CN111165003A

CN111165003A - Communication method and device for ultra-high speed vehicle

Info

Publication number: CN111165003A
Application number: CN201880064142.0A
Authority: CN
Inventors: 朴淳基
Original assignee: Electronics and Telecommunications Research Institute ETRI
Current assignee: Electronics and Telecommunications Research Institute ETRI
Priority date: 2017-10-12
Filing date: 2018-10-05
Publication date: 2020-05-15
Anticipated expiration: 2038-10-05
Also published as: KR20190041404A; KR102565713B1; CN111165003B

Abstract

A communication method and apparatus for an ultra-high speed vehicle is disclosed. The communication device includes: a processor for performing radio resource control functions for communicating between a first mobile device and a communication device; a plurality of DA's located in a path of the first mobile device and transmitting or receiving signals according to a control of the processor; and a memory to store at least one command for execution by the processor, wherein the at least one command is executed to configure a first sliding window comprising n DA's of the plurality of DA's corresponding to a first location of a first mobile device and to communicate with the first mobile device located at the first location using the n DA's. Accordingly, the performance of the communication system can be improved.

Description

Communication method and device for ultra-high speed vehicle

Technical Field

The present invention relates to a communication technique for an ultra-high speed vehicle, and more particularly, to a communication technique for supporting communication between an ultra-high speed vehicle and a ground network.

Background

Communication between the base station and a vehicle moving at a high speed (for example, a train moving at a speed of 350km/h or less) may be performed based on a cellular communication scheme. Further, the communication network dedicated to the vehicle may be installed in a form in which base stations each having a cell coverage of several kilometers are installed along the moving path of the vehicle. In this case, communication between a vehicle moving at a speed up to 500km/h and a base station can support a transmission rate of several megabits per second (Mbps) to several tens of Mbps.

Furthermore, for vehicles moving below 500km/h speed, the communication will be supported for a long term evolution-orbit (LTE-R) based communication system or a 5G communication system. In addition, a leaky coaxial cable (LCX) based communication system may be used for high speed trains or maglev trains. The LCX-based communication system may support communication for vehicles (e.g., maglev trains) moving at speeds of about 600km/h or less. In the LCX-based communication system, the radiation cable may be segmented into units each having a predetermined length, and communication may be performed based on radio waves generated by a leakage current of the segmented cable. In this case, installation and maintenance costs may increase because a constant interval should be maintained between the cable and the receiving node, and precise alignment is required when installing the cable. Further, as the length of the cable becomes longer, reception performance may be degraded as signal loss increases, handover (handoff) may occur between segmented cables, and performance may be degraded at a point of time when the handover occurs.

When the above-described communication scheme is used, a data transmission rate at a boundary between cells (or segmented cables) may be deteriorated, and the data transmission rate tends to be lowered due to the doppler effect as the vehicle speed increases. Therefore, at ultra high speeds (e.g., 1200km/h), communication is almost impossible using conventional communication schemes. That is, when communication is performed based on the cellular communication scheme, communication quality may be deteriorated due to an increase in the doppler effect, and a handover procedure may be frequently performed, thereby degrading communication performance. Furthermore, the above communication scheme has a limitation in supporting communication for ultra-high speed vehicles (e.g., trains traveling at speeds greater than 1220 km/h). Therefore, new functions and designs are needed to overcome the above problems.

Disclosure of Invention

Technical problem

The present invention is directed to a method and apparatus for providing a communication service to an ultra high speed vehicle.

Technical scheme

In order to achieve the above object, according to a first embodiment of the present invention, a communication apparatus may include: a processor that performs a radio resource control function for communication between the communication device and a first mobile device; a plurality of Distributed Antennas (DA) disposed along a movement path of a first mobile device, which transmit and receive signals under control of the processor; and a memory storing at least one instruction for execution by the processor. The at least one instruction may be configured to: configuring a first sliding window comprising n DAs of a plurality of DAs corresponding to a first location of the first mobile device; performing communication with the first mobile device at the first location using n DAs; reconfiguring the first sliding window to include m DA's of a plurality of DA's corresponding to a second location when the first mobile device moves from the first location to the second location; and performing communication with the first mobile device located at the second location using the m DA's, wherein one or more of the n DA's are the same as one or more of the m DA's, each of n and m is an integer equal to or greater than 2, and the first location and the second location belong to the movement path.

Here, synchronization between the n DA or the m DA belonging to the first sliding window may be maintained by the processor.

Here, the n DAs may transmit and receive the same signal using the same radio resource when performing communication with the first mobile device located at the first location.

Here, the m DAs may transmit and receive the same signal using the same radio resource when performing communication with the first mobile device located at the second location.

Here, the location of the first mobile device may be estimated based on a signal received from the first mobile device.

Here, a plurality of Radio Bearers (RBs) may be configured for communication between the communication device and the first mobile device, and a cell radio network temporary identifier (C-RNTI) for each RB is independently configured.

Here, the at least one instruction may be further configured to: configuring a second sliding window comprising k DAs of a plurality of DAs corresponding to a third location of a second mobile device moving along the movement path; and performing communication with the second mobile device located at the third location using the k DA's, where k is an integer equal to or greater than 2, and the second location belongs to the movement path.

Here, the k DA may not overlap with the n DA or the m DA.

Here, the dedicated cell formed by the second sliding window may be different from the dedicated cell formed by the first sliding window.

Here, the communication using the k DA may be performed simultaneously with the communication using the n DA or the communication using the m DA.

In order to achieve the above object, according to a second embodiment of the present invention, a communication method performed by a mobile device may include: performing, when the mobile device is located at a first position in the movement path, communication with a communication device including a plurality of Distributed Antennas (DA) via a sliding window including n DAs corresponding to the first position among a plurality of DAs arranged along the movement path, and performing, when the mobile device moves from the first position to a second position in the movement path, communication with the communication device via a sliding window including m DAs corresponding to the second position among a plurality of DAs arranged along the movement path, wherein one or more of the n DAs are the same as one or more of the m DAs, and each of n and m is an integer equal to or greater than 2.

Here, a dedicated cell formed by the sliding window configured for the mobile device located at the first position may be the same as a dedicated cell formed by the sliding window configured for the mobile device located at the second position.

Here, in the communication between the mobile device located at the first location and the n DA, the same signal may be received from the n DA using the same radio resource.

Here, in the communication between the mobile device located at the second location and the m DAs, the same signal may be received from the m DAs using the same radio resource.

Here, information for estimating the location of the mobile device may be transmitted from the mobile device to the communication device, and the first location and the second location may be estimated by the communication device based on the information.

Advantageous effects

According to the present invention, a sliding window including a plurality of antennas can be moved according to the speed of an ultra-high speed vehicle (e.g., a train moving at a speed of 1220km/h or more), thereby providing a communication service to the ultra-high speed vehicle. Further, since the sliding window moves according to the speed of the ultra-high speed vehicle, the communication quality does not deteriorate and a handover (handover) process can be minimized. Accordingly, the performance of the communication system can be improved.

Drawings

Fig. 1 is a block diagram illustrating a first embodiment of a communication system.

Fig. 2 is a conceptual diagram illustrating a first embodiment of a communication method between a vehicle and a communication system.

FIG. 3 is a graph illustrating a first embodiment of signal strength received at a vehicle.

FIG. 4 is a graph illustrating a second embodiment of signal strength received at a vehicle.

Fig. 5 illustrates a first embodiment showing a port mapping relationship in VA2C of the communication system.

Fig. 6 illustrates a second embodiment showing a port mapping relationship in VA2C of the communication system.

Fig. 7 illustrates a third embodiment showing a port mapping relationship in VA2C of the communication system.

Fig. 8 illustrates a fourth embodiment showing a port mapping relationship in VA2C of the communication system.

Fig. 9 illustrates a fifth embodiment showing a port mapping relationship in VA2C of the communication system.

Fig. 10 illustrates a sixth embodiment showing a port mapping relationship in VA2C of the communication system.

Fig. 11 illustrates a seventh embodiment showing a port mapping relationship in VA2C of the communication system.

Fig. 12 illustrates an eighth embodiment showing a port mapping relationship in VA2C of the communication system.

Fig. 13 illustrates a ninth embodiment showing a port mapping relationship in VA2C of the communication system.

Fig. 14 is a conceptual diagram illustrating a first embodiment of a protocol stack of a communication system.

Fig. 15 is a conceptual diagram illustrating a first embodiment of a downlink resource allocation method in a communication system.

Fig. 16 is a conceptual diagram illustrating a second embodiment of a downlink resource allocation method in a communication system.

Fig. 17 is a conceptual diagram illustrating a third embodiment of a downlink resource allocation method in a communication system.

Fig. 18 is a conceptual diagram illustrating a fourth embodiment of a downlink resource allocation method in a communication system.

Fig. 19 is a conceptual diagram illustrating a fifth embodiment of a downlink resource allocation method in a communication system.

Fig. 20 is a conceptual diagram illustrating a first embodiment of an uplink communication method in a communication system.

Fig. 21 is a conceptual diagram illustrating a second embodiment of an uplink communication method in a communication system.

Fig. 22 is a conceptual diagram illustrating a first embodiment of an uplink resource allocation method in a communication system.

Fig. 23 is a conceptual diagram illustrating a second embodiment of an uplink resource allocation method in a communication system.

Fig. 24 is a conceptual diagram illustrating a third embodiment of an uplink resource allocation method in a communication system.

Fig. 25 is a conceptual diagram illustrating a fourth embodiment of an uplink resource allocation method in a communication system.

Fig. 26 is a conceptual diagram illustrating a first embodiment of a message generation procedure of each RB in the communication system.

Fig. 27 is a conceptual diagram illustrating a first embodiment of downlink resources to which RBs are allocated in a communication system.

Fig. 28 is a conceptual diagram illustrating a first embodiment of uplink resources to which RBs are allocated in a communication system.

Fig. 29 is a conceptual diagram illustrating a first embodiment of a downlink retransmission method when RLC AM is utilized.

Fig. 30 is a conceptual diagram illustrating a first embodiment of an uplink retransmission method when RLC AM is utilized.

Fig. 31 is a conceptual diagram illustrating a first embodiment of a downlink communication method based on a synchronization protocol.

Fig. 32 is a conceptual diagram illustrating a first embodiment of an uplink communication method based on a synchronization protocol.

Fig. 33 is a block diagram illustrating a second embodiment of a communication system.

Fig. 34 is a block diagram illustrating a first embodiment of a probe request/response packet used in a delayed probing process.

Fig. 35 is a block diagram illustrating a second embodiment of a probe request/response packet used in a delayed probing process.

Fig. 36 is a block diagram illustrating a third embodiment of a communication system.

Fig. 37 is a block diagram illustrating a third embodiment of a probe request/response packet used in a delayed probing process.

Fig. 38 is a block diagram illustrating a fourth embodiment of a communication system.

Fig. 39 is a block diagram illustrating a fourth embodiment of a probe request packet used in a delayed probing process.

Fig. 40 is a block diagram illustrating a fourth embodiment of a probe response packet used in a delayed probing process.

Fig. 41 is a block diagram illustrating a fifth embodiment of a communication system.

Fig. 42 is a block diagram illustrating a sixth embodiment of a communication system.

Fig. 43 is a block diagram illustrating a first embodiment of a downlink packet.

Fig. 44 is a block diagram illustrating a seventh embodiment of the communication system.

Fig. 45 is a block diagram illustrating an eighth embodiment of a communication system.

Fig. 46 is a block diagram illustrating a first embodiment of an uplink packet.

Fig. 47 is a conceptual diagram showing the first embodiment of the received signal strength in downlink communication.

Fig. 48 is a conceptual diagram illustrating a first embodiment of received signal strength in uplink communication.

Fig. 49 is a conceptual diagram illustrating a second embodiment of received signal strength in uplink communication.

Fig. 50 is a conceptual diagram illustrating a first embodiment of a system configuration for communication between the communication system and the vehicle.

Fig. 51 is a graph illustrating the first embodiment of the vehicle operation profile.

Fig. 52 is a conceptual diagram illustrating a first embodiment of a CRZ of a vehicle.

Fig. 53 is a conceptual diagram illustrating a first embodiment of a method for allocating time frequency resources in overlapping CRZs.

Fig. 54 is a conceptual diagram illustrating a second embodiment of a method for allocating time frequency resources in an overlapped CRZ.

Fig. 55 is a conceptual diagram illustrating the first embodiment of the RB configured between the communication system and the vehicle.

Fig. 56 is a conceptual diagram illustrating unique identification numbers assigned to antennas included in LA2M of a communication system.

Fig. 57 is a conceptual diagram illustrating a first embodiment of a method for transmitting a unique identification number.

Fig. 58 is a conceptual diagram illustrating a unique identification number identified by a vehicle.

Fig. 59 is a graph illustrating received signal strength of a signal including a unique identification number.

Fig. 60 is a flowchart illustrating a first embodiment of a method for correcting a vehicle position.

Fig. 61 is a conceptual diagram illustrating a second embodiment of a method for transmitting a unique identification number.

Fig. 62 is a conceptual diagram illustrating a downlink CRZ arranged in units of good windows.

Fig. 63 is a conceptual diagram illustrating a third embodiment of a method for transmitting a unique identification number.

Fig. 64 is a conceptual diagram illustrating an uplink CRZ arranged in good window units.

Fig. 65 is a conceptual diagram illustrating a fourth embodiment of a method for transmitting a unique identification number.

Fig. 66 is a conceptual diagram illustrating a first embodiment of downlink resources configured based on the FDD scheme.

Fig. 67 is a conceptual diagram illustrating the first embodiment of the vehicle operation method at the time of emergency.

Fig. 68 is a conceptual diagram illustrating a first embodiment of LA2M and CA2M of a vehicle of a DU-based communication system.

Fig. 69 is a conceptual diagram illustrating a first embodiment of an LCX-based communication system.

Fig. 70 is a conceptual diagram illustrating an LRCM structure in an LCX-based communication system.

Fig. 71 is a conceptual diagram illustrating a first embodiment of a radiation angle according to a slotted arrangement.

Fig. 72 is a sequence diagram illustrating the first embodiment of the communication method between the communication system and the vehicle.

Fig. 73 is a conceptual diagram illustrating a sliding window configured according to the communication method illustrated in fig. 72.

Detailed Description

While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. It should be understood, however, that the description is not intended to limit the invention to the particular embodiments, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Although the terms "first," "second," etc. may be used herein with reference to various elements, such elements should not be construed as limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and a second element could be termed a first element, without departing from the scope of the present invention. The term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes" and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, components, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. To facilitate an overall understanding of the invention, like reference numerals refer to like elements throughout the description of the figures, and the description of like components will not be repeated. In the following embodiments, even though a method (e.g., transmission or reception of a signal) to be performed at a first communication node among communication nodes is described, a corresponding second communication node may perform a method (e.g., reception or transmission of a signal) corresponding to the method performed at the first communication node. That is, when the operation of the ground communication apparatus is described, the corresponding vehicle may perform an operation corresponding to the operation of the ground communication apparatus. In contrast, when the operation of the vehicle is described, the corresponding ground communication device may perform an operation corresponding to the operation of the vehicle.

Fig. 1 is a block diagram showing a first embodiment of a communication system.

Referring to fig. 1, a communication system 100 may include: a Central Communication Unit (CCU)110, a pipe side unit (TSU) 120, a virtual active antenna controller (VA 2C) 130, a line active antenna module (LA 2M) 140, and the like. Here, the communication system 100 may be referred to as a "terrestrial network (GN)", "terrestrial communication device", or the like. The TSU120 may include a plurality of TSUs 120-1 and 120-2, the VA2C130 may include a plurality of VA2C130-1, 130-2, and 130-3, and the LA2M140 may include a plurality of LA2M 140-1, 140-2, 140-3, 140-4, and 140-5.

The CCU110 may be connected to the TSU120 as a lower entity, and may control and manage the TSU120, the VA2C130, and the LA2M 140. The CCU110 may support at least one of a Packet Data Convergence Protocol (PDCP) function, a Radio Link Control (RLC) function, and a Radio Resource Control (RRC) function. Further, the CCU110 may include a processor (e.g., a Central Processing Unit (CPU)), a memory that stores instructions executed by the processor, and the like, and the processor of the CCU110 may perform predetermined operations.

The TSU120 may be connected to the CCU110 as an upper entity and may be connected to at least one of the VA2C130-1, 130-2 and 130-3 as a lower entity, and the TSU120 may manage and control at least one of the VA2C130-1, 130-2 and 130-3. For example, TSU 120-1 can be linked to VA2C130-1 and VA2C130-2, and the like. In this case, TSU 120-1 may be connected to VA2C130-1 via port # C and may be connected to VA2C130-2 via port # B. TSU 120-2 can be connected to VA2C 130-3, and the like. In this case, TSU 120-2 may be connected to VA2C 130-3 through port # A. The TSU120 may support at least one of a PDCP function, an RLC function, a Medium Access Control (MAC) function, and a Physical (PHY) function. Further, the TSU120 may include a processor (e.g., CPU), a memory storing instructions executed by the processor, and the like, and the processor of the TSU120 may perform predetermined operations.

