A study on the separation capability of data streams in wireless communication networks

Abstract

To provide an approach for performing more efficient wireless communication in a network and a method for improving communication adaptation and radio channel considerations and determining the user equipment's spatial data stream separation capability.SOLUTION: In a wireless communication network, a device 10 for performing wireless communication includes a memory 22 in which capability information is stored and a wireless interface arrangement 12 having a signal maintenance capability for separating at least one data stream 141, 142. The device wirelessly transmits a capability signal 16 containing the capability information indicating the signal maintenance capability to a receiving device 18.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present application relates to the field of wireless communication systems or networks, and more particularly to approaches for more efficient wireless communication in such networks. Embodiments relate to improved communication adaptation and wireless channel considerations. Embodiments further relate to methods for determining spatial data stream separation capabilities of user equipment. [Background technology]

[0002] In TSG SA#79 and TSG RAN#79, discussions were held regarding defining mechanisms for optimizing UE radio capability signaling. The RAN sent a LS to the TSG SA (CC'SA WG2), which indicated that "...the network should store and manage such UE capability IDs, so conceptual work should be carried out in SA WG2 and RAN WG2 (with potential involvement of other relevant WGs such as RAN WG3 and CT WG1)."

[0003] Some form of efficient signaling of UE radio capabilities needs to be investigated, which may also depend on an efficient representation of UE capabilities.

[0004] The solution must allow for disabling of specific features or specific radio capabilities that the device has been upgraded to, for example, due to a new SW release.

[0005] Discussions in TSG RAN and SA WG2 have previously explored several options for such an efficient representation. 1. Using a hash function on the UE capabilities. 2. Use all or part of IMEI-SV, i.e. TAC+SVN. 3. Use the newly defined identifier.

[0006] Other options are possible and can be considered.

[0007] Considerations will also determine whether the identifiers used in such efficient representations need to be globally unique (i.e., standardized) or PLMN- or manufacturer-specific. Summary of the Invention [Problem to be solved by the invention]

[0008] Starting from this background, there is a need for improved communications in wireless communication networks.

[0009] Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 shows a schematic block diagram of an apparatus according to one embodiment. [Figure 2] FIG. 2 shows a schematic block diagram of a portion of a wireless communication network according to one embodiment. [Figure 3a] FIG. 3a shows a schematic block diagram of the wireless communication network of FIG. 2 when the relative positions between the devices and the base stations have changed, according to an embodiment. [Figure 3b] FIG. 3b shows a schematic block diagram of the wireless communication network of FIG. 2 after the relative positions between the devices and the base stations have changed, according to an embodiment. [Figure 4] FIG. 4 shows a schematic block diagram of a base station according to an embodiment. [Figure 5] FIG. 5 shows a schematic block diagram of a wireless communication network according to an embodiment, comprising at least one device and at least one base station. [Figure 6] FIG. 6 shows a simplified flow chart of a method of operating the device according to one embodiment. [Figure 7] FIG. 7 shows a schematic block diagram of a measurement environment according to one embodiment. [Figure 8] FIG. 8 illustrates a schematic flow chart of a method for evaluating a wireless propagation channel between a first node and a second node in a wireless communication network according to an embodiment. [Figure 9a] FIG. 9a shows a schematic block diagram of a well-known model of a wireless propagation channel. [Figure 9b] FIG. 9b shows a schematic block diagram of a known form of communication model called the propagation channel. [Figure 9c] FIG. 9c shows a schematic block diagram of a channel model on which at least some of the embodiments described herein are based. DETAILED DESCRIPTION OF THE INVENTION

[0011] In the following description, equal or equivalent elements or elements having equal or equivalent functions are designated by equal or equivalent reference numerals even if they are depicted in different figures.

[0012] In the following description, numerous details are set forth to more thoroughly explain embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring embodiments of the present invention. Furthermore, unless otherwise specified, features of various embodiments described below can be combined.

[0013] The embodiments described herein relate to communications in wireless communication networks, methods, procedures, and measurement environments for providing data and information that enable enhanced communications in wireless communication networks. The embodiments described herein may relate to mobile communication networks, such as Long Term Evolution (LTE) or new wireless / 5G, although the scope of the embodiments is not limited thereto. The embodiments relate to communicating one's capabilities to other nodes, taking into account separation of data streams, to enable other nodes to limit efforts related to optimizing communications. In particular, such communication, taking into account separation capabilities of data streams, may be used to avoid unnecessary optimization efforts at other nodes beyond their own capabilities. The embodiments are not limited to a particular network structure or architecture.

[0014] Other embodiments described herein relate to models that are taken into account when determining device parameters. Such models consider the transmitter antenna and the receiver antenna as excluded from the wireless channel and can therefore take into account cross-effects between antennas, e.g., cross-effects between different communication chains, e.g., transmit and / or receive chains, separately, thereby providing an accurate determination of the wireless channel.

[0015] A first aspect of the embodiments described herein relates to reporting one's capabilities to other network nodes, taking into account separation of data streams. Such capabilities in the described embodiments are based on a priori knowledge of the device's capabilities. That is, the device's capabilities may be characteristics of the device, for example, antenna placement characteristics, such as based on the relative position of the antenna within the housing. This characteristic may be based on the information accessed by the device. The capability of a device may be independent of the channel used. For this reason, device capability must be distinguished from other information, such as a rank indicator (RI), which may be understood as channel-dependent information. While the RI is based on or derived from channel assessments made by the user equipment, capability information according to embodiments is based on a priori knowledge of the device's capabilities and may therefore be independent of the radio channel characteristics of the radio channel used by the device and, therefore, independent of the device's propagation environment. Signal maintenance capability is rather the capability of the air interface arrangement, or of a part / portion / section of the air interface arrangement used for communication. This distinction also applies to other known information, such as a channel quality indicator (CQI) or a precoding matrix indicator (PMI), which are channel-dependent.

[0016] A second aspect of the embodiments described herein relates to determining such separation capability information.

[0017] A third aspect of the embodiments described herein relates to mechanisms for optimizing performance through knowledge of device capabilities that may be based on the particular mode of the wireless propagation channel.

[0018] 1 shows a schematic block diagram of a device 10 configured to perform wireless communication in a wireless communication network. For example, the device 10 may be configured to operate within a cell of the wireless communication network. The device 10 may be any device configured to operate in a wireless communication network, such as an Internet of Things (IoT) device, a user equipment (UE), a vehicle, a base station, etc.

