User equipment, node, and communication method

Abstract

This user equipment performs wireless communication with a node in a mobile communication system and is provided with a transmission unit for transmitting green prioritization information.

Description

User equipment, node, and communication method

[0001] The present invention relates to a user equipment, a node, and a communication method.

[0002] The 3rd Generation Partnership Project (3GPP (registered trademark; the same applies hereinafter)), a standardization project for mobile communication systems, is scheduled to formulate standards for the sixth generation (6G). Meanwhile, in recent years, in order to achieve sustainability, society as a whole is being called upon to achieve carbon neutrality, i.e., virtually zero greenhouse gas emissions. With the aim of achieving carbon neutrality, efforts are being made throughout society to shift from fossil fuels to renewable energy (a decarbonized society). Furthermore, Green Transformation (GX), an effort to transform the economy and society through efforts aimed at a decarbonized society, is being undertaken throughout society. Conventional mobile communication systems did not take GX into consideration.

[0003] 3GPP Technical Specification: TS 38.321 V18.1.0 (2024-04) 3GPP Technical Specification: TS 38.331 V18.1.0 (2024-01) 3GPP Technical Specification: TS 38.413 V18.1.0 (2024-04) 3GPP Technical Specification: TS 38.423 V18.1.0 (2024-03) 3GPP Technical Specification: TS 38.473 V18.1.0 (2024-03) 3GPP Technical Specification: TS 24.501 V18.6.0 (2024-04)

[0004] A user device according to a first aspect is a user device that performs wireless communication with a node in a mobile communication system, and includes a transmitter that transmits green priority information.

[0005] A node according to a second aspect is a node that performs wireless communication with a user device in a mobile communication system, and includes a receiving unit that receives green priority information.

[0006] A communication method according to a third aspect is a communication method used by a user device that performs wireless communication with a node in a mobile communication system, and includes a transmitting step of transmitting green priority information.

[0007] A communication method according to a fourth aspect is a communication method used in a node that performs wireless communication with a user device in a mobile communication system, and includes a receiving step of receiving green priority information.

[0008] 1 is a diagram illustrating an overview of a mobile communication system according to an embodiment. FIG. 2 is a diagram illustrating an example of the configuration of a mobile communication system according to an embodiment. FIG. 3 is a diagram illustrating an example of the configuration of a protocol stack of a radio interface of a U-plane that handles data. FIG. 4 is a diagram illustrating an example of the configuration of a protocol stack of a radio interface of a C-plane that handles signaling (control signals). FIG. 5 is a diagram illustrating an example of the configuration of a UE (user equipment) according to an embodiment. FIG. 6 is a diagram illustrating an example of the configuration of a node according to an embodiment. FIG. 7 is a diagram illustrating an example of the system operation according to the first embodiment. FIG. 8 is a diagram illustrating an example of the system operation according to a first modified example of the first embodiment. FIG. 9 is a diagram illustrating an example of the system operation according to a second modified example of the first embodiment. FIG. 10 is a diagram illustrating an example of the system operation according to a third modified example of the first embodiment. FIG. 11 is a diagram illustrating an example of the system operation according to a fourth modified example of the first embodiment. FIG. 12 is a diagram illustrating an example of the configuration of a node according to a second embodiment. FIG. 13 is a diagram illustrating an example of the system operation according to a first modified example of the second embodiment. FIG. 14 is a diagram illustrating an example of the system operation according to a second modified example of the second embodiment.

[0009] Hereinafter, 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.

[0010] (1) First Embodiment A first embodiment will be described with reference to FIGS. 1 to 8. FIG.

[0011] (1.1) System Overview FIG. 1 is a diagram illustrating an overview of a mobile communication system according to an embodiment. A user equipment (UE) 100 performs wireless communication with a node 200. The node 200 routes user data. The user data is data transmitted and received between the UE 100 and a data center. In the example illustrated in FIG. 1 , the data center includes a data center 410 and a data center 420. The data center 410 is operated using non-sustainable energy. The data center 420 is operated using sustainable energy. Sustainable energy is renewable energy that uses, for example, solar or wind power, and has zero or less CO2 emissions than fossil fuels. Non-sustainable energy is, for example, electricity generated using fossil fuels, such as thermal power generation.

[0012] Assume that the UE 100 can select a network to use from multiple networks. In this case, it is considered that the UE 100 can contribute to sustainability such as decarbonization by routing user data to the data center 420 that operates on as sustainable energy as possible. In the sixth generation (6G) standards to be formulated by 3GPP in the future, there is a possibility that technology and standard specifications will be developed using indicators such as sustainability, GX, and carbon neutrality as a direction different from the conventional approach of reducing the power consumption of devices such as the UE 100 or the node 200 themselves.

[0013] In this embodiment, the green communication mode is one of the operation modes of the UE 100, and is an operation mode in which the UE cooperates with the communication system to realize a sustainable mobile communication system. A sustainable mobile communication system is, for example, a mobile communication system that operates using sustainable energy at a predetermined rate or more. In the following description, sustainable energy will also be referred to as green energy. Non-sustainable energy will also be referred to as non-green energy. Note that the green communication mode may include an operation mode aimed at reducing power consumption of the UE 100 (UE power saving (PS)). Furthermore, the green communication mode may include an operation mode aimed at reducing power consumption of the network (Energy Saving (ES) or Network Energy Saving (NES)).

[0014] UE cooperative green communication is a sustainable communication method that includes a green communication mode, and is also simply referred to as green communication.

[0015] The green priority information is information indicating a desire to execute a green communication mode or UE-cooperative green communication. Alternatively, the green priority information is information for executing UE-cooperative green communication. Alternatively, the green priority information is information indicating a desire to execute a green communication mode or UE-cooperative green communication, and information for executing UE-cooperative green communication. Note that the green priority information is also referred to as Green Preference.

[0016] The green operation information is, for example, information indicating an index of an operation state using green energy. The green operation information is one type of network operation information, and may be any one or more of information indicating an index of an operation state using green energy, information indicating an index of a power-saving operation state, information indicating an index of an operation state using non-green energy, and information indicating an index of a non-power-saving operation state.

[0017] (1.2) System Configuration Example Fig. 2 is a diagram showing a configuration example of a mobile communication system according to an embodiment. The mobile communication system according to the embodiment is a system conforming to the 3GPP standard. For example, the mobile communication system according to the embodiment may be a fifth generation (5G) system or a sixth generation (6G) system.

[0018] The mobile communication system includes a network (NW) 1 and a user equipment (UE) 100. The UE 100 is a mobile communication device that performs wireless communication with the NW 1. The UE 100 may be any device used by a user, such as a mobile phone terminal (including a smartphone), a tablet terminal, a notebook PC (Personal Computer), a communication module (including a communication card or chipset), a sensor or a device provided in a sensor, a vehicle or a device provided in a vehicle (Vehicle UE), or an aircraft or a device provided in an aircraft (Aerial UE). The UE 100 may be a Mobile Termination (MT) of a relay device such as an Integrated Access and Backhaul (IAB) or a Network-Controlled Repeater (NCR).

[0019] NW1 includes a radio access network (RAN) 10 and a core network (CN) 20. When the mobile communication system is a 5th generation system (5GS), the RAN 10 is referred to as a Next Generation Radio Access Network (NG-RAN), and the CN 20 is referred to as a 5G Core Network (5GC).

[0020] The RAN 10 includes a plurality of nodes 200 (nodes 200a to 200c in the illustrated example). The nodes 200 are connected to each other via inter-node interfaces. The nodes 200 are also referred to as base stations. The nodes 200 may be configured (i.e., functionally divided) with a CU (Central Unit) and a DU (Distributed Unit), and the two units may be connected by a fronthaul interface. When the mobile communication system is 5GS, the nodes 200 are referred to as gNBs, the inter-node interface is referred to as an Xn interface, and the fronthaul interface is referred to as an F1 interface.

[0021] Each node 200 manages one or more cells. Each node 200 performs wireless communication with a UE 100 that has established a connection with its own cell. Each node 200 has a radio resource management (RRM) function, a routing function for user data (also simply referred to as "data"), a measurement control function for mobility control and scheduling, and the like. Note that "cell" is used as a term indicating the smallest unit of a wireless communication area. "Cell" is also used as a term indicating a function or resource for performing wireless communication with a UE 100. One cell belongs to one carrier frequency (also simply referred to as "frequency").

[0022] The CN 20 includes a plurality of CN devices 300 (in the illustrated example, CN devices 300a to 300c). The CN devices 300 may include a C-plane device corresponding to the control plane (C-plane) and a U-plane device corresponding to the user plane (U-plane). The C-plane device performs various mobility controls and paging for the UE 100. The C-plane device communicates with the UE 100 using NAS (Non-Access Stratum) signaling. The U-plane device controls data transfer. When the mobile communication system is 5GS, the C-plane device is referred to as an AMF (Access and Mobility Management Function), the U-plane device is referred to as a UPF (User Plane Function), and the interface between the node 200 and the CN device 300 is referred to as an NG interface.

[0023] The UE 100 can reselect one or more cells managed by multiple nodes 200. The node 200 can select or connect to multiple CN devices 300. The multiple nodes 200 and the multiple CN devices 300 each operate on either green energy or non-green energy. The multiple nodes 200 and the multiple CN devices 300 each operate on a combination of green energy and non-green energy in a predetermined ratio. For example, the CU and DU constituting the node 200, as well as the CN device 300, are virtualized and run in a data center that operates on different power sources. Furthermore, the data centers may not only differ from each other in power sources but also in performance (e.g., delay depending on distance). These cells, nodes 200, and CN devices 300 do not necessarily need to be connectable from the UE 100. In other words, there may be limitations on the available combinations (e.g., data paths).

