Patent Description:
Wireless devices within a wireless communications network may be e.g., stations (STAs), User Equipments (UEs), mobile terminals, wireless terminals, terminals, and/or Mobile Stations (MS). Wireless devices are enabled to communicate wirelessly in a cellular communications network or wireless communication network, sometimes also referred to as a cellular radio system, cellular system, or cellular network. The communication may be performed e.g. between two wireless devices, between a wireless device and a regular telephone, and/or between a wireless device and a server via a Radio Access Network (RAN) , and possibly one or more core networks, comprised within the wireless communications network. Wireless devices may further be referred to as mobile telephones, cellular telephones, laptops, or tablets with wireless capability, just to mention some further examples. The wireless devices in the present context may be, for example, portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile devices, enabled to communicate voice and/or data, via the RAN, with another entity, such as another terminal or a server.

The wireless communications network covers a geographical area which may be divided into cell areas, each cell area being served by a network node or Transmission Point (TP), for example, an access node such as a Base Station (BS), e.g. a Radio Base Station (RBS), which sometimes may be referred to as e.g., evolved Node B ("eNB"), "eNodeB", "NodeB", "B node", or BTS (Base Transceiver Station), depending on the technology and terminology used. The base stations may be of different classes such as e.g. Wide Area Base Stations, Medium Range Base Stations, Local Area Base Stations and Home Base Stations, based on transmission power and thereby also cell size. A cell is the geographical area where radio coverage is provided by the base station at a base station site. One base station, situated on the base station site, may serve one or several cells. Further, each base station may support one or several communication technologies. The wireless communications network may also be a non-cellular system, comprising network nodes which may serve receiving nodes, such as wireless devices, with serving beams.

In the context of this disclosure, the expression Downlink (DL) is used for the transmission path from the base station to the wireless device. The expression Uplink (UL) is used for the transmission path in the opposite direction i.e., from the wireless device to the base station.

The standardization organization 3GPP is currently in the process of specifying a New Radio Interface called NR or <NUM>-UTRA, as well as a Fifth Generation (<NUM>) Packet Core Network, which may be referred to as Next Generation Core Network, abbreviated as NG-CN, NGC or <NUM> CN. The current understanding of various concepts related to this work may be based on input from 3GPP TS <NUM> v1.

The <NUM> RAN may comprise base stations supporting evolved LTE and/or New Radio (NR) radio access. In <NUM> RAN, base stations, which may be referred to as eNodeBs or even eNBs, may be directly connected to one or more core networks. In the context of this disclosure, the expression Downlink (DL) may be used for the transmission path from the base station to the wireless device. The expression Uplink (UL) may be used for the transmission path in the opposite direction i.e., from the wireless device to the base station.

With introduction of the <NUM> technology, gigabit over-the-air mobile systems may most likely emerge. One foreseen application of the emerging <NUM> access is to substitute content, e.g., TV content, distribution over wireline accesses with wireless accesses. In that context, the radio connection may be represented by a non-mobility fixed point-to-point connection. Such connections may often be manifested by some sort of Fixed Wireless Terminals (FWT). FWT may be understood as wireless devices as described above, but they are limited to an almost permanent location with almost no roaming abilities. FWT are considered being substitutions for 'Fiber To The Home' (FTTH), a. "Fiber To The Premises" (FTTP). FTTH may be understood as a form of fiber-optic communication delivery, in which an optical fiber is run in an optical distribution network from the central office all the way to living space or a home. In everyday speech, this emerging trend is often described as deployment of "wireless fiber".

In foreseen installations, preferred deployments to achieve sufficiently high end user performance may likely strive to maintain Line-of-Sight (LoS) between as many Customer-Premises Equipment (CPE) and Transmission Points (TPs) as possible. Typical mounting points of TPs may be at different kinds of poles in the area; for example light poles, utility pole sites, or re-using current, if any, macro cellular grid. CPEs are potentially either installed at roof-tops, being wall-mounted, outdoors, or user-deployed in some suitable indoor placement, i.e., behind some, preferably, TP-facing window. Other solutions described may be indoor customer-deployed CPEs.

United States Patent Publication Number <CIT> discloses a system to detect a physical deformation of a pole. <CIT> discloses a method and arrangements for scheduling transmissions resources with variable guard intervals by a base station in a wireless communication network. The method performed by the base station obtains a parameter referring to an expected transmission quality of the communication and/or expected coherence properties of the communication channel. Based on the obtained parameter and how the truncation impacts on the performance loss of the transmission, the transmission on an uplink or downlink resource is scheduled. The parameters referred above are either coherence time, coherence bandwidth, or Signal-to-Noise Ratio, or related parameters such as mobile speed, Doppler spread, delay spread, or path-loss, or a combination thereof. <CIT> discloses a method for determining a range rate for at least one terrestrial transmitter having a fixed location. <CIT> discloses a system that measures reference transmissions in order to detect high wind weather events, such as tornados, based on the relative Doppler shift in the measured signals.

<NPL> investigates the Doppler spectrum of echoes from a sinusoidally vibrating scatterer in order to determine the amplitude of vibration.

Related to the physical installation on site, wind load may induce harmonic oscillations to "tall" vertical structures, such as radio antennas, or the pole structures they may be installed in, and depending on the inherited physical dimensions of the construction, said vibrations may become differently large. In classical mechanics, a harmonic oscillator may be understood as a system that when displaced from its equilibrium position, experiences a restoring force proportional to the corresponding displacement, resulting in so-called harmonic oscillations. The system may oscillate as it undergoes harmonic motion, typically in terms of, e.g., sinusoidal oscillations about the equilibrium point with a constant amplitude and a constant frequency. The harmonic oscillator may be damped if a frictional force proportional to the velocity is also present, the harmonic oscillator. Resonance may be understood as the tendency of a mechanical system to respond at greater amplitude when the frequency of its oscillations matches the natural frequency of vibration of the system, that is, its resonance frequency, i.e. harmonic oscillations, than it does at other frequencies. It may cause violent swaying motions and even catastrophic failure in improperly constructed structures including bridges, buildings, etc..

With certain circumstances fulfilled, wind speeds of <NUM>-<NUM> meters per second (m/s) may be enough to bring poles structures into significant vibrations, such as described in in "<NPL>, "<NPL>, "<NPL>, "<NPL>, "<NPL>, and "<NPL>.