[0019] To perform wireless communication in a wireless communication network, the device 10 may include an air interface arrangement 12. The air interface arrangement 12 may include an antenna arrangement. The device may include a controller, which may be implemented as part of the antenna arrangement 12 or separately. The air interface arrangement 12 may include one or more antenna elements. Having multiple antenna elements allows such antenna elements to be grouped into an antenna array, an antenna panel, or the like. The air interface arrangement 12 allows the device 10 to maintain one or more data streams 141, 142 at a time. Each data stream 141, 142 may include transmitting and / or receiving data and / or signals. Maintaining a data stream 142 at a time may be understood as simultaneously maintaining the data streams 141 and 142. This is not limited to simultaneously transmitting and / or receiving bits of different data streams at a particular instance in time, but may relate more generally to processing data streams. For example, different data streams may be transmitted and / or received in different frames, subframes, time slots, or subcarriers. According to one example, signal maintenance capability, which refers to the ability to separate at least one data stream 141 and / or 142, may be understood as multiple-input multiple-output (MIMO) capability. Signal maintenance capability may also include no capability at all, i.e., device 10 may be configured to maintain or separate only one single data stream 141 or 142. According to one embodiment, device 10 may separate or maintain two or more data streams.

[0020] Separating one data stream from another may be performed by apparatus 10 based on different characteristics or features within data streams 141 and 142. For example, data streams 141 and 142 may differ from each other in at least one of the following: time domain, frequency domain, code domain, spatial domain, orbital angular momentum, or angular difference of a lobe or null of a beam pattern or a portion thereof. Alternatively or additionally, Additionally, data streams 141 and 142 may differ from each other in the polarization domain.

[0021] The embodiments described herein may describe data streams 141 and 142 as beams of a beam pattern to provide a clear description of the embodiments. However, any other distinction or combination of distinctions between the data streams may be implemented. Considering the beams, data streams 141 and 142 may be understood as spatial data streams that can be separated by device 10 based on decorrelation using its MIMO capabilities. Signal maintenance capability relates to the device capabilities of device 10 and may indicate an upper limit of communication that can be maintained or performed using device 10 within a wireless communication network. For example, device 10 may be configured to generate capability signal 16 such that the capability information indicates a maximum number of spatial data streams and / or a maximum number of other data streams simultaneously available in the air interface arrangement. For example, the capability information may at least indicate the capability of device 10 to utilize the indicated number of beams received and / or transmitted by wireless antenna arrangement 12. For example, device 10 may be configured to receive a first spatial data stream in a first beam and simultaneously or sequentially receive a second spatial data stream in a second beam. The air interface arrangement 12 may be configured to separate the first spatial data stream and the second spatial data stream from each other based on signal maintenance capabilities. Alternatively or additionally, the first spatial data stream and the second spatial data stream may be transmitted on a first beam and a second beam, respectively. The data streams transmitted on the first beam and the second beam may be separated from each other based on signal maintenance capabilities. As described above, the first spatial data stream (beam) and the second spatial data stream (beam) may be received or transmitted simultaneously.

[0022] The device 10 may include a memory 22 in which capability information is stored. The capability information may be coded or uncoded, or of any type.

[0023] The device's capabilities may be independent of the device's propagation environment. In other words, the device 10 may be configured to simultaneously acquire a certain number of data streams, for example, in an ideal environment. While some of these data streams may not be sustained in a real-world environment or scenario, given the blocked path to the base station, for example, if a vehicle passes between the UE and the base station, this does not change the signal sustainment capabilities. That said, the sustainment capabilities may be specific to the operating mode or orientation of the device 10. For example, the device 10 may have knowledge of a user positioned relative to the device 10. For example, the device 10 may determine that the user's head is near its display and decide not to transmit beams toward the user's head. Such a scenario may change the current sustainment capabilities or current sustainment capabilities as an effect of the operating mode rather than the effect of the wireless channel. As another example, the device 10 may be configured to sustain different numbers of data streams along different directions departing from the device. That is, if communication partners, e.g., base stations, are positioned at different faces or orientations relative to the device 10, the sustainment capabilities may vary based on the different or varying capabilities of the device 10 along the different faces.

[0024] Device 10 is configured to wirelessly transmit capability signals 16 to receiving device 18. Device 10 may transmit capability signals 16 repeatedly when establishing peer-to-peer communications, during association or re-association with a base station, and / or when determining, for example, at regular or irregular time intervals or when determining variations in its sustained capability. Such associations may occur, for example, when the device is powered up, when performing a handover, when attempting to establish a connection with a new cell, or when attempting to establish a new connection with a new cell. This may occur during association or when configuring a network. Device 10 may alternatively transmit capability signal 16 in response to receiving a corresponding request signal. For example, a base station may transmit each request once, periodically, or at irregular time intervals.

[0025] The capability signal 16 may indicate the signal tenability so that the receiving device 18 can gain knowledge about the tenability of the device 10. This allows the receiving device 18 and / or the device to which the tenability information is forwarded to take the capabilities of the device 10 into account when adapting communications. For example, the receiving device 18 may improve data transmission by adapting the beam and / or by generating a different beam toward the device 10. Based on knowledge of the upper limit of the signal tenability, the receiving device 18 may avoid unnecessary or ineffective attempts to improve or enhance communications.

[0026] FIG. 2 is a schematic block diagram of a wireless communication network 200, each of which represents one cell. For example, the receiving device 18 may be a base station operating a wireless communication network cell. The device 20 may associate or reassociate with the base station 18. Alternatively, the device 20 may already be associated with the base station 18. The device 20 may have at least first and second antenna arrangements 12a and 12b that are part of the air interface arrangement 12. Each antenna arrangement may be implemented to enable beamforming. The device 20 may be configured to use the antenna arrangement 12a or the antenna arrangement 12b individually for wireless communication, i.e., to use either the antenna arrangement 12a or the antenna arrangement 12b. Alternatively, the device 20 may be configured to use the antenna arrangements 121 and 122 in combination for wireless communication. Although the device 20 is described as including two antenna arrangements, each antenna arrangement is implemented to enable beamforming, and the device 20 may include different, particularly higher, numbers of antenna arrangements, e.g., 3, 4, 5, 10, 20, or more.

