WO2020227913A1

WO2020227913A1 - Method and apparatus for beam management

Info

Publication number: WO2020227913A1
Application number: PCT/CN2019/086755
Authority: WO
Inventors: Chunhui Liu; Yuan Dong; Qi Zhang
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2019-05-14
Filing date: 2019-05-14
Publication date: 2020-11-19

Abstract

Various embodiments of the present disclosure provide a method for beam management. The method which may be performed by a network node comprises receiving, from a terminal device, first measurement information about a first beam preferred by the terminal device. The method further comprises transmitting configuration information to the terminal device. The configuration information indicates the terminal device to report second measurement information about one or more target beams different from the first beam.

Description

METHOD AND APPARATUS FOR BEAM MANAGEMENT

FIELD OF THE INVENTION

The present disclosure generally relates to communication networks, and more specifically, to method and apparatus for beam management.

BACKGROUND

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.

Communication service providers and network operators have been continually facing challenges to deliver value and convenience to consumers by, for example, providing compelling network services and performance. With the rapid development of networking and communication technologies, wireless communication networks such as long-term evolution (LTE) and new radio (NR) networks are expected to achieve high traffic capacity and end-user data rate with lower latency. In order to meet dramatically increasing network requirements, one interesting option for communication technique development is to employ multiple antenna technology. Multiple antenna systems allow transmitting signals focused towards certain spatial regions. This creates beams (also referred to as beamforming) whose coverage can go beyond transmissions using non-beamformed signals. Beam management can help achieve potentially performance gain by fine beam alignment for directional links. Thus, it is desirable to enhance beam management.

SUMMARY

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.

In a wireless communication network such as 5G/NR network, a radio device such as a user equipment (UE) and a next generation NodeB (gNB) may be equipped with multiple antenna elements. Generally, the gNB may perform beam management by configuring the UE to report measurements on a limited number of favorable beams and selecting one or more transmission beams for downlink (DL) from the reported favorable beams. However, UEs that are geographically close to each other may report the same or similar set of favorable beams. In this case, the gNB cannot assign the same radio resource to these UEs due to inter-user interference caused by multiuser (MU) transmission. Therefore, it may be desirable to implement beam management in a more efficient way.

Various embodiments of the present disclosure propose a solution for beam management, which can enable measurements on more beam candidates to be reported to a network node by a terminal device, so that the beam management can be performed with increased degree of freedom of MU beam selection. It can be realized that the terms “degree of freedom of MU beam selection” , “MU beam selection degree of freedom” or “MU grouping degree of freedom” mentioned herein refers to the number of usable beams for a UE, which may also be referred to as “MU degree of freedom” . These terms may be used interchangeably in this document. The increase of the number of usable beams for the UE can provide a larger beam selection space and more opportunities to group this UE with other UEs.

According to a first aspect of the present disclosure, there is provided a method performed by a network node such as a gNB. The method comprises receiving, from a terminal device, first measurement information about a first beam preferred by the terminal device. The method further comprises transmitting configuration information to the terminal device. The configuration information indicates the terminal device to report second measurement information about one or more target beams different from the first beam.

In accordance with some exemplary embodiments, the method according to the first aspect of the present disclosure may further comprise: receiving the second measurement information about the one or more target beams from the terminal device; and determining a beam set usable for the terminal device, based at least in part on the second measurement information.

In accordance with some exemplary embodiments, the method according to the first aspect of the present disclosure may further comprise: informing the terminal device of one or more transmission beams from the network node to the terminal device. The one or more transmission beams may be selected from the beam set.

According to a second aspect of the present disclosure, there is provided an apparatus which may be implemented as a network node. The apparatus may comprise one or more processors and one or more memories comprising computer program codes. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the apparatus at least to perform any step of the method according to the first aspect of the present disclosure.

According to a third aspect of the present disclosure, there is provided a computer-readable medium having computer program codes embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to the first aspect of the present disclosure.

According to a fourth aspect of the present disclosure, there is provided an apparatus which may be implemented as a network node. The apparatus comprises a receiving unit and a transmitting unit. In accordance with some exemplary embodiments, the receiving unit may be operable to carry out at least the receiving step of the method according to the first aspect of the present disclosure. The transmitting unit may be operable to carry out at least the transmitting step of the method according to the first aspect of the present disclosure.

According to a fifth aspect of the present disclosure, there is provided a method performed by a terminal device such as a UE. The method comprises transmitting first measurement information about a first beam preferred by the terminal device to a network node. The method further comprises receiving configuration information from the network node. The configuration information indicates the terminal device to report second measurement information about one or more target beams different from the first beam.

In accordance with some exemplary embodiments, the method according to the fifth aspect of the present disclosure may further comprise: transmitting the second measurement information about the one or more target beams to the network node; and receiving, from the network node, information about one or more transmission beams from the network node to the terminal device. The one or more transmission beams may be selected from a beam set which is usable for the terminal device and determined based at least in part on the second measurement information.

According to a sixth aspect of the present disclosure, there is provided an apparatus which may be implemented as a terminal device. The apparatus comprises one or more processors and one or more memories comprising computer program codes. The one or more memories and the computer program codes may be configured to, with the one or more processors, cause the apparatus at least to perform any step of the method according to the fifth aspect of the present disclosure.

According to a seventh aspect of the present disclosure, there is provided a computer-readable medium having computer program codes embodied thereon which, when executed on a computer, cause the computer to perform any step of the method according to the fifth aspect of the present disclosure.

According to an eighth aspect of the present disclosure, there is provided an apparatus which may be implemented as a terminal device. The apparatus comprises a transmitting unit and a receiving unit. In accordance with some exemplary embodiments, the transmitting unit may be operable to carry out at least the transmitting step of the method according to the fifth aspect of the present disclosure. The receiving unit may be operable to carry out at least the receiving step of the method according to the fifth aspect of the present disclosure.

In accordance with some exemplary embodiments, the terminal device may have an amount of traffics to be transmitted to the network node larger than a predefined traffic threshold.

In accordance with some exemplary embodiments, the first measurement information may comprise at least one of: a reference resource indicator, a beam indicator, signal receiving power, signal receiving quality, and channel quality information.

In accordance with some exemplary embodiments, the second measurement information may comprise at least one of: a reference resource indicator, a beam indicator, signal receiving power, signal receiving quality, and channel quality information.

In accordance with some exemplary embodiments, the first beam may be reported to the network node with a probability higher than a predefined probability threshold.

In accordance with some exemplary embodiments, the transmission of the configuration information to the terminal device by the network node may be in response to a beam management event which indicates that a correlation of beams reported to the network node satisfies a predefined criterion. Correspondingly, the reception of the configuration information from the network node by the terminal device may be in response to the beam management event.

In accordance with some exemplary embodiments, the beam management event may comprise that a correlation between a preferred beam per candidate terminal device reported to the network node and the first beam is higher than a predefined correlation threshold.

In accordance with some exemplary embodiments, the preferred beam per candidate terminal device may be reported to the network node with a probability higher than a predefined probability threshold.

In accordance with some exemplary embodiments, the candidate terminal device may have an amount of traffics to be transmitted to the network node larger than a predefined traffic threshold.

In accordance with some exemplary embodiments, the terminal device may have a buffer for storing data to be transmitted to the network node and the buffer has a predefined status. Alternatively or additionally, the terminal device may have channel quality above a first quality threshold. Alternatively or additionally, the terminal device may have a channel of which the time variance is below a predefined variance threshold.