[0024] FIG. 3 is a diagram showing an example of the configuration of a protocol stack of a U-plane radio interface that handles data.

[0025] The U-plane radio interface protocol includes, for example, 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 service data adaptation protocol (SDAP) layer.

[0026] 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 UE 100 and the PHY layer of node 200 via a physical channel. The PHY layer of UE 100 receives downlink control information (DCI) transmitted from node 200 on a physical downlink control channel (PDCCH). Specifically, UE 100 performs blind decoding of the PDCCH using a radio network temporary identifier (RNTI) and acquires successfully decoded DCI as DCI addressed to the UE. The DCI transmitted from node 200 has CRC parity bits scrambled by the RNTI added.

[0027] The MAC layer performs data priority control and retransmission processing using Hybrid ARQ (HARQ). Data and control information are transmitted between the MAC layer of UE 100 and the MAC layer of node 200 via a transport channel. The MAC layer of node 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.

[0028] The RLC layer performs automatic repeat request (ARQ) and segmentation / reassembly of transmission data. 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 UE 100 and the RLC layer of node 200 via logical channels.

[0029] The PDCP layer performs header compression / decompression, encryption / decryption, and the like.

[0030] The SDAP layer maps IP flows (also called QoS flows), which are units for QoS control by the CN 20, to radio bearers, which are units for QoS control by the AS (Access Stratum). Note that if the RAN is connected to the EPC, SDAP may not be required.

[0031] FIG. 4 is a diagram showing an example of the configuration of a protocol stack of a C-plane radio interface that handles signaling (control signals).

[0032] The protocol stack of the C-plane radio interface includes, for example, an RRC (Radio Resource Control) layer and an NAS (Non-Access Stratum) layer instead of the SDAP layer shown in FIG.

[0033] RRC signaling for various settings is transmitted between the RRC layer of UE100 and the RRC layer of node 200. The RRC layer controls logical channels, transport channels, and physical channels in accordance with the establishment, re-establishment, and release of radio bearers. When there is a connection (RRC connection) between the RRC of UE100 and the RRC of node 200, UE100 is in an RRC connected state. When there is no connection (RRC connection) between the RRC of UE100 and the RRC of node 200, UE100 is in an RRC idle state. When the connection between the RRC of UE100 and the RRC of node 200 is suspended, UE100 is in an RRC inactive state.

[0034] The NAS layer (also simply referred to as "NAS") located above the RRC layer performs session management, mobility management, etc. NAS signaling is transmitted between the NAS layer of the UE 100 and the NAS layer of the CN device 300. Note that the UE 100 also has an application layer in addition to the radio interface protocol. The layer below the NAS layer is referred to as the AS layer (also simply referred to as "AS").

[0035] (1.3) Example of Configuration of User Equipment FIG. 5 is a diagram illustrating an example of the configuration of the UE 100 (user equipment) according to the embodiment.

[0036] The UE 100 includes a receiving unit 110, a transmitting unit 120, and a control unit 130. The receiving unit 110 and the transmitting unit 120 configure a wireless communication unit 140 that performs wireless communication with the node 200.

[0037] The receiving unit 110 performs various receptions under the control of the control unit 130. The receiving unit 110 includes an antenna and a receiver. The receiver converts a radio signal received by the antenna into a baseband signal (received signal) and outputs it to the control unit 130. The transmitting unit 120 performs various transmissions under the control of the control unit 130. The transmitting unit 120 includes an antenna and a transmitter. The transmitter converts a baseband signal (transmitted signal) output by the control unit 130 into a radio signal and transmits it from the antenna.

[0038] The control unit 130 performs various controls and processes in the UE 100. The operations of the UE 100 described above and below may be operations controlled by the control unit 130. The control unit 130 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used in the processing by the processor. The processor may include a baseband processor and a CPU (Central Processing Unit). The baseband processor performs modulation / demodulation and encoding / decoding of baseband signals. The CPU executes programs stored in the memory to perform various processes.

[0039] The control unit 130 includes an application processing unit 131, a NAS processing unit 132, and an AS processing unit 133. The application processing unit 131, the NAS processing unit 132, and the AS processing unit 133 are each realized as a program executed by a processor. The application processing unit 131 performs processing of the application layer. The application layer is provided above the NAS layer. The NAS processing unit 132 performs processing of the NAS layer. The AS processing unit 133 performs processing of the AS layer.

[0040] The UE 100 also includes an operation unit (not shown). The operation unit receives operations from a user. The operation unit includes, for example, a touch panel.

[0041] The UE 100 configured as described above performs wireless communication with the node 200 in the mobile communication system. The transmitter 120 transmits green priority information. With the above configuration, the UE 100 can contribute to GX in the mobile communication system.

[0042] In one example of this embodiment, the green priority information is information indicating a desire to perform communication based on the green communication mode.

[0043] The AS processing unit 133 is an example of a first processing unit that performs processing of the first layer. The NAS processing unit 132 is an example of a second processing unit that performs processing of the second layer, which is a layer provided above the first layer and allows the UE 100 to communicate with the CN device 300 via the node 200.

[0044] (1.4) Example of Node Configuration FIG. 6 is a diagram illustrating an example of the configuration of a node 200 (base station, gNB) according to an embodiment.

[0045] The node 200 includes a transmitting unit 210, a receiving unit 220, a control unit 230, and a NW communication unit 240. The transmitting unit 210 and the receiving unit 220 configure a wireless communication unit 250 that performs wireless communication with the UE 100.

[0046] The transmitting unit 210 performs various transmissions under the control of the control unit 230. The transmitting unit 210 includes an antenna and a transmitter. The transmitter converts a baseband signal (transmission signal) output by the control unit 230 into a radio signal and transmits it from the antenna. The receiving unit 220 performs various receptions under the control of the control unit 230. The receiving unit 220 includes an antenna and a receiver. The receiver converts a radio signal received by the antenna into a baseband signal (reception signal) and outputs it to the control unit 230.

[0047] The control unit 230 performs various controls and processes in the node 200. The operations of the node 200 described above and below may be operations under the control of the control unit 230. The control unit 230 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used in the processing by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation / demodulation and encoding / decoding of baseband signals. The CPU executes programs stored in the memory to perform various processes.

[0048] The NW communication unit 240 is connected to adjacent nodes via an inter-node interface, and to the CN device 300 via a node-CN interface.

[0049] The node 200 configured in this way performs wireless communication in the mobile communication system with the UE 100. The receiving unit 220 receives green priority information.

[0050] 7 and 8 are diagrams showing an example of system operation according to the first embodiment. In the system operation according to the first embodiment, green priority information is notified from the UE 100 to the node 200 in a random access procedure.

[0051] In step S10, the AS processing unit 133 is in an RRC idle state. Alternatively, the AS processing unit 133 may be in an RRC inactive state.

[0052] In step S20, the upper layer processing unit 150 notifies the AS processing unit 133 of green priority instruction information. The upper layer processing unit 150 is, for example, the NAS processing unit 132. The notification of the green priority instruction information by the upper layer processing unit 150 is an example of notification of instruction information for causing the AS processing unit 133 to transmit green priority information. The instruction to transmit green priority information may be given by notification of other information, and this also applies to the following examples. When the AS processing unit 133 is notified of the green priority instruction information by the upper layer processing unit 150, it causes the transmitting unit 120 to transmit the green priority information to the node 200. Note that the green priority instruction information is an example of green priority information, but in this embodiment, it is referred to as green priority instruction information to distinguish it from the green priority information transmitted from the transmitting unit 120 to the node 200.

[0053] For example, when the operation unit receives an operation for performing communication based on the green communication mode, the NAS processing unit 132 notifies the AS processing unit 133 of the green priority instruction information. The operation for performing communication based on the green communication mode is, for example, an operation for turning on a green communication mode button on a touch panel included in the operation unit (for example, tapping).

[0054] As another example, the NAS processing unit 132 may notify the AS processing unit 133 of green priority instruction information when receiving a notification from the application processing unit 131. The notification from the application processing unit 131 to the NAS processing unit 132 may also be green priority instruction information. For example, the green priority instruction information notified from the NAS processing unit 132 to the AS processing unit 133 is a slice identifier (described later), and the green priority instruction information notified from the application processing unit 131 to the NAS processing unit 132 is a request for communication based on the green communication mode. These pieces of green priority instruction information may be different from each other or may be the same. For example, the application processing unit 131 notifies the NAS processing unit 132 when a service provider (server) notifies the NAS processing unit 132 of a reconfiguration of an application installed in the UE 100 or a notification of an update to the application. Furthermore, the application processing unit 131 may notify the NAS processing unit 132 when the operation unit receives an operation by the user to turn on the green communication mode button on the application.

[0055] As another example, when the NAS processing unit 132 attempts to establish a PDU (Protocol Data Unit) session corresponding to a target slice in the green communication mode, the NAS processing unit 132 may notify the AS processing unit 133 of green priority instruction information. In this case, the NAS processing unit 132 notifies the AS processing unit 133 of, for example, a slice identifier or a slice group identifier and the green priority instruction information associated therewith. Here, the slice identifier is, for example, NSSAI (Network Slice Selection Assistance Information), S-NSSAI (Single Network Slice Selection Assistance Information), SST (Slice and Service Type), or SD (Slice Differentiator). The slice group identifier is, for example, NSAG (Network Slice AS Group) ID.

[0056] The green priority instruction information notified by the NAS processing unit 132 when the NAS processing unit 132 attempts to establish a PDU session corresponding to a slice that is the target of the green communication mode may be information indicating whether the slice or slice group is the target of the green communication mode. The information may be, for example, 1-bit information. The green priority instruction information may also be the targeted or required green utilization rate for the slice or slice group. For example, the green priority instruction information may indicate that the targeted or required renewable energy utilization rate for the slice or slice group is equal to or greater than a predetermined percentage (e.g., 50%).

