JP6900446B2 - Servers, communication terminals, mobiles, IoT devices, communication systems, methods and programs for providing information - Google Patents

Description

The present invention relates to a communication terminal device used for communication between short-range devices, a mobile body equipped with the communication terminal device, an IoT device and a communication system, and a server, a method and a program for providing information to the communication terminal device. Is.

Conventionally, between short-range devices (D2D: Device-to-) such as V2V (Vehicle-to-Vehicle), V2I (Vehicle-to-Infrastructure), V2P (Vehicle-to-Pedestrian), V2X (Vehicle-to-Everything) A communication method for direct wireless communication with Device) is known.

For example, in the LTE (Long Term Evolution) and next-generation (NR) specifications of 3GPP (3rd Generation Partnership Project), short-range devices such as V2V, V2I, V2P, and V2X do not go through the mobile communication network (core network). Standard specifications for a Sidelink communication system (hereinafter referred to as "PC5 communication system") for direct wireless communication using an interface called PC5 between (D2D) have been established (Non-Patent Documents 1, 2, 3, 4, 5). reference).

Further, as a method of determining and setting the transmission / reception timing of the wireless frame of the PC5 communication method in the communication terminal device, a method using a time reference of Uu communication via a base station (eNB) of a mobile communication network (cellular network) (a method using a time reference of Uu communication via a base station (eNB) of a mobile communication network (cellular network)). Hereinafter, a method using a time reference acquired by a GNSS receiver provided in the own device (hereinafter referred to as "GNSS synchronization method") can be selected (see Non-Patent Documents 6 and 7). .. When the Uu synchronization method is selected, SFN (System Frame Number), which is a time reference for Uu communication, is used as a reference for transmission / reception timing of the wireless frame of the PC5 communication method. On the other hand, when the GNSS synchronization method is selected, the frame number DFN (Direct Frame Number) converted to SFN equivalent based on the UTC (Universal Time Coordinated) time reference generated based on the GNSS reception signal is used as the wireless frame of the PC5 communication method. It is used as a reference for transmission / reception timing of (see Non-Patent Document 7).

3GPP TS 23.285 V16.0.0 (2019-03), 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Architecture enhancements for V2X services (Release 16) 3GPP TS 23.303 V15.1.0 (2018-06), 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Proximity-based services (ProSe); Stage 2 (Release 15) 3GPP TS 24.386 V15.2.0 (2018-12), 3rd Generation Partnership Project; Technical Specification Group Core Network and Terminals; User Equipment (UE) to V2X control function; protocol aspects; Stage 3 (Release 15) 3GPP TR 38.885 V16.0.0 (2019-03), 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; Study on NR Vehicle-to-Everything (V2X) (Release 16) 3GPP TR 23.287 V1.0.0 (2019-05), 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Architecture enhancements for 5G System (5GS) to support Vehicle-to-Everything (V2X) services (Release 16) 3GPP TS 36.300 V15.6.0 (2019-06), 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 15) 3GPP TS 36.331 V15.6.0 (2019-06), 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification (Release 15)

When the Uu synchronization method or the GNSS synchronization method is selected and the transmission / reception timing of the wireless frame of the direct wireless communication method between short-distance devices such as the PC5 communication method is determined and set, the time reference of the Uu synchronization method and the GNSS synchronization are performed. There are the following problems due to the time lag with the time reference of the method. When one communication terminal device selects the Uu synchronization method and the other communication terminal device selects the GNSS synchronization method among a plurality of communication terminal devices that wirelessly communicate with each other by the direct wireless communication method between short-range devices. Due to the deviation of the time reference of both synchronous methods, the transmission / reception timing of the wireless frames between the communication terminal devices communicating with each other may be shifted, and the wireless frames of each other may become a source of radio interference. When the wireless frames serve as radio wave interference sources in this way, the number of wireless frames that can be directly assigned to the wireless communication method in the wireless frames used in each communication terminal device decreases, and the wireless frames of the direct wireless communication system are used. Even if it is assigned, the communication quality may deteriorate.

The above-mentioned problem is not limited to a device that performs wireless communication of a direct wireless communication method between short-distance devices such as the above-mentioned PC5 communication method, and the above-mentioned Uu synchronization method or GNSS synchronization method is selected to transmit and receive a wireless frame. Any device that determines and sets the timing can occur in the same way.

The server according to one aspect of the present invention is a server that provides information. This server determines and sets the transmission / reception timing of the wireless frame based on the time reference of the communication via the base station of the mobile communication network. The wireless frame is based on the first synchronization method and the time reference acquired by the GNSS receiver. From the communication terminal device that can use the second synchronization method for determining and setting the transmission / reception timing of the wireless frame, the transmission / reception timing of the wireless frame when the first synchronization method is selected and the second synchronization method are selected. Information receiving means for receiving information on the time difference from the transmission / reception timing of the wireless frame at the time, information on the time difference from the transmission / reception timing of the wireless frame, and cell identification information for identifying the cell in which the communication terminal device is located. The cell of the cell in which the communication terminal device of the information providing destination is located in the communication terminal device of the information providing destination capable of communicating with the storage means for storing the information in association with each other by the direct wireless communication method between the short-range devices. An information transmission means for transmitting the time difference information corresponding to the identification information is provided.

When the server receives the time difference information, the received time difference information includes a predetermined range including the latest predetermined number of time difference information stored in association with the cell identification information of the cell. If the received time difference information is not within the predetermined range, it is discarded as abnormal data, and the received time difference information is within the predetermined range. If so, the received time difference information may be added as the latest predetermined number of time difference information.
In the server, the time difference is obtained for one or a plurality of cells including a cell in which the communication terminal device of the information providing destination is located in the communication terminal device of the information providing destination capable of communicating by the direct wireless communication method between the short-distance devices. The information and the information transmission means for transmitting the cell identification information may be provided. Here, when new time difference information is added to the latest predetermined number of time difference information, the average value of the latest predetermined number of time difference information after the addition is used as the communication of the information providing destination. It may be transmitted to the terminal device.
In the server, the time difference information may be transmitted using a broadcast channel via the base station of the mobile communication network, or RRC at the time of handover of the communication terminal device via the base station. It may be transmitted using the Connection Recognition, or may be transmitted using the management object of the V2X service via the base station.
In the server, the time difference information may be set in the offsetDFN parameter that shifts the frame number DFN (Direct Frame Number) converted to the equivalent of SFN (System Frame Number).

The communication terminal device according to another aspect of the present invention is a communication terminal device capable of selectively or simultaneously executing communication via a base station of a mobile communication network and communication by a direct wireless communication method between short-range devices. .. This communication terminal device is based on the first synchronization method of determining and setting the transmission / reception timing of the wireless frame based on the time reference of communication via the base station of the mobile communication network and the time reference acquired by the GNSS receiver. A synchronization method selection means that selectively uses a second synchronization method that determines and sets a transmission / reception timing of a wireless frame, a transmission / reception timing of a wireless frame when the first synchronization method is selected, and the second synchronization method. It is provided with an information transmission means for transmitting information on the time difference from the transmission / reception timing of the wireless frame when the synchronization method is selected to the server.

