Method to avoid scaling errors of IQ samples on fronthaul

Abstract

Methods and systems are described for implementing scale offset values between an O- DU and an O-RU. The current disclosure enables an O-DU to interoperate successfully with O-RUs having different implementations for scaling of equalized uplink samples for DMRS-5 BF-EQ. For low-cost O-RUs, low-precision multiplier can be used for scale offset without increasing bit error rate in demodulation and decoding. For more capable O-RUs with high- precision multiplier, better control of scale offset is possible, which may allow reducing quantization errors.

Description

METHOD TO AVOID SCALING ERRORS OF IQ SAMPLES ON FRONTHAUL CROSS REFERENCE TO RELATED INFORMATION

[0001] This application claims the benefit of United States of America priority application No. No.63 / 635,315 filed on April 17, 2024, titled “Method to Avoid Scaling Errors of IQ Samples on Fronthaul.” TECHNICAL FIELD

[0002] The present disclosure generally relates to systems and methods for implementing scale offset values between an O-DU and an O-RU. BACKGROUND

[0003] The current disclosure applies to the O-RAN Open Fronthaul Interface, described in the O-RAN Working Group 4 (WG4) Control, User, and Synchronization (CUS) plane specification. See, e.g., “O-RAN Control, User and Synchronization Plane Specification 14.0”, O-RAN.WG4.CUS.0-R003-v14.00, O-RAN Working Group 4, published, February 2024.

[0004] There is also a corresponding specification for the Management plane (M-Plane).

[0005] In WG4, a work item for uplink performance improvement is ongoing with the aim for WG4 to standardize Demodulation Reference Signal based beamforming (DMRS-BF) for uplink where the O-RAN Radio Unit (O-RU) performs channel estimation based on DMRS signals, and calculates and applies beamforming weights with equalization (DMRS-BF-EQ) or without equalization (DMRS-BF-NEQ) included. Change Requests are currently being written and reviewed, to include the desired functionality, targeting to be included in version 16 of the CUS-plane and M-plane specifications.

[0006] The uplink (UE to gNB) of 5G NR typically uses CP-OFDM (Control Plane – Orthogonal Frequency Division Multiplex), where resource elements (REs) in uplink data transmissions each carry one constellation point from a quadrature amplitude modulation (QAM) scheme, as well as unwanted noise and interference.

[0007] 5G NR also allows DFT-s OFDM (also known as transform precoding), which is useful for UEs near the edge of the coverage area. The UE applies a DFT to the scheduled resource blocks, before OFDM IFFT and CP addition. This results in reduced time-domain crest factor (peak to average power ratio at a certain percentile) and thus allows using higher transmit power without clipping. However, the frequency-domain I (in-phase) and Q(quadrature) samples will get significantly increased crest factor and approximately follow a Normal (Gaussian) distribution.

[0008] For DMRS-BF-EQ, the latest submitted CR is ERI CR-0100 v08. “DMRS-BF-EQ description,” available at ERI-2023.12.23-WG4-CR-0100-DMRS-BF-EQ-description- v08.docx, O-RAN WG4 wiki, April 7, 2024. It proposes to add the new clause 12.6.3 describing parts of DMRS-BF-EQ that are not common with DMRS-BF-NEQ. Other CRs describe DMRS-BF-NEQ, the overall DMRS-BF, as well as other specific aspects of DMRS- BF. When an equalizer is present in the O-RU, the O-DU can send the received equalized IQ (In-phase and Quadrature data) samples to demodulation and decoding, without additional channel estimation, as shown in Figure 12.6.3.1-1 in “DMRS-BF-EQ description.” This requires precise knowledge of the level of the wanted signal.

[0009] For DMRS-BF-EQ, the mean power of equalized IQ samples will approach unity at high Signal to Interference plus Noise Ratio (SINR). However, instantaneous I and Q values can have larger magnitude than unity, e.g., due to noise, constellation points on the outer edge of high-order QAM, and / or due to high frequency-domain crest factor of DFT-spread OFDM. To avoid overflow when quantizing equalized I, Q samples to the fronthaul data format (e.g., fixed point, or block floating-point as already supported for other BF methods in “O-RAN Control, User and Synchronization Plane Specification 14.0”), there is a need to scale down samples. Here it is assumed that unity is mapped to the largest possible value of the fronthaul data format, e.g., 2^15 for signed 16-bit fixed-point. The DMRS-BF-EQ description CR proposes a scale offset for this purpose.

[0010] Clause 8.1.3.4, “UL IQ output level for DMRS-BF-EQ” of “DMRS-BF-EQ description” is included below for reference: <<<<<<<<begin clause 8.1.3.4 of “DMRS-BF-EQ description”>>>>>>>> This clause defines the UL IQ output level when DMRS-BF-EQ is used. In this case, a configured UL gain (see clause 8.1.3.2.3) as used for other beamforming methods is not applicable. In general, the IQ output level shall be scaled by the O-RU, as configured by the O-DU, to avoid detrimental overflow when encoding data for the interface. Following clause 12.6.3.5, the equalized IQ sample output from DMRS-BF-EQ for RE n and layer l is expressed as ^^ாொ ாொ ^,^ + ^^^^^,^ = ^^^,^ × ^^^,^ + ^^^,^where X_(n,l) is a random variable representing the respective wanted signal (i.e., a complex modulation symbol as defined by 3GPP TS 38.211 [4] clause 5.1 for CP-OFDM, and an output of the DFT of the complex modulation symbols for DFT-spread OFDM), ^^^,^is an unknown residual term including e.g., the respective interference plus noise and any channel estimation errors, and ^^^,^is the respective positive real-valued scaling from the equalization. There are two scaling functions specified in clause 12.6.3.5. For scaling function 1, ^^^,^is a monotonic function of SINR with the following properties: 0< ^^^,^ ≤ 1 andௌூே^ோ^^^^^,^^→^^^^,^ = 1.For scaling functionSINR.The power of a statistical signal is defined as the mean value of the instantaneous power of the signal. Therefore, the IQ output power of the equalizer for RE n and layer l is expressed as ^^ூொ,^,^ = ^^ ^ห^^ாொ ଶ ாொ ଶ ଶ ^,^ห+ ห^^^,^ห^ = ^^ ^ห^^^,^ห ^ × ^^^ଶ,^ + ^^^ଶ,^1≈ Q magnitude can become larger than one due to residual noise plus interference, e.g., when SINR is low. For DFT-spread OFDM, the I and Q magnitudes can be significantly larger than one due to its high crest factor in frequency domain. To avoid overflow when encoding data for the fronthaul interface, an O-RU scale offset in dB, eq-scale-offset, is configured by the O-DU via M-plane. The configured value shall be within the range indicated by O-RU declared eq-scale-offset-min and eq-scale-offset-max, where none of the values shall exceed 0 dB. After scaling, the IQ data on the fronthaul interface shall fulfill^^^,^ + ^^^^^,^ = ^^^^^^ × 10^^_^^^^^_^^^^^௧ ଶ^ × ൫^^ாொ ^,^ + ^^^^ாொ ^,^൯,power of each of I and Q, not to the sum of their powers, since the purpose of the scaling is only to avoid overflow when quantizing to the fronthaul data format, not to limit IQ power, and also since equalized data are not subject to random phase rotation from the channel. For high SINR (^^^,^ = 1 and residual noise + interference power approaching zero), thepower in dBFS of each of I and Q on the fronthaul interface approximately equals to the value of eq-scale-offset. The O-DU should configure the scale offset to, with sufficiently high probability (as determined by the O-DU at its discretion), avoid overflow when the O-RU encodes IQ data for the interface, i.e., with sufficiently high probability achieve

[0011] Parameters eq-scale-offset, eq-scale-offset-min, and eq-scale-offset-max might be given in dB unit with e.g., 4 digits after the decimal point. Representing the values in dB allows a large dynamic range when needed. SUMMARY

[0012] One embodiment under the present disclosure comprises a method performed by an O-DU for implementing scale offset values. The method comprises: configuring, at the O- RU, a scale offset value; and fetching, from the O-RU, an approximation to the scale offset value, wherein the approximation is as close as possible to, but does not exceed, the scale offset value.

[0013] Another embodiment comprises a method performed by an O-RU for implementing scale offset values. The method comprises: receiving, from an O-DU, a configuration of a scale offset value; determining an approximation to the scale offset value,wherein the approximation is as close as possible to, but does not exceed, the scale offset value; and storing the approximation in a parameter that can be read by the O-DU.

[0014] Another embodiment comprises a network node for implementing scale offset values. The network node comprises: processing circuitry; and a memory. The memory contains instructions whereby the processing circuitry is operable to perform the steps of: receiving, from an O-DU, a configuration of a scale offset value; determining an approximation to the scale offset value; and storing the approximation in a parameter that can be read by the O-DU.

[0015] Another embodiment comprises a network node for implementing scale offset values. The network node comprises: processing circuitry; and a memory. The memory contains instructions whereby the processing circuitry is operable to perform the steps of: retrieving, from an O-RU, a supported range of scale offset values; configuring, at the O-RU, a scale offset value; fetching, from the O-RU, an approximation to the scale offset value; and undoing, based at least in part on the approximation, an applied scale offset either before, or in conjunction with, demodulation.

