CN102271328B - Air-space information network information transmission method - Google Patents

Abstract

The invention relates to an information transmission method of an aerospace information network, including the processes of network addressing, user search, data forwarding and route maintenance. This scheme can adapt to the dynamic environment of high-speed movement and frequent switching of network users, and has the characteristics of high reliability, small delay, and low routing overhead, and provides a feasible solution for data forwarding in aerospace information networks. The network addressing method in the technical solution of this invention can facilitate the relay node to identify the user and backbone node of the data source and destination, reduce the storage space of the routing table, and reduce the network overhead caused by the frequent user address allocation and recovery by the backbone node . The user search method reduces the overhead of establishing routes for high-speed mobile users, and avoids delays in the process of establishing routes for fixed or low-speed mobile users. The route maintenance method not only ensures the continuity of data transmission during the route reconstruction process when the user switches, but also enables the data transmission to quickly recover to the optimal path.

Description

An information transmission method for aerospace information network

technical field

The invention relates to an information transmission method, in particular to an information transmission method for an aerospace information network.

Background technique

The aerospace information network is a comprehensive network that includes various satellites, high-altitude communication platforms, various aircraft, aircraft, and ground communication stations of different types and characteristics of communication systems. It can be used as an emergency communication system in a disaster or war environment, and can also be used as an extension of a traditional communication network to provide support for the integration of heterogeneous networks, and has broad application prospects. In the aerospace information network, all kinds of satellites and high-altitude communication platforms cover a large area, and their positions are stable (high-altitude communication platforms) or regular (satellites). They constitute the backbone nodes of the network and are responsible for network management and information transmission. Various aircraft, aircraft, and fixed sites on the ground or personnel and vehicles, as user nodes of the network, transmit data between each other through backbone nodes.

In the backbone nodes of the network, the satellite communication system covers a large area and is suitable for broadcast communication. Therefore, the main function of the aerospace information network is to monitor and collect network status information to realize the management of the entire network. When the link between the high-altitude communication platforms is damaged or the link between the user and the high-altitude communication platform is damaged, the satellite system provides relay services for the communication between nodes.

The position of the high-altitude communication platform (airship, balloon) is relatively fixed, and multiple high-altitude communication platforms form a network with a relatively stable topology, which is responsible for relaying information from satellites and users within a certain coverage area. The high-altitude communication platforms can communicate directly or through multi-hop communication. Due to the high altitude of the satellite (for example, the altitude of the satellite in geostationary orbit is 35786 kilometers), the information relay between ground users directly through the satellite requires a large power, and the delay is also relatively large (the round-trip delay is 250-280ms ). The height of the high-altitude communication platform is generally 20-50 kilometers, which is far lower than the height of the satellite. It can receive low-power signals that cannot be monitored by the satellite, and the path loss between the high-altitude communication platform and the ground is small, compared with the geostationary orbit satellite. More than 70 dB less. Therefore, the communication between the ground user and the aircraft should be relayed by the high-altitude communication platform as far as possible, which is convenient for the real-time transmission of user data and the miniaturization of the terminal antenna.

At present, the research on the routing technology of aerospace information network is in its infancy, and the existing research results are few. Similar routing technologies include wireless ad hoc network routing technology and satellite network routing technology. Due to the different characteristics of the network structure, it is difficult for these routing technologies to be well applied in the aerospace information network.

Wireless ad hoc network routing technology: mainly divided into table-driven routing protocols and on-demand routing protocols. In the table-driven routing protocol, each node saves the routing table of all other nodes by itself, and updates the routing table information through regular information exchange between nodes. When there is data to be sent, it is directly forwarded according to the routing table. In the on-demand routing protocol, before the node sends data, it first finds the route to the destination node through the exchange of control information, and then forwards the data according to this route.

Satellite network routing technology: mainly uses the regularity of satellite movement to divide the satellite movement cycle into multiple time slots. In each time slot, the position of the satellite is considered to remain unchanged, forming a series of static routes. When transmitting, it forwards according to the corresponding static route according to the time slot it is in.

Aerospace information network has the following characteristics:

1. The topology of backbone nodes is regular, but the locations of some users change rapidly and dynamically, which is unpredictable. 2. Data is transmitted between users through the backbone nodes in a multi-hop manner.