VA2C130 may include a plurality of ports, and may be connected to TSU120 as an upper entity via upper ports (e.g., ports # a to # C), and may be connected to LA2M140 as a lower entity via ports # a to # o. One upper port (e.g., ports # a to # C) in the VA2C130 may be mapped to at least one lower port (e.g., ports # a to # o). VA2C130-1 can be linked to LA2M 140-1 and LA2M 140-2. In this case, each of the ports # k to # o may be mapped to each antenna belonging to LA2M 140-1 and LA2M 140-2 based on a one-to-one scheme. VA2C130-2 can be linked to LA2M 140-3, LA2M 140-4, and the like. In this case, each of the ports # c to # j may be mapped to each antenna belonging to LA2M 140-3 and LA2M 140-4 based on a one-to-one scheme. VA2C 130-3 can be linked to LA2M 140-5 and the like. In this case, each of ports # a and # b belonging to VA2C 130-3 may be mapped to each antenna belonging to LA2M 140-5 based on a one-to-one scheme.

LA2M140 may be connected to VA2C130 as an upper entity. LA2M140 may include multiple antennas. Antennas belonging to LA2M140 may be referred to as Distributed Antennas (DA), active Antenna Assemblies (AAC), Distributed Units (DU), and so on. LA2M140 may support at least one of MAC functions, PHY functions, and Radio Frequency (RF) functions. Further, LA2M140 may include a processor (e.g., a CPU), a memory storing instructions executed by the processor, or the like, and the processor of LA2M140 may perform predetermined operations.

In addition, LA2M140 may be installed along the path of travel of the vehicle (e.g., track, super speed pipe). When the vehicle moves along the moving path, communication between the vehicle and the communication system may be performed via an antenna installed in the vehicle and an antenna installed along the moving path corresponding to a position of the vehicle.

Referring to fig. 2, LA2M140 may include LA2M 140-1 through 140-5 of communication system 100 shown in fig. 1. The vehicle 200 may move along a moving path, and the sliding window may be configured according to the moving path of the vehicle 200. The sliding window may be configured by the CCU110 and TSU120 of the communication system 100. Here, the vehicle 200 may be a high-speed train, an ultra-high-speed train, a magnetic levitation train, a cabin (capsule) of super high-speed railway (hyper), or the like. The sliding window may include a plurality of antennas, and the communication system 100 may communicate with the vehicle 200 using the plurality of antennas belonging to the sliding window. For example, among all antennas belonging to the LA2M140, an antenna belonging to the sliding window may be operated in an on state (e.g., an activated state, an enabled state), and communication may be performed between the antenna operated in the on state and an antenna installed in the vehicle 200. The antennas installed in the vehicle 200 may be referred to as DA, AAC, DU, or the like. In the vehicle 200, the antenna may be mounted in a cabin active antenna module (CA 2M). Multiple antennas may be installed in vehicle 200, in which case CA2M may include multiple antennas.

The sliding window may move according to the moving speed of the vehicle 200, and the movement of the sliding window brings about the moving effect of the base station. Accordingly, a sliding window (e.g., the communication system 100 performing communication using a plurality of antennas belonging to the sliding window) may be referred to as a mobile cell, a virtual base station, a home base station (ghost base station), and the like. A sliding window may be dedicated to one vehicle 200.

In LA2M140, antennas may be installed at regular intervals (e.g., 10 m). For example, when the mounting interval of the antennas is 10m and the sliding window includes 50 antennas, the length of the sliding window may be 500 m. The number of antennas included in the sliding window may be configured differently, and the number of antennas belonging to the sliding window may be changed according to the installation interval of the antennas. In addition, the received signal strength at the vehicle 200 may vary depending on the number of antennas belonging to the sliding window.

Fig. 3 is a graph illustrating a first embodiment of signal strength received at a vehicle, and fig. 4 is a graph illustrating a second embodiment of signal strength received at a vehicle.

Referring to fig. 3 and 4, all antennas in the sliding window may transmit signals in a Joint Transmission (JT) scheme. When using the JT scheme, all antennas belonging to the sliding window may transmit the same signal (e.g., control information, data, content, etc.) using the same time-frequency resources. The number of antennas in the sliding window of fig. 3 may be twice the number of antennas in the sliding window of fig. 4. In the vehicle 200, an average received signal strength may be determined between a maximum received signal strength and a minimum received signal strength. In fig. 3, the maximum received signal strength may be equal to the maximum received signal strength of fig. 4, and the minimum received signal strength of fig. 3 may be higher than the minimum received signal strength of fig. 4.

The minimum received signal strength may be related to a minimum guaranteed capacity of the vehicle 200 (e.g., a minimum target capacity for downlink in the vehicle 200). The installation interval of the antenna in LA2M140 may be determined in consideration of the minimum guaranteed capacity of the vehicle 200. For example, when the minimum guaranteed capacity of the vehicle 200 is low, the installation interval of the antenna in LA2M140 may be relatively wide, and the installation cost of the communication system 100 may be reduced. That is, as the installation interval of the antenna in LA2M140 decreases, the received signal strength in vehicle 200 may increase, while as the installation interval of the antenna in LA2M140 increases, the installation cost of the communication system may decrease.

Further, according to the movement of the sliding window, the mapping relationship between the upper port and the lower port in VA2C130 can be configured as follows. Here, the sliding window may be configured to include 6 antennas, and may move according to the moving speed of the vehicle 200.

Referring to fig. 5, the sliding window may be controlled and managed by the CCU110 and the TSU 120-1 of the communication system 100 and include antennas connected to ports # k, # l, # m, and # n of VA2C130-1 and antennas connected to ports # i and # j of VA2C 130-2. For example, TSU 120-1 may transmit a signal to port # C of VA2C130-1, and in VA2C130-1, a corresponding signal may be transmitted from port # C to ports # k, # l, # m, and # n in a multicast manner. Furthermore, TSU 120-1 may transmit signals to port # B of VA2C130-2, and in VA2C130-2, corresponding signals may be transmitted in a multicast manner from port # B to ports # i and # j.

Referring to fig. 6, the sliding window may be controlled and managed by the CCU110 and the TSU 120-1 of the communication system 100 and include antennas connected to ports # k, # l, and # m of VA2C130-1 and antennas connected to ports # h, # i, and # j of VA2C 130-2. When the sliding window of fig. 6 is compared with the sliding window of fig. 5, in the sliding window of fig. 6, an antenna connected to port # n of VA2C130-1 may be excluded (i.e., the connection between port # C and port # n is released), and an antenna connected to port # h of VA2C130-2 may be added (i.e., the connection between port # B and port # h is added). For example, TSU 120-1 may transmit signals to port # C of VA2C130-1, and in VA2C130-1, corresponding signals may be transmitted from port # C to ports # k, # l, and # m in a multicast manner. Furthermore, TSU 120-1 may transmit signals to port # B of VA2C130-2, and in VA2C130-2, corresponding signals may be transmitted from port # B to ports # h, # i, and # j in a multicast manner.

Referring to fig. 7, the sliding window may be controlled and managed by the CCU110 and the TSU 120-1 of the communication system 100 and include antennas connected to ports # k and # l of VA2C130-1 and antennas connected to ports # g, # h, # i, and # j of VA2C 130-2. When the sliding window of fig. 7 is compared with the sliding window of fig. 6, in the sliding window of fig. 7, an antenna connected to port # m of VA2C130-1 may be excluded (i.e., the connection between port # C and port # m is released), and an antenna connected to port # g of VA2C130-2 may be added (i.e., the connection between port # B and port # g is added). For example, TSU 120-1 may transmit signals to port # C of VA2C130-1, and in VA2C130-1, corresponding signals may be transmitted in a multicast manner from port # C to ports # k and # l. Furthermore, TSU 120-1 may transmit signals to port # B of VA2C130-2, and in VA2C130-2, corresponding signals may be transmitted from port # B to ports # g, # h, # i, and # j in a multicast manner.

Referring to fig. 8, the sliding window may be controlled and managed by the CCU110 and the TSU 120-1 of the communication system 100 and include an antenna connected to port # k of VA2C130-1 and antennas connected to ports # f, # g, # h, # i, and # j of VA2C 130-2. When the sliding window of fig. 8 is compared with the sliding window of fig. 7, in the sliding window of fig. 8, an antenna connected to port # l of VA2C130-1 may be excluded (i.e., the connection between port # C and port # l is released), and an antenna connected to port # f of VA2C130-2 may be added (i.e., the connection between port # B and port # f is added). For example, TSU 120-1 may send a signal to port # C of VA2C130-1, and in VA2C130-1, a corresponding signal may be sent from port # C to port # k. Furthermore, TSU 120-1 may transmit signals to port # B of VA2C130-2, and in VA2C130-2, corresponding signals may be transmitted from port # B to ports # f, # g, # h, # i, and # j in a multicast manner.

Referring to fig. 9, the sliding window may be controlled and managed by the CCU110 and the TSU 120-1 of the communication system 100 and includes antennas connected to ports # e, # f, # g, # h, # i, and # j of VA2C 130-2. When the sliding window of fig. 9 is compared with the sliding window of fig. 8, in the sliding window of fig. 9, an antenna connected to port # k of VA2C130-1 may be excluded (i.e., the connection between port # C and port # k is released), and an antenna connected to port # e of VA2C130-2 may be added (i.e., the connection between port # B and port # e is added). For example, TSU 120-1 may transmit a signal to port # B of VA2C130-2, and in VA2C130-2, a corresponding signal may be transmitted from port # B to ports # e, # f, # g, # h, # i, and # j in a multicast manner. In this case, TSU 120-1 may not send a signal to port # C of VA2C 130-1.

Referring to fig. 10, the sliding window may be controlled and managed by the CCU110 and the TSU 120-1 of the communication system 100 and includes antennas connected to ports # d, # e, # f, # g, # h and # i of VA2C 130-2. When the sliding window of fig. 10 is compared with the sliding window of fig. 9, in the sliding window of fig. 10, an antenna connected to port # j of VA2C130-2 may be excluded (i.e., the connection between port # B and port # j is released), and an antenna connected to port # d of VA2C130-2 may be added (i.e., the connection between port # B and port # d is added). For example, TSU 120-1 may transmit a signal to port # B of VA2C130-2, and in VA2C130-2, a corresponding signal may be transmitted from port # B to ports # d, # e, # f, # g, # h, and # i in a multicast manner.

Referring to fig. 11, the sliding window may be controlled and managed by the CCU110 and the TSU 120-1 of the communication system 100 and includes antennas connected to ports # c, # d, # e, # f, # g, and # h of VA2C 130-2. When the sliding window of fig. 11 is compared with the sliding window of fig. 10, in the sliding window of fig. 11, an antenna connected to port # i of VA2C130-2 may be excluded (i.e., the connection between port # B and port # i is released), and an antenna connected to port # c of VA2C130-2 may be added (i.e., the connection between port # B and port # c is added). For example, TSU 120-1 may transmit a signal to port # B of VA2C130-2, and in VA2C130-2, a corresponding signal may be transmitted from port # B to ports # c, # d, # e, # f, # g, and # h in a multicast manner.

Referring to fig. 12, the sliding window may be controlled and managed by the CCU110, the TSU 120-1 and the TSU 120-2 of the communication system 100 and include antennas connected to ports # c, # d, # e, # f and # g of VA2C130-2 and antennas connected to port # b of VA2C 130-3. When the sliding window of fig. 12 is compared with the sliding window of fig. 11, in the sliding window of fig. 12, an antenna connected to port # h of VA2C130-2 may be excluded (i.e., the connection between port # B and port # h is released), and an antenna connected to port # B of VA2C 130-3 may be added (i.e., the connection between port # a and port # B is added). For example, TSU 120-1 may transmit signals to port # B of VA2C130-2, and in VA2C130-2, corresponding signals may be transmitted from port # B to ports # c, # d, # e, # f, and # g in a multicast manner. Further, TSU 120-2 may transmit a signal to port # a of VA2C 130-3, and in VA2C 130-3, a corresponding signal may be transmitted from port # a to port # b. Since the signals are transmitted by both TSUs 120-1 and 120-2, the synchronization between TSU 120-1 and TSU 120-2 (e.g., the synchronization between the signals (content) transmitted from TSU 120-1 and TSU 120-2) may be configured by CCU 110. In addition, switching between VA2C130-1, 130-2, and 130-3 may be controlled by CCU 110.

Referring to fig. 13, the sliding window may be controlled and managed by the CCU110, TSU 120-1 and TSU 120-2 of the communication system 100 and includes antennas connected to ports # c, # d, # e and # f of VA2C130-2 and antennas connected to ports # a and # b of VA2C 130-3. When the sliding window of fig. 13 is compared with the sliding window of fig. 12, in the sliding window of fig. 13, an antenna connected to port # g of VA2C130-2 may be excluded (i.e., the connection between port # B and port # g is released), and an antenna connected to port # a of VA2C 130-3 may be added (i.e., the connection between port # a and port # a is added). For example, TSU 120-1 may transmit signals to port # B of VA2C130-2, and in VA2C130-2, corresponding signals may be transmitted from port # B to ports # c, # d, # e, and # f in a multicast manner. Furthermore, TSU 120-2 may transmit signals to port # a of VA2C 130-3, and in VA2C 130-3, corresponding signals may be transmitted from port # a to ports # a and # b in a multicast manner. Since the signals are transmitted by both TSUs 120-1 and 120-2, the synchronization between TSU 120-1 and TSU 120-2 (e.g., the synchronization between the signals (content) transmitted from TSU 120-1 and TSU 120-2) may be configured by CCU 110.

On the other hand, in the CCU110, TSU120, VA2C130, and LA2M140 of the communication system 100, the protocol stack may be configured as follows.

Referring to fig. 14, in the communication system 100, a Control Plane (CP) protocol stack may include a CP-CCU, a CP-TSU, a CP-VA2C, and a CP-LA 2M. The CP-CCU may send a control primitive (controlprimative) to the CP-TSU via the first path P1. The CP-TSU may receive a control primitive from the CP-CCU and send a response/report of the received control primitive to the CP-CCU via the first path P1. The CP-TSU may send a control primitive to CP-LA2M via a second path P2 for controlling CP-LA2M, and may receive a response/report of the control primitive from CP-LA2M via a second path P2. The CP-TSU may send control primitives to the CP-VA2C via a third path P3 for controlling the CP-VA2C, and may receive responses/reports of the control primitives from the CP-VA2C via a third path P3.

The CP-CCU may include an RRC layer. Accordingly, the CP-CCU may support the resource allocation/change/release operation in the sliding window, and may transmit an RRC message for the resource allocation/change/release operation. In addition, the CP-CCU may obtain position information of the vehicle 200, and may configure a sliding window based on the obtained position information. For example, the CP-CCU may configure a sliding window such that the sliding window corresponds to the location of the vehicle 200. The CP-CCU may configure one sliding window for one vehicle 200 and perform a resource allocation operation for the corresponding vehicle 200 within the configured sliding window.

When performing a resource allocation operation, the CP-CCU may transmit a resource allocation message including a Transport Block (TB) size, frequency resource allocation information, time resource allocation information (e.g., a Transmission Time Interval (TTI) period), a frequency hopping pattern, information on mapping between an upper port and a lower port in the VA2C130, and the like, to the CP-TSU via the first path P1. The CP-TSU may receive the resource allocation message via the first path P1 and identify information included in the resource allocation message. The CP-TSU receiving the resource allocation message may transmit control information related to resource allocation to the CP-LA2M (e.g., a plurality of CP-LA2M connected to the CP-TSU) via a second path and transmit control information related to resource allocation to the CP-VA2C (e.g., a plurality of CP-VA2C connected to the CP-TSU) via a third path. The CP-LA2M and CP-VA2C may operate based on control information received from the CP-TSU regarding resource allocation. Control information transmitted from the CP-TSU to the CP-LA2M or CP-VA2C may vary according to the type of User Plane (UP), for example, A1-UP, A2-UP, A3-UP, A4-UP, A5-UP, A6-UP, A7-UP, A8-UP, and A9-UP.

In the communication system 100, the protocol stack of the UP can be configured as A1-UP, A2-UP, A3-UP, A4-UP, A5-UP, A6-UP, A7-UP, A8-UP, A9-UP, and the like. A1-UP, A2-UP, A3-UP, A4-UP, A5-UP or A6-UP may be used for downlink transmission. The protocol stack of the UP for uplink transmission may be the same as the protocol stack of the UP for downlink transmission. Alternatively, the UP protocol stack for uplink transmission may be different from the UP protocol stack for downlink transmission.

LA2M140 may include at least one of an RF layer, a PHY layer, and a MAC layer. The RF layer may include antennas (e.g., DA, AAC). The TSU120 may include at least one of a PDCP layer, an RLC layer, a MAC layer, and a PHY layer. However, in a9-UP, the TSU120 may not include all PDCP, RLC, MAC, and PHY layers. The CCU110 may include at least one of a PDCP layer and an RLC layer. However, in A1-UP, A2-UP, and A3-UP, the CCU110 may not include the PDCP layer and the RLC layer at the same time. One layer may be placed in the CCU110, the TSU120, or the LA2M 140. Alternatively, some functions of one layer may be performed by the CCU110, the TSU120, or the LA2M140, and the remaining functions of the one layer may be performed by an entity that does not perform the some functions of the one layer among the entire entities (e.g., the CCU110, the TSU120, and the LA2M 140).

The PDCP layer may be located in the TSU120 (e.g., TSU120 in A1-UP, A2-UP, or A3-UP), or the PDCP layer may be located in the CCU110 (e.g., CCU110 in A4-UP, A5-UP, A6-UP, A7-UP, A8-UP, or A9-UP) to reduce processing power. The PDCP layer may not support Internet Protocol (IP) header compression. Alternatively, the PDCP layer may be omitted in the communication system.

