingly, device L assigns a new branch ID to device K. The device K transmits the address block information used by the device K to the device L. The device L records the remaining address block information except the address block used by the device L and the assigned branch ID among the received address block information in its routing table.

That is, the routing table of the device L may be expressed as shown in the table below.

Branch ID First address Last address One 22 23 2 24 24 3 26 36

In Table 5, branch ID 3 is assigned for device K.

On the other hand, device I assigns branch ID 1 to device L, and records the first and last addresses according to the address information provided from device L. The upper devices H, B, and A of the device I also add virtual branch IDs to the routing table according to the address information provided from the device L, respectively. Since the method is similar to the case (a) described above, further description is omitted.

9 is a schematic diagram showing the configuration of a Zigbee network environment connected by a mesh structure. In a ZigBee network environment having a mesh structure, each device can directly transmit a packet to a device of the same level without passing through an upper device. According to FIG. 9, each device is connected to a peripheral device located at the same level as itself in the cluster tree structure to form a mesh structure. In this case, each device recognizes the new connected device as its subordinate device and records it in the routing table. Accordingly, the packet can be directly routed without passing through a higher level device. For example, when device E transmits a packet destined for device H, the packet routing path becomes E-C-H rather than E-C-B-H.

10 is a block diagram illustrating a configuration of a device connected in a cluster-tree structure according to an embodiment of the present invention. According to FIG. 10, the device includes a communication unit 110, a control unit 120, an address block calculation unit 130, an address block allocation unit 140, an operation unit 150, and a memory unit 160.

The communication unit 110 is connected to a predetermined upper device and lower device in a cluster-tree structure to perform communication. In addition, the communication unit 110 transmits / receives a connection request message and a response message with a peripheral device in order to form a cluster-tree structure. In the connection request message, one of the aforementioned connection classes 0 to 3 may be displayed.

When the connection request message is received from the plurality of lower devices through the communication unit 110, the control unit 120 selects the connection level in order of high and allows the connection. That is, the communication unit 110 is controlled to transmit the response message to the selected lower device.

The address block calculator 130, the address block allocator 140, and the calculator 150 are means for assigning an address after the cluster-tree structure is formed.

That is, when an address block having a predetermined size is requested from a lower device connected through the communication unit 110, the address block calculator 130 calculates the size of an address block to be used by the device. That is, when a plurality of lower devices are connected, the address block size requested by each lower device is added, and an additional address block size is added in preparation for a connectable lower device in order to calculate an address block size to be used.

The control unit 120 controls the communication unit 110 to request an address block having a size calculated by the address block calculation unit 130 to an upper device of the present device.

When an address block is allocated from an upper device, the address block allocator 140 allocates an address block having a size requested by each lower device according to the connection order to each lower device connected to the device.

On the other hand, when the device belongs to the highest level of the cluster-tree structure, the device operates as the final Zigbee coordinator. In this case, since there is no higher level device, the operation unit 150 is controlled to calculate the size of all available address blocks. The calculation unit 150 may calculate the entire address block by substituting a predetermined network parameter into the following equation.

In Equation 3, S is the entire address block, s is the address of the device, B _L is the size of the entire address block, Cm is a network parameter representing the maximum number of connectable lower devices, and Lm is a cluster-tree structure. Means a network parameter representing the maximum level depth.

Accordingly, when the calculation unit 150 calculates the entire address block, the address block allocation unit 140 divides and allocates the address blocks according to the connection order of the respective lower devices.

Meanwhile, the memory unit 160 stores a routing table in which the number of lower devices connected to the device, branch IDs sequentially assigned according to the connection order of each lower device, and address block information allocated to each lower device are recorded. . When the packet is received through the communication unit 110, the controller 120 refers to the routing table stored in the memory unit 160 to route to the cluster to which the packet destination belongs.

On the other hand, when the connection between the communication unit 110 and the upper device is disconnected and connected to another device, the controller 120 provides routing information stored in the memory unit 160 to another newly connected device. This allows other devices to record the address information of this device in their routing tables.

Alternatively, when the connection of the device previously connected to another device is terminated and connected to the communication unit 110, the controller 120 assigns a branch ID or a virtual branch ID to the other device, and provides address information of the other device. In the memory unit 160. As a result, even when the connection is restored, the existing address can be used as it is without being reassigned.

11 is a flowchart illustrating a routing method of a device according to an embodiment of the present invention. According to FIG. 11, when the cluster-tree structure is formed (S410), an address is allocated to each device belonging to the cluster-tree structure (S420). Since the address allocation method has been described in the description of FIG. 2, further description thereof will be omitted.

