Base station, communication terminal, communication method, and program

Abstract

The purpose of the present invention is to provide a base station capable of achieving communication using a radio resource controlled by a network in an AIoT radio interface. A base station according to the present disclosure comprises a communication unit that transmits, to a communication terminal operating as a reader for an AIoT device, a first message notifying that a wireless resource used for communication with the AIoT device is valid, and transmits, to the communication terminal, a second message notifying the expiration of a validity period of the wireless resource.

Description

Base Station, Communication Terminal, Communication Method, and Program

[0001] The present disclosure relates to a base station, a communication terminal, a communication method, and a program.

[0002] In 3GPP (Registered Trademark) (3rd Generation Partnership Project), the application of AIoT (Ambient Internet of Things) within the 3GPP system has been under consideration. The number of devices related to AIoT is expected to increase exponentially in the future. Furthermore, compared with existing IoT-related devices, power consumption reduction is desired for AIoT-related devices. An AIoT device is an ambient power-enabled IoT device. An AIoT device is an IoT device powered by energy harvesting (environmental power generation) and has either no battery or limited energy storage capacity (e.g., using a capacitor). Energy for an AIoT device is supplied by harvesting radio waves, light, motion, heat, or other suitable power sources.

[0003] Non-Patent Document 1 shows various considerations regarding AIoT. For example, Non-Patent Document 1 shows considerations regarding Topology 2, which is a connection topology for AIoT devices.

[0004] Topology 2 is communication via an intermediate node between a base station and an AIoT device. In Topology 2, an AIoT device communicates bidirectionally with an intermediate node between the device and the base station. The intermediate node is a relay, IAB (Integrated Access and Backhaul) node, UE (User Equipment), repeater, etc. corresponding to ambient IoT. The intermediate node transfers one or both of AIoT data and signaling between the base station and the AIoT device.

[0005] R2-2407984, TP for TR 38.769 update, Huawei, CMCC, T-Mobile USA, 3GPP TSG-RAN WG2 Meeting #127-bis, Hefei, China, 14th - 18th October, 2024

[0006] Non-Patent Document 1 indicates that the radio resources used in the AIoT radio interface between an AIoT device and an intermediate node (UE) are controlled by the network. However, Non-Patent Document 1 does not clearly describe how the network controls the radio resources.

[0007] One of the purposes of this disclosure is to provide a base station, a communication terminal, a communication method, and a program that can realize communication using network-controlled radio resources in an AIoT wireless interface.

[0008] The base station according to this disclosure includes a communication unit that transmits a first message to a communication terminal acting as a reader for an AIoT device, notifying that the radio resources used for communication with the AIoT device are valid, and a second message to the communication terminal notifying that the validity period of the resources has ended.

[0009] The communication terminal relating to this disclosure is a communication terminal that operates as a reader for an AIoT device, and comprises: a first communication unit that receives a first message from a base station notifying that a radio resource used for communication with the AIoT device is valid; and a second communication unit that transmits an R2D message to the AIoT device while the resource is valid, wherein the first communication unit receives a second message from the base station notifying that the validity period of the resource has ended, and the second communication unit stops transmitting the R2D message to the AIoT device after the validity period of the resource has ended.

[0010] The communication method relating to this disclosure includes sending a first message to a communication terminal acting as a reader for an AIoT device, notifying that the wireless resources used for communication with the AIoT device are valid, and sending a second message to the communication terminal, notifying that the validity period of the resources has ended.

[0011] The program relating to this disclosure causes a computer to send a first message to a communication terminal acting as a reader for an AIoT device, notifying that the resources used for communication with the AIoT device are valid, and a second message to the communication terminal notifying that the validity period of the resources has ended.

[0012] This disclosure provides a base station, a communication terminal, a communication method, and a program that can realize communication using network-controlled radio resources in an AIoT wireless interface.

[0013] Figure 1 shows an example of a base station configuration. Figure 2 shows the flow of communication processing performed at the base station. Figure 3 shows an example of a communication terminal configuration. Figure 4 shows the flow of communication processing performed at the communication terminal. Figure 5 shows the process that triggers the gNB to start communication with the UE. Figure 6 shows the process that starts communication with the UE after the gNB receives an Inventory Request message. Figure 7 shows the flow of communication processing between the UE and the gNB when an RLF occurs. Figure 8 shows the RETRIEVE UE CONTEXT Response message. Figure 9 shows the RRC re-establishment message. Figure 10 shows the flow of communication processing when a handover occurs. Figure 11 shows the request message requesting a handover. Figure 12 shows the response message to the handover request message. Figure 13 shows reconfigurationWithSync. Figure 14 is a block diagram showing an example of a base station and gNB configuration. Figure 15 is a block diagram showing an example of a communication terminal and UE configuration.

[0014] Embodiment 1 Figure 1 shows an example of the configuration of a base station 10. The base station 10 may be a computer device that operates by having a processor execute a program stored in memory. The base station 10 may be a device that supports a wireless communication method known as 5G (5th Generation), which is standardized in 3GPP. The base station 10 may be, for example, a gNB (g NodeB) or NG (Next Generation)-RAN (Radio Access Network) node as defined in 3GPP.

[0015] The base station 10 has a communication unit 11. The communication unit 11 may be software or a module whose processing is performed by a processor executing a program stored in memory. Alternatively, the communication unit 11 may be hardware such as a circuit or chip. The communication unit 11 may be used as a means for transmitting or receiving data.

