State switching for passive terminal device

Abstract

A method is disclosed, comprising: receiving, by an apparatus in a radio access network, a trigger signal from a terminal device or an access node in the radio access network, the trigger signal indicating a handover to one or more states; and switching, by the apparatus, to one or more states, wherein the one or more states indicate terminal requirements supporting communications in the radio access network.

Description

Technical Field

[0001] The following example embodiments relate to wireless communications. Background Art

[0002] In the passive Internet of Things, there may be passive end devices that are not equipped with batteries or other power sources. There are challenges in how such passive end devices can obtain energy and communicate over long distances. Summary of the invention

[0003] The scope of protection sought for the various exemplary embodiments is set out by the independent claims.Example embodiments and features described in this specification that do not belong to the scope of the independent claims are to be construed as examples useful for understanding the various embodiments.

[0004] According to one aspect, a device in a radio access network is provided, the device comprising at least one processor and at least one memory, the at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to: receive a trigger signal from a terminal device or an access node in the radio access network, the trigger signal indicating a switch to one or more states; and switch to the one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0005] According to another aspect, an apparatus in a radio access network is provided, the apparatus comprising components for performing the following operations: receiving a trigger signal from a terminal device or an access node in the radio access network, the trigger signal indicating a switch to one or more states; and switching to the one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0006] According to another aspect, a method is provided, comprising: receiving, by an apparatus in a radio access network, a trigger signal from a terminal device or an access node in the radio access network, the trigger signal indicating a switch to one or more states; and switching, by the apparatus, to one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0007] According to another aspect, a computer program is provided, comprising instructions which, when executed by an apparatus in a radio access network, cause the apparatus to at least perform the following operations: receive a trigger signal from a terminal device or access node in the radio access network, the trigger signal indicating a switch to one or more states; and switch to one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0008] According to another aspect, a computer program is provided, comprising instructions for causing an apparatus in a radio access network to perform at least the following operations: receiving a trigger signal from a terminal device or access node in the radio access network, the trigger signal indicating a switch to one or more states; and switching to one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0009] According to another aspect, a computer-readable medium is provided, comprising program instructions for causing an apparatus in a radio access network to at least perform the following operations: receiving a trigger signal from a terminal device or access node in the radio access network, the trigger signal indicating a switch to one or more states; and switching to one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0010] According to another aspect, a non-transitory computer-readable medium is provided, comprising program instructions for causing an apparatus in a radio access network to at least perform the following operations: receiving a trigger signal from a terminal device or access node in the radio access network, the trigger signal indicating a switch to one or more states; and switching to one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0011] According to another aspect, an apparatus in a radio access network is provided, the apparatus comprising at least one processor and at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the apparatus to: receive a trigger signal from an access node of the radio access network, the trigger signal indicating a switch to one or more states; and switch to the one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0012] According to another aspect, an apparatus in a radio access network is provided, the apparatus comprising components for performing the following operations: receiving a trigger signal from an access node of the radio access network, the trigger signal indicating switching to one or more states; and switching to one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0013] According to another aspect, a method is provided, comprising: receiving, by a device in a radio access network, a trigger signal from an access node of the radio access network, the trigger signal indicating switching to one or more states; and switching, by the device, to one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0014] According to another aspect, a computer program is provided, comprising instructions which, when executed by an apparatus in a radio access network, cause the apparatus to at least perform the following operations: receive a trigger signal from a terminal device or access node in the radio access network, the trigger signal indicating a switch to one or more states; and switch to one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0015] According to another aspect, a computer program is provided, comprising instructions for causing an apparatus in a radio access network to perform at least the following operations: receiving a trigger signal from a terminal device or access node in the radio access network, the trigger signal indicating a switch to one or more states; and switching to one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0016] According to another aspect, a computer-readable medium is provided, comprising program instructions for causing an apparatus in a radio access network to at least perform the following operations: receiving a trigger signal from a terminal device or access node in the radio access network, the trigger signal indicating a switch to one or more states; and switching to one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0017] According to another aspect, a non-transitory computer-readable medium is provided, comprising program instructions for causing an apparatus in a radio access network to at least perform the following operations: receiving a trigger signal from a terminal device or access node in the radio access network, the trigger signal indicating a switch to one or more states; and switching to one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0018] According to another aspect, an apparatus in a radio access network is provided, the apparatus comprising at least one processor and at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, together with the at least one processor, cause the apparatus to: transmit a first trigger signal to a first terminal device or a second terminal device in the radio access network, the first trigger signal instructing the first terminal device to switch to one or more first states, wherein the one or more first states indicate a first terminal requirement for the first terminal device to support communication in the radio access network.

[0019] According to another aspect, a device in a radio access network is provided, the device comprising a component for performing the following operations: transmitting a first trigger signal to a first terminal device or a second terminal device in the radio access network, the first trigger signal instructing the first terminal device to switch to one or more first states, the one or more first states indicating a first terminal requirement for the first terminal device to support communication in the radio access network.

[0020] According to another aspect, a method is provided, comprising: transmitting a first trigger signal by an apparatus in a radio access network to a first terminal device or a second terminal device in the radio access network, the first trigger signal instructing the first terminal device to switch to one or more first states, wherein the one or more first states indicate a first terminal requirement for the first terminal device to support communication in the radio access network.

[0021] According to another aspect, a computer program is provided, comprising instructions which, when executed by an apparatus in a radio access network, cause the apparatus to at least perform the following operations: transmit a first trigger signal to a first terminal device or a second terminal device in the radio access network, the first trigger signal instructing the first terminal device to switch to one or more first states, wherein the one or more first states indicate a first terminal requirement for the first terminal device to support communication in the radio access network.

[0022] According to another aspect, a computer program is provided, comprising instructions for causing an apparatus in a radio access network to perform at least the following operations: transmitting a first trigger signal to a first terminal device or a second terminal device in the radio access network, the first trigger signal instructing the first terminal device to switch to one or more first states, wherein the one or more first states indicate a first terminal requirement for the first terminal device to support communications in the radio access network.

[0023] According to another aspect, a computer-readable medium is provided, comprising program instructions for causing an apparatus in a radio access network to perform at least the following operations: transmitting a first trigger signal to a first terminal device or a second terminal device in the radio access network, the first trigger signal instructing the first terminal device to switch to one or more first states, wherein the one or more first states indicate a first terminal requirement for the first terminal device to support communications in the radio access network.

[0024] According to another aspect, a non-transitory computer-readable medium is provided, comprising program instructions for causing an apparatus in a radio access network to at least perform the following operations: transmitting a first trigger signal to a first terminal device or a second terminal device in the radio access network, the first trigger signal instructing the first terminal device to switch to one or more first states, wherein the one or more first states indicate a first terminal requirement for the first terminal device to support communication in the radio access network.

[0025] According to another aspect, a system is provided, which includes at least a first terminal device, a second terminal device and an access node of a radio access network. The first terminal device is configured to: receive a trigger signal from the second terminal device or the access node, the trigger signal indicating one or more states; and switch to the one or more states, wherein the one or more states indicate terminal requirements for supporting communications in the radio access network.

[0026] According to another aspect, a system is provided, comprising at least a first terminal device, a second terminal device and an access node of a radio access network. The first terminal device comprises means for: receiving a trigger signal from the second terminal device or the access node, the trigger signal indicating switching to one or more states; and switching to the one or more states, wherein the one or more states indicate a terminal requirement to support communications in the radio access network. List of Figures

[0027] Hereinafter, various example embodiments will be described in more detail with reference to the accompanying drawings, in which

[0028] Figure 1 An example embodiment of a cellular communication network is shown;

[0029] Figure 2 An example embodiment of a horizontal new radio passive IoT architecture is shown;

[0030] Figure 3 An example embodiment of a fixed vertical new radio passive IoT architecture is shown;

[0031] Figure 4 An example embodiment of an opportunistic vertical new radio passive IoT architecture is shown;

[0032] Figure 5 shows a signaling diagram according to an example embodiment;

[0033] Figure 6 shows a signaling diagram according to an example embodiment;

[0034] Figure 7 shows a flow chart according to an example embodiment;

[0035] Figure 8 shows a flow chart according to an example embodiment;

[0036] Fig. 9 shows a flow chart according to an example embodiment;

[0037] Fig.10 shows a flow chart according to an example embodiment;

[0038] Fig.11 An example embodiment of an apparatus is shown; and

[0039] Fig.12 An example embodiment of an apparatus is shown. DETAILED DESCRIPTION

[0040] The following embodiments are exemplary. Although the specification may refer to "one", "an" or "some" embodiments in several places in the text, this does not necessarily mean that each reference is to the same embodiment, or that a particular feature applies only to a single embodiment. Individual features of different embodiments may also be combined to provide other embodiments.

[0041] In the following, different example embodiments will be described using a radio access architecture based on Long Term Evolution Advanced (LTE-Advanced, LTE-A), New Radio (NR, 5G), beyond 5G or sixth generation (6G) as an example of an access architecture to which the example embodiments may be applied, however, the example embodiments are not limited to such architectures. It is obvious to a person skilled in the art that the example embodiments may also be applied to other kinds of communication networks with appropriate means by appropriately adjusting the parameters and procedures. Some examples of other options for suitable systems may be Universal Mobile Telecommunications System (UMTS) Radio Access Network (UTRAN or E-UTRAN), Long Term Evolution (LTE, basically the same as E-UTRA), Wireless Local Area Network (WLAN or Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Personal Communications Service (PCS), Wideband Code Division Multiple Access (WCDMA), systems using Ultra-Wideband (UWB) technology, sensor networks, mobile ad hoc networks (MANETs), and Internet Protocol Multimedia Subsystem (IMS), or any combination thereof.