[0027] The wireless interface arrangement 12 may be configured to associate each separable data stream with a communication channel of the device. For example, different applications executed by the device may each maintain one or more communication channels that are simultaneously processed by a physical layer (PHY) of the device.

[0028] Figures 3a and 3b show schematic block diagrams of the wireless communication network 200 of Figure 2. The relative positions between the device 20 and the base station 18 are changed between the diagrams of Figures 3a and 3b. In Figure 3a, the antenna arrangement 12b is used by the device 20 to communicate with the base station 18. The antenna arrangement 12b may be implemented to support a first number of data streams, for example, two, and may be used for communication with the base station 18 because it is opposite the base station 18.

[0029] In FIG. 3b, device 20 communicates with base station 18 using antenna arrangement 12a. Antenna arrangement 12a may be configured to maintain a different, second number of data streams, e.g., data stream 143. The device may determine that its signal maintenance capability has changed from the maintenance capability of FIG. 3a to a changed signal maintenance capability. The device may report the changed signal maintenance capability to base station 18, for example, by again transmitting capability signal 16. Alternatively, or in addition to location variations that may result in a change in the antenna arrangement used by device 20 for communication, device 20 may be configured to determine that its signal maintenance capability has changed based on a change in one or more of the device's operating mode, the device's orientation, and / or the location of at least a portion of a user relative to the device. For example, in different operating modes, device 20 may consume different levels of power and be capable of utilizing different numbers of data streams. For example, in different device orientations, the device may utilize different levels of power. Any number of data streams and / or different antenna configurations may be used. Device 20 may be configured to periodically report its changed signal maintenance capabilities in response to determining the change or in response to a request received at air interface configuration 12.

[0030] The capability information transmitted to the receiving device 18 may be specific to each of the devices 20 and 10. This includes the capability information being specific to the device class, i.e., the class to which the device belongs. For example, all devices in the same device series, identically constructed, may have their respective identifiers or capability information stored therein, indicating that they belong to that class. Alternatively, the capability information may indicate the devices individually. Based on this, the receiving device 18 may determine or derive the device's capabilities. That is, the devices 10 and / or 20 may indicate their capabilities in a manner that can be interpreted by the receiving device without further knowledge. Alternatively or additionally, the device may identify itself, for example, using an identifier or identify the class to which it belongs. This allows the receiving device 18 to interpret or derive the capability information if it has further knowledge of the device or class of device. The capability information transmitted using the capability signal 16 may relate to the uplink and / or downlink capabilities of the device. Combined capability information may indicate both uplink and downlink capabilities. The different capabilities of the uplink and downlink may be transmitted as different information within the same signal or as different signals.

[0031] FIG. 4 is a schematic block diagram of a base station 40 according to an embodiment. The base station 40 is configured to operate a wireless communication network, e.g., at least a cell of the wireless communication network 200. By way of example, one or more devices 24 may be associated with the base station 40. The device 24 may be implemented, for example, as the device 10 and / or the device 20. The base station 40 includes an antenna arrangement 26 configured to transmit and / or receive multiple data streams to or from the device 24. By way of example, multiple transmit and / or receive beams may be formed toward the device 24, where the data streams 14, as described, are not limited to such spatial data streams. The base station is configured to receive a capability signal 16 including capability information indicating the signal maintenance capabilities of the device 24. Alternatively, the capability signal 16 may be transmitted by the device 24 but received by a central network node, e.g., in a backbone.

[0032] Base station 40 uses antenna arrangement 26 to transmit all data streams 311 through 32. x where x is any number greater than 1, such as at least 5, at least 10, at least 20, or at least 50. Within the capabilities of the base station 40, one or more data streams 32 imay be used by the base station 40, where i=1,...,x. With knowledge of the signal maintenance capabilities of the device 24, the base station 40 may limit the set 28, for example, by selecting a subset 34 of the set 28 that has a smaller number of data streams 32. This can be understood as the base station 40 deciding to limit its efforts in response to the capability information in consideration of optimizing communication with the device 24. For example, the number of beams or spatial data streams may be limited. Alternatively or additionally, the modulation and coding scheme (MCS), spatial spreading, time slot selection, code selection, etc. may be limited by the capabilities of the device 24. Each of these different characteristics may be understood as a separate or different data stream. Further influencing parameters may be, for example, the adapted data rate, latency, etc.

[0033] The device 24 may provide feedback information 36. This feedback information 36 may be received by the base station 40 as respective wireless data signals. The base station 40 may be configured to adaptively adapt the set 34 in response to the feedback information 36. The feedback information 36 may indicate the data transmission quality of the data transmission between the base station 40 and the device 24. For example, a signal-to-noise ratio (SNR), a signal-plus-interference-to-noise ratio (SINR), a channel quality indicator (CQI), or the like, or a combination thereof, may be transmitted. For example, the base station 40 may determine that the transmission quality in the uplink and / or downlink is below a desired transmission quality. That is, the base station 40 may determine that the channel is of poor quality. The base station may be configured to adapt the set 34 to improve the transmission quality of the data transmission within the signal-sustaining capability of the device. That is, according to an embodiment, the base station 40 is configured to limit efforts to improve the transmission quality to the signal-sustaining capability of the device 24. For example, the capability information may indicate at least the capability of the device 24 to utilize an indicated number of beams received or transmitted by its wireless antenna arrangement 12. Base station 40 may be configured to select a set of data streams 34 such that the number of sets of data streams 34 is at most the number indicated in capability signal 16 .

[0034] As described, base station 40 may be configured to provide or provide association procedures to the network with device 24 when device 24 associates or reassociates with a cell. Base station 40 may be configured to query capability information 16 during such association procedures.

[0035] This can prevent device 24 from transmitting capability signal 16 if it associates with a cell that does not use such information. Alternatively, or in addition to querying capability information, the base station can be configured to transmit a request signal indicating a request for reporting capability information before or after an association or reassociation procedure. Such a request signal can be sent to device 24 itself or to a central database of the wireless network, thereby querying whether device 24 is already known in the central node.