In A7-UP, A8-UP and A9-UP, the RLC layer can support RLC Acknowledged Mode (AM). For example, when RLC AM is supported, a transmitting communication node (e.g., communication system 100 of fig. 1) may transmit packets to a receiving communication node (e.g., vehicle 200 of fig. 2) and store the transmitted packets in a buffer. The receiving communication node may receive the packet from the sending communication node and may send a response message (e.g., an ACK message, a NACK message) to the sending communication node. When an ACK message is received from the receiving communication node in response to the packet, the transmitting communication node may discard the packet stored in the buffer (i.e., the packet transmitted to the receiving communication node). On the other hand, when a NACK message is received from the receiving communication node in response to the packet, the transmitting communication node may retransmit the packet stored in the buffer (i.e., the packet transmitted to the receiving communication node). When the RLC layer is located in the CCU110, it can be easily performed: an operation in which the receiving communication node transmits a response message (e.g., an ACK message or a NACK message) to the received packet, and an operation in which the transmitting communication node retransmits the packet corresponding to the received NACK message. The communication system 100 may include a plurality of TSUs 120, and when an RLC layer is located in each TSU120 among the plurality of TSUs 120 in a1-UP to a6-UP, the CCU110 may control and manage RLC-related operations performed by the plurality of TSUs 120.

Further, the communication nodes belonging to the communication system 100 (e.g., the CCU110, the TSU120, the VA2C130, and the LA2M140) may have a hierarchical tree structure. Herein, a communication node may refer to a communication entity. In the communication system 100, the communication nodes may be synchronized based on a Global Positioning System (GPS), Institute of Electrical and Electronics Engineers (IEEE)1588, or the like. A synchronization layer that performs a synchronization function according to a predetermined synchronization protocol may be located in the CCU 110. Further, a synchronization protocol may be implemented in the CCU110 and the communication nodes performing MAC functions (e.g., TSU120, LA2M 140).

Since the MAC layer is located in the TSU120 of A1-UP, A2-UP, A4-UP, A5-UP, A7-UP, and A8-UP, a synchronization process can be performed between the CCU110 and the TSU 120. Since the MAC layer is located in LA2M140 of A3-UP, A6-UP and A9-UP, a synchronization process can be performed between the CCU110 and LA2M 140. In this case, the TSU120 may perform a relay function during synchronization between the CCU110 and the LA2M 140. Since the connection structure between the correspondent nodes has a 1-to-N structure during downlink communication, the TSU120 can be used as a transport layer when an IP multicast function is used. Here, N may be an integer of 2 or more.

Further, downlink resources for downlink communications in communication system 100 may be allocated as follows.

Referring to fig. 15, a radio frame (radio frame) may include a plurality of subframes (e.g., 10 subframes SF #0 to #9), and the length of the subframes may be differently configured. For example, the length of the subframe may be 0.5ms, 1ms, etc. One subframe may be one TTI. A subframe may include two or more slots, and a slot may include a plurality of symbols. The subframe may include a control region and a data region. Here, the control region may be a control channel of a cellular communication system (e.g., a 4G or 5G communication system), and the data region may be a data channel in the cellular communication system. The communication system 100 may transmit control information to the vehicle 200 using the control region of the sub-frame and may transmit data (e.g., content) to the vehicle 200 using the data region of the sub-frame.

For example, the communication system 100 may determine a minimum capacity of data to be transmitted to the vehicle 200, and may configure the size of the time-frequency resources (e.g., time-frequency resources to transmit data) in consideration of the determined minimum capacity, modulation order, overhead of each layer (e.g., header overhead, trailer overhead), IP header compression ratio, fragmentation, and the like. Here, the time-frequency resources may be configured based on a semi-static scheduling scheme. When the semi-persistent scheduling scheme is utilized, the same time-frequency resources may be configured in the data region of each subframe (e.g., TTI). Further, operations for subframe synchronization and content synchronization (e.g., subframe synchronization and content synchronization in the plurality of TSUs 120 controlled and managed by the CCU 110) may be performed for each subframe (e.g., TTI).

The communication system 100 may transmit semi-static scheduling information for the determined time-frequency resources via the control region and may use the time-frequency resources in the data region indicated by the semi-static scheduling information to transmit data (e.g., data units). The semi-persistent scheduling operations described above may be performed by the CCU110 in the communication system 100, and the CCU110 may control and manage the multiple TSUs 120 connected to the CCU110 to synchronize content for each subframe (e.g., TTI).

Fig. 16 is a conceptual diagram illustrating a second embodiment of a downlink resource allocation method in a communication system, fig. 17 is a conceptual diagram illustrating a third embodiment of a downlink resource allocation method in a communication system, fig. 18 is a conceptual diagram illustrating a fourth embodiment of a downlink resource allocation method in a communication system, and fig. 19 is a conceptual diagram illustrating a fifth embodiment of a downlink resource allocation method in a communication system.

Referring to fig. 16-19, when a semi-persistent scheduling scheme is used, communication system 100 (e.g., CCU110 of communication system 100) may perform operations for subframe synchronization and content synchronization for one, two, or four TTIs. Further, the CCU110 may allocate time-frequency resources within the data region based on a frequency hopping scheme. A frequency hopping pattern may be preconfigured between the communication system 100 and the vehicle 200, and the CCU110 may perform a semi-persistent scheduling operation based on the frequency hopping pattern and TTI periodicity (e.g., the periodicity of TTIs of time-frequency resources allocated for data transmission).

The CCU110 may perform semi-static dispatch operations for a vehicle 200 in a sliding window. In this case, the CCU110 may perform a semi-persistent scheduling operation on all packets processed by the CCU110 once, in terms of user data. Alternatively, packets processed by the CCU110 may be logically classified according to type, priority, etc., and the CCU110 may perform a separate semi-static scheduling operation on each logically classified packet. Further, when the semi-persistent scheduling operation is performed, control information (e.g., semi-persistent scheduling information) may be separated from data or may be processed together with the data. When performing semi-persistent scheduling operations, the CCU110 may allocate sufficient time-frequency resources for control information and data even when null padding (null padding) occurs.

Further, uplink communication may be performed in the communication system 100 as follows.

Referring to fig. 20, a vehicle 200 may transmit an uplink signal to the communication system 100. When the sliding window includes antennas corresponding to ports # i to # n of VA2C130, the antennas corresponding to ports # i to # n of VA2C130 may receive uplink signals of the vehicle 200 and may transmit the received uplink signals and the received signal strength information to the corresponding ports. In VA2C130-1, the uplink signals and the received signal strength information of the vehicle 200 may be transmitted from ports # k to # n to port # C, and in VA2C130-2, the uplink signals and the received signal strength information of the vehicle 200 may be transmitted from ports # i to # j to port # B.

Further, even if the Cyclic Redundancy Check (CRC) check on the uplink signal is successful, the uplink signal may not be transmitted to the upper layer entity (e.g., the TSU 120) if the received signal strength of the uplink signal is less than the threshold. When the A1-UP, A4-UP, or A7-UP shown in FIG. 14 is utilized, the RF layer may perform a soft combining operation on the uplink signal.

For example, when the threshold value of the received signal strength is 20dBm and the received signal strengths of the uplink signals in port # k, port # l, port # m, and port # n are 21dBm, 20dBm, 15dBm, and 14dBm, respectively, VA2C130-1 may discard the uplink signals obtained from ports # m and # n, may generate one uplink signal by performing a soft combining operation on the uplink signals obtained from ports # k and # l, and may transmit the generated one uplink signal to TSU 120-1.

Further, when the threshold value of the received signal strength is 20dBm and the received signal strengths of the uplink signals in the port # i and the port # j are 20dBm and 21dBm, respectively, VA2C130-2 may generate one uplink signal by performing a soft combining operation on the uplink signals obtained from the ports # i and # j and may transmit the generated one uplink signal and the received signal strength information to the TSU 120-1. On the other hand, in port # i and port # j, VA2C130-2 may discard the uplink signal obtained from port # i and may transmit the uplink signal obtained from port # j and the received signal strength information to TSU 120-1 when the received signal strengths of the uplink signals are 18dBm and 21dBm, respectively.

The TSU 120-1 may receive uplink signals from VA2C130-1 and VA2C 130-2. In addition, the TSU 120-1 may receive received signal strength information of uplink signals from VA2C130-1 and VA2C 130-2. The TSU 120-1 may select an uplink signal having the greatest received signal strength among the two uplink signals and may transmit the selected uplink signal to the CCU 110. Alternatively, the TSU 120-1 may select an uplink signal having the smallest error rate among the two uplink signals, and may transmit the selected uplink signal to the CCU 110.

On the other hand, it may not be easy to perform soft combining operations in A2-UP, A3-UP, A5-UP, A6-UP, A8-UP, and A9-UP. For example, when uplink signals and received signal strength information are obtained from port # k, port # l, port # m, and port # n of VA2C130-1, VA2C130-1 may discard uplink signals of which received signal strength is lower than a threshold value among the uplink signals, and may select at least one uplink signal of which received signal strength is higher than the threshold value among the uplink signals. VA2C130-1 may finally select an uplink signal having the largest received signal strength among the selected at least one uplink signal, and may transmit the selected uplink signal and the received signal strength information of the selected uplink signal to TSU 120-1.

Further, when obtaining uplink signals and received signal strength information from port # i and port # j of VA2C130-2, VA2C130-2 may discard uplink signals whose received signal strength is below a threshold value among the uplink signals, and may select at least one uplink signal whose received signal strength is above the threshold value among the uplink signals. VA2C130-2 may finally select the uplink signal having the largest received signal strength among the selected at least one uplink signal, and may transmit the selected uplink signal and the received signal strength information of the selected uplink signal to TSU 120-1.

The TSU 120-1 may receive uplink signals from VA2C130-1 and VA2C 130-2. In addition, the TSU 120-1 may receive received signal strength information of uplink signals from VA2C130-1 and VA2C 130-2. The TSU 120-1 may select an uplink signal having the greatest received signal strength from the two uplink signals and may transmit the selected uplink signal to the CCU 110. Alternatively, the TSU 120-1 may select an uplink signal having the smallest error rate among the two uplink signals, and may transmit the selected uplink signal to the CCU 110.

Referring to fig. 21, a vehicle 200 may transmit an uplink signal to the communication system 100. When the sliding window includes antennas corresponding to ports # a to # f of VA2C130, the antennas corresponding to ports # a to # f of VA2C130 may receive uplink signals of the vehicle 200 and may transmit the received uplink signals and the received signal strength information to the corresponding ports. In VA2C130-2, the uplink signals and the received signal strength information of the vehicle 200 can be transmitted from ports # c to # f to port # B, and in VA2C 130-3, the uplink signals and the received signal strength information of the vehicle 200 can be transmitted from ports # a to # B to port # a.

The processing of the uplink signal in the communication system 100 of fig. 21 may be the same as or similar to the processing of the uplink signal in the communication system 100 of fig. 20. However, the number of uplink signals received at the CCU110 of fig. 21 may be two. For example, the TSU 120-1 may transmit uplink signals obtained from VA2C130-2 to the CCU110, and the TSU 120-2 may transmit uplink signals obtained from VA2C 130-3 to the CCU 110. In addition, the TSU 120-1 and TSU 120-2 may transmit received signal strength information regarding uplink signals to the CCU 110.

Thus, the CCU110 may receive the uplink signals and received signal strength information from the TSU 120-1 and TSU 120-2, and may select the uplink signal having the highest received signal strength among the two uplink signals. Alternatively, the CCU110 may select the uplink signal having the smallest error rate among the two uplink signals.

Further, based on the JT scheme, the performance of uplink communication described with reference to fig. 20 and 21 may be lower than that of downlink communication. However, a Joint Reception (JR) scheme may be used in a1-UP of fig. 14, and the performance of uplink communication may be improved in this case. For example, some uplink signals may be processed based on the JR scheme, and the JR scheme may not be applied to the remaining uplink signals.

Further, uplink resources for uplink communication in the communication system 100 may be allocated as follows.

Fig. 22 is a conceptual diagram illustrating a first embodiment of an uplink resource allocation method in a communication system, fig. 23 is a conceptual diagram illustrating a second embodiment of the uplink resource allocation method in the communication system, fig. 24 is a conceptual diagram illustrating a third embodiment of the uplink resource allocation method in the communication system, and fig. 25 is a conceptual diagram illustrating a fourth embodiment of the uplink resource allocation method in the communication system.

Referring to fig. 22-25, a CP-CCU (e.g., CCU 110) in communication system 100 may perform semi-static scheduling operations on uplink resources. Semi-static scheduling operations may be performed when a request for scheduling uplink resources is received from the vehicle 200. The semi-static scheduling information of the uplink resource may be transmitted via a control region of a downlink subframe, and may be semi-static scheduling information for an uplink subframe as follows: the uplink subframe is located after a predetermined number of TTIs on a time axis from a subframe in which semi-static scheduling information of the uplink resource is transmitted. For example, semi-static scheduling information for uplink subframes #1 to #9 may be received via downlink subframe # 0. The semi-static scheduling information may indicate the same frequency resources for each uplink subframe. Alternatively, the semi-persistent scheduling information may indicate resources configured based on the frequency hopping scheme in the uplink subframe. The resource allocation procedure within the sliding window may be separately performed according to the type of packet (e.g., control information, data), priority, and the like.

Further, Radio Bearers (RBs) may be configured for communication between the communication system 100 and the vehicle 200, and communication between the communication system 100 and the vehicle 200 may be performed using the configured RBs. The RB may be configured as follows.

Fig. 26 is a conceptual diagram illustrating a first embodiment of a message generation procedure of each RB in the communication system, and fig. 27 is a conceptual diagram illustrating a first embodiment of downlink resources to which RBs are allocated in the communication system.

Referring to fig. 26 and 27, a Signaling Radio Bearer (SRB) and a Dedicated Radio Bearer (DRB) may be configured for communication between the communication system 100 and the vehicle 200. Here, the control packet may be control information related to the operation of the vehicle 200, and the service packet may be user data for boarding a passenger (e.g., a terminal carried by the passenger) on the vehicle 200. SRB #1 may be used to inform resource allocation information (e.g., semi-static scheduling information) for communication between communication system 100 and vehicle 200. The RBs used to notify the resource allocation information may not be classified into SRB #1 and SRB # 2. For example, one SRB #1 may be used in communication system 100.

Alternatively, even when SRB #1 and SRB #2 are used in the communication system 100, SRB #1 and SRB #2 may be integrated into one SRB, and the integrated SRB may be used. A cell radio network temporary identifier (C-RNTI) a may be configured for SRB #1 and resources for SRB #1 may be allocated based on C-RNTI a. For example, resources for SRB #1 may be scheduled for each subframe based on C-RNTI A. Alternatively, resources for SRB #1 may be allocated based on C-RNTI A in a semi-persistent scheduling manner.

The IP packet may be used for communication between the communication system 100 and the vehicle 200, and when the IP packet can be processed in one TTI, a plurality of RLC Service Data Units (SDUs) may be concatenated in the DRB # 1. DRB #1 may be used for transmission of control packets for the vehicle 200. C-RNTI B may be configured for DRB #1, and resources for DRB #1 may be allocated based on C-RNTI B. For example, resources for DRB #1 may be scheduled for each subframe based on C-RNTI B. Alternatively, resources for DRB #1 can be allocated based on C-RNTI B in a semi-persistent scheduling manner.

DRB #2 may be used to transmit service packets for passengers boarding the vehicle 200. C-RNTI C may be configured for DRB #2, and resources for DRB #2 may be allocated based on C-RNTI C. For example, resources for DRB #2 may be scheduled for each subframe based on C-RNTI C. Alternatively, resources for DRB #2 may be allocated based on C-RNTIC in a semi-persistent scheduling manner.

In communication between the communication system 100 and the vehicle 200, one vehicle 200 may be configured with a plurality of C-RNTIs (e.g., C-RNTI a, C-RNTI B, and C-RNTI C), and resources may be scheduled based on the plurality of C-RNTIs. For example, a plurality of C-RNTIs may be configured for each RB. In addition, the maximum TB (e.g., the maximum RB to be predicted) may be fixedly allocated for each RB. If no packet is to be transmitted via the fixedly allocated TBs, the corresponding TBs may be processed based on an all-zero padding scheme or a muting scheme. The TB allocation period and the scheduling period may be determined by considering the occurrence frequency of packets of each RB, latency requirements, and the like.

Referring to fig. 28, C-RNTI a may be configured for SRB #1 (or SRB #2), and uplink resources for SRB #1 (or SRB #2) may be allocated based on C-RNTI a. For example, resources for SRB #1 (or SRB #2) may be scheduled for each subframe based on C-RNTI a, and scheduling information for SRB #1 (or SRB #2) may be transmitted via a control region for each downlink subframe. Alternatively, resources for SRB #1 (or SRB #2) may be allocated based on C-RNTI a in a semi-persistent scheduling manner, and scheduling information for SRB #1 (or SRB #2) may be transmitted via a control region of one downlink subframe.

C-RNTI B may be configured for DRB #1, and uplink resources for DRB #1 may be allocated based on C-RNTI B. For example, resources for DRB #1 may be scheduled for each subframe based on C-RNTI B, and scheduling information for DRB #1 may be transmitted via a control region for each downlink subframe. Alternatively, resources for DRB #1 may be allocated based on C-RNTI B in a semi-persistent scheduling manner, and scheduling information for DRB #1 may be transmitted via a control region of one downlink subframe.

