CN111165003B

CN111165003B - Communication method and device for ultra-high speed vehicle

Info

Publication number: CN111165003B
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: 2023-07-11
Anticipated expiration: 2038-10-05
Also published as: KR20190041404A; KR102565713B1; CN111165003A

Abstract

A communication method and apparatus for a super high speed vehicle is disclosed. The communication device includes: a processor for performing radio resource control functions for communication between the first mobile device and the communication device; a plurality of DA's located in a path of the first mobile device and transmitting or receiving signals according to control of the processor; and a memory for storing at least one command executed 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 the first mobile device and to communicate with the first mobile device located at the first location using the n DA's. Thus, 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 technology for a super speed vehicle, and more particularly, to a communication technology for supporting communication between a super speed vehicle and a ground network.

Background

Communication between a base station and a vehicle moving at a high speed (e.g., a train moving at a speed of 350km/h or less) may be performed based on a cellular communication scheme. Further, a communication network dedicated to a vehicle may be installed in a form in which base stations each having a cell coverage of several kilometers are installed along a moving path of the vehicle. In this case, communication between a vehicle moving at a speed of up to 500km/h and a base station may 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 support a communication system for long term evolution orbit (LTE-R) based or 5G communication system. Additionally, leaky coaxial cable (LCX) based communication systems may be used for high speed trains or magnetic levitation trains. LCX-based communication systems may support communication of vehicles (e.g., magnetic levitation 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 leakage currents 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, the reception performance may decrease as the signal loss increases, a handover may occur between segmented cables, and the performance may be deteriorated at a point of time when the handover occurs.

When the above-described communication scheme is utilized, the data transmission rate at the boundary between cells (or segmented cables) may be deteriorated, and as the vehicle speed increases, the data transmission rate tends to decrease due to the doppler effect. Therefore, at ultra-high speeds (e.g., 1200 km/h), communication is nearly impossible with conventional communication schemes. That is, when communication is performed based on a cellular communication scheme, communication quality may be deteriorated due to an increase in doppler effect, and a handover procedure may be frequently performed, thereby degrading communication performance. Further, the above-described communication scheme has a limitation in supporting communication for ultra-high speed vehicles (e.g., trains traveling at speeds greater than 1220 km/h). Thus, 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 communication services to a super high speed vehicle.

Technical proposal

In order to achieve the above object, according to a first embodiment of the present invention, a communication device 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 the 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, wherein the first sliding window comprises n DA (digital data) corresponding to a first position of the first mobile device in a plurality of DA; performing communication with the first mobile device located at the first location using n DA's; 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, wherein one or more DA of the n DA is the same as one or more DA of the m DA, 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 n DA or m DA belonging to the first sliding window may be maintained by the processor.

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

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

Here, the location of the first mobile device may be estimated based on signals 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 including k DA's of the plurality of DA's corresponding to a third position of the 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, wherein 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 private cell formed by the second sliding window may be different from the private 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.

To achieve the above object, according to a second embodiment of the present invention, a communication method performed by a mobile device may include: 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) is performed via a sliding window including n DA's corresponding to the first position among a plurality of DA's disposed along the movement path, and when the mobile device is moved from the first position to a second position in the movement path, communication with the communication device is performed via a sliding window including m DA's corresponding to the second position among a plurality of DA's disposed along the movement path, wherein one or more DA's are identical to one or more DA's of the m DA's, and each of n and m is an integer equal to or greater than 2.

Here, the private cell formed by the sliding window configured for the mobile device located at the first position may be the same as the private 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 DA, the same signal may be received from the m DA using the same radio resource.

Here, information for estimating the position of the mobile device may be transmitted from the mobile device to the communication device, and the first position and the second position 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 may be moved according to the speed of a super-high speed vehicle (e.g., a train moving at 1220km/h or more), thereby providing a communication service for the super-high speed vehicle. Further, since the sliding window moves according to the speed of the super high speed vehicle, the communication quality does not deteriorate, and a handover process can be minimized. Thus, 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 the signal strength received at a vehicle.

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

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

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

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

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

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

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

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

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

Fig. 13 illustrates a ninth embodiment showing a port mapping relationship in VA2C of a 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 for 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 an 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 probe procedure.

Fig. 35 is a block diagram illustrating a second embodiment of probe request/response packets used in the 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 the 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 the 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 a 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 illustrating a first embodiment of the received signal strength in downlink communications.

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

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

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

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

Fig. 52 is a conceptual diagram illustrating a first embodiment of the CRZ of the 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 overlapping CRZs.

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

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

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 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 units of good windows.

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 an FDD scheme.

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

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

Fig. 69 is a conceptual diagram illustrating a first embodiment of an LCX-based communications 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 radiation angles according to a slotted arrangement.

Fig. 72 is a sequence diagram illustrating a first embodiment of a 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 shown 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. 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 element. 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, portions, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, portions, 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. In order to facilitate a general understanding of the present invention, like reference numerals refer to like elements throughout the description of the drawings, and a 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 describing the operation of the ground communication device, the corresponding vehicle may perform an operation corresponding to the operation of the ground communication device. In contrast, when describing the operation of the vehicle, 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 Tube Side Unit (TSU) 120, a virtual active antenna controller (VA 2C, virtual active antenna controller) 130, a line active antenna module (LA 2M, line active antenna module) 140, and the like. Here, the communication system 100 may be referred to as "Ground Network (GN)", "ground communication device", or the like. TSU 120 may include a plurality of TSUs 120-1 and 120-2, VA2C 130 may include a plurality of VA2 Cs 130-1, 130-2 and 130-3, and LA2M 140 may include a plurality of LA2M 140-1, 140-2, 140-3, 140-4 and 140-5.

CCU 110 may be connected to TSU 120 as an underlying entity, and may control and manage TSU 120, VA2C 130, and LA2M 140. The CCU 110 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 CCU 110 may include a processor (e.g., a Central Processing Unit (CPU)), a memory storing instructions executed by the processor, and the like, and the processor of the CCU 110 may perform predetermined operations.

The TSU 120 may be connected to the CCU 110 as an upper entity and to at least one of the VA2 cs 130-1, 130-2, and 130-3 as a lower entity, and the TSU 120 may manage and control at least one of the VA2 cs 130-1, 130-2, and 130-3. For example, TSU 120-1 may be connected to VA2C 130-1, VA2C 130-2, and the like. In this case, TSU 120-1 may be connected to VA2C 130-1 via port #C and may be connected to VA2C 130-2 via port #B. TSU 120-2 may be connected to VA2C 130-3, etc. In this case, TSU 120-2 may be connected to VA2C 130-3 through port #A. The TSU 120 may support at least one of PDCP functions, RLC functions, medium access control (MAC, medium access control) functions, and Physical (PHY) functions. Further, the TSU 120 may include a processor (e.g., a CPU), a memory storing instructions executed by the processor, and the like, and the processor of the TSU 120 may perform predetermined operations.

VA2C 130 may include a plurality of ports and may be connected to TSU 120 as an upper entity via upper layer ports (e.g., ports #a to #c) and may be connected to LA2M 140 as a lower entity via ports #a to #o. One upper layer port (e.g., ports #a to #c) in the VA2C 130 may be mapped to at least one lower layer port (e.g., ports #a to #o). VA2C 130-1 may be coupled to LA2M 140-1 and LA2M 140-2. In this case, each of 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. VA2C 130-2 may be coupled to LA2M 140-3, LA2M 140-4, etc. In this case, each of 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 may be coupled to LA2M 140-5, etc. In this case, each of ports #a and #b belonging to the VA2C 130-3 may be mapped to each antenna belonging to the LA2M 140-5 based on a one-to-one scheme.

The LA2M 140 may be connected to the VA2C 130 as an upper entity. LA2M 140 may include multiple antennas. Antennas belonging to LA2M 140 may be referred to as Distributed Antennas (DA), active Antenna Components (AAC), distributed Units (DUs), etc. LA2M 140 may support at least one of MAC functionality, PHY functionality, and Radio Frequency (RF) functionality. Further, the LA2M 140 may include a processor (e.g., CPU), a memory storing instructions executed by the processor, etc., and the processor of the LA2M 140 may perform predetermined operations.

Further, LA2M 140 may be installed along a moving path of a vehicle (e.g., rail, super loop pipe). When the vehicle moves along the movement 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 movement path corresponding to the position of the vehicle.

