Communication apparatus, base station, and communication method

Abstract

To execute an appropriate operation when an S & F satellite operation is executed.MEANS FOR SOLVING THE PROBLEM: A communication apparatus (100) according to an embodiment includes a controller (120) configured to control communication of predetermined information via a base station (200, 201) that supports a store-and-forward (S & F) satellite operation, and a transmitter (111) configured to transmit validity information regarding validity of the predetermined information to the base station.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a communication device, a base station, and a communication method. [Background technology]

[0002] In mobile communication systems that comply with the technical specifications of 3GPP (Third Generation Partnership Project, a registered trademark; the same applies hereinafter), a standardization project for mobile communication systems, support for store-and-forward (S&F) satellite operation is being considered to extend IoT (Internet of Things)-NTN (Non-Terrestrial Network) technology (see, for example, Non-Patent Document 1).

[0003] In S&F satellite operation, even if either the service link between the communication device and the satellite base station or the feeder link between the satellite base station and the core network is unavailable, the satellite base station stores information, thereby increasing communication opportunities compared to cases where communication occurs only when both the service link and the feeder link are available. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] "R2-2404321" (Overview of the Store and Forward satellite operation) Summary of the Invention [Problem to be solved by the invention]

[0005] However, depending on the orbit of the satellite base station, there is a concern that a service link and / or a feeder link may not be established for a long period of time, and the satellite base station may continue to store the information, causing a malfunction.

[0006] An object of the present disclosure is to provide a communication device, a base station, and a communication method that are capable of performing appropriate operations when S&F satellite operations are performed. [Means for solving the problem]

[0007] A communication device according to a first aspect includes a control unit that controls communication of specified information via a base station that supports store-and-forward (S&F) satellite operation, and a transmission unit that transmits validity information regarding the validity of the specified information to the base station.

[0008] A communication device according to a second aspect includes a transmitter that transmits first information to a base station that supports store-and-forward (S&F) satellite operation, and a controller that controls a receiving process to receive second information from the base station, the second information being a response to the first information. The controller controls the receiving process not to be executed when a predetermined condition is satisfied.

[0009] A base station according to a third aspect is a base station that supports store-and-forward (S&F) satellite operation. The base station includes a controller that controls communication of predetermined information with a communication device, and a receiver that receives validity information regarding the validity of the predetermined information from the communication device. The controller controls to stop transmission of the predetermined information when the expiration date of the predetermined information indicated by the validity information has passed.

[0010] A base station according to a fourth aspect is a base station supporting store-and-forward (S&F) satellite operation, and includes a receiver that receives first information from a communication device, a transmitter that transmits second information to the communication device as a response to the first information, and a controller that controls to stop transmission of the second information when a predetermined condition is satisfied.

[0011] A fifth aspect of the present invention relates to a communication method executed by a communication device, the method comprising the steps of controlling communication of predetermined information via a base station supporting store-and-forward (S&F) satellite operation, and transmitting validity information regarding validity of the predetermined information to the base station.

[0012] A communication method according to a sixth aspect is a communication method executed by a communication device, the communication method comprising the steps of transmitting first information to a base station supporting store-and-forward (S&F) satellite operation, controlling a reception process to receive second information from the base station as a response to the first information, and controlling not to execute the reception process when a predetermined condition is satisfied. [Effects of the Invention]

[0013] According to one aspect of the present disclosure, when an S&F satellite operation is performed, appropriate operations can be performed. [Brief explanation of the drawings]

[0014] The objects, features, advantages, and other features of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. [Figure 1] FIG. 1 is a diagram showing a configuration of a mobile communication system according to an embodiment. [Figure 2] FIG. 2 is a diagram showing a configuration example (part 1) of a protocol stack according to the embodiment. [Figure 3] FIG. 3 is a diagram illustrating a configuration example (part 2) of a protocol stack according to the embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of a scenario according to the embodiment. [Figure 5] FIG. 5 is a diagram illustrating a configuration of a UE according to the embodiment. [Figure 6] FIG. 6 is a diagram illustrating a configuration of a base station according to the embodiment. [Figure 7] FIG. 7 is a sequence diagram illustrating a first operation example of the embodiment. [Figure 8] FIG. 8 is a diagram for explaining a first operation example of the embodiment. [Figure 9] FIG. 9 is a sequence diagram illustrating a second operation example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] A mobile communication system according to an embodiment will be described with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0016] (System Configuration) First, the configuration of a mobile communication system 1 according to this embodiment will be described with reference to Fig. 1. The mobile communication system 1 is, for example, a system that complies with the 3GPP Technical Specification (TS). In the following, the mobile communication system 1 will be described mainly as an example based on a 5th Generation System (5G system) of the 3GPP standard, i.e., a mobile communication system based on NR (New Radio) radio access.

[0017] The mobile communication system 1 includes a network 10 and user equipment (UE) 100 that communicates with the network 10. The network 10 includes a next generation radio access network (NG-RAN) 20, which is a 5G radio access network, and a 5G core network (5GC) 30, which is a 5G core network. Note that the mobile communication system 1 may include an evolved-UMTS terrestrial radio access network (E-UTRAN) and an evolved packet core network (EPC), as the network 10 in a 4th generation system (4G system) and / or a long term evolution (LTE) system conforming to the 3GPP standard.

[0018] The UE 100 is a communication device that communicates via the base station 200. The UE 100 may be a device used by a user. The UE 100 may be a mobile device, such as a mobile phone terminal such as a smartphone, a tablet terminal, a laptop PC, a communication module, or a communication card. The UE 100 may be a vehicle (e.g., a car, a train, etc.) or a device provided therein. The UE 100 may be a transport vehicle other than a vehicle (e.g., a ship, an airplane, etc.) or a device provided therein. The UE 100 may be a sensor or a device provided therein. The UE 100 may be called a terminal, a terminal device, a mobile station, a mobile terminal, a mobile device, a mobile unit, a subscriber station, a subscriber terminal, a subscriber device, a subscriber unit, a wireless station, a wireless terminal, a wireless device, a wireless unit, a remote station, a remote terminal, a remote device, or a remote unit. The UE 100 is an example of a terminal, and the terminal may include factory equipment, etc. Furthermore, the UE 100 may be a BL (Bandwidth Reduced Low Complexity) UE, an IoT UE, an IoT device, or the like.