C-RNTI C may be configured for DRB #2 and uplink resources for DRB #2 may be allocated based on C-RNTI C. For example, resources for DRB #2 may be scheduled for each subframe based on C-RNTI C, and scheduling information for DRB #2 may be transmitted via a control region for each downlink subframe. Alternatively, resources for DRB #2 may be allocated based on C-RNTI C in a semi-persistent scheduling manner, and scheduling information for DRB #2 may be transmitted via a control region of one downlink subframe.

The uplink packet may be received in the communication system 100 via SRB #1, DRB #1, and DRB #2, and the uplink packet received in the communication system 100 may be processed by the PHY layer, the MAC layer, the RLC layer, and the PDCP layer in fig. 26. For example, the uplink packet may be processed in the order of "PHY layer → MAC layer → RLC layer → PDCP layer", and CRC-related operations, header removal operations, data unit separation operations, and the like may be performed in each layer.

Further, when the RLC AM is utilized, the downlink retransmission method between the communication system 100 and the vehicle 200 may be performed as follows.

Referring to fig. 29, when RLC AM is utilized, a plurality of C-RNTIs can be configured for one DRB. When a downlink signal is transmitted via the DRB, a C-RNTI (e.g., C-RNTI B) for initial transmission of the downlink signal may be configured, a C-RNTI (e.g., C-RNTI D) for a response message (e.g., RLC status message) for the downlink signal may be configured, and a C-RNTI (e.g., C-RNTI E) for retransmission of the downlink signal may be configured. That is, in the downlink communication procedure, one C-RNTI for initial transmission of a downlink signal may be configured, and two C-RNTIs for RLC status messages and retransmission procedures of the downlink signal may be configured. Therefore, three C-RNTIs can be configured for the DRB to which the RLC AM is applied. Alternatively, one C-RNTI may be configured for a downlink communication procedure (e.g., an RB of an RLC AM), and resources for initial transmission of downlink signals, resources for RLC status messages, and resources for retransmission of downlink signals may be configured based on the one C-RNTI.

Here, a maximum TB (e.g., a maximum RB to be predicted) may be allocated in one TTI according to a predetermined period (e.g., 1, 2, or 4 TTIs), and an operation of adding zero padding may be performed when the size of data to be transmitted is smaller than the size of the allocated TB. Semi-persistent scheduling operations for initial transmissions, semi-persistent scheduling operations for RLC status message transmissions, and semi-persistent scheduling operations for retransmissions may be performed.

In step S2901, the communication system 100 can transmit a TB including a downlink signal using a resource (e.g., SF #0) of the DRB scheduled by C-RNTI B. In step S2902, the vehicle 200 may receive the TB in SF #0, and may identify an RLC Protocol Data Unit (PDU) based on the received TB. The vehicle 200 may generate an RLC status message (e.g., ACK message, NACK message) based on the reception status of the RLC PDU. When the RLC PDU is not successfully received, the vehicle 200 may generate an RLC status message indicating NACK. In step S2903, the vehicle 200 may transmit an RLC status message indicating NACK using a resource (e.g., SF #3) of the DRB scheduled by C-RNTI D. Here, the C-RNTI D may be transmitted from the communication system 100 to the vehicle 200 via the control region of the downlink subframe.

In step S2904, communication system 100 may receive an RLC status message in SF # 3. When the RLC status message indicates NACK, the communication system 100 may identify RLC PDUs corresponding to the NACK among the RLC PDUs located in the retransmission buffer, and perform a retransmission procedure on the identified RLC PDUs. For example, in step S2905, communication system 100 can perform a retransmission procedure using resources (e.g., SF #5) of the DRB scheduled by C-RNTI E. In step S2906, the vehicle 200 may receive the retransmitted RLC PDU via SF # 5.

As described above, C-RNTI B for initial transmission, C-RNTI D for transmission of an RLC status message, and C-RNTI E for retransmission are independently configured, whereby downlink resources for initial transmission, uplink resources for transmission of a status message, and downlink resources for retransmission can be allocated in a semi-persistent scheduling manner. Therefore, when the JT scheme or the JR scheme is utilized, contents (for example, contents in the TSU) can be easily synchronized.

Further, when the RLC AM is utilized, the uplink retransmission method between the communication system 100 and the vehicle 200 may be performed as follows.

Fig. 30 is a conceptual diagram illustrating a first embodiment of an uplink retransmission method when an RLC AM is used.

Referring to fig. 30, when an uplink signal is transmitted via a DRB, a C-RNTI (e.g., C-RNTI B) for initial transmission of the uplink signal may be configured, a C-RNTI (e.g., C-RNTI D) for a response message (e.g., RLC status message) for the uplink signal may be configured, and a C-RNTI (e.g., C-RNTI E) for retransmission of the uplink signal may be configured. That is, in the uplink communication procedure, one C-RNTI for initial transmission of an uplink signal may be basically configured, and two C-RNTIs for RLC status messages and retransmission procedures of an uplink signal may be additionally configured. Therefore, three C-RNTIs can be configured for the DRB to which the RLC AM is applied. Alternatively, one C-RNTI may be configured for an uplink communication procedure (e.g., RB of RLC AM), and resources for initial transmission of uplink signals, resources for RLC status messages, and resources for retransmission of uplink signals may be configured based on the one C-RNTI.

At step S3001, the vehicle 200 may transmit a TB including an uplink signal using a resource (e.g., SF #0) of the DRB scheduled by C-RNTI B. In step S3002, the communication system 100 may receive a TB in SF #0 and may identify an RLC PDU based on the received TB. The communication system 100 may generate an RLC status message (e.g., ACK message, NACK message) based on the reception status of the RLC PDU. When an RLC PDU is not successfully received, communication system 100 may generate an RLC status message indicating a NACK. In step S3003, the communication system 100 may transmit an RLC status message indicating NACK using the resource (e.g., SF #3) of the DRB scheduled by C-RNTI D. Here, the C-RNTI D may be transmitted from the communication system 100 to the vehicle 200 via the control region of the downlink subframe.

In step S3004, the vehicle 200 may receive the RLC status message in SF # 3. When the RLC status message indicates NACK, the vehicle 200 may identify RLC PDUs corresponding to the NACK among the RLC PDUs located in the retransmission buffer, and perform a retransmission procedure on the identified RLC PDUs. For example, the vehicle 200 may perform a retransmission procedure using a resource (e.g., SF #5) of the DRB scheduled by the C-RNTI E at step S3005. In step S3006, the communication system 100 may receive the retransmitted RLC PDU via SF # 5.

■ method for synchronizing communication nodes in a communication system

Further, a synchronization process may be performed for communication between the communication system 100 and the vehicle 200. For example, synchronization between the

communication nodes

110, 120, 130, and 140 included in the communication system 100 should be established for communication between the communication system 100 and the vehicle 200, and a synchronization procedure between the

communication nodes

110, 120, 130, and 140 may be as follows.

Referring to fig. 31, when downlink communication is performed, the packet transmission order may be "CCU → TSU → VA2C → LA 2M". In UP-A (e.g., A1-UP, A2-UP, A4-UP, A5-UP, A7-UP, and A8-UP in FIG. 14), the MAC layer may be located in the TSU120, and ｃA synchronization layer (e.g., synchronization protocol) may be located in the CCU110 and the TSU 120. In this case, the CCU110 may transmit packets (e.g., scheduled data) to the plurality of TSUs 120 based on an IP multicast scheme.

In UP-B (e.g., A3-UP, A6-UP, and A9-UP in FIG. 14), the MAC layer may be located in LA2M140 and the synchronization layer (e.g., synchronization protocol) may be located in CCU110, TSU120, and LA2M 140. In this case, the synchronization layer of the CCU110 may be connected to the synchronization layer of LA2M140, and the synchronization layer of the TSU120 may perform a relay function between the synchronization layer of the CCU110 and the synchronization layer of LA2M 140. Further, the CCU110 may transmit packets (e.g., scheduled datｃA) to the plurality of TSUs 120 based on an IP multicast scheme, similar to the transmission scheme of UP- ｃA.

Referring to fig. 32, when uplink communication is performed, the packet transmission order may be "LA 2M → VA2C → TSU → CCU". In UP-A (e.g., A1-UP, A2-UP, A4-UP, A5-UP, A7-UP, and A8-UP in FIG. 14), the MAC layer may be located in the TSU120, and ｃA synchronization layer (e.g., synchronization protocol) may be located in the CCU110 and the TSU 120. VA2C130 may receive packets from LA2M140 in a JR scheme and may send packets to CCU 110.

In UP-B (e.g., A3-UP, A6-UP, and A9-UP in FIG. 14), the MAC layer may be located in LA2M140 and the synchronization layer (e.g., synchronization protocol) may be located in CCU110, TSU120, and LA2M 140. In this case, the synchronization layer of the CCU110 may be connected to the synchronization layer of LA2M140, and the synchronization layer of the TSU120 may perform a relay function between the synchronization layer of the CCU110 and the synchronization layer of LA2M 140. Here, the CCU110 may select the best packet among the packets received from the plurality of TSUs 120.

Further, the delay probing procedure for synchronization between the communication nodes in UP- ｃA may be performed as follows.

Fig. 33 is a block diagram illustrating a second embodiment of a communication system, fig. 34 is a block diagram illustrating a first embodiment of a probe request/response packet used in a delayed probing process, and fig. 35 is a block diagram illustrating a second embodiment of a probe request/response packet used in a delayed probing process.

Referring to fig. 33 through 35, correspondent node # a may be the CCU110, correspondent node # B may be the TSU120, and correspondent node # C may be the LA2M 140. The MAC layer may be located in the communication node # B. The communication node # a may use a delay probing procedure to evaluate the packet delay at the communication node # B. In addition, by performing content synchronization based on the communication node # B having the largest delay, an appropriate scheduling time point can be predicted using the delay probe procedure.

The communication node # a may generate probe request packets (e.g., probe request packet # a, probe request packet # B) and transmit the generated probe request packets to the n communication nodes # B. Each of n, m, and l may be a positive integer. The correspondent node # B may receive the probe request packet from the correspondent node # a, and may generate a probe response packet (e.g., probe response packet # a, probe response packet # B) in response to the probe request packet, and may transmit the generated probe response packet to the correspondent node # a. For example, the correspondent node # B may transmit the probe response packet # a to the correspondent node # a in response to the probe request packet # a, and transmit the probe response packet # B to the correspondent node # a in response to the probe request packet # B. The correspondent node # a may receive the probe response packet from the correspondent node # B, and may identify a delay AT the correspondent node # B based on an Absolute Time (AT) included in the probe response packet.

Here, the probe request packet # a may include: a synchronization packet type field, a unique ID field, a destination count field, a destination address field, an AT count field, and an AT #1 field. The synchronization packet type field may indicate the type of the probe request packet (e.g., probe request packet # a, probe request packet # B). The synchronization packet type field in the probe request packet # a may be set to "1". The unique ID field may be configured as a unique ID based on the vehicle ID and RB ID (e.g., RB ID for initial transmission, RB ID for transmission of RLC status message, RB ID for retransmission), sequence ID for each communication node, and the like. The target count field may indicate a depth of a final target of the probe request packet (e.g., a number of hops between a communication node that generated the probe request packet and a communication node that is the final target of the probe request packet). In fig. 33, since the final destination of the probe request packet # a is the correspondent node # B, the destination count field may be set to "1". The destination address field may indicate a destination address (e.g., IP address) of the probe request packet # a. The AT count field may indicate the number of AT fields included in the probe request packet # a. The AT count field in probe request packet # a may be set to "1". The AT #1 field may indicate an AT when the probe request packet # a is transmitted.

The probe request packet # B may be used to improve the accuracy of the delay measurement compared to the probe request packet # a. The probe request packet # B may include: a synchronization packet type field, a unique ID field, a target count field, a target address field, an AT count field, an AT #1 field, a PDU count field, a PDU #1 size field, a PDU #2 size field, a PDU #1 (e.g., dummy packet #1), and a PDU #2 (e.g., dummy packet # 2). Each of the synchronization packet type field, the unique ID field, the target count field, the target address field, the AT count field, and the AT #1 field of the probe request packet # B may be configured to be the same as or similar to each of the synchronization packet type field, the unique ID field, the target count field, the target address field, the AT count field, and the AT #1 field of the probe request packet # a. Here, the sync packet type field of the probe request packet # B may be set to '31'. The PDU count field may indicate the number of PDUs (e.g., dummy packets) included in the probe request packet # B. When two PDUs are included in the probe request packet # B, the PDU count field may be set to "2". The number of PDUs included in the probe request packet # B may vary. The PDU #1 size field may indicate the size of PDU #1, and the PDU #2 size field may indicate the size of PDU # 2.

The probe response packet # a may be used in response to the probe request packet # a. The probe response packet # a may include a synchronization packet type field, a unique ID field, an AT count field, an AT #2 field, and an AT #3 field. The synchronization packet type field may indicate the type of the probe response packet (e.g., probe response packet # a, probe response packet # B). The synchronization packet type field in the probe response packet # a may be set to "51". The unique ID field may be set to the unique ID indicated by the unique ID field of the probe request packet # a. The AT count field may indicate the number of AT fields included in the probe response packet # a. The AT count field in probe response packet # a may be set to "2". The AT #2 field may indicate an AT that receives the probe request packet # a AT the correspondent node # B, and the AT #3 field may indicate an AT that transmits the probe response packet # a AT the correspondent node # B.

The probe response packet # B may be used in response to the probe request packet # B. The probe response packet # B may include a synchronization packet type field, a unique ID field, an AT count field, an AT #2 field, and an AT #3 field. Each of the synchronization packet type field, the unique ID field, the AT count field, the AT #2 field, and the AT #3 field of the probe response packet # B may be configured to be the same as or similar to each of the synchronization packet type field, the unique ID field, the AT count field, the AT #2 field, and the AT #3 field of the probe response packet # a. Here, the synchronization packet type field of the probe response packet # B may be set to "531".

On the other hand, the correspondent node # a may receive a probe response packet from each of the correspondent nodes # B (e.g., the correspondent nodes # B-1 to # B-n), and based on the AT included in the probe response packet, the correspondent node # a may recognize a delay in each of the correspondent nodes # B. The communication node # a may perform scheduling based on the communication node # B having the largest delay of content synchronization among the communication nodes # B. That is, the correspondent node # a may perform scheduling so that the correspondent node # B can perform downlink transmission (or uplink transmission) in the same TTI.

Further, the delay probing procedure for synchronization between the communication nodes in UP-B may be performed as follows.

Fig. 36 is a block diagram illustrating a third embodiment of a communication system, and fig. 37 is a block diagram illustrating a third embodiment of a probe request/response packet used in a delayed probing process.

Referring to fig. 36 and 37, correspondent node # a may be the CCU110, correspondent node # B may be the TSU120, and correspondent node # C may be the LA2M 140. The MAC layer may be located in the communication node # C. The communication node # a may use a delay probing procedure to evaluate the packet delay at the communication node # C. In addition, by performing content synchronization based on the communication node # C having the largest delay, an appropriate scheduling time point can be predicted using the delay probe procedure.

The communication node # a may generate a probe request packet # C and transmit the generated probe request packet # C to the n communication nodes # B. Each of n, m, and l may be a positive integer. Each of the communication nodes # B may receive the probe request packet # C from the communication node # a, and may generate a probe request packet # D based on the probe request packet # C, and may transmit the generated probe request packet # D to the communication node # C. Each of the communication nodes # C may receive the probe request packet # D from the communication node # B, generate a probe response packet # D in response to the probe request packet # D, and transmit the generated probe response packet # D to the communication node # B. Each of the communication nodes # B may receive the probe response packet # D from the communication node # C, generate the probe response packet # C based on the probe response packet # D, and transmit the probe response packet # C to the communication node # a. The communication node # a may receive the probe response packet # C from the communication node # B, and may identify a delay in the communication node # C based on the AT included in the probe response packet # C.

Here, the probe request packet # C may include a synchronization packet type field, a unique ID field, a target count field, a target address #1 field, a target address #2 field, an AT count field, and an AT #1 field. The synchronization packet type field may indicate the type of the probe request packet and may be set to "2". The unique ID field may be configured as a unique ID based on the vehicle ID and RB ID (e.g., RB ID for initial transmission, RB ID for transmission of RLC status message, RB ID for retransmission), sequence ID for each communication node, and the like. The target count field may indicate the depth of the final target of the probe request packet # C. Since the final destination of the probe request packet # C is the correspondent node # C, the destination count field may be set to "2". The destination address #1 field may indicate an address of the correspondent node # B, which is a first destination of the probe request packet # C. The destination address #2 field may indicate an address of the correspondent node # C, which is a second destination of the probe request packet # C. The AT count field may indicate the number of AT fields included in the probe request packet # C, and may be set to "1". The AT #1 field may indicate an AT when the probe request packet # C is transmitted. Further, similar to the probe request packet # B of fig. 35, the probe request packet # C may include at least one PDU, thereby improving the accuracy of the delay measurement.

The probe request packet # D may include a synchronization packet type field, a unique ID field, a target count field, a target address #2 field, an AT count field, and an AT #2 field. The synchronization packet type field may indicate the type of the probe request packet and may be set to "1". The unique ID field of the probe request packet # D may be set to the unique ID indicated by the unique ID field of the probe request packet # C. The target count field may indicate the depth of the final target of the probe request packet # D, and may be set to "1". The destination address #2 field may indicate an address of the communication node # C. The AT count field may indicate the number of AT fields included in the probe request packet # D, and may be set to "1". The AT #2 field may indicate an AT when the probe request packet # D is transmitted. Also, similar to the probe request packet # B of fig. 35, the probe request packet # D may include at least one PDU, thereby improving the accuracy of the delay measurement.

