Networking communication method and apparatus between trains, and train consist

Abstract

A networking communication method and apparatus between trains, and a train consist, which relate to the field of wireless backbone network communications for rail transit. The method is applied to a train consist, and comprises: sending a first topology discovery message of a present train by using preset directional antennas, and receiving first topology discovery messages of other trains that are sent by other train consists; determining a networking situation according to networking topology information in the first topology discovery messages of the other trains; and if the networking situation indicates a convergence-completed state, according to networking topology information of the present train, performing data transmission with a target node in a network by using the preset directional antennas. In the present invention, each train consist can send and receive topology discovery messages by using back-to-back directional antennas, so as to determine the positions of the other train consists relative to the present train by using the topology discovery messages received by means of the back-to-back directional antennas, thereby realizing the wireless networking of the train consists; and data transmitted between nodes is forwarded by using train nodes in a network, such that the reliability of the wireless communication between trains is improved.

Description

FIELD

[0001] The present disclosure relates to the field of wireless backbone network communications for rail transit, and in particular to a method and an apparatus for networking communication between trains, and a train consist.BACKGROUND

[0002] A train communication network (TCN) may include two stages of network architectures, i.e., a train backbone and a consist network. The train backbone is used for reconnection between consists, to achieve dynamic train marshaling and unmarshaling, train-level control and diagnosis functions.

[0003] At present, the train backbone mainly adopts a bus type network and an Ethernet network. Both the bus type network and the Ethernet network are technologies based on physical wires. In a case that the train is to perform dynamic marshaling or unmarshaling, train backbone nodes are physically connected and disconnected with each other at connection points. Multiple times of plugging and unplugging will increase the wear of the connection points, thus affecting communication quality of the train backbone. Based on the above, a new train backbone, wireless train backbone (WLTB) emerged. Wireless reconnection and backbone data transmission are implemented through a wireless technology, effectively alleviate susceptibility of wear and poor contact of physical wires.

[0004] In the conventional technology, the railway wireless reconnection system includes a long-distance reconnection and a short-distance reconnection. The long-distance wireless reconnection system is mainly based on cellular networks (such as GSM-R and LTE-M) and radio stations. The short-distance wireless reconnection system is mainly based on a WiFi technology. GSM-R (a comprehensive dedicated digital mobile communication system developed for railway communication) and LTE-M (a mobile communication system developed for meeting requirements of the Internet of Things or machine-to-machine communication applications) technologies are implemented in a full-duplex mode without limit of transmission distance and with a wide transmission bandwidth. This may cause a high communication cost for participation of communication base stations and network servers in networking. The radio station technology is implemented in a half-duplex communication mode, and the wireless train backbone node (WLTBN) is to support a multi-hop relay communication mode to ensure communication from a source node to a destination node. In the WiFi wireless communication technology, a wireless access point is provided for communication, which provides a wide transmission bandwidth. However, the WiFi wireless communication technology provides a short transmission distance, a small coverage range and a low reliability.

[0005] Therefore, attention is drawn to how to address the issues of small coverage range, low reliability and high communication cost in the conventional wireless reconnection system and implement effective, reliable and low-cost transmission of train backbone data.SUMMARY

[0006] The object of the present disclosure is to provide a method and an apparatus for networking communication between trains, and a train consist, so as to implement the effective, reliable and low-cost transmission of the train backbone data.

[0007] In order to solve the above technical problem, a method for networking communication between trains is provided according to the present disclosure. The method is applied to train consists and includes: sending a first current-train topology discovery message and receiving a first another-train topology discovery message sent by another train consist through a preset directional antenna, where both the first current-train topology discovery message and the first another-train topology discovery message include a sender identifier and networking topology information, and the networking topology information includes identification information of train consist nodes in a network; determining a networking state based on the networking topology information in the first another-train topology discovery message; updating the networking topology information of the current train based on the first another-train topology discovery message, and performing the process of sending the first current-train topology discovery message and receiving the first another-train topology discovery message sent by the another train consist through the preset directional antenna, if the networking state is an uncompleted convergence state; and performing data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train, if the networking state is a completed convergence state, where the preset directional antenna includes two directional antennas arranged back to back at each of the train consists.

[0008] In an embodiment, the updating the networking topology information of the current train based on the first another-train topology discovery message includes: updating the networking topology information of the current train based on the sender identifier and the networking topology information in the first another-train topology discovery message and / or a received signal strength corresponding to the another train consist and a receiving antenna of the another train consist, where the receiving antenna is any one of the directional antennas.

[0009] In an embodiment, the networking topology information further includes topological sort order information of the train consist nodes in the network.

[0010] In an embodiment, the updating the networking topology information of the current train based on the sender identifier and the networking topology information in the first another-train topology discovery message and / or a received signal strength corresponding to the another train consist and a receiving antenna of the another train consist includes: updating identification information and topological sort order information of the train consist nodes corresponding to train consists adjacent to the current train in the networking topology information of the current train, based on the sender identifier in the first another-train topology discovery message and the received signal strength corresponding to the another train consist and the receiving antenna of the another train consist; and updating the networking topology information of the current train based on the networking topology information in the first another-train topology discovery message.

[0011] In an embodiment, the determining a networking state based on the networking topology information in the first another-train topology discovery message includes: determining whether the networking topology information in the first another-train topology discovery messages is the same as the networking topology information of the current train; determining that the networking state is the uncompleted convergence state if negative; and determining that the networking state is the completed convergence state if positive.

[0012] In an embodiment, the preset directional antenna includes the directional antennas arranged back to back at the train consist, and communication directions of the directional antennas are respectively directed toward two ends of the train consist.

[0013] In an embodiment, the sender identifier includes an identifier of the directional antenna adopted by a sender, and the identification information of the train consist nodes in the network includes identifiers of the two directional antennas of each of the train consist nodes.

[0014] In an embodiment, the performing data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train includes: generating communication routing information of the current train based on the networking topology information of the current train, where the communication routing information includes communication paths respectively corresponding to the train consist node of the current train and the other train consist nodes in the network and routing metric values corresponding to the communication paths; sending a second current-train topology discovery message and receiving a second another-train topology discovery message sent by the another train consist through the preset directional antenna, where both the second current-train topology discovery message and the second another-train topology discovery message include the communication routing information; updating the routing metric values corresponding to the communication paths in the communication routing information of the current train, based on the second another-train topology discovery message; and determining a target communication path corresponding to the target node based on the communication routing information of the current train, and sending to-be-sent data to the target node via the target communication path, where the target communication path is any one of the communication paths.

[0015] In an embodiment, the updating the routing metric values corresponding to the communication paths in the communication routing information of the current train, based on the second another-train topology discovery message includes: updating the routing metric values corresponding to single-hop communication paths in the communication routing information of the current train, based on a message sequence number, a CPU load and / or a received signal strength corresponding to the anther train consist in the second another-train topology discovery message; and updating the routing metric values corresponding to multi-hop communication paths in the communication routing information of the current train, based on the communication routing information in the second another-train topology discovery message, where the communication paths in the communication routing information of the current train include the single-hop communication paths and the multi-hop communication paths.

[0016] In an embodiment, the updating the routing metric values corresponding to single-hop communication paths in the communication routing information of the current train, based on a message sequence number, a CPU load and / or a received signal strength corresponding to the another train consist in the second another-train topology discovery message includes: storing the message sequence number, the CPU load and the received signal strength that are obtained by analyzing the second another-train topology discovery messages to corresponding target storage spaces, where the target storage spaces are storage spaces assigned for the other train consists corresponding to the second another-train topology discovery messages; calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space, and determining a signal strength average value score and a signal strength standard deviation score corresponding to the current single-hop communication path by S SPM = 0 , SP ¯ < − 130 S SPM = 1.25 ∗ SP ¯ + 162.5 , − 130 ≤ SP ¯ ≤ − 50 S SPM = 100 , SP ¯ > − 50 and S SPT = 0 , δ > 0.6 ∗ SP ¯ S SPT = − 250 δ / SP ¯ + 150 , 0.2 ∗ SP ¯ ≤ δ ≤ 0.6 ∗ SP ¯ S SPT = 100 , δ < 0.2 * SP ¯ where the current target storage space is any one of the target storage spaces, the current single-hop communication path corresponds to the current target storage space, S SPM represents the signal strength average value score, SP represents the received signal strength average value, S SPT represents the signal strength standard deviation score, and δ represents the received signal strength standard deviation; calculating a CPU load average value corresponding to the current single-hop communication path based on a target CPU load in the current target storage space, and determining a CPU load average value score corresponding to the current single-hop communication path by S CPU = 0 , CPU ¯ > 80 % S CPU = − 500 3 ∗ CPU ¯ + 400 3 , 20 % ≤ CPU ¯ ≤ 80 % S CPU = 100 , CPU ¯ < 20 % where S CPU represents the CPU load average value score and CPU represents the CPU load average value; calculating a packet reception rate corresponding to the current single-hop communication path based on a target message sequence number in the current target storage space, and determining a packet reception rate score corresponding to the current single-hop communication path by S DPR = 0 , DPR < 65 % S DPR = 1000 3 ∗ DPR − 650 3 , 65 % ≤ DPR ≤ 95 % S DPR = 100 , DPR > 95 % where S DPR represents the packet reception rate score, and DPR represents the packet reception rate; calculating an average message reception period corresponding to the current single-hop communication path based on a target second another-train topology discovery message in the current target storage space, and determining an average period score corresponding to the current single-hop communication path by S CYC = 0 , CYCLE _ A > 6 ∗ CYCLE S CYC = − 25 ∗ CYCLE _ A CYCLE + 150,2 ∗ CYCLE ≤ CYCLE _ A ≤ 6 ∗ CYCLE S CYC = 100 , CYCLE _ A < 2 ∗ CYCLE where S CYC represents the average period score, CYCLE _A represents the average message reception period, and CYCLE represents a preset message sending period; and calculating the routing metric value corresponding to the current single-hop communication path by S = ω SPM S SPM + ω SPT S SPT + ω CPU S CPU + ω DPR S DPR + ω CYC S CYC where S represents the routing metric value, ω SPM , ω SPT , ω CPU , ω DPR and ω CYC respectively represent weighted values of the signal strength average value score, the signal strength standard deviation score, the CPU load average value score, the packet reception rate score and the average period score corresponding to the current single-hop communication path.

[0017] In an embodiment, before the calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space, the method for networking communication between trains further includes: determining whether the current target storage space is fully-stored, where a data storage mode of the current target storage space is first-in-first-out; determining the routing metric value corresponding to the current single-hop communication path as a preset routing value if the current target storage space is not fully-stored; and performing the step of calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space if the current target storage space is fully-stored.

[0018] In an embodiment, before the calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space, the method for networking communication between trains further includes: determining whether a duration in which the current target storage space does not update stored data reaches a preset duration, where the preset duration is greater than the preset message sending period; determining the routing metric value corresponding to the current single-hop communication path as the preset routing value, if the preset duration is reached; and performing the step of calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space, if the preset duration is not reached.

[0019] In an embodiment, the determining a target communication path corresponding to the target node based on the communication routing information of the current train includes: determining a preferred communication path with a minimum hop count and a routing metric value unequal to the preset routing value among the communication paths between the current train and the target node based on the communication routing information of the current train; and determining a preferred communication path with a maximum routing metric value among the preferred communication path as the target communication path based on the communication routing information of the current train.

[0020] An apparatus for networking communication between trains is further provided according to the present disclosure, where the apparatus is applied to train consists and includes: a topology networking module, configured to send a first current-train topology discovery message and receive a first another-train topology discovery message sent by another train consist through a preset directional antenna, where both the first current-train topology discovery message and the first another-train topology discovery message include a sender identifier and networking topology information, and the networking topology information includes identification information of train consist nodes in a network; a networking determination module, configured to determine a networking state based on the networking topology information in the first another-train topology discovery message; a networking updating module, configured to update the networking topology information of the current train based on the first another-train topology discovery message, and perform the process of sending the first current-train topology discovery message and receiving the first another-train topology discovery message sent by the another train consist through the preset directional antenna, if the networking state is an uncompleted convergence state; and a data transmitting module, configured to perform data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train, if the networking state is a completed convergence state, where the preset directional antenna includes two directional antennas arranged back to back at each of the train consists.

[0021] In addition, a train consist is provided according to the present disclosure, including: a memory, storing a computer program; and a processor, configured to implement the method for networking communication between trains according the above description when executing the computer program.

[0022] A method for networking communication between trains is provided according to the present disclosure, applied to train consists. The method includes: sending a first current-train topology discovery message and receiving a first another-train topology discovery message sent by another train consist through a preset directional antenna, where the preset directional antenna includes two directional antennas arranged back to back at the train consist, both the first current-train topology discovery message and the first another-train topology discovery message include a sender identifier and networking topology information, and the networking topology information includes identification information of train consist nodes in a network; determining a networking state based on the networking topology information in the first another-train topology discovery message; updating the networking topology information of the current train based on the first another-train topology discovery message, and performing the process of sending the first current-train topology discovery message and receiving the first another-train topology discovery message sent by the another train consist through the preset directional antenna, if the networking state is an uncompleted convergence state; and performing data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train, if the networking state is a completed convergence state.

[0023] It can be seen that, according to the present disclosure, the first current-train topology discovery message is sent and the first another-train topology discovery message sent by another train consist is received using the preset directional antenna. Each train consist sends and receives topology discovery messages through the back-to-back directional antennas, and determines the positions of other train consists relative to the current train by using the topology discovery messages received by the back-to-back directional antennas, thereby implementing wireless networking of the train consists and increasing the distance of the wireless communication. Furthermore, data transmitted between nodes can be forwarded by the train consist nodes in the network, thus supporting wireless reconnection of more trains, and improving the reliability of wireless communication between trains. In addition, an apparatus for networking communication between trains, and a train consist are further provided according to the present disclosure, which have same beneficial effects as mentioned above.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate technical solutions in embodiments of the present disclosure or in the conventional technology, the drawings to be used in the description of the embodiments or the conventional technology are briefly described below. Apparently, the drawings in the following description show only embodiments of the present disclosure, and other drawings may be obtained by those skilled in the art from the drawings without any creative work. FIG. 1 is a flowchart of a method for networking communication between trains according to an embodiment of the present disclosure; FIG. 2 is a schematic diagram of a wireless networking system of a method for networking communication between trains according to another embodiment of the present disclosure; FIG. 3 is a flowchart of a routing communication process after networking in the method for networking communication between trains according to another embodiment of the present disclosure; FIG. 4 is a flowchart of calculation of a routing metric value of a method for networking communication between trains according to another embodiment of the present disclosure; and FIG. 5 is a structural block diagram of an apparatus for networking communication between trains according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] In order to make the objective, the technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure are described below in conjunction with the drawings in the embodiments of the present disclosure. Apparently, the embodiments described below are only some embodiments of the present disclosure, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the present disclosure without any creative work fall within the protection scope of the present disclosure.

[0026] Reference is made to FIG. 1, which is a flowchart of a method for networking communication between trains according to an embodiment of the present disclosure. The method is applied to train consists, and may include steps S101 to S104.

[0027] In step S101, a first current-train topology discovery message is sent and a first another-train topology discovery message sent by another train consist is received through a preset directional antenna, where the preset directional antenna includes two directional antennas arranged back to back at the train consist, both the first current-train topology discovery message and the first another-train topology discovery message include a sender identifier and networking topology information, and the networking topology information includes identification information of train consist nodes in a network.