[0016] The communication unit 11 sends a first message to the communication terminal 20, which acts as a reader for the AIoT device 30, notifying it that the wireless resources used for communication with the AIoT device 30 are valid. Furthermore, the communication unit 11 sends a second message to the communication terminal 20 notifying it that the validity period of the wireless resources has ended.

[0017] The reader communicates with the AIoT device 30 and writes data to or reads data from the AIoT device 30. The communication terminal 20 is, for example, an intermediate node in topology 2. Alternatively, the communication terminal 20 may be a UE as defined in 3GPP.

[0018] Wireless resources may be defined using the frequency band and time used for communication between the communication terminal 20 and the AIoT device 30. The frequency band may be defined, for example, using subcarriers or resource blocks. The time may be defined, for example, using time slots or symbols. A wireless resource being active means that the communication terminal 20 and the AIoT device 30 can communicate using the wireless resource. Furthermore, wireless resources may be allocated by the base station 10.

[0019] The communication terminal 20 may determine that the radio resources allocated for communication between the communication terminal 20 and the AIoT device 30 are valid upon receiving the first message. Alternatively, the communication terminal 20 may determine that the radio resources are valid by confirming explicit information contained in the first message indicating that the radio resources allocated for communication between the communication terminal 20 and the AIoT device 30 are valid. The explicit information may be parameters, information elements, etc. The first message may also contain information indicating the radio resources allocated for communication between the communication terminal 20 and the AIoT device 30. Alternatively, the base station 10 may send a message to the communication terminal 20 containing information indicating the radio resources allocated for communication between the communication terminal 20 and the AIoT device 30 before sending the first message to the communication terminal 20. In other words, the base station 10 may notify the communication terminal 20 of the radio resources allocated for communication between the communication terminal 20 and the AIoT device 30, and then send information indicating that the radio resources are valid.

[0020] Furthermore, the communication unit 11 sends a second message to the communication terminal 20 notifying it of the end of the validity period of the wireless resource. In other words, the base station 10 notifies the communication terminal 20 of the start and end of the validity period of the wireless resource used for communication between the communication terminal 20 and the AIoT device 30.

[0021] The communication terminal 20 may determine that the validity period of the radio resource allocated for communication between the communication terminal 20 and the AIoT device 30 has expired upon receiving the second message. Alternatively, the communication terminal 20 may determine that the validity period of the radio resource has expired upon confirming the explicit information contained in the second message indicating that the radio resource allocated for communication between the communication terminal 20 and the AIoT device 30 is invalid.

[0022] Figure 2 shows the flow of communication processing performed at the base station 10. First, the communication unit 11 sends a first message to the communication terminal 20, which acts as a reader for the AIoT device 30, notifying it that the radio resources used for communication with the AIoT device 30 are valid (S11). Next, the communication unit 11 sends a second message to the communication terminal 20 notifying it that the validity period of the radio resources has ended (S12).

[0023] Figure 3 shows an example configuration of the communication terminal 20. The communication terminal 20 may be a computer device that operates by having a processor execute a program stored in memory. The communication terminal 20 acts as a reader for the AIoT device 30. The communication terminal 20 may also be a UE (User Engineer).

[0024] The communication terminal 20 has a communication unit 21 and a communication unit 22. The communication unit 21 may be used to transmit or receive data with the base station 10. The communication unit 22 may be used to transmit or receive data with the AIoT device 30. Alternatively, although the communication unit 21 and the communication unit 22 are shown with different configurations in Figure 3, the communication unit 21 and the communication unit 22 may be the same.

[0025] The communication units 21 and 22 may be software or modules whose processing is performed by the processor executing a program stored in memory. Alternatively, the communication units 21 and 22 may be hardware such as circuits or chips.

[0026] The communication unit 21 receives a first message from the base station 10 notifying it that the radio resources used for communication with the AIoT device 30 are available. After receiving the first message from the base station 10, the communication terminal 20 can communicate with the AIoT device 30 using the radio resources allocated by the base station 10.

[0027] The communication unit 22 sends an R2D (Reader to Device) message to the AIoT device 30 while the wireless resources are active. An R2D message is a message sent from the communication terminal 20 to the AIoT device 30. In contrast, a D2R (Device to Reader) message is a message sent from the AIoT device 30 to the communication terminal 20. The communication unit 22 receives a D2R message from the AIoT device 30 while the wireless resources are active.

[0028] The communication unit 21 receives a second message from the base station 10 notifying it of the end of the validity period of the radio resource. In other words, after the communication unit 21 receives the second message, it can no longer use the radio resource allocated by the base station 10 for communication between the communication terminal 20 and the AIoT device 30. In other words, the communication unit 22 stops sending R2D messages to the AIoT device 30 after the validity period of the radio resource has ended. The communication unit 22 may also stop receiving D2R messages sent from the AIoT device 30 after the validity period of the radio resource has ended, or it may continue to receive D2R messages.

[0029] Figure 4 shows the flow of communication processing performed in the communication terminal 20. First, the communication unit 21 receives a first message from the base station 10 notifying that the radio resources used for communication with the AIoT device 30 are available (S21). Next, the communication unit 22 sends an R2D message to the AIoT device 30 while the radio resources are available (S22). Next, the communication unit 21 receives a second message from the base station 10 notifying that the validity period of the radio resources has ended (S23).

[0030] As described above, the base station 10 can control the use of wireless resources by the communication terminal 20 by sending messages to the communication terminal 20 notifying it that the wireless resources are available and messages notifying it that the validity period of the resources has ended. The wireless resources are wireless resources used for communication between the communication terminal 20 and the AIoT device 30.