The probe response packet # D may include a synchronization packet type field, a unique ID field, an AT count field, an AT #3 field, and an AT #4 field. The synchronization packet type field may indicate the type of the probe response packet and may be set to "51". The unique ID field of the probe response packet # D may be set to the unique ID indicated by the unique ID field of the probe request packet # D. The AT count field may indicate the number of AT fields included in the probe response packet # D, and may be set to "2". The AT #3 field may indicate an AT when the probe request packet # D is received, and the AT #4 field may indicate an AT when the probe response packet # D is transmitted.

The probe response packet # C may include: a synchronization packet type field, a unique ID field, an AT count field, an AT #2 field, an AT #3 field, an AT #4 field, and an AT #5 field. The synchronization packet type field may indicate the type of the probe response packet and may be set to "52". The unique ID field of the probe response packet # C may be set to the unique ID indicated by the unique ID field of the probe response packet # D. The AT count field may indicate the number of AT fields included in the probe response packet # C, and may be set to "4". The AT #2 field may indicate an AT when the probe request packet # D is transmitted, the AT #3 field may be set to an AT indicated by the AT #2 field of the probe response packet # D, the AT #4 field may be set to an AT indicated by the AT #3 field of the probe response packet # D, and the AT #5 field may indicate an AT when the probe response packet # C is transmitted.

On the other hand, the correspondent node # a may receive a probe response packet from each of the correspondent nodes # B (e.g., the correspondent nodes # B-1 to # B-n), and based on the AT included in the probe response packet, the correspondent node # a may identify a delay in each of the correspondent nodes # B. The communication node # a may perform scheduling based on the communication node # C having the largest delay of content synchronization among the communication nodes # C. That is, the communication node # a may perform scheduling so that the communication node # C may perform downlink transmission (or uplink transmission) in the same TTI.

Further, the delay probe procedure described with reference to fig. 33 to 35 may be applied when the depth (e.g., the number of hops) between the communication node # a and the communication node where the MAC layer is located is 1, and the delay probe procedure described with reference to fig. 36 and 37 may be applied when the depth (e.g., the number of hops) between the communication node # a and the communication node where the MAC layer is located is 2. Applying the delay detection procedure when the depth (e.g., the number of hops) between the communication node # a and the communication node where the MAC layer is located is 3 may be performed as follows.

Fig. 38 is a block diagram illustrating a fourth embodiment of a communication system, fig. 39 is a block diagram illustrating a fourth embodiment of a probe request packet used in a delayed probing process, and fig. 40 is a block diagram illustrating a fourth embodiment of a probe response packet used in a delayed probing process.

Referring to fig. 38 to 40, the correspondent node # a may be the CCU110, and the MAC layer may be located in the correspondent node # D. The communication node # a may use a delay probing procedure to evaluate the packet delay at the communication node # D. In addition, by performing content synchronization based on the communication node # D having the largest delay, an appropriate scheduling time point can be predicted using the delay probe procedure.

The communication node # a may generate a probe request packet # E and transmit the generated probe request packet # E to the n communication nodes # B. Each of n, m, l, o, p, q, and r may be a positive integer. Each communication node # B may receive the probe request packet # E from the communication node # a, and may generate a probe request packet # F based on the probe request packet # E, and may transmit the generated probe request packet # F to the communication node # C. Each communication node # C may receive the probe request packet # F from the communication node # B, generate a probe request packet # G based on the probe request packet # F, and transmit the generated probe request packet # G to the communication node # D. Each communication node # D may receive the probe request packet # G from the communication node # C, generate a probe response packet # G in response to the probe request packet # G, and transmit the probe response packet # G to the communication node # C. Each communication node # C may receive the probe response packet # G from the communication node # D, generate a probe response packet # F based on the probe response packet # G, and transmit the generated probe response packet # F to the communication node # B. Each communication node # B can receive the probe response packet # F from the communication node # C, generate the probe response packet # E based on the probe response packet # F, and transmit the generated probe response packet # E to the communication node # a. The communication node # a may receive the probe response packet # E from the communication node # B, and may identify a delay in the communication node # D based on the AT included in the probe response packet # E.

Here, the probe request packet # E may include: a synchronization packet type field, a unique ID field, a destination count field, a destination address #1 field, a destination address #2 field, a destination address #3 field, an AT count field, and an AT #1 field. The synchronization packet type field may indicate the type of the probe request packet and may be set to "3". The unique ID field may be configured as a unique ID based on the vehicle ID and RB ID (e.g., RB ID for initial transmission, RB ID for transmission of RLC status message, RB ID for retransmission), sequence ID for each communication node, and the like. The target count field may indicate the depth of the final target of the probe request packet # E. Since the final destination of the probe request packet # E is the correspondent node # D, the destination count field may be set to "3". The destination address #1 field may indicate an address of the correspondent node # B, which is a first destination of the probe request packet # E. The destination address #2 field may indicate an address of the correspondent node # C, which is a second destination of the probe request packet # E. The destination address #3 field may indicate an address of the correspondent node # D, which is a third destination of the probe request packet # E. The AT count field may indicate the number of AT fields included in the probe request packet # E, and may be set to "1". The AT #1 field may indicate an AT when the probe request packet # E is transmitted. Further, similar to the probe request packet # B of fig. 35, the probe request packet # E may include at least one PDU to improve the accuracy of the delay measurement.

The probe request packet # F may include: a synchronization packet type field, a unique ID field, a destination count field, a destination address #2 field, a destination address #3 field, an AT count field, and an AT #2 field. The synchronization packet type field may indicate the type of the probe request packet and may be set to "2". The unique ID field of the probe request packet # F may be set to the unique ID indicated by the unique ID field of the probe request packet # E. The target count field may indicate the depth of the final target of the probe request packet # F, and may be set to "2". The destination address #2 field may indicate an address of the communication node # C, and the destination address #3 field may indicate an address of the communication node # D. The AT count field may indicate the number of AT fields included in the probe request packet # F, and may be set to "1". The AT #2 field may indicate an AT when the probe request packet # F is transmitted. Further, similar to the probe request packet # B of fig. 35, the probe request packet # F may include at least one PDU to improve the accuracy of the delay measurement.

The probe request packet # G may include: a synchronization packet type field, a unique ID field, a target count field, a target address #3 field, an AT count field, and an AT #3 field. The synchronization packet type field may indicate the type of the probe request packet and may be set to "1". The unique ID field of the probe request packet # G may be set to the unique ID indicated by the unique ID field of the probe request packet # F. The target count field may indicate the depth of the final target of the probe request packet # G, and may be set to "1". The destination address #3 field may indicate an address of the communication node # D. The AT count field may indicate the number of AT fields included in the probe request packet # G, and may be set to "1". The AT #3 field may indicate an AT when the probe request packet # G is transmitted. Further, similar to the probe request packet # B of fig. 35, the probe request packet # G may include at least one PDU to improve the accuracy of the delay measurement.

The probe response packet # G may include: a synchronization packet type field, a unique ID field, an AT count field, an AT #4 field, and an AT #5 field. The synchronization packet type field may indicate the type of the probe response packet and may be set to "51". The unique ID field of the probe response packet # G may be set to the unique ID indicated by the unique ID field of the probe request packet # G. The AT count field may indicate the number of AT fields included in the probe response packet # G, and may be set to "2". The AT #4 field may indicate an AT when the probe request packet # G is received, and the AT #5 field may indicate an AT when the probe response packet # G is transmitted.

The probe response packet # F may include: a synchronization packet type field, a unique ID field, an AT count field, an AT #3 field, an AT #4 field, an AT #5 field, and an AT #6 field. The synchronization packet type field may indicate the type of the probe response packet and may be set to "52". The unique ID field of the probe response packet # F may be set to the unique ID indicated by the unique ID field of the probe response packet # G. The AT count field may indicate the number of AT fields included in the probe response packet # F, and may be set to "4". The AT #3 field may be set to the AT indicated by the AT #3 field of the probe request packet # G, the AT #4 field may be set to the AT indicated by the AT #4 field of the probe response packet # G, the AT #5 field may be set to the AT indicated by the AT #5 field of the probe response packet # G, and the AT #6 field may indicate the AT when the probe response packet # F is transmitted.

The probe response packet # E may include: a synchronization packet type field, a unique ID field, an AT count field, an AT #2 field, an AT #3 field, an AT #4 field, an AT #5 field, an AT #6 field, and an AT #7 field. The synchronization packet type field may indicate the type of the probe response packet and may be set to "53". The unique ID field of the probe response packet # E may be set to the unique ID indicated by the unique ID field of the probe response packet # F. The AT count field may indicate the number of AT fields included in the probe response packet # E, and may be set to "6". The AT #2 field may be set to the AT indicated by the AT #2 field of the probe request packet # F, the AT #3 field may be set to the AT indicated by the AT #3 field of the probe response packet # F, the AT #4 field may be set to the AT indicated by the AT #4 field of the probe response packet # F, the AT #5 field may be set to the AT indicated by the AT #5 field of the probe response packet # F, the AT #6 field may be set to the AT indicated by the AT #6 field of the probe response packet # F, and the AT #7 field may indicate the AT when the probe response packet # E is transmitted.

On the other hand, the communication node # a may receive the probe response packet # E from each of the communication nodes # B (e.g., the communication nodes # B-1 to # B-n), and based on the AT included in the probe response packet # E, the communication node # a may identify a delay in each of the communication nodes # D. The communication node # a may perform scheduling based on the communication node # D having the largest delay of content synchronization among the communication nodes # D. That is, the communication node # a may perform scheduling so that the communication node # D may perform downlink transmission (or uplink transmission) in the same TTI.

Further, the downlink communication process between the communication system 100 and the vehicle 200 may be performed as follows.

Fig. 41 is a block diagram illustrating a fifth embodiment of a communication system, fig. 42 is a block diagram illustrating a sixth embodiment of a communication system, and fig. 43 is a block diagram illustrating a first embodiment of a downlink packet.

Referring to fig. 41-43, communication node # a may be the CCU110 of the communication system 100, communication node # B may be the TSU120 of the communication system 100, and communication node # C may be the LA2M140 of the communication system 100. In UP- ｃA, the MAC layer may be located at the communication node # B, and the synchronization layer may be located at the communication nodes # ｃA and # B. In the UP-B, the MAC layer may be located at the communication node # C, and the synchronization layer may be located at the communication nodes # a to # C. The synchronization layer of the communication node # a may support a master MAC function. The communication node # a supporting the master MAC function may configure one sliding window for one vehicle 200, control and manage the sliding window according to the movement of the vehicle 200, and may determine the number of SDUs included in the Transport Block (TB) based on semi-static resource allocation information for each vehicle 200 determined through an RRC signaling procedure. In order to determine the number of SDUs, a protocol processing procedure of an underlying communication node (e.g., communication node # B, communication node # C) may be considered. For example, in consideration of a protocol process between the communication node where the MAC layer is located and the communication node # a, the synchronization layer located in the communication node # a may perform a scheduling operation such that a packet is located in a TB allocated to one TTI.

In UP- ｃA, downlink packets may be sent from correspondent node # ｃA to correspondent node # B. In UP-B, downlink packets may be sent from correspondent node # a to correspondent node # C. In this case, the correspondent node # B may forward the downlink packet received from the correspondent node # a to the correspondent node # C. The downlink packet includes: a synchronization packet type field, an AT field, a unique ID field, a predicted System Frame Number (SFN)/Subframe (SF) field, an SDU count field, an SDU #1 size field, an SDU #2 size field, an SDU #3 size field, SDU #1, SDU #2, and SDU # 3.

The synchronization packet type field may indicate the type of packet and may be set to "100". The AT field may indicate an AT when the downlink packet is transmitted. The unique ID field may indicate a unique ID based on a vehicle ID and an RB ID (e.g., an RB ID for initial transmission, an RB ID for transmission of an RLC status message, an RB ID for retransmission). The predicted SFN/SF field may indicate scheduling information (e.g., SFN, SF index) of the SDU included in the downlink packet. The SFN and SF index indicated by the predicted SFN/SF field may be calculated based on the semi-static scheduling information and the delay measured through the delay sounding procedure.

The SDU count field may indicate the number of SDUs scheduled in a TB of one TTI (e.g., the number of SDUs included in a downlink packet). The number of SDU size fields included in the downlink packet may be the same as the value indicated by the SDU count field. The SDU #1 size field may indicate the length of SDU #1 included in the downlink packet, the SDU #2 size field may indicate the length of SDU #2 included in the downlink packet, and the SDU #3 size field may indicate the length of SDU #3 included in the downlink packet.

Further, the uplink communication process between the communication system 100 and the vehicle 200 may be performed as follows.

Fig. 44 is a block diagram illustrating a seventh embodiment of a communication system, fig. 45 is a block diagram illustrating an eighth embodiment of a communication system, and fig. 46 is a block diagram illustrating a first embodiment of an uplink packet.

Referring to fig. 44-46, communication node # a may be the CCU110 of the communication system 100, communication node # B may be the TSU120 of the communication system 100, and communication node # C may be the LA2M140 of the communication system 100. In UP- ｃA, the MAC layer may be located at the communication node # B, and the synchronization layer may be located at the communication nodes # ｃA and # B. In the UP-B, the MAC layer may be located at the communication node # C, and the synchronization layer may be located at the communication nodes # a to # C. The communication node # B or the communication node # C including the MAC layer can transmit an uplink packet including the SDU (protocol processing of the TB received in one TTI has been completed) to the upper layer communication node.

From an uplink perspective, the correspondent node # a can receive multiple uplink packets with the same unique ID and the same received SFN/SF. In this case, the communication node # a may select one uplink packet among the plurality of uplink packets based on the received signal strength indicated by each of the plurality of uplink packets. In addition, the correspondent node # a may process an uplink packet received in an uplink delay window configured in the SFN/SF indicated by the received SFN/SF field in consideration of the uplink delay measured by the delay sounding procedure, and may not process an uplink packet received outside the uplink delay window.

In UP- ｃA, an uplink packet may be transmitted from the correspondent node # B to the correspondent node # ｃA. In UP-B, an uplink packet may be transmitted from the communication node # C to the communication node # a. In this case, the correspondent node # B may forward the uplink packet received from the correspondent node # C to the correspondent node # a. The uplink packet may include: a synchronization packet type field, an AT field, a unique ID field, a signal strength field, a received SFN/SF field, an SDU count field, an SDU #1 size field, an SDU #2 size field, an SDU #3 size field, SDU #1, SDU #2, and SDU # 3.

The synchronization packet type field may indicate the type of packet and may be set to "200". The AT field may indicate an AT when the uplink packet is transmitted. For example, in the UP- ｃA field, the AT field may indicate an AT when the communication node # B transmits an uplink packet, and in the UP-B field, the AT field may indicate an AT when the communication node # C transmits an uplink packet. The unique ID field may indicate a unique ID based on a vehicle ID and an RB ID (e.g., an RB ID for initial transmission, an RB ID for transmission of an RLC status message, an RB ID for retransmission). The signal strength field may indicate a received signal strength for a TB received in a corresponding TTI, a maximum received signal strength among received signal strengths of a plurality of signals when the JR scheme is used, or an average received signal strength of a plurality of signal strengths when the JR scheme is used.

The received SFN/SF field may indicate that the SFN and SF index of the corresponding TB are received on the MAC layer side. The SDU count field may indicate the number of SDUs scheduled for the TB in one TTI (e.g., the number of SDUs included in the uplink packet). The number of SDU size fields included in the uplink packet may be the same as the value indicated by the SDU count field. The SDU #1 size field may indicate the length of SDU #1 included in the uplink packet, the SDU #2 size field may indicate the length of SDU #2 included in the uplink packet, and the SDU #3 size field may indicate the length of SDU #3 included in the uplink packet.

Further, the received signal strength according to the distance in the downlink communication between the communication system 100 and the vehicle 200 may be as follows.

Fig. 47 is a conceptual diagram illustrating a first embodiment of received signal strength in downlink communication.

Referring to fig. 47, LA2M140 of communication system 100 may be mounted on top of a pipe and may be configured with a sliding window that includes multiple antennas. The downlink communication between the communication system 100 and the vehicle 200 may be performed based on a plurality of antennas belonging to a sliding window, and the plurality of antennas belonging to the sliding window may transmit the same signal through the same time-frequency resource. That is, downlink communication may be performed based on the JT scheme.

The vehicle 200 may receive a downlink signal from a plurality of antennas belonging to a sliding window, and may classify a reception period (e.g., a reception window) of the downlink signal into a good window, a dead window (deadwindow), and an interference window according to the received signal strength. The region including the good window, the necrosis window, and the interference window may be referred to as a downlink Capsule Radio Zone (CRZ). For example, a reception period in which the received signal strength of the downlink signal is equal to or greater than a threshold may be referred to as a good window. The reception period during which communication is impossible due to multipath fading, delay spread, etc., may be referred to as a necrosis window. The reception period during which interference occurs with subsequent vehicles following the vehicle 200 may be referred to as an interference window. In the interference window, the received signal strength may decrease after increasing. When the following vehicle is located in the interference window, the signal in the interference window may interfere with the communication of the following vehicle. Thus, the distance between the vehicle 200 and the following vehicle may be configured based on the interference window.

Further, the received signal strength according to the distance in the uplink communication between the communication system 100 and the vehicle 200 may be as follows.

Fig. 48 is a conceptual diagram illustrating a first embodiment of the strength of a signal received in uplink communication, and fig. 49 is a conceptual diagram illustrating a second embodiment of the strength of a signal received in uplink communication.