[0028] It can be understood that the preset directional antenna in this embodiment may be two directional antennas arranged back-to-back at the train consist. That is, each train consist may be provided with the back-to-back directional antennas (that is, preset directional antenna) to send topology discovery message (such as the first current-train topology discovery message) of the current train and receive topology discovery messages (such as the first another-train topology discovery message) sent by other train consists through two opposite communication directions.

[0029] In an embodiment, the specific manner for arranging the preset directional antenna on each train consist in this embodiment may be determined by the designer based on the practical scenarios and user requirements. For example, the preset directional antenna may include back-to-back directional antennas with the communication directions respectively directed toward two ends of the train consist. That is, the communication directions of the two directional antennas arranged back to back of the preset directional antenna may be respectively directed toward two ends of the train consist, so as to broadcast the topology discovery message to the front and rear directions of the train consist. As shown in FIG. 2, the two ends of each train consist may be respectively called direction 1 and direction 2, and the train consist may broadcast the topology discovery message along the direction 1 and direction 2 of the current train through the preset directional antenna, and receive the topology discovery message of another train consist at the same time. The preset directional antenna may include two directional antennas with communication directions respectively directed toward two other opposite directions, which is not limited in the embodiment.

[0030] It should be noted that the first current-train topology discovery message in this step may be a first topology discovery message broadcast outward by the current train consist through the preset directional antenna. The first another-train topology discovery message in this step may be a first topology discovery message sent by another train consist and received by the current train consist through the preset directional antenna. The first topology discovery message may be constructed by each train consist for implementing wireless networking between trains.

[0031] Correspondingly, the specific content of the first current-train topology discovery message and the first another-train topology discovery message in this embodiment, that is, the specific content of the first topology discovery messages described above, may be determined by the designer based on practical scenarios and user requirements. For example, the first current-train topology discovery message and the first another-train topology discovery message may both include a sender identifier, such as an identifier of the train consist that sends the first topology discovery message, and / or an identifier of the directional antenna adopted by the train consist that sends the first topology discovery message. The first current-train topology discovery message and the first another-train topology discovery message may further include networking topology information, that is, the networking topology information is stored by the train consist when constructing the first topology discovery message, so that other train consists that receive the first topology discovery message can update networking topology information stored by themselves and determine the networking state by using the networking topology information.

[0032] The networking topology information in this embodiment may be information used to indicate the topological structure of nodes (that is, the train consist nodes) in the network of the train consists. That is, each train consist may configure and update the stored networking topology information by using the received first topology discovery message (that is, the first another-train topology discovery message).

[0033] Correspondingly, the specific content of the networking topology information in this embodiment may be determined by the designer based on practical scenarios and user requirements. For example, the networking topology information may include the identification information of each of the train consist nodes in the network, such as the identifier of each train consist node in the network or the identifiers of two directional antennas of each train consist node, so as to indicate the number of the train consist nodes in the network. The networking topology information may further include the topological sort order information of the train consist nodes in the network to indicate relative positions of the train consist nodes in the network. For example, in a case that each train consist stores the networking topology information in a form of a topology table, the train consist may broadcast the topology table through the first topology discovery message. The content of the networking topology information is not limited in the embodiment, as long as each train consist can determine the networking state through the networking topology information.

[0034] It should be noted that the networking process, and the data communication after the networking of any one of the train consists is shown as an example in this embodiment. For networking and data communication after the networking of other train consists may be implemented in the same or similar manner as the method provided in this embodiment, which is not limited in this embodiment.

[0035] In an embodiment, in this step, the train consist may send the first current-train topology discovery message and receive the first another-train topology discovery message through the preset directional antenna according to the preset networking message sending period before the network topology converges (that is, the networking is completed). That is, each train consist may periodically construct the first topology discovery message, and broadcast the first topology discovery message along two opposite directions through the preset directional antenna, and receive the first topology discovery message from another train consist.

[0036] Correspondingly, in this embodiment, the specific manner for sending and receiving messages by the train consist through the preset directional antenna, that is, the specific manner of wireless communication between train consists using the preset directional antenna, may be determined by the designer. For example, the wireless communication may be performed in wireless communication manners: WiFi, long term evolution-vehicle to everything (LTE-V2X) or new radio-vehicle to everything (NR-V2X) and the like through the preset directional antenna, to construct a wireless communication system between trains.

[0037] In step S102, a networking state is determined based on the networking topology information in the first another-train topology discovery message.

[0038] It can be understood that in this step, the train consist can determine, based on the networking topology information in the received first topology discovery message (that is, the first another-train topology discovery message) of another train consist, whether the networking is completed between the current train consist and the another train consist, that is, whether the wireless network topology between train consists converges. Therefore, when it is determined that the wireless network topology does not converge, that is, the networking is not completed, step 103 is entered to continue the convergence process of the wireless network topology. When it is determined that the wireless network topology converges, that is, the networking is completed, step 104 is entered to perform data transmission such as backbone data transmission between the current train consist and the target node in the network through the preset directional antenna.

[0039] In an embodiment, the specific manner for determining the networking state by the train consist based on the networking topology information in the first another-train topology discovery message in this step may be determined by the designer based on the practical scenarios and user requirements. For example, the train consist may determine whether the networking topology information in the first another-train topology discovery messages is the same as the current-train networking topology information. If one or more pieces of networking topology information in the first another-train topology discovery message is different from the networking topology information of the current train, it is determined that the networking state is the uncompleted convergence state, and step 103 is entered. If the networking topology information in the first another-train topology discovery messages is the same as the networking topology information of the current train, it is determined that the networking state is the completed convergence state, and step 104 is entered. That is, the train consist compares the networking topology information in the first topology discovery messages (that is, the first another-train topology discovery messages) of other train consists with the networking topology information stored in the current train. In a case that the networking topology information in the first another-train topology discovery messages is the same as the networking topology information of the current train, that is, the all pieces of networking topology information of the train consists are same, it is determined that the wireless network topology between the train consists converges, and each train consist may serve as a node (that is, a train consist node) to form a wireless network (such as a Mesh network, that is, a wireless mesh network).

[0040] For example, in a case the networking topology information in the first topology discovery message only includes the identification information of the train consist nodes in the network, the train consist determines that the networking state is a completed convergence state, in a case that the number of pieces of the identification information in the networking topology information in the first another-train topology discovery message is the same as the number of identifiers of the train consists in the networking topology information stored in current train consist. In a case that the networking topology information in the first topology discovery message includes the identification information and the topological sort order information of the train consist nodes in the network, the train consist determines that the networking state is a completed convergence state, in a case that the number and the sort order of pieces of the identification information in the networking topology information in the first another-train topology discovery message is the same as the number and the sort order of the identifiers of the train consists in the networking topology information stored in the current train consist. For example, in a case that the networking topology information in the first topology discovery message is stored in the form of a topology table shown in Table 1, the train consist determines that the networking state is a completed convergence state when the topology table in the first another-train topology discovery message is the same as the topology table stored in the current train. Table 1: Topology of the wireless networking system shown in FIG. 1.TopologyA(I)->A(II)->B(I)->B(II)->C(II)->C(I)->D(II)->D(I)

[0041] In the above table, A(I) represents an identifier of the directional antenna with a communication direction of the direction 1 at a train consist A.

[0042] In step S103, if the networking state is an uncompleted convergence state, the networking topology information of the current train is updated based on the first another-train topology discovery message, and step S101 is entered.

[0043] It can be understood that in this step, upon determining that the networking is uncompleted, the train consist updates the networking topology information stored in the current train based on the received first topology discovery messages (that is, the first another-train topology discovery messages) sent by other train consists, so as to continue to construct the first current-train topology discovery message using the networking topology information stored in the current train. Step 101 is entered to continue to send the first current-train topology discovery message and receive the first another-train topology discovery message sent by another train consist through the preset directional antenna in a next period, so as to continue the convergence process of the wireless network topology.

[0044] In an embodiment, the specific manner for updating the networking topology information of the current train by the train consist based on the first another-train topology discovery message in this step may be determined by the designer based on the practical scenarios and user requirements. For example, in this step, the train consist may update the networking topology information of the current train based on the sender identifier and the networking topology information in the first another-train topology discovery message and / or a received signal strength and a receiving antenna corresponding to the another train consist. The receiving antenna is any one of the directional antennas. For example, in a case that the networking topology information only includes the identification information of the train consist nodes in the network, the train consist may update the networking topology information of the current train based on the sender identifier and networking topology information in the first another-train topology discovery message. That is, the train consist updates and stores the identification information not stored in the networking topology information of the current train to the networking topology information. In a case that the networking topology information further includes the topological sort order information of the train consist nodes in the network, the train consist may update the networking topology information of the current train based on the sender identifier and networking topology information in the first another-train topology discovery message, the received signal strength corresponding to the another train consist and the receiving antenna of the another train consist.

[0045] For example, the train consist may update the identification information and topological sort order information of the train consist nodes corresponding to other train consists adjacent to the train consist in the networking topology information of the current train, based on the sender identifiers and the received signal strengths and receiving antennas corresponding to other train consists in the first another-train topology discovery messages. The train consist updates the networking topology information based on the networking topology information in the first another-train topology discovery messages, that is, the train consist updates the identification information and corresponding topological sort order information not stored in the networking topology information of the current train. For example, the train consist may update the networking topology information of the current train using the networking topology information in the first another-train topology discovery messages of the other adjacent train consists. As shown in FIG. 1, the current train consist determines a relative position (whether it is along the direction 1 or the direction 2 of the current train consist) between the node for sending the topology discovery message (that is, the first another-train topology discovery message) and the current node through the receiving antenna for receiving the topology discovery message, determines whether the node for sending the message is adjacent to the current node based on the received signal strength of the topology discovery message, fills these information into the topology table, and broadcasts the information with the topology discovery message (that is, the first current-train topology discovery message). After receiving the topology discovery messages of other train consists, each train consist continuously updates its topology table based on the topology tables in the messages, and broadcasts the latest topology table with the topology discovery message until the contents of the topology tables of all train consists are completely consistent, then it is determined that the network topology converges, and the application data message is allowed to be sent. In this case, the sending period of the topology discovery message increases, that is, the sending period of the second topology discovery message (that is, the preset message sending period) may be greater than the sending period of the first topology discovery message (that is, the preset networking message sending period), thus reducing occupancy of wireless resources.

[0046] In step S104, if the networking state is a completed convergence state, data transmission is performed with a target node in the network through the preset directional antenna based on the networking topology information of the current train.

[0047] It can be understood that the target node in this step may be any one of the other train consists in the network that requires to perform data transmission. In this step, upon determining that the networking is completed, the train consist performs data transmission with the target node in the network using the preset directional antenna based on the networking topology information stored in the current train, to implement the backbone data transmission.

[0048] In this step, the specific manner for performing data transmission with the target node in the network by the train consist using the preset directional antenna based on the networking topology information of the current train, may be determined by the designer based on the practical scenarios and user requirements. For example, after determining the target node based on the networking topology information of the current train, the train consist broadcasts the data requires to be sent to the target node (that is, the to-be-sent data) through the preset directional antenna or a directional antenna of the preset directional antenna with a communication direction corresponding to the target node, so that the target node receives the to-be-sent data directly through its preset directional antenna or through forwarding by other train consists, that is, the train consist in the networking and other train consists in addition to the target nodes may forward the to-be-sent data. In order to reduce the data forwarding amount of the train consists in the network, the train consist in this step may also determine a communication path (that is, a target communication path) corresponding to the target node based on the networking topology information of the current train, so as to send the to-be-sent data to the target node via the communication path through the preset directional antenna, and other train consists outside the target communication path do not need to forward the to-be-sent data. This is not limited in the embodiment.

[0049] In an embodiment, after this step, step 101 may be entered to perform networking between train consists after it is detected that a duration of the completed convergence state of the networking reaches a time threshold or a re-networking control instruction is obtained.

[0050] In this embodiment of the present disclosure, the first current-train topology discovery message is sent and the first another-train topology discovery message sent by another train consist is received through the preset directional antenna. Each train consist sends and receives topology discovery messages through the back-to-back directional antennas, and determines the positions of other train consists relative to the current train by using the topology discovery messages received by the back-to-back directional antennas, implementing wireless networking of train consists and increasing the wireless communication distance. Furthermore, data transmitted between nodes can be forwarded by the train consist nodes in the network, thus supporting wireless reconnection of more trains, and improving the reliability of wireless communication between trains.

[0051] Based on the above embodiments, in an embodiment, in order to ensure the reliability of data transmission between a train consist and the target node after the networking is completed, and reduce the data forwarding amount of the train consists, the target communication path between the train consist and the target node is determined by broadcasting the second topology discovery message. Reference is made to FIG. 3, the above step S104 may include steps S201 to S204.

[0052] In step S201, communication routing information of the current train is generated based on the networking topology information of the current train. The communication routing information includes communication paths corresponding to the train consist node of the current train and communication paths corresponding to the train consist nodes of the other train consists in the network and routing metric values corresponding to the communication paths.

[0053] It can be understood that in this step, after determining that the networking state is a completed convergence state, the train consist generates the communication routing information of the current train based on the networking topology information of the current train, so as to determine the target communication path corresponding to the target node by using the communication routing information of the current train.

[0054] In an embodiment, the specific content of the communication routing information of the current train in this step may be determined by the designer based on practical scenarios and user requirements. For example, the communication routing information may include the communication path corresponding to the train consist node (that is, the train consist node of the current train) of the train consist and the communication paths corresponding to other train consist nodes and routing metric values corresponding to the communication paths (for example, the initial routing metric value is set to be a preset routing value). The communication routing information may further include the hop counts corresponding to the communication paths, facilitating the determination of the target communication path. As shown in Table 2 below, the communication routing information may be stored in the form of a routing table. Table 2: Routing table for the train consist A in FIG. 1Number Communication path Hop count Routing metric value 1A---B102A---C103B---C104B---D105C---D206A---B---D207A---C---D20

[0055] In step S202, a second current-train topology discovery message is sent and a second another-train topology discovery message sent by another train consist is received through the preset directional antenna. Both the second current-train topology discovery message and the second another-train topology discovery message include the communication routing information.

[0056] It can be understood that the second current-train topology discovery message in this step may be the second topology discovery message broadcast by the current train consist through its preset directional antenna. The second another-train topology discovery message in this step may be the second topology discovery message sent by another train consist and received by the current train consist through its preset directional antenna. The second topology discovery messages may be constructed by the train consists to implement the configuration update of the communication routing information of the respective train consists. The second topology discovery message in this embodiment may be different from the first topology discovery message in the previous embodiment, or may be the same, which is not limited in the embodiment.

[0057] Correspondingly, the specific contents of the second current-train topology discovery message and the second another-train topology discovery message in this embodiment, that is, the specific contents of the second topology discovery messages described above, may be determined by the designer based on practical scenarios and user requirements. For example, the second current-train topology discovery message and the second another-train topology discovery message may both include communication routing information, so that the current train consist can use the received second topology discovery message (that is, the second another-train topology discovery message) to update the communication routing information stored by the current train consist. The second current-train topology discovery message and the second another-train topology discovery message further include information such as a message sequence number and a CPU load, facilitating calculation of routing metric values.