[0019] The NG-RAN 20 includes multiple base stations 200. Each base station 200 manages at least one cell. One or more base stations 200 may correspond to one or more cells. A base station 200 may be replaced with a cell, or a cell may be replaced with a base station 200. A cell constitutes the smallest unit of a communication area. One cell belongs to one frequency (carrier frequency). The term "cell" may refer to wireless communication resources or to a communication target of the UE 100. Each base station 200 can perform wireless communication with the UE 100 located in its own cell. The base station 200 communicates with the UE 100 using a RAN protocol stack. Details of the protocol stack will be described later. The base station 200 is connected to other base stations 200 (which may be referred to as neighbor base stations) via an Xn interface. The base station 200 communicates with the neighbor base stations via the Xn interface. The base station 200 provides NR user plane and control plane protocol termination for the UE 100 and is connected to the 5GC 30 via an NG interface. Such an NR base station 200 may be referred to as a gNodeB (gNB). Note that a base station 200 in E-UTRAN may be referred to as an evolved Node-B (eNB). An eNB communicates with neighboring eNBs via an X2 interface. The base station 200 may include a satellite base station 201 and a gateway base station 202, which will be described later. The 5GC 30 includes a core network device 300. The core network device 300 includes, for example, an Access and Mobility Management Function (AMF) and / or a User Plane Function (UPF). The AMF manages the mobility of the UE 100. The UPF provides functions specialized for U-plane processing. The AMF and the UPF are connected to the base station 200 via an NG interface. Note that in EPC, the core network device 300 includes, for example, a Mobility Management Entity (MME) and / or a Serving-Gateway (S-GW). The MME manages the mobility of the UE 100. The S-GW controls the transfer of data.The MME / S-GW 300 is connected to the eNB via the S1 interface.

[0020] (Example of protocol stack configuration) Next, an example of the configuration of a protocol stack according to this embodiment will be described with reference to FIGS.

[0021] As shown in Fig. 2, in the control plane, the protocol for the wireless section between UE 100 and base station 200 includes a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a radio resource control (RRC) layer. As shown in Fig. 3, in the user plane, the protocol for the wireless section between UE 100 and base station 200 includes a PHY layer, a MAC layer, an RLC layer, and a PDCP layer. As shown in Fig. 3A, in 5G, a service data adaptation protocol (SDAP) layer is provided as an upper layer of the PDCP layer. Note that, as shown in Fig. 3B, the SDAP layer is not provided in 4G.

[0022] The PHY layer performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data and control information are transmitted between the PHY layer of the UE 100 and the PHY layer of the base station 200 via a physical channel.

[0023] The MAC layer performs data priority control, retransmission processing using Hybrid ARQ (HARQ), random access procedures, etc. Data and control information are transmitted between the MAC layer of UE 100 and the MAC layer of base station 200 via a transport channel. The MAC layer of base station 200 includes a scheduler. The scheduler determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resources to be allocated to UE 100.

[0024] The RLC layer transmits data to the RLC layer on the receiving side using the functions of the MAC layer and PHY layer. Data and control information are transmitted between the RLC layer of the UE 100 and the RLC layer of the base station 200 via logical channels.

[0025] The PDCP layer performs header compression / decompression and encryption / decryption.

[0026] The SDAP (Service Data Adaptation Protocol) layer maps IP flows, which are units for QoS control by the core network, to radio bearers, which are units for QoS control by the AS (Access Stratum).

[0027] The RRC layer controls logical channels, transport channels, and physical channels according to the establishment, re-establishment, and release of radio bearers. RRC signaling for various settings is transmitted between the RRC layer of the UE 100 and the RRC layer of the base station 200. When there is an RRC connection between the RRC of the UE 100 and the RRC of the base station 200, the UE 100 is in an RRC connected state. When there is no RRC connection between the RRC of the UE 100 and the RRC of the base station 200, the UE 100 is in an RRC idle state. When the RRC connection between the RRC of the UE 100 and the RRC of the base station 200 is suspended, the UE 100 is in an RRC inactive state.

[0028] In the control plane, the NAS layer located above the RRC layer in the UE 100 performs session management and mobility management for the UE 100. NAS signaling is transmitted between the NAS layer of the UE 100 and the NAS layer of the core network device 300.

[0029] The UE 100 has an application layer and the like in addition to the radio interface protocol.

[0030] (Radio frame structure) In a 5G system, downlink transmission and uplink transmission are configured within a radio frame having a duration of 10 ms. For example, a radio frame is represented by a system frame number (SFN) ranging from 0 to 1023. For example, a radio frame is configured with 10 subframes. For example, one subframe may be 1 ms long. Furthermore, one subframe may be configured with one or more slots. For example, the number of symbols that make up one slot is 14 for a normal CP (Cyclic Prefix) and 12 for an extended CP. Furthermore, the number of slots that make up one subframe varies depending on the set subcarrier spacing. For example, for a normal CP, if the subcarrier spacing is set to 15 kHz, the number of slots per subframe is 1 (i.e., 14 symbols); if the subcarrier spacing is set to 30 kHz, the number of slots per subframe is 2 (i.e., 28 symbols); if the subcarrier spacing is set to 60 kHz, the number of slots per subframe is 4 (i.e., 56 symbols); and if the subcarrier spacing is set to 120 kHz, the number of slots per subframe is 8 (i.e., 112 symbols). Also, if the subcarrier spacing is set to 60 kHz for an extended CP, the number of slots per subframe is 4 (i.e., 48 symbols). That is, the number of slots constituting one subframe is determined based on the subcarrier spacing set by base station 200. Also, the number of symbols constituting one subframe is determined based on the subcarrier spacing set by base station 200. That is, the number of symbols constituting a 1 ms subframe is determined based on the subcarrier spacing set by base station 200, and the length of each symbol (length in the time direction) changes. In the 4G system, each subframe consists of two slots aligned in the time direction. The length of each subframe is 1 ms. The length of each slot is 0.5 ms. Each subframe includes multiple symbols in the time direction.

[0031] (Assumed scenario) An assumed scenario will be described with reference to Figure 4. In the mobile communication system 1, the network 10 supports wireless access via non-terrestrial networks (NTN). As shown in Figure 4, the NTN provides non-terrestrial access by a satellite base station 201 and a gateway base station 202.

[0032] The UE 100 and the satellite base station 201 communicate with each other via a service link. The service link is a radio link between the UE 100 and the satellite base station 201. The satellite base station 201 and the gateway base station 202 communicate with each other via a feeder link. The feeder link is a radio link between the satellite base station 201 and the gateway base station 202. The satellite base station 201 and the gateway base station 202 may function as a single base station 200. As a single base station 200, the base station 200 may communicate with the UE 100 via a Uu interface, or may communicate with the core network device 300 via a predetermined interface (for example, an S1 interface).

[0033] The satellite base station 201 may be referred to as an NTN payload. The NTN payload may be a network node that provides connectivity between a service link and a feeder link. The NTN payload may be a network node mounted on a satellite or a high-altitude platform station. The NTN payload may be a transport network layer (TNL) node. The satellite may be a space-borne vehicle carrying an NTN payload and orbiting the Earth.

[0034] The gateway base station 202 may be referred to as an NTN gateway. An NTN gateway may be a node that provides connectivity to an NTN payload using a feeder link. An NTN gateway may be a ground station located on the surface of the Earth. An NTN gateway may be a TNL node.