Referring to fig. 48 and 49, LA2M140 of communication system 100 may be mounted on top of a pipe and may be configured with a sliding window that includes multiple antennas. The uplink communication between the communication system 100 and the vehicle 200 may be performed based on a plurality of antennas belonging to a sliding window. The uplink signals transmitted by the vehicle 200 may be received at a plurality of antennas belonging to the sliding window.

In the good window, CRC checking of uplink signals received from the plurality of antennas belonging to the sliding window may be successfully completed, and the received signal strength of the uplink signals may be equal to or greater than a threshold value. The reception period during which communication is impossible due to multipath fading, delay spread, etc., may be referred to as a necrosis window. The reception period during which interference occurs with subsequent vehicles following the vehicle 200 may be referred to as an interference window. In the interference window, the received signal strength may decrease after increasing. The region including the good window, the necrosis window, and the interference window may be referred to as an uplink CRZ. When uplink communication is performed based on the JR scheme, the received signal strength can be improved in the good window of fig. 49.

Further, the system configuration for performing communication between the communication system 100 and the vehicle 200 may be as follows.

Fig. 50 is a conceptual diagram illustrating a first embodiment of a system configuration for communication between a communication system and a vehicle.

Referring to fig. 50, a communication system 100 may include a CCU110, a TSU120, VA2C130, and LA2M 140. The CCU110 may be connected to a Cabin Control Network (CCN) and a Passenger Service Network (PSN) (e.g., Evolved Packet Core (EPC)), and may be connected to the TSU 120. The TSU120 may be connected to VA2C130, and VA2C130 may be connected to LA2M 140. LA2M140 may include multiple antennas. LA2M140 may be mounted in line on top of the duct and may be connected to VA2C130 located outside the duct. In this case, the CCU110, TSU120 and VA2C130 may be located outside of the pipeline. Alternatively, VA2C130 and LA2M140 may be located in the pipeline, and the CCU110 and TSU120 may be located outside of the pipeline.

Each of the vehicles 200-1 and 200-2 may include an antenna, Cabin Equipment (CE), etc., and the CE may be connected to the CCN and the PSN (e.g., EPC). The vehicles 200-1 and 200-2 may move within the pipe and perform downlink/uplink communication with a plurality of antennas belonging to the sliding window. The moving speed of the sliding window #1 may be equal to the moving speed of the vehicle 120-1, and the moving speed of the sliding window #2 may be equal to the moving speed of the vehicle 120-2. The communication of the vehicles 200-1 and 200-2 may be performed in a good window. The interference window of vehicle 120-1 may be configured to not overlap with the good window of vehicle 120-2.

The CCN connected to the CCU110 may be connected to the CCN inside the vehicles 200-1 and 200-2, and control of the vehicles 200-1 and 200-2 may be performed through the CCN. The PSN connected to the CCU110 may be connected to PSNs inside the vehicles 200-1 and 200-2 and may support communication for the passengers of the vehicles 200-1 and 200-2 via the PSNs (e.g., small base stations or access points installed in the vehicles 200-1 and 200-2). Here, the small base station may support a 4G communication protocol, a 5G communication protocol, etc., and the access point may support a Wireless Local Area Network (WLAN) communication protocol.

Further, when vehicles 200-1 and 200-2 move from station A to station B, the operational profile may be as follows.

Fig. 51 is a graph showing the first embodiment of the vehicle operation profile.

Referring to fig. 51, the distance between station a and station B may be 413km, and vehicles 200-1 and 200-2 may accelerate, maintain a constant speed, and decelerate to move from station a to station B in 25 minutes. For example, the vehicles 200-1 and 200-2 may be operated at a maximum speed of 1200km/h by repeating the acceleration operation and the constant speed operation, and the speed may be reduced by repeating the deceleration operation and the constant speed operation.

Further, when a plurality of vehicles run between the station a and the station B, the CRZ of each vehicle may be as follows.

Referring to fig. 52, a plurality of vehicles 200-1 to 200-8 may move within a duct and may move from station a to station B. A CRZ may be configured for each of the plurality of vehicles 200-1 to 200-8. The CRZ may include a good window, a necrosis window, and an interference window. CRZ #3, CRZ #4, CRZ #5, and CRZ #6 may not overlap each other. Accordingly, the entire frequency band in the CRZ #3, CRZ #4, CRZ #5, and CRZ #6 can be used to provide the communication service to the vehicles 200-3, 200-4, 200-5, and 200-6. That is, the same time-frequency resource may be used to provide communication services within non-overlapping CRZs.

However, the CRZ may overlap at the start point (e.g., station a) and the arrival point (e.g., station B) according to the runtime schedule. For example, CRZ #1 of vehicle 200-1 may overlap with CRZ #2 of vehicle 200-2 in station A, and CRZ #7 of vehicle 200-7 may overlap with CRZ #8 of vehicle 200-8 in station B. Interference occurs when the entire frequency band is used within the overlapping CRZ to provide communication services to the vehicles 200-1, 200-2, 200-7, and 200-8. Therefore, within the overlapping CRZ, the time-frequency resources may be configured as follows.

Referring to fig. 53, when the CRZ #1 of the vehicle 200-1 overlaps with the CRZ #2 of the vehicle 200-2, time-frequency resources may be configured based on a Time Division Duplex (TDD) scheme. For example, the entire frequency resources may be configured for CRZ #1 and #2, and orthogonal time resources may be configured for CRZ #1 and # 2. The time-frequency resources may be configured such that no interference occurs between overlapping CRZs. In this case, the vehicle 120-1 belonging to the CRZ #1 may perform communication using TTI #1, and the vehicle 120-1 belonging to the CRZ #2 may perform communication using TTI # 2.

Referring to fig. 54, when the CRZ #1 of the vehicle 200-1 overlaps with the CRZ #2 of the vehicle 200-2, time-frequency resources may be configured based on a Frequency Division Duplex (FDD) scheme. For example, the entire time resources may be configured for CRZ #1 and #2, and orthogonal frequency resources may be configured for CRZ #1 and # 2. The time-frequency resources may be configured such that no interference occurs between overlapping CRZs. In this case, the vehicle 120-1 belonging to the CRZ #1 may perform communication using the frequency band #1, and the vehicle 120-1 belonging to the CRZ #2 may perform communication using the frequency band # 2.

Further, the RB may be configured for communication between the communication system 100 and the vehicle 200, and the RB between the communication system 100 and the vehicle 200 may be configured as follows in the system of fig. 50.

Referring to fig. 55, a plurality of RBs (e.g., SRB #1, DRB #2, DRB #3, DRB #4, and DRB #5) may be configured between the communication system 100 and the vehicle 200. SRB #1 may be used to transmit control information including semi-static scheduling information and the like. Since control information should be transmitted and received without losing packets, transmission of SRB #1 can be performed based on RLC AM. DRBs #1 and #2 connected to the CCN may be used to transmit operation information of the vehicle 200, and DRBs #3 to #5 connected to the PSN may be used to transmit user data (e.g., data of passengers of the vehicle 200).

The priority for packet processing of the RB may be "SRB #1 (priority a) > DRB #1 and #2 (priority B) > DRB #3 to #5 (priority C) connected to the PSN connected to the CCN". The priority (i.e., priority #1, #2, and #3) within the DRB may be determined according to the type (e.g., control information, data) and importance of the packet. When the missing packet is not allowed, communication can be performed based on the RLC AM. When the missing packet is allowed, communication may be performed based on an RLC Transmission Mode (TM) or an RLC Unacknowledged Mode (UM).

C-RNTI may be configured for each RB. The C-RNTI of the RBs for initial transmission (e.g., SRB #1-1, DRB #2-1, DRB #4-1, and DRB #5-1), the C-RNTI of the RBs for transmission of RLC status messages (e.g., SRB #1-2, DRB #2-2, DRB #4-2, and DRB #5-2), and the C-RNTI of the RBs for retransmission (e.g., SRB #1-3, DRB #2-3, DRB #4-3, and DRB #5-3) may be independently configured. The RBs may be scheduled based on independently configured C-RNTIs. For example, initial transmission may be performed through DRB #1-1 scheduled by C-RNTI B-1, transmission of RLC status messages may be performed through DRB #1-2 scheduled by C-RNTI B-2, and retransmission may be performed through DRB #1-3 scheduled by C-RNTI B-3.

That is, an RB to which the RLC AM is applied may be divided into three RBs, and the C-RNTI may be independently configured for each of the three RBs. The C-RNTI for the RB for initial transmission may be basically configured, and the C-RNTI for transmission of the RLC status message and the C-RNTI for retransmission may be additionally configured. Since the C-RNTI is independently configured for each RB, contents can be easily synchronized when communication based on the JT scheme or the JR scheme is performed. Alternatively, one C-RNTI may be configured for an RB to which the RLC AM is applied, and three resources (e.g., a resource for initial transmission, a resource for transmission of an RLC status message, and a resource for retransmission) may be allocated based on the one C-RNTI.

■ method for measuring vehicle position

Further, the communication system 100 may configure a sliding window corresponding to the position of the vehicle 200, and should have information on the position of the vehicle 200 in order to configure the sliding window. The method for measuring the position of the vehicle 200 may be performed as follows.

Fig. 56 is a conceptual diagram illustrating a unique identification number to which an antenna included in LA2M of a communication system is assigned, and fig. 57 is a conceptual diagram illustrating a first embodiment of a method for transmitting a unique identification number.

Referring to fig. 56 and 57, the multiple antennas belonging to LA2M140 of communication system 100 may each be assigned a unique identification number. For example, the unique identification numbers 100200001 through 100200033 may be sequentially assigned to the plurality of antennas. The unique identification number may be mapped to the position of the antenna assigned the unique identification number, and the position of the vehicle 200 may be measured based on the unique identification number. The antenna may transmit a signal including its unique identification number. The unique identification number may be transmitted via pre-allocated time-frequency resources. For example, the time-frequency resources for transmitting the unique identification number may be configured every two TTIs, and the time-frequency resources for the unique identification number may be sequentially configured within one TTI. The number of unique identification numbers transmitted in one TTI may be more than the number of antennas belonging to a good window. In period #1, frequency resources for the unique identification numbers 100200001 through 100200011 may be allocated to be orthogonal. In period #2, frequency resources for the unique identification numbers 100200012 through 100200022 may be allocated to be orthogonal. In period #3, frequency resources for the unique identification numbers 100200023 through 100200033 may be allocated to be orthogonal.

Further, the vehicle 200 may receive signals from the plurality of antennas of the communication system 100, and may identify the unique identification number of each of the plurality of antennas based on the received signals. The unique identification number of the antenna identified in the vehicle 200 may be as follows.

Fig. 58 is a conceptual diagram illustrating a unique identification number recognized by a vehicle, and fig. 59 is a graph illustrating received signal strength of a signal including the unique identification number.

Referring to fig. 58 and 59, vehicle 200 may receive signals from multiple antennas belonging to LA2M140, identify unique identification numbers by decoding the signals, and may select at least one unique identification number for use in position measurements. For example, the vehicle 200 may perform a CRC check on the signals including the unique identification numbers 100200001 through 100200033 and identify the unique identification numbers (e.g., 100200003 through 100200018) that have successfully completed the CRC check. The vehicle 200 may select a unique identification number (e.g., 100200004 to 100200016) having a received signal strength equal to or greater than a threshold value among the identified unique identification numbers 100200003 to 100200018. Since the received signal strength of the signal including the unique identification number 100200014 is the greatest among the selected unique identification numbers 100200004 through 100200016, the position of the antenna that transmitted the signal including the unique identification number 100200014 can be estimated as the position of the vehicle 200.

However, since the position of the vehicle 200 is estimated based on the antenna of the vehicle 200, when the position measurement reference is not the antenna, the estimated position needs to be corrected. The method of correcting the position of the vehicle 200 may be performed as follows.

Referring to fig. 60, the position of the vehicle 200 may be corrected based on the operating mode (e.g., acceleration mode, constant speed mode, deceleration mode) of the vehicle 200. In fig. 51, the acceleration mode of the vehicle 200 may be classified into acceleration modes A, B and C, the constant speed mode of the vehicle 200 may be classified into constant speed modes A, B, C, D and E, and the deceleration mode of the vehicle 200 may be classified into deceleration modes A, B and C. The Absolute Position (AP) of the vehicle 200 may be calculated based on equation 1 below.

[ equation 1]

AP＝DAP+CP

That is, the AP of the vehicle 200 may be the sum of a Detected Absolute Position (DAP) and a Calibrated Position (CP). The DAP may be a location corresponding to the antenna in fig. 58 and 59 that sent the signal including the unique identification number 100200014. The CP may be calculated based on equation 2 below.

[ equation 2]

CP＝PCP+SCP+MCP

The Physical Calibration Position (PCP) may be a physical correction value for a position measurement reference of the vehicle 200. The Schedule Calibration Position (SCP) may be a value used to correct the propagation delay characteristics of a signal that includes a unique identification number. The Mode Calibration Position (MCP) may be a correction value for each operating mode based on the operating history of the vehicle 200. For example, when the operation mode of the vehicle 200 is the acceleration mode C, MCP C or MCP D may be applied. MCP C or MCP D may be a fixed value, and the position of the vehicle 200 may be corrected based on a variable that increases in proportion to the speed in the acceleration mode C. Further, the vehicle 200 may operate in an exception mode (e.g., an operating mode of the vehicle 200 in an emergency), and may define the MCP O applied to the exception mode. MCP O may not be a constant value, but may be a variable that is affected by certain factors.

Further, a method of measuring the position of the vehicle 200 based on the signal transmitted from the vehicle 200 may be as follows.

Referring to fig. 61, the vehicle 200 may be given a unique identification number, and the vehicle 200 may transmit a signal including its unique identification number. The unique identification number of the vehicle 200 may be set to 9009000001. The unique identification number may be transmitted via pre-allocated time-frequency resources. For example, the time-frequency resources for transmitting the unique identification number may be configured every two TTIs, and the time-frequency resources for the unique identification number may be sequentially configured within one TTI. The unique identification number of the vehicle 200 may be repeatedly transmitted via time-frequency resources.

The plurality of antennas included in LA2M140 of communication system 100 may receive a signal including a unique identification number from vehicle 200. When a signal including the unique identification number is transmitted from the vehicle 200 in fig. 56, the antenna corresponding to the unique identification numbers 100200003 to 100200018 among the plurality of antennas included in LA2M140 may receive the signal including the unique identification number of the vehicle 200. The received signal strengths of the signals including the unique identification number of the vehicle 200 received at the antennas corresponding to the unique identification numbers 100200003 through 100200018 may be the same as those shown in the graph of fig. 59.

For example, a signal containing the unique identification number of the vehicle 200 may be received at antennas corresponding to the

unique identification numbers

100200003 and 100200018, but the CRC for the received signal may fail. A signal including the unique identification number of the vehicle 200 may be received from an antenna corresponding to the unique identification number 100200017 and a CRC check of the received signal may be successfully completed, but the received signal strength of the signal may be less than a threshold. In this case, the location of the vehicle 200 may be determined based on the antennas corresponding to the

unique identification numbers

100200004 and 100200016. Since the received signal strength of the signal including the unique identification number of the vehicle 200 received at the antenna corresponding to the unique identification number 100200014 is the greatest, the position of the antenna corresponding to the unique identification number 100200014 can be estimated as the position of the vehicle 200.

Alternatively, the time-frequency resource transmitting the signal including the unique identification number of the vehicle 200 may be mapped to an antenna included in the LA2M140, as shown in tables 1 to 3 below.

[ Table 1]

[ Table 2]

Resource indexing	Time resource	Frequency resource	Unique identification number of antenna	Decoding result	Received signal strength
						#
12	Period #2	A	100200012	900200001	Equal to or greater than a threshold value
						#
13	Period #2	B	100200013	900200001	Equal to or greater than a threshold value
						#
14	Period #2	C	100200014	900200001	Equal to or greater than a threshold value
						#
15	Period #2	D	100200015	900200001	Equal to or greater than a threshold value
						#
16	Period #2	E	100200016	900200001	Equal to or greater than a threshold value
						#
17	Period #2	F	100200017	CRC failure	Less than threshold
						#
18	Period #2	G	100200018	CRC failure	Less than threshold
						#19	Period #2	H	100200019	CRC failure	Less than threshold
#
	20	Period #2	I	100200020	CRC failure	Less than threshold
#21							Period #2	J	100200021	CRC failure	Less than threshold
	#22	Period #2	K	100200022	CRC failure	Less than threshold

[ Table 3]

Each antenna included in LA2M140 may perform a monitoring operation on a preconfigured resource (e.g., the time-frequency resources of tables 1-3 indicated by the resource index) in order to receive a signal including the unique identification number of vehicle 200. For example, a CRC check of the signal including the unique identification number of the vehicle 200 may be successfully performed at the antennas corresponding to the

unique identification numbers

100200003 and 100200016, and the received signal strength of the signal including the unique identification number of the vehicle 200 received at the antennas corresponding to the

unique identification numbers

100200004 and 100200016 may be greater than or equal to a threshold value. In addition, the received signal strength of a signal including the unique identification number of the vehicle 200 received in the time-frequency resource indicated by the resource index #14 may be the maximum, and in this case, the position of the antenna mapped to the resource index #14 may be estimated as the position of the vehicle 200. When the position of the vehicle 200 is estimated, the estimated position may be corrected based on the position correction method described with reference to fig. 60. For example, the estimated location may be the DAP and may be corrected based on the PCP, SCP, or MCP.