[0058] In this step, after the network topology converges (that is, the networking is completed), the train consist sends the second current-train topology discovery message according to the preset message sending period and receive the second another-train topology discovery message sent by the another train consist through the preset directional antenna. That is, each train consist periodically constructs a second topology discovery message, broadcasts the second topology discovery message along two opposite directions through the preset directional antenna, and receives the second topology discovery messages of other train consists at the same time.

[0059] In step S203, routing metric values corresponding to the respective communication paths in the communication routing information of the current train are updated based on the second another-train topology discovery message.

[0060] It can be understood that in this step, after determining that the networking is completed, the train consist updates the communication routing information stored in the current train based on the received second topology discovery messages (that is, the second another-train topology discovery messages) sent by other train consists, so as to continue to periodically construct the second current-train topology discovery message by using the communication routing information stored in the current train, and performs the step 202 of sending the second current-train topology discovery message and receiving the second another-train topology discovery message sent by another train consist through the preset directional antenna, so as to continuously update the communication routing information stored in the current train.

[0061] In an embodiment, the specific manner for updating the routing metric values corresponding to the communication paths in the communication routing information of the current train by the train consist based on the second another-train topology discovery message, may be determined by the designer based on the practical scenarios and user requirements. For example, the train consist may update the routing metric values corresponding to the respective single-hop communication paths in the communication routing information of the current train based on the message sequence number, the CPU load and / or the corresponding received signal strength in the second another-train topology discovery message, and update the routing metric values corresponding to the respective multi-hop communication paths in the communication routing information of the current train based on the communication routing information in the second another-train topology discovery message. The communication paths in the communication routing information of the current train includes the single-hop communication paths and the multi-hop communication paths. The single-hop communication path may be a communication path with a hop count of 1. That is, a path for direct communication between the train consist and the target node, such as A---B and A---C shown in Table 2. The multi-hop communication path may be a communication path with a hop count greater than or equal to 2, that is, a communication path between the train consist and the target node through performing routing hop by other train consists, such as A---B---D and A---C---D shown in Table 2.

[0062] Correspondingly, the specific manner for updating the routing metric values corresponding to the single-hop communication paths in the communication routing information of the current train by the train consist based on the message sequence number, the CPU load and / or the corresponding received signal strength in the second another-train topology discovery message, may be determined by the designer. For example, the train consist may update the routing metric values corresponding to the single-hop communication paths in the communication routing information of the current train based on the message sequence number, CPU load and the corresponding received signal strength in the second another-train topology discovery message. For example, the train consist may store the message sequence numbers, CPU loads and received signal strengths obtained by analyzing the second another-train topology discovery messages to the corresponding target storage spaces. The target storage spaces are storage spaces assigned for the other train consists corresponding to the second another-train topology discovery messages (such as the sliding window shown in FIG. 4).

[0063] A received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path are calculated based on a target received signal strength in a current target storage space. A signal strength average value score and a signal strength standard deviation score corresponding to the current single-hop communication path are respectively calculated by S SPM = 0 , SP ¯ < − 130 S SPM = 1.25 ∗ SP ¯ + 162.5 , − 130 ≤ SP ¯ ≤ − 50 S SPM = 100 , SP ¯ > − 50 and S SPT = 0 , δ > 0.6 ∗ SP ¯ S SPT = − 250 δ / SP ¯ + 150 , 0.2 ∗ SP ¯ ≤ δ ≤ 0.6 ∗ SP ¯ S SPT = 100 , δ < 0.2 * SP ¯ where, the current target storage space is any one of the target storage spaces, the current single-hop communication path corresponds to the current target storage space, S SPM represents the signal strength average value score, SP represents the received signal strength average value, S SPT represents the signal strength standard deviation score, and δ represents the received signal strength standard deviation. That is, the signal strength average value represents an average level of the signal strength. As the distance between the current train and a train consist decreases, the communication quality increases, indicating a larger signal strength average value, and the probability of sending data to the train consist is relatively large. For a cross-consist train consist relatively far from the current train, the communication quality is relatively poor, which indicates a relatively small signal strength average value, and the probability of sending data to the train consist is relatively small. Therefore, the received signal strength average value SP in the current target storage space may be calculated first, and the signal strength average value score S SPM is calculated according to the above equation. The signal strength standard deviation represents the stability of the signal. A more stable signal indicates more stable communication. Therefore, the received signal strength standard deviation δ in the current target storage space may be calculated first, and then the signal strength standard deviation score S SPT is calculated according to the above equation.

[0064] A CPU load average value corresponding to the current single-hop communication path is calculated based on a target CPU load in the current target storage space, and a CPU load average value score corresponding to the current single-hop communication path is calculated by S CPU = 0 , CPU ¯ > 80 % S CPU = − 500 3 ∗ CPU ¯ + 400 3 , 20 % ≤ CPU ¯ ≤ 80 % S CPU = 100 , CPU ¯ < 20 % where, S CPU represents the CPU load average value score and CPU represents the CPU load average value. That is, the CPU load average value represents an average level of the current processing capacity of the train consist. A relatively large CPU load average value indicates a relatively large CPU load of the train consist and a relatively poor processing capacity of the train consist, and the probability of sending data to the train consist is relatively small. A relatively small CPU load average value indicates a relatively small CPU load of the train consist and a relatively strong processing capacity of the train consist, and the probability of sending data to the train consist is relatively large. Therefore, the CPU load average value CPU in the current target storage space may be calculated first, and then the CPU load average value score S CPU is calculated according to the above equation.

[0065] A packet reception rate corresponding to the current single-hop communication path is calculated based on a target message sequence number in the current target storage space. A packet reception rate score corresponding to the current single-hop communication path is calculated by: S DPR = 0 , DPR < 65 % S DPR = 1000 3 ∗ DPR − 650 3 , 65 % ≤ DPR ≤ 95 % S DPR = 100 , DPR > 95 % where, S DPR represents the packet reception rate score, and DPR represents the packet reception rate. That is, the packet reception rate represents the packet receiving situation of a communication path, specifically a ratio of the actual number of received packets to the number of to-be-received packets. Based on the records of the message sequence number in the storage space, a case that the message sequence number is not continuous indicates packet loss. The number of to-be-received messages and the number of actual-received messages are counted to calculate the packet reception rate for the communication path of the receiving end. The larger packet reception rate indicates the larger probability of sending data to the train consist, and the smaller packet reception rate indicates the smaller probability of sending data to the train consist. Therefore, the calculated packet reception rate DPR corresponding to the current single-hop communication path may be used as one of evaluation indicators of the communication quality of the wireless communication link, and then the packet reception rate score S DPR is calculated according to the above equation.

[0066] An average message reception period corresponding to the current single-hop communication path is calculated based on a target second another-train topology discovery message in the current target storage space. An average period score corresponding to the current single-hop communication path is calculated by S CYC = 0 , C Y C L E _ A > 6 ∗ CYCLE S CYC = − 25 ∗ C Y C L E _ A CYCLE + 150,2 ∗ CYCLE ≤ C Y C L E _ A ≤ 6 ∗ CYCLE S CYC = 100 , C Y C L E _ A < 2 ∗ CYCLE where S CYC represents the average period score, CYCLE _A represents the average message reception period, and CYCLE represents a preset message sending period. That is, in this step, the average message reception period CYCLE _A in the current target storage space is calculated, and the average period score S CYC is calculated based on the preset message sending period CYCLE according to the above equation.

[0067] The routing metric value corresponding to the current single-hop communication path is calculated by: S = ω SPM S SPM + ω SPT S SPT + ω CPU S CPU + ω DPR S DPR + ω CYC S CYC where s represents the routing metric value, ω SPM , ω SPT , ω CPU , ω DPR and ω CYC respectively represent weighted values of the signal strength average value score, the signal strength standard deviation score, the CPU load average value score, the packet reception rate score and the average period score corresponding to the current single-hop communication path. That is, after the signal strength average value score S SPM , the signal strength standard deviation score S SPT , the CPU load average value score S CPU , the packet reception rate score S DPR and the average period score S CYC corresponding to the current single-hop communication path are calculated, a final score s may be obtained by performing weighted fusion on these scores through the above equation to serve as the routing metric value of the current single-hop communication path, so as to perform weighted calculation on multiple parameter indicators to serve as the basis for routing selection, thus improving the reliability of wireless communication between trains. ω SPM represents a weighted value of the signal strength average value score S SPM , ω SPT represents a weighted value of the signal strength standard deviation score S SPT , ω CPU represents a weighted value of the CPU load average value score S CPU , ω DPR represents a weighted value of the packet reception rate score S DPR , and ω CYC represents a weighted value of the average period score S CYC . The specific values of ω SPM , ω SPT , ω CPU , ω DPR and ω CYC described above may be determined by the designer. For example, the sum of ω SPM , ω SPT , ω CPU , ω DPR and ω CYC may be equal to 1, that is, ω SPM +ω SPT +ω CPU +ω DPR + ω CYC = 1. For example, ω SPM = 0.2, ω SPT = 0.1, ω CPU = 0.2, ω DPR = 0.4, and ω CYC = 0.1.

[0068] Furthermore, before calculating the received signal strength average value and the received signal strength standard deviation corresponding to the current single-hop communication path based on the target received signal strength in the current target storage space, the train consist may further determine whether the current target storage space is fully-stored, where a data storage mode of the current target storage space is first-in-first-out. If the current target storage space is not fully-stored, the routing metric value corresponding to the current single-hop communication path is determined as a preset routing value. If the current target storage space is fully-stored, the step of calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space is performed, to calculate the routing metric value corresponding to the current single-hop communication path.

[0069] Furthermore, before calculating the received signal strength average value and the received signal strength standard deviation corresponding to the current single-hop communication path based on the target received signal strength in the current target storage space, the train consist may further determine whether a duration in which the current target storage space does not update stored data reaches a preset duration, where the preset duration is greater than the preset message sending period. If the preset duration is reached, the routing metric value corresponding to the current single-hop communication path is determined as the preset routing value. If the preset duration is not reached, the step of calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space is performed to calculate the routing metric value corresponding to the current single-hop communication path.

[0070] As shown in FIG. 4, the train consist first determines whether the current target storage space is fully-stored, that is, whether the number of the stored message reaches the length of the sliding window. If the current target storage space is fully-stored, it is determined whether the duration in which the current target storage space does not update stored data reaches the preset duration (such as the seven preset message sending periods in FIG. 4). If the preset duration is not reached, the routing metric value of the current single-hop communication path corresponding to the current target storage space is calculated. If the current target storage space is not fully-stored or the preset duration is reached, it is determined that the routing metric value corresponding to the current single-hop communication path is the preset routing value (such as 0).

[0071] Correspondingly, the specific manner for updating routing metric values corresponding to the respective multi-hop communication paths in the communication routing information of the current train by the train consist based on the communication routing information in the second another-train topology discovery message, may be determined by the designer. For example, the train consist may add the routing metric values corresponding to the single-hop communication paths in the communication routing information of the current train and the routing metric values of the corresponding communication paths in the communication routing information in the second another-train topology discovery message to obtain the routing metric values corresponding to the multi-hop communication paths. As shown in FIG. 1, if the train consist A of the current train cannot communicate with the train consist D of the another train in one hop (that is, the wireless communication between the two nodes is directly communication-capable without performing relay forwarding by other nodes), and another train consist B or C is required to perform relay forward, then the routing metric value between the train consists A and D is represented by S AD =S AB +S BD , or S AD =S AC +S CD . That is, the train consist A of the current train may add the routing metric value S AB corresponding to the single-hop communication path A---B in the communication routing information of the current train to the routing metric value S BD corresponding to the communication path B---D in the communication routing information of the train consist B of the another train, to obtain the routing metric value S AD corresponding to the multi-hop communication path A---B---D.

[0072] In step S204, a target communication path corresponding to the target node is determined based on the communication routing information of the current train, and the to-be-sent data is sent to the target node via the target communication path. The target communication path is any one of the communication paths.

[0073] It can be understood that in this step, the train consist may select a communication path as the target communication path from the communication paths between the current train consist and the target node based on the communication routing information of the current train, so as to send the to-be-sent data to the target node via the target communication path through the preset directional antenna.

[0074] In an embodiment, the specific manner for determining the target communication path corresponding to the target node based on the communication routing information of the current train in this step may be determined by the designer. For example, the train consist may determine a preferred communication path with a minimum hop count and a routing metric value unequal to the preset routing value (such as 0) among the communication paths between the current train and the target node based on the communication routing information of the current train. The train consist may determine a preferred communication path with a maximum routing metric value among the preferred communication paths as the target communication path based on the communication routing information of the current train. That is, in a case that the hop counts of the communication paths between the current train consist to the target node are inconsistent, the communication path with less hop counts may be preferably selected. In a case that the hop counts are consistent, the communication path (that is, the preferred communication path) with a relatively large metric value is determined as the target communication path.

[0075] In an embodiment, when sending the to-be-sent data to the target node via the target communication path through the preset directional antenna, the train consist sends the to-be-sent data to the target node via the target communication path through the directional antenna of the preset directional antenna in the communication direction corresponding to the target node, avoiding invalid data transmission by the directional antenna in another communication direction.

[0076] In the embodiment of the present disclosure, data transmission is performed between the train consists in the network in manners of Mesh networking and multi-hop routing, without adding infrastructures such as a base station or a ground server. The deployment cost is relatively low. The problem of short transmission distance and small coverage range of WiFi wireless communication technology can be solved. In addition, since multiple communication paths are provided between the train consist and the target node, the target communication path may be flexibly selected according to the communication routing information, ensuring the availability and reliability of the network.

[0077] Corresponding to the method embodiments described above, an apparatus for networking communication between trains is provided in embodiments of the present disclosure. The apparatus for networking communication between trains described below and the method for networking communication between trains described above can be referenced to each other.

[0078] Reference is made to FIG. 5, FIG. 5 is a structural block diagram of an apparatus for networking communication between trains according to an embodiment of the present disclosure. The apparatus is applied to train consists, and includes a topology networking module 10, a networking determination module 20, a networking updating module 30 and a data transmitting module 40.

[0079] The topology networking module 10 is configured to send a first current-train topology discovery message and receive a first another-train topology discovery message sent by another train consist through a preset directional antenna, where the preset directional antenna includes two antennas arranged back to back at the train consist, the first current-train topology discovery message and the first another-train topology discovery message includes a sender identifier and networking topology information, and the networking topology information includes identification information of train consist nodes in a network.

[0080] The networking determination module 20 is configured to determine a networking state based on networking topology information in the first another-train topology discovery message.

[0081] The networking updating module 30 is configured to update the networking topology information of the current train based on the first another-train topology discovery message if the networking state is an uncompleted convergence state, and send the first current-train topology discovery message and receive the first another-train topology discovery message sent by the another train consist via the preset directional antenna.

[0082] The data transmitting module 40 is configured to perform data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train, if the networking state is a completed convergence state.

[0083] In an embodiment, the networking updating module 30 is configured to update the networking topology information of the current train based on the sender identifier and the networking topology information of the first another-train topology discovery message and / or a received signal strength corresponding to the another train consist and receiving antennas of the another train consist. The receiving antenna is any one of the directional antennas.

[0084] In an embodiment, the networking topology information further includes topological sort order information of the train consist nodes in the network.

