CN115336325A

CN115336325A - Proactive measures for reducing the impact of power backoff

Info

Publication number: CN115336325A
Application number: CN202180023202.6A
Authority: CN
Inventors: S·卡波拉尔·德尔·巴里奥; I·韦林; S·K·涅尔森; B·维杰尔加德; S·斯文森; C·罗姆
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2020-03-25
Filing date: 2021-03-11
Publication date: 2022-11-11
Also published as: EP4128885A1; WO2021191498A1; EP4128885A4

Abstract

This document discloses a solution for the case where a terminal device (100) detects a power back-off event. One method comprises the following steps: detecting in the terminal device a need for uplink transmission power reduction in an antenna panel of the terminal device (504); in response to the detecting, performing at least one measurement (510) associated with: at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device; and reporting (512) at least the measurement and/or the need for uplink transmission power reduction to the access node (104) of the serving cell.

Description

Proactive measures for reducing the impact of power backoff

Technical Field

Various embodiments described herein relate to the field of wireless communications, and in particular to counteracting the adverse effects of power backoff conditions in wireless devices.

Background

The transmission power of the terminal device is controlled by various mechanisms. Uplink transmission power control procedures performed by a serving access node (e.g., a base station) are conventionally used to control uplink interference and power consumption of a terminal device. Other mechanisms for controlling transmission power include, for example, controlling exposure of a user of the terminal device to radio frequency radiation. Maximum Permissible Exposure (MPE) and Specific Absorption Rate (SAR) guidelines have been established to define limits on radio energy emissions for users. The terminal device may have built-in functionality to limit the transmission power to meet these limits. Other functions that may result in a power backoff condition in the terminal device are equally contemplated.

Disclosure of Invention

Some aspects of the invention are defined by the independent claims.

Some embodiments of the invention are defined in the dependent claims.

Embodiments and features, if any, described in this specification which do not fall within the scope of the independent claims are to be construed as examples useful for understanding the various embodiments of the invention. Some aspects of the disclosure are defined by the independent claims.

According to one aspect, there is provided an apparatus for a terminal device, the apparatus comprising means for: detecting a need for uplink transmission power reduction in an antenna panel of a terminal device; in response to the detection, performing at least one measurement associated with: at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device; and reporting at least the measurements and/or the need for uplink transmission power reduction to the access node of the serving cell.

In one embodiment, the component is configured to detect a need for uplink transmission power reduction in a serving antenna panel of the terminal device.

In one embodiment, the at least one measurement comprises a measurement of at least one of signal strength or signal quality of a downlink signal received from the at least one non-serving cell.

In one embodiment, the at least one measurement comprises a measurement associated with uplink transmission power in at least one non-serving cell and/or at least one non-serving antenna panel.

In one embodiment, the uplink power reduction includes a power backoff caused by a maximum allowed exposure limit.

In one embodiment, the component is further configured to report to the access node of the serving cell a metric associated with the uplink transmission power of the at least one non-serving cell and/or the at least one non-serving antenna panel.

In one embodiment, the metric indicates a power backoff associated with a maximum allowed exposure limit for a non-serving cell and/or a non-serving antenna panel.

In one embodiment, the component is configured to: the metric is reported with a measured downlink signal strength indicator or a measured downlink signal quality indicator of the at least one non-serving cell.

In one embodiment, the component is configured to: performing at least one measurement and reporting the at least one measurement before the uplink transmission power is reduced.

According to an aspect, there is provided an apparatus for an access node, the apparatus comprising means for: receiving a measurement report from a terminal device connected to the access node, the measurement report comprising measurement data relating to at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device, the measurement report further comprising an indication of a need for uplink transmission power reduction in the terminal device; and performing a handover decision for the terminal device based on the measurement data and the indication.

In one embodiment, the measurement data is indicative of a signal strength or signal quality of a downlink signal received by the terminal device from the at least one non-serving cell.

In one embodiment, the indication comprises at least one information element indicating uplink transmission power of the terminal device in the at least one non-serving cell and/or in the at least one non-serving antenna panel.

In one embodiment, the at least one information element indicates a power backoff associated with a maximum allowed exposure limit of the non-serving cell and/or the non-serving antenna panel.

In one embodiment, the component is configured to: preventing a handover to a non-serving cell or a non-serving antenna panel associated with uplink transmission power reduction.

In one embodiment, the component is configured to: the terminal device is handed over to a non-serving cell or a non-serving antenna panel independent of the uplink transmission power reduction.

In one embodiment, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause execution of the apparatus.

According to one aspect, there is provided a method comprising: detecting, by the terminal device, a need for uplink transmission power reduction in an antenna panel of the terminal device; in response to the detection, performing at least one measurement associated with: at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device; and reporting, by the terminal device, at least the measurement and/or the need for uplink transmission power reduction to the access node of the serving cell.

In one embodiment, a terminal device detects a need for uplink transmission power reduction in a serving antenna panel of the terminal device.

In one embodiment, a terminal device reports a metric associated with uplink transmission power of at least one non-serving cell and/or at least one non-serving antenna panel to an access node of a serving cell.

In one embodiment, the terminal device reports the metric together with a measured downlink signal strength indicator or a measured downlink signal quality indicator of the at least one non-serving cell.

In one embodiment, the terminal device performs at least one measurement and reports the at least one measurement prior to the uplink transmission power reduction.

According to an aspect, there is provided a method comprising: receiving, by an access node, a measurement report from a terminal device connected to the access node, the measurement report comprising measurement data relating to at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device, the measurement report further comprising an indication of a need for uplink transmission power reduction in the terminal device; and performing, by the access node, a handover decision for the terminal device based on the measurement data and the indication.

In one embodiment, the indication comprises at least one information element indicating an uplink transmission power of the terminal device in the at least one non-serving cell and/or in the at least one non-serving antenna panel.

In one embodiment, the access node prevents switching to a non-serving cell or non-serving antenna panel associated with uplink transmission power reduction.

In one embodiment, the access node switches the terminal device to a non-serving cell or non-serving antenna panel independent of uplink transmission power reduction.

According to one aspect, there is provided a computer program product embodied on a computer readable medium and comprising computer program code readable by a computer, wherein the computer program code configures the computer to perform a computer process comprising: detecting, in a terminal device, a need for uplink transmission power reduction in an antenna panel of the terminal device; in response to the detection, performing at least one measurement associated with: at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device; and reporting at least the measurement and/or the need for uplink transmission power reduction to the access node of the serving cell.

