Methods, devices and medium for indicating two or more preferred downlink reference signals during an access procedure

Abstract

Embodiments of the present disclosure relate to methods, devices and computer readable storage medium for indicating preferred downlink (DL) reference signals (RSs). In a method, a terminal device performs measurements on a plurality of DL RSs. The terminal device determines two or more preferred DL RSs based on the measurements. Then, the terminal device transmits an indication of the two or more preferred DL RSs during an access procedure.

Description

METHODS, DEVICES AND MEDIUM FOR INDICATING TWO OR MORE PREFERRED DOWNLINK REFERENCE SIGNALS DURING AN ACCESS PROCEDUREFIELDS

[0001] Various embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, devices and computer readable storage medium for indicating preferred downlink (DL) reference signals (RSs).BACKGROUND

[0002] This section introduces aspects that may facilitate a better understanding of the disclosure. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.

[0003] Distributed Multiple -Input -Multiple -Output (MIMO), also called D-MIMO, is a concept aimed at next-generation mobile systems, e.g., the fifth generation (5G) advanced and the sixth generation (6G) systems, in which a geographical area is covered by spreading out Access Points (APs) or Transmission and Reception Points (TRPs) that are coordinated by a Baseband Unit (BBU) or a Distributed Unit (DU) with baseband capability, instead of dividing that area into disjoint regions (cells). Each AP or TRP may be equipped with a plurality of different beams and the APs or TRPs need to collaborate to serve the users in the area. It is expected that D-MIMO guarantees high connectivity, reduces interference, and improves spectral efficiency, resulting in a better user experience when compared to the traditional Centralized MIMO (C-MIMO) architecture, where all the antennas of the base station (BS) are co-located.

[0004] For user equipment (UEs), signals may arrive and emanate from all different directions. Hence, it is beneficial to have an antenna implementation at the UE which has the possibility to generate omni-directional-like coverage in addition to the high gain narrow beams. One way to increase the omni-directional coverage at a UE is to install a plurality of panels and point the panels in different directions.SUMMARY

[0005] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0006] As described above, UEs may be equipped with a plurality of antenna panels that maysteer several beams in different directions. Currently, during initial access, a UE may transmit a PRACH in one direction, which is associated with a preferred SSB. The preferred SSB may be any SSB with a reference signal receiving power (RSRP) above a certain threshold, which hence might not indicate the best SSB beam. In D-MIMO deployments, the number of APs might be much larger than the number of UEs, and several APs will be used to communicate with each UE. In this case, the indication for a single preferred SSB beam will only give to the network partial information about suitable APs and suitable beams per AP.

[0007] To overcome or mitigate at least one of the above-mentioned problems or other problems or provide a useful solution, embodiments of the present disclosure propose methods, devices and storage medium for LBT.

[0008] In a first aspect of the present disclosure, there is provided a method implemented at a terminal device. In the method, the terminal device performs measurements on a plurality of downlink reference signals. The terminal device determines two or more preferred downlink reference signals based on the measurements. Then, the terminal device transmits an indication of the two or more preferred downlink reference signals during an access procedure.

[0009] In an example, the terminal device may perform, based at least in part on at least one rule, one or more physical random access channel (PRACH) transmissions to indicate the two or more preferred downlink reference signals.

[0010] In an example, the terminal device may obtain an association between the one or more PRACH transmissions and the two or more downlink reference signals. In an example, the one or more PRACH transmissions may be performed further based on the obtained association.

[0011] In an example, the terminal device may receive the association between the one or more PRACH transmissions and the two or more downlink reference signals.

[0012] In an example, the terminal device may be configured with a plurality of sets of downlink reference signals.

[0013] In an example, the at least one rule may indicate that one PRACH transmission is performed for one set of downlink reference signals among the plurality of sets of downlink reference signals.

[0014] In an example, the one PRACH transmission may indicate a downlink reference signal from the one set of downlink reference signals. In an example, respective measured signal powers of one or more downlink reference signals from the one set of downlink reference signals may be equal to or greater than a threshold power.

[0015] In an example, the at least one rule may indicate that a single PRACH transmission isperformed for one or more sets of downlink reference signals among the plurality of sets of downlink reference signals.

[0016] In an example, the single PRACH transmission may indicate a plurality of downlink reference signals from the plurality of sets of downlink reference signals. In an example, each of the plurality of downlink reference signals may be corresponding to a different set of downlink reference signals among the plurality of sets of downlink reference signals.

[0017] In an example, the terminal device may obtain a configuration for a PRACH transmission, and determine the at least one rule based on the configuration for the PRACH transmission.

[0018] In an example, the terminal device may receive the configuration for the PRACH transmission.

[0019] In an example, the terminal device may transmit an indication for priority of the two or more preferred downlink reference signals.

[0020] In an example, the plurality of downlink reference signals may be associated with a same cell.

[0021] In an example, the downlink reference signal may comprise a synchronization signal block.

[0022] In an example, the access procedure may comprise at least one of a random access procedure or an initial access procedure.

[0023] In a second aspect of the present disclosure, there is provided a method implemented at a network device. In the method, the network device transmits, to a terminal device, an indication for at least one rule to be used by the terminal device to indicate two or more preferred downlink reference signals during an access procedure of the terminal device.

[0024] In an example, the network device may transmit, to the terminal device, an association between the one or more PRACH transmissions and the two or more downlink reference signals.

[0025] In an example, the network device may transmit, to the terminal device, a configuration for a PRACH transmission. In an example, the configuration for the PRACH transmission indicates the at least one rule.

[0026] In an example, the at least one rule may indicate that one PRACH transmission is performed for one set of downlink reference signals among a plurality of sets of downlink reference signals.

[0027] In an example, the one PRACH transmission may indicate a downlink reference signalfrom the one set of downlink reference signals. In an example, respective measured signal power of one or more downlink reference signals from the one set of downlink reference signals may be equal to or greater than threshold power.

[0028] In an example, the at least one rule may indicate that a single PRACH transmission is performed for one or more sets of downlink reference signals among a plurality of sets of downlink reference signals.

[0029] In an example, the single PRACH transmission may indicate a plurality of downlink reference signals from the plurality of sets of downlink reference signals. In an example, each of the plurality of downlink reference signals may be corresponding to a different set of downlink reference signals among the plurality of sets of downlink reference signals.

[0030] In an example, the network device may receive, from the terminal device, an indication for priority of the two or more preferred downlink reference signals.

[0031] In an example, the two or more preferred downlink reference signals may be associated with a same cell.

[0032] In an example, the downlink reference signal may comprise a synchronization signal block.

[0033] In an example, the access procedure may comprise at least one of a random access procedure or an initial access procedure.

[0034] In a third aspect of the present disclosure, there is provided a terminal device. The terminal device comprises a processor and a memory coupled to the processor, the memory containing instructions executable by the processor, whereby the terminal device is operative to perform the method according to the first aspect.

[0035] In a fourth aspect of the present disclosure, there is provided a network device. The terminal device comprises a processor and a memory coupled to the processor, the memory containing instructions executable by the processor, whereby the network device is operative to perform the method according to the second aspect.

[0036] In a fifth aspect of the present disclosure, there is provided an apparatus. The apparatus comprises means for performing the method according to the first or second aspect.

[0037] In a sixth aspect of the disclosure, there is provided a computer-readable storage medium having instructions stored thereon, the instructions, which, when executed by at least one processor of a device, cause the device to perform the method according to the first or second aspect.

[0038] With the present disclosure, during an access procedure, a terminal device indicates, to a network, two or more preferred DL RSs which may be received from one or more network devices. Such indication for two or more preferred DL RSs may allow a network to attain more information about suitable network devices for the terminal device during the access procedure, thereby improving access efficiency.BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Through the more detailed description of some embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, where the same reference generally refers to the same components in the embodiments of the present disclosure.

[0040] FIG. 1A is a diagram showing example beam management procedures.

[0041] FIG. IB is a diagram showing example uplink beam management procedures.

[0042] FIG. 1C is a diagram showing a structure of a terminal device arranged with three antenna panels.

[0043] FIG. ID is a diagram showing an example generation process of UE beams with different beamwidths.

[0044] FIG. IE is a diagram showing example configurations for synchronization signal blocks (SSBs) and transmitting (Tx) beams for D-MIMO deployment.

[0045] FIG. IF is a diagram showing an example time and frequency structure of a single SSB transmission.

[0046] FIG. 1G is a diagram showing an example transmission process of synchronization signal (SS) bursts.

[0047] FIG. 1H is a diagram showing a 4-step random-access procedure.

[0048] FIG. 2 is a diagram showing an example communication environment in which embodiments of the present disclosure can be implemented.

[0049] FIG. 3 is a diagram showing a flowchart of an example method for indicating two or more preferred DL RSs in accordance with some embodiments of the present disclosure.

[0050] FIG. 4 is a signaling diagram an example access procedure in accordance with some embodiments of the present disclosure.

[0051] FIGS. 5 A and 5B are diagrams showing an example process of PRACH transmissions using a wide beam from each UE panel in accordance with some embodiments of the presentdisclosure.

[0052] FIG. 6 is a block diagram showing a flowchart of another example method for indicating two or more preferred DL RSs in accordance with some other embodiments of the present disclosure.

[0053] FIG. 7 is a block diagram showing functional structures of a terminal device in accordance with some embodiments.

[0054] FIG. 8 is a block diagram showing functional structures of a network device in accordance with some embodiments.

[0055] FIG. 9 is a block diagram showing a communication device in accordance with some embodiments.

[0056] FIG. 10 is a block diagram showing a computer readable storage medium in accordance with some embodiments of the present disclosure.

[0057] FIG. 11 is a block diagram showing an example of a communication system in accordance with some embodiments.

[0058] FIG. 12 is a block diagram showing a UE in accordance with some embodiments.

