KR20080072784A - Method for automatically assigning ipv6 address in sensor network based ipv6 - Google Patents

Abstract

A method for allocating an IPv6(Internet Protocol Version6) address automatically in a sensor network based on IPv6 is provided to add an interface identifier and prefix information and create the IPv6 address to allocate the IPv6 address automatically. A method for allocating an IPv6 automatically address in a sensor network based on IPv6 comprises the following steps of: generating an interface identifier in a sensor node which wants to join a sensor network(S904); requesting neighbor nodes to check whether the generated interface identifier is unique on the sensor network(S906); requesting a neighbor router to provide prefix information if it is determined that the generated interface identifier is unique(S910); and adding the prefix information provided from the neighbor router and the generated interface identifier to create an IPv6(S914).

Description

{Method for Automatically assigning IPv6 address in sensor network based IPv6}

1 is a network conceptual diagram of a 6LoWPAN sensor network according to the present invention;

FIG. 2 is a hierarchical diagram for explaining a communication protocol between sensor nodes of the 6LoWPAN sensor network of FIG. 2; FIG.

3 is a diagram illustrating a table for internal network address mapping of a 6LoWPAN network;

4 illustrates a table for external network address mapping.

FIG. 5 is a diagram illustrating a packet structure of a physical layer and a link layer of FIG. 2. FIG.

6 is a diagram illustrating a header format of an IPv6 packet of a network layer.

7 is a diagram for explaining a neighbor table created by an association operation between sensor nodes according to the present invention;

8 is a view for explaining the automatic IPv6 address assignment method according to the present invention.

9 illustrates the format of a 128-bit IPv6 link local address in accordance with the present invention.

The present invention relates to a method for automatically assigning IPv6 addresses in a sensor network system, and more particularly, to a method for automatically allocating IPv6 addresses so that each sensor node can directly communicate with an Internet network in a 6LoWPAN network.

The applicant has applied for a hierarchical routing method on a low power wireless personal area network based on Internet Protocol version 6 in the application number 2005-062896.

In general, a personal area network (PAN) is a concept in contrast to a well-known local area network (LAN) or a long-distance network (WAN), each individual has its own network, wireless sensor network and home network, etc. It can be used in various fields.

In an effort to implement such a PAN wirelessly, a high-speed wireless personal area network specification is introduced as the IEEE 802.15.3 standard, and a low power wireless personal area network as one of the sensor networks as the IEEE 802.15.4-2003 standard. Area Networks (LoWPAN) specification has been released.

IEEE 802.15.4 is a standard for MAC and PHY of LR-WPAN (Low-Rate Wireless Personal Area Network), and it is recognized as the most suitable communication technology for sensor network implementation. . IEEE 802.15.4 is designed to be suitable for wireless personal area network environment with low transmission rate and relatively short transmission distance, and has technology suitable for sensor network.

ZigBee is a popular low-power sensor network. However, Invensys, one of the key members of the ZigBee Alliance, realized that ZigBee would not be able to create more coverage, and withdrew from the ZigBee Alliance and formed the BoF for the convergence of sensor and IPv6 networks at the 61st IETF meeting. . After IPv6 began discussions through the IETF, most of the specifications were completed, and efforts to apply IPv6 in practice have been strengthened, and as part of this effort, Low Power Wireless Personal Area Networks (LoWPAN) The IE6 Internet draft (montenegro lowpan-ipv6-over-802.15), which created the '6LoWPAN Working Group', which intends to transmit IPv6 packets, has an adaptation layer between the IEEE802.15.4 MAC layer and the IPv6 layer for IPv6 packet delivery. 4) was announced.

According to this Internet draft (montenegro-lowpan-ipv6-over-802.15.4), the interface identifier of the 6LoWPAN device is based on EUI-64 [EUI64]. The interface identifier can be used to create a routing table for multi-hop routing in 6LoWPAN.

There is a need for an IPv6 address allocation technique for devices in 6LoWPAN to communicate with devices in an IPv6 network.

An object of the present invention is to provide a method for automatically generating and assigning an IPv6 address to a sensor node using IPv6 prefix information and sensor information based on routers and gateways in order to satisfy such a request. .

In order to achieve the above object of the present invention, the method of the present invention generates an interface identifier at a sensor node to join a sensor network, and requests neighbor nodes whether the generated interface identifier is unique in the sensor network (Neighbor Solicitation). Check it. Subsequently, if it is determined by the neighbor advertisement that the generated interface identifier is unique in the sensor network, a router Solicitation is requested from a neighbor router, and the neighbor router is provided from the neighbor router having the shortest hop distance among the neighbor routers. The IPv6 address is generated by combining the prefix information and the generated interface identifier. Register the IPv6 address generated by the neighbor router with the shortest hop distance and make it your default router. Therefore, the IPv6 address of the sensor node is automatically assigned.