According to one aspect, there is provided a computer program product embodied on a computer readable medium and comprising computer program code readable by a computer, wherein the computer program code configures the computer to perform a computer process comprising: receiving, in the access node, a measurement report from a terminal device connected to the access node, the measurement report comprising measurement data relating to at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device, the measurement report further comprising an indication of a need for uplink transmission power reduction in the terminal device; and performing a handover decision for the terminal device based on the measurement data and the indication.

Drawings

Embodiments are described below, by way of example only, with reference to the accompanying drawings, in which

Fig. 1 illustrates a wireless communication scenario in which some embodiments of the present invention may be applied;

fig. 2 shows an embodiment of a terminal device comprising multiple antenna panels pointing in different spatial directions, and also shows the effect of uplink power backoff;

figures 3 and 4 illustrate embodiments of a process for cancelling power backoff effects;

figure 5 shows a signaling diagram of an embodiment for reporting neighbor cell measurements upon detection of a power backoff event in the serving antenna panel;

FIG. 6 illustrates the effect of the embodiment of FIG. 5;

figure 7 illustrates a signaling diagram of an embodiment for reporting neighbor cell measurements upon detection of a power backoff event in a non-serving antenna panel;

FIG. 8 illustrates the effect of the embodiment of FIG. 5; and

fig. 9 and 10 show block diagrams of the structure of an apparatus according to some embodiments of the invention.

Detailed Description

The following embodiments are examples. Although the specification may refer to "an", "one", or "some" embodiment in various places, this does not necessarily mean that each such reference points to the same embodiment, or that the feature only applies to a single embodiment. Individual features of different embodiments may also be combined to provide other embodiments. Furthermore, the words "comprising" and "including" should be understood as not limiting the described embodiments to consist of only those features which have been mentioned, and such embodiments may also comprise features/structures which have not been specifically mentioned.

In the following, different exemplary embodiments will be described using a radio access architecture based on long term evolution advanced (LTE-advanced) or new radio (NR, 5G) as an example of an access architecture to which the embodiments can be applied, without limiting the embodiments to such an architecture. Those skilled in the art will recognize that embodiments may also be applied to other kinds of communication networks with suitable modules by appropriately adjusting parameters and procedures. Some examples of other options applicable to the system are Universal Mobile Telecommunications System (UMTS) radio Access network (UTRAN or E-UTRAN), long term evolution (LTE, same as E-UTRA), wireless local area network (WLAN or WiFi), 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 subsystems (IMS), or any combination thereof.

Fig. 1 depicts an example of a simplified system architecture, showing only some elements and functional entities, all of which are logical units, the implementation of which may differ from that shown. The connections shown in FIG. 1 are logical connections; the actual physical connections may vary. It is clear to a person skilled in the art that the system typically comprises other functions and structures than those shown in fig. 1.

The embodiments are not, however, limited to the systems given as examples, but a person skilled in the art may apply the solution to other communication systems having the necessary characteristics.

The example of fig. 1 shows a portion of an exemplary radio access network.

Fig. 1 shows terminal devices or

user equipments

100 and 102 configured to make a wireless connection with an access node (such as an (e/g) NodeB) 104 providing a cell over one or more communication channels in the cell. (e/g) NodeB refers to eNodeB or gNodeB as defined in the 3GPP specification. The physical link from the user equipment to the (e/g) NodeB is called an uplink or reverse link, and the physical link from the (e/g) NodeB to the user equipment is called a downlink or forward link. It will be appreciated that the (e/g) NodeB or its functionality may be implemented using any node, host, server, or access point, etc. entity suitable for such usage.

A communication system typically comprises more than one (e/g) NodeB, in which case the (e/g) nodebs may also be configured to communicate with each other via wired or wireless links designed for this purpose. These links may be used not only for signaling purposes, but also for routing data from one (e/g) NodeB to another (e/g) NodeB. (e/g) a NodeB is a computing device configured to control the radio resources of the communication system to which it is coupled. A NodeB may also be referred to as a base station, access point, access node, or any other type of interface device that includes a relay station capable of operating in a wireless environment. (e/g) the NodeB includes or is coupled to a transceiver. The antenna unit is provided with a connection from the transceiver of the (e/g) NodeB, which establishes a bi-directional radio link to the user equipment. The antenna unit may comprise a plurality of antennas or antenna elements. (e/g) the NodeB is further connected to a core network 110 (CN or next generation core NGC). Depending on the system, the CN side partner may be a serving gateway (S-GW, routing and forwarding user data packets), a packet data network gateway (P-GW, for providing connectivity of User Equipment (UE) with external packet data networks), or a Mobility Management Entity (MME), etc.

User equipment (user device) (also referred to as UE, user equipment (user equipment), user terminal, terminal equipment, etc.) illustrates one type of equipment to which resources on the air interface are allocated and assigned, and thus any of the features of the user equipment described herein may be implemented with a corresponding apparatus, such as a relay node. One example of such a relay node is a base station-oriented layer 3 relay (self-backhauling relay).

User equipment generally refers to portable computing devices, including wireless mobile communication devices with or without Subscriber Identity Modules (SIMs), including but not limited to the following types of devices: mobile stations (mobile phones), smart phones, personal Digital Assistants (PDAs), handsets, devices using wireless modems (alarm devices or measuring devices, etc.), portable and/or touch screen computers, tablets, games, notebooks and multimedia devices. It should be understood that the user equipment may also be an almost exclusive uplink-only device, an example of which is a camera or camcorder that loads images or video clips to the network. The user device may also be a device with the capability to operate in an internet of things (IoT) network, in which scenario objects are provided with the capability to transmit data over the network without human-to-human or human-to-computer interaction. The user device may also utilize the cloud. In some applications, the user device may include a small portable device with a radio (such as a watch, headset, or glasses), and the computing is performed in the cloud. The user equipment (or in some embodiments a layer 3 relay node) is configured to perform one or more of the user equipment functions. A user equipment may also be referred to as a subscriber unit, mobile station, remote terminal, access terminal, user terminal, or User Equipment (UE), to name a few.

The various techniques described herein may also be applied to network physical systems (CPS) (systems that cooperate with computing elements to control physical entities). CPS can implement and utilize a large number of interconnected ICT devices (sensors, actuators, processor microcontrollers, etc.) embedded at different locations in a physical object. The mobile network physical system in which the physical system in question has an inherent mobility is a sub-category of network physical systems. Examples of mobile physical systems include mobile robots and electronic devices transported by humans or animals.

