Patent ID: 12250666

DESCRIPTION OF EMBODIMENTS

In the 5G, there are no clear definitions similar to the LTE-WLAN aggregation and the LTE/WLAN Radio Level Integration with IPsec Tunnel in the 4G.

In order to implement IoT services in the 5G, for example, a terminal device may perform DC duplication and transmit the same duplicated data a plurality of times. In this case, for example, the terminal device transmits the data by using different paths in order to increase a probability of arrival of the data. Assuming such a case, in the 5G, it is needed to define a communication standard using a plurality of paths. The plurality of paths are, for example, a path that directly connects a base station device (gNB) from the terminal device wirelessly and a path via a relay device (communication device) between the terminal device and the base station device.

Therefore, a base station device, a relay device, and a communication system that relay communication between the terminal device and the base station device in 5G are provided.

Hereinafter, the present embodiments will be described in detail with reference to the drawings. Problems and examples in the present description are examples and do not limit the scope of rights of the present application. In particular, as long as the described expressions are technologically equivalent even if the described expressions are different, the technologies of the present application may be applied and the scope of rights is not limited even if the expressions are different.

First Embodiment

A first embodiment will be described.

FIG.1is a diagram illustrating an example of a wireless communication system1in the first embodiment. The wireless communication system1includes a terminal device10, a base station device20, and a relay device30.

For example, when the terminal device10transmits data to the base station device20or to another communication device via the base station device20, the terminal device10may duplicate the data to be transmitted and transmits the duplicated data by using a plurality of paths. The plurality of paths includes, for example, a path directly connected to the base station device20wirelessly and a path in which the relay device30connected wirelessly relays and transmits data to the base station device20.

The terminal device10and the base station device20perform wireless communication by a first wireless communication method (communication C1). Then, the terminal device10and the base station device20transmit/receive first data D1by the first wireless communication method.

Furthermore, the terminal device10and the relay device30perform wireless communication by a second wireless communication method (communication C2). Then, the terminal device10and the relay device30transmit/receive second data D2by the second wireless communication method. Note that, the second wireless communication method is not limited to wireless communication or wired communication, and may also be an interface.

The relay device30and the base station device20perform wireless communication by the first wireless communication method or the second wireless communication method (communication C3). Then, the relay device30and the base station device20transmit/receive the second data D2by the first wireless communication method or the second wireless communication method.

When the terminal device10performs wireless communication with the base station device20, the terminal device10may use both the communication C1in which the terminal device10is directly connected to the base station device20wirelessly and the communication C2and the communication C3in which the communication is performed via the relay device30. In this case, the first data D1and the second data D2transmitted by the terminal device10may also be, for example, the same duplicated data.

The relay device30uses the communication C2and the communication C3to relay wireless communication between the terminal device10and the base station device20.

The base station device20includes a control unit21and a transmission/reception unit22. When the terminal device10performs data transmission (wireless communication) by using the communication C1and both of the communication C2and the communication C3, the transmission/reception unit22receives the first data D1via the communication C1and the second data D2via the communication C3. The first data D1is data transmitted by the first wireless communication method, and is data compatible with (conforming to) the first wireless communication method. On the other hand, the second data D2is data transmitted by either the first wireless communication method or the second wireless communication method, and is data compatible with (conforming to) either the first wireless communication method or the second wireless communication method. The transmission/reception unit22may identify a bearer in the first wireless communication method of each piece of data regardless of by which wireless communication method the second data D2is transmitted (S1).

When the second data D2is data transmitted by the second wireless communication method, the base station device20may identify the first data D1and the second data D2as different bearers by, for example, managing an identifier of a communication partner device such as the terminal device10or the relay device30and each bearer in association with each other.

On the other hand, for example, when the second data D2is data transmitted by the first wireless communication method, since the first data D1and the second data D2are data transmitted from the same terminal device10by the same wireless communication method, the base station device20performs the processing S1to identify each as a different bearer.

The control unit21may converge wireless communication by a layer (convergence layer) that converges each piece of data by wireless communication in the first wireless communication method regardless of by which wireless communication method the second data D2is transmitted (S2).