[0042] Figure 1 An example of a simplified system architecture showing some elements and functional entities is depicted, all of which are logical units, the implementation of which may differ from what is shown. Figure 1 The connections shown in are logical connections; the actual physical connections may be different. It is obvious to those skilled in the art that the system may also include Figure 1 The functions and structures are different from those shown.

[0043] However, the exemplary embodiments are not limited to the systems given as examples, but a person skilled in the art may apply the solution to other communication systems equipped with the necessary properties.

[0044] Figure 1 The example of FIG. 1 shows a portion of an exemplary radio access network.

[0045] Figure 1 A user device 100 and a user device 102 are shown, which are configured to be wirelessly connected to an access node 104 (such as an evolved Node B (abbreviated as eNB or eNodeB) or a next generation Node B (abbreviated as gNB or gNodeB)) providing the radio cell on one or more communication channels in the radio cell. The physical link from the user equipment to the access node may be referred to as an uplink (UL) or reverse link, and the physical link from the access node to the user equipment may be referred to as a downlink (DL) or forward link. The user equipment may also communicate directly with another user equipment via sidelink (SL) communications. It should be understood that the access node or its functionality may be implemented by using any node, host, server or access point entity suitable for this purpose.

[0046] The communication system may include more than one access node, in which case the access nodes may also be configured to communicate with each other via wired or wireless links designed for this purpose. These links may be used for signaling purposes. The access node may be a computing device configured to control the radio resources of the communication system to which it is coupled. The access node may also be referred to as a base station, a base transceiver station (BTS), an access point, or any other type of interface device, including a relay station capable of operating in a wireless environment. The access node may include a transceiver or be coupled to a transceiver. A connection may be provided from the transceiver of the access node to an antenna unit that establishes a bidirectional radio link to a user device. The antenna unit may include multiple antennas or antenna elements. The access node may also be connected to a core network 110 (CN or next generation core NGC). Depending on the system, the counterpart on the CN side may be a service gateway (S-GW, routing and forwarding user data packets), a packet data network gateway (P-GW), which is used to provide connectivity of user equipment to an external packet data network, a user plane function (UPF), a mobility management entity (MME), an access and mobility management function (AMF), or a location management function (LMF), etc.

[0047] The user equipment illustrates one type of apparatus to which resources on the air interface may be allocated and assigned, and thus any features described herein by way of the user equipment may be implemented by way of a corresponding apparatus such as a relay node.

[0048] An example of such a relay node may be a layer 3 relay towards an access node (self-backhaul relay). A self-backhaul relay node may also be referred to as an integrated access and backhaul (IAB) node. An IAB node may comprise two logical parts: a mobile terminal (MT) part, which is responsible for the backhaul link(s) (i.e., the link(s) between the IAB node and the donor node, also referred to as the parent node) and a distributed unit (DU) part, which is responsible for the access link(s) (i.e., the sub-link(s) between the IAB node and the user equipment(s), and / or the sub-link(s) between the IAB node and other IAB nodes (multi-hop scenario)).

[0049] Another example of such a relay node may be a layer 1 relay called a repeater. A repeater may amplify a signal received from an access node and forward it to a user equipment and / or amplify a signal received from a user equipment and forward it to an access node.

[0050] User equipment may also be referred to as a subscriber unit, mobile station, remote terminal, access terminal, user terminal, terminal device, active terminal device, passive terminal device or user equipment (UE), just to mention some names or devices. User equipment may refer to a portable computing device, which includes wireless mobile communication devices operating with or without a subscriber identity module (SIM), including but not limited to the following types of devices: mobile station (mobile phone), smart phone, personal digital assistant (PDA), mobile phone, device using wireless modem (alarm or measurement device, etc.), laptop computer and / or touch screen computer, tablet computer, game console, notebook, multimedia device, lightweight (RedCap) device, wireless sensor device or any device integrated in a vehicle.

[0051] It should be understood that the user device may also be a device that is almost exclusively uplink, an example of which may be a camera or video camera that loads images or video clips to a network. The user device may also be a device with the ability to operate in an Internet of Things (IoT) network, where an IoT network is a scene in which objects can be provided with data transmitted over a network without the need for human-to-human or human-to-computer interaction. The user device may also utilize the cloud. The user device may also utilize the cloud. In some applications, the user device may include a small portable or wearable device (such as a watch, headset, or glasses) with a radio component, and the calculation may be performed in the cloud or in another user device. The user device (or in some example embodiments, a layer 3 relay node) may be configured to perform one or more of the user device functionality.

[0052] The various techniques described herein may also be applied to cyber-physical systems (CPS) (systems where collaborative computing elements control physical entities). CPS can enable the implementation and utilization of a large number of interconnected ICT devices (sensors, actuators, processor microcontrollers, etc.), where the ICT devices are embedded in physical objects at different locations. Mobile cyber-physical systems are a subcategory of cyber-physical systems, in which the physical systems discussed may have inherent mobility. Examples of mobile physical systems include mobile robots and electronic devices transported by humans or animals.

[0053] Additionally, although the apparatus has been depicted as a single entity, different units, processors and / or memory units may be implemented ( Figure 1 not shown).

[0054] 5G implements the use of multiple-input multiple-output (MIMO) antennas, more base stations or nodes (the so-called small cell concept) compared to LTE (including macro sites operating in cooperative operation with smaller stations), and the use of various radio technologies according to service requirements, use cases and / or available spectrum. 5G mobile communications can support a wide range of use cases and related applications, including video streaming, augmented reality, different ways of data sharing, and various formats of machine-type applications (such as (massive) machine-type communications (mMTC), including vehicle safety, different sensors and real-time control). 5G can have multiple radio interfaces, namely below 6GHz, cmWave and mmWave, and can also be integrated with existing traditional radio access technologies (such as LTE). Integration with LTE can be implemented as a system at least in the early stages, in which macro coverage can be provided by LTE, and 5G radio interface access can come from small cells by aggregation to LTE. In other words, 5G can support inter-RAT operability (such as LTE-5G) and inter-RI operability (inter-radio interface operability, such as below 6GHz-cmWave-mmWave). One of the concepts considered for use in 5G networks may be network slicing, in which multiple independent and dedicated virtual subnetworks (network instances) can be created within essentially the same infrastructure to run services with different requirements for latency, reliability, throughput and mobility.

[0055] The current architecture in LTE networks can be completely distributed in the radio and completely concentrated in the core network. Low-latency applications and services in 5G may need to bring content close to the radio, which leads to local interruptions and multi-access edge computing (MEC). 5G can achieve analysis and knowledge generation at the data source. This approach may need to utilize resources that may be discontinuously connected to the network, such as laptops, smart phones, tablet computers and sensors. MEC can provide a distributed computing environment for application and service hosting. It can also have the ability to store and process content close to cellular subscribers to obtain faster response times. Edge computing can cover a wide range of technologies, such as wireless sensor networks, mobile data collection, mobile signature analysis, collaborative distributed peer-to-peer self-organizing networking and processing, which can also be classified as local cloud / fog computing and net / grid computing, dew computing, mobile edge computing, micro-cloud, distributed data storage and retrieval, autonomous self-repairing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (large-scale connection and / or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analysis, time-critical control, medical applications).

[0056] The communication system may also be able to communicate with or utilize services provided by other networks, such as the public switched telephone network or the Internet 112. The communication network may also be able to support the use of cloud services, for example, at least a portion of the core network operations may be performed as a cloud service (this is in the Figure 1 114). The communication system may also include a central control entity or the like which provides facilities for networks of different operators to collaborate, for example in spectrum sharing.

[0057] Edge cloud can be brought into the radio access network (RAN) by leveraging network function virtualization (NFV) and software defined networking (SDN). The use of edge cloud can mean access node operations that are at least partially performed on a server, host, or node, where the server, host, or node is operably coupled to a remote radio head (RRH) or a radio unit (RU), or access node operations performed in an access node including a radio portion. Node operations may also be distributed among multiple servers, nodes, or hosts. For example, the execution of RAN real-time functions on the RAN side (in a distributed unit (DU) 104) and the execution of non-real-time functions in a centralized manner (in a central unit (CU) 108) can be achieved by applying a cloudRAN architecture.

[0058] It should also be understood that the distribution of workload between core network operations and access node operations may be different from that of LTE or even non-existent. Some other technological advances that may be used include big data and all-IP, which may change the way networks are being built and managed. 5G (or new radio, NR) networks may be designed to support multiple layers, where MEC servers may be placed between the core and access nodes. It should be understood that MEC may also be applied in 4G networks.

[0059] 5G may also make use of non-terrestrial communications (e.g., satellite communications), for example by providing backhaul to enhance or supplement the coverage of 5G services. Possible use cases may be to provide service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices, or for passengers in vehicles, or to ensure service availability for critical communications, as well as future rail / maritime / aeronautical communications. Satellite communications may make use of geostationary earth orbit (GEO) satellite systems, but may also make use of low earth orbit (LEO) satellite systems, especially large constellations (systems in which hundreds of (nano) satellites are deployed). At least one satellite 106 in a large constellation may cover several satellite-supported network entities that create a cell on the ground. The cell on the ground is created by a relay node 104 on the ground or by a gNB located on the ground or in a satellite.

[0060] 6G networks are expected to adopt flexible decentralized and / or distributed computing systems and architectures and ubiquitous computing with local spectrum licensing, spectrum sharing, infrastructure sharing and intelligent automated management enhanced by mobile edge computing, artificial intelligence, short packet communications and blockchain technology. Key features of 6G may include management and control functions for intelligent connectivity, programmability, integrated sensing and communications, reduction of energy footprint, trusted infrastructure, scalability and affordability. In addition to these, 6G also targets new use cases that cover the integration of positioning and sensing capabilities into system definitions to unify user experience across the physical and digital worlds.