In accordance with some exemplary embodiments, the terminal device may be configured for multiuser grouping at a frequency higher than a predefined grouping threshold. Alternatively or additionally, the terminal device may be configured for multiuser scheduling at a frequency higher than a predefined scheduling threshold.

In accordance with some exemplary embodiments, the first beam and the one or more target beams may have a correlation which is within a predefined correlation range.

In accordance with some exemplary embodiments, the beam set usable for the terminal device may comprise at least a second beam for which channel quality reported to the network node by the terminal device is above a second quality threshold. Alternatively or additionally, the beam set may comprise at least a third beam, and a difference in channel quality between the first beam and the third beam for the terminal device is below a predefined comparison threshold. Optionally, the beam set may comprise the first beam.

In accordance with some exemplary embodiments, the beam set may be usable for one or more other terminal devices in the same multiuser group with the terminal device.

In accordance with some exemplary embodiments, the one or more transmission beams from the network node to the terminal device may correspond to one or more reception beams of the network node with respect to the terminal device. Optionally, the one or more transmission beams may be used as the reception beams of the network node with respect to the terminal device.

According to a ninth aspect of the present disclosure, there is provided a method implemented in a communication system which may include a host computer, a base station and a UE. The method may comprise providing user data at the host computer. Optionally, the method may comprise, at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station which may perform any step of the method according to the first aspect of the present disclosure.

According to a tenth aspect of the present disclosure, there is provided a communication system including a host computer. The host computer may comprise processing circuitry configured to provide user data, and a communication interface configured to forward the user data to a cellular network for transmission to a UE. The cellular network may comprise a base station having a radio interface and processing circuitry. The base station’s processing circuitry may be configured to perform any step of the method according to the first aspect of the present disclosure.

According to an eleventh aspect of the present disclosure, there is provided a method implemented in a communication system which may include a host computer, a base station and a UE. The method may comprise providing user data at the host computer. Optionally, the method may comprise, at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station. The UE may perform any step of the method according to the fifth aspect of the present disclosure.

According to a twelfth aspect of the present disclosure, there is provided a communication system including a host computer. The host computer may comprise processing circuitry configured to provide user data, and a communication interface configured to forward user data to a cellular network for transmission to a UE. The UE may comprise a radio interface and processing circuitry. The UE’s processing circuitry may be configured to perform any step of the method according to the fifth aspect of the present disclosure.

According to a thirteenth aspect of the present disclosure, there is provided a method implemented in a communication system which may include a host computer, a base station and a UE. The method may comprise, at the host computer, receiving user data transmitted to the base station from the UE which may perform any step of the method according to the fifth aspect of the present disclosure.

According to a fourteenth aspect of the present disclosure, there is provided a communication system including a host computer. The host computer may comprise a communication interface configured to receive user data originating from a transmission from a UE to a base station. The UE may comprise a radio interface and processing circuitry. The UE’s processing circuitry may be configured to perform any step of the method according to the fifth aspect of the present disclosure.

According to a fifteenth aspect of the present disclosure, there is provided a method implemented in a communication system which may include a host computer, a base station and a UE. The method may comprise, at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE. The base station may perform any step of the method according to the first aspect of the present disclosure.

According to a sixteenth aspect of the present disclosure, there is provided a communication system which may include a host computer. The host computer may comprise a communication interface configured to receive user data originating from a transmission from a UE to a base station. The base station may comprise a radio interface and processing circuitry. The base station’s processing circuitry may be configured to perform any step of the method according to the first aspect of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure itself, the preferable mode of use and further objectives are best understood by reference to the following detailed description of the embodiments when read in conjunction with the accompanying drawings, in which:

Fig. 1A is a diagram illustrating an example of beam management according to an embodiment of the present disclosure;

Fig. 1B is a diagram illustrating an exemplary communication scenario according to an embodiment of the present disclosure;

Fig. 2A is a diagram illustrating exemplary beam sets according to some embodiments of the present disclosure;

Figs. 2B-2C are diagrams illustrating examples of UE distribution according to some embodiments of the present disclosure;

Fig. 3 is a flowchart illustrating an exemplary beam management procedure according to some embodiments of the present disclosure;

Fig. 4 is a diagram illustrating an exemplary frame structure according to an embodiment of the present disclosure;

Fig. 5A is a diagram illustrating an example of beam distribution according to an embodiment of the present disclosure;

Fig. 5B is a diagram illustrating another example of beam distribution according to an embodiment of the present disclosure;

Fig. 6A is a flowchart illustrating a method according to some embodiments of the present disclosure;

Fig. 6B is a flowchart illustrating another method according to some embodiments of the present disclosure;

Fig. 7 is a block diagram illustrating an apparatus according to some embodiments of the present disclosure;

Fig. 8A is a block diagram illustrating another apparatus according to some embodiments of the present disclosure;

Fig. 8B is a block diagram illustrating yet another apparatus according to some embodiments of the present disclosure;

Fig. 9 is a block diagram illustrating a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments of the present disclosure;

Fig. 10 is a block diagram illustrating a host computer communicating via a base station with a UE over a partially wireless connection in accordance with some embodiments of the present disclosure;

Fig. 11 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment of the present disclosure;

Fig. 12 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment of the present disclosure;

Fig. 13 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment of the present disclosure; and

Fig. 14 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

The embodiments of the present disclosure are described in detail with reference to the accompanying drawings. It should be understood that these embodiments are discussed only for the purpose of enabling those skilled persons in the art to better understand and thus implement the present disclosure, rather than suggesting any limitations on the scope of the present disclosure. 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.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as new radio (NR) , long term evolution (LTE) , LTE-Advanced, wideband code division multiple access (WCDMA) , high-speed packet access (HSPA) , and so on. Furthermore, the communications between a terminal device and a network node in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , 4G, 4.5G, 5G communication protocols, and/or any other protocols either currently known or to be developed in the future.

The term “network node” refers to a network device in a communication network via which a terminal device accesses to the network and receives services therefrom. The network node may refer to a base station (BS) , an access point (AP) , a multi-cell/multicast coordination entity (MCE) , a controller or any other suitable device in a wireless communication network. The BS may be, for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a next generation NodeB (gNodeB or gNB) , a remote radio unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, a low power node such as a femto, a pico, and so forth.

Yet further examples of the network node comprise multi-standard radio (MSR) radio 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, positioning nodes and/or the like. More generally, however, the network node may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a terminal device access to a wireless communication network or to provide some service to a terminal device that has accessed to the wireless communication network.

The term “terminal device” refers to any end device that can access a communication network and receive services therefrom. By way of example and not limitation, the terminal device may refer to a mobile terminal, a user equipment (UE) , or other suitable devices. The UE may be, for example, a subscriber station, a portable subscriber station, a mobile station (MS) or an access terminal (AT) . The terminal device may include, but not limited to, portable computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, a mobile phone, a cellular phone, a smart phone, a tablet, a wearable device, a personal digital assistant (PDA) , a vehicle, and the like.

As yet another specific example, in an Internet of things (IoT) scenario, a terminal device may also be called an IoT device and represent a machine or other device that performs monitoring, sensing and/or measurements etc., and transmits the results of such monitoring, sensing and/or measurements etc. to another terminal device and/or a network equipment. The terminal device may in this case be a machine-to-machine (M2M) device, which may in a 3rd generation partnership project (3GPP) context be referred to as a machine-type communication (MTC) device.