Additionally, although the apparatus is depicted as a single entity, different units, processors, and/or memory units (not all shown in fig. 1) may be implemented.

5G supports many more base stations or nodes than LTE (so-called small cell concept) using multiple-input multiple-output (MIMO) antennas (including macro stations cooperating with small base stations and employing multiple radio technologies, depending on service requirements, use cases and/or available spectrum). The 5G mobile communication supports various use cases and related applications including video streaming, augmented reality, different data sharing approaches, and various forms of machine type applications such as (large scale) machine type communication (mtc), including vehicle safety, different sensors, and real-time control. 5G is expected to have multiple wireless interfaces, i.e., below 6GHz, cmWave and mmWave, and is also capable of integrating with existing legacy radio access technologies such as LTE. Integration with LTE may be implemented at least at an early stage as a system in which macro coverage is provided by LTE and 5G radio interface access comes from cells by aggregation to LTE. In other words, 5G is planned to support both inter-RAT operability (such as LTE-5G) and inter-RI operability (inter-radio interface operability, such as below 6GHz (cmWave), above 6GHz (cmWave, mmWave)). One of the concepts considered for use in 5G networks is network slicing, where multiple independent and dedicated virtual subnetworks (network instances) can be created in the same infrastructure to run services with different requirements on latency, reliability, throughput and mobility.

Current architectures in LTE networks are fully distributed in the radio and are usually fully centralized in the core network. Low-latency applications and services in 5G require the content to be brought close to the radio, resulting in local break out and multi-access edge computation (MEC). 5G allows analysis and knowledge generation to be performed at the data source. This approach requires the utilization of resources such as laptops, smart phones, tablets, and sensors that may not be continuously connected to the network. MECs provide a distributed computing environment for application and service hosting. It also has the ability to store and process content in the vicinity of cellular subscribers to speed response times. Edge computing covers a wide range of technologies such as wireless sensor networks, mobile data acquisition, mobile signature analysis, collaborative distributed peer-to-peer ad hoc networks and processes (which can also be classified as local cloud/fog computing and grid/mesh computing), dew computing, mobile edge computing, cloudlets (cloudlets), distributed data storage and retrieval, autonomic self-healing networks, remote cloud services, augmented and virtual reality, data caching, internet of things (large scale connectivity and/or latency critical), critical communications (autonomous driving, traffic safety, real-time analysis, time critical control, healthcare applications).

The communication system is also capable of communicating with, or utilizing, other networks, such as the public switched telephone network or the internet 112. The communication network may also support the use of cloud services, e.g., at least a portion of the core network operations may be performed as a cloud service (this is depicted in fig. 1 by the "cloud" 114). The communication system may also comprise a central control entity or the like providing the networks of different operators with facilities for cooperation, e.g. in spectrum sharing.

Edge clouds can be introduced into Radio Access Networks (RANs) by utilizing network function virtualization (NVF) and Software Defined Networking (SDN). Using an edge cloud may mean that access node operations are to be performed at least in part in a server, host, or node that is operatively coupled to a remote radio head or base station that includes a radio portion. Node operations may also be distributed among multiple servers, nodes, or hosts. The application of the clooud RAN architecture enables RAN real-time functions to be performed on the RAN side (in the distributed unit DU 104) and non-real-time functions to be performed in a centralized manner (in the centralized unit CU 108).

It should also be understood that the allocation of functionality between core network operation and base station operation may be different from that of LTE, or even non-existent. Some other technological advances that may be used are big data and all IP, which may change the way the network is built and managed. The 5G (or new radio NR) network is designed to support multiple hierarchies where MEC servers can be placed between the core and the base stations or nodebs (gnbs). It should be understood that MEC may also be applied to 4G networks.

The 5G may also utilize satellite communications to enhance or supplement the coverage of the 5G service, such as by providing backhaul. Possible use cases are to provide service continuity for machine-to-machine (M2M) or internet of things (IoT) devices or for on-board passengers, or to ensure service availability for critical communications as well as future rail, maritime, and/or airborne communications. Satellite communications may utilize Geostationary Earth Orbit (GEO) satellite systems, but may also utilize Low Earth Orbit (LEO) satellite systems, particularly giant constellations (systems in which hundreds of (nanometers) satellites are deployed). Each satellite 106 in the giant constellation may cover several satellite-enabled network entities that create terrestrial cells. The terrestrial cell may be created by the terrestrial relay node 104 or a gNB located in the ground or satellite.

It is clear 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 comprise a plurality of (e/g) nodebs, which the user equipment may access, and which may also comprise other apparatuses, such as physical layer relay nodes or other network elements, etc. The at least one (e/g) NodeB may be a home (e/g) NodeB. In addition, in a geographical area of the radio communication system, a plurality of radio cells of different kinds and a plurality of radio cells may be provided. The radio cells may be macro cells (or umbrella cells), which are large cells typically up to tens of kilometers in diameter, or smaller cells such as micro cells, femto cells, or pico cells. The (e/g) NodeB of fig. 1 may provide any kind of these cells. A cellular radio system may be implemented as a multi-layer network comprising several cells. Typically, in a multi-layer network, one access node provides one or more cells, and thus a plurality of (e/g) nodebs are required to provide such a network structure.

To meet the need for improved deployment and performance of communication systems, the concept of "plug and play" (e/g) nodebs was introduced. Typically, in addition to a home (e/g) NodeB (H (e/g) NodeB), a network capable of using a "plug and play" (e/g) NodeB includes a home NodeB gateway or HNB-GW (not shown in fig. 1). An HNB gateway (HNB-GW), typically installed within an operator's network, may aggregate traffic from a large number of HNBs back to the core network.