Typical assessments of oscillations of pole structures or radio antennas, show on oscillations frequencies in the range of <NUM> Hertz (Hz) for a first mode of vibration, <NUM>-<NUM> for a second mode, and up to <NUM> for e.g. a sixth mode. A mode may be understood as a standing wave state of excitation. A mode of vibration may be characterized by a modal frequency and a mode shape. <FIG> is a schematic representation illustrating mode shape for six lowest natural frequencies, with a lowest mode shown on the left, and the sixth mode to the right. Mode shape may be understood as the envelope of the vibrational dislocation; typically the maximum/minimum point of the vibrational movement. <FIG> typically illustrates these "envelopes" of the vibrational dislocation for each of the resonance states of the vibration. Resonance may be interpreted as when a vibrating system drives another system to oscillate with greater amplitude at a specific preferential frequency. Natural frequencies may be understood as resonance frequencies. The arrows in <FIG> illustrate that an antenna mounted at a certain location along a pole will somehow be dislocated when pole starts to vibrate. In <FIG>, the dashed line illustrates intended antenna direction. Misdirected directions are exemplified by arrows.

The modes of vibration above the lowest one may be considered as having critical impact on structure integrity.

In practice, induced harmonic oscillation may cause material fatigue, which if omitted may cause failure and costly site rebuilds.

Further, embodiments of the invention are defined by the claims. Moreover, examples, embodiments and descriptions, which are not covered by the claims are presented not as embodiments of the invention, but as background art or examples useful for understanding the invention. It is an object of the embodiments herein to improve the maintenance of mechanical structures in a wireless communications network. It is a particular object of the embodiments herein to improve the management of a movement of a radio antenna in a wireless communications network.

According to a first aspect of embodiments herein, the object is achieved by a method performed by a first node. The method is for managing a movement of a radio antenna. The first node operates in a wireless communications network. The first node obtains a first estimation of the movement of the radio antenna. The movement is associated with a displacement of the radio antenna in two or three dimensions. The radio antenna is connected to a second node operating in the wireless communications network. The movement is with respect to at least one wireless device operating in the wireless communications network. The first node determines whether the movement of the radio antenna is above a threshold over a time period, based on the obtained first estimation. The determining is based on an analysis of one or more properties of radio transmissions to or from the radio antenna over the time period. The first node initiates providing a message comprising at least an instruction to perform an action that contributes to counteracting harmful effects of for the movement to the second node operating in the wireless communications network. The initiation of the providing of the message is based on a result of the determination.

According to a third aspect of embodiments herein, the object is achieved by a first node configured for managing the movement of the radio antenna. The first node is configured to operate in the wireless communications network. The first node is configured to obtain a first estimation of the movement of the radio antenna. The movement is associated with a displacement of the radio antenna in two or three dimensions. The radio antenna is configured to be connected to the second node configured to operate in the wireless communications network. The movement is with respect to the at least one wireless device configured to operate in the wireless communications network. The first node is further configured to determine whether the movement of the radio antenna is above the threshold over the time period, based on the obtained first estimation. To determine is configured to be based on the analysis of the one or more properties of the radio transmissions to or from the radio antenna over the time period. The first node is further configured to initiate providing the message comprising at least an instruction to perform an action that contributes to counteracting harmful effects of for the movement to the second node configured to operate in the wireless communications network. The initiation of the providing of the message is configured to be based on the result of the determination.

According to a fifth aspect of embodiments herein, the object is achieved by a computer program. The computer program comprises instructions which, when executed on at least one processor, cause the at least one processor to carry out the method performed by the first node.

According to a sixth aspect of embodiments herein, the object is achieved by a computer-readable storage medium. The computer-readable storage medium has stored thereon a computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method performed by the first node. By determining whether the movement of the radio antenna is above the threshold over the time period based on the analysis of the one or more properties of the radio transmissions to or from the radio antenna, and initiating providing the message to the second node or third node, the first node is enabled to manage the movement of the radio antenna by monitoring it, and notifying another node, such as the third node, thereby enabling the performance of an action to remedy the movement. That is, any harmful effect the movement may have or may be expected to have on the radio antenna and any associated equipment. This may be performed by the radio node, without requiring dedicated equipment, such as accelerometers, strain gauges, etc.. Hence, the managing of the movement may be performed with lower cost, complexity and involving fewer experts specialized personnel than existing methods.

Examples of embodiments herein are described in more detail with reference to the accompanying drawings, and according to the following description.

As part of the development of the embodiments disclosed herein, a problem associated with existing methods will first be identified and discussed.

As described in the background section, oscillations, e.g., harmonic oscillations induced by the wind may cause torsional and transversal oscillation modes, that is, twisting and shivering modes, into a pole structure, or a radio antenna.

Efficient load, e.g. wind load, and/or oscillation cycle monitoring that may trigger preemptive site pole maintenance is advantageous in terms of preventing total structural failure caused by material fatigue. Existing methods in maintenance of mechanical structures require that structural vibrations are detected and monitored with dedicated equipment, such as accelerometers, strain gauges, etc., which in turn are connected, in some wired or wireless manner, to their own dedicated infrastructure. Given that accelerometers, and/or other dedicated equipment require some dedicated infrastructure, such dedicated equipment has a high cost the cost and requires maintenance all by itself. Moreover sensor, infrastructure operations, which may also be required, add to the cost. This may result in that pole owners may prone to turn down such investments, and that a pole may likely lack any structural monitoring. Structural damages caused by e.g., wind oscillations will, however, represent an even larger cost to its operator.

Embodiments herein address the foregoing problems of the existing methods by enabling to obtain similar vibrational information of mechanical structures such as a radio antenna, from equipment installed for other purposes, for example using radio properties of installed radio equipment, such as, for example, <NUM> equipment. In general, embodiments herein may be understood to relate to a method for identifying harmful oscillations in a mechanical structure. The identification of the harmful oscillations may be performed by detection of oscillation, such as harmonic oscillation, of the mechanical structure, e.g., radio antenna, or a radio antenna. As a summarized overview, embodiments herein may be understood to relate to a method to use information derived from a Doppler spectrum to identify and classify structural vibrations e.g., in radio towers. Embodiments herein may be understood to further relate to a method to use said information to monitor or predict structural damage to the radio towers, local wind conditions, or seismic activity.

Embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which examples are shown. In this section, the embodiments herein will be illustrated in more detail by a number of exemplary embodiments. It should be noted that the exemplary embodiments herein are not mutually exclusive. Components from one embodiment may be tacitly assumed to be present in another embodiment and it will be obvious to a person skilled in the art how those components may be used in the other exemplary embodiments.