[0031] As a result, the communication terminal 20 can communicate using network-controlled wireless resources in the AIoT wireless interface.

[0032] Embodiment 2 The communication processing flow in gNB 60, AF (Application Function) entity 40, and AIoT controller 50 will be explained using Figure 5. gNB 60 corresponds to the base station 10 in Figure 1. Figure 5 shows the processing flow that triggers gNB 60 to start communication with UE 70. UE 70 corresponds to the communication terminal 20 in Figure 3. UE 70 may be used as a reader for AIoT device 30. AF entity 40 and AIoT controller 50 may be computer devices that operate by a processor executing a program stored in memory.

[0033] AF entity 40 is an entity that provides application services. AF entity 40 may, for example, provide application services using data generated by AIoT device 30. Using data generated by AIoT device 30 may involve processing, analyzing, calculating, displaying, or providing the data generated by AIoT device 30 to other devices.

[0034] The AIoT controller 50 may be a device that controls the gNB 60 and UE 70. Controlling the gNB 60 and UE 70 may mean controlling the communication between the gNB 60 and UE 70.

[0035] First, the AF entity 40 sends an Inventory Request message or an AIoT service request to the AIoT controller 50 (S31). The Inventory Request message may be used, for example, to request confirmation of the location of an AIoT device, and the AIoT service request may be used to collect data held by the AIoT device. Alternatively, the AIoT service request message may be used to write data to the AIoT device. The Inventory Request message and the AIoT service request may include, for example, identification information of the AIoT device as filter information. The filter information may be, for example, information for extracting the AIoT device to be accessed. The filter information may also be called filter criteria information. Furthermore, the Inventory Request message and the AIoT service request may include identification information of the reader. Furthermore, the Inventory Request message and the AIoT service request may include information indicating the frequency of access to the AIoT device. The frequency of access to the AIoT device may be the frequency of collecting data from the AIoT device, or the frequency of writing data to the AIoT device. The frequency of access to AIoT devices may, for example, be information indicating periodicity.

[0036] Next, the AIoT controller 50 performs authentication processing related to the Inventory Request message and AIoT service request (S32). The authentication processing related to the Inventory Request message and AIoT service request may be performed to determine whether or not to send the Inventory Request message and AIoT service request to the gNB 60. For example, the processing related to the Inventory Request message and AIoT service request may be a process to authenticate the AF entity 40. Specifically, the processing related to the Inventory Request message and AIoT service request may be a process to determine whether or not to accept the Inventory Request message and AIoT service request sent from the AF entity 40.

[0037] If the AIoT controller 50 determines that it should send an Inventory Request message or an AIoT service request to the gNB 60, it sends the Inventory Request message or AIoT service request to the gNB 60 (S33). The AIoT controller 50 may also send the Inventory Request message or AIoT service request to the gNB 60 that communicates with the reader indicated by the reader identification information contained in the Inventory Request message or AIoT service request.

[0038] Upon receiving an Inventory Request message or an AIoT service request, the gNB60 initiates communication with the UE70, which communicates with at least one AIoT device indicated by the filter criteria information.

[0039] Next, Figure 6 will be used to explain the communication processing flow in gNB60, UE70, and AIoT device 30. Figure 6 shows the process by which gNB60 starts communication with UE70 after receiving an Inventory Request message or an AIoT service request.

[0040] First, gNB60 sends a paging message to UE70 (S41). For example, gNB60 may send a paging message to initiate communication with UE70, which is in an idle state. When sending a paging message, an idle state may refer to a state in which resources between gNB60 and UE70 have been released. Alternatively, an idle state may refer to a state in which gNB60 does not hold any information about UE70. gNB60 may send a paging message triggered by receiving an Inventory Request message or an AIoT service request. Or, gNB60 may send a paging message triggered by receiving a message other than an Inventory Request message or an AIoT service request.

[0041] A paging message may be used to invoke a single UE70, or it may be used to invoke multiple UEs. The paging message may also contain filter information.

[0042] Next, UE70 performs random access with gNB60 (S42). The random access procedure may be, for example, a two-step random access procedure or a three-step random access procedure. Alternatively, the random access procedure may be CBRA (Contention Based Random Access) or CFRA (Contention Free Random Access).

[0043] In the three-step random access procedure, for example, the UE 70 transmits Message 1 including a random ID to the gNB 60. Next, the gNB 60 transmits Message 2 including the random ID included in Message 1 to the UE 70. Next, the UE 70 transmits Message 3 including the device ID of the UE 70 to the gNB 60. Also, the three-step random access procedure may be a four-step random access procedure including a step of transmitting contention resolution from the gNB 60 to the UE 70.

[0044] In the two-step random access procedure, for example, the UE 70 executes a step (i.e., transmits Message 1 including a random ID and a device ID to the leader) that plays the same roles as Messages 1 and 3 in the three-step random access procedure to the gNB 60. Next, the gNB 60 executes a step (i.e., transmits Message 2 including the random ID included in Message 1 to the device 10) that plays the same role as Message 2 in the three-step random access procedure.

