KR100780794B1 - Routing method for transmitting data packet on zigbee network and recording medium thereof - Google Patents

Abstract

A routing method for data packet transmission in a ZigBee network and a recording medium for the same are provided to increase the efficiency of data packet transmission by minimizing the routing frequency of a beacon transmission node when a source node transmits data packets to a destination node. A source node, which stores routing information to a destination node, transmits data packets to the destination node according to the stored routing information(210). In case no routing information to the destination node is stored in the source node, the source node transmits data packets to the destination node, based on a neighbor node table list(220). In case a node, which shares a route node with the destination node, and the destination node do not exist in the neighbor node table list, the source node performs routing discovery(230). Then the source node transmits data packets to the destination node through a route determined through routing discovery(240).

Description

Routing method for transmitting data packet on Zigbee network and Recording medium

1 illustrates a Zigbee network network having a tree structure applied to the present invention.

2 is a flowchart illustrating a routing method for data packet transmission in a Zigbee network according to the present invention.

3 is a detailed flowchart of FIG. 2.

4 illustrates a logical link of a Zigbee network network having a tree structure according to the present invention.

5 illustrates a Zigbee network network having another tree structure according to the present invention.

6 illustrates a network applied to routing discovery according to the present invention.

FIG. 7 illustrates information transmitted from a parent node of FIG. 1 when an address is assigned to a child node.

FIG. 8A illustrates a time position of a superframe of a parent node and a child node of FIG. 1.

FIG. 8B illustrates the information format transmitted to the child node of FIG. 1.

9A to 9C illustrate a process of calculating information of a node sharing a root node with a destination node of FIG. 1.

FIG. 10 illustrates a beacon transmission schedule structure of the Zigbee network of FIG. 1.

11A illustrates a time position of each node in a Zigbee network according to an embodiment of the present invention.

11B illustrates a time position of each node of a Zigbee network according to another embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Zigbee network, and more particularly, to a routing method for transmitting data packets in a Zigbee network and a recording medium thereof.

The Zigbee network is based on the Physical (HY) layer and the Medium Access Control (MAC) layer of the IEEE 802.15.4 standard for low power sensor network configurations.

Zigbee network defines an interface for intercommunication between different layers, such as sending or receiving data frames. The Zigbee network also performs frame handling, route discovery and maintenance, network management and address assignment, and device management. In the IEEE 802.15.4 standard, the devices used are classified as full function devices (FFDs) and reduced function devices (RFDs), while in the Zigbee network, they are classified in terms of their functional aspects. It is divided into kinds of device.

Firstly, the Zigbee Coordinator can only be an FFD, and one Zigbee Coordinator is required within one Zigbee network and plays a central role in initializing network information or managing other devices.

Secondly, Zigbee routers can be FFDs just like a coordinator, and there can be multiple Zigbee routers for multi-hop routing within a single Zigbee network.

Third, the Zigbee terminal device does not participate in direct network routing as an RFD, but may participate in a network through a Zigbee coordinator or a Zigbee router already formed in the network. In addition, although several Zigbee terminal devices can exist in one network, only one FFD can be connected.

However, in the conventional ZigBee network routing method, when each node in the network network transmits a beacon, the beacons of each node collide with each other, thereby causing an error in data transmission, and a source node to transmit a data packet. If a route to the destination node is not found and the route is to be searched, the routing request message is routed without any classification of nodes in the process of broadcasting a routing request message, resulting in inefficient energy consumption.

Accordingly, the first technical problem of the present invention is to provide a routing method for data packet transmission in a Zigbee network that reduces the number of routing request message transmissions when the source node performs routing discovery in transmitting data packets to a destination node. To provide.

It is a second object of the present invention to provide a computer-readable recording medium having recorded thereon a program for executing a routing method for data packet transmission in a Zigbee network.

In order to solve the first technical problem, the present invention, the step of transmitting a data packet of the source node to the destination node according to the routing information in the predetermined source node, the routing information stored to the destination node, the source If the routing information to the destination node is not stored in the node, transmitting the data packet to the destination node by referring to the neighbor node table list of the source node, and the destination node in the neighbor node table list of the source node. Performing routing discovery if a node sharing a root node and the destination node do not exist, and transmitting a data packet to the destination node through a path determined by the routing discovery; Packet transmission It provides a routing method.

In order to solve the second technical problem, the present invention provides a computer-readable recording medium having recorded thereon a program for executing a routing method for data packet transmission in a Zigbee network.