<FIG> depicts two non-limiting examples, in panels a and b respectively, of a wireless communications network <NUM>, sometimes also referred to as a radio system, radio network or wireless communications system, in which embodiments herein may be implemented. The wireless communications network <NUM> may for example be a network such as a Long-Term Evolution (LTE), e.g. LTE Frequency Division Duplex (FDD), LTE Time Division Duplex (TDD), LTE Half-Duplex Frequency Division Duplex (HD-FDD), LTE operating in an unlicensed band, Wideband Code Division Multiple Access (WCDMA), Universal Terrestrial Radio Access (UTRA) TDD, Global System for Mobile communications (GSM) network, GSM/Enhanced Data Rate for GSM Evolution (EDGE) Radio Access Network (GERAN) network, EDGE network, network comprising of any combination of Radio Access Technologies (RATs) such as e.g. Multi-Standard Radio (MSR) base stations, multi-RAT base stations etc., any 3rd Generation Partnership Project (3GPP) cellular network, WiFi network, Worldwide Interoperability for Microwave Access (WiMax), 3GPP New Radio (NR) or another <NUM> system or any cellular network or system. Thus, although terminology from LTE may be used in this disclosure to exemplify embodiments herein, this should not be seen as limiting the scope of the embodiments herein to only the aforementioned system. Other wireless systems may also benefit from exploiting the ideas covered within this disclosure. It may also be understood that the wireless communication network <NUM> may operate in one or more of licensed, license assisted, and unlicensed spectrum.

The wireless communications network <NUM> comprises a plurality of nodes whereof a first node <NUM>, a second node <NUM>, and a third node <NUM> are depicted in both examples of <FIG>. Each of the first node <NUM> and the third node <NUM> may be a network node such as the network node <NUM> described below. The second node <NUM> is a network node <NUM> as described below, and has a radio antenna <NUM> connected to it, which may be a single array or a multi-array antenna. That the radio antenna <NUM> is connected to the second node <NUM> may be understood that they are arranged for communicating with each other. In some particular examples, in fact the typical examples, the radio antenna <NUM> and the second node <NUM> may be physically co-located or attached as part of a same physical structure, e.g., as part of a same base station.

Typically, as depicted in panel a) of <FIG>, the first node <NUM> may be the same network node as the second node <NUM>.

In some alternative examples, such as that depicted in panel b) of <FIG>, the first node <NUM> may be another node in the wireless communications network <NUM>, for example, a node in the cloud <NUM>. That is, a so-called virtual node or virtual machine. In yet other examples, the first node <NUM> may be, e.g., a core network node, such as, e.g., Mobility Management Entity (MME), Self-Optimizing/Organizing Network (SON) node, a coordinating node, positioning node, Minimization of Drive Test (MDT) node, etc.. or a different logical entity than the second node <NUM>.

The third node <NUM> may be, in some examples, a wireless device, such as the wireless device <NUM> described below, or a communication device that is enabled to operate in the wireless communications network <NUM> via a wired connection. For example, the third node <NUM>, as depicted in <FIG>, may be a desktop.

The wireless communications network <NUM> comprises a plurality of network nodes whereof a network node <NUM> is depicted in <FIG>. In some embodiments, the network node <NUM> may be a radio network node such as e.g., a Transmission Point, a base station, an eNB, eNodeB, or a Home Node B, a Home eNodeB, femto Base Station, BS, Radio Access Point, Remote Radio Unit (RRU), Remote Radio Head (RRH), or any other network unit capable to serve a wireless device or a machine type node in the wireless communications network <NUM>. In such embodiments, the network node <NUM> may be e.g., a Wide Area Base Station, Medium Range Base Station, Local Area Base Station and Home Base Station, based on transmission power and thereby also coverage size. The network node <NUM> may be a stationary relay node or a mobile relay node. The network node <NUM> may support one or several communication technologies, and its name may depend on the technology and terminology used. In some non-limiting examples, the network node <NUM> may serve receiving nodes with serving beam-formed beams, which may also be referred to herein simply as beams. In some embodiments, the network node <NUM> may correspond to any type of radio network node or any network node, which communicates with another radio network node or wireless device.

In 3GPP LTE and <NUM> RAN, any of the first node <NUM>, the second node <NUM> and the third node <NUM> may be directly connected to one or more networks.

The wireless communications network <NUM> comprises at least one wireless device <NUM>. In the example scenario of <FIG>, only the one wireless device <NUM> is shown to simplify the Figure. The one wireless device <NUM> may also be referred to herein as the wireless device <NUM>. The wireless device <NUM>, such as a UE, may be also known as e.g. mobile terminal, wireless terminal and/or mobile station, mobile telephone, cellular telephone, or laptop with wireless capability, or a CPE, just to mention some further examples. The wireless device in the present context may be, for example, portable, pocket-storable, hand-held, computer-comprised, or a vehicle-mounted mobile device, enabled to communicate voice and/or data, via a RAN, with another entity, such as a server, a laptop, a Personal Digital Assistant (PDA), or a tablet computer, sometimes referred to as a tablet with wireless capability, or simply tablet, a Machine-to-Machine (M2M) device, a device equipped with a wireless interface, such as a printer or a file storage device, modem, Laptop Embedded Equipped (LEE), Laptop Mounted Equipment (LME), USB dongles, CPE or any other radio network unit capable of communicating over a radio link in the wireless communications network <NUM>. The wireless device <NUM> may be wireless, i.e., it may be enabled to communicate wirelessly in the wireless communication network <NUM> and, in some particular examples, may be able support beamforming transmission. The communication may be performed e.g., between two devices, between a device and a network node, and/or between a device and a server. The communication may be performed e.g., via a RAN and possibly one or more core networks, comprised within the wireless communications network <NUM>. In a typical scenario, the second node <NUM> may be a transmission point serving the wireless device <NUM>, as depicted in both examples of <FIG>.

The second node <NUM> may communicate with the wireless device <NUM> over a first link <NUM>, e.g., a radio link. The first node <NUM> may communicate with the third node <NUM> over a second link <NUM>, e.g., a radio link or a wired link. The first node <NUM> may communicate with the second node <NUM> over a third link <NUM>, e.g., a radio link or a wired link, e.g., in examples where they are co-located. The first node <NUM> may communicate with the wireless device <NUM> over a fourth link <NUM>, e.g., a radio link.

Any reference herein to the terms "first", "second", "third" or "fourth" will be understood to refer a manner of distinguishing between different instances of the terms they may modify. "First", "second", "third" or "fourth" are not intended to confer a cumulative or chronological meaning to the terms they modify.

Embodiments of a method performed by a first node <NUM>, the method being for managing a movement of the radio antenna <NUM>, will now be described with reference to the flowchart depicted depicted in <FIG>. The first node <NUM> operates in the wireless communications network <NUM>.