[0059] FIG. 13 is a block diagram showing a network node in accordance with some embodiments.

[0060] FIG. 14 is a block diagram of a host in accordance with some embodiments.

[0061] FIG. 15 is a block diagram illustrating a virtualization environment in which functions implemented by some embodiments may be virtualized.

[0062] FIG. 16 is a communication diagram of a host communicating via a network node with a UE over a partially wireless connection in accordance with some embodiments.DETAILED DESCRIPTION

[0063] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0064] Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and / or is implied from the context in which it is used. All references to a / an / the element, apparatus,component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and / or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description.

[0065] Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present disclosure should be or are in any single embodiment of the disclosure. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Furthermore, the described features, advantages, and characteristics of the disclosure may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the disclosure may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the disclosure.

[0066] As used herein, the terms "first", "second" and so forth refer to different elements. The singular forms "a" and "an" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "has", "having", "includes" and / or "including" as used herein, specify the presence of stated features, elements, and / or components and the like, but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. The term "based on" is to be read as "based at least in part on". The term "one embodiment" and "an embodiment" are to be read as "at least one embodiment". The term "another embodiment" is to be read as "at least one other embodiment". Other definitions, explicit and implicit, may be included below.

[0067] As used herein, the term “terminal device” refers to a device which is intended for accessing services via an access network and configured to communicate over the access network. The terminal device may be able to communicate with a network node, such as a base station, or with another terminal device by transmitting and / or receiving wireless signals. For instance, the terminal device may include, but is not limited to: a mobile phone, a smart phone, a sensor device, a meter, a vehicle, a household appliance, a medical appliance, a media player, a camera, or anytype of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, a tablet computer, a laptop, or a personal computer (PC). The terminal device may also include a portable, pocketstorable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and / or data, via a wireless connection. In the following description, the terms “terminal device”, “user equipment” and “UE” may be used interchangeably.

[0068] As used herein, the term “network device” or “network node” refers to a device in a communication network via which a terminal device receives services from the network. The terms “network node”, “network function” may be used interchangeably. A network function can be implemented either as a network element on a dedicated hardware, as a software instance running on a dedicated hardware, or as a virtualised function instantiated on an appropriate platform, e.g., on a cloud infrastructure. The network node comprises an access network node via which a terminal device accesses an access network. Examples of access 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)). In the following description, the terms “network device”, “network node”, “base station” and “BS” may be used interchangeably.

[0069] The network node may further comprise a core network node. Examples of core network nodes may include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), an evolved Packet Data Gateway (ePGW), a trusted wireless local area network (WLAN) access network (TWAN) node, a Home Subscriber Server (HSS), an Access and Mobility Management Function (AMF), a Session Management Function (SMF), a Network Slice Selection Function (NSSF), a Serving Gateway (SGW), a Packet Gateway (PGW), an Authentication Server Function (AUSF), a Subscription Identifier De-concealing function (SIDF), a Unified Data Management (UDM), a Security Edge Protection Proxy (SEPP), a Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0070] As used herein, the term “communication device” refers to a device capable of communications. Examples of a communication device may comprise a terminal device and a network device.

[0071] Even though D-MIMO systems employ mature technologies like MIMO, there are many technical challenges to deploy the D-MIMO systems efficiently, for example, because of the user-centric nature (also referred to as "cell-free" nature) of these systems. Aspects such as channel state information (CSI) acquisition joint transmission or reception modes (more general for downlink (DL) and uplink (UL)), DL or UL beam management, deployment architectures, and Initial Access (IA) procedures are some examples of issues to be solved or improved in suchsystems.

[0072] In New Radio (NR), a sounding reference signal (SRS) is used for providing CSI to the gNB in the UL. The usage of SRS includes, e.g., deriving the appropriate transmission or reception beams, performing link adaptation (e.g., setting a transmission rank and a modulation and coding scheme (MCS)), and selecting DL (e.g., for physical downlink shared channel (PDSCH) transmissions) and UL (e.g., for physical uplink shared channel (PUSCH) transmissions) MIMO precoding.

[0073] In Long Term Evolution (LTE) and NR, the SRS is configured via Radio Resource Control (RRC) siganling, where parts of the configuration may be updated (for reduced latency) through medium access control (MAC) control element (CE) (or MAC-CE) signaling. The configuration includes, for example, the SRS resource allocation (the physical resource mapping and the sequence to use) as well as the time-domain behavior (aperiodic, semi-persistent, or periodic). For an aperiodic SRS transmission, the RRC configuration does not activate an SRS transmission from the UE, but, instead, a dynamic activation trigger is transmitted from the gNB in the DL, via downlink control information (DCI) in a physical downlink control channel (PDCCH) which instructs the UE to transmit the SRS once, at a predetermined time.

[0074] When configuring SRS transmissions, the gNB configures, through the "SRS-Config IE", a set of SRS resources and a set of SRS resource sets, where each SRS resource set contains one or more SRS resources. Each SRS resource set may be configured with a certain usage (depending on what the SRS transmission needs to be used for, as specified in 3GPP TS 38.214, VERSION 18.0.0), by setting the RRC parameter 'usage' to one of 'antennaSwitching', 'codebook', 'nonCodebook', and 'beamManagement', for example.

[0075] An SRS resource set that is configured with usage 'antennaSwitching' is used for reciprocity -based DL precoding (e.g., used to sound the channel in the UL so that the gNB can use reciprocity to set a suitable DL precoders). The UE is expected to transmit one SRS port per UE antenna port.

[0076] An SRS resource set that is configured with usage 'codebook' is used for codebook (CB)-based UL transmission (e.g., used to sound the different UE antennas and help the gNB to determine or signal a suitable UL precoder, transmission rank, and MCS for PUSCH transmissions). There are up to two SRS resources in an SRS resource set with usage 'codebook'. The mapping from SRS ports to UE antenna ports is, however, up to UE implementation and not known to the gNB.

[0077] An SRS resource set that is configured with usage 'nonCodebook' is used for noncodebook (NCB)-based UL transmission. Specifically, the UE transmits one SRS resource percandidate beam. Suitable candidate beams are determined by the UE based on CSI-RS measurements in the DL and, hence, reciprocity needs to hold. The gNB then, by indicating a subset of these SRS resources, determines which UL beam(s) that the UE needs to apply for PUSCH transmission. One UL layer is transmitted per indicated SRS resource. The mapping from SRS ports to UE antenna ports is still up to UE implementation and not known to the gNB.

[0078] An SRS resource set that is configured with usage 'beamManagemenf is used (e.g., for frequency bands above 6 GHz, e.g., for Frequency Range 2 (FR2), to evaluate different UE beams for analog beamforming arrays. The UE transmits one SRS resource per analog beam, and the gNB performs a reference signal receiving power (RSRP) measurement per transmitted SRS resource and, in this way, determine a suitable UE beam that is reported to the UE.

[0079] Multi-beam operations are supported in NR. In high frequency range (e.g., FR2), a plurality of radio frequency (RF) beams may be used to transmit and receive signals at a gNB and a UE. For each DL beam from a gNB, there is an associated best UE Rx beam for receiving signals from the DL beam. The DL beam and the associated UE Rx beam form a beam pair. The beam pair can be identified through a so-called beam management process (or procedure) in NR.

[0080] A DL beam is identified by an associated DL reference signal (RS) transmitted in the beam, either periodically, semi-persistently, or aperiodically. The DL RS may be sent through a synchronization signal block (SSB), including a primary synchronization signal (PSS), a secondary synchronization signal (SSS) and a physical broadcast channel (PBCH). The DL RS may also be sent through a Channel State Information RS (CSI-RS). By measuring all the DL RSs, the UE may determine and report to the gNB the best DL beam to use for DL transmissions. The gNB may then transmit a burst of a DL-RS in the reported best DL beam to allow the UE to evaluate candidate receiving (RX) beams of a UE (also called UE RX beams).

[0081] Beam management may be divided into three procedures, as illustrated in FIG. 1 A. The purpose of a Pl procedure, as shown in FIG. 1A, is to find a coarse direction for a UE 102 using a wide transmitting (TX) beam of a gNB 104 where the wide TX beam covers the whole angular sector. The purpose of a P2 procedure is to refine the TX beam of the gNB 104 by performing a new beam search around the coarse direction found in the Pl procedure. A P3 procedure is used for the UE 102 that has analog beamforming to allow the UE 103 to find a suitable UE RX beam.

[0082] The Pl procedure is expected to utilize beams with rather large beamwidths where the beam reference signals are transmitted periodically and are shared between all UEs of the cell. Example reference signals to use for the Pl procedure are periodic CSI-RSs or SSBs. The UE 102 may then report the N best beams to the gNB 104 and their corresponding RSRP values where N represents any positive integer. The P2 procedure is expected to use aperiodic or semi-persistent CSI-RSs transmitted in narrow beams around the coarse direction found in the Pl procedure.

[0083] The P3 procedure is expected to use aperiodic or semi-persistent CSI-RSs repeatedly transmitted in one narrow beam of the gNB 104. One alternative way is to allow the UE 102 to determine a suitable UE RX beam based on the periodic SSB transmission. Each SSB includes four Orthogonal Frequency Division Multiplexing (OFDM) symbols, and thus a maximum of four UE RX beams can be evaluated during each SSB burst transmission. One benefit with using an SSB instead of a CSI-RS is that no extra overhead of CSI-RS transmission is needed.

[0084] In NR, several signals can be transmitted from different antenna ports of the same base station. These signals can have the same large-scale properties such as Doppler shift / spread, average delay spread, or average delay. These antenna ports may be called to be quasi co-located (QCL). If the UE knows that two antenna ports are QCL with respect to a certain parameter (e.g., Doppler spread), the UE can estimate that parameter based on one of the antenna ports and apply that estimate for receiving signal on the other antenna port. For example, there may be a QCL relation between a CSI-RS for tracking (or TRS) and a PDSCH demodulation reference signal (DMRS). When UE receives the PDSCH DMRS, the UE may use the measurements already made on the TRS to assist the DMRS reception.