Referring to fig. 2, the LA2M 140 may include LA2M 140-1 through 140-5 of the 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 CCU 110 and TSU 120 of 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 a super high-speed rail (hypershop), 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 LA2M 140, an antenna belonging to the sliding window may operate in an on state (e.g., an active state, an enabled state), and communication may be performed between the antenna operating in the on state and an antenna installed in the vehicle 200. The antenna mounted 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, capsule active antenna module). Multiple antennas may be installed in the vehicle 200, in which case the 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, the sliding window (e.g., the communication system 100 that performs communication using a plurality of antennas belonging to the sliding window) may be referred to as a mobile cell, a virtual base station, a recovery base station (ghost base station), or the like. A sliding window may be dedicated to one vehicle 200.

In the LA2M 140, antennas may be installed at regular intervals (e.g., 10M). 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 500m. The number of antennas included in the sliding window may be differently configured, 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 the signal strength received at the vehicle, and fig. 4 is a graph illustrating a second embodiment of the signal strength received at the vehicle.

Referring to fig. 3 and 4, all antennas in the sliding window may transmit signals in a joint transmission (JT, joint transmission) scheme. When the JT scheme is utilized, all antennas belonging to the sliding window may transmit the same signal (e.g., control information, data, content, etc.) using the same time-frequency resource. 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 of the downlink in the vehicle 200). The installation interval of the antennas in the LA2M 140 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 antennas in the LA2M 140 may be relatively wide, and the installation cost of the communication system 100 may be reduced. That is, as the mounting interval of the antennas in the LA2M 140 decreases, the received signal strength in the vehicle 200 may increase, and as the mounting interval of the antennas in the LA2M 140 increases, the mounting 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 the VA2C 130 may be configured as follows. Here, the sliding window may be configured to include 6 antennas, and may be moved according to a moving speed of the vehicle 200.

Referring to fig. 5, the sliding window may be controlled and managed by CCU 110 and TSU 120-1 of communication system 100 and includes antennas connected to ports #k, #l, #m and #n of VA2C 130-1 and antennas connected to ports #i and #j of VA2C 130-2. For example, TSU 120-1 may send signals to port #C of VA2C 130-1, and in VA2C 130-1, corresponding signals may be sent from port #C to ports #k, #l, #m, and #n in a multicast manner. In addition, TSU 120-1 may send signals to port #B of VA2C 130-2, and in VA2C 130-2, corresponding signals may be sent from port #B to ports #i and #j in a multicast manner.

Referring to fig. 6, the sliding window may be controlled and managed by CCU 110 and TSU 120-1 of communication system 100 and includes antennas connected to ports #k, #l and #m of VA2C 130-1 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, the antenna connected to port #n of VA2C 130-1 (i.e., the connection between port #c and port #n is released) may be excluded, and the antenna connected to port #h of VA2C 130-2 (i.e., the connection between port #b and port #h is added) may be added. For example, TSU 120-1 may send signals to port #C of VA2C 130-1, and in VA2C 130-1, corresponding signals may be sent from port #C to ports #k, #l and #m in a multicast manner. In addition, TSU 120-1 may send signals to port #B of VA2C 130-2, and in VA2C 130-2, corresponding signals may be sent 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 CCU 110 and TSU 120-1 of communication system 100 and includes antennas connected to ports #k and #l of VA2C 130-1 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, the antenna connected to port #m of VA2C 130-1 (i.e., the connection between port #c and port #m is released) may be excluded, and the antenna connected to port #g of VA2C 130-2 (i.e., the connection between port #b and port #g is added) may be added. For example, TSU 120-1 may send signals to port #C of VA2C 130-1, and in VA2C 130-1, corresponding signals may be sent from port #C to ports #k and #l in a multicast manner. In addition, TSU 120-1 may send signals to port #B of VA2C 130-2, and in VA2C 130-2, corresponding signals may be sent 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 CCU 110 and TSU 120-1 of communication system 100 and includes an antenna connected to port #k of VA2C 130-1 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, the antenna connected to port #l of VA2C 130-1 (i.e., the connection between port #c and port #l is released) may be excluded, and the antenna connected to port #f of VA2C 130-2 (i.e., the connection between port #b and port #f is added) may be added. For example, TSU 120-1 may send a signal to port #C of VA2C 130-1 and in VA2C 130-1, a corresponding signal may be sent from port #C to port #k. In addition, TSU 120-1 may send signals to port #B of VA2C 130-2, and in VA2C 130-2, corresponding signals may be sent 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 CCU 110 and TSU 120-1 of 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, the antenna connected to port #k of VA2C 130-1 (i.e., the connection between port #c and port #k is released) may be excluded, and the antenna connected to port #e of VA2C 130-2 (i.e., the connection between port #b and port #e is added) may be added. For example, TSU 120-1 may send signals to port #B of VA2C 130-2, and in VA2C 130-2, corresponding signals may be sent 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 CCU 110 and TSU 120-1 of 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, the antenna connected to port #j of VA2C 130-2 (i.e., the connection between port #b and port #j is released) may be excluded, and the antenna connected to port #d of VA2C 130-2 (i.e., the connection between port #b and port #d is added) may be added. For example, TSU 120-1 may send signals to port #B of VA2C 130-2, and in VA2C 130-2, corresponding signals may be sent 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 CCU 110 and TSU 120-1 of 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, the antenna connected to port #i of VA2C 130-2 (i.e., the connection between port #b and port #i is released) may be excluded, and the antenna connected to port #c of VA2C 130-2 (i.e., the connection between port #b and port #c is added) may be added. For example, TSU 120-1 may send signals to port #B of VA2C 130-2, and in VA2C 130-2, corresponding signals may be sent 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 CCU 110, TSU 120-1, and TSU 120-2 of communication system 100 and includes antennas connected to ports #c, #d, #e, #f, and #g of VA2C 130-2 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, the antenna connected to port #h of VA2C 130-2 (i.e., the connection between port #b and port #h is released) may be excluded, and the antenna connected to port #b of VA2C 130-3 (i.e., the connection between port #a and port #b is added) may be added. For example, TSU 120-1 may send signals to port #B of VA2C 130-2, and in VA2C 130-2, corresponding signals may be sent from port #B to ports #c, #d, #e, #f, and #g in a multicast manner. In addition, TSU 120-2 may send signals to port #A of VA2C 130-3 and in VA2C 130-3, corresponding signals may be sent from port #A to port #b. Since signals are transmitted by both TSUs 120-1 and 120-2, synchronization between TSU 120-1 and TSU 120-2 (e.g., synchronization between signals (content) transmitted from TSU 120-1 and TSU 120-2) may be configured by CCU 110. In addition, switching between VA2C 130-1, 130-2 and 130-3 may be controlled by CCU 110.

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

On the other hand, in the CCU 110, TSU 120, VA2C 130, and LA2M 140 of the communication system 100, the protocol stack may be configured as follows.

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

The CP-CCU may include an RRC layer. Accordingly, the CP-CCU may support a 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 location information of the vehicle 200, and may configure a sliding window based on the obtained location 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 a 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 to the CP-TSU via the first path P1, the resource allocation message including a Transport Block (TB) size, frequency resource allocation information, time resource allocation information (e.g., transmission time interval (TTI, transmission time interval) period), a frequency hopping pattern, information about mapping between upper and lower ports in the VA2C 130, and the like. 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 that receives the resource allocation message may transmit control information related to the resource allocation to the CP-LA2M (e.g., a plurality of CP-LA2M connected to the CP-TSU) via the second path, and transmit control information related to the resource allocation to the CP-VA2C (e.g., a plurality of CP-VA2C connected to the CP-TSU) via the third path. The CP-LA2M and the CP-VA2C may operate based on control information related to resource allocation received from the CP-TSU. The control information transmitted from the CP-TSU to the CP-LA2M or CP-VA2C may vary according to the type of User Plane (UP) (e.g., A1-UP, A2-UP, A3-UP, A4-UP, A5-UP, A6-UP, A7-UP, A8-UP, and A9-UP).

In communication system 100, the protocol stack of UP may 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.

The LA2M 140 may include at least one of an RF layer, a PHY layer, and a MAC layer. The RF layer may include an antenna (e.g., DA, AAC). The TSU 120 may include at least one of a PDCP layer, an RLC layer, a MAC layer, and a PHY layer. However, in A9-UP, the TSU 120 may not include all of the PDCP layer, RLC layer, MAC layer, and PHY layer. The CCU 110 may include at least one of a PDCP layer and an RLC layer. However, among A1-UP, A2-UP, and A3-UP, the CCU 110 may not include both the PDCP layer and the RLC layer. One layer may be placed in CCU 110, TSU 120, or LA2M 140. Alternatively, some functions of one layer may be performed by the CCU 110, the TSU 120, or the LA2M 140, 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 CCU 110, the TSU 120, and the LA2M 140).

