Mobile body, wireless terminal device, communication system, communication method and program

Abstract

To provide a communication system that enables low latency terminal-to-terminal communication even using traditional wireless terminal devices of conventional types that do not have terminal-to-terminal direct communication interfaces.SOLUTION: A communication system includes a plurality of wireless terminal devices mounted on a plurality of mobile bodies respectively. The wireless terminal device of any one of the mobile bodies includes a pseudo-core network device for mobile communication, a pseudo-IAB donor connected to the pseudo-core network device, and a mobile IAB node. The mobile IAB node has a backhaul communication unit that performs backhaul link communication with the pseudo-IAB donor and an access link communication unit that performs access link communication of mobile communication with the wireless terminal devices of one or more other mobile bodies.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a mobile object such as a vehicle having a communication function, a wireless terminal device, a communication system, a communication method, and a program. Regarding. [Background technology]

[0002] In recent years, the expansion and diversification of wireless services has led to expectations for the dramatic development of the Internet of Things (IoT), and the use of mobile communications is expanding beyond information terminals such as smartphones to all areas, including automobiles, homes, home appliances, and industrial equipment. To support the diversification of services, it is essential to make efforts to significantly improve the performance and functionality of mobile communications systems, not only by increasing system capacity but also by increasing the number of connected devices and by providing high reliability and low latency. The fifth generation mobile communication system (5G) (Fifth Generation Mobile Communication System) not only features enhanced mobile broadband (eMBB), which is a further extension of the mobile broadband communication capabilities of LTE (Long Term Evolution) of the fourth generation mobile communication system (4G), but also features ultra-reliable and low latency communication (URLLC) and massive machine type communication (mMTC), which are multiple simultaneous connections. By utilizing these features, the system can provide flexible wireless communication to meet a wide variety of needs, such as real-time transmission of high-resolution video, wireless message transmission for industrial machinery, and IoT systems using a large number of devices (see, for example, Non-Patent Document 1).

[0003] Meanwhile, Intelligent Transport Systems (ITS), which are constructed as an integrated system that exchanges information between vehicles, between vehicles and people, between vehicles and road facilities, etc., have long been studied alongside the widespread use of automobiles. ITS is a system that utilizes cutting-edge information and communication technologies with the aim of improving road traffic safety, transportation efficiency, and comfort, and in recent years, there has been active global research into the advancement of ITS and the realization of an autonomous driving society. Against this background, expectations are rising for the realization of connected car services and autonomous driving technology that utilize Vehicle-to-Everything (V2X) communications, which connects vehicles with all manner of things, in order to further develop ITS (see, for example, Non-Patent Document 2). V2X refers to communication between vehicles and everything, and includes communication between vehicles (V2V: Vehicle-to-Vehicle), communication between vehicles and roadside units (RSU: Road Side Unit) (V2I: Vehicle-to-Infrastructure), communication between vehicles and pedestrians (V2P: Vehicle-to-Pedestrian), and communication between vehicles and networks (V2N: Vehicle-to-Network). In particular, V2X that uses cellular communication technology of mobile communication systems is also called "cellular V2X" (for example, Non-Patent Document 3).

[0004] Cellular V2X is also being studied by 3GPP (3rd Generation Partnership Project) (registered trademark), which is examining and formulating standard specifications for mobile communication system technologies for the third-generation mobile communication system (3G) and beyond. Specifications for the 4G wireless access standard LTE (Long Term Evolution) and the new 5G wireless access standard NR (New Radio) include the uplink (UL) and downlink (DL) communication methods for the communication interface Uu between a base station and a wireless terminal device, primarily for wide-area communications with a maximum communication distance of several kilometers or more. Standard specifications for the sidelink (SL) communication method, which performs direct wireless communication using an interface called PC5, are also being formulated for short-range communications with a communication distance of several meters to several hundred meters (see, for example, Non-Patent Documents 3, 4, 5, and 6). In 3GPP, SL was standardized for LTE D2D (Device-to-Device) communications starting with 3GPP Release 12 (see, for example, Non-Patent Documents 4 and 5), and was extended for LTE V2X starting with 3GPP Release 14 (see, for example, Non-Patent Document 6). NR SL, based on NR, introduced in 3GPP Release 15, was specified in 3GPP Release 16 (see, for example, Non-Patent Documents 7, 8, and 9). Note that interface names such as Uu and PC5 are not abbreviations but names based on the definitions in 3GPP TS23.002 (see, for example, Non-Patent Document 10). While V2V Direct, which is based on direct terminal-to-terminal wireless communication using the PC5 interface, is well-known as an approach to achieving V2V in LTE and NR, there is also V2N2V (Vehicle-to-Network-to-Vehicle), which is achieved by terminal-to-terminal wireless communication via a base station using UL transmission and DL reception on the Uu interface (see, for example, Non-Patent Documents 11, 12, 13, and 14).Direct terminal-to-terminal communication, such as V2V Direct, using a PC5 interface has the advantage of easily achieving low transmission delay (low latency) in terminal-to-terminal communication because it does not go through the mobile communications carrier's base station equipment or backbone communication network (see, for example, Non-Patent Document 11) and enabling communication outside the coverage area of ​​the mobile communications carrier's base station, which is likely to occur in depopulated areas and mountainous regions (see, for example, Non-Patent Document 12). However, since communication only uses wireless terminal equipment with low antenna gain, the communication distance is short and it cannot be applied to general user terminal equipment without a PC5 interface. On the other hand, terminal-to-terminal communication via base stations, such as V2N2V, using a Uu interface, has the advantage of easily achieving a longer communication distance than direct terminal communication because communication goes through base stations with high antenna gain and is applicable to general user terminal equipment without a PC5 interface. However, since communication goes through the mobile communications carrier's base station equipment or backbone communication network, it is inferior to direct terminal-to-terminal communication in terms of the theoretical limit of low-latency transmission performance. Summary of the Invention [Problem to be solved by the invention]

