KR102565713B1 - Communication method and apparatus for ultra-speed vehicle - Google Patents

Abstract

A communication method and apparatus for a high-speed vehicle are disclosed. A communication device includes a processor that performs a radio resource control function for communication between a first mobile device and the communication device, a plurality of DAs located on a path of the first mobile device and transmitting and receiving signals under the control of the processor; and a memory storing at least one command executed by the processor, wherein the at least one command includes n DAs corresponding to a first position of the first mobile device among the plurality of DAs; A window is set, and communication is performed with the first mobile device located at the first location using the n DAs. Accordingly, the performance of the communication system can be improved.

Description

Communication method and apparatus for ultra-high speed vehicle {COMMUNICATION METHOD AND APPARATUS FOR ULTRA-SPEED VEHICLE}

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

Communication between a high-speed vehicle (eg, a train moving at a speed of 350 km/h or less) and a base station may be performed based on a cellular communication method. In addition, a vehicle-specific communication network may be installed in a form in which base stations having a cell coverage of several km are installed in a vehicle movement path. In this case, communication between a vehicle moving at a speed of up to 500 km/h and a base station can support a transmission rate of several mega bits per second (Mbps) to several tens of Mbps.

In addition, communication for a vehicle moving at a speed of 500 km/h or less will be supported in a long term evolution-railway (LTE-R) based communication system or a 5G communication system. In addition, a leaky coaxial cable (LCX)-based communication system may be used for high-speed trains, maglev trains, etc. ) can support communication for In an LCX-based communication system, a radiation cable may be segmented in a predetermined unit, and communication may be performed based on radio waves generated by leakage current of the segmented cable. In this case, since a predetermined distance must be maintained between the cable and the receiving node, and precise alignment is required when mounting the cable, installation and maintenance costs may increase. In addition, as the length of the cable increases, signal loss may decrease, and reception performance may deteriorate, and handover may occur between segmented cables, and performance may deteriorate at the point where the handover occurs.

When the communication methods described above are used, the data transmission rate may decrease at the boundary of a cell (or segmented cable), and as the vehicle speed increases, the data transmission rate tends to decrease due to the Doppler effect, , communication becomes almost impossible in the existing communication method at ultra-high speed (eg, 1200 km/h). That is, in the case of using a cellular communication method, communication quality may be degraded due to an increase in the Doppler effect, and communication performance may be degraded due to frequent handover procedures. In addition, the communication methods described above have limitations in supporting communication for high-speed vehicles (eg, trains moving at a speed of 1220 km/h or higher). Therefore, some new functions and designs are needed to overcome this.

An object of the present invention to solve the above problems is to provide a communication method and apparatus for providing a communication service to a high-speed vehicle.

To achieve the above object, a communication device according to a first embodiment of the present invention includes a processor that performs a radio resource control function for communication between a first mobile device and the communication device, located on a path of the first mobile device; a plurality of DAs that transmit and receive signals under the control of the processor, and a memory in which at least one command executed by the processor is stored, wherein the at least one command is selected from among the plurality of DAs; setting a first sliding window including n DAs corresponding to a first position of , performing communication with the first mobile device located at the first position using the n DAs, and When is moved from the first position to the second position, the first sliding window is reset to include m DAs corresponding to the second position among the plurality of DAs, and using the m DAs and perform communication with the first mobile device located at the second location, wherein at least one DA of the n DAs is equal to at least one DA of the m DAs, and each of n and m is 2 is an integer greater than or equal to, and the first location and the second location belong to the path.

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

Here, when communication with the first mobile device located in the first location is performed, the n DAs can transmit and receive the same signal using the same radio resource.

Here, when communication with the first mobile device located in the second location is performed, the m DAs can transmit and receive the same signal using the same radio resource.

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

Here, a plurality of RBs for communication between the communication device and the first mobile device may be configured, and a C-RNTI for each of the plurality of RBs may be independently configured.

Here, the at least one command sets a second sliding window including k DAs corresponding to a third position of a second mobile device moving along the path among the plurality of DAs, and the k and perform communication with the second mobile device located at the third location using DAs, wherein k may be an integer greater than or equal to 2, and the third location may belong to the route.

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

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

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

A communication method performed by a mobile device according to a second embodiment of the present invention for achieving the above object is, when the mobile device is located at a first position on the route, the first among a plurality of DAs located on the route. performing communication with a communication device including the plurality of DAs through a sliding window including n DAs corresponding to 1 location, and when the mobile device moves from the first location to a second location on the route case, performing communication with the communication device through the sliding window including m DAs corresponding to the second position among a plurality of DAs located on the path, wherein one or more of the n DAs DA is equal to one or more DAs among the m DAs, and each of n and m is an integer of 2 or greater.

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

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

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

Here, information used to estimate the location of the mobile device may be transmitted from the mobile device to the communication device, and in the communication device, the first location and the second location may be estimated based on the information. there is.

According to the present invention, since a sliding window including a plurality of antennas can be moved according to the speed of a high-speed vehicle (for example, a train moving at a speed of 1220 km/h or higher), a communication service is provided to the high-speed vehicle. can be provided. In addition, since the sliding window moves according to the speed of the ultra-high speed vehicle, the Doppler effect is reduced, so communication quality may not deteriorate and handover procedures may be minimized. Accordingly, the performance of the communication system can be improved.

1 is a block diagram illustrating a first embodiment of a communication system.
2 is a conceptual diagram illustrating a first embodiment of a communication method between a vehicle and a communication system.
3 is a graph showing a first embodiment of received signal strength in a vehicle.
4 is a graph illustrating a second embodiment of received signal strength in a vehicle.
5 is a first embodiment illustrating a mapping relationship between ports in VA2C of a communication system.
6 is a second embodiment showing a mapping relationship between ports in VA2C of a communication system.
7 is a third embodiment showing a mapping relationship between ports in VA2C of a communication system.
8 is a fourth embodiment showing a mapping relationship between ports in VA2C of a communication system.
9 is a fifth embodiment illustrating a mapping relationship between ports in VA2C of a communication system.
10 is a sixth embodiment showing a mapping relationship between ports in VA2C of a communication system.
11 is a seventh embodiment showing a mapping relationship between ports in VA2C of a communication system.
12 is an eighth embodiment illustrating a mapping relationship between ports in VA2C of a communication system.
13 is a ninth embodiment showing a mapping relationship between ports in VA2C of a communication system.
14 is a conceptual diagram illustrating a first embodiment of a protocol stack of a communication system.
15 is a conceptual diagram illustrating a first embodiment of a downlink resource allocation method in a communication system.
16 is a conceptual diagram illustrating a second embodiment of a downlink resource allocation method in a communication system.
17 is a conceptual diagram illustrating a third embodiment of a downlink resource allocation method in a communication system.
18 is a conceptual diagram illustrating a fourth embodiment of a downlink resource allocation method in a communication system.
19 is a conceptual diagram illustrating a fifth embodiment of a downlink resource allocation method in a communication system.
20 is a conceptual diagram illustrating a first embodiment of an uplink communication method in a communication system.
21 is a conceptual diagram illustrating a second embodiment of an uplink communication method in a communication system.
22 is a conceptual diagram illustrating a first embodiment of an uplink resource allocation method in a communication system.
23 is a conceptual diagram illustrating a second embodiment of an uplink resource allocation method in a communication system.
24 is a conceptual diagram illustrating a third embodiment of an uplink resource allocation method in a communication system.
25 is a conceptual diagram illustrating a fourth embodiment of an uplink resource allocation method in a communication system.
26 is a conceptual diagram illustrating a first embodiment of a message generation procedure for each RB in a communication system.
27 is a conceptual diagram illustrating a first embodiment of downlink resources to which RBs are allocated in a communication system.
28 is a conceptual diagram illustrating a first embodiment of uplink resources to which RBs are allocated in a communication system.
29 is a conceptual diagram illustrating a first embodiment of a downlink retransmission method when RLC AM is used.
30 is a conceptual diagram illustrating a first embodiment of an uplink retransmission method when RLC AM is used.
31 is a conceptual diagram illustrating a first embodiment of a downlink communication method based on a synchronization protocol.
32 is a conceptual diagram illustrating a first embodiment of an uplink communication method based on a synchronization protocol.
33 is a block diagram showing a second embodiment of a communication system.
34 is a block diagram showing a first embodiment of a probe request/response packet used in a delayed probe procedure.
35 is a block diagram showing a second embodiment of a probe request/response packet used in a delayed probe procedure.
36 is a block diagram showing a third embodiment of a communication system.
37 is a block diagram showing a third embodiment of a probe request/response packet used in a delayed probe procedure.
38 is a block diagram showing a fourth embodiment of a communication system.
39 is a block diagram illustrating a fourth embodiment of a probe request packet used in a delayed probe procedure.
40 is a block diagram showing a fourth embodiment of a probe response packet used in a delayed probe procedure.
41 is a block diagram showing a fifth embodiment of a communication system.
42 is a block diagram showing a sixth embodiment of a communication system.
43 is a block diagram illustrating a first embodiment of a downlink packet.
44 is a block diagram showing a seventh embodiment of a communication system.
45 is a block diagram showing an eighth embodiment of a communication system.
46 is a block diagram showing a first embodiment of an uplink packet.
47 is a conceptual diagram illustrating a first embodiment of received signal strength in downlink communication.
48 is a conceptual diagram illustrating a first embodiment of received signal strength in uplink communication.
49 is a conceptual diagram illustrating a second embodiment of received signal strength in uplink communication.
50 is a conceptual diagram showing a first embodiment of a system structure for communication between a communication system and a vehicle.
51 is a graph showing a first embodiment of a driving profile of a vehicle.
52 is a conceptual diagram illustrating a first embodiment of a CRZ of a vehicle.
53 is a conceptual diagram illustrating a first embodiment of a method of allocating time-frequency resources in overlapping CRZs.
54 is a conceptual diagram illustrating a second embodiment of a method for allocating time-frequency resources in overlapping CRZs.
55 is a conceptual diagram illustrating a first embodiment of an RB established between a communication system and a vehicle.
56 is a conceptual diagram illustrating a unique identification number assigned to an antenna included in LA2M of a communication system.
57 is a conceptual diagram illustrating a first embodiment of a method of transmitting a unique identification number.
58 is a conceptual diagram illustrating a unique identification number identified in a vehicle.
59 is a graph showing the received signal strength of a signal including a unique identification number.
60 is a flowchart showing a first embodiment of a vehicle position correction method.
61 is a conceptual diagram illustrating a second embodiment of a method of transmitting a unique identification number.
62 is a conceptual diagram illustrating downlink CRZs arranged in units of good windows.
63 is a conceptual diagram illustrating a third embodiment of a method of transmitting a unique identification number.
64 is a conceptual diagram illustrating uplink CRZs arranged in units of good windows.
65 is a conceptual diagram illustrating a fourth embodiment of a method of transmitting a unique identification number.
66 is a conceptual diagram illustrating a first embodiment of downlink resources configured based on the FDD scheme.
67 is a conceptual diagram illustrating a first embodiment of a vehicle driving method when an emergency situation occurs.
68 is a conceptual diagram illustrating a first embodiment of LA2M of a DU-based communication system and CA2M of a vehicle.
69 is a conceptual diagram illustrating a first embodiment of an LCX-based communication system.
70 is a conceptual diagram illustrating an LRCM structure in an LCX-based communication system.
71 is a conceptual diagram illustrating a first embodiment of a radiation angle according to an arrangement of slots.
72 is a flowchart illustrating a first embodiment of a communication method between a communication system and a vehicle.
FIG. 73 is a conceptual diagram illustrating a sliding window set according to the communication method shown in FIG. 72 .

Since the present invention can make various changes and have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention. The terms and/or include any combination of a plurality of related recited items or any of a plurality of related recited items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this application, they should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail. In order to facilitate overall understanding in the description of the present invention, the same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components are omitted. In the following embodiments, even when a method (eg, transmission or reception of a signal) performed in a first communication node among communication nodes is described, a second communication node corresponding thereto is performed in the first communication node. A method corresponding to the method (eg, receiving or transmitting a signal) may be performed. That is, when the operation of the ground communication device is described, a vehicle corresponding thereto may perform an operation corresponding to that of the ground communication device. Conversely, when the operation of the vehicle is described, a ground communication device corresponding thereto may perform an operation corresponding to the operation of the vehicle.

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

Referring to FIG. 1, a communication system 100 includes a central communication unit (CCU) 110, a tube side unit (TSU) 120, a virtual active antenna controller (VA2C) 130, and a liner active antenna module (LA2M). (140) and the like. Here, the communication system 100 may be referred to as a "ground network (GN)", a "terrestrial communication device", and the like. The TSU 120 may include a plurality of TSUs 120-1 and 120-2, and the VA2C 130 may include a plurality of VA2Cs 130-1, 130-2, and 130-3. , and the LA2M 140 may include a plurality of LA2Ms 140-1, 140-2, 140-3, 140-4, and 140-5.

The CCU 110 may be connected to the sub-entity TSU 120 and may control/manage the TSU 120, the VA2C 130, and the 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. In addition, the CCU 110 may include a processor (eg, a central processing unit (CPU)), a memory storing instructions executed by the processor, and the like, and the processor of the CCU 110 Predefined actions can be performed.

The TSU 120 may be connected to the CCU 110 as a higher entity, may be connected to at least one VA2C (130-1, 130-2, and 130-3) as a lower entity, and may be connected to at least one VA2C (130-1). , 130-2, 130-3) can be controlled/managed. For example, TSU#1 120-1 may be connected to VA2C#1 130-1, VA2C#2 130-2, and the like. In this case, TSU#1 120-1 may be connected to VA2C#1 130-1 through port #C and connected to VA2C#2 130-2 through port #B. TSU#2 120-2 may be connected to VA2C#3 130-3 and the like. In this case, TSU#2 120-2 may be connected to VA2C#3 130-3 through port #A. The TSU 120 may support at least one of a PDCP function, an RLC function, a medium access control (MAC) function, and a physical (PHY) function. Also, the TSU 120 may include a processor (eg, CPU), a memory storing instructions executed by the processor, and the like, and the processor of the TSU 120 may perform predefined operations.

The VA2C 130 may include a plurality of ports, may be connected to the higher entity TSU 120 using upper ports (eg, ports #A to #C), and may be connected to lower ports (eg, ports #A to #C). It can be connected to the LA2M (140) as a sub-entity using ports #a to #o). In the VA2C 130, one upper port (eg, ports #A to #C) may be mapped to at least one lower port (eg, ports #a to #o). VA2C#1 (130-1) may be connected to LA2M#1 (140-1), LA2M#2 (140-2), etc. In this case, ports #k to #o belonging to VA2C#1 (130-1) Each may be mapped one-to-one to antennas belonging to LA2M#1 (140-1) and LA2M#2 (140-2). VA2C#2 (130-2) may be connected to LA2M#3 (140-3), LA2M#4 (140-4), etc. In this case, ports #c to #j belonging to VA2C#2 (130-2) Each may be mapped one-to-one to antennas belonging to LA2M#3 (140-3) and LA2M#4 (140-4). VA2C#3 (130-3) may be connected to LA2M#5 (140-5), etc. In this case, ports #a and #b belonging to VA2C#3 (130-3) are each connected to LA2M#5 (140-5). ) may be mapped one-to-one to antennas belonging to.

The LA2M 140 may be connected to the higher entity VA2C 130. LA2M 140 may include a plurality of antennas. An antenna belonging to the LA2M 140 may be referred to as a distributed antenna (DA), an active antenna component (ACC), or a distributed unit (DU). The LA2M 140 may support at least one of a MAC function, a PHY function, and a radio frequency (RF) function. In addition, the LA2M 140 may include a processor (eg, CPU), a memory storing instructions executed by the processor, and the like, and the processor of the LA2M 140 may perform predefined operations.

