KR101079137B1 - Method for allowing a family-based address in a wireless sensor network, and method for hierarchical routing a path setting using the same - Google Patents

Abstract

Disclosed are a family-based addressing method and a hierarchical routing routing method using the same in a wireless network. As an address is requested from the node, the maximum number of child nodes extracted from the NWK IB and the current number of child nodes extracted from the neighbor node table are compared. If the current number of child nodes and the maximum number of child nodes are the same, addressing is rejected. If the current number of child nodes is smaller than the maximum number of child nodes, the number of digits of its own address is increased by one digit, and the address of the child node is given while increasing the number of single digits. Accordingly, in the wireless sensor network, the parent node dynamically assigns the address of the child node reflecting its own address in response to the addressing request of the child node, thereby facilitating routing path setting.

Description

FAMILY-BASED ADDRESS IN A WIRELESS SENSOR NETWORK AND METHODOLOGICAL ROUTING PATH SETTING USING THE SAME

The present invention relates to a wireless sensor network, and more particularly, to a family-based addressing method and a hierarchical routing routing method using the same in a wireless network.

A general mobile communication system transmits and receives data between a mobile terminal and a base station. The mobile station and the base station directly transmit and receive data without passing through other mobile terminals / nodes. However, a sensor network uses other sensor nodes when it wants to transfer data of a sensor node to a sink node.

Hereinafter, the structure of the wireless sensor network will be described with reference to FIG. 1. As shown in FIG. 1, the wireless sensor network consists of a sink node and a plurality of sensor nodes. Although FIG. 1 illustrates only one sink node, the wireless sensor network may consist of at least two sink nodes according to a user's setting.

The sensor node collects information about a target set by a designated user. Target information collected by the sensor node may include ambient temperature or movement of an object. The sensor node transmits the collected information to the sink node.

The sink node receives data transmitted by sensor nodes constituting the wireless sensor network. The sensor node located within a certain distance from the sink node directly transmits data to be transmitted to the sink node. However, a sensor node not located within the predetermined distance transmits the collected data to sensor nodes adjacent to the sink node instead of directly transmitting the collected data to the sink node.

As described above, the reason why a node that is not located within a certain distance transmits data by using adjacent nodes is to minimize power consumption due to data transmission. That is, the distance between the sink node and the sensor node and the power consumed by the sensor node to transmit data to the sink node are generally proportional to each other.

Therefore, the sensor node that is not located within a certain distance from the sink node can minimize the power consumption due to the data transmission by transmitting the collected data using a plurality of sensor nodes. Hereinafter, a node that plays a role of relaying data of another sensor node is called a relay node. Of course, the relay node also transmits the data collected by the relay node to another sink node or directly.

As described above, the sensor node collects information of the target and delivers the information to the sink node. In general, however, the target and sink nodes are not fixed but are somewhat mobile.

2 is a diagram illustrating a process of delivering information about a fixed target to a sink node with guaranteed mobility. For example, this is the case when the temperature information on a specific area is transmitted to a moving vehicle. In this way, the vehicle receives real-time temperature information about the specific area. Meanwhile, FIG. 3 illustrates a process of transmitting information about a target with guaranteed mobility to a fixed sink node. For example, this is the case where information about a moving object is transferred to a fixed sink node.

4 illustrates a process of setting a routing path for transmitting a data to a sink node by a sensor node in a general wireless sensor network. Hereinafter, a process in which the sensor node 1 establishes a routing path to the sink node will be described with reference to FIG. 4.

The sensor node 1 generates a routing request (RREQ) message including its address (source address) information and sink node address (destination address) information. The sensor node 1 broadcasts the generated routing request message to neighboring sensor nodes.

4, the sensor node 2, the sensor node 4, and the sensor node 5 receive the RREQ message. The sensor nodes receiving the RREQ message compare the destination address with their own address. If the destination address and its own address are not the same, the sensor nodes update the received RREQ message and broadcast it to neighbor nodes. The updated information includes the hop count number.

In addition, the sensor node receiving the RREQ message generates a routing table using the received RREQ message. The routing table includes an address of a source node, an address of a destination node, a hop count number, and an address of a sensor node broadcasting the RREQ message.

