Improved SRS channel estimation for frequency hopping SRS and other SRS in open fronthaul
Patent Information
- Application Number
- PCT/SE2026/050112
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-13
- Filing Date
- 2026-02-23
- Publication Date
- 2026-08-27
Smart Images
Figure SE2026050112_27082026_PF_FP_ABST
Abstract
Description
[0001] 23-02-2026
[0002] IMPROVED SRS CHANNEL ESTIMATION FOR FREQUENCY HOPPING SRS AND OTHER SRS IN OPEN FRONTHAUL
[0003] TECHNICAL FIELD
[0004] The present disclosure relates to improved channel estimation in radio communication systems.
[0005] BACKGROUND
[0006] Massive MIMO is one key technology in 4G, 5G and beyond, which are widely deployed globally. It features with a large number of antennas used on the base-station side, where the number of antennas is typically much larger than the number of user-layers, for example, 64 antennas serving 8 or 16 user-layers in frequency range 1 (FR1), which comprises sub-6 GHz frequency bands, and 256 / 512 antennas serving 2 or 4 layers in FR2, which comprises frequency bands from 24.25 GHz to 52.6 GHz. A user layer when used herein e.g., means an independent downlink or uplink data stream intended for one user. One user or UE may have one or multiple user layers. User layer is also referred to as layer, e.g., in 3GPP terminology. Massive MIMO is also referred to as massive bcamforming, which is able to form narrow beams focusing on different directions to counteract against the increased path loss at higher frequency bands. It also benefits multi-user MIMO which allows for transmissions from / to multiple users simultaneously over separate spatial channels resolved by massive MIMO technologies nulling the interferences between users, while keeping high performance, e.g., throughput, for each user. Therefore, it can significantly increase the spectrum efficiency and cell capacity.
[0007] i Inkom till Patent- och registreringsverket 2026 02- 2323-02-2026
[0008] At the base-station side, the interface between the distributed unit (DU) and the radio unit (RU) is the fronthaul (FH) interface, as shown in Figure 1. The great benefits of massive MIMO at the air-interface also introduce new challenges at the base-station side. The legacy CPRI-type fronthaul transports time-domain IQ samples per antenna branch. As the number of antennas scales up in massive MIMO systems, the required fronthaul capacity also increases proportionally, which significantly drives up the fronthaul costs. To address this challenge, the fronthaul interface evolves from CPRI to eCPRI, a packet-based fronthaul interface. In eCPRI, other functional split options between a DU and a RU are supported, referred to as different lower-layer split (LLS) options. In the eCPRI standard specification, the terms eREC (eCPRI Radio Equipment Control) and eRE (eCPRI Radio Equipment) are used instead of DU and RU. The basic idea is to move the frequency-domain beamforming function from DU to RU so that frequency samples or data of user-layers are transported over the fronthaul interface. Note that the frequency-domain beamforming is sometimes also referred to as precoding in the downlink (DL) direction and equalizing or pre-equalizing in uplink (UL) direction. By doing this, the required fronthaul capacity and thereby the fronthaul costs are significantly reduced, as the number of user layers is typically much fewer than the number of antennas in massive MIMO. In O-RAN open fronthaul interface specification [1], DU is referred to as O-DU (O-RAN DU) while RU is referred to as O-RU (O-RAN RU).
[0009] Figure 2 shows the downlink (DL) Weight-based Dynamic Beamforming (WDBF) implementation supported by the current O-RAN WG4 specification [1]. By having the DL beamforming function in the O-RU, the number of streams going through the fronthaul interface becomes the number of layers. The DL beamforming weights are calculated in the O-DU based on the SRS signal sent back from the O-RU.23-02-2026
[0010] Figure 3 shows the control-plane (C-plane) and user-plane (U-plane) data flow for WDBF in DL in current O-RAN open fronthaul specification. For every slot, the O-DU sends first C-plane messages to convey the scheduling information to the O-RU. The scheduling information includes the REs (Resource Elements) to be scheduled, the beam ID (referred as beamld in the specification) which represents the beamforming weights stored in the O-RU, or the beam forming weights (BFWs) together with its beam ID to be used if not stored. Then, the O-DU sends the DL U-Plane data (IQ data after modulation which may be compressed) to the O-RU. The O-RU receives the scheduling information and the DL U-Plane data. Then, the O-RU processes the received IQ data according to the scheduling information received, e.g., perform beamforming (i.e., apply the beamforming weights received directly or indicated by the beam ID received), perform IFFT and add cyclic prefix, etc., to generate OFDM IQ data, send the OFDM IQ data to the DFE and RF-frontend, and send the OFDM signal out from the antennas.
[0011] There is another type of beamforming methods defined in the current O-RAN WG4 specification, referred as Channel Information based Beamforming (CIBF). In CIBF, instead of transferring BFWs or beamld, the O-DU transfers to the O-RU the scheduled layers and the SRS channel estimates of the scheduled layers in the C-plane messages. The O-RU uses the received information (i.e., the scheduled REs, the scheduled layers and their channel estimates for the scheduled REs) to calculate the BFWs and perform beamforming to the received DL U-Plane data using the calculated BFWs.. In the specification, each scheduled layer is conveyed by a field called “ueld” in C-plane message. Although the field name is “ueld”, the ueld represents a layer, not a UE. For a UE with multiple layers scheduled, it needs multiple ueld(s) where each ueld represents one layer of the UE.
[0012] In the current O-RAN WG4 open-fronthaul CUS specification [1], O-RAN CU plane (control plane and user plane) distinguishes logical data flows on transport level, based on the eAxC ID presented in the eCPRI transport header of the C- and U-plane messages. It allows to distinguish RU’s logical flows, representing spatial streams (e.g. beamformed data stream), which are the layers when WDBF or CIBF is used.23-02-2026
[0013] In O-RAN open fronthaul, a C- or U-plane message contains an eCPRI transport header, in which the “ecpriRtcid / ecpriPcid” field represents the eAxC ID used. A C- or U-plane message further contains one or more sections using a specific Section Type. Multiple Section Types are defined to carry different types of scheduling information for different purposes. For example, Section Type 0 (ST0) is used to represent unused resource blocks or symbols. Section Type 1 (ST1) is used to represent used (scheduled) resource elements (REs) for most DL / UL channels, e.g., PUSCH (Physical Uplink Shared Channel), PDSCH (Physical Downlink Shared Channel), etc., when WDBF is used. Each section can be attached with one or more Section Extensions. Each Section Extension attached includes additional information than that described by the section. For example, Section Extension 1 (SE1) is used to provide beamforming weights. Section Extension 4 (SE4) is used to provide modulation compression parameters. Section Extension 10 (SE10) is used to provide beamforming weights or uelds when port (or layer) grouping is used.
[0014] There currently exist certain challenges. One problem of WDBF and CIBF in the current O-RAN open fronthaul specification is that a large amount of SRS IQ data is sent from O-RU to O-DU over the fronthaul interface, which increases the fronthaul bit rate. In this case, O-RU sends the IQ data of the SRS symbols of all antennas to the O-DU. It means that the number of FH spatial streams for transporting SRS IQ data equal to the number of antennas, while the number of FH spatial streams for transporting IQ data of PUSCH data equal to the number of the beamformed streams or layers after beamforming in O-RU which is much less than the number of antennas. As a result, the amount of the SRS IQ data per symbol is much more than that of the IQ data of PUSCH data symbol. For example, for 64 antennas and 8 spatial streams or layers used for PUSCH, the IQ data of a fully loaded SRS symbol is 8 times more than that of a fully loaded PUSCH symbol. In O-RAN, this issue can be addressed by delaying sending SRS IQ data in DL slots. But this would cause longer delay and increase O- RU costs for data buffering.23-02-2026
[0015] Another problem is that the O-DU processing capacity is highly loaded by SRS processing. When one O-DU is connected to multiple O-RUs, the SRS is scheduled simultaneously across the network due to the time division duplex (TDD) pattern. All SRS IQ data from multiple O-RUs arriving at the DU at the same time. This imposes a significant processing load on the O-DU, as it must handle SRS for channel estimation from all O-RUs simultaneously. This significantly reduces the statistical multiplexing gain for O-DU processing, which assumes that the processing load from different RUs are not at the peak simultaneously. Given limited hardware resources in O-DU, this may significantly limit SRS processing capability, i.e., the number of users sending SRS, which limits the system capacity in terms of the number of served users which utilize SRS for scheduling and beamforming etc. Also, the simultaneous transmission of SRS samples from multiple RUs to a DU limits statistical multiplexing gain in fronthaul transport when fronthaul links are aggregated.
[0016] To further address these problems, O-RAN agrees to standardize a new functional split which moves SRS channel estimation function to the O-RU. It is currently referred to as SRS based beamforming (SRS-BF). Then SRS processing is offloaded to the O-RU, which could increase the O-DU capacity to process more antenna carriers and users.
[0017] Figure 4 shows one variant of SRS-BF implementation for DL with a functional split. In this variant, both SRS channel estimation and DL beamforming weights calculation are moved to the O-RU. O-RU also calculates some SRS-based RRM measurements (e.g., time-offset, SINR, signal power) and sends these measurements back to the O-DU. Further, O-RU sends SRS channel estimates back to the O-DU. The SRS channel estimates may be compressed to reduce the amount of data over fronthaul interface. Both SRS RRM measurements and SRS channel estimates are used by the O-DU for scheduling and other purposes. Since DL beamforming weights calculation are also moved to the O-RU, there is no beamforming weights transported over the fronthaul interface, which reduces the fronthaul bit rate in the direction from O-DU to O-RU.23-02-2026
[0018] Figure 5 shows another variant of SRS-BF implementation for DL. In this variant, SRS channel estimation is moved to the O-RU while DL beamforming weights calculation is kept in the O-DU. In this variant, the O-DU can reuse most of functionalities in WDBF, which makes easier to migrate to SRS-BF. The main benefit is to offload the O-DU processing from SRS channel estimation.
[0019] In SRS-BF, the key is to perform SRS channel estimation in the O-RU. To enable this, the O-DU needs to provide SRS configuration information to the O-RU via C-Plane messages. After receiving the C-Plane message containing SRS configuration information, the O-RU can generate the corresponding SRS sequences and perform SRS channel estimation for each UE which sent the SRS signal.
[0020] In 3GPP, SRS can be sent in some symbols in the special slot which contains both DL and UL transmissions or an UL slot which only contains UL transmissions. SRS can be configured as periodic, aperiodic, or semi-periodic. Each UE is informed by the base station of the SRS configuration which will be used by the UE to generate its SRS. The SRS of one UE can have multiple SRS ports if it has multiple antenna ports. One antenna port may be one physical antenna or a virtual antenna by beamforming with multiple antennas. Each SRS port corresponds to the SRS sent by one UE antenna port. The SRS ports of one or more UEs are allocated with orthogonal resources in frequency domain, time domain, or code domain. In frequency domain, different ports can use different Comb Offsets, i.e., using different resource elements (REs) in the same PRBs. They can also use different PRB ranges. In time domain, they can use different symbols. In code domain, they can use different Cyclic Shifts (CS) which makes the SRS sequence orthogonal. An SRS symbol can multiplex many SRS ports.23-02-2026
[0021] For example, with full bandwidth sounding per UE, one SRS symbol can multiplex 48 SRS ports. With half bandwidth sounding per UE, one SRS symbol can multiplex 96 SRS ports. The number of SRS ports further increases when multiple SRS symbols are used, e.g., 2, 4, 6 SRS symbols. SRS also supports various features such as frequency hopping, repetition, antenna switching etc. It is also constrained by the UE capabilities such as 1T4R, 2T4R, 1T2R, bandwidth part, etc. Considering all these above, SRS resource multiplexing can be very complicated, much more complicated than DMRS resources which only have a few ports and a few configurations.
