Patent Application
20250088867
This application claims priority from, and the benefit of, Finland Application No. 20236015, filed on Sep. 11, 2023, the contents of which is incorporated herein by reference in its entirety.
The present disclosure relates to beam management, in particular to UE measurement reporting for beam selection.
Any discussion of the background art throughout the specification should in no way be considered as an admission that such art is widely known or forms part of common general knowledge in the field.
Regarding event-triggered measurement reports for Mobility, 3GPP specification 38.331 specified following events defined for handover in 5G NR:
As illustrated in
Hence, there is a need to ensure that the UE selects and obtains a maximum possible rank under a UE-triggered reporting/event context.
In accordance with a first aspect of the present disclosure, there is provided a User Equipment, UE, configured to establish communication with one or more network nodes configured in a cell serving the UE, comprising:
In some examples, for a beam set comprising at least two beams, the UE is configured to determine a correlation between the at least two beams comprised in the beam set, wherein a higher correlation between said beams indicates a lower rank associated with said beam set.
In some examples: the first beam set comprises one beam transmitted with two antenna ports, wherein the first rank corresponds to a Rank Indicator, RI, of 2; and the UE is configured to:
In some examples:
In some examples:
In some examples, the number of the one or more network nodes is less than or equal to a third threshold.
In some examples: the first beam set comprises two beams each transmitted with one antenna port, wherein the first rank corresponds to an RI of 2; and the UE is further configured to:
In some examples: the first beam set comprises two beams each transmitted with two antenna ports, wherein the first rank corresponds to an RI lower than 4; and the UE is further configured to:
In some examples, the one or more beams comprised in the second beam set are all different from at least one beam comprised in the first beam set.
In accordance with a second aspect of the present disclosure, there is provided a network node, configured in a cell serving a User Equipment, UE and configured to establish communication with the UE, the network node comprising:
In some examples: the first beam set comprises one beam transmitted with two antenna ports, wherein the first rank corresponds to a Rank Indicator, RI, of 2; and the network node is configured to:
In some examples: the first beam set comprises two beams each transmitted with one antenna port, wherein the first rank corresponds to an RI of 2; and the network node is further configured to:
In some examples: the first beam set comprises two beams each transmitted with two antenna ports, wherein the first rank corresponds to an RI lower than 4; and the network node is further configured to:
In some examples, the network node is configured to configure the UE to report at least one of the following:
In some examples: the network node is configured to transmit to the UE a list of Synchronization Signal and Physical Broadcast Channel Block Resource Indicator, SSBRI, or CSI Reference Signal Resource Indicator, CRI, related to beams transmitted from the network node to the UE for the UE to perform measurement and determine the achievable second rank and the associated second beam set.
In accordance with a third aspect of the present disclosure, there is provided a communications system, comprising: a User Equipment, UE, in accordance with any one of the first aspect and its related examples; and one or more network nodes in accordance with any one of the second aspect and its related examples, wherein the one or more network nodes are configured in a cell serving the UE.
In accordance with a fourth aspect of the present disclosure, there is provided a method of a User Equipment, UE, configured to establish communication with one or more network nodes configured in a cell serving the UE, the method comprising:
In accordance with a fifth aspect of the present disclosure, there is provided a method of a network node, configured in a cell serving a User Equipment, UE and configured to establish communication with the UE, the method comprising:
In accordance with a sixth aspect of the present disclosure, there is provided a computer program comprising instructions for causing an apparatus to perform the method according to the fourth aspect, or for causing an apparatus to perform the method according to the fifth aspect.
In accordance with a seventh aspect of the present disclosure, there is provided a memory storing computer readable instructions for causing an apparatus to perform the method according to the fourth aspect, or for causing an apparatus to perform the method according to the fifth aspect.
In addition, according to some other example embodiments, there is provided, for example, a computer program product for a wireless communication device comprising at least one processor, including software code portions for performing the respective steps disclosed in the present disclosure, when said product is run on the device. The computer program product may include a computer-readable medium on which said software code portions are stored. Furthermore, the computer program product may be directly loadable into the internal memory of the computer and/or transmittable via a network by means of at least one of upload, download and push procedures.
