JP7485033B2 - Wireless communication system, communication method, base station, and terminal - Google Patents

Description

The present invention relates to a wireless communication system, a communication method, a base station, and a terminal.

An example of a self-operated cellular radio system operated by a site owner under license is a wireless communication system such as L5G (local 5G). The L5G system is not limited to being operated by a single operator, and there are cases where radio interference occurs when the area of another L5G system operated by another operator is adjacent.

In addition, the L5G system aims to increase communication speed, reduce latency, and improve reliability by using NR (New Radio), a 5G wireless communication method (see, for example, Patent Document 1).

Kazuki Takeda and 5 others, "NR Physical Layer Specifications for 5G", NTT DOCOMO Technical Journal, Nov. 2018, Vol. 26 No. 3, pp. 47-58

However, in the past, there was a problem that a UE (user equipment) that had not been assigned resources was unable to immediately transmit eURLLC (enhanced Ultra-Reliable and Low Latency Communications), which is a UL (uplink) signal that should be transmitted with the highest priority.

In addition, in the past, in order for a UE to be able to transmit eURLLC immediately, it was necessary to assign many resources in advance in terms of time. Furthermore, there were problems in that if the same resources were assigned to multiple UEs, collisions would occur, and if different resources were assigned to multiple UEs, the amount of unused resources during normal times would increase, reducing efficiency.

The present invention aims to provide a wireless communication system, a communication method, a base station, and a terminal that can efficiently shorten waiting time below the configured grant without increasing unused resources under normal circumstances.

According to one aspect of the present invention, a wireless communication system is provided which is connected to a higher-level network and includes a base station capable of accommodating a plurality of terminals, each of which includes a sequence generation unit which generates a code sequence in which a highest priority packet corresponds to a random access signal which can be separated for each terminal, and a sequence control unit which controls the transmission of the code sequence to the base station when a highest priority packet is generated, and the base station includes a memory unit which stores the code sequence which has been received in advance from each of the terminals, a determination unit which, when receiving a sequence of a random access signal from the terminal, determines whether the sequence matches any of the code sequences stored in the memory unit, a conversion unit which converts the code sequence which the determination unit determines to match into a highest priority packet, a communication unit which transmits the highest priority packet converted by the conversion unit to the higher-level network , and a wireless communication unit which allocates and transmits resources and sequences to be used for each of the terminals, and receives the code sequence in advance from each of the terminals .

Moreover, a communication method according to one aspect of the present invention is a communication method performed between a base station connected to a higher-level network and a plurality of terminals, the method comprising the steps of: a sequence generation step in which each of the terminals generates a code sequence that associates a top priority packet with a random access signal that can be separated for each terminal; a sequence control step in which, when a top priority packet is generated, the terminal transmits the code sequence to the base station; a storage step in which the code sequence previously received by the base station from each of the terminals; a determination step in which, when the base station receives a sequence of a random access signal from the terminal, the base station determines whether the sequence matches any of the stored code sequences; a conversion step in which the code sequence that is determined to match is converted into a top priority packet ; a communication step in which the base station allocates and transmits resources and sequences to be used for each of the terminals, and receives the code sequence in advance from each of the terminals .

In addition, a base station according to one embodiment of the present invention is characterized in that, in a base station connected to a higher-level network and capable of accommodating a plurality of terminals, it has: a memory unit that pre-stores a code sequence in which a top priority packet corresponds to a random access signal that can be separated for each of the terminals; a wireless communication unit that receives the code sequence from the terminal when a top priority packet is generated; a conversion unit that converts the code sequence received by the wireless communication unit into a top priority packet; a communication unit that transmits the top priority packet converted by the conversion unit to the higher-level network ; and a wireless communication unit that allocates and transmits resources and sequences to be used for each of the terminals, and receives the code sequences in advance from each of the terminals .

Furthermore, a terminal according to one aspect of the present invention is characterized in having a sequence generation unit that generates a code sequence that associates a top priority packet with a random access signal that can be separated from other terminals , a wireless communication unit that receives an allocation of resources and sequences to be used from a base station and transmits the code sequence in advance to the base station, and a sequence control unit that controls the transmission of the code sequence to the base station when a top priority packet is generated.

According to the present invention, waiting times can be efficiently shortened compared to configured grants without increasing unused resources during normal times.