The Router Solicitation message is sent by the sensor node to search for router nodes on the link, and the sensor node sends a message to the router node immediately with multicast router solicitation (Router Advertisement) without waiting for regular router messages.

Router Advertisement messages are sent by router nodes on a regular basis or in response to Router Solicitation messages, which include information required by the sensor node, such as hop limit, link prefix, link MTU, and router uptime.

Neighbor Solicitation messages are sent to neighboring sensor nodes to retrieve the link layer address of the sensor node, which contains the link layer address of the sent sensor node.

 Neighbor Advertisement messages are sent by neighbor sensor nodes in response to Neighbor Solicitation messages.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. This embodiment is described in sufficient detail to enable those skilled in the art to practice the invention.

1 shows a network conceptual diagram of a 6LoWPAN sensor network according to the present invention.

Referring to FIG. 1, 6LoWPAN 100 is connected to an existing Internet network 200 through a gateway 130 to ensure interoperability of an IPv6 network.

6LoWPAN 100 includes a plurality of sensor nodes, namely one PAN coordinator 102, multiple routers 104, 106, 108, 110, and end devices 112, 114, 116, 118, 120, 122, 124, 126, 128). According to the IEEE 802.15.4 specification, the devices of the 6LoWPAN 100 are divided into FFDs that implement the complete protocol set of IEEE 802.15.4 and RFDs that do not have router functions. The PAN coordinator 102 and the routers ((104) 106, 108, and 110 are FFD devices, and end devices 112, 114, 116, 118, 120, 122, 124, 126, and 128 are RFD devices.

In addition, devices of 6LoWPAN according to IEEE 802.15.4 standard have a hierarchical tree structure that is connected to parent and child on network. The child is dynamically assigned a 16-bit address from the parent via an association. That is, the IEEE 802.15.4 device can dynamically allocate a 16-bit address during association with a neighboring device (or router), also called a parent device, and can communicate with the parent or child only with the assigned address.

The PAN coordinator 102 is an FFD device that is the most important manager of the 6LoWPAN. The PAN coordinator 102 may initiate synchronization of the entire 6LoWPAN through the transmission of a beacon. The end device may be connected to a router to communicate with an end device connected to another router, and the router routes packets received from the end device or another router according to a hierarchical routing method.

The IPv6 network 200 is a local area network (LAN) made up of devices capable of transmitting IPv6 packets according to the IPv6 protocol, and the gateway 130 compresses and decomposes IPv6 packets on the IPv6 network 200 at an adaptation layer to provide 6LoWPAN ( 100), and restores and recombines the compressed IPv6 packet on the 6LoWPAN network 100 to the IPv6 network 200.

2 is a hierarchical diagram for describing a communication protocol between a 6LoWPAN sensor network and an IPv6 network.

Referring to FIG. 2, the 6LoWPAN gateway 130 includes a protocol stack for communicating with the 6LoWPAN network 100 and a protocol stack for communicating with the IPv6 network 200 to perform protocol conversion. The protocol stack for communicating with the 6LoWPAN network 100 at the gateway 130 includes an IEEE 802.15.4 physical layer 131, an IEEE 802.15.4 MAC (MAC) link layer 132, an adaptation layer (133), It consists of an IPv6 network layer 134, and a protocol stack for communicating with the IPv6 network 200 consists of an Ethernet physical layer 137, an Ethernet MAC layer 138, and an IPv6 network layer 134 for a LAN. In the gateway 130, the physical layer 131 and the MAC layer 132 conform to the IEEE 802.15.4-2003 standard, and the adaptation layer 133 conforms to the IETF Internet draft (montenegro-lowpan-ipv6-over-802.15.4) standard. The IPv6 network layer 134 is in accordance with RFC 2460 and related standards. In addition, the physical layer 137 and the MAC layer 138 comply with the conventional LAN standard.

The devices on the 6LoWPAN network 100 are composed of a physical layer 160, a MAC layer 161, an adaptation layer 162, an IPv6 network layer 163 according to the IEEE 802.15.4-2003 standard, and an IPv6 network. The application layer 165 is positioned on the layer 163 via a transport layer 164 such as TCP / UDP / ICMP.

Devices on the IPv6 network 200 are composed of a physical layer 201, MAC (MAC) layer 202, IPv6 network layer 203 in accordance with the conventional LAN standard, TCP / UDP / over the IPv6 network layer 203 The application layer 205 is located via a transport layer such as ICMP.