[0022] Improved quality of channel estimation is a general desire, as well as efficient communication of SRS structure over fronthaul and enabling of efficient SRS handling in O-RU.
[0023] SUMMARY
[0024] In O-RAN (Open Radio Access Network) systems implementing SRS-based beamforming (SRS-BF), Sounding Reference Signal (SRS) channel estimation is performed in the O-RAN Radio Unit (O-RU) rather than the O-RAN Distributed Unit (O-DU). This approach offloads processing from the O-DU and reduces fronthaul traffic. However, when User Equipment (UE) devices employ frequency hopping, their SRS transmissions are distributed across multiple symbols within a slot, with each symbol covering a different frequency range. Other SRS sequences also distribute transmissions over multiple symbols.
[0025] Traditional per-symbol channel estimation approaches create discontinuities between channel estimates of adjacent SRS blocks and introduce ambiguity when channel estimates are downsampled, degrading radio performance.23-02-2026
[0026] The disclosed approach addresses these challenges through two complementary mechanisms. First, frequency hopping indications are embedded within control plane (C-plane) messages sent from the O-DU to the O-RU. These indications enable the O-RU to identify which SRS blocks belong to the same frequency hopping pattern (or other kind of pattern) without requiring exhaustive searching through all possible SRS configurations.
[0027] The frequency hopping indications may include a hopping index that indicates the position in frequency of a Physical Resource Block (PRB) range of each hop relative to the PRB ranges of other hops in the same frequency hopping pattern. This frequency-ordered indexing enables the O-RU to easily concatenate the hops in the correct sequence without additional searching. The indications may also specify whether the frequency hopping pattern continues over more than one slot or is confined to a single slot, helping to limit the scope of processing operations.
[0028] Beyond frequency hopping, these indications provide broader benefits for SRS pattern detection. The same indication mechanisms can be used to identify other types of SRS transmission patterns using multiple symbols, such as SRS repetition and SRS antenna switching. This unified approach eliminates the need for multiple separate indication fields and helps the O-RU identify various symbol patterns with reduced computational effort. The knowledge of these symbol patterns assists channel estimation for these cases as well, even when concatenation is not performed.
[0029] Second, upon receiving these indications, the O-RU may concatenate the individual SRS blocks from multiple symbols into a single large effective SRS block covering the aggregated bandwidth. Channel estimation can then be performed on this concatenated block rather than on individual narrow-bandwidth segments. This concatenation process transforms frequency domain representations of SRS signals spanning different frequency ranges into a contiguous frequency domain representation covering the full bandwidth.23-02-2026
[0030] This approach provides several significant advantages. The explicit indications eliminate the cumbersome and resource-consuming process of traversing entire grids of SRS blocks to identify frequency hopping or other patterns, reducing processing complexity regardless of whether concatenation is subsequently performed. The concatenated channel estimation achieves higher processing gain compared to individual block estimation because noise suppression techniques become more effective over wider bandwidths. Time-domain based channel estimation methods, for example, can remove more noise from the tail of the impulse response while preserving channel information, significantly improving signal-to-noise ratio. The method eliminates discontinuities between adjacent SRS blocks and resolves ambiguities in channel estimate selection during downsampling operations. The frequency-ordered hopping index particularly simplifies the concatenation process by providing direct ordering information.
[0031] The resulting improved channel estimates enhance beamforming weight quality and scheduling decisions, leading to increased UE throughput and overall system performance. The approach is applicable to various frequency hopping scenarios, including intra-slot hopping, inter-slot hopping, and cases involving SRS repetition or antenna switching.
[0032] In a first aspect then, there is provided a method performed by an O-RAN Radio Unit (O-RU) for receiving control plane scheduling commands from an O-RAN Distributed Unit (O-DU). The method involves receiving a frequency hopping indication from the O-DU that allows the O-RU to determine the frequency hopping patterns used by one or more user equipment devices.
[0033] The frequency hopping indication may include a hopping index that indicates the position in frequency of a Physical Resource Block range of a hop within a frequency hopping pattern. This hopping index shows where each hop sits relative to the Physical Resource Block ranges of other hops in the same frequency hopping pattern.
[0034] Additionally, the frequency hopping indication may specify whether the frequency hopping pattern continues over more than one slot, or alternatively, it may indicate that the pattern does not extend beyond a single slot.23-02-2026
[0035] The frequency hopping indication may also include a field indicating the number of hops in the pattern.
[0036] In some implementations, the frequency hopping indication includes a first hop symbol that identifies the initial symbol of the hopping sequence.
[0037] Alternatively, the frequency hopping indication may use only the number of hops as the frequency hopping indication, without requiring additional parameters. In a second aspect there is provided a method performed by an O-DU for performing control plane scheduling commands to an O-RU. The method involves transmitting a frequency hopping indication to the O-RU that enables the O-RU to determine the frequency hopping patterns used by one or more user equipment devices.
[0038] The same variations described for the first aspect may be applied to this second aspect, including the hopping index indicating frequency positions, the indication of whether hopping spans multiple slots, the field for number of hops, the first hop symbol identifier, and the option to use only the number of hops as the indication.
[0039] In a third aspect there is provided an O-RAN Radio Unit adapted to perform the method of the first aspect.
[0040] In a fourth aspect there is provided a computer program that, when run on one or more processors of an O-RAN Radio Unit, causes the O-RU to perform the method of the first aspect.
[0041] In a fifth aspect there is provided an O-RAN Radio Unit comprising processing circuitry and memory configured to receive a frequency hopping indication from an O-DU. This configuration allows the O-RU to determine the frequency hopping patterns used by one or more user equipment devices.
[0042] In a sixth aspect there is provided a tangible, non-transient computer-readable medium comprising instructions. When these instructions are executed by processing circuitry of an O-RAN Radio Unit connected to an O-RAN Distributed Unit over fronthaul, they cause the processing circuitry to receive a frequency hopping indication from the O-DU. This enables the O-RU to determine the frequency hopping patterns used by one or more user equipment devices.
[0043] io23-02-2026
[0044] In a seventh aspect there is provided an O-RAN Distributed Unit adapted to perform the method of the second aspect.
[0045] In an eighth aspect there is provided a computer program that, when run on one or more processors of an O-RAN Distributed Unit, causes the O-DU to perform the method of the second aspect.
[0046] In a ninth aspect there is provided an O-RAN Distributed Unit comprising processing circuitry and memory configured to transmit a frequency hopping indication to an O-RU. This configuration allows the O-RU to determine the frequency hopping patterns used by one or more user equipment devices.
[0047] In a tenth aspect there is provided a tangible, non-transient computer-readable medium comprising instructions. When these instructions are executed by processing circuitry of an O-RAN Distributed Unit connected to an O-RAN Radio Unit over fronthaul, they cause the processing circuitry to transmit a frequency hopping indication to the O-RU. This enables the O-RU to determine the frequency hopping patterns used by one or more user equipment devices.23-02-2026
[0048] BRIEF DESCRIPTION OF THE DRAWINGS AND TABLES
[0049] Figure 1 shows an illustration of fronthaul interface between a Radio Unit, RU, and a Distributed Unit, DU.
[0050] Figure 2 shows a DL WDBF implementation supported by current O-RAN open fronthaul specification.
[0051] Figure 3 shows C-plane and U-plane data flows for DL in current O-RAN open fronthaul specification.
[0052] Figure 4 shows a first variant of SRS-BF functional split for DL.
[0053] Figure 5 shows a second variant of SRS-BF functional split for DL.
[0054] Figure 6 shows an example of concatenating SRS ports for 3 UEs.
[0055] Figure 7 shows an example of selecting down sampled channel estimates for one UE. Figure 8 shows an example of simplification of SRS blocks for multiple UEs.
[0056] Figure 9 shows an example of intra-slot hopping SRS ports for one UE.
[0057] Figure 10 shows a communication system according to some embodiments.
[0058] Figure 11 shows a communication system according to other embodiments.
[0059] Figure 12 shows a block diagram of a wireless device.
[0060] Figure 13 shows a block diagram of a network node.
[0061] Figure 14 shows a block diagram of a virtualization environment.
[0062] Figure 15 shows sending of a frequency hopping indication from an O-DU to an O-RU. Table 1 shows an SRS configuration description format.
[0063] Table 2 shows a first section description format for SRS block level.
[0064] Table 3 shows a first UE level SRS configuration description format.
[0065] Table 4 shows an SRS port level SRS configuration description format.
[0066] Table 5 shows a second section description format for SRS block level.
[0067] Table 6 shows a third section description format for SRS block level.
[0068] Table 7 shows a second UE level SRS configuration description format.
[0069] Table 8 shows a third UE level SRS configuration description format.
[0070] DETAILED DESCRIPTION
[0071] The C-Plane SRS configuration description structure needs to be carefully designed to23-02-2026
[0072] optimize for flexibility (supporting all possible resource multiplexing), O-RU processing efficiency (for O-RU to easily get the necessary information for generating SRS sequences) and FH efficiency (reduce the number of bytes used for SRS configuration description). Depending on SRS UE capabilities and based on channel quality measurements (e.g., CSI report) for those UEs, SRS UEs may be scheduled with frequency hopping with a certain PRB range spread across multiple symbols within a slot (e.g., intra-slot frequency hopping) or adjacent slot. In this scenario, SRS of a UE in each symbol is transmitted in a narrower bandwidth and therefore the UE can send more power for SRS which increases SINR of the received SRS at the O-RU. The SRS transmission in each symbol can carry SRS for one or more SRS ports.
[0073] In addition to frequency hopping within a slot or in adjacent slots, frequency hopping can be used over multiple slots which are not adjacent, e.g., over multiple special slots which have both DL and UL slots. This is usually referred to as inter-slot frequency hopping. This is useful when the number of hops needed is larger than the number of SRS symbol in one slot.
[0074] In this disclosure, an SRS block is identified by a PRB (physical resource block) cluster and a symbol, in which the SRS sequences of one or more SRS ports of one or more UEs are multiplexed. A PRB cluster is defined as a unique continuous PRB range used at least by one UE in any SRS symbol in the slot. An SRS block represents the SRS data of the PRB range of a single SRS PRB cluster (PRB range) in a single symbol. In an SRS block, the SRS sequences of one or more SRS ports of one or more UEs are multiplexed.23-02-2026
[0075] In the current proposals for the C-Plane message conveying SRS configurations from O-DU to O-RU in O-RAN WG4, e.g., the proposed message structure in PCT / SE2024 / 051026, PCT / SE2025 / 050129, and PCT / SE2025 / 050137, SRS configuration is provided for UE SRS ports in each SRS block. The O-RU may perform channel estimation per SRS block.
[0076] However, for frequency hopping UEs, doing per SRS block estimation is not the best way to estimate the channel. It will cause discontinuity between the channel estimates of two adjacent SRS blocks since the SRS blocks are individually estimated. The discontinuity affects the channel estimation negatively and reduces channel estimation quality. It also causes ambiguity when channel estimates are downsampled in frequency domain. All these can degrade radio performance for these UEs, e.g., reducing UE throughput.
[0077] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges.