[0005] There is a problem in that it is necessary to realize low-latency terminal-to-terminal communication between multiple moving objects such as vehicles, even when using conventional wireless terminal devices that do not have an interface for a direct terminal-to-terminal communication method such as the SL communication method. [Means for solving the problem]

[0006] A communication system according to one aspect of the present invention is a communication system including a plurality of wireless terminal devices mounted on each of a plurality of mobile bodies. Any one of the wireless terminal devices of the plurality of mobile bodies includes a mobile communication pseudo core network device, a pseudo IAB (Integrated Access and Backhaul) donor connected to the pseudo core network device, and a Mobile IAB node. The Mobile IAB node includes a backhaul communication unit that performs backhaul link communication with the pseudo IAB donor, and an access link communication unit that performs mobile communication access link communication with one or more other mobile body wireless terminal devices. The one or more other mobile body wireless terminal devices include an access link communication unit that performs mobile communication access link communication with the Mobile IAB node of any one of the mobile body wireless terminal devices.

[0007] In the communication system, any one of the mobile bodies may have an electronic control unit connected to the pseudo core network device, and the other one or more mobile bodies may have an electronic control unit connected to a wireless terminal device of the other mobile body.

[0008] A communication system according to another aspect of the present invention is a communication system including a plurality of wireless terminal devices mounted on each of a plurality of mobile bodies. One of the wireless terminal devices of the plurality of mobile bodies includes a mobile station device capable of wireless communication with a mobile communication base station, a local core network device, a local IAB donor connected to the local core network device, a MobileIAB node, and a connection switching unit. The MobileIAB node includes a backhaul communication unit that performs backhaul link communication with the local IAB donor, and an access link communication unit that performs mobile communication access link communication with one or more other mobile body wireless terminal devices. The connection switching unit switches the connection of the end user node so that the end user node of the mobile body is connected to the mobile station device when the mobile station device is within the coverage area of ​​the base station cell, and is connected to the local core network device when the mobile station device is not within the coverage area of ​​the base station cell. The other one or more mobile body wireless terminal devices include an access link communication unit that performs mobile communication access link communication with the MobileIAB node of any one of the other mobile body wireless terminal devices.

[0009] In the communication system, the end user node may be an electronic control unit.

[0010] In the communication system, the multiple moving bodies are each vehicles, and the information transmitted and received between the wireless terminal device of any one of the moving bodies and the wireless terminal device of one or more other moving bodies may be information for the multiple vehicles to travel in formation.

[0011] According to yet another aspect of the present invention, a wireless terminal device is mountable in a mobile body. The wireless terminal device includes a mobile communication pseudo core network device, a pseudo IAB donor connected to the pseudo core network device, and a Mobile IAB node. The Mobile IAB node includes a backhaul communication unit that communicates with the pseudo IAB donor via a backhaul link, and an access link communication unit that communicates with one or more other mobile body wireless terminal devices via a mobile communication access link.

[0012] A mobile body according to yet another aspect of the present invention includes the wireless terminal device, and may include an electronic control unit connected to the pseudo core network device.

[0013] According to yet another aspect of the present invention, a wireless terminal device is mountable on a mobile body. The wireless terminal device includes a mobile station device capable of wireless communication with a mobile communication base station, a local core network device, a local IAB donor connected to the local core network device, a Mobile IAB node, and a connection switching unit. The Mobile IAB node includes a backhaul communication unit that performs backhaul link communication with the local IAB donor, and an access link communication unit that performs mobile communication access link communication with one or more other mobile body wireless terminal devices. The connection switching unit switches the connection of the end user node so that the end user node of the mobile body is connected to the mobile station device when the mobile station device is within the coverage area of ​​the base station cell, and the end user node of the mobile body is connected to the local core network device when the mobile station device is not within the coverage area of ​​the base station cell.

[0014] A mobile object according to yet another aspect of the present invention includes the wireless terminal device. The mobile object may include an electronic control unit as the end user node.

[0015] In any of the above-mentioned moving bodies, the moving body may be a vehicle, and the information transmitted and received between the wireless terminal device of the moving body and the wireless terminal device of the other one or more moving bodies may be information for multiple vehicles to travel in a formation.

[0016] A communication method according to yet another aspect of the present invention is a communication method for a plurality of wireless terminal devices mounted on a plurality of mobile bodies, the communication method including: performing backhaul link communication between any one of the wireless terminal devices of the plurality of mobile bodies and a pseudo IAB donor connected to a mobile communication pseudo core network device equipped in the wireless terminal device, via a Mobile IAB (Integrated Access and Backhaul) node equipped in the wireless terminal device; and performing mobile communication access link communication between the wireless terminal device of any one of the mobile bodies and one or more other wireless terminal devices of the mobile bodies, via the Mobile IAB node.