The method may comprise the actions described below. In some embodiments all the actions may be performed. In some embodiments, one or more actions may be performed. The order in which the actions are performed may be different than that depicted in <FIG>. One or more embodiments may be combined, where applicable. All possible combinations are not described to simplify the description. In <FIG>, optional actions are indicated with dashed lines.

Embodiments herein may be understood to aim at identifying oscillations, e.g., harmonic oscillations, of the mechanical structure, e.g., radio antenna, or a radio antenna. in a vertical structure, such as a pole structure or the radio antenna <NUM>, which may be harmful for the physical integrity of the mechanical structure.

In order to eventually detect if there are such oscillations, and if they are harmful, in this Action <NUM>, the first node <NUM> may obtain a first estimation. The first estimation is of the movement of the radio antenna <NUM>. Obtaining may be understood as determining or calculating itself, or receiving or fetching from another node in the wireless communications network <NUM>.

The movement of the radio antenna <NUM> may be understood as a displacement in two or three dimensions of the radio antenna <NUM>. The movement may be caused by a wind <NUM> or a seismic activity exerting a force on the radio antenna <NUM>.

The movement may be detected or measured herein based on an analysis of one or more properties of radio transmissions to or from the radio antenna <NUM> over a time period. The radio transmissions may comprise reference signals. That the radio transmissions are to or from the radio antenna <NUM> may be understood as that the radio transmissions may be one of: a) transmitted by the second node <NUM> and measured by the at least one wireless device <NUM>; and b) transmitted by the at least one wireless device <NUM> and measured by the second node <NUM>. In examples wherein the radio transmissions are transmitted by the second node <NUM>, the radio transmissions may be e.g., Cell Specific Reference Signal (CRS), or Demodulation Reference Signals (DMRS). In examples wherein the radio transmissions are transmitted by the at least one wireless device <NUM>, the radio transmissions may be e.g., Sounding Reference Signals (SRS).

In accordance with this, the movement of the radio antenna <NUM> may be understood herein to be with respect to the at least one wireless device <NUM> operating in the wireless communications network <NUM>. In some examples, the movement may be with respect to a plurality of wireless devices such as the at least one wireless device <NUM>. For example, the plurality of wireless devices may served by the second node <NUM>. The at least one wireless device <NUM> may be assumed to be static, or moving, but that its movement is unchanging, e.g., moving at a constant speed, not oscillating or changing its movement frequently. In the examples wherein the at least one wireless device <NUM> comprises a plurality of wireless devices, any oscillation on the individual wireless devices may be assumed to be evened out among the plurality.

The one or more properties of radio transmissions may comprise, for example, phase of a transmission channel, and additionally an amplitude of the transmission channel. In some embodiments, the analysis may be based on: a) obtained measurements of at least a phase of the radio transmissions over the time period; b) a division of the obtained measurements in subsets of periods of time comprised in the time period; and c) a Fourier transform over each of the subsets of periods of time. The obtaining of the first estimation in this Action <NUM> may then be further based on a set of Doppler spectrum values obtained from the Fourier transform over each of the subsets of periods of time. This process is schematically represented In <FIG>, which is described later.

According to the foregoing, in some embodiments, the analysis may be a Doppler spectrum analysis. The first estimation may be based on at least one of: i) calculating a frequency of the movement of the radio antenna <NUM>, based on time variations of the set of Doppler spectrum values, and ii) calculating an amplitude of the movement of the radio antenna <NUM>, based on the values in set of Doppler spectrum values. For example, the amplitude of the movement of the radio antenna <NUM> may be calculated based on the integral of the values in the set of Doppler spectrum values. The analysis may be then based on a detection of a time-harmonic variation of the set of Doppler spectrum values. For example, this may be performed in relation to the oscillations depicted in <FIG>.

For calculating the frequency of the movement of the radio antenna <NUM>, based on time variations of the set of Doppler spectrum values, the Doppler value for each subset of time may represent a velocity of the radio antenna <NUM> at that moment in time. By integrating the set of velocities, the position variations may be obtained and hence, e.g., the amplitude.

In some examples, the analysis may be entirely performed by the first node <NUM>. In other words, the first node <NUM> may first, measure an amplitude and a phase of a transmission channel, e.g., the first link <NUM>, between the second node <NUM> and the at least one wireless device <NUM>, repeatedly over time. The first node <NUM> may then divide the resulting measurement data in into certain groups of time, for example, groups covering short periods of time. Next, the first node <NUM> may perform a Fourier transform over the time domain for each group to produce the set of Doppler spectrum values. The first node <NUM> may then detect time-harmonic variation in the achieved Doppler spectrum, that is, the set of Doppler spectrum values.

The first node <NUM> may then obtain itself, or from another node in the wireless communications network <NUM>, at least one of: a) a calculation of a first measure of a corresponding frequency of the movement or oscillations of the radio antenna <NUM> by analyzing time variations of the set of Doppler spectrum values, and b) a calculation of a second measure of a corresponding amplitude of the movement of the radio antenna <NUM> from the set of Doppler spectrum values.

In other examples, one or more of the steps of the analysis, e.g., any of the measurements, the division and the Fourier transform may be performed by another node or nodes, in the wireless communications network <NUM>, e.g., by the second node <NUM> or, and then obtained or received by the first node <NUM>. This may be the case for example, in examples wherein the first node <NUM> and the second node <NUM> are different nodes. Accordingly this Action <NUM> is option.

In order to detect if the oscillations of the radio antenna <NUM> are harmful, in this Action <NUM>, the first node <NUM> determines whether the movement of the radio antenna <NUM> is above a threshold over the time period. Determining may be understood as calculating. As described earlier, the radio antenna <NUM> is connected to the second node <NUM> operating in the wireless communications network <NUM>. The movement is with respect to the at least one wireless device <NUM>, operating in the wireless communications network <NUM>. The determining is based on the analysis of the one or more properties of the radio transmissions to or from the radio antenna <NUM> over the time period. The analysis may be understood to be obtained by the first node <NUM>. In some examples, the analysis may be understood to be obtained by the first node <NUM>, autonomously, as described in Action <NUM>. In other examples, the analysis may be performed as described in Action <NUM>, but by another node or nodes in the wireless communications network <NUM>. The analysis may then be obtained by the first node <NUM> by receiving or fetching it.

In some examples, the determining in this Action <NUM> may be based on the first estimation of the movement of the radio antenna <NUM>, obtained as described in Action <NUM>. In other examples, the determining may be based on a similar first estimation, obtained by another node or nodes in the wireless communications network <NUM>, and then obtained, that is, received or fetched, by the first node <NUM>.