In the preferred environment to which the present invention is applied, each node of the Zigbee network network is densely located so that most of the nodes are in each other's radio frequency (RF) intervals, and the number of nodes is large, so that all nodes are neighboring to each other. There are channel conflicts and memory limitations to store in the table list, and there are many environments where message packets are sent.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings, but the present invention is not limited thereto.

1 shows a network of a Zigbee tree structure applied to the present invention.

First, the Zigbee standard defines the following network layer (NWK layer) specific constants. The first is nwkMaxChildren (Cm), which means the maximum number of nodes in a network can accept child nodes. Second, nwkMaxDepth (Lm) means the maximum number of depths that the network can have. The third is nwkMaxRouter (Rm), which means the maximum number of nodes a node can accept as its child node. When the above three constants of the network are predetermined, the structure of the network is determined.

Therefore, by using specific constants of nwkMaxChildren (Cm), nwkMaxDepth (Lm) and nwkMaxRouter (Rm) of the network network, the maximum number of beacon transmission nodes among the nodes of the tree network can be known, and the address of each node is determined. By applying the concept of depth (Depth) to manage the beacon transmission time of the same depth as a group.

Next, the address allocation mechanism in the Zigbee network is as follows. Here, if nwkMaxChildren (Cm) = 4, nwkMaxRouters (Rm) = 4, nwkMaxDepth (Lm) = 3 constituting the Zigbee network, the equation for obtaining Cskip (d) and the Cskip value per depth are shown in Table 1 below. .

The address allocation mechanism using Cskip provides an address range. Here, Cskip (d) means a partial block size of an address that a node having a depth d may have. This address range allows you to quickly verify that a particular network's address belongs to the device. And through the device of its child node or elsewhere in the device tree. As a result, any device can make simple basic routing decisions on device tree packets up or down.

In the address allocation mechanism using Cskip, a parent node assigns an address to a child node by applying Equation 3 below.

Equation 3 shows a method of allocating an address of each node in a Zigbee network. First, in Step 1, the address of the child node with index 1 is the value of the parent node plus 1. Step 2 shows that the address of the child node at index 2 is the address value of the child node at index 1 plus the value of Cskip, and the address of the child node at index 3 is Cskip at the address value of the child node at index 2. The sum is the address value. In this way, the address value can be obtained by considering the value of Cm. Through this process, each node to which the Cskip value and the address value are assigned in the network can be configured, as shown in FIG.

2 is a flowchart illustrating a routing method for data packet transmission in a Zigbee network according to the present invention.

First, the data packet of the source node is transmitted from the predetermined source node to which the routing information to the destination node is stored according to the routing information (step 210). When the source node to which the data packet is to be sent to the destination node stores the routing information to the destination node, the data node transmits the data packet to the destination node according to the routing information stored by the source node.

If routing information to the destination node is not stored in the source node, the data packet is transmitted to the destination node by referring to the neighbor node table list of the source node (step 220).

Since all nodes share the address information of each node in the Zigbee network, the source node refers to the neighbor node table list of the source node according to the address information of the destination node, so that the node or the destination node that shares the destination node and the root node If present in the node's neighbor node table list, the source node calculates the time at which the node sharing the destination node and the root node or the destination node is activated, and transmits the data packet to the destination node which is the final destination.

Next, in step 230, if the node sharing the root node and the destination node and the destination node do not exist in the neighbor node table list of the source node, routing discovery is performed.

In the neighbor node table list of the source node, if the node sharing the destination node and the root node and the destination node do not exist, the depth in which the destination node exists, the lower depth adjacent to the destination node, or a node belonging to the upper depth adjacent to the destination node is present. If a data packet of a source node is transmitted, routing discovery is performed because data is likely to be transmitted to a destination node.

That is, when a routing request message is transmitted during routing discovery, a destination node exists, a lower depth adjacent to the destination node, or a higher depth adjacent to the destination node without applying a broadcast. It sends an RREQ to the node it belongs to and receives a route reply. If the node storing routing information to the destination node exists in the destination node's neighbor table list during the routing discovery, the neighbor node table list of the source node is updated and the source node is stored in the node storing the routing information to the destination node. Send data packet of node.

Finally, the data packet is transmitted to the destination node through the path determined by the routing discovery (step 240). On the other hand, if there is no node that stores routing information to the destination node in the neighbor node table list, the data packet is transmitted to the destination node through tree routing. In general, since the default depth is 7 in a Zigbee network, tree routing is performed within a range of 14 hops.