[0057] When the NAS processing unit 132 attempts to establish a PDU session corresponding to the target slice of the green communication mode, and the NAS processing unit 132 notifies the AS processing unit 133 of green priority instruction information, when the green priority instruction information is notified from the application processing unit 131 to the NAS processing unit 132, the NAS processing unit 132 notifies the AS processing unit 133 of the green priority instruction information.

[0058] The NAS processing unit 132 may notify the AS processing unit 133 of the green priority instruction information based on a policy. For example, a policy is downloaded in advance from the CN device 300 to the UE 100 in accordance with a subscription (contract), and the NAS processing unit 132 notifies the AS processing unit 133 of the green priority instruction information in accordance with the policy. The policy may be, for example, a green communication policy indicating that communication is to be performed based on a green communication mode, or a green communication policy indicating a targeted or required green utilization rate. The NAS processing unit 132 may notify the AS processing unit 133 of the green priority instruction information at the time when the policy is downloaded or at a predetermined time after the download is completed, or at the time when a Service Request (communication session establishment request) is to be performed in accordance with the policy.

[0059] In the illustrated example, a case is described in which the AS processing unit 133 is in an RRC idle state or an RRC INACTIVE state, but the RRC idle state or the RRC INACTIVE state may be a state in which the AS processing unit 133 transitions to the RRC idle state or the RRC INACTIVE state after communication between the AS processing unit 133 and the AMF is performed. In that case, the NAS processing unit 132 may notify the AS processing unit 133 of green priority instruction information at the time when the NAS processing unit 132 notifies the AMF of green priority information.

[0060] Furthermore, when green communication is permitted by the AMF, the NAS processing unit 132 may notify the AS processing unit 133 of green priority instruction information. Here, the AMF permits green communication by referring to a subscription, for example. The AMF may permit green communication based on the green priority information from the NAS processing unit 132.

[0061] Furthermore, when the NAS processing unit 132 is connected to an AMF that supports green communication, or when the UE 100 registers its location in a tracking area (TA) that supports green communication, the NAS processing unit 132 may notify the AS processing unit 133 of green priority instruction information. Supporting green communication means being compatible with green communication or having the ability to perform green communication. Furthermore, when the NAS processing unit 132 receives a notification from the AMF that green communication is supported, the NAS processing unit 132 may notify the AS processing unit 133 of green priority instruction information.

[0062] When the AS processing unit 133 receives green priority instruction information from the upper layer processing unit 150, it switches its own communication mode from the normal communication mode to the green communication mode. That is, the AS processing unit 133 switches its own communication mode from the normal communication mode to the green communication mode depending on whether or not it has received green priority instruction information from the upper layer processing unit 150. Note that the green priority instruction information notified to the AS processing unit 133 from the upper layer processing unit 150 may be information indicating that communication will be performed based on the green communication mode. In this case, the AS processing unit 133 switches its own communication mode to the green communication mode, which is the communication mode indicated by the green priority instruction information, based on the content of the green priority instruction information notified from the upper layer processing unit 150.

[0063] The instruction information notified from the NAS processing unit 132 to the AS processing unit 133 may be information indicating that communication based on the green communication mode is to be terminated. In this case, the AS processing unit 133 terminates the green communication mode and switches its own communication mode to the normal communication mode based on the instruction information notified from the upper layer processing unit 150.

[0064] In step S30, the UE 100 transmits a physical random access channel (PRACH) to the node 200. The node 200 receives the PRACH.

[0065] Here, the AS processing unit 133 includes the green priority information in a physical random access channel (PRACH). When its own communication mode is a green communication mode, the AS processing unit 133 includes the green priority information in the PRACH. The AS processing unit 133 causes the transmitting unit 120 to transmit the PRACH including the green priority information. In other words, when the green priority information has been notified to the AS processing unit 133 from the upper layer processing unit 150, the AS processing unit 133 causes the transmitting unit 120 to transmit the green priority information to the node 200.

[0066] Information indicating the PRACH resource used to transmit the PRACH including the green priority information may be notified from the node 200 to the UE 100. For example, the node 200 includes information indicating the PRACH resource used to transmit the PRACH including the green priority information and information indicating the PRACH resource used to transmit the PRACH not including the green priority information in a system information block (SIB) and transmits the SIB to the UE 100. When the AS processing unit 133 causes the transmitter 120 to transmit the green priority information to the node 200, the AS processing unit 133 selects the PRACH resource indicated by the information indicating the PRACH resource used to transmit the PRACH including the green priority information when selecting a PRACH resource. The AS processing unit 133 causes the transmitter 120 to transmit the PRACH using the selected PRACH resource, thereby transmitting the green priority information to the node 200. The information indicating the PRACH resource may be information indicating any one of time, frequency, and random access preamble, or information for determining any one of these. Furthermore, multiple PRACH resources used for transmitting the PRACH including green priority information may be indicated. For example, each of the multiple PRACH resources may indicate a different green utilization rate.

[0067] As described above, in one example of this embodiment, the green priority information is information indicating a desire to perform communication based on the green communication mode (referred to as green communication desire information). The green communication desire information is, for example, 1-bit information. In this case, the green priority information is information indicating whether or not the UE 100 desires to perform communication based on the green communication mode. For example, the green priority information is set to a value of 1 if the UE 100 desires to perform communication based on the green communication mode, and set to a value of 0 if the UE 100 does not desire to perform communication based on the green communication mode. Note that the green communication desire information may also be information indicating whether or not the communication mode of the UE 100 is the green communication mode.

[0068] As another example, the green communication desire information may be information indicating a request for green communication from NW1. As another example, the green communication desire information may be information indicating a threshold or target value for an index for green operation. An index for green operation is, for example, the green energy usage rate in NW1. For example, the green communication desire information may be information that targets a green energy usage rate of a certain level or higher (e.g., 50%) in green communication in NW1, or information that requests a green energy usage rate of a certain level or higher in green communication in NW1.

[0069] The green communication desire information may be information corresponding to the content of the green priority instruction information notified from the upper layer processing unit 150 to the AS processing unit 133. The green communication desire information may be information different from the information corresponding to the content of the green priority instruction information notified from the upper layer processing unit 150 to the AS processing unit 133.

[0070] The green priority information may be information other than information indicating a desire to perform communication based on the green communication mode. As another example, the green priority information may be information indicating that a decrease in the quality of the logical transmission path is permitted. That is, the green priority information may be information indicating the required quality of the logical transmission path in communication based on the green communication mode. A decrease in the quality of the logical transmission path can be permitted by setting the required quality for communication based on the green communication mode to be lower than that for communication based on the normal communication mode. Furthermore, the green priority information may indicate the required quality of the logical transmission path in communication based on the green communication mode by the decrease (relaxation) in communication based on the green communication mode compared to the required quality of the logical transmission path in communication based on the normal communication mode. The green priority information may be, for example, a QoS class identifier (e.g., Quality Class Identifier (QCI), 5QI) of the logical transmission path. The green priority information may also be a value indicating a relaxation value or relaxation amount for each parameter, such as packet delay amount, packet error rate, bit rate, priority, and averaging window. The logical transmission path corresponds to a network slice (e.g., identified by an S-NSSAI), a virtual communication path (e.g., a PDU session), a QoS flow (QFI), a radio bearer, or an LCH (Logical Channel).

[0071] The green priority information may also include an identifier of a logical transmission path to which the green priority information applies. Examples of the identifier of the logical transmission path include a QFI, a bearer ID, a Radio Link Control (RLC) channel identifier, a logical channel identifier (LCID), a slice identifier, or a slice group identifier. Here, the slice identifier is, for example, Network Slice Selection Assistance Information (NSSAI), Single Network Slice Selection Assistance Information (S-NSSAI), a Slice and Service Type (SST), or a Slice Differentiator (SD). The slice group identifier is, for example, an NSAG ID. Note that, when the entire communication performed by the UE 100 operates in the green communication mode, rather than a specific network slice, the green priority information does not need to include an identifier of the logical transmission path.

[0072] In addition, if, in step S20, instruction information indicating that communication based on the green communication mode is to be terminated is notified from the NAS processing unit 132, in step S30, the AS processing unit 133 transmits a PRACH including green priority termination information to the node 200.

[0073] Here, the green priority cancellation information is, for example, information indicating that communication based on the green communication mode is no longer desired. The green priority cancellation information may also be information indicating that communication based on the green communication mode is to be cancelled. The green priority cancellation information may include an identifier of a logical transmission path for which communication based on the green communication mode is to be cancelled. For example, for a radio bearer to which information indicating that a degradation in the quality of the logical transmission path is permitted (relaxed QoS) is assigned, the UE 100 cancels the relaxed QoS and applies the QoS before the relaxed QoS was assigned.

[0074] Furthermore, instead of the green priority information, the UE 100 may transmit to the node 200 information indicating that communication other than communication based on the green communication mode is desired. The information indicating that communication other than communication based on the green communication mode is desired may be, for example, normal communication priority information or game communication priority information. The normal communication priority information is information indicating that communication based on the normal communication mode will be performed. The game communication priority information is information indicating that communication based on the game communication mode will be performed. Note that in the game communication mode, the UE 100 performs communication that prioritizes performance (data rate, delay amount, etc.) over the green energy index, for example. The information indicating that communication other than communication based on the green communication mode is desired may be, for example, information indicating that high quality is required for the logical transmission path.