In some embodiments, the determination in this Action <NUM> may be further based on a detection of a time-harmonic variation of the set of Doppler spectrum values. In some embodiments, the determining <NUM> may be further based on the set of Doppler spectrum values obtained from the Fourier transform over each of the subsets of periods of time, as described in Action <NUM>.

The threshold may be different for different criteria. For example, the determination in this Action <NUM> may comprise determining if any, or both, of the first measure of the corresponding frequency and the second measure of the corresponding amplitude of the radio antenna <NUM>, as described in Action <NUM>, over the time period are above a first threshold, such as an established threshold of maintenance, e.g., a threshold_of_maintenance, or a second threshold, such as a threshold of structural integrity, e.g., a threshold_of_structural_integrity. The threshold of maintenance may be understood as a threshold above which maintenance is required for the mast construction to prevent it from physically breaking. The threshold of structural integrity may be understood as a threshold reflecting vibrations in handheld tools. It may be measured in "time-averaged acceleration", typically as "averaged acceleration over X working hours". Over the time period may be understood as comprising any of e.g., time-averaged, instant, etc..

The time period may be, for example a number of minutes.

In this Action <NUM>, the first node <NUM> may obtain, based on the result of the determination of Action <NUM>, a second estimation of one of: a) a velocity of the wind <NUM> and b) the seismic activity. The velocity of the wind <NUM> may be understood to comprise a speed of the wind <NUM>. In some examples, the velocity of the wind <NUM> may also comprise a direction of the wind <NUM>.

The velocity of the wind <NUM> may be estimated for example by analyzing oscillation modes with respect to amplitude and frequency. The direction of the wind may be for example deducted by analyzing the direction of the vibrations from a plurality of wireless devices.

The first node <NUM> may then map the movement, e.g., the harmonic oscillation, of the radio antenna <NUM> to the estimated velocity of the wind <NUM>. The first node <NUM> may for example, measure a path loss of the radio transmissions. The first node <NUM> may then obtain a measure of, or itself detect a time-harmonic variation in the set of Doppler spectrum values, and calculate the first measure of the corresponding frequency and, optionally, additionally calculate the second measure of the corresponding amplitude of the radio antenna <NUM>, as described in Action <NUM>. Next, the first node <NUM> may map a calculated oscillation of the corresponding frequency and, optionally of the corresponding amplitude, to the obtained second estimation of the velocity of the wind <NUM>. This may be done based on a height of a tower the radio antenna <NUM> may be located, a weight of a mounted equipment of the radio antenna <NUM>, etc..

The seismic activity may be estimated for example by analyzing the vibrational characteristics of the movement of the radio antenna <NUM> and determining if they correspond to a pattern of wind load, or to a pattern caused by seismic activity, e.g., by the type of radio antenna <NUM>, type of mast it may be mounted on, and its position and surroundings. In some non-limiting examples, the seismic activity may be estimated for example by first determining the second estimation of the velocity of the wind <NUM> and, if no correlation may be established with the movement of the radio antenna <NUM>, as e.g., obtained in Action <NUM>, the radio node <NUM> may determine that the detected movement of the radio antenna <NUM> may be caused by seismic activity. The radio node <NUM> may base the second estimation of the seismic activity on an analysis of such a correlation between the movement of the radio antenna <NUM> and the velocity of the wind <NUM> at a number of network nodes, based on geographical area.

In some examples, this Action <NUM> may be performed after Action <NUM> instead of before.

In this Action <NUM>, the first node <NUM> initiates providing a message to one of: the second node <NUM>, e.g., via the third link <NUM>, and the third node <NUM> operating in the wireless communications network <NUM>, e.g., via the second link <NUM>. The initiation of the providing of the message is based on a result of the determination. To initiate providing may be understood as to trigger the providing, e.g., by instructing or enabling another node to perform the providing, or to autonomously perform the providing. Providing may be understood as e.g., sending, or transmitting.

That the initiation of the providing of the message is based on a result of the determination may be understood as that the first node <NUM> may only initiate the providing of the message in this Action <NUM> when the movement of the radio antenna <NUM> is above the threshold over the time period, but not otherwise.

The message may either comprise a notification to another node regarding the obtained determination in Action <NUM>, or a report deriving from it, e.g., a weather report, or a report on seismic activity. A notification may comprise an alarm, a written notification, a light pattern, a sound, or another form of notification. A remedial action may be understood as an action that contributes to counteracting the harmful effect of the movement of the radio node <NUM>. The message may alternatively, or in addition, provide a recommendation or an instruction to perform a remedial action for the detected harmful movement. Hence, in some embodiments, the message may trigger at least one of: a) a report regarding maintenance of the radio antenna <NUM>; b) shut down of the radio antenna <NUM>; c) a report of a weather condition, e.g., a report of the second estimation of the velocity of the wind <NUM>; and d) a report on seismic activity. For example, the first node <NUM> may instruct the second node <NUM> directly to shut down the radio antenna <NUM> if the movement of the radio antenna <NUM> is above the threshold over the time period. In another example, the first node <NUM> may send the report on seismic activity to the second node <NUM> for transmission to another node in the wireless communications network <NUM>.

In examples wherein the message may be a report of the weather condition, the third node <NUM> may be a weather-entity in Operational Support Systems (OSS). The third node <NUM> may also be a wireless device located in a news station or a seismic control center. In some examples, before initiating providing the message, the first node <NUM> may first gather weather information from multiple sites into a weather map and or a weather forecast.

There may be different thresholds for initiating providing different types of messages. For example, if the first node <NUM> determines in Action <NUM> may that any, or both, of the first measure of the corresponding frequency of the movement or oscillations of the radio antenna <NUM> and the second measure of the corresponding amplitude of the movement or oscillations of the radio antenna <NUM>, as described in Action <NUM>, over the time period is above the threshold of maintenance, the first measure and the second measure being time-averaged, the first node <NUM> may trigger pro-active site maintenance through the message by triggering a first set of selected actions.

In another example, if the first node <NUM> determines in Action <NUM> that any, or both, of the first measure of the corresponding frequency of the movement or oscillations of the radio antenna <NUM> and the second measure of the corresponding amplitude of the movement or oscillations of the radio antenna <NUM>, as described in Action <NUM>, over the time period is above the threshold of structural integrity, the first measure and the second measure being instant measures, the first node <NUM> may trigger through the message a second set of selected actions, such as one or more of: sending a critical alarm, reorganizing, e.g., in some SON-like manner, a radio grid to cope with an upcoming scenario such as, e.g., "site X may suffer structural damages within X hours given current vibrations". The first node <NUM> may alternatively, or in addition, trigger the shutdown of equipment, such as the radio antenna <NUM> or the second node <NUM> entirely.