[0085] In an embodiment, the networking updating module 30 may include an adjacent updating sub-module and a topology updating sub-module.

[0086] The adjacent updating sub-module is configured to update identification information and topological sort order information of the train consist nodes corresponding to train consists adjacent to the train consist in the networking topology information of the current train, based on the sender identifier in the first another-train topology discovery message and the received signal strength corresponding to the another train consist and the receiving antenna of the another train consist.

[0087] The topology updating sub-module is configured to update the networking topology information of the current train based on the networking topology information in the first another-train topology discovery message.

[0088] In an embodiment, the networking determination module 20 is configured to determine whether the networking topology information in the first another-train topology discovery messages is the same as the networking topology information of the current train. If one or more pieces of networking topology information in the first another-train topology discovery messages are different from the networking topology information of the current train, it is determined that the networking state is the uncompleted convergence state, the networking determination module 20 sends a starting signal to the networking updating module 30. If the networking topology information in the first another-train topology discovery messages is the same as the networking topology information of the current train, it is determined that the networking state is the completed convergence state, the networking determination module 20 sends a starting signal to the data transmitting module 40.

[0089] In an embodiment, the preset directional antenna includes the directional antennas arranged back to back at the train consist, and communication directions of the directional antennas are respectively directed toward two ends of the train consist.

[0090] In an embodiment, the sender identifier includes an identifier of the directional antenna adopted by the sender, and the identification information of the train consist nodes in the network includes identifiers of the two directional antennas of each of the train consist nodes.

[0091] In an embodiment, the data transmitting module 40 may include a routing generating sub-module, a topology routing sub-module, a routing updating sub-module and a routing transmitting sub-module.

[0092] The routing generating sub-module is configured to generate communication routing information of the current train based on the networking topology information of the current train. The communication routing information includes communication paths respectively corresponding to the train consist node of the current train and the train consist nodes of the other train consists in the network and routing metric values corresponding to the communication paths.

[0093] The topology routing sub-module is configured to send a second current-train topology discovery message and receiving a second another-train topology discovery message sent by the another train consist through the preset directional antenna. The second current-train topology discovery message and the second another-train topology discovery message include the communication routing information.

[0094] The routing updating sub-module is configured to update the routing metric values of the communication paths in the communication routing information of the current train, based on the second another-train topology discovery message.

[0095] The routing transmitting sub-module is configured to determine a target communication path corresponding to the target node based on the communication routing information of the current train, and send to-be-sent data to the target node via the target communication path. The target communication path is any one of the communication paths.

[0096] In an embodiment, the routing updating sub-module may include a single-hop updating unit and a multi-hop updating unit.

[0097] The single-hop updating unit is configured to update the routing metric values of single-hop communication paths in the communication routing information of the current train, based on a message sequence number, a CPU load and / or a received signal strength corresponding to the another train consist in the second another-train topology discovery message.

[0098] The multi-hop updating unit is configured to update the routing metric values corresponding to multi-hop communication paths in the communication routing information of the current train based on the communication routing information in the second another-train topology discovery message. The communication paths in the communication routing information of the current train includes the single-hop communication paths and the multi-hop communication paths.

[0099] In an embodiment, the single-hop updating unit may include an analyzing storage sub-unit, a strength sub-unit, a CPU load sub-unit, a packet reception rate sub-unit, a period sub-unit and a weighting sub-unit.

[0100] The analyzing storage sub-unit is configured to store the message sequence numbers, the CPU loads and the received signal strengths that are obtained by analyzing the second another-train topology discovery messages to corresponding target storage spaces. The target storage spaces are storage spaces assigned for the other train consists corresponding to the second another-train topology discovery messages.

[0101] The strength sub-unit is configured to calculate a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on the target received signal strength in the current target storage space, and determine a signal strength average value score and a signal strength standard deviation score corresponding to the current single-hop communication path by S SPM = 0 , SP ¯ < − 130 S SPM = 1.25 * SP ¯ + 162.5 , − 130 ≤ SP ¯ ≤ − 50 S SPM = 100 , SP ¯ > − 50 and S SPT = 0 , δ > 0.6 * SP ¯ S SPT = − 250 δ / SP ¯ + 150 , 0.2 * SP ¯ ≤ δ ≤ 0.6 * SP ¯ S SPT = 100 ,   δ < 0.2 * SP ¯ where the current target storage space is any one of the target storage spaces, the current single-hop communication path corresponds to the current target storage space, S SPM represents the signal strength average value score, SP represents the received signal strength average value, S SPT represents the signal strength standard deviation score, and δ represents the received signal strength standard deviation.

[0102] The CPU load sub-unit is configured to calculate a CPU load average value corresponding to the current single-hop communication path based on a target CPU load in the current target storage space, and determine a CPU load average value score corresponding to the current single-hop communication path by S CPU = 0 , CPU ¯ > 80 % S CPU = − 500 3 * CPU ¯ + 400 3 , 20 % ≤ CPU ¯ ≤ 80 % S CPU = 100 , CPU ¯ < 20 % where S CPU represents the CPU load average value score and CPU represents the CPU load average value.

[0103] The packet reception rate sub-unit is configured to calculate a packet reception rate corresponding to the current single-hop communication path based on a target message sequence number in the current target storage space, and determine a packet reception rate score corresponding to the current single-hop communication path by: S DPR = 0 , DPR < 65 % S DPR = 1000 3 ∗ DPR − 650 3 , 65 % ≤ DPR ≤ 95 % S DPR = 100 ,   DPR > 95 % where S DPR represents the packet reception rate score, and DPR represents the packet reception rate.

[0104] The period sub-unit is configured to calculate an average message reception period corresponding to the current single-hop communication path based on a target second another-train topology discovery message in the current target storage space, and determine an average period score corresponding to the current single-hop communication path by S CYC = 0 , CYCLE _ A > 6 ∗ CYCLE S CYC = − 25 ∗ CYCLE _ A CYCLE + 150,2 ∗ CYCLE ≤ CYCLE _ A ≤ 6 ∗ CYCLE S CYC = 100 , CYCLE _ A < 2 ∗ CYCLE where S CYC represents the average period score, CYCLE _A represents the average message reception period, and CYCLE represents a preset message sending period.

[0105] The weighting sub-unit is configured to calculate the routing metric value corresponding to the current single-hop communication path by: S = ω SPM S SPM + ω SPT S SPT + ω CPU S CPU + ω DPR S DPR + ω CYC S CYC where s represents the routing metric value, ω SPM , ω SPT , ω CPU , ω DPR and ω CYC respectively represent weighted values of the signal strength average value score, the signal strength standard deviation score, the CPU load average score, the packet reception rate score and the average period score corresponding to the current single-hop communication path.

[0106] In an embodiment, the single-hop updating unit may further include a first unit sub-unit and a first determination sub-unit.

[0107] The first unit sub-unit is configured to determine whether the current target storage space is fully-stored. A data storage mode of the current target storage space is first-in-first-out. If the current target storage space is fully-stored, the first unit sub-unit sends a starting signal to the strength sub-unit.

[0108] The first determination sub-unit is configured to determine the routing metric value corresponding to the current single-hop communication path as a preset routing value if the current target storage space is not fully-stored.

[0109] In an embodiment, the single-hop updating unit further includes a second unit sub-unit and a second determination sub-unit.

[0110] The second unit sub-unit is configured to determine whether a duration in which the current target storage space does not update stored data reaches a preset duration. If the preset duration is not reached, the second unit sub-unit sends a starting signal to the strength sub-unit. The preset duration is greater than the preset message sending period.

[0111] The second determination sub-unit is configured to determine the routing metric value corresponding to the current single-hop communication path as the preset routing value, if the preset period is reached.

[0112] In an embodiment, the routing transmitting sub-module includes an initial selection sub-module and a final selection sub-module.

[0113] The initial selection sub-module is configured to determine a preferred communication path with a minimum hop count and a routing metric value unequal to the preset routing value among the communication paths between the current train and the target node based on the communication routing information of the current train.

[0114] The final selection sub-module is configured to determine a preferred communication path with a maximum routing metric value among the preferred communication paths as the target communication path based on the communication routing information of the current train.

[0115] In this embodiment according to the present disclosure, the first current-train topology discovery message is sent and the first another-train topology discovery message sent by another train consist is received by the topology networking module 10 through the preset directional antenna. Each train consist sends and receives topology discovery messages through the back-to-back directional antennas, and determines the positions of other train consists relative to the current train by using the topology discovery messages received by the back-to-back directional antennas, thereby implementing wireless networking of the train consists and increasing the distance of the wireless communication. Furthermore, the data transmitted between nodes is forwarded by the train consist nodes in the network, thus supporting wireless reconnection of more trains, and improving the reliability of wireless communication between trains.

[0116] Corresponding to the above method embodiments, a train consist is provided according to an embodiment of the present disclosure, and the train consist described below and the method for networking communication between trains described above can be referred to each other.

[0117] A train consist, includes: a memory, storing a computer program; and a processor, configured to implement steps of the method for networking communication between trains provided according to the method embodiments described above when performing the computer program.

[0118] In this embodiment, the train consist may be provided with a preset directional antenna, and the preset directional antenna includes two directional antennas arranged back to back.

[0119] Corresponding to the above method embodiment, in an embodiment of the present disclosure, a readable storage medium is further provided. The readable storage medium described below and the method for networking communication between trains described above may be referred to each other.

[0120] A readable storage medium storing a computer program. The computer program, when being executed by a processor, causes the processor to perform the steps of the method for networking communication between trains provided according to the above method embodiments.

[0121] The readable storage medium may be a readable storage media storing program codes, such as a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disc or an optical disc.

[0122] The embodiments in the specification are described in a progressive manner. Each of the embodiments mainly focuses on differences from other embodiments, and references can be made to each other for the same or similar parts among the embodiments. The apparatus, the train consist and the readable storage medium disclosed in the embodiments correspond to the method disclosed in the embodiment, and thus the description thereof is simple, and the related description may be referred to the description of the method.

[0123] The method and apparatus for networking communication between trains, and train consist provided in the present disclosure are described in detail above. The principle and implementation of the present disclosure are illustrated by using specific embodiments herein. The above descriptions of the embodiments are only used to facilitate understanding of the method and the core idea of the present disclosure. It should be noted that, various improvements and modifications may be made by those skilled in the art to the present disclosure without departing from the principle of the present disclosure, and these improvements and modifications also fall within the protection scope of the claims of the present disclosure.

Examples

Embodiment Construction

[0025]In order to make the objective, the technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure are described below in conjunction with the drawings in the embodiments of the present disclosure. Apparently, the embodiments described below are only some embodiments of the present disclosure, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the present disclosure without any creative work fall within the protection scope of the present disclosure.

[0026]Reference is made to FIG. 1, which is a flowchart of a method for networking communication between trains according to an embodiment of the present disclosure. The method is applied to train consists, and may include steps S101 to S104.

[0027]In step S101, a first current-train topology discovery message is sent and a first another-train topology discovery messag...

FIELD

[0001] The present disclosure relates to the field of wireless backbone network communications for rail transit, and in particular to a method and an apparatus for networking communication between trains, and a train consist.BACKGROUND

[0002] A train communication network (TCN) may include two stages of network architectures, i.e., a train backbone and a consist network. The train backbone is used for reconnection between consists, to achieve dynamic train marshaling and unmarshaling, train-level control and diagnosis functions.

[0003] At present, the train backbone mainly adopts a bus type network and an Ethernet network. Both the bus type network and the Ethernet network are technologies based on physical wires. In a case that the train is to perform dynamic marshaling or unmarshaling, train backbone nodes are physically connected and disconnected with each other at connection points. Multiple times of plugging and unplugging will increase the wear of the connection points, thus affecting communication quality of the train backbone. Based on the above, a new train backbone, wireless train backbone (WLTB) emerged. Wireless reconnection and backbone data transmission are implemented through a wireless technology, effectively alleviate susceptibility of wear and poor contact of physical wires.

[0004] In the conventional technology, the railway wireless reconnection system includes a long-distance reconnection and a short-distance reconnection. The long-distance wireless reconnection system is mainly based on cellular networks (such as GSM-R and LTE-M) and radio stations. The short-distance wireless reconnection system is mainly based on a WiFi technology. GSM-R (a comprehensive dedicated digital mobile communication system developed for railway communication) and LTE-M (a mobile communication system developed for meeting requirements of the Internet of Things or machine-to-machine communication applications) technologies are implemented in a full-duplex mode without limit of transmission distance and with a wide transmission bandwidth. This may cause a high communication cost for participation of communication base stations and network servers in networking. The radio station technology is implemented in a half-duplex communication mode, and the wireless train backbone node (WLTBN) is to support a multi-hop relay communication mode to ensure communication from a source node to a destination node. In the WiFi wireless communication technology, a wireless access point is provided for communication, which provides a wide transmission bandwidth. However, the WiFi wireless communication technology provides a short transmission distance, a small coverage range and a low reliability.

[0005] Therefore, attention is drawn to how to address the issues of small coverage range, low reliability and high communication cost in the conventional wireless reconnection system and implement effective, reliable and low-cost transmission of train backbone data.SUMMARY

[0006] The object of the present disclosure is to provide a method and an apparatus for networking communication between trains, and a train consist, so as to implement the effective, reliable and low-cost transmission of the train backbone data.

[0007] In order to solve the above technical problem, a method for networking communication between trains is provided according to the present disclosure. The method is applied to train consists and includes: sending a first current-train topology discovery message and receiving a first another-train topology discovery message sent by another train consist through a preset directional antenna, where both the first current-train topology discovery message and the first another-train topology discovery message include a sender identifier and networking topology information, and the networking topology information includes identification information of train consist nodes in a network; determining a networking state based on the networking topology information in the first another-train topology discovery message; updating the networking topology information of the current train based on the first another-train topology discovery message, and performing the process of sending the first current-train topology discovery message and receiving the first another-train topology discovery message sent by the another train consist through the preset directional antenna, if the networking state is an uncompleted convergence state; and performing data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train, if the networking state is a completed convergence state, where the preset directional antenna includes two directional antennas arranged back to back at each of the train consists.

[0008] In an embodiment, the updating the networking topology information of the current train based on the first another-train topology discovery message includes: updating the networking topology information of the current train based on the sender identifier and the networking topology information in the first another-train topology discovery message and / or a received signal strength corresponding to the another train consist and a receiving antenna of the another train consist, where the receiving antenna is any one of the directional antennas.

[0009] In an embodiment, the networking topology information further includes topological sort order information of the train consist nodes in the network.

[0010] In an embodiment, the updating the networking topology information of the current train based on the sender identifier and the networking topology information in the first another-train topology discovery message and / or a received signal strength corresponding to the another train consist and a receiving antenna of the another train consist includes: updating identification information and topological sort order information of the train consist nodes corresponding to train consists adjacent to the current train in the networking topology information of the current train, based on the sender identifier in the first another-train topology discovery message and the received signal strength corresponding to the another train consist and the receiving antenna of the another train consist; and updating the networking topology information of the current train based on the networking topology information in the first another-train topology discovery message.

[0011] In an embodiment, the determining a networking state based on the networking topology information in the first another-train topology discovery message includes: determining whether the networking topology information in the first another-train topology discovery messages is the same as the networking topology information of the current train; determining that the networking state is the uncompleted convergence state if negative; and determining that the networking state is the completed convergence state if positive.