FIG. 1 is a diagram illustrating an example of a configuration of a wireless communication system according to an embodiment. 1A is a sequence diagram showing a dynamic grant in a 5G NR of a comparative example, and FIG. 1B is a sequence diagram showing a configured grant in a 5G NR of a comparative example. FIG. 2 is a functional block diagram illustrating functions of a terminal according to an embodiment. FIG. 2 is a functional block diagram illustrating functions of a base station and a control station according to an embodiment. 11 is a flowchart illustrating an operation performed by a base station at the time of initial setting. 11 is a flowchart illustrating an operation performed by a terminal during initial setting. 11 is a flowchart illustrating an example of an operation performed by a base station during normal operation. 11 is a flowchart illustrating an operation performed by a terminal during normal operation. FIG. 2 is a diagram illustrating an example of a hardware configuration of a base station according to an embodiment.

An embodiment of a wireless communication system will be described below with reference to the drawings. FIG. 1 is a diagram showing an example of the configuration of a wireless communication system 1 according to an embodiment. As shown in FIG. 1, for example, the wireless communication system 1 is an L5G system that has multiple base stations (gNB: next generation NodeB) 3-1, 3-2, each of which accommodates multiple terminals (UE: User Equipment) 2, and a control station 4, and enables wireless communication by NR. Hereinafter, when one of the multiple configurations, such as base stations 3-1 and 3-2, is not specified, it will be simply abbreviated as base station 3, etc.

Terminal 2 is, for example, a mobile user terminal, and performs wireless communication with base station 3. Base station 3 is a wireless base station that accommodates multiple terminals 2 and provides NR wireless, and each is connected to a higher-level network.

The control station 4 includes a resource control unit 40, and controls the base stations 3-1 and 3-2, for example, by wired communication. The resource control unit 40 controls resource allocation for the base stations 3-1 and 3-2. The control station 4 and the base stations 3-1 and 3-2 may be configured to communicate wirelessly, such as via IAB (Integrated Access and Backhaul) or WiGig (Wireless Gigabit). The resource control unit 40 may also be included in a 5G core network.

Next, in order to provide a specific explanation of the wireless communication system 1 according to one embodiment, communication between a terminal (UE) and a base station (BS) in a comparative example will be explained first. FIG. 2 is a sequence diagram showing communication between a terminal (UE) and a base station (BS) in a comparative example. FIG. 2(a) is a sequence diagram showing a dynamic grant in 5G NR. FIG. 2(b) is a sequence diagram showing a configured grant in 5G NR.

As shown in Figure 2(a), in the standardized 5G NR dynamic grant, after UL (uplink) traffic occurs, the UE sends a scheduling request (SR) to the BS (S100).

When the BS receives the SR, it notifies the UE of the schedule via DCI (Downlink Control Information) (S102).

After that, the UE transmits the data packet to the BS via the Physical Uplink Shared CHannel (PUSCH) (S104). In other words, the BS can forward the traffic to the upper network.

On the other hand, as shown in FIG. 2(b), in the Configured grant in 5G NR, when UL traffic occurs, a data packet is transmitted to the BS using pre-specified resources without transmitting an SR (S200). In other words, the BS can forward traffic to the upper network faster than with the Dynamic grant, without exchanging messages after traffic occurs.

However, in the comparative example, with the Configured grant, although this depends on how the resources are specified, in order to enable immediate transmission of packet data, it was necessary to specify many resources in advance in terms of time. Also, in the comparative example, if the same resources were specified for multiple UEs, collisions would occur, and if different resources were specified for multiple UEs, unused resources in normal times would increase, reducing efficiency.

Next, using Figures 3 and 4, we will explain specific configuration examples of the terminal 2, base station 3, and control station 4 in one embodiment.

3 is a functional block diagram illustrating functions of a terminal 2 according to one embodiment. As shown in FIG. 3, the terminal 2 has a wireless communication unit 20, a sequence control unit 21, a sequence generation unit 22, a memory unit 23, and a conversion unit 24.

The wireless communication unit 20 performs wireless communication with the base station 3, for example, by NR. For example, the wireless communication unit 20 receives a packet transmitted by the base station 3 and outputs it to the sequence control unit 21. In addition, the wireless communication unit 20 transmits the packet (such as the code sequence described below) converted by the conversion unit 24 to the base station 3 via the PUSCH or PUCCH (Physical Uplink Control CHannel) in accordance with the control of the sequence control unit 21.

For example, the wireless communication unit 20 transmits a code sequence (correspondence table) described below to the base station 3 in advance during initial configuration. In addition, when a top priority packet is generated, the wireless communication unit 20 transmits the corresponding code sequence to the base station 3 using resources designated by the base station 3.