For example, when the second data D2is data transmitted by the second wireless communication method, the base station device20performs the processing S2to converge the second data D2by the convergence layer of the first wireless communication method. The base station device20performs communication by regarding communication with the terminal device10which is a first communication device and communication with the relay device30which is a second communication device as communication with the same communication device. Although the base station device20actually performs a plurality of (two in this case) types of communication with different communication devices (terminal device10and relay device30) through different communication paths (communication C1and communication C3), the base station device20regards this plurality of types of communication as one type of communication performed with one terminal device (for example, terminal device10). For example, the base station device20may regard the relay device30as a relay station in communication with the terminal device10, and may recognize communication with the relay device30as communication with the terminal device10.

In the first embodiment, for example, in a case where the base station device20is a base station device compatible with 5G, the base station device20may cope with simultaneous transmission of data of the terminal device10in 5G through another path.

Second Embodiment

A second embodiment will be described.

<Exemplary Configuration of Wireless Communication System>

FIG.2is a diagram illustrating an exemplary configuration of a communication system11. The communication system11includes a terminal device (communication device)100, a base station device200, a relay device (communication device)300, and an internet protocol (IP) network400. The communication system11is, for example, a wireless communication system that performs wireless communication conforming to 5G. The base station device200is, for example, a gNodeB (gNB). Furthermore, the terminal device100is a device that performs communication with the base station device200or with another communication device via the base station device200, and is, for example, a mobile communication terminal such as a smartphone or a tablet terminal. Furthermore, the terminal device100may also be, for example, a working machine installed in a factory or an unmanned traveling vehicle. Moreover, the terminal device100is a communication device capable of performing wireless communication conforming to IoT services (for example, compatible with URLLC).

The terminal device100transmits data to, for example, another communication device on the IP network400. The terminal device100may, for example, perform DC duplication (duplicate transmission, simultaneous transmission) and transmit data to another communication device.

The DC duplication is, for example, a data transmission method in which data is duplicated when an URLLC data transmission trigger occurs and the data is transmitted by using a plurality of paths. In the DC duplication, by transmitting the data through the plurality of paths, the terminal device100improves a probability that the data reaches a destination, and achieves high reliability. Furthermore, by transferring, to the destination, data received first among the data received through the plurality of paths, the base station device200may transmit the data to the destination in a shorter time, and achieves low latency.

The terminal device100duplicates, for example, data to be transmitted in the DC duplication. Then, the terminal device100transmits one of the duplicated data to the base station device200via wireless communication directly connected to the base station device200(path R1). Moreover, the terminal device100transmits another one of the duplicated data to the base station device200(path R2-2) via the relay device300(path R2-1). When the base station device200receives the data from either one of the path R1 or the path R2-2, the base station device200transmits the data to the IP network400and transmits the data to a destination communication device.

Furthermore, communication between the terminal device100and the relay device300may also be an interface. For example, the relay device300may also be an external terminal device or a dongle type terminal device. In this case, the terminal device100and the relay device300may also be, for example, a communication terminal that is connected a computer such as a notebook PC.

<Exemplary Structure of Relay Device>

FIG.3is a diagram illustrating an exemplary structure of the relay device300. The relay device300is a communication device that relays communication between the terminal device100and the base station device200. The relay device300is, for example, a relay device (wireless LAN (WLAN) termination: WT) compatible with short-range wireless communication such as Wi-Fi.

The relay device300includes a central processing unit (CPU)310, a storage320, a memory330such as a dynamic random access memory (DRAM), and radio frequency (RF) circuits350-1and350-2.

The storage320is an auxiliary storage device that stores programs and data, such as a flash memory, a hard disk drive (HDD), or a solid state drive (SSD). The storage320stores a relay transmission program321.

The memory330is an area into which a program stored in the storage320is loaded. Furthermore, the memory330is also used as an area in which the program stores data.

The RF circuits350-1and350-2are devices that are wirelessly connected to the terminal device100and the base station device200.