[0036] FIG. 5 shows a schematic block diagram of a wireless communication network 500 according to an embodiment. The wireless communication network 500 may include at least one device 10, 20, and / or 24. The wireless communication network may further include at least one base station 18 and / or 40. The wireless communication network 500 may optionally include a database 38 accessible to the at least one base station 40. The database 38 may include the signal maintenance capabilities of the device 10. The capability signal 16 may be transmitted directly or indirectly to the database 38. Based thereon, the database 38 may include criteria for at least the first and second data signals or data streams that the device 10 can maintain. Such criteria may be at least one of an error vector magnitude (EVM), a signal-to-interference-and-noise ratio (SINR), a bit error rate (BER), a block error rate (BNER), and / or a combination thereof. This may allow accurate information about the capabilities of the device 10 residing at the base station 40 to be obtained. The wireless communication network 500 may be configured to repeatedly update the database 38, for example, by updating capabilities associated with the device class by a manufacturer and / or by receiving a capability signal 16 directly or indirectly from the device 10. According to an embodiment, a method for operating an apparatus for wireless communication in a wireless communication network, wherein the apparatus includes a radio interface arrangement having signal maintenance capabilities for separating at least one data stream, includes wirelessly transmitting a capability signal to a receiving device, the capability signal including capability information indicative of the signal maintenance capabilities. This method may be used, for example, to operate the device 10 and / or 20.

[0037] According to one embodiment, a method for operating a base station for operating at least a cell of a wireless communication network, the cell having a device associated with the base station, the base station configured to transmit and / or receive a plurality of data streams using an antenna arrangement, includes receiving a capability signal including capability information indicative of a signal maintenance capability of the device. In another step, a set of data streams is used for communication with the device. In another step, a set of data streams is selected based on the capability information. The sequence or order of the steps may be implemented differently.

[0038] To obtain information about signal maintenance capabilities distributed in a network such as those described in connection with FIGS. 1 to 5, an embodiment provides a method 600 shown in FIG. 6. Step 610 includes operating a device in an operational mode such that the device maintains at least a first data signal using the device's air interface configuration. That is, in step 610, the device may be tested considering the number of data streams or data signals maintained in the operational mode. In step 620, the device's signal maintenance capabilities are determined within the operational mode. In step 630, the signal maintenance capabilities are stored in memory. Optionally, the operational mode may be stored in memory along with the maintenance capabilities. Such storage may be performed implicitly, for example, if the device 10 has only a single operational mode to be determined or tested.

[0039] The method may optionally include changing an operational mode of the device with respect to at least one data signal. The method may include determining a signal-sustaining capability of the device associated with the changed operational mode. The method may further include storing the changed signal-sustaining capability in memory for the associated changed operational mode. That is, when a device can operate under different operational modes associated with different data stream capabilities, it may be advantageous to store the signal-sustaining capability along with the operational mode.

[0040] Changing the operating mode may involve at least one of changing the correlation between antenna elements of the device, for example, by activating or deactivating one or more antenna elements, antenna panels, or antenna arrays. Alternatively or additionally, changing the operating mode may involve changing the channel propagation to or from the antenna elements of the device, for example, if the user is located at least partially along a direction in which a beam can or is intended to be formed. Alternatively or additionally, changing the operating mode may involve changing the orientation of the device relative to a link antenna of a base station or measurement equipment used to test the device, as described in connection with FIGS. 3a and 3b, while the receiving device 18 may be implemented with one or more link antennas. Such link antennas may simulate at least part of the functionality of a base station. Alternatively or additionally, changing the operating mode may involve changing the number of data channels maintained between the measurement setup and the device.

[0041] Method 600, in which each step may be performed independently, as well as the described extensions, may be performed to rely on a channel model that takes into account antenna correlation between antennas used to transmit signals using signal-sustaining capabilities and / or antenna correlation between antennas used to receive signals using signal-sustaining capabilities. As in antennas, a channel correlation refers to an arrangement of one or more antenna elements suitable for combining and transmitting or receiving signals. That is, in an antenna array, an antenna element is the smallest radiating portion of the array. Antenna correlation between antennas may have greater importance compared to antenna correlation between elements of the same antenna.

[0042] The step of operating the device in the operational mode includes the step of causing the device to receive at least a first data stream. The method may be performed to maintain a particular reference state of the channel. For example, the device may be tested in a measurement environment, e.g., a measurement chamber such as an anechoic chamber. The device may be radiated from one or more faces to simulate the particular reference state. Radiation may be performed from all faces at once, from different faces at different times, e.g., corresponding to the antenna being tested at that time, and / or from a constant direction while the device is moved or rotated. The method may further include determining antenna correlation between at least a first antenna and a second antenna of the air interface arrangement.

[0043] That is, antenna correlations indicative of impairments between at least the antennas can be determined under reference conditions, i.e., signal maintenance capabilities may be determined taking into account the reference conditions of the channel. The antenna correlations may be determined to include information about antenna correlations of antennas in different antenna configurations of the air interface configuration.

[0044] Alternatively or additionally, the method may be performed to determine signal maintenance capabilities for at least a first use case and a second use case of the device, where the first use case and the second use case may differ in terms of the antennas used by the device in the operating mode. For example, the different use cases may refer to different antennas and / or different antenna arrangements for the device to maintain the data stream. For example, based on the rotation of the device and / or the user relative to the base station, the device may maintain the same data stream but use a different antenna panel or antenna arrangement or set for communication, thus changing the use case. Alternatively or additionally, the usage method may be changed based on other circumstances. For example, the user may change their position relative to the device, such as holding the device to a different ear or removing the device from a table and placing it next to their head. The device may detect such changes and change the use of the air interface arrangement, for example, to not form a beam to or through the user's head. The signal maintenance capabilities may be stored with the use cases. That is, the device may act on determined changes in channel propagation to or from the device's antennas.

[0045] A device may report its signal tenacity capabilities along with the associated use case and / or may report changes in signal tenacity capabilities during operation, for example, when switching from one operating mode or use case to another.

[0046] 7 shows a schematic block diagram of a measurement environment 700 according to an embodiment. The measurement environment 700 includes a holder 42 configured to hold a device 44, e.g., devices 10 and / or 20, or a similar type of device. The measurement environment 700 includes a control unit 46 configured to control the device 44 to operate under an operational mode. The control unit 46 may be adapted to send one or more control signals 48 to the device 44 in a wired or wireless manner in the measurement environment 700 to control its operational mode. In the controlled operational mode, the device 44 may maintain at least one data stream 14 using the wireless interface arrangement of the device 44.

[0047] The measurement environment 700 may include a determination unit 52 configured to determine a signal tenacity capability of the device 44 associated with an operational mode. The measurement environment 700 may include a memory 54 configured to store the signal tenacity capability, optionally together with the associated operational mode.