[0035] Meanwhile, support for store-and-forward (S&F) satellite operation is currently being considered to extend IoT-NTN technology in mobile communication systems that comply with the technical specifications of 3GPP, a mobile communication system standardization project. In S&F satellite operation, even if either the service link between the UE 100 and the base station 200 (specifically, the satellite base station 201) or the feeder link between the satellite base station 201 and the core network (e.g., the core network device 300) is unavailable, the satellite base station 201 stores information, thereby increasing communication opportunities compared to a case in which communication is performed only when both the service link and the feeder link are available.

[0036] However, depending on the orbit of the satellite base station 201, there is a concern that a service link and / or a feeder link may not be established for a long period of time, causing the satellite base station 201 to continue storing information, which may result in malfunction. Therefore, the following describes operations that enable appropriate operations to be performed when S&F satellite operations are performed.

[0037] (Configuration of user device) The configuration of the UE 100 according to the embodiment will be described with reference to Fig. 5. The UE 100 includes a communication unit 110 and a control unit 120.

[0038] The communication unit 110 performs wireless communication with the base station 200 by transmitting and receiving radio signals to and from the base station 200. The communication unit 110 has at least one transmission unit 111 and at least one reception unit 112. The transmission unit 111 and the reception unit 112 may be configured to include multiple antennas and RF (Radio Frequency) circuits. The antenna converts a signal into radio waves and radiates the radio waves into space. The antenna also receives radio waves in space and converts the radio waves into a signal. The RF circuit performs analog processing of the signal transmitted and received via the antenna. The RF circuit may include a high-frequency filter, an amplifier, a modulator, a low-pass filter, etc.

[0039] The control unit 120 performs various controls in the UE 100. The control unit 120 controls communication with the base station 200 via the communication unit 110. The operations of the UE 100 described above and below may be controlled by the control unit 120. The control unit 120 may include at least one processor capable of executing a program and a memory that stores the program. The processor may execute the program to perform the operations of the control unit 120. The control unit 120 may include a digital signal processor that performs digital processing of signals transmitted and received via the antenna and the RF circuit. The digital processing includes processing of a RAN protocol stack. The memory stores programs executed by the processor, parameters related to the programs, and data related to the programs. The memory may include at least one of a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), and a flash memory. All or a part of the memory may be included in the processor.

[0040] (Base station configuration) The configuration of the base station 200 according to the embodiment will be described with reference to Fig. 6. The base station 200 includes a communication unit 210, a network communication unit 220, and a control unit 230.

[0041] The communication unit 210 receives a radio signal from the UE 100 and transmits the radio signal to the UE 100, for example. The communication unit 210 has at least one transmission unit 211 and at least one reception unit 212. The transmission unit 211 and the reception unit 212 may be configured to include an RF circuit. The RF circuit performs analog processing of a signal transmitted and received via an antenna. The RF circuit may include a high-frequency filter, an amplifier, a modulator, a low-pass filter, etc.

[0042] The network communication unit 220 transmits and receives signals to and from the network. For example, the network communication unit 220 receives signals from adjacent base stations connected via an Xn interface (or an X2 interface), which is an interface between base stations, and transmits the signals to the adjacent base stations. The network communication unit 220 also receives signals from the core network device 300 connected via an NG interface (or an S1 interface), and transmits the signals to the core network device 300.

[0043] The control unit 230 performs various controls in the base station 200. The control unit 230 controls, for example, communication with the UE 100 via the communication unit 210. The control unit 230 also controls, for example, communication with a node (e.g., a neighboring base station, the core network device 300) via the network communication unit 220. The operations of the base station 200 described above and below may be operations controlled by the control unit 230. The control unit 230 may include at least one processor capable of executing a program and a memory that stores the program. The processor may execute the program to perform the operations of the control unit 230. The control unit 230 may include a digital signal processor that performs digital processing of signals transmitted and received via the antenna and the RF circuit. The digital processing includes processing of a protocol stack of the RAN. The memory stores the program executed by the processor, parameters related to the program, and data related to the program. All or a part of the memory may be included in the processor.

[0044] The configuration of the satellite base station 201 and the gateway base station 202 may be the same as that of the base station 200 described above.

[0045] (First operation example) A first operation example will be described with reference to Figures 7 and 8. Previously described explanations may be omitted. In this operation example, operations on the control plane (C-plane) will be described as an example.

[0046] The UE 100 and the satellite base station 201 may be able to communicate only while a service link is established. Also, the satellite base station 201 and the gateway base station 202 may be able to communicate only while a feeder link is established. In this operation example, the satellite base station 201 supports S&F satellite operation. Therefore, hereinafter, the satellite base station 201 may store data and / or signaling to / from the UE 100 until a service link is established. The satellite base station 201 may forward the data and / or signaling to / from the UE 100 once the service link is established. Similarly, the satellite base station 201 may store data and / or signaling to / from the gateway base station 202 until a feeder link is established. The satellite base station 201 may forward the data and / or signaling to / from the gateway base station 202 once the feeder link is established.

[0047] Step S101: The transmitter 211 of the satellite base station 201 may transmit information relating to the S&F state (hereinafter referred to as S&F state information) to the UE 100. The receiver 112 of the UE 100 may receive the longest time information from the satellite base station 201.

[0048] The transmitter 211 of the satellite base station 201 may transmit a system information block (SIB) including the S&F status information by broadcast, or may transmit the S&F status information by an individual RRC message to the UE 100. The system information block (SIB) may be simply referred to as system information. Also, an RRC early data request (RRCEarlyDataRequest) message and / or an RRC early data complete (RRCEarlyDataComplete) message, which will be described later, may be simply referred to as an RRC message.

[0049] The S&F status information may include information indicating whether S&F is executable. If the S&F status information indicates that S&F is executable, the control unit 120 may determine that the satellite base station 201 is executable. On the other hand, if the S&F status information indicates that S&F is not executable or if the control unit 120 does not receive S&F status information (i.e., the S&F status information is not included in the system information block), the control unit 120 may determine that the satellite base station 201 is not executable. For example, the S&F status information may include information indicating whether S&F is supported.

[0050] The S&F status information may include information indicating the expected longest transmission time, or may include derivation information for deriving the expected longest transmission time. The derivation information may be, for example, satellite ephemeris (orbit, etc.) information. The control unit 120 may derive the expected longest transmission time based on the derivation information. When the S&F status information includes information indicating the expected longest transmission time and / or derivation information, the control unit 120 may determine that the satellite base station 201 is in a state where S&F can be performed. The expected longest transmission time may simply be referred to as transmission time. In other words, the expected longest transmission time may simply be a time length.

[0051] Here, the expected longest transmission time may be, for example, the expected longest time from when UE 100 transmits information to satellite base station 201 until UE 100 receives a response to the information. That is, the expected longest transmission time may operate from when UE 100 transmits information to satellite base station 201 until UE 100 receives a response to the information. For example, the expected longest transmission time may be started based on UE 100 transmitting information to satellite base station 201. Furthermore, the expected longest transmission time may be stopped based on UE 100 receiving a response to the information from satellite base station 201.