[0016] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an indication of the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] For a more complete understanding of the present disclosure, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

[0018] Fig.1 illustrates a flow-chart of a method embodiment under the present disclosure;

[0019] Fig.2 illustrates a flow-chart of a method embodiment under the present disclosure;

[0020] Fig.3 illustrates an example of O-DU and O-RU architecture;

[0021] Fig. 4 shows a schematic of a communication system embodiment under the present disclosure;

[0022] Fig. 5 shows a schematic of a user equipment embodiment under the present disclosure;

[0023] Fig. 6 shows a schematic of a network node embodiment under the present disclosure;

[0024] Fig.7 shows a schematic of a virtualization environment embodiment under the present disclosure. DETAILED DESCRIPTION

[0025] Before describing various embodiments of the present disclosure in detail, it is to be understood that this disclosure is not limited to the parameters of the particularly exemplified systems, methods, apparatus, products, processes, and / or kits, which may, of course, vary. Thus, while certain embodiments of the present disclosure will be described in detail, with reference to specific configurations, parameters, components, elements, etc., the descriptions are illustrative and are not to be construed as limiting the scope of the claimed embodiments. In addition, the terminology used herein is for the purpose of describing the embodiments and is not necessarily intended to limit the scope of the claimed embodiments. Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0026] In relation to the current technology described above, there currently exist certain challenges. The eq-scale-offset is applied by the O-RU to reduce sample magnitude before quantization on the fronthaul interface (to avoid overflow when encoding the fronthaul data format) and can also be used to optimize quantization performance. To optimize quantization performance might require fine granularity of scale offset values. For example, with fixed- point quantization, quantization noise decreases when signal level increases, until some point where the clipping (overflow) error starts to dominate over the error caused by approximation to the steps of the quantizer. Thus, there is an optimum level where quantization errors are minimized, depending on data format and signal properties (e.g., probability distribution function).

[0027] The O-DU will undo the effect of eq-scale-offset before or during demodulation and decoding. It can be expected that the O-DU has more computational power and may support high-precision multiplication while at least some O-RUs can be more cost-optimized and mainly use multipliers with relatively low precision. Undoing an approximation to a scale offset applied by an O-RU can be done, e.g., by applying an inverse of the approximation to values received from the O-RU for which the approximation was applied. If the values received from the O-RU are IQ samples to be demodulated, it might also be possible to scale, by the approximation, any decision boundaries or expected coordinates of constellation points. Combinations of such methods are also possible.

[0028] Demodulation, sometimes called modulation de-mapping, can be done in different ways, e.g., depending on the type of decoder. Hard-decision methods output bits and are typically based on decision boundaries between neighbor constellation points. Soft-decision methods often output so called log-likelihood ratio, LLR. The LLR calculation is based on distances from the received IQ sample to the expected coordinates of multiple constellation points. Here, the expected coordinates of constellation points are the IQ sample values that would be received without any noise and distortion or interference.

[0029] The O-RU will typically convert the eq-scale-offset from dB to linear and apply it as linear multiplication. Thus, the O-RU may need to approximate the configured scale offset to its linear multiplication format before applying it. If the O-RU uses a low-precision format, this approximation could become inaccurate, which means that the O-DU cannot completely undo the scale offset applied by the O-RU. The resulting scale error can lead to increased bit error rate and reduced data throughput, which is undesired.

[0030] It is important for the O-DU to accurately know the scale offset value applied by the O-RU. For some parameters with few options, this can be handled by the O-RU declaring a list of supported values. However, for an O-RU supporting many different values of eq-scale- offset it would be impractical to declare all supported values of eq-scale-offset between eq- scale-offset-min and eq-scale-offset-max.

[0031] Declaring a supported step size also has problems. If the O-RU uses a fixed-point multiplier, the corresponding step size in dB units will not be constant over the supported range of eq-scale-offset, but will increase when eq-scale-offset decreases. For example, with an unsigned 8-bit fixed-point multiplier followed by division by 256 (shift right by 8 bits), the step size in the lowest end of the range is 6 dB (from 1 / 256 to 2 / 256) while the step size in the upper end of the range is ~0.034 dB (from 254 / 256 to 255 / 256).

[0032] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges.

[0033] In certain embodiments, the following procedure can be carried out: ^ The O-DU configures (or sends) the desired (target) scale offset value to the O- RU e.g., via M-plane during creation of an rx-carrier (uplink carrier); ^ The O-RU determines its best approximation to the target scale offset (Preferably it shall select an approximation that is as close as possible but does not exceed the target value);^ The O-RU stores this value in a parameter that can be read by the O-DU (same name or different name can be used but it might be preferred to use a different name); ^ The O-DU fetches the value provided by the O-RU, which should be accurate to the precision of the data format used when reading and writing values. Different options may be possible to ensure that the O-RU has stored the value before it is being fetched by the O-DU: The O-DU can wait a certain time before reading back the value, write the configured value as part of carrier creation and fetch the new value when the carrier is created, wait for a state change in the O- RU (e.g., an ACTIVE state), or subscribe to a notification that a value has changed.

[0034] Certain embodiments can comprise, e.g., the O-DU configures a desired scale offset value, within the supported range as declared by the O-RU and when the result is ready, the O-DU fetches the O-RUs (best) approximation to the scale offset value. The O-DU will then use the fetched value to undo the O-RU applied scale offset, either before, or in conjunction with, demodulation.

[0035] In some variations, the value to fetch can be considered ready e.g., after a timer expired, after rx-carrier creation, after the rx-carrier has changed to ACTIVE state, or based on a notification that a value has changed.

[0036] Based on the configured scale offset value, the O-RU can determine a suitable scale offset to apply on equalized IQ samples before encoding to the fronthaul data format. eq-scale- offset-used, which is the value that it will use for its scaling of equalized IQ samples. It shall be as close as possible to the O-DU configured value, but to avoid overflow when quantizing IQ samples with the fronthaul data format, it is preferred that the determined value is not larger than the O-DU configured value.

[0037] Certain embodiments may provide one or more of the following technical advantages. The current disclosure enables an O-DU to interoperate successfully with O-RUs having different implementations for scaling of equalized uplink samples for DMRS-BF-EQ. For low-cost O-RUs, low-precision multiplier can be used for scale offset without increasing bit error rate in demodulation and decoding. For more capable O-RUs with high-precision multiplier, better control of scale offset is possible, which may allow reducing quantization errors. In addition, the teachings of certain embodiments may improve data rate, latency, and / or power consumption.

[0038] It is desired to optimize quantization performance (e.g., to allow fronthaul bitrate reduction). Then a finer granularity of eq-scale-offset values may be needed and some O-RUs might support that. It is known that performance of fixed-point quantization can be tuned by proper scaling. For block floating-point formats (as used in O-RAN), where a common exponent is shared for e.g., all resource elements (REs) of a resource block (RB), the signal level can also impact performance. The reason is that the scaling affects the probability of different exponent values. If one RE needs a higher exponent, then it will increase quantization noise for all REs in same RB. By proper scaling, the probability of exponent increase can be controlled, and thus also the quantization performance.

[0039] The present disclosure can allow an O-DU to properly interoperate both with a low- complexity DMRS-BF-EQ O-RU, e.g., supporting only scale offsets that are a negative power of two, {0 dB, -6.02 dB, -12.04 dB, …}, and to interoperate with a high-performance O-RU supporting scale offsets with fine granularity. For the latter O-RU type, better performance (lower quantization noise) can be achieved for a given fronthaul data format by fine-tuning eq- scale-offset.

[0040] Example: An O-DU has determined that it needs at least 10 dB headroom for peaks and configures eq-scale-offset-config to -10.0000 dB (dB with four digits after the decimal point). ^ An O-RU that only supports scaling by integer powers of two will store 20*log10(2^-2) = -12.0412 dB in eq-scale-offset-used; ^ An O-RU that uses an 8-bit multiplier will store 20*log10(floor(10^(- 10.0000 / 20)*2^8) / 2^8) = -10.1030 dB in eq-scale-offset-used.

[0041] In all cases above, the O-DU knows, with a precision of ~0.00005 dB (assuming proper rounding of dB values to the nearest value with four decimals), which scale offset that the O-RU actually used. This ensures no impact on demodulation and detection performance (e.g., bit error rate), irrespective of multiplier precision in the O-RU.

[0042] Without the teachings of the present disclosure, the first example would result in an error of 2 dB if the O-DU assumes that the O-RU has used the configured value. This can lead to significant performance degradation, especially for high-order modulation.