[0075] In step S40, the node 200 transmits a random access response to the UE 100. The UE 100 receives the random access response. Here, the node 200 transmits the random access response by including scheduling information indicating the PUSCH resource allocated to the UE 100 in the random access response.

[0076] In step S50, the UE 100 transmits an RRC connection request message to the node 200. The node 200 receives the RRC connection request message. Here, the UE 100 transmits the RRC connection request message to the node 200 based on the scheduling information. Alternatively, when the UE 100 is in an RRC INACTIVE state, the UE 100 transmits an RRC resume request to the node 200.

[0077] In step S60, the node 200 transmits an RRC connection message to the UE 100. The UE 100 receives the RRC connection message. Alternatively, if the node 200 receives an RRC recovery request message from the UE 100 in step S50, the node 200 may transmit an RRC recovery message to the UE 100.

[0078] In step S70, the AS processing unit 133 enters an RRC connected state.

[0079] In step S80, the UE 100 transmits an RRC connection complete (RRC Setup Complete) message to the node 200. The node 200 receives the RRC connection complete message. Note that, if the UE 100 was in the RRC INACTIVE state in step S10 (if the UE 100 transmitted an RRC recovery request in step S50), the UE 100 transmits an RRC recovery complete (RRC Resume Complete) message to the node 200 in step S80.

[0080] In step S90, node 200 selects an AMF to transmit the initial UE message. Here, node 200 selects the AMF based on the green priority information notified from UE 100. Node 200 selects the AMF of a CN device 300 operating in green mode as the AMF to transmit the initial UE message. A CN device 300 operating in green mode is a CN device 300 with green operation information that satisfies the conditions indicated by the green priority information. For example, node 200 selects the AMF of a CN device 300 with a green operation rate that satisfies the target value or required value of the green operation rate indicated by the green priority information.

[0081] The green operating information for the CN device 300 is notified in advance from the CN device 300 to the node 200. The procedure by which the green operating information is shared in the network will be described later in the second embodiment.

[0082] In step S100, the node 200 sends an initial UE message to the CN device 300 including the selected AMF. That is, the node 200 sends the initial UE message to the CN device 300 operating in green mode. The CN device 300 receives the initial UE message.

[0083] Here, based on the green priority information, the node 200 may set up green communication for the UE 100 that has notified the green priority information. For example, when the green priority information, such as a slice identifier or a slice group identifier, includes an identifier of a logical transmission path, the node 200 may include the identifier of the logical transmission path in the initial UE message.

[0084] In step S110, the CN device 300 transmits an initial context setup request to the node 200. The node 200 receives the initial context setup request.

[0085] In step S120, the transmitter 120 transmits UE Assistance Information (UAI) to the node 200. The node 200 receives the UAI. The UAI is an RRC message that prompts the node 200 to change the parameters of the UE 100 used in the node 200.

[0086] In step S130, the node 200 transmits an RRC reconfiguration message to the UE 100. The UE 100 receives the RRC reconfiguration message.

[0087] In step S140, the UE 100 transmits an RRC reconfiguration complete message to the node 200. The node 200 receives the RRC reconfiguration complete message.

[0088] In step S150, a data radio bearer (DRB) between the UE 100 and the node 200 is established.

[0089] Here, based on the green priority information, the node 200 may set up green communication for the UE 100 that has notified the green priority information. For example, when the green priority information includes an identifier of a logical transmission path, the node 200 may establish a DRB based on the identifier of the logical transmission path.

[0090] In step S160, the node 200 transmits an initial context setup response to the CN device 300. The CN device 300 receives the initial context setup response.

[0091] In step S170, the upper layer processing unit 150 transmits a PDU session establishment request message (PDU Session Establishment Request) to the CN device 300 by NAS signaling. Here, the upper layer processing unit 150 transmits the PDU session establishment request message to the transmitter 120 via the node 200 to the CN device 300. The CN device 300 receives the PDU session establishment request message.

[0092] In step S180, the CN device 300 transmits a PDU session establishment accept message (PDU Session Establishment Accept) to the upper layer processing unit 150. The upper layer processing unit 150 receives the PDU session establishment accept message.

[0093] In step S190, a PDU session is established between the upper layer processing unit 150 and the CN device 300. Here, the CN device 300 (AMF) may set up a green PDU session for the UE 100 that has notified the node 200 of green priority information. The green PDU session is a PDU session based on green communication. For example, the CN device 300 may allocate a network slice for green communication to the PDU session. A slice identifier or slice group identifier included in the green priority information may be used to allocate the network slice for green communication. The CN device 300 may change or optimize the data path (routing) within the CN device 300 to increase the green energy utilization rate for communication of the green PDU session.

[0094] In step S1100, data communication is performed between UE 100 and CN device 300 via node 200. UL data is transmitted as user data from UE 100 to CN device 300 via node 200. DL data is transmitted from CN device 300 to UE 100 via node 200. Note that communication not shown in Figs. 7 and 8 may be performed between the above steps.

[0095] (1.6) First Modification of First Embodiment With reference to FIG. 9 , the first modification of the first embodiment will be described, focusing on the differences from the first embodiment. The first modification of the first embodiment differs from the first embodiment in that the green priority information is transmitted in an RRC message rather than in a random access procedure. That is, in the first modification of the first embodiment, the control unit 130 includes the green priority information in the RRC message. The transmission unit 120 transmits an RRC message including the green priority information to the node 200. In the first modification of the first embodiment, the RRC message is an RRC connection request message. That is, in the first modification of the first embodiment, the RRC message that the transmission unit 120 transmits to the node 200 including the green priority information is a message requesting the establishment of an RRC connection.

[0096] 9 is a diagram showing an example of system operation according to the first modification of the first embodiment. Note that the processes of steps S210, S220, S240, S260, S270, and S280 are similar to the processes of steps S10, S20, S40, S60, S70, and S80 in FIG. 7, and therefore descriptions thereof will be omitted. Furthermore, the processes from step S280 onward are similar to the processes from step S90 to step S1100 shown in FIG. 8, and therefore descriptions thereof will be omitted.

[0097] In step S230, the UE 100 transmits the PRACH to the node 200. The node 200 receives the PRACH. Unlike the first embodiment, this PRACH does not include green priority information.

[0098] In step S250, the UE 100 transmits an RRC connection request message to the node 200. The node 200 receives the RRC connection request message.

[0099] Here, the AS processing unit 133 includes the green priority information in the RRC connection request message. When its own communication mode is the green communication mode, the AS processing unit 133 includes the green priority information in the RRC connection request message. The AS processing unit 133 causes the transmitting unit 120 to transmit an RRC connection request message including the green priority information. In other words, when the green priority information has been notified to the AS processing unit 133 from the upper layer processing unit 150, the AS processing unit 133 causes the transmitting unit 120 to transmit the green priority information to the node 200. Here, the AS processing unit 133 may use, for example, a value defined in the Establishment Cause or Resume Cause included in the RRC connection request message (e.g., "Green-communication") as the green priority information. The information indicated by and included in the green priority information is the same as in the first embodiment. Furthermore, as in the first embodiment, green priority cancellation information may be transmitted instead of the green priority information.

[0100] Note that, when the UE 100 is in an RRC INACTIVE state, the UE 100 includes green priority information in an RRC recovery request message and transmits the message to the node 200. Note that, between the steps described above, communication not shown in FIG. 9 may be performed.

[0101] (1.7) Second Modification of First Embodiment With reference to FIG. 10 , the second modification of the first embodiment will be described, focusing on differences from the first embodiment. The second modification of the first embodiment differs from the first embodiment in that the green priority information is not notified by the random access procedure but is included in an RRC message, such as an RRC connection completion message or an RRC recovery completion message. That is, in the second modification of the first embodiment, the RRC message that the transmitter 120 transmits to the node 200 including the green priority information is an RRC connection completion message or an RRC recovery completion message. That is, in the second modification of the first embodiment, the RRC message that the transmitter 120 transmits to the node 200 including the green priority information is a message notifying the completion of the RRC connection or a message notifying the completion of the recovery of the RRC connection.

[0102] 10 is a diagram showing an example of system operation according to the second modification of the first embodiment. Note that the processes of steps S310, S320, S340, S350, S360, and S370 are similar to the processes of steps S10, S20, S40, S50, S60, and S70 in FIG. 7 , and therefore their explanations are omitted. Also, the process of step S330 is similar to the process of step S230 in FIG. 9 , and therefore its explanation is omitted. Also, the process from step S380 onward is similar to the processes from step S90 to step S1100 shown in FIG. 8 , and therefore its explanation is omitted.

[0103] In step S380, the UE 100 transmits an RRC connection complete message to the node 200. The node 200 receives the RRC connection complete message.

[0104] Here, the transmitter 120 includes the green priority information in the RRC connection completion message and transmits it to the node 200. When its own communication mode is the green communication mode, the AS processing unit 133 causes the transmitter 120 to transmit the green priority information to the node 200. In other words, when the green priority information has been notified to the AS processing unit 133 from the upper layer processing unit 150, the AS processing unit 133 causes the transmitter 120 to transmit the green priority information to the node 200. Here, the AS processing unit 133 may use, for example, a value included in the RRC connection completion message (e.g., "Green-communication") as the green priority information. The information indicated by the green priority information and the information included in the green priority information are the same as in the first embodiment. Furthermore, as in the first embodiment, green priority cancellation information may be transmitted instead of the green priority information.

[0105] Note that, when the UE 100 is in an RRC INACTIVE state, the UE 100 includes green priority information in an RRC recovery completion message and transmits the message to the node 200. Note that, between the steps described above, communication not shown in Fig. 10 may be performed.

