Beam management during initial access

Abstract

A method of operating a wireless communication device (102) configured to connect to a communication network (100), the method comprising: monitoring a plurality of downlink reference signals (411) transmitted by at least one access node of the communication network (100) using a plurality of downlink transmission beams (361-364), each of the plurality of downlink reference signals (411) being associated with a respective at least one of a plurality of random access opportunities (415-418); and accessing at least two of the plurality of random access opportunities (415-418). access opportunities (415, 418), the at least two random access opportunities (415, 418) being associated with at least two downlink reference signals (411) selected from the plurality of downlink reference signals (411) based on the monitoring; and establishing a multi-beam operation between the wireless communication device (102) and the communication network (100), wherein the multi-beam operation is established based on at least two downlink transmission beams (361, 364) for transmitting the selected at least two downlink reference signals (411).

Description

Technical Field

[0001] Various examples relate to beam management for multi-beam operation in a communication system. More particularly, various examples relate to beam management during initial access of a wireless communication device to a cellular network. Background Art

[0002] Multiple-input, multiple-output (MIMO) technology is sometimes used to enhance the reliability and / or throughput of communications over wireless links. Here, both the transmitter node and the receiver node include multiple antennas capable of operating in a phase-coherent manner. As a result, signals can be redundantly transmitted along multiple spatial data streams (diversity multi-antenna mode), or multiple signals can be transmitted on multiple spatial data streams (spatial multiplexing multi-antenna operating mode). Spatial data streams can be defined by focusing the transmit energy for transmission (transmit beam, TX beam) and / or the receive sensitivity for reception (receive beam, RX beam) to specific spatial directions. Here, the process of identifying the appropriate beam is generally referred to as beam establishment or beam management.

[0003] Beam management typically requires control signaling between nodes of a MIMO communication system. For example, where the MIMO communication system is implemented by a base station of a cellular network and a wireless communication device that can attach to the cellular network, the initial access of the wireless communication device to the cellular network may introduce a control signaling framework that, according to a reference implementation, makes beam management difficult to implement at this early stage. Summary of the Invention

[0004] Therefore, advanced techniques for beam management during initial access are needed.

[0005] A method for operating a user equipment (UE) is provided. The UE is configured to connect to a communication network. The method includes monitoring multiple downlink reference signals. The multiple downlink reference signals are transmitted by at least one access node of the communication network. The multiple downlink reference signals are transmitted using multiple downlink transmit beams. Each of the multiple downlink reference signals is associated with at least one of a plurality of random access opportunities. The method also includes accessing at least two RA opportunities among the multiple RA opportunities. The at least two RA opportunities are associated with at least two downlink reference signals. The at least two downlink reference signals are selected from the multiple downlink reference signals. The selection is based on the monitoring. The method also includes establishing multi-beam operation between the UE and the communication network. The multi-beam operation is established based on the at least two downlink transmit beams used to transmit the selected at least two downlink reference signals.

[0006] A computer program, a computer program product, or a computer-readable storage medium includes program code. The program code is executable by at least one processor. Execution of the program code causes the at least one processor to perform a method for operating a UE. The UE is configured to connect to a communications network. The method includes monitoring multiple downlink reference signals. The multiple downlink reference signals are transmitted by at least one access node of the communications network. The multiple downlink reference signals are transmitted using multiple downlink transmit beams. Each of the multiple downlink reference signals is associated with at least one of a plurality of random access opportunities. The method also includes accessing at least two RA opportunities from the multiple RA opportunities. The at least two RA opportunities are associated with at least two downlink reference signals. The at least two downlink reference signals are selected from the multiple downlink reference signals. The selection is based on the monitoring. The method also includes establishing multi-beam operation between the UE and the communications network. The multi-beam operation is established based on the at least two downlink transmit beams used to transmit the selected at least two downlink reference signals.