The PDCP layer may be located in the TSU 120 (e.g., TSU 120 of A1-UP, A2-UP, or A3-UP), or the PDCP layer may be located in the CCU 110 (e.g., CCU 110 of 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 may support an RLC acknowledged mode (AM, acknowledged mode). For example, when RLC AM is supported, a transmitting communication node (e.g., communication system 100 of fig. 1) may transmit a packet to a receiving communication node (e.g., vehicle 200 of fig. 2) and store the transmitted packet in a buffer. The receiving communication node may receive the packet from the transmitting communication node and may send a response message (e.g., ACK message, NACK message) to the transmitting 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 receiving a NACK message from a receiving communication node in response to a 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 CCU 110, 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 TSU 120 among the plurality of TSUs 120 in A1-UP to A6-UP, the CCU 110 may control and manage RLC-related operations performed by the plurality of TSUs 120.

In addition, communication nodes (e.g., CCU 110, TSU 120, VA2C 130, and LA2M 140) belonging to the communication system 100 may have a hierarchical tree structure. Here, 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 performing a synchronization function according to a predetermined synchronization protocol may be located in CCU 110. Further, synchronization protocols may be performed in CCU 110 and communication nodes (e.g., TSU 120, LA2M 140) that perform MAC functions.

Since the MAC layer is located in TSU 120 of A1-UP, A2-UP, A4-UP, A5-UP, A7-UP, and A8-UP, a synchronization process can be performed between CCU 110 and TSU 120. Since the MAC layer is located in LA2M 140 of A3-UP, A6-UP, and A9-UP, a synchronization procedure can be performed between CCU 110 and LA2M 140. In this case, the TSU 120 may perform a relay function during synchronization between the CCU 110 and the LA2M 140. Since the connection structure between communication nodes has a1 to N structure during downlink communication, the TSU 120 can be used as a transport layer when using an IP multicast function. Here, N may be an integer of 2 or more.

Further, downlink resources for downlink communication in the 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 a control region of the subframe, and may transmit data (e.g., content) to the vehicle 200 using a data region of the subframe.

For example, the communication system 100 may determine a minimum capacity of data to be transmitted to the vehicle 200, and may configure a size of a time-frequency resource (e.g., a time-frequency resource transmitting the data) in consideration of the determined minimum capacity, a modulation order, overhead per layer (e.g., header overhead, trailer overhead), IP header compression rate, segmentation, and the like. Here, the time-frequency resources may be configured based on a semi-static scheduling scheme. When a 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 among 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 indicated by the semi-static scheduling information in the data region to transmit data (e.g., data units). The semi-static scheduling operations described above may be performed by CCU 110 in communication system 100, and CCU 110 may control and manage multiple TSUs 120 connected to CCU 110 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 to 19, when a semi-static scheduling scheme is used, the communication system 100 (e.g., CCU 110 of the communication system 100) may perform operations of subframe synchronization and content synchronization for one, two, or four TTIs. In addition, CCU 110 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 CCU 110 may perform a semi-static scheduling operation based on the frequency hopping pattern and TTI periodicity (e.g., periodicity of TTIs of time-frequency resources allocated for data transmission).

CCU 110 may perform semi-static dispatch operations on a vehicle 200 in a sliding window. In this case, the CCU 110 may perform a semi-persistent scheduling operation on all packets processed by the CCU 110 with respect to user data. Alternatively, packets processed by CCU 110 may be logically classified according to type, priority, etc., and CCU 110 may perform a separate semi-static scheduling operation on each logically classified packet. Further, when performing the semi-persistent scheduling operation, control information (e.g., semi-persistent scheduling information) may be separated from data, or the control information and the data may be processed together. When performing semi-persistent scheduling operations, CCU 110 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 the VA2C 130, the antennas corresponding to ports #i to #n of the VA2C 130 may receive uplink signals of the vehicle 200 and may transmit information corresponding to the received uplink signals and received signal strength to the corresponding ports. In VA2C 130-1, the uplink signals and received signal strength information of vehicle 200 may be transmitted from ports #k to #n to port #c, and in VA2C 130-2, the uplink signals and received signal strength information of vehicle 200 may be transmitted from ports #i to #j to port #b.

Further, even if a Cyclic Redundancy Check (CRC) check is successful on the uplink signal, the uplink signal may not be transmitted to an upper entity (e.g., TSU 120) if the received signal strength of the uplink signal is less than a threshold. When using A1-UP, A4-UP, or A7-UP shown in fig. 14, 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 the ports #k, #l, #m, and #n are 21dBm, 20dBm, 15dBm, and 14dBm, respectively, the VA2C 130-1 may discard the uplink signals obtained from the ports #m and #n, may generate one uplink signal by performing a soft combining operation on the uplink signals obtained from the ports #k and #l, and may transmit the generated one uplink signal to the 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 ports #i and #j are 20dBm and 21dBm, respectively, the VA2C 130-2 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, when the received signal strengths of the uplink signals are 18dBm and 21dBm, respectively, the VA2C 130-2 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 the TSU 120-1.

TSU 120-1 may receive uplink signals from VA2C 130-1 and VA2C 130-2. In addition, TSU 120-1 may receive received signal strength information of uplink signals from VA2C 130-1 and VA2C 130-2. 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 CCU 110. Alternatively, 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 CCU 110.

On the other hand, performing soft combining operations in A2-UP, A3-UP, A5-UP, A6-UP, A8-UP, and A9-UP may not be easy. For example, when the uplink signals and the received signal strength information are obtained from the ports #k, #l, #m and #n of the VA2C 130-1, the VA2C 130-1 may discard uplink signals having received signal strengths lower than the threshold value among the uplink signals and may select at least one uplink signal having received signal strength higher than the threshold value among the uplink signals. The VA2C 130-1 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 the TSU 120-1.

Further, when the uplink signal and the received signal strength information are obtained from the ports #i and #j of the VA2C 130-2, the VA2C 130-2 may discard the uplink signal having the received signal strength lower than the threshold among the uplink signals, and may select at least one uplink signal having the received signal strength higher than the threshold among the uplink signals. The VA2C 130-2 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 the TSU 120-1.

TSU 120-1 may receive uplink signals from VA2C 130-1 and VA2C 130-2. In addition, TSU 120-1 may receive received signal strength information of uplink signals from VA2C 130-1 and VA2C 130-2. 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 CCU 110. Alternatively, 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 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 the VA2C 130, the antennas corresponding to ports #a to #f of the VA2C 130 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 the VA2C 130-2, the uplink signals and the received signal strength information of the vehicle 200 may be transmitted from the ports #c to #f to the port #b, and in the VA2C 130-3, the uplink signals and the received signal strength information of the vehicle 200 may be transmitted from the ports #a to #b to the port #a.

The processing of the uplink signal in the communication system 100 of fig. 21 may be the same 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 CCU 110 of fig. 21 may be two. For example, TSU 120-1 may transmit an uplink signal obtained from VA2C 130-2 to CCU 110, and TSU 120-2 may transmit an uplink signal obtained from VA2C 130-3 to CCU 110. In addition, TSU 120-1 and TSU 120-2 may transmit received signal strength information regarding the uplink signal to CCU 110.

Accordingly, CCU 110 may receive the uplink signal and the received signal strength information from TSU 120-1 and TSU 120-2, and may select an uplink signal having the highest received signal strength among the two uplink signals. Alternatively, the CCU 110 may select an 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 in this case, the performance of uplink communication may be improved. 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 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, and fig. 25 is a conceptual diagram illustrating a fourth embodiment of an uplink resource allocation method in a communication system.

Referring to fig. 22-25, a CP-CCU (e.g., CCU 110) in communication system 100 may perform a semi-persistent scheduling operation on uplink resources. When a request for scheduling uplink resources is received from the vehicle 200, a semi-static scheduling operation may be performed. The semi-persistent scheduling information of the uplink resource may be transmitted via a control region of the downlink subframe, and may be semi-persistent scheduling information for the following uplink subframe: the uplink subframe is located after a predetermined number of TTIs on a time axis from a subframe in which semi-persistent scheduling information of uplink resources 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-static scheduling information may indicate resources configured based on a frequency hopping scheme in the uplink subframe. The resource allocation procedure within the sliding window may be performed individually according to the type of packet (e.g., control information, data), priority, etc.

Further, a Radio Bearer (RB) 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 RB. 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, signaling radio bearers (SRBs, signaling radio bearer) and dedicated radio bearers (DRBs, dedicated radio bearer) 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 a passenger (e.g., a terminal carried by the passenger) boarding 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. RBs for informing of resource allocation information may not be classified into srb#1 and srb#2. For example, one srb#1 may be used in the 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 the 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.