While some example embodiments will be described herein with particular reference to the above application, it will be appreciated that the present disclosure is not limited to such a field of use, and is applicable in broader contexts.
Notably, it is understood that methods according to the present disclosure relate to methods of operating the apparatuses according to the above example embodiments and variations thereof, and that respective statements made with regard to the apparatuses likewise apply to the corresponding methods, and vice versa, such that similar description may be omitted for the sake of conciseness. In addition, the above aspects may be combined in many ways, even if not explicitly disclosed. The skilled person will understand that these combinations of aspects and features/steps are possible unless it creates a contradiction which is explicitly excluded.
Implementations of the disclosed apparatuses may include using, but not limited to, one or more processor, one or more application specific integrated circuit (ASIC) and/or one or more field programmable gate array (FPGA). Implementations of the apparatus may also include using other conventional and/or customized hardware such as software programmable processors, such as graphics processing unit (GPU) processors.
Other and further example embodiments of the present disclosure will become apparent during the course of the following discussion and by reference to the accompanying drawings.
Example embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:
In the following, different exemplifying embodiments will be described using, as an example of a communication network to which examples of embodiments may be applied, a communication network architecture based on 3GPP standards for a communication network, such as a 5G/NR, without restricting the embodiments to such an architecture, however. It is apparent for a person skilled in the art that the embodiments may also be applied to other kinds of communication networks where mobile communication principles are integrated with a D2D (device-to-device) or V2X (vehicle to everything) configuration, such as SL (side link), e.g. Wi-Fi, worldwide interoperability for microwave access (WiMAX), Bluetooth®, personal communications services (PCS), ZigBee®, wideband code division multiple access (WCDMA), systems using ultra-wideband (UWB) technology, mobile ad-hoc networks (MANETs), wired access, etc. Furthermore, without loss of generality, the description of some examples of embodiments is related to a mobile communication network, but principles of the disclosure can be extended and applied to any other type of communication network, such as a wired communication network.
The following examples and embodiments are to be understood only as illustrative examples. Although the specification may refer to “an”, “one”, or “some” example(s) or embodiment(s) in several locations, this does not necessarily mean that each such reference is related to the same example(s) or embodiment(s), or that the feature only applies to a single example or embodiment. Single features of different embodiments may also be combined to provide other embodiments. Furthermore, terms like “comprising” and “including” should be understood as not limiting the described embodiments to consist of only those features that have been mentioned; such examples and embodiments may also contain features, structures, units, modules, etc., that have not been specifically mentioned.
A basic system architecture of a (tele)communication network including a mobile communication system where some examples of embodiments are applicable may include an architecture of one or more communication networks including wireless access network subsystem(s) and core network(s). Such an architecture may include one or more communication network control elements or functions, access network elements, radio access network elements, access service network gateways or base transceiver stations, such as a base station (BS), an access point (AP), a NodeB (NB), an eNB or a gNB, a distributed unit (DU) or a centralized/central unit (CU), which controls a respective coverage area or cell(s) and with which one or more communication stations such as communication elements or functions, like user devices or terminal devices, like a user equipment (UE), or another device having a similar function, such as a modem chipset, a chip, a module etc., which can also be part of a station, an element, a function or an application capable of conducting a communication, such as a UE, an element or function usable in a machine-to-machine communication architecture, or attached as a separate element to such an element, function or application capable of conducting a communication, or the like, are capable to communicate via one or more channels via one or more communication beams for transmitting several types of data in a plurality of access domains. Furthermore, core network elements or network functions, such as gateway network elements/functions, mobility management entities, a mobile switching center, servers, databases and the like may be included.
The following description may provide further details of alternatives, modifications and variances: a gNB comprises e.g., a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC, e.g., according to 3GPP TS 38.300 V16.6.0 (2021-06) section 3.2 incorporated by reference.