Preferably, having a network structure of a tree structure, all nodes have a maximum number (Cm) that a node of the network can accept child nodes (Cm), the maximum number of depth (Lm) and one node that the network can have Share the maximum number of routers (Rm) that a router can accept as its child nodes, use a Zigbee address allocation mechanism, and all nodes have the same superframe duration.

More preferably, each node of the Zigbee network network may be to store the depth, index, address, beacon transmission time and information of the node sharing the root node of each node. The index is determined according to the size of address values of nodes having the same parent node. For example, the address values may be determined in the order of the smaller address values, and the present invention is not limited thereto.

3 is a detailed flowchart of FIG. 2.

First, it is determined whether routing information is stored in the source node (step 310), and when routing information is stored in the source node, a data packet is transmitted to the destination node (step 340).

If routing information is not stored in the source node, it is determined whether the destination node exists in the neighbor node table list of the source node (step 320). If the destination node exists in the neighbor node table list, the neighbor node table list is determined. In operation 321, the data packet is transmitted to the destination node.

If the destination node does not exist in the neighbor node table list, it is determined whether a node sharing the destination node and the root node exists in the neighbor node table list (step 325).

If there is a node sharing the root node with the destination node in the neighbor node table list, the data packet is transmitted to the node sharing the root node (step 326), and the node sharing the root node finally receives the data packet to the destination node. It transmits (step 340). Since the node sharing the destination node and the root node stores information about the destination node, the node transmits data to the destination node along the path according to the stored information.

If the node sharing the root node and the destination node does not exist in the neighbor node table list, the source node refers to the neighbor node table list of the source node, the depth at which the destination node exists in the neighbor node table list, the lower depth adjacent to the destination node, and In step 327, the routing request message is transmitted to a node belonging to an upper depth adjacent to the destination node.

Next, it is determined whether there is a node that stores routing information of the destination node in a depth where the destination node exists, a lower depth adjacent to the destination node, and an upper depth adjacent to the destination node (step 330). If there is no node storing the node, tree routing is performed (step 339), and the data packet is transmitted to the destination node through the tree routing (step 340).

Next, if there is a node storing routing information of the destination node, it is determined whether there are a plurality of information storage nodes (step 331), and if the information storage node is a single node, the data packet is stored in the node storing the routing information. In step 332, the node receiving the data packet finally transmits the data packet to the destination node in step 340.

Finally, when there are a plurality of nodes storing routing information of the destination node, the data packet is transmitted to one of the plurality of nodes according to the remaining energy amount and the received signal strength among the plurality of nodes (step 333), and finally In step 340, the data packet is transmitted to the destination node.

Preferably, when the residual energy amounts of the plurality of nodes are determined to be the same, when the residual energy amounts are not the same, the data packet may be transmitted to a node having a relatively large residual energy amount, and finally, the data packet may be transmitted to the destination node. When the remaining energy amount is the same, a data packet may be transmitted to a node having a larger received signal strength indication (RSSI), and finally, a data packet may be transmitted to a destination node.

4 illustrates a logical link of a Zigbee network network having a tree structure according to the present invention.

Logically, nodes sharing the destination node and the root node store routing information to the destination node. However, since the node located at the last depth among the nodes sharing the destination node and the root node cannot be routed, data cannot be transmitted to the destination node.

Referring to FIG. 4, each node of the network is connected by a link 480. When a source node (not shown) transmits a data packet to a node sharing the same root node 400, the node 430 is connected to the destination node 430. The data packet of the source node may be sent.

That is, the nodes 431 to 434 linked to the same parent node 420 as the destination node 430 share the same root node at the same depth (depth n) as the destination node, so that the source node can send data to the 431 to 434 nodes. Sending the packet may transmit the data packet to the destination node.

It also belongs to a parent node (depth n-1) 420 of the destination node, a child node (depth n + 1) 440 of the destination node, and an upper depth (n-2 depth) adjacent to the parent node of the destination node. The source node transmits the data packet to a node 410 sharing the root node 400, a node 450 belonging to a lower depth (depth n + 2) adjacent to the child node of the destination node, and sharing the root node with the destination node. When sent, a data packet can be sent to the destination node. Referring to FIG. 4, a node connected by a link 490 may transmit a data packet to a destination node. However, since the node 460 located at the last depth among the nodes sharing the destination node and the root node 400 is not routeable, data cannot be transmitted to the destination node.