[0007] A wireless communication device is configured to connect to a communication network. The wireless communication device includes control circuitry configured to monitor a plurality of downlink reference signals transmitted by at least one access node of the communication network using a plurality of downlink transmit beams, each of the plurality of downlink reference signals being associated with at least one of a plurality of random access opportunities. The control circuitry is further configured to access at least two random access opportunities of the plurality of random access opportunities, the at least two random access opportunities being associated with at least two downlink reference signals selected from the plurality of downlink reference signals based on the monitoring. The control circuitry is further configured to establish multi-beam operation between the wireless communication device and the communication network, wherein the multi-beam operation is established based on the at least two downlink transmit beams used to transmit the selected at least two downlink reference signals.

[0008] A method for operating at least one access node of a communication network is provided. The method includes transmitting multiple downlink reference signals. The multiple downlink reference signals are transmitted using multiple downlink transmit beams. Each of the multiple downlink reference signals is associated with at least one of a plurality of RA opportunities. The method also includes monitoring access by a UE to at least two RA opportunities associated with at least two of the multiple downlink reference signals. The method also includes establishing multi-beam operation based on the monitoring of the access. The multi-beam operation is between a user end user (EU) and the communication network. The multi-beam operation is established based on at least two of the multiple downlink transmit beams used to transmit the at least two downlink reference signals.

[0009] A computer program, a computer program product, or a computer-readable storage medium includes program code. The program code is executable by at least one processor. Execution of the program code causes the at least one processor to perform a method for operating at least one access node of a communications network. The method includes transmitting multiple downlink reference signals. The multiple downlink reference signals are transmitted using multiple downlink transmission beams. Each of the multiple downlink reference signals is associated with at least one of a plurality of RA opportunities. The method also includes monitoring access by a UE to at least two RA opportunities associated with at least two of the multiple downlink reference signals. The method also includes establishing multi-beam operation based on the monitoring of the access. Multi-beam operation is between the UE and the communications network. The multi-beam operation is established based on at least two of the multiple downlink transmission beams used to transmit the at least two downlink reference signals.

[0010] At least one access node of a communication network includes control circuitry. The control circuitry is configured to transmit a plurality of downlink reference signals using a plurality of downlink transmission beams, each of the plurality of downlink reference signals being associated with at least one of a plurality of random access opportunities. The control circuitry is further configured to monitor accesses by a wireless communication device to at least two random access opportunities associated with at least two of the plurality of downlink reference signals. Furthermore, the control circuitry is further configured to establish multi-beam operation between the wireless communication device and the communication network based on the monitoring of the accesses, wherein the multi-beam operation is established based on at least two downlink transmit beams of the plurality of downlink transmission beams used to transmit the at least two downlink reference signals.

[0011] It is to be understood that the features mentioned above and those yet to be explained below can be used not only in the respective combination indicated but also in other combinations or alone, without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Communication systems according to various examples are schematically illustrated.

[0013] Figure 2 Schematically shows various examples of Figure 1 MIMO operation of the communication system.

[0014] Figure 3 Transmission beam scanning of a base station of a communication system according to various examples is schematically illustrated.

[0015] Figure 4 Receive beam scanning of a wireless communication device of a communication system according to various examples is schematically illustrated.

[0016] Figure 5 Multi-beam operation of a wireless communication system according to various examples is schematically illustrated.

[0017] Figure 6 Schematically illustrated are cellular networks according to various examples.

[0018] Figure 7 A number of connection modes are schematically illustrated in which the wireless communication device may be operated according to various examples.

[0019] Figure 8 Schematically illustrating multiple random access opportunities for initial access of a wireless communication device to a cellular network according to various examples.

[0020] Figure 9 is a signaling diagram of communications between a wireless communication device and a cellular network according to various examples.

[0021] Figure 10 is a flow chart of a method according to various examples.