The communication terminal device according to still another aspect of the present invention is a communication terminal device that performs communication between short-range devices by a direct wireless communication method based on a time reference acquired by a GNSS receiver. This communication terminal device receives information on the time difference between the time reference of communication via the base station of the mobile communication network in the cell in which the communication terminal device is located and the time reference acquired by the GNSS receiver from the server. The information receiving means includes a transmission / reception timing correction means for correcting the time reference acquired by the GNSS receiver based on the received time difference information to determine and set the transmission / reception timing of the wireless frame.

In the communication terminal device, the time difference information may be received via the base station using the broadcast channel, or the RRC Connection Recognition at the time of handover of the communication terminal device may be performed via the base station. It may be received using the management object of the V2X service via the base station.
In the communication terminal device, the time difference information may be set to an offsetDFN parameter that shifts the frame number DFN (Direct Frame Number) converted to the equivalent of SFN (System Frame Number).
In the communication terminal device, the wireless communication method for communication via the base station of the mobile communication network is 3GPP Cat. M or Cat. It may be a wireless communication method conforming to the NB specifications.
In the communication terminal device, it may be mounted on a mobile body that moves on the ground, on the water, or in the air, or may be mounted on an IoT device.

The mobile body according to still another aspect of the present invention includes any of the above-mentioned communication terminal devices.

The IoT device according to still another aspect of the present invention includes any of the above-mentioned communication terminal devices.

The communication system according to still another aspect of the present invention includes any of the above-mentioned servers and the above-mentioned communication terminal device.

A method according to yet another aspect of the present invention is a method of providing information. This method determines and sets the transmission / reception timing of the wireless frame based on the time reference of the communication via the base station of the mobile communication network. The wireless frame is based on the first synchronization method and the time reference acquired by the GNSS receiver. From the communication terminal device that can use the second synchronization method for determining and setting the transmission / reception timing of the wireless frame, the transmission / reception timing of the wireless frame when the first synchronization method is selected and the second synchronization method are selected. Receiving information on the time difference from the transmission / reception timing of the wireless frame at that time, information on the time difference from the transmission / reception timing of the wireless frame, and cell identification information for identifying the cell in which the communication terminal device is located. , In the communication terminal device of the information providing destination that can be stored in association with each other and by the direct wireless communication method between the short-range devices, and in the cell identification information of the cell in which the communication terminal device of the information providing destination is located. The transmission of the corresponding time difference information includes.

A program according to still another aspect of the present invention is a program executed by a computer or processor provided in a server that provides information. This program determines and sets the transmission / reception timing of the wireless frame based on the time reference of communication via the base station of the mobile communication network. The wireless frame is based on the first synchronization method and the time reference acquired by the GNSS receiver. From the communication terminal device that can use the second synchronization method for determining and setting the transmission / reception timing of the wireless frame, the transmission / reception timing of the wireless frame when the first synchronization method is selected and the second synchronization method are selected. Program code for receiving information on the time difference from the transmission / reception timing of the wireless frame at the time, information on the time difference from the transmission / reception timing of the wireless frame, and cell identification for identifying the cell in which the communication terminal device is located. The communication terminal device of the information providing destination is located in the communication terminal device of the information providing destination capable of communicating by the program code for storing the information in association with each other and the direct wireless communication method between the short-range devices. Includes a program code for transmitting the time difference information corresponding to the cell identification information of the cell.
The program according to still another aspect of the present invention is a computer provided in a communication terminal device capable of selectively or simultaneously executing communication via a base station of a mobile communication network and communication by a direct wireless communication method between short-range devices. Or it is a program executed in the processor. This program determines and sets the transmission / reception timing of the wireless frame based on the time reference of communication via the base station of the mobile communication network. The wireless frame is based on the first synchronization method and the time reference acquired by the GNSS receiver. The program code for selectively using the second synchronization method for determining and setting the transmission / reception timing of the radio frame, the transmission / reception timing of the wireless frame when the first synchronization method is selected, and the second synchronization method. The program code for sending the information of the time difference from the transmission / reception timing of the wireless frame when is selected to the server, and
including.
The program according to still another aspect of the present invention is a computer provided in a communication terminal device capable of selectively or simultaneously executing communication via a base station of a mobile communication network and communication by a direct wireless communication method between short-range devices. Or it is a program executed in the processor. This program is for receiving information on the time difference between the time reference of communication via the base station of the mobile communication network in the cell in which the communication terminal device is located and the time reference acquired by the GNSS receiver from the server. The program code includes a program code and a program code for correcting the time reference acquired by the GNSS receiver to determine and set the transmission / reception timing of the wireless frame based on the received time difference information.

In the server, the communication terminal device, the mobile body, the IoT device, the communication system, the method and the program, the direct wireless communication method is a direct wireless communication method using a PC5 interface included in the standard specifications of 3GPP. It may be.

According to the present invention, even if the signal sources of the time reference used as the reference of the transmission / reception timing of the wireless frame are different from each other in a plurality of communication terminal devices that wirelessly communicate with each other by the direct wireless communication method between the short-range devices, the direct wireless communication is performed. Interference in the wireless frame of the system can be suppressed.

Explanatory drawing which shows an example of the whole structure of the communication system which concerns on embodiment. The explanatory view which shows an example of the data communication between vehicles by the PC5 communication system which concerns on embodiment. The explanatory view which shows an example of the interference by the synchronization method of the transmission / reception timing of the wireless frame in the direct wireless communication between UEs of a plurality of vehicles. The block diagram which shows an example of the main part structure of the server which concerns on this embodiment. The flowchart which shows an example of the information processing when the time difference (offsetDFN) information is received (acquired) and transmitted (delivered) periodically in the server which concerns on embodiment. The block diagram which shows an example of the main part composition of the UE of the vehicle which concerns on embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory diagram showing an example of the overall configuration of the communication system according to the present embodiment. In the communication system of the present embodiment, for example, the communication terminal device 31 of the vehicle 30 as a plurality of moving bodies traveling on the road as a vehicle moving route is directly connected between short-range devices (D2D: Device-to-Device). It is suitable for communication systems capable of direct wireless communication such as V2V (Vehicle-to-Vehicle) and V2X (Vehicle-to-Everything) by the PC5 communication method for wireless communication.

In the example of FIG. 1, the case of three vehicles 30 (1) to 30 (3) having communication terminal devices 31 (1) to 31 (3), respectively, is shown, but the vehicle 30 and the communication terminal device are shown. The number of 31 may be one or two, or four or more. Further, the vehicle 30 in the present embodiment is, for example, an automobile such as a passenger car, a truck, or a bus, and the present invention is not limited to the type and number of vehicles. The present invention can also be applied to a case where the moving body is a moving body other than a vehicle such as a flying body or a ship that moves on a moving path set in the sky or water.