[0078] In this disclosure, certain embodiments propose to concatenate the SRS blocks (each has a narrow bandwidth with different PRB ranges) in multiple symbols as one large effective SRS block covering the aggregated bandwidth of all individual smaller SRS blocks. Then, the channel estimation is performed using the large effective SRS block. For intra-slot frequency hopping UEs, the SRS data span over multiple consecutive symbols, e.g., 2, 4, 6 symbols. It can be assumed that the channel experienced over these symbols is the same. Using the large effective SRS block by concatenating the SRS blocks in multiple symbols is equivalent to the case when SRS is sent with full bandwidth in one symbol but with higher power. For example, if frequency hopping is done over 4 symbols with a quarter bandwidth used in each symbol, it is equivalent to sending SRS with full bandwidth in one symbol with 4 times power. Performing channel estimation using the large effective SRS block by concatenating the SRS blocks in multiple symbols improves the channel estimation quality. There is no discontinuity and ambiguity issues between smaller SRS blocks since the channel estimation is done on the large effective SRS block. Channel estimation on a large bandwidth can achieve higher processing gain than doing it on a smaller bandwidth because more noise can be suppressed by channel filtering techniques, e.g., using MMSE channel estimation, using time-domain based channel estimation.23-02-2026
[0079] For example, in time-domain based channel estimation, the raw estimates are transformed to channel taps in time domain or tap domain, e.g., by FFT. In the time domain, the energy of channel taps concentrates in the beginning of the impulse response and the noise is flat over all taps in the impulse response. Removing the tail of the impulse response removes a lot of noise but very little channel information. In this way, the SNR in the channel impulse response is significantly improved. The gain is referred to as processing gain. The processing gain is proportional to the SRS bandwidth. That’s why performing channel estimation on using the large effective SRS block by concatenating the SRS blocks in multiple symbols achieves higher processing gain than doing it on each individual smaller SRS block.
[0080] Transform the impulse response back to frequency domain improve significantly the quality of the frequency domain channel estimates. The improved channel estimates will improve beamforming weights quality and scheduling quality, which improves the radio performance, e.g., increases UE throughput.
[0081] The proposed method can improve the channel estimation quality by concatenating the SRS blocks of multiple hops if the channel over multiple symbols containing multiple hops is considered as unchanged. It is applicable to the hops in the same slot and in adjacent slots. For the hops in non-adjacent slots, the proposed method is useful for stationary and slow-moving UEs, e.g., for users using fixed wireless access (FWA) service.
[0082] Concatenation may be performed by transforming received time domain SRS signals to frequency domain, where the signals span different parts of a full bandwidth but together cover the full bandwidth. The frequency domain representations are concatenated (possibly also merged or truncated in case of overlap) to create a contiguous frequency domain representation covering the full bandwidth. The frequency domain SRS signals can be first processed by a matched filter using generated SRS sequence per SRS block based on the received SRS configuration. In this case, the concatenation may be performed to concatenate the outputs of the matched filters of the SRS blocks spanning different parts of a full bandwidth to one output signal covering the full bandwidth for further channel estimation.
[0083] As mentioned, the current proposals in O-RAN WG4 for the C-Plane message conveying SRS configurations from O-DU to O-RU, SRS configuration is provided for UE SRS ports in each SRS block. The O-RU needs to detect the frequency hopping UEs. It’s a cumbersome23-02-2026
[0084] process to identify multiple SRS blocks distributed across various symbols in a slot and then concatenate the multiple SRS blocks as one large effective SRS block for channel estimation. In this disclosure, certain embodiments also propose to add an explicit frequency hopping indication in the C-Plane message conveying SRS configuration to indicate the SRS blocks used for frequency hopping. Then, the O-RU can use it to easily identify the SRS blocks to concatenate to one large effective SRS block for channel estimation, without the need to blindly detect the SRS blocks used for frequency hopping UEs.
[0085] A large effective SRS block is defined as concatenated multiple SRS blocks with nonoverlapping PRB ranges from multiple symbols corresponding to same SRS ports of those corresponding SRS UEs, such that total concatenated PRB ranges equal to the aggregated SRS bandwidth of the multiple SRS blocks.
[0086] For example, concatenating multiple SRS blocks in non-overlapping PRB ranges in different symbols can start with the SRS block that has the lowest PRB value for a specific symbol and append the next SRS block whose PRB start position is adjacent to the previous selected SRS block with non-overlapping PRB range and there is no gap between two adjacent SRS blocks. Repeat this process for all relevant SRS blocks distributed across various symbols in a slot, corresponding to the same SRS ports such that it becomes one large effective SRS block. For hops over more than one slots can be done in a similar way to concatenate the hops in multiple slots. Note that the concatenation may be used for some of hops (not all hops) considering the channel may change more for multiple slots if the time between slots is large. Certain embodiments can also be applicable to the cases when groupOrSequenceHopping or cyclicShiftHopping is used for frequency hopping scenarios. groupOrSequenceHopping and cyclicShiftHopping are the schemes defined in 3GPP. Certain embodiments can also be applicable to the cases when SRS repetition or SRS antenna port or antenna switching is used.
[0087] The following provides examples to represent frequency hopping indication in a compact way in the C-Plane message conveying SRS configurations.
[0088] Example 1
[0089] One example embodiment under the present disclosure can use a first hop symbol as a frequency hopping indication. This can involve in certain embodiments, adding a field of first hop symbol in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s)..
[0090] In the section descriptions of the SRS blocks or UEs not using frequency hopping, the field of23-02-2026
[0091] first hop symbol is set to a special value indicating no frequency hopping for the SRS block. In the section descriptions of SRS blocks or UEs using frequency hopping, the field of first hop symbol is set to the symbol ID of the symbol of the first hop. For example, if O-RU reads a valid value of first hop symbol for a UE in a SRS block, O-RU can calculate the difference between the symbol ID value (also provided in the section description for the UE) and the value of first hop symbol as d = symbolld - firstHopSymbol and then O-RU can determine this SRS block is the (d+ 1 )th hop for the UE. In this way, O-RU can easily find the hopping pattern of the UE and then concatenate all SRS blocks (hops) together for channel estimation. Instead of setting symbol ID in the field of first hop symbol, an alternative is to make this field (first hop symbol) as 1 bit flag. In the section description of the SRS block or the UE in the first hop symbol of frequency hopping, the field of first hop symbol is set 1. In the section descriptions of other SRS blocks or UEs, the field of first hop symbol is set 0. In this way, O-RU will get the first hop symbol from reading this flag and the symbolld field in the corresponding part of the section description. For example, if O-RU reads the flag equals 1, O-RU knows the SRS block is the first hop for the UE. Then, O-RU reads also the symbol ID of this SRS block and thereby knows the symbol ID of first hop symbol. For any of the rest of symbols, O-RU can calculate the difference between the symbol ID value and the first hop symbol derived in the previous step as d = symbolld - firstHopSymbol and then O-RU can determine the SRS block is the (d+ 1 )th hop for the UE.
[0092] This example is useful for hops in one slot. The SRS blocks for the same UE (indicated by a UE ID in the C-Plane message) with the same value of first hop symbol indicated are determined as the hops for the same UE and can be concatenated.
[0093] The first hop symbol may be generally used to indicate the first symbol containing SRS of a UE which sends multiple SRS symbols in one slot. It can be used to indicate frequency hopping, SRS repetition and SRS antenna switching which use multiple symbols for SRS transmission. It is also beneficial for O-RU to get the SRS symbol pattern used for SRS repetition or SRS antenna switching which would also help channel estimation for these cases. To cover all cases, the first hop symbol may be called first symbol. It is more efficient to use one field for multiple purposes without using multiple fields. To differentiate single symbol SRS, frequency hopping, SRS repetition and SRS antenna switching, an additional field can be added to indicate the type of SRS.
[0094] With SRS repetition, SRS of a UE are sent from the same SRS port(s) in the same PRB range23-02-2026
[0095] repeatedly in multiple symbols. With SRS antenna switching, SRS of a UE are sent from different SRS port(s) in the same PRB range in multiple symbols.
[0096] In an alternative or as an additional option there may be, for a last hop symbol, an indication that the symbol is the last symbol of a frequency hopping pattern or other SRS symbol pattern, e.g., SRS repetition, SRS antenna switching.
[0097] Example 2
[0098] Another example embodiment under the present disclosure can use a first hop symbol and number of hops as a frequency hopping indication. This can involve adding a field of first hop symbol and a field of number of hops in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s). The usage of the field of first hop symbol can be the same as described previously to get the symbol ID of the first hop symbol. The field of number of hops is typically set to the number of hops used. In the section descriptions of the SRS blocks or UEs not using frequency hopping, the field of number of hops may be set to 0. Adding number of hops is useful in that O-RU can stop searching next symbol for the UE when symbolId – firstHopSymbol + 1 = numOfHops for the current symbol.
[0099] The main use case of this example is for hops in one slot. With number of hops, it makes the search easier for O-RU. The search is limited to the number of symbols indicated by number of hops starting from the first hop symbol indicated by first hop symbol. It can be also used for hops in multiple slots. In this case, indication of number of hops helps the search for hops over multiple slots, while indication of first hop symbol only helps the search within each slot. If the number of hops in one slot is less than the number of hops indicated, O-RU knows it hops over multiple slots. O-RU will continue search until it reaches the number of hops indicated for the UE.
[0100] As described previously, the first hop symbol may be generally used to indicate the first symbol containing of SRS of a UE which sends multiple SRS symbols in one slot. Similarly, the number of hops may be generally used to indicate the number of symbols containing of SRS of a UE. They can be used to indicate frequency hopping, SRS repetition and SRS antenna switching which use multiple symbols for SRS transmission. In this case, the first hop symbol may be called first symbol and number of hops may be called number of23-02-2026
[0101] symbols. It is more efficient to use one field for multiple purposes without using multiple fields. To differentiate single symbol SRS, frequency hopping, SRS repetition and SRS antenna switching, an additional field can be added to indicate the type of SRS.
[0102] Example 3
[0103] Another example embodiment under the present disclosure can use only number of hops as frequency hopping indication. This can involve adding a field of number of hops in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s). In this example, the information of first hop symbol is not explicitly conveyed from 0-DU to O-RU. O-RU will first identify the SRS blocks or UEs with nonzero value of number of hops, compare the symbol IDs of them and then determine the first hop from the lowest symbol ID. If the section descriptions are provided symbol by symbol in time, the first symbol that has non-zero value of number of hops is determined by O-RU as the first hop symbol.
[0104] This example is useful for hops in one or more slots. The SRS blocks for the same UE (indicated by a UE ID in the C-Plane message) with the same value of number of hops indicated are determined as the hops for the same UE and can be concatenated.
[0105] As described previously, the number of hops may be generally used to indicate the number of symbols containing of SRS of a UE. It can be used to indicate frequency hopping, SRS repetition and SRS antenna switching which use multiple symbols for SRS transmission. In this case, number of hops may be called number of symbols. It is more efficient to use one field for multiple purposes without using multiple fields. To differentiate single symbol SRS, frequency hopping, SRS repetition and SRS antenna switching, an additional field can be added to indicate the type of SRS.
[0106] Example 4
[0107] In certain embodiments, as an alternative to number of hops in example 2 and 3, a hopping symbol mask can be used instead of number of hops. The hopping symbol mask is a bitmask indicating the symbols used in frequency hopping. The hopping symbol mask explicitly indicates the symbols used for frequency hopping. O-RU compares the symbol ID with the bitmask and then knows the position of the SRS block in the frequency hopping pattern.23-02-2026
[0108] The main use case of this example is for hops in one slot.