Meanwhile, the LA2M 140 may be installed on a vehicle movement path (eg, a rail or a tube of a hyperloop). When a vehicle moves along a movement path, communication between the vehicle and a communication system may be performed through an antenna installed in the vehicle and an antenna installed in a movement path corresponding to a location of the vehicle.

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

Referring to FIG. 2 , the LA2M 140 may include LA2M#1 to #5 (l40-1 to 140-5) of the communication system 100 shown in FIG. The vehicle 200 may move along a moving path, and a sliding window may be set according to the moving path of the vehicle 200 . The sliding window may be set by the CCU 110 and the TSU 120 of the communication system 100 . Here, the vehicle 200 may be a high-speed train, a high-speed train, a maglev train, or a hyperloop capsule. 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, antennas belonging to a sliding window may operate in an on state (eg, active state, enable state), Communication between the antennas operating in the state and the antenna installed in the vehicle 200 may be performed. Antennas installed in the vehicle 200 may be referred to as DA, ACC, DU, and the like, and in the vehicle 200, the antenna may be installed in a capsule active antenna module (CA2M). A plurality of antennas may be installed in the vehicle 200, and in this case, CA2M may include a plurality of antennas.

The sliding window may move according to the moving speed of the vehicle 200, and when the sliding window moves, an effect of moving the base station may occur. Therefore, a sliding window (eg, the communication system 100 performing communication using a plurality of antennas belonging to the sliding window) is referred to as a moving cell, a virtual base station, a ghost base station, and the like. It can be. One sliding window may be dedicated for one vehicle 200 .

In the LA2M 140, antennas may be installed at regular intervals (eg, 10 m). For example, when the antenna installation interval is 10 m and the sliding window includes 50 antennas, the length of the sliding window may be 500 m. The number of antennas included in the sliding window may be set in various ways, and the number of antennas belonging to the sliding window may vary according to the installation interval of the antennas. In addition, the received signal strength in the vehicle 200 may vary according to the number of antennas belonging to the sliding window.

3 is a graph showing received signal strength in a vehicle according to a first embodiment, and FIG. 4 is a graph showing received signal strength in a vehicle according to a second embodiment.

Referring to FIGS. 3 and 4 , all antennas belonging to the sliding window may transmit signals in a joint transmission (JT) method. When the JT method is used, all antennas belonging to the sliding window can transmit the same signal (eg, control information, data, content, etc.) using the same time-frequency resources. The number of antennas belonging to the sliding window of FIG. 3 may be twice the number of antennas belonging to the sliding window of FIG. 4 . The average received signal strength in the vehicle 200 may be determined between a maximum (max) received signal strength and a minimum (min) received signal strength. The maximum received signal strength in FIG. 3 may be the same as the maximum received signal strength in FIG. 4 , and the lowest received signal strength in FIG. 3 may be higher than the lowest received signal strength in FIG. 4 .

The lowest received signal strength may be related to the lowest guaranteed capacity of the vehicle 200 (eg, the lowest target capacity of downlink in the vehicle 200). An antenna installation interval 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 antenna installation interval in the LA2M 140 may be relatively wide, and the installation cost of the communication system 100 may be reduced. That is, as the installation interval of the antennas in the LA2M 140 becomes narrower, the received signal strength in the vehicle 200 may be improved, and as the installation interval of the antennas in the LA2M 140 widens, the installation cost of the communication system 100 increases. can increase

Meanwhile, in the VA2C 130, the mapping relationship between the upper port and the lower port may be set as follows according to the movement of the sliding window. Here, the sliding window may be set to include 6 antennas and may move according to the moving speed of the vehicle 200 .

5 is a first embodiment illustrating a mapping relationship between ports in VA2C of a communication system.

Referring to FIG. 5, the sliding window may be controlled/managed by the CCU 110 and the TSU#1 (120-1) of the communication system 100, and the port #k of the VA2C#1 (130-1), It may include antennas connected to port #l, port #m, and port #n, and antennas connected to port #i and port #j of VA2C#2 (130-2). For example, TSU#1 (120-1) can transmit a signal to port #C of VA2C#1 (130-1), and in VA2C#1 (130-1), the corresponding signal is transmitted from port #C to port # k, port #l, port #m, and port #n may be transmitted in a multicast method. In addition, TSU#1 (120-1) may transmit a signal to port #B of VA2C#2 (130-2), and in VA2C#2 (130-2), the corresponding signal is transmitted from port #B to port #i and It can be transmitted in a multicast method through port #j.

6 is a second embodiment showing a mapping relationship between ports in VA2C of a communication system.

Referring to FIG. 6, the sliding window may be controlled/managed by the CCU 110 and the TSU#1 (120-1) of the communication system 100, and the port #k of the VA2C#1 (130-1), It may include antennas connected to ports #l and port #m, and antennas connected to ports #h, port #i and port #j of VA2C#2 (130-2). Comparing the sliding window of FIG. 6 with the sliding window of FIG. 5, the antenna connected to port #n of VA2C#1 (130-1) is excluded from the sliding window of FIG. 6 (i.e., the connection between port #C and port #n). released), and an antenna connected to port #h of VA2C#2 130-2 may be added (ie, connection between port #B and port #h added). For example, TSU#1 (120-1) can transmit a signal to port #C of VA2C#1 (130-1), and in VA2C#1 (130-1), the corresponding signal is transmitted from port #C to port # k, port #l and port #m may be transmitted in a multicast manner. In addition, TSU # 1 (120-1) may transmit a signal to port # B of VA2C # 2 (130-2), and in VA2C # 2 (130-2), the corresponding signal is transmitted from port # B to port # h, It can be transmitted in a multicast method through port #i and port #j.

7 is a third embodiment showing a mapping relationship between ports in VA2C of a communication system.

Referring to FIG. 7 , the sliding window may be controlled/managed by the CCU 110 and TSU#1 120-1 of the communication system 100, and port #k and VA2C#1 130-1. It may include antennas connected to port #l and antennas connected to ports #g, port #h, port #i, and port #j of VA2C#2 (130-2). Comparing the sliding window of FIG. 7 with the sliding window of FIG. 6, the antenna connected to port #m of VA2C#1 (130-1) is excluded from the sliding window of FIG. 7 (that is, the connection between port #C and port #m). release), and an antenna connected to port #g of VA2C#2 130-2 may be added (ie, connection between port #B and port #g added). For example, TSU#1 (120-1) can transmit a signal to port #C of VA2C#1 (130-1), and in VA2C#1 (130-1), the corresponding signal is transmitted from port #C to port # It can be transmitted in a multicast method to k and port #l. In addition, TSU#1 (120-1) can transmit a signal to port #B of VA2C#2 (130-2), and in VA2C#2 (130-2), the corresponding signal is transmitted from port #B to port #g, It can be transmitted in a multicast method to port #h, port #i, and port #j.

8 is a fourth embodiment showing a mapping relationship between ports in VA2C of a communication system.

Referring to FIG. 8 , the sliding window may be controlled/managed by the CCU 110 and TSU#1 (120-1) of the communication system 100, and is connected to port #k of VA2C#1 (130-1). It may include connected antennas and antennas connected to port #f, port #g, port #h, port #i, and port #j of VA2C#2 (130-2). Comparing the sliding window of FIG. 8 with the sliding window of FIG. 7, the antenna connected to port #l of VA2C#1 (130-1) is excluded from the sliding window of FIG. 8 (that is, the connection between port #C and port #l). release), and an antenna connected to port #f of VA2C#2 130-2 can be added (ie, connection between port #B and port #f added). For example, TSU#1 (120-1) can transmit a signal to port #C of VA2C#1 (130-1), and in VA2C#1 (130-1), the corresponding signal is transmitted from port #C to port # can be sent to k. In addition, TSU # 1 (120-1) may transmit a signal to port # B of VA2C # 2 (130-2), and in VA2C # 2 (130-2), the corresponding signal is transmitted from port # B to port # f, It can be transmitted in a multicast manner to port #g, port #h, port #i, and port #j.

9 is a fifth embodiment illustrating a mapping relationship between ports in VA2C of a communication system.

Referring to FIG. 9, the sliding window may be controlled/managed by the CCU 110 and TSU#1 (120-1) of the communication system 100, and port #e of VA2C#2 (130-2), It may include antennas connected to port #f, port #g, port #h, port #i and port #j. Comparing the sliding window of FIG. 9 with the sliding window of FIG. 8, the antenna connected to port #k of VA2C#1 (130-1) is excluded from the sliding window of FIG. 9 (that is, the connection between port #C and port #k). release), and an antenna connected to port #e of VA2C#2 130-2 may be added (ie, connection between port #B and port #e added). For example, TSU#1 (120-1) can transmit a signal to port #B of VA2C#2 (130-2), and in VA2C#2 (130-2), the corresponding signal is transmitted from port #B to port # e, port #f, port #g, port #h, port #i, and port #j may be transmitted in a multicast manner. In this case, TSU#1 (120-1) may not transmit a signal to port #C of VA2C#1 (130-1).

10 is a sixth embodiment showing a mapping relationship between ports in VA2C of a communication system.

Referring to FIG. 10, the sliding window may be controlled/managed by the CCU 110 and TSU#1 (120-1) of the communication system 100, and port #d of VA2C#2 (130-2), It may include antennas connected to port #e, port #f, port #g, port #h and port #i. Comparing the sliding window of FIG. 10 with the sliding window of FIG. 9, the antenna connected to port #j of VA2C#2 (130-2) is excluded from the sliding window of FIG. 10 (i.e., the connection between port #B and port #j). release), and an antenna connected to port #d of VA2C#2 130-2 may be added (ie, connection between port #B and port #d added). For example, TSU#1 (120-1) can transmit a signal to port #B of VA2C#2 (130-2), and in VA2C#2 (130-2), the corresponding signal is transmitted from port #B to port # d, port #e, port #f, port #g, port #h, and port #i.

11 is a seventh embodiment showing a mapping relationship between ports in VA2C of a communication system.

Referring to FIG. 11, the sliding window may be controlled/managed by the CCU 110 and TSU#1 (120-1) of the communication system 100, and port #c of VA2C#2 (130-2), It may include antennas connected to port #d, port #e, port #f, port #g and port #h. Comparing the sliding window of FIG. 11 with the sliding window of FIG. 10, the antenna connected to port #i of VA2C#2 (130-2) is excluded from the sliding window of FIG. 11 (i.e., the connection between port #B and port #i). release), and an antenna connected to port #c of VA2C#2 130-2 can be added (ie, connection between port #B and port #c added). For example, TSU#1 (120-1) can transmit a signal to port #B of VA2C#2 (130-2), and in VA2C#2 (130-2), the corresponding signal is transmitted from port #B to port # c, port #d, port #e, port #f, port #g, and port #h may be transmitted in a multicast manner.

12 is an eighth embodiment illustrating a mapping relationship between ports in VA2C of a communication system.

Referring to FIG. 12, the sliding window may be controlled/managed by the CCU 110, TSU#1 120-1, and TSU#2 120-2 of the communication system 100, and VA2C#2 ( 130-2) may include antennas connected to port #c, port #d, port #e, port #f, and port #g, and an antenna connected to port #b of VA2C#3 (130-3). Comparing the sliding window of FIG. 12 with the sliding window of FIG. 11, the antenna connected to port #h of VA2C#2 (130-2) is excluded from the sliding window of FIG. 12 (i.e., the connection between port #B and port #h). released), and an antenna connected to port #b of VA2C#3 (130-3) can be added (ie, connection between port #A and port #b added). For example, TSU#1 (120-1) can transmit a signal to port #B of VA2C#2 (130-2), and in VA2C#2 (130-2), the corresponding signal is transmitted from port #B to port # c, port #d, port #e, port #f, and port #g may be transmitted in a multicast manner. In addition, TSU#2 (120-2) can transmit a signal to port #A of VA2C#3 (130-3), and in VA2C#3 (130-3), the corresponding signal is transmitted from port #A to port #b. can be transmitted Since the signal is transmitted by the two TSUs 120-1 and 120-2, synchronization between TSU#1 120-1 and TSU#2 120-2 (eg, TSU#1 120-2) 1) and synchronization of signals (eg, contents) transmitted from TSU#2 120-2 may be set by the CCU 110. Also, switching among the VA2Cs 130-1, 130-2, and 130-3 may be controlled by the CCU 110.

13 is a ninth embodiment showing a mapping relationship between ports in VA2C of a communication system.

Referring to FIG. 13, the sliding window may be controlled/managed by the CCU 110, TSU#1 120-1 and TSU#2 120-2 of the communication system 100, and VA2C#2 ( 130-2) may include antennas connected to ports #c, port #d, port #e, and port #f, and antennas connected to ports #a and port #b of VA2C#3 (130-3). Comparing the sliding window of FIG. 13 with the sliding window of FIG. 12, the antenna connected to port #g of VA2C#2 (130-2) is excluded from the sliding window of FIG. 13 (i.e., the connection between port #B and port #g). release), and an antenna connected to port #a of VA2C#3 130-3 may be added (ie, a connection between port #A and port #a may be added). For example, TSU#1 (120-1) can transmit a signal to port #B of VA2C#2 (130-2), and in VA2C#2 (130-2), the corresponding signal is transmitted from port #B to port # c, port #d, port #e, and port #f may be transmitted in a multicast manner. In addition, TSU#2 (120-2) may transmit a signal to port #A of VA2C#3 (130-3), and in VA2C#3 (130-3), the corresponding signal is transmitted from port #A to port #a and It can be transmitted in a multicast method to port #b. Since the signal is transmitted by the two TSUs 120-1 and 120-2, synchronization between TSU#1 120-1 and TSU#2 120-2 (eg, TSU#1 120-2) 1) and synchronization of signals (eg, contents) transmitted from TSU#2 120-2 may be set by the CCU 110.

Meanwhile, in the CCU 110, the TSU 120, the VA2C 130, and the LA2M 140 of the communication system 100, a protocol stack may be set as follows.

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

Referring to FIG. 14 , the protocol stack on the control plane (CP) side of the communication system 100 may include CP-CCU, CP-TSU, CP-VA2C, and CP-LA2M. The CP-CCU may transmit a control primitive to the CP-TSU through the first path P1. The CP-TSU may receive a control primitive from the CP-CCU, and may transmit a response/report to the received control primitive to the CP-CCU through the first path P1. The CP-TSU may transmit a control primitive to the CP-LA2M through the second path (P2) for control of the CP-LA2M, and a response/report for the control primitive from the CP-LA2M through the second path (P2). can receive The CP-TSU may transmit a control primitive to the CP-VA2C through the third path (P3) for control of the CP-VA2C, and a response/report for the control primitive from the CP-VA2C through the third path (P3). can receive

CP-CCU may include an RRC layer. Accordingly, the CP-CCU can support resource allocation/change/release operations in a sliding window and can transmit an RRC message for resource allocation/change/release operations. Also, the CP-CCU may obtain location information of the vehicle 200 and set a sliding window based on the obtained location information. For example, the CP-CCU may set a sliding window to correspond to the position of the vehicle 200 . The CP-CCU may set one sliding window for one vehicle 200 and perform a resource allocation operation for the corresponding vehicle 200 within the set sliding window.

When a resource allocation operation is performed, the CP-CCU is a transport block (TB) size, frequency resource allocation information, time resource allocation information (eg, transmission time interval (TTI) period), hopping pattern, VA2C In step 130, a resource allocation message including mapping information between an upper port and a lower port may be transmitted to the CP-TSU through the first path P1. The CP-TSU may receive a resource allocation message through the first path P1 and may check information included in the resource allocation message. Upon receiving the resource allocation message, the CP-TSU may transmit control information related to resource allocation to the CP-LA2M (eg, a plurality of CP-LA2Ms connected to the CP-TSU) through the second path, and the third path. Control information related to resource allocation may be transmitted to the CP-VA2C (eg, a plurality of CP-VA2Cs connected to the CP-TSU). CP-LA2M and CP-VA2C may operate based on control information related to resource allocation received from CP-TSU. The control information transmitted from CP-TSU to CP-LA2M or CP-VA2C is the type of user plane (UP) (e.g., A1-UP, A2-UP, A3-UP, A4-UP, A5-UP, A6 -UP, A7-UP, A8-UP, A9-UP).