[0106] (1.8) Third Modification of First Embodiment With reference to FIGS. 11 and 12 , the third modification of the first embodiment will be described, focusing on differences from the first embodiment. In the first embodiment, the first modification of the first embodiment, and the second modification of the first embodiment described above, cases where green priority information is notified to the node 200 when an RRC connection is established have been described. The third modification of the first embodiment differs from the first embodiment, the first modification of the first embodiment, and the second modification of the first embodiment in that the green priority information is notified to the node 200 after the RRC connection is completed. In the third modification of the first embodiment, the RRC message containing the green priority information notified to the node 200 is a UAI. That is, in the third modification of the first embodiment, the RRC message containing the green priority information and transmitted to the node 200 by the transmitter 120 is a message (UAI) that prompts a change in the parameters of the UE 100 used in the node 200.

[0107] 11 and 12 are diagrams showing an example of system operation according to the third modified example of the first embodiment. Note that the processes of steps S410, S420, S440, S450, S460, S470, and S480 in Fig. 11 are similar to the processes of steps S10, S20, S40, S50, S60, S70, and S80 in Fig. 7, and therefore descriptions thereof will be omitted. Furthermore, the process of step S430 is similar to the process of step S230 in Fig. 9, and therefore descriptions thereof will be omitted. Furthermore, the processes of steps S4100, S4110, S4130, S4140, S4150, S4160, S4170, S4180, S4190, and S4200 in FIG. 12 are similar to the processes of steps S100, S110, S130, S140, S150, S160, S170, S180, S190, and S1100 in FIG. 8, and therefore will not be described.

[0108] In step S490, the node 200 selects an AMF to send the initial UE message. Note that the AMF selected by the node 200 is not necessarily the AMF of the CN device 300 operating in green mode.

[0109] In step S4100, the node 200 sends an initial UE message to the CN device 300 including the selected AMF.

[0110] In step S4120, the transmitter 120 transmits the UAI to the node 200. The node 200 receives the UAI.

[0111] Here, the AS processing unit 133 includes green priority information in the UAI. When its own communication mode is the green communication mode, the AS processing unit 133 includes green priority information in the UAI. The AS processing unit 133 causes the transmitting unit 120 to transmit the UAI including the green priority information. In other words, when the upper layer processing unit 150 has notified the AS processing unit 133 of green priority information, the AS processing unit 133 causes the transmitting unit 120 to transmit the green priority information to the node 200. Here, the AS processing unit 133 may use, for example, a value included in the UAI (e.g., "Green-communication") as the green priority information. The information indicated by the green priority information and the information included in the green priority information are the same as in the first embodiment. Furthermore, as in the first embodiment, green priority cancellation information may be transmitted instead of the green priority information.

[0112] When the node 200 receives a UAI including green priority information, the node 200 may implement one or more of power saving of the cell it manages, offloading to another cell, or power saving of the UE 100.

[0113] In power saving of the cell that it manages, for example, if node 200 tolerates data delays with the cooperation of UE 100, it synchronizes the transmission timing of PDSCH to multiple UEs 100 by allocating and scheduling PDSCH discretely (distributedly) in time, and performs microsleep during periods when node 200 does not transmit PDSCH to UE 100 (i.e., periods when communication between node 200 and UE 100 does not occur).

[0114] In offloading to another cell, when the node 200 is operating on non-green energy, the node 200 hands over the UE 100 to another cell (a cell other than the cell it manages) that is operating on green energy, for example. This allows the node 200 to reduce traffic in the cell it manages that is operating on non-green energy, thereby improving the green utilization rate of the entire NW1. For example, if data delay is acceptable with the cooperation of the UE 100, the node 200 hands over the UE 100 to a cell that is geographically far from the node 200 but uses a data center that is operating on green energy. In this case, the NW1 can perform various processes (CU processing, DU processing, and other processes) using a data center that is geographically far from the node 200 but is operating on green energy. This gives the NW1 the option of performing various processes using a data center that is operating on green energy, thereby improving the green utilization rate of the entire NW1.

[0115] In power saving of the UE 100, for example, it is preferable that the discontinuous reception (Connected mode Discontinuous Reception: C-DRX) mode setting of the UE 100 be optimized according to the period during which the node 200 performs microsleep.

[0116] Note that node 200 may notify CN device 300 of the green priority information received from UE 100. Node 200 may, for example, include the green priority information in a UE Context Modification message included in an initial context setup response and notify CN device 300 of the green priority information. Upon being notified of the green priority information, CN device 300 may, for example, change QoS settings such as a PDU session and a QoS flow for UE 100 that transmitted the green priority information to node 200.

[0117] (1.9) Fourth Modification of First Embodiment With reference to FIG. 13 , the fourth modification of the first embodiment will be described, focusing on the differences from the third modification of the first embodiment. In the fourth modification of the first embodiment, the green priority information is notified to the CN device 300 by the NAS processing unit 132, and is then notified from the CN device 300 to the node 200. That is, in the fourth modification of the first embodiment, the NAS processing unit 132 (an example of a second processing unit) uses the NAS layer to transmit the green priority information to the CN device 300 via the node 200. That is, the NAS processing unit 132 transmits the green priority information to the CN device 300 by NAS signaling. The CN device 300, having been notified of the green priority information, notifies the node 200 of the green priority information.

[0118] FIG. 13 is a diagram showing an example of system operation according to a fourth modified example of the first embodiment. Note that the processes of steps S5100, S5110, S5120, S5130, S5140, S5150, S5160, S5180, S5190, and S5200 in FIG. 13 are similar to the processes of steps S100, S110, S120, S130, S140, S150, S160, S180, S190, and S1100 in FIG. 8 , and therefore descriptions thereof will be omitted. Also, the process of step S590 in FIG. 13 is similar to the process of step S490 in FIG. 12 , and therefore descriptions thereof will be omitted. Also, the processes prior to step S590 in FIG. 13 are similar to the processes from step S310 to step S380 in FIG. 10 , and therefore descriptions thereof will be omitted.

[0119] In step S5170, the upper layer processing unit 150 transmits a PDU session establishment request message to the CN device 300. The upper layer processing unit 150 causes the transmitting unit 120 to transmit the PDU session establishment request message to the CN device 300 via the node 200. The CN device 300 receives the PDU session establishment request message.

[0120] Here, the NAS processing unit 132 includes the green priority information in the PDU session establishment request message and transmits it to the CN device 300 via the node 200. The NAS processing unit 132 may use, for example, a value defined in the PDU session establishment request message (for example, "Green-communication") as the green priority information. The information indicated by the green priority information and the information included in the green priority information are the same as in the first embodiment. Also, as in the first embodiment, green priority cancellation information may be transmitted instead of the green priority information.

[0121] The AMF of the CN device 300 that receives the PDU session establishment request message including the green priority information includes the green priority information in a UE Context Modification message or the like and notifies the node 200. Here, the AMF uses, for example, a value defined in the UE Context Modification message (for example, “Green-communication”) as the green priority information.

[0122] The AMF may notify the node 200 including the green priority information and may change QoS settings such as a PDU session and a QoS flow for the UE 100. Furthermore, instead of notifying the node 200 including the green priority information, the AMF may change QoS settings such as a PDU session and a QoS flow for the UE 100.

[0123] As described above, node 200 may implement one or more of the following: power saving of the cell it manages, offloading to another cell, or power saving of UE 100 (see the processing of step S4120 in Figure 12).

[0124] The node 200 may notify the UE 100 of notification information notifying that the node 200 is capable of communication based on the green communication mode (referred to as node-green communication possible notification information), or notification information notifying that the node 200 has been configured to perform communication based on the green communication mode (referred to as node-green communication setting completion notification information). That is, when the receiving unit 220 receives the green priority information, the transmitting unit 210 may notify the UE 100 that communication based on the green communication mode is possible or that such communication is being performed. The notification of the node-green communication possible notification information or the node-green communication setting completion notification information may be performed in any of the procedures of the first embodiment and the first, second, third, and fourth modifications of the first embodiment described above.

[0125] For example, in the processing of step S130 in FIG. 8 (or step S4130 in FIG. 12 or step S5130 in FIG. 13), node 200 notifies UE 100 of node green communication availability notification information or node green communication setup completion notification information by including it in an RRC reconfiguration message (such as RRC Reconfiguration).

[0126] The UE 100 receives node-green communication possible notification information or node-green communication setting completion notification information from the node 200. Therefore, the receiving unit 110 receives information from the node 200 notifying that the node 200 is capable of communication based on the green communication mode or that settings for communication based on the green communication mode have been made.

[0127] In addition, the CN device 300 may notify the UE 100 of notification information (referred to as CN green communication possible notification information) notifying that the CN device 300 is capable of communication based on the green communication mode, or notification information (referred to as CN green communication setting completion notification information) notifying that the CN device 300 has been configured to perform communication based on the green communication mode.

[0128] For example, in the processing of step S180 of Figure 8 (or step S4180 of Figure 12, or step S5180 of Figure 13), CN device 300 notifies UE 100 of CN green communication possible notification information or CN green communication setting completion notification information by including it in a PDU session establishment acceptance message.

[0129] UE 100 receives CN green communication possible notification information or CN green communication setting completion notification information from CN device 300 via node 200. Therefore, receiving unit 110 receives information from CN device 300 notifying that CN device 300 is capable of communication based on the green communication mode or that setting for communication based on the green communication mode has been performed on UE 100.

[0130] (2) Second Embodiment The second embodiment will be described, focusing mainly on the differences from the first embodiment. In the first embodiment described above, a case where the node 200 hands over the UE 100 from the current cell to another cell operating in green mode has also been described. To do this, the node 200 needs to know the operating status using green energy of other nodes, such as neighboring nodes, or of cells managed by the other nodes. In the second embodiment, a procedure for solving this problem will be described.