<FIG> schematically illustrates how to obtain the set of Doppler spectrum values, according to an example. In general terms, the Doppler spectrum may be calculated by a fast Fourier transform (FFT), of radio channel estimates over a relatively short period in the time domain. In more detail, <FIG> schematically indicates a time-frequency diagram of the radio channel on which radio waves have been transmitted between the second node <NUM> and the one wireless device <NUM>. The FFT is determined for the time-frequency representation over time in a window of length w time units, resulting in the Doppler spectrum-frequency representation in <FIG>. The Doppler spectrum-frequency representation is averaged over frequency, resulting in the average Doppler spectrum representation of <FIG>. Alternatively, the Doppler spectrum in <FIG> may represent a single frequency of the Doppler spectrum-frequency representation in <FIG>. This procedure may be repeated for multiple short periods of time resulting in the time varying Doppler spectrum of <FIG>. Hence, multiple Doppler shifts may be determined from a short-term frequency transform of a time series of the radio channel estimates. The Time in <FIG> corresponds to one value of the set of Doppler spectrum values. The set of Doppler spectrum values is illustrated in <FIG>.

Embodiments of a method performed by the third node <NUM>, the method being for managing the movement of the radio antenna <NUM>, will now be described with reference to the flowchart depicted depicted in <FIG>. The third node <NUM> operates in the wireless communications network <NUM>.

The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the first node <NUM>, and will thus not be repeated here to simplify the description. For example, in examples wherein the radio transmissions may have been transmitted by the second node <NUM>, the radio transmissions may be e.g., Cell Specific Reference Signal (CRS). In examples wherein the radio transmissions may have been transmitted by the at least one wireless device <NUM>, the radio transmissions may be e.g., Sounding Reference Signals (SRS).

In order to enable the third node <NUM> to manage the movement of the radio antenna <NUM> being above the threshold by performing one or more remedial actions, in this Action <NUM>, the third node <NUM> receives the message from the first node <NUM> operating in the wireless communications network <NUM>. The reception of the message may be e.g., via the second link <NUM>. The receiving <NUM> of the message is based on a result of the determination of whether the movement of the radio antenna <NUM> is above the threshold over the time period. As stated earlier, the radio antenna <NUM> is connected to the second node <NUM> operating in the wireless communications network <NUM>. The movement is with respect to the at least one wireless device <NUM> operating in the wireless communications network <NUM>. The determination is based on the analysis of the one or more properties of radio transmissions between the at least one wireless device <NUM> and the radio antenna <NUM> over the time period, as described earlier.

As described earlier, the radio transmissions may comprise reference signals. The radio transmissions may be one of: a) transmitted by the second node <NUM> and measured by at the least one wireless device <NUM>; and b) transmitted by the at least one wireless device <NUM> and measured by the second node <NUM>.

The analysis may be the Doppler spectrum analysis described above.

In some embodiments, the analysis may be based on: a) the measurements of at least the phase of the radio transmissions over the time period; b) the division of the obtained measurements in the subsets of periods of time comprised in the time period; and c) the Fourier transform over each of the subsets of periods of time. The determination may be further based on the set of Doppler spectrum values obtained from the Fourier transform over each of the subsets of periods of time.

The determination may be further based on the detection of the time-harmonic variation of the set of Doppler spectrum values.

In some embodiments, the message may comprise at least one of: a) the report regarding maintenance of the radio antenna <NUM>; b) the report of the weather condition; and c) the report on the seismic activity.

In embodiments wherein the determination may be further based on the detection of the time-harmonic variation of the set of Doppler spectrum values, the third node <NUM> may, in this Action <NUM>, receive, from the first node <NUM>, the first estimation of the movement of the radio antenna <NUM>, e.g., in the form of a first indication of the first estimation. The reception of the first estimation may be e.g., via the second link <NUM>. The first estimation may be based on at least one of: i) the calculation of the frequency of the movement of the radio antenna <NUM>, based on time variations of the set of Doppler spectrum values, and ii) the calculation of the amplitude of the movement of the radio antenna <NUM>, based on the values in the set of Doppler spectrum values.

This is an optional Action. If performed, it may be combined with any or both of Action <NUM> and Action <NUM> in a single Action.

In this Action <NUM>, the third node <NUM> may receive, based on the result of the determination, the second estimation of one of: the velocity of the wind <NUM> and the seismic activity e.g., in the form of a second indication of the second estimation. The receiving in this Action <NUM> may be e.g., via the second link <NUM>.

In this Action <NUM>, the third node <NUM> may initiate performance of an action to remedy the movement of the radio antenna <NUM> being above the threshold over the time period. To initiate performance may be understood as to trigger the performance, e.g., by instructing another node to perform the action to remedy, or remedial action, or to autonomously perform the remedial action.

The action may comprise at least one of: i) shut down of the radio antenna <NUM>; ii) a reorganization of an antenna grid comprising the radio antenna <NUM>, and c) sending another message based on the report of the weather condition or the seismic activity.

Another action may be to adjust wire tension by adjusting turnbuckles of pole struts to reduce and/or minimize pole oscillations which may be harmful in the long run.

This is an optional Action, since the message may be an alarm in the form of e.g., a light signal, and the remedial action may then be taken by a user of the third node <NUM>.

To summarize the foregoing in other words with a particular non-limiting example, embodiments herein may be understood to relate to identifying and classifying radio pole harmonic oscillations using Doppler analysis. Wind-induced pole harmonic oscillations may be identified enabling efficient radio site operations and pre-emptive maintenance. Wind-induced pole harmonic oscillations may be identified and used to report local weather conditions, such as wind. This may be done in combination with existing methods for judging rain intensity by signal path loss characteristics. Embodiments herein may be used for wide-area weather condition reporting, and potentially prediction.

One benefit of embodiments herein is that they enable low-cost and efficient radio site, pole, and radio antenna operations and pre-emptive maintenance by monitoring.

Another further advantage of embodiments herein is that they enable site-local weather reports, e.g., wind reports, or seismic reports.

To perform the method actions described above in relation to <FIG> and <FIG>, the first node <NUM> may comprise the following arrangement depicted in <FIG>. The first node <NUM> is configured to manage the movement of the radio antenna <NUM>. As stated earlier, the first node <NUM> is configured to operate in a wireless communications network <NUM>.

The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the first node <NUM>, and will thus not be repeated here.