[0043] Clause 8.1.3.4 of “DMRS-BF-EQ description,” discussed above, is proposed to be changed as follows for v09 of the CR, where changes due to the present disclosure are shown in bold:<<<<<<<<begin proposed changes to clause 8.1.3.4>>>>>>>> To avoid overflow when encoding data for the fronthaul interface, an O-RU scale offset in dB, eq-scale-offset-config, is configured by the O-DU via M-plane as part of carrier creation. The configured value shall be within the range indicated by O-RU declared eq-scale-offset-min and eq-scale-offset-max, where none of the values shall exceed 0 dB. After carrier creation, the O- DU fetches the read-only parameter eq-scale-offset-used from the O-RU. This parameter shall be the O-RU’s best approximation of the eq-scale-offset-config, but shall not exceed eq-scale-offset-config. After scaling, the IQ data on the fronthaul interface shall fulfillpower of each of I and Q, not to the sum of their powers, since the purpose of the scaling is only to avoid overflow when quantizing to the fronthaul data format, not to limit IQ power, and also since equalized data are not subject to random phase rotation from the channel. <<<<<<<<end proposed changes to clause 8.1.3.4>>>>>>>>

[0044] A possible method embodiment under the present disclosure is shown in Figure 1. Method 200 comprises a method performed by an O-DU for implementing scale offset values. Step 210 is configuring, at the O-RU, a scale offset value. Step 220 is fetching, from the O- RU, an approximation to the scale offset value, wherein the approximation is as close as possible to, but does not exceed, the scale offset value. Method 200 can comprise a variety of additional and / or alternative steps and / or optional steps.

[0045] A possible method embodiment under the present disclosure is shown in Figure 1. Method 400 comprises a method performed by an O-RU for implementing scale offset values. Step 410 is receiving, from an O-DU, a configuration of a scale offset value. Step 420 is determining an approximation to the scale offset value, wherein the approximation is as close as possible to, but does not exceed, the scale offset value. Step 430 is storing the approximation in a parameter that can be read by the O-DU. Method 400 can comprise a variety of additional and / or alternative steps and / or optional steps.

[0046] Figure 3 illustrates a O-DU and O-RU architecture. O-DU 610 can be coupled to O-RU 630 across fronthaul interface 620. Antenna(e) 640 of O-RU can be used to communicate with other nodes, UEs, etc.

[0047] Figure 4 shows an example of a communication system 3100 in accordance with some embodiments. In the example, the communication system 3100 includes a telecommunication network 3102 that includes an access network 3104, such as a radio access network (RAN), and a core network 3106, which includes one or more core network nodes 3108. The access network 3104 includes one or more access network nodes, such as network nodes 3110a and 3110b (one or more of which may be generally referred to as network nodes 3110), or any other similar 3rd Generation Partnership Project (3GPP) access nodes or non- 3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 3102 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 3102 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 3102, including one or more network nodes 3110 and / or core network nodes 3108.

[0048] Examples of an ORAN network node include an O-RAN radio unit (O-RU), an O- RAN distributed unit (O-DU), an O-RAN central unit (O-CU), including an O-CU control plane (O-CU-CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an A1, F1, W1, E1, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an O2 interface defined by the O-RAN Alliance or comparable technologies.The network nodes 3110 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 3112a, 3112b, 3112c, and 3112d (one or more of which may be generally referred to as UEs 3112) to the core network 3106 over one or more wireless connections.

[0049] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 3100 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 3100 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0050] The UEs 3112 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 3110 and other communication devices. Similarly, the network nodes 3110 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 3112 and / or with other network nodes or equipment in the telecommunication network 3102 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 3102.

[0051] In the depicted example, the core network 3106 connects the network nodes 3110 to one or more host computing systems, such as host 3116. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 3106 includes one more core network nodes (e.g., core network node 3108) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 3108. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0052] The host 3116 may be under the ownership or control of a service provider other than an operator or provider of the access network 3104 and / or the telecommunication network 3102. The host 3116 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0053] As a whole, the communication system 3100 of Figure 4 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0054] In some examples, the telecommunication network 3102 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 3102 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 3102. For example, the telecommunications network 3102 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive IoT services to yet further UEs.

[0055] In some examples, the UEs 3112 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 3104 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 3104. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN(Evolved-UMTS Terrestrial Radio Access Network) New Radio – Dual Connectivity (EN- DC).

[0056] In the example, the hub 3114 communicates with the access network 3104 to facilitate indirect communication between one or more UEs (e.g., UE 3112c and / or 3112d) and network nodes (e.g., network node 3110b). In some examples, the hub 3114 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 3114 may be a broadband router enabling access to the core network 3106 for the UEs. As another example, the hub 3114 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 3110, or by executable code, script, process, or other instructions in the hub 3114. As another example, the hub 3114 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 3114 may be a content source. For example, for a UE that is a VR device, display, loudspeaker, or other media delivery device, the hub 3114 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 3114 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 3114 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy IoT devices.

[0057] The hub 3114 may have a constant / persistent or intermittent connection to the network node 3110b. The hub 3114 may also allow for a different communication scheme and / or schedule between the hub 3114 and UEs (e.g., UE 3112c and / or 3112d), and between the hub 3114 and the core network 3106. In other examples, the hub 3114 is connected to the core network 3106 and / or one or more UEs via a wired connection. Moreover, the hub 3114 may be configured to connect to an M2M service provider over the access network 3104 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 3110 while still connected via the hub 3114 via a wired or wireless connection. In some embodiments, the hub 3114 may be a dedicated hub – that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 3110b. In other embodiments, the hub 3114 may be a non-dedicated hub – that is, a device which is capable of operating to route communications between the UEs and network node 3110b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0058] Figure 5 shows a UE 3200 in accordance with some embodiments. The UE 3200 presents additional details of some embodiments of the UE 3112 of Figure 4. As used herein, a UE refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage / playback device, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), an Augmented Reality (AR) or Virtual Reality (VR) device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0059] A UE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle- to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0060] The UE 3200 includes processing circuitry 3202 that is operatively coupled via a bus 3204 to an input / output interface 3206, a power source 3208, a memory 3210, a communication interface 3212, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 5. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0061] The processing circuitry 3202 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 3210. The processing circuitry 3202 may be implemented as one or more hardware-implemented state machines (e.g., indiscrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 3202 may include multiple central processing units (CPUs).

[0062] In the example, the input / output interface 3206 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 3200. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0063] In some embodiments, the power source 3208 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 3208 may further include power circuitry for delivering power from the power source 3208 itself, and / or an external power source, to the various parts of the UE 3200 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 3208. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 3208 to make the power suitable for the respective components of the UE 3200 to which power is supplied.

[0064] The memory 3210 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 3210 includes one or more application programs 3214, such as an operating system, web browser application,a widget, gadget engine, or other application, and corresponding data 3216. The memory 3210 may store, for use by the UE 3200, any of a variety of various operating systems or combinations of operating systems.

[0065] The memory 3210 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD- DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 3210 may allow the UE 3200 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 3210, which may be or comprise a device-readable storage medium.

[0066] The processing circuitry 3202 may be configured to communicate with an access network or other network using the communication interface 3212. The communication interface 3212 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 3222. The communication interface 3212 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 3218 and / or a receiver 3220 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 3218 and receiver 3220 may be coupled to one or more antennas (e.g., antenna 3222) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0067] In the illustrated embodiment, communication functions of the communication interface 3212 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location,another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0068] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 3212, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0069] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0070] A UE, when in the form of an Internet of Things (IoT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an IoT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgicalrobot. A UE in the form of an IoT device comprises circuitry and / or software in dependence of the intended application of the IoT device in addition to other components as described in relation to the UE 3200 shown in Figure 5.

[0071] As yet another specific example, in an IoT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0072] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0073] Figure 6 shows a network node 3300 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)), O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O-CU).

[0074] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio.Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0075] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0076] The network node 3300 includes a processing circuitry 3302, a memory 3304, a communication interface 3306, and a power source 3308. The network node 3300 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 3300 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 3300 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 3304 for different RATs) and some components may be reused (e.g., a same antenna 3310 may be shared by different RATs). The network node 3300 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 3300, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 3300.

[0077] The processing circuitry 3302 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other network node 3300 components, such as the memory 3304, to provide network node 3300 functionality.

[0078] In some embodiments, the processing circuitry 3302 includes a system on a chip (SOC). In some embodiments, the processing circuitry 3302 includes one or more of radio frequency (RF) transceiver circuitry 3312 and baseband processing circuitry 3314. In some embodiments, the radio frequency (RF) transceiver circuitry 3312 and the baseband processing circuitry 3314 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 3312 and baseband processing circuitry 3314 may be on the same chip or set of chips, boards, or units.

[0079] The memory 3304 may comprise any form of volatile or non-volatile computer- readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer- executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 3302. The memory 3304 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 3302 and utilized by the network node 3300. The memory 3304 may be used to store any calculations made by the processing circuitry 3302 and / or any data received via the communication interface 3306. In some embodiments, the processing circuitry 3302 and memory 3304 is integrated.