[0085] Information about assumptions regarding QCL may be signaled to the UE from the network. In NR, four types of QCL relations between a transmitted source RS and transmitted target RS are defined:• Type A: {Doppler shift, Doppler spread, average delay, delay spread}• Type B: {Doppler shift, Doppler spread}• Type C: {average delay, Doppler shift}• Type D: {Spatial Rx parameter}

[0086] QCL type D is introduced in NR to facilitate beam management with analog beamforming and is known as spatial QCL. In general, if two transmitted antenna ports are spatially QCL, the UE may use the same Rx beam to receive signals from the two transmitted antenna ports. This is helpful for a UE that uses analog beamforming to receive signals, since the UE needs to adjust its RX beam in a direction prior to receiving a certain signal. If the UE knows that a signal is spatially QCL with another signal it has received earlier, then it may use the same RX beam to receive the later signal.

[0087] In NR, the spatial QCL relation for a DL or UL signal or channel may be indicated to the UE by using a "beam indication". The "beam indication" is used to help the UE to find a suitable RX beam for DL reception, and / or a suitable TX beam for UL transmission. In NR, the "beam indication" for DL is conveyed to the UE by indicating a transmission configurationindicator (TCI) state to the UE, while in UL the "beam indication" may be conveyed by indicating a DL-RS or UL-RS as spatial relation (in NR release 15 or 16 (Rel-15 / 16)) or a TCI state (in NR release 17 (Rel-17)).

[0088] As mentioned above, for UEs, the signals may arrive and emanate from all different directions. Hence, it is beneficial to have an antenna implementation at the UE which has the possibility to generate omni-directional-like coverage in addition to the high gain narrow beams. One way to increase the omni-directional coverage at a UE is to install a plurality of panels and point the panels in different directions, as illustrated in FIG. 1C. A UE 106 in FIG. 1C has three antenna panels 108, 110 and 112 pointing in opposite directions to improve coverage. The UE 106 may have one baseband chain that may be connected in an alternate way to one of the three panels 108, 110 and 112 depending on the switch setting. However, in Release 18 (Rel-18), a UE may perform receptions with multi-Rx DL chain (for example, via two antennal panels) simultaneously, from two different directions (at FR2 - mmWave).

[0089] An antenna panel of a UE (also called a UE panel or a UE antenna panel) may generate beams of different beam widths, as illustrated in FIG. ID. UEs may generate wider beams by turning off one or more power amplifiers (PAs) of the panel, which may have a negative impact on the available output power. However, it is possible to mitigate the power loss when generating wide beams by applying dual -polarized beamforming (e.g., using array size invariant (ASI) beamforming). It is useful for the UE to generate a wide beam of a panel during beam sweeping procedures (also called beam sweep procedures) to first find a coarse direction to a serving AP or TRP, which would enable the UE to select and activate a suitable UE panel. In the example as shown in FIG. ID, a UE may generate one wide beam 114, 5 half-wide beams 116, and 9 narrow beams 118 for each panel.

[0090] A D-MIMO system is a system with a plurality of geographically distributed antenna panels, possibly with respective radio and processing units, where such panels jointly coordinate transmissions and receptions to serve one or more UEs. One type of D-MIMO deployment is based on coordination of macro gNBs, as considered in 3GPP Rel-18 MIMO Working Item. Another type of D-MIMO deployment, considered as a candidate for 6G, is based on several small-sized low-powered panels or nodes densely deployed in a specific part of the cell, which requires a capacity or reliability enhancement, e.g., in crowded parts of a macro cell area such as public squares or stadiums.

[0091] In the case of macro deployments, the D-MIMO panels and respective radio and processing units, are referred to as TRPs. In the case of dense localized deployments, the D- MIMO panels, and respective radio and processing units, are referred to as access points (APs) or Radio Units (RUs). In the context of the present disclosure, the terms “TRP”, “RU” and “AP”may be used interchangeably.

[0092] There are different levels of coordination between TRPs which may allow for different D-MIMO transmission modes. These modes depend on a transmission scheme such as:• Non-coherent joint transmissions (NCJT), where the same or different layers may be transmitted from different TRPs without per-TRP precoding accounting for the instantaneous (amplitude and) phase of the DL channel, as defined in 3GPP TR 36.741, VERSION 14.0.0; i. NC-JT Case 1 where different layers are transmitted across TRPs, ii. NC-JT Case 2a where different layers are transmitted across TRPs with spatial diversity or multiplexing, e.g., space-time block codes, iii. NC-JT Case 2b - Single Frequency Network (SFN) where the same layer is transmitted across TRPs.• Coherent joint transmissions (CJT), where the same layer(s) is(are) sent from different TRPs and precoded per-TRP, such that the signals associated with the different TRP layer transmissions add up constructively at a spatial location where the intended UE is.

[0093] For high-band and higher frequency bands, the usage of D-MIMO systems is considered with the aim of improving coverage, reliability, and robust mobility, rather than spectral efficiency as prioritized in mid-bands. NCJT schemes are the major type of transmission schemes to be considered for high-bands, since inter-TRP phase calibration needed for CJTs is more challenging to be addressed at high-bands due to both tighter link budget and the phase noise which may make CJT infeasible at high frequencies.

[0094] Several candidate approaches may be used to deploy D-MIMO systems at higher frequencies with respect to the transmission of reference signals in different beams. FIG. IE depicts four candidate processes, where one or more SSBs are transmitted per AP. In a process 120, one SSB is transmitted per beam of each AP. One benefit of this process 120 is that the AP will know a beam to be used for a UE, based on the SSB beam report, without an additional second beam management procedure (e.g., the P2 procedure as shown in FIG. 1A) using CSI-RSs in more narrow beams. In a process 122, each SSB is covering a plurality of narrow beams, and, however, there are still a plurality of SSB beams per AP. In a process 124, there is only a single SSB beam per AP while in a process 126, one SSB is shared between a plurality of different beams from a plurality of APs. A preferred process of the candidate processes 120, 122, 124 and 126 depends for example on the number of APs within a cluster, the number of beams per AP, and / or the like. The benefit of the process 126 is that the SSB overhead may be kept low, but extensive P2 procedures (as shown in FIG. 1A) may be needed to determine suitable APs andbeams per AP.

[0095] For frequencies between 6GHz and 24 GHz, it is expected that high gain beam forming may be used (at least for the lower part of the frequency band), where the beam forming is done in a frequency selective digital domain (in similar way as for low and midband). This differs from FR2 where analog or time domain digital beamforming is used. In addition, for FR2 and higher frequencies, a base station including a digital narrow band receiver may be used to evaluate all candidate TRP beams on a single received signal, which catches interest in the industry ecosystem.

[0096] In NR, a UE may perform an Initial Access (IA) procedure to find a cell to camp on (cell search) and to request a connection through random access (e.g., a random access procedure). The cell search is carried out when a UE is initially entering the coverage area of a system (for idle or inactive -state UEs). To enable mobility, cell search is also continuously carried out by UEs moving within the system (for connected-state, and idle or inactive-state UEs). In the following, cell search will be described based on the reception of Synchronization Signal blocks (SSBs), which are used for initial cell search as well as idle or inactive -state mobility. An SSB in NR comprises (at least) a primary and secondary synchronization signal (denoted as PSS and SSS). The sequence index of these signals constitutes a physical cell identity (PCI) used for scrambling and demodulation of other channels, such as a Physical Broadcast Channel (PBCH). The PBCH contains a master information block (MIB) that the UE needs to obtain to receive the minimum system information and to determine the system timing. SSBs are periodically transmitted on the downlink (DL) from each NR cell and under a beamforming operation. The SSBs are beam-swept using a beam -sweeping procedure.

[0097] FIG. IF illustrates the time and frequency structure of a single SSB transmission. As shown in FIG. IF, an SSB 128 spans four OFDM symbols 130 in the time domain and 240 subcarriers in the frequency domain. A PSS 132 is transmitted in the first OFDM symbol 134 of the SSB 128 and occupies 127 subcarriers 136 in the frequency domain. The remaining subcarriers are empty. An SSS 138 is transmitted in the third OFDM symbol 140 of the SSB 128 and occupies the same set of subcarriers as the PSS 132. There are eight and nine empty subcarriers on each side of the SSS 138.

[0098] The beam-sweeping procedure in NR defines that SSBs are transmitted in periodic SS Bursts and there may be several SS Bursts in a SS Burst Set, as shown in FIG. 1G. The SS burst set composition is carrier-frequency -dependent, including the maximum number of SSBs (4 or 8 for Frequency Range 1 (FR1)), and 64 for FR2) within an SS burst set, an SSB mapping pattern, and an SS burst set mapping to slots in a radio frame. Regardless of the SS burst set composition, the transmission of SSBs within an SS burst set 142 is confined to a 5 ms window 144 to reduce power consumption and complexity of UEs for radio resource management (RRM) measurements.A UE located in an area covered by only one beam may receive one SSB during every SS Burst Set period (or duration) 146 (with periodicity from 5ms to 160ms, however, default is 20 ms). A UE may receive a plurality of SS Burst transmissions if several beams cover its location. After a beam-sweeping reception, the UE is supposed to choose a preferred SSB (e.g., the strongest SSB or any SSB with an RSRP above a certain threshold). This allows the UE to decode the preferred SSB (e.g., to camp on a cell and acquire initial system information) and extract its time index.