3. The distance between nodes is long, and the data propagation delay cannot be ignored.

Therefore, the application of the existing wireless ad hoc network routing technology and satellite network routing technology in the aerospace information network will have the following problems:

High routing overhead: If the table-driven routing in the wireless ad hoc network is used, the network nodes need to exchange information regularly to update the routing information. Due to the fast movement of nodes such as satellites and aircraft in the aerospace information network, the position changes quite frequently. To ensure the correctness of routing information, network nodes need to exchange information frequently to obtain the latest routing information. This leads to a large amount of routing overhead and wastes limited network resources.

Large data delay: If the on-demand routing protocol in the wireless ad hoc network is used, the network nodes will search for the route only when there is data to be transmitted, which reduces the routing overhead. However, due to the long distance between the network nodes, the data The propagation delay cannot be ignored, so the route lookup process will increase the delay of data transmission and reduce the transmission efficiency.

Poor reliability: Since the users served by the aerospace information network include not only traditional ground users, but also high-speed moving aircraft, aircraft and other users, the topology of the network has the characteristics of randomness and dynamics. It is difficult to correctly reflect the topology of the entire network and provide reliable routing information by simply relying on satellite movement laws to divide a series of static topology routing methods.

Contents of the invention

The technical problem solved by the present invention is to provide an information transmission method for aerospace information network, which overcomes the large routing overhead and data delay when the existing wireless ad hoc network routing technology and satellite network routing technology are applied in the aerospace information network Large, poor reliability technical issues.

The technical solution of the present invention is to provide an information transmission method for an aerospace information network, the aerospace information network includes a backbone node and a user node, including the following steps:

Network addressing: build the address structure of the aerospace information network, the address structure of the network layer header includes the address of the source user node for sending data, the address of the destination user node for receiving data, the address of the source backbone node accessed by the source user and the address of the destination user The address of the destination backbone node for access, the address of the source backbone node and the address of the destination backbone node are allocated when the aerospace information network is constructed, and the address of the source user node and the address of the target user node are allocated when the user joins the aerospace information network;

Receive information: receive the data to be transmitted;

User search: The backbone nodes of the aerospace information network form a subnet within its coverage area, and the backbone nodes construct the corresponding relationship between the known backbone nodes and users. When there is data to be sent to the user, the backbone node that sends the data searches The subnet where the data destination user is located;

Information sending: The backbone node sending data calculates the route between the backbone node sending data and the backbone node of the destination user according to the subnet where the destination user is found, writes the destination backbone node address into the network layer header of the data, and then sends it according to the route data.

A further technical solution of the present invention is: in the network addressing step, the address of the source backbone node and the address of the destination backbone node are respectively addressed with 10 bits.

A further technical solution of the present invention is: in the network addressing step, the address structure of the aerospace information network also includes source user types and destination user types.

A further technical solution of the present invention is: in the user search step, the source backbone node sending data to search for the subnet where the data destination user is located includes the following steps:

Send query information: the source backbone node sending data sends subnet query information;

Receiving query information: The backbone node that receives the subnet query information judges whether it has received the query information through the address of the source user node, the address of the destination user node and the serial number. In the subnet, if the destination user is not in its own subnet, the query information will be forwarded; if the backbone node that receives the query information finds that the destination user is in its own subnet, it will forward the query information to the source backbone node that originally sent the subnet query information The node replies with a subnet reply message.

A further technical solution of the present invention is: in the user search step, the backbone nodes passing through the subnet query information and the subnet response message in the transmission process will include the source backbone node, source user node, and destination backbone node and destination user node information Recorded in the self-saved user-backbone node relationship table.

A further technical solution of the present invention is: in the user search step, for a fixed user or a low-speed mobile user, when the user registers to a certain backbone node subnet, the backbone node sends a subnet update message and notifies all backbone nodes of this information .

A further technical solution of the present invention is: in the user search step, for high-speed mobile users, start the user search process when there is data to be sent.

A further technical solution of the present invention is: the backbone nodes participating in data forwarding calculate the route according to the source backbone node address and the destination backbone node address in the network layer packet header, and continue to forward data.