[0109] The hopping symbol mask may be generally used to indicate the symbols containing of SRS of a UE. It can be used to indicate frequency hopping, SRS repetition and SRS antenna switching which uses multiple symbols for SRS transmission. In this case, the hopping symbol mask may be called symbol mask. It is more efficient to use one field for multiple purposes without using multiple fields. To differentiate single symbol SRS, frequency hopping, SRS repetition and SRS antenna switching, an additional field can be added to indicate the type of SRS.
[0110] Example 5
[0111] Another example embodiment under the present disclosure can use frequency hopping ID as frequency hopping indication. This can involve adding a field of frequency hopping ID in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s). Frequency hopping ID represents a unique hopping pattern used. O-DU will set the same frequency hopping ID in the section descriptions of the SRS blocks or UEs using the same frequency pattern. A special frequency hopping ID value will be set in the section descriptions of the SRS blocks or UEs not using frequency hopping. Every unique hopping pattern for intra-slot or inter-slot hopping is assigned to a unique frequency hopping ID. The UEs sharing the same hopping pattern (the SRS of multiple UEs hops over the same SRS blocks in multiple symbols) may be assigned to the same frequency hopping ID. Then, O-RU can determine that the SRS blocks of UEs with the same frequency hopping ID are in the same hopping pattern by reading the UE IDs and frequency hopping IDs.
[0112] This example may be useful for hops in one or more slots. The SRS blocks for the same UE (indicated by a UE ID in the C-Plane message) with the same value of frequency hopping ID indicated may be determined as the hops for the same UE and can be concatenated
[0113] Example 6
[0114] Another example embodiment under the present disclosure can use hopping PRB cluster ID bitmask as frequency hopping indication. This can involve adding a field of hopping PRB cluster ID bitmask in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s). Hopping PRB cluster ID bitmask is a bitmask23-02-2026
[0115] indicating the PRB clusters used in frequency hopping if PRB cluster IDs is used, c.g. usage of PRB cluster ID in C-Plane message for conveying SRS configuration is used in PCT / SE2024 / 051026, PCT / SE2025 / 050129, and PCT / SE2025 / 050137.
[0116] The main use case is for hops in one slot. PRB cluster ID bitmask provides the information about the hopping position in frequency. It not only helps to find the hops of the UEs but also help SRS sequence generation of each hop, because using the bitmask can derive the PRB range of each hop, which are used for SRS sequence generation. SRS sequence of other hops can be generated when O-RU reads the first PRB cluster ID bitmask in any SRS block. If PRB clusters are defined for frequence hopping in M-Planc, it may be extended to support hops in multiple slots.
[0117] Example 7:
[0118] Use hopping index and number of hops as frequency hopping indication. Add a field of hopping index and number of hops and in the part of the C-Plane message (section description) describing an SRS block or a UE. The field of number of hops is set to the number of hops used. The field hopping index can be frequency indexed or time indexed. If frequency indexing is used, hopping index is set to i-1 for the ith lowest hop in frequency which contains the ith lowest PRB range in frequency. For example, hopping index is set to 0 for the lowest hop in frequency which contains the lowest PRB range in frequency. Hopping index is set to 1 for the second lowest hop in frequency which contains the second lowest PRB range in fr equency. If time indexing is used, hopping index is set to i-1 for the ith hop in time. For example, hopping index is set to 0 for the earliest hop in time. Hopping index is set to 1 for the second hop in time.
[0119] Using hopping index with frequency indexing is preferred. One benefit of frequency indexing for hopping index is that O-RU can easily use hopping index to concatenate the hops together as one effective larger SRS block for channel estimation, without the need to search all hops. The concatenation can be simply done following the hop index order.
[0120] For this example, in the section descriptions of the SRS blocks or UEs not using frequency hopping, the field of number of hops may be set to 0 and the field of hop index may be set to 0.
[0121] The hopping index may be generally used to indicate the symbol index of multiple symbols containing SRS of a UE in one slot. As described previously, the number of hops may be23-02-2026
[0122] generally used to indicate the number of symbols containing SRS of a UE. They can be used to indicate frequency hopping, SRS repetition and SRS antenna switching which use multiple symbols for SRS transmission. In this case, the hopping index may be called symbol index and number of hops may be called number of symbols. It is more efficient to use one field for multiple purposes without using multiple fields. To differentiate single symbol SRS, frequency hopping, repetition and antenna switching, an additional field can be added to indicate the type of SRS.
[0123] When indicating also SRS repetition and SRS antenna switching, the use of the hop index may be broadened and it may be called called a symbol index, and a frequency hopping indication may be generalized into a pattern indication for indicating an SRS transmission pattern. The pattern indication may comprise an indication of whether the pattern is for e.g. frequency hopping, SRS antenna switching, SRS repetition or something else. The pattern indication may comprise the symbol index. The pattern indication may comprise an indication of a number of symbols in the pattern.
[0124] The symbol index can be a value per symbol that indicates generally a position in the pattern, e.g. the position in frequency relative to SRSs of other symbols of the pattern when the pattern is frequency hopping or a temporal position in the pattern when the pattern is for SRS antenna switching or SRS repetition. The antenna or antenna port used for the SRS of a symbol when using SRS antenna switching may be determined using the symbol index of the port.
[0125] Example of additional indication parameters:
[0126] In addition to the above examples, the frequency hopping indication may also include indication to indicate if this hop is part of intra-slot hopping or inter-slot hopping. If intra-slot hopping is indicated, it means that the hopping involving this hop described in the section description is done in multiple symbols within a slot. If inter-slot hopping is indicated, it means that the hopping involving this hop described in the section description is done in multiple symbols over multiple slots. Differentiating between intra-slot and inter-slot hopping would reducing the O-RU searching efforts.
[0127] As described previously, the frequency hopping indication may be used to indicate frequency hopping, SRS repetition and SRS antenna switching which use multiple symbols for SRS23-02-2026
[0128] transmission of a UE. To differentiate single symbol SRS, frequency hopping, repetition and antenna switching, an additional field can be added to indicate the type of SRS.
[0129] The examples should not be viewed as strictly exclusive. Fields from one example may be used together with all or parts of another example when appropriate.
[0130] Certain embodiments may provide one or more of the following technical advantages.
[0131] • Constructing a large effective SRS block for SRS ports with intra-slot hopping by concatenating frequency hopped SRS blocks and performing SRS channel estimation based on the large effective SRS block improves the quality of channel estimates due to higher processing gain achieved from wider bandwidth used. The improved channel estimates will improve the radio performance, e.g., UE throughput.
[0132] • It resolves the ambiguity of selecting channel estimate positions for SRS ports for intra-slot frequency hopping when channel estimate values are downsampled depend on PRB bundling sizes of 2 or 4 or 8, as concatenating SRS blocks would make a single effective PRB range (i.e. one effective large SRS block) and help the receiver to correctly identify selection of channel estimation.
[0133] • Explicitly adding the frequency hopping indication in the C-Plane message conveying SRS configuration make it easier for the O-RU to obtain the frequency hopping SRS blocks, which will be used for concatenating frequency hopped SRS blocks and perform channel estimation • Proposed frequency hopping indication can be used to indicate other types of SRS transmission using multiple symbols, e.g., SRS repetition, SRS antenna switching. It is more efficient to use one field for multiple purposes without using multiple fields. It will also help O-RU to identify the symbol pattern with less efforts. The knowledge of the symbol pattern will help channel estimation for these cases as well.
[0134] 2.323-02-2026
[0135] 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.
[0136] The following show some examples of frequency hopping use cases and example embodiments for certain proposed methods under the present disclosure.
[0137] Concatenating SRS Ports for Intra Slot Frequency Hopping Scenarios
[0138] Figure 6 shows an example of SRS configuration for 3 UEs. In this configuration the SRS ports are concatenated. In this example, each UE has two antenna ports (SRS ports). Four SRS symbols are used, i.e., symbol 10,11, 12 and 13 in the slot. In frequency domain multiplexing, Comb 4 is used. UE 0 uses quarter bandwidth, UE 1 and UE 2 uses half bandwidth. It also shows PRB clusters (PRB ranges) used for SRS. UE 0 is scheduled with two ports with four PRB clusters 2, 1, 4 and 3 in symbol 10, 11, 12 and 13, respectively. UE 1 is scheduled with two ports with two PRB cluster 0 and 5 in symbol 11 and symbol 12, respectively. UE 2 is scheduled with two ports with two PRB clusters 0 and 5 in symbol 12 and symbol 13, respectively.
[0139] For the overlapping PRB range (i.e. PRB cluster 0 overlaps with PRB cluster 3 and 4), two antenna ports of one UE use two Cyclic Shifts: CS 0 and CS 6 and two antenna ports of second UE use two Cyclic Shifts: CS 3 and CS 9. In Figure 6, it shows in total 8 SRS blocks in this example.
[0140] For the use case described above, indicate explicitly in the C-Plane section description that PRB cluster 0 of symbol 11 should be concatenated with PRB cluster 5, symbol 12 for UE 1. Likewise, indicate explicitly PRB cluster 3 of symbol 13, PRB cluster 4 of symbol 12, PRB cluster 1 of symbol 11, PRB cluster 2 of symbol 10 should be concatenated for UE0 and indicate explicitly PRB cluster 0 of symbol 12 should be concatenated with PRB clusters, symbol 13 for UE 2.
[0141] In this case, SRS receiver concatenates PRB clusters (individual SRS blocks) for those corresponding UEs and perform SRS channel estimation on the concatenated PRB range (a large effective SRS block). If the channel estimates are going to be sent to O-DU, the aggregated SRS channel estimates will be sent to O-DU. They are preferably not sent in separately per PRB range of each SRS block.23-02-2026
[0142] Resolution of Ambiguity of SRS Ports for Intra Slot Frequency Hopping Scenarios Figure 7 shows an example of SRS configuration for one UE. This example includes selecting down sampled channel estimates for one UE. In this example, the UE has two antenna ports (SRS ports). Four SRS symbols are used, i.e., symbol 10,11, 12 and 13 in the slot. In frequency domain multiplexing, Comb 4 is used. UE 0 uses quarter bandwidth. It also shows PRB clusters used for SRS. UE 0 is scheduled with two ports with four PRB clusters 0, 1, 2 and 3 in symbol 10, 11, 12 and 13, respectively. Two antenna ports of the UE use two cyclic Shifts: CS 0 and CS 6. In Figure 7, it shows in total 4 SRS blocks in this example. For the use case described above, channel estimates are downsampled depending on PRB bundling size which is 4 in this example. If SRS receiver is performed on each SRS block individually, each SRS block produce its own samples of channel estimate for the shaded PRB region. This could result in ambiguity of selecting or estimating channel for the adjacent SRS block for the overlapped PRB region corresponding to PRB bundling size which is 4 in this example. It also causes discontinuity in shaded PRB region.
[0143] This is resolved by concatenating PRB ranges (individual SRS blocks) spread across multiple symbols and make an effective PRB range (i.e. one large effective SRS blocks) which makes it continuous in PRB ranges and thus remove ambiguity in selecting channel estimates when down sampled is done based on PRB bundling size which is 4 in this example.