[0052] For example, when S&F is executable, the control unit 120 may execute the following process even if only the service link is available.

[0053] Thereafter, the control unit 120 of the UE 100 may start an EDT procedure for performing one uplink data transmission during the random access procedure in response to a request to establish or resume an RRC connection from a layer higher than the RRC layer. The control unit 120 may select a random access preamble configured for the EDT (e.g., Mobile Originated Early Data Transmission (MO-EDT)). The control unit 120 may also select resources (e.g., time and / or frequency resources) of a Physical Random Access Channel (PRACH) configured for the EDT. The satellite base station 201 may transmit, to the UE 100, information for configuring one or more random access preambles for the EDT and / or information for configuring one or more PRACHs for the EDT. For example, the information for configuring one or more random access preambles for the EDT and / or information for configuring one or more PRACHs for the EDT may be included in system information and / or an RRC message. For example, information for configuring one or more random access preambles for EDT and / or information for configuring one or more PRACHs for EDT may be included in system information and / or RRC messages that include S&F status information.

[0054] Note that the EDT (procedure) may allow one uplink data transmission followed optionally by one downlink data transmission during the random access procedure. In the EDT, an S1 connection may be established or re-established upon reception of uplink data. The S1 connection may be released or suspended upon transmission of S1 downlink data. The EDT may refer to both control plane EDT (CP-EDT) and user plane EDT (UP-EDT).

[0055] Step S102: In the random access procedure, the transmitter 111 of the UE 100 may transmit the selected random access preamble (message 1) to the satellite base station 201. That is, the transmitter 111 may transmit the selected random access preamble using the selected PRACH resource. The receiver 212 of the satellite base station 201 may receive the random access preamble from the UE 100.

[0056] Step S103: The transmitter 211 of the satellite base station 201 may transmit a random access response (message 2) to the UE 100. The receiver 112 of the UE 100 may receive the random access response from the satellite base station 201.

[0057] Step S104: The transmitter 111 of the UE 100 may transmit an RRC early data request (RRCEarlyDataRequest) message to the satellite base station 201. The receiver 212 of the satellite base station 201 may receive the RRC early data request message from the UE 100. For example, the RRC early data request message may include a mobile subscription identifier (e.g., a Temporary Mobile Subscriber Identity) and / or an identifier of the UE 100 (e.g., a temporary UE 100 identifier (UE Temporary Identity)). The RRC early data request message may also include information indicating an establishment cause for the RRC early data request. Note that the RRC early data request message is a message used to start the CP-EDT.

[0058] 8, the control unit 120 may include validity information (for example, "dataExpiration") regarding the validity of the predetermined information in the RRC early data request message, so that the UE 100 can transmit the validity information to the satellite base station 201.

[0059] The validity information is information regarding the validity of the predetermined information. Here, the predetermined information may be (user) data, control information, or signaling. For example, the validity information may indicate the validity of an RRC Early Data Complete (RRCE Early Data Complete) message, which is a response to an RRC Early Data Request message, as the validity of the predetermined information. The (user) data may be mapped to an Uplink Shared Channel (UL-SCH). That is, the predetermined information may be data of the UL-SCH. Also, the predetermined information may be an RRC Early Data Request message (e.g., information included in the RRC Early Data Request message). Also, the predetermined information may be information transmitted from the UE 100 to the satellite base station 201 in the uplink (i.e., uplink information). The control unit 120 may receive (monitor, wait for) a response from the satellite base station 201 while the information transmitted in the uplink is valid. That is, the validity information may indicate the validity of a response to the uplink information (e.g., reception of an RRC Early Data Complete message). That is, the predetermined information may be uplink information related to a downlink response (for example, reception of an RRC Early Data Complete message).

[0060] The validity information may include information indicating the expiration date of the predetermined information. The information may be a numerical value (e.g., a timer value) indicating an elapsed time such as s / m, or the expiration date may be indicated by a date and / or a time. The validity information may also include information indicating whether the communication is delay tolerant. The validity information may also include information indicating delay tolerance. The information may also include information indicating delay tolerance in stages (e.g., high / middle / low). The validity information may also include information indicating the validity period of the predetermined information.

[0061] The validity information may be set in units of data (e.g., packet data unit (PDU)). In this case, the control unit 120 may include the validity information in, for example, a PDCP header or in a UE assistance information (UE Assistance Information) message. The UE assistance information message is a message used for indicating UE assistance information to the network 10. The control unit 120 may include the validity information in the UE assistance information message as UE assistance information.

[0062] The validity information may be set for each RRC connection. For example, a relatively long validity period may be set for an RRC connection used for delay-tolerant communication, and a relatively short validity period may be set for an RRC connection used for communication that is not delay-tolerant communication.

[0063] Step S105: The control unit 120 of the UE 100 may start a timer based on the transmission of the RRC early data request message. The control unit 120 may start the timer when an acknowledgment (ACK) for the RRC early data request message, i.e., information indicating that the message has been successfully received at the satellite base station 201, is received in the RRC layer or a lower layer (e.g., the RLC layer, etc.). The timer may also be referred to as a validity-related timer. The satellite base station 201 may also set information indicating a timer value for the UE 100. For example, the satellite base station 201 may transmit system information and / or an RRC message including information indicating the timer value to the UE 100. The information indicating the timer value may be included in the system information and / or the RRC message including the S&F status information.

[0064] The control unit 120 may set the timer to a timer value corresponding to the expiration date based on the validity information, for example. Here, when the control unit 120 knows the expected longest transmission time by information indicating the expected longest transmission time and / or deriving the expected longest transmission time, it may determine whether the expected longest transmission time or the expiration date of the predetermined information will elapse first. If the expected longest transmission time elapses first, the control unit 120 may set the timer to a value corresponding to the expected longest transmission time. The control unit 120 may set the timer value to the shorter value of the expected longest transmission time or the expiration date.

[0065] Alternatively, the control unit 120 may set the timer value to the longer of the expected longest transmission time or the expiration date. For example, if the expiration date is later than the expected longest transmission time, the control unit 120 may set the timer to a value corresponding to the expiration date. Therefore, when the control unit 120 has both validity information and information related to the expected longest transmission time, the control unit 120 may preferentially apply (e.g., set as the timer value) a value based on the validity information. Alternatively, when the control unit 120 has both validity information and information related to the expected longest transmission time, the control unit 120 may preferentially apply (e.g., set as the timer value) a value based on the expected longest transmission time.

[0066] Step S106: The timer expires. The control unit 120 may execute the process of step S107 in response to the expiration of the timer. Note that, if the expiration date is a date and / or a time, the control unit 120 may execute the process of step S107 in response to the passage of the date and / or the time.

[0067] Step S107: The control unit 120 may stop the reception process of the RRC early data complete. For example, the control unit 120 may end the process of waiting for the RRC early data complete or may end the monitoring for receiving the RRC early data complete. Therefore, the control unit 120 may stop the reception process of the RRC early data complete before receiving the RRC early data complete message.