[0048] Methods according to embodiments, such as methods implemented or performed at least in part by use of measurement environment 700, include connecting or placing a device to be tested in the measurement environment. For example, the device may be attached to a holder 42, e.g., a chuck, fixture, or other suitable device. The device may be placed on a table, a floor, or the like. The method includes transmitting a number of multiplexed signals to the device, for example, using a link antenna. The method includes demultiplexing the multiplexed signals with a device, for example, device 44. The results of the demultiplexing step may be transmitted to a measurement environment. The method includes comparing the demultiplexed signals with the multiplexed signals to obtain a comparison result. That is, it may be determined whether device 44 successfully demultiplexes the multiplexed signals. Based thereon, the signal maintenance capability of the device may be determined based on the comparison result. That is, it may be tested whether the device can demultiplex a number of multiplexed signals. The test may be performed iteratively, such that the number of multiplexed signals transmitted to the device is increased or decreased in different iterations. This may be implemented to determine the maximum number of multiplexed signals that can be demultiplexed by the device.

[0049] Thus, the comparison result may be determined to indicate the number of successfully demultiplexed signals. According to an embodiment, the demultiplexed signals may be provided to a device, and it may be determined whether the device can successfully multiplex the signals. Signal processing techniques, such as correlation functions or autocorrelation functions, may be used to compare the multiplexed and demultiplexed signals.

[0050] According to an embodiment, the method for determining signal sustainability may additionally include one or more of the following steps: connecting a device to a measurement environment or placing the device in the measurement environment; supplying multiple signals to the device; multiplexing the multiplexed signals to the measurement environment; demultiplexing the multiplexed signals in the measurement environment; and comparing the demultiplexed signals with the multiplexed signals to obtain a comparison result. Furthermore, the signal sustainability may be determined based on the comparison result. Thus, the comparison result may be determined to indicate the number of successfully multiplexed signals. The step of comparing the demultiplexed signals with the multiplexed signals may also be implemented using signal processing techniques.

[0051] The described embodiments relate to UEs reporting specific capabilities and how having the same knowledge benefits both the UE and the network. As networks continue to evolve from one generation to the next, toward New Radio (NR) and beyond, not only will the number of mobile devices supported by these networks increase, but so will the number of device types. In other words, these networks are required to support an ever-increasing variety of user equipment (UE) and provide the required quality of service for each UE category and capability. Within standardization groups such as 3GPP, for example, 3GPP TR 23.743 V0.2.0 As shown in (2018-08), the discussion of UE capabilities is an ongoing topic.

[0052] At base stations, multi-antenna systems and related technologies enable radio access networks to deliver higher data rates, increased capacity, and improved reliability in a manner that is spectrally efficient and energy-efficient. In 5G NR, these developments relate to frequency bands in the frequency ranges known as Frequency Range 1-FR1 (450 MHz-6,000 MHz) and Frequency Range 2-FR2 (24,250 MHz-52,600 MHz). However, these technologies relate to specific operating frequencies, future releases, and future evolutions and systems beyond 5G, regardless of the current definitions of FR1 and FR2.

[0053] “Effect of Antenna Mutual Coupling on MIMO Channel Estimation and Capacity”(Xia Liu and Marek E. Bialkowski , School of According to the ITEE, The University of Queensland, Brisbane, QLD 4072, Australia, "Mathematical analysis and simulation results show that when the spacing of antenna elements at either the transmitter or receiver is between 0.2 and 0.4, mutual coupling reduces the level of spatial correlation, impairing the accuracy of MIMO channel estimation." The design and implementation of the antennas used by the UE impacts its ability to accurately assess channel characteristics, which can also affect the UE's ability to achieve maximum performance in higher-rank MIMO channels.

[0054] Another embodiment provides a method for evaluating a wireless propagation channel between a first node and a second node in a wireless communication network. An example of this embodiment is shown in FIG. 8, which illustrates a schematic flowchart of a method 800 for evaluating a wireless propagation channel between a first node and a second node in a wireless communication network. Step 810 includes measuring characteristics of the wireless propagation channel between the first node and the second node to obtain a measurement result. Step 820 includes correcting the measurement result at least in part from interference or impairments on a second communication chain of the first node resulting from operating a first communication chain of the first node and / or from impairments on a fourth communication chain of the second node resulting from operating a third communication chain of the second node. Each communication chain is configured to wirelessly transmit and / or receive signals using an air interface. Correcting the measurement result results in a corrected measurement result of the propagation channel.

[0055] The embodiments described herein relate, at least in part, to interference, e.g., with respect to step 820. In the context of wireless signal transmission and reception, the term interference can be used to describe unwanted signals that affect the transmission / reception of wanted signals. With respect to wanted signals, and in some instances, unwanted signals can be considered a form of noise. In the context of the described embodiments, such type of interference can be understood as impairment, i.e., the effect of one signal on another.

[0056] A device configured to wirelessly transmit and / or receive signals may utilize a communication chain to transmit or receive the signals. Communication chain is used as a term to describe a transmit chain and / or a receive chain. Such a chain may include amplifiers, digital-to-analog and / or analog-to-digital converters, antenna elements, signal processing steps, etc.

[0057] An apparatus may include one or more communication chains. For example, multiple or multiple transmit chains and / or multiple or multiple receive chains may be implemented, particularly in connection with MIMO devices. Therefore, the presented methods also apply to apparatuses such as apparatus 10, 20, 24, or 44.

[0058] The inventors have found it particularly interesting and advantageous to consider the transmit chain, including the antenna elements used therein, as part of the device, rather than as part of the wireless propagation channel. For example, Figure 9a shows a schematic block diagram of a known model of a wireless propagation channel 900, including a section 910 relating to the transmitter, a section 930 relating to the receiver, and a section 950 relating to the channel. The different transmit chains d1(i) to d D Antenna elements 9521 to 9522 used by the transmitter for (i) M are considered as part of the channel 950. The receiver antenna elements 9541 to 954 NThe well-known model of Figure 9a shows a configuration in which the channel 950 includes both propagation and antenna effects. In this sense, the channel is better referred to as a "wireless channel."

[0059] Figure 9b shows a less well-known model in which the channel includes only propagation effects. In this sense, the channel can be called a "propagation channel." Antenna elements 953 and 954 are considered to be part of transmitter 910' and receiver 930', respectively.