[0061] It is obvious to a person skilled in the art that the depicted system is only an example of a part of a radio access system, and in practice the system may include multiple access nodes, the user equipment may have access to multiple radio cells, and the system may also include other devices, such as physical layer relay nodes or other network elements, etc. At least one of the access nodes may be a Home eNodeB or a Home gNodeB.

[0062] In addition, the access node can also be divided into: a radio unit (RU), which includes a radio transceiver (TRX), i.e., a transmitter (Tx) and a receiver (Rx); one or more distributed units (DU), which can be used for so-called layer 1 (L1) processing and real-time layer 2 (L2) processing; and a central unit (CU) (also called a centralized unit), which can be used for non-real-time L2 and layer 3 (L3) processing. The CU can be connected to one or more DUs, for example, by using an F1 interface. This division can achieve CU centralization relative to the cell site and DU, while the DU can be more decentralized and can even be kept at the cell site. The CU and DU can also be collectively referred to as a baseband or baseband unit (BBU). The CU and DU can also be included in a radio access point (RAP).

[0063] A CU may be defined as a logical node that hosts higher layer protocols such as the Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and / or Packet Data Convergence Protocol (PDCP) of an access node. A DU may be defined as a logical node that hosts the Radio Link Control (RLC), Medium Access Control (MAC), and / or Physical (PHY) layers of an access node. The operation of a DU may be at least partially controlled by a CU. A CU may include a control plane (CU-CP), which may be defined as a logical node that hosts the RRC and control plane portions of the PDCP protocol for the CU of an access node. A CU may also include a user plane (CU-UP), which may be defined as a logical node that hosts the user plane portions of the PDCP protocol and the SDAP protocol for the CU of an access node.

[0064] The cloud computing platform can also be used to run the CU and / or DU. The CU can run in a cloud computing platform that can be referred to as a virtualized CU (vCU). In addition to the vCU, there can also be a virtualized DU (vDU) running in the cloud computing platform. In addition, there can also be a combination in which the DU can use a so-called bare metal solution, such as an application-specific integrated circuit (ASIC) or a customer-specific standard product (CSSP) system-on-chip (SoC) solution. It should also be understood that the workload distribution between the above-mentioned access node units or between different core network operations and access node operations may be different.

[0065] Additionally, in a geographical area of ​​the radio communication system, a plurality of different kinds of radio cells and a plurality of radio cells may be provided. A radio cell may be a macro cell (or umbrella cell), which may be a large cell up to tens of kilometers in diameter, or a smaller cell, such as a micro cell, a femto cell or a pico cell. Figure 1The access node(s) may provide any kind of these cells. A cellular radio system may be implemented as a multi-layer network comprising several radio cells. In a multi-layer network, one access node may provide one radio cell or multiple radio cells, and therefore multiple access nodes may be required to provide such a network structure.

[0066] In order to meet the need to improve the deployment and performance of communication systems, the concept of "plug and play" access nodes can be introduced. In addition to the home eNodeB or home gNodeB, the network that can use the "plug and play" access node may include a home node B gateway or HNB-GW ( Figure 1 (not shown). The HNB-GW, which may be installed in the operator's network, may aggregate services from a large number of home eNodeBs or home gNodeBs back to the core network.

[0067] Regarding IoT applications, the 3rd Generation Partnership Project (3GPP) specified narrowband IoT (NB-IoT), enhanced machine type communication (eMTC), and NR lightweight (RedCap) before NR Release 18 to meet the requirements for low-complexity and low-power devices for wide-area IoT communications. For example, these IoT devices may consume tens or hundreds of milliwatts of power during transmission and reception. However, in order to realize the Internet of Things, IoT devices with even lower power consumption may be required, such as for applications that require battery-free devices.

[0068] In recent years, the number of IoT connections has grown rapidly and is predicted to reach billions by 2030. With the expectation of interconnecting more and more "things" to improve productivity and increase the comfort of life, IoT devices may need to further reduce size, complexity and power consumption. For example, replacing the battery of an IoT device may be impractical due to the large consumption of materials and manpower.

[0069] However, for example, in applications with a very large number of devices (e.g., ID tags and sensors), energy can be harvested from the environment to provide self-sustaining communications for IoT devices. For example, energy can be harvested by collecting solar energy, piezoelectric energy, or radio wave energy. Radio wave energy conversion can be used to collect, for example, RFID, NFC, Bluetooth, 4G, 5G, WiFi, and other radio wave energy in the surrounding environment and convert it into electrical energy. Currently, 5G radio frequency energy can be harvested in a specific frequency band within a range of 180 meters to collect up to 6μW of power.

[0070] One issue with current 3GPP technologies for targeted use cases is the ability to work with energy harvesting given the limited device size. Cellular devices may consume tens or even hundreds of milliwatts of power for transceiver processing. Taking a NB-IoT module as an example, the current draw for receive processing may be around 60mA with a supply voltage above 3.1V, and 70mA for transmit processing at a transmit power of 0dBm. However, given the small size of a few square centimeters for actual devices, the output power provided by the energy harvester may be less than 1 milliwatt. Since the available power is much less than the consumed power, it may be impractical to directly power a cellular device via energy harvesting in most cases.

[0071] One possible solution is to integrate energy harvesting with rechargeable batteries or supercapacitors. However, there are still some problems to be solved. First, in practical situations, both rechargeable batteries and supercapacitors may suffer from shortened lifespans. It is difficult to provide a constant charging current or voltage through energy harvesting, and due to the extremely small output power from the energy harvester, long-term continuous charging may be required. Both constant charging current and long-term continuous charging are detrimental to battery life. For supercapacitors, the lifespan may be significantly reduced in high temperature environments (e.g., less than 3 years at 50 degrees Celsius).

[0072] Second, if the device is equipped with a battery or supercapacitor, the size of the device may be significantly increased. Since a small-sized button battery can provide only a few tens of milliamperes of current, a battery with a much larger size (e.g., AA battery) may be required to power a cellular device, but the size of the battery may even be larger than the NB-IoT module itself. In order to store energy for a suitable operating duration (e.g., one second), the required capacitance of the supercapacitor may be in the order of one hundred millifarads. The size of such a supercapacitor may also be larger than the NB-IoT module itself.

[0073] Radio Frequency Identification (RFID) is the technology that enables battery-free tags (devices). Commercial passive RFID tags can consume as little as 1 microwatt of power. The key technologies that enable this low power consumption are envelope detection for downlink data reception, and backscatter communication for uplink data transmission. RFID is designed for short-range communications, with a typical effective range of less than 10 meters. Since RFID's air interface has remained virtually unchanged since 2005, this simple transmission scheme can be a barrier to improving its link budget and ability to support scalable networks.

[0074] For example, backscatter communication is an energy-saving communication technology for IoT devices. With backscatter communication, IoT devices can reflect or backscatter external excitation signals (e.g., power beacons) by tuning a set of antenna impedances. The frequency, phase, and / or amplitude of the excitation signal can then be modulated based on the data of these IoT devices. Backscatter communication can enable IoT devices to transmit their data without active transmission of radio frequency (RF) signals, which results in lower energy consumption. IoT devices and / or other end devices can use backscatter to communicate with their peers and / or relay information to other devices.

[0075] There can be three types of backscatter communication systems: monostatic backscatter communication, bistatic backscatter communication, and ambient backscatter communication. In monostatic backscatter communication, a backscatter device (e.g., an IoT device) modulates and reflects a dedicated excitation signal transmitted by the intended receiver of the data.

[0076] In bistatic backscatter communications, an IoT device modulates and reflects a dedicated high-power excitation signal from a different RF source than the intended receiver (e.g., a base station or TV tower).

[0077] In ambient backscatter communications, the dedicated high power excitation signal is replaced by an RF data signal that is intended for other devices. Thus, ambient backscatter communications do not require the generation of a dedicated excitation signal.

[0078] Due to the low power consumption of backscatter communication, many non-3GPP technologies have begun to invest in related research, such as WiFi, Bluetooth, ultra-wideband (UWB) and long-range (LoRa). Various studies have shown that power consumption of a few microwatts or tens of microwatts can be achieved for passive tags based on or with small modifications to the above air interfaces. A significant proportion of research is aimed at long-distance communication. Among them, LoRa tags implemented with commercial off-the-shelf components can, for example, send their sensing data to a receiver from 381 meters away. At present, most research focuses on independent detailed technologies for various optimization goals. It is difficult to see a comprehensive system design that fully meets the requirements of the target use case.

[0079] To support and integrate passive IoT in 5G NR network infrastructure, two challenges may need to be overcome first. The first challenge is how passive IoT devices can obtain energy, since they are not equipped with a power source themselves. The second challenge is how to achieve long-distance backhaul, that is, how battery-free passive IoT devices can send signals with enough power to reach the NR gNB, which can be located thousands of meters away from the passive IoT devices.

[0080] The latter challenge is likely to be more difficult than the former and may be the first time such an issue has arisen in practice. The reason for this is that previous passive IoT deployments were based on Bluetooth or WiFi technologies, where IoT devices only needed to cover short distances on the order of meters.

[0081] However, NR integration of passive IoT can be challenging. This is because the energy obtained by passive IoT devices through various energy harvesting techniques can be very weak compared to the energy that the NR UL signal power needs to compensate for the path loss of the radio link to the gNB (which may be a kilometer or more away from the passive IoT device).

[0082] In summary, in order for passive IoT devices to successfully communicate with the NR backhaul, it may be necessary to provide a passive IoT infrastructure for NR.

[0083] Some example embodiments are described below using the principles and terminology of NR technology, but the example embodiments are not limited to NR communication systems.