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

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

In communication between the communication system 100 and the vehicle 200, multiple C-RNTIs (e.g., C-RNTI A, C-RNTI B, and C-RNTI C) may be configured for one vehicle 200 and resources may be scheduled based on the multiple C-RNTIs. For example, multiple 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 there are no packets to send via a fixed allocated TB, the corresponding TB 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 frequency of occurrence of packets per RB, latency requirements, and the like.

Referring to fig. 28, a 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 the 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.

The C-RNTI B may be configured for the DRB#1, and uplink resources for the DRB#1 may be allocated based on the C-RNTI B. For example, resources for drb#1 may be scheduled for each subframe based on the 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.

The C-RNTI C may be configured for DRB#2 and uplink resources for DRB#2 may be allocated based on the C-RNTI C. For example, resources for drb#2 may be scheduled for each subframe based on the 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 the 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.

Uplink packets may be received in the communication system 100 via srb#1, drb#1, and drb#2, and the uplink packets received in the communication system 100 may be processed by the PHY layer, MAC layer, RLC layer, and 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 an operation related to CRC, a header removing operation, a data unit separating operation, etc. may be performed in each layer.

Further, when 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 may be configured for one DRB. When a downlink signal is transmitted via the DRB, a C-RNTI (e.g., C-RNTI B) for an initial transmission of the downlink signal, a C-RNTI (e.g., C-RNTI D) for a response message (e.g., RLC status message) for the downlink signal, and a C-RNTI (e.g., C-RNTI E) for a retransmission of the downlink signal may be configured. That is, one C-RNTI for the initial transmission of the downlink signal may be configured during downlink communication, and two C-RNTIs for the RLC status message and the retransmission process of the downlink signal may be configured. Therefore, three C-RNTIs may 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., RB of RLC AM), and resources for initial transmission of a downlink signal, resources for RLC status message, and resources for retransmission of a downlink signal 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 the 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-static scheduling operation for initial transmission, semi-static scheduling operation for RLC status message transmission, and semi-static scheduling operation for retransmission may be performed.

In step S2901, the communication system 100 may transmit a TB including a downlink signal using resources (e.g., SF # 0) of a DRB scheduled by the C-RNTI B. In step S2902, vehicle 200 may receive the TB in SF #0 and may identify RLC protocol data units (PDUs, protocol data unit) 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 the resources (e.g., SF # 3) of the DRB scheduled by the 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, the 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 an RLC PDU corresponding to the NACK among RLC PDUs located in the retransmission buffer and perform a retransmission procedure on the identified RLC PDU. For example, the communication system 100 may perform a retransmission procedure using resources (e.g., SF # 5) of the DRB scheduled by the C-RNTI E at step S2905. In step S2906, the vehicle 200 may receive the retransmitted RLC PDU via SF # 5.

As described above, the C-RNTI B for initial transmission, the C-RNTI D for transmission of the RLC status message, and the C-RNTI E for retransmission are independently configured, whereby downlink resources for initial transmission, uplink resources for transmission of the 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, the contents (e.g., contents in 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 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 an initial transmission of the uplink signal, a C-RNTI (e.g., C-RNTI D) for a response message (e.g., RLC status message) for the uplink signal, and a C-RNTI (e.g., C-RNTI E) for retransmission of the uplink signal may be configured. That is, one C-RNTI for the initial transmission of the uplink signal may be basically configured during uplink communication, and two C-RNTIs for the retransmission process of the RLC status message and the uplink signal may be additionally configured. Therefore, three C-RNTIs may 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 an uplink signal, resources for RLC status message, and resources for retransmission of an uplink signal may be configured based on the one C-RNTI.

In step S3001, the vehicle 200 may transmit a TB including an uplink signal using a resource (e.g., SF # 0) of a DRB scheduled by the C-RNTI B. In step S3002, the communication system 100 may receive the TB in SF #0 and may identify RLC PDU based on the received TB. The communication system 100 may generate RLC status messages (e.g., ACK messages, NACK messages) based on the reception status of the RLC PDUs. When the RLC PDU is not successfully received, the communication system 100 may generate an RLC status message indicating NACK. In step S3003, the communication system 100 may transmit an RLC status message indicating NACK using resources (e.g., SF # 3) of the DRB scheduled by the 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, vehicle 200 may receive the RLC status message in SF # 3. When the RLC status message indicates NACK, the vehicle 200 may identify an RLC PDU corresponding to the NACK from among RLC PDUs located in the retransmission buffer, and perform a retransmission procedure on the identified RLC PDU. For example, at step S3005, the vehicle 200 may perform a retransmission procedure using the resources (e.g., SF # 5) of the DRB scheduled by the C-RNTI E. 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 the 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→la2M". 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 TSU 120, and the synchronization layer (e.g., synchronization protocol) may be located in CCU 110 and TSU 120. In this case, CCU 110 may send packets (e.g., scheduled data) to multiple 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 LA2M 140, and the synchronization layer (e.g., synchronization protocol) may be located in CCU 110, TSU 120, and LA2M 140. In this case, the synchronization layer of the CCU 110 may be connected to the synchronization layer of the LA2M 140, and the synchronization layer of the TSU 120 may perform a relay function between the synchronization layer of the CCU 110 and the synchronization layer of the LA2M 140. Further, similar to the UP-a transmission scheme, CCU 110 may send packets (e.g., scheduled data) to multiple TSUs 120 based on an IP multicast scheme.

Referring to fig. 32, when uplink communication is performed, the packet transmission order may be "LA2m→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 TSU 120, and the synchronization layer (e.g., synchronization protocol) may be located in CCU 110 and TSU 120. VA2C 130 may receive the packet from LA2M 140 in accordance with the JR scheme and may send the packet 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 LA2M 140, and the synchronization layer (e.g., synchronization protocol) may be located in CCU 110, TSU 120, and LA2M 140. In this case, the synchronization layer of the CCU 110 may be connected to the synchronization layer of the LA2M 140, and the synchronization layer of the TSU 120 may perform a relay function between the synchronization layer of the CCU 110 and the synchronization layer of the LA2M 140. Here, CCU 110 may select the best packet among the packets received from the plurality of TSUs 120.

Furthermore, the delay probing process for synchronization between communication nodes in the UP-a 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 probe process, and fig. 35 is a block diagram illustrating a second embodiment of a probe request/response packet used in a delayed probe process.

Referring to fig. 33 to 35, a communication node #a may be CCU 110, a communication node #b may be TSU 120, and a communication node #c may be LA2M 140. The MAC layer may be located in the communication node #b. The communication node #a may evaluate the packet delay at the communication node #b using a delay probing procedure. In addition, by performing content synchronization based on the communication node #b having the largest delay, an appropriate scheduling point in time can be predicted using the delay probing process.

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 communication node #b may receive the probe request packet from the communication node #a, and may generate probe response packets (e.g., probe response packet #a, probe response packet #b) in response to the probe request packet, and may transmit the generated probe response packets to the communication node #a. For example, the communication node #b may transmit a probe response packet #a to the communication node #a in response to the probe request packet #a, and transmit a probe response packet #b to the communication node #a in response to the probe request packet #b. The communication node #a may receive the probe response packet from the communication node #b, and may identify a delay AT the communication node #b based on an Absolute Time (AT) included in the probe response packet.

Here, the probe request packet #a may include: a sync 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 sync packet type field may indicate the type of probe request packet (e.g., probe request packet #a, probe request packet #b). The sync packet type field in probe request packet #a may be set to "1". The unique ID field may be configured as 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), a serial ID for each communication node, etc. 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 generating 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 communication 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 accuracy of delay measurement compared to the probe request packet #a. The probe request packet #b may include: a sync packet type field, a unique ID field, a destination count field, a destination 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 sync 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 sync 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 sync packet type field may indicate the type of the probe response packet (e.g., probe response packet #a, probe response packet #b). The sync packet type field in 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 the AT that receives the probe request packet #a AT the communication node #b, and the AT #3 field may indicate the AT that transmits the probe response packet #a AT the communication 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 sync 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 sync 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 sync packet type field of the probe response packet #b may be set to "531".

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

Further, the delay probing process for synchronization between communication nodes in the 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 probe procedure.

Referring to fig. 36 and 37, communication node #a may be CCU 110, communication node #b may be TSU 120, and communication node #c may be LA2M 140. The MAC layer may be located in the communication node #c. The communication node #a may evaluate the packet delay at the communication node #c using a delay probing procedure. In addition, by performing content synchronization based on the communication node #c having the largest delay, an appropriate scheduling point in time can be predicted using the delay probing process.