[0017] According to yet another aspect of the present invention, there is provided a communication method for a plurality of wireless terminal devices mounted on a plurality of mobile bodies, the communication method including: performing backhaul link communication between any one of the wireless terminal devices of the plurality of mobile bodies and a local IAB donor connected to a local core network device equipped in the wireless terminal device, using a MobileIAB (Integrated Access and Backhaul) node equipped in the wireless terminal device; performing mobile communication access link communication between the wireless terminal device of the one of the mobile bodies and one or more other wireless terminal devices of mobile bodies located in the vicinity of the wireless terminal device, using the MobileIAB node; and switching a connection of the end user node of the one of the mobile bodies so that the mobile station device connects an end user node of the mobile body to the mobile station device when the mobile station device is within the coverage area of ​​a mobile communication base station, and connects the end user node of the mobile body to the local core network device when the mobile station device is not within the coverage area of ​​the base station.

[0018] A program according to yet another aspect of the present invention is a program executed on a computer or processor included in a wireless terminal device that can be mounted in a mobile body, the program including: program code for performing backhaul link communication, by a Mobile IAB node included in the wireless terminal device, with a pseudo IAB donor connected to a mobile communication pseudo core network device included in the wireless terminal device; and program code for performing mobile communication access link communication, by the Mobile IAB node, with one or more other mobile wireless terminal devices.

[0019] A program according to yet another aspect of the present invention is a program executed on a computer or processor included in a wireless terminal device mountable in a mobile body, the program including: program code for performing backhaul link communication, by a Mobile IAB node included in the wireless terminal device, with a local IAB donor connected to a local core network device included in the mobile body; program code for performing mobile communication access link communication, by the Mobile IAB node, with wireless terminal devices of one or more other mobile bodies located in the vicinity of the wireless terminal device; and program code for switching connection of the end user node so that when the mobile station device included in the mobile body is within the coverage area of ​​a mobile communication base station, the end user node of the mobile body is connected to the mobile station device, and when the mobile station device is not within the coverage area of ​​the base station, the end user node of the mobile body is connected to the local core network device.

[0020] All or part of the program may include a trained model used in machine learning or a trained model created by machine learning. [Effects of the Invention]

[0021] According to the present invention, low-latency terminal-to-terminal communication is possible even when using conventional wireless terminal devices that do not have an interface for the conventional terminal-to-terminal direct communication method. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is an explanatory diagram showing an example of the overall configuration of a communication system according to an embodiment. [Figure 2] 5A and 5B are explanatory diagrams showing another example of the overall configuration of the communication system according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments will be described with reference to the drawings. Note that each drawing merely shows a schematic representation of the shape, size, and positional relationship to the extent that the contents of the present invention can be understood, and therefore the present invention is not limited to the shape, size, and positional relationship exemplified in each drawing. Furthermore, the numerical values ​​exemplified below are merely preferred examples of the present invention, and therefore the present invention is not limited to the exemplified numerical values.

[0024] As mentioned above, direct terminal-to-terminal communication such as V2V Direct using the conventional PC5 interface has the problem that it is only possible to communicate using wireless terminal devices with low antenna gain, resulting in a short communication distance and making it impossible to apply to general conventional wireless terminal devices (UE) that do not have a PC5 interface. Furthermore, terminal-to-terminal communication via base stations such as V2N2V using the conventional Uu interface has the problem that communication goes through the mobile carrier's base station equipment and backbone communication network, resulting in a lower theoretical limit of low-latency transmission performance compared to direct terminal-to-terminal communication. Furthermore, communication is impossible outside the range of the mobile carrier's base station, which is common in depopulated areas and mountainous regions.

[0025] The system according to the embodiment described herein is a novel communication system for direct end-to-end communication that can solve the above-mentioned problems by utilizing MobileIAB (Integrated Access and Backhaul) nodes, which enables multiple mobile bodies such as vehicles (e.g., trucks) to communicate directly with each other without using the interfaces of conventional direct end-to-end communication methods such as Sidelink communication. This communication system can be used, for example, to transmit and receive various information when multiple mobile bodies such as vehicles travel in a group, such as in a platoon, an electronically coupled vehicle, or an electronically towed vehicle.

[0026] As explained below, IAB is a technology that integrates wireless relay functions for the backhaul link side of a mobile communication network with access control functions for wireless terminal devices, and technical studies, specification formulation, and standardization are currently underway in 3GPP. IAB nodes, which perform the relay function in IAB, have the characteristic of being able to directly accommodate mobile stations (UE), which are wireless terminal devices for fifth-generation mobile communication systems, and 3GPP Release 18 is currently studying Mobile IAB, which will support the mobility of IAB nodes.