The RF circuit350-1is, for example, a wireless device compatible with Wi-Fi and is wirelessly connected to the terminal device100. The RF circuit350-1includes an antenna351-1corresponding to a corresponding wireless protocol.

The RF circuit350-2is, for example, a wireless device compatible with an NR and is wirelessly connected to the base station device200. The RF circuit350-2includes an antenna351-2corresponding to a corresponding wireless protocol. Note that the RF circuit350-2may be a wireless device corresponding to a protocol wirelessly connected to the base station device200, and may also be a wireless device corresponding to other than the NR.

The CPU310is a processor or computer that implements each processing by loading a program stored in the storage320into the memory330and executing the loaded program.

The CPU310constructs an inter-terminal communication unit and an inter-base station communication unit to perform relay transmission control processing, by executing the relay transmission program321. The relay transmission control processing is processing of relaying, transmitting, and controlling communication between the terminal device100and the base station device200.

The CPU310constructs the inter-terminal communication unit, an inter-base station communication unit relay unit, and a conversion unit to perform communication control processing, by executing a communication control module3211included in the relay transmission program321. The communication control processing is processing of controlling relay transmission in which data received from the terminal device100is transmitted to the base station device200and data received from the base station device200is transmitted to the terminal device100.

The CPU310constructs the inter-terminal communication unit, the inter-base station communication unit relay unit, and the conversion unit to perform terminal side communication processing, by executing a terminal side communication module3212included in the relay transmission program321. The terminal side communication processing is processing of performing wireless connection and data transmission/reception with the terminal device100.

The CPU310constructs the inter-terminal communication unit, the inter-base station communication unit relay unit, and the conversion unit to perform base station side communication processing, by executing a base station side communication module3213included in the relay transmission program321. The base station side communication processing is processing of executing wireless connection and data transmission/reception with the base station device200.

<Exemplary Structure of Base Station Device200>

FIG.4is a diagram illustrating an exemplary structure of the base station device200. The base station device200is, for example, a communication device that performs wireless communication with the relay device300and the terminal device100. The base station device200includes a CPU210, a storage220, a memory230such as a DRAM, a network interface card (NIC)240, and RF circuits250-1and250-2.

The storage220is an auxiliary storage device that stores programs and data, such as a flash memory, an HDD, or an SSD. The storage220stores a communication control program221and a data transmission/reception program222.

The memory230is an area into which a program stored in the storage220is loaded. Furthermore, the memory230is also used as an area in which the program stores data.

The RF circuits250-1and250-2are devices that are wirelessly connected to the terminal device100and the relay device300.

The RF circuit250-1is, for example, a wireless device compatible with the NR and is wirelessly connected to the terminal device100. The RF circuit250-1has an antenna251-1corresponding to a corresponding wireless protocol.

The RF circuit250-2is, for example, a wireless device compatible with Wi-Fi and is wirelessly connected to the relay device300. The RF circuit250-2includes an antenna251-2corresponding to a corresponding wireless protocol. Note that the RF circuit250-2may be a wireless device corresponding to a protocol wirelessly connected to the relay device300, and may also be a wireless device corresponding to other than Wi-Fi. The RF circuit250-2is compatible with the NR when, for example, the protocol wirelessly connected to the relay device300is compatible with the NR.

The CPU210is a processor or computer that implements each processing by loading a program stored in the storage220into the memory230and executing the loaded program.

The CPU210constructs a transmission/reception unit and a control unit to perform communication control processing, by executing the communication control program221. The communication control processing is processing of controlling communication directly connected to the terminal device100and communication relayed via the relay device300.

The CPU210constructs the control unit and the transmission/reception unit to perform duplication control processing, by executing a duplication control module2211included in the communication control program221. The duplication control processing is processing of controlling the same data received through a plurality of paths and controlling transmission of an ACK/NACK to a transmission source device.

The CPU210constructs the transmission/reception unit to perform data transmission/reception processing, by executing the data transmission/reception program222. The data transmission/reception processing is processing of transmitting/receiving data in communication between the terminal device100and the relay device300.