The first node <NUM> is further configured to, e.g. by means of a determining module <NUM> configured to, determine whether the movement of the radio antenna <NUM> is above the threshold over the time period, the radio antenna <NUM> being configured to be connected to the second node <NUM> configured to operate in the wireless communications network <NUM>. The movement is with respect to the at least one wireless device <NUM> configured to operate in the wireless communications network <NUM>. To determine being configured to be based on an analysis of one or more properties of the radio transmissions to or from the radio antenna <NUM> over the time period.

The analysis may be the Doppler spectrum analysis.

The radio transmissions may comprise reference signals. The radio transmissions may be configured to be one of: a) transmitted by the second node <NUM> and measured by the at least one wireless device <NUM>; and b) transmitted by the at least one wireless device <NUM> and measured by the second node <NUM>.

In some embodiments, the analysis may be configured to be based on: a) the measurements configured to be obtained of at least the phase of the radio transmissions over the time period; b) the division of the obtained measurements configured to be in the subsets of periods of time comprised in the time period; and c) the Fourier transform over each of the subsets of periods of time. To determine may be further configured to be based on the set of Doppler spectrum values configured to be obtained from the Fourier transform over each of the subsets of periods of time.

The first node <NUM> is further configured to, e.g., by means of an initiating module <NUM> configured to, initiate providing the message to one of: the second node <NUM> and the third node <NUM> configured to operate in the wireless communications network <NUM>, the initiation of the providing of the message being configured to be based on the result of the determination.

In some embodiments, the message may be configured to trigger at least one of: a) the report regarding maintenance of the radio antenna <NUM>; b) the shutdown of the radio antenna <NUM>; c) the report of the weather condition; and d) the report on the seismic activity.

In some embodiments, the determination may be further configured to be based on the detection of the time-harmonic variation of the set of Doppler spectrum values. In some of such embodiments, the first node <NUM> may be further configured to, e.g., by means of an obtaining module <NUM> configured to, obtain the first estimation of the movement of the radio antenna <NUM>. The first estimation may be configured to be based on at least one of: i) calculating the frequency of the movement of the radio antenna <NUM>, based on time variations of the set of Doppler spectrum values, and ii) calculating the amplitude of the movement of the radio antenna <NUM>, based on the values in set of Doppler spectrum values.

In some embodiments, the first node <NUM> may be further configured to, e.g., by means of the obtaining module <NUM> configured to, obtain, based on the result of the determination, the second estimation of one of: the velocity of the wind <NUM> and the seismic activity.

The embodiments herein in the first node <NUM> may be implemented through one or more processors, such as a processor <NUM> in the first node <NUM> depicted in <FIG>, together with computer program code for performing the functions and actions of the embodiments herein. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the in the first node <NUM>. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the first node <NUM>.

The first node <NUM> may further comprise a memory <NUM> comprising one or more memory units. The memory <NUM> is arranged to be used to store obtained information, store data, configurations, schedulings, and applications etc. to perform the methods herein when being executed in the first node <NUM>.

The first node <NUM> may comprise an interface unit to facilitate communications between the first node <NUM> and other nodes or devices, e.g., any of the second node <NUM>, the third node <NUM>, and the at least one wireless device <NUM>. The interface may, for example, include a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard.

In some embodiments, the first node <NUM> may receive information from, e.g., any of the second node <NUM>, the third node <NUM>, and the at least one wireless device <NUM>, through a receiving port <NUM>. In some embodiments, the receiving port <NUM> may be, for example, connected to one or more antennas in first node <NUM>, such as the radio antenna <NUM>, in some examples. In other embodiments, the first node <NUM> may receive information from another structure in the wireless communications network <NUM> through the receiving port <NUM>. Since the receiving port <NUM> may be in communication with the processor <NUM>, the receiving port <NUM> may then send the received information to the processor <NUM>. The receiving port <NUM> may also be configured to receive other information.

The processor <NUM> in the first node <NUM> may be further configured to transmit or send information to e.g., any of the second node <NUM>, the third node <NUM>, and the at least one wireless device <NUM>, through a sending port <NUM>, which may be in communication with the processor <NUM>, and the memory <NUM>.

Those skilled in the art will also appreciate that the determining module <NUM>, the initiating module <NUM>, and the obtaining module <NUM>, described above may refer to a combination of analog and digital modules, and/or one or more processors configured with software and/or firmware, e.g., stored in memory, that, when executed by the one or more processors such as the processor <NUM>, perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single Application-Specific Integrated Circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a System-on-a-Chip (SoC).

Also, in some embodiments, the different modules <NUM>-<NUM> described above may be implemented as one or more applications running on one or more processors such as the processor <NUM>.

Thus, the methods according to the embodiments described herein for the first node <NUM> may be respectively implemented by means of a computer program <NUM> product, comprising instructions, i.e., software code portions, which, when executed on at least one processor <NUM>, cause the at least one processor <NUM> to carry out the actions described herein, as performed by the first node <NUM>. The computer program <NUM> product may be stored on a computer-readable storage medium <NUM>. The computer-readable storage medium <NUM>, having stored thereon the computer program <NUM>, may comprise instructions which, when executed on at least one processor <NUM>, cause the at least one processor <NUM> to carry out the actions described herein, as performed by the first node <NUM>. In some embodiments, the computer-readable storage medium <NUM> may be a non-transitory computer-readable storage medium, such as a CD ROM disc, or a memory stick. In other embodiments, the computer program <NUM> product may be stored on a carrier containing the computer program <NUM> just described, wherein the carrier is one of an electronic signal, optical signal, radio signal, or the computer-readable storage medium <NUM>, as described above.

To perform the method actions described above in relation to <FIG>, the third node <NUM> may comprise the following arrangement depicted in <FIG>. The third node <NUM> is configured to manage the movement of the radio antenna <NUM>. As stated earlier, the third node <NUM> is configured to operate in a wireless communications network <NUM>.

The detailed description of some of the following corresponds to the same references provided above, in relation to the actions described for the third node <NUM>, and will thus not be repeated here.

The third node <NUM> is further configured to, e.g. by means of a receiving module <NUM> configured to, receive the message from the first node <NUM> configured to operate in the wireless communications network <NUM>. To receive the message is configured to be based on the result of the determination of whether the movement of the radio antenna <NUM> is above the threshold over the time period. The radio antenna <NUM> is configured to be connected to the second node configured to operate in the wireless communications network <NUM>. The movement is with respect to the at least one wireless device <NUM> configured to operate in the wireless communications network <NUM>. The determination is configured to be based on the analysis of the one or more properties of the radio transmissions between the at least one wireless device <NUM> and the radio antenna <NUM> over the time period.