[0027] To further develop mobile communication networks using NR, 3GPP has established the Integrated Access and Backhaul (IAB) specification since Release 16, which applies the NR radio interface not only to links for communication between base stations and terminals and between terminals, i.e., access links, but also to links for communication between base stations and backbone networks, i.e., backhaul links, thereby enabling flexible and inexpensive network design and deployment and enabling the rapid provision of high-speed, high-capacity communication services over a wide area (see, for example, Non-Patent Document 15). The IAB defines IAB nodes, which serve as relay nodes responsible for both access links and backhaul links, and IAB donors, which are base station nodes that are wired to the backbone networks and wirelessly connected to IAB nodes via an interface called F1. The Backhaul Adaptation Protocol (BAP) has been established to route user Internet Protocol (IP) traffic between multiple IAB nodes and IAB donors that are directly and parallel connected (see, for example, Non-Patent Document 16). The NR base station functions can be divided into a central unit (CU), which is primarily responsible for radio resource control, and distributed units (DUs), which are primarily responsible for radio signal processing and radio wave transmission and reception, and can be configured to interconnect through an interface called F1 (see, for example, non-patent documents 17 and 18). The application of IAB makes it possible to install IAB nodes with functions equivalent to a base station's distributed unit (DU) without using a wired backhaul, which is expected to enable the expansion and densification of outdoor small cells and indoor NR networks. An IAB node consists of an IAB-Mobile Termination (IAB-MT), which has functions equivalent to those of a wireless terminal device (UE) in connecting to the network, and an IAB-DU, which corresponds to the DU function of a base station. The IAB-MT is a function that connects to the DU of an IAB donor or parent node as a backhaul link via the NR radio access interface (NR Uu).On the other hand, the IAB-DU is a function for connecting wireless terminal devices and child nodes as access links, and also has the function of connecting to the CU via the F1 interface, similar to the DU of a base station. The basic functions of the IAB specified by 3GPP include accommodating wireless terminal devices (UE) conforming to the initial version of NR, Release 15, and supporting multi-hop relay using multiple IAB nodes. In Release 16, the basic architecture of the IAB was defined as follows: Standalone mode, which uses NR for both C-Plane (Control-Plane) and U-Plane (User-Plane) transmission; and Evolved UTRAN and New Radio - Dual Connectivity (EN-DC) mode, which applies LTE for C-Plane transmission and NR for U-Plane transmission, i.e., C / U split transmission using LTE and NR. However, Release 17 newly specified the NR-DC mode, which applies C / U split transmission using NR Dual Connectivity (NR-DC) (see, for example, Non-Patent Documents 19 and 20).

[0028] 3GPP's IAB technical studies up to Release 17 were based on the assumption that IAB nodes were stationary. However, to continue supporting terminals in Release 15, the initial version of 5G, while further enhancing functionality, the Mobile IAB specification is being studied for Release 18, assuming application to Vehicle Mounted Relay (VMR). This specification supports dynamic inter-cell mobility (IAB node handover) across the coverage areas of multiple IAB donors. In particular, IAB nodes that support dynamic mobility are called "Mobile IAB nodes." Technical studies are planned for Group Mobility, which reduces the signaling load on network nodes during handover by simultaneously processing handovers for multiple wireless terminal devices (UEs) under the Mobile IAB node (see, for example, Non-Patent Documents 21, 22, and 23). The realization of Mobile IAB technology means that base station nodes for cellular mobile communications, which have traditionally been assumed to be stationary, will now be able to move around while also communicating with existing wireless terminal devices (legacy terminals).This means that it is expected that new communication services will be realized by utilizing mobile communications technology through Mobile IAB.

[0029] Although this document describes embodiments of the present invention assuming application to a fifth-generation mobile communication system (hereinafter referred to as a "5G system"), the concept of the present invention can be applied to any system using a similar cell configuration and physical channel configuration. Furthermore, the reference signal sequence used for channel estimation and the coding scheme used for error correction are not limited to those defined in the LTE system or the 5G system, and any type may be used as long as it is suitable for these applications. Embodiments of the present invention may also be applied to next-generation mobile communication systems (also referred to as "NR systems") that are later than the fifth generation.

[0030] Fig. 1 is a diagram showing an example of the overall configuration of a communication system according to an embodiment. In Fig. 1, the communication system according to the embodiment is configured using multiple wireless terminal devices 10(1), 10(2), and 10(3) mounted on vehicles 30(1), 30(2), and 30(3), which are multiple moving bodies traveling in a group in cooperation with each other on a road 90, which is a predetermined travel route.

[0031] While FIG. 1 illustrates an example in which three vehicles 30 are equipped with wireless terminal devices 10, the number of vehicles 30 traveling in a group may be two, four, or more. The illustrated example illustrates a case in which three vehicles 30(1) to 30(3) form a platoon (in a front-to-back direction relative to each other) and travel in a group, i.e., in a platoon. However, the relative positions of the vehicles 30 are not limited as long as the wireless terminal devices 10 mounted on the vehicles 30 are positioned so as to enable direct communication with each other. Furthermore, the vehicles 30 may be mobile objects such as automobiles, trucks, buses, and motorcycles that travel on roads 90, which are ground routes; they may be mobile objects capable of flying along routes in space, such as the sky; or they may be mobile objects capable of traveling along routes underground, on water (e.g., above the sea), or underwater (e.g., under the sea).

[0032] Vehicle 30 may be an electric vehicle, a fuel cell vehicle, or a hybrid vehicle having both an internal combustion engine and an electric motor. Furthermore, if vehicle 30 has multiple seats for occupants or passengers, vehicle 30 may be a vehicle in which the front-most and left-most seat is not the driver's seat. In other words, vehicle 30 may be a vehicle in which only the front-most and right-most seat is the driver's seat, or may be an autonomous vehicle that does not have a driver's seat at all.