[0012] In an embodiment, the preset directional antenna includes the directional antennas arranged back to back at the train consist, and communication directions of the directional antennas are respectively directed toward two ends of the train consist.

[0013] In an embodiment, the sender identifier includes an identifier of the directional antenna adopted by a sender, and the identification information of the train consist nodes in the network includes identifiers of the two directional antennas of each of the train consist nodes.

[0014] In an embodiment, the performing data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train includes: generating communication routing information of the current train based on the networking topology information of the current train, where the communication routing information includes communication paths respectively corresponding to the train consist node of the current train and the other train consist nodes in the network and routing metric values corresponding to the communication paths; sending a second current-train topology discovery message and receiving a second another-train topology discovery message sent by the another train consist through the preset directional antenna, where both the second current-train topology discovery message and the second another-train topology discovery message include the communication routing information; updating the routing metric values corresponding to the communication paths in the communication routing information of the current train, based on the second another-train topology discovery message; and determining a target communication path corresponding to the target node based on the communication routing information of the current train, and sending to-be-sent data to the target node via the target communication path, where the target communication path is any one of the communication paths.

[0015] In an embodiment, the updating the routing metric values corresponding to the communication paths in the communication routing information of the current train, based on the second another-train topology discovery message includes: updating the routing metric values corresponding to single-hop communication paths in the communication routing information of the current train, based on a message sequence number, a CPU load and / or a received signal strength corresponding to the anther train consist in the second another-train topology discovery message; and updating the routing metric values corresponding to multi-hop communication paths in the communication routing information of the current train, based on the communication routing information in the second another-train topology discovery message, where the communication paths in the communication routing information of the current train include the single-hop communication paths and the multi-hop communication paths.

[0016] In an embodiment, the updating the routing metric values corresponding to single-hop communication paths in the communication routing information of the current train, based on a message sequence number, a CPU load and / or a received signal strength corresponding to the another train consist in the second another-train topology discovery message includes: storing the message sequence number, the CPU load and the received signal strength that are obtained by analyzing the second another-train topology discovery messages to corresponding target storage spaces, where the target storage spaces are storage spaces assigned for the other train consists corresponding to the second another-train topology discovery messages; calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space, and determining a signal strength average value score and a signal strength standard deviation score corresponding to the current single-hop communication path by S SPM = 0 , SP ¯ < − 130 S SPM = 1.25 ∗ SP ¯ + 162.5 , − 130 ≤ SP ¯ ≤ − 50 S SPM = 100 , SP ¯ > − 50 and S SPT = 0 , δ > 0.6 ∗ SP ¯ S SPT = − 250 δ / SP ¯ + 150 , 0.2 ∗ SP ¯ ≤ δ ≤ 0.6 ∗ SP ¯ S SPT = 100 , δ < 0.2 * SP ¯ where the current target storage space is any one of the target storage spaces, the current single-hop communication path corresponds to the current target storage space, S SPM represents the signal strength average value score, SP represents the received signal strength average value, S SPT represents the signal strength standard deviation score, and δ represents the received signal strength standard deviation; calculating a CPU load average value corresponding to the current single-hop communication path based on a target CPU load in the current target storage space, and determining a CPU load average value score corresponding to the current single-hop communication path by S CPU = 0 , CPU ¯ > 80 % S CPU = − 500 3 ∗ CPU ¯ + 400 3 , 20 % ≤ CPU ¯ ≤ 80 % S CPU = 100 , CPU ¯ < 20 % where S CPU represents the CPU load average value score and CPU represents the CPU load average value; calculating a packet reception rate corresponding to the current single-hop communication path based on a target message sequence number in the current target storage space, and determining a packet reception rate score corresponding to the current single-hop communication path by S DPR = 0 , DPR < 65 % S DPR = 1000 3 ∗ DPR − 650 3 , 65 % ≤ DPR ≤ 95 % S DPR = 100 , DPR > 95 % where S DPR represents the packet reception rate score, and DPR represents the packet reception rate; calculating an average message reception period corresponding to the current single-hop communication path based on a target second another-train topology discovery message in the current target storage space, and determining an average period score corresponding to the current single-hop communication path by S CYC = 0 , CYCLE _ A > 6 ∗ CYCLE S CYC = − 25 ∗ CYCLE _ A CYCLE + 150,2 ∗ CYCLE ≤ CYCLE _ A ≤ 6 ∗ CYCLE S CYC = 100 , CYCLE _ A < 2 ∗ CYCLE where S CYC represents the average period score, CYCLE _A represents the average message reception period, and CYCLE represents a preset message sending period; and calculating the routing metric value corresponding to the current single-hop communication path by S = ω SPM S SPM + ω SPT S SPT + ω CPU S CPU + ω DPR S DPR + ω CYC S CYC where S represents the routing metric value, ω SPM , ω SPT , ω CPU , ω DPR and ω CYC respectively represent weighted values of the signal strength average value score, the signal strength standard deviation score, the CPU load average value score, the packet reception rate score and the average period score corresponding to the current single-hop communication path.

[0017] In an embodiment, before the calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space, the method for networking communication between trains further includes: determining whether the current target storage space is fully-stored, where a data storage mode of the current target storage space is first-in-first-out; determining the routing metric value corresponding to the current single-hop communication path as a preset routing value if the current target storage space is not fully-stored; and performing the step of calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space if the current target storage space is fully-stored.

[0018] In an embodiment, before the calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space, the method for networking communication between trains further includes: determining whether a duration in which the current target storage space does not update stored data reaches a preset duration, where the preset duration is greater than the preset message sending period; determining the routing metric value corresponding to the current single-hop communication path as the preset routing value, if the preset duration is reached; and performing the step of calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space, if the preset duration is not reached.

[0019] In an embodiment, the determining a target communication path corresponding to the target node based on the communication routing information of the current train includes: determining a preferred communication path with a minimum hop count and a routing metric value unequal to the preset routing value among the communication paths between the current train and the target node based on the communication routing information of the current train; and determining a preferred communication path with a maximum routing metric value among the preferred communication path as the target communication path based on the communication routing information of the current train.

[0020] An apparatus for networking communication between trains is further provided according to the present disclosure, where the apparatus is applied to train consists and includes: a topology networking module, configured to send a first current-train topology discovery message and receive a first another-train topology discovery message sent by another train consist through a preset directional antenna, where both the first current-train topology discovery message and the first another-train topology discovery message include a sender identifier and networking topology information, and the networking topology information includes identification information of train consist nodes in a network; a networking determination module, configured to determine a networking state based on the networking topology information in the first another-train topology discovery message; a networking updating module, configured to update the networking topology information of the current train based on the first another-train topology discovery message, and perform the process of sending the first current-train topology discovery message and receiving the first another-train topology discovery message sent by the another train consist through the preset directional antenna, if the networking state is an uncompleted convergence state; and a data transmitting module, configured to perform data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train, if the networking state is a completed convergence state, where the preset directional antenna includes two directional antennas arranged back to back at each of the train consists.

[0021] In addition, a train consist is provided according to the present disclosure, including: a memory, storing a computer program; and a processor, configured to implement the method for networking communication between trains according the above description when executing the computer program.

[0022] A method for networking communication between trains is provided according to the present disclosure, applied to train consists. The method includes: sending a first current-train topology discovery message and receiving a first another-train topology discovery message sent by another train consist through a preset directional antenna, where the preset directional antenna includes two directional antennas arranged back to back at the train consist, both the first current-train topology discovery message and the first another-train topology discovery message include a sender identifier and networking topology information, and the networking topology information includes identification information of train consist nodes in a network; determining a networking state based on the networking topology information in the first another-train topology discovery message; updating the networking topology information of the current train based on the first another-train topology discovery message, and performing the process of sending the first current-train topology discovery message and receiving the first another-train topology discovery message sent by the another train consist through the preset directional antenna, if the networking state is an uncompleted convergence state; and performing data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train, if the networking state is a completed convergence state.

[0023] It can be seen that, according to the present disclosure, the first current-train topology discovery message is sent and the first another-train topology discovery message sent by another train consist is received using the preset directional antenna. Each train consist sends and receives topology discovery messages through the back-to-back directional antennas, and determines the positions of other train consists relative to the current train by using the topology discovery messages received by the back-to-back directional antennas, thereby implementing wireless networking of the train consists and increasing the distance of the wireless communication. Furthermore, data transmitted between nodes can be forwarded by the train consist nodes in the network, thus supporting wireless reconnection of more trains, and improving the reliability of wireless communication between trains. In addition, an apparatus for networking communication between trains, and a train consist are further provided according to the present disclosure, which have same beneficial effects as mentioned above.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate technical solutions in embodiments of the present disclosure or in the conventional technology, the drawings to be used in the description of the embodiments or the conventional technology are briefly described below. Apparently, the drawings in the following description show only embodiments of the present disclosure, and other drawings may be obtained by those skilled in the art from the drawings without any creative work. FIG. 1 is a flowchart of a method for networking communication between trains according to an embodiment of the present disclosure; FIG. 2 is a schematic diagram of a wireless networking system of a method for networking communication between trains according to another embodiment of the present disclosure; FIG. 3 is a flowchart of a routing communication process after networking in the method for networking communication between trains according to another embodiment of the present disclosure; FIG. 4 is a flowchart of calculation of a routing metric value of a method for networking communication between trains according to another embodiment of the present disclosure; and FIG. 5 is a structural block diagram of an apparatus for networking communication between trains according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] In order to make the objective, the technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure are described below in conjunction with the drawings in the embodiments of the present disclosure. Apparently, the embodiments described below are only some embodiments of the present disclosure, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the present disclosure without any creative work fall within the protection scope of the present disclosure.

[0026] Reference is made to FIG. 1, which is a flowchart of a method for networking communication between trains according to an embodiment of the present disclosure. The method is applied to train consists, and may include steps S101 to S104.

[0027] In step S101, a first current-train topology discovery message is sent and a first another-train topology discovery message sent by another train consist is received through a preset directional antenna, where the preset directional antenna includes two directional antennas arranged back to back at the train consist, both the first current-train topology discovery message and the first another-train topology discovery message include a sender identifier and networking topology information, and the networking topology information includes identification information of train consist nodes in a network.

[0028] It can be understood that the preset directional antenna in this embodiment may be two directional antennas arranged back-to-back at the train consist. That is, each train consist may be provided with the back-to-back directional antennas (that is, preset directional antenna) to send topology discovery message (such as the first current-train topology discovery message) of the current train and receive topology discovery messages (such as the first another-train topology discovery message) sent by other train consists through two opposite communication directions.

[0029] In an embodiment, the specific manner for arranging the preset directional antenna on each train consist in this embodiment may be determined by the designer based on the practical scenarios and user requirements. For example, the preset directional antenna may include back-to-back directional antennas with the communication directions respectively directed toward two ends of the train consist. That is, the communication directions of the two directional antennas arranged back to back of the preset directional antenna may be respectively directed toward two ends of the train consist, so as to broadcast the topology discovery message to the front and rear directions of the train consist. As shown in FIG. 2, the two ends of each train consist may be respectively called direction 1 and direction 2, and the train consist may broadcast the topology discovery message along the direction 1 and direction 2 of the current train through the preset directional antenna, and receive the topology discovery message of another train consist at the same time. The preset directional antenna may include two directional antennas with communication directions respectively directed toward two other opposite directions, which is not limited in the embodiment.

[0030] It should be noted that the first current-train topology discovery message in this step may be a first topology discovery message broadcast outward by the current train consist through the preset directional antenna. The first another-train topology discovery message in this step may be a first topology discovery message sent by another train consist and received by the current train consist through the preset directional antenna. The first topology discovery message may be constructed by each train consist for implementing wireless networking between trains.

[0031] Correspondingly, the specific content of the first current-train topology discovery message and the first another-train topology discovery message in this embodiment, that is, the specific content of the first topology discovery messages described above, may be determined by the designer based on practical scenarios and user requirements. For example, the first current-train topology discovery message and the first another-train topology discovery message may both include a sender identifier, such as an identifier of the train consist that sends the first topology discovery message, and / or an identifier of the directional antenna adopted by the train consist that sends the first topology discovery message. The first current-train topology discovery message and the first another-train topology discovery message may further include networking topology information, that is, the networking topology information is stored by the train consist when constructing the first topology discovery message, so that other train consists that receive the first topology discovery message can update networking topology information stored by themselves and determine the networking state by using the networking topology information.

[0032] The networking topology information in this embodiment may be information used to indicate the topological structure of nodes (that is, the train consist nodes) in the network of the train consists. That is, each train consist may configure and update the stored networking topology information by using the received first topology discovery message (that is, the first another-train topology discovery message).

[0033] Correspondingly, the specific content of the networking topology information in this embodiment may be determined by the designer based on practical scenarios and user requirements. For example, the networking topology information may include the identification information of each of the train consist nodes in the network, such as the identifier of each train consist node in the network or the identifiers of two directional antennas of each train consist node, so as to indicate the number of the train consist nodes in the network. The networking topology information may further include the topological sort order information of the train consist nodes in the network to indicate relative positions of the train consist nodes in the network. For example, in a case that each train consist stores the networking topology information in a form of a topology table, the train consist may broadcast the topology table through the first topology discovery message. The content of the networking topology information is not limited in the embodiment, as long as each train consist can determine the networking state through the networking topology information.

[0034] It should be noted that the networking process, and the data communication after the networking of any one of the train consists is shown as an example in this embodiment. For networking and data communication after the networking of other train consists may be implemented in the same or similar manner as the method provided in this embodiment, which is not limited in this embodiment.

[0035] In an embodiment, in this step, the train consist may send the first current-train topology discovery message and receive the first another-train topology discovery message through the preset directional antenna according to the preset networking message sending period before the network topology converges (that is, the networking is completed). That is, each train consist may periodically construct the first topology discovery message, and broadcast the first topology discovery message along two opposite directions through the preset directional antenna, and receive the first topology discovery message from another train consist.

[0036] Correspondingly, in this embodiment, the specific manner for sending and receiving messages by the train consist through the preset directional antenna, that is, the specific manner of wireless communication between train consists using the preset directional antenna, may be determined by the designer. For example, the wireless communication may be performed in wireless communication manners: WiFi, long term evolution-vehicle to everything (LTE-V2X) or new radio-vehicle to everything (NR-V2X) and the like through the preset directional antenna, to construct a wireless communication system between trains.

[0037] In step S102, a networking state is determined based on the networking topology information in the first another-train topology discovery message.

[0038] It can be understood that in this step, the train consist can determine, based on the networking topology information in the received first topology discovery message (that is, the first another-train topology discovery message) of another train consist, whether the networking is completed between the current train consist and the another train consist, that is, whether the wireless network topology between train consists converges. Therefore, when it is determined that the wireless network topology does not converge, that is, the networking is not completed, step 103 is entered to continue the convergence process of the wireless network topology. When it is determined that the wireless network topology converges, that is, the networking is completed, step 104 is entered to perform data transmission such as backbone data transmission between the current train consist and the target node in the network through the preset directional antenna.