[0144] Simplifying Concatenating PRB Clusters of SRS Ports for Intra Slot Frequency Hopping Scenarios
[0145] Figure 8 shows an example of SRS configuration for many UEs spread across multiple symbols, this embodiment can simplify the SRS blocks. In this example, UEs have single antenna port (SRS port). Four SRS symbols are used, i.e., symbol 10,11, 12 and 13 in the slot. In frequency domain multiplexing, Comb 4 is used. It also shows PRB clusters used for SRS. UE 0 to UE 143 uses quarter bandwidth and scheduled with single port with four PRB clusters 0, 1, 2 and 3 in symbol 10, 11, 12 and 13 respectively. UE 144 to 287 uses partial bandwidth whose size is equal to quarter bandwidth. In Figure 8, it shows in total 16 SRS blocks in this example.
[0146] Figure 9 shows an example of SRS configuration for single UE. In this example, UE has two23-02-2026
[0147] antenna ports (SRS ports). Four SRS symbols are used, i.e., symbol 10, 11, 12 and 13 with intra-slot hopping. In frequency domain multiplexing, Comb 4 is used. UE 0 uses quarter bandwidth. It also shows PRB clusters (PRB ranges) used for SRS. UE 0 is scheduled with two ports with four PRB clusters 0, 1, 2 and 3 in symbol 10, 11, 12 and 13, respectively. Two antenna ports of UE 0 use two Cyclic Shifts: CS 0 and CS 6
[0148] Figure 9 also illustrates how hop index (hopIdx) and number of hops (numFreqHops) are set in this case. Hop index is set in frequency order, e.g., hopIdx = 0 for the lowest PRB hop, and hopIdx = 3 for the highest PRB hop. The number of hops (numFreqHops) is set to 4 in this case. This example shows that it is beneficial to set hop index in frequency order. If hop index is set in time order, it is not possible to use hop index directly for frequency concatenation.
[0149] With the current prior art proposals for the C-Plane message conveying SRS configurations from O-DU to O-RU in O-RAN WG4, O-RU has to traverse in the entire grid of SRS blocks and figure out which SRS blocks in the entire grid arc frequency hopped so that those SRS blocks could be concatenated for channel estimation. In this process there could be SRS blocks which resemble to concatenate because of same PRB range, and such SRS blocks belongs to UEs with partial bandwidth and should be discarded.
[0150] It’s a cumbersome and resource-consuming process to identify multiple SRS blocks distributed across various symbols in a slot and the complexity increases with number of symbols and SRS blocks.
[0151] Adding explicit indication for frequency hopped SRS blocks or UEs in the C-Plane section description will make this process much easier and efficient.
[0152] Another example of intra-slot frequency hopping
[0153] Adding Frequency Hopping Indication in C-Plane Section Description
[0154] In this disclosure, certain embodiments include adding frequency hopping indication based on Section Type WW conveying SRS configuration, proposed in PCT / SE2025 / 050129 and PCT / SE2025 / 050137. But the indication can be added in the section description of any other design of Section Type for conveying SRS configuration. The indication can be also added in a section extension for the Section Type for conveying SRS configuration.23-02-2026
[0155] In the following two examples, first hop symbol and number of hops as frequency hopping indication are used, or hop index and number of hops as frequency hopping indication are used. But using any other parameter as the frequency hopping indication is not excluded. For convenience, section description format of Section Type WW is shown in Tables 1-4. Table 1 shows the overall data structure of Section Type WW (the SRS configuration description format). Table 2 shows the section description format for a section (Section description format (SRS block level SRS configuration description)). Table 3 shows the format for the UE description part of the section description of a section (UE level SRS configuration description format). Table 4 shows the format for the UE port description part of the section description of a section (SRS port level SRS configuration description format).
[0156] Table Example Embodiment 1
[0157] One example embodiment of a table can involve adding frequency hopping indication on SRS block level in each section of Section Type WW.
[0158] In this example, a field of firstFreqHopSymbol and a field of numHops are added in the section description format of a section. “firstFreqHopSymbol” represents the symbol ID of the first hop symbol. “numFreqHops” represents the number of frequency hops. As described previously, using these two parameter values sent from O-DU to O-RU, O-RU can easily determine which SRS blocks are part of which frequency hopping SRS and which SRS blocks are not part of frequency hopping at all, without the need to search through all SRS blocks in the section description. Then, SRS blocks can be concatenated as one large effective SRS block for channel estimation.
[0159] Table 5 illustrates a possible section description format (SRS block level SRS configuration description). As shown in Table 5, the field of firstFreqHopSymbol is added in Octet 4 and the field of numFreqHops is added in Octet 5. Compared to Table 2, these two fields are added using the reserved fields in Octet 4 and Octet 5, respectively, in Table 2.
[0160] Table 6 shows another example, where a field of hopldx and a field of numFreqHops are added in the section description format of a section, “hopldx” represents the hop index in frequency order. “numFreqHops” represents the number of frequency hops. As described previously, using these two parameter values sent from O-DU to O-RU, O-RU can easily determine which SRS blocks are part of which frequency hopping SRS and which SRS blocks are not part of frequency hopping at all, without the need to search through all SRS23-02-2026
[0161] blocks in the section description. Then, SRS blocks can be concatenated as one large effective SRS block for channel estimation. As shown in Table 6, the field of numFreqHops is added in Octet 4 and the field of hopIdx is added in Octet 5.
[0162] The values of the two fields apply for all UEs in the SRS block described by the section. This may require the O-DU to schedule the frequency hopping UEs in the same SRS blocks. O-RU may declare that it only supports scheduling the frequency hopping UEs in the same SRS blocks.
[0163] Tabic Example Embodiment 2
[0164] Another example embodiment of a table can involve adding priority indication on UE level in each UE description part of each section of Section Type WW. In this example, a field of firstFreqHopSymbol and a field of numFreqHops are in the UE description part of section description format of a section. “firstFreqHopSymbol” represents the symbol ID of the first hop symbol. “numFreqHops” represents the number of frequency hops. The values of the two fields apply for the UE described by the UE description part of the section. As described previously, using these two parameter values sent from O-DU to O-RU, O-RU can easily determine which UEs use frequency hopping and also the SRS blocks of these UEs, without the need to search through all SRS blocks in the section description. Then, SRS blocks of the UEs doing frequency hopping can be concatenated as one large effective SRS block for channel estimation.
[0165] Table 7 illustrates an example table embodiment with UE level SRS configuration description format. As shown in Table 7, the field of firstFreqHopSymbol and the field of numFreqHops arc added in Octet 2. Compared to Table 2, these two fields are added using the reserved field in Octet 2 in Table 2.
[0166] Table 8 shows an example, where a field of hopldx and a field of numFreqHops are in the UE description part of section description format of a section, “hopldx” represents the hop index in frequency order. “numFreqHops” represents the number of frequency hops. As described previously, using these two parameter values sent from O-DU to O-RU, O-RU can easily determine which SRS blocks are part of which frequency hopping SRS and which SRS blocks are not part of frequency hopping at all, without the need to search through all SRS blocks in the section description. Then, SRS blocks can be concatenated as one large23-02-2026
[0167] effective SRS block for channel estimation. As shown in Table 8, the field of numFreqHops is added in Octet 2 and the field of hopIdx is added in Octet 3.
[0168] Additional Embodiments
[0169] Certain embodiments under the present disclosure can comprise cloud implementations. For example, the O-DU can be implemented as virtualized O-DU in a Cloud environment.
[0170] Certain embodiments under the present disclosure can comprise O-RAN implementations. Various embodiments will be proposed for SRS-BF in O-RAN WG4 specification. Regarding possible technical specification impacts, certain embodiments are related to O-RAN WG4 specification and will be proposed to O-RAN WG4 specification.
[0171] Embodiments described above may be implemented in the settings described below.
[0172] Figure 10 shows an example of a communication system 1000 in accordance with some embodiments.
[0173] In the example, the communication system 1000 includes a telecommunications network 1002 that includes an access network 1004, such as a radio access network (RAN), and a core network 1006, which includes one or more core network nodes 1008. The access network 1004 includes one or more access network nodes or base stations of various types, access network nodes 1010A and 1010B are depicted (which may be collectively referred to as network nodes 1010), or any other similar 3rd Generation Partnership Project (3GPP) access nodes or non-3GPP access points (APs). Some embodiments of the access network 1004 may include more than one access network technology. The network nodes 1010 of access network 1004 facilitate direct or indirect connection of wireless devices, also referred to as user equipments (UEs), such as by connecting UEs 1012A, 1012B, 1012C, and 1012D (one or more of which may be generally referred to as UEs 1012) to the core network 1006 over one or more wireless connections.
[0174] Moreover, 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 telecommunications network 1002 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a network node in the telecommunications network 1002 that supports an ORAN specification (e.g., a specification23-02-2026
[0175] published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other network nodes to implement one or more functionalities of any network node in the telecommunications network 1002, including one or more access network nodes 1010 and / or core network nodes 1008.
[0176] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open 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). An ORAN network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN network 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 O-2 interface defined by the O-RAN Alliance or comparable technologies. The network nodes 1010 facilitate direct or indirect connection of one or more UEs 1012 to the core network 1006 over one or more wireless connections. 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 1000 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 1000 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.
[0177] The UEs 1012 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 1010 and other communication devices. Similarly, the network nodes 1008, 1010 are arranged, capable, configured, and / or operable to communicate directly or indirectly (e.g., via other devices of telecommunications network 1002) with the UEs 1012 and / or with other23-02-2026
[0178] network nodes or equipment in the telecommunications network 1002 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunications network 1002. More specifically, UEs 1012 may send messages, data, and / or other signals to network nodes 1008, 1010 or other elements of the telecommunications network 1002 by transmitting such signals to the relevant device directly without the signals passing through any intervening devices or by transmitting such signals to the relevant device indirectly through an intervening device (or multiple intervening devices) that then transmit the signal to the relevant device. Similarly, network nodes 1008, 1010 may send messages, data, and other signals to UEs 10122, other network nodes 1008, 1010, and other devices in telecommunications network 1002 directly or indirectly. As one specific example, a core network node 108 may transmit a particular message to a UE 1012 by transmitting the message to an access network node 1010 that will then transmit the message to the intended UE 1012. Similarly, a core network node 108 may receive a particular message from a UE 1012 by receiving the message from an access network node 1010 that itself received the message from the UE 1012.
[0179] In the depicted example, the core network 1006 connects elements of the access network 1004 (e.g., one or more of the network nodes 1010) to one or more host computing systems, such as host 1016. 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 1006 includes one or more core network nodes (e.g., core network node 1008) of various types, one or more of which may be generally referred to as network nodes 1008. Network nodes 1008 are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, access network nodes, and / or hosts, such that the descriptions thereof arc generally applicable to the corresponding components of the core network node 1008. Example core network nodes provide 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).
[0180] The host 1016 may be under the ownership or control of a service provider other than an operator or provider of the access network 1004 and / or the telecommunications network 1002. The host 1016 may be operated by the service provider or on behalf of the service23-02-2026
[0181] provider. The host 1016 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.
[0182] As a whole, the communication system 1000 of Figure 10 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 1000 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 (Wi-Fi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (Wi-Max), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, Li-Fi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox. Moreover, the communication system 1000 may be configured to support multiple different standards, protocols, or other rule sets, with individual components supporting all of the relevant rule sets or with different components or sub-systems within the communication system 1000 supporting different standards, protocols, or rule sets.