[0084] Some example embodiments provide a framework comprising: a set of baselines of NR passive IoT architecture variants and their associated use cases, NR states of terminal devices belonging to the above architecture variants, and state change triggers that enable passive IoT devices to be integrated into 5G NR networks.

[0085] Depending on the use case scenario, the NR passive IoT (NR-pIoT) architecture can support horizontal or vertical deployment. The horizontal NR-pIoT (H-NR-pIoT) layer can be applicable to NR small cell deployment. The vertical NR-pIoT (V-NR-pIoT) layer can be applicable to NR macro cell deployment.

[0086] Figure 2 An example embodiment of an H-NR-pIoT architecture is shown, where one or more passive IoT devices 201, 202, 203 are within the coverage of a short-range NR network 204 (e.g., NR small cell, indoor deployment, smart home, etc.).

[0087] Here, a passive IoT device may also be referred to as a passive IoT terminal, a passive end device, a tag, a passive tag, or a passive radio. A passive end device (passive IoT device) may be defined as an end device that is not equipped with a battery or any other power source. However, a passive end device may include a capacitor for storing the harvested energy.

[0088] In the H-NR-pIoT architecture, a given passive IoT device 201 may be configured to: 1) communicate directly with the gNB 204; 2) offload its measurements to neighboring passive IoT devices 202, 203 upon receiving an explicit trigger from the gNB 204 or from neighboring passive IoT devices 202, 203; 3) the passive IoT device 201 relays measurements of one or more neighboring passive IoT devices 202, 203 to the gNB 204 if the passive IoT device 201 is instructed to do so by the gNB 204 via an explicit trigger, and / or harvests energy from radio signals transmitted by one or more neighboring passive IoT devices 202, 203 and / or by the gNB 204.

[0089] The V-NR-pIoT layer can be used when the passive IoT device is in the coverage of a remote NR network (e.g., macro cell deployment). This article defines three variants of the V-NR-pIoT layer: 1) fixed V-NR-pIoT for sparsely populated NR cells; 2) opportunistic V-NR-pIoT for densely populated NR cells; and 3) hybrid V-NR-pIoT for any other situation.

[0090] The V-NR-pIoT variant may include a passive IoT device and an NR active device that acts as an NR head and enables interaction between passive IoT terminals and the NR backhaul.

[0091] Figure 3 An example embodiment of a fixed V-NR-pIoT architecture is shown, where one or more passive IoT devices 301, 302, 303 are in close proximity to an active NR terminal device 300. For example, the active NR terminal device 300 may be an NR relay, an NR roadside unit, etc. The fixed V-NR-pIoT architecture may be deployed in sparsely populated NR cells and / or with a larger passive IoT device deployment, for example for automated agricultural applications such as crop monitoring, fishery monitoring, etc.

[0092] The active terminal device 300 can act as a fixed or semi-fixed collection communication unit, and it can enable the transmission of information (control signals and / or data) between the passive IoT devices 301, 302, 303 and the gNB 304. In other words, the active terminal device 300 can be deployed at a known fixed location, or the active terminal device 300 can be moved between known locations to support the wireless link of the passive IoT devices 301, 302, 303 to the NR backhaul 304. The active terminal device can refer to a terminal device that is, for example, equipped with a battery or connected to a power grid or other external power source. The active terminal device 300 can also act as an enabler for energy harvesting by (multiple) passive IoT devices 301, 302, 303 via the radio signals relayed to and from the gNB 304.

[0093] In a fixed V-NR-pIoT architecture, a given passive IoT device 301 can be configured to offload data (e.g., measurements) to one or more neighboring passive IoT devices 302, 303, offload data (e.g., measurements) to an active end device 300, relay data (e.g., measurements) from neighboring passive IoT devices 302, 303 to the active end device 300 and vice versa, and / or harvest energy from radio signals to / from any neighboring passive IoT devices 302, 303 and / or active end device 300.

[0094] Figure 4 An example embodiment of an opportunistic V-NR-pIoT architecture is shown, in which one or more passive IoT devices 401 are in close proximity to a random active NR terminal device 400, such as any mobile NR UE close to the passive IoT terminal 401. In other words, the active NR terminal device 400 is assigned to support the operation of the radio link of the passive IoT device 401 to the NR backhaul 404. The gNB 404 can use the approximate location of the active terminal device 400 (such as its serving beam information) to identify whether the active terminal device 400 is in the vicinity of one or more passive IoT devices 401 (e.g., within a predefined distance). After identifying that the active terminal device 400 is in the vicinity of one or more passive IoT devices 401, the gNB 404 can request the active terminal device 400 to relay radio signals (control signals and / or data) between any passive IoT device 401 and the gNB 404. The opportunistic V-NR-pIoT architecture can be deployed in densely populated NR cells, such as smart homes, offices, smart factories, etc.

[0095] In the hybrid V-NR-pIoT architecture, some active terminal devices can be intentionally deployed at fixed locations, while other active terminal devices can be randomly assigned relay roles by the gNB.

[0096] Passive IoT devices belonging to any of the above H-NR-pIoT or V-NR-pIoT architectures can be triggered to switch to any of the following states: peer offloading, head offloading, energy harvesting, peer relaying, peer control relaying and / or backhaul offloading.

[0097] In the peer-to-peer offloading state, a passive IoT device transmits its measurements to another (neighboring) passive IoT device. The passive IoT device can embed the measurements in the original transmission signal (i.e., the signal without the payload). The measurements can include sensor data such as temperature, humidity, etc. For example, if a passive IoT device runs out of storage space in its internal memory, and / or there are no active end devices nearby, the peer-to-peer offloading state can be used. The peer-to-peer offloading state can be denoted as state A in this article.

[0098] In the head-offload state, the passive IoT device transmits its measurements to the active end device. The head-offload state may be denoted as state B herein.

[0099] In the energy harvesting state, the passive IoT device harvests and stores energy in a capacitor for a dedicated period of time by listening to any incoming radio signals. The energy harvesting state can be denoted as state C in this article.

[0100] In the peer-to-peer relay state, a passive IoT device relays (via broadcast) the measurements of another (neighboring) passive IoT device. The peer-to-peer relay state may be denoted as state D herein.

[0101] In the peer control relay state, the passive IoT device relays (via broadcast) an NR control signal targeted at another (neighboring) passive IoT device. The NR control signal can be a DL control signal or a relayed DL signal. For example, the control signal can be used to instruct the passive IoT device to perform an operation such as collecting sensor data, or to provide the network with an identifier of the passive IoT device for locating / pinpointing the passive IoT device. The peer control relay state can be represented as state E in this article.

[0102] In the backhaul offload state, the passive IoT terminal transmits its measurements to the gNB. The backhaul offload state may be denoted as state F in this document.

[0103] Active end devices belonging to any of the above V-NR-pIoT architecture variants can be triggered to switch to any of the following states: collection, data relay and / or control relay.

[0104] In the collecting state, the active terminal device collects measurements from one or more passive IoT devices. The collection may mean that the active terminal device stores the received measurements in its internal memory and / or forwards them to the gNB. The collecting state may be denoted herein as state G.

[0105] In the data relay state, the active terminal device relays the measurements of one or more passive IoT devices to the gNB. The data relay state can be denoted as state H in this article.

[0106] In the control relay state, the active terminal device relays the NR control signal targeting the passive IoT device. The NR control signal can be a DL control signal or a relayed DL signal. The control relay state can be represented as state I in this article.

[0107] An end device (passive or active) may be statically configured or triggered via an explicit trigger signal to dynamically switch to one or more of the above states.

[0108] The trigger signal for the active terminal device may be in the form of a coded payload sent over a dedicated control channel. For example, the active terminal device may be triggered by the gNB to switch to a specific state G / H / I or a set of states via a short message indicator (SMI) sent over a physical downlink control channel (PDCCH), where the three flags G, H, I may be configured together with at least the time period P for which they are active and the start S of the time period.

[0109] For example, if (G, H, I) = (1, 0, 0), where P = 10 subframes and S = 0 subframes, the active terminal device can collect data (e.g., measurements) for a duration of P = 10 subframes starting from the moment the SMI is received based on the status G from one or more passive IoT devices.

[0110] Similarly, a passive IoT device can be triggered by the gNB (via direct DL signaling or relayed DL signaling) to switch between the above-mentioned states A to F. Due to the limited processing power of passive IoT devices, the trigger signal can be implemented by sending a known signal (e.g., a raw reference signal (RS)) on state-specific radio resources. For example, an RS received via PRB_A can trigger a passive IoT terminal to switch to state A (peer unloading state). As another example, an RS received on PRB_E can trigger a passive IoT terminal to switch to state E (peer controlled relay state). PRB is an abbreviation for physical resource block. It should be noted that a known signal transmitted via state-specific radio resources can also be used as a trigger signal for active terminal devices.

[0111] Figure 5A signaling diagram according to an example embodiment for an H-NR-pIoT architecture is shown. In this example embodiment, an access node (e.g., a gNB) of a radio access network may transmit one or more trigger signals to a first passive terminal device in the radio access network, the one or more trigger signals instructing the first terminal device to switch to one or more states. The one or more states indicate terminal requirements to support communications in the radio access network.

[0112] refer to Figure 5 In block 501, the access node transmits a trigger signal to the first passive terminal device, the trigger signal indicating switching to state C (i.e., the energy collection state described above). The first passive terminal device switches to state C as indicated by the trigger signal. State C indicates that the first passive terminal device collects energy from one or more received radio signals.

[0113] In block 502, in response to switching to state C, a first passive terminal device harvests energy from one or more received radio signals. The first passive terminal device may store the harvested energy in a capacitor.