The RREQ message broadcast by the sensor node 1 is delivered to the sink node through various paths. The sink node routes routing using the hop count number included in the delivered RREQ message. That is, the path with the smallest hop count is set as the routing path. Accordingly, the sink node sends a message to the sensor node 4 with a routing reply (RREP). The sensor node 4 transmits the RREP message to the sensor node 1 using the stored routing table. By performing the above-described processes, a routing path between the sensor node 1 and the sink node is established. The sensor node 1 transfers the collected information to the sink node by using the set routing path.

Technical Challenge

Therefore, the technical problem of the present invention has been made in view of the above, an object of the present invention is to provide a family-based addressing method in which the address of the parent node is reflected in the address of the child node in the wireless sensor network.

Another object of the present invention is to provide a hierarchical routing routing method in a wireless sensor network using the family-based addressing method described above.

Technical solution

In order to realize the above object of the present invention, a family-based addressing method according to an embodiment includes (a) the number of maximum child nodes extracted from the network information base (NWK IB) as addressing is requested from a node; Comparing the number of current child nodes extracted from the neighbor node table; (b) if the current number of child nodes is the same as the maximum number of child nodes, rejecting addressing; And (c) if the current number of child nodes is smaller than the maximum number of child nodes, increasing the number of digits of its own address by one digit and giving the address of the child node while increasing the number of single digits.

In order to achieve the above object of the present invention, a hierarchical routing routing method according to another embodiment includes (a) one or more descendant nodes on a wireless sensor network composed of a plurality of nodes and transmitting packets between nodes. As they request to join the ancestor nodes, assigning an address such that the address of the parent node is reflected in the address of the child node on a family basis; And (b) as the routing begins on the wireless sensor network, establishing a hierarchical routing path using the family-based reflected address.

Favorable effect

As described above, according to the present invention, on a wireless sensor network, for example, a low-power wireless personal area network (6LoWPAN) based on Internet Protocol version 6, a parent node dynamically responds to an address request from a child node. By assigning the address of the child node reflecting the address, it is easy to set the routing path.

1 is a conceptual diagram illustrating the structure of a wireless sensor network.

2 is a conceptual diagram illustrating a moving target in a wireless sensor network.

3 is a conceptual diagram illustrating a sink node moving in a wireless sensor network.

4 is a conceptual diagram illustrating a process of setting a routing path in a wireless sensor network.

5 is a conceptual diagram illustrating a configuration of a wireless sensor network suitable for applying the present invention.

6 shows an example of a wireless sensor network protocol stack suitable for application of the present invention.

7 is a diagram illustrating a header format of a general IPv6.

FIG. 8 shows an example of a data frame format of the MAC / PHY layer shown in FIG. 6.

9 is a conceptual diagram illustrating a multi-hop tree according to the present invention.

10 is a block diagram illustrating a sensor node having an address assigned by a family-based addressing method according to the present invention.

11 is a conceptual diagram illustrating a family-based routing address assignment method according to an embodiment of the present invention.

FIG. 12 is a conceptual diagram illustrating a routing process by the family-based routing address granting method shown in FIG. 11.

13 is a flowchart illustrating a family-based addressing method according to an embodiment of the present invention.

14 is a flowchart illustrating a hierarchical routing path setting method according to an embodiment of the present invention.

Best Mode for Carrying Out the Invention

Hereinafter, various embodiments of a family-based addressing method and a hierarchical routing routing method and apparatus using the same according to various aspects of the present invention will be described in detail with reference to the accompanying drawings. It is not limited to the embodiments of the present invention, those skilled in the art will be able to implement the invention in various other forms without departing from the spirit of the invention.

The main terms used in connection with the present invention are defined as follows.

Current Node refers to a node on a wireless sensor network, that is, when an IEEE 802.15.4 device receives an IPv6 packet.

Depth means the hop-distance from the coordinator: 10 of the wireless sensor network to the device. For example, the depth of coordinator 10 is zero.

Maximum Number of Children (MC) is the maximum number of children the device (eg node) can have.

A neighbor table refers to a table that contains information of neighboring devices in a personal operating space (POS). The neighbor table includes a personal area network ID (PAN Id: 16 bits), a neighbor short address (Neighbor. 16 bit short address: 16 bits), a neighbor EIU 64 address (Neighbor.IEEE EUI 64 bit address). (64 bits), a neighbor device type (Neighbor. Device type: 2 bits), a neighbor relationship (Neighbor.Relationship: 2 bits), and a neighbor depth (Neighbor.Depth: 8 bits). In the neighbor table, a neighbor device type (2 bits) field is '00', a coordinator, '01' indicates a router, and '10' indicates an end device. '11' is reserved. In the neighbor table, if a neighbor relationship (2 bits) field is '00', it represents a parent, and if it is '01', it represents a child, and '10' and '11' are reserved. have.