In some embodiments, the analysis may be configured to be based on: a) the measurements, configured to be obtained, of at least the phase of the radio transmissions over the time period; b) the division of the measurements configured to be in the subsets of periods of time comprised in the time period; and c) the Fourier transform over each of the subsets of periods of time. The determination may be further configured to be based on the set of Doppler spectrum values configured to be obtained from the Fourier transform over each of the subsets of periods of time.

In some embodiments, the message may be configured to comprise at least one of: a) the report regarding maintenance of the radio antenna <NUM>; b) the report of the weather condition; and c) the report on the seismic activity.

In some embodiments, the determination may be further configured to be based on the detection of the time-harmonic variation of the set of Doppler spectrum values. In some of such embodiments, the third node <NUM> may be further configured to, e.g., by means of the receiving module <NUM> configured to, receive, from the first node <NUM>, the first estimation of the movement of the radio antenna <NUM>. The first estimation may be configured to be based on at least one of: i) the calculation of the frequency of the movement of the radio antenna <NUM>, based on time variations of the set of Doppler spectrum values, and ii) the calculation of the amplitude of the movement of the radio antenna <NUM>, based on the values in the set of Doppler spectrum values.

In some embodiments, the third node <NUM> may be further configured to, e.g., by means of the receiving module <NUM> configured to, receive, based on the result of the determination, the second estimation of one of: the velocity of the wind <NUM> and the seismic activity.

The third node <NUM> is further configured to, e.g., by means of an initiating module <NUM> configured to, initiate performance of the action to remedy the movement of the radio antenna <NUM> being above the threshold over the time period.

The action may be configured to comprise at least one of: i) shut down of the radio antenna <NUM>; ii) the reorganization of the antenna grid comprising the radio antenna <NUM>, and iii) sending the another message based on the report of the weather condition or the seismic activity.

The embodiments herein in the third node <NUM> may be implemented through one or more processors, such as a processor <NUM> in the third node <NUM> depicted in <FIG>, together with computer program code for performing the functions and actions of the embodiments herein. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the in the third node <NUM>. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the third node <NUM>.

The third node <NUM> may further comprise a memory <NUM> comprising one or more memory units. The memory <NUM> is arranged to be used to store obtained information, store data, configurations, schedulings, and applications etc.. to perform the methods herein when being executed in the third node <NUM>.

The third node <NUM> may comprise an interface unit to facilitate communications between the third node <NUM> and other nodes or devices, e.g., any of the first node <NUM>, the second node <NUM>, and the at least one wireless device <NUM>. The interface may, for example, include a transceiver configured to transmit and receive radio signals over an air interface in accordance with a suitable standard.

In some embodiments, the third node <NUM> may receive information from, e.g., any of the first node <NUM>, the second node <NUM>, and the at least one wireless device <NUM>, through a receiving port <NUM>. In some embodiments, the receiving port <NUM> may be, for example, connected to one or more antennas in third node <NUM>. In other embodiments, the third node <NUM> may receive information from another structure in the wireless communications network <NUM> through the receiving port <NUM>. Since the receiving port <NUM> may be in communication with the processor <NUM>, the receiving port <NUM> may then send the received information to the processor <NUM>. The receiving port <NUM> may also be configured to receive other information.

The processor <NUM> in the third node <NUM> may be further configured to transmit or send information to e.g., any of the first node <NUM>, the second node <NUM>, the third node <NUM>, and the at least one wireless device <NUM>, through a sending port <NUM>, which may be in communication with the processor <NUM>, and the memory <NUM>.

Those skilled in the art will also appreciate that the receiving module <NUM> and the initiating module <NUM> described above may refer to a combination of analog and digital modules, and/or one or more processors configured with software and/or firmware, e.g., stored in memory, that, when executed by the one or more processors such as the processor <NUM>, perform as described above. One or more of these processors, as well as the other digital hardware, may be included in a single Application-Specific Integrated Circuit (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a System-on-a-Chip (SoC).

Thus, the methods according to the embodiments described herein for the third node <NUM> may be respectively implemented by means of a computer program <NUM> product, comprising instructions, i.e., software code portions, which, when executed on at least one processor <NUM>, cause the at least one processor <NUM> to carry out the actions described herein, as performed by the third node <NUM>. The computer program <NUM> product may be stored on a computer-readable storage medium <NUM>. The computer-readable storage medium <NUM>, having stored thereon the computer program <NUM>, may comprise instructions which, when executed on at least one processor <NUM>, cause the at least one processor <NUM> to carry out the actions described herein, as performed by the third node <NUM>. In some embodiments, the computer-readable storage medium <NUM> may be a non-transitory computer-readable storage medium, such as a CD ROM disc, or a memory stick. In other embodiments, the computer program <NUM> product may be stored on a carrier containing the computer program <NUM> just described, wherein the carrier is one of an electronic signal, optical signal, radio signal, or the computer-readable storage medium <NUM>, as described above.

Claim 1:
A method performed by a first node (<NUM>) for identifying oscillatory or vibrational movement of a radio antenna (<NUM>) in a mechanical structure, said movement causing harmful effects to the mechanical structure, the first node (<NUM>) operating in a wireless communications network (<NUM>), the method comprising:
- obtaining (<NUM>) a first estimation of the movement of the radio antenna (<NUM>), wherein the movement is associated with a displacement of the radio antenna (<NUM>) in two or three dimensions, wherein the radio antenna (<NUM>) being connected to a second node (<NUM>) operating in the wireless communications network (<NUM>), wherein the movement being with respect to at least one wireless device (<NUM>) operating in the wireless communications network (<NUM>);
- determining (<NUM>), based on the obtained first estimation, whether the movement of the radio antenna (<NUM>) is above a threshold over a time period, and the determining (<NUM>) being further based on an analysis of one or more properties of radio transmissions to or from the radio antenna (<NUM>) over the time period, wherein the one or more properties of radio transmissions comprises an amplitude of a transmission channel and a phase of the transmission channel, and
- initiating (<NUM>) of providing a message comprising at least an instruction to perform an action that contributes to counteracting harmful effects of the movement, to the second node (<NUM>) operating in the wireless communications network (<NUM>), the initiation of the providing of the message being based on a result of the determination,
wherein the analysis is a Doppler spectrum analysis, and wherein the analysis is based on:
a. obtained measurements of at least the amplitude and the phase of the transmission channel over the time period;
b. a division of the obtained measurements in subsets of periods of time comprised in the time period;
c. a Fourier transform over each of the subsets of periods of time; and
wherein the determining (<NUM>) is further based on a set of Doppler spectrum values obtained from the Fourier transform over each of the subsets of periods of time.