[0114] In block 503, the access node transmits a trigger signal to the first passive terminal device indicating switching to state A (i.e., the above-mentioned peer-to-peer unloading state). The first passive terminal device switches to state A as indicated by the trigger signal. State A indicates that the first passive terminal device embeds the first set of measurements in the original transmission signal (i.e., a signal without a payload) for transmission to the neighboring terminal device.

[0115] In block 504, in response to switching to state A, the first passive terminal device transmits the original transmission signal embedded with the first set of measurements to a neighboring terminal device (e.g., to a second passive terminal device). In other words, the first passive terminal device offloads its measurements to the neighboring terminal device. The first passive terminal device may use the energy harvested in block 502 to transmit the first set of measurements.

[0116] Here, the terms "first passive terminal device" and "second passive terminal device" are used to distinguish terminal devices, and do not necessarily refer to specific identifications of terminal devices.

[0117] In block 505, the access node transmits a trigger signal to the first passive terminal device indicating a switch to state D (i.e., the peer-to-peer relay state described above). The first passive terminal device switches to state D as indicated by the trigger signal. State D indicates that the first passive terminal device relays a second set of measurements from a neighboring terminal device to the access node via backscatter.

[0118] In this document, the terms "first set of measurements" and "second set of measurements" are used to distinguish between the sets of measurements, and they do not necessarily imply a specific order of the sets of measurements.

[0119] In block 506, the first passive terminal device receives a second set of measurements from a neighboring terminal device.

[0120] In block 507, in response to switching to state D, the first passive terminal device relays a second set of measurements received from a neighboring terminal device to the access node via backscatter.

[0121] In block 508, the access node transmits a trigger signal to the first passive terminal device indicating switching to state E (i.e., the peer control relay state described above). The first passive terminal device switches to state E as indicated by the trigger signal. State E indicates that the first passive terminal device relays one or more control signals received from the access node to a neighboring terminal device by backscattering.

[0122] In block 509, the first passive terminal device receives a control signal from the access node.

[0123] In block 510, in response to switching to state E, the first passive terminal device relays a control signal received from an access node to a neighboring terminal device via backscatter.

[0124] In block 511, the access node transmits a trigger signal to the first passive terminal device indicating switching to state F (i.e., the backhaul offload state described above). The first passive terminal device switches to state E as indicated by the trigger signal. State F indicates that the first passive terminal device transmits the first set of measurements (or the third set of measurements) to the access node via backscatter (i.e., offloading the measurements of the first passive terminal device to the access node).

[0125] In block 512, in response to switching to state F, the first passive terminal device transmits the first set of measurements (or the third set of measurements) to the access node via backscatter. In other words, the first passive terminal device offloads its measurements to the access node.

[0126] Figure 6 A signaling diagram according to an example embodiment for a V-NR-pIoT architecture is shown. In this example embodiment, an access node (e.g., a gNB) of a radio access network may transmit one or more first trigger signals to a first passive terminal device via an active terminal device, the one or more first trigger signals indicating that the first terminal device switches to one or more first states. In addition, the access node may transmit one or more second trigger signals to the active terminal device, the one or more second trigger signals indicating that the active terminal device switches to one or more second states. The one or more first states and the one or more second states indicate terminal requirements for supporting communications in the radio access network.

[0127] refer to Figure 6In block 601, the access node may identify that a second terminal device is within a predefined distance (eg, in the vicinity) from a first terminal device. The second terminal device may refer to an active terminal device, and the first terminal device may refer to a first passive terminal device.

[0128] In block 602, the access node transmits a trigger signal to the first passive terminal device via the active terminal device, the trigger signal indicating a switch to state A (i.e., the above-mentioned peer-to-peer unloading state). The first passive terminal device switches to state A as indicated by the trigger signal. State A indicates that the first passive terminal device embeds a first set of measurements into an original transmission signal (i.e., a signal without a payload) to be sent (transmitted) to a neighboring terminal device.

[0129] In block 603, in response to switching to state A, the first passive terminal device transmits an original transmission signal embedded with the first set of measurements to a neighboring terminal device, (eg, to a second passive terminal device). In other words, the first passive terminal device offloads its measurements to the neighboring terminal device.

[0130] In block 604, the access node transmits a trigger signal to the active terminal device, the trigger signal indicating a switch to state G (i.e., the above-mentioned collecting state). The active terminal device switches to state G as indicated by the trigger signal. State G indicates that the active terminal device collects a set of measurements from one or more passive terminal devices (e.g., from the first passive terminal device and / or the second passive terminal device).

[0131] The trigger signals of blocks 602 and 604 may be sent in response to identifying that an active terminal device is within a predefined distance from the first passive terminal device.

[0132] In block 605, the access node transmits a trigger signal to the first passive terminal device via the active terminal device, the trigger signal indicating a switch to state B (i.e., the header unloading state described above). The first passive terminal device switches to state B as indicated by the trigger signal. State B indicates that the first passive terminal device transmits the first set of measurements (or the third set of measurements) to the active terminal device by backscattering.

[0133] In block 606, in response to switching to state B, the first passive terminal device transmits the first set of measurements (or the third set of measurements) to the active terminal device via backscatter. In other words, the first passive terminal device offloads its measurements to the active terminal device.

[0134] In block 607, in response to switching to state G, the active terminal device collects the first set of measurements (or the third set of measurements) received from the first passive terminal device. For example, the active terminal device may store the received measurements in its internal memory.

[0135] In block 608, the access node transmits a trigger signal to the active terminal device, the trigger signal indicating a switch to state H (i.e., the data relay state described above). The active terminal device switches to state H as indicated by the trigger signal. State H indicates that the active terminal device relays a set of measurements received from one or more passive terminal devices (e.g., from the first passive terminal device and / or the second passive terminal device) to the access node.

[0136] In block 609 , the first passive terminal device transmits the first set of measurements (or the fourth set of measurements) to the active terminal device via backscatter.

[0137] In block 610, in response to switching to state H, the active terminal device relays the first set of measurements (or the fourth set of measurements) received from the first passive terminal device to the access node. The active terminal device may relay the first set of measurements using active transmission of one or more RF signals (rather than using backscatter).

[0138] In block 611, the access node transmits a trigger signal to the first passive terminal device via the active terminal device, the trigger signal indicating a switch to state D (i.e., the above-mentioned peer relay state). The first passive terminal device switches to state D as indicated by the trigger signal. State D indicates that the first passive terminal device relays the second set of measurements received from the neighboring terminal device to the active terminal device via backscatter.

[0139] In block 612, the first passive terminal device receives a second set of measurements from a neighboring terminal device.

[0140] In block 613, in response to switching to state D, the first passive terminal device relays the second set of measurements received from the neighboring terminal device to the active terminal device via backscatter.

[0141] In response to switching to state H, the active terminal device relays the second set of measurements received from the first passive terminal device to the access node in block 614. The active terminal device may relay the second set of measurements using active transmission of one or more RF signals (rather than using backscatter).

[0142] In block 615, the access node transmits a trigger signal to the first passive terminal device via the active terminal device, the trigger signal indicating switching to state C (i.e., the energy collection state described above). The first passive terminal device switches to state C as indicated by the trigger signal. State C indicates that the first passive terminal device collects energy from one or more received radio signals.

[0143] In block 616, in response to switching to state C, the first passive terminal device harvests energy from the one or more received radio signals. The first passive terminal device may store the harvested energy in a capacitor.

[0144] In block 617, the access node transmits a trigger signal to the active terminal device, the trigger signal indicating switching to state I (i.e., the control relay state described above). The active terminal device switches to state I as indicated by the trigger signal. State I indicates that the active terminal device relays one or more control signals received from the access node to one or more passive terminal devices (e.g., to the first passive terminal device and / or the second passive terminal device).

[0145] In block 618, the access node transmits a first control signal to the active terminal device that is targeted to the first passive terminal device.

[0146] In block 619, in response to switching to state I, the active terminal device relays the first control signal received from the access node to the first passive terminal device. The active terminal device may relay the first control signal with active transmission of one or more RF signals (rather than using backscatter).

[0147] In block 620, the access node transmits a trigger signal to the first passive terminal device via the active terminal device, the trigger signal indicating switching to state E (i.e., the peer control relay state described above). The first passive terminal device switches to state E as indicated by the trigger signal. State E indicates that the first passive terminal device relays one or more control signals received from the access node to a neighboring terminal device by backscattering.

[0148] In block 621, the access node transmits a second control signal targeted at a second passive terminal device to the active terminal device.

[0149] In block 622, in response to switching to state I, the active terminal device relays the second control signal received from the access node to the first passive terminal device. Alternatively or additionally, the active terminal device may relay the second control signal directly to the second passive terminal device. The active terminal device may relay the second control signal using active transmission of one or more RF signals (rather than using backscatter).

[0150] In block 623, in response to switching to state E, the first passive terminal device relays the second control signal (targeted to the second passive terminal device) received from the active terminal device to the second passive terminal device via backscatter.

[0151] Figure 7 A flow chart according to an example embodiment of a method performed by an apparatus such as, or comprising, or included in a passive terminal device in a radio access network is shown. The passive terminal device may also be referred to herein as a first terminal device.

[0152] Reference Figure 7In block 701, a trigger signal is received from a terminal device (e.g., an active terminal device or an adjacent passive terminal device) or from an access node in a radio access network, the trigger signal indicating a switch to one or more states. For example, the trigger signal may include a reference signal received on one or more state-specific radio resources, wherein receiving the reference signal on the one or more state-specific radio resources indicates a switch to the one or more states.

[0153] At block 702, the apparatus switches to the one or more states, wherein the one or more states indicate terminal requirements to support communications in a radio access network.