<Exemplary Structure of Terminal Device100>

FIG.5is a diagram illustrating an exemplary structure of the terminal device100. The terminal device100is a communication device that performs wireless communication with the relay device300and the base station device200.

The terminal device100includes a CPU110, a storage120, a memory130such as a DRAM, and RF circuits150-1and150-2.

The storage120is an auxiliary storage device that stores programs and data, such as a flash memory, an HDD, or an SSD. The storage120stores a communication program121.

The memory130is an area into which a program stored in the storage120is loaded. Furthermore, the memory130is also used as an area in which the program stores data.

The RF circuits150-1and150-2are devices that are wirelessly connected to the relay device300and the base station device200.

The RF circuit150-1is, for example, a wireless device compatible with Wi-Fi and is wirelessly connected to the relay device300. The RF circuit150-1includes an antenna151-1corresponding to a corresponding wireless protocol.

The RF circuit150-2is, for example, a wireless device compatible with the NR and is wirelessly connected to the base station device200. The RF circuit150-2includes an antenna151-2corresponding to a corresponding wireless protocol.

The CPU110is a processor or computer that implements each processing by loading a program stored in the storage120into the memory130and executing the loaded program.

The CPU110constructs a first communication unit and a second communication unit to perform communication processing, by executing the communication program121. The communication processing is processing of controlling communication with the relay device300and the base station device200.

The CPU110constructs the first communication unit and the second communication unit to perform duplication processing, by executing a duplication module1211included in the communication program121. The duplication processing is processing of performing the DC duplication, which is processing of duplicating data and transmitting the duplicated data to the relay device300and the base station device200.

<Data Transmission in DC Duplication>

An example of data transmission processing in the DC duplication is indicated below. Note that there are three examples of the data transmission processing, pattern 1 to pattern 3, and each of the examples will be described below.

<1. Data Transmission Processing>

<1.1 Pattern 1>

FIG.6is a diagram illustrating an example of data transmission (pattern 1) in the DC duplication. For example, the terminal device100performs data transmission by using the DC duplication when an URLLC data transmission trigger occurs. The terminal device100transmits data by using two paths (path R11 and path R12-1) in the DC duplication.

In the path R11, the terminal device100performs wireless communication compatible with the NR with the base station device200. The NR in the path R11 includes, for example, wireless communication function using millimeter waves (mmWAVE), and a beam sweeping function for performing transmission by switching a beam direction. The terminal device100uses the path R11 to transmit the data to the base station device200.

In the data communication in the path R11, each of the base station device200and the terminal device100supports layers (hierarchical layers) conforming to the NR and transmits/receives the data. The layers supported by the base station device200and the terminal device100in the path R11 include, for example, a physical (PHY) layer as a layer 1, a medium access control (MAC) layer as a layer 2, a radio link control (RLC) layer, and a packet data convergence protocol (PDCP) layer.

On the other hand, in the path R12-1, the terminal device100performs wireless communication compatible with Wi-Fi (WLAN) with the relay device300. The terminal device100and the relay device300perform communication in the path R12-1 on the basis of, for example, a specification standardized by the Institute of Electrical and Electronics Engineers (IEEE). Furthermore, the terminal device100converts PDCP data into data that may be transmitted on Wi-Fi by using, for example, an LTE-WLAN aggregation adaptation protocol (LWAAP) or a tunneling protocol which is compatible with the NR and is similar to the LWAAP. Furthermore, the relay device300uses the LWAAP to convert, for example, received data into data that may be transmitted by the N R.

Note that, communication between the terminal device100and the relay device300may also be, for example, communication other than the WLAN, such as communication based on LTE, communication based on WCDMA (registered trademark), or communication compatible with Bluetooth (registered trademark).

When the relay device300receives the data in the path R12-1, the relay device300transmits the data to the base station device200using a path R12-2. With this, the relay device300relays the data transmitted by the terminal device100to the base station device200.