[0099] Once a UE has found a cell, it may access the cell. This is done as part of the Random- Access (RA) procedure. FIG. 1H shows a 4-step random-access procedure 148 as reference. As shown in FIG. 1H, at Step 1 - Preamble (PRACH), in order to access the cell, a UE 150 at first transmits (152) a preamble, also referred to as a Physical Random Access Channel (PRACH) or a PRACH preamble, at the transmission time of the preferred SSB chosen in the beam-sweeping procedure. Preambles is transmitted (152) in a configurable subset of slots (called RACH slots), which may have a plurality of frequency -domain RACH occasions. The association of different SSB time indices and different Random Access Channel (RACH) time or frequency occasions and / or different preamble sequences is a feature of the NR initial access that creates the possibility to establish a suitable beam pair (gNB beam and UE beam) during the initial-access phase. In practice, SSB time indices may correspond to SSB transmissions in different DL beams, which enables the network to determine, based on the received preamble, the DL beam matching with the UE UL beam. This beam may then be used as an initial beam for subsequent DL transmissions to the UE. Furthermore, if the association between an SSB time index and a RACH occasion indicates that a given time-domain RACH occasion corresponds to one specific SSB time index, the network will know, in time, when preamble transmission from UEs within a specific DL beam will take place. Assuming this beam correspondence, the network may then focus the UL receiver beam on the corresponding direction for beam-formed preamble reception. In practice, this implies that a UL receiver beam will be swept over the coverage area, and the UL beam sweeping is synchronized with the corresponding DL beam sweeping for the SSB transmission. It is to be noted that beam sweeping for a preamble transmission may be used when analog beamforming is applied at the receiver side. If digital beamforming is applied, beam -formed preamble reception may be done from a plurality of directions simultaneously.

[0100] In Step 2 - Random Access Response (RAR), RAR is transmitted (154) as a response from a network 156 that it has properly received the preamble. It is transmitted (154) as a conventional DL PDCCH / PDSCH and includes: (i) information about the RA preamble sequence which the network 156 has detected and for which the response is valid, (ii) a timing correction calculated by the network 156 based on the preamble receive timing, (iii) a scheduling grant, indicating resources the UE 150 will use for the transmission of the subsequent Message 3, and (iv) a temporary identity, e.g., the Temporary Cell-Radio Network Temporary Identifier (TC-RNTI), used for further communications between the UE 150 and the network 156.

[0101] In Step 3 - Message 3 (Contention Resolution), Message 3 is transmitted (158). After RAR, the UL of the UE 150 is time synchronized. However, before user data may be transmitted to / from the UE 150, a unique identity within the cell, e.g., the Cell-Radio Network Temporary Identifier (C-RNTI), needs to be assigned to the UE 150 (unless the UE 150 already has a C-RNTI assigned). Depending on the UE state, there may also be a need for additional message exchange for setting up the connection.

[0102] In Step 4 - Message 4 (Contention Resolution and Contention Setup), Message 4 is transmitted (160). The last step in the RA procedure consists of a DL message (Message 4) for contention resolution. Message 4 is MAC data sent by the network 156 (e.g., gNB) to confirm the correct identification of the UE 150, and that contention has been resolved. The contention resolution mechanism differs depending on whether the UE 150 already has a valid identity in the form of a C-RNTI or not. It is noted that the network 156 may know from the Message 3 whether the UE 150 has a valid C-RNTI or not.

[0103] As described above, UEs may be equipped with a plurality of antenna panels pointing in different directions, but only a subset (one or few) of the UE panels may be used at each time instance. Thus, the usage of UE panels is limited. Furthermore, currently, during initial access, a UE may transmit a PRACH in one direction, which is associated with a preferred SSB (e.g., any SSB with an RSRP above a certain threshold, which hence might not indicate the best SSB beam), as described above. In D-MIMO deployments, the number of APs might be much larger than the number of UEs, and several APs will be used to communicate with each UE. In this case, the indication for a single preferred SSB beam will only give to the network partial information about suitable APs and suitable beams per AP.

[0104] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Some embodiments of the present disclosure propose a scheme for indicating preferred DL RS(s). With this scheme, during an access procedure, a terminal device (such as a UE) indicates two or more preferred DL RSs which may be received from one or more network devices such as APs. In an example, the terminal device will transmit a burst of PRACHs (or similar UL RSs), where each PRACH indicates one preferred SSB per one or more APs. In another example, the terminal device may transmit a single PRACH (or similar UL RS), where the single PRACH indicates a preferred SSB per one or more network devices. In yet another example, the terminal device may be triggered to report one or more preferred SSB per one or more network devices during initial access.

[0105] This scheme may allow the network to attain more information about suitable APs and / or beam(s) per APs during initial access for multi-panel UEs in D-MIMO deployments. Thismay reduce the delay and latency for communications between the network and the UE and reduce signaling overhead in terms of additional beam sweep procedures. In the case of macro-diversity, the robustness and flexibility of PRACH transmissions may be enhanced, which may reduce the contention probability in the next steps, e.g., the transmissions of Message 3 (Msg 3) and Message 4 (Msg 4) and provide a shorter initial access process statistically. In this way, AP selection and beam selection per AP may be improved during initial access for multi-panel UEs in D-MIMO deployments.

[0106] FIG. 2 illustrates an example communication environment 200 in which embodiments of the present disclosure can be implemented.

[0107] As shown in FIG. 2, the communication environment 200 comprises a terminal device 210 and a plurality of network devices 220-1, 220-2, 220-3, ... , 220-N (where N represent a positive integer). The network devices 220-1, ... , 220-N may be individually or collectively referred to as network device(s) 220. The terminal device 210 may operate as a UE. The network device 220 may operate as a gNB, a TRP, an AP, and / or an RU, which may coordinate with each other to provide services for the terminal device 210. In an example, the plurality of network devices 220-1, ... , 220-N may be deployed as a D-MIMO system.

[0108] The terminal device 210 is arranged with a plurality of antennal panels 230-1, 230- 2, ... , 230-M where M represents a positive integer. The antennal panels 230-1, ... , 230-M may be individually or collectively referred to as antenna panel(s) or panel(s) 230. Different antenna panels may point to different directions, one antenna panel 230 may generate different types of beams, for example, with different beam widths. The terminal device 210 may communicate with one or more network devices 220 using one of the antenna panels 230 at one time instance or communicate with one or more network devices 220 using more than one antennal panel 230 simultaneously.

[0109] In some embodiments, the network device 220 may be capable of frequency selective digital domain beamforming (using a digital narrowband receiver, a fully digital beamforming solution as in FR1 or lower parts of FR2, and / or the like), time-domain or analog beamforming or combination of analog / time -domain and frequency selective beamforming. In the case that the plurality of network devices 220-1, ... , 220-N are deployed as a D-MIMO system, the candidate processes as shown in FIG. IE may be applied. For example, a plurality of DL reference signals may be transmitted by one of the network devices 220, and each of the DL reference signals may cover one or more beams of the network device 220. Alternatively, or in addition, one DL reference signal may be transmitted by one or more of the network devices 220. The DL reference signal may comprise an SSB and any other DL reference signals that has been or can be used in the future by the terminal device 210 for cell search, initial access, random access, channelmeasurement, and / or other purposes.

[0110] It is to be understood that the numbers of devices are illustrated in FIG. 2 only for the purpose of illustration without suggesting any limitations. The communication environment 200 may include any suitable numbers of terminal devices and network devices for implementing embodiments of the present disclosure. In some embodiments, in the case that the plurality of network devices 220-1, ... , 220-N operate as small-sized low-powered panels or nodes that are densely deployed in a specific part of a cell provided by a macro base station, the communication environment 200 may further comprise the macro base station which may schedule the transmissions or receptions of the plurality of network devices 220-1, ... , 220-N.

[0111] In the context of the present disclosure, the terms "configured", "indicated", "activated", "fixed in the standards" and “fixed in the specification” are used. The term "configured" may means a radio resource control (RRC) configuration, while the term "indicated" or "activated" means either a medium access control (MAC) control element (CE) or downlink control information (DO). The term "fixed in the standards" or "fixed in the specification" means a procedural text in RRC or MAC specification which describes a certain procedure that the UE needs to follow, or a text in the specification for stage-2 or LI, where, e.g., UE actions or assumption is directly specified.

[0112] In the following, some example terms are used. However, any other terms may be also appliable. Further, the "configuration" may also be provided in a broadcast or multicast, or groupcast message. A broadcast message may be used by the network to send signals to a wide area such as a cell in Long Term Evolution (LTE) or New Radio (NR). A multicast or groupcast message is a message targeted to certain UEs within that wide area e.g., by using specific RNTI known by those UEs.

[0113] In the communication environment 200, during an access procedure (e.g., including an initial access procedure or a random access procedure), the terminal device 220 determines two or more preferred DL RSs based on the measurements on the DL RSs and then indicates the two or more preferred DL RSs to the network device(s) 220 or other network devices. With such an indication, the network may have more information to determine suitable network device(s) 220 for the terminal device 210.

[0114] Some example implementations will be described below with reference to FIGS. 3 to 5B.

[0115] Reference is first made to FIG. 3 which shows a flowchart of an example method 300 for indicating two or more preferred DL RSs in accordance with some embodiments of the present disclosure. The method 300 may be implemented by the terminal device 210 as shown in FIG. 2.For the purpose of discussion, the method 300 will be described from the perspective of the terminal device 210.

[0116] As shown in FIG. 3, at block 310, the terminal device 210 performs measurements on a plurality of DL RSs. In some embodiments, the DL RSs may comprise SSBs. For example, each network device 220 may transmit two or more SSBs or similar broadcast reference signal or other DL RSs. The terminal device 210 may monitor and measure these DL RSs.

[0117] At block 320, the terminal device 210 determines two or more preferred DL RSs based on the measurements. For example, the terminal device 210 may choose the strongest DL RS or any DL RS with a measured signal strength, power or quality (such as an RSRP, Reference Signal Receiving Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR), and / or other signal quality metrics) equal to or greater than a certain threshold in strength, power or quality.