In FIG. 1, the communication system of the present embodiment includes a server 10 capable of communicating with each of the communication terminal devices 31 of a plurality of vehicles 30. The communication system may include a communication terminal device 31 of a plurality of vehicles 30. The server 10 stores and manages information related to wireless frame synchronization when the communication terminal device 31 of each vehicle 30 performs direct wireless communication between the vehicles 30 by the PC5 communication method, and this information is stored in the communication terminal device of each vehicle 30. It can be transmitted to 31 and provided. The server 10 may transmit information to the communication terminal device 31 of each vehicle 30 in response to an information request received from the communication terminal device 31, and may periodically or irregularly transmit information regardless of the information request. It may be delivered autonomously at the timing of.

The information request transmitted from the communication terminal device 31 to the server 10 may include information on the current position of the communication terminal device 31. In this case, the server 10 does not need to separately acquire the information on the current position of the communication terminal device 31.

The server 10 is, for example, a MEC (Multi-access Edge Computing) device provided in the base station 16 of the mobile communication network 15. The server 10 composed of the MEC device may be provided outside the node or core network between the base station 16 and the core network of the mobile communication network 15. Further, the server 10 may be provided in the core network of the mobile communication network 15 as shown by the broken line in the figure.

The base station 16 forms one or more cells (also referred to as sectors or sector cells). The cell may be formed two-dimensionally on the ground or the sea, or may be formed three-dimensionally from the sky toward the ground or the sea. The cell may be a macro cell, a small cell, a femto cell, a pico cell, a large cell, or the like. The plurality of cells may form a cellular structure that is distributed so as to be two-dimensionally or three-dimensionally adjacent to each other, or may form a hierarchical cell structure in which some or all of them are hierarchically overlapped. .. The base station 16 is a macrocell base station, a small cell base station, a femtocell base station, a picocell base station, a large cell base station, a fixed base station fixedly installed on the ground, etc. It may be a type base station or the like. The base station 16 may be a wireless communication device called an eNodeB (evolved Node B: eNB), a gNodeB (gNB), an en-gNodeB (en-gNB), an access point, or the like.

The communication terminal device 31 of the vehicle 30 is a user device (hereinafter referred to as "UE") that can be used as a subscriber of the mobile communication service. The UE 31 may be a wireless communication device called a user terminal, a terminal, a terminal device, a mobile station, a mobile device, or the like. The UE 31 of the vehicle 30 may be a device used in a state of being carried by the user in the vehicle 30, or a device installed by being incorporated in the vehicle 30 (for example, a device incorporated as a part of a navigation device). May be good.

The UE 31 of the vehicle 30 communicates with the server 10 via the base station 16 of the mobile communication network (cellular network) by the network communication method (for example, 3G, LTE, or next-generation NR method) which is the first communication method. It is possible (hereinafter, communication by the network communication method is also referred to as "Uu communication"). The network communication method of Uu communication is 3GPP Cat. M or Cat. It may be a wireless communication method conforming to the NB specifications.

Further, the UE 31 of the vehicle 30 can perform wireless communication with another vehicle (hereinafter, also referred to as “vehicle-to-vehicle communication”) by a second communication method that does not go through a base station of a mobile communication network (cellular network). .. The second communication method is, for example, a Sidelink method using a PC-5 (hereinafter, also referred to as “PC5”) interface (hereinafter, also referred to as a “PC5 communication method” or a “PC-5 Sidelink method”). The PC-5 interface is a D2D (Device to Device) interface in which UEs, UEs and other devices (for example, vehicles), vehicles, or vehicles and other devices communicate directly without going through a base station. Yes, it has been standardized since 3GPP Release 12. In the PC5 communication method (Sidelink method), UEs, UEs and other devices (for example, vehicles), vehicles, or vehicles and other devices are compared without using a base station by using a PC-5 interface or the like. It is a short-range wireless communication method that directly communicates in a small area.

Further, the UE 31 of the vehicle 30 communicates with the UE of the vehicle of the data transmission destination by the second communication method without using the base station of the mobile communication network (cellular network) by the PC5 communication method (Sidelink method). A single direct wireless communication (hereinafter referred to as "single hop communication") may be performed without the UE of the vehicle, or a multi with a plurality of direct wireless communications via the UE of one or more other vehicles. Hop communication may be performed.

In the PC5 communication method, the Layer-2 ID is a communication identifier (frame identifier) that identifies a frame (also referred to as a “MAC packet”) that is a data processing unit in the data link layer (Layer-2) of the layered communication model. (Hereinafter, abbreviated as "L2ID" as appropriate) is defined. The three-digit number illustrated in a frame behind the vehicle 30 in FIG. 1 is the value of L2ID as a communication identifier assigned to the vehicle 30 (UE31) (see FIG. 2 described later).

In the example of FIG. 1, UEs 31 (1) to 31 (3) of a plurality of vehicles 30 (1) to 30 (3) are in the same cell 80, but are in different cells. You may. Further, the UEs 31 (1) to 31 (3) of the vehicles 30 (1) to 30 (3) may selectively or simultaneously perform the direct wireless communication and the Uu communication by the PC5 communication method.

FIG. 2 is an explanatory diagram showing an example of data communication between vehicles by the PC5 communication method according to the present embodiment. Below each of the plurality of vehicles 30 (1) to 30 (3) in FIG. 2, an example of the layered communication models 310 (1) to 310 (3) in the UEs 31 (1) to 31 (3) of each vehicle is used. Shown. In each layered communication model 310 (1) to 310 (3), from the bottom to the top, layer 1 (L1) composed of physical layers, MAC (media access control) layer and RLC (radio link control) layer Layer 2 (L2) that processes data in frame units by PDCP (packet data convergence) layer, network layer that processes data in packet units using various protocols (for example, IP, Non-IP, ARP), application layer It is composed of. Data in the application layer is also called a "message".

In FIG. 2, the UE 31 (1) of the vehicle 30 (1), which is the first communication terminal device (communication terminal device on the transmitting side), uses, for example, a part of the uplink radio resource of mobile communication, and is layer 2 ( Data (message) is transmitted in frame units by designating a Terminal L2ID (hereinafter, appropriately abbreviated as "Dst.L2ID") which is a frame identifier as a communication identifier of a transmission destination (communication destination) in L2). In the example of FIG. 2, Dst. "Yyy" is specified as the L2ID. The UEs 31 (2) and 31 (3) of the receiving side vehicles 30 (2) and 30 (3), which are the second communication terminal devices (receiving side communication terminal devices), are the transmission destinations included in the header of the received frame. It is determined whether or not the frame identifier (Dst. L2ID) of the above matches the frame identifier (L2ID) assigned to the own device.

Further, in FIG. 2, in the UE 31 (2) of the vehicle 30 (2), the frame identifier (Dst. L2ID) of the transmission destination included in the header of the received frame: yyy is assigned to the frame identifier (L2ID) of the own device. ): It is determined that the data matches yyy, and the data is processed so as to raise the packet including the data (message) of the received frame to the upper layer, so that the data can be used for the application. On the other hand, in the UE 31 (3) of the vehicle 30 (3), the frame identifier (Dst. L2ID): yyy of the transmission destination included in the header of the received frame is changed to the frame identifier (L2ID): zzz assigned to the own device. By determining that they do not match and processing the packet containing the received frame data (message) so as not to raise it to the upper layer, the data cannot be used for the application.