[0045] CBRA is a procedure in which an access timing message transmitted from the UE 70 to the gNB 60 may overlap with an access timing message transmitted from another device. The overlapping of the access timing message transmitted from the UE 70 may be alternatively expressed as a collision or occurrence of a collision of the access contention message. CFRA may be, for example, a procedure in which the timing for the UE 70 to access the gNB 60 is controlled by the gNB 60. By controlling the procedure for the UE 70 to access the gNB 60 by the gNB 60, the occurrence of a collision can be avoided. On the other hand, in CBRA, the random ID transmitted from the UE 70 to the gNB 60 may overlap with the random ID transmitted from the UE. The overlapping of the random ID transmitted from the UE may be alternatively expressed as a collision or occurrence of a collision of the random ID.

[0046] When the random access procedure succeeds, a connection between the UE 70 and the gNB 60 is established. The establishment of the connection between the UE 70 and the gNB 60 may also be referred to as the establishment or configuration of a channel.

[0047] Random access may be performed, for example, as an RRC Setup procedure between the UE 70 and the gNB 60. When the RRC Setup procedure succeeds, the RRC state of the UE 70 transitions from the idle state to the connected state. Also, an RRC Resume procedure may be performed for the UE 70 in the inactive state to transition to the connected state.

[0048] Next, the gNB 60 transmits a message instructing the activation of resources to the UE 70 (S43). For example, the gNB 60 may transmit an RRC message to the UE 70 as a message instructing the activation of resources. Specifically, the RRC message may be an RRCReconfiguration message. The RRC message includes information indicating the resources used for communication between the UE 70 and the AIoT device 30. The resources used for communication between the UE 70 and the AIoT device 30 may be described as the resources allocated in the gNB 60. Further, the RRC message may or may not include information explicitly indicating that the resources are to be made active.

[0049] When the UE 70 receives an RRC message that does not include information explicitly indicating that the resources are to be made active, the UE 70 may recognize or determine that the resources included in the RRC message are active by receiving the RRC message.

[0050] Alternatively, information explicitly indicating that a resource should be enabled may be notified from gNB60 to UE70 using a MAC (Medium Access Control) CE (Control Element). When UE70 receives a MAC CE that explicitly indicates that a resource should be enabled, it may recognize or determine that the resource included in the RRC message is enabled.

[0051] Alternatively, information explicitly indicating that a resource is enabled may be notified from gNB60 to UE70 using DCI (Downlink Control Information) format. When UE70 receives DCI format information explicitly indicating that a resource is enabled, it may recognize or determine that the resource included in the RRC message is enabled.

[0052] Next, UE70 communicates data with AIoT device 30 using the allocated resources (S44). Messages sent from UE70 to AIoT device 30 are R2D messages, and messages sent from AIoT device 30 to UE70 are D2R messages. For example, UE70, as the reader, may establish a connection with AIoT device 30 by performing AIoT paging processing before performing data communication.

[0053] Next, gNB60 sends a message to UE70 instructing it to disable the active resources used for communication between UE70 and AIoT device 30 (S45). gNB60 may also send the message as a completion of communication between UE70 and AIoT device 30 or as a releasing procedure for resources used for communication between UE70 and AIoT device 30. Alternatively, gNB60 may send the message as a termination procedure for communication between UE70 and AIoT device 30.

[0054] gNB60 may send an RRC message to UE70 as a message instructing it to disable the resource. Specifically, the RRC message may be an RRCReconfiguration message or an RRCRelease message.

[0055] Alternatively, information instructing to disable a resource may be communicated from gNB60 to UE70 using a MAC (Medium Access Control) CE (Control Element). gNB60 may use a MAC CE to instruct to disable a resource if it used a MAC CE to instruct to enable a resource. Alternatively, gNB60 may use a MAC CE to instruct to disable a resource, but not by the same means used to instruct to enable a resource.

[0056] Alternatively, information instructing the UE70 to disable a resource may be communicated from gNB60 to UE70 using the DCI (Downlink Control Information) format. gNB60 may use the DCI format to instruct the UE70 to disable a resource if it used the DCI format to instruct the UE70 to enable a resource. Alternatively, gNB60 may use the DCI format to instruct the UE70 to disable a resource, without using the same means used to instruct the UE70 to enable a resource.

[0057] Here, gNB60 may send the message shown in step S45 based on the message received from UE70. For example, UE70 may send User Assistance Information (UAI) or other information, such as MAC CE, to gNB60 to prompt it to send a message instructing it to disable a resource. The UAI or other information may be, for example, a message or information indicating a request or report to gNB60.

[0058] As explained above, gNB60 can use messages from various layers to notify UE70 whether the resources used for communication with AIoT device30 are enabled or disabled.

[0059] Embodiment 3 Next, we will describe the state of the resources when an RLF (Radio Link Failure) occurs.

[0060] Figure 7 shows the communication process flow between UE70 and gNB60 when RLF occurs. First, UE70 detects a radio fault between itself and gNB60 (S51). The radio fault may be, for example, a fault at the physical layer. UE70 may also detect a radio fault when it loses synchronization with gNB60.

[0061] Next, UE70 starts the first timer (S52). The first timer may be a T310 timer as defined in 3GPP. The T310 timer stops if it can synchronize with gNB60 before it expires. In Figure 7, assume that UE70 was unable to synchronize with gNB60.

[0062] Next, the T310 timer expires (S53). Next, triggered by the expiration of the T310 timer, UE70 sends an RRC re-establishment request message to gNB60 (S54). UE70 determines that an RLF has occurred, triggered by the expiration of the T310 timer.