-Personal Area Network ID (PAN Id) means a wireless sensor network 16-bit identifier assigned to the wireless sensor network for management. Here, a personal operating space (POS) means an area within a detection range of wireless transmission of an IEEE 802.15.4 packet.

Reduced Function Device (RFD) is an IEEE 802.15.4 device in a wireless sensor network that does not have a router function and cannot transmit IPv6 packets to a next hop device. That is, the partial function device can only be an end device on the wireless sensor network.

A router is an FFD that can route packets to a next hop device on a wireless sensor network, and a short address is a 16-bit address dynamically assigned to the device from its parent.

An internet protocol version 6 based wireless sensor network suitable for application of the present invention is as shown in FIG. 5. In this embodiment, the wireless sensor network is Low Power Wireless Personal Area Networks (LoWPAN).

5 is a conceptual diagram illustrating a configuration of a wireless sensor network suitable for applying the present invention. 6 shows an example of a wireless sensor network protocol stack suitable for application of the present invention.

Referring to FIG. 5, the wireless sensor network consists of one PAN coordinator 10, a plurality of routers 20a, 20b, 20c and termination devices 30a, 30b, 30c, 30d, 30e.

According to the IEEE 802.15.4 specification, devices in a wireless sensor network are a full function device (FFD) that implements a complete protocol set of IEEE 802.15.4, and a reduced function that does not have a router function. Device: hereinafter referred to as RFD). The PAN coordinator 10 and the routers 20a, 20b, and 20c are FFD devices, and the terminators 30a, 30b, 30c, 30d, and 30e are RFD devices.

The FFD supports all network types supported by IEEE 802.15.4, can exchange data between the FFD and RFD, can act as a PAN coordinator, and performs all functions described in IEEE 802.15.4.

In comparison, the RFD is designed to be suitable for smaller and lighter devices. These devices have the effect of lowering the price of energy by reducing the energy consumption rate as much as possible with simple functions and simple operation, minimizing the use resources, and lowering the chip implementation price.

The RFD can be used only as an end device in all network types. This means that RFDs can't send peer-to-peer data because they don't have routing capabilities and can't act as PAN coordinators.

The Star form, consisting of RFD and FFD with various functions in one PAN coordinator, can solve the lack of wireless interface of home network, PC peripherals, toys, game consoles, and health assistants. Peer-to-Peer communication may utilize ad-hoc routing capabilities provided by the network layer. This can be applied to a variety of sensor networks, remote controls, actuators, and the like.

Devices of a wireless sensor network according to the IEEE 802.15.4 standard are connected to a parent device and a child device on the network. The child device is dynamically assigned a 16-bit short address from the parent device through association.

That is, the IEEE 802.15.4 device may be dynamically allocated a short address of 16 bits during association with a neighbor device (or router), also called a parent device. Only the assigned short address can know communication with the parent or child. On the other hand, disassociation is a procedure for removing an existing association with a neighboring device.

The PAN coordinator (10) is a full-function device (FFD) that becomes the most important manager of the wireless sensor network. The PAN coordinator 10 may initiate synchronization of the entire wireless sensor network through the transmission of beacons.

The terminators 30a, 30b, 30c, 30d, and 30e may be connected to any one of the routers 20a, 20b, and 20c to communicate with the terminator connected to the router. The routers 20a, 20b, and 20c route packets received from at least one or more of the terminators 30a, 30b, 30c, 30d, and 30e or from another router according to the hierarchical routing routing method according to the present invention. do.

6 shows an example of a wireless sensor network protocol stack suitable for application of the present invention.

Referring to FIG. 6, protocols of a physical layer (L1), a MAC (MAC) layer (L2), an adaptation layer (L3), and an IPv6 layer (L4) are mounted on the wireless sensor network protocol stack. TPC, UDP, and ICMP are located on the IPv6 (L4), and the application layer is located thereon.

The physical layer (L1) and MAC layer (L2) is in accordance with the IEEE 802.15.4-2003 standard, the adaptation layer (L3) is IETF Internet draft (montenegro-lowpan-ipv6-over-802.15.4) The IPv6 layer (L4) is in accordance with RFC 2460 and related standards.