In FIGS. 1 and 2, UEs 31 (1) to 31 (3) of the vehicles 30 (1) to 30 (3) are wireless frames (for example, PSSCH (Physical Sidelink Shared)) when performing direct wireless communication of the PC5 communication method. Uu synchronization method as the first synchronization method and second synchronization method as a synchronization method for determining and setting the transmission / reception timing of (Channel), PSCCH (Physical Sidelink Control Channel), and PSBCH (Physical Sidelink Broadcast Channel) are assigned. It is possible to select from the GNSS synchronization method as the synchronization method of.

The Uu synchronization method is a method using a time reference of Uu communication via the base station 16 of the mobile communication network (cellular network) 15, and the signal source of the time reference is the base station 16, the server 10, or the core of the mobile communication network 15. It is a node device in the network.

On the other hand, the GNSS synchronization method is a method using a time reference acquired by a GNSS (Global Navigation Satellite System) receiver provided in the UE 31 as a current position acquisition means by receiving a radio wave from the GNSS satellite 20, and is a method of using the time reference. The signal source is the GNSS receiver in the own device.

In the example of FIG. 1, for example, the UE 31 (1) of the vehicle 30 (1) determines the transmission / reception timing of the wireless frame in the direct wireless communication of the PC5 communication method mainly by using the Uu synchronization method. On the other hand, the UEs 31 (2) and 31 (3) of the vehicles 30 (2) and 30 (3) are of wireless frames in the direct wireless communication of the PC5 communication method because, for example, Uu communication cannot always be turned on. The transmission / reception timing is determined using the GNSS synchronization method. In this way, between the UE 31 (1) of the vehicle 30 (1) and the UEs 31 (2) and 31 (3) of the vehicles 30 (2) and 30 (3), the radio frame in the direct wireless communication of the PC5 communication method If the synchronization method used to determine the transmission / reception timing is different, the transmission / reception timing of the wireless frames between the UEs communicating with each other will be different due to the difference in the time reference between the two synchronization methods, and the wireless frames of each other will be a source of radio wave interference. There is a risk.

FIG. 3 is an explanatory diagram showing an example of interference caused by different synchronization methods of transmission / reception timing of wireless frames in direct wireless communication between UEs 31 of a plurality of vehicles 30.
In FIG. 3, SFN (System Frame Number) is an identification number of a radio frame (for example, 10 ms unit) which is a basic unit in the time axis of the Uu synchronization method used in Uu communication, and each radio frame has 10 subframes. It is composed of (Subframe # = 0 to 9) (for example, in units of 1 ms). DFN (Direct Frame Number) is an identification number of a wireless frame (for example, 10 ms unit) which is a basic unit in the time axis of direct wireless communication of the PC5 communication method defined by converting it into SFN equivalent, and each wireless frame is 10. It is composed of 10 subframes (Subframe # = 0 to 9) (for example, in units of 1 ms). Here, the SFN and DFN numbers are set so that, for example, 0 to 1023 are cyclically repeated.

When Uu communication is performed between UEs 31, the SFN number and subframe number used for the Uu communication are recognized by each other between the UEs 31, and the Uu communication via the base station 16 of the mobile communication network (cellular network) 15 described above is performed. By the Uu synchronization method using a time reference, synchronization processing is performed in which the transmission / reception timings of wireless frames are matched with each other between the UEs 31.

On the other hand, when the direct wireless communication of the PC5 communication method is performed between the UEs 31, the SFN number (or DFN number) and the subframe number used for the direct wireless communication are recognized by each other between the UEs 31, and the wireless frames are transmitted and received between the UEs 31. Synchronous processing is performed to match the timing with each other. For example, in the example of FIG. 3, subframes 41 and 51 with subframe number = 3 (hereinafter, also referred to as “PC5 subframe”) in the radio frame with SFN = DFN = 1 are used for direct wireless communication between UEs. ..

As the synchronization method in the direct wireless communication of the PC5 communication method, the Uu synchronization method using the time reference of the Uu communication via the base station 16 and the time reference of the GNSS receiver receiving the radio wave from the GNSS satellite 20 are used. The GNSS synchronization method to be used can be selectively used. Therefore, if the synchronization methods are different between the plurality of UEs 31 that perform direct wireless communication of the PC5 communication method, they communicate with each other due to the time difference (time difference) ΔTs between the time reference of the Uu synchronization method and the time reference of the GNSS synchronization method. The transmission / reception timing of the PC5 subframes 41 and 51 between the UEs 31 is shifted by ΔTs.

In the direct wireless communication of the PC5 communication method specified by the above-mentioned 3GPP, the time difference (time difference) ΔTs of the transmission / reception timing of the PC5 subframes 41 and 51 is allowed up to 1.95 μs (= ΔTmax). If the deviation is more than this, the wireless frames 40 and 50 of each UE 31 may become radio wave interference sources. When the wireless frames serve as radio wave interference sources in this way, the number of wireless frames (subframes) to which the PC5 communication method can be assigned in the wireless frames used by each UE 31 decreases. Further, even if the wireless frame of the PC5 communication method is assigned, the communication quality may deteriorate.

Therefore, in the communication system of the present embodiment, the server 10 capable of communicating with each of the UEs 31 (1) to 31 (3) of the plurality of vehicles 30 (1) to 30 (2) by Uu communication via the base station 16 is used. The synchronization of wireless frames in the direct wireless communication of the PC5 communication system is optimized.

The server 10 collects and distributes information as follows, for example. First, the server 10 can use both the Uu synchronization method and the GNSS synchronization method among the plurality of vehicles 30 in the cell 80 for each cell 80 of the base station 16 UE31 (1) of the vehicle 30 (1). ), The information of the time difference ΔTs between the transmission / reception timing of the wireless frame when the Uu synchronization method is selected and the transmission / reception timing of the wireless frame when the GNSS synchronization method is selected is received. Further, the server 10 stores the information of the time difference ΔTs and the cell identification information (cell ID) in association with each other. Further, the server 10 has a time difference ΔTs corresponding to the cell 80 in which the UE is located in the UEs 31 (2) and 31 (3) of the other vehicles 30 (2) and 30 (3) communicating by the PC5 communication method. Send information about.

FIG. 4 is a block diagram showing an example of the main configuration of the server 10 according to the present embodiment. In FIG. 4, the server 10 includes an information storage unit (storage means) 101, a request reception unit (request reception means) 102, an information transmission unit (information transmission means) 103, and an information reception unit (information reception means) 104. , Information processing unit (information processing means) 105.