A gNB Central Unit (gNB-CU) comprises e.g., a logical node hosting e.g., RRC, SDAP and PDCP protocols of the gNB or RRC and PDCP protocols of the en-gNB that controls the operation of one or more gNB-DUs. The gNB-CU terminates the F1 interface connected with the gNB-DU.
A gNB Distributed Unit (gNB-DU) comprises e.g., a logical node hosting e.g., RLC, MAC and PHY layers of the gNB or en-gNB, and its operation is partly controlled by the gNB-CU. One gNB-DU supports one or multiple cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface connected with the gNB-CU.
A gNB-CU-Control Plane (gNB-CU-CP) comprises e.g., a logical node hosting e.g., the RRC and the control plane part of the PDCP protocol of the gNB-CU for an en-gNB or a gNB. The gNB-CU-CP terminates the E1 interface connected with the gNB-CU-UP and the F1-C interface connected with the gNB-DU.
A gNB-CU-User Plane (gNB-CU-UP) comprises e.g., a logical node hosting e.g., the user plane part of the PDCP protocol of the gNB-CU for an en-gNB, and the user plane part of the PDCP protocol and the SDAP protocol of the gNB-CU for a gNB. The gNB-CU-UP terminates the E1 interface connected with the gNB-CU-CP and the F1-U interface connected with the gNB-DU, e.g., according to 3GPP TS 38.401 V16.6.0 (2021-07) section 3.1 incorporated by reference.
Different functional splits between the central and distributed unit are possible, e.g., called options:
A gNB supports different protocol layers, e.g., Layer 1 (L1)—physical layer.
The layer 2 (L2) of NR is split into the following sublayers: Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP) and Service Data Adaptation Protocol (SDAP), where e.g.:
Layer 3 (L3) includes e.g., Radio Resource Control (RRC), e.g., according to 3GPP TS 38.300 V16.6.0 (2021-06) section 6 incorporated by reference.
A RAN (Radio Access Network) node or network node like e.g. a gNB, base station, gNB CU or gNB DU or parts thereof may be implemented using e.g. an apparatus with at least one processor and/or at least one memory (with computer-readable instructions (computer program)) configured to support and/or provision and/or process CU and/or DU related functionality and/or features, and/or at least one protocol (sub-)layer of a RAN (Radio Access Network), e.g. layer 2 and/or layer 3.
The gNB CU and gNB DU parts may e.g., be co-located or physically separated. The gNB DU may even be split further, e.g., into two parts, e.g., one including processing equipment and one including an antenna. A Central Unit (CU) may also be called BBU/REC/RCC/C-RAN/V-RAN, O-RAN, or part thereof. A Distributed Unit (DU) may also be called RRH/RRU/RE/RU, or part thereof. Hereinafter, in various example embodiments of the present disclosure, the CU-CP (or more generically, the CU) may also be referred to as a (first) network node that supports at least one of central unit control plane functionality or a layer 3 protocol of a radio access network; and similarly, the DU may be referred to as a (second) network node that supports at least one of distributed unit functionality or the layer 2 protocol of the radio access network.
A gNB-DU supports one or multiple cells, and could thus serve as e.g., a serving cell for a user equipment (UE).
A user equipment (UE) may include a wireless or mobile device, an apparatus with a radio interface to interact with a RAN (Radio Access Network), a smartphone, an in-vehicle apparatus, an IoT device, a M2M device, or else. Such UE or apparatus may comprise: at least one processor; and at least one memory including computer program code; wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to perform certain operations, like e.g. RRC connection to the RAN. A UE is e.g., configured to generate a message (e.g., including a cell ID) to be transmitted via radio towards a RAN (e.g., to reach and communicate with a serving cell). A UE may generate and transmit and receive RRC messages containing one or more RRC PDUs (Packet Data Units).
The UE may have different states (e.g., according to 3GPP TS 38.331 V16.5.0 (2021-06) sections 42.1 and 4.4, incorporated by reference).