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 the 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 a 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 sync 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 sync 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 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), a serial ID for each communication node, etc. 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 communication node #c, the destination count field may be set to "2". The destination address #1 field may indicate the address of the communication node #b, which is the first destination of the probe request packet #c. The destination address #2 field may indicate the address of the communication node #c, which is the 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 accuracy of delay measurement.

The probe request packet #d may include a synchronization packet type field, a unique ID field, a destination count field, a destination address #2 field, an AT count field, and an AT #2 field. The sync 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 the 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. Further, similar to the probe request packet #b of fig. 35, the probe request packet #d may include at least one PDU, thereby improving accuracy of 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 sync 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 sync 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 sync 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 communication node #a may receive the probe response packet from each of the communication nodes #b (e.g., communication nodes #b-1 to #b-n), and the communication node #a may identify a delay in each of the communication nodes #b based on the AT included in the probe response packet. The communication node #a may perform scheduling based on the communication node #c having the maximum delay of the content synchronization among the communication nodes #c. That is, the communication node #a may perform scheduling such that the communication node #c may perform downlink transmission (or uplink transmission) in the same TTI.

Further, the delay probing process described with reference to fig. 33 to 35 may be applied when the depth (e.g., hop count) between the communication node #a and the communication node where the MAC layer is located is 1, and the delay probing process described with reference to fig. 36 and 37 may be applied when the depth (e.g., hop count) between the communication node #a and the communication node where the MAC layer is located is 2. The application delay probing process may be performed as follows when the depth (e.g., hop count) between the communication node #a and the communication node where the MAC layer is located is 3.

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 probe process, and fig. 40 is a block diagram illustrating a fourth embodiment of a probe response packet used in a delayed probe process.

Referring to fig. 38 to 40, a communication node #a may be a CCU 110, and a MAC layer may be located in a communication node #d. The communication node #a may evaluate the packet delay at the communication node #d using a delay probing procedure. In addition, by performing content synchronization based on the communication node #d having the largest delay, an appropriate scheduling point in time can be predicted using the delay probing process.

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 may 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 sync 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 sync 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 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), a serial ID for each communication node, etc. The target count field may indicate the depth of the final target of the probe request packet #e. Because the final destination of probe request packet #e is communication node #d, the destination count field may be set to "3". The destination address #1 field may indicate the address of the communication node #b, which is the first destination of the probe request packet #e. The destination address #2 field may indicate the address of the communication node #c, which is the second destination of the probe request packet #e. The destination address #3 field may indicate the address of the communication node #d, which is the 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 accuracy of delay measurement.

The probe request packet #f may include: a sync 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 sync packet type field may indicate the type of the probe request packet and may be set to "2". The unique ID field of probe request packet #f may be set to the unique ID indicated by the unique ID field of 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 the address of communication node #c, and the destination address #3 field may indicate the address of 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 accuracy of delay measurement.

The probe request packet #g may include: a sync packet type field, a unique ID field, a destination count field, a destination address #3 field, an AT count field, and an AT #3 field. The sync packet type field may indicate the type of the probe request packet and may be set to "1". The unique ID field of probe request packet #g may be set to the unique ID indicated by the unique ID field of 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 the 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 accuracy of delay measurement.

The probe response packet #g may include: a sync packet type field, a unique ID field, an AT count field, an AT #4 field, and an AT #5 field. The sync 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 sync 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 sync 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 an AT indicated by the AT #3 field of the probe request packet #g, the AT #4 field may be set to an AT indicated by the AT #4 field of the probe response packet #g, the AT #5 field may be set to an AT indicated by the AT #5 field of the probe response packet #g, and the AT #6 field may indicate an AT the time of transmitting the probe response packet #f.

The probe response packet #e may include: a sync 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 sync packet type field may indicate the type of the probe response packet and may be set to "53". The unique ID field of probe response packet #e may be set to the unique ID indicated by the unique ID field of 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 an AT indicated by the AT #2 field of the probe request packet #f, the AT #3 field may be set to an AT indicated by the AT #3 field of the probe response packet #f, the AT #4 field may be set to an AT indicated by the AT #4 field of the probe response packet #f, the AT #5 field may be set to an AT indicated by the AT #5 field of the probe response packet #f, the AT #6 field may be set to an AT indicated by the AT #6 field of the probe response packet #f, and the AT #7 field may be indicative of an 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., 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 maximum delay of the content synchronization among the communication nodes #d. That is, the communication node #a may perform scheduling such 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 to 43, a communication node #a may be a CCU 110 of the communication system 100, a communication node #b may be a TSU 120 of the communication system 100, and a communication node #c may be a LA2M 140 of the communication system 100. In UP-A, the MAC layer may be located at communication node #B, and the synchronization layer may be located at communication nodes #A 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 communication node #a may support the master MAC function (master MAC function). The communication node #a supporting the main MAC function may configure one sliding window for one vehicle 200, control and manage the sliding window according to movement of the vehicle 200, and may determine the number of SDUs included in a Transport Block (TB) based on semi-static resource allocation information for each vehicle 200 determined through an RRC signaling procedure. To determine the number of SDUs, protocol processing procedures of lower layer communication nodes (e.g., communication node #b, communication node #c) may be considered. For example, in consideration of a protocol process between a communication node where the MAC layer is located and a communication node #a, a 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-A, a downlink packet may be transmitted from a communication node #A to a communication node #B. In UP-B, a downlink packet may be transmitted from communication node #A to communication node #C. In this case, the communication node #b may forward the downlink packet received from the communication node #a to the communication 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, an SDU #1, an SDU #2, and an SDU #3.

The sync 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., RB ID for initial transmission, RB ID for transmission of RLC status message, RB ID for retransmission). The predicted SFN/SF field may indicate scheduling information (e.g., SFN, SF index) of SDUs included in the downlink packet. The SFN and SF indices indicated by the predicted SFN/SF field may be calculated based on semi-static scheduling information and the delay measured through the delay probing process.

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 procedure 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 to 46, a communication node #a may be a CCU 110 of the communication system 100, a communication node #b may be a TSU 120 of the communication system 100, and a communication node #c may be a LA2M 140 of the communication system 100. In UP-A, the MAC layer may be located at communication node #B, and the synchronization layer may be located at communication nodes #A 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 may transmit an uplink packet including SDU (protocol processing of the TB received in one TTI has been completed) to the upper layer communication node.

From an uplink perspective, the communication node #a may receive a plurality of uplink packets having 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 communication 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 probing process, and may not process an uplink packet received outside the uplink delay window.

In UP-A, an uplink packet may be sent from communication node #B to communication node #A. In UP-B, an uplink packet may be sent from communication node #C to communication node #A. In this case, the communication node #b may forward the uplink packet received from the communication node #c to the communication 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, an SDU #1, an SDU #2, and an SDU #3.

The sync 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-a field, the AT field may indicate an AT when the communication node #b transmits an uplink packet, and in the UP-B, 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., RB ID for initial transmission, RB ID for transmission of RLC status message, 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 SFN and SF indexes of the corresponding TBs received at the MAC layer side. The SDU count field may indicate the number of SDUs scheduled for a TB in one TTI (e.g., the number of SDUs included in an 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.

Referring to fig. 47, LA2M 140 of communication system 100 may be mounted on top of a pipe and may be configured with a sliding window including multiple antennas. Downlink communication between the communication system 100 and the vehicle 200 may be performed based on a plurality of antennas belonging to the 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 downlink signals from a plurality of antennas belonging to a sliding window, and may classify a reception period (e.g., a reception window) of the downlink signals into a good window, a necrosis window (dead window), and an interference window according to the received signal strength. The area comprising the good window, the necrotic window and the interference window may be referred to as the downlink cabin radio area (CRZ, downlink capsule radio zone). For example, a reception period in which the received signal strength of the downlink signal is equal to or greater than a threshold value may be referred to as a good window. The reception period in which communication is impossible due to multipath fading, delay spread, or the like may be referred to as a necrotic window. The period of reception that causes interference to a subsequent vehicle 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 a subsequent vehicle is located in the interference window, signals in the interference window may interfere with communications of the subsequent vehicle. Thus, the distance between the vehicle 200 and the subsequent 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 signal strength received in uplink communications, and fig. 49 is a conceptual diagram illustrating a second embodiment of the signal strength received in uplink communications.

Referring to fig. 48 and 49, LA2M 140 of communication system 100 may be mounted on top of a pipe and may be configured with a sliding window including multiple antennas. 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 a sliding window.