The information receiving unit 104 selects the cell ID as the identification information of the cell 80 in which the UE 31 (1) of the vehicle 30 (1) is located, the transmission / reception timing of the wireless frame when the Uu synchronization method is selected, and the GNSS synchronization method. The information of the time difference from the transmission / reception timing of the wireless frame at that time is received from the UE 31 (1) by Uu communication via the base station 16 of the mobile communication network 15. The UE 31 (1) determines and sets the transmission / reception timing of the wireless frame based on the Uu synchronization method and the time reference acquired by the GNSS receiver, which determines and sets the transmission / reception timing of the wireless frame based on the time reference of the Uu communication. It is a UE that can use the GNSS synchronization method. Further, the information of the time difference of the reception target is, for example, data including the value of offsetDFN. The offsetDFN is a value set in the offsetDFN parameter for shifting the timing of the DFN, which is the frame number converted to the SFN equivalent described above.

The information processing unit 105 performs a process for storing the cell ID and the offsetDFN received by the information receiving unit 104 in the information storage unit 101.

As shown in Table 1, for example, the information storage unit 101 stores the cell ID received by the information reception unit 104 and the value of the offsetDFN in association with each other.

In the request receiving unit 102, from the UEs 31 (2) and 31 (3) of the information providing destination vehicles 30 (2) and 30 (3) capable of communicating by the PC5 communication method, the UEs 31 (2) and 31 (3) are Receives the request of offsetDFN corresponding to the cell ID of the cell 80 in the area. The request receiving unit 102 may receive the cell ID of the cell 80 in which each UE 31 (2), 31 (3) is located, together with the request of the offsetDFN.

The information transmission unit 103 corresponds to the UEs 31 (2) and 31 (3) of the information providing destination vehicles 30 (2) and 30 (3) capable of communicating by the PC5 communication method, respectively, of the UEs 31 (2) and 31 (3). The offsetDFN data corresponding to the cell ID of the cell 80 in which is located is transmitted.

The information transmission unit 103 transmits the cell ID of each cell and the offsetDFN data corresponding to each cell for a plurality of cells in which the information providing destination UEs 31 (2) and 31 (3) may be located. You may. Further, the information transmission unit 103 does not respond to the request from the UEs 31 (2) and 31 (3), but delivers the offsetDFN data to the UEs 31 (2) and 31 (3) at a predetermined timing, for example. May (push type delivery).

Further, the information transmission unit 103 can transmit the information of the time difference (offsetDFN) to the UEs 31 (2) and 31 (3) of the information providing destinations by various distribution routes. For example, the information transmission unit 103 distributes the time difference (offsetDFN) information to the UEs 31 (2) and 31 (3) by the SIB (System Information Block) 21 of the notification channel via the base station 16 of the mobile communication network 15. Alternatively, the time difference (offsetDFN) information may be transmitted by the RRC Connection Recognition at the time of handover of the UEs 31 (2) and 31 (3). Further, even if the information transmission unit 103 transmits the time difference (offsetDFN) information to the UEs 31 (2) and 31 (3) using the management object of the V2X service via the base station 16 of the mobile communication network 15. Good.

Further, the main targets such as UEs 31 (2) and 31 (3) of the information providing destination vehicles 30 (2) and 30 (3) for transmitting the offsetDFN data are, for example, the following (A) and (B). As illustrated, it is a device in which it is difficult to extract time difference information (offsetDFN) by itself.

(A) UE of the vehicle to which the PC5 communication function is retrofitted:
This vehicle is, for example, a vehicle (connected car) capable of Uu communication already on the market, and is a vehicle to which an external device (dongle) for direct wireless communication of the PC5 communication method is added. In the UE of this vehicle, an add-on of an external device (dongle) is realized by using a standard IF such as USB, but in the Uu communication module of the UE main body and the Uu synchronization method via the standard IF, it is on the order of μsec. Since it is difficult to secure delays, a GNSS synchronization method using a GNSS receiver provided in an external device (dongle) is selected.

(B) IoT device (UE) having a PC5 communication function:
This IoT device is used for Uu communication with NB-IoT / Cat. It is a device using M, for example, a UE incorporated in a traffic light, a watching GNSS terminal, or the like. NB-IoT / Cat. In IoT devices that use M, Uu may not always be expected due to use cases. In this case, the time reference output from the GNSS receiver must be used as the synchronization signal source.

In the server 10 of the present embodiment, the time difference information (offsetDFN) received by the server 10 from the UE 31 of the vehicle 30 may fluctuate with time. For example, with respect to the clock source vibration used in the base station 16, the clock frequency has a characteristic of fluctuating depending on the temperature. That is, the relative frequency difference between the clock period of the time reference received from the base station 16 in the Uu synchronization system and the clock period of the time reference in the GNSS synchronization system varies depending on the temperature. Therefore, when there is such a temperature fluctuation in the clock period, it is not sufficient to correct the time difference between the transmission / reception timing of the Uu-synchronous wireless frame and the transmission / reception timing of the GNSS-synchronized wireless frame only once. Needs to be updated regularly.

Therefore, in the present embodiment, the reception (acquisition) and transmission (distribution) of the time difference (offsetDFN) information from the UE 31 of the plurality of vehicles 30 may be performed periodically.

Figure 5 is received (acquired) the information of the time difference (OffsetDFN) in the information processing unit 105 of the server 10 according to the embodiment and transmission (distribution) is a flow chart showing an example of a periodically when the Hare line information ..
In FIG. 5, when the server 10 newly receives the information of the time difference (offsetDFN) (S101), the server 10 determines whether or not the absolute value of the time difference (offsetDFN) of the new reception is equal to or more than the threshold value for determining the predetermined abnormal data. (S102). When the absolute value of the time difference (offsetDFN) of the new reception is equal to or greater than the threshold value (YES in S102), it is discarded as abnormal data due to a measurement error of the time difference (offsetDFN) or the like (S103). By discarding the abnormal data in this way, it is possible to avoid erroneous setting of the transmission / reception timing of the wireless frame during the direct wireless communication of the PC5 communication method due to the abnormal data in the UE 31.

When the absolute value of the new reception time difference (offsetDFN) is smaller than the threshold value (NO in S102), the server 10 further determines that the absolute value of the new reception time difference (offsetDFN) is within a predetermined allowable range for update determination. Whether or not it is determined (S104). Here, the permissible range is, for example, the maximum permissible deviation amount ΔTmax (for example, 1.95 μs) of the transmission / reception timing of the PC5 subframes 41 and 51 in the direct wireless communication of the PC5 communication method defined by the above-mentioned 3GPP.

Here, when the absolute value of the time difference (offsetDFN) of the new reception is within the permissible range (YES in S104), there is no large interference during the direct wireless communication of the PC5 communication method and the communication quality does not deteriorate. Repeat S104. As a result, it is possible to avoid unnecessary update processing (shift processing) of the transmission / reception timing of the wireless frame during direct wireless communication of the PC5 communication method.

On the other hand, when the absolute value of the time difference (offsetDFN) of the new reception exceeds the permissible range (NO in S104), the server 10 has the latest predetermined number (N) of the time difference (offsetDFN) data. By deleting the oldest time difference (offsetDFN) data and adding the newly received time difference (offsetDFN) data, the latest predetermined number (N) time difference (offsetDFN) information is updated (S105). ). The server 10 calculates the average value of the time difference (offsetDFN) of the latest predetermined number (N) after the update, and delivers the average value of the time difference (offsetDFN) to the UE 31 of the vehicle 30 (S106). As a result, the time when the server 10 receives from the UE 31 of the vehicle 30 due to the time-dependent change of the clock frequency of the base station 16 while avoiding a sudden shift in the transmission / reception timing of the wireless frame during the direct wireless communication of the PC5 communication method. It is possible to deal with fluctuations in the difference information (offsetDFN) over time.