Further, the AP can be obtained by applying a C algorithm (e.g., the position correction method shown in fig. 60) to the DAP obtained from the vehicle 200. Vehicle 200 may send the AP to communication system 100 via a DRB connected to the CCN. The AP can be obtained by applying a G algorithm (e.g., a position correction method shown in fig. 60) to the DAP obtained in the communication system 100. Further, the communication system 100 can obtain a correct AP by applying the F algorithm to the AP obtained from the communication system 100 and the AP obtained from the vehicle 200. Here, the F algorithm may take into account the propagation delay. The communication system 100 can transmit the AP obtained via the F algorithm to the vehicle 200 through the DRB connected to the CCN. Vehicle 200 may obtain an AP from communication system 100, and the obtained AP may be used as an input to the C algorithm.

In addition, a necrosis window may occur when the antenna included in LA2M140 transmits a signal including a unique identification number via the same time-frequency resource. In view of the necrosis window, the time-frequency resources of the signal including the unique identification number of the antenna may be configured as follows.

Fig. 62 is a conceptual diagram illustrating a downlink CRZ arranged in good window units, and fig. 63 is a conceptual diagram illustrating a third embodiment of a method for transmitting a unique identification number.

Referring to fig. 62 and 63, an antenna belonging to a good window of CRZ #1 may transmit a signal including a unique identification number using a frequency band #1, an antenna belonging to a good window of CRZ #2 may transmit a signal including a unique identification number using a frequency band #2, an antenna belonging to a good window of CRZ #3 may transmit a signal including a unique identification number using a frequency band #3, and an antenna belonging to a good window of CRZ #4 may transmit a signal including a unique identification number using a frequency band # 4. Further, the antenna belonging to the good window of the CRZ #5 may transmit a signal including the unique identification number using the frequency band #5, the antenna belonging to the good window of the CRZ #6 may transmit a signal including the unique identification number using the frequency band #6, and the antenna belonging to the good window of the CRZ #7 may transmit a signal including the unique identification number using the frequency band # 7.

The frequency resources for the antennas included in LA2M140 may be sequentially configured based on the above-described method. In this case, it is possible to prevent the reception performance of the signal including the unique identification number of the antenna from being deteriorated due to the necrosis window and the interference window. Here, when only the frequency bands #1 to #5 are configured, it is possible to prevent the reception performance from being degraded due to the necrosis window and the interference window. However, the frequency bands #1 to #7 may be configured to sufficiently cover the necrosis window and the interference window.

Furthermore, a necrosis window may occur when a signal comprising the unique identification number of the vehicle 200 is transmitted via the same time-frequency resource. The time-frequency resource of the signal including the unique identification number of the vehicle 200 may be configured as follows, taking into account the necrosis window.

Fig. 64 is a conceptual diagram illustrating an uplink CRZ arranged in good window units, and fig. 65 is a conceptual diagram illustrating a fourth embodiment of a method for transmitting a unique identification number.

Referring to fig. 64 and 65, a vehicle belonging to a good window of CRZ #1 may transmit a signal including a unique identification number using a frequency band #1, a vehicle belonging to a good window of CRZ #2 may transmit a signal including a unique identification number using a frequency band #2, a vehicle belonging to a good window of CRZ #3 may transmit a signal including a unique identification number using a frequency band #3, and a vehicle belonging to a good window of CRZ #4 may transmit a signal including a unique identification number using a frequency band # 4. Further, a vehicle belonging to the good window of CRZ #5 may transmit a signal including a unique identification number using the frequency band #5, a vehicle belonging to the good window of CRZ #6 may transmit a signal including a unique identification number using the frequency band #6, and a vehicle belonging to the good window of CRZ #7 may transmit a signal including a unique identification number using the frequency band # 7.

The frequency resources for transmission of the unique identification number may be sequentially configured based on the above-described method. In this case, it is possible to prevent the reception performance of the signal including the unique identification number of the vehicle from being deteriorated due to the necrosis window and the interference window. Here, when only the frequency bands #1 to #5 are configured, it is possible to prevent the reception performance from being degraded due to the necrosis window and the interference window. However, the frequency bands #1 to #7 may be configured to sufficiently cover the necrosis window and the interference window.

In addition, when time-frequency resources are allocated based on the FDD scheme in the overlapping CRZ, a data region of the overlapping CRZ may be configured in different frequency bands, and a control region of the overlapping CRZ may be configured in the entire frequency band. In this case, since interference may occur between CRZ overlapping in the control area, the scheduling information transmitted via the control area may not be received at the vehicle 200. To solve this problem, the control area may be configured as follows.

Referring to fig. 66, since the CRZ of adjacent vehicles is likely to overlap, the frequency bands may be allocated according to the departure order of the vehicles. For example, the frequency resource for vehicle 200-8 in fig. 52 may be set to frequency band #1, the frequency resource for vehicle 200-7 in fig. 52 may be set to frequency band #2, the frequency resource for vehicle 200-6 in fig. 52 may be set to frequency band #3, and the frequency resource for vehicle 200-5 in fig. 52 may be set to frequency band # 4. Further, the frequency resource for vehicle 200-4 in fig. 52 may be set to frequency band #1, the frequency resource for vehicle 200-3 in fig. 52 may be set to frequency band #2, the frequency resource for vehicle 200-2 in fig. 52 may be set to frequency band #3, and the frequency resource for vehicle 200-1 in fig. 52 may be set to frequency band # 4.

The band #1 may include a control region #1 and a data region #1, and may transmit scheduling information for the data region #1 via the control region # 1. The band #2 may include a control region #2 and a data region #2, and may transmit scheduling information for the data region #2 via the control region # 2. The band #3 may include a control region #3 and a data region #3, and may transmit scheduling information for the data region #3 via the control region # 3. Band #4 may include a control region #4 and a data region #4, and scheduling information for the data region #4 may be transmitted via the control region # 4.

However, when the CRZs do not overlap, a cross-scheduling scheme may be used. For example, the scheduling information for the data regions #1 to #4 may be transmitted via the control region # 1. That is, even when the band #1 is allocated for the vehicle 200-4, the communication system 100 can transmit the scheduling information for the data regions #1 to #4 to the vehicle 200-4 via the control region # 1.

Further, when an emergency occurs during the operation of the vehicles 200-1, 200-2, 200-3, 200-4, 200-5, 200-6, 200-7, and 200-8, a specific vehicle may be evacuated to an emergency space as follows.

Referring to fig. 67, when an emergency occurs during the operation of the vehicles 200-1, 200-2, 200-3, 200-4, 200-5, 200-6, 200-7, and 200-8, the vehicle 200-4, the vehicle 200-5, and the vehicle 200-6 may evacuate to the emergency space. In this case, the CRZ #3 of the vehicle 200-3 may overlap the CRZ of the vehicle 200-7, and the vehicle 200-3 and the vehicle 200-7 use the same frequency band (e.g., the frequency band #2 in fig. 66), so that interference may be generated. In this case, the control region allocated to the vehicle 200-3 may be changed from the band #2 to the band #1 via the RRC signaling procedure. The messages for the RRC signaling procedure may include: information requesting a change of the C-RNTI of the vehicle 200-3 (or, information indicating that the C-RNTI of the vehicle 200-3 is used for the band #1), information indicating a time point of changing the band (for example, SF #9), and the like. When the C-RNTI is configured not to overlap over the entire band, the C-RNTI may not be changed even if the control region is changed.

Further, the communication system 100 described above with reference to fig. 1 to 67 may be referred to as a "Distributed Unit (DU) based communication system". The DU-based communication system may support the following functions.

-function # 1: transmission and reception of control packets for controlling operation of vehicle 200

-function # 2: transmission and reception of service packets for passengers of vehicle 200

-function # 3: wireless communication function with a communication node (e.g., sensor) installed in a moving path (e.g., ultra-high speed pipe) of the vehicle 200

-function # 4: radio communication based position measurement functionality

Communication between the CCN of the DU-based communication system and the CCN inside the vehicle 200 may be performed, and communication between the PSN of the DU-based communication system and the PSN inside the vehicle 200 may be performed. The DU-based communication system may also be connected to a communication node (e.g., a sensor) installed in a moving path (e.g., an ultra high speed pipe) of the vehicle 200, may support a control function and a data upload function of the corresponding communication node, and may measure the position of the vehicle 200 using the corresponding communication node. In communication between the DU-based communication system and the vehicle 200, the sliding window for the vehicle 200 may move according to the moving speed of the vehicle 200, so that a pseudo fixed cell environment may be created. In this case, the minimum movement unit of the sliding window may be DU units. The DU may include at least one LA2M140 or at least one antenna. LA2M140 of the DU-based communication system and CA2M of the vehicle 200 may be configured as follows.

Fig. 68 is a conceptual diagram illustrating a first embodiment of LA2M of the DU-based communication system and CA2M of the vehicle.

Referring to fig. 68, when LA2M140 of the DU-based communication system and CA2M of the vehicle 200 use high frequency (e.g., millimeter wave), LA2M140 of the DU-based communication system may be composed of n × m elements, and CA2M of the vehicle may be composed of p × q elements. Here, each of n, m, p, and q may be a positive integer. LA2M140 of the DU-based communication system and CA2M of the vehicle 200 may be composed of small antennas. When LA2M140 of a DU-based communication system is composed of multiple elements, LA2M140 may be referred to as AAC. Alternatively, when LA2M140 of the DU-based communication system supports only an antenna function, LA2M140 may be referred to as a Remote Radio Head (RRH).

LA2M140 of the DU-based communication system may include an entity supporting analog RF switching functions (e.g., P2M or M2P selection functions) or an entity supporting optical switching functions (e.g., radio over fiber/ethernet (RoF/E)). RoF/E can be used as a wired interface between LA2M140 and VA2C130 in a DU-based communication system. In LA2M140 of the DU-based communication system, one port (e.g., a port of a higher layer) may be connected to the entire DU port (e.g., a port of a lower layer), and the entire DU port may be connected to one port, so that a soft combining function may be performed. Alternatively, in LA2M140 of the DU-based communication system, ports may be connected in a point-to-multipoint (P2MP) scheme, and the DU ports may be designed to selectively perform a soft combining function. Alternatively, in LA2M140 of the DU-based communication system, the DU ports may be independently connected to VA2C 130.

The beam width supported by the antenna of the DU-based communication system may be different from the beam width supported by the antenna of the vehicle 200. When the beam of the vehicle 200 is aligned with the beam of the DU-based communication system, the signal to interference plus noise ratio (SINR) may increase. The SINR may be reduced when the beam of the vehicle 200 is misaligned with the beam of the DU-based communication system. However, even when the beam of the vehicle 200 is misaligned with the beam of the DU-based communication system, if the contents are synchronized and the JT scheme is used, the SINR may increase.

In addition, VA2C130 of the DU-based communication system may support a sliding window, may be connected to an upper entity TSU120, and may be connected to at least one LA2M140 as a lower entity. Therefore, VA2C130 may transmit signals received from TSU120 to LA2M140 based on the P2MP scheme. In addition, VA2C130 may perform soft combining on the signals received from LA2M140 based on the MP2P scheme, and may transmit the signals received from LA2M140 to TSU 120. The TSU120 may be connected to VA2C130 via optical fibers, and VA2C130 may be connected to LA2M140 via optical fibers. In this case, depending on the length of the optical fiber, signal loss may occur, and an optical repeater may be used to prevent the signal loss.

The TSU120 of the DU-based communication system may perform base station functions of the cellular communication system. The TSU120 may be connected to the CCU110 as an upper entity and may be connected to at least one VA2C130 as a lower entity. The TSU120 may support PHY functions, MAC functions, synchronization functions, and the like. The MAC layer of the TSU120 may support a slave MAC function (slaveMAC function) and process data related to the MAC. The synchronization layer of the TSU120 may perform the transmission and reception functions of probe request/response packets to measure the time delay of the underlying entities. In addition, the synchronization layer and MAC layer of the TSU120 may generate a MAC frame based on the downlink data packet, acquire the MAC frame from the uplink PHY packet, and generate an uplink synchronization packet based on the acquired MAC frame. In this case, the synchronization of the downlink content may be performed based on a synchronization protocol, and the uplink content may be selected.

The CCU110 of the DU-based communication system may perform EPC functions of a cellular communication system and may support RRC functions, RLC functions, PDCP functions, synchronization functions, non-access stratum (NAS)) functions, and the like. The RRC layer of the CCU110 may support a radio resource control function, and the RLC layer of the CCU110 may support a data unit segmentation/combination function, an automatic repeat request (ARQ) function, a redundancy detection function, and the like. The PDCP layer of the CCU110 may support an IP header compression function, a ciphering function, and an integrity protection function. The synchronization layer of the CCU110 may support a transmission and reception function of a probe request/response packet for measuring a delay of a lower entity, and may support a primary MAC function based on semi-static scheduling of an RRC layer.

The synchronization layer of the CCU110 may transmit downlink data packets to the TSU120 in consideration of the operation of the MAC layer of the TSU 120. The synchronization layer of the CCU110 may select valid uplink data packets from the uplink data packets received from the TSU120 and may discard invalid uplink data packets. The synchronization layer of the CCU110 may perform a downlink content synchronization function, an uplink content selection function, and the like based on a predetermined synchronization protocol. The CCU110 may perform a matching function between the CCN and the PSN connected to the DU-based communication system. The communication function for the passengers of the vehicle 200 may be supported by the CCN of the DU-based communication system and the CCN of the vehicle 200 when an emergency occurs.

The CE of the vehicle 200 may perform a UE function of the cellular communication system, and may perform a PHY function, a MAC function, an RLC function, a PDCP function, and the like. In addition, the CE of the vehicle 200 may perform a matching function between the CCN and the PSN connected to the vehicle 200.

On the other hand, in the communication system 100, LCX may be used instead of the DU, and the communication system using LCX may be referred to as "LCX-based communication system". The LCX based communication system may be configured as follows.

Referring to fig. 69, the LCX-based communication system may include: CCU110, TSU120, virtual Linear Radiating Cable Module (LRCM) controller (VLC)150, LRCM 160, and the like. The CCU110 may be connected to the CCN and PSN, and may be connected to the TSU120 as a lower entity. In an LCX-based communication system, the functions of the CCU110 may be the same as or similar to the functions of the CCU110 in the communication system 100 described above (e.g., a DU-based communication system). The TSU120 may be connected to the CCU110 as an upper entity and may be connected to the VLC 150 as a lower entity. The functionality of the TSU120 in the LCX-based communication system may be the same as or similar to the functionality of the TSU120 in the communication system 100 described above (e.g., DU-based communication system).

The VLC 150 may be connected to an upper entity TSU120 and a lower entity LRCM 160. The function of the VLC 150 in the LCX-based communication system may be the same as or similar to the function of the VA2C130 in the communication system 100 described above (e.g., DU-based communication system). The LRCM 160 may be connected to the upper entity VLC 150 and may include a Radiating Cable (RC) (e.g., a Radiating Cable Segment (RCs)). Communication between the LCX-based communication system and the vehicles 200-1 and 200-2 may be performed via the LRCM. The functionality of LRCM 160 in an LCX-based communication system may be the same as or similar to the functionality of LA2M140 in communication system 100 (e.g., a DU-based communication system) described above.

The vehicles 200-1 and 200-2 may include Cabin TRX Antenna Modules (CTAM), CE, etc., and the CE may be connected to the CCN and PSN. Sliding windows for the vehicles 200-1 and 200-2 may be configured, and communication between the vehicles 200-1 and 200-2 and the LCX-based communication system may be performed within the sliding windows.

The LCX based communication system may support the following functions.

-function # 3: radio communication based position measurement functionality

Communication between the CCN of the LCX-based communication system and the CCNs inside the vehicles 200-1 and 200-2 may be performed, and communication between the PSN of the LCX-based communication system and the PSNs inside the vehicles 200-1 and 200-2 may be performed. The LCX-based communication system may also be connected to a communication node (e.g., a sensor) installed in a moving path (e.g., an ultra-high speed pipe) of the vehicle 200, may support a control function and a data upload function for the corresponding communication node, and may measure the position of the vehicle 200 using the corresponding communication node. In communication between the LCX-based communication system and the vehicle 200, the sliding window for the vehicle 200 may move according to the moving speed of the vehicle 200, so that a pseudo-fixed cell environment may be created. In this case, the minimum movement unit of the sliding window may be an LRCM unit.

In an LCX based communication system, LRCM 160 may be configured as follows.

Referring to fig. 70, the LRCM 160 may include a plurality of RCSs having a predetermined length (e.g., 150m), and may transmit a signal (e.g., a source signal) received from the VLC 150 to the plurality of RCSs. The length of the LRCM 160 may be 1.8 km. Since signal loss increases with increasing RCS length, the signal can be amplified by analog repeaters 165-1 and 165-2. The RCS may be connected to the ports of LRCM 160 via optical fibers rather than analog repeaters 165-1 and 165-2. The LRCM 160 may be connected to the VLC 150 via RoF/E.

Further, the radiation angle of the RCS may be determined according to the arrangement of the slots. The radiation angle according to the slotted arrangement may be as follows.

Referring to fig. 71, a plurality of slots may be located in the LRCM 160, and a radiation angle may be determined according to an arrangement of the plurality of slots.