In the communication system 100, the protocol stack of the UP side is set to A1-UP, A2-UP, A3-UP, A4-UP, A5-UP, A6-UP, A7-UP, A8-UP, A9-UP, etc. It can be. A1-UP, A2-UP, A3-UP, A4-UP, A5-UP or A6-UP may be used for downlink transmission. A protocol stack of the UP side used for uplink transmission may be the same as a protocol stack of the UP side used for downlink transmission. Alternatively, a UP-side protocol stack used for uplink transmission may be different from a UP-side protocol stack used for downlink transmission.

The LA2M 140 may include at least one of an RF layer, a PHY layer, and a MAC layer. RF can be an antenna (eg 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 the A9-UP, the TSU 120 may not include all of the PDCP layer, the RLC layer, the MAC layer, and the PHY layer. The CCU 110 may include at least one of a PDCP layer and an RLC layer. However, in 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 located in the CCU 110, the TSU 120 or the LA2M 140. Alternatively, some functions of one layer may be performed by the CCU 110, TSU 120, or LA2M 140, and the remaining functions of one layer may be performed by an entire entity (eg, CCU 110, TSU (120), LA2M (140)) may be performed by an entity that does not perform some functions of one layer.

The PDCP layer may be located in the TSU 120 (eg, the TSU 120 in A1-UP, A2-UP or A3-UP), or the PDCP layer may be located in the CCU 110 to reduce processing power. ) (eg, CCU 110 in A4-UP, A5-UP, A6-UP, A7-UP, A8-UP or A9-UP). The PDCP layer may not support an internet protocol (IP) header compression function. Alternatively, the PDCP layer may be omitted in the communication system.

In A7-UP, A8-UP and A9-UP, the RLC layer may support RLC acknowledged mode (AM). For example, when RLC AM is supported, a transmitting communication node (eg, the communication system 100 of FIG. 1) transmits a packet to a receiving communication node (eg, the vehicle 200 of FIG. 2). and can store the transmitted packet in a buffer. The receiving communication node may receive a packet from the transmitting communication node, and may transmit a response message (eg, an ACK message or a NACK message) for the packet to the transmitting communication node. When an ACK message is received as a response to the packet from the receiving communication node, the transmitting communication node may discard the packet stored in the buffer (that is, the packet transmitted to the receiving communication node). On the other hand, when a NACK message is received as a response to the packet from the receiving communication node, the transmitting communication node may retransmit the packet stored in the buffer (ie, the packet transmitted to the receiving communication node). When the RLC layer is located in the CCU 110, the receiving communication node transmits a response message (eg, ACK message, NACK message) to the received packet and the transmitting communication node responds to the received NACK message The operation of retransmitting the packet can be easily performed. The communication system 100 may include a plurality of TSUs 120, and when the RLC layer is located in each of the plurality of TSUs 120 in A1-UP to A6-UP, the CCU 110 may include a plurality of TSUs 120. RLC-related operations performed by the TSUs 120 may be controlled/managed.

Meanwhile, communication nodes (eg, CCU 110, TSU 120, VA2C 130, LA2M 140) belonging to the communication system 100 may have a hierarchical tree structure. Here, a communication node may refer to a communication entity. Communication nodes in the communication system 100 may be synchronized based on a global positioning system (GPS), Institute of Electrical and Electronics Engineers (IEEE) 1588, and the like. A synchronization layer performing a synchronization function according to a predefined synchronization protocol may be located in the CCU 110 . In addition, the synchronization protocol may be located in the CCU 110 and a communication node (eg, TSU 120 or LA2M 140) that performs a MAC function.

Since the MAC layer is located in the TSU 120 in A1-UP, A2-UP, A4-UP, A5-UP, A7-UP, and A8-UP, synchronization between the CCU 110 and the TSU 120 is performed. It can be. Since the MAC layer is located in the LA2M 140 in A3-UP, A6-UP, and A9-UP, a synchronization procedure between the CCU 110 and the LA2M 140 can be performed. In this case, the TSU 120 may perform a relay function in a synchronization procedure between the CCU 110 and the LA2M 140. Since a connection structure between communication nodes in a downlink communication procedure is a 1:N connection structure, the TSU 120 can be used as a transport layer when an IP multicast function is used. Here, N may be an integer of 2 or greater.

Meanwhile, downlink resources used for downlink communication in the communication system 100 may be allocated as follows.

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

Referring to FIG. 15, a radio frame may include a plurality of subframes (eg, 10 subframes (SF#0 to #9)), and the length of the subframe may vary. can be set. For example, the length of a subframe may be 0.5 ms, 1 ms, and the like. One subframe may be one TTI. A subframe may include two or more slots, and a slot may include a plurality of symbols. A subframe may include a control area and a data area. Here, the control area may be a control channel of a cellular communication system (eg, 4G or 5G communication system), and the data area may be a data channel in the cellular communication system. The communication system 100 may transmit control information to the vehicle 200 using the control area of the subframe and transmit data (eg, content) to the vehicle 200 using the data area of the subframe. there is.

For example, the communication system 100 may determine the lowest capacity of data to be transmitted to the vehicle 200, and determine the determined lowest capacity, modulation order, and overhead of each layer (eg, For example, the size of a time-frequency resource (eg, a time-frequency resource to transmit data) may be set in consideration of header overhead, tail overhead), IP header compression rate, segmentation, and the like. . Here, the time-frequency resource may be configured based on a semi-static scheduling method. When the semi-static scheduling method is used, the same time-frequency resource may be configured within the data region for each subframe (eg, TTI). In addition, for subframe synchronization and content synchronization (eg, subframe synchronization and content synchronization in the plurality of TSUs 120 controlled / managed by the CCU 110) for each subframe (eg, TTI) action can be performed.

The communication system 100 may transmit quasi-static scheduling information for the determined time-frequency resource through the control region, and use the time-frequency resource indicated by the quasi-static scheduling information in the data region to generate data (for example, , data unit) can be transmitted. The above-described quasi-static scheduling operation may be performed by the CCU 110 of the communication system 100, and the CCU 110 performs the CCU 110 so that content is synchronized by subframe (eg, by TTI). A plurality of TSUs 120 connected to may be controlled/managed.

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, and FIG. 18 is a conceptual diagram illustrating a downlink resource allocation method in a communication system A conceptual diagram illustrating a fourth embodiment of a downlink resource allocation method, and FIG. 19 is a conceptual diagram illustrating a fifth embodiment of a downlink resource allocation method in a communication system.

16 to 19, when the semi-static scheduling method is used, the communication system 100 (eg, the CCU 110 of the communication system 100) performs subframe synchronization for each 1, 2, or 4 TTI. And an operation for content synchronization may be performed. Also, the CCU 110 may allocate time-frequency resources within the data domain based on a frequency hopping scheme. A hopping pattern may be preset between the communication system 100 and the vehicle 200, and the CCU 110 determines the hopping pattern and a TTI period (eg, a TTI period in which time-frequency resources for data transmission are allocated). Based on this, a semi-static scheduling operation may be performed.

The CCU 110 may perform a semi-static scheduling operation for one vehicle 200 within one sliding window. In this case, the CCU 110 may perform one semi-static scheduling operation for all packets processed by the CCU 110 in terms of user data. Alternatively, packets processed by the CCU 110 may be logically classified according to types, priorities, etc., and the CCU 110 may perform a separate semi-static scheduling operation for each of the logically classified packets. . Also, when a semi-static scheduling operation is performed, control information (eg, semi-static scheduling information) may be distinguished from data, or control information and data may be processed together. When a semi-static scheduling operation is performed, the CCU 110 may allocate sufficient time-frequency resources for control information and data even if null padding occurs.

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

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

Referring to FIG. 20 , the 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, antennas corresponding to ports #i to #n of the VA2C 130 can receive uplink signals of the vehicle 200. and transmits the received uplink signal and received signal strength information to a corresponding port. In VA2C#1 (130-1), the uplink signal and received signal strength information of the vehicle 200 may be transmitted from ports #k to #n to port #C, and in VA2C#2 (130-2), the vehicle ( 200), uplink signal and received signal strength information may be transmitted from ports #i and #j to port #B.

Meanwhile, even when the cyclic redundancy check (CRC) of the uplink signal is successfully completed, if the received signal strength of the uplink signal is less than a threshold value, the corresponding uplink signal is sent to a higher entity (eg, the TSU 120). may not be able to transmit. When A1-UP, A4-UP or A7-UP shown in FIG. 14 is used, the RF layer may perform a soft combining operation on uplink signals.

For example, if the threshold for the received signal strength is 20 dBm, and the received signal strengths of the uplink signals at port #k, port #l, port #m, and port #n are 21 dBm, 20 dBm, 15 dBm, and 14 dBm, respectively, VA2C#1 (130-1) may discard the uplink signals obtained from ports #m and #n, and perform a soft combining operation on the uplink signals obtained from ports #k and #l to obtain one Uplink signals of can be generated, and one generated uplink signal can be transmitted to TSU # 1 (120-1).

In addition, when the threshold for the received signal strength is 20 dBm and the received signal strengths of the uplink signals at ports #i and port #j are 20 dBm and 21 dBm, respectively, VA2C#2 (130-2) operates ports #i and # One uplink signal may be generated by performing a soft combining operation on the uplink signals obtained from j, and the generated one uplink signal and received signal strength information may be transmitted to TSU#1 (120-1). can transmit On the other hand, when the received signal strength of the uplink signal at ports #i and port #j are 18 dBm and 21 dBm, VA2C#2 (130-2) may discard the uplink signal obtained from port #i, and The uplink signal and received signal strength information obtained from #j may be transmitted to TSU#1 120-1.

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

Meanwhile, it may not be easy to perform soft combining operations in A2-UP, A3-UP, A5-UP, A6-UP, A8-UP, and A9-UP of FIG. 14 . For example, when uplink signal and received signal strength information is obtained from port #k, port #l, port #m, and port #n of VA2C#1 (130-1), VA2C#1 (130-1) may discard an uplink signal having a received signal strength less than a threshold among uplink signals, and may select at least one uplink signal having a received signal strength greater than or equal to a threshold among uplink signals. VA2C#1 (130-1) may finally select an uplink signal having the largest received signal strength from among the selected at least one uplink signal, and receive signal strength for the finally selected uplink signal and the finally selected uplink signal. Information may be transmitted to TSU#1 (120-1).

In addition, when uplink signal and received signal strength information are acquired from port #i and port #j of VA2C#2 (130-2), VA2C#2 (130-2) is less than the threshold among uplink signals An uplink signal having a received signal strength may be discarded, and at least one uplink signal having a received signal strength equal to or greater than a threshold may be selected from among uplink signals. VA2C#2 (130-2) may select a final uplink signal having the largest received signal strength from among the selected at least one uplink signal, and receive signal strength for the final selected uplink signal and the finally selected uplink signal. Information may be transmitted to TSU#1 (120-1).

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

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

Referring to FIG. 21 , the 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, antennas corresponding to ports #a to #f of the VA2C 130 can receive uplink signals of the vehicle 200. and transmits the received uplink signal and received signal strength information to a corresponding port. In VA2C#2 (130-2), the uplink signal and received signal strength information of the vehicle 200 may be transmitted from ports #c to #f to port #B, and in VA2C#3 (130-3), the vehicle ( 200), uplink signal and received signal strength information may be transmitted from ports #a and #b to port #A.

An uplink signal processing procedure in the communication system 100 of FIG. 21 may be the same as or similar to the previously described uplink signal processing procedure in the communication system 100 of FIG. 20 . However, the number of uplink signals received by the CCU 110 of FIG. 21 may be two. For example, TSU#1 120-1 may transmit an uplink signal obtained from VA2C#2 130-2 to CCU 110, and TSU#2 120-2 may transmit VA2C#3 ( The uplink signal obtained from 130-3) may be transmitted to the CCU 110. In addition, TSU#1 120-1 and TSU#2 120-2 may transmit received signal strength information for an uplink signal to the CCU 110.

Therefore, the CCU 110 can receive uplink signal and received signal strength information from TSU#1 120-1 and TSU#2 120-2, and has the largest received signal strength among the two uplink signals. It is possible to select an uplink signal having Alternatively, the CCU 110 may select an uplink signal having the smallest error rate among two uplink signals.

Meanwhile, performance of uplink communication described with reference to FIGS. 20 and 21 may be lower than performance of downlink communication based on the JT scheme. However, in A1-UP of FIG. 14, a joint reception (JR) method may be used, and in this case, performance of uplink communication may be improved. For example, among all uplink signals, some uplink signals may be processed based on the JR method, and the JR method may not be applied to the remaining uplink signals.

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

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, and FIG. A conceptual diagram illustrating a third embodiment of an uplink resource allocation method, and FIG. 25 is a conceptual diagram illustrating a fourth embodiment of an uplink resource allocation method in a communication system.

22 to 25, in the communication system 100, a CP-CCU (eg, CCU 110) may perform a semi-static scheduling operation for uplink resources. The semi-static scheduling operation may be performed when a request for scheduling of uplink resources is received from the vehicle 200 . The semi-static scheduling information of uplink resources may be transmitted through a control region of a downlink subframe, and located after a preset number of TTIs from the downlink subframe in which the semi-static scheduling information of uplink resources is transmitted on the time axis This may be semi-static scheduling information for uplink subframes. For example, semi-static scheduling information for uplink subframes #1 to #9 may be received through downlink subframe #0. The semi-static scheduling information may indicate the same frequency resource for each uplink subframe. Alternatively, the semi-static scheduling information may indicate a resource configured based on a frequency hopping scheme in an uplink subframe. Within the sliding window, the resource allocation procedure may be individually performed according to the type and priority of packets (eg, control information and data).

Meanwhile, a radio bearer (RB) may be set 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 set RB. RB can be set as follows.

26 is a conceptual diagram illustrating a first embodiment of a message generation procedure for each RB in a communication system, and FIG. 27 is a conceptual diagram illustrating a first embodiment of downlink resources allocated to RBs in a communication system.

Referring to FIGS. 26 and 27 , a signaling radio bearer (SRB) and a dedicated radio bearer (DRB) may be configured for communication between the communication system 100 and the vehicle 200 . Here, the control packet may be control information related to driving of the vehicle 200, and the service packet may be user data for a passenger riding in the vehicle 200 (eg, a terminal carried by the passenger). SRB#1 may be used to inform resource allocation information (eg, semi-static scheduling information) for communication between the communication system 100 and the vehicle 200. RBs used to inform resource allocation information may not be divided 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 set for SRB#1, and resources for SRB#1 may be allocated based on C-RNTI A. For example, resources for SRB#1 may be scheduled for each subframe based on C-RNTI A. Alternatively, resources for SRB#1 may be allocated in a semi-static scheduling method based on C-RNTI A.

An IP packet may be used in communication between the communication system 100 and the vehicle 200, and when the IP packet can be processed within one TTI, a plurality of RLC service data units (SDUs) in DRB#1 are concatenated ( concatenation) can be DRB#1 may be used for transmission of control packets of the vehicle 200. C-RNTI B may be set for DRB#1, and resources for DRB#1 may be allocated based on C-RNTI B. For example, resources for DRB#1 may be scheduled for each subframe based on C-RNTI B. Alternatively, resources for DRB#1 may be allocated in a semi-static scheduling method based on C-RNTI B.