Since the nodes 471 to 479 do not share the root node with the destination node, it is highly likely that they do not directly store routing information for the destination node. Therefore, the nodes 471 to 479 apply another method. Send a data packet to the node. For example, data may be transmitted to a destination node by applying a routing discovery or a tree routing method.

5 illustrates a Zigbee network network having another tree structure according to the present invention.

The information of nodes sharing the root node of each node is calculated from the maximum number of child nodes linked to each node of the Zigbee network, the maximum number of routers linked to each node of the network, and the maximum depth of the network. Can be.

Referring to FIG. 5, the maximum number (Cm) that a node of a network can accept child nodes is 4, the maximum number of depths (Lm) that a network can have is also 4, and one node has its own child. Maximum number Rm that can accept a router as a node In FIG. 6, a node 510 sharing a root node with a destination node 500 and a node 520 not sharing a root node are illustrated. In this case, if NDepthRouterMax (NDRM) is defined as NDepthRouterMax (NDRM), the number of nodes that can transmit data packets to the destination node for each depth is NDepthRouterMax = nwkMaxRouters ⁱ = Rm ⁱ and i represents the depth, and if Rm = Cm NDepthRouterMax = nwkMaxChildren ⁱ = Cm ⁱ to be. Table 2 below shows a comparison of the number of nodes sharing the destination node and the root node and the number of nodes not sharing the destination node and the root node in the network according to FIG. 5.

According to FIG. 5 and Table 2, if the number of nodes sharing the destination node and the root node and the number of nodes not sharing the destination node and the root node are generalized,

First, when Cm = Rm, the number of nodes sharing the destination node and the root node is 1, and if the depth of the node is smaller than the depth of the destination node, the number of nodes sharing the destination node and the root node is 1, and the depth of the node is If the depth of the destination node is the same, the number of nodes sharing the destination node and the root node is Cm-1, and if the depth of the node is larger than the depth of the destination node, the number of nodes sharing the destination node and the root node is Cm ^{i. -destdepth} , where i represents the depth and destdepth means the depth of the destination node.

If Cm = Rm, the number of nodes that do not share the destination node and the root node is Cm ⁱ -1 if the node's depth is smaller than the depth of the destination node. If the depth of is equal to the depth of the destination node, the number of nodes sharing the root node with the destination node is Cm ^{i - destdepth-} (Cm-1), and if the depth of the node is larger than the depth of the destination node, the destination node and the root The number of nodes sharing the node is Cm ⁱ -Cm ^{i - destdepth} , where i represents the depth and destdepth means the depth of the destination node.

Next, if Cm ≠ Rm, the number of nodes sharing the destination node and the root node is 1, and if the depth of the node is smaller than the depth of the destination node, the number of nodes sharing the destination node and the root node is 1, and the depth of the node Is the same as the depth of the destination node, the number of nodes sharing the destination node and the root node is Rm-1, if the depth of the node is greater than the depth of the destination node, the number of nodes sharing the destination node and the root node is Rm ^{i - destdepth} , where i represents the depth, and destdepth means the depth of the destination node.

If Cm ≠ Rm, the number of nodes that do not share the destination node and the root node is Rm ⁱ -1 if the node's depth is smaller than the depth of the destination node. If the depth of is equal to the depth of the destination node, the number of nodes sharing the root node with the destination node is Rm ^{i - destdepth-} (Rm-1), and if the depth of the node is larger than the depth of the destination node, the destination node and the root The number of nodes sharing the node is Rm ⁱ -Rm ^{i - destdepth} , where i represents the depth and destdepth means the depth of the destination node.

In a ZigBee network having a tree structure, the nodes sharing the destination node and the root node increase as the depth increases, so the probability of being in the neighbor node table list of the source node increases. If there is a node sharing the root node and the destination node in the neighbor node table list, the data packet is transmitted. Of course, because the beacon transmission time of the node sharing the root node and the destination node existing in the neighbor node table list of the source node is known, the data of the source node may be transmitted by contention competition in the contention access period (CAP) section of the super frame. Can be transmitted.