[0039] In an embodiment, the specific manner for determining the networking state by the train consist based on the networking topology information in the first another-train topology discovery message in this step may be determined by the designer based on the practical scenarios and user requirements. For example, the train consist may determine whether the networking topology information in the first another-train topology discovery messages is the same as the current-train networking topology information. If one or more pieces of networking topology information in the first another-train topology discovery message is different from the networking topology information of the current train, it is determined that the networking state is the uncompleted convergence state, and step 103 is entered. If the networking topology information in the first another-train topology discovery messages is the same as the networking topology information of the current train, it is determined that the networking state is the completed convergence state, and step 104 is entered. That is, the train consist compares the networking topology information in the first topology discovery messages (that is, the first another-train topology discovery messages) of other train consists with the networking topology information stored in the current train. In a case that the networking topology information in the first another-train topology discovery messages is the same as the networking topology information of the current train, that is, the all pieces of networking topology information of the train consists are same, it is determined that the wireless network topology between the train consists converges, and each train consist may serve as a node (that is, a train consist node) to form a wireless network (such as a Mesh network, that is, a wireless mesh network).

[0040] For example, in a case the networking topology information in the first topology discovery message only includes the identification information of the train consist nodes in the network, the train consist determines that the networking state is a completed convergence state, in a case that the number of pieces of the identification information in the networking topology information in the first another-train topology discovery message is the same as the number of identifiers of the train consists in the networking topology information stored in current train consist. In a case that the networking topology information in the first topology discovery message includes the identification information and the topological sort order information of the train consist nodes in the network, the train consist determines that the networking state is a completed convergence state, in a case that the number and the sort order of pieces of the identification information in the networking topology information in the first another-train topology discovery message is the same as the number and the sort order of the identifiers of the train consists in the networking topology information stored in the current train consist. For example, in a case that the networking topology information in the first topology discovery message is stored in the form of a topology table shown in Table 1, the train consist determines that the networking state is a completed convergence state when the topology table in the first another-train topology discovery message is the same as the topology table stored in the current train. Table 1: Topology of the wireless networking system shown in FIG. 1.TopologyA(I)->A(II)->B(I)->B(II)->C(II)->C(I)->D(II)->D(I)

[0041] In the above table, A(I) represents an identifier of the directional antenna with a communication direction of the direction 1 at a train consist A.

[0042] In step S103, if the networking state is an uncompleted convergence state, the networking topology information of the current train is updated based on the first another-train topology discovery message, and step S101 is entered.

[0043] It can be understood that in this step, upon determining that the networking is uncompleted, the train consist updates the networking topology information stored in the current train based on the received first topology discovery messages (that is, the first another-train topology discovery messages) sent by other train consists, so as to continue to construct the first current-train topology discovery message using the networking topology information stored in the current train. Step 101 is entered to continue to send the first current-train topology discovery message and receive the first another-train topology discovery message sent by another train consist through the preset directional antenna in a next period, so as to continue the convergence process of the wireless network topology.

[0044] In an embodiment, the specific manner for updating the networking topology information of the current train by the train consist based on the first another-train topology discovery message in this step may be determined by the designer based on the practical scenarios and user requirements. For example, in this step, the train consist may update the networking topology information of the current train based on the sender identifier and the networking topology information in the first another-train topology discovery message and / or a received signal strength and a receiving antenna corresponding to the another train consist. The receiving antenna is any one of the directional antennas. For example, in a case that the networking topology information only includes the identification information of the train consist nodes in the network, the train consist may update the networking topology information of the current train based on the sender identifier and networking topology information in the first another-train topology discovery message. That is, the train consist updates and stores the identification information not stored in the networking topology information of the current train to the networking topology information. In a case that the networking topology information further includes the topological sort order information of the train consist nodes in the network, the train consist may update the networking topology information of the current train based on the sender identifier and networking topology information in the first another-train topology discovery message, the received signal strength corresponding to the another train consist and the receiving antenna of the another train consist.

[0045] For example, the train consist may update the identification information and topological sort order information of the train consist nodes corresponding to other train consists adjacent to the train consist in the networking topology information of the current train, based on the sender identifiers and the received signal strengths and receiving antennas corresponding to other train consists in the first another-train topology discovery messages. The train consist updates the networking topology information based on the networking topology information in the first another-train topology discovery messages, that is, the train consist updates the identification information and corresponding topological sort order information not stored in the networking topology information of the current train. For example, the train consist may update the networking topology information of the current train using the networking topology information in the first another-train topology discovery messages of the other adjacent train consists. As shown in FIG. 1, the current train consist determines a relative position (whether it is along the direction 1 or the direction 2 of the current train consist) between the node for sending the topology discovery message (that is, the first another-train topology discovery message) and the current node through the receiving antenna for receiving the topology discovery message, determines whether the node for sending the message is adjacent to the current node based on the received signal strength of the topology discovery message, fills these information into the topology table, and broadcasts the information with the topology discovery message (that is, the first current-train topology discovery message). After receiving the topology discovery messages of other train consists, each train consist continuously updates its topology table based on the topology tables in the messages, and broadcasts the latest topology table with the topology discovery message until the contents of the topology tables of all train consists are completely consistent, then it is determined that the network topology converges, and the application data message is allowed to be sent. In this case, the sending period of the topology discovery message increases, that is, the sending period of the second topology discovery message (that is, the preset message sending period) may be greater than the sending period of the first topology discovery message (that is, the preset networking message sending period), thus reducing occupancy of wireless resources.

[0046] In step S104, if the networking state is a completed convergence state, data transmission is performed with a target node in the network through the preset directional antenna based on the networking topology information of the current train.

[0047] It can be understood that the target node in this step may be any one of the other train consists in the network that requires to perform data transmission. In this step, upon determining that the networking is completed, the train consist performs data transmission with the target node in the network using the preset directional antenna based on the networking topology information stored in the current train, to implement the backbone data transmission.

[0048] In this step, the specific manner for performing data transmission with the target node in the network by the train consist using the preset directional antenna based on the networking topology information of the current train, may be determined by the designer based on the practical scenarios and user requirements. For example, after determining the target node based on the networking topology information of the current train, the train consist broadcasts the data requires to be sent to the target node (that is, the to-be-sent data) through the preset directional antenna or a directional antenna of the preset directional antenna with a communication direction corresponding to the target node, so that the target node receives the to-be-sent data directly through its preset directional antenna or through forwarding by other train consists, that is, the train consist in the networking and other train consists in addition to the target nodes may forward the to-be-sent data. In order to reduce the data forwarding amount of the train consists in the network, the train consist in this step may also determine a communication path (that is, a target communication path) corresponding to the target node based on the networking topology information of the current train, so as to send the to-be-sent data to the target node via the communication path through the preset directional antenna, and other train consists outside the target communication path do not need to forward the to-be-sent data. This is not limited in the embodiment.

[0049] In an embodiment, after this step, step 101 may be entered to perform networking between train consists after it is detected that a duration of the completed convergence state of the networking reaches a time threshold or a re-networking control instruction is obtained.

[0050] In this embodiment of the present disclosure, the first current-train topology discovery message is sent and the first another-train topology discovery message sent by another train consist is received through the preset directional antenna. Each train consist sends and receives topology discovery messages through the back-to-back directional antennas, and determines the positions of other train consists relative to the current train by using the topology discovery messages received by the back-to-back directional antennas, implementing wireless networking of train consists and increasing the wireless communication distance. Furthermore, data transmitted between nodes can be forwarded by the train consist nodes in the network, thus supporting wireless reconnection of more trains, and improving the reliability of wireless communication between trains.

[0051] Based on the above embodiments, in an embodiment, in order to ensure the reliability of data transmission between a train consist and the target node after the networking is completed, and reduce the data forwarding amount of the train consists, the target communication path between the train consist and the target node is determined by broadcasting the second topology discovery message. Reference is made to FIG. 3, the above step S104 may include steps S201 to S204.

[0052] In step S201, communication routing information of the current train is generated based on the networking topology information of the current train. The communication routing information includes communication paths corresponding to the train consist node of the current train and communication paths corresponding to the train consist nodes of the other train consists in the network and routing metric values corresponding to the communication paths.

[0053] It can be understood that in this step, after determining that the networking state is a completed convergence state, the train consist generates the communication routing information of the current train based on the networking topology information of the current train, so as to determine the target communication path corresponding to the target node by using the communication routing information of the current train.

[0054] In an embodiment, the specific content of the communication routing information of the current train in this step may be determined by the designer based on practical scenarios and user requirements. For example, the communication routing information may include the communication path corresponding to the train consist node (that is, the train consist node of the current train) of the train consist and the communication paths corresponding to other train consist nodes and routing metric values corresponding to the communication paths (for example, the initial routing metric value is set to be a preset routing value). The communication routing information may further include the hop counts corresponding to the communication paths, facilitating the determination of the target communication path. As shown in Table 2 below, the communication routing information may be stored in the form of a routing table. Table 2: Routing table for the train consist A in FIG. 1Number Communication path Hop count Routing metric value 1A---B102A---C103B---C104B---D105C---D206A---B---D207A---C---D20

[0055] In step S202, a second current-train topology discovery message is sent and a second another-train topology discovery message sent by another train consist is received through the preset directional antenna. Both the second current-train topology discovery message and the second another-train topology discovery message include the communication routing information.

[0056] It can be understood that the second current-train topology discovery message in this step may be the second topology discovery message broadcast by the current train consist through its preset directional antenna. The second another-train topology discovery message in this step may be the second topology discovery message sent by another train consist and received by the current train consist through its preset directional antenna. The second topology discovery messages may be constructed by the train consists to implement the configuration update of the communication routing information of the respective train consists. The second topology discovery message in this embodiment may be different from the first topology discovery message in the previous embodiment, or may be the same, which is not limited in the embodiment.

[0057] Correspondingly, the specific contents of the second current-train topology discovery message and the second another-train topology discovery message in this embodiment, that is, the specific contents of the second topology discovery messages described above, may be determined by the designer based on practical scenarios and user requirements. For example, the second current-train topology discovery message and the second another-train topology discovery message may both include communication routing information, so that the current train consist can use the received second topology discovery message (that is, the second another-train topology discovery message) to update the communication routing information stored by the current train consist. The second current-train topology discovery message and the second another-train topology discovery message further include information such as a message sequence number and a CPU load, facilitating calculation of routing metric values.

[0058] In this step, after the network topology converges (that is, the networking is completed), the train consist sends the second current-train topology discovery message according to the preset message sending period and receive the second another-train topology discovery message sent by the another train consist through the preset directional antenna. That is, each train consist periodically constructs a second topology discovery message, broadcasts the second topology discovery message along two opposite directions through the preset directional antenna, and receives the second topology discovery messages of other train consists at the same time.

[0059] In step S203, routing metric values corresponding to the respective communication paths in the communication routing information of the current train are updated based on the second another-train topology discovery message.

[0060] It can be understood that in this step, after determining that the networking is completed, the train consist updates the communication routing information stored in the current train based on the received second topology discovery messages (that is, the second another-train topology discovery messages) sent by other train consists, so as to continue to periodically construct the second current-train topology discovery message by using the communication routing information stored in the current train, and performs the step 202 of sending the second current-train topology discovery message and receiving the second another-train topology discovery message sent by another train consist through the preset directional antenna, so as to continuously update the communication routing information stored in the current train.

[0061] In an embodiment, the specific manner for updating the routing metric values corresponding to the communication paths in the communication routing information of the current train by the train consist based on the second another-train topology discovery message, may be determined by the designer based on the practical scenarios and user requirements. For example, the train consist may update the routing metric values corresponding to the respective single-hop communication paths in the communication routing information of the current train based on the message sequence number, the CPU load and / or the corresponding received signal strength in the second another-train topology discovery message, and update the routing metric values corresponding to the respective multi-hop communication paths in the communication routing information of the current train based on the communication routing information in the second another-train topology discovery message. The communication paths in the communication routing information of the current train includes the single-hop communication paths and the multi-hop communication paths. The single-hop communication path may be a communication path with a hop count of 1. That is, a path for direct communication between the train consist and the target node, such as A---B and A---C shown in Table 2. The multi-hop communication path may be a communication path with a hop count greater than or equal to 2, that is, a communication path between the train consist and the target node through performing routing hop by other train consists, such as A---B---D and A---C---D shown in Table 2.

[0062] Correspondingly, the specific manner for updating the routing metric values corresponding to the single-hop communication paths in the communication routing information of the current train by the train consist based on the message sequence number, the CPU load and / or the corresponding received signal strength in the second another-train topology discovery message, may be determined by the designer. For example, the train consist may update the routing metric values corresponding to the single-hop communication paths in the communication routing information of the current train based on the message sequence number, CPU load and the corresponding received signal strength in the second another-train topology discovery message. For example, the train consist may store the message sequence numbers, CPU loads and received signal strengths obtained by analyzing the second another-train topology discovery messages to the corresponding target storage spaces. The target storage spaces are storage spaces assigned for the other train consists corresponding to the second another-train topology discovery messages (such as the sliding window shown in FIG. 4).

[0063] A received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path are calculated based on a target received signal strength in a current target storage space. A signal strength average value score and a signal strength standard deviation score corresponding to the current single-hop communication path are respectively calculated by S SPM = 0 , SP ¯ < − 130 S SPM = 1.25 ∗ SP ¯ + 162.5 , − 130 ≤ SP ¯ ≤ − 50 S SPM = 100 , SP ¯ > − 50 and S SPT = 0 , δ > 0.6 ∗ SP ¯ S SPT = − 250 δ / SP ¯ + 150 , 0.2 ∗ SP ¯ ≤ δ ≤ 0.6 ∗ SP ¯ S SPT = 100 , δ < 0.2 * SP ¯ where, the current target storage space is any one of the target storage spaces, the current single-hop communication path corresponds to the current target storage space, S SPM represents the signal strength average value score, SP represents the received signal strength average value, S SPT represents the signal strength standard deviation score, and δ represents the received signal strength standard deviation. That is, the signal strength average value represents an average level of the signal strength. As the distance between the current train and a train consist decreases, the communication quality increases, indicating a larger signal strength average value, and the probability of sending data to the train consist is relatively large. For a cross-consist train consist relatively far from the current train, the communication quality is relatively poor, which indicates a relatively small signal strength average value, and the probability of sending data to the train consist is relatively small. Therefore, the received signal strength average value SP in the current target storage space may be calculated first, and the signal strength average value score S SPM is calculated according to the above equation. The signal strength standard deviation represents the stability of the signal. A more stable signal indicates more stable communication. Therefore, the received signal strength standard deviation δ in the current target storage space may be calculated first, and then the signal strength standard deviation score S SPT is calculated according to the above equation.

[0064] A CPU load average value corresponding to the current single-hop communication path is calculated based on a target CPU load in the current target storage space, and a CPU load average value score corresponding to the current single-hop communication path is calculated by S CPU = 0 , CPU ¯ > 80 % S CPU = − 500 3 ∗ CPU ¯ + 400 3 , 20 % ≤ CPU ¯ ≤ 80 % S CPU = 100 , CPU ¯ < 20 % where, S CPU represents the CPU load average value score and CPU represents the CPU load average value. That is, the CPU load average value represents an average level of the current processing capacity of the train consist. A relatively large CPU load average value indicates a relatively large CPU load of the train consist and a relatively poor processing capacity of the train consist, and the probability of sending data to the train consist is relatively small. A relatively small CPU load average value indicates a relatively small CPU load of the train consist and a relatively strong processing capacity of the train consist, and the probability of sending data to the train consist is relatively large. Therefore, the CPU load average value CPU in the current target storage space may be calculated first, and then the CPU load average value score S CPU is calculated according to the above equation.