[0154] For example, the terminal requirements may include performing at least one of the following: embedding a first set of measurements to be sent to an adjacent terminal device in an original transmission signal, transmitting the first set of measurements to the terminal device by backscattering, transmitting the first set of measurements to an access node by backscattering, relaying a second set of measurements from an adjacent terminal device to the terminal device or the access node by backscattering, relaying a control signal from the terminal device or from the access node to an adjacent terminal device by backscattering, and / or harvesting energy from one or more received radio signals.

[0155] The first set of measurements may include sensor data measured by the device, such as temperature, humidity, etc. The second set of measurements may include sensor data measured by neighboring end devices, such as temperature, humidity, etc.

[0156] The control signal may be used to instruct the device or adjacent terminal equipment to perform an operation, such as collecting sensor data, or providing an identification of the device or adjacent terminal equipment to an access node for locating / pointing the device or adjacent terminal equipment.

[0157] Figure 8 A flow chart according to an example embodiment of a method performed by an apparatus such as, or comprising, or included in an active terminal device in a radio access network is shown. The active terminal device may also be referred to herein as a second terminal device.

[0158] Reference Figure 8 , in block 801 , a trigger signal instructing a switch to one or more states is received from an access node of a radio access network.

[0159] For example, the trigger signal may include a short message indicator, which includes one or more state-specific bit flags, wherein the value of the one or more state-specific bit flags indicates switching to one or more states. The short message indicator may also indicate a time period for keeping one or more states active. The short message indicator may also indicate the start of the time period.

[0160] In block 802, the apparatus switches to the one or more states, wherein the one or more states indicate terminal requirements to support communications in a radio access network.

[0161] For example, the terminal requirements may include performing at least one of: collecting a set of measurements from one or more passive terminal devices, relaying the set of measurements from the one or more passive terminal devices to the access node, and / or relaying a control signal from the access node to the one or more passive terminal devices.

[0162] Fig. 9 A flow chart of an example embodiment of a method performed by an apparatus such as, or including, or comprised in an access node (e.g., a gNB) in a radio access network is shown.

[0163] Reference Fig. 9 In block 901, the apparatus transmits a first trigger signal to a first terminal device (e.g., a passive terminal device) or a second terminal device (e.g., an active terminal device) in a radio access network, the first trigger signal instructing the first terminal device to switch to one or more first states, wherein the one or more first states indicate a first terminal requirement for the first terminal device to support communication in the radio access network. If the first trigger signal is transmitted to the second terminal device (active terminal device), the second terminal device may relay or forward the first trigger signal to the first terminal device (passive terminal device).

[0164] For example, the first trigger signal may include a reference signal transmitted on one or more state-specific radio resources, wherein the transmission of the reference signal on the one or more state-specific radio resources indicates switching to the one or more first states.

[0165] For example, the first terminal requirement may instruct the first terminal device to perform at least one of the following: embedding a first set of measurements to be sent to an adjacent terminal device in an original transmission signal, transmitting the first set of measurements to a second terminal device by backscattering, transmitting the first set of measurements to an apparatus by backscattering, relaying a second set of measurements from an adjacent terminal device to a second terminal device or an apparatus by backscattering, relaying a first control signal from a second terminal device or from an apparatus to an adjacent terminal device by backscattering, and / or harvesting energy from one or more received radio signals.

[0166] Fig.10 A flow chart of another example embodiment of a method performed by an apparatus is shown, the apparatus being such as, or comprising, or included in an access node (e.g., a gNB) in a radio access network.

[0167] Reference Fig.10In block 1001, the apparatus transmits a first trigger signal to a first terminal device (e.g., a passive terminal device) or to a second terminal device (e.g., an active terminal device) in a radio access network, the first trigger signal instructing the first terminal device to switch to one or more first states, wherein the one or more first states indicate that the first terminal device supports a first terminal requirement for communication in the radio access network. If the first trigger signal is transmitted to the second terminal device (active terminal device), the second terminal device may relay or forward the first trigger signal to the first terminal device (passive terminal device).

[0168] For example, the first trigger signal may include a reference signal transmitted on one or more state-specific radio resources, wherein generating the reference signal on the one or more state-specific radio resources indicates switching to the one or more first states.

[0169] For example, the first terminal requirement may instruct the first terminal device to perform at least one of the following: embedding a first set of measurements to be sent to an adjacent terminal device in an original transmission signal, transmitting the first set of measurements to a second terminal device by backscattering, transmitting the first set of measurements to an apparatus by backscattering, relaying a second set of measurements from an adjacent terminal device to a second terminal device or an apparatus by backscattering, relaying a first control signal from a second terminal device or from an apparatus to an adjacent terminal device by backscattering, and / or harvesting energy from one or more received radio signals.

[0170] In block 1002 , the apparatus transmits a second trigger signal to a second terminal device, the second trigger signal instructing the second terminal device to switch to one or more second states, wherein the one or more second states indicate a second terminal requirement for the second terminal device to support communications in a radio access network.

[0171] In this document, the terms "first trigger signal" and "second trigger signal" are used to distinguish trigger signals, and they do not necessarily mean a specific order of trigger signals. Similarly, the terms "one or more first states" and "one or more second states" are used to distinguish states corresponding to the first terminal device and the second terminal device, respectively. Similarly, the terms "first terminal requirement" and "second terminal requirement" are used to distinguish terminal requirements corresponding to the first terminal device and the second terminal device, respectively.

[0172] For example, the second trigger signal may include a short message indicator, the short message indicator includes one or more state-specific bit flags, wherein the value of the one or more state-specific bit flags indicates switching to one or more second states. The short message indicator may also indicate a time period for keeping the one or more second states activated. The short message indicator may also indicate the start of the time period.

[0173] For example, the second terminal requirement may instruct the second terminal device to perform at least one of: collect a set of measurements from the first terminal device, relay a set of measurements from the first terminal device to the apparatus, and / or relay a second control signal from the apparatus to the first terminal device.

[0174] The terms "first control signal" and "second control signal" are used herein to distinguish trigger signals, and they do not necessarily imply a specific order of the control signals.

[0175] The above is based on Figures 5 to 10 There is no absolute time order for the described boxes, related functions and information exchanges (messages), and some of them may be executed simultaneously or in an order different from the described order. Other functions may also be executed between or within them, and other information may be sent and / or other rules may be applied. Some boxes or parts of boxes or one or more pieces of information may also be discarded or replaced with corresponding boxes or parts of boxes or one or more pieces of information.

[0176] Fig.11 An example embodiment of an apparatus 1100 is shown, which may be an apparatus such as, or comprising, or included in a terminal device in a radio access network. The terminal device may be, for example, a passive terminal device (passive IoT device) or an active terminal device as described above.

[0177] The device 1100 includes at least one processor 1110. The at least one processor 1110 interprets computer program instructions and processes data. The at least one processor 1110 may include one or more programmable processors. The at least one processor 1110 may include programmable hardware with embedded firmware, and may alternatively or additionally include one or more application specific integrated circuits (ASICs).

[0178] At least one processor 1110 is coupled to at least one memory 1120. At least one processor is configured to read data from and write data to at least one memory 1120. At least one memory 1120 may include one or more memory cells. The memory cell may be volatile or non-volatile. It should be noted that in some example embodiments, there may be one or more non-volatile memory cells and one or more volatile memory cells, alternatively, there may be one or more non-volatile memory cells, or alternatively, there may be one or more volatile memory cells. The volatile memory may be, for example, a random access memory (RAM), a dynamic random access memory (DRAM), or a synchronous dynamic random access memory (SDRAM). The non-volatile memory may be, for example, a read-only memory (ROM), a programmable read-only memory (PROM), an electrically erasable programmable read-only memory (EEPROM), flash memory, optical storage, or magnetic storage. In general, the memory may be referred to as a non-transitory computer-readable medium. At least one memory 1120 stores computer-readable instructions, which are executed by at least one processor 1110 to perform one or more of the above-described example embodiments. For example, non-volatile memory stores computer readable instructions, and at least one processor 1110 executes the instructions using volatile memory to temporarily store data and / or instructions.

[0179] The computer readable instructions may be pre-stored in at least one memory 1120, or, alternatively or additionally, they may be received by the device via an electromagnetic carrier signal, and / or may be copied from a physical entity (such as a computer program product). The execution of the computer readable instructions causes the device 1100 to perform one or more of the above functionalities.

[0180] In the context of this document, "memory" or "computer-readable media" or "computer-readable media" may be any non-transitory medium or media or components that can contain, store, communicate, propagate, or transport instructions for use by or in connection with an instruction execution system, apparatus, or device (such as a computer).

[0181] The device 1100 may also include or be connected to an input unit 1130. The input unit 1130 may include one or more interfaces for receiving input. The one or more interfaces may include, for example, one or more temperature, motion and / or orientation sensors, one or more cameras, one or more accelerometers, one or more microphones, one or more buttons and / or one or more touch detection units. In addition, the input unit 1130 may include an interface to which an external device may be connected.

[0182] The device 1100 may also include an output unit 1140. The output unit may include or be connected to one or more displays capable of rendering visual content, such as a light emitting diode (LED) display, a liquid crystal display (LCD), and / or a liquid crystal on silicon (LCoS) display. The output unit 1140 may also include one or more audio outputs. The one or more audio outputs may be, for example, a speaker.