[0068] The control unit 120 may maintain the RRC idle state in response to expiration of the timer. The control unit 120 may terminate the EDT procedure in response to expiration of the timer. Therefore, the control unit 120 may terminate the EDT procedure before receiving an RRC Early Data Complete message. In this case, the control unit 120 may consider that the uplink data transmission was not successful (i.e., failed) in the EDT procedure.

[0069] Step S108: The transmitter 211 of the satellite base station 201 may transfer the NAS message, which is the initial UE message, to the gateway base station 202. The receiver 212 of the gateway base station 202 may receive the initial UE message from the satellite base station 201.

[0070] The controller 230 of the satellite base station 201 initiates an initial UE message procedure. If the controller 230 initiates an S1-AP initial UE message procedure, the controller 230 may establish an S1 connection. Alternatively, the controller 230 may initiate an NG-AP initial UE message procedure.

[0071] The transmitter 211 of the gateway base station 202 may forward the initial UE message to the core network device 300. The core network device 300 may receive the initial UE message from the gateway base station 202.

[0072] The core network device 300 may control the transmission of uplink data from the MME to the S-GW. The core network device 300 may also control the transmission of a PDU session ID and uplink data from the AMF to the SMF. The SMF may forward the uplink data to the UPF.

[0073] Step S109: If downlink data is available, the core network device 300 may forward the downlink data to the gateway base station 202 via the DL NAS transport procedure. The core network device 300 may also indicate to the gateway base station 202 whether more data is expected.

[0074] Gateway base station 202 may forward the downlink data to satellite base station 201. Gateway base station 202 may indicate to satellite base station 201 whether more data is expected.

[0075] Step S110: If no downlink data is available, the core network device 300 may trigger a connection establishment indication procedure to indicate to the gateway base station 202 whether more data is expected. The gateway base station 202 may indicate to the satellite base station 201 whether more data is expected.

[0076] Step S111: The control unit 230 of the satellite base station 201 may perform a transmission decision. The control unit 230 may perform a transmission decision of the RRC Early Data Complete message based on, for example, validity information included in the RRC Early Data Request message. The control unit 230 may perform, for example, the same operations as those of the UE 100 in steps S105 and S106.

[0077] For example, when a timer based on the validity information has expired, that is, when the RRC Early Data Complete message is not valid, the control unit 230 may stop the transmission of the RRC Early Data Complete message. In this way, the control unit 230 may perform control to stop the transmission of the predetermined information when the expiration date has passed. In this case, the control unit 230 may discard the downlink data to the UE 100 without storing it. On the other hand, for example, when the timer has not expired, that is, when the RRC Early Data Complete message is valid, the control unit 230 may perform the process of step S112. In this way, the control unit 230 may determine whether to stop the transmission (transmission) of the predetermined information based on the validity information.

[0078] Step S112: The transmitter 211 of the satellite base station 201 may transmit (transmit) an RRC early data complete message to the UE 100. The receiver 112 of the UE 100 may receive the RRC early data complete message from the satellite base station 201. The RRC early data complete message may be used to confirm that the CP-EDT procedure has been successfully completed. The RRC early data complete message may include downlink data.

[0079] The control unit 120 of the UE 100 may maintain the RRC idle state based on the reception of the RRC Early Data Complete message.

[0080] Step S113: As a release procedure, the satellite base station 201 and / or the gateway base station 202 and the core network device 300 may release the S1 connection or may initiate an AN release procedure. The satellite base station 201 and / or the gateway base station 202 may execute the release procedure even if the satellite base station 201 does not transmit an RRC Early Data Complete message.

[0081] As described above, the control unit 120 of the UE 100 may control communication of the predetermined information via the satellite base station 201 that supports S&F satellite operation. The transmission unit 111 may transmit validity information regarding the validity of the predetermined information to the satellite base station 201. This allows the satellite base station 201 to determine the validity of the predetermined information based on the validity information. If the predetermined information is invalid, the satellite base station 201, for example, discards the predetermined information, thereby preventing the amount of data waiting to be transmitted from continuing to increase and preventing the task holding area and memory area of ​​the satellite base station 201 from becoming overwhelmed. Furthermore, it becomes possible to prevent the satellite base station 201 from wasting radio resources by sending invalid predetermined information to the UE 100.

[0082] Furthermore, the validity of the predetermined information may be the validity of second information (e.g., an RRC Early Data Complete message) that is a response to first information (e.g., an RRC Early Data Request message) from UE 100. If the expiration date of the second information indicated by the validity information has elapsed before the second information is received, control unit 120 may perform control not to execute the reception process of the second information. This makes it possible to avoid unnecessary power consumption caused by UE 100 waiting for invalid second information for a long period of time.

[0083] Furthermore, the receiving unit 112 may receive information indicating the expected longest transmission time of the predetermined information from the satellite base station 201. The control unit 120 may perform control so as not to execute the reception process of the second information when either the expected longest transmission time or the expiration date has elapsed. This makes it possible to avoid unnecessary power consumption caused by the UE 100 waiting for invalid second information for a long period of time, taking into consideration not only the expiration date of the predetermined information but also the expected longest transmission time.

[0084] Furthermore, the validity of the predetermined information may be the validity of second information that is a response to the first information from UE 100. Transmitter 111 may transmit an RRC message to satellite base station 201 as the first information in the EDT procedure. Controller 120 terminates the EDT procedure if the expiration date of the second information indicated by the validity information has passed before receiving the second information. This makes it possible to avoid unnecessary power consumption in the EDT procedure, which would otherwise be caused by UE 100 waiting for invalid second information for a long period of time.

[0085] Furthermore, the transmitter 111 may transmit an RRC message including validity information. This allows the satellite base station 201 to receive the RRC message and know the expiration date of the response to the RRC message. Therefore, management of the expiration date becomes easier compared to, for example, knowing the expiration date of the response after receiving the RRC message.

[0086] (Second operation example) The second operation example will be described with reference to FIG. 9. Previously described explanations may be omitted. In this operation example, a case will be described in which UE 100 transmits information indicating that a response is not required. Note that in this operation example, a response means a response in the RRC layer unless otherwise specified. A response does not mean an acknowledgment (ACK) in a layer lower than the RRC layer, i.e., information indicating that the message has been successfully received on the satellite base station 201 side.

[0087] Step S201: This corresponds to step S101. Here, control unit 230 of satellite base station 201 may, for example, include setting information related to the response (hereinafter, response setting information) in the S&F status information. Alternatively, control unit 230 of satellite base station 201 may generate an RRC message including the response setting information regardless of the S&F status information. Transmitting unit 211 may broadcast the RRC message or transmit it individually to UE 100.

[0088] The response setting information may be, for example, information for satellite base station 201 to notify UE 100 that it will not transmit a response to information from UE 100. For example, the response setting information may be a setting indicating that communication between satellite base station 201 and UE 100 is communication in which no response is sent from satellite base station 201. Furthermore, the response setting information may be, for example, information for setting UE 100 to perform step S205 after processing step S204.