[0183] As one example, in certain embodiments, access network 1004 may contain some access network nodes 1010 that support 3GPP radio access technologies (RAT), such as LTE or NR, while other access network nodes 1010 support (or the same access network nodes 1010 additionally support) non-3GPP RATs, such as Wi-Fi or a proprietary RAT. As another example, telecommunications network 1002 may support multiple generations of related communication standards (c.g., 4G and 5G 3 GPP communication standards) and, as a result, may include an access network 104 and / or a core network 106 that supports multiple different standard generations or may include multiple access networks 104 and / or multiple core networks 106 with individual networks 104, 106 supporting different standard generations. Telecommunications network 1002 may support network slicing to provide different logical networks to different devices that are connected to the telecommunications network 1002. For example, the telecommunications network 1002 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile23-02-2026
[0184] Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive IoT services to yet further UEs.
[0185] In some examples, one or more of the UEs 1012 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 1004 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 1004.
[0186] Additionally, a UE may be configured for operating in single- or multi-RAT or multistandard 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).
[0187] In the example, the hub 1014 communicates with the access network 1004 to facilitate indirect communication between one or more UEs (e.g., UE 1012C and / or 1012D) and network nodes (e.g., network node 1010B). In some examples, the hub 1014 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 1014 may be a broadband router enabling access to the core network 1006 for the UEs. As another example, the hub 1014 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 1010, or by executable code, script, process, or other instructions in the hub 1014.
[0188] As another example, the hub 1014 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 1014 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 1014 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 1014 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 1014 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.
[0189] The hub 1014 may have a constant / persistent or intermittent connection to the network node 1010B. The hub 1014 may also allow for a different communication scheme and / or schedule between the hub 1014 and UEs (e.g., UE 1012C and / or 1012D), and between the hub 1014 and the core network 1006. In other examples, the hub 1014 is connected to the core network 1006 and / or one or more UEs via a wired connection. Moreover, the hub 1014 may be23-02-2026
[0190] configured to connect to an M2M service provider over the access network 1004 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 1010 while still connected via the hub 1014 via a wired or wireless connection. In some embodiments, the hub 1014 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 1010B. In other embodiments, the hub 1014 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 1010B, but which is additionally capable of operating as a communication start and / or end point for certain data channels.
[0191] Figure 11 is another example of a communication system 1100 according to some embodiments. As used herein, the communication system 1100 includes multiple access points (APs) 1110 (with four exemplary APs 1110A, 1110B, 1110C, and 1110D being depicted) and multiple wireless devices, referred to in the context of communication system 1100 as stations (STAs) 1112 (referred to individually as STA 1112A, STA 1112B, STA 1112C, STA 1112D, and STA 1112E). STA 1112A is served by AP 1110 A in a first basic service set (BSS) 1120A. STA 1110B and STA 1110C are served by AP 1110B in a second BSS, BSS 1120B. STA 1112D is served by AP 1110C in a third BSS, BSS 1120C. STA 1112E is served by AP 1110D in a fourth BSS, BSS 1120D. Stations 1112 may be non-AP STAs and correspond to various kinds of wireless devices, for example, user terminals, such as mobile or stationary computing devices like smartphones, laptop computers, desktop computers, tablet computers, gaming devices, head-mounted displays (HMDs) for Augmented Reality (AR) or Virtual Reality (VR), or the like. Further, stations 1112 could, for example, correspond to other kinds of equipment like smart home devices, printers, multimedia devices, data storage devices, or the like.
[0192] Each of STAs 1112 may connect through a radio link to one of APs 1110. For example, depending on location or channel conditions experienced by a given STA 1112, the STA may select an appropriate AP and BSS for establishing the radio link. The radio link may be based on one or more orthogonal frequency-division multiplexing (OFDM) carriers from a frequency spectrum that is shared on the basis of a contention-based mechanism, e.g., an unlicensed or license exempt band like 2.4 GHz Industrial, Scientific, and Medical (ISM) band, the 5 GHz band, the 6 GHz band, or the 60 GHz band.
[0193] Each AP 1110 may provide data connectivity to STAs 1112 connected to a particular AP 1110. As illustrated, APs 1110 may be connected to a data network 1130. In this way, APs 1110 may also provide data connectivity between STAs 1112 and other entities, e.g., to one23-02-2026
[0194] or more servers, service providers, data sources, data sinks, user terminals, or the like.
[0195] Accordingly, the radio link established between a given STA 1112 and its serving AP 1110 may be used for providing various kinds of services to STA 1112, c.g., a voice service, a multimedia service, or other data service. Such services may be based on applications that are executed on STA 1112 and / or on a device linked to STA 1112. By way of example, Figure 11 illustrates an application service platform 1132 provided in data network 1130. The application(s) executed on STA 1112 and / or on one or more other devices linked to STA 1112 may use the radio link for data communication with one or more other STA 1112 and / or the application service platform 1132, thereby enabling utilization of the corresponding scrvice(s) at STA 1112.
[0196] Figure 12 shows a wireless device 1200, which may be configured to operate in communication system 1000 of Figure 10 or in communication system 1100 of Figure 110. The wireless device 1200 may be alternatively referred to as a UE 1200, like a UE 1012 within the context of communication system 1000, or as a station (STA) 1200 or as a nonaccess-point station (non-AP STA) 1200, like a STA 1112 within the context of the communication system 1100, in accordance with respective embodiments. As used herein, a wireless device refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other wireless devices. Examples of a wireless device 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 device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, and wireless terminal. Other examples include any type of 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.
[0197] A wireless device 1200 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-evcrything (V2X). In other examples, wireless device 1200 may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, wireless device 1200 may represent a device that is intended for sale to, or operation23-02-2026
[0198] 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, wireless device 1200 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).
[0199] In particular embodiments, wireless device 1200 includes processing circuitry 1202 that is operatively coupled via a bus 1204 to an input / output interface 1206, a power source 1208, a memory 1210, a communication interface 1212, and / or any other component, or any combination thereof. Certain embodiments of wireless device 1200 may include all or a subset of the components shown in Figure 12. The level of integration between the components may vary from one embodiment of wireless device 1200 to another. In general, in a particular embodiment of wireless device 1200, processing circuitry 1202, input / output interface 1206, power source 1208, memory 1210, and communication interface 1212 may, in whole or in part, represent or include physical components common to or shared by one or more of the other elements of wireless device 1200. Further, certain embodiments of wireless devices 1200 may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.
[0200] The processing circuitry 1202 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 1210. The processing circuitry 1202 may be implemented as one or more hardware-implemented state machines (e.g., in discrete 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 1202 may include multiple central processing units (CPUs). In the example, the input / output interface 1206 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 wireless device 1200. 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 resistive23-02-2026
[0201] 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.
[0202] In some embodiments, the power source 1208 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 to supply power to circuitry or to charge an associated battery. The power source 1208 may further include power circuitry for delivering power from the power source 1208 itself, and / or an external power source, to the various parts of wireless device 1200 via input circuitry or an interface such as an electrical power cable. Power source 1208 may perform any formatting, converting, or other modification to make accessible power suitable for the respective components of the wireless device 1200 to which power is supplied.
[0203] The memory 1210 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 1210 includes one or more programs 1214, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 1216. The memory 1210 may store, for use by wireless device 1200, any of a variety of various operating systems or combinations of operating systems.
[0204] The memory 1210 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 1210 may allow wireless device 1200 to access23-02-2026
[0205] instructions, 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 1210, which may be or comprise a device-readable storage medium.
[0206] The processing circuitry 1202 may be configured to communicate with an access network or other network via or using the communication interface 1212. The communication interface 1212 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 1222. The communication interface 1212 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 wireless device or a network node in an access network). Each transceiver may include a transmitter 1218 and / or a receiver 1220 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 1218 and receiver 1220 may be coupled to one or more antennas (e.g., antenna 1222) and may share circuit components, software or firmware, or alternatively be implemented separately.
[0207] In the illustrated embodiment, communication functions of the communication interface 1212 may include cellular communication, Wi-Fi communication (e.g., according to an IEEE 802.11 family standard), 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 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 / intemet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.
[0208] In particular embodiments, wireless device 1200 may provide an output of data captured via a sensor, through its communication interface 1212, via a wireless connection to a network node, and / or in any appropriate manner. Data captured by sensors of a wireless device 1200 can be communicated through a wireless connection to a network node via another wireless device 1200. In particular embodiments, such output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from23-02-2026
[0209] 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).
[0210] As another example, wireless device 1200 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, wireless device 1200 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.
[0211] Wireless device 1200, 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, 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 surgical robot. In particular embodiments, wireless device 1200 represents an IoT device that 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 example embodiment of wireless device 1200 shown in Figure 12.
[0212] As yet another specific example, in an IoT scenario, wireless device 1200 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 wireless device and / or a network node. Wireless device 1200 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, wireless device 1200 may implement the 3GPP NB-loT standard. In other scenarios, wireless device 1200 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 functions23-02-2026
[0213] associated with its operation.
[0214] In practice, any number of wireless devices 1200 may be used together with respect to a single use case. For example, a first wireless device 1200 might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second wireless device 1200 that is a remote controller operating the drone. When a user makes changes from the remote controller, the first wireless device 1200 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 wireless device 1200 can also include more than one of the functionalities described above. For example, wireless device 1200 might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators. Figure 13 shows a network node 1300 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 telecommunications network. In accordance with respective embodiments, network node 1300 may be configured to operate in communication system 1000 of Figure 10, like network nodes 1008 or 1010, or in communication system 1100 of Figure 11, like an AP 1110 or a station 1112. 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).
[0215] Network nodes 1300 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. Network node 1300 may be a relay node or a relay donor node controlling a relay. Network nodes 1300 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 (RRU s), 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).
[0216] Other examples of network nodes 1300 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 coordination23-02-2026
[0217] 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). In particular embodiments, network node 1300 includes a processing circuitry 1302, a memory 1304, a communication interface 1306, and a power source 1308. In general, in a particular embodiment of network node 1300, processing circuitry 1302, memory 1304, communication interface 1306, and power source 1308 may, in whole or in part, represent or include physical components common to or shared by one or more of the other elements of network node 1300.
[0218] The network node 1300 may be composed of multiple distinct network entities (e.g., a NodeB entity and a RNC entity, or a BTS entity and a BSC entity, etc.), which may each have or utilize their own respective physical components. In certain scenarios in which the network node 1300 comprises multiple such entities (e.g., BTS and BSC), one or more of the separate entities 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 1300 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memories 1304 or portions of memory 1304 for different RATs) and some components may be reused (e.g., a same antenna 1310 may be shared by different RATs). The network node 1300 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1300, for example GSM, WCDMA, LTE, NR, Wi-Fi (e.g., according to an IEEE 802.11 family standard), 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 1300.
[0219] The processing circuitry 1302 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 components, such as the memory 1304, to provide network node 1300 functionality.
[0220] In some embodiments, the processing circuitry 1302 includes a system on a chip (SOC). In some embodiments, the processing circuitry 1302 includes one or more of radio frequency23-02-2026
[0221] (RF) transceiver circuitry 1312 and baseband processing circuitry 1314. In some embodiments, the RF transceiver circuitry 1312 and the baseband processing circuitry 1314 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 1312 and baseband processing circuitry 1314 may be on the same chip or set of chips, boards, or units.
[0222] The memory 1304 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 1302. The memory 1304 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 1302 and utilized by the network node 1300. The memory 1304 may be used to store any calculations made by the processing circuitry 1302 and / or any data received via the communication interface 1306. In some embodiments, the processing circuitry 1302 and memory 1304 is integrated.