[0065] A packet reception rate corresponding to the current single-hop communication path is calculated based on a target message sequence number in the current target storage space. A packet reception rate score corresponding to the current single-hop communication path is calculated by: S DPR = 0 , DPR < 65 % S DPR = 1000 3 ∗ DPR − 650 3 , 65 % ≤ DPR ≤ 95 % S DPR = 100 , DPR > 95 % where, S DPR represents the packet reception rate score, and DPR represents the packet reception rate. That is, the packet reception rate represents the packet receiving situation of a communication path, specifically a ratio of the actual number of received packets to the number of to-be-received packets. Based on the records of the message sequence number in the storage space, a case that the message sequence number is not continuous indicates packet loss. The number of to-be-received messages and the number of actual-received messages are counted to calculate the packet reception rate for the communication path of the receiving end. The larger packet reception rate indicates the larger probability of sending data to the train consist, and the smaller packet reception rate indicates the smaller probability of sending data to the train consist. Therefore, the calculated packet reception rate DPR corresponding to the current single-hop communication path may be used as one of evaluation indicators of the communication quality of the wireless communication link, and then the packet reception rate score S DPR is calculated according to the above equation.

[0066] An average message reception period corresponding to the current single-hop communication path is calculated based on a target second another-train topology discovery message in the current target storage space. An average period score corresponding to the current single-hop communication path is calculated by S CYC = 0 , C Y C L E _ A > 6 ∗ CYCLE S CYC = − 25 ∗ C Y C L E _ A CYCLE + 150,2 ∗ CYCLE ≤ C Y C L E _ A ≤ 6 ∗ CYCLE S CYC = 100 , C Y C L E _ A < 2 ∗ CYCLE where S CYC represents the average period score, CYCLE _A represents the average message reception period, and CYCLE represents a preset message sending period. That is, in this step, the average message reception period CYCLE _A in the current target storage space is calculated, and the average period score S CYC is calculated based on the preset message sending period CYCLE according to the above equation.

[0067] The routing metric value corresponding to the current single-hop communication path is calculated by: S = ω SPM S SPM + ω SPT S SPT + ω CPU S CPU + ω DPR S DPR + ω CYC S CYC where s represents the routing metric value, ω SPM , ω SPT , ω CPU , ω DPR and ω CYC respectively represent weighted values of the signal strength average value score, the signal strength standard deviation score, the CPU load average value score, the packet reception rate score and the average period score corresponding to the current single-hop communication path. That is, after the signal strength average value score S SPM , the signal strength standard deviation score S SPT , the CPU load average value score S CPU , the packet reception rate score S DPR and the average period score S CYC corresponding to the current single-hop communication path are calculated, a final score s may be obtained by performing weighted fusion on these scores through the above equation to serve as the routing metric value of the current single-hop communication path, so as to perform weighted calculation on multiple parameter indicators to serve as the basis for routing selection, thus improving the reliability of wireless communication between trains. ω SPM represents a weighted value of the signal strength average value score S SPM , ω SPT represents a weighted value of the signal strength standard deviation score S SPT , ω CPU represents a weighted value of the CPU load average value score S CPU , ω DPR represents a weighted value of the packet reception rate score S DPR , and ω CYC represents a weighted value of the average period score S CYC . The specific values of ω SPM , ω SPT , ω CPU , ω DPR and ω CYC described above may be determined by the designer. For example, the sum of ω SPM , ω SPT , ω CPU , ω DPR and ω CYC may be equal to 1, that is, ω SPM +ω SPT +ω CPU +ω DPR + ω CYC = 1. For example, ω SPM = 0.2, ω SPT = 0.1, ω CPU = 0.2, ω DPR = 0.4, and ω CYC = 0.1.

[0068] Furthermore, before calculating the received signal strength average value and the received signal strength standard deviation corresponding to the current single-hop communication path based on the target received signal strength in the current target storage space, the train consist may further determine whether the current target storage space is fully-stored, where a data storage mode of the current target storage space is first-in-first-out. If the current target storage space is not fully-stored, the routing metric value corresponding to the current single-hop communication path is determined as a preset routing value. If the current target storage space is fully-stored, the step of calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space is performed, to calculate the routing metric value corresponding to the current single-hop communication path.

[0069] Furthermore, before calculating the received signal strength average value and the received signal strength standard deviation corresponding to the current single-hop communication path based on the target received signal strength in the current target storage space, the train consist may further determine whether a duration in which the current target storage space does not update stored data reaches a preset duration, where the preset duration is greater than the preset message sending period. If the preset duration is reached, the routing metric value corresponding to the current single-hop communication path is determined as the preset routing value. If the preset duration is not reached, the step of calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space is performed to calculate the routing metric value corresponding to the current single-hop communication path.

[0070] As shown in FIG. 4, the train consist first determines whether the current target storage space is fully-stored, that is, whether the number of the stored message reaches the length of the sliding window. If the current target storage space is fully-stored, it is determined whether the duration in which the current target storage space does not update stored data reaches the preset duration (such as the seven preset message sending periods in FIG. 4). If the preset duration is not reached, the routing metric value of the current single-hop communication path corresponding to the current target storage space is calculated. If the current target storage space is not fully-stored or the preset duration is reached, it is determined that the routing metric value corresponding to the current single-hop communication path is the preset routing value (such as 0).

[0071] Correspondingly, the specific manner for updating routing metric values corresponding to the respective multi-hop communication paths in the communication routing information of the current train by the train consist based on the communication routing information in the second another-train topology discovery message, may be determined by the designer. For example, the train consist may add the routing metric values corresponding to the single-hop communication paths in the communication routing information of the current train and the routing metric values of the corresponding communication paths in the communication routing information in the second another-train topology discovery message to obtain the routing metric values corresponding to the multi-hop communication paths. As shown in FIG. 1, if the train consist A of the current train cannot communicate with the train consist D of the another train in one hop (that is, the wireless communication between the two nodes is directly communication-capable without performing relay forwarding by other nodes), and another train consist B or C is required to perform relay forward, then the routing metric value between the train consists A and D is represented by S AD =S AB +S BD , or S AD =S AC +S CD . That is, the train consist A of the current train may add the routing metric value S AB corresponding to the single-hop communication path A---B in the communication routing information of the current train to the routing metric value S BD corresponding to the communication path B---D in the communication routing information of the train consist B of the another train, to obtain the routing metric value S AD corresponding to the multi-hop communication path A---B---D.

[0072] In step S204, a target communication path corresponding to the target node is determined based on the communication routing information of the current train, and the to-be-sent data is sent to the target node via the target communication path. The target communication path is any one of the communication paths.

[0073] It can be understood that in this step, the train consist may select a communication path as the target communication path from the communication paths between the current train consist and the target node based on the communication routing information of the current train, so as to send the to-be-sent data to the target node via the target communication path through the preset directional antenna.

[0074] In an embodiment, the specific manner for determining the target communication path corresponding to the target node based on the communication routing information of the current train in this step may be determined by the designer. For example, the train consist may determine a preferred communication path with a minimum hop count and a routing metric value unequal to the preset routing value (such as 0) among the communication paths between the current train and the target node based on the communication routing information of the current train. The train consist may determine a preferred communication path with a maximum routing metric value among the preferred communication paths as the target communication path based on the communication routing information of the current train. That is, in a case that the hop counts of the communication paths between the current train consist to the target node are inconsistent, the communication path with less hop counts may be preferably selected. In a case that the hop counts are consistent, the communication path (that is, the preferred communication path) with a relatively large metric value is determined as the target communication path.

[0075] In an embodiment, when sending the to-be-sent data to the target node via the target communication path through the preset directional antenna, the train consist sends the to-be-sent data to the target node via the target communication path through the directional antenna of the preset directional antenna in the communication direction corresponding to the target node, avoiding invalid data transmission by the directional antenna in another communication direction.

[0076] In the embodiment of the present disclosure, data transmission is performed between the train consists in the network in manners of Mesh networking and multi-hop routing, without adding infrastructures such as a base station or a ground server. The deployment cost is relatively low. The problem of short transmission distance and small coverage range of WiFi wireless communication technology can be solved. In addition, since multiple communication paths are provided between the train consist and the target node, the target communication path may be flexibly selected according to the communication routing information, ensuring the availability and reliability of the network.

[0077] Corresponding to the method embodiments described above, an apparatus for networking communication between trains is provided in embodiments of the present disclosure. The apparatus for networking communication between trains described below and the method for networking communication between trains described above can be referenced to each other.

[0078] Reference is made to FIG. 5, FIG. 5 is a structural block diagram of an apparatus for networking communication between trains according to an embodiment of the present disclosure. The apparatus is applied to train consists, and includes a topology networking module 10, a networking determination module 20, a networking updating module 30 and a data transmitting module 40.

[0079] The topology networking module 10 is configured to send a first current-train topology discovery message and receive a first another-train topology discovery message sent by another train consist through a preset directional antenna, where the preset directional antenna includes two antennas arranged back to back at the train consist, the first current-train topology discovery message and the first another-train topology discovery message includes a sender identifier and networking topology information, and the networking topology information includes identification information of train consist nodes in a network.

[0080] The networking determination module 20 is configured to determine a networking state based on networking topology information in the first another-train topology discovery message.

[0081] The networking updating module 30 is configured to update the networking topology information of the current train based on the first another-train topology discovery message if the networking state is an uncompleted convergence state, and send the first current-train topology discovery message and receive the first another-train topology discovery message sent by the another train consist via the preset directional antenna.

[0082] The data transmitting module 40 is configured to perform data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train, if the networking state is a completed convergence state.

[0083] In an embodiment, the networking updating module 30 is configured to update the networking topology information of the current train based on the sender identifier and the networking topology information of the first another-train topology discovery message and / or a received signal strength corresponding to the another train consist and receiving antennas of the another train consist. The receiving antenna is any one of the directional antennas.

[0084] In an embodiment, the networking topology information further includes topological sort order information of the train consist nodes in the network.

[0085] In an embodiment, the networking updating module 30 may include an adjacent updating sub-module and a topology updating sub-module.

[0086] The adjacent updating sub-module is configured to update identification information and topological sort order information of the train consist nodes corresponding to train consists adjacent to the train consist in the networking topology information of the current train, based on the sender identifier in the first another-train topology discovery message and the received signal strength corresponding to the another train consist and the receiving antenna of the another train consist.

[0087] The topology updating sub-module is configured to update the networking topology information of the current train based on the networking topology information in the first another-train topology discovery message.

[0088] In an embodiment, the networking determination module 20 is configured to determine whether the networking topology information in the first another-train topology discovery messages is the same as the networking topology information of the current train. If one or more pieces of networking topology information in the first another-train topology discovery messages are different from the networking topology information of the current train, it is determined that the networking state is the uncompleted convergence state, the networking determination module 20 sends a starting signal to the networking updating module 30. If the networking topology information in the first another-train topology discovery messages is the same as the networking topology information of the current train, it is determined that the networking state is the completed convergence state, the networking determination module 20 sends a starting signal to the data transmitting module 40.

[0089] In an embodiment, the preset directional antenna includes the directional antennas arranged back to back at the train consist, and communication directions of the directional antennas are respectively directed toward two ends of the train consist.

[0090] In an embodiment, the sender identifier includes an identifier of the directional antenna adopted by the sender, and the identification information of the train consist nodes in the network includes identifiers of the two directional antennas of each of the train consist nodes.

[0091] In an embodiment, the data transmitting module 40 may include a routing generating sub-module, a topology routing sub-module, a routing updating sub-module and a routing transmitting sub-module.

[0092] The routing generating sub-module is configured to generate communication routing information of the current train based on the networking topology information of the current train. The communication routing information includes communication paths respectively corresponding to the train consist node of the current train and the train consist nodes of the other train consists in the network and routing metric values corresponding to the communication paths.

[0093] The topology routing sub-module is configured to send a second current-train topology discovery message and receiving a second another-train topology discovery message sent by the another train consist through the preset directional antenna. The second current-train topology discovery message and the second another-train topology discovery message include the communication routing information.

[0094] The routing updating sub-module is configured to update the routing metric values of the communication paths in the communication routing information of the current train, based on the second another-train topology discovery message.

[0095] The routing transmitting sub-module is configured to determine a target communication path corresponding to the target node based on the communication routing information of the current train, and send to-be-sent data to the target node via the target communication path. The target communication path is any one of the communication paths.

[0096] In an embodiment, the routing updating sub-module may include a single-hop updating unit and a multi-hop updating unit.

[0097] The single-hop updating unit is configured to update the routing metric values of single-hop communication paths in the communication routing information of the current train, based on a message sequence number, a CPU load and / or a received signal strength corresponding to the another train consist in the second another-train topology discovery message.

[0098] The multi-hop updating unit is configured to update the routing metric values corresponding to multi-hop communication paths in the communication routing information of the current train based on the communication routing information in the second another-train topology discovery message. The communication paths in the communication routing information of the current train includes the single-hop communication paths and the multi-hop communication paths.

[0099] In an embodiment, the single-hop updating unit may include an analyzing storage sub-unit, a strength sub-unit, a CPU load sub-unit, a packet reception rate sub-unit, a period sub-unit and a weighting sub-unit.

[0100] The analyzing storage sub-unit is configured to store the message sequence numbers, the CPU loads and the received signal strengths that are obtained by analyzing the second another-train topology discovery messages to corresponding target storage spaces. The target storage spaces are storage spaces assigned for the other train consists corresponding to the second another-train topology discovery messages.

[0101] The strength sub-unit is configured to calculate a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on the target received signal strength in the current target storage space, and determine a signal strength average value score and a signal strength standard deviation score corresponding to the current single-hop communication path by S SPM = 0 , SP ¯ < − 130 S SPM = 1.25 * SP ¯ + 162.5 , − 130 ≤ SP ¯ ≤ − 50 S SPM = 100 , SP ¯ > − 50 and S SPT = 0 , δ > 0.6 * SP ¯ S SPT = − 250 δ / SP ¯ + 150 , 0.2 * SP ¯ ≤ δ ≤ 0.6 * SP ¯ S SPT = 100 ,   δ < 0.2 * SP ¯ where the current target storage space is any one of the target storage spaces, the current single-hop communication path corresponds to the current target storage space, S SPM represents the signal strength average value score, SP represents the received signal strength average value, S SPT represents the signal strength standard deviation score, and δ represents the received signal strength standard deviation.

[0102] The CPU load sub-unit is configured to calculate a CPU load average value corresponding to the current single-hop communication path based on a target CPU load in the current target storage space, and determine a CPU load average value score corresponding to the current single-hop communication path by S CPU = 0 , CPU ¯ > 80 % S CPU = − 500 3 * CPU ¯ + 400 3 , 20 % ≤ CPU ¯ ≤ 80 % S CPU = 100 , CPU ¯ < 20 % where S CPU represents the CPU load average value score and CPU represents the CPU load average value.

[0103] The packet reception rate sub-unit is configured to calculate a packet reception rate corresponding to the current single-hop communication path based on a target message sequence number in the current target storage space, and determine a packet reception rate score corresponding to the current single-hop communication path by: S DPR = 0 , DPR < 65 % S DPR = 1000 3 ∗ DPR − 650 3 , 65 % ≤ DPR ≤ 95 % S DPR = 100 ,   DPR > 95 % where S DPR represents the packet reception rate score, and DPR represents the packet reception rate.