A further technical solution of the present invention is: in the information transmission method of the aerospace information network, it also includes routing reconstruction when the user switches between different subnets, and the routing reconstruction includes the following steps:

Registration at the new backbone node: When the user switches between different subnets, that is, switching from the old backbone node subnet to the new backbone node subnet, the user registers at the new backbone node;

Cancellation of registration: the new backbone node sends a cancellation of registration information to notify the old backbone node to delete the user's registration information;

Routing reconstruction: the old backbone node sends the received deregistration information to the source backbone node, and notifies the source backbone node to perform route reconstruction, and the source backbone node performs route reconstruction;

A further technical solution of the present invention is: in the route reconstruction step, if the new route between the source backbone node and the destination user has not been established, the source backbone node will continue to send data to the old backbone node, and the old backbone node will send the data It is forwarded to the new backbone node, and then forwarded to the user by the new backbone node. the

The technical effects of the present invention are: the present invention provides an information transmission method for an aerospace information network, and a feasible routing solution is designed according to the characteristics of the aerospace information network, including network addressing, user search, data forwarding and routing maintenance processes. This scheme can adapt to the dynamic environment of high-speed movement and frequent switching of network users, and has the characteristics of high reliability, small delay, and low routing overhead, and provides a feasible solution for data forwarding in aerospace information networks. The network addressing method in the technical solution of this invention can facilitate the relay node to identify the user and backbone node of the data source and destination, reduce the storage space of the routing table, and reduce the network overhead caused by the frequent user address allocation and recovery by the backbone node . According to the different mobility of the users in the user search method, the subnets where the users are located are determined by means of search on demand and real-time update respectively. It reduces the routing overhead of high-speed mobile users and avoids delays in the routing establishment process of fixed or low-speed mobile users. In the technical solution of the present invention, the combination of partial route reconstruction and full route reconstruction ensures the continuity of data transmission when users switch between subnets, improves the reliability of routing, and quickly restores data transmission to the optimal path.

Description of drawings

Fig. 1 is the flow chart of the present invention.

Fig. 2 is a schematic diagram of the user search process of the object of the present invention.

Fig. 3 is a flowchart of a preferred embodiment of the present invention.

Fig. 4 is a flowchart of route reconstruction in the present invention.

Fig. 5 is a schematic diagram of route maintenance during switching in the present invention.

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with specific embodiments.

As shown in Figure 1, the specific embodiment of the present invention is: provide a kind of information transmission method of aerospace information network, described aerospace information network comprises backbone node, user node, comprises the following steps:

Step 100: Network addressing, namely: constructing the address structure of the aerospace information network, the address structure of the network layer header includes the address of the source user node for sending data, the address of the destination user node for receiving data, and the source backbone for source user access The node address and the destination backbone node address accessed by the destination user, the source backbone node address and the destination backbone node address are allocated when the aerospace information network is constructed, the source user node address and the destination user node address are connected when the user joins the aerospace information Network time distribution.

The specific implementation process is as follows: the network addressing of the present invention modifies the address structure of the traditional network layer header, and designs the address structure of the aerospace information network, including the source user, the destination user, the source backbone node and the destination backbone node information, And the node type information, as shown in Table 1. In the present invention, the source backbone node is a backbone node accessed by a source user sending data, and the destination backbone node is a backbone node accessed by a destination user of data.

Table 1 Design of network layer header address structure

The user address of the traditional network is assigned by the gateway or router of the subnet where the user is located, and the subnet where the user is located is determined by the subnet mask. In order to represent a large number of hosts in the network, a 32-bit address structure is used. This allocation method is more suitable in fixed networks, but in the space information network where users move dynamically, when users frequently move between different subnets, addresses need to be allocated and reclaimed frequently, which increases network overhead .

The network addressing of the present invention is based on the structure and characteristics of the aerospace information network. The number of backbone nodes and users of the network is far smaller than the number of users of the Internet, and a relatively small address space can be used to identify the backbone nodes and users respectively. The 32-bit address information space has been re-divided, and the meanings of the modified parts are as follows:

Source user address - 18 bits, indicating the source node sending data, which is the user node of the aerospace information network service.

Source backbone address - 10 bits, indicating the network backbone node accessed by the source user.

Source user type - 4 bits, used to distinguish the identity and function of the source user in the network or task.

Destination user address - 18 bits, indicating the destination node for receiving data, which is the user node of the aerospace information network service.

Destination backbone address - 10 bits, indicating the network backbone node accessed by the destination user.

Destination user type - 4 bits, used to distinguish the identity and function of the destination user in the network or task.

The addresses of the backbone nodes are assigned during the initialization process of building the network. When a new backbone node joins, the address of the backbone node is assigned to it, and all the backbone nodes in the network update relevant information. For a network user node, when it joins the network, the network assigns a user address to it, and notifies other nodes in the network of the user's address information. When a node exits the network, the address of the node is taken back, and this information is notified to other nodes in the network.