[0063] Next, UE70 starts a second timer (S55) triggered by the transmission of the RRC re-establishment request message. The second timer may be a T311 timer as defined in 3GPP. The T311 timer stops when it receives the RRC re-establishment message. The RRC re-establishment message is a response to the RRC re-establishment request message. In Figure 7, assume that UE70 did not receive the RRC re-establishment message.

[0064] Next, the second timer expires (S56). Then, triggered by the expiration of the second timer, UE70 transitions from the connected state to the idle state (S57).

[0065] UE70 may consider the resources used for communication with the AIoT device 30 to be invalid from the time the first timer is started until the transition from the connected state to the idle state. In other words, UE70 may consider the resources used for communication with the AIoT device 30 to be invalid even if it does not receive a message from gNB60 instructing it to invalidate the resources used for communication with the AIoT device 30.

[0066] Alternatively, UE70 may consider the resources used for communication with the AIoT device 30 to be invalid after the second timer has started. In other words, UE70 may consider the resources used for communication with the AIoT device 30 to be invalid because it has sent an RRC re-establishment request.

[0067] Alternatively, if UE70 receives an RRC re-establishment message or RRC Setup message from a gNB different from gNB60, i.e., a non-serving cell, it may consider the resources used for communication with the AIoT device 30 to be invalid.

[0068] Alternatively, UE70 may consider the resources used for communication with the AIoT device 30 to be invalid when a third timer, different from the first and second timers, expires. The third timer may be called, for example, an AIoT resource utilization timer.

[0069] The third timer may be started at substantially the same time as the first or second timer. Here, the third timer may expire earlier than the first and second timers.

[0070] UE70 may consider the resources used for communication with the AIoT device 30 to be valid until the third timer expires. UE70 may also consider the resources used for communication with the AIoT device 30 to be invalid if the third timer expires before the first or second timer expires.

[0071] Alternatively, if the UE 70 starts the second timer and the third timer at substantially the same time, it may temporarily disable the resources used for communication with the AIoT device 30. Temporarily disabling a resource means that the resource is in a suspended state. The UE 70 also sends an RRC re-establishment request message before starting the second timer, after starting it, or at substantially the same time as starting it.

[0072] In such a situation, if UE70 receives an RRC re-establishment message from gNB60, i.e., the serving cell, before the third timer expires, it may perform a resource reactivation process to bring the suspended resource back into an active state.

[0073] Next, we will describe an example in which gNB60 considers that the use of resources between UE70 and AIoT device 30 (hereinafter referred to as AIoT resources) has been completed. When gNB60 considers that the use of AIoT resources has been completed, it may instruct UE70 to perform processing related to the completion, release, or termination of AIoT resources.

[0074] gNB60 may consider the use of the AIoT resource to be complete when it receives an RRC re-establishment request message from UE70.

[0075] Alternatively, gNB60 may consider its use of the AIoT resource complete when it receives a RETRIEVE UE CONTEXT REQUEST message from another gNB (i.e., a non-serving cell). The other gNB may be referred to as another NG-RAN node. The RETRIEVE UE CONTEXT REQUEST message may also be a message requesting that information about UE70 (UE CONTEXT) be sent to the other gNB.

[0076] Alternatively, gNB60 may consider the use of the AIoT resource complete when it sends a RETRIEVE UE CONTEXT Response message to another gNB. The RETRIEVE UE CONTEXT Response may include information indicating that UE70 is acting as a reader for the AIoT device 30 and information indicating the AIoT resource, as shown in Figure 8, for example.

[0077] For example, as shown in Figure 9, UE70 may perform a restart process and enable the resources used for communication with the AIoT device 30 when it receives an RRC re-establishment message accompanied by an AIoT resource resume instruction.

[0078] Next, we will explain the processing that occurs when an RLF (Rapid Left Flag) occurs, which differs from that shown in Figure 7, using Figure 10. Figure 10 shows the flow of communication processing when a handover occurs. gNB60 is the source gNB, and gNB80 is the target gNB.

[0079] First, gNB60 sends a request message to gNB80 requesting a handover of UE70 (S61). The request message may include, for example, information indicating that UE70 will act as a reader for AIoT device 30 and information indicating the AIoT resources. Next, gNB80 sends a response message to gNB60 (S62).

[0080] Next, gNB60 sends an instruction message to UE70 instructing it to perform a handover to gNB80 (S63). The instruction message may be, for example, an RRCReconfiguration message including reconfigurationWithSync.

[0081] Next, upon receiving an instruction message, UE70 starts a fourth timer (S64). The fourth timer may be a T304 timer as defined in 3GPP. Next, UE70 executes a random access procedure with gNB80 (S65). In Figure 10, it is assumed that the random access procedure was successful.

[0082] Next, the fourth timer stops if the random access procedure with gNB80 is successful (S66). UE70 identifies that an RLF has occurred when the T304 timer stops or expires. Steps S67 to S70 are the same as steps S54 to S57 in Figure 7, so a detailed explanation is omitted.

[0083] UE70 may consider the resources used for communication with the AIoT device 30 to be invalid from the time the fourth timer is started until the transition from the connected state to the idle state. In other words, UE70 may consider the resources used for communication with the AIoT device 30 to be invalid even if it does not receive a message from gNB60 instructing it to invalidate the resources used for communication with the AIoT device 30.

[0084] Alternatively, UE70 may consider the resources used for communication with the AIoT device 30 to be invalid after the fourth timer has stopped or expired. In other words, UE70 may consider the resources used for communication with the AIoT device 30 to be invalid when it sends an RRC re-establishment request message.