[0080] The communication interface 3306 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 3306 comprises port(s) / terminal(s) 3316 to send and receive data, for example to and from a network over a wired connection. The communication interface 3306 also includes radio front-end circuitry 3318 that may be coupled to, or in certain embodiments a part of, the antenna 3310. Radio front-end circuitry 3318 comprises filters 3320 and amplifiers 3322. The radio front-end circuitry 3318 may be connected to an antenna 3310 and processing circuitry 3302. The radio front-end circuitry may be configured to condition signals communicated between antenna 3310 and processing circuitry 3302. The radio front-end circuitry 3318 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 3318 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 3320 and / or amplifiers 3322. The radio signal may then be transmitted via the antenna3310. Similarly, when receiving data, the antenna 3310 may collect radio signals which are then converted into digital data by the radio front-end circuitry 3318. The digital data may be passed to the processing circuitry 3302. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0081] In certain alternative embodiments, the network node 3300 does not include separate radio front-end circuitry 3318, instead, the processing circuitry 3302 includes radio front-end circuitry and is connected to the antenna 3310. Similarly, in some embodiments, all or some of the RF transceiver circuitry 3312 is part of the communication interface 3306. In still other embodiments, the communication interface 3306 includes one or more ports or terminals 3316, the radio front-end circuitry 3318, and the RF transceiver circuitry 3312, as part of a radio unit (not shown), and the communication interface 3306 communicates with the baseband processing circuitry 3314, which is part of a digital unit (not shown).

[0082] The antenna 3310 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 3310 may be coupled to the radio front- end circuitry 3318 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 3310 is separate from the network node 3300 and connectable to the network node 3300 through an interface or port.

[0083] The antenna 3310, communication interface 3306, and / or the processing circuitry 3302 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 3310, the communication interface 3306, and / or the processing circuitry 3302 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0084] The power source 3308 provides power to the various components of network node 3300 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 3308 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 3300 with power for performing the functionality described herein. For example, the network node 3300 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 3308. As a further example, the power source 3308 may comprise a source of power in the form of a battery or battery pack which isconnected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0085] Embodiments of the network node 3300 may include additional components beyond those shown in Figure 6 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 3300 may include user interface equipment to allow input of information into the network node 3300 and to allow output of information from the network node 3300. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 3300. In some embodiments providing a core network node, such as core network node 3108 of Figure 4, some components, such as the radio front-end circuitry 3318 and the RF transceiver circuitry 3312 may be omitted.

[0086] Figure 7 is a block diagram illustrating a virtualization environment 3400 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 3400 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 3400 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O2 interface. Virtualization may facilitate distributed implementations of a network node, UE, core network node, or host.

[0087] Applications 3402 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 3400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0088] Hardware 3404 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices asdescribed herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 3406 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 3408a and 3408b (one or more of which may be generally referred to as VMs 3408), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 3406 may present a virtual operating platform that appears like networking hardware to the VMs 3408.

[0089] The VMs 3408 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 3406. Different embodiments of the instance of a virtual appliance 3402 may be implemented on one or more of VMs 3408, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0090] In the context of NFV, a VM 3408 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 3408, and that part of hardware 3404 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 3408 on top of the hardware 3404 and corresponds to the application 3402.

[0091] Hardware 3404 may be implemented in a standalone network node with generic or specific components. Hardware 3404 may implement some functions via virtualization. Alternatively, hardware 3404 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 3410, which, among others, oversees lifecycle management of applications 3402. In some embodiments, hardware 3404 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 3412 which may alternatively be used for communication between hardware nodes and radio units.

[0092] Although the computing devices described herein (e.g., UEs, network nodes) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0093] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer- readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally. Example Embodiments

[0094] Below are given additional possible embodiments under the present disclosure.

[0095] Embodiment 1: A first embodiment comprises a method performed by a network node for implementing scale offset values, the method comprising the steps of: a. The O-DU configures (or sends) the desired (target) scale offset value to the O-RU e.g., via M-plane during creation of an rx-carrier (uplink carrier); b. The O-RU determines its best approximation to the target scale offset (Preferably it shall select an approximation that is as close as possible but does not exceed the target value); c. The O-RU stores this value in a parameter that can be read by the O-DU (same name or different name can be used but it might be preferred to use a different name); d. The O-DU fetches the value provided by the O-RU, which should be accurate to the precision of the data format used when reading and writing values. Different options may be possible to ensure that the O- RU has stored the value before it is being fetched by the O-DU: The O- DU can wait a certain time before reading back the value, write the configured value as part of carrier creation and fetch the new value when the carrier is created, wait for a state change in the O-RU (e.g., an ACTIVE state), or subscribe to a notification that a value has changed.

[0096] Embodiment 2: A second possible embodiment comprises a method performed by a network node (e.g., O-DU) for implementing scale offset values, the method comprising the steps of: a. the O-DU configures a desired scale offset value, within the supported range as declared by the O-RU; b. when the result is ready, the O-DU fetches the O-RUs (best) approximation to the scale offset value; c. the O-DU will then use the fetched value to undo the O-RU applied scale offset, either before, or in conjunction with, demodulation.

[0097] Embodiment 3: A third possible embodiment comprises a method performed by a network node (e.g., O-RU) for implementing scale offset values, the method comprising the steps of: a. declaring a supported range, such that the O-DU configures a desired scale offset value, within the supported range;b. transmitting to the O-DU an O-RU best approximation to the scale offset value, wherein the O-DU will then use the fetched value to undo the O- RU applied scale offset, either before, or in conjunction with, demodulation.

[0098] Embodiment 4: Another possible embodiment comprises the method of any one of embodiments 1 to 3, wherein the value to fetch can be considered ready e.g., after a timer expired, after rx-carrier creation, after the rx-carrier has changed to ACTIVE state, or based on a notification that a value has changed.

[0099] Embodiment 5: Another possible embodiment comprises the method of any one of embodiments 1 to 4, wherein based on the configured scale offset value, the O-RU can determine a suitable scale offset to apply on equalized IQ samples before encoding to the fronthaul data format. eq-scale-offset-used, which is the value that it will use for its scaling of equalized IQ samples. It shall be as close as possible to the O-DU configured value, but to avoid overflow when quantizing IQ samples with the fronthaul data format, it is preferred that the determined value is not larger than the O-DU configured value.

[0100] Embodiment 6: Another possible embodiment comprises a network node for implementing scale offset values, the network node comprising: processing circuitry configured to perform any of the steps of any of embodiments 1 to 5; and power supply circuitry configured to supply power to the processing circuitry.

[0101] Certain embodiments for implementing certain teachings of the present disclosure can be implemented via a Change Request to O-RAN.WG4.CUS.0. Such a possible Change Request to implement certain disclosed embodiments is provided below. <<<<<<<<begin proposed Change Request to O-RAN.WG4.CUS.0.>>>>>>>> Change Request Document O-RAN.WG4.CUS.0 ver 15.00 CR ERI-0100 rev 8 Title: DMRS-BF-EQ description Source to WG: Ericsson Target WG : WG4 Category: B CR Creation Date 2023.12.23 Use one of the following categories: A (mirror corresponding to a change in an earlier release) B (addition of feature), C (functional modification of feature) D (editorial modification) F (correction) Detailed explanations of the above categories can be found in 3GPP TR 21.900. Reason for Part of the CUS-plane changes from ULPI WI Change:Summary of Add clause 12.6.3 (and sub-clauses) describing DMRS-BF-EQ and update clause 8.1.3 to change: include DMRS-BF-EQ aspects. Consequences if not aproved: Clauses affected: All Y N Other specs N Other core specifications: <fill in related CRs if “Y”> affected: X Test specifications: <fill in related CRs if “Y”> (show related CRs) X O&M Specifications: <fill in related CRs if “Y”> Supporting material: Other comments: <change the following clauses and sub-clauses according to change marks> 8.1.3 Digital power scaling IQ power level in dBFS (dB full scale) is a logarithmic representation of the power level for an IQ sample carried over the digital interface. IQ power level in dBFS is proportional to logarithm of I²+Q²: IQ power level [dBFS] = 10·log10( I²+Q² ) - 10·log10(FS) = 10∙log10 (I2+Q2) - 10∙log10(FS0 ^ 2-FS_Offset) Where: I is the in-phase portion of a received constellation point; Q is the quadrature portion of a received constellation point; FS is the Full Scale (maximum) permitted value of I or Q based on their digital representations; FS_Offset is an M-Plane parameter (value 0 is used if this parameter is not supported by O-RU or not set by O-DU); FS0= max(I²) = max(Q²) = max(I²+Q²) with max over all IQ values that can be represented by IQ data format in U-Plane message. The actual IQ values that may occur in a U-Plane message are restricted by ^^ଶ + ^^ଶ ≤ ^^^^ = ^^^^^ ∙ 2ିிௌ_ை^^^^௧. For frequency domain IQ data, 0 dBFS shall be the maximum power level which can be carried by one subcarrier. The smallest non-zero IQ power level is defined by the interface resolution. It can be expected that an O-RU will normalize any received DL value to its internal representation of full scale so that a 0 dBFS can be properly handled. EXAMPLE 1: FS_Offset = 0 I = min I, Q = 0With 9-bit mantissa 2's complement + 4-bit exponent compression: min I = -256^215= -223^ FS0= 246, FS = FS0^2-FS_Offset= 2460 dBFS ^ average(I²+Q²) = 246Interface resolution ^ 1 / (246)^ -138.47 dBFS EXAMPLE 2: FS_Offset=10 I=min I, Q=0 With 14-bit mantissa 2's complement + 4-bit exponent compression: min I = -213^215= -228^ FS0 = 256, FS = FS0 ^ 2-FS_Offset= 256-10= 2460 dBFS ^ average(I²+Q²) = 246Interface resolution ^ 1 / (246)^ -138.47 dBFS 8.1.3.2.1 DL and UL gain definition commonality The gain of an array is the relation between the levels of a test signal seen at its input and output, also called digital power scaling. The gain of an array may be calculated from the gain of one element of the array while assuming all elements have same gain. Figure 8.1.3.2.1-1 depicts the gain relations between the digital interface and the RF reference plane to an assumed lossless antenna (i.e., antenna insertion losses are counted as part of the gain in both DL and UL direction). For DMRS-BF-EQ, UL gain is not applicable since equalization will compensate the IQ output level for channel variations. See clause 8.1.3.2.4. [figure deleted] Figure 8.1.3.2.1-1: D OL-R aUnd UL gain over fronthaul interface Both DL and UL gains in [dB] shall be described by the following relations DL gain [dB] = RF output level [dBm] – IQ input level [dBFS] UL gain [dB] = IQ output level [dBFS] – RF input level [dBm] where: 'RF output level [dBm]' and 'RF input level [dBm]' are RF signal level in dBm at a reference plane to an assumed lossless antenna when the antenna is integrated inside the O-RU, or at the antenna connector if the antenna is not integrated inside the O-RU. The rms output power [dBm] is measured per array element as Total Radiated Power TRP (i.e., excluding any antenna directivity gain). The rms input power [dBm] is measured per array element after including the antenna directivity gain. Note that the antenna directivity gain results from the array element directivity + 10·log10(number of elements). Hence, when evaluating the array element gain, the antenna directivity is reduced to the array element directivity. 'IQ input level [dBFS]' and 'IQ output level [dBFS]' are 10·log10(average(I²+Q²)) normalized such that 0 dBFS is the maximum nominal (r.m.s.) power level which can beachieved with a constant IQ signal with arbitrary phase (i.e., for frequency-domain IQ signal for one sub-carrier, constant over time). In O-RUs supporting beamforming, the actual DL gain and UL gain of the array element may be impacted by the gain level of beamforming weight used and which may change dynamically during operation. Such dependency on the beam pattern shall be excluded when describing any configurable gain or reported gain (as O-RU capability). For an exact definition of DL and UL gain, the respective input test signals shall be declared by the O-RU vendor; this is not in scope of the present document. [For information only: This can be e.g., continuous-wave (CW) signal at carrier center or test signals / reference signals defined by 3GPP; for DL gain those being defined to test accuracy of the maximum output power (3GPP TS 36.141