For example, the relay device300converts PDCP data in the NR into data that may be transmitted by Wi-Fi by the LWAAP, and uses the path R12-2 to transmit the data to the base station device200. Note that, when receiving the data by the Wi-Fi method in the path R12-1, the relay device300may also transfer the data to the base station device200by the Wi-Fi method in the path R12-2 without converting the received data into PDCP data. In this case, the relay device300does not have to be compatible with the LWAAP.

The base station device200receives data via each of the path Rh and the path R12-2. The base station device200transmits, for example, previously received data to the IP network400and transmits the data to a destination. The base station device200discards, for example, data that is not transmitted.

For example, when the terminal device100is a working device installed in a factory, the destination is a factory management control system (auto-factory controller)500that manages and analyzes an operating status of the working device in the factory and controls the working device.

FIG.7is a diagram illustrating an example of a protocol stack of the communication system ofFIG.6. In the following drawings, UE indicates the terminal device100, WT indicates the relay device300, and gNB indicates the base station device200.

The base station device200and the terminal device100support the PDCP layer, the RLC layer, the MAC layer, and the PHY layer in the NR. Furthermore, since the base station device200and the terminal device100are compatible with the WLAN, the base station device200and the terminal device100support the LWAAP (layer and function), 802.11x (IEEE standard, x is the standard number), and the PHY layer (physical layer corresponding to the layer 1 of the WLAN). Moreover, the base station device200and the terminal device100each include a duplication layer (duplication function), and support transmission of duplicated data in the DC duplication and reception of the duplicated data.

Since the relay device300relays communication between the terminal device100and the base station device200in the WLAN, the relay device300is compatible with the LWAAP, 802.11x, and the PHY layer. The relay device300is connected to the base station device200by, for example, an Xw interface.

By processing the PDCP data received from the terminal device100by the NR and data received from the relay device300by the WLAN and processed by the LWAAP by the duplication layer, the base station device200converges a data packet by the PDCP layer.

With this, the relay device300may relay communication between the terminal device and the base station device in the 5G.

<1.2 Pattern 2>

FIG.8is a diagram illustrating an example of the data transmission (pattern 2) in the DC duplication. The terminal device100performs data transmission by the DC duplication, for example, when an URLLC data transmission trigger occurs. The terminal device100transmits data by using two paths (path R21 and path R22-1) in the DC duplication.

In the path R21, the terminal device100performs wireless communication compatible with the NR with the base station device200. In the data communication in the path R21, each of the base station device200and the terminal device100supports layers in the NR and transmits/receives the data. The layers supported by the base station device200and the terminal device100in the path R21 include, for example, the PHY layer, the MAC layer, the RLC layer, and the PDCP layer.

On the other hand, in the path R22-1, the terminal device100performs wireless communication compatible with Wi-Fi with the relay device300. The relay device300uses the LWAAP to convert, for example, received data into data that may be transmitted by the NR.

When the relay device300receives the data via the path R22-1, the relay device300uses a path R22-2 to transmit the data to the base station device200. With this configuration, the relay device300relays the data transmitted by the terminal device100to the base station device200.

The relay device300transmits, for example, PDCP data to the base station device200by using the path R22-2 compatible with an NR. Note that the NR in the path R22-2 may also be in the same frequency band, or may also be in a different frequency band as the NR in the path R21. For example, the relay device300performs tethering and operates as a relay station between the terminal device100and the base station device200.

The base station device200receives data via each of the path R21 and the path R22-2. The base station device200transmits, for example, previously received data to the IP network400and transmits the data to a destination. The base station device200discards, for example, data that is not transmitted.

Note that the base station device200receives the same data (for example, with the same sequence number) from the same terminal device100in the NR. In other words, the base station device200receives the same data from the same user via two bearers (Bearer1and Bearer2) of the NR. In order to solve this double reception, the base station device200shares processing of the PDCP layer among a plurality of bearers.

FIG.9is a diagram illustrating an example of a protocol stack of the communication system ofFIG.8. The base station device200and the terminal device100support the PDCP layer, the RLC layer, the MAC layer, and the PHY layer in the NR. Furthermore, since the terminal device100is compatible with the WLAN, the terminal device100supports the LWAAP, 802.11x, and the PHY layer of the WLAN. Moreover, the base station device200and the terminal device100each include a duplication layer (duplication function), and support transmission of duplicated data in the DC duplication and reception of the duplicated data.