The sequence control unit 21 acquires the resources and sequences allocated by the base station 3 for each UE via the wireless communication unit 20, and outputs them to the sequence generation unit 22. In addition, when a top priority packet occurs within the terminal 2 or outside the terminal 2, the sequence control unit 21 controls the conversion unit 24 and the wireless communication unit 20 to transmit a code sequence, which will be described later, to the base station 3.

The sequence generation unit 22 generates a code sequence that associates a sequence assigned to each UE with a highest priority packet that may be transmitted, and outputs the code sequence to the storage unit 23. For example, the sequence generation unit 22 generates a code sequence that associates a highest priority packet with a random access signal that can be separated for each UE. As a specific example, the sequence generation unit 22 associates a sequence number to be used with a message that may be transmitted.

The storage unit 23 stores the code sequence generated by the sequence generation unit 22. For example, the storage unit 23 stores a code sequence in which the sequence assigned to each UE is associated with the highest priority packet that may be transmitted as a correspondence table.

The conversion unit 24 converts the highest priority packet into a series, for example, using a correspondence table stored in the memory unit 23 under the control of the series control unit 21, and outputs it to the wireless communication unit 20.

Figure 4 is a functional block diagram illustrating functions possessed by the base station 3 and the control station 4 in one embodiment. As described above, the control station 4 includes a resource control unit 40 and communicates with the base station 3 via a communication unit (not shown).

The resource control unit 40 outputs the sequence range used by the base station 3 and the terminal 2 to the base station 3. The resource control unit 40 also acquires the usage sequence and resource information for each terminal 2 from the base station 3.

The base station 3 has a signal generating unit 30, a wireless communication unit 31, a demodulating unit 32, a memory unit 33, a judgment unit 34, a conversion unit 35, and a communication unit 36.

The signal generation unit 30 generates a signal indicating the sequence range and resource range that can be used by each terminal 2 based on the sequence range input from the resource control unit 40, and outputs the signal to the wireless communication unit 31.

The wireless communication unit 31 performs wireless communication, for example, by NR, with each of the terminals 2. For example, the wireless communication unit 31 transmits to each of the terminals 2 the signal indicating the sequence range and resource range that each of the terminals 2 can use, input from the signal generation unit 30, to the terminals 2 that contain the signal.

Specifically, the wireless communication unit 31 individually assigns contention-based resources (Contention based UL data transmission resources) to each terminal 2, for example, by DCI or a connection request signal (RRC (Radio Resource Control) connection request).

At this time, the wireless communication unit 31 transmits frequency resources to be assigned to each terminal 2. For example, the wireless communication unit 31 transmits a PRB (Physical Resource Block) or an RE (Resource Element).

The wireless communication unit 31 may also transmit time resources (frames or OFDM (Orthogonal Frequency Division Multiplexing) symbols) to be assigned to each terminal 2. When it is not necessary to assign time resources individually, the wireless communication unit 31 assigns the entire time period.

The wireless communication unit 31 may also transmit sequence numbers (range of numbers) to be assigned to each terminal 2. When it is not necessary to assign sequence numbers individually, the wireless communication unit 31 will permit the use of the entire range.

In addition, the wireless communication unit 31 may assign and transmit resources and sequences of different corresponding patterns for each terminal 2. In other words, the base station 3 enables separation of multiple top priority packets that are simultaneously generated by multiple terminals 2 accommodated therein, so that the packets are not included in the same sequence.

In addition, the wireless communication unit 31 may assign and transmit the same corresponding pattern of resources and sequences to multiple terminals 2 that are performing wireless communication in precise synchronization.

In addition, the wireless communication unit 31 may transmit contention-based resources to the terminal 2 by multicast.

In addition, the wireless communication unit 31 receives a code sequence (correspondence table) in advance from each terminal 2 and outputs it to the demodulation unit 32. In addition, the wireless communication unit 31 receives a code sequence from the terminal 2 when a top priority packet is generated.

The demodulation unit 32 demodulates the signals received by the wireless communication unit 31 from each terminal 2, and outputs them to the memory unit 33, the determination unit 34, and the control station 4. For example, the demodulation unit 32 demodulates a correspondence table (code sequence) transmitted in advance by each terminal 2 during initial configuration, and stores it in the memory unit 33. The demodulation unit 32 also demodulates the sequence transmitted by the terminal 2 when a top priority packet is generated, and outputs it to the determination unit 34. The demodulation unit 32 also demodulates the usage sequence and resource information of each terminal 2, and outputs it to the resource control unit 40.