[0022] Figure 11 is a flow chart of a method according to various examples. DETAILED DESCRIPTION

[0023] Some examples of the present disclosure generally provide multiple circuits or other electrical devices. All references to circuits and other electrical devices and the functions provided by each are not intended to be limited to only what is shown and described herein. Although specific labels may be assigned to the various circuits or other electrical devices disclosed, such labels are not intended to limit the operating scope of the circuits and other electrical devices. Based on the specific type of electrical implementation desired, such circuits and other electrical devices can be combined and / or separated from each other in any manner. It should be recognized that any circuit or other electrical device disclosed herein may include any number of microcontrollers, graphics processor units (GPUs), integrated circuits, memory devices (e.g., flash memory, random access memory (RAM), read-only memory (ROM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM) or other operating software thereof that cooperate with each other to perform the operations disclosed herein. In addition, any one or more electrical devices may be configured to execute program code contained in a non-transitory computer-readable medium programmed to perform any number of the functions disclosed.

[0024] Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood that the following description of the embodiments should not be construed as limiting. The scope of the present invention is not intended to be limited by the embodiments or drawings described below, which are intended to be illustrative only.

[0025] The accompanying drawings are to be considered schematic representations, and the elements shown in the drawings are not necessarily shown to scale. Instead, the various elements are represented so that their functions and general uses become apparent to those skilled in the art. Any connection or coupling between the functional blocks, devices, components, or other physical or functional units shown in the accompanying drawings or described herein may also be achieved through indirect connections or couplings. Couplings between components may also be established through wireless connections. Functional blocks may be implemented in hardware, firmware, software, or a combination thereof.

[0026] Techniques are described that facilitate initial access of a UE to a communication network (e.g., a cellular network). In particular, techniques that facilitate initial access using MIMO operation are described. In particular, the techniques described herein facilitate beam management during initial access of a wireless communication device (UE) to a cellular network (NW). The techniques described herein can be used to reliably determine, at a base station (BS) of a cellular NW, one or more downlink (DL) transmit (TX) beams to be used for transmitting data to a UE. The one or more DL TX beams can then be used for subsequent data communications, such as application data and / or higher layer control data. Alternatively or additionally, using the techniques described herein, one or more uplink (UL) receive (RX) beams can be determined at the BS. The DL TX beams and UL RX beams are so-called BS beams because they are employed by the BS.

[0027] In some examples, a UE beam, i.e., a UL TX beam and / or a DL RX beam, may also be determined. The RX beam may be defined by an RX spatial filter. Alternatively or additionally, the TX beam may be defined by a TX spatial filter. More generally, transmission using a spatial filter produces a specific beam or beam pattern.

[0028] Once a beam is determined, the beam may be used for subsequent data communications, such as application data and / or higher layer control data.

[0029] According to various examples, a UE can access multiple random access (RA) opportunities, each associated with a different BS beam. Based on the multiple RO accesses, multi-beam operation can be established. That is, multi-beam operation can be appropriately configured using information transmitted or determined based on the multiple RO accesses. For example, the BS can obtain information about multiple high-quality beam pairs between the BS and the UE with low latency during initial access. This can reduce the overall control signaling overhead. The capacity of the wireless link between the UE and the BS can be estimated. The multiple beam pairs determined based on the multiple RO accesses can be used for multi-beam operation.

[0030] For example, the UE may monitor multiple DL reference signals (RSs). The DL RSs may be transmitted by the BS using multiple DL TX beams. Then, based on a comparison of the RX properties (e.g., RX amplitudes) of the multiple DL RSs, the UE may determine two or more strongest DL TX beams. The DL RSs may be associated with different ROs. The UE may accordingly select those ROs associated with the DL RSs that have been transmitted using the two or more strongest DL TX beams. Then, multi-beam operation (e.g., UL and / or DL ​​multi-beam operation) may be established based on the two or more strongest DL TX beams and / or UL RX beams corresponding to those DL TX beams (e.g., having the same antenna weights). For example, the two or more strongest DL TX beams and / or the corresponding two or more UL RX beams may be used for transmission according to the multi-beam operation, e.g., for subsequent data communication during connected mode. The two or more strongest DL TX beams and / or the corresponding two or more strongest UL RX beams may also be refined: such beam refinement may include, for example, determining sub-beams having narrower beamwidths.