[0183] The device 1100 also includes a connectivity unit 1150. The connectivity unit 1150 implements wireless connectivity to one or more external devices. The connectivity unit 1150 includes at least one transmitter and at least one receiver, which can be integrated into the device 1100, or the device 1100 can be connected to the at least one transmitter and at least one receiver. At least one transmitter includes at least one transmitting antenna, and at least one receiver includes at least one receiving antenna. The connectivity unit 1150 may include an integrated circuit or a group of integrated circuits that provide wireless communication capabilities to the device 1400. Alternatively, the wireless connection can be a hardwired application-specific integrated circuit (ASIC). The connectivity unit 1150 may include one or more components controlled by a corresponding control unit, such as: a power amplifier, a digital front end (DFE), an analog-to-digital converter (ADC), a digital-to-analog converter (DAC), a frequency converter, a modulator (demodulator) and / or an encoder / decoder circuit system.

[0184] It should be noted that the apparatus 1100 may also include Fig.11 Various components are not shown in the figure. The various components can be hardware components and / or software components.

[0185] Fig.12 The apparatus 1200 shows an example embodiment of an apparatus, such as or including or included in a network element of a radio access network. An access node may also be referred to as, for example, a network node, a network element, a radio access network (RAN) node, a next generation radio access network (NG-RAN) node, a NodeB, an eNB, a gNB, a base transceiver station (BTS), a base station, a NR base station, a 5G base station, an access point (AP), an integrated access and backhaul (IAB) node, an IAB donor node, a distributed unit (DU), a central unit (CU), a baseband unit (BBU), a radio unit (RU), a radio head, a remote radio head (RRH), or a transmit and receive point (TRP).

[0186] The device 1200 may include, for example, a circuit or chipset suitable for implementing one or more of the above-described example embodiments. The device 1200 may be an electronic device including one or more electronic circuits. The device 1200 may include a communication control circuit 1210, such as at least one processor and at least one memory 1220 storing instructions, which, when executed by the at least one processor, causes the device 1200 to perform one or more of the above-described example embodiments. Such instructions may, for example, include computer program code (software) 1222, wherein the at least one memory and the computer program code (software) 1222 are configured to cause the device 1200 to perform some of the above-described example embodiments together with the at least one processor. In this context, computer program code may also refer to instructions that cause the device 1200 to perform one or more of the above-described example embodiments. That is, at least one processor and at least one memory 1220 storing instructions may cause the described performance of the device.

[0187] The processor is coupled to the memory 1220. The processor is configured to read and write data from and to the memory 1220. The memory 1220 may include one or more memory cells. The memory cell may be volatile or non-volatile. It should be noted that in some example embodiments, there may be one or more non-volatile memory cells and one or more volatile memory cells, or alternatively, there may be one or more non-volatile memory cells, or alternatively, there may be one or more volatile memory cells. The volatile memory may be, for example, a random access memory (RAM), a dynamic random access memory (DRAM), or a synchronous dynamic random access memory (SDRAM). The non-volatile memory may be, for example, a read-only memory (ROM), a programmable read-only memory (PROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, an optical storage, or a magnetic storage. In general, the memory may be referred to as a non-transitory computer-readable medium. The memory 1220 stores computer-readable instructions executed by the processor. For example, the non-volatile memory stores computer-readable instructions, and the processor executes the instructions using the volatile memory to temporarily store data and / or instructions.

[0188] The computer readable instructions may be pre-stored in the memory 1220, or alternatively or additionally, they may be received by the device via an electromagnetic carrier signal and / or may be copied from a physical entity (such as a computer program product). The execution of the computer readable instructions causes the device 1200 to perform one or more of the above functions.

[0189] Memory 1220 may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. The memory may include a configuration database for storing configuration data. For example, the configuration database may store a current neighboring cell list, and in some example embodiments, may store the structure of frames used in detected neighboring cells.

[0190] The device 1200 may also include a communication interface 1230, which includes hardware and / or software for implementing a communication connection according to one or more communication protocols. The communication interface 1230 includes at least one transmitter (Tx) and at least one receiver (Rx), which may be integrated into the device 1200, or the device 1200 may be connected to at least one transmitter (Tx) and at least one receiver (Rx). The communication interface 1230 may include one or more components controlled by a corresponding control unit, such as: a power amplifier, a digital front end (DFE), an analog-to-digital converter (ADC), a digital-to-analog converter (DAC), a frequency converter, a modulator (demodulator) and / or an encoder / decoder circuit system.

[0191] The communication interface 1230 provides the apparatus with radio communication capabilities to communicate in a cellular communication system. The communication interface may, for example, provide a radio interface to one or more user equipments. The apparatus 1200 may also include another interface towards a core network such as a network coordinator apparatus and / or an access node of a cellular communication system.

[0192] The apparatus 1200 may further include a scheduler 1240 configured to allocate radio resources. The scheduler 1240 may be configured together with the communication control circuit 1210, or may be configured separately.

[0193] It should be noted that the apparatus 1200 may also include Fig.12 Various components are not shown in the figure. The various components can be hardware components and / or software components.

[0194] As used in this application, the term "circuitry" may refer to one or more or all of the following: a) a hardware circuit implementation only (such as an implementation in analog only and / or an implementation in digital circuitry); and b) a combination of hardware circuitry and software, such as (where applicable): i) a combination of (multiple) analog and / or digital hardware circuits with software / firmware, and ii) any portion of (multiple) hardware processors (including (multiple) digital signal processors), software and (multiple) memories with software that work together to enable a device such as a mobile phone to perform various functions; and c) (multiple) hardware circuits and / or (multiple) processors, such as (multiple) microprocessors or portions of (multiple) microprocessors, that require software (e.g., firmware) for operation, but the software may not be present when not required for operation.

[0195] This definition of circuitry applies to all uses of the term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to a particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0196] The techniques and methods described herein can be implemented by various means. For example, these techniques can be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. For hardware implementations, the (multiple) devices of the example embodiments can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), graphics processing units (GPUs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. For firmware or software, the implementation can be performed by a module of at least one chipset (e.g., a process, a function, etc.) that performs the functions described herein. The software code can be stored in a memory unit and executed by a processor. The memory unit can be implemented within a processor or outside a processor. In the latter case, it can be communicatively coupled to the processor via various means as known in the art. Additionally, as will be appreciated by those skilled in the art, the components of the system described herein can be rearranged and / or supplemented by additional components to support the implementation of the various aspects described herein, etc., and are not limited to the precise configurations set forth in the given figures.

[0197] It is obvious to those skilled in the art that, as technology advances, the disclosed concept can be implemented in various ways. The embodiments are not limited to the above-described example embodiments, but can be varied within the scope of the claims. Therefore, all words and expressions should be interpreted broadly, and they are intended to illustrate but not limit the example embodiments. List of abbreviations 3GPP: Third Generation Partnership Project 4G: Fourth Generation 5G: New Radio / Fifth Generation 6G: Sixth Generation ADC: Analog-to-Digital Converter AP: Access Point ASIC: Application-Specific Integrated Circuit BBU: Baseband Unit CN: Core Network CPS: Cyber-Physical System CSSP: Customer Specific Standard Product CU: Central Unit CU-CP: Central Unit Control Plane CU-UP: Central Unit User Plane DAC: Digital to Analog Converter DFE: Digital Front End DL: Downlink DRAM: Dynamic Random Access Memory DSP: Digital Signal Processor DSPD: Digital Signal Processing Device DU: Distributed Unit EEPROM: Electrically Erasable Programmable Read-Only Memory eMTC: Enhanced Machine Type Communication eNB: Evolved NodeB / 4G base station FPGA: Field Programmable Gate Array GEO: Geostationary Earth Orbit gNB: Next-generation NodeB / 5G base station GPU: Graphics Processing Unit HNB-GW: Home Node B Gateway H-NR-pIoT: Horizontal New Radio Passive IoT IAB: Integrated Access and Backhaul IMS: Internet Protocol Multimedia Subsystem IoT: Internet of Things L1: Layer 1 L2: Layer 2 L3: Layer 3 LCD: Liquid Crystal Display LCoS: Liquid Crystal on Silicon LED: Light Emitting Diode LEO: Low Earth Orbit LoRa: Long Range LTE: Long Term Evolution LTE-A: Long Term Evolution Advanced M2M: Machine to Machine MAC: Media Access Control MANET: Mobile Ad Hoc Network MEC: Multi-access Edge Computing MIMO: Multiple Input Multiple Output MME: Mobility Management Entity mMTC: Massive Machine Type Communications MT: Mobile Terminal NB-IoT: Narrowband Internet of Things NFV: Network Function Virtualization NGC: Next Generation Core NR: New Radio NR-pIoT: New Radio Passive IoT PCS: Personal Communications Service PDA: Personal Digital Assistant PDCCH: Physical Downlink Control Channel PDCP: Packet Data Convergence Protocol P-GW: Packet Data Network Gateway PHY: Physical PLD: Programmable Logic Device PRB: Physical Resource Block PROM: Programmable Read Only Memory RAM: Random Access Memory RAN: Radio Access Network RAP: Radio Access Point RAT: Radio Access Technology RedCap: Lightweight RF: Radio Frequency RFID: Radio Frequency Identification RI: Radio Interface RLC: Radio Link Control ROM: Read Only Memory RRC: Radio Resource Control RRH: Remote Radio Head RU: Radio Unit RX: Receiver SDAP: Service Data Adaptation Protocol SDN: Software Defined Networking SDRAM: Synchronous Dynamic Random Access Memory S-GW: Serving Gateway SIM: Subscriber Identity Module SL: Sidelink SMI: Short Message Indicator SoC: System on Chip TRP: Transceiver Point TRX: Transceiver TX: Transmitter UE: User Equipment UL: Uplink UMTS: Universal Mobile Telecommunications System UTRAN: UMTS Radio Access Network UWB: Ultra Wideband vCU: Virtualized Central Unit vDU: Virtualized Distributed Unit V-NR-pIoT: Vertical New Radio Passive IoT WCDMA: Wideband Code Division Multiple Access WiMAX: Worldwide Interoperability for Microwave Access WLAN: Wireless Local Area Network

Claims

1. A device in a radio access network, the device comprising: at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to: receiving a trigger signal from a terminal device or an access node in the radio access network, the trigger signal indicating a switch to one or more states; as well as Switching to the one or more states, wherein the one or more states indicate terminal requirements to support communications in the radio access network.