[0060] In contrast, FIG. 9c shows a schematic block diagram of a channel model underlying at least some of the embodiments described herein. This is based on the finding that antenna correlation between antenna elements 952 (transmit antennas) and / or cross-correlation between antenna elements 954 (receive antennas) can be taken into account. This allows the measurement results of method 800 to be corrected to obtain characteristics of the wireless propagation channel 950″ independent of the antenna characteristics of the first and second nodes, i.e., the transmitter and receiver. Such obtained impairment information may be stored in a memory. The stored impairment information may be later retrieved from the memory, and wireless communication may be configured in the wireless communication channel using the impairment information to determine the characteristics of the wireless communication channel independent of the impairments. That is, particularly with regard to capability information, a device including multiple antenna elements or antenna arrangements in its air interface configuration may face antenna correlation in the transmit antennas and / or the receive antennas. This antenna correlation may, at least in part, influence the structural form or design of the device, such that different designs or positions or distances between antenna elements have different antenna correlations. This can result in different devices with different designs containing the same number of antennas, but with different data stream capabilities in different operating modes and / or orientations, etc. Embodiments relate to identifying such effects and correcting measurement results based on this knowledge.

[0061] The step of correcting the measurement results may be performed such that the corrected measurement results of the propagation channel exclude the antenna of the first node and the antenna of the second node from a propagation channel model that models the propagation channel. Alternatively or additionally, the method may include using the corrected channel propagation information to adjust the wireless communication. The step of adjusting the wireless communication may include at least one of: a quick or immediate adjustment of an ongoing, ongoing, or existing communication; an adjustment at the start of the next burst, slot, subframe, frame, or hyperframe of the wireless communication; a change in frequency; a change in beam; an antenna panel; an antenna polarization; power; modulation and / or coding; a change in radio access technology (RAT); a change in network; a change in device orientation; a change in communication direction; and a change in use case. Alternatively or additionally, the adjustment may be postponed, i.e., performed at a later stage. Combinations are included.

[0062] According to one embodiment, the method 800 may include requesting an adjustment at a network entity and processing the request. The method may include not performing the adjustment if the feedback is negative. That is, the adjustment may be announced, and the adjustment may be skipped or abandoned if the device responds with negative feedback.

[0063] Method 800 may alternatively or additionally include storing the adjustments and / or adjustment requests for subsequent analysis and / or performance optimization of the device and / or the device.

[0064] Based on this consideration, embodiments provide a device, e.g., device 10, 20, 24, and / or 44, that includes a memory that stores fault information thereon indicative of a fault to a second communication chain of the device resulting from operating a first communication chain of the device, e.g., a fault between antenna elements 952 and / or a fault between antenna elements 954. Such a device may optionally be configured to transmit the fault information in separate information that may take into account characteristics of the device. In this regard, embodiments provide a device, e.g., a receiving device such as device 18 or base station 40, configured to control wireless communications to another device based on interference information indicative of interference to a second communication chain of the other device resulting from operating a first communication chain of the other device. That is, the device may take into account interference that would occur in the other device when using a particular configuration of wireless communications. For example, knowledge that a particular combination of beams, frequencies, codes, etc. results in increased interference compared to other combinations may be used to cause the device to prefer combinations with lower interference over other combinations.

[0065] In other words, referring again to FIG. 9c, boxes 952 and 954 refer to antenna correlations of antennas. Box 952 relates to a TX antenna, e.g., in a base station. Antenna 954 relates to an RX antenna, e.g., in a UE. The transmitter, e.g., a base station, may be provided with antenna correlations by manufacturer disclosure. TX correlations (of base station antennas), e.g., are a one-time process since correlations are unlikely to change normally. RX correlations (of UE antennas) may be provided in a dynamic process as each new UE connects during a call, and the UE is necessarily of a different type / design / manufacture / user configuration. The receiver, e.g., a UE, may provide updated antenna correlation information depending on how the UE is held / located. The correlation information may be used by the transmitter (base station) to improve propagation channel estimation, improve channel precoding quality, achieve required channel quality faster, reduce adaptation time, and / or respond to changes faster.

[0066] The embodiments described in connection with capability information being transmitted in receive mode also apply to base stations. For example, in a given region / location, a base station may provide up to, for example, rank 4 for single-user MIMO or up to, for example, rank 8 (4x rank 2) for multi-user MIMO, while maintaining full SU-MIMO (single-user MIMO) rank in adjacent regions. This contrasts with the typical high rank at the center of a cell and low rank at the periphery of the cell, and can provide spatial consistency in user experience throughout the coverage region in a multi-cell environment. The results of beamforming optimization can be verified by field measurements, for example, by using a UE in the field reporting the consistency of the observed rank and SU-MIMO rank in the space / location / coverage region. UE directionality may be taken into account and averaged. A UE with low rank capability may provide erroneous results for the SU-MIMO rank in the spatial domain. Reporting may be dynamic depending on how the UE is held; for example, a particular location may generate a low-rank resolution for the UE. The UE may report its maximum rank capability, for example, upon registration with the network or periodically from time to time. With this information, the network knows what to expect from the UE in a given environment. Embodiments introduce a new metric that accounts for the best lowest layer performance (MSC level) or the ratio of best / worst eigenvalues. For example, a superposition of the propagation environment, the base station transmission strategy, and the resulting UE capability may be obtained as a measure of multiplexing robustness in a given environment. UE capability in such an environment / probing can be tested for a particular given rank and multi-layer transmission balance.

[0067] The results may be UE-specific. The UE may have a different number of streams in the downlink and uplink, e.g., four Rx and two Tx, and the base station may not be able to estimate the UE's antenna / receiver capabilities from observing the signals transmitted by the UE. Therefore, embodiments provide feedback on spatial beam separation capabilities in both directions under known spatial decorrelation due to propagation. Additionally, the measurement environment and base station beamforming are described.

[0068] Furthermore, if some spatial relationship between the Tx and Rx antenna patterns is known (a measure of how closely the Tx and Rx patterns correspond), one can be used to optimize the other. For example, an analog beamforming network from four Rx antennas to four Rx ports may be used to generate two Tx beams using all four antennas, or some of them.