As communications transition to higher frequencies, terminal devices may be equipped with a greater number of antenna panels to ensure efficient radiation characteristics. Fig. 2 shows an embodiment in which the terminal device 100 is equipped with four antenna panels 200-206, each pointing in a different radiation direction. Each antenna panel may provide a spherical radiation pattern and the combined radiation pattern of the antenna panels may provide an omnidirectional radiation pattern. Each antenna panel 200-206 may include multiple antenna elements to provide the ability for adaptive spatial directivity, beamforming, or multiple-input multiple-output transmission and reception. Each antenna panel may form an antenna array, and examples of possible configurations of each antenna array include an 8 × 1 (one row of eight antennas), a 4 × 2 (two rows of four antennas), an 8 × 2, etc. antenna array. As shown in fig. 2, each antenna panel may experience the environment differently due to different directivity. For example, the antenna panel may be capable of detecting different sets of access nodes and have different reception qualities. For example, antenna panel 200 may be best suited to communicate with access node 104 located in the radiation direction of antenna panel 200, while

antenna panels

204, 206 may be best suited to communicate with

access nodes

122, 120 located in the respective radiation directions of

antenna panels

204, 206, respectively.

Terminal devices connected to a serving cell or serving access node (e.g., access node 104) may be configured by the serving cell to report signal strength measurements of neighboring cells for mobility and beam tracking purposes. One example of reported signal strength is Reference Signal Received Power (RSRP). Other examples are Reference Signal Received Quality (RSRQ) and signal to interference and noise ratio (SINR). The reporting may be event-triggered or periodic. Some triggers are described in the specifications of the third generation partnership project (3 GPP). To report neighbor cell measurements, the terminal device may combine measurements from multiple antenna panels by selecting, for example, the strongest of all antenna panel measurements for a particular neighbor cell. Thus, cell-level measurements of a certain neighboring cell can be generated by using the best measurements in all antenna panels. The neighbor cell measurements may be downlink measurements.

Maximum Permissible Exposure (MPE) is mentioned in the background. The government has enacted exposure guidelines to prevent health problems due to thermal effects. MPE is a specification for the power density of millimeter wave systems. The Federal Communications Commission (FCC) has defined the MPE threshold as 10W/m2 (1 mW/cm 2). For a certain distance separating the human tissue from the antenna, a power back-off (PBO) is required to comply with regulations. However, the required PBO is typically quite large (e.g., up to 30dB for devices transmitting with maximum Effective Isotropic Radiated Power (EIRP) limitations). Such a large PBO may result in an unexpected Radio Link Failure (RLF) because such a fallback would reduce the uplink transmission capacity for successful delivery of uplink data packets. Depending on EIRP, PBO may be triggered at different user antenna spacings. For example, a 4 x 1 antenna array with an EIRP of 34dBm may require PBO when the user is 14cm from the antenna. When the user is almost touching the antenna (2 mm separation), the maximum allowable EIRP may only be 10dBm, so the power needs to be backed off by 24dB. The transmission range of the terminal equipment is therefore affected by PBO, and 20-dB PBO may reduce the range by up to 90%. PBO is only applicable for uplink and thus can result in severe link imbalance when the UE is power limited. This is illustrated in fig. 2, where a hand near an

antenna panel

200, 204 causes PBO at the antenna panel, with the result that there is a link imbalance in the communication between the antenna panel and the

respective access node

104, 122. The terminal device 100 is able to detect downlink signals from the

access nodes

104, 122 via the

respective antenna panels

200, 204, but the uplink transmission capacity is reduced due to PBO, resulting in an imbalance. Even though this does not prevent propagation, e.g., neither uplink nor downlink path loss is affected by hand, PBO throttles the transmission power of the terminal device, reducing the reception power of the access node and thus the uplink SINR. The

antenna panels

202, 206 are not PBO limited and therefore, the link balance between the antenna panel 206 and the access node 120 may be maintained.

Handover decisions are typically made based on downlink measurements. This, in combination with the link imbalance mentioned above, may result in a situation where the connection of the terminal device is switched to an access node communicating with the PBO-restricted antenna panel. Thus, handover may lead to uplink quality degradation and possible radio link failure. On the other hand, connection of terminal devices via PBO-restricted antenna panels may fail due to uplink failure caused by PBO.

Fig. 3 and 4 show a flow chart of a process for managing connections in a PBO situation. Fig. 3 shows a procedure for a terminal device, while fig. 4 shows a procedure for a network node serving the terminal device, such as an access node performing handover decisions for the terminal device.

Referring to fig. 3, the process includes the following operations performed by the terminal device: detecting (block 300) a need for uplink transmission power reduction in an antenna panel of a terminal device; in response to the detection, performing (block 302) at least one measurement associated with: at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device; and reporting (block 304) the at least one measurement to an access node of the serving cell.

In one embodiment, blocks 302 and 304 are performed prior to the uplink transmission power reduction in the terminal device.

In one embodiment, block 302 also includes reporting a need for uplink transmission power reduction.

Referring to fig. 4, the process includes the following operations performed by the network node: receiving (block 400) a measurement report from a terminal device connected to an access node, the measurement report comprising measurement data relating to at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device, the measurement report further comprising an indication of a need for uplink transmission power reduction in the terminal device; and performing (blocks 402, 404) a handover decision of the terminal device based on the measurement data and the indication.

Block 402 may include determining whether to perform a handover. If a handover does not need to be performed, the process may end. Otherwise, the process may proceed to block 206 where at block 206 the connection is handed over to one of the non-serving cells of the terminal device, thereby also causing the connection to be handed over from one antenna panel of the terminal device to another antenna panel of the terminal device.

Embodiments provide several advantages. The measurement report is triggered before PBO (uplink transmission power reduction) is in effect so that the effect of PBO can be cancelled before PBO is achieved. The terminal device sends information about the PBO to the network (access node) to enable a more informed handover decision. The network may then redirect the connection to cells and antenna panels that are not affected by PBO. The network can also avoid switching the connection to the PBO affected antenna panel. Thus, radio link failures may be avoided or reduced.

In an embodiment of block 300, a terminal device detects a need for uplink transmission power reduction in a serving antenna panel of the terminal device. A serving antenna panel may be understood as an antenna panel that transmits radio signals of a connection between a terminal device and a serving cell.

In the embodiments of blocks 302 and 304, the at least one measurement performed and reported to the serving access node comprises a measurement of at least one of a signal strength (e.g., RSRP or SINR) or a signal quality (e.g., RSRQ) of a downlink signal received from the at least one non-serving cell.

In one embodiment, the uplink power reduction includes PBO caused by MPE limitations. The need for PBO as a result of MPE can be detected by using any proximity detection sensor for detecting the proximity of a user (e.g., a user's hand) by a terminal device. Proximity detection may be based on (passive) infrared proximity sensors, short range radar built into the antenna panel, etc.