[0033] 1, a wireless terminal device 10(1) mounted on a vehicle 30(1) at the front of a group of vehicles 30 (hereinafter also referred to as the "leading vehicle") in the direction of travel includes a pseudo network side device 110 and a Mobile IAB node 120. The pseudo network side device 110 includes a mobile communication pseudo core network device (hereinafter also referred to as the "pseudo mobile core") 111 and a pseudo IAB donor 112 connected to the pseudo mobile core 111. The pseudo mobile core 111 functions as a core network of a mobile communication network when not connected to a wide-area mobile communication network, and is connected to an on-board ECU 31, which is an electronic control unit mounted on the leading vehicle 30(1).

[0034] The pseudo IAB donor 112 functions as an IAB donor even when it is not connected to a wide-area mobile communication network. The pseudo IAB donor 112 is a parent node for the Mobile IAB node 120 and relays communication between the Mobile IAB node 120 and the pseudo mobile core 111.

[0035] The pseudo IAB donor 112 and the pseudo mobile core 111 can communicate, for example, via an S1-U interface or an NG interface, and the pseudo IAB donor 112 and the mobile IAB node 120 can communicate, for example, via an NR-Uu interface or an F1 interface.

[0036] The Mobile IAB node 120 includes an IAB-MT (Mobile Termination) 121 as a backhaul communication unit that performs backhaul link communication with the pseudo IAB donor 112, and an IAB-DU (Distributed Unit) 122 as an access link communication unit that performs mobile communication access link communication with wireless terminal devices 10(2) and 10(3) of following vehicles 30(2) and 30(3), which are wireless terminal devices of one or more other mobile bodies, via an antenna 120a. The IAB-MT 121 has functions equivalent to those of a user equipment (UE) as a normal mobile station device in connection with a core network. The IAB-DU 122 has functions equivalent to those of a wide-area base station in connection with the UE over the access link.

[0037] The MAC scheduler of the Mobile IAB node 170 also schedules the UEs of the following vehicles 30(2) and 30(3). 130 The wireless resource allocation control unit 100 performs wireless resource allocation control for controlling the allocation of wireless resources to the wireless devices.

[0038] The wireless terminal devices 10(2), 10(3) mounted on the intermediate vehicle 30(2) and the rear vehicle 30(3), which are the other vehicles positioned around the lead vehicle 30(1) as a plurality of moving bodies, each include a mobile wireless terminal UE130 as an access link communication unit. The UE130 communicates via an antenna 130a with the Mobile IAB node 120 of the wireless terminal device 10(1) of the lead vehicle 30(1) over a mobile communication access link. The UE130 is also connected to an on-board ECU 31, which is an electronic control unit mounted on each of the intermediate vehicle 30(2) and the rear vehicle 30(3).

[0039] The UE 130 includes, for example, an antenna, a transmission / reception switching unit (DUP), a receiving unit, a CP removal unit, an FFT unit, a signal separation unit, a propagation path compensation unit, a demodulation unit, a decoding unit, a DMRS propagation path (channel) estimation unit, a signal multiplexing unit, an IFFT unit, a CP insertion unit, a transmitting unit, and a control unit. The antenna can be used for both Uu communication and direct communication between terminals. The DMRS propagation path (channel) estimation unit estimates a wireless propagation path (equivalent propagation path) based on, for example, the reception result of a known demodulation reference signal (DMRS) transmitted from a base station. The demodulation unit demodulates and decodes a data signal included in a transmission signal based on the estimation result of the wireless propagation path (equivalent propagation path). The other components have the same functions as conventional components, so their description will be omitted.

[0040] The on-board ECU 31 of each vehicle is connected to a drive control unit, instruments, sensor unit, etc. via a network within the vehicle, and is a device that controls each unit and transmits and receives data to and from each unit.

[0041] According to the communication system of this embodiment, terminal-to-terminal communication is possible via the wireless terminal devices 10(1) to 10(3) installed in each vehicle 30(1) to 30(3), and information can be transmitted and received between the on-board ECU 31 of the leading vehicle 30(1) and the on-board ECUs 31 of the following intermediate vehicle 30(2) and the trailing vehicle 30(3).

[0042] The information transmitted between vehicles is, for example, position information indicating the current position of the vehicles. Furthermore, the information transmitted from the leading vehicle 30(1) to the following intermediate vehicle 30(2) and the following tail vehicle 30(3) is, for example, information such as the speed, acceleration, and steering information of the control target for group traveling. Furthermore, the information transmitted from the following intermediate vehicle 30(2) and the following tail vehicle 30(3) to the leading vehicle 30(1) is, for example, information on the monitoring images captured by the following vehicles and information on the instruments of the following vehicles.

[0043] In particular, according to the communication system of this embodiment, the following intermediate vehicle 30(2) and the trailing vehicle 30(3) are provided with a general-purpose UE 130 that performs communication over a mobile communication access link, and the UE 130 is simply connected to the on-board ECU 31. There is no need to provide an interface for a direct terminal-to-terminal communication method such as the SL communication method in each vehicle 30(1) to 30(3). Terminal-to-terminal communication is possible even when conventional terminals that do not have an interface for a direct terminal-to-terminal communication method are used. Furthermore, the radio resource control function of the Mobile IAB node 170 allows efficient and low-latency terminal-to-terminal communication by selecting and controlling resources that avoid or reduce interference from peripheral devices or systems that use the same frequency band.