[0069] The embodiments provide a test that enables conformance testing of multi-stream capabilities (single-user MIMO) that allows for up to Nx MCS / modulations, e.g., 256QAM or different, e.g., 1024QAM for FR1 and 64QAM up to 256QAM for FR2. The embodiments further provide for a measurement environment equipped to provide full rank >2 or similar multi-streams with X dB spatial stream separation, i.e., testing whether the UE is capable of full MUX or interference suppression, for example. Test ranks of 1, 2, 3, 4, etc. can be implemented. The embodiments do not focus on over-the-air cables with long-term stable phase and channel estimation. Instead, the embodiments target the spatial separability of the streams as a characteristic of the test environment. This is implemented by using co-polarization, cross-polarization, and hybrid mixed polarization at specific ranks.

[0070] As another aspect, over-the-air (OTA) testing may be used to obtain OTA performance, depending at least in part on perceived rank and signal decorrelation. The UE may report its observed maximum rank, its capability information, which may be a combination of channel and UE capabilities. Using an antenna test function (ATF), embodiments introduce ATF-prime after MIMO equalization, which means that the power and SINR of the decorrelated streams with or without power correction may be performed, which indicates the MUX level.

[0071] Additionally, embodiments can take advantage of the ability to extract inter-stream impairments as a result of varying metrics to represent stream coupling, which can be used with gNB measurement equipment to further decouple the multiplexed streams.

[0072] The spatial capabilities of the UE can set an upper limit on the available performance for improving measurements.

[0073] Embodiments may be able to reduce the amount of signaling, power consumption and interference.

[0074] Embodiments may classify UEs into (spatial) capability classes where the capabilities may be directionally dependent. For example, a certificate may state that a UE has a capability of rank 4 in 30% of the sphere, rank 3 in 50%, rank 2 in 80%, etc. Any number of other ranks and / or sphere sizes are possible.

[0075] The principles on which the embodiments are based can be extended to carrier aggregation, including performance measurements for dual connectivity, e.g., LTE+NR / EN-DC, simultaneous DL-CA, UL-CA, and UL-DL-CA (DL = Downlink, UL = Uplink, CA = Carrier Aggregation). Here, scheduler and network synchronization may also play a role. The result is a category / score / KPI (Key Performance Indicator) based on the test criteria.

[0076] It provides information used by other entities in the network for overall optimization of the links and the network.

[0077] Information about the UE or UE capability classification may be provided to the network to update whether the effective capabilities depend on, for example, the network configuration or the channel, allowing individual link and network performance to be optimized.

[0078] For mobile network operators (MNOs), once the UE has confirmed its spatial capabilities, the MNO can use it to test and optimize network performance by optimizing base station antennas to match the channel propagation characteristics of specific locations and deployments.

[0079] The first aspect relates to reporting the spatial stream separation capabilities of a device.

[0080] a) Device capabilities can be modified by use case (hand, head and body influences), orientation, operating frequency [carrier aggregation {intra-band contiguous / non-contiguous, inter-band}], antenna panel selection and beam direction. b) Includes UE, IoT devices and base station equipment. c) Each device for which capability information exists should be able to use the information to adjust / adapt / improve / optimize spatial stream generation / creation according to defined criteria - not always "increasing", but sometimes "decreasing" (e.g., when limiting factors are known / detected / predicted).

[0081] The second aspect relates to the measurement method and is defined as follows:

[0082] a) How spatial separability is determined. b) What techniques are used to generate and radiate spatially separated streams that maintain the required properties during transmission? c) What methods can be used to control / verify / measure the spatial separation of the streams fed into the device under test?

[0083] The third aspect relates to mechanisms for optimizing performance through knowledge of device capabilities.

[0084] a) Traditionally, the characteristics of both the transmit antenna and the receive antenna are "lumped" together with the characteristics of the "propagation channel" to form a single entity called the "wireless channel." By evaluating the characteristics of both the transmit antenna and the receive antenna (optionally along with their radio frequency front-end circuitry used for either transmission or reception [not ignoring various forms of duplex operation, including full-duplex communication]), the propagation channel itself can be treated as a single entity. In essence, the "wireless channel" is divided into a transmit chain including the transmit antenna, the propagation channel, and a receive chain including the receive antenna. Correlations between two or more transmit chains including those antennas can be determined (see 2 above)—as can correlations between two or more receive chains including those antennas. Such information, known independently of the wireless channel, allows for a better estimation of the general propagation channel.

[0085] Embodiments provide apparatus (e.g., base stations, terminals (including UEs), IoT devices, test equipment, test environments) that include a combination of transmit antennas and transmit chains and a combination of receive antennas and receive chains, where each combination has specific characteristics that can be evaluated to determine the capabilities of either or both of the combinations. In other words, a) the transmit capabilities of the apparatus and the receive capabilities of the apparatus are not necessarily the same; b) it may be possible / necessary / useful to determine the capabilities of only the transmit combination, only the receive combination, or both combinations together. Evaluation of the apparatus is typically performed using test and measurement equipment (measurement environments), generally prior to deployment in a network. However, this should not exclude examples where alternative assessment methods include self-assessment (via built-in test equipment (BITE) functionality), network-assisted assessment where one or more base stations and / or one or more terminals are configured / controlled to perform such assessment.

[0086] b) The Tx branch correlation and Rx branch correlation information can be used to adjust / adapt / improve / optimize the characteristics of the spatially separated streams.

[0087] This may be performed in the time domain, frequency domain, code domain, spatial domain, orbital angular momentum, angular difference of a lobe or null or part thereof and polarization domain.

[0088] The measurements used may include at least one of an error vector magnitude (EVM), a signal-to-interference-and-noise ratio (SINR), a bit error rate (BER), a block error rate (BLER), and combinations thereof.

[0089] Additionally, coordination can be performed according to frequency division multiplexing (FDM) standards, which can include carrier aggregation, where a particular combination of bands is its own capability as well as the bands used as primary and / or secondary carriers. However, further examples include use with multiple networks or multiple radio access technologies (multi-RAT) in dual connectivity (DC) or multi-connectivity (also between different RATs).

[0090] Adjustments can be made automatically based on certain criteria (thresholds / events / network signaling / built-in performance self-measurement / changes in usage / low battery level / temperature detection / interference indication).

[0091] Adjustments can be made immediately.

[0092] The adjustment can be scheduled to occur at the beginning of the next burst / slot / subframe / frame.