As one particular example, the terminal device may be a UE implementing the 3GPP narrow band Internet of things (NB-IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances, e.g. refrigerators, televisions, personal wearables such as watches etc. In other scenarios, a terminal device may represent a vehicle or other equipment, for example, a medical instrument that is capable of monitoring, sensing and/or reporting etc. on its operational status or other functions associated with its operation.

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.

From analog communication technologies through LTE, each generation of mobile technology is motivated by the need to address the challenges which are not overcome by its predecessor. The mobile technology such as 5G is positioned to address the demands and business beyond LTE. It is expected to enable a fully mobile and connected society, related to the tremendous growth in connectivity and density/volume of traffics which may be required in the near future.

Next-generation communication networks can provide a set of mechanisms by which UEs and gNBs can establish highly directional transmission links, typically using high-dimensional phased arrays, to benefit from the resulting beamforming gain and sustain the acceptable communication quality. Directional links, however, require fine alignment of transmission (Tx) and reception (Rx) beams, which may be achieved through a set of operations related to beam management. The beam management is fundamental to perform a variety of control tasks including initial access of idle users, which allows a UE to establish a physical link connection with a gNB, and beam tracking for connected users, which enables beam adaptation schemes, handover, path selection and/or radio link failure recovery procedures.

Fig. 1A is a diagram illustrating an example of beam management according to an embodiment of the present disclosure. For simplicity, Fig. 1A only schematically depicts beam selection and alignment for a transmit point (TP) (e.g., a gNB) and a UE. It will be appreciated that signaling messages and channel configurations shown in Fig. 1A are just as examples, and more or less alternative signaling messages and channel configurations may be involved in the beam management according to the embodiments of the present disclosure.

As shown in Fig. 1A, an exemplary beam management procedure in 5G network may comprise the following three phases:

● P1: initial beam selection, where a wide TP Tx beam is initially selected;

● P2: TP Tx beam refinement, where the TP determines its Tx beam according to the UE’s report; and

● P3: UE Rx beam refinement, where a UE Rx beam is determined in the case that the TP Tx beam is selected.

In the exemplary beam management procedure, during phase P1, the UE can access the network through random access channel (RACH) based on a synchronization signal (SS) from the TP, and exchange messages such as Msg2, Msg3 and Msg4 with the gNB. During phase P2, the TP can configure channel state information-reference signal (CSI-RS) for the UE to measure available beams. Then the UE can report a list of beam candidates and their corresponding quality values, e.g., reference signal receiving power (RSRP) and etc., through physical uplink control channel/physical uplink shared channel (PUCCH/PUSCH) . On reception of this report, the TP can select a beam as the downlink (DL) Tx beam for this UE and perform the corresponding DL transmissions on physical downlink control channel/physical downlink shared channel (PDCCH/PDSCH) . Afterwards, the UE during phase P3 can select its Rx beam for the TP, according to the DL Tx beam selected by the TP.

In the beam management procedure, a base station such as a gNB can configure DL reference signals. Then a UE can monitor the DL reference signals to evaluate the beam quality and report beam measurements to the base station. From the UE’s perspective, in beam reporting, the favorable beams are reported by the UE to greedily increase possible UE data rate. On the other hand, from the gNB’s perspective, the gNB is much more interested in increasing system throughput by selecting proper beams from the reported beams in consideration of MU grouping.

As an example, the gNB may configure the UE to report measurements for all or many beams, while many reports may reduce the UL data rate for the UE and the UL throughput for the gNB, and too frequent beam measurement and reporting may shorten the life cycle of the UE’s battery. In the popular configurations, the gNB can configure the UE to report a limited number of favorable beams. Even though the beam selection is performed by the gNB, this selection is constrained by the beam reports from the UE, since the gNB needs to select proper beams from a set of favorable beams reported by the UE.

Fig. 1B is a diagram illustrating an exemplary communication scenario according to an embodiment of the present disclosure. For simplicity, Fig. 1B only depicts exemplary network elements such as a gNB, several UEs and reflectors. The UEs can be attached to a NR cell which is provisioned by the gNB in a specific area such as a rural area. It will be appreciated that there may be other network scenarios where more than one network node such as gNB can be deployed in the network to implement different system structures and provide services to more than one terminal device such as UE. In practice, a wireless communication system may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or terminal device. The wireless communication system may provide communication and various types of services to one or more wireless devices to facilitate the wireless devices’ access to and/or use of the services provided by, or via, the wireless communication system.

In the scenario as shown in Fig. 1B, there may be some issues on system throughput degradation. In the case that the UEs are configured to report a limited number of favorable beams to the gNB, if these UEs are located in the same area especially with line of sight, most of them may probably report the same or a similar set of favorable beams to the gNB. Since those reported beams are close to each other in degree, the gNB cannot assign the same time and frequency radio resource to these UEs. Otherwise, the MU grouping transmission may probably cause strong inter-user interference. In the meantime, there may be some beam candidates usable for data transmission, while the gNB cannot know these beam candidates according to the beam reports from the UEs.

Fig. 2A is a diagram illustrating exemplary beam sets according to some embodiments of the present disclosure. In a NR system equipped with massive multiple-input multiple-output (MIMO) technology, there may be a lot of beams defined by different beamforming weights. In this system, UEs may be configured to report a set of favorable beams to a gNB. As shown in Fig. 2A, different beam sets can be maintained (e.g., in a table) by the gNB, for example, including but not limited to:

● a set of beams ever reported (e.g., which can be determined according to beam reports from a UE, such as report1 and report2 shown in Fig. 2A) ;

● a set of beam candidates for data traffic (e.g., which may be filtered from the set of beams ever reported) ; and

● a set of beam selected (e.g., from the set of beam candidates according to a specific rule) .

It can be seen that the set of beam selected is dependent on the set of beams ever reported. Since the beam reports from the UE are limited, the selection of beams for data traffic by the gNB is constrained and may not be optimal in terms of overall network performance. However, if the gNB configures the UE to measure and report all beams, it may induce large overhead for beam management and be unfriendly for power saving at UE side.

In order to improve the system throughput without increasing signaling overhead for beam reports significantly, the present disclosure according to some exemplary embodiments proposes an efficient beam management scheme with increased degree of freedom for MU beam selection. According to the proposed beam management scheme, a terminal device such as UE may be required by a network node such as gNB to measure one or more beams that are not reported before and/or have low correlation with the previously reported beam. Based at least in part on the beam reports from the UE, the gNB may have more beam candidates to be configured as DL Tx beam for the UE. In an exemplary embodiment, the UE may be informed with quasi co-located (QCL) configuration of the DL Tx beam which may not have the best reference signal receiving power/channel quality information (RSRP/CQI) compared with the reported favorable beam. Although the DL Tx beam configured for the UE may not be the favorable beam reported by the UE, the increased degree of freedom for MU grouping or beam selection can improve system throughput and data rate, especially for the UEs which have big data buffer sizes (and optionally good channel quality) and report the same beam index to the gNB due to deployment under the same beam area. In accordance with an exemplary embodiment where beam correspondence is provided, the beam reports about measurements on DL reference signals can be used for UL as well. In this case, the proposed solution can be applied for both DL and UL MU transmissions.