If the node sharing the root node with the destination node does not exist in the neighbor node table list, routing discovery is performed. The routing discovery requests routing to the same depth as the destination node, the upper depth adjacent to the destination node, and the lower depth adjacent to the destination node based on the depth of the destination node among the nodes present in the neighbor node table list of the destination node (Routing REQuest: RREQ). How to send a message. Since the node sharing the root node with the destination node does not exist in the neighbor node table list, routing discovery is performed. This method is faster than broadcasting and uses fewer RREQ messages, resulting in lower network energy consumption.

6 illustrates a network applied to routing discovery according to the present invention. In ZigBee routing, each node is classified according to a class as shown in FIG. 6. The rank of each node is shown by the serial number within the node. As such, when the routing is performed for each node, the number of transmissions can be reduced compared to the conventional Zigbee routing.

The node sharing the root node with the destination node connected to the other link 620 among the links 610 of the Zigbee network network communicates the routing information of the destination node when directly communicating in the neighbor table list or among the nodes in the neighbor table list. It is used to find out whether there is a stored node. In FIG. 6, nodes of 1 to 3 levels correspond to this, and the number of each class means the number of hops to the destination node. That is, a node of a 1 st class is a node located within 1 hop of a path with a destination node, and it can be seen that it is easier to transmit information to a destination node than a 2 or 3 class node.

The nodes connected by the link 620 belong to a depth in which the destination node exists, a lower depth adjacent to the destination node, and an upper depth adjacent to the destination node, which are used when sending a routing request message through routing discovery. When a plurality of nodes of the same class storing routing information of the destination node exist in the neighbor node table list by routing discovery, the data packet of the source node is transmitted to a node having a relatively large amount of energy of the node. If the remaining energy of the same is the same as the received signal strength (Received Signal Strength Indication (RSSI)) transmits the data packet of the source node to a node having a relatively strong.

In the ZigBee standard, the default depth is 7, so dividing it by 5 or more is not efficient. Therefore, in the present invention, a node that does not share the destination node and the root node can be designated as a fourth grade. Of course, a method of dynamically defining a grade later is also possible, and the present invention is not limited thereto.

In the present invention, a method of determining depth and index information of each node is determined based on address information of each node according to the size or memory access power of each node or the memory access power and the computation power of each node.

When the size of the memory space of each node is large or the memory access power is smaller than the computational power of each node, the information of each node is stored in the memory and the information of each node is read and used. When a parent node assigns an address to a child node, the child node sends information containing the node information sharing the root node to the child node, so the child node stores both the node information of the parent node and the information of the node sharing the root node. Done. The Zigbee Network Standard defines nwkcMaxDepth as 15. Of course, even in a dense network with a larger depth and a larger network, the present invention can determine the depth and index information of each node from the address of each node.

FIG. 7 illustrates information transmitted from a parent node of FIG. 1 when an address is assigned to a child node.

The parent node transmits the information of the node sharing the root node including the address information of the parent node when assigning an address to the child node, and the child node is connected to the child node and the node's information and its own node are sent to the node belonging to the child depth. Transmit with the information of the node sharing the root node containing the information of. Depending on the implementation, information of a node sharing a root node may be transmitted to an end node of a network, or information of a node sharing a root node may be transmitted to a parent node of an end node.

Referring to FIG. 7, when a parent node allocates an address to a child node, the parent node allocates and transmits depth, index, address, and beacon transmission time information of the child node, and simultaneously transmits information of a node sharing a root node to the child node. do.

The depth is the depth where the child node is located, the address index is the sequence number given by Cskip (depth: d) in the Zigbee address allocation scheme, the address is the address that the child node itself has, and the beacon transmission time is an option. If selected, it means the time that the child node itself is activated to transmit a beacon. As described above, this information is not allocated to the end node or the node located at the maximum depth.

The maximum depth defined by the Zigbee standard is 15. The size of information of nodes sharing the root node may be relatively large or small depending on the hardware memory capacity of the node. If the hardware memory capacity is small, it calculates the information of the node sharing the root node with the destination node using the destination address.

FIG. 8A illustrates a time position of a superframe of a parent node and a child node of FIG. 1.

Referring to FIG. 8A, a superframe duration (SD) 801 of each node is determined based on a beacon interval (BI) 800 of a coordinator in a Zigbee network network, and a beacon of each node is determined. Frame transmission time is determined for each depth. The beacon frame transmission time determines the beacon transmission time of all nodes in such a manner that the parent node 810 determines the beacon transmission time of the child nodes 821 to 824 linked thereto.

FIG. 8B illustrates the information format transmitted to the child node of FIG. 1.