The gateway 130 has an address mapping table for interworking a 6LoWPAN network having a 16-bit address system and a 128-bit IPv6 network.

3 shows a table for internal network address mapping of a 6LoWPAN network, and FIG. 4 shows a table for external network address mapping.

Referring to FIG. 3, the internal network address mapping table includes a 64-bit interface identifier and a 16-bit address. Since the size of the table should be able to hold mapping information for all devices in the 6LoWPAN, it will have a 16 power entry of 2 according to the 16-bit address system. Whenever a node is added to 6LoWPAN that constitutes one PAN, the node performs an association procedure to inform its gateway of its 64-bit address, and the gateway that receives the 64-bit address allocates 16-bit addresses and maps internal network addresses. Store two values in the table. Through this process, the node communicates inside the 6LoWPAN using a 16-bit address.

Referring to FIG. 4, the external network address mapping table includes a 128-bit IPv6 address, a 16-bit address, and an expiration time (ET). The ET field indicates the expiration time of the value and becomes invalid after the expiration time. In other words, when a packet is sent from an external IPv6 network, the gateway temporarily assigns a 16-bit address to the packet's source address and temporarily uses the 16-bit address instead of the 128-bit address only during the expiration time.

In the 6LoWPAN network, a frame conforming to the IEEE 802.15.4-2003 standard includes a beacon frame for transmitting a beacon, a data frame for transmitting data, and a response frame for notifying the other party of receiving a frame successfully, and a MAC command frame. Separated by.

5 is a diagram illustrating a packet format and a data frame structure of a physical layer and a link layer of FIG. 2.

As shown in FIG. 5, a packet data unit (PPDU) of a physical layer includes a 5-octet synchronization header (SHR) 402 and a 1-octet physical layer header (PHR) 404. ), And a physical layer service data unit (PSDU: PHY Service Data Unit) 406. The sync header 402 is composed of a 4-octet preamble sequence and a 1 octet Start of Frame Delimiter (SOFD). The physical layer header 404 includes frame length (FL) information. PSDU 406 is 5+ (4-20) + n octets long and consists of a MAC packet data unit (MPDU).

Data frame format of the MAC layer in the physical layer is a MAC header (MHR: MAC Header) (412), MAC Service Data Unit (MSDU: MAC Service Data Unit) (414), MAC footer (MFR: MAC Footer) (416) It is composed. The header 412 includes a frame control (FC) of 2 octets, a sequence number (SN) of 1 octet, and an addressing field (AD) of 4 to 20 octets. The MSDU 414 is an n octet Data Payload field and the footer 416 consists of a two octet frame check sequence (FCS).

The addressing field includes a destination PAN ID of two octets, a destination address of two or eight octets, a source PAN ID of two octets, and a source address of two or eight octets. In other words, the field size changes to 4 or 20 octets depending on the 16-bit address and the 64-bit address.

FIG. 6 is a diagram for describing the non-separated encapsulation header format of an adaptation layer.

Referring to FIG. 6, the frame transferred from the link layer to the adaptation layer includes an adaptation layer header field 502 and a data field 504. The header field 502 includes a 2-bit link fragment (LF), a 7-bit protocol type (prot_type), a 1-bit M (M) routing, and a final destination field (FD).

If LF is '00', it indicates unfragmented packets, and if '11', it indicates decomposed packets (Interior Fragment).

The 7-bit field of the protocol type (prot_type) is provided by the link fragment.

The "M" bit is used to indicate whether there is a "Final Destination" field used for ad hoc mesh routing or hierarchical routing. If M is set to '1', the Final Destination field takes precedence over IPv6 packets.

The FD includes a 1-bit address type (S) 512, a 7-bit hops left 514, and a final destination address field 516.

The "S" field 512 is '0' if the address field is EUI-64 and '1' if it is a 16-bit short address.

The 7-bit field 514 of "Hops Left" is decremented by 1 at each forwarding node before sending the packet to the next hop. If Hops Left is '0', the packet is discarded.

The "Address" field 516 is the 16-bit short address of the final destination or link layer address that is EUI-64.

6 shows a header format of an IPv6 packet.

Referring to FIG. 6, the IPv6 format is 40 octets representing a 4-bit IPv6 version, a 4-bit priority field, a 3-octet flow label field, a 2-octet payload length field, and a 1-octet TCP / UDP / ICMP header. Next header field, one octet hop limit field, 16 octets 128-bit source address and 16 octets 128-bit destination address.