The memory unit 33 pre-stores a code sequence (correspondence table) that associates a highest priority packet with a random access signal that can be separated for each terminal 2, for example.

When the wireless communication unit 31 receives a sequence of random access signals from the terminal 2, the judgment unit 34 judges whether or not the sequence matches any of the code sequences stored in the memory unit 33, and outputs the judgment result to the conversion unit 35.

The conversion unit 35 converts the code sequence that the determination unit 34 determines to be a match into a top priority packet using the code sequence stored in the memory unit 33, and outputs the converted top priority packet to the communication unit 36.

The communication unit 36 transmits the highest priority packet converted by the conversion unit 35 to a higher-level network.

Next, an example of the operation of the base station 3 and the terminal 2 will be described with reference to Figures 5 to 8. Figure 5 is a flowchart illustrating the operation performed by the base station 3 at the time of initial configuration. As shown in Figure 5, the base station 3 first determines the UEs to be permitted for contention-based UL transmission (S300). The base station 3 then allocates resources and sequences to be used for each UE and notifies each UE (S302).

Thereafter, the base station 3 receives a notification (code sequence) in advance as a correspondence table for each UE that corresponds a sequence to the highest priority packet (S304), and stores the received code sequence in the memory unit 33 (S306).

Figure 6 is a flowchart illustrating an example of the operation performed by terminal 2 during initial configuration. As shown in Figure 6, terminal 2 receives notification of resources and sequence allocation to be used for each UE from base station 3 (S400).

Then, terminal 2 generates a code sequence (correspondence table) by matching the assigned sequence with the highest priority packet (S402), and notifies base station 3 of the generated code sequence (S404).

Figure 7 is a flow chart illustrating an example of the operation performed by base station 3 during normal operation. As shown in Figure 7, base station 3 attempts to detect a specified sequence (code sequence) from the UL signal (S500). In addition, base station 3 may calculate a correlation value between the correspondence table and the sequence to determine whether the stored code sequence matches the received sequence.

The base station 3 determines whether or not a top priority packet was detected (whether or not the stored code sequence matches the received sequence) (S502). If the base station 3 detects a top priority packet (S502: Yes), it proceeds to processing of S504, and if the base station 3 does not detect a top priority packet (S502: No), it returns to processing of S500.

In the process of S504, the base station 3 converts the detected sequence (code sequence) into a top priority packet (content data). The base station 3 then transfers the converted top priority packet (content data) to the upper network (S506).

Figure 8 is a flowchart illustrating the operations performed by terminal 2 during normal operation. As shown in Figure 8, terminal 2 monitors the input of the highest priority packet (S600).

Then, terminal 2 determines whether or not a top priority packet has been input (S602). If terminal 2 determines that a top priority packet has been input (S602: Yes), it proceeds to processing of S604, and if terminal 2 determines that a top priority packet has not been input (S602: No), it returns to processing of S600.

In the process of S604, the terminal 2 converts the highest priority packet into a sequence (code sequence). The terminal 2 then transmits the code sequence to the base station 3 using the resources specified by the base station 3 (S606).

In this way, the wireless communication system 1 enables each terminal 2 to transmit an UL signal to the base station 3 on a contention basis, efficiently shortening the waiting time below the configured grant without increasing unused resources under normal circumstances.

In addition, each function possessed by the terminal 2, the base station 3, and the control station 4 may be configured in part or in whole by hardware such as a PLD (Programmable Logic Device) or an FPGA (Field Programmable Gate Array), or may be configured as a program executed by a processor such as a CPU.

For example, the terminal 2 and base station 3 of the present invention can be realized using a computer and a program, and the program can be recorded on a storage medium or provided via a network.

Figure 9 is a diagram showing an example of the hardware configuration of a base station 3 according to one embodiment. As shown in Figure 9, for example, the base station 3 has an input unit 50, an output unit 51, a communication unit 52, a CPU 53, a memory 54, and a HDD 55 connected via a bus 56, and has the functions of a computer. In addition, the base station 3 is capable of inputting and outputting data to and from a computer-readable storage medium 57.

The input unit 50 is, for example, a keyboard and a mouse. The output unit 51 is, for example, a display device such as a display. The communication unit 52 is, for example, a wired and wireless network interface.