Since the relay device300relays communication of the terminal device100in the WLAN, the relay device300is compatible with the LWAAP, 802.11x, and the PHY layer of the WLAN. Furthermore, since the relay device300relays communication with the base station device200in the NR, the relay device300supports the PDCP layer, the RLC layer, the MAC layer, and the PHY layer in the NR. The relay device300is connected to the base station device200by, for example, a Uu interface.

By processing the PDCP data received from the terminal device100by the NR and data received from the relay device300by the WLAN and processed by the LWAAP by the duplication layer, the base station device200converges a data packet by the PDCP layer.

Note that, the base station device200and the terminal device100may also share the PDCP layer for data transmission/reception with the relay device300(dotted line portion ofFIG.9) and the PDCP layer for data transmission/reception with the terminal device100or the base station device200. Furthermore, the base station device200may also share the RLC layer, the MAC layer, and the PHY layer (NR) for data transmission/reception with the relay device300and the RLC layer, the MAC layer, and the PHY layer (NR) in communication with the terminal device100.

<1.3 Pattern 3>

FIG.10is a diagram illustrating an example of the data transmission (pattern 3) in the DC duplication. Processing in a path R31, a path R32-1, and a path R32-2 of the terminal device100and the relay device300is similar to the processing in the path R21, the path R22-1, and the path R22-2 illustrated inFIG.8.

The base station device200receives the same data from the same terminal device100in the NR. In other words, the base station device200receives the same data from the same user using two bearers of the NR. In order to solve this double reception, the base station device200includes a control layer (control function: control) that controls two pieces pf data between bearers.

FIG.11is a diagram illustrating an example of a protocol stack of the communication system ofFIG.10. The base station device200and the terminal device100support the PDCP layer, the RLC layer, the MAC layer, and the PHY layer in the NR. Furthermore, since the terminal device100is compatible with the WLAN, the terminal device100supports the LWAAP, 802.11x, and the PHY layer of the WLAN. Furthermore, the base station device200and the terminal device100each include a control layer (control function: control), and solve transmission/reception of the same data in a plurality of bearers in the DC duplication.

Since the relay device300relays communication of the terminal device100in the WLAN, the relay device300is compatible with the LWAAP, 802.11x, and the PHY layer of the WLAN. Furthermore, since the relay device300relays communication with the base station device200in the NR, the relay device300supports the PDCP layer, the RLC layer, the MAC layer, and the PHY layer in the NR. The relay device300is connected to the base station device200by, for example, a Uu interface.

By processing PDCP data received from the terminal device100by the NR and data received from the relay device300by the WLAN and processed by the LWAAP by the control layer, the base station device200converges a data packet by the PDCP layer.

Note that, the base station device200may also share the PDCP layer, the RLC layer, the MAC layer, and the PHY layer (NR) for data transmission/reception with the relay device300and the PDCP layer, the RLC layer, the MAC layer, and the PHY layer (NR) in communication with the terminal device100.

<2. Data Transmission Sequence>

Data transmission sequence will be described below. For the data transmission sequence, three sequences will be described such as presence or absence of replies with an affirmative response (acknowledgement (ACK)) and a negative response (negative-acknowledgement (NACK)), and a case of making a scheduling request. In the following sequences, a wireless section in the WLAN and a wireless section in the NR are described in a similar manner, and a message corresponding to the affirmative response in the WLAN and the NR is expressed as ACK, and a message corresponding to the negative response in the WLAN and the NR is expressed as NACK in a similar manner.

<2.1 Sequence 1>

FIG.12is a diagram illustrating an example of a sequence 1 for transmitting a NACK to the terminal device100. The terminal device100duplicates data when the DC duplication is performed. Hereinafter, the duplicated data will be expressed as URLLC 1 and URLLC 2. The terminal device100transmits the URLLC 1 to the base station device200(S11).