[0089] Control unit 120 of UE 100 may determine, based on the S&F state information, whether satellite base station 201 will transmit a response to the information from UE 100. For example, when satellite base station 201 is in a state where it can execute S&F, control unit 120 may determine that satellite base station 201 will not transmit a response to the information from UE 100. On the other hand, when satellite base station 201 is not in a state where it can execute S&F, control unit 120 may determine that satellite base station 201 will transmit a response to the information from UE 100.

[0090] Steps S202 and S203: This corresponds to steps S102 and S103.

[0091] Step S204: This corresponds to step S104. Here, control unit 120 may include information indicating whether a response is unnecessary or not (hereinafter, response information) in the RRC early data request message. In this way, UE 100 can transmit the response information to satellite base station 201 by transmitting the RRC early data request message.

[0092] For example, when power saving is prioritized over the reliability of each data transmission, the control unit 120 of the UE 100 may include the response information in the RRC early data request message.

[0093] The response information may be, for example, information indicating that a response is not required. Note that the control unit 120 may indicate that a response is required by not including the information indicating that a response is not required in the message.

[0094] The control unit 120 may execute the process of step S205 when a predetermined condition is satisfied. The predetermined condition may be at least one of the following. Sending information indicating that a response is not required to the satellite base station 201 In the EDT procedure, transmitting an RRC message including information indicating that a response is not required to the satellite base station 201 Receiving response setting information from the satellite base station 201 The satellite base station 201 determines not to transmit a response to the information from the UE 100.

[0095] As described in the first operation example, the predetermined condition may be that the expiration date of the RRC early data completion has passed, for example, that a timer has expired.

[0096] Step S205: This corresponds to step S107. The control unit 120 of the UE 100 may stop the reception process of the RRC early data complete. The control unit 120 may stop the reception process of the RRC early data complete when the RRC layer or a lower layer (e.g., the RLC layer, etc.) receives an acknowledgment (ACK) to the RRC early data request message, i.e., information indicating that the message has been successfully received on the satellite base station 201 side. Furthermore, the control unit 120 may terminate the EDT procedure before receiving the RRC early data complete message when a predetermined condition is satisfied. The control unit 120 may maintain the RRC idle state.

[0097] Steps S206 to S208: This corresponds to steps S108 to S110.

[0098] Step S209: The control unit 230 of the satellite base station 201 may perform the transmission decision. The control unit 230 may decide whether or not a predetermined condition is satisfied. The predetermined condition may be at least one of the following: Receiving information indicating that a response is not required from the UE 100 In the EDT procedure, receiving an RRC message from the UE 100 including information indicating that a response is not required Sending response setting information to UE 100 The satellite base station 201 is operational.

[0099] Similarly to the UE 100, the predetermined condition may be that the validity period of the RRC early data complete message has elapsed, for example, that a timer has expired.

[0100] If the predetermined condition is satisfied, the control unit 230 may not execute the process of step S210. Therefore, the control unit 230 may stop the transmission of the RRC early data complete message. If the predetermined condition is satisfied, the control unit 230 may perform control to stop the transmission (transmission) of the RRC early data complete message. In this case, the control unit 230 may discard the downlink data to the UE 100 without storing it. On the other hand, if the predetermined condition is not satisfied, the control unit 230 may execute the process of step S210. In this way, the control unit 230 may determine whether to stop the transmission (transmission) of the RRC early data complete message based on whether the predetermined condition is satisfied.

[0101] Steps S210 and S211: This corresponds to steps S112 and S113.

[0102] As described above, the transmitter 111 of the UE 100 may transmit the first information (for example, an RRC early data request message) to the satellite base station 201. The controller 120 may control a reception process for receiving the second information (for example, an RRC early data complete message) from the satellite base station 201. The controller 120 may perform control so as not to execute the reception process when a predetermined condition is satisfied. This makes it possible to avoid unnecessary power consumption caused by the UE 100 waiting for the second information for a long period of time.

[0103] Furthermore, the predetermined condition may be transmitting information indicating that the second information is unnecessary to satellite base station 201. This allows satellite base station 201 to understand that the second information is unnecessary. As a result, when UE 100 is not waiting for the second information, it is possible to avoid wasting radio resources that would otherwise be wasted by satellite base station 201 sending information to UE 100.

[0104] Furthermore, the predetermined condition may be that satellite base station 201 receives, from the base station, information for notifying UE 100 that it will not transmit the second information. This allows UE 100 to be controlled not to execute reception processing when it does not receive the second information from satellite base station 201, thereby preventing UE 100 from consuming unnecessary power due to waiting for the second information for a long period of time.

[0105] Furthermore, in the EDT procedure, transmission unit 111 may transmit an RRC message as the first information to satellite base station 201. When a predetermined condition is satisfied, control unit 120 may terminate the EDT procedure before receiving the second information. This makes it possible to avoid unnecessary power consumption caused by UE 100 waiting for the second information for a long period of time in the EDT procedure.

[0106] Furthermore, the predetermined condition may be transmitting an RRC message including information indicating that the second information is unnecessary to the satellite base station 201. This allows the satellite base station 201 to receive the RRC message and understand that a response to the RRC message is unnecessary. As a result, it is possible to avoid the satellite base station 201 wasting radio resources by sending information to the UE 100.

[0107] (Other embodiments) In the above-described operation examples, the EDT procedure in the C-plane (i.e., CP-EDP) has been described as an example, but the present invention is not limited to this. For example, a similar operation may be performed in an EDT procedure in the user plane (U-plane) (i.e., UP-EDT). For example, the control unit 120 of the UE 100 may include validity information and / or response information in an RRC connection resume request message. Note that the RRC connection resume request message may be used to request resumption of a suspended RRC connection, or may be used to perform UP-EDT.

[0108] Furthermore, similar to the above-described operation examples, control unit 230 of satellite base station 201 may determine whether to stop transmission of an RRC Connection Release message instead of an RRC Early Data Complete message based on the validity information and / or response information. Note that the RRC Connection Release message may be a message for instructing the release of the RRC connection, or may be a message used to complete the UP-EDT procedure.

[0109] Furthermore, the control unit 120 of the UE 100 may include the validity information and / or the response information in another RRC message. For example, the control unit 120 may include the validity information and / or the response information in at least one of the following messages. Request message used to request a Radio Resource Control (RRC) connection Completion message used to confirm successful completion of Radio Resource Control (RRC) connection procedures Other messages

[0110] The request message may be, for example, an RRC Setup Request message, an RRC Reestablishment Request message, an RRC Connection Reestablishment Request message, an RRC Resume Request message, an RRC Resume Request 1 message, an RRC Connection Resume Request message, and / or an RRC Connection Request message. The RRC Setup Request message and the RRC Connection Request message may be messages for requesting establishment of an RRC connection. The RRC Reestablishment Request message and the RRC Connection Reestablishment Request message may be messages for requesting reestablishment of an RRC connection. The RRC Resume Request message and the RRC Resume Request 1 message may be messages for requesting resumption of a suspended RRC connection or for performing a Radio Access Network (RAN) based Notification Area (RNA) update.