[0044] In addition, the communication system of this embodiment is suitable for applications such as transmitting control messages between vehicles in autonomous truck platooning with the following vehicle (see Figure 1) and autonomous driving and platooning BRT (Bus Rapid Transit), which electronically connect multiple vehicles through direct communication between terminals, and transmitting surrounding surveillance video from the following vehicle to the lead vehicle.

[0045] For example, in the case of autonomous truck platooning (Figure 1), vehicle-to-vehicle communication (terminal-to-terminal direct communication) between the forward link (FL) and backward link (BL) enables the transmission of vehicle control messages (e.g., control information such as speed, acceleration, distance between vehicles, and steering) between vehicles, as well as the transmission of monitor images (still images and video) and sensor information. Using this vehicle-to-vehicle communication (terminal-to-terminal direct communication) in autonomous truck platooning can alleviate driver shortages and improve working conditions. Furthermore, the application of 5G's ultra-low latency and highly reliable communication in vehicle-to-vehicle communication (terminal-to-terminal direct communication) can shorten the distance between vehicles during platooning, improving fuel efficiency and CO2 emissions by reducing the air resistance of the vehicle platoon, while also alleviating congestion by increasing road capacity.

[0046] 2(a) and 2(b) are diagrams showing another example of the overall configuration of a communication system according to an embodiment. In FIGS. 2(a) and 2(b), components similar to those in FIG. 1 are denoted by the same reference numerals, and descriptions thereof will be omitted. The communication system according to this embodiment is an example of a 5G system, and includes a base station 40 connected to a core network (e.g., EPC, 5GC, or NGC) 50 of a mobile communication network directly or via an extended UPF (User Plane Function) 51. The UPF 51 is a node that processes user data traffic. While the example of FIG. 1 shows an example including one base station 40, the number of base stations may be multiple. The cell formed by the base station 40 may be a single cell, or three or more cells.

[0047] The core network 50 is, for example, an IP (Internet Protocol)-based EPC (Evolved Packet Core) defined by the 3rd Generation Partnership Project (3GPP). The core network 15 may be a core network dedicated to the 5G system, or a core network shared by the 5G system and the LTE system. The core network device (EPC device or 5GC device) is, for example, a Service Capability Exposure Function (SCEF), a Network Exposure Function (NEF), a User Plane Function (UPF) that processes user data, or the like, which are logical nodes having standard interfaces for providing services defined by 3GPP to third-party application providers. The core network device (EPC device or 5GC device) may also be a V2X Application Enabler (VAE) that enables the cooperation of multiple Vehicle-to-Everything (V2X) services. Note that some functions of the core network device (for example, the functions of the UPF or the functions of logical nodes other than the UPF) may be included in the base station 40, as in this embodiment.

[0048] Base station 40 is, for example, a gNodeB (gNB) or en-gNodeB (en-gNB) of a 5G system, and can communicate wirelessly with wireless terminal devices (also called "terminals," "user terminals," "user equipment," "UE," "mobile stations," "mobile devices," etc.) located in a cell, which is the wireless communication area formed by the base station.

[0049] The base station 40 is a wide-area mobile radio base station, has the above-mentioned IAB donor function, and relays communications between the core network 50 and MobileIAB nodes.

[0050] In Figures 2(a) and (b), a wireless terminal device 10(1) mounted on a lead car 30(1) which is one of the multiple vehicles 30 includes a UE 140 which is a mobile station device capable of wireless communication with a mobile communication base station, a local core network device (CNE) 150, a local IAB donor 160 connected to the local core network device (CNE) 150, a Mobile IAB node 170, and a connection switching unit 180.

[0051] The local core network device (CNE) 150 functions as a core network of a mobile communication network even when not connected to a wide-area mobile communication network, and is connected to an end user node 32 such as an on-board ECU, which is an electronic control unit installed in the lead vehicle 30(1).

[0052] The local IAB donor 160 functions as an IAB donor even when not connected to a wide-area mobile communication network. The local IAB donor 160 is a parent node for the Mobile IAB node 170 and relays communications between the Mobile IAB node 170 and the local core network device (CNE) 150.

[0053] The Mobile IAB node 170 has an IAB-MT as a backhaul communication unit that performs backhaul link communication with the local IAB donor 160, and an IAB-DU as an access link communication unit that performs mobile communication access link communication with the wireless terminal devices 10(2) and 10(3) of the following vehicles 30(2) and 30(3).

[0054] The local IAB donor 160 and the local core network device (CNE) 150 may communicate via, for example, an S1-U interface or an NG interface, and the local IAB donor 160 and the Mobile IAB node 170 may communicate via, for example, an NR-Uu interface or an F1 interface.