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

In communication between the communication system 100 and the vehicle 200, a plurality of C-RNTIs (eg, C-RNTI A, C-RNTI B, and C-RNTI C) may be configured for one vehicle 200. and resources may be scheduled based on a plurality of C-RNTIs. For example, a plurality of C-RNTIs may be configured for each RB. In addition, a maximum TB (eg, a predicted maximum RB) for each RB may be fixedly allocated. When there is no packet to be transmitted through a fixedly allocated TB, the corresponding TB may be processed based on an all zero padding method or a muting method. The TB allocation period and scheduling period may be determined by considering packet generation frequency and delay requirements for each RB.

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

Referring to FIG. 28, C-RNTI A may be configured for SRB#1 (or SRB#2), and uplink resources for SRB#1 (or SRB#2) based on C-RNTI A can be assigned. For example, resources for SRB#1 (or SRB#2) may be scheduled for each subframe based on C-RNTI A, and in this case, scheduling information for SRB#1 (or SRB#2) may be transmitted through the control region in each downlink subframe. Alternatively, resources for SRB#1 (or SRB#2) may be allocated in a semi-static scheduling method based on C-RNTI A, and in this case, scheduling information for SRB#1 (or SRB#2) may be transmitted through a control region of one downlink subframe.

C-RNTI B may be configured for DRB#1, and uplink resources for DRB#1 may be allocated based on C-RNTI B. For example, resources for DRB#1 may be scheduled for each subframe based on C-RNTI B, and in this case, scheduling information for DRB#1 may be transmitted through a control region for each downlink subframe. . Alternatively, resources for DRB#1 may be allocated in a semi-static scheduling method based on C-RNTI B, and in this case, scheduling information for DRB#1 is transmitted through a control region of one downlink subframe. can

C-RNTI C may be configured for DRB#2, and uplink resources for DRB#2 may be allocated based on C-RNTI C. For example, resources for DRB#2 may be scheduled for each subframe based on C-RNTI C, and in this case, scheduling information for DRB#2 may be transmitted through the control region for each downlink subframe. . Alternatively, resources for DRB#2 may be allocated in a semi-static scheduling method based on C-RNTI C, and in this case, scheduling information for DRB#2 is transmitted through a control region of one downlink subframe. can

Uplink packets may be received in the communication system 100 through SRB#1, DRB#1, and DRB#2, and the uplink packets received in the communication system 100 are the PHY layer, MAC layer, and RLC of FIG. layer and PDCP layer. For example, uplink packets may be processed in the order of “PHY layer→MAC layer→RLC layer→PDCP layer”, and CRC related operations, header removal operations, data unit separation operations, etc. may be performed in each of the layers. there is.

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

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

Referring to FIG. 29, when RLC AM is used, a plurality of C-RNTIs may be configured for one DRB. When a downlink signal is transmitted through the DRB, a C-RNTI (eg, C-RNTI B) for initial transmission of the downlink signal may be set, and a response message (eg, C-RNTI B) for the downlink signal A C-RNTI (eg, C-RNTI D) for an RLC status message) may be set, and a C-RNTI (eg, C-RNTI E) for retransmission of a downlink signal may be set. It can be. That is, in a downlink communication procedure, one C-RNTI used for initial transmission of a downlink signal can be basically configured, and additionally two C-RNTIs used for an RLC status message and a retransmission procedure of a downlink signal. RNTIs may be configured. Accordingly, three C-RNTIs may be configured for DRB to which RLC AM is applied. Alternatively, one C-RNTI may be set for a downlink communication procedure (eg, RB of RLC AM), and resources for initial transmission of a downlink signal based on one C-RNTI, RLC status message Resources for and resources for retransmission of downlink signals may be set.

Here, the maximum TB (eg, predicted maximum RB) within one TTI may be allocated according to a preset period (eg, 1, 2, or 4 TTI), and the data to be transmitted is larger than the size of the allocated TB. When is small, an operation of adding zero padding may be performed. A semi-static scheduling operation for initial transmission, a semi-static scheduling operation for RLC state information transmission, and a 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 a resource (eg, SF#0) scheduled by the C-RNTI B of the DRB. In step S2902, the vehicle 200 may receive a TB in SF#0 and may check an RLC protocol data unit (PDU) based on the received TB. The vehicle 200 may generate an RLC status message (eg, an ACK message or a NACK message) based on the reception status of the RLC PDU. If 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 by using a resource (eg, SF#3) scheduled by C-RNTI D of the DRB. Here, the C-RNTI D may be signaled from the communication system 100 to the vehicle 200 through the control region of the downlink subframe.

In step S2904, the communication system 100 may receive an RLC status message from SF#3. When the RLC status message indicates NACK, the communication system 100 may check an RLC PDU corresponding to the NACK among RLC PDUs located in the retransmission buffer and perform a retransmission procedure for the checked RLC PDU. For example, in step S2905, the communication system 100 may perform a retransmission procedure using a resource (eg, SF#5) scheduled by C-RNTI E of the DRB. In step S2906, the vehicle 200 may receive the retransmitted RLC PDU through SF#5.

As described above, the downlink resources for initial transmission, RLC Uplink resources for transmission of status messages and downlink resources for retransmission may be semi-statically allocated. Accordingly, when the JT method or the JR method is used, contents (eg, contents in TSUs) can be easily synchronized.

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

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 through the DRB, a C-RNTI (eg, C-RNTI B) for initial transmission of the uplink signal may be set, and a response to the uplink signal A C-RNTI (eg, C-RNTI D) for a message (eg, an RLC status message) may be set, and a C-RNTI (eg, C-RNTI E for retransmission of an uplink signal) ) can be set. That is, in the uplink communication procedure, one C-RNTI used for the initial transmission of the uplink signal can be basically set, and additionally two C-RNTI used for the RLC status message and the retransmission procedure of the uplink signal. RNTIs may be configured. Accordingly, three C-RNTIs may be configured for DRB to which RLC AM is applied. Alternatively, one C-RNTI may be configured for an uplink communication procedure (eg, RB of RLC AM), and resources for initial transmission of an uplink signal based on one C-RNTI, RLC status message Resources for and resources for retransmission of uplink signals may be configured.

In step S3001, the vehicle 200 may transmit a TB including an uplink signal using a resource (eg, SF#0) scheduled by the C-RNTI B of the DRB. In step S3002, the communication system 100 may receive a TB in SF#0, and may identify an RLC PDU based on the received TB. The communication system 100 may generate an RLC status message (eg, an ACK message or a NACK message) based on the reception status of the RLC PDU. If 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 by using a resource (eg, SF#3) scheduled by C-RNTI D of the DRB. Here, the C-RNTI D may be signaled from the communication system 100 to the vehicle 200 through the control region of the downlink subframe.

In step S3004, the vehicle 200 may receive an RLC status message from SF#3. When the RLC status message indicates NACK, the vehicle 200 may check an RLC PDU corresponding to the NACK among RLC PDUs located in the retransmission buffer and perform a retransmission procedure for the checked RLC PDU. For example, in step S3005, the vehicle 200 may perform a retransmission procedure using a resource (eg, SF#5) scheduled by C-RNTI E of the DRB. In step S3006, the communication system 100 may receive the retransmitted RLC PDU through SF#5.

■ Synchronization method between communication nodes in a communication system

Meanwhile, a synchronization procedure 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 must be established for communication between the communication system 100 and the vehicle 200, and communication nodes 110 , 120, 130, 140) may be as follows.

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

Referring to FIG. 31 , when downlink communication is performed, the transmission order of packets may be “CCU→TSU→VA2C→LA2M”. In user plane (UP)-A (eg, A1-UP, A2-UP, A4-UP, A5-UP, A7-UP, and A8-UP of FIG. 14), the MAC layer is located in the TSU 120 The synchronization layer (eg, synchronization protocol) may be located in the CCU 110 and the TSU 120. In this case, the CCU 110 may transmit packets (eg, scheduled data) to the plurality of TSUs 120 based on the IP multicast method.

In UP-B (eg, A3-UP, A6-UP, and A9-UP of FIG. 14), the MAC layer may be located in the LA2M 140, and the synchronization layer (eg, synchronization protocol) is the 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 performs a relay function between the synchronization layer of the CCU 110 and the synchronization layer of the LA2M 140. can be done Also, similar to the transmission method in UP-A, the CCU 110 may transmit packets (eg, scheduled data) to the plurality of TSUs 120 based on the IP multicast method.

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

Referring to FIG. 32, when uplink communication is performed, the transmission order of packets may be “LA2M→VA2C→TSU→CCU”. In UP-A (eg, A1-UP, A2-UP, A4-UP, A5-UP, A7-UP, and A8-UP of FIG. 14), the MAC layer may be located in the TSU 120, and Layers (eg, synchronization protocols) may be located in CCU 110 and TSU 120 . VA2C (130) may receive a packet from the LA2M (140) in the JR scheme, the packet may be transmitted to the CCU (110).

In UP-B (eg, A3-UP, A6-UP, and A9-UP of FIG. 14), the MAC layer may be located in the LA2M 140, and the synchronization layer (eg, synchronization protocol) is the 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 performs a relay function between the synchronization layer of the CCU 110 and the synchronization layer of the LA2M 140. can be done Here, the CCU 110 may select an optimal packet from packets received from the plurality of TSUs 120 .

Meanwhile, a delay probe procedure for synchronization between communication nodes in UP-A may be performed as follows.

33 is a block diagram showing a second embodiment of a communication system, FIG. 34 is a block diagram showing a first embodiment of a probe request/response packet used in a delay probe procedure, and FIG. 35 is a block diagram showing a delay probe procedure It is a block diagram showing the second embodiment of the probe request/response packet used.

Referring to FIGS. 33 to 35 , 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 at communication node #B. The delay probe procedure can be used by communication node #A to evaluate packet delay at communication node #B. In addition, the delay probe procedure may be used to predict an appropriate scheduling time point by performing content synchronization based on communication node #B having the largest delay.

The communication node #A may generate probe request packets (eg, probe request packet #A and probe request packet #B) and transmit the generated probe request packets to n number of communication nodes #Bs. Each of n, m and l may be a positive integer. Communication node #B may receive a probe request packet from communication node #A, and may generate probe response packets (eg, probe response packet #A, probe response packet #B) as a response to the probe request packet. and may transmit the generated probe response packet to the communication node #A. For example, communication node #B may transmit probe response packet #A to communication node #A in response to probe request packet #A, and probe response packet #B in response to probe request packet #B. You can send to #A. The communication node #A may receive probe response packets from the communication nodes #Bs, and may check a delay at the communication node #B based on an absolute time (AT) included in the probe response packets.

Here, the probe request packet #A may include a sync packet type field, a unique ID field, a destination number field, a destination address field, an AT number field, and an AT#1 field. The sync packet type field may indicate the probe request packet type (eg, probe request packet #A or probe request packet #B). In the probe request packet #A, the sync packet type field may be set to '1'. The unique ID field is set to a unique ID based on vehicle ID and RB ID (eg, RB ID for initial transmission, RB ID for transmitting RLC status message, RB ID for retransmission), sequence ID for each communication node, etc. It can be. The number of destinations field may indicate the depth of the final destination of the probe request packet (eg, the number of hops between the communication node that generated the probe request packet and the communication node that is the final destination of the probe request packet). there is. In FIG. 33, since the final destination of the probe request packet #A is the communication node #B, the number of destinations field may be set to “1”. The destination address field may indicate a destination address (eg, IP address) of the probe request packet #A. The AT number field may indicate the number of AT fields included in probe request packet #A. In the probe request packet #A, the AT number field may be set to '1'. The AT#1 field may indicate an AT at the transmission time of probe request packet #A.

Probe request packet #B may be used to improve the accuracy of delay measurement compared to probe request packet #A. Probe Request Packet#B contains the Sync Packet Type field, Unique ID field, Destination Count field, Destination Address field, AT Count field, AT#1 field, PDU Count field, PDU#1 Size field, PDU#2 Size field, PDU# 1 (eg, dummy packet #1) and PDU#2 (eg, dummy packet #2). The Sync Packet Type field, Unique ID field, Destination Count field, Destination Address field, AT Count field, and AT#1 field of Probe Request Packet #B are respectively the Sync Packet Type field, Unique ID field, Destination Count of Probe Request Packet #A. field, the destination address field, the AT number field, and the AT#1 field may be set identically or similarly. Here, the sync packet type field of the probe request packet #B may be set to "31". The number of PDUs field may indicate the number of PDUs (eg, dummy packets) included in probe request packet #B. When two PDUs are included in probe request packet #B, the number of PDUs field may be set to “2”. The number of PDUs included in 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.

Probe response packet #A may be used as a response to probe request packet #A. The probe response packet #A may include a sync packet type field, a unique ID field, an AT number field, an AT#2 field, and an AT#3 field. The sync packet type field may indicate probe response packet types (eg, probe response packet #A or probe response packet #B). In the probe response packet #A, the sync packet type field may be set to "51". The unique ID field may be set to a unique ID indicated by the unique ID field of probe request packet #A. The AT number field may indicate the number of AT fields included in probe response packet #A. In the probe response packet #A, the AT number field may be set to "2". The AT#2 field may indicate an AT from which communication node #B has received probe request packet #A, and the AT#3 field may indicate an AT to which communication node #B has transmitted probe response packet #A.

Probe response packet #B may be used as a response to probe request packet #B. Probe response packet #B may include a sync packet type field, a unique ID field, an AT number field, an AT#2 field, and an AT#3 field. The Sync Packet Type field, Unique ID field, AT Count field, AT#2 field, and AT#3 fields of probe response packet #B, respectively, are the Sync Packet Type field, Unique ID field, AT Count field, AT It may be set the same as or similar to the #2 field and the AT#3 field. Here, the sync packet type field of probe response packet #B may be set to "531".

Meanwhile, the communication node #A may receive a probe response packet from each of the communication nodes #Bs (eg, communication nodes #B-1 to #B-n), based on the AT included in the probe response packet. You can check the delay at each of the #Bs. The communication node #A may perform scheduling based on the communication node #B having the largest delay for contents synchronization in the communication nodes #Bs. That is, communication node #A may perform scheduling so that communication nodes #Bs can perform downlink transmission (or uplink transmission) in the same TTI.

Meanwhile, a delay probe procedure for synchronization between communication nodes in UP-B may be performed as follows.

36 is a block diagram showing a third embodiment of a communication system, and FIG. 37 is a block diagram showing a third embodiment of a probe request/response packet used in a delayed probe procedure.

Referring to FIGS. 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 at communication node #C. The delay probe procedure can be used by communication node #A to evaluate packet delay at communication node #C. In addition, the delay probe procedure may be used to predict an appropriate scheduling time by performing content synchronization based on the communication node #C having the largest delay.

The communication node #A may generate a probe request packet #C and transmit the generated probe request packet #C to n communication nodes #Bs. Each of n, m and l may be a positive integer. Each of the communication nodes #Bs may receive probe request packet #C from communication node #A, generate probe request packet #D based on probe request packet #C, and transmit probe request packet #D to communication node #B. #Cs can be sent. Each of the communication nodes #C may receive probe request packet #D from communication node #B, generate a probe response packet #D as a response to the probe request packet #D, and generate probe response packet #D. can be transmitted to the communication node #B. Each of the communication nodes #Bs may receive probe response packet #D from communication node #C, generate probe response packet #C based on probe response packet #D, and transmit probe response packet #C to communication node #C. You can send to #A. Communication node #A may receive probe response packets #Cs from communication nodes #Bs, and may check delays at communication nodes #Cs based on ATs included in probe response packets #Cs.