[0031] Figure 1 A communication system is schematically shown. The communication system comprises two nodes 101, 102 configured to communicate with each other via a wireless link 114. Figure 1 In the example of FIG, the node 101 is implemented by an access node, more specifically, by a BS, and the node 102 is implemented by a UE. The BS 101 may be a cellular NW ( Figure 1 As a general rule, the techniques described herein can be used in various types of communication systems, such as also for peer-to-peer communication, etc. However, for simplicity, the various techniques will be described below in the context of a communication system implemented by a BS and a UE of a cellular NW.

[0032] Communication on wireless link 114 may employ time division duplex (TDD) and / or frequency division duplex (FDD). With TDD, communication in the DL and UL occurs at different times using the same frequency. With FDD, communication in the DL and UL occurs at the same time using different frequencies.

[0033] Figure 2 Details regarding BS 101 are shown. BS 101 includes control circuitry implemented by processor 1011 and non-volatile memory 1015. Processor 1011 can load program code stored in memory 1015. Processor 1011 can then execute the program code. Execution of the program code causes the processor to perform the techniques described herein, such as: communicating over a wireless link using MIMO; performing beam scanning; transmitting signals such as RSs; scheduling signals for transmission over a wireless link; participating in initial access by UE 102; monitoring UE 102 accessing a RO; participating in establishment of MIMO operation; participating in data transmission in accordance with MIMO operation, etc.

[0034] Figure 2 Details regarding UE 102 are also shown. UE 102 includes control circuitry implemented by processor 1021 and non-volatile memory 1025. Processor 1021 can load program code stored in memory 1025. The processor can execute the program code. Execution of the program code causes the processor to perform the techniques described herein, such as: communicating over a wireless link using MIMO and / or FDD; performing beam scanning; participating in initial access of UE 102 to the cellular NW of BS 101; monitoring RSs (i.e., attempting to receive RSs); selecting one or more ROs; participating in establishment of MIMO operation; participating in data transmission in accordance with MIMO operation, etc.

[0035] Figure 2 Also shown are details regarding the communication between BS 101 and UE 102 over wireless link 114. BS 101 includes an interface 1012 that can access and control multiple antennas 1014. Likewise, UE 102 includes an interface 1022 that can access and control multiple antennas 1024.

[0036] Although Figure 2 The scenario shows antenna 1014 coupled to BS 101, but as a general rule, a transmit-receive point (TRP) spaced apart from the BS may be employed.

[0037] The interfaces 1012, 1022 may each include one or more TX chains and one or more receiver chains. For example, such RX chains may include low noise amplifiers, analog-to-digital converters, mixers, etc. Analog and / or digital beamforming may be possible.

[0038] Thus, phase-coherent transmission and / or reception (communication) may be achieved across the multiple antennas 1014, 1024. Thus, the BS 101 and the UE 102 implement a MIMO communication system.

[0039] As a general rule, a receiver of a MIMO communication system receives a signal y obtained from multiplying an input signal by a transmission matrix H. Figure 2 Includes the component h for the transmission matrix H 11 and h 13 Two example labels.

[0040] The transmission matrix H defines the channel impulse response of wireless link 114. The rank of the transmission matrix corresponds to the number of linearly independent rows or columns and, as such, indicates how many independent data streams can be used simultaneously; this is sometimes referred to as the number of layers. The rank can be set in different MIMO transmission modes. For MIMO transmission modes, the amplitude and / or phase (antenna weights) of each of antennas 1014, 1024 are appropriately controlled by interfaces 1012, 1022.