Referring to FIG. 8B, when the depth of the parent node 860 is 1, the address index is 1, the address is 1, and the beacon transmission time is SD1, the child nodes 861 to 864 receive information of the parent node. Store in addition to the node's own information.

For example, the child node 861 having an address of 2 has the depth 2, the address index 1, the address 2, and the beacon transmission time SD2, which is the child node's own information, the depth 1, the address index 1, and the address of the parent node. 1, the beacon transmission time SD1 is stored in the memory of the child node itself. When an address is assigned to a node belonging to a lower depth of a child node in the same manner as above, the node belonging to the lower depth also stores information of a node sharing a root node in its own information in memory.

Since the parent node plays a role of managing the child node, it stores the information of the child node. Of course, nodes that share the same root node as a whole store information of all the nodes belonging to it.

However, when a node having no free space in the memory space is arranged in the network, the node information cannot be stored in the memory. Therefore, the node information sharing the destination and the root node is obtained by hardware operation.

As described above, since each node of the network stores information of nwkMaxChildren (Cm), nwkMaxRouters (Rm), and nwkMaxDepth (Lm), Cskip can be obtained from the information of nwkMaxChildren, nwkMaxRouters, nwkMaxDepth. This value is determined by the Zigbee standard and will not be described. The process of obtaining the information of the node sharing the destination node and the root node from the values of nwkMaxChildren, nwkMaxRouters, nwkMaxDepth and Cskip (Cs) is as follows.

The Cs value is obtained from the network with the values Cm = 4, Rm = 4, and Lm = 3, as shown in Table 1, and from the Cskip (Cs) values according to Table 1, information about nodes sharing the destination node and the root node is obtained. This process is the same as in Figs. 9a to 9c.

9A to 9C illustrate a process of calculating information of a node sharing a root node with a destination node of FIG. 1.

Referring to FIG. 9A and Table 1, the Cs value of depth 0 is 21, the address of the node sharing the root node and the destination node belonging to depth 1 is 43 from the range to which the address of the destination node belongs, and the address index Can be found to be 3.

Referring to FIG. 9B and Table 1, the Cs value of the depth 1 is 5, and the address of the node sharing the root node with the destination node belonging to the depth 2 is 49 from the range to which the address of the destination node belongs according to the Cs value of the depth 1 is 49. It can be found that the address index is 2.

Referring to FIG. 9C and Table 1, the Cs value of the depth 2 is 1, and according to the Cs value of the depth 2, the address of the node sharing the root node and the destination node belonging to the depth 3 is 53 from the range to which the address of the destination node belongs. It can be found that the address index is 4.

9A to 9C, information of a node sharing a destination node and a root node can be obtained, and this information can be obtained by comparing with the information of one's node on a path for transmitting data packets to not only the source node but also the destination node. It can be routed through the path of.

FIG. 10 illustrates a beacon transmission schedule structure of the Zigbee network of FIG. 1. Referring to FIG. 10, the superframe duration of each node of the network is determined according to the beacon interval of the coordinator. 1 and Table 1, the address of the coordinator located at depth 0 is 0, the address of the node located at depth 1 is determined by the Cs value of the coordinator of depth 0, and the Cs value of the coordinator of depth 0 is 21, the nodes located at depth 1 are arranged in order according to the index order. Since the address of the node located at the depth 2 is determined by the Cs value of the parent node of each node located at the depth 2 and the Cs value of the parent node is 5, the nodes located at the depth 2 are arranged in order according to the index order. . The node corresponding to the last end node does not transmit the beacon. If it is assumed to transmit the beacon, each node located in the depth 3 according to the index order because the Cs value of the parent node of each node located in the depth 3 is 1 Arranged in order and finally has a beacon transmission schedule structure of the Zigbee network as shown in FIG.

In a network having such a beacon transmission schedule structure, each node calculates an activation time of a destination node through information of a node sharing a root node and a destination node, and a node transmitting data to the source node or the destination node is calculated. Send the data packet of the source node in time.

FIG. 11A illustrates a time position of each node of a Zigbee network according to an embodiment of the present invention, and FIG. 11B illustrates a time position of each node of a Zigbee network according to another embodiment of the present invention.

In the ZigBee network, synchronization of the beacon transmission period is determined by applying any one of scheduling having a buffer period or scheduling without a buffer period.