Figs. 2B-2C are diagrams illustrating examples of UE distribution according to some embodiments of the present disclosure. In the examples shown in Figs. 2B-2C, antenna beams are classified into eight groups (which are marked by “1” to “8” ) according to the vertical and horizontal degrees. One dot denotes one beam reported by a UE in a past period of time, for example, according to a specific beam management scheme. In the example shown in Fig. 2B, UEs are uniformly distributed over the coverage (which consists of eight areas respectively corresponding to eight groups of beams) . In the example shown in Fig. 2C, UEs are mainly distributed in the up-left corner (which corresponds to the group of beam marked by “1” ) . It can be appreciated that the UE distribution against difference beams as shown in Fig. 2B or Fig. 2C is just as an example, and other UE distribution may be possible in practice. Regardless of the UE distribution, the proposed solution according to exemplary embodiments can identify a scenario of interest (e.g., a scenario in which UEs are mainly located in a specific area, as shown in Fig. 2C) by setting an appropriate criterion and/or considering one or more measurement parameters.

In accordance with some exemplary embodiments, the scenario of interest can be identified by evaluating a cell from the statistic views of traffic demand and reported beams. For example, a scenario in which there are many UEs especially with large traffic demand and the beams preferred by the UEs are highly correlated may be identified as the scenario of interest for which the proposed beam management procedure may be triggered to increase MU grouping opportunities. According to an exemplary embodiment, one or more metrics can be used to evaluate this scenario, for example, including but not limited to:

● the CSI-RS indicators quasi co-located beam for beam measurements reported by a UE; and/or

● the corresponding physical layer-RSRP (L1-RSRP) , CQI, precoding matrix indicator (PMI) , rank indication (RI) , etc.

In accordance with some exemplary embodiments, the constraint of MU grouping opportunities can be recognized for a cell of a gNB, for example, by performing the following operations:

● determining whether a UE’s traffic demand is large than a given buffer status threshold;

● counting the number of reports for each beam for a certain period of time, according to the beam reports;

● normalizing the number of reports for each beam by the total number of beams reported to the gNB, so as to obtain a probability density function of beam preference by UEs; and

● determining the most popular beams based at least in part on a probability threshold.

According to an exemplary embodiment, if the determined most popular beams are highly correlated and the beam qualities (e.g., RSRP, signal to interference plus noise ratio (SINR) , etc. ) are relatively good, then the gNB determines that the MU grouping opportunities are constrained. In response to determination of the constrained MU grouping opportunities, a beam management procedure can be triggered to increase the MU grouping degrees of freedom.

Fig. 3 is a flowchart illustrating an exemplary beam management procedure according to some embodiments of the present disclosure. In the exemplary beam management procedure, a gNB can select one or more target UEs for which MU opportunities can be increased, as shown in block 302. According to some exemplary embodiments, various criteria may be defined for target UE selection. In an exemplary embodiment, the target UE selection may be based at least in part on the measurement results of beam preference. For example, those UEs reporting most popular beams may be selected as the target UEs for beam management. Alternatively or additionally, the target UEs may be selected by considering one or more of the following factors related to MU grouping preference:

● buffer size/buffer status in history or in current time (e.g., a UE with large buffer size is more probably to be scheduled in the following time, which may increase the possibility of MU grouping usage) ;

● channel quality (e.g., a UE having good channel quality on the most popular beam is more preferred to be grouped with other UEs) ; and

● time variance of channel (e.g., a UE with low time variance of channel, which can be identified according to the channel time variance detection by the gNB, may have a more stable channel in time domain and thus have good ability to maintain a stable MU grouping beam pool) .

Alternatively or additionally, the target UE selection may be dependent on the historical MU grouping/scheduling results. For example, the gNB can record the MU grouping/scheduling results in a period of time, and the target UEs can be selected from the most frequently grouped/scheduled UEs.

According to the exemplary beam management procedure in Fig. 3, the gNB can select one or more target beams for beam management, as shown in block 304. The gNB may configure the target UEs to perform measurements on the one or more target beams and report additional beam measurements to the gNB. It can be appreciated that the target beams can be selected for each target UE individually or for all the target UEs.

According to an exemplary embodiment, the gNB may use additional beam reporting configuration to indicate the target UEs to report all beams not reported before. This embodiment is quite natural, while it may cause the following issues:

● big amount of power consuming in UE side;

● for the case that lots of semi-persistent/periodic CSI reports are configured, a large amount of physical resource blocks (PRBs) may be occupied for PUCCH transmission, which may cause a low link budget in UL as well as less frequency resource for PUSCH; and/or

● for the case that lots of aperiodic CSI (A-CSI) reports are configured, the schedule ability in gNB side may be required for these reports, which may reduce the ability of data scheduling; besides, the offset parameter K2 with larger value may be always configured for the UE to generate a CSI report on PUSCH, which may enlarge the latency of the acknowledgement/negative acknowledgement (ACK/NACK) feedback for DL in some frame structure.

Fig. 4 is a diagram illustrating an exemplary frame structure according to an embodiment of the present disclosure. The exemplary frame structure shown in Fig. 4 consists of 7 DL subframes (which is indicated by “D” ) , 2 UL subframes (which is indicated by “U” ) , and 1 special subframe (which is indicated by “S” ) . A UL grant (e.g., A-CSI grant or UL data grant) may be indicated in a DL subframe. In the case that the network only supports K1>=K2 for one UL slot (where K1 is the ACK timing parameter, e.g., if the DL data reception is in slot N, then the corresponding ACK feedback is in slot N+K1, and if the UL assignment is in slot N, then the corresponding UL data transmission is in slot N+K2) , the DL transmission after A-CSI downlink control information (DCI) needs to be acknowledged after A-CSI PUSCH, which may increase the ACK/NACK feedback latency with respect to the DL transmission.

In order to balance the impact of additional beam reporting and MU degrees of freedom, the gNB may not select all beams which are not reported before as the target beams. In accordance with some exemplary embodiments, one or more beams which are less correlated with the reported favorable beams may be selected as the target beams for beam management. Optionally, the gNB can configure the UE to report the channel quality for at least a part of the target beams.

Fig. 5A is a diagram illustrating an example of beam distribution according to an embodiment of the present disclosure. As shown in Fig. 5A, for the reported beam, the beams surrounded usually have higher correlation and can be considered as high correlation beams. In this example, the target beams may comprise at least part of the beams surrounding the high correlation beams, which may have lower correlation with the reported beams and high possibility to have good channel quality in the same time. It can be realized that there may be more ways to select the target beams with less correlation, and optionally limitation on the number of the target beams may also be added to save reporting resource of the UE.

In accordance with some exemplary embodiments, the gNB can configure the UE to report measurements on the target beams separately. In this case, the UE can report each target beam with RSRP/CQI. According to the exemplary beam management procedure as shown in Fig. 3, the gNB can maintain a set of usable beams for each target UE, based at least in part on the beam reports (e.g., CSI reports) from the target UEs. The gNB can update the set of usable beam in response to reception of one or more beam reports.

In accordance with some exemplary embodiments, the gNB may select all or some of the target beams into the set of usable beams, for example, according to at least one of the following the criteria:

● a beam for which the channel quality is higher than an absolute channel quality threshold can be added into the set of usable beams; and

● a target beam for which a gap of the channel quality with respect to the originally reported beam (e.g., the most popular beam) is smaller than a relative channel quality threshold can be added into the set of usable beams (e.g., in this case, the gap of the channel quality can be obtained by comparison between the target beam report and the previous report for the most popular beam) .