In this state, when the device receives a packet designated as a destination (S430), the device checks whether the device is a destination. In other words, it is checked whether the destination address of the packet is the same as its own address (S440). Accordingly, if identical, the contents recorded in the body of the corresponding packet are read and the corresponding operation is performed.

On the other hand, if it is not the same, it refers to the routing table stored in the memory unit 160 (S450). Accordingly, it is checked whether the address block information to which the destination address of the packet belongs is recorded in the routing table (S460).

If it is recorded in the routing table, the corresponding packet is routed to the branch to which the corresponding address block is allocated (S480). Accordingly, the lower device that receives the routed packet also checks whether it is the destination device. As a result, if it is not the destination device, the packet is routed to the branch to which the corresponding address block is assigned by referring to the routing table.

On the other hand, if the destination address is not recorded in its routing table, the device routes the packet to the higher level device (S490). The upper device also checks its routing table to see if address block information including the destination address is recorded. In this way, packets can be routed to the destination device.

As described above, according to the present invention, after each device in a Zigbee network environment is connected in a cluster-tree structure, an address is newly assigned. As a result, the entire address block can be efficiently used. In addition, when the connection on the cluster tree structure is disconnected or restored again, or when a new device is connected, the existing address can be used as it is. Thus, time and power waste due to address reallocation can be prevented.

 In addition, although the preferred embodiment of the present invention has been shown and described above, the present invention is not limited to the specific embodiments described above, but the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

Claims (23)

In the address assignment method in a network environment including a plurality of devices, (a) connecting the plurality of devices in a cluster-tree structure; (b) sequentially requesting, by each device belonging to the lowest level to the next higher level of the cluster tree structure, an address block having a predetermined size to be used by the higher level device; And, (c) assigning, by each device belonging to the highest level or the next lower level of the cluster tree structure, an address block having a size requested by its lower device to the lower device. The method of claim 1, Step (c) is, A device belonging to a predetermined level sequentially allocates an address block of a size requested by its lower device in order of connection of each lower device. The method of claim 2, Each device belonging to the highest level to the next lower level has a number of lower devices connected thereto, a branch ID sequentially assigned according to the connection order of the lower devices, and an address block allocated to each of the lower devices. Storing the routing table further comprising: an address assignment method. The method of claim 3, Disconnecting a branch connecting the predetermined first device and the cluster tree structure; Connecting the first device to a predetermined second device among peripheral devices; Transmitting, by the first device, information stored in its routing table to the second device; The second device assigning a predetermined branch ID to the first device, and then recording the assigned branch ID and the information in its routing table; Receiving each of the higher level devices from the upper level to the highest level of the second device by receiving the information; And Assigning a virtual branch ID to the received information by each higher level device from the upper level to the highest level of the second device, and then recording the virtual branch ID and the information in its own routing table. Addressing method comprising a. The method of claim 4, wherein Connecting a predetermined third device of the lower devices of the first device to a predetermined fourth device belonging to the cluster-tree structure; Transmitting, by the first device, first information stored in its routing table to the third device; Storing, by the third device, first information received from the first device in its routing table; Transmitting, by the third device, information stored in its routing table to the fourth device; The fourth device assigning a predetermined branch ID to the third device, and then recording the assigned branch ID and the information in its routing table; Receiving each of the higher level devices from the upper level to the highest level of the fourth device by receiving the information; And, And assigning a virtual branch ID to the information by each higher level device from the upper level to the highest level of the fourth device, and then recording the virtual branch ID and the information in its routing table. And an address assignment method. The method of claim 2, Interconnecting a plurality of devices belonging to the same level on the cluster tree structure to form a mesh structure; If another device belonging to the same level is connected, assigning a predetermined branch ID to the connected other device; Receiving information stored in a routing table of the other device; And, And storing the branch ID assigned to the other device and the information received from the other device in its routing table. The method of claim 1, In step (a), Each of the plurality of devices setting a predetermined connection level by itself; Receiving, by a predetermined fifth device, a connection request message indicating each connection class from at least one peripheral device; Selecting, by the fifth device, a predetermined device according to the connection class indicated in the connection request message; And, And transmitting, by the fifth device, a response message to the selected device, and connecting to the selected device. (a) connecting a plurality of devices in a cluster-tree structure; (b) sequentially requesting, by each of the devices belonging to the lowest level to the next higher level of the cluster tree structure, to the higher level device of its own address block size; (c) sequentially assigning, by the lower level device to the lower level of the cluster tree structure, an address block having a size requested by the lower device to the lower device; (d) Each device belonging to the highest level to the next lower level stores a routing table in which the number of lower devices connected thereto, the branch ID for each of the lower devices, and the address block allocated for each lower device are recorded. Doing; And, (e) if a predetermined first device belonging to the cluster tree structure receives the predetermined packet, checking the destination address of the packet, and then routing the packet to a predetermined device to which an address block including the destination address is allocated. Routing method in a network environment comprising a. The method of claim 8, In step (e), Verifying, by the first device, a destination address of the packet; Determining, by the first device, whether the destination address belongs to an address block allocated to its lower device; If it is determined to belong to the address block, transmitting the packet to a lower device to which the address block is allocated; And, If it is determined that it does not belong to the address block, transmitting the packet to a higher device by the first device. In the address assignment method of the device constituting the network environment, (a) at least one subordinate device being connected in a cluster-tree structure; (b) receiving an address block of a predetermined size from the at least one lower device; (c) combining an address block size requested from each of the at least one lower device, and requesting an upper level device for an address block having a predetermined size; (d) assigning an address block of a requested size to the upper device; And, (e) allocating an address block of a size requested by each of the at least one lower device among the allocated address blocks according to the connection order of the at least one lower device. The method of claim 10, Allocating an address block having a size requested by each of the at least one lower device among all address blocks according to the connection order of the at least one lower device when the upper device does not exist. Address allocation method. The method of claim 11, And requesting, by the upper device, an address block of a predetermined size to be used by the lower device when the lower device does not exist. In a network device belonging to a network environment connected by a cluster-tree structure, A communication unit connected to a predetermined upper device and at least one lower device on the cluster-tree structure to perform communication; An address block calculation unit for calculating a size of an address block to be used by combining sizes of the requested address blocks when an address block having a predetermined size is requested from each of the at least one lower device; A control unit which controls the communication unit to request the upper device to an address block having a size calculated by the address block calculator; And, And an address block allocator for allocating an address block of the requested size to each of the at least one lower device according to the connection order when the address block of the calculated size is allocated from the upper device. Network device. The method of claim 13, And a computing unit calculating the total address block using a predetermined network parameter when the communication unit is not connected to the upper device. The method of claim 14, The computing unit may calculate the entire address block by using the following equation:

In the above equation, S is a global address block, s is its own address, B _L is the size of the global address block, Cm is a network parameter representing the maximum number of connectable lower devices, and Lm is the maximum of the cluster-tree structure. Network parameter representing level depth. The method of claim 14, The address block assignment unit, And dividing the entire address block calculated by the calculating unit according to the connection order of each of the at least one lower device, and assigning the total address block to each of the at least one lower device. The method of claim 16, And a memory unit configured to store a routing table in which the number of the at least one lower device, a branch ID sequentially assigned according to the connection order of each of the lower devices, and an address block allocated to each of the lower devices are stored. Network device, characterized in that. The method of claim 17, The control unit, When a predetermined packet is received through the communication unit, after checking a destination address of the packet, a lower device to which an address block including the destination address is allocated is searched using a routing table stored in the memory unit, and the lower device If is found, the network device controls the communication unit to route the packet to the discovered lower device. The method of claim 18, The control unit, And if the lower device is not found, controlling the communication unit to route the packet to the upper device. The method of claim 18, The control unit, When a predetermined first device is connected to the communication unit and information stored in the routing table of the first device is received, a branch ID is assigned to the first device, and then the branch ID and the received information are routed to the memory unit. Network device characterized in that the writing to the table. Maintaining, by the node, a table in which address blocks allocated for each branch held by a node are recorded; Upon receipt of a packet, the node referring to the table to determine whether an address block to which a destination address of the received packet belongs is recorded in the table; If it is verified that the node has been written, routing the packet to a branch to which an address block to which the destination address of the packet belongs is assigned; And If the node is found to be unrecorded, routing the packet to a higher node of the node . At least one lower device connected to a tree; Receiving an address block of a predetermined size from the at least one lower device; Requesting, by the upper device, the sum of the address block sizes requested from each of the at least one lower device; Receiving an address block of a size requested for the upper device; And Each of the at least one lower device among the allocated address blocks Allocating an address block of a requested size to the at least one lower device. Connecting to nodes and trees; Connecting with neighboring nodes within one hop not connected to the tree; And And recording the neighbor node in a table.

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