The base station device200performs processing such as decoding on the received URLLC 1 (S12).

Moreover, the terminal device100transmits the URLLC 2 to the relay device300(S13).

When the relay device300receives the URLLC 2 without error, the relay device300transmits an ACK to the terminal device100(S14). Then, the relay device300performs relay processing (S15) and transmits the URLLC 2 to the base station device200(S16).

When the base station device200receives the URLLC 2 without error, the base station device200transmits an ACK to the relay device300(S17). Then, the base station device200transmits the URLLC 2 to the IP network400(not illustrated). Moreover, the base station device200transmits a NACK to the terminal device100(S18).

When the terminal device100receives the NACK, the terminal device100retransmits the URLLC 1 (S19). Then, when the base station device200receives the URLLC 1 without error, the base station device200transmits an ACK to the terminal device100(S20).

Note that, the base station device200may also transmit data to the IP network400at the timing when the data is received from either one of the terminal device100or the relay device300without error, without waiting by for reception of data from another device. Furthermore, the base station device200may also transmit both the data received from the terminal device100and the relay device300to the IP network400.

<2.2 Sequence 2>

FIG.13is a diagram illustrating an example of a sequence 2 for transmitting an ACK to the terminal device100. Processing S31to processing S36are similar to the processing S21to the processing S26inFIG.11.

When the base station device200receives the URLLC 2 without error, the base station device200transmits an ACK to the relay device300(S37). Then, the base station device200transmits the URLLC 2 to the IP network400(not illustrated). Moreover, the base station device200transmits an ACK to the terminal device100(S38). In this case, unlike the sequence 1, the terminal device100does not retransmit the URLLC 1.

Note that the timing when the base station device200transmits the ACK to the terminal device100may also be, for example, the timing when it is recognized that the URLLC 1 has been received without error in the processing S31.

<2.3 Sequence 3>

FIG.14is a diagram illustrating an example of a sequence 3 with wireless resource allocation. The terminal device100duplicates data when the DC duplication is performed.

The terminal device100transmits, to the base station device200, a scheduling request (SR) requesting wireless resource allocation (S51). Then, the terminal device100transmits the URLLC 1 to the relay device300(S52).

When the relay device300receives the URLLC 1 without error, the relay device300transmits an ACK to the terminal device100(S53).

When the base station device200receives the SR (S51), the base station device200allocates wireless resources, and transmits, to the terminal device100, UL_grant, which is a message including information regarding the allocated wireless resources (S54).

When the terminal device100receives the UL_grant (S54), the terminal device100transmits the URLLC 2 to the base station device200by using the allocated wireless resources (S55).

When the base station device200receives the URLLC 2, the base station device200performs processing in PUSCH (S56).

The relay device300performs relay processing (S57) and transmits the URLLC 2 to the base station device200(S58).

When the base station device200receives the URLLC 2 without error, the base station device200transmits an ACK to the relay device300(S59). Then, the base station device200transmits the URLLC 2 to the IP network400(not illustrated). Moreover, the base station device200transmits a NACK to the terminal device100(S60).

Thereafter, processing S61and processing S62are similar to the processing S19and the processing S20inFIG.11.

Other Embodiments

The first embodiment and the second embodiment may also be combined. Furthermore, each of the patterns of the data transmission processing and each of the patterns of the sequences in the second embodiment may also be combined. Furthermore, in the first and second embodiments, data transmission in a direction (uplink direction) from the terminal device100(or10) to the base station device200(or20) has been described. However, the first and second embodiments may also be applied to data transmission in a reverse direction (downlink direction). In the case of the downlink direction, for example, the base station device200(or20) receives data transmitted from the IP network400to the terminal device100(or10), duplicates the data, and transmits the duplicated data through two paths. The terminal device100(or10) performs processing on, for example, data received first.

All examples and conditional language provided herein are intended for the pedagogical purposes of aiding the reader in understanding the invention and the concepts contributed by the inventor to further the art, and are not to be construed as limitations to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although one or more embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.