[0118] At block 330, the terminal device 210 transmits an indication of the two or more preferred DL RSs during an access procedure. As such, more information about the network device(s) and / or beams of the network device(s) may be provided to the network to facilitate the access procedure, including, e.g., a random access procedure and an initial access procedure.

[0119] In some embodiments, the plurality of DL RSs are associated with a same cell. For example, these DL RSs may be associated with the same physical cell index (PCI) which may identify a cell. In an example, the terminal device 210 may perform the access procedure targeting a certain cell. In this example, the terminal device 210 may consider measurements on DL RSs associated with that cell. In other words, the terminal device 210 may only take DL RSs belonging to the cell, which the terminal device 210 is performing the access procedure to, into consideration.

[0120] The terminal device 210 may use any suitable approach to indicate that two or more preferred DL RSs. In some embodiments, the terminal device 210 may explicitly indicate the preferred DL RSs. For example, the terminal device 210 may include a report of the preferred DL RSs in Msg 3.

[0121] In some embodiments, the terminal device 210 may indicate the two or more preferred DL RSs implicitly using one or more PRACH transmissions. In an example, the terminal device 210 may perform one or more PRACH transmissions based at least in part on at least one rule, to indicate the two or more preferred DL RSs. Such an implicit indication may be further based on association between the one or more PRACH transmissions and the two or more DL RSs. Accordingly, after the network receive the one or more PRACH transmissions, the network may know the associated DL RSs. This association may be configured by the network. For example, the terminal device 210 may receive the association between the one or more PRACHtransmissions and the two or more DL RSs from the network. Alternatively, or in addition, this association may be predefined or fixed in the standards or specifications.

[0122] The terminal device 210 may obtain the at least one rule for PRACH transmissions in any suitable way. In some embodiments, the terminal device 210 may receive an indication for the at least one rule from the network, e.g., via one of the network devices 220 or other network devices which may schedule the terminal device 210 and / or the network devices 220.

[0123] In some embodiments, the at least one rule may be indicated by a configuration for a PRACH transmission (also referred to as a PRACH configuration) to be performed during the access procedure. For example, the terminal device 210 may obtain the configuration for the PRACH transmission and then determine the at least one rule from the configuration. This configuration may be received by the terminal device 210 from the network or predefined or fixed in the standard or specification. It is also possible that some rules are indicated by this configuration, and some other rules are indicated by a separate configuration or message such as by another broadcast configuration, or by a multicast or groupcast message, or by a signal specific to the terminal device 210.

[0124] In some embodiments, the terminal device 210 may be configured with a plurality of sets of DL RSs. Each set of DL RSs may correspond to one network device 220. In some embodiments, the at least one rule may indicate that one PRACH transmission is performed for one set of DL RSs among the plurality of sets of DL RSs. In an example, the terminal device 210 may perform one PRACH transmission per set of DL RSs (such as a set of SSBs) where e.g., each set of DL RSs is associated with one network device 220, that is, each network device 220 transmits a unique set of DL RSs.

[0125] In some embodiments, one PRACH transmission for one set of DL RSs may indicate a DL RS from the set of DL RSs. In an example, the terminal device 210 may report one DL RS from each set of DL RSs. For example, the terminal device 210 may select one DL RS with a measured signal power (such as a RSRP) above a certain threshold or the DL RS with the highest measured signal power. In this way, the terminal device 210 may indicate one suitable DL beam or the best DL beam from each network device 220. Thus, through indications for multiple DLRS beams, AP selection and beam selection may be improved in a signaling efficient way.

[0126] In some embodiments, respective measured signal powers of one or more DL RSs from the one set of DL RSs is equal to or greater than a threshold power. The threshold power may be configured by the network, predefined in the standards or specifications, or preset by the terminal device 210 itself. In an example, the terminal device 210 may only perform a PRACH transmission associated with a set of DL RSs if at least one DL RS from that set of DL RSs is received with a measured signal power over a certain threshold power.

[0127] In some embodiments, the at least one rule may indicate that a single PRACH transmission is performed for one or more sets of DL RSs among the plurality of sets of DL RSs. For example, the single PRACH transmission may indicate one or more set of DL RSs. In some embodiments, the single PRACH transmission may indicate a plurality of DL RSs from the plurality of sets of DL RSs. Each of the plurality of DL RSs is corresponding to a different set of DL RSs among the plurality of sets of DL RSs. For example,

[0128] In an example, the terminal device 210 may perform a single PRACH transmission, where the single PRACH transmission is used to indicate a plurality of DL RSs, for example one DL RS per set of DL RSs. In another example, the terminal device 210 may only perform a single PRACH transmission associated with X sets of DL RSs, where for example the X sets of DL RSs may be selected such that at least one DL RL in each of the X sets of DL RSs are received with a measured signal power over a certain threshold power.

[0129] In some embodiments, the single PRACH transmission may separately indicate which sets of DL RSs are suitable and then indicate a suitable DL RS per set of DL RSs. In some other embodiments, the single PRACH transmission may only indicate the preferred set of DL RSs but not the DL RS per set of DL RSs. In these embodiments, the network will get information about best network devices 220, but not best DL beam per network device. The network device 220 may perform beam sweeps to determine the best DL beam. As such, PRACH signaling overhead may be reduced.

[0130] In some embodiments, the at least one rule may indicate that the terminal device 210 performs more than one PRACH transmissions where a single PRACH transmission is used to indicate a plurality of DL RSs, for example one DL RS per set of DL RSs from different network devices 220. In an example, the terminal device 210 may group the DL RSs from different sets of DL RSs where combined Signal to Noise Ratio (SNR) value, or large-scale coefficients, over a plurality of DL RSs exceeds a certain threshold. In another example, if the terminal device 210 knows that network devices 220 (or antenna ports) sending different sets of DL RSs are QCL, e.g., type-D, then the terminal device 210 will perform a single PRACH transmission associated with set of DL RSs with the network devices 220 that are QCL.

[0131] It is to be understood that the rules as described above may be applied separately or in combination. For example, one rule may indicate that a single PRACH transmission is performed for two or more preferred DL RSs. Another rule may indicate that the terminal device 210 only perform a PRACH transmission associated with a set of DL RSs in which at least one DL RS is received with a measured signal power over a certain threshold power. In this case, the terminal device 210 may perform the PRACH transmissions by taking the two rules into account. For example, based on these two rules, the terminal device 210 may perform a single PRACHtransmission associated with a set of DL RSs in which at least one DL RS is received with a measured signal power over a certain threshold power.

[0132] In some embodiments, the terminal device 210 may transmit an indication for priority of the two or more preferred DL RSs. In an example, the terminal device 210 may explicitly indicate this priority. For example, one bit may be used to indicate “better” and “good” beams. In another example, the terminal device 210 may implicit indicate this priority using the ordering of the indications for the two or more preferred DL RSs. For example, if the two or more preferred DL RSs are indicated by indexes, the terminal device 210 may use the ordering of these associated indexes to indicate the priority levels of the two or more preferred DL RSs.

[0133] FIG. 4 shows an example access procedure 400 according to some embodiments of the present disclosure. In this example, two APs 402 and 404, denoted by API and AP2, respectively, are example implementations of the network device 220 in FIG. 2, and a UE 406 is an example implementation of the terminal device 210 in FIG. 2. The DL RS comprise an SSB.

[0134] As shown in FIG. 4, at Stepl, each AP 402 or 404 transmits (408, 410) two or more SSBs or similar broadcast reference signal in 6G and additional system information (e.g., Remaining Minimum System Information (RMSI) in NR, other system information (OSI), or similar information block in 6G. It is to be noted that the additional system information may not be transmitted by the APs 402 and 404, but may be distributed by another network node such as another AP or a macro base station. The SSB and / or RMSI may contain information about a PRACH configuration. The PRACH configuration may indicate one or more rules for transmitting PRACHs to indicate two or more preferred SSBs.

[0135] At Step 2, the UE 406 receives (412) the SSBs and RMSI, including the PRACH configuration. At Step3, based on SSB measurements and the PRACH configuration, the UE 406 transmits (414) one or more PRACHs (such as one or more PRACH preambles) to indicate two or more preferred SSBs. The preferred SSBs may be indicated to the network using PRACHs in different ways.

[0136] In some embodiments, the PRACH configuration may indicate that the UE 406 transmits one PRACH per set of SSBs (where e.g., each set of SSBs is associated with one AP 402 or 404, i.e., each AP 402 or 404 is transmitting a unique set of SSBs). In one embodiment, the UE 406 reports one SSB from each set of SSBs. For example, the UE 406 can select one SSB above a certain threshold RSRP or the SSB with highest RSRP where RSRP is used as an example metric of a measured signal power. That is, the UE 406 indicates one suitable SSB beam or the best SSB beam from each AP 402 or 404. There is a one-to-one mapping between a PRACH and a SSB (which for example may be indicated in the PRACH configuration). In this case, the UE may transmit a PRACH to indicate the mapped SSB. In one embodiment, the UE 406 onlytransmits a PRACH associated with a SSB set, where at least one SSB is received with an RSRP over a certain threshold value.

[0137] In some embodiments, the PRACH configuration may indicate that the UE 406 transmits a single PRACH, where the single PRACH is used to indicate multiple SSBs, for example one SSB per set of SSBs (where e.g., each set of SSBs is associated with one AP 402 or 404, i.e., each AP 402 or 404 is transmitting a unique set of SSBs). In one embodiment, the UE only transmits PRACH(s) associated with one or more sets of SSBs (also called SSB set(s)) where at least one SSB is received with an RSRP over a certain threshold value.

[0138] In one embodiment, the UE 406 only transmits PRACH(s) associated with X SSB set(s), where for example the X SSB sets can be selected such that at least one SSB in each of the X SSB sets are received with an RSRP over a certain threshold value. In one embodiment, the PRACH may separately indicate which SSB sets are suitable, and then indicate a suitable SSB per SSB set. In one embodiment, the PRACH may only indicate the preferred SSB set (and not the actual SSB per SSB set). In this embodiment, the network will get information about best APs, but not best SSB beam per AP, which will save PRACH overhead signaling.