[0041] For example, diversity MIMO transmission mode relies on redundantly transmitting the same data using multiple TX antennas. Consequently, multiple data streams carry the same data. Therefore, the signal-to-noise ratio can be increased. Different encodings (e.g., Alamouti encoding) can be used to generate redundant signals.

[0042] Another MIMO transmission mode is spatial multiplexing. Spatial multiplexing allows for increased data rates: the data is divided into different data streams, and these different data streams can be transmitted simultaneously over the wireless link 114.

[0043] Diversity MIMO transmission mode and spatial multiplexing multi-antenna transmission mode can be described as using multiple beams that define spatial data streams. Therefore, these modes are also referred to as multi-beam operation. By using beams, the direction of the wavefront of the signal transmitted by the transmitter of the communication system is controlled. By phase-coherently adding the individual signals originating from each antenna 1014, 1024, the energy is focused in the respective direction. In this way, the spatial data streams can be steered. The spatial data streams transmitted on the multiple beams can be independent, resulting in spatial multiplexing multi-antenna transmission; or correlated with each other (e.g., redundant), resulting in diversity MIMO transmission.

[0044] As a general rule, RX beams may be employed instead of or in addition to such TX beams.

[0045] The concept of beam can be used in so-called beam scanning. Figure 3 and Figure 4 Explain the details about beam scanning.

[0046] Figure 3DL TX beams 301-309 used by BS 101 are shown. In some examples, BS 101 may employ beam scanning 300. Here, BS 101 activates beams 301-309 on different resources (e.g., different time-frequency resources, and / or using orthogonal codes) so that UE 102 can monitor the individual signals transmitted on DL TX beams 301-309. As a general rule, monitoring the signals may involve attempting to receive the signals. This may include blind decoding, etc. UE 102 may then select the best DL TX beam 301-309 (e.g., based on RX properties of the received signal, such as amplitude and / or phase and / or angle of arrival, etc.) and provide a corresponding indication to BS 101. As a general rule, the best DL TX beam 301-309 may be the strongest beam. In addition, other quality metrics, such as signal-to-noise ratio, may be considered. Subsequent data may then be transmitted on the selected DL TX beam 301-309. In particular, such beam management can be facilitated by using RSs (ie, signals with well-defined transmit characteristics such as sequence, amplitude, phase, and / or precoding, etc.) RSs are sometimes also referred to as pilot signals.

[0047] It is possible to coordinate such DL TX beam scanning 300 implemented by the BS 101 with the DL RX beam scanning 310 implemented by the UE 102 . Figure 4 DL RX beam scanning 310 is shown in . DL RX beam scanning 310 includes multiple DL RX beams 311 *- 313 * (for simplicity, RX beams are denoted by “*” herein). DL RX beam scanning 310 does not necessarily have to be coordinated with DL TX beam scanning 300 .

[0048] Figure 5 Aspects regarding diversity MIMO transmission mode are schematically illustrated. Here, multiple transmit antennas are used to define multiple spatial data streams carrying the same data; this can also be viewed as the coherent combination of multiple DL TX beams 301-303 with optimized phase shifts.

[0049] Figure 6 A cellular NW 100 is schematically shown. Figure 6 The example shows a cellular NW 100 according to the 3GPP NR / 5G architecture. The details of the 3GPP 5G architecture are described in 3GPP TS 23.501, version 15.3.0 (2017-09). Figure 1The following and other parts of the description illustrate the technology in the 3GPP 5G framework of cellular NW, but similar techniques can be easily applied to other communication protocols. Examples include 3GPP LTE 4G (for example, in the MTC or NB-IOT framework) and even non-cellular wireless systems (for example, IEEE Wi-Fi technology).

[0050] exist Figure 1 In the scenario of , UE 102 may be connected to cellular NW 100 via a data connection. For example, UE 102 may be one of the following: a cellular phone; a smart phone; an IOT device; an MTC device; a sensor; an actuator, etc.