[0131] (2.1) Example of Node Configuration Fig. 14 is a diagram showing an example of the configuration of a node 200a (base station, gNB) according to the second embodiment. The node 200a is composed of a CU 260a and a DU 270a. The configuration of the node 200a is the same as the configuration of the node 200 according to the first embodiment, but Fig. 14 differs from Fig. 6 in that the configurations of the CU 260a and the DU 270a are described in detail.

[0132] The CU 260a includes a control unit 231a and a NW communication unit 241a. The control unit 231a performs various control and processing operations in the CU 260a. The control unit 231a has a configuration similar to that of the control unit 230, particularly the configuration of the CU 260a.

[0133] The NW communication unit 241a has a configuration similar to that of the CU 260a in particular of the configuration of the NW communication unit 240. The NW communication unit 241a is connected to an adjacent node (node ​​200b, as an example) via an Xn interface. FIG. 14 shows the CU 260b constituting node 200b. Note that, like node 200a, node 200b is composed of a CU 260b and a DU 270b. The NW communication unit 241a is also connected to the NW communication unit 242a of the DU 270a via an F1 interface. The NW communication unit 241a is also connected to the CN device 300a via an NG interface.

[0134] The DU 270a includes a transmitter 210a, a receiver 220a, a controller 232a, and a network communication unit 242a. The controller 232a performs various controls and processes in the DU 270a. The controller 232a has a configuration similar to that of the controller 230, particularly the configuration of the DU 270a.

[0135] The NW communication unit 242a has a configuration similar to that of the NW communication unit 240, particularly the configuration of the DU 270a. As described above, the NW communication unit 242a is connected to the NW communication unit 241a of the CU 260a via the F1 interface. The transmission unit 210a has a configuration similar to that of the transmission unit 210. The transmission unit 210a performs various transmissions to the UE 100. The reception unit 220a has a configuration similar to that of the reception unit 220. The reception unit 220a receives various signals from the UE 100.

[0136] The node 200a configured in this manner is an example of a communication device in a network of a mobile communication system including a user device and a network. The NW communication unit 241a notifies green operation information regarding the green operation status via the Xn interface. The Xn interface is an example of a first interface that interconnects multiple nodes. The first interface is an example of a network interface for notifying green operation information.

[0137] (2.2) System Operation Example FIG. 15 is a diagram illustrating an example of system operation according to the second embodiment. In the illustrated example, two nodes 200, a node 200a and a node 200b, are shown, but the number of nodes 200 may be three or more. Node 200a is configured with a CU 260a and a DU 270a. Node 200b is configured similarly to node 200a, but in the illustrated example, only the CU 260b is shown for node 200b. Nodes 200a and 200b may each include multiple DUs.

[0138] In step S600, the CU 260a and the CU 260b are communicatively connected to each other via the Xn interface, i.e., the CU 260a and the CU 260b are capable of transmitting and receiving XnAP messages to each other using the XnAP (Xn Application Protocol).

[0139] In step S610, the CU 260a transmits an NG-RAN node configuration update to the CU 260b via the Xn interface. Here, the NW communication unit 241a of the CU 260a includes green operation information about the node 200a in the NG-RAN node configuration update and transmits the same to the node 200b. Therefore, the NW communication unit 241a of the CU 260a notifies the node 200b of the green operation information about the node 200a via the Xn interface.

[0140] The CU 260b receives the NG-RAN node setting update. The node 200b, which has been notified of the green operation information, grasps the operation status of the node 200a using green energy.

[0141] The green operation information may be linked to a cell ID (e.g., a physical layer cell ID or a cell global identity). When the green operation information is linked to a cell ID, the green operation information for node 200a includes green operation information for the cell managed by node 200a. When the green operation information is linked to a cell ID, node 200b, which has been notified of the green operation information, understands the operation status using green energy for the cell managed by node 200a.

[0142] In step S620, the CU 260b transmits an NG-RAN node setting update to the CU 260a via the Xn interface. Here, the NW communication unit 241b (not shown in FIG. 14) of the CU 260b includes green operation information for the node 200b in the NG-RAN node setting update and transmits it to the node 200a. The CU 260b receives the NG-RAN node setting update including the green operation information. The node 200a, which has been notified of the green operation information, grasps the operation status of the node 200b using green energy.

[0143] The XnAP message in which the CU 260a or CU 260b includes the green operation information is not limited to the NG-RAN node setting update. As another example, the XnAP message in which the green operation information is included may be an Xn Setup Request or an Xn Setup Response.

[0144] As another example, the XnAP message including the green operation information may be a Resource Status Update. In this case, for example, node 200b requests node 200a to include the green operation information in the Resource Status Update using a Resource Status Request. In response to the Resource Status Request, node 200a includes the green operation information in the Resource Status Update and transmits it to node 200b.

[0145] As another example, the XnAP message including the green operation information may be an XnAP message other than an Xn Setup Request, an Xn Setup Response, an NG-RAN node configuration update, and a Resource Status Update. The XnAP message may be called, for example, a "green operation status update."

[0146] In step S630, the CU 260a and the CU 260b are connected to each other via the Xn interface.

[0147] In step S640, the CU 260a sends a handover request message to the CU 260b via the Xn interface. Here, the CU 260a decides to hand over the UE 100 in the green communication mode. If the DU 270a receives green priority information from the UE 100, the CU 260a determines that the UE 100 is in the green communication mode.

[0148] The control unit 231a of the CU 260a determines the CU 260 to which to send a handover request message based on the green operation information for the node 200b. In the illustrated example, the node 200b is assumed to have the highest green operation rate among the nodes 200 that have notified the node 200a of their green operation information. Alternatively, the node 200b may satisfy the target green operation rate indicated by the green priority information. The CU 260a determines the node 200b (CU 260b) as the CU 260 to which to send a handover request message based on the green operation rate indicated by the green operation information. Note that the CU 260 determined by the CU 260a to which to send the handover request message does not necessarily have to be the CU 260 that sent the green operation information to the CU 260a.

[0149] The handover request message transmitted from the CU 260a to the CU 260b is a handover request message for handing over the UE 100 determined to be in the green communication mode from the cell of the node 200a to the cell of the node 200b.

[0150] In one example of this embodiment, the source side node 200a refers to the green operation information of adjacent nodes to determine a node (for example, node 200b) that is a candidate target and sends a handover request to that node, and the node then refers to its own green operation information (including the green operation information of each DU that it manages) to determine a target cell from among the cells that it manages.

[0151] Alternatively, the source node 200a may determine a target candidate cell by referring to the green operation information of adjacent nodes and transmit a handover request to the node managing that cell. For example, the NW communication unit 241a of the CU 260a may include a cell ID in a handover request message and transmit it to the node 200b. The cell ID may be, for example, a cell ID specifying the cell with the highest green operation rate, or a cell ID of a cell that satisfies the target green operation rate indicated by the green priority information. The cell with the highest green operation rate is determined by the CU 260a based on the green operation information. In this case, the green operation information is linked to the cell ID. Therefore, the NW communication unit 241a (an example of a notification unit) of the CU 260a notifies another node (i.e., the node 200b) of the cell that is connected to the UE 100 from among the cells it manages.

[0152] The NW communication unit 241a of the CU 260a may include the green priority information for the UE 100 in a handover request message and transmit it to the node 200b. Accordingly, the NW communication unit 241a of the CU 260a notifies the node 200b via the Xn interface of the green priority information by including it in a handover request message for handing over the UE 100 from the node 200a to the node 200b. The NW communication unit 241a of the CU 260a is an example of a notification unit that notifies another node interconnected via the first interface of the green priority information by including it in a handover request message for handing over a node that wirelessly communicates with the UE 100 to another node. The handover may be a change of the PCell of the UE 100. For example, the NW communication unit 241a of the CU 260a includes the green priority information in an AS Context included in an RRC container included in the handover request message and transmits the message. The NW communication unit 241a of the CU 260a may transmit the green priority information in an area other than the AS Context included in the RRC container.

[0153] The CU 260b receives the above-described handover request message from the CU 260a. That is, the NW communication unit 241b of the CU 260b receives the green priority information transmitted from the UE 100 from the node 200a.

[0154] When the CU 260b receives the handover request message, it determines a cell to which the UE 100 is to be handed over from among the cells managed by the node 200b. For example, if the handover request message includes green priority information, the CU 260b determines a cell with the highest green utilization rate as the handover destination cell based on the green priority information.

[0155] A reception quality report may be transmitted from the UE 100 to the node 200a. The reception quality report indicates the measurement results of the reference signals of the UE 100 for each of the serving cell and the neighboring cells. The reference signal may be, for example, a synchronization signal block (SSB) or a CSI-RS. When the reception quality report is transmitted from the UE 100 to the node 200a, the CU 260a determines the handover destination cell based on the reception quality report. When determining the handover destination cell, the node 200a may take into account the green priority information and the green operation information in addition to the reception quality report. For example, the node 200a may determine the handover destination cell based on the reception quality report from among cells whose green operation information satisfies the conditions indicated by the green priority information.

[0156] In step S650, the CU 260b transmits a handover request acceptance message to the CU 260a via the Xn interface. Here, the CU 260b transmits the handover request acceptance message to the CU 260a, including a parameter instructing handover (for example, the RRC parameter reconfigurationWithSync).

[0157] The CU 260a receives the handover request accept message and transmits reconfigurationWithSync in the received handover request accept message to the UE 100. The UE 100 executes handover based on reconfigurationWithSync.

[0158] As described in the first embodiment, the green priority information for the UE 100 is notified to the node 200a from the UE 100. That is, the receiver 220a of the node 200a receives the green priority information from the UE 100. The procedure for notifying the node 200a of the green priority information from the UE 100 is executed before the processing of step S640. Before the processing of step S640 may be before the processing of step S600.