[0085] Alternatively, if UE70 receives an RRC re-establishment or RRC Setup from a gNB different from gNB60, i.e., a non-serving cell, it may consider the resources used for communication with the AIoT device 30 to be invalid.

[0086] Alternatively, UE70 may consider the resources used for communication with the AIoT device 30 to be invalid when a third timer, which is different from the fourth timer and the second timer, expires. The third timer may be called, for example, an AIoT resource utilization timer.

[0087] The third timer may start at substantially the same time as the fourth timer or the second timer. Here, the third timer may expire earlier than the fourth timer and the second timer.

[0088] UE70 may consider the resources used for communication with the AIoT device 30 to be valid until the third timer expires. UE70 may also consider the resources used for communication with the AIoT device 30 to be invalid if the third timer expires before the fourth timer or the second timer expires.

[0089] Alternatively, if the UE70 starts the second timer and the third timer at substantially the same time, it may temporarily disable the resources used for communication with the AIoT device 30. Temporarily disabling the resources means that the resources are in a suspended state. The UE70 also sends an RRC re-establishment request to the gNB60 before starting the second timer, after starting it, or at substantially the same time as starting it.

[0090] In such a situation, if UE70 receives an RRC re-establishment message from gNB60 before the third timer expires, it may perform resource restart processing to bring the suspended resource back into an active state.

[0091] Next, we will describe an example in which gNB60 considers that the use of resources between UE70 and AIoT device 30 (hereinafter referred to as AIoT resources) has been completed. When gNB60 considers that the use of AIoT resources has been completed, it may instruct UE70 to perform processing related to the completion, release, or termination of AIoT resources.

[0092] gNB60 may consider the use of the AIoT resource complete when it sends a request message to gNB80 requesting a handover from UE70, as shown in Figure 11. For example, the request message requesting a handover may include information indicating that UE70 will act as a reader for the AIoT device 30 and information indicating the AIoT resource.

[0093] Alternatively, gNB60 may consider the use of the AIoT resource complete when it receives a response message from gNB80 to the handover request message, as shown in Figure 12. For example, the response message may include information indicating that UE70 will act as a reader for the AIoT device 30 and the AIoT resource.

[0094] Alternatively, gNB60 may consider the use of the AIoT resource complete when it sends an instruction message to UE70 instructing it to perform a handover to gNB80.

[0095] For example, when UE70 receives an RRCReconfiguration that includes a reconfigurationWithSync with an AIoT resource resume instruction, it sends an RRCReconfiguration complete message to gNB80. In this case, UE70 may perform a resume process and enable the resources used for communication with the AIoT device 30. reconfigurationWithSync may include an aIoTResourceResumeIndication, as shown in Figure 13.

[0096] As explained above, if an RLF occurs between UE70 and gNB60, UE70 can decide to disable the AIoT resource even if it does not receive a message instructing it to disable the resource. Similarly, gNB60 can decide to disable the AIoT resource even if it does not send a message instructing it to disable the resource.

[0097] Figure 14 is a block diagram showing an example configuration of a base station 10 and a gNB 60 (hereinafter referred to as base station 10, etc.). Referring to Figure 14, base station 10, etc. includes an RF transceiver 1001, a network interface 1003, a processor 1004, and a memory 1005. The RF transceiver 1001 performs analog RF signal processing to communicate with UEs. The RF transceiver 1001 may include multiple transceivers. The RF transceiver 1001 is coupled with an antenna 1002 and a processor 1004. The RF transceiver 1001 receives modulation symbol data (or OFDM symbol data) from the processor 1004, generates a transmit RF signal, and supplies the transmit RF signal to the antenna 1002. The RF transceiver 1001 also generates a baseband receive signal based on the received RF signal received by the antenna 1002 and supplies this to the processor 1004.

[0098] The network interface 1003 is used to communicate with network nodes (e.g., other core network nodes). The network interface 1003 may include, for example, a network interface card (NIC) compliant with the IEEE 802.3 series.

[0099] The processor 1004 performs data plane processing and control plane processing, including digital baseband signal processing for wireless communication.

[0100] The processor 1004 may include multiple processors. For example, the processor 1004 may include a modem processor (e.g., DSP) that performs digital baseband signal processing and a protocol stack processor (e.g., CPU or MPU) that performs control plane processing.

[0101] Memory 1005 is composed of a combination of volatile memory and non-volatile memory. Memory 1005 may include a plurality of physically independent memory devices. Volatile memory is, for example, Static Random Access Memory (SRAM) or Dynamic RAM (DRAM), or a combination thereof. Non-volatile memory is Mask Read Only Memory (MROM), Electrically Erasable Programmable ROM (EEPROM), flash memory, or hard disk drive, or any combination thereof. Memory 1005 may include storage located away from the processor 1004. In this case, the processor 1004 may access memory 1005 via the network interface 1003 or an I / O interface not shown.

[0102] The memory 1005 may store a software module (computer program) containing a set of instructions and data for performing processing by the base station 10, etc., as described in the above-described embodiments. In some implementations, the processor 1004 may be configured to read the software module from the memory 1005 and execute it to perform the processing of the base station 10, etc., as described in the above-described embodiments.