FIG. 6 is a block diagram showing an example of a main configuration of the UE 31 of the vehicle 30 according to the present embodiment. In FIG. 6, the UE 31 includes an information acquisition unit (information receiving means) 311, a vehicle information acquisition unit 312, and an information storage unit (information storage means) 313.

The information acquisition unit 311 receives and acquires the above-mentioned time difference information (offsetDFN) corresponding to the cell 80 in which the UE 31 is located from the server 10 by Uu communication. For example, the information acquisition unit 311 uses a network communication system (for example, a next-generation NR system such as 3G system, LTE system, 5G, etc.) and uses a wireless resource assigned to the UE 31 to perform a mobile communication network (cellular network). ) 15 Receives time difference information (offsetDFN) from the server 10 by wirelessly communicating with the base station 16.

The information acquisition unit 311 may receive the time difference (offsetDFN) information in the SIB21 of the broadcast channel, or may receive the time difference (offsetDFN) information in the RRC Connection Recognition at the time of handover of the UE 31. Further, the information acquisition unit 311 may receive the information of the time difference (offsetDFN) by using the management object of the V2X service.

Further, the information acquisition unit 311 uses the time difference information (offsetDFN) to obtain the time difference information (offsetDFN) corresponding to each cell and the corresponding cell ID for a plurality of cells in which the UE 31 may be located. It may be received and acquired.

Further, the information acquisition unit 311 can output the time reference used in the Uu synchronization method by communicating with the base station 16 of the mobile communication network (cellular network) 15.

The vehicle information acquisition unit 312 acquires the position information and speed information of the current position of the UE 31 of the own vehicle 30 by the above-mentioned GNSS receiver, the drive control device of the vehicle 30, and the like.

The information storage unit 313 stores (associates) the time difference information (offsetDFN) acquired from the server 10 by the information acquisition unit 311 with the cell ID. Further, the information storage unit 313 stores the information of the communication destination map and the position information and the speed information of the current position of the UE 31 of the own vehicle 30 acquired by the vehicle information acquisition unit 312.

Further, the UE 31 includes an identifier acquisition unit (identifier acquisition means) 314, an identifier selection unit (identifier selection means) 315, and a data transmission unit (data transmission means) 316.

Further, when the identifier acquisition unit 314 transmits data to the UE or the like of a surrounding vehicle, the identifier acquisition unit 314 refers to the communication destination map stored in the information storage unit 313, and another other in the vicinity of the current position of the UE 31 of the own vehicle 30. Acquire a plurality of communication identifiers (L2IDs) corresponding to the UE of the vehicle. Further, when the identifier acquisition unit 314 receives data from the UEs of surrounding vehicles, the identifier acquisition unit 314 refers to the communication destination map stored in the information storage unit 313, and other units around the current position of the UE 31 of the own vehicle 30. Acquire a plurality of communication identifiers (L2IDs) corresponding to the UE of the vehicle.

When the identifier selection unit 315 transmits data to the UE or the like of a surrounding vehicle, the identifier selection unit 315 obtains the L2ID corresponding to the desired vehicle (UE) from the plurality of communication identifiers (L2ID) acquired by the identifier acquisition unit 314. Select as L2ID. In addition, the identifier selection unit 315 sets the L2ID corresponding to a specific vehicle (UE) according to at least one of the type of communication service accompanied by data transmission by the PC5 communication method and the purpose of communication. It may be selected as L2ID. In this case, data is transmitted by designating a different vehicle (UE) for each type of communication service that involves data transmission by the PC5 communication method, for each purpose of the communication, or for each combination of the type and use. can do.

The data transmission unit 316 sets the L2ID corresponding to the specific vehicle (UE) to be data transmitted to Dst. Frames containing data added as L2ID (destination communication identifier) are single-hop communication of PC5 communication method (hereinafter also referred to as "PC5 single-hop communication") and multi-hop communication of PC5 communication method (hereinafter "PC5 multi-hop"). It is also referred to as "communication"), or is transmitted to the surrounding area by Uu communication of the network communication method via the base station of the mobile communication network (cellular network).

The UE 31 also includes a data receiving unit (data receiving means) 317 and a data processing unit (data processing means) 318. The data receiving unit 317 uses PC5 single-hop communication, PC5 multi-hop communication, or Uu communication, which is a network communication method via a base station of a mobile communication network (cellular network), to receive a frame containing data from the UE of a nearby vehicle. Receive.

The data processing unit 318 applies Dst.D. to the data received by the data receiving unit 317. Data processing that enables the application to use the received data when the destination L2ID added as the L2ID matches the L2ID corresponding to the management area including the current position of the own vehicle 30 (UE31). I do.

Further, the UE 31 includes a GNSS receiving unit 330 and a synchronization method selection unit (synchronization method selection means) 331. The GNSS receiving unit 330 receives radio waves from the GNSS satellite 20 and outputs a time reference used in the GNSS synchronization method. The synchronization method selection unit 331 selectively uses the above-mentioned Uu synchronization method and GNSS synchronization method as the synchronization method for determining and setting the transmission / reception timing of the wireless frame in the direct wireless communication of the PC5 communication method.

In addition, the UE 31 includes an information transmission unit (information transmission means) 319 that transmits various information to the server 10. When the UE 31 can extract the time difference (offsetDFN) between the time reference of the Uu synchronization method and the time reference of the GNSS synchronization method, the information transmission unit 319 transmits the extracted time difference (offsetDFN) to the server 10 together with the cell ID. Send.

Further, the UE 31 includes a communication control unit (communication control means) 320 that controls data communication with another UE and communication with the server 10. For example, the communication control unit 320 determines and sets the transmission / reception timing of the wireless frame in the direct wireless communication of the PC5 communication method according to the synchronization method selected by the synchronization method selection unit 331.

For example, the UE 31 (1) of the vehicle 30 (1) in FIG. 1 selects the Uu synchronization method described above, and determines the transmission / reception timing of the wireless frame 40 and the subframe 41 based on the time reference of the Uu synchronization method. And set.

Further, the UEs 31 (2) and 31 (3) of the vehicles 30 (2) and 30 (3) in FIG. 1 described above select the above-mentioned GSNN synchronization method, and the time reference of the GSNN synchronization method is used in the own device. By correcting using the extracted time difference (offsetDFN) or the time difference (offsetDFN) received from the server 10, the transmission / reception timing of the wireless frame and the subframe is determined and set. For example, the following equation (1) is used to determine the transmission / reception timing (start timing time) of each DFN radio frame (for example, in units of 10 ms), and the following equation (2) is used to determine the subframe number of each subframe in the DFN. The transmission / reception timing (start timing time) of a frame (for example, in units of 1 ms) is determined.