Here, the probe request packet #C may include a sync packet type field, a unique ID field, a destination number field, a destination address #1 field, a destination address #2 field, an AT number field, and an AT#1 field. The sync packet type field may indicate the probe request packet type and may be set to "2". The unique ID field is set to a unique ID based on vehicle ID and RB ID (eg, RB ID for initial transmission, RB ID for transmitting RLC status message, RB ID for retransmission), sequence ID for each communication node, etc. It can be. The number of destinations field may indicate the depth of the final destination of the probe request packet #C. Since the final destination of the probe request packet #C is the communication node #C, the number of destinations field may be set to "2". The destination address #1 field may indicate the address of communication node #B, which is the first destination of probe request packet #C, and the destination address #2 field may indicate the address of communication node #C, which is the second destination of probe request packet #C. can be instructed. The AT number field may indicate the number of AT fields included in probe request packet #C and may be set to "1". The AT#1 field may indicate an AT at the transmission time of probe request packet #C. Also, probe request packet #C may include at least one PDU similarly to probe request packet #B of FIG. 35 to improve delay measurement accuracy.

The probe request packet #D may include a sync packet type field, a unique ID field, a destination number field, a destination address #2 field, an AT number field, and an AT#2 field. The sync packet type field may indicate the type of probe request packet and may be set to "1". The unique ID field of probe request packet #D may be set to a unique ID indicated by the unique ID field of probe request packet #C. The number of destinations field may indicate the depth of the final destination of the probe request packet #D and may be set to "1". The destination address #2 field may indicate the address of communication node #C. The AT number field may indicate the number of AT fields included in probe request packet #D and may be set to "1". The AT#2 field may indicate an AT at the transmission time of probe request packet #D. Also, probe request packet #D may include at least one PDU similarly to probe request packet #B of FIG. 35 to improve accuracy of delay measurement.

The probe response packet #D may include a sync packet type field, a unique ID field, an AT number field, an AT#3 field, and an AT#4 field. The sync packet type field may indicate the probe response packet type and may be set to "51". The unique ID field of probe response packet #D may be set to a unique ID indicated by the unique ID field of probe request packet #D. The AT number field may indicate the number of AT fields included in probe response packet #D and may be set to "2". The AT#3 field may indicate the AT at the time of receiving the probe request packet #D, and the AT#4 field may indicate the AT at the time of transmission of the probe response packet #D.

The probe response packet #C may include a sync packet type field, a unique ID field, an AT number 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 probe response packet type and may be set to "52". The unique ID field of probe response packet #C may be set to a unique ID indicated by the unique ID field of probe response packet #D. The AT number field may indicate the number of AT fields included in probe response packet #C and may be set to "4". The AT#2 field may indicate the AT at the time of transmission of the probe request packet #D, the AT#3 field may be set to the AT indicated by the AT#2 field of the probe response packet #D, and the AT#4 field field may be set to the AT indicated by the AT#3 field of the probe response packet #D, and the AT#5 field may indicate the AT at the transmission time of the probe response packet #C.

Meanwhile, the communication node #A may receive the probe response packet #C from each of the communication nodes #Bs (eg, communication nodes #B-1 to #B-n), and transmit the probe response packet #C to the AT included in the probe response packet #C. Based on this, it is possible to check the delay at each of the communication nodes #C. The communication node #A may perform scheduling based on the communication node #C having the largest delay for content synchronization in the communication nodes #Cs. That is, communication node #A may perform scheduling so that communication nodes #Cs can perform downlink transmission (or uplink transmission) in the same TTI.

Meanwhile, the delay probe procedure described with reference to FIGS. 33 to 35 can be applied when the depth (eg, the number of hops) between the communication node #A and the communication node where the MAC layer is located is 1, and FIG. 36 and The delay probe procedure described with reference to FIG. 37 can be applied when the depth (eg, the number of hops) between communication node #A and the communication node where the MAC layer is located is 2. A delay probe procedure applied when the depth (eg, number of hops) between communication node #A and the communication node where the MAC layer is located is 3 may be performed as follows.

38 is a block diagram showing a fourth embodiment of a communication system, FIG. 39 is a block diagram showing a fourth embodiment of a probe request packet used in a delay probe procedure, and FIG. 40 is a block diagram showing a probe request packet used in a delay probe procedure. It is a block diagram showing a fourth embodiment of a probe response packet.

38 to 40, the communication node #A may be the CCU 110, and the MAC layer may be located in the communication node #D. The delay probe procedure can be used by communication node #A to evaluate packet delay at communication node #D. In addition, the delay probe procedure may be used to predict an appropriate scheduling time by performing content synchronization based on the communication node #D having the largest delay.

The communication node #A may generate a probe request packet #E and transmit the generated probe request packet #E to n communication nodes #Bs. Each of n, m, l, o, p, q and r may be a positive integer. Each of the communication nodes #Bs may receive probe request packet #E from communication node #A, generate probe request packet #F based on probe request packet #E, and transmit probe request packet #F to communication node #B. #Cs can be sent. Each of the communication nodes #C may receive probe request packet #F from communication node #B, generate probe request packet #G based on probe request packet #F, and send probe request packet #G to communication node #C. It can be sent to #Ds. Each of the communication nodes #Ds may receive a probe request packet #G from the communication node #C, generate a probe response packet #G as a response to the probe request packet #G, and communicate the probe response packet #G. You can transmit to Node#C. Each of communication nodes #C may receive probe response packet #G from communication node #D, generate probe response packet #F based on probe response packet #G, and transmit probe response packet #F to communication node #C. #B can be sent. Each of the communication nodes #Bs may receive probe response packet #F from communication node #C, generate probe response packet #E based on probe response packet #F, and transmit probe response packet #E to communication node #B. You can send to #A. Communication node #A may receive probe response packets #Es from communication nodes #Bs, and may check delays at communication nodes #Ds based on ATs included in probe response packets #Es.

Here, probe request packet #E may include a sync packet type field, a unique ID field, a destination number field, a destination address #1 field, a destination address #2 field, a destination address #3 field, an AT number field, and an AT#1 field. can The sync packet type field may indicate the probe request packet type and may be set to "3". The unique ID field is set to a unique ID based on vehicle ID and RB ID (eg, RB ID for initial transmission, RB ID for transmitting RLC status message, RB ID for retransmission), sequence ID for each communication node, etc. It can be. The number of destinations field may indicate the depth of the final destination of the probe request packet #E. Since the final destination of probe request packet #E is communication node #D, the number of destinations field may be set to "3". The destination address #1 field may indicate the address of communication node #B, which is the first destination of probe request packet #E, and the destination address #2 field may indicate the address of communication node #C, which is the second destination of probe request packet #E. , and the destination address #3 field may indicate the address of communication node #D, which is the third destination of the probe request packet #E. The AT number field may indicate the number of AT fields included in probe request packet #E and may be set to "1". The AT#1 field may indicate an AT at the transmission time of probe request packet #E. In addition, probe request packet #E may include at least one PDU similarly to probe request packet #B of FIG. 35 to improve delay measurement accuracy.

The probe request packet #F may include a sync packet type field, a unique ID field, a destination number field, a destination address #2 field, a destination address #3 field, an AT number field, and an AT#2 field. The sync packet type field may indicate the probe request packet type and may be set to "2". The unique ID field of probe request packet #F may be set to a unique ID indicated by the unique ID field of probe request packet #E. The number of destinations field may indicate the depth of the final destination 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 number field may indicate the number of AT fields included in probe request packet #F and may be set to "1". The AT#2 field may indicate an AT at the transmission time of probe request packet #F. Also, probe request packet #F may include at least one PDU similarly to probe request packet #B of FIG. 35 to improve delay measurement accuracy.

The probe request packet #G may include a sync packet type field, a unique ID field, a destination number field, a destination address #3 field, an AT number field, and an AT#3 field. The sync packet type field may indicate the type of probe request packet and may be set to "1". The unique ID field of probe request packet #G may be set to a unique ID indicated by the unique ID field of probe request packet #F. The number of destinations field may indicate the depth of the final destination of the probe request packet #G and may be set to "1". The destination address #3 field may indicate the address of communication node #D. The AT number 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 at the transmission time of probe request packet #G. Also, probe request packet #G may include at least one PDU similarly to probe request packet #B of FIG. 35 to improve delay measurement accuracy.

The probe response packet #G may include a sync packet type field, a unique ID field, an AT number field, an AT#4 field, and an AT#5 field. The sync packet type field may indicate the probe response packet type and may be set to "51". The unique ID field of the probe response packet #G may be set to a unique ID indicated by the unique ID field of the probe request packet #G. The AT number field may indicate the number of AT fields included in probe response packet #G and may be set to "2". The AT#4 field may indicate the AT at the time of receiving the probe request packet #G, and the AT#5 field may indicate the AT at the time of transmission of the probe response packet #G.

The probe response packet #F may include a sync packet type field, a unique ID field, an AT number 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 probe response packet type and may be set to "52". The unique ID field of probe response packet #F may be set to a unique ID indicated by the unique ID field of probe response packet #G. The AT number field may indicate the number of AT fields included in probe response packet #F and may be set to "4". The AT#3 field may be set to the AT indicated by the AT#3 field of the probe request packet #G, and the AT#4 field may be set to the AT indicated by the AT#4 field of the probe response packet #G. , the AT#5 field can be set to the AT indicated by the AT#5 field of the probe response packet #G, and the AT#6 field can indicate the AT at the transmission time of the probe response packet #F.

Probe Reply Packet#E will contain the Sync Packet Type field, Unique ID field, AT Count field, AT#2 field, AT#3 field, AT#4 field, AT#5 field, AT#6 field, and AT#7 field. can The sync packet type field may indicate the probe response packet type and may be set to "53". The unique ID field of probe response packet #E may be set to a unique ID indicated by the unique ID field of probe response packet #F. The AT number field may indicate the number of AT fields included in probe response packet #E and may be set to "6". The AT#2 field may be set to the AT indicated by the AT#2 field of the probe request packet #F, and the AT#3 field may be set to the AT indicated by the AT#3 field of the probe response packet #F. there is. The AT#4 field may be set to the AT indicated by the AT#4 field of probe response packet #F, and the AT#5 field may be set to the AT indicated by the AT#5 field of probe response packet #F. , the AT#6 field may be set to the AT indicated by the AT#6 field of the probe response packet #F, and the AT#7 field may indicate the AT at the transmission time of the probe response packet #E.

Meanwhile, the communication node #A may receive the probe response packet #E from each of the communication nodes #Bs (eg, communication nodes #B-1 to #B-n), and transmit the probe response packet #E to the AT included in the probe response packet #E. Based on this, it is possible to check the delay at each of the communication nodes #Ds. Communication node #A may perform scheduling based on communication node #D having the largest delay for synchronization of contents in communication nodes #D. That is, communication node #A can perform scheduling so that communication nodes #D can perform downlink transmission (or uplink transmission) in the same TTI.

Meanwhile, a downlink communication procedure between the communication system 100 and the vehicle 200 may be performed as follows.

41 is a block diagram showing a communication system according to a fifth embodiment, FIG. 42 is a block diagram showing a communication system according to a sixth embodiment, and FIG. 43 is a block diagram showing a downlink packet according to the first embodiment. am.

41 to 43, the communication node #A may be the CCU 110 of the communication system 100, the communication node #B may be the TSU 120 of the communication system 100, and the communication node # C may be LA2M 140 of 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 UP-B, the MAC layer may be located at communication node #C, and the synchronization layer may be located at communication nodes #A to #C. The synchronization layer of communication node #A may support a master MAC function. The communication node #A supporting the master MAC function can set one sliding window for one vehicle 200, control/manage the sliding window according to the movement of the vehicle 200, and follow the RRC signaling procedure. The number of SDUs included in a transport block (TB) may be determined based on the semi-static resource allocation information for each vehicle 200 determined by the method. To determine the number of SDUs, protocol processing procedures of subordinate communication nodes (eg, communication node #B and communication node #C) may be considered. For example, a synchronization layer located at communication node #A may perform a scheduling operation so that packets are located in a TB allocated to one TTI in consideration of a protocol processing procedure between the communication node where the MAC layer is located and communication node #A. .

In UP-A, downlink packets can be transmitted from communication node #A to communication node #B. In UP-B, downlink packets can 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 sync packet type field, an AT field, a unique ID field, a predicted system frame number (SFN)/subframe (SF) field, a SDU number field, a SDU#1 size field, a SDU#2 size field, and a SDU#3 field. Size field, SDU#1, SDU#2 and SDU#3.

The sync packet type field may indicate a packet type and may be set to "100". The AT field may indicate an AT at a transmission time of a downlink packet. The unique ID field may indicate a unique ID based on a vehicle ID and an RB ID (eg, an RB ID for initial transmission, an RB ID for transmission of an RLC status message, and an RB ID for retransmission). The predicted SFN/SF field may indicate scheduling information (eg, SFN, SF index) of SDUs included in a downlink packet. The SFN and SF indexes indicated by the predicted SFN/SF field may be calculated based on semi-static scheduling information and a delay measured by a delay probe procedure.

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

Meanwhile, an uplink communication procedure between the communication system 100 and the vehicle 200 may be performed as follows.

44 is a block diagram showing a communication system according to a seventh embodiment, FIG. 45 is a block diagram showing a communication system according to an eighth embodiment, and FIG. 46 is a block diagram showing a first embodiment of an uplink packet. am.

44 to 46, the communication node #A may be the CCU 110 of the communication system 100, the communication node #B may be the TSU 120 of the communication system 100, and the communication node # C may be LA2M 140 of 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 UP-B, the MAC layer may be located at communication node #C, and the synchronization layer may be located at communication nodes #A to #C. Communication node #B or communication node #C including the MAC layer may transmit an uplink packet including SDUs for which protocol processing for the TB received in one TTI is completed to an upper communication node.

From an uplink point of view, 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 from among a 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 the received uplink packet within the uplink delay window set in the SFN/SF indicated by the received SFN/SF field in consideration of the uplink delay measured by the delay probe procedure. and may not process an uplink packet received outside the uplink delay window.

In UP-A, an uplink packet may be transmitted from communication node #B to communication node #A. In UP-B, uplink packets can be transmitted 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. Uplink packet includes Sync Packet Type field, AT field, Unique ID field, Signal Strength field, Received SFN/SF field, SDU Count field, SDU#1 Size field, SDU#2 Size field, SDU#3 Size field, SDU #1, SDU#2 and SDU#3.

The sync packet type field may indicate a packet type and may be set to "200". The AT field may indicate an AT at a transmission time of an uplink packet. For example, in UP-A, the AT field can indicate AT when communication node #B transmits an uplink packet, and in UP-B, the AT field indicates when communication node #C transmits an uplink packet. AT can be indicated in . The unique ID field may indicate a unique ID based on a vehicle ID and an RB ID (eg, an RB ID for initial transmission, an RB ID for transmission of an RLC status message, and an RB ID for retransmission). The signal strength field is the received signal strength for the TB received in the corresponding TTI, the maximum received signal strength among the received signal strengths of each of the plurality of signals when the JR method is used, or the plurality of signals when the JR method is used. Average received signal strength may be indicated.

The received SFN/SF field may indicate the SFN and SF index received by the corresponding TB in terms of the MAC layer. The SDU number field may indicate the number of SDUs (eg, the number of SDUs included in an uplink packet) scheduled in a TB within one TTI. The number of SDU size fields included in the uplink packet may be the same as the value indicated by the SDU number 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 size of SDU#3 The field may indicate the length of SDU#3 included in the uplink packet.

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

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

Referring to FIG. 47 , the LA2M 140 of the communication system 100 may be installed on the ceiling of the tube, and a sliding window including a plurality of antennas may be set. Downlink communication between the communication system 100 and the vehicle 200 can be performed based on a plurality of antennas belonging to the sliding window, and the plurality of antennas belonging to the sliding window transmit the same signal through the same time-frequency resource. can That is, downlink communication may be performed based on the JT scheme.