[0223] The communication interface 1306 is used in wired or wireless communication of signaling and / or data with UEs, other network nodes, and / or any other network equipment. In the illustrated embodiment, communication interface 1306 comprises port(s) / terminal(s) 1316 to send and receive data, for example to and from a network over a wired connection. In particular embodiments, network node 1200 may be capable of wireless communication and communication interface 1306 may also include radio front-end circuitry 1318 that may be coupled to, or in certain embodiments a part of, an antenna 1310. Particular embodiments of radio front-end circuitry 1318 include filter(s) 1320 and amplifier(s) 1322. The radio frontend circuitry 1318 may be connected to an antenna 1310 and processing circuitry 1302. The radio front-end circuitry may be configured to condition signals communicated between antenna 1310 and processing circuitry 1302. The radio front-end circuitry 1318 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 1318 may convert the digital data into a radio signal(s) having the appropriate channel and bandwidth parameters using a combination of filters 1320 and / or amplifiers 1322. The radio signal(s) may then be transmitted via the antenna 1310. Similarly,23-02-2026
[0224] when receiving data, the antenna 1310 may collect radio signals which are then converted into digital data by the radio front-end circuitry 1318. The digital data may be passed to the processing circuitry 1302. In other embodiments, the communication interface may comprise different components and / or different combinations of components.
[0225] In certain alternative embodiments, network node 1300 may be capable of wireless communication but does not include separate radio front-end circuitry 1318, instead, the processing circuitry 1302 includes radio front-end circuitry and is connected to the antenna 1310. Similarly, in some embodiments, all or some of the RF transceiver circuitry 1312 is part of the communication interface 1306. In still other embodiments, the communication interface 1306 includes one or more ports or terminals 1316, the radio front-end circuitry 1318, and the RF transceiver circuitry 1312, as part of a radio unit (not shown), and the communication interface 1306 communicates with the baseband processing circuitry 1314, which is part of a digital unit (not shown).
[0226] The antenna 1310 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 1310 may be coupled to the radio front-end circuitry 1318 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 1310 is separate from the network node 1300 and connectable to the network node 1300 through one or more interfaces or ports.
[0227] The antenna 1310, communication interface 1306, and / or the processing circuitry 1302 may be configured to perform some or all of the receiving operations and / or obtaining operations described herein as being performed by the network node 1300. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 1310, the communication interface 1306, and / or the processing circuitry 1302 may be configured to perform some or all of the transmitting or sending operations described herein as being performed by the network node 1300. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.
[0228] The power source 1308 provides power to the various components of network node 1300 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 1308 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 1300 with power for performing the functionality described herein. For example, the network node 1300 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an23-02-2026
[0229] input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 1308. As a further example, the power source 1308 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.
[0230] Embodiments of the network node 1300 may include additional components beyond those shown in Figure 13 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 1300 may include user interface equipment to allow input of information into the network node 1300 and to allow output of information from the network node 1300. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 1300.
[0231] Figure 14 is a block diagram illustrating a virtualization environment 1400 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 1400 hosted by one or more of hardware nodes, such as a hardware computing device that operates as an access network node, UE, core network node, or host. Further, in embodiments in which a 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 1400 includes components defined by the O- RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface.
[0232] Applications 1402 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 1400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.
[0233] Hardware 1404 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described23-02-2026
[0234] 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 1406 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VM 1408A and VM 1408B (which may be collectively referred to as VMs 1408), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 1406 may present a virtual operating platform that appears like networking hardware to one or more of the VMs 1408.
[0235] The VMs 1408 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by virtualization layer 1406. Different embodiments of the instance of a virtual appliance 1402 may be implemented on one or more of VMs 1408, 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.
[0236] In the context of NFV, each of the VMs 1408 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 1408, and that part of hardware 1404 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 of the VMs 1408 on top of the hardware 1404 and corresponds to an application 1402.
[0237] Hardware 1404 may be implemented in a standalone network node with generic or specific components. Hardware 1404 may implement some functions via virtualization. Alternatively, hardware 1404 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 1410, which, among others, oversees lifecycle management of applications 1402. In some embodiments, hardware 1404 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 1412 which may alternatively be used for communication between hardware nodes23-02-2026
[0238] and radio units.
[0239] Although the computing devices described herein (c.g., UEs, network nodes, hosts) 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.
[0240] 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.23-02-2026
[0241] EMBODIMENTS
[0242] Group A Embodiments
[0243] 1. A method performed by an O-DU for performing C-Plane scheduling commands to a O-RU, the method comprising:
[0244] transmitting a frequency hopping indication to the O-RU, such that the O-RU can determine the frequency hopping pattem(s) used by one or more UEs.
[0245] 2. The method of embodiment 1, wherein the O-DU uses a first hop symbol as a frequency hopping indication.
[0246] 3. The method of embodiment 2, wherein the frequency hopping indication comprises adding a field of first hop symbol in the part of the C-Plane message (section description) describing the SRS configuration of an SRS block(s) or a UE(s).
[0247] 4. The method of embodiment 2 or 3, wherein the section descriptions of the SRS blocks or UEs not using frequency hopping, the field of first hop symbol is set to a special value indicating no frequency hopping for the SRS configuration of an SRS block(s) or a UE(s).
[0248] 5. The method of any of embodiments 2 to 4, wherein in the section descriptions of SRS blocks or UEs using frequency hopping, the field of first hop symbol is set to the symbol ID of the symbol of the first hop.
[0249] 6. The method of any of embodiments 2 to 5, wherein instead of setting symbol ID in the field of first hop symbol, an alternative is to make this field (first hop symbol) as 1 bit flag.
[0250] 7. The method of embodiment 6, wherein:
[0251] in the section description of the SRS block or the UE in the first hop symbol of frequency hopping, the field of first hop symbol is set 1; and
[0252] in the section descriptions of other SRS blocks or UEs, the field of first hop symbol is set 0.
[0253] 8. The method of embodiment 1, wherein the O-DU uses a first hop symbol and number of hops as a frequency hopping indication.23-02-2026
[0254] 9. The method of embodiment 8, wherein the frequency hopping indication involves adding a field of first hop symbol and a field of number of hops in the part of the C-Plane message (section description) describing the SRS configuration of an SRS block(s) or a UE(s).
[0255] 10. The method of embodiment 8 or 9, wherein the field of number of hops is set to the number of hops used.
[0256] 11. The method of any of embodiments 8 to 10, wherein in the section descriptions of the SRS blocks or UEs not using frequency hopping, the field of number of hops is set to 0.
[0257] 12. The method of any of embodiments 8 to 11, wherein using first hop symbol, number of hops and the PRB range information conveyed in other fields (e.g., startPrbc, numPrbc, startSrsPrb, numSrsPrb, clusterlD) for the SRS block in the message, full frequency hopping patterns for frequency hopping UEs can be determined, and the O-RU can use the information do the SRS block concatenation and perform channel estimation.
[0258] 13. The method of embodiment 1, wherein the O-DU uses only number of hops as frequency hopping indication.
[0259] 14. The method of embodiment 13, wherein the frequency hopping indication involves adding a field of number of hops in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s).
[0260] 15. The method of embodiment 13 or 14, wherein:
[0261] the information of first hop symbol is not explicitly conveyed from O-DU to O-RU; and
[0262] the O-RU will first identify the SRS blocks or UEs with non-zero number of hops, compare the symbol IDs of them and then determine the first hop from the lowest symbol ID.
[0263] 16. The method of embodiment 1, wherein the O-DU uses a hopping symbol mask as frequency hopping indication.23-02-2026
[0264] 17. The method of embodiment 16, wherein the hopping symbol mask is a bitmask indicating the symbols used in frequency hopping.
[0265] 18. The method of embodiment 1, wherein the O-DU uses a frequency hopping ID as frequency hopping indication.
[0266] 19. The method of embodiment 18, wherein the frequency hopping indication involves adding a field of frequency hopping ID in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s).
[0267] 20. The method of embodiment 18 or 19, wherein the frequency hopping ID represents a unique hopping pattern used.
[0268] 21. The method of any of embodiments 18 to 20, wherein:
[0269] O-DU will set the same frequency hopping ID in the section descriptions of the SRS blocks or UEs using the same frequency pattern; and
[0270] a special frequency hopping ID value will be set in the section descriptions of the SRS blocks or UEs not using frequency hopping.
[0271] 22. The method of embodiment 1, wherein the O-DU uses a hopping PRB cluster ID bitmask as frequency hopping indication.
[0272] 23. The method of embodiment 22, wherein the frequency hopping indication involves adding a field of hopping PRB cluster ID bitmask in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s).
[0273] 24. The method of embodiment 22 or 23, wherein hopping PRB cluster ID bitmask is a bitmask indicating the PRB clusters used in frequency hopping if PRB cluster IDs is used.
[0274] 24a The method of any of the embodiments 1-24 or any of the group B embodiments wherein the frequency hopping indication comprises a hopping index indicating a position in frequency of a PRB range of a hop of a frequency hopping pattern relative to PRB ranges of23-02-2026
[0275] other hops of the same frequency hopping pattern.
[0276] 24 b The method of embodiment 24a wherein the frequency hopping indication also comprises an indication of a number of hops in the frequency hopping pattern.
[0277] 24 c. The method of any of the preceding embodiments or any of the group B embodiments wherein the frequency hopping indication comprises an indication that the frequency hopping pattern continues over more than one slot, or wherein the frequency hopping indication comprises an indication that it does not.
[0278] Group B Embodiments
[0279] 25. A method performed by an O-RU for receiving C-Plane scheduling commands from a O-DU, the method comprising:
[0280] receiving a frequency hopping indication from the O-DU, such that the O-RU can determine the frequency hopping pattem(s) used by one or more UEs.
[0281] 26. The method of embodiment 25, wherein the O-DU uses a first hop symbol as a frequency hopping indication.
[0282] 27. The method of embodiment 26, wherein the frequency hopping indication comprises adding a field of first hop symbol in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s).
[0283] 28. The method of embodiment 26 or 27, wherein the section descriptions of the SRS blocks or UEs not using frequency hopping, the field of first hop symbol is set to a special value indicating no frequency hopping for the SRS configuration of an SRS block(s) or a UE(s).
[0284] 29. The method of any of embodiments 26 to 28, wherein in the section descriptions of SRS blocks or UEs using frequency hopping, the field of first hop symbol is set to the symbol ID of the symbol of the first hop.23-02-2026
[0285] 30. The method of any of embodiments 26 to 29, wherein instead of setting symbol ID in the field of first hop symbol, an alternative is to make this field (first hop symbol) as 1 bit flag.
[0286] 31. The method of embodiment 30, wherein:
[0287] in the section description of the SRS block or the UE in the first hop symbol of frequency hopping, the field of first hop symbol is set 1; and
[0288] in the section descriptions of other SRS blocks or UEs, the field of first hop symbol is set 0.
[0289] 32. The method of embodiment 25, wherein the O-DU uses a first hop symbol and number of hops as a frequency hopping indication.
[0290] 33. The method of embodiment 32, wherein the frequency hopping indication involves adding a field of first hop symbol and a field of number of hops in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s)..
[0291] 34. The method of embodiment 32 or 33, wherein the field of number of hops is set to the number of hops used.
[0292] 35. The method of any of embodiments 32 to 34, wherein in the section descriptions of the SRS blocks or UEs not using frequency hopping, the field of number of hops is set to 0.
[0293] 36. The method of any of embodiments 32 to 35, wherein using first hop symbol, number of hops and the PRB range information conveyed in other fields (e.g., startPrbc, numPrbc, startSrsPrb, numSrsPrb, clusterlD) for the SRS block in the message, full frequency hopping patterns for frequency hopping UEs can be determined, and the O-RU can use the information do the SRS block concatenation and perform channel estimation.