Through the redesign of the network layer header, the backbone nodes in the network can clearly grasp the source node and destination node information when forwarding data, and can easily identify the identity of the user sending and receiving the information, and through the source backbone address and destination backbone address items, which can quickly and accurately find routes and forward data. At the same time, since the routing tables and network state information tables stored in the network backbone nodes are marked with 10-bit backbone node addresses, compared with the 32-bit IP addresses in the traditional Internet, the storage space occupied by the routing tables is also smaller. significantly reduced.

Step 200: Receive information, that is, receive data to be transmitted.

Step 300: user search, that is: the backbone nodes of the aerospace information network form a subnet within its coverage area, and the backbone nodes construct the correspondence between the known backbone nodes and users, and when there is data to be sent to the user, send The backbone node of the data searches for the subnet where the data destination user is located.

The specific implementation process is as follows: In the present invention, each backbone node in the aerospace information network forms a subnet within its coverage area, and the backbone node is responsible for the information transmission of users in the subnet. Each backbone node saves the corresponding relationship table between the backbone nodes and users known by itself, and updates it according to the received subnet update message. By way of example, the table structure is shown in Table 2.

Table 2 Correspondence between backbone nodes and users

user address backbone address Effective time airplane 01 High Altitude Communication Platform 01 T1=1 minute Ground station 01 LEO 11 T2=6 minutes car 02 High Altitude Communication Platform 02 T3=6 hours ... ... ...

When there is data to be sent to the user, the source backbone searches its own backbone node and user correspondence table, and if it contains a valid correspondence, the source backbone finds the destination backbone from the table to search or calculate the route. If there is no valid corresponding relationship in the table, the source backbone starts the subnet query process for the destination user. The effective time is determined by the types of user nodes and backbone nodes. Different types of nodes have different online time of users in the subnet, and corresponding valid time of subnet information is different. For example, in the above table, the valid time of the position relationship between the aircraft and the high-altitude communication platform is 1 minute, the valid time of the ground station and the low-orbit satellite is 6 minutes, and the valid time of the vehicle and the high-altitude communication platform is 6 hours.

The backbone node is updating the corresponding relationship table between the backbone node and the user and searching for the target user. The process is as follows:

1. For fixed users or users with relatively low mobile speed, when the user registers to a backbone node subnet, the backbone node sends a subnet update message to notify all backbone nodes of this information. Since the update frequency of such information is very low, it will not increase the burden on the network, and the location of the user can be known in time. The format of the subnet update message is shown in Table 3. the

Table 3 Subnet update message format

2 bytes 18bit 10bit 2 bytes message type user address backbone address Effective time

When there is data to be sent to fixed users or low-speed users, the source backbone searches the corresponding relationship table between backbone nodes and users, and finds the destination backbone corresponding to the destination user.

2. For high-speed mobile users (such as airplanes, aircraft, etc.), due to their irregular movements and frequent switching between subnets, if the subnet information of all users is updated in real time, a large amount of communication will be generated Overhead, especially when there are many users moving at high speed in the network, this overhead will occupy a large amount of network resources. Therefore, user search is performed in an on-demand manner, and the user search process is started only when there is data to be sent.

The target user subnet query process is shown in Figure 2. When the source user M wants to send data to the destination user N, M first sends the data to the source backbone node A where M is located, and A searches for the subnet where the destination user N is located. A first sends the subnet query information (REQ: request), and each backbone node that receives the REQ checks the source and destination information and the serial number to determine whether it has received the REQ. If it has received it, it will not process it, otherwise it will judge Whether the destination user is in its own subnet, if not, continue to broadcast REQ. When the backbone node B receives the REQ, it finds that the destination user is in its own subnet, so it replies to the source backbone A with a reply message (REP: reply). After receiving the REP, A knows that the destination backbone is B, calculates the route from A to B, and sends data information.

The backbone nodes through which REQ and REP are transmitted will record the source backbone, source user and destination backbone and destination user information in the user-backbone relationship table saved by themselves, so that there is data to be sent to the source at these relay nodes User or destination user, it can be sent directly, which reduces the query time and facilitates data transmission.