[0055] The connection switching unit 180 switches the connection of the end user node 32 so that when the UE 140 is within the cell of the base station 40 (within the range of the IAB donor) as shown in Figure 2(a), the connection switching unit 180 connects the end user node 32 of the lead vehicle 30(1) to the UE 140, and when the UE 140 is not within the cell of the base station 40 (within the range of the IAB donor) as shown in Figure 2(b), the connection switching unit 180 connects the end user node 32 of the lead vehicle 30(1) to the local core network device (CNE) 150. When direct terminal-to-terminal communication is performed with the wireless terminal devices 10(2) and 10(3) of the following vehicles 30(2) and 30(3) as shown in Figure 2(b), for example, the MAC scheduler of the Mobile IAB node 170 schedules the UEs of the following vehicles 30(2) and 30(3) to be connected to the end user node 32 of the lead vehicle 30(1). 130 The wireless resource allocation control unit 100 performs wireless resource allocation control for controlling the allocation of wireless resources to the wireless devices.

[0056] The wireless terminal devices 10(2), 10(3) mounted on the intermediate vehicle 30(2) and the rear vehicle 30(3), which are the other multiple moving bodies positioned around the lead vehicle 30(1), respectively, are equipped with a UE 130 as an access link communication unit. The UE 130 communicates via a mobile communication access link with the Mobile IAB node 170 of the wireless terminal device 10(1) of the lead vehicle 30(1). The UE 130 is connected to an end user node 32, such as an on-board ECU, which is an electronic control unit mounted on each of the intermediate vehicle 30(2) and the rear vehicle 30(3).

[0057] According to the communication system of this embodiment, as shown in FIG. 2(a), when each vehicle 30(1) to 30(3) is within the cell of the base station 40 (within the area of ​​the IAB donor), the UE of each vehicle 30(1) to 30(3) connects to the core network 50 of the mobile communication network via the base station 40, thereby enabling terminal-to-terminal communication between the leading vehicle 30(1) and the following intermediate vehicle 30(2) and trailing vehicle 30(3). Furthermore, since each wireless terminal device 10(1) to (3) is within the coverage area of ​​the base station 40 and connected to the core network 50 of the mobile communication network, it is also possible for a remote operation and monitoring center to remotely monitor and operate each vehicle 30(1) to (3). Furthermore, the base station 40 controls wireless resource allocation so as not to use the same frequency and the same time slot as other wireless terminal devices within the cell of the base station 40, thereby achieving efficient terminal-to-terminal communication with little co-channel interference.

[0058] On the other hand, as shown in Figure 2(b), when the vehicles 30(1) to 30(3) are not within the cell of the base station 40 (within the IAB donor's range), direct terminal-to-terminal communication can be performed between the lead vehicle 30(1) and the following intermediate vehicle 30(2) and rear vehicle 30(3) by using the Mobile IAB node 170 of the lead vehicle 30(1). In this way, regardless of whether the vehicles are within the cell of the base station 40 (within the IAB donor's range), terminal-to-terminal communication is possible via the wireless terminal devices 10(1) to 10(3) mounted on the respective vehicles 30(1) to 30(3), and information can be transmitted and received between the on-board ECU 31 of the lead vehicle 30(1) and the on-board ECU 31 of the following intermediate vehicle 30(2) and rear vehicle 30(3).

[0059] As described above, according to this embodiment, even if conventional terminals that do not have an interface for a direct terminal-to-terminal communication method such as the SL communication method are used between multiple wireless terminal devices 10(1) to 10(3) mounted on multiple vehicles 30(1) to 30(3), low-latency terminal-to-terminal communication is possible without going through the base station 40 or the core network 50. Furthermore, the wireless resource control function of the Mobile IAB node 170 allows for efficient and low-latency terminal-to-terminal communication by selecting and controlling resources that avoid or reduce interference from peripheral devices or systems that use the same frequency band.

[0060] This invention can provide a communication system that can improve fuel efficiency and reduce CO2 emissions by reducing the air resistance of vehicles, while also alleviating congestion by increasing road capacity, thereby contributing to the achievement of Goal 9 of the Sustainable Development Goals (SDGs), which is to "build resilient infrastructure, promote industry, innovation and infrastructure."

[0061] The process steps and components of the communication systems, base stations, and wireless terminals (terminals, terminal devices, user equipment (UE), mobile stations, mobile devices) described herein may be implemented by various means. For example, these steps and components may be implemented in hardware, firmware, software, or a combination thereof.

[0062] For hardware implementation, the processing units and other means used to implement the above steps and components in an entity (e.g., various wireless terminal devices, Node B, eNodeB, gNodeB, terminal, hard disk drive device, or optical disk drive device) may be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processors (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, computers, or combinations thereof.

[0063] Furthermore, with regard to firmware and / or software implementations, the means, such as a processing unit, used to realize the above components may be implemented with a program (e.g., code, such as procedures, functions, modules, instructions, etc.) that performs the functions described herein. In general, any computer / processor-readable medium tangibly embodying firmware and / or software code may be used to implement the means, such as a processing unit, used to realize the above steps and components described herein. For example, the firmware and / or software code may be stored in a memory and executed by a computer or processor, such as in a controller. The memory may be implemented within the computer or processor or external to the processor. Furthermore, the firmware and / or software code may be stored in a computer- or processor-readable medium, such as random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), flash memory, floppy disk, compact disk (CD), digital versatile disk (DVD), magnetic or optical data storage device, etc. The code may be executed by one or more computers or processors and may cause the computers or processors to perform certain aspects of the functionality described herein.

[0064] The medium may be a non-transitory recording medium. The program code may be in any format as long as it can be read and executed by a computer, processor, or other device or machine. For example, the program code may be in any of source code, object code, and binary code, or may be a mixture of two or more of these codes.