[0040] , clause 6.2 or TS 38.141

[0041] , clause 6.2) and for UL gain those being defined to test absolute accuracy of Received Interference Power (3GPP TS 36.133

[0038] , clause 10.1.1 or TS 38.133

[0037] , clause 10.1.1)]. In Figure 8.1.3.2.1-2 the details of DL gain are described. For every tx-array, the O-RU shall report (as a capability) the maximal configurable DL gain of one element of the array (alternatively the nominal power per tx- array element mapped to 0 dBFS). In addition, the O-DU shall configure over the M-Plane the DL gain to be used per tx-array element for a certain carrier configuration. The values for the max configurable DL gain and configured DL gain shall be configured assuming: ^ No power loss / gain due to beamforming weights; ^ all available DL power may be allocated to one RE in a single eAxC (if dynamic range optimization is used by configuring non-zero value in M-Plane parameter Reference_Level then single RE can have allocated available DL power less Reference_Level value; see clause 8.1.3.3); [figure deleted] digital input to O-RU Figure 8.1.3.2.1-2: Details of DL gain In Figure 8.1.3.2.1-3 the details of UL gain are described. For every rx-array, O-RU shall report (as a capability) an UL gain_correction_range in dB of one element of the array (applicable to all the elements of the array). The gain_correction_range shall be signed, have a max and min value, and a step size. In addition, the O-DU shall configure over the M-Plane a gain_correction value to be applied to the signal received by each array- element to calculate the IQ data in each eAxC (for purpose of backward compatibility this shall be configured as a sum of a common gain correction applicable to all eAxCs of given array carrier and an individual gain correction of each eAxC). The O-RU shall then configure its UL gain (see clause 8.1.3.2.3) of the rx-array element for that carrier (rx-array carrier element) if the IQ compression method is configured as static. In case the compression method is dynamic, the UL gain of the O-RU shall be dynamic and based on compressioninformation received in realtime over the C-Plane as specified in clause 8.1.3.2.3. The values for the UL gain shall be configured assuming no power loss / gain due to beamforming weights. [figure deleted] digital output of O-RU Figure 8.1.3.2.1-3: Details of UL gain 8.1.3.2.2 DL gain definition The DL gain of a TX array carrier element shall be provided as part of the O-RU carrier set- up procedure. The configured (by the O-DU over the M-Plane) DL gain of a TX array carrier element (i.e., "TX array carrier element" refers to the TX array element serving the respective carrier configured on the respective TX array) shall be defined by mapping the Reference_Level dBFS (see clause 8.1.3.3) carried over any subcarrier (of the carrier) on the digital interface to the maximum RMS power the TX array carrier element may output at the assumed-lossless antenna connector port (i.e., including all insertion losses). In single-carrier operation, the configured DL gain shall apply to the carrier. In multiple-carrier operation, the configured DL gain should be lower accommodating the number of multiple carriers and their bandwidths. The O-DU shall scale down the level of the signals at the interface and / or set tx-array-carrier gain values to avoid saturation in the O-RU for single or multiple-carrier configurations. Configured DL_gain [in dB] ≤ maximum TX power per array element [in dBm] – Reference_Level [in dBFS], which is valid for each individual spatial stream served under the TX array carrier element. The following statements shall apply to the above equation: 1) The maximum configured DL gain of a TX array carrier is equivalent to mapping 0 dBFS carried over any subcarrier (of the carrier) on the digital interface to the maximum RMS power the TX array carrier element is supposed to output + 10 ^ log10 (the number of array elements) – Reference_Level [in dBFS]. 2) For a category A O-RU, the tx-array output rms power is measured over 1 polarization 3) For a category B O-RU, the tx-array output rms power shall be measured over all polarizations addressed by the respective precoding operations 4) Configured DL_gain [in dB] = target TX carrier power per array element [in dBm] - Reference_Level [in dB] where target TX carrier power per array element ≤ maximum TX power per array element.5) If the O-RU reports a minimum DL gain capability, then the O-DU shall also ensure that Configured DL_gain [in dB] ≥ minimum DL gain per array element [in dB] – Reference_Level [in dBFS] where the minimum DL gain per array element is the capability reported by O-RU. 8.1.3.2.3 UL gain definition except for DMRS-BF-EQ This clause defines UL gain for all cases except when DMRS-BF-EQ is used. For DMRS- BF-EQ, the notion of a configured UL gain is not applicable and instead the output level is described in clause 8.1.3.4. The UL gain or scaling of an rx-array carrier element (i.e., "rx- array carrier element" refers to the rx-array element serving the respective eAxC configured on the respective rx-array) shall be defined by mapping -152 dBm at the assumed-lossless antenna port to the smallest power level an IQ sample can carry over the digital interface (i.e., average(I²+Q²) = 1) while considering the configured gain_correction value and the IQ compression properties to be used; configured gain_correction is sum of RX carrier specific gain_correction and eAxC specific gain_correction. In addition, in order to avoid saturation over the interface when beamforming is used over the rx-array carrier, the largest power level that can be received at the assumed-lossless antenna port by the rx-array carrier element shall be equivalent to 0 dBFS - 10·log10(number of array elements). The configured gain- correction shall allow the adjustment of the level of the smallest & largest receivable power. The following principles shall apply: 1) The UL gain of an RX eAxC shall be equal to the UL gain of the rx-array carrier element, and contributions to IQ in the eAxC from all rx-array elements shall have the same gain 2) The minimum and maximum power levels that can be received by the RX eAxC shall be scaled by +10·log10(number of array elements) from the respective values of the rx-array carrier element (i.e. when signals are received with equal levels from all the elements of the rx array meaning no tapering used and all rx elements have same design properties). In case an rx-array has only one rx-array element, then the scale factor shall be unity. The reason behind this principle is to allow applying tapering (beam ID dependent) to an rx-array without impacting the quality of the IQ data being transferred over the interface (i.e., in a worst case scenario, the signal is received from only one rx- array element from the rx-array). 3) Assumed-lossless antenna port means antenna losses shall be part of the unit under test. 4) The -152 dBm shall be considered as the smallest level that can be measured by a narrow subcarrier of 1.25 kHz for a system with 3 dB of equivalent noise figure and without being impacted by the interface noise (i.e., 20 dB margin considered). 5) Configured_UL_gain [in dB] = Interface resolution [dBFS] - (-152 dBm) + gain_correction [dB]; valid for each received individual spatial stream (i.e. configured_UL_gain is configured by O-RU and not by the O-DU). The UL gain shall depend on the digital interface resolution (in dBFS) representing the smallest level that can be used. The interface resolution depends on the compression scheme which can be static or dynamic. For this reason, when multiple compression methods or IQ bitwidths are used for data streams received from an rx-array carrier element, the configuredgain shall be applied to all the intended compression methods and IQ bitwidths following the formula defined in principle #5 above for each compression method and IQ bitwidth. For example, when using block floating point compression, the interface resolution shall be defined as Interface resolution [dBFS]=−20 × log^^ ^2ெ^^௧^^^^_^^௧^^ି^ × 2ଶಶ^^^^^^^_್^^ೞି^^ where:Mantissa_bits is the number of mantissa bits in the defined block floating point notation. Exponent_bits is the number of exponent bits in the defined block floating point notation. It is assumed that the gain_correction is 0 dB by default, unless a different value is needed due to special circumstances (details beyond the scope of the present document). The gain_correction is configured as one value per rx array carrier and does not change once an array carrier is activated. The O-RU applies a configured value of gain_correction regardless of used compression. EXAMPLE: With rx-array formed by 10 array elements and gain_correction of 0 dB: 9-bit mantissa 2's complement + 4-bit exponent ^ Interface resolution=-138.5 dBFS Default UL gain [dB] = -138.5 dBFS + 152 dBm + 0 dB = 13.5 dB The UL gain and power scaling are summarized in Table 8.1.3.2.3-1. Table 8.1.3.2.3-1: Example of UL gain and power scaling for an rx array with 10 elements and for block floating point compression based on 9-bit mantissa and 4-bit exponent Interface resolution -138.5 dBFS rx-array carrier element Rx-array carrier with 10 elements UL Gain 13.5dB 13.5 dB Lowest received power level -152 dBm ^ -138.5 dBFS -142 dBm^ -128.5 dBFS without degradation due to interface (excluding losses due to beamforming weights) Largest possible received power -23.5 dBm ^ -10 dBFS -13.5 dBm ^ 0 dBFS level 8.1.3.3 TX power budget for Category A and Category B O-RUs This clause describes the handling of the power budget in a category A and category B O- RU. In general, care shall be taken to avoid exceeding the maximum rms power rating of a tx-array element. In this clause, ^^a,k is the maximum rms power rating (in W) of tx-array element k of a tx- array a with K elements. For simplicity it is assumed all K elements of the array have the same maximum rms power rating (i.e., for every array a and every ^^ and ^^´, ^^a,k= ^^a,k´). For an O-RU with tx-array a, the maximum rms power rating of tx-array element shall be reported as read-only parameter. This will be a common value for all array elements of the tx-array a.NOTE 1: The maximum rms power rating can be reported as form of gain when mapped to 0dBFS. The maximum rms power rating of array can be derived from ^^a,k by scaling linearly with the number of elements K (i.e., ^^a=K·^^a,k) In addition, let ^^^^,^^,^^ be the gain (in dB) configured for tx-array element ^^ of tx-array ^^ for array carrier ^^. It is considered that the configured gain is same to every element (i.e., for every tx-array carrier ^^, every tx-array ^^ and every element ^^ and ^^´, ^^^^,^^,^^ = ^^^^,^^,^^´). Hence, the O-DU should configure the O-RU by providing a value for ^^^^,^^,^^ in parameter 'gain' of tx-array-carrier. The total gain of array carrier c served on array a can be derived from the configured gain ^^^^,^^,^^ as: ^^^^,^^ [dB]= ^^^^,^^,^^ [dB]+10 ^ log10(K). where: ^^^^,^^ is the total gain of array carrier c served on array a ^^^^,^^,^^ is the configured gain of array element k of array a for carrier c Hence, the power p^^,^^,^^ of array carrier c served on tx-array element k of array a can be derived as p^^,^^,k [dBm] = ^^^^,^^,^^ [dB] + 0 dBFS. As a result, the total power of p^^,^^ of array carrier c served on tx-array a is derived as p^^,^^ [dB]= p^^,^^,^^ [dB] + 10 ^ log10(K), where: K is the total number of array elements in array a Finally, the total power p^^.k used on tx-array element k of tx-array a serving all configured carriers is derived as pୟ,୩ = 10 ^ log^^,ೌ,ೖ^^ ^ 10^^ . ^ In scenarios where a tx-array element k is shared between multiple tx-arrays, the O-DU shall ensure that the configured gains ^^^^,^^,^^ are constrained by: ^^ 10^^,ೌ,ೖାோ^^^^^^^^_^^௩^^^^^≤ 1000 ^ ^^^where:^^^ = m^in ൫^^^,^൯Reference_Levelc(in dB) is the array-carrier specific IQ normalization level optionally configured via M-Plane per array carrier (the value 0 is used if this parameter is notsupported by the O-RU or not configured by the O-DU). The index a spans over every tx-array a that shares array element k and has array carrier configured. The summing over c includes every array carrier c that is configured for tx-array a. NOTE 2: In general m^^,^^ can be different for different values of tx-array a. However, tx-arrays not used in a given configuration do not contribute to the above constraint. If O-RU reports via M-Plane the minimum gain of the tx-array element then the O-DU shall ensure that the configured gains ^^^^,^^,^^ are constrained by: ^^^^^^_^^^^^^^^^,^ ≤ ^^^,^,^ + ^^^^^^^^^^^^^^^^^^_^^^^^^^^^^^where Min_Gaina,k(in dB) is the tx-array element specific minimum gain optionally reported by the O-RU via the M-Plane parameter min-gain. For every configured array carrier c over a tx-array a, the O-DU shall ensure that the input power levels of all resource elements used over all eAxCs x are constrained by: ^^ 10ோா^^,ಳ^ಷ,^ೄ,ೌ≤ 10ோ^^^^^^^^_^^௩^^^^^^^and,^ ≤where:^^^^^ௗ,^௫ி,^ௌ,^= input power level in an n of an eAxC x of array carrier c configured over tx-array a. ^^^^^ ௗ,^௫ி,^ௌ,^ = 10 ∙ log^^൫^^^,௫,^,^ଶ + ^^^,௫,^,^ଶ൯ − 10 ∙ log^^(^^^^^ ∙ 2ିிௌ_ை^^^^௧)^^^,௫,^,^and ^^^,௫,^,^are decompressed IQ sample value components, ^^^^^and FS_Offset are defined in clause 8.1.3.1. The summing over x includes every eAxC x of array carrier c that is used simultaneously in DL on the tx-array a. The summing over n includes every RE of the eAxC x that is used simultaneously in DL. When beamforming is used in O-RU, an additional constraint applies to all the beamforming weights to be used for beamforming in order to ensure that the tx power per tx-array element after the beamforming has well-defined upper bound and does not exceed the limit of the maximum rms power rating of the tx-array element. To simplify the notation and cover all beamforming types, i.e. frequency-domain beamforming and time-domain beamforming, any individual beamforming weight (a complex number multiplier used by O-RU in beamformingoperation) is denoted as w. For any beamforming weight w to be used by O-RU to perform beamforming operations, the entity controlling the generation of the weight (i.e., O-DU or O-RU) shall ensure that |^^|^^ ≤ ^^.This constraint is applicable to every beamforming weight, used in frequency or time domain. The constraint is applicable to every explicit or implied beamforming weight applied by O- RU regardless of the source of the beamforming weight (e.g. received from O-DU, predefined by O-RU, generated by O-RU from beam attributes or from channel information, etc.). <add the following clause> This clause defines the UL IQ output level when DMRS-BF-EQ is used. In this case, a configured UL gain (see clause 8.1.3.2.3) as used for other beamforming methods is not applicable. In general, the IQ output level shall be scaled by the O-RU, as configured by the O-DU, to avoid detrimental overflow when encoding data for the interface. Following clause 12.6.3.5, the equalized IQ sample output from DMRS-BF-EQ for RE ^^ and layer ^^ is expressed as I ாொ ^,^ + ^^Qாொ ^,^ = ^^^,^ × ^^^,^ + ^^^,^where ^^^,^is a randomsignal (i.e., a complex modulation symbol as 5.1 for CP-OFDM, and an output of the DFT of the complex modulation symbols for DFT-spread OFDM), ^^^,^is an unknown residual term including e.g., the respective interference plus noise and any channel estimation errors, and ^^^,^is the respective positive real-valued scaling from the equalization. There are two scaling functions specified in clause 12.6.3.5. For scaling function 1, ^^^,^is a monotonic function of SINR with the following properties: 0< ^^^,^ ≤ 1 andௌூேlோi^m,^→^^^^,^ = 1.For scaling function 2, ^^^,^ = 1, which is independent from SINR.The power of a statistical signal is defined as the mean value of the instantaneous power of the signal. Therefore, the IQ output power of the equalizer for RE ^^ and layer ^^ is expressed as ^^ூொ,^,^ = ^^ ^หIாொ ଶ ^,^ห+ หQாொ ଶ ^,^ห^ = ^^ ^ห^^ଶ ^,^ห ^ × ^^^ଶ,^ + ^^^ଶ,^where ^^^ଶ,^ =For both CP-OFDM and DFT-spread OFDM, the power of ^^^,^equals one: ^^^,^,^ = ^^ ^ห^^ଶ ^,^ห ^ = 1.Then, the IQ power of equalizer^^ூொ,^,^ = ^^ ^หIாொ ^,^ห+ หQாொ ^,^ห^ = ^^^ଶ,^ + ^^^ଶ,^Independent of scalingଶthat ^^^,^ = 1 and^^^ଶ,^ ≪ 1. Then, in this case, ≈ I or Q or both can belarger than one when high-order modulation is used. For example, the corner constellation points of 64-QAM have magnitude 7 / √42 ≈ 1.08 for each of I and Q. Further, the I and Q magnitude can become larger than one due to residual noise plus interference, e.g., when SINR is low. For DFT-spread OFDM, the I and Q magnitudes can be significantly larger than one due to its high crest factor in frequency domain. To avoid overflow when encoding data for the fronthaul interface, an O-RU scale offset in dB, eq-scale-offset, is configured by the O-DU via M-plane. The configured value shall be within the range indicated by O-RU declared eq-scale-offset-min and eq-scale-offset-max, where none of the values shall exceed 0 dB. After scaling, the IQ data on the fronthaul interface shall fulfill ^^^,^ + ^^^^^,^ = ^^^^^^ × 10^୯_^ୡୟ୪^_୭^^^^^ ଶ^ × ൫Iாொ ^,^ + ^^Qாொ ^,^൯,where FS^ =power that canbe represented by restriction on full scale here differs from the definition in clause 8.1.3.1 in that it only pertains to instantaneous power of each of I and Q, not to the sum of their powers, since the purpose of the scaling is only to avoid overflow when quantizing to the fronthaul data format, not to limit IQ power, and also since equalized data are not subject to random phase rotation from the channel.For high SINR (^^^,^ = 1 and residual noise + interference power approaching zero), thepower in dBFS of each of I and Q on the fronthaul interface approximately equals to the value of eq-scale-offset. The O-DU should configure the scale offset to, with sufficiently high probability (as determined by the O-DU at its discretion), avoid overflow when the O-RU encodes IQ data for the interface, i.e., with sufficiently high probability achieve ாொ ି^୯_^ୡୟ୪^_୭^^ ^,^ , ^^ாொ ^,^ ≤ 10^^^ max൫ห^^ห ห ห൯ଶ^, which ensures that, withmax ^ห^^^,^หଶ, ห^^^,^หଶ^ ≤ ^^^^^.<add the following clauses12.6.3 DMRS-BF-EQ description DMRS based beamforming with equalization (DMRS-BF-EQ) is a beamforming method wherein as one possible implementation the O-RU computes UE channel estimates based on the received PUSCH DMRS symbols, then computes weights for beamforming with equalization based on those channel estimates and applies the weights to the PUSCH data, see Figures 12.6.3.1-1 and 12.6.3.1-2. In Clause 12.6.3, port-reduction refers to the operation that applies weights for beamforming with equalization to user data (PUSCH and / or DMRS). Similarly, port-reduced refers to the output of such an operation. [figure deleted] NOTE: The above figure illustrates some of the high level functionalities inside the O-RU and O-DU, and do not bind the internal design of each of the O-RU and O-DU. Figure 12.6.3.1-1: O-RU supporting DMRS-BF-EQ, excluding port-reduced DMRS; O-DU illustrated with PUSCH equalizer bypass [figure deleted] NOTE: The above figure illustrates some of the high level functionalities inside the O-RU and O-DU, and do not bind the internal design of each of the O-RU and O-DU. Figure 12.6.3.1-2: O-RU supporting DMRS-BF-EQ, including port-reduced DMRS; O-DU illustrated with equalizer and advanced receiver The two Figures 12.6.3.1-1 and 12.6.3.1-2 show the two different usages of an O-RU supporting DMRS-BF-EQ. The first figure shows that case where SINR reports are requested by the O-DU, but port-reduced DMRS are not requested. This case supports non-DMRS-based O-DU algorithms. The second figure shows that case where port-reduced DMRS are requested by the O-DU, but SINR reports are not requested. This case supports DMRS-based O-DUalgorithms. An O-RU supporting DMRS-BF-EQ shall support sending port-reduced DMRS data and SINR data to O-DU. It is an optional O-RU capability to