[0159] (2.3) First Modification of Second Embodiment With reference to FIG. 16 , the first modification of the second embodiment will be described, focusing on the differences from the second embodiment. When handing over the UE 100 from the current cell to another cell operating in green energy, the node 200 needs to know the operating status using green energy of the CU or multiple DUs constituting other nodes, such as adjacent nodes, or each of the cells managed by the multiple DUs. In the first modification of the second embodiment, a procedure for solving this problem will be described.

[0160] In a first modified example of the second embodiment, the NW communication unit 241a provided in the CU 260a notifies the CU 260a of green operation information to the DU 270a via the F1 interface. Alternatively, the NW communication unit 242a provided in the DU 270a notifies the DU 270a of green operation information to the CU 260a via the F1 interface. The F1 interface is an example of a second interface connecting the aggregation unit (CU) and the distribution unit (DU). The second interface is an example of a network interface for notifying the green operation information. Note that the CU 260a and the DU 270a are each an example of a communication device in the network of a mobile communication system including a user device and a network.

[0161] (2.3) System Operation Example Fig. 16 is a diagram showing a system operation example according to the first modified example of the second embodiment. Note that the processes of steps S730, S740, and S750 are the same as those of steps S630, S640, and S650 in Fig. 15 except that the relationship between node 200a and node 200b is reversed, and therefore description thereof will be omitted.

[0162] In step S700, the DU 270a and the CU 260a are connected to each other via an F1 interface, i.e., the DU 270a and the CU 260a are able to send and receive F1AP messages to each other using F1AP (F1 Application Protocol).

[0163] In step S710, the DU 270a transmits a node DU setting update to the CU 260a via the F1 interface. The NW communication unit 242a of the DU 270a transmits the node DU setting update including the green operation information for the DU 270a to the CU 260a via the F1 interface. Thus, the NW communication unit 242a of the DU 270a notifies the CU 260a of the green operation information for the DU 270a from the DU 270a via the F1 interface.

[0164] The CU 260a receives the node DU setting update including the green operation information. The CU 260a, having been notified of the green operation information, grasps the operation status of the DU 270a using green energy. Note that, as described below in step S735, the green operation information for the DU 270a may be transmitted to the node 200b in step S735. The green operation information for the DU 270a may be used by the node 200b to determine a handover destination. Note that, the green operation information for the DU 270a may be used by the node 200a to determine a handover destination in step S740.

[0165] In step S720, the CU 260a transmits a node CU setting update to the DU 270a via the F1 interface. Here, the NW communication unit 241a of the CU 260a transmits green operation information for the CU 260a to the DU 270a via the F1 interface, including the green operation information for the CU 260a in the node CU setting update. Therefore, the NW communication unit 241a of the CU 260a notifies the DU 270a of the green operation information for the CU from the CU to the DU via the F1 interface. Note that the CU 260a may be provided with a DU other than the DU 270a. In this case, the F1 interface is an example of a second interface connecting the CU and multiple DUs. If the CU 260a is provided with a DU other than the DU 270a, the NW communication unit 241a of the CU 260a may notify one of the multiple DUs from the CU 260a of the green operation information for another of the multiple DUs via the F1 interface. This node CU setting update may also include green operation information of DUs of node 200a other than DU 270a. Together with this node CU setting update, green operation information of DUs of node 200a other than DU 270a may also be transmitted to DU 270a.

[0166] The NW communication unit 241a of the CU 260a may include green operation information about a DU of another node 200 (for example, the DU 270b of the node 200b) in a node CU setting update and transmit it to the DU 270a via the F1 interface.

[0167] The DU 270a receives the node CU setting update including the green operation information. The DU 270a, having been notified of the green operation information, grasps the operation status of the CU 260a using green energy.

[0168] The green operation information may be linked to a cell ID (e.g., a physical layer cell ID or a cell global identity). When the green operation information is linked to a cell ID, the green operation information for the DU 270a includes green operation information for the cell managed by the DU 270a. When the green operation information is linked to a cell ID, the CU 260a, which has been notified of the green operation information, grasps the operation status using green energy for the cell managed by the DU 270a.

[0169] Furthermore, when the green operation information is linked to a cell ID, the green operation information for CU 260a includes green operation information for the cells managed by each of the multiple DUs included in node 200a. When the green operation information is linked to a cell ID, DU 270a, which has been notified of the green operation information, understands the operation status using green energy for the cells managed by each of the multiple DUs included in node 200a.

[0170] The F1AP message in which the DU 270a includes the green operation information is not limited to a node DU setting update. The F1AP message in which the CU 260a includes the green operation information is not limited to a node CU setting update. As another example, the F1AP message in which the green operation information is included may be an F1 Setup Request or an F1 Setup Response.

[0171] As another example, the F1AP message including the green operation information may be an F1AP message other than an F1 Setup Request, an F1 Setup Response, a node DU setting update, or a node CU setting update. The F1AP message may be called, for example, a "green operation status update."

[0172] In step S735, the CU 260a transmits an NG-RAN node setting update to the CU 260b via the Xn interface. Here, the NW communication unit 241a of the CU 260a includes green operation information in the NG-RAN node setting update and transmits it to the node 200b. The green operation information is one or more of the green operation information about the DU 270a that the CU 260a received from the DU 270a, or the green operation information about the CU 260a. The green operation information may be used by the node 200b to determine the handover destination. Note that, if the CU 260a is provided with a DU other than the DU 270a, the green operation information that the NW communication unit 241a of the CU 260a includes in the NG-RAN node setting update and transmits it to the node 200b may be green operation information about the DU other than the DU 270a. The green operation information for CU 260a and the green operation information for DU 270a are examples of green operation information for node 200. In other words, the green operation information for node 200 includes green operation information for CU 260a and green operation information for DU 270a.

[0173] (2.4) Second Modification of Second Embodiment With reference to Fig. 17, a second modification of the second embodiment will be described, focusing on differences from the second embodiment. When the CN device 300 causes the node 200 to hand over the UE 100 to another cell, the CN device 300 needs to know the operating status using green energy for the cell managed by the node 200. In the second modification of the second embodiment, a procedure for solving this problem will be described.

[0174] In a second modification of the second embodiment, the NW communication unit 241a included in the CU 260a notifies the CN device 300 of green operation information about the CU 260a from the CU 260a via the NG interface. Alternatively, the NW communication unit 241a included in the CU 260a receives green operation information about the CN device 300 from the CN device 300 via the NG interface. The NG interface is an example of a third interface connecting the aggregation unit (CU) and the core network device (CN). The third interface is an example of a network interface for notifying green operation information. Note that the CN device 300a (or AMF) is an example of a communication device in the network of a mobile communication system including a user device and a network.

[0175] (2.4) System Operation Example FIG. 17 is a diagram illustrating an example of system operation according to a second modification of the second embodiment. In the illustrated example, two nodes 200, node 200a and node 200b, are shown as nodes 200, but the number of nodes 200 may be three or more. Node 200a is configured with a CU 260a and a DU 270a. Node 200b is configured similarly to node 200a, but in the illustrated example, only CU 260b is shown for node 200b. In the illustrated example, CN device 300a is shown as CN device 300, but the number of CN devices 300 may be two or more.

[0176] In step S800a, the CU 260a and the CN device 300a are connected to each other via the NG interface, i.e., the CU 260a and the CN device 300a are able to send and receive NGAP messages to each other using the NGAP (NG Application Protocol).

[0177] In step S810a, the CU 260a transmits a RAN setting update to the CN device 300a via the NG interface. Here, the CU 260a includes green operation information for the node 200a in the RAN setting update. The CU 260a causes the NW communication unit 241a of the CU 260a to transmit the RAN setting update including the green operation information for the node 200a to the CN device 300a. Therefore, the NW communication unit 241a of the CU 260a notifies the CN device 300a of the green operation information for the CU 260a from the CU 260a via the NG interface.

[0178] The CN device 300a receives the RAN configuration update including the green operation information. The CN device 300a, which has been notified of the green operation information, grasps the operation status of the node 200a using green energy.

[0179] In step S820a, the CN device 300a transmits an AMF setting update to the CU 260a via the NG interface. The NW communication unit 241a of the CU 260a receives the AMF setting update including the green operation information for the CN device 300a via the NG interface. Thus, the NW communication unit 241a of the CU 260a receives the green operation information for the CN device 300a from the CN device 300a via the NG interface.

[0180] As described above, the CU 260a receives an AMF setting update including the green operation information. The CU 260a, having been notified of the green operation information, grasps the operation status of the CN device 300a using green energy. Note that in step S90 of the procedure ( FIG. 8 ) in the first embodiment described above, in the process of the node 200 selecting an AMF, the node 200 may select an AMF based on the green operation information for the CN device 300a.

[0181] In step S800b, the CU 260b and the CN device 300a are connected to each other via the NG interface.

[0182] In step S810b, the CU 260b transmits a RAN setting update to the CN device 300a via the NG interface. Here, the NW communication unit 241b (not shown in FIG. 14) of the CU 260b includes green operation information for the node 200b in the RAN setting update and transmits it to the CN device 300a.

[0183] The CN device 300a receives the RAN configuration update including the green operation information. The CN device 300a, which has been notified of the green operation information, grasps the operation status of the node 200b using green energy.

[0184] In step S820b, the CN device 300a transmits an AMF setting update to the CU 260b via the NG interface. The NW communication unit 241b of the CU 260b receives the AMF setting update including the green operation information for the CN device 300a via the NG interface. Thus, the NW communication unit 241b of the CU 260b receives the green operation information for the CN device 300a from the CN device 300a via the NG interface.