A UE is e.g., either in RRC_CONNECTED state or in RRC_INACTIVE state when an RRC connection has been established.
In RRC_CONNECTED state a UE may:
The RRC protocol includes e.g. the following main functions:
The general functions and interconnections of the described elements and functions, which also depend on the actual network type, are known to those skilled in the art and described in corresponding specifications, so that a detailed description thereof may omitted herein for the sake of conciseness. However, it is to be noted that several additional network elements and signaling links may be employed for a communication to or from an element, function or application, like a communication endpoint, a communication network control element, such as a server, a gateway, a radio network controller, and other elements of the same or other communication networks besides those described in detail herein below.
A communication network architecture as being considered in examples of embodiments may also be able to communicate with other networks, such as a public switched telephone network or the Internet. The communication network may also be able to support the usage of cloud services for virtual network elements or functions thereof, wherein it is to be noted that the virtual network part of the telecommunication network can also be provided by non-cloud resources, e.g. an internal network or the like. It should be appreciated that network elements of an access system, of a core network etc., and/or respective functionalities may be implemented by using any node, host, server, access node or entity etc. being suitable for such a usage. Generally, 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 virtualized function instantiated on an appropriate platform, e.g., a cloud infrastructure.
Furthermore, a network element, such as communication elements, like a UE, a terminal device, control elements or functions, such as access network elements, like a base station/BS, a gNB, a radio network controller, a core network control element or function, such as a gateway element, or other network elements or functions, as described herein, and any other elements, functions or applications may be implemented by software, e.g., by a computer program product for a computer, and/or by hardware. For executing their respective processing, correspondingly used devices, nodes, functions or network elements may include several means, modules, units, components, etc. (not shown) which are required for control, processing and/or communication/signaling functionality. Such means, modules, units and components may include, for example, one or more processors or processor units including one or more processing portions for executing instructions and/or programs and/or for processing data, storage or memory units or means for storing instructions, programs and/or data, for serving as a work area of the processor or processing portion and the like (e.g. ROM, RAM, EEPROM, and the like), input or interface means for inputting data and instructions by software (e.g. floppy disc, CD-ROM, EEPROM, and the like), a user interface for providing monitor and manipulation possibilities to a user (e.g. a screen, a keyboard and the like), other interface or means for establishing links and/or connections under the control of the processor unit or portion (e.g. wired and wireless interface means, radio interface means including e.g. an antenna unit or the like, means for forming a radio communication part etc.) and the like, wherein respective means forming an interface, such as a radio communication part, can be also located on a remote site (e.g. a radio head or a radio station etc.). It is to be noted that in the present specification processing portions should not be only considered to represent physical portions of one or more processors, but may also be considered as a logical division of the referred processing tasks performed by one or more processors. It should be appreciated that according to some examples, a so-called “liquid” or flexible network concept may be employed where the operations and functionalities of a network element, a network function, or of another entity of the network, may be performed in different entities or functions, such as in a node, host or server, in a flexible manner. In other words, a “division of labor” between involved network elements, functions or entities may vary case by case.
UE-initiated Beam Management: In Rel-15 to Rel-18 5G NR, the Beam management has been specified in 3 phases controlled by network: Phase #1 (P1), Phase #2 (P2) and Phase #3 (P3), as described in 3GPP in TS 38.214 section 5.1.5 (TCI and QCL framework) and 5.1.6 (CSI-RS reception procedures) and illustrated in
The following beam management procedures are supported within one or multiple TRPs (Transmit Receive Points) of the serving cell:
The present disclosure focuses on reporting for P2.
In TS38.214, CSI-ResourceConfig specifies what type of reference signal (nzp-CSI-RS-SSB, csi-IM-Resource) is to be transmitted. It also configures the types ofthe transmission (periodic, aperiodic, semipersistent). The parameter reportConfigType indicates the scheduling method of the report. It can be periodic, aperiodic and semiPersistent as shown in the table below.