It can be appreciated that there may be other proper criteria applicable for selection of the set of usable beams. In accordance with some exemplary embodiments, the set of usable beams may be fed into MU grouping. Optionally, the set of usable beams can be maintained as a beam pool for each target UE or for all target UEs. The gNB can configure MU grouping for the target UEs based at least in part on the maintained beam pool.

Fig. 5B is a diagram illustrating another example of beam distribution according to an embodiment of the present disclosure. Similar to Fig. 5A, three types of beams are shown in Fig. 5B, including 2 reported beams, 10 high correlation beams, and 12 target beams for which additional beam measurements are reported. In addition, Fig. 5B also shows 2 beams in a MU grouping beam pool selected from those 12 target beams. It will be realized that the distribution and configuration of different types of beams as described in Fig. 5A or Fig. 5B is just an example. Other suitable beam selection criteria, the associated configuration parameters and the specific values thereof may also be applicable to implement the proposed methods.

In accordance with an exemplary embodiment, the gNB can determine beam 0 and beam 1 as the most popular beams for four target UEs (e.g., UE0, UE1, UE2 and UE3) , for example, according to the following beam reports:

- Target UE0 reported beam {0, 1} ;

- Target UE1 reported beam {0, 1} ;

- Target UE2 reported beam {0, 1} ; and

- Target UE3 reported beam {0, 1} .

Generally, those UEs (such as UE0, UE1, UE2 and UE3) in the same MU group cannot share the same time and frequency resource due to lack of spatial difference. According to the exemplary embodiment, the gNB can indicate the target UEs to report measurements on one or more target beams different from the previously reported beams. Based at least in part on the target beam reports, the gNB can select a set of usable beams for each target UE. As an example, for each of UE0, UE1, UE2 and UE3, the gNB can maintain a beam set as follows for MU grouping.

- Target UE0 beam set {5, 7, 8, 9} ;

- Target UE1 beam set {6, 7, 8, 10} ;

- Target UE2 beam set {7, 9, 10, 11} ; and

- Target UE3 beam set {9, 10, 12, 13} .

In this way, the possibility for MU grouping can be increased significantly, which brings benefits to cell throughput. Optionally, the beam set maintained for MU grouping may further comprise at least one of the originally reported beams (e.g., the most popular beams or favorable beams) by the target UEs. In this case, for each of UE0, UE1, UE2 and UE3, the gNB can maintain a beam set as follows for MU grouping.

- Target UE0 beam set {0, 1, 5, 7, 8, 9}

- Target UE1 beam set {0, 1, 6, 7, 8, 10} ;

- Target UE2 beam set {0, 1, 7, 9, 10, 11} ; and

- Target UE3 beam set {0, 1, 9, 10, 12, 13} .

It is noted that some embodiments of the present disclosure are mainly described in relation to LTE or NR specifications being used as non-limiting examples for certain exemplary network configurations and system deployments. As such, the description of exemplary embodiments given herein specifically refers to terminology which is directly related thereto. Such terminology is only used in the context of the presented non-limiting examples and embodiments, and does naturally not limit the present disclosure in any way. Rather, any other system configuration or radio technologies may equally be utilized as long as exemplary embodiments described herein are applicable.

Fig. 6A is a flowchart illustrating a method 610 according to some embodiments of the present disclosure. The method 610 illustrated in Fig. 6A may be performed by a network node or an apparatus communicatively coupled to the network node. In accordance with an exemplary embodiment, the network node may comprise a base station such as eNB/gNB. The network node can be configured to communicate with one or more terminal devices such as UEs which may be able to support multiple antenna technology.

According to the exemplary method 610 illustrated in Fig. 6A, the network node can receive, from a terminal device, first measurement information about a first beam preferred by the terminal device, as shown in block 612. Optionally, the terminal device may have an amount of traffics to be transmitted to the network node larger than a predefined traffic threshold. In accordance with some exemplary embodiments, the first measurement information may comprise at least one of: a reference resource indicator (e.g., a CSI-RS indicator, a CSI resource index, etc. ) , a beam indicator, signal receiving power, signal receiving quality, and channel quality information (e.g., L1-RSRP, CQI, PMI, RI, etc. ) . As an example, the first beam of the network node preferred by the terminal device may correspond to the best RSRP/CQI compared to other beams. In some cases, the first beam is also preferred by other terminal devices and reported to the network node. According to an exemplary embodiment, the first beam may be reported to the network node with a probability higher than a predefined probability threshold.

In accordance with some exemplary embodiments, the network node may transmit configuration information to the terminal device, as shown in block 614. The configuration information can indicate the terminal device to report second measurement information about one or more target beams different from the first beam. Similar to the first measurement information, the second measurement information may comprise a reference resource indicator, a beam indicator, signal receiving power, signal receiving quality, channel quality information, or any combination thereof. According to an exemplary embodiment, the first beam and the one or more target beams may have a correlation which is within a predefined correlation range.

In accordance with some exemplary embodiments, the transmission of the configuration information to the terminal device by the network node may be in response to a beam management event which indicates that a correlation of beams reported to the network node satisfies a predefined criterion. According to an exemplary embodiment, the beam management event may comprise that a correlation between a preferred beam per candidate terminal device reported to the network node and the first beam is higher than a predefined correlation threshold. Optionally, the candidate terminal device may have an amount of traffics to be transmitted to the network node larger than a predefined traffic threshold.

In accordance with some exemplary embodiments, the preferred beam per candidate terminal device may be reported to the network node with a probability higher than a predefined probability threshold. In this case, the preferred beam per candidate terminal device and the first beam may be considered as the most popular beams. For example, the beam management event that the most popular beams are highly correlated can enable the network node to identify the specific scenario triggering a beam management procedure as described with respect to Fig. 3, and select, according to a predefined criterion, the terminal device as a target device to which the configuration information for beam management is transmitted.

In accordance with an exemplary embodiment where the terminal device is selected as the target device for beam management, the terminal device may have a buffer for storing data to be transmitted to the network node and the buffer has a predefined status (e.g., with large buffer size) . Alternatively or additionally, the terminal device may have channel quality above a first quality threshold. Optionally, the terminal device may have a channel of which the time variance is below a predefined variance threshold.

In accordance with an exemplary embodiment where the terminal device is selected as the target device for beam management, the terminal device may be configured for MU grouping at a frequency higher than a predefined grouping threshold. Alternatively or additionally, the terminal device may be configured for MU scheduling at a frequency higher than a predefined scheduling threshold.

In accordance with some exemplary embodiments, the network node may receive the second measurement information about the one or more target beams from the terminal device. Based at least in part on the second measurement information, the network node can determine a beam set usable for the terminal device. As an example, the beam set may comprise one or more beams in a MU grouping beam pool maintained for the terminal device by the network node. Optionally, the beam set may be usable for one or more other terminal devices in the same MU group with the terminal device.

According to an exemplary embodiment, the beam set usable for the terminal device may comprise at least a second beam for which channel quality reported to the network node by the terminal device is above a second quality threshold. Alternatively or additionally, the beam set may comprise at least a third beam, and a difference in channel quality between the first beam and the third beam for the terminal device is below a predefined comparison threshold. Optionally, the beam set may comprise the first beam.

In accordance with some exemplary embodiments, the network node can select one or more transmission beams from the beam set, and inform the terminal device of the one or more transmission beams from the network node to the terminal device. In the case that the beam correspondence is provided, a transmission beam in DL can also be used for reception in UL as well. As such, the one or more transmission beams of the network node may correspond to one or more reception beams of the network node with respect to the terminal device.