[0103] Figure 15 is a block diagram showing an example configuration of the communication terminal 20 and UE70 (hereinafter referred to as the communication terminal 20, etc.). The Radio Frequency (RF) transceiver 1101 performs analog RF signal processing to communicate with the gNB60. The analog RF signal processing performed by the RF transceiver 1101 includes frequency upconversion, frequency downconversion, and amplification. The RF transceiver 1101 is coupled with the antenna 1102 and the baseband processor 1103. That is, the RF transceiver 1101 receives modulation symbol data (or OFDM symbol data) from the baseband processor 1103, generates a transmit RF signal, and supplies the transmit RF signal to the antenna 1102. The RF transceiver 1101 also generates a baseband receive signal based on the received RF signal received by the antenna 1102 and supplies this to the baseband processor 1103.

[0104] The baseband processor 1103 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. Digital baseband signal processing includes (a) data compression / decompression, (b) data segmentation / concatenation, (c) generation / decomposition of transmission format (transmission frame), (d) transmission path coding / decoding, (e) modulation (symbol mapping) / demodulation, and (f) generation of OFDM symbol data (baseband OFDM signal) by Inverse Fast Fourier Transform (IFFT). Meanwhile, control plane processing includes communication management at Layer 1, Layer 2, and Layer 3.

[0105] The baseband processor 1103 may include a modem processor (e.g., Digital Signal Processor (DSP)) for performing digital baseband signal processing and a protocol stack processor (e.g., Central Processing Unit (CPU) or Micro Processing Unit (MPU)) for performing control plane processing. In this case, the protocol stack processor for performing control plane processing may be shared with the application processor 1104 described later.

[0106] The application processor 1104 is also called a CPU, MPU, microprocessor, or processor core. The application processor 1104 may include multiple processors (multiple processor cores). The application processor 1104 implements various functions of the communication terminal 20, etc., by executing system software programs (Operating System (OS)) and various application programs (for example, a calling application, a web browser, a mailer, a camera operation application, a music playback application) read from memory 1106 or memory not shown.

[0107] In some implementations, the baseband processor 1103 and the application processor 1104 may be integrated on a single chip, as shown by the dashed line (1105) in Figure 15. In other words, the baseband processor 1103 and the application processor 1104 may be implemented as a single System on Chip (SoC) device 1105. An SoC device is sometimes called a System Large Scale Integration (LSI) or chipset.

[0108] Memory 1106 is volatile memory, non-volatile memory, or a combination thereof. Memory 1106 may include multiple physically independent memory devices. Volatile memory is, for example, Static Random Access Memory (SRAM) or Dynamic RAM (DRAM), or a combination thereof. Non-volatile memory is Mask Read Only Memory (MROM), Electrically Erasable Programmable ROM (EEPROM), flash memory, or hard disk drive, or any combination thereof. For example, memory 1106 may include an external memory device accessible from the baseband processor 1103, the application processor 1104, and the SoC 1105. Memory 1106 may also include an internal memory device integrated within the baseband processor 1103, the application processor 1104, or the SoC 1105. Furthermore, memory 1106 may include memory within a Universal Integrated Circuit Card (UICC).

[0109] The memory 1106 may store a software module (computer program) containing instruction sets and data for processing by the device 10, etc., as described in the above-described embodiments. In some implementations, the baseband processor 1103 or application processor 1104 may be configured to read the software module from the memory 1106 and execute it to perform the processing of the device 10, etc., as described in the above-described embodiments.

[0110] In the examples described above, the program includes a set of instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more of the functions described in the embodiments. The program may be stored on a non-temporary computer-readable medium or a physical storage medium. Examples, but not limited to, include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technologies, CD-ROM, digital versatile disc (DVD), Blu-ray® disc or other optical disc storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices. The program may be transmitted over a temporary computer-readable medium or a communication medium. Examples, but not limited to, include temporary computer-readable medium or a communication medium that includes electrical, optical, acoustic or other forms of propagating signals.

[0111] Although the present disclosure has been described above with reference to embodiments, the present disclosure is not limited to the embodiments described above. Various modifications to the structure and details of the present disclosure can be made as can be understood by those skilled in the art within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0112] Each drawing is merely illustrative to illustrate one or more embodiments. Each drawing may be associated with one or more other embodiments, rather than being associated with only one specific embodiment. As those skilled in the art will understand, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings, for example, to create embodiments not explicitly shown or described. Not all features or steps shown in any one drawing to illustrate an exemplary embodiment are necessarily required, and some features or steps may be omitted. The order of steps described in any of the drawings may be changed as appropriate.