Rel-16 enables mTRP operation with simultaneous scheduling of PDSCH on two beams from two TRPs. Rel-18 is addressing the indication of two TCI (Transmit Configuration Index) states simultaneously in the unified TCI framework. In the scope of Rel-19 preparation, some use cases where UE could benefit from initiating the beam switch are being identified. Mostly the benefits are regarding the delays of CSI L1-RSRP/L1-SINR reporting and the overhead of the reporting. The clear advantages with UE triggered reporting are that the delays may be shorter between reports for a period of time to avoid e.g. failures and this event-triggered reporting is only transmitted when UE needs it (as opposed to increasing the periodicity of a periodic measurement report).
In view of the above, it is proposed in accordance with the present disclousure the following.
As a new event, the UE uses the correlation of the measured beams, hence the maximum achievable rank for simultaneous reception/transmission, to trigger a new report of the best beam pair. As such, if the current indicated beams for PDSCH and/or PUSCH are providing a smaller rank than another pair measured by the UE, then this constitutes an event and the new pair should be reported to network as an event-triggered beam reporting and UE-initiated beam pair switching; in addition to the (transmission/reception) beam pair, the UE may also be configured to report corresponding measurement such as achievable rank, RSRP, SINR, etc.
In one alternative embodiment, the reporting event may be triggered:
The UE could be at least partly configured e.g., via RRC to perform the above-suggested triggering. The configuration may comprise one or more of: (min/max) rank the UE should consider for the above event or simply a condition that the achievable rank with a beam pair is higher than currently indicated rank (or previously reported rank), the quantity(ies) to report when the event occurs, TRPs or reference signals resources to consider, TCI (Transmit Configuration Index) states or TCI state groups to consider, etc.
The above-described solution is illustrated in
Current specifications focus on X-layer (e.g., X=4) DL scheduling across two TCJ states belonging to two TRPs. In this disclosure, we generalize the solution to more cases i.e., where for example 4-layer DL scheduling may also be configured on 2 TCI states originating from the same TRP or where 4 TCI states may be indicated. All these aspects are related to potential Rel-19 MIMO proposals and scope.
In summary, it is proposed in accordance with the present disclosure that the UE measurement of a higher rank than current rank constitutes the event which then triggers the UE beam reporting of the specific beam pair yielding this higher rank.
Therein, that the UE is able to detect a “better” beam pair (with “better” here taking into account the rank) than the currently selected beam pair from gNB because the UE is computing the correlation between the beams whereas the gNB only received power reports (RSRP and/or SINR).
A numerical example: With reference to
In comparison to the conventional techniques as shown e.g., in
The below use cases aim at UE triggering a TCI state addition or a pair of TCI states switch in order to maximize the rank, and therefore eventually throughput. The TCI states could come from or could correspond to one or multiple TRPs (a TRP may be represented by or correspond to a coresetPoolIndex, or an SRS resource set, or a DL reference signal (resource) set, in the specification).
In the present disclosure, a specific rank corresponds to a Rank Indicator (RI) that indicates the number of layers transmitted. For example, rank 1 corresponds to an RI of 1 indicating one layer, rank 2 corresponds to an RI of 2 indicating two layers, and rank 4 corresponds to an RI of 4 indicating 4 layers.
In the first case, UE is currently scheduled with 2 layers only and UE detects that it can go up to rank 4, i.e., 4 layers, with a specific beam pair, which it reports to the network (when configured for this). The use case is generalized to N groups of M beams, where the typical use case is N=4 and M=2, where each beam is a 2-port CSI-RS.
In the second case, UE is also currently scheduled with 2 layers only although these 2 layers come from two different TCI states. This would be the case of single-polarized antenna elements at the UE for example, where diversity cannot be achieved from polarization. As a result, to achieve rank 4, the UE needs to simultaneously receive 4 different TCI states (each of them carrying 1-port CSI RS). This use case can be seen as an example with M=4 where each beam is a 1-port CSI-RS.