In the above equations (1) and (2), "Tcurent" represents the current UTC time (in milliseconds) obtained from the GNSS device, and "Tref" is 0:00:00 on January 1, 1900. Represents the UTC time of. Each of the above equations (1) and (2) converts the current time obtained from the GSNN device into a frame timing equivalent to that of SFN and SubframeNumber, which are defined frame timing times used in Uu communication. The above equations (1) and (2) are examples of correction by sliding forward (in the direction of earlier timing) on the time axis using offsetDFN.

The communication control units 320 of the UEs 31 (2) and 31 (3) of the vehicles 30 (2) and 30 (3) are preset based on the frame timing corrected by the above equations (1) and (2). The data communication of the PC5 communication method is controlled by the DFN of the predetermined number and the subframe 51 of the subframe number. By this control, the transmission / reception timing of the subframe 51 of the wireless frame 50 when the UEs 31 (2) and 31 (3) of the vehicles 30 (2) and 30 (3) perform data communication of the PC5 communication method, and the vehicle-to-vehicle communication. The transmission / reception timing of the subframe 41 of the wireless frame 40 when the UE 31 (1) of the vehicle 30 (1), which is the other party side of the above, performs data communication of the PC5 communication method, matches. Therefore, the subframes 41 and 51 of the wireless frames 40 and 50 of the data communication of the PC5 communication method do not receive interference from the subframes of other communication or interfere with the subframes of other communication. Suppressing the interference of the radio frame in the direct wireless communication of the PC5 communication method between the UE 31 (1) of the 30 (1) and the UEs 31 (2) and 31 (3) of the vehicles 30 (2) and 30 (3). Can be done.

Further, the communication control unit 320 performs single-hop communication with the UE of the data transmission destination by the PC5 communication method based on the information received from the server 10 via one or a plurality of other UEs by the PC5 communication method. It may be controlled to switch to at least one communication of communication and Uu communication via the mobile communication network. Further, the communication control unit 320 may control so as to suppress the transmission power by the PC5 communication method based on the information received from the server 10.

As described above, according to the present embodiment, even when the signal sources of the time reference used as the reference of the transmission / reception timing of the wireless frame are different from each other in the plurality of UEs 31 that directly perform wireless communication with each other by the PC5 communication method, the direct wireless communication of the PC5 communication method is performed. Since the subframe of the wireless frame used for the above does not receive interference from the subframe of other communication or interfere with the subframe of other communication, the interference of the wireless frame in the direct wireless communication of the PC5 communication method is suppressed. can do.

The processing steps described in this specification and the components of the communication terminal device (UE), the base station, the server, the MEC device, and the communication system can be implemented by various means. For example, these steps and components may be implemented in hardware, firmware, software, or a combination thereof.

Regarding hardware implementation, means such as a processing unit used to realize the above steps and components in an entity (for example, various wireless communication devices, eNodeBs, terminals, hard disk drive devices, or optical disk drive devices) One or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processors (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors , Controllers, microprocessors, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, computers, or combinations thereof.

For firmware and / or software implementation, means such as processing units used to implement the above components are programs (eg, procedures, functions, modules, instructions) that perform the functions described herein. , Etc.) may be implemented. Generally, any computer / processor readable medium that clearly embodies the firmware and / or software code is a means such as a processing unit used to implement the steps and components described herein. May be used to implement. For example, the firmware and / or software code may be stored in memory and executed by a computer or processor, for example, in a control device. The memory may be implemented inside the computer or processor, or may be implemented outside the processor. Further, the firmware and / or software code may be, for example, a random access memory (RAM), a read-only memory (ROM), a non-volatile random access memory (NVRAM), a programmable read-only memory (PROM), or an electrically erasable PROM (EEPROM). ), FLASH memory, floppy (registered trademark) discs, compact discs (CDs), digital versatile discs (DVDs), magnetic or optical data storage devices, etc. Good. The code may be executed by one or more computers or processors, or the computers or processors may be made to perform functional embodiments described herein.

Further, the medium may be a non-temporary recording medium. Further, the code of the program may be read and executed by a computer, a processor, or another device or device machine, and the format thereof is not limited to a specific format. For example, the code of the program may be any of source code, object code, and binary code, or may be a mixture of two or more of these codes.

Also, the description of the embodiments disclosed herein is provided to allow one of ordinary skill in the art to manufacture or use the disclosure. Various amendments to this disclosure will be readily apparent to those of skill in the art and the general principles defined herein are applicable to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but should be accepted in the broadest range consistent with the principles and novel features disclosed herein.

10: Server 15: Mobile communication network 16: Base station 20: GNSS satellite (artificial satellite)
30, 30 (1) to 30 (3): Vehicle 31, 31 (1) to 31 (3): Communication terminal device (UE)
40: Wireless frame synchronized by Uu synchronization method 41: Subframe used for direct wireless communication 50: Wireless frame synchronized by GNSS synchronization method 51: Subframe used for direct wireless communication 80: Cell 101: Information storage unit 102: Request reception Unit 103: Information transmission unit 104: Information reception unit 105: Information processing unit 311: Information acquisition unit 312: Vehicle information acquisition unit 313: Information storage unit 314: Identifier acquisition unit 315: Identifier selection unit 316: Data transmission unit 317: Data Reception unit 318: Data processing unit 319: Information transmission unit 320: Communication control unit 330: GNSS reception unit 331: Synchronization method selection unit

Claims (19)