Fig. 6B is a flowchart illustrating a method 620 according to some embodiments of the present disclosure. The method 620 illustrated in Fig. 6B may be performed by a terminal device or an apparatus communicatively coupled to the terminal device. In accordance with an exemplary embodiment, the terminal device such as a UE may be configured to communicate with a network node such as a gNB and support multiple antenna technology.

According to the exemplary method 620 illustrated in Fig. 6B, the terminal device can transmit first measurement information about a first beam preferred by the terminal device to a network node, as shown in block 622. It can be appreciated that the network node mentioned here can be configured to perform the exemplary method 610 illustrated in Fig. 6A, and the terminal device described in connection with Fig. 6B may correspond to the terminal device described with respect to Fig. 6A.

In accordance with some exemplary embodiments, the terminal device may receive configuration information from the network node, as shown in block 624. The configuration information indicates the terminal device to report second measurement information about one or more target beams different from the first beam. For instance, the first measurement information and the second measurement information may each comprise a reference resource indicator, a beam indicator, signal receiving power, signal receiving quality, and/or channel quality information.

In accordance with some exemplary embodiments, the reception of the configuration information from the network node by the terminal device may be in response to a beam management event which indicates that a correlation of beams reported to the network node satisfies a predefined criterion. The beams reported to the network node may comprise a preferred beam per candidate terminal device reported to the network node and the first beam. According to an exemplary embodiment, the terminal device and the candidate terminal device may each have large traffic demand towards the network node. The preferred beam per candidate terminal device and the first beam may belong to the most popular beams which are reported to the network node with a probability higher than a predefined probability threshold. The beam management event may occur in a situation where a correlation between the preferred beam per candidate terminal device reported to the network node and the first beam is higher than a predefined correlation threshold,

In accordance with some exemplary embodiments, the reception of the configuration information from the network node by the terminal device implies that the terminal device is selected as a target device for beam management by the network node, for example, due to one or more state characteristics of the terminal device, including but not limited to, large buffer size, good channel quality, small channel time variance, frequently participating in MU grouping/scheduling, etc.

In accordance with some exemplary embodiments, the terminal device can transmit the second measurement information about the one or more target beams to the network node. The one or more target beams may be less correlated with the first beam, for example, compared to those beams close to the first beam. Optionally, the terminal device can receive, from the network node, information about one or more transmission beams from the network node to the terminal device. The one or more transmission beams may be selected from a beam set which is usable for the terminal device and optionally for one or more other terminal devices in the same MU group with the terminal device. As described with respect to Fig. 6A, the beam set can be determined by the network node based at least in part on the second measurement information, for example, by considering the absolute and/or relative channel quality related to the one or more target beams reported by the terminal device. Optionally, the one or more transmission beams can also be used as reception beams of the network node with respect to the terminal device.

The proposed solution according to some exemplary embodiments can enable a gNB to configure a UE to report information about additional beams besides the favorable beam for the UE to derive a complete view on beam management, for example, in the case that a set of favorable beams reported to the gNB by UEs are the same or similar. According to an exemplary embodiment, a scenario in which MU opportunities are limited by a specific UE distribution in locations can be identified according to a predefined criterion. In the identified scenario, the gNB can choose to configure the UEs in a way such that one or more other beams less correlated with the favorable beams previously reported can be additionally reported to the gNB by the UEs. If the other beams reported by the UEs according to the configuration by the gNB are still usable for data traffic, the gNB can apply MU grouping/scheduling for the UEs to increase the network throughput. In this way, the gNB may have more beam candidates and can increase the number of MU layers. The increased degrees of freedom for MU beam selection and MU grouping can advantageously improve system performance and enhance resource utilization.

The various blocks shown in Figs. 6A-6B may be viewed as method steps, and/or as operations that result from operation of computer program code, and/or as a plurality of coupled logic circuit elements constructed to carry out the associated function (s) . The schematic flow chart diagrams described above are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of specific embodiments of the presented methods. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated methods. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.

Fig. 7 is a block diagram illustrating an apparatus 700 according to various embodiments of the present disclosure. As shown in Fig. 7, the apparatus 700 may comprise one or more processors such as processor 701 and one or more memories such as memory 702 storing computer program codes 703. The memory 702 may be non-transitory machine/processor/computer readable storage medium. In accordance with some exemplary embodiments, the apparatus 700 may be implemented as an integrated circuit chip or module that can be plugged or installed into a network node as described with respect to Fig. 6A, or a terminal device as described with respect to Fig. 6B. In such case, the apparatus 700 may be implemented as a network node as described with respect to Fig. 6A, or a terminal device as described with respect to Fig. 6B.

In some implementations, the one or more memories 702 and the computer program codes 703 may be configured to, with the one or more processors 701, cause the apparatus 700 at least to perform any operation of the method as described in connection with Fig. 6A. In other implementations, the one or more memories 702 and the computer program codes 703 may be configured to, with the one or more processors 701, cause the apparatus 700 at least to perform any operation of the method as described in connection with Fig. 6B. Alternatively or additionally, the one or more memories 702 and the computer program codes 703 may be configured to, with the one or more processors 701, cause the apparatus 700 at least to perform more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

Fig. 8A is a block diagram illustrating an apparatus 810 according to some embodiments of the present disclosure. As shown in Fig. 8A, the apparatus 810 may comprise a receiving unit 811 and a transmitting unit 812. In an exemplary embodiment, the apparatus 810 may be implemented in a network node such as a base station. The receiving unit 811 may be operable to carry out the operation in block 612, and the transmitting unit 812 may be operable to carry out the operation in block 614. Optionally, the receiving unit 811 and/or the transmitting unit 812 may be operable to carry out more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

Fig. 8B is a block diagram illustrating an apparatus 820 according to some embodiments of the present disclosure. As shown in Fig. 8B, the apparatus 820 may comprise a transmitting unit 821 and a receiving unit 822. In an exemplary embodiment, the apparatus 820 may be implemented in a terminal device such as UE. The transmitting unit 821 may be operable to carry out the operation in block 622, and the receiving unit 822 may be operable to carry out the operation in block 624. Optionally, the transmitting unit 821 and/or the receiving unit 822 may be operable to carry out more or less operations to implement the proposed methods according to the exemplary embodiments of the present disclosure.

Fig. 9 is a block diagram illustrating a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments of the present disclosure.

With reference to Fig. 9, in accordance with an embodiment, a communication system includes a telecommunication network 910, such as a 3GPP-type cellular network, which comprises an access network 911, such as a radio access network, and a core network 914. The access network 911 comprises a plurality of

base stations

912a, 912b, 912c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a

corresponding coverage area

913a, 913b, 913c. Each

base station

912a, 912b, 912c is connectable to the core network 914 over a wired or wireless connection 915. A first UE 991 located in a coverage area 913c is configured to wirelessly connect to, or be paged by, the corresponding base station 912c. A second UE 992 in a coverage area 913a is wirelessly connectable to the corresponding base station 912a. While a plurality of

UEs

991, 992 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 912.

The telecommunication network 910 is itself connected to a host computer 930, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. The host computer 930 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider.