[0185] As described above, the CU 260b receives the AMF setting update including the green operation information. The CU 260b, having been notified of the green operation information, grasps the operation status of the CN device 300a using green energy.

[0186] The green operation information for CU 260a or CU 260b may be linked to a cell ID (e.g., a physical layer cell ID, a cell global identity). When the green operation information is linked to a cell ID, the green operation information for CU 260a or CU 260b includes green operation information for the cell managed by CU 260a or CU 260b. When the green operation information is linked to a cell ID, CN device 300a, which has been notified of the green operation information, grasps the operation status using green energy for the cell managed by CU 260a or CU 260b.

[0187] The green operation information for the CN device 300a may also be linked to a cell ID (e.g., a physical layer cell ID, a cell global identity). When the green operation information is linked to a cell ID, the green operation information for the CN device 300a includes green operation information for a cell managed by a node 200 with which the CN device 300a communicates.

[0188] The NGAP message in which the CU 260a or CU 260b includes the green operation information is not limited to a RAN setting update. Furthermore, the NGAP message in which the CN device 300a includes the green operation information is not limited to an AMF setting update. As another example, the NGAP message in which the green operation information is included may be an NG Setup Request or an NG Setup Response.

[0189] As another example, the NGAP message including the green operation information may be an NGAP message other than an NG Setup Request, an NG Setup Response, a RAN Configuration Update, and an AMF Configuration Update. The NGAP message may be called, for example, a "green operation status update."

[0190] In step S830, the CU 260a and the CN device 300a are connected to each other via the NG interface.

[0191] In step S840, the CU 260b and the CN device 300a are connected to each other via the NG interface.

[0192] In step S850, the CU 260a sends a handover required message to the CN device 300a via the NG interface. The CN device 300a then decides to hand over the UE 100 in the green communication mode. If the DU 270a of the node 200a has received green priority information from the UE 100, the CN device 300a determines that the UE 100 is in the green communication mode.

[0193] The NW communication unit 241a of the CU 260a may include the green priority information for the UE 100 in a handover required message and transmit the message to the CN device 300a.

[0194] The CN device 300a determines the CU 260 to which to send the handover request message based on the green operation information for node 200b notified in step S810b. In the example shown in the figure, it is assumed that node 200b has the highest green operation rate among the nodes 200. The CN device 300a determines node 200b as the CU 260 to which to send the handover request message based on the green operation rate indicated by the green operation information. Note that the CU 260 that the CN device 300a determines to send the handover request message does not have to be the CU 260 that sent the green operation information to the CN device 300a.

[0195] In step S860, the CN device 300a transmits a handover request message to the CU 260b via the NG interface. Here, the CU 260b decides to hand over the UE 100, which is in the green communication mode. The CN device 300a may include green priority information for the UE 100 in the handover request message and transmit it to the node 200b. When the CU 260b receives the green priority information from the CN device 300a, it determines that the UE 100 indicated by the green priority information is in the green communication mode.

[0196] The CU 260b receives the above-mentioned handover request message from the CN device 300a. Upon receiving the handover request message, the CU 260b determines a cell to hand over the UE 100 to from among the cells managed by the node 200b. For example, if the handover request message includes green priority information, the CU 260b determines the cell with the highest green utilization rate as the cell to hand over to based on the green priority information.

[0197] It should be noted that the procedures shown in Figures 15, 16, and 17 may be executed in combination. For example, the procedures shown in Figures 15, 16, and 17 may be executed in parallel or sequentially.

[0198] In each of Figures 15, 16, and 17, the procedure for notifying green operation information via an interface may be omitted. This procedure corresponds to the processing from steps S600 to S620 in Figure 15. This procedure corresponds to the processing from steps S700 to S720 in Figure 16. This procedure corresponds to the processing from steps S800a to S820b in Figure 17.

[0199] Furthermore, the handover procedure may be omitted in each of Figures 15, 16, and 17. This procedure corresponds to the processing from step S630 to step S650 in Figure 15. This procedure corresponds to the processing from step S730 to step S750 in Figure 16. This procedure corresponds to the processing from step S830 to step S860 in Figure 17.

[0200] In the above-described embodiments and their variations, an example in which the node 200 is divided into a CU and a DU has been described, but this is not limiting. The node 200 does not have to be divided into a CU and a DU. If the node 200 is not divided into a CU and a DU, in the procedures described in the second embodiment and the variations of the second embodiment, the communication between the CU 260a and the CU 260b may be communication between the node 200a and the node 200b. In this case, for example, the NW communication unit 241a of the CU 260a notifies the node 200b of the green operation information about the node 200a via the Xn interface. Similarly, the NW communication unit 241b of the CU 260b notifies the node 200a of the green operation information about the node 200b via the Xn interface.

[0201] Furthermore, if the node 200 is not divided into a CU and a DU, in the procedure described in the second modification of the second embodiment, the communication between the CU 260a (or CU 260b) and the CN device 300a may be communication between the node 200a (or node 200b) and the CN device 300a. The NW communication unit 240a of the node 200a notifies the CN device 300a of the green operation information about the node 200a from the node 200a via the NG interface. If the node 200 is not divided into a CU and a DU, the NG interface is an example of a third interface connecting the node and a core network device (CN).

[0202] A program may be provided that causes a computer (UE 100, nodes 200, 200a, 200b) to execute the operations according to the above-described embodiments. The program may be recorded on a computer-readable medium. The computer-readable medium can be used to install the program on 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 or a DVD-ROM. Furthermore, circuits that execute the processes performed by the UE 100 or the nodes 200, 200a, 200b may be integrated, and at least a portion of the UE 100 or the nodes 200, 200a, 200b may be configured as a semiconductor integrated circuit (chipset, system-on-chip (SoC)).

[0203] In the above embodiment, an example has been described in which the nodes 200, 200a, and 200b are NR base stations (gNBs). However, the nodes 200, 200a, and 200b may be LTE base stations (eNBs) or 6G base stations. The nodes 200, 200a, and 200b may also be relay nodes such as IAB (Integrated Access and Backhaul) nodes. The nodes 200, 200a, and 200b may be DUs of the IAB nodes. The UE 100 may also be a Mobile Termination (MT) of the IAB node.

[0204] Furthermore, the term "node" primarily refers to a base station, but may also refer to a core network device or a part of a base station (CU, DU, or RU (Radio Unit)). Furthermore, a node may be configured by a combination of at least a part of a core network device and at least a part of a base station.

[0205] One embodiment of the present invention has been described in detail above with reference to the drawings, but the specific configuration is not limited to that described above, and various design changes and the like are possible within the scope that does not deviate from the gist of the present invention.

[0206] 1... Network 10... RAN 20... CN 100... UE 110... Receiving unit 120... Transmitting unit 130... Control unit 140... Wireless communication unit 200, 200a, 200b... Nodes 210, 210a... Transmitting unit 220, 220a... Receiving unit 230, 231a, 232a... Control unit 240, 241a, 242a... NW communication unit 250... Wireless communication unit 300, 300a... CN device

Claims

1. A user device that performs wireless communication with a node in a mobile communication system, the user device having a transmitter that transmits green priority information.

2. The user device according to claim 1, wherein the green priority information is information indicating a desire to perform communication based on the green communication mode.

3. The user device according to claim 1, wherein the green priority information is information indicating a required quality of a logical transmission path in communication based on the green communication mode.

4. The user device according to claim 1, wherein the green priority information includes an identifier of a logical transmission path to which the green priority information applies.

5. The user equipment according to claim 1, further comprising: a control unit that includes the green priority information in a physical random access channel (PRACH); and a transmission unit that transmits the physical random access channel including the green priority information to the node.

6. The user equipment according to claim 1, further comprising: a control unit that includes the green priority information in an RRC message; and a transmission unit that transmits the RRC message including the green priority information to the node.

7. The user equipment according to claim 6, wherein the RRC message is a message requesting establishment of an RRC connection.

8. The user equipment according to claim 6, wherein the RRC message is a message notifying completion of an RRC connection or a message notifying completion of restoration of an RRC connection.

9. The user equipment according to claim 6, wherein the RRC message is a message (UE Assistance Information) that prompts a change of a parameter of the user equipment used in the node.

10. A user device as described in claim 1, comprising: a first processing unit that performs processing of a first layer; and a second processing unit that performs processing of a second layer, which is a layer higher than the first layer and enables the user device to communicate with a core network device (CN) via the node, wherein the second processing unit uses the second layer to transmit the green priority information to the core network device.

11. A user device as described in claim 1, comprising: a first processing unit that performs processing of a first layer; and a second processing unit that performs processing of a second layer that is located above the first layer, wherein the second processing unit notifies the first processing unit of instruction information for transmitting green priority information, and when the first processing unit is notified of the instruction information from the second processing unit, the first processing unit causes the transmitting unit to transmit the green priority information to the node.

12. The user equipment according to claim 1, wherein the transmitter transmits green priority cancellation information to the node.

13. A user device as described in claim 1, comprising a receiving unit that receives information from the node notifying that the node or core network device (CN) is capable of communication based on the green communication mode, or that settings have been made in the user device to perform communication based on the green communication mode.

14. A node that performs wireless communication with a user device in a mobile communication system, the node having a receiving unit that receives green priority information.

15. The node according to claim 14, further comprising a transmitting unit that, when the receiving unit receives the green priority information, notifies the user device that communication based on the green communication mode is possible or that such communication is being performed.

16. A communication method used by a user device that performs wireless communication with a node in a mobile communication system, the communication method comprising: a transmitting step of transmitting green priority information.

17. A communication method used in a node that performs wireless communication with a user device in a mobile communication system, the communication method comprising: a receiving step of receiving green priority information.

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