The control information that needs to be exchanged in the process of finding the subnet where the destination user is located in the on-demand mode includes subnet query messages (REQ, request) and subnet response messages (REP, reply). The structure of the messages is shown in Table 4 and Table 5.

Table 4 Subnet query message format

2 bytes 18bit 10bit 18bit 2 bytes 2 bytes type target user source backbone address source user address serial number Effective time

Table 5 Subnet reply message format

2 bytes 18bit 10bit 18bit 10bit 2 bytes 2 bytes type target user source backbone address source user address destination backbone address serial number Effective time

Step 400: Information sending: the backbone node sending the data calculates the route between the backbone node sending the data and the backbone node of the destination user according to the found subnet where the destination user is located, and writes the address of the destination backbone node into the network layer packet header of the data, and then Send data according to the route.

The specific implementation process is as follows:

When the source backbone node finds the destination backbone to which the destination user belongs, it calculates the route from the source backbone to the destination backbone, and forwards data according to this route.

Due to the long distance between the backbone nodes, the propagation delay cannot be ignored, so the delay is taken as the main cost to calculate the route between the backbone nodes, and the path with the smallest delay is selected.

The backbone nodes store the movement rules of all backbone nodes in the entire network, and the positions and distances of all backbone nodes at this time can be calculated according to the movement rules.

Let s be the source node, t be the destination node, is a path from source node to destination node, Indicates the delay cost of the link formed by node i and node j on the transmission path. then take the path The delay cost of data transmission is the sum of the delay costs of each link on the path, as shown in formula (1).

(1)

Using Dijkstra's shortest path algorithm, with the goal of minimizing the delay cost, calculate the route between the backbone nodes, and forward data according to this route.

As shown in Figure 3, the preferred embodiment of the present invention is: in the information transmission method of the aerospace information network, it also includes routing reconstruction when the user switches between different subnets, due to the high-speed movement of the user, during the data transmission process In the process, users may move from a subnet of a backbone node to another subnet, causing the original route to fail, resulting in interruption of transmission. A route maintenance strategy is designed to solve this problem, and route reconstruction is performed when users switch between different subnets. The route reconstruction method adopted is a combination of partial reconstruction and full route reconstruction. Partial route reconstruction is used during the switching process, and the source node is notified to perform full route reconstruction. Before the completion of full route reconstruction, the partially reconstructed route is used to transmit data, which ensures This ensures the continuity of communication and quickly restores data transmission to the optimal path.

As shown in Figure 4, the route reconstruction includes the following steps:

Step 501: Register on the new backbone node, that is, when the user switches between different subnets, the user registers on the new backbone node.

Step 502: cancel registration, that is: the new backbone node deletes the user's information in the old backbone node and notifies the old backbone node;

Step 503: Route reconstruction, that is, the old backbone node sends the received deregistration information to the source backbone node, and notifies the source backbone node to perform route reconstruction, and the source backbone node performs route reconstruction.

The specific implementation process is shown in Figure 5, and the examples are as follows: Assume that a mobile node M such as an airplane moves in the subnet of the backbone node A. When M moves to the overlapping area of the coverage of A and B, it selects The new backbone node B is connected. At this time, M sends a REG to B, and B replies with an ACK to add M to the B subnet, and forwards it to A through B to cancel the registration information (DREG: delete registration information), and delete M in A. information in the subnet, and notify node A that node M has joined the subnet of B. After receiving the DREG, A sends the DREG information to the source backbone, and notifies the source backbone to perform route reconstruction. If the process of establishing a new route from the source node to the M node has not been started at this time, the source node will continue to send data to A, then A will forward the data to B, and then B will forward it to M. The continuity of data transmission when the node performs subnet switching avoids retransmission and network delay caused by transmission interruption.

The information formats of REG and DREG are shown in Table 6 and Table 7.

Table 6 REG message format

2 bytes 18bit 10bit 10bit message type user address The new backbone address to register old backbone address

Table 7 DREG message format

2 bytes 18bit 10bit 10bit message type Unregistered user address new backbone address old backbone address

During the effective time, the user may move out of the subnet of the backbone node, and the switching strategy designed by the technical solution of the present invention can avoid transmission interruption caused by the switching.