[0093] Adjustments can be initiated by changing frequency / beam / antenna panel / antenna polarization / power / modulation and / or coding / RAT / network / orientation / direction / use case.

[0094] Adjustments can be made with cues / sequences / delays / schedules.

[0095] The reconciliation request can be processed (i.e., accepted, rejected, or referred to a higher entity for further processing).

[0096] The adjustments and adjustment requests may be stored for subsequent analysis and / or performance optimization of the device and / or network.

[0097] The adjustments and adjustment requests can be stored on the device, in the network, or in the test environment.

[0098] While some aspects have been described in the context of an apparatus, it will be apparent that these aspects also represent descriptions of corresponding methods, where a block or device corresponds to a method step or function of a method step, and similarly, aspects described in the context of a method step also represent descriptions of a corresponding block or item or function of a corresponding apparatus.

[0099] Depending on particular implementation requirements, embodiments of the present invention may be implemented in hardware or software. The implementation can be carried out using a digital storage medium, such as a floppy disk, DVD, CD, ROM, PROM, EPROM, EEPROM or flash memory, having electronically readable control signals stored thereon and cooperating (or capable of cooperating) with a programmable computer system so that the respective methods are performed.

[0100] Some embodiments of the present invention comprise a data carrier having electronically readable control signals that can cooperate with a programmable computer system to perform one of the methods described herein.

[0101] Generally, embodiments of the present invention may be implemented as a computer program product having program code operable to perform one of the methods of the present invention when the computer program product runs on a computer, The program code may for example be stored on a machine readable carrier.

[0102] Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier.

[0103] In other words, an embodiment of the inventive method is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer.

[0104] A further embodiment of the inventive method is, therefore, a data carrier (or digital storage medium or computer readable medium) comprising, recorded on it, a computer program for performing one of the methods described herein.

[0105] A further embodiment of the inventive method is, therefore, a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. The data stream or sequence of signals can for example be arranged to be transmitted by a data communication connection, for example the Internet.

[0106] A further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein.

[0107] A further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein.

[0108] In some embodiments, a programmable logic device (e.g., a field programmable gate array) can be used to perform some or all of the functions of the methods described herein. In some embodiments, a field programmable gate array can cooperate with a microprocessor to perform one of the methods described herein. In general, the methods are preferably performed by any hardware apparatus.

[0109] The above-described embodiments merely illustrate the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be apparent to those skilled in the art. It is therefore intended that the present invention be limited only by the scope of the impending claims, and not by the specific details expressed by the manner in which the embodiments herein have been described and illustrated.

Claims

1. 1. A method for determining a signal maintenance capability of a device, the method comprising: operating a device in an operational mode to cause the device to maintain at least a first data stream using a wireless interface device of the device; determining the signal maintenance capability of the device independent of the propagation environment of the device and associated with the mode of operation; storing the signal maintenance capability in a memory; A method comprising:

2. changing the operational mode of the device with respect to the at least first data stream; determining the signal maintenance capability of the device associated with the changed operational mode; storing the modified signal maintenance capability and the associated modified operating mode in the memory; The method of claim 1 further comprising:

3. The step of changing the operation mode and determining the signal maintenance capability includes: modifying the correlation between antenna elements of said device; modifying the channel propagation to or from the antenna elements of the device; changing the orientation of the device relative to the link antenna of measurement equipment used to test the device; Varying the number of data channels maintained between the measurement setup and the device; The method of claim 2 , wherein the method is associated with at least one of:

4. 4. The method according to claim 2 or 3, wherein the method is performed in a manner that relies on a channel model that takes into account antenna correlation between antenna elements used for signal transmission using the signal maintenance capability and / or antenna correlation between antenna elements used for signal reception using the signal maintenance capability.

5. The step of operating the device in the operating mode is performed such that the device maintains the at least first data stream in a particular reference state for a channel, the reference state being used to determine the antenna correlation, and the method further comprises: determining the antenna correlation between at least a first antenna and a second antenna of the wireless interface device such that the signal maintenance capability is determined taking into account a reference condition of the channel; further comprising: The method of claim 4.

6. the signal-staying capability is determined for at least a first use case and a second use case of the device, the first use case and the second use case differing with respect to an antenna that the device uses in the operational mode and with respect to at least one of whether the device is hand-held, held near a head, or produces a body effect; wherein the signal maintenance capability is stored with the use case.

6. The method according to claim 4 or 5.

7. The method of any one of claims 4 to 6, wherein the antenna correlation is determined to include information about the antenna correlation of antennas in different antenna arrangements of the wireless interface device.

8. connecting the device to a measurement environment or placing the device in a measurement environment; transmitting a number of multiplexed signals to said device; demultiplexing the multiplexed signal in the device; comparing the demultiplexed signal with the multiplexed signal to obtain a comparison result related to the signal maintenance capability; determining the signal maintenance capability based on the comparison for later use; 8. The method of claim 1, comprising:

9. The method of claim 8 , wherein the comparison result is determined to indicate the number of successfully demultiplexed signals.

10. 10. The method of claim 8 or 9, wherein the step of comparing the multiplexed and demultiplexed signals comprises the use of signal processing techniques.

11. connecting the device to a measurement environment or placing the device in a measurement environment; providing a number of signals to the device; causing the device to multiplex the multiple signals and transmitting the multiplexed signals to the measurement environment; demultiplexing the multiplexed signal in the measurement environment; comparing the demultiplexed signal with the multiplexed signal to obtain a comparison result; determining the signal maintenance capability based on the comparison; 11. The method of claim 1, comprising:

12. The method of claim 11 , wherein the comparison result is determined to indicate the number of successfully multiplexed signals.

13. 13. The method of claim 11 or 12, wherein the step of comparing the demultiplexed signal and the multiplexed signal comprises the use of signal processing techniques.

14. A computer readable digital storage medium storing a computer program having a program code for performing the method of any one of claims 1 to 13 when the computer program is run on a computer.

15. Apparatus configured to perform at least part of the method according to any one of claims 1 to 13.

16. a holder configured to hold the device; a control unit configured to control the device to operate under an operational mode in which the device maintains at least a first data stream using a wireless interface device of the device; a determination unit configured to determine a signal maintenance capability of the device independent of a propagation environment of the device and associated with the operation mode; a memory, wherein the measurement environment is configured to store the signal maintenance capability in the memory; Measurement environment, including:

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