The CPU 53 controls each component constituting the base station 3 and performs predetermined processing, etc. The memory 54 and HDD 55 store data, etc. The storage medium 57 is capable of storing programs, etc. that execute the functions of the base station 3. Note that the architecture constituting the base station 3 is not limited to the example shown in FIG. 9. In addition, the terminal 2 and the control station 4 may also have the same hardware configuration as the base station 3.

Note that the term "computer" here includes hardware such as the OS and peripheral devices. Additionally, "computer-readable storage medium" refers to storage devices such as portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs.

Furthermore, "computer-readable storage medium" may include something that dynamically holds a program for a short period of time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, or something that holds a program for a certain period of time, such as volatile memory inside a computer that is the server or client in that case.

Although an embodiment of the present invention has been described above with reference to the drawings, it is clear that the above-mentioned embodiment is merely an example of the present invention and the present invention is not limited to the above-mentioned embodiment. Therefore, addition, omission, substitution, and other modifications of components may be made without departing from the technical concept and scope of the present invention.

1: Wireless communication system, 2: Terminal (UE), 3-1, 3-2: Base station (gNB), 4: Control station, 20: Wireless communication unit, 21: Series control unit, 22: Series generation unit, 23: Memory unit, 24: Conversion unit, 30: Signal generation unit, 31: Wireless communication unit, 32: Demodulation unit, 33: Memory unit, 34: Determination unit, 35: Conversion unit, 36: Communication unit, 40: Resource control unit, 50: Input unit, 51: Output unit, 52: Communication unit, 53: CPU, 54: Memory, 55: HDD, 56: Bus, 57: Storage medium

Claims (6)

In a wireless communication system having a base station connected to a higher-level network and capable of accommodating a plurality of terminals,
Each of the terminals
a sequence generation unit that generates a code sequence in which a random access signal that can be separated for each terminal is associated with a highest priority packet;
a sequence control unit that controls the code sequence to be transmitted to the base station when a top priority packet is generated,
The base station,
a storage unit that stores the code sequence previously received from each of the terminals;
a determination unit that, when receiving a sequence of a random access signal from the terminal, determines whether or not the sequence matches any of the code sequences stored in the storage unit;
a conversion unit that converts the code sequence that the determination unit determines to match into a highest priority packet;
a communication unit that transmits the highest priority packet converted by the conversion unit to a higher-level network ;
a wireless communication unit that allocates resources and sequences to be used for each of the terminals and transmits the resources and sequences, and receives the code sequences from each of the terminals in advance;
A wireless communication system comprising : The wireless communication unit includes:
The wireless communication system according to claim 1 , wherein resources and sequences of different corresponding patterns are assigned to each of the terminals for transmission. The wireless communication unit includes:
2. The wireless communication system according to claim 1 , wherein the same corresponding pattern of resources and sequences are assigned to a plurality of terminals performing wireless communication in synchronization with each other, and transmitted to the terminals. A communication method between a base station connected to a higher-level network and multiple terminals,
a sequence generating step in which each terminal generates a code sequence in which a random access signal separable for each terminal corresponds to a highest priority packet;
a sequence control step of controlling the terminal to transmit the code sequence to the base station when a top priority packet is generated;
a storage step of storing the code sequence previously received by the base station from each of the terminals;
a determination step of determining whether or not a sequence of a random access signal received by the base station from the terminal matches any of the stored code sequences;
a conversion step of converting the code sequence determined to match into a highest priority packet;
a communication step of transmitting the converted top priority packet to a higher-level network ;
a wireless communication step of the base station allocating resources and sequences to be used for each of the terminals and transmitting the resources and sequences, and receiving the code sequences from each of the terminals in advance;
A communication method comprising: In a base station that is connected to a higher-level network and can accommodate multiple terminals,
a storage unit that stores in advance a code sequence in which a highest priority packet is associated with a random access signal that can be separated for each terminal;
a wireless communication unit that receives the code sequence from the terminal when a top priority packet is generated;
a conversion unit that converts the code sequence received by the wireless communication unit into a highest priority packet;
a communication unit that transmits the highest priority packet converted by the conversion unit to a higher-level network ;
a wireless communication unit that allocates resources and sequences to be used for each of the terminals and transmits the resources and sequences, and receives the code sequences from each of the terminals in advance;
A base station comprising: a sequence generating unit for generating a code sequence in which a random access signal separable from other terminals corresponds to a highest priority packet;
a wireless communication unit that receives from a base station an allocation of resources and sequences to be used and transmits the code sequence to the base station in advance;
and a sequence control unit that controls the code sequence to be transmitted to the base station when a top priority packet is generated.

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