Fig. 5 shows a signaling diagram combining the embodiments of fig. 3 and 4 and shows an embodiment in which a PBO event is detected in the serving antenna panel (i.e., the antenna panel used to communicate with the serving cell over the connection). Referring to fig. 5, a terminal device (UE) and an access node 104 establish a Radio Resource Control (RRC) connection in block 500. The terminal device may configure the antenna panel 200 for transmitting and receiving radio signals over the RRC connection (see fig. 2). As a result, access node 104 becomes the serving access node and antenna panel 200 becomes the serving antenna panel, while access nodes 1200 and 122 are non-serving access nodes and antenna panels 202-206 are non-serving antenna panels.

In step 502, data and signaling information is transmitted over the RRC connection. Then, assume that the user brings his/her hand close to the service antenna panel 200. As a result, proximity detection in the terminal device detects the proximity of the hand and triggers a PBO event for the serving antenna panel in the terminal device. Further, depending on the position and proximity measurements of the hand, a PBO event may be triggered for one or more non-serving antenna panels. The terminal device may trigger execution of block 302 as a result of the triggered PBO event (block 506). In an embodiment of block 302, the terminal device measures downlink signals received from the non-serving access node via the non-serving antenna panel (steps 508, 510) and obtains measurement data based on the measurements. For example, the terminal device may establish table 1 below in block 510 based on the measurements performed in block 302.

TABLE 1

Cell identifier	Metrics (RSRP)	Antenna panel identifier	PBO
				122	-	200
122	-80dBm	204	10dB
				122	-	206
122	-90dBm	202	Is free of
				120	-	200
120	-	204
				120	-90dBm	202	Is free of
120	-85dBm	206	Is composed of

The terminal device may perform all measurements indicated in table 1, e.g. attempt to measure all non-serving cells using all non-serving antenna panels. As shown in table 1, only some antenna panels can detect signals from a certain non-serving access node due to the different directivities of the antenna panels. PBO levels may be incorporated only when the corresponding antenna panel is able to detect a non-serving access node. According to the contents of table 1, the terminal device may construct a measurement report and transmit the measurement report to the serving access node in step 512. The measurement report may include, for example, information indicated in table 2 or table 3.

TABLE 2

Cell identifier	Measurement (RSRP)	PBO
			122	-80dBm	10dB
120	-85dBm	0dB

TABLE 3

Cell identifier	Metrics (RSRP)	RSULP
			122	-80dBm	-95dBm
120	-85dBm	-85dBm

Thus, the measurement report may include the cell identifier of the detected non-serving cell, the metric measured from the downlink signal received from the respective non-serving cell, and the PBO metric associated with each non-serving cell. In the embodiment of table 2, the PBO metric is PBO with respect to nominal uplink transmission power of antenna panels capable of communicating with the reported non-serving cell. In the embodiment of table 3, the PBO metric is the absolute uplink transmission power, for example, reported in dBm (decibel per milliwatt). The terminal device may filter the contents of table 1 because in case multiple antenna panels are able to detect a certain non-serving cell, the measurement report only indicates the metric of the non-serving antenna panel that provides the best measurement quality or signal strength. The granularity of the PBO metric may be determined according to the implementation. For example, eight states (three bits) may be sufficient.

The measurement of the PBO metric may be understood as an embodiment of a measurement associated with uplink transmission power in at least one non-serving cell and/or at least one non-serving antenna panel. The terminal device may measure the PBO metric based on the proximity detection and using a mapping table that maps proximity to PBO metric values. The mapping table may include information that enables mapping each of a plurality of proximities or proximity ranges to a certain PBO metric, e.g., degree of PBO in dBm. The mapping table may be specific to each terminal device. For example, different handset models may have different radiation characteristics and therefore different mapping tables and values of the PBO metric for various proximities.

The PBO state may change during the warning or when measurements are performed and reported, as the user may move his/her hand relative to the antenna panel. Thus, the PBO metric may be understood as an estimate of the expected PBO level or target PBO.

As described above, the terminal device can report to the serving access node a metric associated with uplink transmission power of at least one non-serving cell and/or at least one non-serving antenna panel, e.g., a PBO metric associated with MPE limitations resulting from detected proximity of users. And as described above, the terminal device may report the metric together with a measured downlink signal strength indicator (e.g., RSRP) or a measured downlink signal quality indicator (e.g., RSRQ) of the at least one non-serving cell.

In one embodiment, the terminal device also measures a corresponding metric for the serving access node via the serving antenna panel and/or via the non-serving antenna panel. As a result, the measurement report may additionally indicate the PBO metric of the serving antenna panel and the measurement metric of the antenna panel that provides the best connection quality with the serving cell.

After receiving the measurement report in step 512, the serving access node may analyze the measurement report and determine the need for handover. By using the reported PBO metrics, the access node is able to incorporate the PBO metrics into handover decisions and adjust the reported (RSRP, RSRQ, SINR, etc.) metrics by the PBO metrics. Thus, the access node can take into account the effects of PBO and make handover decisions that can reduce the probability of radio link failure. For example, if the measurement report indicates that the connection quality via the serving access node falls below a threshold level when the PBO metric is incorporated, the access node may trigger a handover (block 514) to a non-serving cell unrelated to uplink transmission power reduction, e.g., cell 120 in the case of the measurement report of table 2 or table 3. Accordingly, in block 516, the RRC connection is handed over from the access node 104 to the access node 120. In connection with the handover, the terminal device switches the RRC connection from serving antenna panel 200 to the antenna panel determined in block 518 to provide the best connection quality with access node 120, i.e., antenna panel 206. Thus, access node 120 becomes the serving access node and antenna panel 206 becomes the serving antenna panel.

Steps 504 through 518 may be performed before PBO is actually effected in the antenna panel 200 (block 520). For example, detecting a PBO event 504 may trigger a one-time measurement report that is measured and reported before PBO takes effect. Therefore, the PBO can be prevented from hindering the connection quality. In another embodiment, block 504 may trigger a monitoring interval in which the terminal device operates in a mode in which it periodically measures and transmits measurement reports including PBO metrics. The terminal device may exclude reporting PBO metrics unless operating in a particular mode. As mentioned above, the trigger for the monitoring interval is the detection of the proximity of a user's hand or the like at a first distance relative to the terminal device. The first distance may be greater than a second distance that triggers PBO (block 520). The use of such a warning zone between the first and second distances enables the transmission of multiple measurement reports and the monitoring of the status of the terminal device for handover. The warning zone also provides time for counteracting the effects of PBO and taking appropriate action. The periodicity and parameters included in the measurement report during the warning area may be configured by the serving access node. The length or duration of the warning area depends on various characteristics, such as the mobility of the terminal device, the state of the radio channel, etc.