Connections

921 and 922 between the telecommunication network 910 and the host computer 930 may extend directly from the core network 914 to the host computer 930 or may go via an optional intermediate network 920. An intermediate network 920 may be one of, or a combination of more than one of, a public, private or hosted network; the intermediate network 920, if any, may be a backbone network or the Internet; in particular, the intermediate network 920 may comprise two or more sub-networks (not shown) .

The communication system of Fig. 9 as a whole enables connectivity between the connected

UEs

991, 992 and the host computer 930. The connectivity may be described as an over-the-top (OTT) connection 950. The host computer 930 and the connected

UEs

991, 992 are configured to communicate data and/or signaling via the OTT connection 950, using the access network 911, the core network 914, any intermediate network 920 and possible further infrastructure (not shown) as intermediaries. The OTT connection 950 may be transparent in the sense that the participating communication devices through which the OTT connection 950 passes are unaware of routing of uplink and downlink communications. For example, the base station 912 may not or need not be informed about the past routing of an incoming downlink communication with data originating from the host computer 930 to be forwarded (e.g., handed over) to a connected UE 991. Similarly, the base station 912 need not be aware of the future routing of an outgoing uplink communication originating from the UE 991 towards the host computer 930.

Fig. 10 is a block diagram illustrating a host computer communicating via a base station with a UE over a partially wireless connection in accordance with some embodiments of the present disclosure.

Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to Fig. 10. In a communication system 1000, a host computer 1010 comprises hardware 1015 including a communication interface 1016 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 1000. The host computer 1010 further comprises a processing circuitry 1018, which may have storage and/or processing capabilities. In particular, the processing circuitry 1018 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The host computer 1010 further comprises software 1011, which is stored in or accessible by the host computer 1010 and executable by the processing circuitry 1018. The software 1011 includes a host application 1012. The host application 1012 may be operable to provide a service to a remote user, such as UE 1030 connecting via an OTT connection 1050 terminating at the UE 1030 and the host computer 1010. In providing the service to the remote user, the host application 1012 may provide user data which is transmitted using the OTT connection 1050.

The communication system 1000 further includes a base station 1020 provided in a telecommunication system and comprising hardware 1025 enabling it to communicate with the host computer 1010 and with the UE 1030. The hardware 1025 may include a communication interface 1026 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 1000, as well as a radio interface 1027 for setting up and maintaining at least a wireless connection 1070 with the UE 1030 located in a coverage area (not shown in Fig. 10) served by the base station 1020. The communication interface 1026 may be configured to facilitate a connection 1060 to the host computer 1010. The connection 1060 may be direct or it may pass through a core network (not shown in Fig. 10) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, the hardware 1025 of the base station 1020 further includes a processing circuitry 1028, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The base station 1020 further has software 1021 stored internally or accessible via an external connection.

The communication system 1000 further includes the UE 1030 already referred to. Its hardware 1035 may include a radio interface 1037 configured to set up and maintain a wireless connection 1070 with a base station serving a coverage area in which the UE 1030 is currently located. The hardware 1035 of the UE 1030 further includes a processing circuitry 1038, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. The UE 1030 further comprises software 1031, which is stored in or accessible by the UE 1030 and executable by the processing circuitry 1038. The software 1031 includes a client application 1032. The client application 1032 may be operable to provide a service to a human or non-human user via the UE 1030, with the support of the host computer 1010. In the host computer 1010, an executing host application 1012 may communicate with the executing client application 1032 via the OTT connection 1050 terminating at the UE 1030 and the host computer 1010. In providing the service to the user, the client application 1032 may receive request data from the host application 1012 and provide user data in response to the request data. The OTT connection 1050 may transfer both the request data and the user data. The client application 1032 may interact with the user to generate the user data that it provides.

It is noted that the host computer 1010, the base station 1020 and the UE 1030 illustrated in Fig. 10 may be similar or identical to the host computer 930, one of

base stations

912a, 912b, 912c and one of

UEs

991, 992 of Fig. 9, respectively. This is to say, the inner workings of these entities may be as shown in Fig. 10 and independently, the surrounding network topology may be that of Fig. 9.

In Fig. 10, the OTT connection 1050 has been drawn abstractly to illustrate the communication between the host computer 1010 and the UE 1030 via the base station 1020, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from the UE 1030 or from the service provider operating the host computer 1010, or both. While the OTT connection 1050 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network) .

Wireless connection 1070 between the UE 1030 and the base station 1020 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE 1030 using the OTT connection 1050, in which the wireless connection 1070 forms the last segment. More precisely, the teachings of these embodiments may improve the latency and the power consumption, and thereby provide benefits such as lower complexity, reduced time required to access a cell, better responsiveness, extended battery lifetime, etc.

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 1050 between the host computer 1010 and the UE 1030, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 1050 may be implemented in software 1011 and hardware 1015 of the host computer 1010 or in software 1031 and hardware 1035 of the UE 1030, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 1050 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 the

software

1011, 1031 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1050 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect the base station 1020, and it may be unknown or imperceptible to the base station 1020. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating the host computer 1010’s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that the

software

1011 and 1031 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 1050 while it monitors propagation times, errors etc.

Fig. 11 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Fig. 9 and Fig. 10. For simplicity of the present disclosure, only drawing references to Fig. 11 will be included in this section. In step 1110, the host computer provides user data. In substep 1111 (which may be optional) of step 1110, the host computer provides the user data by executing a host application. In step 1120, the host computer initiates a transmission carrying the user data to the UE. In step 1130 (which may be optional) , the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1140 (which may also be optional) , the UE executes a client application associated with the host application executed by the host computer.

Fig. 12 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Fig. 9 and Fig. 10. For simplicity of the present disclosure, only drawing references to Fig. 12 will be included in this section. In step 1210 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step 1220, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1230 (which may be optional) , the UE receives the user data carried in the transmission.

Fig. 13 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Fig. 9 and Fig. 10. For simplicity of the present disclosure, only drawing references to Fig. 13 will be included in this section. In step 1310 (which may be optional) , the UE receives input data provided by the host computer. Additionally or alternatively, in step 1320, the UE provides user data. In substep 1321 (which may be optional) of step 1320, the UE provides the user data by executing a client application. In substep 1311 (which may be optional) of step 1310, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep 1330 (which may be optional) , transmission of the user data to the host computer. In step 1340 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure.

Fig. 14 is a flowchart illustrating a method implemented in a communication system, in accordance with an embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Fig. 9 and Fig. 10. For simplicity of the present disclosure, only drawing references to Fig. 14 will be included in this section. In step 1410 (which may be optional) , in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step 1420 (which may be optional) , the base station initiates transmission of the received user data to the host computer. In step 1430 (which may be optional) , the host computer receives the user data carried in the transmission initiated by the base station.

In general, the various exemplary embodiments may be implemented in hardware or special purpose chips, circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the disclosure is not limited thereto. While various aspects of the exemplary embodiments of this disclosure may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

As such, it should be appreciated that at least some aspects of the exemplary embodiments of the disclosure may be practiced in various components such as integrated circuit chips and modules. It should thus be appreciated that the exemplary embodiments of this disclosure may be realized in an apparatus that is embodied as an integrated circuit, where the integrated circuit may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor, a digital signal processor, baseband circuitry and radio frequency circuitry that are configurable so as to operate in accordance with the exemplary embodiments of this disclosure.