An IPv6 header format applied to the present invention is shown in FIG. 7 below.

7 is a diagram illustrating a header format of IPv6 applied to the present invention. FIG. 8 shows an example of a data frame format of the MAC / PHY layer shown in FIG. 6.

Referring to FIG. 7, the IPv6 header format has a size of 10 rows x 32 bits = 40 octets, version, priority, flow level, payload length, next header, hop limit, 128 bits of source address, and 128 bits. Consists of the destination address.

In addition, the frame according to the IEEE 802.15.4-2003 standard is a beacon frame for transmitting beacons in the coordinator, a data frame for transmitting data, a response frame for notifying the other party when the data frame is successfully received, MAC command It is divided into frames.

Referring to FIG. 8, the data frame of the MAC / PHY layer includes a packet format of the physical layer and a packet format of the MAC layer.

The packet format of the physical layer includes a preamble sequence, a start of frame delimiter, a frame length, and a MAC layer data unit (MPDU).

The packet format of the MAC layer includes a frame control, a sequence number, an addressing field, a data payload, and a frame check sequence (FCS).

Each device of the wireless sensor network to which the present invention is applied may be represented as a node of a tree having multiple hops, as shown in FIG. 9 below.

9 is a conceptual diagram illustrating a multi-hop tree according to the present invention. For convenience of description, the same reference numerals are given to the same configuration of the wireless sensor network shown in FIG. 5.

Referring to FIG. 9, Node A corresponding to a root in the tree structure is a PAN coordinator and a depth is '0'. Node B, Node D, and Node F are routers, and Node C, Node E, Node G, Node H, and Node I are end devices.

The nodes are low power communication devices each having a wireless communication function. The nodes may each be a source node that generates data or an intermediate node that relays data from a source node and a destination node to a destination node or intermediate data. In addition, each node may be connected to other nodes in a hierarchical structure.

10 is a block diagram illustrating a sensor node for performing the hierarchical routing path setting method according to the present invention.

Referring to FIG. 10, a sensor node for performing the hierarchical routing path setting method according to the present invention includes a logic processor 100, a hardware processor 200, and an antenna 300.

The logic processor 100 may include an application module 110, a sensing processing module 120, an IP processing module 130, an adaptive layer packet processing module 140, a routing processing module 150, and a neighbor node information management module 160. ), The MAC layer module 170. In this embodiment, the logic processing unit 100 is logically separated, but not hardware separated.

The hardware processing unit 200 includes a sensor device 210 for performing observation of an environment, a central processing unit (CPU) 220, a memory 230, a network device 240 for communicating, and a flash memory for performing long-term recording of data. 250.

Typically, in wireless sensor networks, eg, ZigBee networks, each node is provided in a table with information for managing and maintaining the network. The information stored in the table is called a network information base (NWK IB). The network information base may be stored in the memory.

The network information base includes the maximum number of children, the maximum depth of the network tree, the maximum number of Zigbee routers that can be a child, the information related to broadcast transmission, the neighbor table having the information of neighbor nodes, the route table, and the security related information. Include.

The neighbor table stores information such as a PAN identifier, a 64-bit address of its parent or child, a 16-bit network address, a device type, and a relationship between itself and a neighbor node (eg, parent, child, neighbor).

The neighbor table includes the neighbor node's receiver during the superframe's activity period, 64-bit address of all neighbors, beacon instruction (order), authority to participate in the network, transmission failure rate, potential parent, average link quality indicator (link). information such as a quality indicator, a logical channel value, a beacon frame arrival time, and a beacon transmission time offset may be selectively stored.

The route table stores information used when searching a route to transmit data from a multihop network to a destination.

The memory 230 stores information of neighbor nodes. The neighbor node information may be provided via the MAC layer module 170. The service of the MAC layer module 170 includes beaconing. The neighbor node information is used in the routing processing module process to find a short path.

Meanwhile, the sensor device 210 may include a temperature sensor, a humidity sensor, an illuminance sensor, an infrared sensor, or the like.

The network device 240 may be in bidirectional communication with another node having a particular identifier. For example, Blue Tooth, IEEE802.15.4, ZigBee, etc. may be mounted on the network device 240.