Fig. 6 illustrates the effect of the embodiment of fig. 5. In fig. 6, the uplink and downlink received signal levels of antenna panel 200 and serving access node 104 are shown by solid lines, the uplink and downlink received signal levels of non-serving antenna panel 204 and non-serving access node 122 are shown by dashed lines, and the uplink and downlink received signal levels of non-serving antenna panel 206 and non-serving access node 120 are shown by dashed-dotted lines. Upon detecting the approach of the hand and as a result performing block 504, the terminal device may start the measurement of block 506. For example, the measurement may be performed upon detection of a hand approaching the terminal device or upon detection of a hand within a certain detection area of the proximity sensor. As shown, PBO in both

antenna panels

200 and 204 will cause the uplink transmit power to drop the received power level at the serving access node (gNB) below the receiver sensitivity level, thereby severely degrading the uplink communication quality and causing possible radio link failure. Without knowing the PBO at antenna panel 204, the access node may trigger a handoff to access node 122 because the reported RSRP is high (see table 1 above), again leading to problems with PBO and radio link failure. However, by incorporating PBO metrics into the measurement report, the access node may scale the RSRP accordingly and detect that the access node 120 associated with no PBO will provide the best connection quality. As a result, handover to an access node providing satisfactory uplink performance can be performed.

In one embodiment, the access node uses the measurement report to prevent handover to a non-serving cell or non-serving antenna panel associated with uplink transmission power reduction. Fig. 7 shows such an embodiment. In fig. 7, the same reference numerals as in fig. 5 denote the same or substantially similar operations or functions. Referring to fig. 7, a terminal device may detect a PBO event in one or more non-serving antenna panels in block 700. The serving antenna panel may also be subject to PBO, or it may not be. Detection of PBO events in the non-serving antenna panel may also trigger measurements and reporting in the same manner as described in connection with fig. 5. Accordingly, the terminal device may perform blocks 506 to 512 and report the measurements in the manner described above. The measurement report may also include the measurements and PBO metrics of the serving antenna panel, or it may not include the measurements and PBO metrics of the serving antenna panel. As described above, the measurement report may be a single PBO event triggered measurement report, or the terminal device may transmit a series of measurement reports during the alert zone.

The access node may use the received measurement report and PBO metrics when making the next handover decision. For example, if the serving antenna panel is not experiencing PBO, the access node may trigger a handover via conventional means, such as when detecting that the downlink connection quality with the terminal device falls below a threshold. In this case, the access node 104 may use the PBO metrics received in step 512 to select a target cell for handover such that the target cell is not associated with PBO (block 704). Accordingly, the access node may avoid a situation where an operational link is replaced by a link subject to PBO. A switch may be made in block 516 and a serving antenna panel selected in block 518 in the manner described above.

Fig. 8 illustrates the effect of the embodiment of fig. 7. It is assumed that the terminal device is moving such that the signal quality towards the serving access node 104 is decreasing and the signal quality towards the

other access nodes

120, 122 is increasing. When a PBO event is detected in non-serving antenna panel 204, the terminal device may trigger the reporting of PBO metrics in a measurement report. When the signal quality of the serving access node falls below a handover threshold level, the serving access node may perform block 704 and perform a handover decision. Without reporting the PBO metric, the access node may select the access node 122 as the target for handover because the reported downlink signal quality is higher. However, this would be a poor decision due to the PBO in the corresponding antenna panel 204, resulting in a possible radio link failure due to poor uplink quality. By incorporating the PBO metric in the measurement report, the access node may consider the PBO metric and select the access node 120 as a handover target in block 704, thereby reducing the probability of radio link failure after handover.

Fig. 9 shows an embodiment of a structure of the above-described functions of an apparatus performing the functions of the network node in the above-described embodiments, for example, the process of fig. 4 or any one of the embodiments thereof. As described above, the apparatus for a network node may be configured to perform a handover decision of a terminal device (e.g. the terminal device 100 described above). In one embodiment, the apparatus may be circuitry or an electronic device implementing some embodiments of the invention in a network node. The means for performing the above functions may thus be comprised in such a device, which may comprise, for example, circuitry for a network node, such as a chip, chipset, processor, microcontroller, or a combination of such circuitry.

Referring to fig. 9, the apparatus may comprise a communication controller 10, the communication controller 10 providing the apparatus with the capability to perform the above-described functions of the network node. In some embodiments, the device may include a radio interface 25 that provides the device with radio communication capabilities, and the communication controller 10 may employ the radio interface 25. The radio interface 25 may enable wireless communication with terminal devices served by the network node. The radio interface 25 may include a number of antennas and associated analog components, such as amplifiers, filters, frequency converters, and analog-to-digital converters, needed to transmit and receive radio signals. Communication controller 10 and/or radio interface 25 may include a radio modem configured to perform transmission and reception of messages in a cellular network. In some embodiments, the radio interface is used for communicating with other network nodes.

In some embodiments, the apparatus comprises a second communication interface 22 configured to provide the apparatus with communication capabilities towards the core network 110. In some embodiments, the communication interface 22 may also be used to communicate with other network nodes via a wired connection. In the context of a 5G network, the communication interface 22 may be configured to communicate over an Xn interface, an F1 interface, and/or an NG interface.

The communication controller 10 may include at least one processor or processing circuitry. The apparatus may further comprise a memory 20, the memory 20 storing one or more computer program products 24, the one or more computer program products 24 configuring the operation of the above-mentioned processor of the apparatus. The memory 20 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 removable memory. The memory 20 may also store a configuration database 26, the configuration database 26 storing the operating configuration of the device. For example, the configuration database 26 may store rules for incorporating the uplink performance of the terminal device into handover decisions in the manner described above.