[0139] In some embodiments, the PRACH configuration may indicate that the UE 406 transmits more than one PRACH, where the single PRACH is used to indicate multiple SSBs, for example one SSB per set of SSBs from different APs 402 and 404. In one embodiment, the UE 406 may group the SSBs from different SSB sets where combined SNR value, or large-scale coefficients, over multiple SSBs exceeds a certain threshold. In one embodiment, if the UE 406 knows that APs (or antenna ports) sending different SSB sets are QCL, e.g., type-D, then the UE 406 may transmit a single PRACH associated with SSB sets from the APs that are QCL.

[0140] At Step 4, the APs 402 and 404 receive (416, 418) the PRACH transmission and can determine a suitable SSB beam based on the received PRACH. At Step 5, the APs 402 and 404 may communicate (420, 422) with the UE 406 using the preferred SSB beam indicated by the UE 406.

[0141] FIGS. 5A and 5B show an example process of PRACH transmissions to indicate two or more preferred DL RSs according to some embodiments of the present disclosure. In this example, APs 502, 504, 506 and 508 operate as example implementations of the network device 220 in FIG. 2, denoted by API, AP2, AP3 and AP4. The UE 406 is arranged with three antenna panels (also called called UE panels) 510, 512 and 514.

[0142] As shown in FIG. 5A, in Stepl, each AP 502, 504, 506 or 508 transmits a set of SSBs. The UE 406 receives the PRACH configuration, e.g., in the SSB and / or in some additional system information (like RMSI in NR). The PRACH configuration indicates to the UE 406 to transmitone PRACH per SSB set, where each transmitted PRACH is associated with an SSB that is received with an RSRP (as an example implementation of a measured power metric) above a certain threshold, and / or the SSB received with highest RSRP of the corresponding set of SSBs. In one embodiment, in case the UE 406 does not receive any SSB above a certain threshold of a set of SSBs, the UE 406 does not have to transmit a PRACH for that SSB set. In one embodiment, for each transmitted PRACH, the UE 406 may use a UE panel and / or a UE beam that was used to receive the SSB associated with the transmitted PRACH. In this way, each AP with a good link budget to the UE 406 will get information of a preferred SSB beam, which then directly can be used for communication with the UE 406.

[0143] In one embodiment, a beam report is introduced during initial access (for example included in Msg3 in NR or in a similar message in 6G), where this beam report may indicate one or more preferred SSB beams per SSB set. In one embodiment, the beam report only includes a preferred SSB from an SSB set where at least one SSB from that set of SSBs has been received with an RSRP over a certain threshold.

[0144] In one embodiment, the beam report may indicate preferred SSB(s) from X number of SSB sets, where X for example can be indicated in system information or hardcoded in the spec or based on scenario key performance indicators (KPIs) and requirements. In one embodiment, X can vary, depending on how many SSB sets or beams are received with an RSRP over a certain threshold. In one embodiment, X can vary, depending on how many SSB sets or beams are received over another certain threshold for the interference estimation, e.g., for interference- aware transmission.

[0145] In one embodiment, the beam report may comprise two parts, including a first part that indicates the SSB set, and a second part that indicates the SSB per set. For example, the UE 406 may be indicated that there are 4 SSB sets and 8 SSBs per SSB set. In this case, if the UE 406 reports SSB beams from two SSB sets (i.e., X = 2), one or more bitfield in the first part of the beam report is used to indicate which two of the four SSB sets that the report is associated with (where for example each SSB set has an SSB set index). The second part of the report comprises one or more bitfields that indicate the SSB index for the SSB in the two indicated SSB sets. The SSB index is local within the SSB set. So, for example, in case an SSB set includes 8 SSBs, the local index can be indicated with 3 bits, i.e., 8 codepoints.

[0146] In one embodiment, the system information, indicates that the UE 406 measures and reports on another reference signal than an SSB, for example a CSI-RS in NR or another DL RS in 6G. In this case, the report in Msg 3 or similar message during initial access can indicate the index of these other DL RSs (e.g., CSI-RSs in NR), instead of an index of an SSB. Thus, the APs 502, 504, 506 or 508 may attain more suitable beams if other DL RSs are transmitted in the narrowbeams, e.g., CSI-RS (which requires much less overhead signaling and saving energy consumption. Further, the network can also attain information about the suitable AP beam.

[0147] In one embodiment, the UE 406 can indicate priority of the preferred DL RSs. For example, based on the level of RSRPs, or if the UE 406 is able to evaluate potential transmission rank given a certain DL RS, the DL RS may be prioritized. The indication may be communicated by ordering the indications if the indications are in a form where each DL RS is indicated by an index. Alternatively, one bit may be used to indicate “better” and “good” beams. The network may configure whether this indication is used and which metric or threshold to be used in the system information, or dedicated RRC message like RRC redirection message.

[0148] FIG. 6 shows a flowchart of an example method 600 for indicating two or more preferred DL RSs in accordance with some embodiments of the present disclosure. The method 600 may be implemented by the network device 220 as shown in FIG. 2 or other network devices. For the purpose of discussion, the method 600 will be described from the perspective of the network device 220.

[0149] As shown in FIG. 6, at block 610, the network device the network device transmits, to a terminal device, an indication for at least one rule to be used by the terminal device to indicate two or more preferred downlink reference signals during an access procedure of the terminal device.

[0150] In an example, the network device may transmit, to the terminal device, an association between the one or more PRACH transmissions and the two or more downlink reference signals.

[0151] In an example, the network device may transmit, to the terminal device, a configuration for a PRACH transmission. In an example, the configuration for the PRACH transmission indicates the at least one rule.

[0152] In an example, the at least one rule may indicate that one PRACH transmission is performed for one set of downlink reference signals among a plurality of sets of downlink reference signals.

[0153] In an example, the one PRACH transmission may indicate a downlink reference signal from the one set of downlink reference signals. In an example, respective measured signal power of one or more downlink reference signals from the one set of downlink reference signals may be equal to or greater than threshold power.

[0154] In an example, the at least one rule may indicate that a single PRACH transmission is performed for one or more sets of downlink reference signals among a plurality of sets of downlink reference signals.

[0155] In an example, the single PRACH transmission may indicate a plurality of downlink reference signals from the plurality of sets of downlink reference signals. In an example, each of the plurality of downlink reference signals may be corresponding to a different set of downlink reference signals among the plurality of sets of downlink reference signals.

[0156] In an example, the network device may receive, from the terminal device, an indication for priority of the two or more preferred downlink reference signals.

[0157] In an example, the two or more preferred downlink reference signals may be associated with a same cell.

[0158] In an example, the downlink reference signal may comprise a synchronization signal block.

[0159] In an example, the access procedure may comprise at least one of a random access procedure or an initial access procedure.

[0160] All operations and features related to the network or network device as described above with reference to FIGS. 2 to 5B are likewise applicable to the method 600 and have similar effects. For the purpose of simplification, the details will be omitted.

[0161] FIG. 7 shows function units of a terminal device 700 in accordance with some embodiments of the present disclosure.

[0162] As shown in FIG. 7, the terminal device 700 comprises a measurement unit 710 configured to perform measurements on a plurality of downlink reference signals. The terminal device 700 further comprises a determination unit 720 configured to determine two or more preferred downlink reference signals based on the measurements. The terminal device 700 further comprises a transmission unit 730 configured to transmit an indication of the two or more preferred downlink reference signals during an access procedure.

[0163] In some embodiments, the terminal device 700 may further comprise units for implementing actions or operations related to the terminal device according to any of the above- mentioned embodiments described with reference to FIGS. 2 to 5B.

[0164] FIG. 8 shows function units of a network device 800 in accordance with some embodiments of the present disclosure.

[0165] As shown in FIG. 8, the network device 800 comprises a transmission unit 810 configured to transmit, to a terminal device, an indication for at least one rule to be used by the terminal device to indicate two or more preferred downlink reference signals during an access procedure of the terminal device.

[0166] In some embodiments, the network device 800 may further comprise units for implementing actions or operations related to the network or the network device according to any of the above-mentioned embodiments described with reference to FIGS. 2 to 6.

[0167] FIG. 9 shows a communication device 900 in accordance with some embodiments of the present disclosure.

[0168] As shown in FIG. 9, the communication device 900 may comprise a memory 910 containing instructions 915. The communication device 900 may further comprise a processor 905 that executes the instructions 915 to implement actions or operations according to any of the above-mentioned embodiments described with reference to FIGS. 2 to 6.

[0169] In some embodiments, the communication device 900 may operate as a terminal device. In these embodiments, the communication device 900 may be operative to: perform measurements on a plurality of downlink reference signals; determine two or more preferred downlink reference signals based on the measurements; and transmit an indication of the two or more preferred downlink reference signals during an access procedure.

[0170] In some embodiments, the communication device 900 may operate as a network device. In these embodiments, the communication device 900 may be operative to: transmit, to a terminal device, an indication for at least one rule to be used by the terminal device to indicate two or more preferred downlink reference signals during an access procedure of the terminal device.

[0171] The processor 905 may be any kind of processing component, such as one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The memory 910 may be any kind of storage component, such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc.

[0172] FIG. 10 shows a computer readable storage medium in accordance with some embodiments.

[0173] As shown in FIG. 10, the computer readable storage medium 1000 comprising instructions 915 which when executed by a processor system of a device, the processor system may comprise one or more processors to perform any above-mentioned embodiments described with reference to FIGS. 2 to 6 by any combination of the processors.

[0174] The computer readable storage medium 1000 may be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable readonly memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives.