In the third case, UE is already scheduled with 4 layers across 2 TCI states although throughput is low. UE can detect that if a different pair of beams was selected, beams would be better decorrelated, hence the maximum achievable throughput would be higher, although the individual received power level (e.g. L1-RSRP) of each of the new beams could be slightly lower than the one of the beams used for scheduling currently. Based on this, the UE triggers a beam pair report to switch one or both beams to the network.
For use case 3, the UE is connected to 2 beams but cannot reach the max rank. UE has detected another pair that could actually reach rank 4 which triggers the UE to report this new pair. Then, network switches to the new pair and schedules 4 layer transmission.
Case 1: UE is scheduled with 2 layers in FR2 with a 2-port CSI (i.e., 1 TCI state)
Case 2: UE is scheduled with 2 layers in FR2 with two 1-port CSI (i.e. 2 TCI states)
Case 3: UE is scheduled with 4 layers in FR2 with two 2-port CSI (i.e. 2 TCI states)
Furthermore, gNB may provide UE with a list of SSBRI/CRI among which UE can measure correlation and trigger a beam pair switch if a higher rank is detected. As such, the search is reduced for UE and gNB remains in control of the beams where UE can trigger the beam pair switch.
As shown in
Specifically, for the above first use case, as shown in
Specifically, for the above second use case, as shown in
Specifically, for the above third use case, as shown in
It is noted that, although in the above-illustrated example embodiments (with reference to the figures), the messages communicated/exchanged between the network components/elements may appear to have specific/explicit names, depending on various implementations (e.g., the underlining technologies), these messages may have different names and/or be communicated/exchanged in different forms/formats, as can be understood and appreciated by the skilled person.
According to some example embodiments, there are also provided corresponding methods suitable to be carried out by the apparatuses (network elements/components) as described above, such as the UE, the CU, the DU, etc.
It should nevertheless be noted that the apparatus (device) features described above correspond to respective method features that may however not be explicitly described, for reasons of conciseness. The disclosure of the present document is considered to extend also to such method features. In particular, the present disclosure is understood to relate to methods of operating the devices described above, and/or to providing and/or arranging respective elements of these devices.
Further, according to some further example embodiments, there is also provided a respective apparatus (e.g., implementing the UE, the CU, the DU, etc., as described above) that comprises at least one processing circuitry, and at least one memory for storing instructions to be executed by the processing circuitry, wherein the at least one memory and the instructions are configured to, with the at least one processing circuitry, cause the respective apparatus to at least perform the respective steps as described above.
Yet in some other example embodiments, there is provided a respective apparatus (e.g., implementing the UE, the CU, the DU, etc., as described above) that comprises respective means configured to at least perform the respective steps as described above.
It is to be noted that examples of embodiments of the disclosure are applicable to various different network configurations. In other words, the examples shown in the above described figures, which are used as a basis for the above discussed examples, are only illustrative and do not limit the present disclosure in any way. That is, additional further existing and proposed new functionalities available in a corresponding operating environment may be used in connection with examples of embodiments of the disclosure based on the principles defined.
It should also to be noted that the disclosed example embodiments can be implemented in many ways using hardware and/or software configurations. For example, the disclosed embodiments may be implemented using dedicated hardware and/or hardware in association with software executable thereon. The components and/or elements in the figures are examples only and do not limit the scope of use or functionality of any hardware, software in combination with hardware, firmware, embedded logic component, or a combination of two or more such components implementing particular embodiments of the present disclosure.
It should further be noted that the description and drawings merely illustrate the principles of the present disclosure. Those skilled in the art will be able to implement various arrangements that, although not explicitly described or shown herein, embody the principles of the present disclosure and are included within its spirit and scope. Furthermore, all examples and embodiment outlined in the present disclosure are principally intended expressly to be only for explanatory purposes to help the reader in understanding the principles of the proposed method. Furthermore, all statements herein providing principles, aspects, and embodiments of the present disclosure, as well as specific examples thereof, are intended to encompass equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20236015 | Sep 2023 | FI | national |