Packet information arriving at the network device 240 is processed via the MAC layer module 170 and then provided to the adaptation layer packet processing module 140. The adaptation layer packet processing module 140 performs a packet processing process. The packet processing process includes header parsing, packet fragmentation (separation / reassembly), header compression, and the like.

Packets arriving at them by adaptive layer packet processing are delivered to the application module 110 via the IP processing module 130. The IP processing module 130 performs a routing process if the packet is to be routed.

The sensor node may be operated as a source node to which a packet is transmitted, may be operated as a next hop node (or a relay node) to deliver the packet, or may be operated as a destination node to which the packet is delivered.

11 is a conceptual diagram illustrating a family-based routing address assignment method according to an embodiment of the present invention. In particular, the case where the address is given by the family-based address method, the max charge MC is 3, and the address is defined in ternary numbers is shown.

Referring to FIG. 11, node 0 is disposed at a top level, and node 0 is a child node, and is connected to node 1, node 2, and node 3 (not shown). In Fig. 11, for convenience of description, the address of the node is described in the circle defining the node. Therefore, nodes 1 to 3 are connected to node 0, which is a parent node.

The child node refers to a node connected directly below the node with respect to any one node (any node) in a hierarchical structure. On the other hand, the parent node is a concept in contrast to the child node, and refers to a node that is directly connected to the top of the node for any one node. Here, the connection means a logical connection or a wireless connection, not a physical connection or a wired connection.

Node 1 is a child node, connected to node 10, node 11 and node 12, and node 10 is a child node, connected to node 100, node 101 and 102, node 11 Is a child node and is connected to node 110, node 111 and node 112.

The node giving the address is the parent node. Therefore, if there is an address request from a new node, it is determined whether there is a child, and if there is no child, it raises its own number of digits by one digit, and sequentially increases the number of single digits and assigns the address as a child node. . If the child is smaller than the maximum number of children, an extra address is given. In this case, an address is given as a child node by adding 1 to the donated single unit digit.

Of course, if the current number of children is the same as the maximum number of children, it is obvious to refuse in response to the addressing request.

The addressing method of the family-based hierarchical routing routing method is as follows.

The address uses a numbering system based on the maximum number of children (hereafter MC). For example, if MC is 3, the ternary number is used as the address numbering system.

The child's address is assigned by increasing the number of digits to the parent node's address and sequentially increasing the value of the last digit. At this time, unlike the conventional hierarchical routing path setting method, the root node (or top node) of the tree has an address of '0', and a node of depth 2 (child nodes of the root node) is (MC). It consists of -1) pieces.

Using this method, the depth of the node becomes [number of digits of node address + 1] (except for nodes having depth 1 and 2), and the address of the parent node becomes [address of child node / MC].

As described above, the family-based hierarchical routing routing method according to the present invention can change the addressing method, thereby addressing new nodes through a more intuitive and simple calculation, and a simple method. Routing is possible.

FIG. 12 is a conceptual diagram illustrating a routing process by the family-based routing address granting method shown in FIG. 11. In particular, it shows that the address of the source node is 100 ₍₃₎ and the address of the destination node is 112 ₍₃₎ .

Referring to FIG. 12, when a packet is to be transmitted from node 100 ₍₃₎ to node 112 ₍₃₎ , the path selection and packet transmission method is the same as a general hierarchical routing path setting method.

However, in family-based routing, it is easier to determine whether the current node belongs to the ancestor group or descendant group of the destination node, thereby reducing the complexity of the calculation. For example, node 112 ₍₃₎ , which is the destination node, has the same number of digits as node 100 ₍₃₎ , and therefore has the same depth. In addition, the address end of each of the source node and the destination node is removed to obtain the address of the parent node.

In Fig. 12, the parent of node 112 _{(3) as the} destination node is node 11 ₍₃₎ and the parent of node 100 _{(3) as the} source node is node 10 ₍₃₎ . Therefore, since the parent node of the source node and the parent node of the destination node are different from each other, it can be easily confirmed that the hop count is increased to transmit a packet.

13 is a flowchart illustrating a family-based addressing method according to an embodiment of the present invention.

Referring to FIG. 13, as addressing is requested from a new node (step S105), the maximum number of child nodes and the number of current child nodes are extracted (step S110). The maximum number of child nodes is extracted from a network information base (NWK IB). The number of current child nodes is extracted from the neighbor node table.

Then, it is checked whether the maximum number of child nodes is the same as the current number of child nodes (step S115).