[0175] In some embodiments, an apparatus capable of performing the method 400 or 500 may comprise means for performing the respective operations of the method 400 or 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.Example System

[0176] FIG. 11 shows an example of a communication system 1100 in accordance with some embodiments.

[0177] In the example, the communication system 1100 includes a telecommunication network 1102 that includes an access network 1104, such as a radio access network (RAN), and a core network 1106, which includes one or more core network nodes 1108. The access network 1104 includes one or more access network nodes, such as network nodes 1110a and 1110b (one or more of which may be generally referred to as network nodes 1110), or any other similar 3rdGeneration Partnership Project (3 GPP) access nodes or non-3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 1102 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 1102 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 1102, including one or more network nodes 1110 and / or core network nodes 1108.

[0178] 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). The 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 access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platformorchestrated by a Service Management and Orchestration Framework via an 0-2 interface defined by the 0-RAN Alliance or comparable technologies. The network nodes 1110 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 1112a, 1112b, 1112c, and 1112d (one or more of which may be generally referred to as UEs 1112) to the core network 1106 over one or more wireless connections.

[0179] 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 1100 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 1100 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0180] The UEs 1112 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 1110 and other communication devices. Similarly, the network nodes 1110 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 1112 and / or with other network nodes or equipment in the telecommunication network 1102 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 1102.

[0181] In the depicted example, the core network 1106 connects the network nodes 1110 to one or more hosts, such as host 1116. 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 1106 includes one more core network nodes (e.g., core network node 1108) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 1108. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0182] The host 1116 may be under the ownership or control of a service provider other thanan operator or provider of the access network 1104 and / or the telecommunication network 1102, and may be operated by the service provider or on behalf of the service provider. The host 1116 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.

[0183] As a whole, the communication system 1100 of FIG. 11 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0184] In some examples, the telecommunication network 1102 is a cellular network that implements 3 GPP standardized features. Accordingly, the telecommunications network 1102 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 1102. For example, the telecommunications network 1102 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive loT services to yet further UEs.

[0185] In some examples, the UEs 1112 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 1104 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 1104. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0186] In the example, the hub 1114 communicates with the access network 1104 to facilitate indirect communication between one or more UEs (e.g., UE 1112c and / or 1112d) and networknodes (e.g., network node 1110b). In some examples, the hub 1114 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 1114 may be a broadband router enabling access to the core network 1106 for the UEs. As another example, the hub 1114 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 1110, or by executable code, script, process, or other instructions in the hub 1114. As another example, the hub 1114 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 1114 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 1114 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 1114 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 1114 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0187] The hub 1114 may have a constant / persistent or intermittent connection to the network node 1110b. The hub 1114 may also allow for a different communication scheme and / or schedule between the hub 1114 and UEs (e.g., UE 1112c and / or 1112d), and between the hub 1114 and the core network 1106. In other examples, the hub 1114 is connected to the core network 1106 and / or one or more UEs via a wired connection. Moreover, the hub 1114 may be configured to connect to an M2M service provider over the access network 1104 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 1110 while still connected via the hub 1114 via a wired or wireless connection. In some embodiments, the hub 1114 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 1110b. In other embodiments, the hub 1114 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 1110b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0188] FIG. 12 shows a UE 1200 in accordance with some embodiments. As used herein, a UE refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage 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 vehicleembedded / integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0189] A UE may support device-to-device (D2D) communication, for example by implementing a 3 GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle- to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0190] The UE 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 UEs may utilize all or a subset of the components shown in FIG. 12. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0191] 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).

[0192] 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 the UE 1200. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digitalcamera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0193] 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. 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 the UE 1200 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 1208. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 1208 to make the power suitable for the respective components of the UE 1200 to which power is supplied.

[0194] 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 application 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 the UE 1200, any of a variety of various operating systems or combinations of operating systems.

[0195] 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 the UE 1200 to access instructions, application programs and thelike, 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.

[0196] The processing circuitry 1202 may be configured to communicate with an access network or other network 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 UE 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.

[0197] In the illustrated embodiment, communication functions of the communication interface 1212 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short- range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0198] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 1212, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0199] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or theswitch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0200] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT 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 head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), 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. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 1200 shown in FIG. 12.

[0201] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0202] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0203] FIG. 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 telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)), O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O-CU).

[0204] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0205] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0206] The network node 1300 includes a processing circuitry 1302, a memory 1304, a communication interface 1306, and a power source 1308. The network node 1300 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 1300 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 1300 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1304 for different RATs) and somecomponents 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, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1300.

[0207] 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 network node 1300 components, such as the memory 1304, to provide network node 1300 functionality.

[0208] 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 frequency (RF) transceiver circuitry 1312 and baseband processing circuitry 1314. In some embodiments, the radio frequency (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.

[0209] 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.

[0210] The communication interface 1306 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 1306 comprises port(s) / terminal(s) 1316 to send and receive data, forexample to and from a network over a wired connection. The communication interface 1306 also includes radio front-end circuitry 1318 that may be coupled to, or in certain embodiments a part of, the antenna 1310. Radio front-end circuitry 1318 comprises filters 1320 and amplifiers 1322. The radio front-end 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 having the appropriate channel and bandwidth parameters using a combination of filters 1320 and / or amplifiers 1322. The radio signal may then be transmitted via the antenna 1310. Similarly, 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.

[0211] In certain alternative embodiments, the network node 1300 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).

[0212] 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 an interface or port.

[0213] The antenna 1310, communication interface 1306, and / or the processing circuitry 1302 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 1310, the communication interface 1306, and / or the processing circuitry 1302 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0214] 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 an 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.

[0215] Embodiments of the network node 1300 may include additional components beyond those shown in FIG. 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.

[0216] FIG. 14 is a block diagram of a host 1400, which may be an embodiment of the host 1116 of FIG. 11, in accordance with various aspects described herein. As used herein, the host 1400 may be or comprise various combinations hardware and / or software, including a standalone server, a blade server, a cloud-implemented server, a distributed server, a virtual machine, container, or processing resources in a server farm. The host 1400 may provide one or more services to one or more UEs.

[0217] The host 1400 includes processing circuitry 1402 that is operatively coupled via a bus 1404 to an input / output interface 1406, a network interface 1408, a power source 1410, and a memory 1412. Other components may be included in other embodiments. Features of these components may be substantially similar to those described with respect to the devices of previous figures, such as FIGS. 12 and 13, such that the descriptions thereof are generally applicable to the corresponding components of host 1400.

[0218] The memory 1412 may include one or more computer programs including one or more host application programs 1414 and data 1416, which may include user data, e.g., data generated by a UE for the host 1400 or data generated by the host 1400 for a UE. Embodiments of the host 1400 may utilize only a subset or all of the components shown. The host application programs 1414 may be implemented in a container-based architecture and may provide support for videocodecs (e.g., Versatile Video Coding (VVC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), MPEG, VP9) and audio codecs (e.g., FLAC, Advanced Audio Coding (AAC), MPEG, G.711), including transcoding for multiple different classes, types, or implementations of UEs (e.g., handsets, desktop computers, wearable display systems, heads-up display systems). The host application programs 1414 may also provide for user authentication and licensing checks and may periodically report health, routes, and content availability to a central node, such as a device in or on the edge of a core network. Accordingly, the host 1400 may select and / or indicate a different host for over-the-top services for a UE. The host application programs 1414 may support various protocols, such as the HTTP Live Streaming (HLS) protocol, Real-Time Messaging Protocol (RTMP), Real-Time Streaming Protocol (RTSP), Dynamic Adaptive Streaming over HTTP (MPEG-DASH), etc.

[0219] FIG. 15 is a block diagram illustrating a virtualization environment 1500 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 1500 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 1500 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.

[0220] Applications 1502 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 1500 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0221] Hardware 1504 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described 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 1506 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1508a and 1508b(one or more of which may be generally referred to as VMs 1508), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 1506 may present a virtual operating platform that appears like networking hardware to the VMs 1508.

[0222] The VMs 1508 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1506. Different embodiments of the instance of a virtual appliance 1502 may be implemented on one or more of VMs 1508, 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.

[0223] In the context of NFV, a VM 1508 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 1508, and that part of hardware 1504 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1508 on top of the hardware 1504 and corresponds to the application 1502.

[0224] Hardware 1504 may be implemented in a standalone network node with generic or specific components. Hardware 1504 may implement some functions via virtualization. Alternatively, hardware 1504 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 1510, which, among others, oversees lifecycle management of applications 1502. In some embodiments, hardware 1504 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 1512 which may alternatively be used for communication between hardware nodes and radio units.

[0225] FIG. 16 shows a communication diagram of a host 1602 communicating via a network node 1604 with a UE 1606 over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with various embodiments, of the UE (such as a UE 1112a of FIG. 11 and / or UE 1200 of FIG. 12), network node (such as network node1110a of FIG. 11 and / or network node 1300 of FIG. 13), and host (such as host 1116 of FIG. 11 and / or host 1400 of FIG. 14) discussed in the preceding paragraphs will now be described with reference to FIG. 16.

[0226] Like host 1400, embodiments of host 1602 include hardware, such as a communication interface, processing circuitry, and memory. The host 1602 also includes software, which is stored in or accessible by the host 1602 and executable by the processing circuitry. The software includes a host application that may be operable to provide a service to a remote user, such as the UE 1606 connecting via an over-the-top (OTT) connection 1650 extending between the UE 1606 and host 1602. In providing the service to the remote user, a host application may provide user data which is transmitted using the OTT connection 1650.

[0227] The network node 1604 includes hardware enabling it to communicate with the host 1602 and UE 1606. The connection 1660 may be direct or pass through a core network (like core network 1106 of FIG. 11) and / or one or more other intermediate networks, such as one or more public, private, or hosted networks. For example, an intermediate network may be a backbone network or the Internet.