In the good window, the CRC check on the uplink signal received from the plurality of antennas subordinate to the sliding window may be successfully completed, and the received signal strength of the uplink signal may be equal to or greater than the threshold value. The reception period in which communication is impossible due to multipath fading, delay spread, or the like may be referred to as a necrotic window. The period of reception that causes interference to a subsequent vehicle 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 area including the good window, the bad 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 structure for communication between the communication system 100 and the vehicle 200 may be as follows.

Referring to fig. 50, a communication system 100 may include a CCU 110, a TSU 120, a VA2C 130, and a LA2M 140.CCU 110 may be connected to a cabin control network (CCN, capsule control network) and a passenger service network (PSN, passenger service network) (e.g., evolved Packet Core (EPC)), and may be connected to TSU 120. The TSU 120 may be connected to the VA2C 130, and the VA2C 130 may be connected to the LA2M 140.LA2M 140 may include multiple antennas. The LA2M 140 may be mounted in line on top of the pipe and may be connected to the VA2C 130 located outside the pipe. In this case, the CCU 110, TSU 120, and VA2C 130 may be located outside the pipe. Alternatively, VA2C 130 and LA2M 140 may be located in the pipeline, and CCU 110 and TSU 120 may be located outside 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 a CCN and a PSN (e.g., EPC). Vehicles 200-1 and 200-2 may move within the tunnel and perform downlink/uplink communications with multiple 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 vehicles 200-1 and 200-2 may be performed in a good window. The interference window of the vehicle 120-1 may be configured to not overlap with the good window of the vehicle 120-2.

The CCNs connected to the CCU 110 may be connected to CCNs inside the vehicles 200-1 and 200-2, and control of the vehicles 200-1 and 200-2 may be performed by the CCNs. The PSNs connected to CCU 110 may be connected to PSNs inside vehicles 200-1 and 200-2, and may support communications for passengers of vehicles 200-1 and 200-2 via the PSNs (e.g., small base stations or access points installed in 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 a first embodiment of an outline of the operation of the vehicle.

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 constant speed, and decelerate to move from station a to station B within 25 minutes. For example, the vehicles 200-1 and 200-2 may operate at a maximum speed of 1200km/h by repeating the acceleration operation and the constant speed operation, and may reduce the speed 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 pipe and may move from station a to station B. The CRZ for each of the plurality of vehicles 200-1 to 200-8 may be configured. The CRZ may include a good window, a necrotic window, and an interference window. Crz#3, crz#4, crz#5, and crz#6 may not overlap each other. Accordingly, communication services can be provided to the vehicles 200-3, 200-4, 200-5, and 200-6 using the entire frequency bands in the crz#3, crz#4, crz#5, and crz#6. That is, the same time-frequency resources may be used to provide communication services within non-overlapping CRZ.

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

Referring to fig. 53, when crz#1 of vehicle 200-1 overlaps crz#2 of 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 CRZs #1 and #2, and orthogonal time resources may be configured for CRZs #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 TTI #1, and the vehicle 120-1 belonging to the CRZ #2 may perform communication using the TTI # 2.

Referring to fig. 54, when crz#1 of vehicle 200-1 overlaps crz#2 of 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 CRZs #1 and #2, and orthogonal frequency resources may be configured for CRZs #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 in the system of fig. 50 may be configured as follows.

Referring to fig. 55, a plurality of RBs (e.g., srb#1, drb#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 RB may be "srb#1 (priority a) > drbs#1 and #2 (priority B) connected to CCN > drbs#3 to #5 (priority C) connected to PSN". The priorities (i.e., priorities #1, #2, and # 3) within the DRBs may be determined according to the type (e.g., control information, data) and importance of the packets. When the lost packet is not allowed, communication may be performed based on the RLC AM. When the lost packet is allowed, communication may be performed based on RLC Transmission Mode (TM) or RLC Unacknowledged Mode (UM).

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

That is, the 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 JR scheme is performed. Alternatively, one C-RNTI may be configured for the RB to which the RLC AM is applied, and three resources (e.g., a resource for initial transmission, a resource for transmission of the RLC status message, and a resource for retransmission) may be allocated based on the one C-RNTI.

■ Method for measuring the position of a vehicle

Further, the communication system 100 may configure a sliding window corresponding to the position of the vehicle 200, and should have information about 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 unique identification numbers to which antennas included in LA2M of the communication system are assigned, and fig. 57 is a conceptual diagram illustrating a first embodiment of a method for transmitting unique identification numbers.

Referring to fig. 56 and 57, a plurality of antennas belonging to the LA2M 140 of the communication system 100 may be respectively assigned unique identification numbers. For example, the unique identification numbers 100200001 to 100200033 may be sequentially assigned to the plurality of antennas. The unique identification number may be mapped to the position of the antenna to which the unique identification number is assigned, 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, time-frequency resources for transmitting unique identification numbers may be configured every two TTIs, and time-frequency resources for unique identification numbers may be sequentially configured within one TTI. The number of unique identification numbers transmitted within one TTI may be more than the number of antennas belonging to a good window. In period #1, the frequency resources for the unique identification numbers 100200001 to 100200011 may be allocated to be orthogonal. In period #2, the frequency resources for the unique identification numbers 100200012 to 100200022 may be allocated to be orthogonal. In period #3, the frequency resources for the unique identification numbers 100200023 to 100200033 may be allocated to be orthogonal.

Further, the vehicle 200 may receive signals from a plurality of antennas of the communication system 100, and may identify a 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 identified 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, the vehicle 200 may receive signals from multiple antennas belonging to the LA2M 140, identify a unique identification number by decoding the signals, and may select at least one unique identification number for location measurement. For example, vehicle 200 may perform a CRC check on a signal including 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) from among the identified unique identification numbers 100200003 to 100200018 that has a received signal strength equal to or greater than a threshold value. Since the received signal strength of the signal including the unique identification number 100200014 is the largest among the selected unique identification numbers 100200004 to 100200016, the position of the antenna transmitting 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 operation 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, absolute position) of the vehicle 200 can be calculated based on the following equation 1.

[ equation 1]

AP＝DAP+CP

That is, the AP of the vehicle 200 may be the sum of the detected absolute position (DAP, detective absolute position) and the calibrated position (CP, calibration position). The DAP may be a location corresponding to the antenna in fig. 58 and 59 that transmits the signal including the unique identification number 100200014. 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 Scheduling Calibration Position (SCP) may be a value for correcting the propagation delay characteristics of the signal including the 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. The 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 operation mode of the vehicle 200 in an emergency situation), and an mcpo applied to the exception mode may be defined. The MCP O may not be a constant value, but may be a variable that is affected by some factor.

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, a unique identification number may be given to the vehicle 200, 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, time-frequency resources for transmitting unique identification numbers may be configured every two TTIs, and time-frequency resources for unique identification numbers 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 the LA2M 140 of the communication system 100 may receive signals including a unique identification number from the vehicle 200. When a signal including a unique identification number is transmitted from the vehicle 200 in fig. 56, an antenna corresponding to the unique identification numbers 100200003 to 100200018 among the plurality of antennas included in the LA2M 140 may receive the signal including the unique identification number of the vehicle 200. The received signal strengths of the signals including the unique identification numbers of the vehicle 200 received at the antennas corresponding to the unique identification numbers 100200003 to 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 the 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 the antenna corresponding to the unique identification number 100200017, and the CRC check on the received signal may be successfully completed, but the received signal strength of the signal may be less than the threshold. In this case, the position 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 largest, 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 resources that transmit the signal including the unique identification number of the vehicle 200 may be mapped to the antennas 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 a threshold value
						#
18	Period #2	G	100200018	CRC failure	Less than a threshold value
						#19	Period #2	H	100200019	CRC failure	Less than a threshold value
#
	20	Period #2	I	100200020	CRC failure	Less than a threshold value
#21							Period #2	J	100200021	CRC failure	Less than a threshold value
	#22	Period #2	K	100200022	CRC failure	Less than a threshold value

TABLE 3

/>

Each antenna included in LA2M140 may perform a monitoring operation on preconfigured resources (e.g., time-frequency resources indicated by the resource index of tables 1-3) in order to receive a signal including a 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 the 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 largest, 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 estimating the position of the vehicle 200, the estimated position may be corrected based on the position correction method described with reference to fig. 60. For example, the estimated position may be a DAP, and may be corrected based on a PCP, SCP, or MCP.

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

In addition, when the antennas included in the LA2M 140 transmit signals including unique identification numbers via the same time-frequency resources, a necrosis window may occur. The time-frequency resources of the signal including the unique identification number of the antenna may be configured as follows in consideration of the necrosis window.