2. The apparatus of claim 1, wherein the terminal requirement comprises performing at least one of: embedding a first set of measurements to be sent to a neighboring terminal device in an original transmission signal; transmitting the first set of measurements to the terminal device by backscattering; transmitting the first set of measurements to the access node by backscattering; relaying a second set of measurements from the neighboring terminal device to the terminal device or to the access node by backscattering; relaying a control signal from the terminal device or from the access node to the adjacent terminal device by backscattering; and / or harvesting energy from one or more received radio signals.

3. The apparatus according to claim 2, further configured to: In response to switching to the one or more states, the original transmission signal embedded with the first set of measurements is transmitted to the neighboring terminal device, wherein the neighboring terminal device includes a second passive terminal device.

4. The device according to any one of claims 2 to 3, further configured to: In response to switching to the one or more states, the second set of measurements received from the neighboring terminal device are relayed to the terminal device or the access node via backscatter.

5. The device according to any one of claims 2 to 4, further configured to: In response to switching to the one or more states, the control signal received from the terminal device or from the access node is relayed to the neighboring terminal device by backscatter.

6. The device according to any one of the preceding claims, further configured to: In response to switching to the one or more states, the first set of measurements is transmitted to the terminal device via backscatter, wherein the terminal device comprises an active terminal device.

7. The device according to any one of the preceding claims, further configured to: In response to switching to the one or more states, the first set of measurements is transmitted to the access node via backscatter.

8. The apparatus according to any one of the preceding claims, further configured to: In response to switching to the one or more states, energy is harvested from one or more received radio signals.

9. An apparatus according to any of the preceding claims, wherein the trigger signal comprises a reference signal received on one or more state-specific radio resources, wherein receiving the reference signal on the one or more state-specific radio resources indicates switching to the one or more states.

10. The apparatus of any preceding claim, wherein the trigger signal is received from the access node via the terminal device.

11. An apparatus according to any preceding claim, wherein the apparatus comprises, or is comprised in, a first passive terminal device.

12. An apparatus in a radio access network, the apparatus comprising: at least one processor and at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to: receiving a trigger signal from an access node of the radio access network, the trigger signal indicating a switch to one or more states; as well as Switching to the one or more states, wherein the one or more states indicate terminal requirements to support communications in the radio access network.

13. An apparatus according to claim 12, wherein the terminal requirement includes performing at least one of the following: collecting a set of measurements from one or more passive terminal devices, relaying the set of measurements from the one or more passive terminal devices to the access node, and / or relaying a control signal from the access node to the one or more passive terminal devices.

14. The apparatus according to claim 13, further configured to: In response to switching to the one or more states, the set of measurements is collected from the one or more passive end devices.

15. The apparatus according to any one of claims 13 to 14, further configured to: In response to switching to the one or more states, the set of measurements received from the one or more passive terminal devices are relayed to the access node.

16. The apparatus according to any one of claims 13 to 15, further configured to: In response to switching to the one or more states, the control signal received from the access node is relayed to the one or more passive terminal devices.

17. The apparatus according to any one of claims 12 to 16, wherein the trigger signal comprises a short message indicator, the short message indicator comprises one or more state-specific bit flags, wherein values ​​of the one or more state-specific bit flags indicate switching to the one or more states.

18. The apparatus of claim 17, wherein the short message indicator further indicates a time period for keeping the one or more states active.

19. The apparatus of claim 18, wherein the short message indicator further indicates a start of the time period.

20. The apparatus according to any one of claims 12 to 19, wherein the apparatus comprises an active terminal device, or the apparatus is comprised in the active terminal device.

21. An apparatus in a radio access network, the apparatus comprising: at least one processor and at least one memory, the at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the apparatus to: A first trigger signal is transmitted to a first terminal device or a second terminal device in the radio access network, wherein the first trigger signal instructs the first terminal device to switch to one or more first states, wherein the one or more first states indicate a first terminal requirement for the first terminal device to support communication in the radio access network.

22. An apparatus according to claim 21, wherein the first terminal requirement instructs the first terminal device to perform at least one of the following: embedding a first set of measurements to be sent to an adjacent terminal device in an original transmission signal; transmitting the first set of measurements to the second terminal device by backscattering; transmitting the first set of measurements to the apparatus by backscattering; relaying a second set of measurements from the adjacent terminal device to the second terminal device or the apparatus by backscattering; relaying a first control signal from the second terminal device or from the apparatus to the adjacent terminal device by backscattering; and / or harvesting energy from one or more received radio signals.

23. An apparatus according to any one of claims 21 to 22, wherein the first trigger signal comprises a reference signal transmitted on one or more state-specific radio resources, wherein the reference signal transmitted on the one or more state-specific radio resources indicates a switch to the one or more first states. 24 . The apparatus according to claim 21 , wherein the first trigger signal is transmitted to the first terminal device via the second terminal device.

25. The apparatus according to any one of claims 21 to 24, further configured to: A second trigger signal is transmitted to the second terminal device instructing the second terminal device to switch to one or more second states, wherein the one or more second states indicate a second terminal requirement for the second terminal device to support communications in the radio access network.

26. An apparatus according to claim 25, wherein the second terminal requirement instructs the second terminal device to perform at least one of the following: collect a set of measurements from the first terminal device; relay the set of measurements from the first terminal device to the apparatus; and / or relay a second control signal from the apparatus to the first terminal device.

27. An apparatus according to any one of claims 25 to 26, wherein the second trigger signal comprises a short message indicator, the short message indicator comprises one or more state-specific bit flags, wherein the values ​​of the one or more state-specific bit flags indicate switching to the one or more second states.

28. The apparatus of claim 27, wherein the short message indicator further indicates a time period for keeping the one or more second states active.

29. The apparatus of claim 28, wherein the short message indicator further indicates a start of the time period.

30. The apparatus of any one of claims 25 to 29, wherein the second trigger signal is transmitted to the second terminal device in response to identifying that the second terminal device is within a predefined distance from the first terminal device.

31. The apparatus according to any one of claims 21 to 30, wherein the first terminal device is a passive terminal device, and the second terminal device is an active terminal device.

32. The apparatus according to any one of claims 21 to 31, wherein the apparatus comprises or is comprised in an access node of the radio access network.

33. An apparatus in a radio access network, the apparatus comprising means for: receiving a trigger signal from a terminal device or an access node in the radio access network, the trigger signal indicating a switch to one or more states; and Switching to the one or more states, wherein the one or more states indicate terminal requirements to support communications in the radio access network.

34. An apparatus in a radio access network, the apparatus comprising means for: receiving a trigger signal from an access node of the radio access network, the trigger signal indicating a switch to one or more states; and Switching to the one or more states, wherein the one or more states indicate terminal requirements to support communications in the radio access network.

35. An apparatus in a radio access network, the apparatus comprising means for: A first trigger signal is transmitted to a first terminal device or a second terminal device in the radio access network, wherein the first trigger signal instructs the first terminal device to switch to one or more first states, and the one or more first states indicate a first terminal requirement for the first terminal device to support communication in the radio access network.

36. A method comprising: receiving, by an apparatus in a radio access network, a trigger signal from a terminal device or an access node in the radio access network, the trigger signal indicating a switch to one or more states; as well as The apparatus switches to the one or more states, wherein the one or more states indicate terminal requirements to support communications in the radio access network.

37. A method comprising: receiving, by an apparatus in a radio access network from an access node of the radio access network, a trigger signal indicating a switch to one or more states; as well as The apparatus switches to the one or more states, wherein the one or more states indicate terminal requirements to support communications in the radio access network.

38. A method comprising: A first trigger signal is transmitted by a device in a radio access network to a first terminal device or a second terminal device in the radio access network, wherein the first trigger signal instructs the first terminal device to switch to one or more first states, wherein the one or more first states indicate a first terminal requirement for the first terminal device to support communication in the radio access network.

39. A computer program comprising instructions for causing an apparatus in a radio access network to at least: receiving a trigger signal from a terminal device or an access node in the radio access network, the trigger signal indicating a switch to one or more states; and Switching to the one or more states, wherein the one or more states indicate terminal requirements to support communications in the radio access network.

40. A computer program comprising instructions for causing an apparatus in a radio access network to at least: receiving a trigger signal from an access node of the radio access network, the trigger signal indicating switching to one or more states; and Switching to the one or more states, wherein the one or more states indicate terminal requirements to support communications in the radio access network.

41. A computer program comprising instructions for causing an apparatus in a radio access network to at least: A first trigger signal is transmitted to a first terminal device or a second terminal device in the radio access network, wherein the first trigger signal instructs the first terminal device to switch to one or more first states, wherein the one or more first states indicate a first terminal requirement for the first terminal device to support communication in the radio access network.

42. A system comprising at least a first terminal device, a second terminal device and an access node of a radio access network; The first terminal device is configured as follows: receiving a trigger signal from the second terminal device or the access node, the trigger signal indicating switching to one or more states; and Switching to the one or more states, wherein the one or more states indicate terminal requirements to support communications in the radio access network.

43. A system comprising at least a first terminal device, a second terminal device and an access node of a radio access network; The first terminal device includes a component for performing the following: receiving a trigger signal from the second terminal device or the access node, the trigger signal indicating switching to one or more states; and Switching to the one or more states, wherein the one or more states indicate terminal requirements to support communications in the radio access network.

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