support simultaneous provision of port-reduced DMRS data and SINR data. As shown in Figure 12.6.3.1-1, the O-RU is expected to carry out DMRS symbol extraction, DMRS channel estimation, a calculation of weights for beamforming with equalization and then apply the weights to the user data, excluding DMRS symbols. In addition, the post- equalization SINR data is calculated by the O-RU. Then, the O-RU transfers the equalized PUSCH data and the SINR data to the O-DU. The O-DU performs demodulation and decoding using the equalized PUSCH data and SINR data as input. See clause 12.6.3.5 for specific requirements for processing PUSCH data. In addition to the O-DU illustrated in Figure 12.6.3.1-1, other O-DU implementations not using port-reduced DMRS are also supported, such as non-DMRS-based advanced receivers and non-DMRS-based CoMP receivers. Because the O-DU may require certain RRM measurements defined on signals before port- reduction (beamforming and equalization) and / or defined on DMRS channel estimates, both of which are not in general available in the O-DU, it is mandatory for the O-RU using DMRS- BF-EQ to have the capability to perform certain RRM measurements and convey those to the O-DU, see Table 10.2-1. As shown in Figure 12.6.3.1-2, if the O-RU is configured to convey port-reduced DMRS to the O-DU (O-RU supporting DMRS-BF-EQ shall have the capability of sending port-reduced DMRS symbols), calculation of weights for beamforming with equalization is done for DMRS symbols in addition to PUSCH data. In this case, these port-reduced DMRS symbols (including equalization) are transferred to the O-DU where they can be used by DMRS-based receiver algorithms, e.g., a DMRS-based advanced receiver (a more complex receiver such as a SIC receiver) is implemented in the O-DU. The O-DU performs equalization or advanced DMRS- based features, which may include DMRS extraction, DMRS channel estimation, equalization and combining weight calculation and weight application. Finally, the O-DU will perform demodulation and decoding. In addition to the O-DU illustrated in Figure 12.6.3.1-2, other O-DU implementations using port-reduced DMRS are also supported, such a DMRS-based CoMP receivers. For the case with non-DMRS-based algorithms in O-DU, because the O-RU executes DMRS channel estimation and beamforming including equalization, with some impact on O-RU complexity, the O-DU DMRS channel estimation and equalization can be omitted (when not employing equalizers or DMRS-based advanced receivers) and only be performed once in thesystem, e.g., in a gNB for 5G NR , and the PUSCH processing can be optimized to achieve low PUSCH latency (similar to WDBF). When equalization is not performed in the O-DU, the O- DU only includes demodulation and decoding L1 functions, which are not performance differentiators. For the case with DMRS-based algorithms in O-DU, the port-reduced DMRS provides a possibility to share DMRS channel estimation and equalization implementations between DMRS-BF-EQ and DMRS-BF-NEQ in the O-DU. Sending port-reduced DMRS enables O- DU implementations with DMRS channel estimation and equalization to interwork with both DMRS-BF-EQ O-RU and DMRS-BF-NEQ O-RU. However, there are differences in areas such as O-RU configurations and RRM measurements tied to the two beamforming methods that needs to be catered to by the O-DU. For both the case with non-DMRS-based and the case with DMRS-based algorithms in O-DU, the O-RU’s equalized PUSCH IQ data and SINR data are mathematically defined in Clauses 12.6.3.4 and 12.6.3.5, which supports stand-alone testing. DMRS Extraction: here the DMRS REs may be extracted from the frequency-domain data flows from each receive antenna. While the most straightforward method would simply extract every relevant RE in every DMRS symbol for every antenna element, it is not excluded that an O-RU implementation may optimize this step in some manner. DMRS Channel Estimation: in one possible implementation of the O-RU, the DMRS data may be processed to calculate an estimate of the effective RF channels between each UE antenna port and each O-RU’s receive antenna. No specific algorithm is specified. Beamforming with Equalization Weight Calculation: For DMRS-BF-EQ, DMRS-based channel estimates may be used to calculate weights for beamforming with equalization, used to reduce the data dimensionality from number-of-antennas to number of UE data layers. This operation is done as a port-reduction (including equalization) of the PUSCH data. Equalization is performed to support non-DMRS-based O-DU algorithms. If configured, e.g. when equalizer is enabled in O-DU or if an advanced receiver is implemented in the O-DU, the DMRS symbols are beamformed and equalized in the same way as PUSCH data, and the port-reduced DMRS symbols will be sent to the O-DU. If configured the O-RU will provide SINR measurements for each UE-layer, which may be used in the O-DU demodulator for log-likelihood ratio (LLR) calculation. The equalized PUSCH data signal can then be processed by the O-DU demodulator.12.6.3.3 DMRS-BF-EQ specific operational aspects As part of the DMRS-BF-EQ operation, O-RU shall report RRM measurements if requested by O-DU. The O-RU shall declare which RRM measurements it supports, including mandatory RRM measurements, and the O-DU shall configure via M-Plane which RRM measurements it wants delivered, if any. See clause 9.2 for a full description of the RRM measurements associated with DMRS-BF. As part of the DMRS-BF-EQ operation, O-RU shall report SINR measurements if requested by O-DU. The O-RU shall declare which SINR resolutions it supports, and the O-DU shall configure the O-RU via M-Plane which SINR resolution it wants delivered, if any. See clause 7.4.11 for a full description of the SINR measurements associated with DMRS-BF-EQ. To support DMRS-BF-EQ without PUSCH equalizer in O-DU, it shall be possible for O-DU to configure O-RU to convey SINR data for each UE-layer from O-RU to O-DUusing an O-RU to O-DU C-Planeflow carried by Section Type 9. The SINR data may be used for log-likelihood ratio (LLR) calculation in the O-DU. Signal-to-Interference-plus-Noise Ratio (SINR) is the post-equalization SINR defined as the power of signal of interest (S) divided by the sum of the interference power (I) (the inter-cell and SU / MU mutual intereferences) plus the power of background noise (N). ^^^^^^^^ =^^ ^^ ^^EXAMPLE: In the case of MMSE-the SINR for the i-th layer may be calculated as ^^^^^^^^^^^^^^^^−^^^^^^,^^= 1 1− ^^^^^^^^^^−^^^^^^,^^ − 1where scalar GMMSE-IRC,i is the i-th element in the vector GMMSE-IRC, which can be calculated as ^^ெெௌாିூோ^ = (^^ + ^^ு^^ି^^^)ି^^^ு^^ି^^^ெெௌாିூோ^ = ^^^^^^^^[^^ெெௌாିூோ^^^]where the matrix H is the channel estimate of size #antennas by #layers and the matrix Q is the interference+noise covariance matrix of size #antennas by #antennas. The #antennas refers to the number of O-RU receive antennas and the #layers refers to the number of layers over all users in a MU-MIMO user group. The operator diag[X] returns a vector consisting of all diagonal elements of the square matrix X. SINR data shall be conveyed according to a time-resolution and frequency-resolution that is M-Plane-configured. The SINR data resolution may be different from the resolution for the weight calculation for beamforming with equalization. The O-DU can assume that the SINRdata can be used for the specific time-frequency tile that the SINR data report corresponds to. EXAMPLE: In the case with one SINR data report for the whole time slot and PRB, the SINR may be calculated using an average of SINR estimates obtained from DMRS allocated to the UE. SINR data may be compressed. The format of Section Type 9 used to convey SINR data is described in clause 7.4.12. The timing of the conveyance of Section Type 9 from O-RU to O- DU is described in clause 4.4.3. As part of the DMRS-BF-EQ operation, the O-RU shall provide equalized PUSCH IQ-data Iாொ ^+ ^^Qா^ொfor the i-th layer of the U-plane. The equalized PUSCH IQ-data for the i-th layer shall be a variable Xi multiplied with the scalar Gi plus an unknown error term ^^^. The variable X shall for CP-OFDM be the output of the modulation mapper defined inTR 38.211 [4] clause 5.1 and shall for DFT-spread OFDM (transform precoding) be the of the output of the modulation mapper. Iாொ ^+ ^^Qாொ ^= ^^^ × ^^^ + ^^^Scalar Gi shall either be a function Since SINRiis supplied to the O- DU as the SINR data, the O-DU can compute the scaling Gi. There are two different functions defined. Scaling function 1: ^^^= ^^^^^^^^^^^^^^^^^^With this function, the output from amay be used as equalized PUSCH IQ-data without applying any may also use this function, but the O- RU is in this case expected to apply a suitable scaling to the output of the equalization function. Scaling function 2: ^^^ = 1With this function, the output from an equalization operation which for CP-OFDM outputs the constellation points without any bias may be used as equalized PUSCH IQ-data without applying any scaling. Other equalizers may also use this function, but the O-RU is in this case expected to apply a suitable scaling to the output of the equalization function. O-RU supporting DMRS-BF-EQ shall declare which one of these scaling functions that is being used with the M-plane parameter equalization-data-scaling. O-DU supporting DMRS- BF-EQ shall support both Scaling function 1 and Scaling function 2. Further, unlike other beamforming methods, the notion of an O-RU configured gain is not applicable for DMRS-BF and instead the IQ output level is described in clause 8.1.3.4.When port-reduced DMRS is provided, the requirements on equalized PUSCH IQ-data shall also be applicable to the equalized port-reduced DMRS IQ-data. NOTE: Equalization put requirements on both the amplitude and phase of the equalized PUSCH data, which in particular means that the O-RU is expected to perform frequency offset compensation. <<<<<<<<end proposed Change Request to O-RAN.WG4.CUS.0.>>>>>>>>