The vehicle 200 may receive a downlink signal from a plurality of antennas belonging to a sliding window, and a reception period (eg, a reception window) of the downlink signal may be a good window or a dead window according to the received signal strength. It can be classified into (dead) window and interference (interference) window. A zone including a good window, a dead window, and an interference window may be referred to as a downlink capsule radio zone (CRZ). For example, a reception period in which the received signal strength of a downlink signal is greater than or equal to a threshold value may be referred to as a good window. A reception period in which communication is impossible due to multi-path fading, delay spreading, or the like may be referred to as a dead window. A reception interval acting as interference to vehicles following the vehicle 200 may be referred to as an interference window. In the interference window, the received signal strength may increase and then decrease. When the following vehicle is located within the interference window, signals within the interference window may interfere with the communication of the following vehicle. Accordingly, the distance between the vehicle 200 and the following vehicle may be set based on the interference window.

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

48 is a conceptual diagram illustrating received signal strength in uplink communication according to a first embodiment, and FIG. 49 is a conceptual diagram illustrating received signal strength in uplink communication according to a second embodiment.

48 and 49, the LA2M 140 of the communication system 100 may be installed on the ceiling of the tube, and a sliding window including a plurality of antennas may be set. Uplink communication between the communication system 100 and the vehicle 200 may be performed based on a plurality of antennas belonging to the sliding window. An uplink signal transmitted by the vehicle 200 may be received by a plurality of antennas belonging to a sliding window.

In the good window, CRC for uplink signals received from a plurality of antennas belonging to the sliding window may be successfully completed, and the received signal strength of the uplink signal may be greater than or equal to a threshold value. A reception period in which communication is impossible due to multi-path fading, delay spreading, etc. may be referred to as a dead window. A reception interval acting as interference to vehicles following the vehicle 200 may be referred to as an interference window. In the interference window, the received signal strength may increase and then decrease. A zone including a good window, a dead window, and an 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 .

Meanwhile, a system structure for communication between the communication system 100 and the vehicle 200 may be as follows.

50 is a conceptual diagram showing a first embodiment of a system structure for communication between a communication system and a vehicle.

Referring to FIG. 50 , the communication system 100 may include a CCU 110 , a TSU 120 , a VA2C 130 and an LA2M 140 . The CCU 110 may be connected to a capsule control network (CCN) and a passenger service network (PSN) (eg, an evolved packet core (EPC)), and may be connected to the 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 a plurality of antennas. The LA2M (140) may be installed in a row on the ceiling of the tube, and may be connected to the VA2C (130) located outside the tube. In this case, the CCU 110, TSU 120, and VA2C 130 may be located outside the tube. Alternatively, the VA2C 130 and LA2M 140 may be located inside the tube, and the CCU 110 and TSU 120 may be located outside the tube. Alternatively, the TSU 120, VA2C 130, and LA2M 140 may be positioned within the tube, and the CCU 110 may be positioned outside the tube.

The vehicles 200-1 and 200-2 may include an antenna, capsule equipment (CE), and the like, and the CE may be connected to a CCN and a PSN (eg, EPC). The vehicles 200-1 and 200-2 can move within the tube and can perform downlink/uplink communication with a plurality of antennas belonging to the sliding window. The moving speed of sliding window #1 may be the same as that of vehicle #1 (120-1), and the moving speed of sliding window #2 may be the same as that of vehicle #2 (120-2). Communication between the vehicles 200-1 and 200-2 may be performed within a good window. The interference window of vehicle #1 (120-1) may be set not to overlap with the good window of vehicle #2 (120-2).

The CCN connected to the CCU 110 may be connected to the CCN inside the vehicles 200-1 and 200-2, and control of the vehicles 200-1 and 200-2 may be performed through the CCN. The PSN connected to the CCU 110 may be connected to the PSN inside the vehicles 200-1 and 200-2, and communication for the occupants of the vehicles 200-1 and 200-2 is performed through the PSN (for example, the vehicle ( 200-1, 200-2) can be supported through a small base station or access point) installed. Here, the small base station may support a 4G communication protocol, a 5G communication protocol, and the like, and the access point may support a wireless local area network (WLAN) communication protocol.

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

51 is a graph showing a first embodiment of a driving profile of a vehicle.

Referring to FIG. 51 , the distance between stations A and B may be 413 km, and vehicles 200-1 and 200-2 may perform acceleration operation, constant speed operation, and deceleration operation to move from station A to station B within 25 minutes. can For example, the vehicles 200-1 and 200-2 may operate at a maximum speed of 1200 km/h by repeating acceleration operation and constant speed operation, and may reduce speed by repeating deceleration operation and constant speed operation.

Meanwhile, when a plurality of vehicles are operated between stations A and B, the CRZ of each of the vehicles may be as follows.

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

Referring to FIG. 52 , a plurality of vehicles 200-1 to 200-8 can move within the tube and move from station A to station B. A CRZ for each of the plurality of vehicles 200-1 to 200-8 may be set. A CRZ may include a good window, a dead window, and an interference window. CRZ#3, CRZ#4, CRZ#5 and CRZ#6 may not overlap each other. Therefore, communication services can be provided to the corresponding vehicles 200-3, 200-4, 200-5, and 200-6 using the entire frequency band within CRZ#3, CRZ#4, CRZ#5, and CRZ#6. . That is, a communication service can be provided using the same time-frequency resource in a non-overlapping CRZ.

However, CRZs may overlap according to service schedules at the departure point (eg, station A) and the arrival point (eg, station B). For example, CRZ#1 of vehicle #1 (200-1) at station A may overlap CRZ#2 of vehicle #2 (200-2), and CRZ#2 of vehicle #7 (200-7) at station B. CRZ#7 may overlap CRZ#8 of vehicle #8 (200-8). When a communication service is provided to corresponding vehicles 200-1, 200-2, 200-7, and 200-8 using the entire frequency band within the overlapping CRZ, interference may occur. Accordingly, time-frequency resources within overlapping CRZs may be configured as follows.

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

Referring to FIG. 53, when CRZ#1 of vehicle #1 (200-1) overlaps CRZ#2 of vehicle #2 (200-2), time-frequency resources are based on a time division duplex (TDD) scheme. can be set. For example, all frequency resources may be set for CRZ#1 and #2, and time resources may be set for CRZ#1 and #2 to be orthogonal. Time-frequency resources may be set so that interference does not occur between overlapping CRZs. In this case, vehicle #1 (120-1) belonging to CRZ#1 can perform communication using TTI#1, and vehicle #2 (120-1) belonging to CRZ#2 uses TTI#2. communication can be performed.

54 is a conceptual diagram illustrating a second embodiment of a method for allocating time-frequency resources in overlapping CRZs.

Referring to FIG. 54, when CRZ#1 of vehicle #1 (200-1) overlaps CRZ#2 of vehicle #2 (200-2), time-frequency resources based on frequency division duplex (FDD) scheme can be set. For example, total time resources may be set for CRZ#1 and #2, and frequency resources may be set for CRZ#1 and #2 to be orthogonal. Time-frequency resources may be set so that interference does not occur between overlapping CRZs. In this case, vehicle #1 (200-1) belonging to CRZ#1 can perform communication using frequency band #1, and vehicle #2 (200-1) belonging to CRZ#2 uses frequency band #2. You can use it to communicate.

Meanwhile, an RB may be set for communication between the communication system 100 and the vehicle 200, and in the system of FIG. 50, an RB between the communication system 100 and the vehicle 200 may be set as follows.

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

Referring to FIG. 55, a plurality of RBs (eg, SRB#1, DRB#1, DRB#2, DRB#3, DRB#4, DRB#5) between the communication system 100 and the vehicle 200 can be set. SRB#1 may be used for transmission of control information including semi-static scheduling information and the like. Since control information must be transmitted and received without packet loss, SRB#1 transmission can be performed based on RLC AM. DRBs #1 and #2 connected to the CCN may be used to transmit driving information of the vehicle 200, and DRBs #3 to #5 connected to the PSN may be used to transmit user data (eg, for passengers of the vehicle 200). data) can be used.

The priority of packet processing for each 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” there is. Priorities (ie, priorities #1, #2, and #3) within the DRB may be determined according to packet types (eg, control information, data) and importance. If packet loss is not tolerated, communication may be performed based on RLC AM. When packet loss is acceptable, communication may be performed based on RLC TM (transport mode) or RLC UM (unacknowledged mode).

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

That is, RBs to which RLC AM is applied may be classified into three RBs, and C-RNTIs for each of the three RBs may be independently set. C-RNTI for RB for initial transmission may be set by default, and additionally, C-RNTI for RLC status message transmission and C-RNTI for retransmission may be set. Since the C-RNTI is independently set for each RB, synchronization of contents can be facilitated when communication based on the JT method or the JR method is performed. Alternatively, one C-RNTI may be configured for an RB to which RLC AM is applied, and three resources (eg, resources for initial transmission, resources for transmitting RLC status messages) based on one C-RNTI , resources for retransmission) may be allocated.

■ How to measure vehicle position

Meanwhile, the communication system 100 may set a sliding window corresponding to the position of the vehicle 200, and the position of the vehicle 200 should be known in order to set the sliding window. Methods for measuring the position of the vehicle 200 may be performed as follows.

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

Referring to FIGS. 56 and 57 , unique identification numbers may be assigned to a plurality of antennas belonging to the LA2M 140 of the communication system 100 . For example, unique identification numbers 100200001 to 100200033 may be sequentially assigned to a plurality of antennas. The unique identification number may be mapped with the location of the antenna to which the unique identification number is assigned, and the location of the vehicle 200 may be measured based on the unique identification number. The antenna may transmit a signal including its own identification number. The unique identification number may be transmitted through a pre-allocated time-frequency resource. For example, a time-frequency resource for transmission of a unique identification number may be set every two TTIs, and a time-frequency resource for a unique identification number within one TTI may be sequentially set. The number of unique identification numbers transmitted within one TTI may be greater than or equal to the number of antennas belonging to a good window. Frequency resources for unique identification numbers 100200001 to 100200011 in interval #1 can be allocated orthogonally, frequency resources for unique identification numbers 100200012 to 100200022 in interval #2 can be allocated orthogonally, and unique recognition in interval #3 Frequency resources for numbers 100200023 to 100200033 may be allocated orthogonally.

Meanwhile, the vehicle 200 may receive signals from a plurality of antennas of the communication system 100 and check 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.

58 is a conceptual diagram illustrating unique identification numbers identified in a vehicle, and FIG. 59 is a graph illustrating received signal strength of signals including unique identification numbers.

58 and 59, the vehicle 200 may receive signals from a plurality of antennas belonging to the LA2M 140, and identify unique identification numbers by decoding the signals, and identify the identified unique identification numbers. At least one unique identification number to be used for location measurement may be selected from among the number of locations. For example, the vehicle 200 may perform CRC on signals including unique identification numbers 100200001 to 100200033, and identify the unique identification numbers (eg, 100200003 to 100200018) for which the CRC is successfully completed. . The vehicle 200 may select a unique identification number (eg, 100200004 to 100200016) having a reception signal strength equal to or greater than a threshold value from among the identified identification numbers 100200003 to 100200018. Among the selected unique identification numbers 100200004 to 100200016, since the received signal strength of the signal including the unique identification number 100200014 is the greatest, the position of the antenna transmitting the signal including the unique identification number 100200014 can be estimated as the position of the vehicle 200. there is.

However, since the location of the vehicle 200 is estimated based on the antenna of the vehicle 200, correction of the estimated location is required when the measurement standard of the location is not the antenna but another entity. The position correction method of the vehicle 200 may be performed as follows.

60 is a flowchart showing a first embodiment of a vehicle position correction method.

Referring to FIG. 60 , the position of the vehicle 200 may be corrected based on a driving mode (eg, acceleration mode, constant speed mode, deceleration mode) of the vehicle 200 . In FIG. 51 , the acceleration modes of the vehicle 200 can be classified into acceleration modes A, B, and C, the constant speed modes of the vehicle 200 can be classified into constant speed modes A, B, C, D, and E, and the vehicle The deceleration modes of 200 can be classified as A, B and C. An absolute position (AP) of the vehicle 200 may be calculated based on Equation 1 below.

That is, the AP of the vehicle 200 may be the sum of a detective absolute position (DAP) and a calibration position (CP). The DAP may be a location corresponding to an antenna transmitting a signal including a unique identification number 100200014 in FIGS. 58 and 59 . CP may be calculated based on Equation 2 below.

A physical calibration position (PCP) may be a physical calibration value for a position measurement standard of the vehicle 200 . A scheduling calibration position (SCP) may be a value for correcting propagation delay characteristics of a signal including a unique identification number. A mode calibration position (MCP) may be a correction value for each driving mode based on the driving history of the vehicle 200 . For example, when the driving mode of the vehicle 200 is acceleration mode C, MCP C or MCP D may be applied. MCP C or MCP D may be a fixed value, and the position of the vehicle 200 may be corrected based on a variable value that increases in proportion to speed in acceleration mode C. Meanwhile, the vehicle 200 may operate in an exception mode (eg, a driving mode of the vehicle 200 in an emergency situation), and MCP O applied to the exception mode may be defined. MCP O may not be a constant value, but a variable value affected by a specific factor.

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

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

Referring to FIG. 61 , a unique identification number may be assigned to the vehicle 200, and the vehicle 200 may transmit a signal including the unique identification number. The unique identification number of the vehicle 200 may be set to 900900001. The unique identification number may be transmitted through a pre-allocated time-frequency resource. For example, time-frequency resources for transmission of a unique identification number may be set every two TTIs, and time-frequency resources for a unique identification number may be sequentially set within one TTI. The unique identification number of the vehicle 200 may be repeatedly transmitted through time-frequency resources.

A plurality of antennas included in the LA2M 140 of the communication system 100 may receive a signal including a unique identification number from the vehicle 200 . When a signal including a unique identification number is transmitted from the vehicle 200 of FIG. 56, among a plurality of antennas included in the LA2M 140, antennas corresponding to unique identification numbers 100200003 to 100200018 are uniquely recognized by the vehicle 200. A signal including a number may be received. The received signal strength of the signal including the unique identification number of the vehicle 200 received through the antennas corresponding to the unique identification numbers 100200003 to 100200018 may be the same as the graph of FIG. 59 .

For example, signals including the unique identification numbers of the vehicle 200 may be received from antennas corresponding to unique identification numbers 100200003 and 100200018, but CRC for the received signals may fail. A signal including the unique identification number of the vehicle 200 can be received from the antenna corresponding to the unique identification number 100200017, and the CRC for the received signal can be successfully completed, but the received signal strength of the signal is less than the threshold value. can In this case, the location of the vehicle 200 may be determined based on antennas corresponding to unique identification numbers 100200004 and 100200016. Since the reception signal strength of the signal including the unique identification number of the vehicle 200 received from the antenna corresponding to the unique identification number 100200014 is the highest, the position of the antenna corresponding to the unique identification number 100200014 is the position of the vehicle 200. can be estimated

Alternatively, a time-frequency resource through which a signal including a unique identification number of the vehicle 200 is transmitted may be mapped to an antenna included in the LA2M 140 as shown in Tables 1 to 3 below.

Each of the antennas included in the LA2M 140 receives a signal including a unique identification number of the vehicle 200 through preset resources (eg, time-frequency indicated by resource indexes in Tables 1 to 3). resource) can be monitored. For example, the antennas corresponding to the unique identification numbers 100200003 and 100200016 can successfully perform CRC on the signal including the unique identification number of the vehicle 200, and the antennas corresponding to the unique identification numbers 100200004 and 100200016 The received signal strength of the signal including the unique identification number of the vehicle 200 received from may be greater than or equal to the 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 resource index #14 may be the largest, and in this case, the antenna mapped to resource index #14. The location of may be estimated as the location of the vehicle 200 . When the position of the vehicle 200 is estimated, the estimated position may be corrected based on the position correction method described with reference to FIG. 60 . For example, the estimated position can be DAP, and can be corrected based on PCP, SCP or MCP.