FIG. 7 is a diagram illustrating a neighbor table created by an association operation between sensor nodes according to the present invention.

Referring to FIG. 7, the neighbor table includes a personal area network ID (PAN Id: 16 bits), a neighbor short address (SAD: Short ADdress: 16 bits), and a neighbor EIU 64 address (EAD: IEEE EUI Extended ADdress: 64 bits). ), Neighbor.Device type (2 bits), Neighbor.Relationship (2 bits), Neighbor Depth (Neighbor.Depth: 8 bits), Maximum number of children (MC), Routing Includes items such as Maximum Number of Router Children (RC).

The Neighbor Device Type (2 bits) field of the neighbor table indicates a coordinator if '00', a router if '01', an end device if '10', and '11' indicates a reservation ( Reserved). Neighbor.Relationship (2 bits) field of the neighbor table indicates parent when '00' and child when '01' and '10' and '11' are reserved.

In an IPv6-based sensor network, each sensor node has its own IPv6 address. This address assignment allows the sensor node to communicate directly with the end-to-end PC and sensor node. Therefore, the sensor network is connected to the gateway and the router in the connection with the backbone network, and the sensors allocate the IPv6 address to the sensor node using the IPv6 prefix information and the sensor information from the router and the gateway.

Router and gateway of the present invention is a device capable of communication by connecting to any type of IP-based network, and is an IP-based sensor network that automatically allocates IPv6 addresses instead of direct input through a series of processes as follows.

8 is a diagram illustrating a method of automatically allocating an IPv6 address according to the present invention.

1. In order to assign an IPv6 address to a sensor network, a gateway or an IPv6 router of a sensor node has an IPv6 prefix to be used (S902).

2. Interface of IPv6 address based on information (for example, 16-bit short address and PAN ID combination, or 64-bit extended address) that IP-based sensor node has to join IPv6 and allocate IPv6. An identifier (IID) is generated (S904).

The interface identifier of IEEE 802.15.4 is based on the EUI 64-bit identifier assigned to the IEEE 802.15.4 device. The interface identifier is formed from EUi-64 according to the 'IPv6 over Ethernet' specification (RFC2464). All IEEE 802.15.4 devices have IEEE 64-bit addresses.

Connect a 16-bit zero to a 16-bit PAN ID to get a 32-bit address. The 48-bit address is obtained by concatenating the 16-bit address to the 32-bit address. Create a 64-bit interface identifier by concatenating 16-bit zeros to a 48-bit address.

3. The neighbor solicitation message of ICMPv6 is loaded with the Interface Identifier that is made by its own so that other sensor nodes check whether it is used (S906). If another sensor node is using the neighbor identifier message that I am using the Interface Identifier is returned (S908). Repeat steps S904 and S906 to confirm that the interface identifier is unique.

4. If the neighbor advertisement message does not come for a certain time, it is determined that the interface identifier is unique in the network, and requests information from the IPv6 router by transmitting a router solicitation message (S910).

5. When the router solicitation message arrives at the IPv6 router or periodically reaches a predetermined time, the IPv6 router transmits a router advertisement message (S912).

6. The IP-based sensor node that listens to the router advertisement message creates its own 64-bit IPv6 address as shown in FIG. 9 by combining the previously created interface identifier with the prefix information included in the router advertisement message (S914). .

7. When a router advertisement message is received from multiple IPv6 routers (or gateways), a prefix is generated using the router advertisement message information of the IPv6 router with the shortest hop distance, and the router with the shortest hop distance becomes the default router.

The generated 128-bit IPv6 address is delivered to the gateway through the router and registered in the external network address mapping table (S916).

At this time, the addresses used by the IP-based sensor nodes during the 4 and 5 processes are the link-local addresses. That is, the link-local prefix :: created interface identifier is included as an IPv6 address.

 Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

As described above, in the present invention, a 6LoWPAN sensor node can automatically allocate an IPv6 address for connecting to an IPv6 network by combining its interface identifier and prefix.

Claims (2)

Generating an interface identifier at the sensor node to join the sensor network; Confirming by requesting neighboring nodes whether the generated interface identifier is unique in the sensor network; Requesting prefix information from a neighbor router when the generated interface identifier is determined to be unique in the sensor network by neighbor confirmation; And And combining the prefix information provided from the neighbor router and the generated interface identifier to create an IPv6 address of the sensor network. The method of claim 1, wherein the generated IPv6 address is And registering the IPv6 address generated in the neighboring router having the shortest hop distance as its default router, and automatically assigning the IPv6 address of the sensor node of the sensor network.

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