Claims

CLAIMS What is claimed is:

1. A method (200) performed by an Open Radio Access Network – Distributed Unit, O-DU (610), for implementing scale offset values, the method comprising: configuring (210), at an Open Radio Access Network-Radio Unit, O-RU (630), a scale offset value; and fetching (220), from the O-RU, an approximation to the scale offset value, wherein the approximation is as close as possible to, but does not exceed, the scale offset value.

2. The method of claim 1, further comprising, prior to the configuring, receiving from the O-RU a declaration of a supported range of scale offset values.

3. The method of claim 2, wherein the scale offset value is within the supported range.

4. The method of any of claims 1 to 3, further comprising receiving, from the O-RU, one or more values to which the approximation has been applied by the O-RU.

5. The method of any of claims 1 to 4, further comprising undoing, based at least in part on the approximation, an effect of an applied approximation either before, or in conjunction with, demodulation.

6. The method of claim 5, wherein the undoing comprises at least one of: applying an inverse of the approximation; scaling a decision boundary by the approximation; scaling the expected coordinates of constellation points by the approximation.

7. The method of any of claims 1 to 6, wherein the scale offset value comprises eq-scale- offset-config.

8. The method of any of claims 1 to 7, further comprising receiving, from the O-RU, a notification of at least one of: the approximation has changed; a timer expired; the approximation is available; the approximation has been stored.

9. The method of any of claims 1 to 8, wherein the fetching is performed after at least one of: after a timer expired; after creation of a reception, rx, carrier; after the rx carrier has changed to ACTIVE state; receiving a notification that an approximation has changed.

10. The method of any of claims 1 to 9, wherein the demodulation is performed on In phase and Quadrature, IQ, samples, or assisted by Signal to Interference plus Noise Ratio, SINR, values, to which IQ samples or SINR values the approximation has been applied by the O-RU.

11. The method of any of claims 1 to 10, wherein the configuring is performed via the Management Plane, M-Plane.

12. A method (400) performed by an Open Radio Access Network – Radio Unit, O-RU (630), for implementing scale offset values, the method comprising: receiving (410), from an Open Radio Access Network – Distributed Unit, O-DU (610), a configuration of a scale offset value; determining (420) an approximation to the scale offset value, wherein the approximation is as close as possible to, but does not exceed, the scale offset value; and storing (430) the approximation in a parameter that can be read by the O-DU.

13. The method of claim 12, further comprising, prior to the receiving, providing for the O- DU a declaration of a supported range of scale offset values.

14. The method of claim 13, wherein the scale offset value is within the supported range.

15. The method of any of claims 12 to 14, wherein the scale offset value comprises eq-scale- offset-config.

16. The method of any of claims 12 to 15, further comprising transmitting, to the O-DU, a notification of at least one of: the approximation has changed; a timer expired; the approximation is available; the approximation has been stored.

17. The method of any of claims 12 to 16, wherein the storing is performed after at least one of: after a timer expired; after creation of a reception, rx, carrier; after the rx carrier has changed to ACTIVE state; receiving a notification that an approximation has changed.

18. The method of any of claims 12 to 17, wherein the receiving is performed via the Management plane, M-plane.

19. The method of any of claims 12 to 18, wherein the O-RU applies the approximation on one or more values to be sent from the O-RU to the O-DU before converting the one or more values to a data format used on a fronthaul interface between the O-RU and the O-DU.

20. The method of claim 19, wherein the one or more values comprise at least one of: one or more In-phase and Quadrature, IQ, samples; one or more Signal to Interference plus Noise Ratio, SINR, values.

21. A network node (3300) for implementing scale offset values, the network node comprising: processing circuitry (3302) configured to perform any of the steps of any of claims 1 to 20; power supply circuitry (3308) configured to supply power to the processing circuitry.

22. A network node (3300) for implementing scale offset values, the network node comprising: processing circuitry (3302); and a memory (3304) containing instructions whereby the processing circuitry is operable to perform the steps of: receiving, from an Open Radio Access Network – Distributed Unit, O-DU (610), a configuration of a scale offset value; determining an approximation to the scale offset value, wherein the approximation is as close as possible to, but does not exceed, the scale offset value; and storing the approximation in a parameter that can be read by the O-DU.

23. The network node of claim 22, wherein the network node comprises an Open Radio Access Network – Radio Unit, O-RU (630).

24. A network node (3300) for implementing scale offset values, the network node comprising:processing circuitry (3302); and a memory (3308) containing instructions whereby the processing circuitry is operable to perform the steps of: configuring, at an Open Radio Access Network – Radio Unit, O-RU (630), a scale 5 offset value; fetching, from the O-RU, an approximation to the scale offset value, wherein the approximation is as close as possible to, but does not exceed, the scale offset value.

25. The network node of claim 24, wherein the network node comprises an Open Radio10Access Network – Distributed Unit, O-DU (610).

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