The communication controller may comprise an RRC controller 12, the RRC controller 12 being configured to establish, operate and terminate an RRC connection between the network node and a terminal device connected to the network node. The communications controller 10 may also include a handover controller 14, the handover controller 14 being configured to make handover decisions (blocks 514 and 704). The handover controller may comprise downlink estimation circuitry 19 and uplink estimation circuitry 17 as sub-circuitry. The downlink estimation circuitry 19 may be configured to process downlink measurement data received from the terminal device for which the handover decision is made. The downlink measurement data may comprise RSRP, RSRQ, SINR or other metrics measured by the terminal device from downlink signals received from neighbouring cells. The uplink estimation circuitry 17 may be configured to process uplink transmission power metrics received from the terminal device, e.g. PBO metrics associated with each neighbouring cell. The handover controller may then select a target cell for handover based on the outputs of the two circuitry 17, 19, e.g. the combined uplink and downlink performance of each neighbouring cell which is a candidate target cell for handover. The handover controller may thus select a target cell for handover that is capable of providing acceptable downlink and uplink performance, e.g. a target cell that is independent of PBO in the terminal device.

Fig. 10 shows an apparatus comprising processing circuitry, such as at least one processor, and at least one memory 40 comprising computer program code (software) 44, wherein the at least one memory and the computer program code (software) are configured to, with the at least one processor, cause the apparatus to perform the process of fig. 3 or any of its embodiments described above for the terminal device. The apparatus may be for a terminal device. The apparatus may be circuitry or an electronic device implementing some embodiments of the invention in a terminal device. The means for performing the above functions may thus be comprised in such a device, which may comprise circuitry for a terminal device, such as a chip, a chipset, a processor, a microcontroller, or a combination of such circuitry, for example. The processing circuitry may implement a communication controller 30 that controls communications with the cellular network infrastructure in the manner described above. The communication controller may be configured to establish and manage RRC connections and data transmissions over the RRC connections.

The communication controller may include a proximity detection module 39, which proximity detection module 39 is configured to perform proximity measurements during operation of the terminal device in the manner described above and to detect the proximity of an object triggering a PBO event based on the measurements. Depending on the embodiment, the trigger may be in response to detection of proximity in the serving antenna panel and/or the non-serving antenna panel. Upon triggering the PBO event, the proximity detection module may cause the neighbor cell measurement circuitry 37 to perform additional neighbor cell measurements for handover of the terminal device. The neighbor cell measurement circuitry 37 may then measure the downlink signals received from the neighbor cells detected by the antenna panel and generate the above-described measurement reports including neighbor cell measurement data. As described above, the neighbor cell measurement circuitry may include the PBO metric for each reported non-serving cell in a measurement report. As described above, the PBO metric may indicate PBO of an antenna module capable of detecting a non-serving cell.

The PBO event may also cause the proximity detection module 39 to have the PBO controller 38 control the PBO of the uplink transmission power in the terminal device. The proximity detection module or PBO controller may insert a delay to enable PBO so that the neighbor cell measurement circuitry 37 has time to make and report measurements and the serving access node has time to react to a detected PBO event by issuing a handover to the terminal device. The PBO controller may output PBO commands to the antenna panel controller 35 to control the selection and configuration of one or more serving antenna panels. The antenna panel controller 35 may then reduce the transmission power of the serving antenna panel associated with the PBO event.

Referring to fig. 9, the memory 40 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 removable memory. The memory 40 may include a configuration database 46 for storing configuration parameters, such as characteristics of the warning areas, types of measurements to be made and reported in relation to the PBO event, and the like. The memory 40 may also store the mapping table or mapping database 48 described above, which mapping table or mapping database 48 defines the PBO metrics for various proximity or proximity ranges.

The apparatus may also include a communication interface 42, the communication interface 42 including hardware and/or software for providing the apparatus with radio communication capabilities with one or more access nodes, as described above. The communication interface 42 may comprise the hardware and software required to enable radio communication over a radio interface (e.g. in accordance with the specifications of the LTE or 5G radio interface).

The apparatus may also include an application processor 32, the application processor 32 executing one or more computer program applications that generate a need to transmit and/or receive data through the communication controller 30. The application processor may form an application layer of the device. The application processor may execute a computer program forming the main function of the apparatus. For example, if the apparatus is a sensor device, the application processor may execute one or more signal processing applications to process measurement data acquired from one or more sensor heads. If the device is a computer system of a vehicle, the application processor may execute a media application and/or an autonomous driving and navigation application. The application processor may generate data to be transmitted in the wireless network.

As used in this application, the term "circuitry" refers to one or more of the following: (a) Hardware-only circuit implementations, such as implementations using only analog and/or digital circuitry, (b) combinations of circuits and software and/or firmware, such as (as applicable): (i) A combination of a processor or processor core, or (ii) a processor/software (including a digital signal processor), software, and at least one portion of memory that cooperate to cause a device to perform a particular function, and (c) circuitry that requires software or firmware for operation (even if such software or firmware is not physically present), such as a microprocessor or a portion of a microprocessor.

This definition of "circuitry" applies to the use of that term in this application. As a further example, as used in this application, the term "circuitry" would also encompass an implementation of only a processor (or multiple processors) or portion of a processor (e.g., one core of a multi-core processor) and its (or their) accompanying software and/or firmware. The term "circuitry" would also cover, according to one embodiment of the present invention, baseband integrated circuits, application Specific Integrated Circuits (ASICs), and/or Field Programmable Grid Array (FPGA) circuits for the apparatus (e.g., if applicable to the particular element). The processes or methods described in fig. 3-4 or any embodiment thereof may also be performed in the form of one or more computer processes defined by one or more computer programs. Separate computer programs may be provided in one or more devices that perform the functions of the processes described in connection with the figures. The computer program may be in source code form, object code form, or in some intermediate form, and may be stored in some sort of carrier, which may be any entity or device capable of carrying the program. Such carriers include transitory and/or non-transitory computer media, e.g., recording media, computer memory, read-only memory, electrical carrier signals, telecommunications signals, and software distribution packages. Depending on the required processing power, the computer program may be executed in a single electronic digital processing unit or may be distributed over several processing units.

The embodiments described herein are applicable to the wireless network defined above, but also to other wireless networks. The protocols used, the specifications of the wireless networks and their network elements develop rapidly. Such development may require additional changes to the described embodiments. Accordingly, all words and expressions should be interpreted broadly and they are intended to illustrate, not to limit, the embodiments. It is clear to a person skilled in the art that with the advancement of technology, the inventive concept may be implemented in various ways. The embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. An apparatus for a terminal device, comprising means for:

detecting a need for uplink transmission power reduction in an antenna panel of the terminal device;

in response to the detection, performing at least one measurement associated with: at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device; and

reporting the at least one measurement and/or the need for uplink transmission power reduction to an access node of a serving cell.