Referring again to fig. 69, the VLC 150 of the LCX-based communication system may control and manage the sliding window. The VLC 150 may be connected to the upper entity TSU120 via optical fiber and may be connected to the lower entity LRCM 160 via optical fiber. In this case, depending on the length of the optical fiber, signal loss may occur, and an optical repeater may be used to prevent the signal loss. The VLC 150 may transmit the signal received from the TSU120 to at least one LRCM 160 based on the P2MP scheme. The VLC 150 may perform soft combining on the signals received by the LRCM 160 based on the MP2P scheme and may send the signals to the TSU 120.

The TSU120 of the LCX-based communication system may perform base station functions of the cellular communication system. The TSU120 may be connected to the CCU110 as an upper entity and may be connected to the VLC 150 as a lower entity. The TSU120 may support PHY functions, MAC functions, synchronization functions, and the like. The MAC layer of the TSU120 may support slave MAC functions and process data related to MAC. The synchronization layer of the TSU120 may perform the transmission and reception functions of probe request/response packets to measure the time delay of the underlying entities. In addition, the synchronization layer and MAC layer of the TSU120 may generate a MAC frame based on the downlink data packet, acquire the MAC frame from the uplink PHY packet, and generate an uplink synchronization packet based on the acquired MAC frame. In this case, the synchronization of the downlink content may be performed based on a synchronization protocol, and the uplink content may be selected.

The CCU110 of the LCX-based communication system may perform EPC functions of the cellular communication system and may support RRC functions, RLC functions, PDCP functions, synchronization functions, NAS functions, and the like. The RRC layer of the CCU110 may support a radio resource control function, and the RLC layer of the CCU110 may support a data unit segmentation/combination function, an automatic repeat request (ARQ) function, a redundancy detection function, and the like. The PDCP layer of the CCU110 may support an IP header compression function, a ciphering function, and an integrity protection function. The synchronization layer of the CCU110 may support a transmission and reception function of a probe request/response packet for measuring a delay of a lower entity, and may support a primary MAC function based on semi-static scheduling of an RRC layer.

The synchronization layer of the CCU110 may transmit downlink data packets to the TSU120 in consideration of the operation of the MAC layer of the TSU 120. The synchronization layer of the CCU110 may select valid uplink data packets from the uplink data packets received from the TSU120 and may discard invalid uplink data packets. The synchronization layer of the CCU110 may perform a downlink content synchronization function, an uplink content selection function, and the like based on a predetermined synchronization protocol. The CCU110 may perform a matching function between the CCN and the PSN connected to the LCX-based communication system. The communication functions for the passengers of vehicle 200 may be supported by the CCN of the LCX-based communication system and the CCN of vehicle 200 when an emergency occurs.

The CTAM of the vehicles 200-1 and 200-2 may be an antenna in communication with the LRCM 160 of the LCX based communication system. The CEs of the vehicles 200-1 and 200-2 may perform UE functions of the cellular communication system, and may perform PHY functions, MAC functions, RLC functions, PDCP functions, and the like. In addition, the CE of the vehicle 200 may perform a matching function between the CCN and the PSN connected to the vehicle 200.

Further, in the communication system 100, the DU-based communication system, and the LCX-based communication system as described above, the communication method may be performed as follows.

Fig. 72 is a sequence diagram illustrating a first embodiment of a communication method between the communication system and the vehicle, and fig. 73 is a conceptual diagram illustrating a sliding window configured according to the communication method illustrated in fig. 72.

Referring to fig. 72 and 73, a communication system 100 (e.g., a terrestrial communication device) may be the communication system shown in fig. 1 or fig. 50. For example, the communication system 100 may include: CCU110, TSU120, VA2C130, LA2M140, etc., and each of CCU110, TSU120, VA2C130, and LA2M140 may be configured the same as or similar to CCU, TSU, VA2C, and LA2M shown in fig. 14. Further, the communication system 100 may be a DU-based communication system or an LCX-based communication system (for example, the LCX-based communication system shown in fig. 69). The vehicle 200-1 may be configured the same as or similar to the vehicle 200-1 shown in fig. 50, and the vehicle 200-2 may be configured the same as or similar to the vehicle 200-2 shown in fig. 50. For example, vehicles 200-1 and 200-2 may include antennas, CEs, and the like. Alternatively, the vehicle 200-1 may be configured the same as or similar to the vehicle 200-1 in fig. 69, and the vehicle 200-2 may be configured the same as or similar to the vehicle 200-2 in fig. 69. In this case, the vehicles 200-1 and 200-2 may include CTAM, CE, and the like.

The vehicle 200-1 may measure its own position and transmit position information indicating the position (e.g., a first position) of the vehicle 200-1 to the communication system 100 (S7201). For example, the vehicle 200-1 may notify the communication system 100 of the first location measured at T0. The position of the vehicle 200-1 may be measured based on the position measurement method described with reference to fig. 56 to 60. Alternatively, the location information of the vehicle 200-1 may be obtained from a GPS. The communication system 100 may obtain location information from the vehicle 200-1. Alternatively, the communication system 100 may measure the position of the vehicle 200-1 based on the position measurement method described with reference to fig. 61. The position of the vehicle 200-1 may be periodically measured and the position information of the vehicle 200-1 may be periodically transmitted to the communication system 100.

The communication system 100 may configure the first sliding window based on the location information of the vehicle 200-1 (S7202). The first sliding window may include n DA's (e.g., antennas, RCS) installed in an area corresponding to the location of the vehicle 200-1. Here, n may be an integer of 2 or more. For example, when n is 4 and the first position of the vehicle 200-1 corresponds to the position where DA #10 is set, the first sliding window configured according to the first position of the vehicle 200-1 may include DA #10 to # 13. In addition, the communication system 100 may configure the first sliding window in consideration of the good window, the necrosis window, and the interference window described with reference to fig. 47 to 49.

After the configuration of the sliding window is completed, communication between the communication system 100 and the vehicle 200-1 may be performed (S7203). For example, the communication system 100 may transmit downlink signals (e.g., D1, D2, D3) to the vehicle 200-1 via the DA #10 to #13 belonging to the first sliding window, and the vehicle 200-1 may receive the downlink signals (e.g., D1, D2, D3) from the communication system 100. The resources used in the downlink communication between the communication system 100 and the vehicle 200-1 may be downlink resources shown in fig. 15 to 19 and 27. When performing downlink communication, the communication system 100 may transmit semi-persistent scheduling information via the control region and may transmit data through the data region indicated by the semi-persistent scheduling information. The vehicle 200-1 may receive the semi-static scheduling information from the communication system 100 and may receive data through the data region indicated by the semi-static scheduling information. When downlink communication is performed based on the RLC AM, the downlink retransmission procedure described with reference to fig. 29 may be performed. In this case, the C-RNTI for initial downlink transmission, the C-RNTI for transmission of the RLC status message, and the C-RNTI for downlink retransmission may be independently configured.

Further, the vehicle 200-1 may transmit uplink signals (e.g., D1, D2, D3) to the communication system 100, and the communication system 100 may receive the uplink signals (e.g., D1, D2, D3) from the communication system 100 via the DA #10 to #13 belonging to the first sliding window. The resource for uplink communication between the communication system 100 and the vehicle 200-1 may be the uplink resource shown in fig. 22 to 25 and 28. When performing uplink communications, communication system 100 may transmit semi-static scheduling information via a control region. The vehicle 200-1 may receive the semi-static scheduling information from the communication system 100 and may transmit data through the data region indicated by the semi-static scheduling information. The communication system 100 may receive data through the data region indicated by the semi-static scheduling information. When uplink communication is performed based on the RLC AM, the uplink retransmission procedure described with reference to fig. 30 may be performed. In this case, the C-RNTI for initial uplink transmission, the C-RNTI for transmission of the RLC status message, and the C-RNTI for uplink retransmission may be independently configured.

Before performing communication between the communication system 100 and the vehicle 200-1, the

communication nodes

110, 120, 130, and 140 included in the communication system 100 may be synchronized with each other based on the delayed probe procedure described with reference to fig. 33 to 40. For example, the synchronization procedure may be performed by exchanging probe request packets and probe response packets between the

communication nodes

110, 120, 130, and 140. That is, synchronization between the DA #10 to #13 belonging to the first sliding window can be maintained by the CCU110 included in the communication system 100. When the synchronization process is completed, the DA #10 to #13 belonging to the first sliding window may simultaneously transmit the same signal. Alternatively, when the synchronization process is completed, the time offset between the reception time points of the signals received via the DA #10 to #13 belonging to the first sliding window may be within a predetermined range (e.g., Cyclic Prefix (CP)).

Further, the RBs (e.g., SRB and DRB) may be configured for communication between communication system 100 and vehicle 200-1. For example, SRB #1, DRB #2, DRB #3, DRB #4, and DRB #5 shown in fig. 55 may be configured for communication between the communication system 100 and the vehicle 200-1, and step S7203 may be performed using SRB #1, DRB #2, DRB #3, DRB #4, and DRB # 5.

Further, when the position of the vehicle is periodically measured, the vehicle 200-1 may measure its own position at T3, and may transmit position information indicating the position (e.g., the second position) of the vehicle 200-1 to the communication system 100 (S7204). The communication system 100 may obtain location information from the vehicle 200-1.

The communication system 100 may reconfigure the first sliding window based on the position information of the vehicle 200-1 (S7205). The first sliding window may include m DA's (e.g., antennas, RCS) installed in an area corresponding to the location of the vehicle 200-1. Here, m may be an integer of 2 or more. For example, when m is 4 and the second position of the vehicle 200-1 corresponds to the position where the DA #12 is set, the first sliding window reconfigured according to the second position of the vehicle 200-1 may include the DA #12 to # 15. One or more of the m DA included in the first sliding window reconfigured in step S7205 may be the same as one or more of the n DA included in the first sliding window configured in step S7202.

After the reconfiguration of the sliding window is completed, communication between the communication system 100 and the vehicle 200-1 may be performed (S7206). For example, the communication system 100 may transmit downlink signals (e.g., D4, D5, D6) to the vehicle 200-1 through the DA #12 to #15 belonging to the first sliding window, and the vehicle 200-1 may receive downlink signals (e.g., D4, D5, D6) from the communication system 100. Synchronization between the DA #12 to #15 belonging to the first sliding window may be maintained by the CCU110 included in the communication system 100. Therefore, the DA #12 to #15 belonging to the first sliding window can simultaneously transmit the same signal. Alternatively, the time offset between the reception time points of the signals received from DA #12 to #15 belonging to the first sliding window may be within a predetermined range. Further, the vehicle 200-1 may transmit uplink signals (e.g., D4, D5, D6) to the communication system 100, and the communication system 100 may receive the uplink signals (e.g., D4, D5, D6) from the vehicle 200-1 via the DA #12 to #15 belonging to the first sliding window.

Further, the communication system 100 may communicate not only with the vehicle 200-1, but also with other vehicles (e.g., the vehicle 200-2). In this case, the vehicle 200-2 may transmit position information indicating its own position (e.g., a third position) to the communication system 100 (S7207). The communication system 100 may obtain location information from the vehicle 200-2.

The communication system 100 may configure the first sliding window based on the location information of the vehicle 200-2 (S7208). The second sliding window may include k DAs (e.g., antennas, RCS) installed in an area corresponding to the location of the vehicle 200-2. Here, k may be an integer of 2 or more. For example, when k is 4 and the third position of the vehicle 200-2 corresponds to the position where DA #1 is set, the second sliding window configured according to the third position of the vehicle 200-2 may include DA #1 to # 4. The k DA ' S included in the second sliding window configured in step S7208 may not overlap with the n DA ' S included in the first sliding window configured in step S7202 or the m DA ' S included in the first sliding window configured in step S7205.

After the configuration of the sliding window is completed, communication between the communication system 100 and the vehicle 200-2 may be performed (S7209). For example, the communication system 100 may transmit downlink signals (e.g., D1', D2', D3') to the vehicle 200-2 via the DA #1 to #4 belonging to the second sliding window, and the vehicle 200-2 may receive the downlink signals (e.g., D1', D2', D3') from the communication system 100. Synchronization between the DA #1 to #4 belonging to the second sliding window may be maintained by the CCU110 included in the communication system 100. Therefore, the DA #1 to #4 belonging to the second sliding window can transmit the same signal at the same time. Alternatively, the time offset between the reception time points of the signals received from the DA #1 to #4 belonging to the second sliding window may be within a predetermined range. Further, the vehicle 200-2 may transmit uplink signals (e.g., D1', D2', D3') to the communication system 100, and the communication system 100 may receive the uplink signals (e.g., D1', D2', D3') from the vehicle 200-2 via the DA #1 to #4 belonging to the second sliding window.

When the position of the vehicle 200-2 is changed, as in the embodiment according to the above-described steps S7204 to S7206, communication between the communication system 100 and the vehicle 200-2 may be performed through the reconfigured second sliding window. For example, when the position of the vehicle 200-2 is changed from the third position corresponding to DA #1 to the fourth position corresponding to DA #3, the second sliding window may be reconfigured to include DA #3 to #6, and communication between the communication system 100 and the vehicle 200-2 may be performed using DA #3 to #6 included in the second sliding window. In addition, the embodiment according to steps S7207 to S7209 may be performed simultaneously with the embodiment according to steps S7201 to S7203 or the embodiment according to steps S7204 to S7206.

Embodiments of the present disclosure may be implemented as program instructions executable by various computers and recorded on computer-readable media. The computer readable medium may include program instructions, data files, data structures, or a combination thereof. The program instructions recorded on the computer-readable medium may be specially designed and configured for the present disclosure, or may be well known and available to those skilled in the computer software art.

Examples of computer readable media may include hardware devices such as ROM, RAM, and flash memory, which are specially configured to store and execute program instructions. Examples of program instructions include both machine code, such as produced by a compiler, and high-level language code that may be executed by the computer using an interpreter. The above exemplary hardware devices may be configured to operate as at least one software module to perform embodiments of the present disclosure, and vice versa.

Although embodiments of the present disclosure and their advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the scope of the disclosure.

Claims

1. A communication device that performs communication with a first mobile device, the communication device comprising: a processor that performs a radio resource control function for communication between the communication device and the first mobile device; a plurality of distributed antennas DA disposed along a moving path of the first mobile device, which transmit and receive signals under the control of the processor; and a memory storing at least one instruction for execution by the processor, wherein the at least one instruction is configured to:

configuring a first sliding window comprising n distributed antennas DA of the plurality of distributed antennas DA corresponding to a first location of the first mobile device;

performing communication with the first mobile device located at the first location using the n distributed antennas DA;

reconfiguring the first sliding window to include m distributed antennas DA of the plurality of distributed antennas DA corresponding to a second location when the first mobile device moves from the first location to the second location; and

performing communication with the first mobile device located at the second location using the m distributed antennas DA,

wherein one or more of the n distributed antennas DA are the same as one or more of the m distributed antennas DA, each of n and m is an integer equal to or greater than 2, and the first position and the second position belong to the movement path.

2. The communication device of claim 1, wherein synchronization between the n distributed antennas DA or the m distributed antennas DA belonging to the first sliding window is maintained by the processor.

3. The communication device of claim 1, wherein the n distributed antennas DA transmit and receive the same signals using the same radio resources when performing communication with the first mobile device located at the first location.

4. The communication device of claim 1, wherein the m distributed antennas DA transmit and receive the same signals using the same radio resources when performing communication with the first mobile device located at the second location.

5. The communication device of claim 1, wherein the location of the first mobile device is estimated based on a signal received from the first mobile device.

6. The communication device of claim 1, wherein a plurality of radio bearers RB are configured for communication between the communication device and the first mobile device, and a cell radio network temporary identifier, C-RNTI, for each radio bearer RB is independently configured.

7. The communication device of claim 1, wherein the at least one instruction is further configured to:

configuring a second sliding window including k distributed antennas DA of the plurality of distributed antennas DA corresponding to a third location of a second mobile device moving along the movement path; and

performing communication with the second mobile device located at the third location using the k distributed antennas DA,

wherein k is an integer equal to or greater than 2, and the second position belongs to the movement path.

8. The communication device of claim 7, wherein the k distributed antennas DA do not overlap with the n distributed antennas DA or the m distributed antennas DA.

9. The communication device of claim 7, wherein a dedicated cell formed by the second sliding window is different from a dedicated cell formed by the first sliding window.

10. The communication device according to claim 7, wherein the communication with the k distributed antennas DA is performed simultaneously with the communication with the n distributed antennas DA or the communication with the m distributed antennas DA.

11. A communication method performed by a mobile device moving along a movement path, the communication method comprising:

when the mobile device is located at a first position in the movement path, performing communication with a communication device including a plurality of distributed antennas DA disposed along the movement path via a sliding window including n distributed antennas DA corresponding to the first position, and

performing communication with the communication device via a sliding window including m distributed antennas DA corresponding to a second position among the plurality of distributed antennas DA disposed along the movement path when the mobile device moves from the first position to the second position in the movement path,

wherein one or more of the n distributed antennas DA are the same as one or more of the m distributed antennas DA, and each of n and m is an integer equal to or greater than 2.

12. The communication method of claim 11, wherein the dedicated cell formed by the sliding window configured for the mobile device located at the first location is the same as the dedicated cell formed by the sliding window configured for the mobile device located at the second location.

13. The communication method according to claim 11, wherein in the communication between the mobile device located at the first location and the n distributed antennas DA, the same signals are received from the n distributed antennas DA using the same radio resources.

14. The communication method according to claim 11, wherein in the communication between the mobile device located at the second location and the m distributed antennas DA, the same signals are received from the m distributed antennas DA using the same radio resources.

15. The communication method according to claim 11, wherein information for estimating the position of the mobile device is transmitted from the mobile device to the communication device, and the first position and the second position are estimated by the communication device based on the information.