[0111] The completion message may be, for example, an RRC Setup Complete message, an RRC Connection Setup Complete message, an RRC Reestablishment Complete message, and / or an RRC Resume Complete message. The RRC Setup Complete message and the RRC Connection Setup Complete message may be messages used to confirm that the establishment of the RRC connection has been successfully completed. The RRC Reestablishment Complete message and the RRC Connection Reestablishment Complete message may be messages used to confirm that the reestablishment of the RRC connection has been successfully completed. The RRC Resume Complete message and the RRC Connection Resume Complete message may be messages used to confirm that the resumption of the RRC connection has been successfully completed.

[0112] The other messages may be, for example, not only the above-mentioned UE assistance information message, but also a UE capability information message used to transfer UE radio access capabilities requested by the network and / or a UE information response message used to transfer information requested by the network.

[0113] The validity information included in the request message and / or the completion message may be set for each RRC connection, and therefore, in this case, the validity information may be information regarding the validity of predetermined information transmitted by the RRC connection based on the RRC message.

[0114] The validity information may be information (hereinafter, requirement information) about a requirement (of the predetermined information). Therefore, validity (or expiration date) may be replaced with requirement. For example, when the requirement of the predetermined information is satisfied (or not satisfied), the control unit 120 of the UE 100 may execute the process of the above-mentioned operation example, and the control unit 120 of the satellite base station 201 may not execute the process of the above-mentioned operation example (for example, ).

[0115] In the above-described operation example, the expected longest transmission time is the expected longest time from when UE 100 transmits information to satellite base station 201 until UE 100 receives a response to the information, but is not limited to this. The expected longest transmission time may be, for example, the expected longest time from when UE 100 transmits information to satellite base station 201 until the information reaches its final destination, or the expected longest time from when information is transmitted from the final communication partner of UE 100 until the information reaches UE 100.

[0116] In the above-described operation example, the predetermined information has been described taking as an example the second information (e.g., an RRC Early Data Complete message) that is a response to the first information (e.g., an RRC Early Data Request message) from the UE 100 as the predetermined information, but is not limited to this. For example, the predetermined information may be information that is transmitted from the UE 100 to the network 10 and does not require a response from the network 10 side (e.g., any of the base station 200, the satellite base station 201, the gateway base station 202, the core network device 300, and / or a final destination). In this case, the satellite base station 201 may not transmit the predetermined information to the gateway base station 202 when the expiration date and / or the expected longest transmission time of the predetermined information has elapsed (or when a predetermined condition is satisfied). Alternatively, the predetermined information may be information that is transmitted from the network 10 side (e.g., any of the base station 200, the satellite base station 201, the gateway base station 202, the core network device 300, and / or a final destination) to the UE 100 and does not require a response from the UE 100. When the expiration date and / or the expected longest transmission time of the predetermined information has elapsed (or when a predetermined condition is satisfied), the satellite base station 201 may not transmit the predetermined information to the UE 100. Similarly, the gateway base station 202 may not transmit the predetermined information to the satellite base station 201.

[0117] The steps in the operations of each of the above-described embodiments do not necessarily have to be executed in chronological order according to the order depicted in the flow diagrams or sequence diagrams. For example, the steps in the operations may be executed in an order different from that depicted in the flow diagrams or sequence diagrams, or may be executed in parallel. Some of the steps in the operations may be deleted, or additional steps may be added to the process. Furthermore, the above-described operational flows are not limited to being executed independently, but may also be executed by combining two or more operational flows. For example, some steps of one operational flow may be added to another operational flow, or some steps of one operational flow may be replaced with some steps of another operational flow.

[0118] In the above-described embodiment, an NR-based mobile communication system has been described as an example of the mobile communication system 1. However, the mobile communication system 1 is not limited to this example. The mobile communication system 1 may be a system compliant with a TS of either LTE or another generation system (e.g., 6th generation) of the 3GPP standard. The base station 200 may be an eNB that provides E-UTRA user plane and control plane protocol termination for the UE 100 in LTE. The mobile communication system 1 may be a system compliant with a TS of a standard other than the 3GPP standard. The base station 200 may be an IAB (Integrated Access and Backhaul) donor or an IAB node. The base station 200 may be functionally divided into a CU (Central Unit) and a DU (Distributed Unit).

[0119] A program may be provided that causes a computer to execute each process performed by UE 100 or base station 200. The program may be recorded in a computer-readable medium. Using the computer-readable medium, the program can be installed in a computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM (Compact Disk Read Only Memory) or a DVD-ROM (Digital Versatile Disk Read Only Memory). Furthermore, circuits that execute each process performed by UE 100 or base station 200 may be integrated, and at least a part of UE 100 or base station 200 may be configured as a semiconductor integrated circuit (chip set, SoC (System On Chip)).

[0120] In the above embodiments, "transmit" may mean processing at least one layer in a protocol stack used for transmission, or may mean physically transmitting a signal wirelessly or via a wired connection. Alternatively, "transmit" may mean a combination of processing at least one layer and physically transmitting a signal wirelessly or via a wired connection. Similarly, "receive" may mean processing at least one layer in a protocol stack used for reception, or may mean physically receiving a signal wirelessly or via a wired connection. Alternatively, "receive" may mean a combination of processing at least one layer and physically receiving a signal wirelessly or via a wired connection. Similarly, "obtain / acquire" may mean obtaining information from stored information, obtaining information from information received from another node, or obtaining information by generating information. Similarly, the terms "based on" and "depending on / in response to" do not mean "based only on" or "depending only on," unless otherwise specified. The phrase "based on" means both "based only on" and "based at least in part on." Similarly, the phrase "depending on" means both "depending only on" and "depending at least in part on." Similarly, "include" and "comprise" do not mean including only the listed items, but may mean including only the listed items or may include additional items in addition to the listed items. Similarly, in this disclosure, "or" does not mean an exclusive or, but does mean a logical or. Furthermore, any reference to elements using designations such as "first," "second," etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements.Thus, a reference to a first and a second element does not imply that only two elements may be employed therein or that the first element must precede the second element in some way. In this disclosure, where articles are added by translation, such as a, an, and the in English, these articles shall include the plural unless the context clearly indicates otherwise.

[0121] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0122] (Addendum) The following additional notes are about the features of the above-described embodiment.

[0123] (Appendix 1) A communication device, a control unit for controlling communication of predetermined information via a base station supporting store-and-forward (S&F) satellite operation; a transmission unit that transmits validity information regarding the validity of the predetermined information to the base station. Communication equipment.

[0124] (Appendix 2) the validity of the predetermined information is validity of second information that is a response to the first information from the communication device; The control unit controls so as not to execute a process of receiving the second information if the expiration date of the second information indicated by the validity information has passed before the second information is received. 2. The communication device of claim 1.