It should be appreciated that at least some aspects of the exemplary embodiments of the disclosure may be embodied in computer-executable instructions, such as in one or more program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types when executed by a processor in a computer or other device. The computer executable instructions may be stored on a computer readable medium such as a hard disk, optical disk, removable storage media, solid state memory, random access memory (RAM) , etc. As will be appreciated by one of skill in the art, the function of the program modules may be combined or distributed as desired in various embodiments. In addition, the function may be embodied in whole or partly in firmware or hardware equivalents such as integrated circuits, field programmable gate arrays (FPGA) , and the like.

The present disclosure includes any novel feature or combination of features disclosed herein either explicitly or any generalization thereof. Various modifications and adaptations to the foregoing exemplary embodiments of this disclosure may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings. However, any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this disclosure.

Claims

A method (610) performed by a network node, comprising:

receiving (612) , from a terminal device, first measurement information about a first beam preferred by the terminal device; and

transmitting (614) configuration information to the terminal device, wherein the configuration information indicates the terminal device to report second measurement information about one or more target beams different from the first beam.
The method according to claim 1, wherein the terminal device has an amount of traffics to be transmitted to the network node larger than a predefined traffic threshold.
The method according to any of claims 1-2, wherein the first measurement information and the second measurement information each comprise at least one of:

a reference resource indicator;

a beam indicator;

signal receiving power;

signal receiving quality; and

channel quality information.
The method according to any of claims 1-3, wherein the first beam is reported to the network node with a probability higher than a predefined probability threshold.
The method according to any of claims 1-4, wherein the transmission of the configuration information to the terminal device is in response to a beam management event which indicates that a correlation of beams reported to the network node satisfies a predefined criterion.
The method according to claim 5, wherein the beam management event comprises that a correlation between a preferred beam per candidate terminal device reported to the network node and the first beam is higher than a predefined correlation threshold.
The method according to claim 6, wherein the preferred beam per candidate terminal device is reported to the network node with a probability higher than a predefined probability threshold.
The method according to any of claims 6-7, wherein the candidate terminal device has an amount of traffics to be transmitted to the network node larger than a predefined traffic threshold.
The method according to any of claims 1-8, wherein the terminal device has a buffer for storing data to be transmitted to the network node and the buffer has a predefined status.
The method according to any of claims 1-9, wherein the terminal device has channel quality above a first quality threshold.
The method according to any of claims 1-10, wherein the terminal device has a channel of which the time variance is below a predefined variance threshold.
The method according to any of claims 1-11, wherein the terminal device is configured for multiuser grouping at a frequency higher than a predefined grouping threshold.
The method according to any of claims 1-12, wherein the terminal device is configured for multiuser scheduling at a frequency higher than a predefined scheduling threshold.
The method according to any of claims 1-13, wherein the first beam and the one or more target beams have a correlation which is within a predefined correlation range.
The method according to any of claims 1-14, further comprising:

receiving the second measurement information about the one or more target beams from the terminal device; and

determining a beam set usable for the terminal device, based at least in part on the second measurement information.
The method according to claim 15, wherein the beam set comprises at least a second beam for which channel quality reported to the network node by the terminal device is above a second quality threshold.
The method according to any of claims 15-16, wherein the beam set comprises at least a third beam, and wherein a difference in channel quality between the first beam and the third beam for the terminal device is below a predefined comparison threshold.
The method according to any of claims 15-17, wherein the beam set comprises the first beam.
The method according to any of claims 15-18, wherein the beam set is usable for one or more other terminal devices in the same multiuser group with the terminal device.
The method according to any of claims 15-19, further comprising:

informing the terminal device of one or more transmission beams from the network node to the terminal device, wherein the one or more transmission beams are selected from the beam set.
The method according to claim 20, wherein the one or more transmission beams correspond to one or more reception beams of the network node with respect to the terminal device.
A method (620) performed by a terminal device, comprising:

transmitting (622) first measurement information about a first beam preferred by the terminal device to a network node; and

receiving (624) configuration information from the network node, wherein the configuration information indicates the terminal device to report second measurement information about one or more target beams different from the first beam.
The method according to claim 22, wherein the terminal device has an amount of traffics to be transmitted to the network node larger than a predefined traffic threshold.
The method according to any of claims 22-23, wherein the first measurement information and the second measurement information each comprise at least one of:

a reference resource indicator;

a beam indicator;

signal receiving power;

signal receiving quality; and

channel quality information.
The method according to any of claims 22-24 wherein the first beam is reported to the network node with a probability higher than a predefined probability threshold.
The method according to any of claims 22-25, wherein the reception of the configuration information from the network node is in response to a beam management event which indicates that a correlation of beams reported to the network node satisfies a predefined criterion.
The method according to claim 26, wherein the beam management event comprises that a correlation between a preferred beam per candidate terminal device reported to the network node and the first beam is higher than a predefined correlation threshold.
The method according to claim 27, wherein the preferred beam per candidate terminal device is reported to the network node with a probability higher than a predefined probability threshold.
The method according to any of claims 27-28, wherein the candidate terminal device has an amount of traffics to be transmitted to the network node larger than a predefined traffic threshold.
The method according to any of claims 22-29, wherein the terminal device has a buffer for storing data to be transmitted to the network node and the buffer has a predefined status.
The method according to any of claims 22-30, wherein the terminal device has channel quality above a first quality threshold.
The method according to any of claims 22-31, wherein the terminal device has a channel of which the time variance is below a predefined variance threshold.
The method according to any of claims 22-32, wherein the terminal device is configured for multiuser grouping at a frequency higher than a predefined grouping threshold.
The method according to any of claims 22-33, wherein the terminal device is configured for multiuser scheduling at a frequency higher than a predefined scheduling threshold.
The method according to any of claims 22-34, wherein the first beam and the one or more target beams have a correlation which is within a predefined correlation range.
The method according to any of claims 22-35, further comprising:

transmitting the second measurement information about the one or more target beams to the network node; and

receiving, from the network node, information about one or more transmission beams from the network node to the terminal device, wherein the one or more transmission beams are selected from a beam set which is usable for the terminal device and determined based at least in part on the second measurement information.
The method according to claim 36, wherein the beam set comprises at least a second beam for which channel quality reported to the network node by the terminal device is above a second quality threshold.
The method according to any of claims 36-37, wherein the beam set comprises at least a third beam, and wherein a difference in channel quality between the first beam and the third beam for the terminal device is below a predefined comparison threshold.
The method according to any of claims 36-38, wherein the beam set comprises the first beam.
The method according to any of claims 36-39, wherein the beam set is usable for one or more other terminal devices in the same multiuser group with the terminal device.
The method according to any of claims 36-40, wherein the one or more transmission beams correspond to one or more reception beams of the network node with respect to the terminal device.
A network node (700) , comprising:

one or more processors (701) ; and

one or more memories (702) comprising computer program codes (703) ,

the one or more memories (702) and the computer program codes (703) configured to, with the one or more processors (701) , cause the network node (700) at least to perform the method according to any one of claims 1-21.
A terminal device (700) , comprising:

one or more processors (701) ; and

one or more memories (702) comprising computer program codes (703) ,

the one or more memories (702) and the computer program codes (703) configured to, with the one or more processors (701) , cause the terminal device (700) at least to perform the method according to any one of claims 22-41.
A computer-readable medium having computer program codes embodied thereon for use with a computer, wherein the computer program codes comprise codes for performing the method according to any one of claims 1-21.
A computer-readable medium having computer program codes embodied thereon for use with a computer, wherein the computer program codes comprise codes for performing the method according to any one of claims 22-41.