Meanwhile, the AP may be obtained by applying the C algorithm (eg, the position correction method shown in FIG. 60 ) to the DAP obtained from the vehicle 200 . The vehicle 200 may transmit an AP to the communication system 100 through a DRB connected to the CCN. The AP may be obtained by applying the G algorithm (eg, the position correction method shown in FIG. 60 ) to the DAP obtained in the communication system 100 . Also, the communication system 100 may obtain an accurate AP by applying the F algorithm to the AP obtained from the vehicle 200 and the AP obtained from the communication system 100 . Here, the F algorithm may consider propagation delay. The communication system 100 may transmit the AP obtained through 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 of a C algorithm.

Meanwhile, when antennas included in the LA2M 140 transmit a signal including a unique identification number through the same time-frequency resource, a dead window may occur. Considering the dead window, the time-frequency resource for the signal including the unique identification number of the antenna can be set as follows.

62 is a conceptual diagram illustrating downlink CRZs arranged in units of good windows, and FIG. 63 is a conceptual diagram illustrating a method of transmitting a unique identification number according to a third embodiment.

62 and 63, antennas belonging to the good window of CRZ#1 can transmit signals including unique identification numbers using frequency band #1, and antennas belonging to the good window of CRZ#2 use frequency band #1. A signal including a unique identification number can be transmitted using #2, antennas belonging to the good window of CRZ#3 can transmit a signal including a unique identification number using frequency band #3, and Antennas belonging to the good window may transmit a signal including a unique identification number using frequency band #4. In addition, antennas belonging to the good window of CRZ#5 can transmit a signal including a unique identification number using frequency band #5, and antennas belonging to the good window of CRZ#6 use frequency band #6 to transmit a unique identification number. A signal including a number can be transmitted, and antennas belonging to the good window of CRZ#7 can transmit a signal including a unique identification number using frequency band #7.

Based on the method described above, frequency resources for antennas included in the LA2M 140 may be sequentially set, and in this case, the reception performance of the signal including the unique identification number of the antenna is improved by the dead window and the interference window. degradation can be prevented. Here, when only frequency bands #1 to #5 are set, reception performance degradation due to a dead window and an interference window can be prevented. However, in order to sufficiently cover the dead window and the interference window, frequency bands #1 to #7 may be set.

Meanwhile, when a signal including a unique identification number of the vehicle 200 is transmitted through the same time-frequency resource, a dead window may occur. Considering the dead window, a time-frequency resource for a signal including a unique identification number of the vehicle 200 may be set as follows.

64 is a conceptual diagram illustrating uplink CRZs arranged in good window units, and FIG. 65 is a conceptual diagram illustrating a fourth embodiment of a method of transmitting a unique identification number.

64 and 65, a vehicle belonging to the good window of CRZ#1 may transmit a signal including a unique identification number using frequency band #1, and a vehicle belonging to the good window of CRZ#2 may use frequency band #1. A signal including a unique identification number can be transmitted using #2, and a vehicle belonging to the good window of CRZ#3 can transmit a signal including a unique identification number using frequency band #3, and a signal including a unique identification number can be transmitted using frequency band #3. A vehicle belonging to the good window may transmit a signal including a unique identification number using frequency band #4. In addition, a vehicle belonging to the good window of CRZ#5 can transmit a signal including a unique identification number using frequency band #5, and a vehicle belonging to the good window of CRZ#6 uses frequency band #6 to transmit a unique identification number. A signal including a number may be transmitted, and a vehicle belonging to the good window of CRZ#7 may transmit a signal including a unique identification number using frequency band #7.

Based on the method described above, frequency resources for transmission of the unique identification number may be sequentially set, and in this case, the dead window and the interference window reduce the reception performance of the signal including the unique identification number of the vehicle. can be prevented Here, when only frequency bands #1 to #5 are set, reception performance degradation due to a dead window and an interference window can be prevented. However, in order to sufficiently cover the dead window and the interference window, frequency bands #1 to #7 may be set.

Meanwhile, when time-frequency resources are allocated based on the FDD scheme in overlapping CRZs, data areas of overlapping CRZs may be set to different frequency bands, and control areas of overlapping CRZs may be set to the entire frequency band. It can be. In this case, since interference may occur between overlapping CRZs in the control region, scheduling information transmitted through the control region may not be received by the vehicle 200 . In order to solve this problem, the control area can be set as follows.

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

Referring to FIG. 66 , since CRZs of adjacent vehicles are highly likely to overlap, frequency bands may be allocated according to vehicle departure order. For example, the frequency resource for vehicle #8 (200-8) in FIG. 52 may be set to frequency band #1, and the frequency resource for vehicle #7 (200-7) in FIG. 52 may be set to frequency band #2. , the frequency resource for vehicle #6 (200-6) in FIG. 52 may be set as frequency band #3, and the frequency resource for vehicle #5 (200-5) in FIG. 52 may be set as frequency band It can be set to #4. Also, the frequency resource for vehicle #4 (200-4) in FIG. 52 may be set to frequency band #1, and the frequency resource for vehicle #3 (200-3) in FIG. 52 may be set to frequency band #2. The frequency resource for vehicle #2 (200-2) in FIG. 52 may be set to frequency band #3, and the frequency resource for vehicle #1 (200-1) in FIG. 52 may be set to frequency band #4. can be set to

Frequency band #1 may include control region #1 and data region #1, and scheduling information for data region #1 may be transmitted through control region #1. Frequency band #2 may include control region #2 and data region #2, and scheduling information for data region #2 may be transmitted through control region #2. Frequency band #3 may include control region #3 and data region #3, and scheduling information for data region #3 may be transmitted through control region #3. Frequency band #4 may include control region #4 and data region #4, and scheduling information for data region #4 may be transmitted through control region #4.

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

On the other hand, if an emergency occurs while the vehicle (200-1, 200-2, 200-3, 200-4, 200-5, 200-6, 200-7, 200-8) is running, the specific vehicle will: You can evacuate to the emergency space together.

67 is a conceptual diagram illustrating a first embodiment of a vehicle driving method when an emergency situation occurs.

Referring to FIG. 67 , when an emergency occurs while vehicles 200-1, 200-2, 200-3, 200-4, 200-5, 200-6, 200-7, and 200-8 are running, the vehicle Vehicle #4 (200-4), vehicle #5 (200-5), and vehicle #6 (200-6) can evacuate to the emergency space. In this case, CRZ#3 of vehicle #3 (200-3) may overlap the CRZ of vehicle #7 (200-7), and vehicle #3 (200-3) and vehicle #7 (200-7) Interference may occur because the same frequency band (eg, frequency band #2 in FIG. 66) is used. In this case, the control region allocated to vehicle #3 (200-3) through the RRC signaling procedure may be changed from frequency band #2 to frequency band #1. The message used for the RRC signaling procedure is information requesting a change of the C-RNTI of vehicle #3 (200-3) (or, the C-RNTI of vehicle #3 (200-3) is used for frequency band #1. information indicating that the frequency band is changed), information indicating a time point at which the frequency band is changed (eg, SF#9), and the like. When the C-RNTI is configured not to overlap in the entire frequency band, the C-RNTI may not change even when the control region is changed.

Meanwhile, the communication system 100 described above with reference to FIGS. 1 to 67 may be referred to as a “distributed unit (DU)-based communication system”. A DU-based communication system can support the following functions.

- Function #1: Control packet transmission/reception function for vehicle 200 operation control

- Function #2: function of transmitting and receiving service packets for the occupants of the vehicle 200

-Function #3: Wireless communication function with a communication node (eg, sensor) installed on a moving path of the vehicle 200 (eg, a tube of a hyperloop)

- Function #4: Location measurement function based on wireless communication

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. In addition, the DU-based communication system may be connected to a communication node (eg, a sensor) installed on a moving path (eg, a tube of a hyperloop) of the vehicle 200, and control functions and data for the communication node It is possible to support an upload function and the like, and the location of the vehicle 200 can be measured using a corresponding communication node. In the communication between the DU-based communication system and the vehicle 200, a sliding window for the vehicle 200 is moved according to the moving speed of the vehicle 200, thereby creating a similar fixed cell environment. In this case, the minimum movement unit of the sliding window may be a DU unit. A 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.

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

Referring to FIG. 68, when the LA2M 140 of the DU-based communication system and the CA2M of the vehicle 200 use high frequency (eg, millimeter wave), the LA2M 140 of the DU-based communication system n It may be composed of ×m elements, and CA2M of the vehicle 200 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-scale 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 the LA2M 140 of the DU-based communication system supports only an antenna function, the LA2M 140 may be referred to as a remote radio head (RRH).

The LA2M (140) of the DU-based communication system is an entity that supports an analog RF switching function (eg, P2M or M2P selection function) or an optical switching function (eg, radio over fiber/Ethernet (RoF/E)) may include entities that support RoF/E may be used as a wired interface between the LA2M 140 and the VA2C 130 in a DU-based communication system. In the LA2M (140) of the DU-based communication system, one port (eg, upper port) may be connected to all DU ports (eg, lower ports), and all DU ports are connected to one port By being connected, a soft combining function can be performed. Alternatively, ports in the LA2M 140 of the DU-based communication system may be connected in a point to multipoint communication (P2MP) method, and the DU ports may be designed to selectively perform a soft combining function. Alternatively, DU ports in the LA2M (140) of the DU-based communication system may be independently connected to the VA2C (130).

A beam width supported by an antenna of a DU-based communication system may be different from a beam width supported by an antenna of the vehicle 200 . When the beam of the vehicle 200 is aligned with the beam of the DU-based communication system, 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, the SINR may decrease. However, even when the beam of the vehicle 200 is not aligned with the beam of the DU-based communication system, the SINR may increase if the content is synchronized and the JT scheme is used.

Meanwhile, the VA2C (130) of the DU-based communication system may support a sliding window, may be connected to the TSU (120) as a higher entity, and may be connected to at least one LA2M (140) as a lower entity. Accordingly, the VA2C 130 may transmit the signal received from the TSU 120 to the LA2M 140 based on the P2MP method. In addition, the VA2C 130 may perform soft combining on the signal received from the LA2M 140 based on the MP2P scheme and transmit the signal received from the LA2M 140 to the TSU 120. The TSU 120 may be connected to the VA2C 130 through an optical fiber, and the VA2C 130 may be connected to the LA2M 140 through an optical fiber. In this case, signal loss may occur depending on the length of the optical fiber, and an optical repeater may be used to prevent signal loss.

The TSU 120 of the DU-based communication system may perform a function of a base station of a cellular communication system. The TSU 120 may be connected to the CCU 110 as a higher entity and may be connected to at least one VA2C 130 as a lower entity. The TSU 120 may support a PHY function, a MAC function, a synchronization function, and the like. The MAC layer of the TSU 120 may support a slave MAC function and may process MAC related data. The synchronization layer of the TSU 120 may perform a transmission/reception function of a probe request/response packet in order to measure a time delay of a sub-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, obtain a MAC frame from the uplink PHY packet, and may obtain a MAC frame based on the obtained MAC frame. Synchronous packets can be created. In this case, synchronization of downlink content may be performed based on a synchronization protocol, and uplink content may be selected.

The CCU 110 of the DU-based communication system may perform the EPC function of the cellular communication system, and may support an RRC function, an RLC function, a PDCP function, a synchronization function, a non-access stratum (NAS) function, and the like. The RRC layer of the CCU 110 may support a radio resource control function, and the RLC layer of the CCU 110 may support a data unit division/assembly function, an automatic repeat request (ARQ) function, a duplicate detection function, and the like. The PDCP layer of the CCU 110 may support an IP header compression function, an encryption function, an integrity protection function, and the like. The synchronization layer of the CCU 110 may support a transmission/reception function of a probe request/response packet for measuring delay of a lower entity, and may support a master MAC function based on semi-static scheduling of an RRC layer.

The synchronization layer of the CCU 110 may transmit a downlink data packet to the TSU 120 in consideration of the operation of the MAC layer of the TSU 120. The synchronization layer of the CCU 110 may select a valid uplink data packet from among uplink data packets received from the 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, and the like, based on a predefined synchronization protocol. The CCU 110 may perform a matching function between a CCN connected to a DU-based communication system and a PSN. When an emergency occurs, the communication function for the occupants 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.

Meanwhile, 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". An LCX-based communication system can be configured as follows.

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

Referring to FIG. 69, the LCX-based communication system may include a CCU 110, TSU 120, virtual linear radiating cable module (LRCM) controller (VLC) 150, and LRCM 160. The CCU 110 may be connected to the CCN and the PSN, and may be connected to the TSU 120 as a sub-entity. A function of the CCU 110 in the LCX-based communication system may be the same as or similar to that of the CCU 110 in the above-described communication system 100 (eg, a DU-based 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. The function of the TSU 120 in the LCX-based communication system may be the same as or similar to that of the TSU 120 in the above-described communication system 100 (eg, a DU-based communication system).

The VLC 150 may be connected to the TSU 120 as an upper entity and may be connected to the LRCM 160 as a lower entity. A function of the VLC 150 in the LCX-based communication system may be the same as or similar to that of the VA2C 130 in the above-described communication system 100 (eg, a DU-based communication system). The LRCM 160 may be connected to the VLC 150 as an upper entity, and may include a radiating cable (RC) (eg, a radiating cable segment (RCS)). Communication between the LCX-based communication system and the vehicles 200-1 and 200-2 may be performed through LRCM. A function of the LRCM 160 in the LCX-based communication system may be the same as or similar to that of the LA2M 140 in the above-described communication system 100 (eg, a DU-based communication system).

The vehicles 200-1 and 200-2 may include a capsule TRX antenna module (CTAM), CE, and the like, and the CE may be connected to the CCN and the PSN. Sliding windows for the vehicles 200-1 and 200-2 may be set, and communication between the vehicles 200-1 and 200-2 and the LCX-based communication system may be performed within the sliding window.

An LCX-based communication system can support the following functions.

- Function #1: Control packet transmission/reception function for vehicle 200 operation control

- Function #2: function of transmitting and receiving service packets for the occupants of the vehicle 200

- Function #3: Location measurement function based on wireless communication

Communication between the CCN of the LCX-based communication system and the CCN inside the vehicles 200-1 and 200-2 can be performed, and the PSN of the LCX-based communication system and the PSN inside the vehicles 200-1 and 200-2 Communication between the two can be performed. In addition, the LCX-based communication system may be connected to a communication node (eg, a sensor) installed on a moving path of the vehicle 200 (eg, a tube of a hyperloop), and control functions and data for the communication node It is possible to support an upload function and the like, and the location of the vehicle 200 can be measured using a corresponding communication node. In the communication between the LCX-based communication system and the vehicle 200, a sliding window for the vehicle 200 is moved according to the moving speed of the vehicle 200, thereby creating a similar fixed cell environment. In this case, the minimum movement unit of the sliding window may be an LRCM (160) unit.

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

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

Referring to FIG. 70, the LRCM 160 may include a plurality of RCSs having a predefined length (eg, 150m), and a signal (eg, a source signal) received from the VLC 150 is It can be transmitted to a plurality of RCSs. The length of LRCM 160 may be 1.8 km. Since signal loss increases as the RCS length increases, signals can be amplified by the analog repeaters 165-1 and 165-2. The RCS may be connected to a port of the LRCM 160 through an optical fiber instead of the analog repeaters 165-1 and 165-2. LRCM 160 may be connected to VLC 150 via RoF/E.

Meanwhile, the radiation angle of the RCS may be determined according to the arrangement of the slots. A radiation angle according to the arrangement of slots may be as follows.