[0125] (Appendix 3) a receiving unit that receives information indicating an expected longest transmission time of the predetermined information from the base station; The control unit controls so as not to execute the reception process of the second information when either the expected longest transmission time or the expiration date has elapsed. 3. The communications device of claim 2.

[0126] (Appendix 4) the validity of the predetermined information is validity of second information that is a response to the first information from the communication device; the transmitter transmits a radio resource control (RRC) message to the base station as the first information in an early data transmission (EDT) procedure in which one uplink data transmission is performed during a random access procedure; The control unit terminates the EDT procedure when the expiration date of the second information indicated by the validity information has passed before receiving the second information. 4. A communication device according to any one of claims 1 to 3.

[0127] (Appendix 5) The transmitter transmits the RRC message including the validity information. 5. A communication device according to any one of claims 1 to 4.

[0128] (Appendix 6) A communication device, a transmitter configured to transmit the first information to a base station supporting store-and-forward (S&F) satellite operation; a control unit that controls a receiving process of receiving second information that is a response to the first information from the base station, The control unit controls the reception process not to be executed when a predetermined condition is satisfied. Communication equipment.

[0129] (Appendix 7) The predetermined condition is to transmit information indicating that the second information is unnecessary to the base station. 7. The communications device of claim 6.

[0130] (Appendix 8) The predetermined condition is that the base station receives information for notifying the communication device that the base station will not transmit the second information. 8. The communication device of claim 6 or 7.

[0131] (Appendix 9) the transmitter transmits a radio resource control (RRC) message to the base station as the first information in an early data transmission (EDT) procedure in which one uplink data transmission is performed during a random access procedure; The control unit terminates the EDT procedure before receiving the second information when the predetermined condition is satisfied. 9. The communication device of any one of appendixes 6 to 8.

[0132] (Appendix 10) The predetermined condition is to transmit the RRC message including information indicating that the second information is unnecessary to the base station. 10. The communication device of any one of appendixes 6 to 9.

[0133] (Appendix 11) 1. A base station supporting store-and-forward (S&F) satellite operation, comprising: a control unit that controls communication of predetermined information with a communication device; a receiving unit that receives validity information regarding the validity of the predetermined information from the communication device, The control unit performs control to stop transmission of the predetermined information when the expiration date of the predetermined information indicated by the validity information has passed. Base station.

[0134] (Appendix 12) 1. A base station supporting store-and-forward (S&F) satellite operation, comprising: a receiving unit that receives first information from a communication device; a transmitting unit that transmits second information that is a response to the first information to the communication device; a control unit that performs control to stop transmission of the second information when a predetermined condition is satisfied. Base station.

[0135] (Appendix 13) 1. A communication method performed in a communication device, comprising: controlling communication of predetermined information via a base station supporting store-and-forward (S&F) satellite operation; transmitting validity information regarding validity of the predetermined information to the base station. Communication method.

[0136] (Appendix 14) 1. A communication method performed in a communication device, comprising: transmitting the first information to a base station that supports store-and-forward (S&F) satellite operation; a step of controlling a receiving process for receiving second information, which is a response to the first information, from the base station; and a step of controlling not to execute the reception process when a predetermined condition is satisfied. Communication method. [Explanation of symbols]

[0137] 10: Network 100: Communication equipment (UE) 110: Communications Department 111: Transmitter 112: Receiving unit 120: Control unit 200:Base station 201:Satellite base station 202: Gateway base station 210: Communications Department 211: Transmission unit 212: Receiving unit 220: Network Communication Department 230: Control unit 300: Core network equipment

Claims

1. A communication device (100), a control unit (120) for controlling communication of predetermined information via base stations (200, 201) supporting store-and-forward (S&F) satellite operation; a transmission unit (111) that transmits validity information regarding the validity of the predetermined information to the base station. Communication equipment.

2. the validity of the predetermined information is validity of second information that is a response to the first information from the communication device; The control unit controls so as not to execute a process of receiving the second information if the expiration date of the second information indicated by the validity information has passed before the second information is received. The communication device according to claim 1 .

3. a receiving unit that receives information indicating an expected longest transmission time of the predetermined information from the base station; The control unit controls so as not to execute the reception process of the second information when either the expected longest transmission time or the expiration date has elapsed. The communication device according to claim 2 .

4. the validity of the predetermined information is validity of second information that is a response to the first information from the communication device; the transmitter transmits a radio resource control (RRC) message to the base station as the first information in an early data transmission (EDT) procedure in which one uplink data transmission is performed during a random access procedure; The control unit terminates the EDT procedure if the expiration date of the second information indicated by the validity information has passed before receiving the second information.

3. The communication device according to claim 1 or 2.

5. The transmitter transmits the RRC message including the validity information. The communication device according to claim 4.

6. A communication device (100), a transmitter (111) for transmitting first information to a base station (200, 201) supporting store-and-forward (S&F) satellite operation; a control unit (120) for controlling a receiving process for receiving second information, which is a response to the first information, from the base station; The control unit controls the reception process not to be executed when a predetermined condition is satisfied. Communication equipment.

7. The predetermined condition is to transmit information indicating that the second information is unnecessary to the base station. The communication device according to claim 6.

8. The predetermined condition is that the base station receives information for notifying the communication device that the base station will not transmit the second information.

8. The communication device according to claim 6 or 7.

9. the transmitter transmits a radio resource control (RRC) message to the base station as the first information in an early data transmission (EDT) procedure in which one uplink data transmission is performed during a random access procedure; The control unit terminates the EDT procedure before receiving the second information if the predetermined condition is satisfied.

8. The communication device according to claim 6 or 7.

10. The predetermined condition is to transmit the RRC message including information indicating that the second information is unnecessary to the base station. The communication device according to claim 9.

11. A base station (200, 201) supporting store-and-forward (S&F) satellite operation, comprising: a control unit (230) for controlling communication of predetermined information with a communication device; a receiving unit (212) that receives validity information regarding the validity of the predetermined information from the communication device, The control unit performs control to stop transmission of the predetermined information when the expiration date of the predetermined information indicated by the validity information has passed. Base station.

12. A base station (200, 201) supporting store-and-forward (S&F) satellite operation, comprising: a receiving unit (212) that receives first information from the communication device (100); a transmitting unit (211) that transmits second information, which is a response to the first information, to the communication device; a control unit (230) that performs control to stop transmission of the second information when a predetermined condition is satisfied. Base station.

13. A communication method executed in a communication device (100), comprising: controlling communication of predetermined information via base stations (200, 201) supporting store-and-forward (S&F) satellite operation; transmitting validity information regarding validity of the predetermined information to the base station. Communication method.

14. A communication method executed in a communication device (100), comprising: transmitting first information to a base station (200, 201) that supports store-and-forward (S&F) satellite operation; a step of controlling a receiving process for receiving second information, which is a response to the first information, from the base station; and a step of controlling not to execute the reception process when a predetermined condition is satisfied. Communication method.

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