If it is checked in step S115 that the maximum number of child nodes and the current number of child nodes are the same (step S120), the addressing is rejected (step S120).

When it is checked in step S115 that the maximum number of child nodes is not equal to the current number of child nodes, it is checked whether or not the current child node exists (step S125).

If it is checked in step S125 that the current child node does not exist, since a new child node is generated, the number of own address digits is increased one by one (step S130). The own address is stored in the MAC information base (MAB) of the MAC layer. The above-mentioned address is stored, for example, in the form of data in units of bits, for example, in the form of 16 bits of data. In the case of storing the address in the above bit unit, the calculation process for routing is simple. In another example, the address may be stored in a byte unit. When storing the address in the above byte unit, the address form with the MAC is compatible.

Subsequently, the unit number of digits is increased to give the address of the child node (step S135). In this case, the first child node is assigned '0' to the single digit, the second child node is assigned '1' to the single digit, and the third child node is assigned to ' Give 2 '.

In the step S125, if it is checked that the current child node exists, the address of the child node is given by adding 1 to the already provided single unit digit (step S140).

14 is a flowchart illustrating a hierarchical routing path setting method according to an embodiment of the present invention.

Referring to Fig. 14, first, a family-based address is assigned (step S205). Since step S205 described above is the same as that described with reference to FIG. 15, a detailed description thereof will be omitted.

After the family-based address is given, as hierarchical routing starts (step S210), the depths of the corresponding nodes are determined based on the addresses of the source node and the destination node (step S215). Here, the depth of the node is [node number of nodes + 1]. The exceptions are nodes with depth 1 and nodes with depth 2. For example, if the address of the node is '101', the depth of the node is 4, and if the address of the node is '10310', the depth of the node is 6.

Subsequently, the addresses of the corresponding parent nodes are obtained by removing 10 nN digits (where N is 0 and a natural number) from the addresses of the source node and the destination node (step S220).

Subsequently, a path connecting the parent nodes to each other is set as a routing path (step S225).

As described above, although described with reference to the preferred embodiments of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the present invention described in the claims below It will be appreciated that it can be changed.

On a wireless sensor network, e.g., 6LoWPAN based on Internet Protocol version 6, the parent node dynamically assigns the address of the child node reflecting its address in response to the addressing request of the child node. Routing path setting can be facilitated.

Claims (9)

(a) comparing the number of maximum child nodes extracted from the network information base (NWK IB) with the number of current child nodes extracted from the neighbor node table as an address is requested from the node; (b) if the current number of child nodes is the same as the maximum number of child nodes, rejecting addressing; And (c) if the current number of child nodes is smaller than the maximum number of child nodes, increasing the number of digits of its own address by one digit and giving the address of the child node while increasing the number of single digits; Family-based addressing. The method of claim 1, wherein step (c) (c-1) checking whether a current child node exists; (c-2) if there is no current child node, raising the number of digits of the address of the own node by one digit, and sequentially increasing the number of single digits to give an address as a child node; And (c-3) if there is a current child node, adding 1 to the donated single unit digit, giving an address as a child node, and feeding back to step (a). Addressing method. 2. The method of claim 1 wherein the depth of each of the nodes is equal to the number of digits of the node. 2. The family-based method of claim 1, wherein the parent node address of each of the addressed nodes is calculated by removing 10 ^ N digits (where N is 0) from the address of the node. Addressing method. 2. The method of claim 1 wherein the address of the highest node of the addressed nodes is zero. 6. The method of claim 5, wherein the highest number of addresses of remaining nodes other than the highest node is one or more. (a) On a wireless sensor network that consists of a plurality of nodes and transmits packets between nodes, as one or more descendant nodes request to join ancestor nodes, the address of the parent node on the family basis is based on the address of the child node. Assigning an address to be reflected; And and (b) establishing a hierarchical routing path using the address reflected based on the family as routing starts on the wireless sensor network. 8. The method of claim 7, wherein step (b) (b-1) determining the depths of the nodes based on the addresses of the source node and the destination node; (b-2) obtaining an address of the corresponding parent node by removing 10 ＾ N digits (where N is 0) from the addresses of the source node and the destination node; And (b-3) setting a path connecting the corresponding parent nodes to each other as a routing path. 8. The method of claim 7, wherein the depth of the node is equal to the number of digits of the node.

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