In determining the synchronization of the beacon period based on the coordinator, scheduling without a buffer section is referred to as non beacon schedule transmission offset (NBSTO), and scheduling with a buffer section is referred to as beacon schedule transmission offset (Beacon Schedule). Tx Offset: BSTO). Referring to FIGS. 11A and 11B, FIG. 11A is a non-beacon schedule Tx Offset (NBSTO) which is a scheduling having no buffering interval, and FIG. 11B is a beacon schedule transmission offset (Beacon) which is a scheduling having a buffering interval. Schedule Tx Offset: BSTO). The time when the destination node is activated by each method is as follows.

가 목적지 노드의 뎁스이고,

가

이면,

가

뎁스에서의 목적지 노드와 동일한 루트 노드를 공유하는 노드의 인덱스인 경우 상기 목적지 노드의 부모 노드의 비콘 프레임 수신 후 목적지 노드가 활성화되는 시간

은 하기의 수학식 3에 의해 연산 된다.If the Zigbee network is a network in which the beacon transmission period is determined by applying a scheduling method that does not have a buffer period, SD is the superframe duration of the node, Rm is the maximum number of routers linked to each node of the network, and SD Is the superframe duration of the node, Rm is the maximum number of routers linked to each node in the network,

Is the depth of the destination node,

end

If,

end

In the case of the index of a node sharing the same root node as the destination node in the depth, the time when the destination node is activated after receiving the beacon frame of the parent node of the destination node

Is calculated by Equation 3 below.

 Having a structure of the network shown in Table 1 and FIGS. 9A to 9C, and when the destination address is 53, the time at which the destination node is activated is calculated by Equation 3,

의 값을 구할 수 있고, SD의 값이 1일 경우,

If we get the value of SD and the value of SD is 1,

의 값이 된다. 즉 목적지 노드는 코디네이터의 비콘 전송 시간이 지난 이후 13SD 시간 이후에 활성화 되므로 소스 노드는 코디네이터의 비콘 전송 시간을 기준으로 13SD시간이 지난 후 목적지 노드가 활성화되는 시간에 소스 노드의 데이터 패킷을 전송하면 목적지 노드와 동기를 맞출 수 있다.

Becomes the value of. That is, since the destination node is activated after 13SD time after the coordinator's beacon transmission time has passed, the source node transmits the data packet of the source node at the time when the destination node is activated after 13SD time based on the coordinator's beacon transmission time. You can synchronize with the node.

When transmitting data packets of the source node by directly participating in the CAP section of the destination node without receiving the beacon frame of the destination node, a time corresponding to the maximum beacon maximum length (beaconMaxLength) in the superframe structure may be additionally added to afterwakeuptime.

가 목적지 노드의 뎁스이고,

가

이면,

가

뎁스에서의 목적지 노드와 동일한 루트 노드를 공유하는 노드의 인덱스인 경우 상기 목적지 노드의 부모 노드의 비콘 프레임 수신 후 목적지 노드가 활성화되는

은 하기의 수학식 4에 의해 연산 된다.In a ZigBee network, a beacon transmission period is determined by applying a scheduling method that does not have a buffer period, SD is a superframe duration of a node, BTO is a time of a buffer period, and Rm is linked to each node of the network. Is the maximum number of routers

Is the depth of the destination node,

end

If,

end

In the case of an index of a node sharing the same root node as the destination node in the depth, the destination node is activated after receiving the beacon frame of the parent node of the destination node.

Is calculated by Equation 4 below.

Immediately after the beacon transmission time of the destination node elapses, when the data packet of the source node is transmitted by participating in the CAP section of the destination node, that is, the node participates in the CAP section of the destination node without receiving the beacon frame of the node's parent node. When sending a data packet, the afterwakeuptime needs to be added to the maximum beacon maximum length (beaconMaxLength) in the superframe structure.

Meanwhile, whether to receive the beacon frame of the parent node of the destination node and participate in the CAP section of the destination node to transmit the data packet of the source node, or directly participate in the CAP section of the destination node without receiving the beacon frame of the parent node of the destination node. Whether to transmit the data packet of the source node is determined according to the characteristics of the system of the network, the energy state, environmental variables outside the system, the present invention is not limited thereto.

The present invention can be embodied as code that can be read by a computer (including all devices having an information processing function) in a computer-readable recording medium.