The technical effects of the present invention are: the present invention provides an information transmission method for an aerospace information network, and a feasible routing solution is designed according to the characteristics of the aerospace information network, including network addressing, user search, data forwarding and routing maintenance processes. This scheme can adapt to the dynamic environment of high-speed movement and frequent switching of network users, and has the characteristics of high reliability, small delay, and low routing overhead, and provides a feasible solution for data forwarding in aerospace information networks. The network addressing method in the technical solution of this invention can facilitate the relay node to identify the user and backbone node of the data source and destination, reduce the storage space of the routing table, and reduce the network overhead caused by the frequent user address allocation and recovery by the backbone node . According to the different mobility of users in the user search method, the subnet where the user is located is determined by using the method of search on demand and real-time update respectively. It reduces the routing overhead of high-speed mobile users and avoids delays in the routing establishment process of fixed or low-speed mobile users. In this scheme, the combination of partial route reconstruction and full route reconstruction ensures the continuity of data transmission when users switch between subnets, and improves the reliability of routes.

The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be assumed that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some simple deduction or replacement can be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (10)

1. an empty day information network information transferring method, a described empty day information network comprises backbone node, user node, comprises the steps:

Network addressing: the address structure that builds empty day information network, the address structure in network layer packet header comprises that the source user node address that sends data is, the object backbone node address that backbone node address, source and the object user of the object user node address that receives data, source user access access, backbone node address, described source and object backbone node address are distributed when building empty day information network, and described source user node address, object user node address are distributed when user adds empty day information network;

Reception information: receive data waiting for transmission;

User searches: the backbone node of empty day information network forms a subnet in its coverage, backbone node builds its known backbone node and user's corresponding relation, when having data to send to user, the backbone node that sends data is searched the subnet at data object user place;

Information sends: the backbone node that sends data calculates the route that sends the backbone node of data and object user's backbone node according to the subnet at the object user place of finding, and by the network layer packet header of object backbone node address data writing, then according to route, send data.

2. empty day according to claim 1 information network information transferring method, is characterized in that, in network addressing step, backbone node address, described source and object backbone node address adopt 10 to address respectively.

3. empty day according to claim 1 information network information transferring method, is characterized in that, in network addressing step, the address structure of described empty day information network also comprises source user type and object user type.

4. empty day according to claim 1 information network information transferring method, is characterized in that, in user's finding step, the subnet that the source backbone node of transmission data is searched data object user place comprises the steps:

Send Query Information: the source backbone node that sends data sends subnet Query Information;

Receive Query Information: the backbone node of receiving subnet Query Information judges whether to receive this Query Information by source user node address and object user node address and sequence number, if receive, do not process, otherwise judge that object user is whether in the subnet of self, if object user, not in the subnet of oneself, forwards this Query Information; If receive, the backbone node discovery object user of Query Information is within the subnet of oneself, to the source backbone node reply subnet response message that starts most to send subnet Query Information.

5. empty day according to claim 4 information network information transferring method, it is characterized in that, in user's finding step, in the backbone node of subnet Query Information and subnet response message process in transmitting procedure is preserved source backbone node wherein and source user node and object backbone node and object user node information recording user and backbone node relation table at self.

6. empty day according to claim 1 information network information transferring method, it is characterized in that, in user's finding step, for fixed-line subscriber or low speed mobile subscriber, when user is registered to certain backbone node subnet, this backbone node sends subnet updating message, by this information, notifies all backbone nodes.

7. empty day according to claim 1 information network information transferring method, is characterized in that, in user's finding step, for high-speed mobile user, starts user's search procedure when having data to send.

8. empty day according to claim 4 information network information transferring method, is characterized in that, participates in the backbone node of data retransmission according to the backbone node address, source in network layer packet header and object backbone node address computation route, and forwarding data.

9. empty day according to claim 1 information network information transferring method, it is characterized in that, at empty day, also comprise when user is switched between different sub-network and carry out rerouting in information network information transferring method, described rerouting comprises the steps:

At new backbone node, register: when user is switched between different sub-network, from old backbone node subnet, be switched to new backbone node subnet, user registers at new backbone node;

Cancel register: new backbone node sends cancel register information, notifies old backbone node to delete user's log-on message;

Rerouting: old backbone node is issued source backbone node by the cancel register information of receiving, notification source backbone node carries out rerouting, carries out rerouting by source backbone node.

10. empty day according to claim 9 information network information transferring method, it is characterized in that, in rerouting step, if source backbone node and object user's new route is not also set up, source backbone node can continue to send the data to old backbone node, by old backbone node, by this data retransmission, give new backbone node, then be transmitted to user by new backbone node.