2. The apparatus of claim 1, wherein the means is configured to: detecting the need for the uplink transmission power reduction in a serving antenna panel of the terminal device.

3. The apparatus according to claim 1 or 2, wherein the at least one measurement comprises a measurement of at least one of: a signal strength or a signal quality of a downlink signal received from the at least one non-serving cell.

4. The apparatus according to any preceding claim, wherein the at least one measurement comprises a measurement associated with uplink transmission power in the at least one non-serving cell and/or the at least one non-serving antenna panel.

5. The apparatus according to any preceding claim, wherein the uplink power reduction comprises a power backoff caused by a maximum allowed exposure limit.

6. The apparatus of any preceding claim, wherein the means is further configured to: reporting, to the access node of the serving cell, a metric associated with uplink transmission power of the at least one non-serving cell and/or the at least one non-serving antenna panel.

7. The apparatus of claim 6, wherein the metric indicates a power backoff associated with the maximum allowed exposure limit for the non-serving cell and/or the non-serving antenna panel.

8. The apparatus of claim 6 or 7, wherein the means is configured to: reporting the metric with a measured downlink signal strength indicator or a measured downlink signal quality indicator of the at least one non-serving cell.

9. The apparatus of any preceding claim, wherein the means is configured to: performing the at least one measurement and reporting the at least one measurement prior to the uplink transmission power reduction.

10. An apparatus for an access node, comprising means for:

receiving a measurement report from a terminal device connected to the access node, the measurement report comprising measurement data relating to at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device, the measurement report further comprising an indication of a need for uplink transmission power reduction in the terminal device; and

performing a handover decision for the terminal device based on the measurement data and the indication.

11. The apparatus of claim 10, wherein the measurement data is indicative of a signal strength or a signal quality of a downlink signal received by the terminal device from the at least one non-serving cell.

12. The apparatus according to claim 10 or 11, wherein the indication comprises at least one information element indicating an uplink transmission power of the terminal device in the at least one non-serving cell and/or in the at least one non-serving antenna panel.

13. The apparatus according to any of the preceding claims 10 to 12, wherein the uplink power reduction comprises a power backoff caused by a maximum allowed exposure limit.

14. The apparatus according to claim 13 when dependent on claim 12, wherein the at least one information element indicates a power backoff associated with the maximum allowed exposure limit for the non-serving cell and/or the non-serving antenna panel.

15. The apparatus of any preceding claim 10 to 14, wherein the means is configured to: preventing a handover to a non-serving cell or a non-serving antenna panel associated with the uplink transmission power reduction.

16. The apparatus of any preceding claim 10 to 15, wherein the means is configured to: switching the terminal device to a non-serving cell or a non-serving antenna panel independent of the uplink transmission power reduction.

17. An apparatus as claimed in any preceding claim, wherein the means comprises at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the execution of the apparatus.

18. A method, comprising:

detecting, by the terminal device, a need for uplink transmission power reduction in an antenna panel of the terminal device;

reporting, by the terminal device, the at least one measurement and/or the need for uplink transmission power reduction to an access node of a serving cell.

19. The method of claim 18, wherein the terminal device detects the need for the uplink transmission power reduction in a serving antenna panel of the terminal device.

20. The apparatus according to claim 18 or 19, wherein the at least one measurement comprises a measurement of at least one of: a signal strength or a signal quality of a downlink signal received from the at least one non-serving cell.

21. The method according to any of the preceding claims 18 to 20, wherein the at least one measurement comprises a measurement associated with uplink transmission power in the at least one non-serving cell and/or the at least one non-serving antenna panel.

22. The method according to any of the preceding claims 18 to 21, wherein the uplink power reduction comprises a power backoff caused by a maximum allowed exposure limit.

23. The method according to any of the preceding claims 18 to 22, wherein the terminal device reports to the access node of the serving cell a metric associated with uplink transmission power of the at least one non-serving cell and/or the at least one non-serving antenna panel.

24. The method of claim 23, wherein the metric indicates a power backoff associated with the maximum allowed exposure limit for the non-serving cell and/or the non-serving antenna panel.

25. The method according to claim 23 or 24, wherein the terminal device reports the metric together with a measured downlink signal strength indicator or a measured downlink signal quality indicator of the at least one non-serving cell.

26. The method according to any of the preceding claims 18 to 25, wherein the terminal device performs the at least one measurement and reports the at least one measurement before the uplink transmission power is reduced.

27. A method, comprising:

receiving, by an access node, a measurement report from a terminal device connected to the access node, the measurement report comprising measurement data relating to at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device, the measurement report further comprising an indication of a need for uplink transmission power reduction in the terminal device; and

performing, by the access node, a handover decision for the terminal device based on the measurement data and the indication.

28. The method of claim 27, wherein the measurement data indicates a signal strength or a signal quality of a downlink signal received by the terminal device from the at least one non-serving cell.

29. The method according to claim 27 or 28, wherein the indication comprises at least one information element indicating an uplink transmission power of the terminal device in the at least one non-serving cell and/or in the at least one non-serving antenna panel.

30. The method according to any of the preceding claims 27 to 29, wherein the uplink power reduction comprises a power backoff caused by a maximum allowed exposure limit.

31. The method according to claim 30 as dependent on claim 29, wherein the at least one information element indicates a power backoff associated with the maximum allowed exposure limit of the non-serving cell and/or the non-serving antenna panel.

32. The method of any preceding claim 27 to 31, wherein the access node prevents handover to a non-serving cell or a non-serving antenna panel associated with the uplink transmission power reduction.

33. The method of any preceding claim 27 to 32, wherein the access node switches the terminal device to a non-serving cell or a non-serving antenna panel independent of the uplink transmission power reduction.

34. A computer program product embodied on a computer readable medium and comprising computer program code readable by a computer, wherein the computer program code configures the computer to perform a computer process comprising:

detecting, in a terminal device, a need for uplink transmission power reduction in an antenna panel of the terminal device;

35. A computer program product embodied on a computer readable medium and comprising computer program code readable by a computer, wherein the computer program code configures the computer to perform a computer process comprising:

receiving, in an access node, a measurement report from a terminal device connected to the access node, the measurement report comprising measurement data relating to at least one non-serving cell of the terminal device and/or at least one non-serving antenna panel of the terminal device, the measurement report further comprising an indication of a need for uplink transmission power reduction in the terminal device; and