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

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

The frequency resources for the antennas included in the LA2M 140 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 bands #1 to #5 are configured, it is possible to prevent a decrease in reception performance 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.

Further, when signals including the unique identification number of the vehicle 200 are transmitted via the same time-frequency resource, a necrosis window may occur. Considering the necrosis window, the time-frequency resource of the signal including the unique identification number of the vehicle 200 may be configured as follows.

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

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

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

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

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

The band #1 may include a control region #1 and a data region #1, and scheduling information for the data region #1 may be transmitted via the control region # 1. The band #2 may include a control region #2 and a data region #2, and scheduling information for the data region #2 may be transmitted via the control region # 2. The band #3 may include a control region #3 and a data region #3, and scheduling information for the data region #3 may be transmitted via the control region # 3. The 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 CRZ does not overlap, a cross-scheduling scheme may be used. For example, scheduling information for the data areas #1 to #4 may be transmitted via the control area # 1. That is, even when the frequency band #1 is allocated for the vehicle 200-4, the communication system 100 can transmit the schedule information for the data areas #1 to #4 to the vehicle 200-4 via the control area # 1.

In addition, 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 vehicles 200-4, 200-5, and 200-6 may be evacuated to an emergency space. In this case, the crz#3 of the vehicle 200-3 may overlap with the CRZ of the vehicle 200-7, and the vehicle 200-3 and the vehicle 200-7 use the same frequency band (e.g., frequency band #2 in fig. 66), so that interference may occur. In this case, the control region allocated to the vehicle 200-3 may be changed from the frequency band #2 to the frequency band #1 via the RRC signaling procedure. The message for the RRC signaling procedure may include: information requesting to change the C-RNTI of the vehicle 200-3 (or information indicating that the C-RNTI of the vehicle 200-3 is used for the frequency band # 1), information indicating a time point (e.g., SF # 9) of changing the frequency band, and the like. When the C-RNTI is configured not to overlap over the entire frequency band, the C-RNTI may not be changed even though 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 function

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., a super speed pipe) of the vehicle 200, may support a control function and a data uploading function of the corresponding communication node, and may measure a position of the vehicle 200 using the corresponding communication node. In the communication between the DU-based communication system and the vehicle 200, the sliding window for the vehicle 200 may be moved according to the moving speed of the vehicle 200, so that a pseudo-stationary cell environment may be created. In this case, the minimum moving unit of the sliding window may be a DU unit. The DU may include at least one LA2M 140 or at least one antenna. The LA2M 140 of the DU based communication system and the CA2M of the vehicle 200 may be configured as follows.

Referring to fig. 68, when the LA2M 140 of the DU-based communication system and the CA2M of the vehicle 200 use high frequencies (e.g., millimeter waves), the LA2M 140 of the DU-based communication system may be composed of n×m elements, and the CA2M of the vehicle may be composed of p×q elements. Here, each of n, m, p, and q may be a positive integer. The LA2M 140 of the DU based communication system and the CA2M of the vehicle 200 may be composed of small antennas. When the LA2M 140 of the DU based communication system is composed of a plurality of elements, the LA2M 140 may be referred to as AAC. Alternatively, when LA2M 140 of the DU based communication system supports only antenna functions, LA2M 140 may be referred to as a Remote Radio Head (RRH).

LA2M 140 of a DU based communication system may include an entity supporting an analog RF switching function (e.g., P2M or M2P select function) or an entity supporting an optical switching function (e.g., radio over fiber/ethernet (RoF/E)). RoF/E may be used as a wired interface between LA2M 140 and VA2C 130 in a DU-based communication system. In the LA2M 140 of the DU-based communication system, one port (e.g., a port of a higher layer) may be connected to an 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 the LA2M 140 of the DU-based communication system, ports may be connected in a point-to-multipoint (P2 MP) scheme, and the DU ports may be designed to selectively perform a soft combining function. Alternatively, in the LA2M 140 of the DU-based communication system, the DU port may be independently connected to the VA2C 130.

The beamwidth supported by the antennas of the DU based communication system may be different from the beamwidth supported by the antennas of the vehicle 200. When the beam of vehicle 200 is aligned with the beam of the DU-based communication system, the signal-to-interference-plus-noise ratio (SINR) may increase. When the beam of the vehicle 200 is misaligned with the beam of the DU based communication system, SINR may be reduced. 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, the VA2C 130 of the DU-based communication system may support a sliding window, may be connected to the upper layer entity TSU 120, and may be connected to at least one LA2M 140 as a lower layer entity. Accordingly, the VA2C 130 may transmit the signal received from the TSU 120 to the LA2M 140 based on the P2MP scheme. In addition, the VA2C 130 may perform soft combining on the signal received from the LA2M 140 based on the MP2P scheme, and may transmit the signal received from the LA2M 140 to the TSU 120. The TSU 120 may be connected to the VA2C 130 via optical fibers, and the VA2C 130 may be connected to the LA2M 140 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 signal loss.

TSU 120 of the DU based communication system may perform the base station functions of the cellular communication system. The TSU 120 may be connected to the CCU 110 as an upper layer entity and may be connected to at least one VA2C 130 as a lower layer entity. TSU 120 may support PHY functions, MAC functions, synchronization functions, and the like. The MAC layer of TSU 120 may support the slave MAC function (slave MAC function) and process MAC related data. The synchronization layer of the TSU 120 may perform the transmit and receive functions of probe request/response packets to measure the time delay of the underlying entity. In addition, the synchronization layer and the MAC layer of the TSU 120 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, synchronization of the downlink content may be performed based on the synchronization protocol, and the uplink content may be selected.

CCU 110 of the DU based communication system may perform EPC functions of the 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 CCU 110 may support a radio resource control function, and the RLC layer of CCU 110 may support a data unit segmentation/combining function, an automatic repeat request (ARQ) function, a redundancy detection function, and the like. The PDCP layer of the CCU 110 may support an IP header compression function, a ciphering function, and an integrity protection function. The synchronization layer of CCU 110 may support a transmission and reception function of probe request/response packets for measuring a delay of a lower layer entity, and may support a main MAC function based on semi-static scheduling of an RRC layer.

The synchronization layer of CCU 110 may send downlink data packets to TSU 120 in view of the operation of the MAC layer of TSU 120. The synchronization layer of CCU 110 may select a valid uplink data packet from among the uplink data packets received from TSU 120 and may discard an invalid uplink data packet. The synchronization layer of the CCU 110 may perform a downlink content synchronization function, an uplink content selection function, etc., based on a predetermined synchronization protocol. CCU 110 may perform a matching function between a CCN connected to the DU based communication system and a PSN. When an emergency occurs, 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.

The CE of the vehicle 200 may perform a UE function of a 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 connected to the vehicle 200 and the PSN.

On the other hand, in the communication system 100, LCX may be used instead of DU, and a 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, an LCX-based communication system may include: CCU 110, TSU 120, virtual Linear Radiating Cable Module (LRCM) controller (VLC) 150, LRCM 160, etc. CCU 110 may be connected to a CCN and a PSN, and may be connected to TSU 120 as a lower entity. In LCX-based communication systems, the functionality of CCU 110 may be the same as or similar to the functionality of CCU 110 in communication system 100 (e.g., DU-based communication system) described above. The TSU 120 may be connected to the CCU 110 as an upper entity and may be connected to the VLC 150 as a lower entity. The functionality of TSU 120 in an LCX-based communication system may be the same as or similar to the functionality of TSU 120 in communication system 100 (e.g., a DU-based communication system) described above.

The VLC 150 may be connected to the upper layer entity TSU 120 and the lower layer entity LRCM 160. The functionality of the VLC 150 in the LCX-based communication system may be the same as or similar to the functionality of the VA2C 130 in the communication system 100 described above (e.g., DU-based communication system). The LRCM 160 may be connected to the upper layer 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 the LRCM 160 in the LCX based communication system may be the same as or similar to the functionality of the LA2M 140 in the communication system 100 described above (e.g., DU based communication system).

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

LCX-based communication systems may support the following functions.

Function #3: radio communication based position measurement function

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 communication nodes (e.g., sensors) installed in a moving path (e.g., a super speed pipeline) of the vehicle 200, may support a control function and a data uploading function for the corresponding communication nodes, and may measure the position of the vehicle 200 using the corresponding communication nodes. In communication between the LCX-based communication system and the vehicle 200, a sliding window for the vehicle 200 may be moved according to the moving speed of the vehicle 200, so that a pseudo-stationary cell environment may be created. In this case, the minimum moving unit of the sliding window may be an LRCM unit.