A server that provides information
For each of the plurality of base stations in the mobile communication network, the first synchronization method in which the transmission / reception timing of the wireless frame is determined and set based on the time reference of the communication via the base station and the time reference acquired by the GNSS receiver. a second synchronization method with the first communication terminal device communication available-the direct radio communication system between the short-range device by selecting the synchronization method from that set by determining the reception timing of the radio frame based on the When in the cell of the base station, the radio frame transmission / reception timing when the first synchronization method is selected and the radio when the second synchronization method is selected from the first communication terminal device. An information receiving means that periodically receives information on the time difference from the frame transmission / reception timing,
For each of the plurality of base stations, for each cell of the base station, the time difference information received from the first communication terminal device and the cell that identifies the cell in which the first communication terminal device is located are identified. A storage means for storing identification information in association with each other,
The second communication terminal apparatus that communicates directly by radio communication system between the short-range device selects the second synchronization method in each of a plurality of cells of the base station of the mobile communication network, the GNSS receiver The time difference information and the cell identification information stored in association with each other in the storage means are stored in the storage means so that the transmission / reception timing of the wireless frame can be determined and set by correcting the time reference acquired in. Information transmission means that is periodically transmitted to the communication terminal device of 2 and
A server characterized by being equipped with. In the server of claim 1,
When the time difference information is received, the received time difference information falls within a predetermined range including the latest predetermined number of time difference information stored in association with the cell identification information of the cell. Judge whether or not there is
If the received time difference information is not within the predetermined range, it is discarded as abnormal data.
When the received time difference information is within the predetermined range, the server is characterized in that the received time difference information is added as the latest predetermined number of time difference information. In the server of claim 2.
When you add information on the latest predetermined number time difference information to a new time difference of the average value of the most recent time difference information of a predetermined number after the addition, the communication terminal apparatus information providing destination A server characterized by sending. In any of the servers of claims 1 to 3,
A server characterized in that the time difference information is transmitted via a base station of a mobile communication network using a broadcast channel, RRC Connection Recognition at the time of handover, or a management object of a V2X service. In any of the servers of claims 1 to 4,
The server characterized in that the time difference information is set to an offsetDFN parameter that shifts a frame number DFN (Direct Frame Number) converted to SFN (System Frame Number). A communication terminal device capable of selectively or simultaneously executing communication via a base station of a mobile communication network and communication by a direct wireless communication method between short-range devices.
The transmission / reception timing of the wireless frame is determined based on the time reference acquired by the GNSS receiver and the first synchronization method that determines and sets the transmission / reception timing of the wireless frame based on the time reference of communication via the base station of the mobile communication network. and a second synchronization method to set determined by the synchronization method selection means directly you select a synchronization method used for wireless communication method between the near device,
The server according to any one of claims 1 to 5, which provides information on the time difference between the transmission / reception timing of the wireless frame when the first synchronization method is selected and the transmission / reception timing of the wireless frame when the second synchronization method is selected. Information transmission means to be sent regularly to
A communication terminal device comprising. It is a communication terminal device that performs direct wireless communication between short-range devices based on the time reference acquired by the GNSS receiver.
A time reference for communication via the base station and a time reference acquired by the GNSS receiver , which are stored in association with each other in the server according to any one of claims 1 to 5 for each of the plurality of base stations in the mobile communication network. an information receiving means for time difference information and the cell identification information of the cell of the base station periodically receives from the server and,
On the basis of the information and the cell identification information of the time difference received from the server, the communication terminal apparatus using the information of the time difference corresponding to the cell visited, to correct the time reference acquired by the GNSS receiver a reception timing correction means for setting determines the reception timing of the non-linear frame,
A communication terminal device comprising. In the communication terminal device of claim 7,
A communication terminal device characterized in that the time difference information is received via a base station of the mobile communication network using a broadcast channel, an RRC Connection Recognition at the time of handover, or a management object of a V2X service. In the communication terminal device according to any one of claims 6 to 8.
The communication terminal device, characterized in that the time difference information is set to an offsetDFN parameter that shifts a frame number DFN (Direct Frame Number) converted to SFN (System Frame Number). In the communication terminal device according to any one of claims 6 to 9.
The wireless communication method for communication via the base station of the mobile communication network is 3GPP Cat. M or Cat. A communication terminal device characterized by being a wireless communication system conforming to NB specifications. In the communication terminal device according to any one of claims 6 to 10.
A communication terminal device characterized in that it is mounted on a moving body that moves on the ground, on the water, or in the air. In the communication terminal device according to any one of claims 6 to 11.
A communication terminal device characterized by being mounted on an IoT device. A mobile body including the communication terminal device according to any one of claims 6 to 12. An IoT device including the communication terminal device according to any one of claims 6 to 12. A communication system comprising the server according to any one of claims 1 to 5 and the communication terminal device according to any one of claims 6 to 14. It ’s a way of providing information,
For each of the plurality of base stations in the mobile communication network, the first synchronization method in which the transmission / reception timing of the wireless frame is determined and set based on the time reference of the communication via the base station and the time reference acquired by the GNSS receiver. a second synchronization method with the first communication terminal device communication available-the direct radio communication system between the short-range device by selecting the synchronization method from that set by determining the reception timing of the radio frame based on the When in the cell of the base station, the radio frame transmission / reception timing when the first synchronization method is selected and the radio when the second synchronization method is selected from the first communication terminal device. Periodically receiving information on the time difference from the frame transmission / reception timing,
For each of the plurality of base stations, for each cell of the base station, the time difference information received from the first communication terminal device and the cell that identifies the cell in which the first communication terminal device is located are identified. To store the identification information in association with each other,
The GNSS receiver is a second communication terminal device that selects the second synchronization method in each of the cells of a plurality of base stations of the mobile communication network and performs communication between short-range devices by a direct wireless communication method. The second communication terminal uses the time difference information and the cell identification information stored in association with each other so that the acquired time reference can be corrected to determine and set the transmission / reception timing of the wireless frame. Sending to the device on a regular basis
A method characterized by including. A program that runs on a computer or processor on a server that provides information.
For each of the plurality of base stations in the mobile communication network, the first synchronization method in which the transmission / reception timing of the wireless frame is determined and set based on the time reference of the communication via the base station and the time reference acquired by the GNSS receiver. a second synchronization method with the first communication terminal device communication available-the direct radio communication system between the short-range device by selecting the synchronization method from that set by determining the reception timing of the radio frame based on the When in the cell of the base station, the radio frame transmission / reception timing when the first synchronization method is selected and the radio when the second synchronization method is selected from the first communication terminal device. A program code for periodically receiving information on the time difference from the frame transmission / reception timing,
For each of the plurality of base stations, for each cell of the base station, the time difference information received from the first communication terminal device and the cell that identifies the cell in which the first communication terminal device is located are identified. Program code for storing identification information in association with each other,
The second communication terminal apparatus that communicates directly by radio communication system between the short-range device selects the second synchronization method in each of a plurality of cells of the base station of the mobile communication network, the GNSS receiver The second communication uses the time difference information and the cell identification information stored in association with each other so that the transmission / reception timing of the wireless frame can be determined and set by correcting the time reference acquired in. Program code to be sent to the terminal device on a regular basis,
A program characterized by including. A program executed by a computer or processor provided in a communication terminal device capable of selectively or simultaneously executing communication via a base station of a mobile communication network and communication by a direct wireless communication method between short-range devices.
The transmission / reception timing of the wireless frame is determined based on the time reference acquired by the GNSS receiver and the first synchronization method that determines and sets the transmission / reception timing of the wireless frame based on the time reference of communication via the base station of the mobile communication network. and a second synchronization method to set determined by the program code of order to select the synchronization method used for direct wireless communication system between the short range device,
The server according to any one of claims 1 to 5, which provides information on the time difference between the transmission / reception timing of the wireless frame when the first synchronization method is selected and the transmission / reception timing of the wireless frame when the second synchronization method is selected. With the program code to send to
A program characterized by including. A program executed by a computer or processor provided in a communication terminal device that performs direct wireless communication between short-range devices based on a time reference acquired by a GNSS receiver.
A time reference for communication via the base station and a time reference acquired by the GNSS receiver , which are stored in association with each other in the server according to any one of claims 1 to 5 for each of the plurality of base stations in the mobile communication network. and program code for receiving regular time difference information and the cell identification information of the cell of the base station, from the server and,
On the basis of the information and the cell identification information of the time difference received from the server, the communication terminal apparatus using the information of the time difference corresponding to the cell visited, to correct the time reference acquired by the GNSS receiver and program code for setting determines the reception timing of the non-linear frame,
A program characterized by including.

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