The computer-readable recording medium includes all kinds of recording devices in which data is stored which can be read by a computer system. Examples of computer-readable recording devices include ROM, RAM, CD-ROM, magnetic tape, floppy disks, optical data storage devices, and the like. The computer readable recording medium can also be distributed over network coupled computer devices so that the computer readable code is stored and executed.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical details of the appended claims.

According to the present invention, in a ZigBee network in which a beacon interval of a coordinator is divided in depth units and an address is assigned to a beacon of each node that has given an address of a network, routing of a beacon transmitting node is performed when a source node transmits a data packet to a destination node. By reducing the number of times, the transmission efficiency of the data packet of the source node can be increased, and the energy efficiency of the network and each node can be improved.

Claims (13)

Transmitting a data packet of a source node to a destination node according to the routing information at a predetermined source node in which routing information to a destination node is stored; If the routing information to the destination node is not stored in the source node, transmitting the data packet to the destination node by referring to the neighbor node table list of the source node; If the node sharing the root node of the destination node and the destination node does not exist in the neighbor node table list of the source node, the depth in which the destination node exists in the list of the neighbor node table of the source node, the destination Transmitting a routing request message to a node belonging to a lower depth adjacent to the node and a higher depth adjacent to the destination node; When there are a plurality of nodes including routing information to the destination node according to the routing request message, the data packet is transmitted to a node having a relatively large amount of remaining energy among the plurality of nodes, and the received signal is relatively received when the amount of remaining energy is the same. Performing routing discovery of transmitting data packets to a high strength node; And And transmitting the data packet to the destination node through the path determined by the routing discovery. The method of claim 1, Each node of the Zigbee network network, Information of the maximum number of child nodes linked to each node, the maximum number of routers linked to each node of the network and the maximum depth of the network, and share the superframe duration of each node of the network. A routing method for data packet transmission in a Zigbee network characterized by the same. The method of claim 2, Each node of the Zigbee network network, And a depth, an index, an address, a beacon transmission time of each node, and information of nodes sharing a root node of each node. The method of claim 3, wherein Information of nodes sharing the root node of each node, In the Zigbee network, characterized in that the maximum number of child nodes linked to each node of the Zigbee network network, the maximum number of routers linked to each node of the network and the maximum depth of the network network calculated Routing method for data packet transmission. The method of claim 1, The step of transmitting the data packet to the destination node, Transmitting the data packet to the destination node when the destination node exists in the neighbor node table list of the source node; When the destination node does not exist, transmitting the data packet to a node sharing the root node if a node sharing the root node exists in the neighbor node table list of the source node; And And transmitting the data packet to a destination node in a node sharing the root node receiving the data packet. delete The method of claim 1, The step of transmitting a data packet to the destination node, In the list of the neighbor node table of the source node, if there is no depth belonging to the destination node, a lower depth adjacent to the destination node and a node belonging to an upper depth adjacent to the destination node, And transmitting the data packet to the destination node through tree routing. delete The method of claim 1, The Zigbee network network, A synchronization method of data packet transmission in a Zigbee network, characterized in that the synchronization of the beacon transmission period is determined by applying any one of the scheduling having a buffer interval or the scheduling having no buffer interval. The method of claim 9, When the Zigbee network is a network in which a beacon transmission period is determined by applying scheduling without the buffer period, SD is the superframe duration of the node, Rm is the maximum number of routers linked to each node in the network,

Is the depth of the destination node,

end

If,

end

In the case of the index of a node sharing the same root node as the destination node in the depth, the time when the destination node is activated after receiving the beacon frame of the parent node of the destination node

silver,

 Routing method for data packet transmission in a Zigbee network, characterized in that calculated by. The method of claim 9, If the Zigbee network is a network in which a beacon transmission period is determined by applying the scheduling having the buffer period, SD is the superframe duration of the node, BTO is the time of the buffer interval, Rm is the maximum number of routers linked to each node in the network,

Is the depth of the destination node,

end

If,

end

In the case of an index of a node sharing the same root node as the destination node in the depth, the destination node is activated after receiving the beacon frame of the parent node of the destination node.

silver,

Routing method for data packet transmission in a Zigbee network, characterized in that calculated by. The method of claim 9, The time for transmitting the data packet of the data packet of the source node to the destination node without receiving the beacon frame of the parent node of the destination node is the time when the destination node is activated plus the beacon duration of the destination node. A routing method for data packet transmission in a Zigbee network. A recording medium for executing the method of any one of claims 1 to 5, 7, and 9 to 12 on a computer.

Images