[0294] 37. The method of embodiment 25, wherein the O-DU uses only number of hops as frequency hopping indication.23-02-2026
[0295] 38. The method of embodiment 37, wherein the frequency hopping indication involves adding a field of number of hops in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s).
[0296] 39. The method of embodiment 37 or 38, wherein:
[0297] the information of first hop symbol is not explicitly conveyed from O-DU to O-RU; and
[0298] the O-RU will first identify the SRS blocks or UEs with non-zero number of hops, compare the symbol IDs of them and then determine the first hop from the lowest symbol ID.
[0299] 40. The method of embodiment 37, wherein the O-DU uses a hopping symbol mask as frequency hopping indication.
[0300] 41. The method of embodiment 40, wherein the hopping symbol mask is a bitmask indicating the symbols used in frequency hopping.
[0301] 42. The method of embodiment 25, wherein the O-DU uses a frequency hopping ID as frequency hopping indication.
[0302] 43. The method of embodiment 42, wherein the frequency hopping indication involves adding a field of frequency hopping ID in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s)..
[0303] 44. The method of embodiment 42 or 43, wherein the frequency hopping ID represents a unique hopping pattern used.
[0304] 45. The method of any of embodiments 42 to 44, wherein:
[0305] O-DU will set the same frequency hopping ID in the section descriptions of the SRS blocks or UEs using the same frequency pattern; and
[0306] a special frequency hopping ID value will be set in the section descriptions of the SRS blocks or UEs not using frequency hopping.
[0307] 46. The method of embodiment 25, wherein the O-DU uses a hopping PRB cluster ID23-02-2026
[0308] bitmask as frequency hopping indication.
[0309] 47. The method of embodiment 46, wherein the frequency hopping indication involves adding a field of hopping PRB cluster ID bitmask in the part of the C-Plane message (section description) describing an SRS configuration of an SRS block(s) or a UE(s).
[0310] 48. The method of embodiment 46 or 47, wherein hopping PRB cluster ID bitmask is a bitmask indicating the PRB clusters used in frequency hopping if PRB cluster IDs is used.
[0311] 49. The method of any of embodiments 25 to 48, further comprising performing frequency hopping and / or concatenation of SRS blocks according to the indication.
[0312] 49a The method of any of the embodiments 25-49 wherein the frequency hopping indication comprises a hopping index indicating a position in frequency of a PRB range of a hop of a frequency hopping pattern relative to PRB ranges of other hops of the same frequency hopping pattern.
[0313] 49 b The method of embodiment 49a wherein the frequency hopping indication also comprises an indication of a number of hops in the frequency hopping pattern.
[0314] 49 c. The method of any of the embodiments 25-49b wherein the frequency hopping indication comprises an indication that the frequency hopping pattern continues over more than one slot, or wherein the frequency hopping indication comprises an indication that it does not.
[0315] Group C Embodiments
[0316] 50. A network node for performing / receiving C-Plane scheduling commands, the network node comprising:
[0317] processing circuitry configured to perform any of the operations of any of the Group A or B or D embodiments;
[0318] a power source circuitry configured to supply power to the processing circuitry.23-02-2026
[0319] 51. An O-DU for performing C-Plane scheduling commands to an O-RU, comprising: processing circuitry configured to perform any of the operations of any of the Group A embodiments;
[0320] a power source circuitry configured to supply power to the processing circuitry.
[0321] 52. An O-RU for receiving C-Plane scheduling commands from an O-DU, comprising: processing circuitry configured to perform any of the operations of any of the Group B or D embodiments;
[0322] a power source circuitry configured to supply power to the processing circuitry.
[0323] Group D embodiments
[0324] D 1. A method for channel estimation performed by an O-RAN O-RU comprising the following steps:
[0325] receiving, for a plurality of OFDM symbols, an SRS from a same UE in each of the plurality of OFDM symbols, wherein the frequency range spanned by the SRS of any one symbol of the plurality does not overlap with the frequency range of the SRS of any of the other symbols of the plurality and wherein the frequency ranges of the SRSs together span a contiguous frequency range;
[0326] concatenating, in frequency domain, the received SRSs into a concatenated SRS spanning the whole of the contiguous frequency range; and
[0327] performing channel estimation on the concatenated SRS.
[0328] “Frequency range” can here mean a range of OFDM subcarriers.
[0329] D2. A method according to any of the group B embodiments wherein the frequency hopping indication comprises an indication for a symbol that the symbol is the last in the hopping pattern.23-02-2026
[0330] D3. A method according to any of the group B embodiments wherein the frequency hopping indication comprises an indication for a symbol that the symbol is the first in the hopping pattern.
[0331] D4. A method according to any of the group B embodiments wherein the frequency hopping indication comprises an indication for a symbol that the symbol is an intermediate symbol in the hopping pattern.
[0332] D5. A method performed by an O-RU for receiving C-Plane scheduling commands from a O-DU, the method comprising:
[0333] receiving a pattern indication from the O-DU, such that the O-RU can determine an SRS symbol transmission pattem(s) used by one or more UEs.
[0334] D6. A method according to embodiment D5 wherein the pattern indication comprises an indication of purpose of the use of the SRS symbol transmission pattern.
[0335] D7. A method according to embodiment D6 wherein the indication of purpose indicates that the SRS symbol transmission pattern is to be used for one of frequency hopping, SRS repetition or SRS antenna switching.
[0336] D8. A method according to embodiment D5, D6 or D7 wherein for a particular symbol of the pattern a symbol index indicates:
[0337] when the purpose is frequency hopping: the position in frequency of the SRS of the particular symbol of the pattern relative to the SRS of other symbols of the pattern; or
[0338] when the purpose is antenna port or antenna switching: the position of the symbol in the pattern and / or the antenna or antenna port used to transmit the SRS of the particular symbol of the pattern; or
[0339] when the purpose is SRS repetition: the position of the symbol in the pattern.
[0340] D9. A method wherein the indication made for a particular symbol in embodiment D8 is made for each symbol of the pattern.
[0341] D10. A method according to any of embodiments D5-D9 wherein the pattern indication comprises an indication of the number of symbols in the SRS symbol transmission pattern.23-02-2026
[0342] D11. An O-RAN O-RU adapted to perform the method of any of the embodiments D5-D10.
[0343] D12. A method performed on an O-RAN O-DU comprising sending the indication(s) of any of the embodiments D5-D10 to an O-RAN O-RU.
[0344] D13. An O-RAN O-DU adapted to perform the method
[0345] D14. A computer program comprising instructions which when run on a processor of an O-RAN O-RU causes the O-RU to perform the method of any of the embodiments D5-D10.
[0346] D15. A computer program comprising instructions which when run on a processor of an O-RAN O-DU causes the O-DU to perform the method of embodiment D12.
[0347] El. A method performed by an O-RAN O-RU comprising receiving a frequency hopping indication or an indication relating to an SRS transmission pattern from an O-RAN O-DU.
[0348] REFERENCES
[0349] 1. O-RAN Control, User and Synchronization Plane Specification 16.01, link:
[0350] https: / / specifications.o-ran.org / download?id=738.23-02-2026
[0351] ABBREVIATIONS
[0352] At least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above.
[0353] Abbreviation Explanation
[0354] AMF Access and Mobility Function
[0355] CU-CP Central Unit Control Plane
[0356] CN Core Network
[0357] DL Downlink
[0358] DU Distributed Unit
[0359] O-CU-CP ORAN CU-CP
[0360] O-DU ORAN DU
[0361] ORAN Open RAN
[0362] PRB Physical Resource Block
[0363] RAN Radio Access Network
[0364] RIC RAN Intelligence Controller
[0365] RRC Radio resource control
[0366] SON Self Organizing Network
[0367] UE User Equipment
[0368] UL Uplink
[0369]
Claims
23-02-2026CLAIMS1. A method performed by an O-RAN Radio Unit, O-RU, for receiving C-Plane scheduling commands from an O-RAN Distributed Unit, O-DU, the method comprising:receiving a frequency hopping indication from the O-DU, such that the O-RU can determine the frequency hopping pattem(s) used by one or more UEs.
2. A method according to claim 1 wherein the frequency hopping indication comprises a hopping index indicating a position in frequency of a PRB range of a hop of a frequency hopping pattern relative to PRB ranges of other hops of the same frequency hopping pattern.
3. A method according to claim 1 or 2 wherein the frequency hopping indication comprises an indication that the frequency hopping pattern continues over more than one slot, or wherein the frequency hopping indication comprises an indication that it does not.
4. A method according to any preceding claim wherein the frequency hopping indication comprises a field of number of hops.
5. A method according to claim 4 wherein the frequency hopping indication comprises a first hop symbol.
6. A method according to claim 4 wherein only number of hops is used as a frequency hopping indication.o 7. A method performed by an O-DU for performing C-Plane scheduling commands to a O- RU, the method comprising:transmitting a frequency hopping indication to the O-RU, such that the O-RU can determine the frequency hopping pattem(s) used by one or more UEs.
8. A method according to claim 7 wherein the frequency hopping indication comprises a hopping index indicating a position in frequency of a PRB range of a hop of a frequency hopping pattern relative to PRB ranges of other hops of the same frequency hopping pattern.
9. A method according to claim 7 or 8 wherein the frequency hopping indication comprises an indication that the frequency hopping pattern continues over more than one slot, or wherein the frequency hopping indication comprises an indication that it does not.23-02-2026an indication that the frequency hopping pattern continues over more than one slot, or wherein the frequency hopping indication comprises an indication that it does not.
10. A method according any of claims 7-9 wherein the frequency hopping indication comprises a field of number of hops.
11. A method according to claim 10 wherein the frequency hopping indication comprises a first hop symbol.
12. The method of embodiment 1, wherein the O-DU uses only number of hops as frequency hopping indication.
13. An O-RAN Radio Unit, O-RU, adapted to perform the method of any of the claims 1-6.
14. A computer program adapted to, when run on one or more processors of an O-RAN Radio Unit, O-RU, cause the O-RU to perform the method of any of the claims 1 -6.
15. An O-RAN Radio Unit, O-RU comprising processing circuitry and a memory configured to receive a frequency hopping indication from the O-DU, such that the O-RU can determine the frequency hopping pattem(s) used by one or more UEs.
16. A tangible, non-transient computer-readable medium comprising instructions that, when executed by processing circuitry of an O-RAN Radio Unit, O-RU connected to an O-RAN Distributed Unit, O-DU over fronthaul, cause the processing circuitry to perform operations comprising receiving a frequency hopping indication from the O-DU, such that the O-RU can determine the frequency hopping pattem(s) used by one or more UEs.
17. An O-RAN Distributed Unit, O-DU, adapted to perform the method of any of the claims 7-12.
18. A computer program adapted to, when run on one or more processors of an O-RAN Distributed Unit, O-DU, cause the O-DU to perform the method of any of the claims 7-12.
19. An O-RAN Distributed Unit, O-DU comprising processing circuitry and a memory23-02-2026configured to transmit a frequency hopping indication to the O-RU, such that the O-RU can determine the frequency hopping pattem(s) used by one or more UEs.
20. A tangible, non-transient computer-readable medium comprising instructions that, when executed by processing circuitry of an O-RAN Radio Unit, O-RU connected to an O-RAN Distributed Unit, O-DU over fronthaul, cause the processing circuitry to perform operations comprising transmitting a frequency hopping indication to the O-RU, such that the O-RU can determine the frequency hopping pattem(s) used by one or more UEs.