71 is a conceptual diagram illustrating a first embodiment of a radiation angle according to an arrangement of slots.

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

Referring back to FIG. 69 , the VLC 150 of the LCX-based communication system may control/manage the sliding window. The VLC 150 may be connected to the higher entity TSU 120 through an optical fiber and to the lower entity LRCM 160 through an optical fiber. In this case, signal loss may occur depending on the length of the optical fiber, and an optical repeater may be used to prevent the signal loss. The VLC 150 may transmit the signal received from the TSU 120 to 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 transmit the corresponding signal to the TSU 120.

The TSU 120 of the LCX-based communication system may perform a function of a base station of a 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. The TSU 120 may support a PHY function, a MAC function, a synchronization function, and the like. The MAC layer of the TSU 120 may support a slave MAC function and may process MAC related data. The synchronization layer of the TSU 120 may perform a transmission/reception function of a probe request/response packet in order to measure a time delay of a sub-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, obtain a MAC frame from the uplink PHY packet, and may obtain a MAC frame based on the obtained MAC frame. Synchronous packets can be created. In this case, downlink content synchronization may be performed based on a synchronization protocol, and uplink content may be selected.

The CCU 110 of the LCX-based communication system may perform the EPC function of the cellular communication system, and may support an RRC function, an RLC function, a PDCP function, a synchronization function, a NAS function, and the like. The RRC layer of the CCU 110 may support a radio resource control function, and the RLC layer of the CCU 110 may support a division/assembly function of a data unit, an ARQ function, a duplication detection function, and the like. The PDCP layer of the CCU 110 may support an IP header compression function, an encryption function, an integrity protection function, and the like. The synchronization layer of the CCU 110 may support a transmission/reception function of a probe request/response packet for measuring delay of a lower entity, and may support a master MAC function based on semi-static scheduling of an RRC layer.

The synchronization layer of the CCU 110 may transmit a downlink data packet to the TSU 120 in consideration of the operation of the MAC layer of the TSU 120. The synchronization layer of the CCU 110 may select a valid uplink data packet from among uplink data packets received from the 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, and the like, based on a predefined synchronization protocol. The CCU 110 may perform a matching function between a CCN connected to a DU-based communication system and a PSN. When an emergency occurs, the communication function for the occupants of the vehicle 200 may be supported by the CCN of the DU-based communication system and the CCN of the vehicle 200 .

The CTAMs of the vehicles 200-1 and 200-2 may be antennas communicating with the LRCM 160 of the LCX-based communication system. The CEs of the vehicles 200-1 and 200-2 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.

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

72 is a flowchart illustrating a first embodiment of a communication method between a communication system and a vehicle, and FIG. 73 is a conceptual diagram illustrating a sliding window set according to the communication method shown in FIG. 72 .

Referring to FIGS. 72 and 73 , the communication system 100 (eg, a land communication device) may be the communication system shown in FIG. 1 or FIG. 50 . For example, the communication system 100 may include a CCU 110, TSU 120, VA2C 130, LA2M 140, and the like, and the CCU 110 and TSU included in the communication system 100. (120), VA2C (130) and LA2M (140) can be set the same as or similar to the CCU, TSU, VA2C and LA2M shown in FIG. Also, the communication system 100 may be a DU-based communication system or an LCX-based communication system (eg, the LCX-based communication system shown in FIG. 69). Vehicle #1 (200-1) may have the same or similar configuration as vehicle #1 (200-1) shown in FIG. 50, and vehicle #2 (200-2) may be configured as vehicle #2 ( 200-2) may be configured identically or similarly. For example, the vehicles 200-1 and 200-2 may include an antenna, CE, and the like. Alternatively, vehicle #1 (200-1) may have the same or similar configuration as vehicle #1 (200-1) of FIG. 2) may be configured identically or similarly. In this case, the vehicles 200-1 and 200-2 may include CTAM and CE.

Vehicle #1 (200-1) may measure its own location and transmit location information indicating the location (eg, first location) of vehicle #1 (200-1) to the communication system 100. It can (S7201). For example, vehicle #1 (200-1) may inform the communication system 100 of the first position measured at T0. The location of vehicle #1 (200-1) may be measured based on the location measurement method described with reference to FIGS. 56 to 60 . Alternatively, location information of vehicle #1 (200-1) may be acquired from GPS. The communication system 100 may obtain location information from vehicle #1 (200-1). Alternatively, the communication system 100 may measure the location of vehicle #1 (200-1) based on the location measurement method described with reference to FIG. 61 . The location of vehicle #1 (200-1) may be periodically measured, and location information of vehicle #1 (200-1) may be periodically transmitted to the communication system 100.

The communication system 100 may set a first sliding window based on the location information of vehicle #1 (200-1) (S7202). The first sliding window may include n DAs (eg, antennas and RCSs) installed in an area corresponding to the location of vehicle #1 (200-1). Here, n may be an integer of 2 or greater. For example, when n is 4 and the first position of vehicle #1 (200-1) corresponds to the position where DA #10 is disposed, set according to the first position of vehicle #1 (200-1) The first sliding window may include DA #10 to 13. Also, the communication system 100 may set the first sliding window in consideration of the good window, the dead window, and the interference window described with reference to FIGS. 47 to 49 .

After the setting of the sliding window is completed, communication between the communication system 100 and the vehicle #1 (200-1) may be performed (S7203). For example, the communication system 100 may transmit downlink signals (eg, D1, D2, D3) to vehicle #1 (200-1) through DAs #10 to 13 belonging to the first sliding window, , Vehicle #1 (200-1) may receive downlink signals (eg, D1, D2, D3) from the communication system 100. Resources used for downlink communication between the communication system 100 and vehicle #1 200-1 may be downlink resources shown in FIGS. 15 to 19 and FIG. 27 . When downlink communication is performed, the communication system 100 may transmit quasi-static scheduling information through a control region and may transmit data through a data region indicated by the quasi-static scheduling information. Vehicle #1 (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, each of the C-RNTI for initial downlink transmission, the C-RNTI for RLC status message transmission, and the C-RNTI for downlink retransmission may be set independently.

In addition, vehicle #1 (200-1) may transmit uplink signals (eg, D1, D2, D3) to the communication system 100, and the communication system 100 may transmit DA # belonging to the first sliding window. Through 10 to 13, uplink signals (eg, D1, D2, D3) may be received from vehicle #1 (200-1). Resources used for uplink communication between the communication system 100 and vehicle #1 200-1 may be uplink resources shown in FIGS. 22 to 25 and FIG. 28 . When uplink communication is performed, the communication system 100 may transmit semi-static scheduling information through the control region. Vehicle #1 (200-1) may receive semi-static scheduling information from the communication system 100 and transmit data to the communication system 100 through a data area indicated by the semi-static scheduling information. The communication system 100 may receive data through a data area indicated by the semi-static scheduling information. When uplink communication is performed based on RLC AM, the uplink retransmission procedure described with reference to FIG. 30 may be performed. In this case, each of the C-RNTI for initial uplink transmission, the C-RNTI for RLC status message transmission, and the C-RNTI for uplink retransmission may be set independently.

Before communication between the communication system 100 and the vehicle #1 (200-1) is performed, the communication nodes 110, 120, 130, and 140 included in the communication system 100 refer to FIGS. 33 to 40. They can be synchronized with each other based on the described delay probe procedure. For example, a synchronization procedure may be performed by exchanging probe request packets and probe response packets between the communication nodes 110 , 120 , 130 , and 140 . That is, synchronization of DAs #10 to 13 belonging to the first sliding window may be maintained by the CCU 110 included in the communication system 100 . When the synchronization procedure is completed, DAs #10 to 13 belonging to the first sliding window may transmit the same signals at the same time. Alternatively, when the synchronization procedure is completed, the time offset between reception times of signals received through DA # 10 to 13 belonging to the first sliding window may be within a predefined range (eg, cyclic prefix (CP)). .

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

Meanwhile, when the position of the vehicle #1 is periodically measured, the vehicle #1 (200-1) may measure the position at T3, and the position of the vehicle #1 (200-1) (eg, the second position ) may be transmitted to the communication system 100 (S7204). The communication system 100 may obtain location information from vehicle #1 (200-1).

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

After the setting of the sliding window is completed, communication between the communication system 100 and the vehicle #1 (200-1) may be performed (S7206). For example, the communication system 100 may transmit downlink signals (eg, D4, D5, and D6) to vehicle #1 (200-1) through DAs #12 to 15 belonging to the first sliding window, , Vehicle #1 (200-1) may receive downlink signals (eg, D4, D5, D6) from the communication system 100. Synchronization of DAs #12 to 15 belonging to the first sliding window may be maintained by the CCU 110 included in the communication system 100 . Accordingly, DAs #12 to 15 belonging to the first sliding window may transmit the same signals at the same time. Alternatively, a time offset between reception points of signals received through DA #s 12 to 15 belonging to the first sliding window may be within a predefined range. In addition, vehicle #1 (200-1) may transmit uplink signals (eg, D4, D5, D6) to the communication system 100, and the communication system 100 may transmit DA # belonging to the first sliding window. Through 12 to 15, uplink signals (eg, D4, D5, and D6) may be received from vehicle #1 (200-1).

Meanwhile, the communication system 100 may perform communication with vehicle #1 (200-1) as well as other vehicles (eg, vehicle #2 (200-2)). In this case, vehicle #2 (200-2) may transmit location information indicating its location (eg, third location) to the communication system 100 (S7207). The communication system 100 may obtain location information from vehicle #2 (200-2).

The communication system 100 may set a second sliding window based on the location information of vehicle #2 (200-2) (S7208). The second sliding window may include k DAs (eg, antennas and RCSs) installed in an area corresponding to the location of vehicle #2 (200-2). Here, k may be an integer greater than or equal to 2. For example, when k is 4 and the third position of vehicle #2 (200-2) corresponds to the position where DA #1 is disposed, set according to the third position of vehicle #2 (200-2) The second sliding window may include DA #1 to 4. The k DAs included in the second sliding window set in step S7208 do not overlap with the n DAs included in the first sliding window set in step S7202 or the m DAs included in the first sliding window set in step S7205. can

After the setting of the sliding window is completed, communication between the communication system 100 and the vehicle #2 (200-2) may be performed (S7209). For example, the communication system 100 transmits downlink signals (eg, D1', D2', D3') to vehicle #2 (200-2) through DAs #1 to 4 belonging to the second sliding window. and vehicle #2 (200-2) can receive downlink signals (eg, D1', D2', D3') from the communication system 100. Synchronization of DAs #1 to 4 belonging to the second sliding window may be maintained by the CCU 110 included in the communication system 100 . Accordingly, DAs #1 to 4 belonging to the second sliding window may transmit the same signals at the same time. Alternatively, a time offset between reception points of time of signals received through DAs #1 to 4 belonging to the second sliding window may be within a predefined range. In addition, vehicle #2 (200-2) may transmit uplink signals (eg, D1', D2', D3') to the communication system 100, and the communication system 100 may enter the second sliding window. Uplink signals may be received from vehicle #2 (200-2) through DAs #1 to 4 to which they belong.

When the location of the vehicle #2 (200-2) is changed, communication between the communication system 100 and the vehicle #2 (200-2) is reset, as in the embodiments according to steps S7204 to S7206 described above. This can be done using a sliding window. For example, when the position of vehicle #2 (200-2) is changed from the third position corresponding to DA #1 to the fourth position corresponding to DA #3, the second sliding window includes DA #3 to 6 communication between the communication system 100 and vehicle #2 (200-2) can be performed using DAs #3 to 6 included in the second sliding window. Further, the embodiment according to steps S7207 to S7209 may be performed simultaneously with the embodiment according to steps S7201 to S7203 or the embodiment according to steps S7204 to S7206.

The methods according to the present invention may be implemented in the form of program instructions that can be executed by various computer means and recorded on a computer readable medium. Computer readable media may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on a computer readable medium may be specially designed and configured for the present invention or may be known and usable to those skilled in computer software.

Examples of computer readable media include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter or the like as well as machine language codes generated by a compiler. The hardware device described above may be configured to operate with at least one software module to perform the operations of the present invention, and vice versa.

Although described with reference to the above embodiments, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the present invention described in the claims below. You will be able to.

Claims (15)

A communication device that communicates with a first mobile device, comprising:
a processor performing a radio resource control function for communication between the first mobile device and the communication device;
a plurality of distributed antennas (DAs) located on a path of the first mobile device and transmitting and receiving signals under the control of the processor; and
A memory in which at least one instruction executed by the processor is stored;
The at least one command,
setting a first sliding window including n DAs corresponding to a first position of the first mobile device among the plurality of DAs;
communicate with the first mobile device located at the first location using the n DAs;
when the first mobile device moves from the first position to the second position, resetting the first sliding window to include m DAs corresponding to the second position among the plurality of DAs; and
and perform communication with the first mobile device located at the second location using the m DAs;
At least one DA among the n DAs is identical to one or more DAs among the m DAs;
Each of n and m is an integer greater than or equal to 2, the first position and the second position belong to the path,
Synchronization of downlink communication and uplink communication through the n DAs belonging to the first sliding window or synchronization between downlink communication and uplink communication through the m DAs is maintained by the processor, and A plurality of radio bearers (RBs) for communication between the first mobile devices are configured, and a cell-radio network temporary identifier (C-RNTI) for each of the plurality of RBs is independently configured. delete The method of claim 1,
and when communication with the first mobile device located at the first location is performed, the n DAs transmit and receive the same signal using the same radio resource. The method of claim 1,
and when communication with the first mobile device located at the second location is performed, the m DAs transmit and receive the same signal using the same radio resource. The method of claim 1,
and wherein the position of the first mobile device is estimated based on a signal received from the first mobile device. delete The method of claim 1,
The at least one command,
setting a second sliding window including k DAs corresponding to a third position of a second mobile device moving along the path among the plurality of DAs; and
and perform communication with the second mobile device located at the third location using the k DAs;
wherein k is an integer greater than or equal to 2, and the third position belongs to the route. The method of claim 7,
The k DAs do not overlap with the n DAs or the m DAs. The method of claim 7,
The dedicated cell formed by the second sliding window is different from the dedicated cell formed by the first sliding window. The method of claim 7,
Communication using the k DAs is performed simultaneously with communication using the n DAs or the m DAs. A method of communication performed by a mobile device moving along a route, comprising:
When the mobile device is located at a first position on the route, the plurality of distributed antennas (DAs) are transmitted through a sliding window including n DAs corresponding to the first position among a plurality of distributed antennas (DAs) located on the route. performing communication with a communication device including DAs of; and
When the mobile device moves from the first position to the second position on the route, the communication device through the sliding window including m DAs corresponding to the second position among the plurality of DAs located on the route Including the step of performing communication with,
At least one DA among the n DAs is the same as at least one DA among the m DAs, and each of n and m is an integer of 2 or greater;
Synchronized downlink communication and synchronized uplink communication with the n DAs are performed, synchronized downlink communication and synchronized uplink communication with the m DAs are performed, and A plurality of radio bearers (RBs) for communication are set, and a cell-radio network temporary identifier (C-RNTI) for each of the plurality of RBs is independently set. The method of claim 11,
wherein a dedicated cell formed by the sliding window set for the mobile device located in the first position is the same as a dedicated cell formed by the sliding window set for the mobile device located in the second position. The method of claim 11,
and wherein, in communication between the mobile device located at the first location and the n DAs, the same signal is received through the same radio resource from the n DAs. The method of claim 11,
and in communication between the mobile device located at the second location and the m DAs, the same signal is received through the same radio resource from the m DAs. The method of claim 11,
information used to estimate the location of the mobile device is transmitted from the mobile device to the communication device, wherein the first location and the second location are estimated based on the information.

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