[0065] Moreover, the description of the embodiments disclosed herein is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. [Explanation of symbols]

[0066] 10, 10(1) to 10(3): Wireless terminal device 15: Core network 30, 30(1)~30(3): Vehicle 31: Vehicle ECU 32: End user node 40:Base station 50: Core network 90: Road 110: Pseudo network side device 111: Pseudo Mobile Core 112: Pseudo IAB donor 120: Mobile IAB node 120a: Antenna 130a: Antenna 140a: Antenna 160: Local IAB donors 170: Mobile IAB node 170a: Antenna 180: Connection switch unit [Prior art documents] [Non-patent literature]

[0067] [Non-Patent Document 1] Report ITU-R M.2410, "Minimum Requirements Related to Technical Performance for IMT-2020 Radio Interface(s)," Nov. 2017. [Non-patent document 2] Manabu Mikami and Hitoshi Yoshino, "Field Trial of 5G Low Latency Radion Communication System Towards Application to Truck Platooning," IEICE Transactions on Communications, vol.E102-B, no.8, pp.1447-1457, Aug. 2019. [Non-patent document 3] Alessandro Bazzi, Antoine O. Berthet, Claudia Campolo, Barbara Mavi, Masini, Antonella Molinaro, and Alberto Zanella, "On the Design of SL for Cellular V2X: A Literature Review and Outlook for Future," IEEE Access, vol.9, pp. 97953-97980, July 2021. [Non-patent document 4] 3GPP TR36.843 V12.0.1,"Study on LTE Device to Device Proximity Services; Radio aspects; (Release 12)," March 2014. [Non-Patent Document 5] Pavel Mach, Zdenek Becvar, and Tomas Vanek, "In-Band Device-to-Device Communication in OFDMA Cellular Networks: A Survey and Challenges," IEEE Communication Surveys & Tutorials, vol.17, no.4, pp.1885-1922, June 2015.

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Claims

1. A communication system including a wireless terminal device mounted on each of a plurality of moving objects that move as a group, a wireless terminal device mounted on a first moving body included in the plurality of moving bodies moving as a group, a pseudo core network device for mobile communications; a pseudo-IAB (Integrated Access and Backhaul) donor connected to the pseudo-core network device; a Mobile IAB node; The Mobile IAB node a backhaul communication unit that performs backhaul link communication with the pseudo IAB donor; an access link communication unit that performs wireless communication of an access link for mobile communication with a wireless terminal device mounted on a second moving body, which is different from the first moving body, among the plurality of moving bodies that move as the group; A communication system in which a wireless terminal device mounted on the second mobile body is equipped with an access link communication unit that performs wireless communication of a mobile communication access link between the wireless terminal device mounted on the first mobile body and the Mobile IAB node of the wireless terminal device.

2. 2. The communication system of claim 1, the first mobile entity comprises an electronic control unit connected to the pseudo core network device; The second mobile object comprises an electronic control unit connected to a wireless terminal of the second mobile object.

3. 3. The communication system of claim 2, each of the plurality of moving bodies is a vehicle; A communication system in which information transmitted and received between the wireless terminal device of the first moving body and the wireless terminal device of the second moving body is information for the plurality of moving bodies to travel in formation.

4. A wireless terminal device that can be mounted on a second moving body that moves together with a first moving body as part of a group, a pseudo core network device for mobile communications; a pseudo-IAB (Integrated Access and Backhaul) donor connected to the pseudo-core network device; a Mobile IAB node; and Equipped with The Mobile IAB node includes a backhaul communication unit that performs backhaul link communication with the pseudo IAB donor, and an access link communication unit that performs wireless communication of a mobile communication access link with a wireless terminal device that can be mounted on the first mobile body. Wireless terminal device.

5. A mobile object comprising the wireless terminal device of claim 4.

6. The moving body of claim 5, an electronic control unit connected to the pseudo core network device; Mobile object.

7. 7. The moving body according to claim 5 or 6, the first moving body and the second moving body are vehicles, The information transmitted and received between the wireless terminal device of the first moving body and the wireless terminal device of the second moving body is information for a plurality of vehicles to travel in formation.

8. A communication method for a wireless terminal device mounted on each of a plurality of moving objects moving as a group, comprising: A wireless terminal device mounted on a first mobile object included in the plurality of mobile objects moving as the group performs backhaul link communication with a pseudo IAB donor connected to a mobile communication pseudo core network device provided in the wireless terminal device, using a Mobile IAB (Integrated Access and Backhaul) node provided in the wireless terminal device; A wireless terminal device mounted on the first moving body performs wireless communication of a mobile communication access link with a wireless terminal device mounted on a second moving body, which is different from the first moving body, among the plurality of moving bodies moving as the group, by the Mobile IAB node; A communication method, including:

9. A program executed on a computer or a processor provided in a wireless terminal device that can be mounted on a second moving body that moves together with a first moving body as part of a group, the program comprising: A program code for performing backhaul link communication between a Mobile IAB (Integrated Access and Backhaul) node included in the wireless terminal device and a pseudo IAB donor connected to a mobile communication pseudo core network device included in the wireless terminal device; program code for performing wireless communication over a mobile communication access link between the Mobile IAB node and a wireless terminal device of the first mobile body; Including, the program.

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