[0104] The period sub-unit is configured to calculate an average message reception period corresponding to the current single-hop communication path based on a target second another-train topology discovery message in the current target storage space, and determine an average period score corresponding to the current single-hop communication path by S CYC = 0 , CYCLE _ A > 6 ∗ CYCLE S CYC = − 25 ∗ CYCLE _ A CYCLE + 150,2 ∗ CYCLE ≤ CYCLE _ A ≤ 6 ∗ CYCLE S CYC = 100 , CYCLE _ A < 2 ∗ CYCLE where S CYC represents the average period score, CYCLE _A represents the average message reception period, and CYCLE represents a preset message sending period.

[0105] The weighting sub-unit is configured to calculate the routing metric value corresponding to the current single-hop communication path by: S = ω SPM S SPM + ω SPT S SPT + ω CPU S CPU + ω DPR S DPR + ω CYC S CYC where s represents the routing metric value, ω SPM , ω SPT , ω CPU , ω DPR and ω CYC respectively represent weighted values of the signal strength average value score, the signal strength standard deviation score, the CPU load average score, the packet reception rate score and the average period score corresponding to the current single-hop communication path.

[0106] In an embodiment, the single-hop updating unit may further include a first unit sub-unit and a first determination sub-unit.

[0107] The first unit sub-unit is configured to determine whether the current target storage space is fully-stored. A data storage mode of the current target storage space is first-in-first-out. If the current target storage space is fully-stored, the first unit sub-unit sends a starting signal to the strength sub-unit.

[0108] The first determination sub-unit is configured to determine the routing metric value corresponding to the current single-hop communication path as a preset routing value if the current target storage space is not fully-stored.

[0109] In an embodiment, the single-hop updating unit further includes a second unit sub-unit and a second determination sub-unit.

[0110] The second unit sub-unit is configured to determine whether a duration in which the current target storage space does not update stored data reaches a preset duration. If the preset duration is not reached, the second unit sub-unit sends a starting signal to the strength sub-unit. The preset duration is greater than the preset message sending period.

[0111] The second determination sub-unit is configured to determine the routing metric value corresponding to the current single-hop communication path as the preset routing value, if the preset period is reached.

[0112] In an embodiment, the routing transmitting sub-module includes an initial selection sub-module and a final selection sub-module.

[0113] The initial selection sub-module is configured to determine a preferred communication path with a minimum hop count and a routing metric value unequal to the preset routing value among the communication paths between the current train and the target node based on the communication routing information of the current train.

[0114] The final selection sub-module is configured to determine a preferred communication path with a maximum routing metric value among the preferred communication paths as the target communication path based on the communication routing information of the current train.

[0115] In this embodiment according to the present disclosure, the first current-train topology discovery message is sent and the first another-train topology discovery message sent by another train consist is received by the topology networking module 10 through the preset directional antenna. Each train consist sends and receives topology discovery messages through the back-to-back directional antennas, and determines the positions of other train consists relative to the current train by using the topology discovery messages received by the back-to-back directional antennas, thereby implementing wireless networking of the train consists and increasing the distance of the wireless communication. Furthermore, the data transmitted between nodes is forwarded by the train consist nodes in the network, thus supporting wireless reconnection of more trains, and improving the reliability of wireless communication between trains.

[0116] Corresponding to the above method embodiments, a train consist is provided according to an embodiment of the present disclosure, and the train consist described below and the method for networking communication between trains described above can be referred to each other.

[0117] A train consist, includes: a memory, storing a computer program; and a processor, configured to implement steps of the method for networking communication between trains provided according to the method embodiments described above when performing the computer program.

[0118] In this embodiment, the train consist may be provided with a preset directional antenna, and the preset directional antenna includes two directional antennas arranged back to back.

[0119] Corresponding to the above method embodiment, in an embodiment of the present disclosure, a readable storage medium is further provided. The readable storage medium described below and the method for networking communication between trains described above may be referred to each other.

[0120] A readable storage medium storing a computer program. The computer program, when being executed by a processor, causes the processor to perform the steps of the method for networking communication between trains provided according to the above method embodiments.

[0121] The readable storage medium may be a readable storage media storing program codes, such as a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disc or an optical disc.

[0122] The embodiments in the specification are described in a progressive manner. Each of the embodiments mainly focuses on differences from other embodiments, and references can be made to each other for the same or similar parts among the embodiments. The apparatus, the train consist and the readable storage medium disclosed in the embodiments correspond to the method disclosed in the embodiment, and thus the description thereof is simple, and the related description may be referred to the description of the method.

[0123] The method and apparatus for networking communication between trains, and train consist provided in the present disclosure are described in detail above. The principle and implementation of the present disclosure are illustrated by using specific embodiments herein. The above descriptions of the embodiments are only used to facilitate understanding of the method and the core idea of the present disclosure. It should be noted that, various improvements and modifications may be made by those skilled in the art to the present disclosure without departing from the principle of the present disclosure, and these improvements and modifications also fall within the protection scope of the claims of the present disclosure.

Examples

Embodiment Construction

[0025]In order to make the objective, the technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure are described below in conjunction with the drawings in the embodiments of the present disclosure. Apparently, the embodiments described below are only some embodiments of the present disclosure, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the present disclosure without any creative work fall within the protection scope of the present disclosure.

[0026]Reference is made to FIG. 1, which is a flowchart of a method for networking communication between trains according to an embodiment of the present disclosure. The method is applied to train consists, and may include steps S101 to S104.

[0027]In step S101, a first current-train topology discovery message is sent and a first another-train topology discovery messag...

Claims

1. A method for networking communication between trains, applied to train consists, comprising: sending a first current-train topology discovery message and receiving a first another-train topology discovery message sent by another train consist through a preset directional antenna, wherein both the first current-train topology discovery message and the first another-train topology discovery message comprise a sender identifier and networking topology information, and the networking topology information comprises identification information of train consist nodes in a network; determining a networking state based on the networking topology information in the first another-train topology discovery message; updating the networking topology information of the current train based on the first another-train topology discovery message, and performing the process of sending the first current-train topology discovery message and receiving the first another-train topology discovery message sent by the another train consist through the preset directional antenna, if the networking state is an uncompleted convergence state; and performing data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train, if the networking state is a completed convergence state, wherein the preset directional antenna comprises two directional antennas arranged back to back at each of the train consists.

2. The method for networking communication between trains according to claim 1, wherein the updating the networking topology information of the current train based on the first another-train topology discovery message comprises: updating the networking topology information of the current train based on the sender identifier and the networking topology information in the first another-train topology discovery message and / or a received signal strength corresponding to the another train consist and a receiving antenna of the another train consist, wherein the receiving antenna is any one of the directional antennas.

3. The method for networking communication between trains according to claim 2, wherein the networking topology information further comprises topological sort order information of the train consist nodes in the network.

4. The method for networking communication between trains according to claim 3, wherein the updating the networking topology information of the current train based on the sender identifier and the networking topology information in the first another-train topology discovery message and / or a received signal strength corresponding to the another train consist and a receiving antenna of the another train consist comprises: updating identification information and topological sort order information of the train consist nodes corresponding to train consists adjacent to the current train in the networking topology information of the current train, based on the sender identifier in the first another-train topology discovery message and the received signal strength corresponding to the another train consist and the receiving antenna of the another train consist; and updating the networking topology information of the current train based on the networking topology information in the first another-train topology discovery message.

5. The method for networking communication between trains according to claim 1, wherein the determining a networking state based on the networking topology information in the first another-train topology discovery message comprises: determining whether the networking topology information in the first another-train topology discovery messages is the same as the networking topology information of the current train; determining that the networking state is the uncompleted convergence state if negative; and determining that the networking state is the completed convergence state if positive.

6. The method for networking communication between trains according to claim 1, wherein the preset directional antenna comprises the directional antennas arranged back to back at the train consist, and communication directions of the directional antennas are respectively directed toward two ends of the train consist.

7. The method for networking communication between trains according to claim 1, wherein the sender identifier comprises an identifier of the directional antenna adopted by a sender, and the identification information of the train consist nodes in the network comprises identifiers of the two directional antennas of each of the train consist nodes.

8. The method for networking communication between trains according to any one of claims 1 to 7, wherein the performing data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train comprises: generating communication routing information of the current train based on the networking topology information of the current train, wherein the communication routing information comprises communication paths respectively corresponding to the train consist node of the current train and the other train consist nodes in the network and routing metric values corresponding to the communication paths; sending a second current-train topology discovery message and receiving a second another-train topology discovery message sent by the another train consist through the preset directional antenna, wherein both the second current-train topology discovery message and the second another-train topology discovery message comprise the communication routing information; updating the routing metric values corresponding to the communication paths in the communication routing information of the current train, based on the second another-train topology discovery message; and determining a target communication path corresponding to the target node based on the communication routing information of the current train, and sending to-be-sent data to the target node via the target communication path, wherein the target communication path is any one of the communication paths.

9. The method for networking communication between trains according to claim 8, wherein the updating the routing metric values corresponding to the communication paths in the communication routing information of the current train, based on the second another-train topology discovery message comprises: updating the routing metric values corresponding to single-hop communication paths in the communication routing information of the current train, based on a message sequence number, a CPU load and / or a received signal strength corresponding to the anther train consist in the second another-train topology discovery message; and updating the routing metric values corresponding to multi-hop communication paths in the communication routing information of the current train, based on the communication routing information in the second another-train topology discovery message, wherein the communication paths in the communication routing information of the current train comprises the single-hop communication paths and the multi-hop communication paths.

10. The method for networking communication between trains according to claim 9, wherein the updating the routing metric values corresponding to single-hop communication paths in the communication routing information of the current train, based on a message sequence number, a CPU load and / or a received signal strength corresponding to the another train consist in the second another-train topology discovery message comprises: storing the message sequence number, the CPU load and the received signal strength that are obtained by analyzing the second another-train topology discovery messages to corresponding target storage spaces, wherein the target storage spaces are storage spaces assigned for the other train consists corresponding to the second another-train topology discovery messages; calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space, and determining a signal strength average value score and a signal strength standard deviation score corresponding to the current single-hop communication path by S SPM = 0 , SP ¯ < − 130 S SPM = 1.25 * SP ¯ + 162.5 , − 130 ≤ SP ¯ ≤ − 50 S SPM = 100 , SP ¯ > − 50 and S SPT = 0 , δ > 0.6 * SP ¯ S SPT = − 250 δ / SP ¯ + 150 , 0.2 * SP ¯ ≤ δ ≤ 0.6 * SP ¯ S SPT = 100 ,   δ < 0.2 * SP ¯ wherein the current target storage space is any one of the target storage spaces, the current single-hop communication path corresponds to the current target storage space, SSPM represents the signal strength average value score, SP represents the received signal strength average value, SSPT represents the signal strength standard deviation score, and δ represents the received signal strength standard deviation; calculating a CPU load average value corresponding to the current single-hop communication path based on a target CPU load in the current target storage space, and determining a CPU load average value score corresponding to the current single-hop communication path by S CPU = 0 , CPU ¯ > 80 % S CPU = − 500 3 * CPU ¯ + 400 3 , 20 % ≤ CPU ¯ ≤ 80 % S CPU = 100 , CPU ¯ < 20 % wherein SCPU represents the CPU load average value score and CPU represents the CPU load average value; calculating a packet reception rate corresponding to the current single-hop communication path based on a target message sequence number in the current target storage space, and determining a packet reception rate score corresponding to the current single-hop communication path by: S DPR = 0 , DPR < 65 % S DPR = 1000 3 ∗ DPR − 650 3 , 65 % ≤ DPR ≤ 95 % S DPR = 100 , DPR > 95 % wherein SDPR represents the packet reception rate score, and DPR represents the packet reception rate; calculating an average message reception period corresponding to the current single-hop communication path based on a target second another-train topology discovery message in the current target storage space, and determining an average period score corresponding to the current single-hop communication path by S CYC = 0 , CYCLE _ A > 6 ∗ CYCLE S CYC = − 25 ∗ CYCLE _ A CYCLE + 150,2 ∗ CYCLE ≤ CYCLE _ A ≤ 6 ∗ CYCLE S CYC = 100 , CYCLE _ A < 2 ∗ CYCLE wherein SCYC represents the average period score, CYCLE _A represents the average message reception period, and CYCLE represents a preset message sending period; and calculating the routing metric value corresponding to the current single-hop communication path by: S = ω SPM S SPM + ω SPT S SPT + ω CPU S CPU + ω DPR S DPR + ω CYC S CYC wherein S represents the routing metric value, ωSPM, ωSPT, ωCPU, ωDPR and ωCYC respectively represent weighted values of the signal strength average value score, the signal strength standard deviation score, the CPU load average value score, the packet reception rate score and the average period score corresponding to the current single-hop communication path.

11. The method for networking communication between trains according to claim 10, wherein before the calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space, the method further comprises: determining whether the current target storage space is fully-stored, wherein a data storage mode of the current target storage space is first-in-first-out; determining the routing metric value corresponding to the current single-hop communication path as a preset routing value if the current target storage space is not fully-stored; and performing the step of calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space if the current target storage space is fully-stored.

12. The method for networking communication between trains according to claim 10, wherein before the calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space, the method further comprises: determining whether a duration in which the current target storage space does not update stored data reaches a preset duration, wherein the preset duration is greater than the preset message sending period; determining the routing metric value corresponding to the current single-hop communication path as the preset routing value, if the preset duration is reached; and performing the step of calculating a received signal strength average value and a received signal strength standard deviation corresponding to a current single-hop communication path based on a target received signal strength in a current target storage space, if the preset duration is not reached.

13. The method for networking communication between trains according to claim 10, wherein the determining a target communication path corresponding to the target node based on the communication routing information of the current train comprises: determining a preferred communication path with a minimum hop count and a routing metric value unequal to the preset routing value among the communication paths between the current train and the target node based on the communication routing information of the current train; and determining a preferred communication path with a maximum routing metric value among the preferred communication path as the target communication path based on the communication routing information of the current train.

14. An apparatus for networking communication between trains, applied to train consists, comprising: a topology networking module, configured to send a first current-train topology discovery message and receive a first another-train topology discovery message sent by another train consist through a preset directional antenna, wherein both the first current-train topology discovery message and the first another-train topology discovery message comprise a sender identifier and networking topology information, and the networking topology information comprises identification information of train consist nodes in a network; a networking determination module, configured to determine a networking state based on the networking topology information in the first another-train topology discovery message; a networking updating module, configured to update the networking topology information of the current train based on the first another-train topology discovery message, and perform the process of sending the first current-train topology discovery message and receiving the first another-train topology discovery message sent by the another train consist through the preset directional antenna, if the networking state is an uncompleted convergence state; and a data transmitting module, configured to perform data transmission with a target node in the network through the preset directional antenna based on the networking topology information of the current train, if the networking state is a completed convergence state, wherein the preset directional antenna comprises two directional antennas arranged back to back at each of the train consists.

15. A train consist, comprising: a memory, storing a computer program; and a processor, configured to implement the method for networking communication between trains according to any one of claims 1 to 13 when executing the computer program.

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