[0228] The UE 1606 includes hardware and software, which is stored in or accessible by UE 1606 and executable by the UE’s processing circuitry. The software includes a client application, such as a web browser or operator-specific “app” that may be operable to provide a service to a human or non-human user via UE 1606 with the support of the host 1602. In the host 1602, an executing host application may communicate with the executing client application via the OTT connection 1650 terminating at the UE 1606 and host 1602. In providing the service to the user, the UE's client application may receive request data from the host's host application and provide user data in response to the request data. The OTT connection 1650 may transfer both the request data and the user data. The UE's client application may interact with the user to generate the user data that it provides to the host application through the OTT connection 1650.

[0229] The OTT connection 1650 may extend via a connection 1660 between the host 1602 and the network node 1604 and via a wireless connection 1670 between the network node 1604 and the UE 1606 to provide the connection between the host 1602 and the UE 1606. The connection 1660 and wireless connection 1670, over which the OTT connection 1650 may be provided, have been drawn abstractly to illustrate the communication between the host 1602 and the UE 1606 via the network node 1604, without explicit reference to any intermediary devices and the precise routing of messages via these devices.

[0230] As an example of transmitting data via the OTT connection 1650, in step 1608, the host 1602 provides user data, which may be performed by executing a host application. In some embodiments, the user data is associated with a particular human user interacting with the UE1606. In other embodiments, the user data is associated with a UE 1606 that shares data with the host 1602 without explicit human interaction. In step 1610, the host 1602 initiates a transmission carrying the user data towards the UE 1606. The host 1602 may initiate the transmission responsive to a request transmitted by the UE 1606. The request may be caused by human interaction with the UE 1606 or by operation of the client application executing on the UE 1606. The transmission may pass via the network node 1604, in accordance with the teachings of the embodiments described throughout this disclosure. Accordingly, in step 1612, the network node 1604 transmits to the UE 1606 the user data that was carried in the transmission that the host 1602 initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1614, the UE 1606 receives the user data carried in the transmission, which may be performed by a client application executed on the UE 1606 associated with the host application executed by the host 1602.

[0231] In some examples, the UE 1606 executes a client application which provides user data to the host 1602. The user data may be provided in reaction or response to the data received from the host 1602. Accordingly, in step 1616, the UE 1606 may provide user data, which may be performed by executing the client application. In providing the user data, the client application may further consider user input received from the user via an input / output interface of the UE 1606. Regardless of the specific manner in which the user data was provided, the UE 1606 initiates, in step 1618, transmission of the user data towards the host 1602 via the network node 1604. In step 1620, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 1604 receives user data from the UE 1606 and initiates transmission of the received user data towards the host 1602. In step 1622, the host 1602 receives the user data carried in the transmission initiated by the UE 1606.

[0232] One or more of the various embodiments improve the performance of OTT services provided to the UE 1606 using the OTT connection 1650, in which the wireless connection 1670 forms the last segment.

[0233] In an example scenario, factory status information may be collected and analyzed by the host 1602. As another example, the host 1602 may process audio and video data which may have been retrieved from a UE for use in creating maps. As another example, the host 1602 may collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, the host 1602 may store surveillance video uploaded by a UE. As another example, the host 1602 may store or control access to media content such as video, audio, VR or AR which it can broadcast, multicast or unicast to UEs. As other examples, the host 1602 may be used for energy pricing, remote control of non -time critical electrical load to balance power generation needs, location services, presentation services (such as compiling diagrams etc.from data collected from remote devices), or any other function of collecting, retrieving, storing, analyzing and / or transmitting data.

[0234] In some examples, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 1650 between the host 1602 and UE 1606, in response to variations in the measurement results. The measurement procedure and / or the network functionality for reconfiguring the OTT connection may be implemented in software and hardware of the host 1602 and / or UE 1606. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which the OTT connection 1650 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1650 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not directly alter the operation of the network node 1604. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling that facilitates measurements of throughput, propagation times, latency and the like, by the host 1602. The measurements may be implemented in that software causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 1650 while monitoring propagation times, errors, etc.

[0235] Although the computing devices described herein (e.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.

[0236] 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. Abbreviations

Claims

WHAT IS CLAIMED IS:

1. A method (300) at a terminal device (210), the method (300) comprising: performing (310) measurements on a plurality of downlink reference signals; determining (320) two or more preferred downlink reference signals based on the measurements; and transmitting (330) an indication of the two or more preferred downlink reference signals during an access procedure.

2. The method (300) of claim 1, wherein transmitting (330) the indication of the two or more preferred downlink reference signals comprises: performing, based at least in part on at least one rule, one or more physical random access channel, PRACH, transmissions to indicate the two or more preferred downlink reference signals.

3. The method (300) of claim 2, further comprising: obtaining an association between the one or more PRACH transmissions and the two or more downlink reference signals, wherein the one or more PRACH transmissions are performed further based on the obtained association.

4. The method (300) of claim 3, wherein obtaining the association between the one or more PRACH transmissions and the two or more downlink reference signals comprises: receiving the association between the one or more PRACH transmissions and the two or more downlink reference signals.

5. The method (300) of any of claims 2-4, wherein the terminal device (210) is configured with a plurality of sets of downlink reference signals.

6. The method (300) of claim 5, wherein the at least one rule indicates that one PRACHtransmission is performed for one set of downlink reference signals among the plurality of sets of downlink reference signals.

7. The method (300) of claim 6, wherein the one PRACH transmission indicates a downlink reference signal from the one set of downlink reference signals.

8. The method (300) of claim 7, wherein respective measured signal powers of one or more downlink reference signals from the one set of downlink reference signals is equal to or greater than a threshold power.

9. The method (300) of claim 5, wherein the at least one rule indicates that a single PRACH transmission is performed for one or more sets of downlink reference signals among the plurality of sets of downlink reference signals.

10. The method (300) of claim 9, wherein the single PRACH transmission indicates a plurality of downlink reference signals from the plurality of sets of downlink reference signals, and each of the plurality of downlink reference signals is corresponding to a different set of downlink reference signals among the plurality of sets of downlink reference signals.

11. The method (300) of any of claims 2-10, further comprising: obtaining a configuration for a PRACH transmission; and determining the at least one rule based on the configuration for the PRACH transmission.

12. The method (300) of claim 11, wherein obtaining the configuration for the PRACH transmission comprises: receiving the configuration for the PRACH transmission.

13. The method (300) of any of claims 1-12, further comprising: transmitting an indication for priority of the two or more preferred downlink referencesignals.

14. The method (300) of any of claims 1-13, wherein the plurality of downlink reference signals are associated with a same cell.

15. The method (300) of any of claims 1-14, wherein the downlink reference signal comprises a synchronization signal block.

16. The method (300) of any of claims 1-15, wherein the access procedure comprises at least one of a random access procedure or an initial access procedure.

17. A method (600) at a network device (220), the method (600) comprising: transmitting (610), to a terminal device (210), an indication for at least one rule to be used by the terminal device (210) to indicate two or more preferred downlink reference signals during an access procedure of the terminal device (210).

18. The method (600) of claim 17, further comprising: transmitting, to the terminal device (210), an association between the one or more PRACH transmissions and the two or more downlink reference signals.

19. The method (600) of claim 17 or 18, further comprising: transmitting, to the terminal device (210), a configuration for a PRACH transmission, wherein the configuration for the PRACH transmission indicates the at least one rule.

20. The method (600) of any of claims 17-19, wherein the at least one rule indicates that one PRACH transmission is performed for one set of downlink reference signals among a plurality of sets of downlink reference signals.

21. The method (600) of claim 20, wherein the one PRACH transmission indicates adownlink reference signal from the one set of downlink reference signals.

22. The method (600) of claim 21, wherein respective measured signal power of one or more downlink reference signals from the one set of downlink reference signals is equal to or greater than threshold power.

23. The method (600) of any of claims 17-19, wherein the at least one rule indicates that a single PRACH transmission is performed for one or more sets of downlink reference signals among a plurality of sets of downlink reference signals.

24. The method (600) of claim 23, wherein the single PRACH transmission indicates a plurality of downlink reference signals from the plurality of sets of downlink reference signals, and each of the plurality of downlink reference signals is corresponding to a different set of downlink reference signals among the plurality of sets of downlink reference signals.

25. The method (600) of any of claims 17-24, further comprising: receiving, from the terminal device (210), an indication for priority of the two or more preferred downlink reference signals.

26. The method (600) of any of claims 17-25, wherein the two or more preferred downlink reference signals are associated with a same cell.

27. The method (600) of any of claims 17-26, wherein the downlink reference signal comprises a synchronization signal block.

28. The method (600) of any of claims 17-27, wherein the access procedure comprises at least one of a random access procedure or an initial access procedure.

29. A terminal device (210, 900), comprising:a processor (905); and a memory (910), the memory (910) containing instructions (915) executable by the processor (905), whereby the terminal device (210) is operative to: perform (310) measurements on a plurality of downlink reference signals; determine (320) two or more preferred downlink reference signals based on the measurements; and transmit (330) an indication of the two or more preferred downlink reference signals during an access procedure.

30. The terminal device (210) of claim 29, wherein the terminal device (210) is further operative to implement the method (300) according to any of claims 2-16.

31. A network device (220, 900), comprising: a processor (905); and a memory (910), the memory (910) containing instructions (915) executable by the processor (905), whereby the network device (220) is operative to: transmit (610), to a terminal device (210), an indication for at least one rule to be used by the terminal device (210) to indicate two or more preferred downlink reference signals during an access procedure of the terminal device (210).

32. The network device (220) of claim 29, wherein the network device (220) is further operative to implement the method (600) according to any of claims 18-28.

33. A computer-readable storage medium (1000) having instructions (915) stored thereon, the instructions (915), which when executed by at least one processor of a device, causing the at least one processor to perform the method (300) according to any of claim 1-16 or the method (600) according to any of claims 17-28.

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