In an LCX-based communication system, the 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., 150 m), 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 1.8km. 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 the LRCM 160 via optical fibers instead of the analog repeaters 165-1 and 165-2. The LRCM 160 may be connected to the VLC 150 via RoF/E.

Furthermore, the radiation angle of the RCS may be determined from the slotted arrangement. The radiation angle according to the arrangement of the slots 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 layer entity TSU 120 via fiber and may be connected to the lower layer entity LRCM 160 via 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 signal loss. The VLC 150 may transmit signals received from the TSU 120 to the at least one LRCM 160 based on the P2MP scheme. The VLC 150 may perform soft combining on the signal received by the LRCM 160 based on the MP2P scheme, and may transmit the signal to the TSU 120.

TSU 120 of the LCX-based communication system may perform the base station functions of the cellular communication system. The TSU 120 may be connected to the CCU 110 as an upper entity and may be connected to the VLC 150 as a lower entity. TSU 120 may support PHY functions, MAC functions, synchronization functions, and the like. The MAC layer of TSU 120 may support slave MAC functions and process MAC related data. The synchronization layer of the TSU 120 may perform the transmit and receive functions of probe request/response packets to measure the time delay of the underlying entity. In addition, the synchronization layer and the MAC layer of the TSU 120 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, synchronization of the downlink content may be performed based on the synchronization protocol, and the uplink content may be selected.

The CCU 110 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 CCU 110 may support a radio resource control function, and the RLC layer of CCU 110 may support a data unit segmentation/combining function, an automatic repeat request (ARQ) function, a redundancy detection function, and the like. The PDCP layer of the CCU 110 may support an IP header compression function, a ciphering function, and an integrity protection function. The synchronization layer of CCU 110 may support a transmission and reception function of probe request/response packets for measuring a delay of a lower layer entity, and may support a main MAC function based on semi-static scheduling of an RRC layer.

The synchronization layer of CCU 110 may transmit downlink data packets to TSU 120 in view of the operation of the MAC layer of TSU 120. The synchronization layer of CCU 110 may select a valid uplink data packet from among the uplink data packets received from TSU 120 and may discard an invalid uplink data packet. The synchronization layer of the CCU 110 may perform a downlink content synchronization function, an uplink content selection function, etc., based on a predetermined synchronization protocol. CCU 110 may perform a matching function between a CCN connected to the LCX-based communication system and a PSN. When an emergency situation occurs, the communication function for the passengers of the vehicle 200 may be supported by the CCN of the LCX-based communication system and the CCN of the vehicle 200.

The CTAMs of vehicles 200-1 and 200-2 may be antennas that communicate with 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 connected to the vehicle 200 and the PSN.

Further, in the communication system 100, the DU-based communication system, and the LCX-based communication system 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 shown in fig. 72.

Referring to fig. 72 and 73, the communication system 100 (e.g., a terrestrial communication device) may be the communication system shown in fig. 1 or 50. For example, the communication system 100 may include: CCU 110, TSU 120, VA2C 130, LA2M 140, etc., and each of CCU 110, TSU 120, VA2C 130, and LA2M 140 may be configured the same or similar to CCU, TSU, VA C and LA2M shown in fig. 14. Further, communication system 100 may be a DU-based communication system or an LCX-based communication system (e.g., the LCX-based communication system shown in fig. 69). The vehicle 200-1 may be configured the same or similar to the vehicle 200-1 shown in fig. 50, and the vehicle 200-2 may be configured the same 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., 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 position 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 position information of the vehicle 200-1 (S7202). The first sliding window may include n DA (e.g., antenna, 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 necrotic 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 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 the downlink resources shown in fig. 15 to 19 and 27. When performing downlink communication, the communication system 100 may transmit semi-static scheduling information via a control region and may transmit data through a data region indicated by the semi-static scheduling information. The vehicle 200-1 may receive semi-static scheduling information from the communication system 100 and may receive data through a data area indicated by the semi-static scheduling information. When downlink communication is performed based on 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 an uplink signal (e.g., D1, D2, D3) to the communication system 100, and the communication system 100 may receive the uplink signal (e.g., D1, D2, D3) from the communication system 100 via DA #10 to #13 belonging to the first sliding window. The resources used for uplink communication between the communication system 100 and the vehicle 200-1 may be uplink resources shown in fig. 22 to 25 and 28. When performing uplink communication, the communication system 100 may transmit semi-static scheduling information via the control region. The vehicle 200-1 may receive the semi-static schedule information from the communication system 100 and may transmit data through a data area indicated by the semi-static schedule information. The communication system 100 may receive data through a data region indicated by 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 communication between the communication system 100 and the vehicle 200-1 is performed, the

communication nodes

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

communication nodes

110, 120, 130, and 140. That is, synchronization between da#10 to #13 belonging to the first sliding window can be maintained by the CCU 110 included in the communication system 100. When the synchronization process is completed, 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 da#10 to #13 belonging to the first sliding window may be within a predetermined range (e.g., cyclic Prefix (CP)).

Further, RBs (e.g., SRB and DRB) may be configured for communication between the communication system 100 and the vehicle 200-1. For example, srb#1, drb#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#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., 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 (e.g., antenna, 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 DA#12 is set, the first sliding window reconfigured according to the second position of the vehicle 200-1 may include DA#12 to #15. One or more DA among the m DA ' S included in the first sliding window reconfigured in step S7205 may be the same as one or more DA ' S among the n DA ' S 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 DA #12 to #15 belonging to the first sliding window, and the vehicle 200-1 may receive the downlink signals (e.g., D4, D5, D6) from the communication system 100. Synchronization between DA #12 to #15 belonging to the first sliding window may be maintained by CCU 110 included in communication system 100. Therefore, DA #12 to #15 belonging to the first 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 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 uplink signals (e.g., D4, D5, D6) from the vehicle 200-1 via 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., the 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 position information of the vehicle 200-2 (S7208). The second sliding window may include k DA (e.g., antenna, 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 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 DA #1 to #4 belonging to the second sliding window may be maintained by CCU 110 included in communication system 100. Therefore, 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 DA #1 to #4 belonging to the second sliding window may be within a predetermined range. Further, the vehicle 200-2 may transmit an uplink signal (e.g., D1', D2', D3 ') to the communication system 100, and the communication system 100 may receive the uplink signal (e.g., D1', D2', D3') from the vehicle 200-2 via 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 steps S7204 to S7206 described above, communication between the communication system 100 and the vehicle 200-2 can 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 embodiments according to steps S7207 to S7209 may be performed simultaneously with the embodiments according to steps S7201 to S7203 or the embodiments 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 combinations 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 having skill in the computer software arts.

Examples of computer readable media may include hardware devices such as ROM, RAM, and flash memory that are specially configured to store and perform program instructions. Examples of program instructions include 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 device 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 radio resource control functions 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, wherein the first sliding window comprises n Distributed Antennas (DA) corresponding to a first position of the first mobile device in the plurality of Distributed Antennas (DA);

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 the second location when the first mobile device moves from the first location to the second location;

Performing communication with the first mobile device located at the second location using the m distributed antennas DA;

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

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

wherein one or more of the n distributed antennas DA are identical to one or more of the m distributed antennas DA, each of n, m, and k is an integer equal to or greater than 2, the first, second, and third positions belong to the moving path, and the k distributed antennas DA do not overlap with the n distributed antennas DA or the m distributed antennas DA.

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 signal using the same radio resource 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 signal using the same radio resource 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 RBs are configured for communication between the communication device and the first mobile device, and the cell radio network temporary identifier C-RNTI for each radio bearer RB is independently configured.

7. The communication device of claim 1, wherein the private cell formed by the second sliding window is different from the private cell formed by the first sliding window.

8. The communication device according to claim 1, wherein communication with the k distributed antennas DA is performed simultaneously with communication with the n distributed antennas DA or communication with the m distributed antennas DA.

9. 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 moving path, performing communication with a communication device including a plurality of distributed antennas DA provided along the moving path via a sliding window including n distributed antennas DA corresponding to the first position, and

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

wherein one or more of the n distributed antennas DA are identical to one or more of the m distributed antennas DA, each of n and m is an integer equal to or greater than 2, and a dedicated cell formed by a sliding window configured for the mobile device located at the first location is identical to a dedicated cell formed by a sliding window configured for the mobile device located at the second location.

10. The communication method according to claim 9, wherein in the communication between the mobile device located at the first location and the n distributed antennas DA, the same signal is received from the n distributed antennas DA using the same radio resource.

11. The communication method according to claim 9, wherein in the communication between the mobile device located at the second location and the m distributed antennas DA, the same signal is received from the m distributed antennas DA using the same radio resource.

12. The communication method according to claim 9, 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.