[0113] Some or all of the above embodiments may also be described as follows, but are not limited to the following: (Note 1) A base station comprising a communication unit that transmits a first message to a communication terminal acting as a reader for an AIoT device, notifying that a radio resource used for communication with the AIoT device is valid, and a second message to the communication terminal notifying that the validity period of the radio resource has ended. (Note 2) A communication terminal acting as a reader for an AIoT device, comprising: a first communication unit that receives a first message from a base station notifying that a radio resource used for communication with the AIoT device is valid; and a second communication unit that transmits an R2D message to the AIoT device while the radio resource is valid, wherein the first communication unit receives a second message from the base station notifying that the validity period of the radio resource has ended, and the second communication unit stops transmitting the R2D message to the AIoT device after the validity period of the radio resource has ended. (Note 3) A base station comprising: a communication unit that transmits a first message to a communication terminal acting as a leader for an AIoT device, notifying that the radio resources used for communication with the AIoT device are valid; and a determination unit that determines that the radio resources are invalid when the communication unit receives a message regarding the re-establishment of the RRC connection of the communication terminal. (Note 4) A communication terminal acting as a leader for an AIoT device, comprising: a communication unit that receives a first message from a base station notifying that the radio resources used for communication with the AIoT device are valid; and a determination unit that determines that the radio resources are invalid when it detects that a failure has occurred in the radio link between the base station and the communication terminal. (Note 5) A base station comprising: a communication unit that transmits a first message to a communication terminal acting as a leader for an AIoT device, notifying that the radio resources used for communication with the AIoT device are valid; and a determination unit that determines that the radio resources are invalid when the communication unit receives a message regarding the handover of the communication terminal.(Note 6) A communication terminal that operates as a leader for an AIoT device, comprising: a communication unit that receives a first message from a base station notifying that the radio resources used for communication with the AIoT device are valid; and a determination unit that determines that the radio resources are invalid when the communication unit receives a message from the base station regarding a handover to another base station. (Note 7) A communication method that transmits a first message to a communication terminal that operates as a leader for an AIoT device notifying that the radio resources used for communication with the AIoT device are valid, and transmits a second message to the communication terminal notifying that the validity period of the radio resources has ended. (Note 8) A communication method performed on a communication terminal acting as a reader for an AIoT device, comprising: receiving a first message from a base station notifying that a radio resource used for communication with the AIoT device is valid; transmitting an R2D message to the AIoT device while the radio resource is valid; receiving a second message from the base station notifying that the validity period of the radio resource has ended; and stopping the transmission of the R2D message to the AIoT device after the validity period of the radio resource has ended. (Note 9) A program that causes a computer to transmit a first message to a communication terminal acting as a reader for an AIoT device notifying that a radio resource used for communication with the AIoT device is valid, and a second message to the communication terminal notifying that the validity period of the radio resource has ended.(Note 10) A program to be executed by a computer which is a communication terminal acting as a reader for an AIoT device, the program to receive a first message from a base station notifying that the radio resources used for communication with the AIoT device are valid, to send an R2D message to the AIoT device while the radio resources are valid, to receive a second message from the base station notifying that the validity period of the radio resources has ended, and to stop sending the R2D message to the AIoT device after the validity period of the radio resources has ended.

[0114] This application claims priority based on Japanese Patent Application No. 2024-194428, filed on 6 November 2024, and incorporates all of its disclosures herein.

[0115] 10 Base station 11 Communication unit 20 Communication terminal 21 Communication unit 22 Communication unit 30 AIoT device 40 AF entity 50 AIoT controller 60 gNB 70 UE 80 gNB

Claims

1. A base station comprising communication means for transmitting a first message to a communication terminal acting as a reader for an AIoT device, notifying the terminal that the radio resources used for communication with the AIoT device are valid, and a second message to the communication terminal notifying the terminal that the validity period of the radio resources has ended.

2. A communication terminal that operates as a leader for an AIoT device, comprising: a first communication means that receives a first message from a base station notifying that a radio resource used for communication with the AIoT device is active; and a second communication means that transmits an R2D message to the AIoT device while the radio resource is active, wherein the first communication means receives a second message from the base station notifying that the validity period of the radio resource has ended, and the second communication means stops transmitting the R2D message to the AIoT device after the validity period of the radio resource has ended.

3. A base station comprising: communication means for transmitting a first message to a communication terminal acting as a leader for an AIoT device, notifying that the radio resources used for communication with the AIoT device are valid; and determination means for determining that the radio resources are invalid when the communication means receives a message regarding the re-establishment of the RRC connection of the communication terminal.

4. A communication terminal that operates as a leader for an AIoT device, comprising: communication means for receiving a first message from a base station notifying that the radio resources used for communication with the AIoT device are valid; and determination means for determining that the radio resources are invalid when a failure occurs in the radio link between the base station and the communication terminal.

5. A base station comprising: communication means for transmitting a first message to a communication terminal acting as a leader for an AIoT device, notifying that the radio resources used for communication with the AIoT device are valid; and determination means for determining that the radio resources are invalid when the communication means receives a message regarding a handover from the communication terminal.

6. A communication terminal that operates as a leader for an AIoT device, comprising: communication means for receiving a first message from a base station notifying that a radio resource used for communication with the AIoT device is valid; and determination means for determining that the radio resource is invalid when the communication means receives a message from the base station regarding a handover to another base station.

7. A communication method comprising sending a first message to a communication terminal acting as a reader for an AIoT device, notifying that the wireless resources used for communication with the AIoT device are valid, and sending a second message to the communication terminal, notifying that the validity period of the wireless resources has ended.

8. A communication method performed in a communication terminal acting as a reader for an AIoT device, comprising: receiving a first message from a base station notifying that a radio resource used for communication with the AIoT device is valid; transmitting an R2D message to the AIoT device while the radio resource is valid; receiving a second message from the base station notifying that the validity period of the radio resource has ended; and stopping the transmission of the R2D message to the AIoT device after the validity period of the radio resource has ended.

9. A program that causes a computer to send a first message to a communication terminal acting as a reader for an AIoT device, notifying it that the wireless resources used for communication with the AIoT device are valid, and a second message to the communication terminal notifying it that the validity period of the wireless resources has ended.

10. A program to be executed by a computer which is a communication terminal acting as a leader for an AIoT device, the program to cause the computer to receive a first message from a base station notifying that a radio resource used for communication with the AIoT device is valid, to send an R2D message to the AIoT device while the radio resource is valid, to receive a second message from the base station notifying that the validity period of the radio resource has ended, and to stop sending the R2D message to the AIoT device after the validity period of the radio resource has ended.

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