[0051] UE 102 may be connected to the core NW (CN) 115 of the cellular NW 100 via a RAN 111, which is typically formed by one or more BSs 101 (for simplicity, the RAN 111 is not shown in FIG. Figure 1 Only a single BS 101 is shown in the figure. A wireless link 114 is established between the RAN 111 (specifically, one or more BSs 112 of the RAN 111) and the UE 102.

[0052] Radio link 114 implements a time-frequency resource grid. Typically, OFDM is used: here, a carrier comprises a plurality of subcarriers. The subcarriers (in the frequency domain) and the symbols (in the time domain) then define the time-frequency resource elements of the time-frequency resource grid. Thus, a protocol time base is defined, for example, by the duration of frames and subframes comprising a plurality of symbols, and the start and stop positions of the frames and subframes. Different time-frequency resource elements can be assigned to different logical channels, or RSs, of radio link 114. Examples include: physical DL shared channel (PDSCH); physical DL control channel (PDCCH); physical UL shared channel (PUSCH); physical UL control channel (PUCCH); channels used for random access, etc. For FDD, PUCCH and PUSCH are communicated on radio link 114 in the UL frequency band 601, and PDCCH and PDSCH are in the DL frequency band 602 (hence the designations "UL band" and "DL band").

[0053] CN 115 includes a user plane (UP) 191 and a control plane (CP) 192. Application data, such as data services, are typically routed via UP 191. For this purpose, a UP function (UPF) 121 is provided. UPF 121 may implement a router function. Application data may pass through one or more UPFs 121. Figure 1In the scenario of UE 102, UPF 121 acts as a gateway to a data NW (DN) 180 (e.g., the Internet or a local NW). Application data can be transmitted between UE 102 and one or more servers 181 of data NW 180. Server 181 can execute an application that provides services associated with the application data.

[0054] The cellular NW 100 also includes a mobility control node, here implemented by an access and mobility management function (AMF) 131. The cellular NW 100 also includes a session control node, here implemented by a session management function (SMF) 132. The cellular NW 100 also includes a policy control function (PCF) 133; an NW slice selection function (NSSF) 135; an authentication server function (AUSF) 136; and a unified data management (UDM) 137.

[0055] Figure 6 Also shown are the protocol reference points N1-N22 between these nodes.

[0056] The AMF 131 provides one or more of the following functions: connection management (sometimes also referred to as registration management); NAS termination for communications between the CN 115 and the UE 102; connection management; reachability management; mobility management; connection authentication; and connection authorization. After the UE registers with the NW, the AMF 131 creates a UE context 459 and maintains the UE context for at least as long as the UE 102 is registered with the cellular NW 100. The UE context 459 may include one or more identities (UEIDs) of the UE 102, such as temporary identities.

[0057] The SMF 132 supports the data connection 189. If the corresponding UE 102 operates in connected mode, the data connection 189 is established by the SMF 132. The data connection 189 is established on the radio link 114. The radio link 114 may belong to the underlying physical medium, and the data connection 189 may include a set of logical channels, scheduling rules, etc. The data connection 189 may include one or more data flows or bearers, such as dedicated data flows / bearers or default data flows / bearers. The state of the data connection is also defined at the RRC layer, such as typically layer 3 of the OSI model. The SMF 132 provides one or more of the following functions: session management, including session establishment, modification, and release, including data flow / bearer establishment of UP data flows / bearers between the RAN 111 and the UPF 121; selection and control of UPFs; configuration of traffic diversion, etc.

[0058] Figure 7Various aspects of different connection modes 401-402 are shown, in which the UE 102 can operate according to various examples. When operating in the connection mode 401, a data connection 189 is established between the UE 102 and the cellular NW 100. Application data can be transmitted to and from the UE 102. Transitioning to the connection mode 401 is called initial access.

[0059] When operating the UE 102 in idle connected mode 402, the data connection 189 is released. It is possible for the AMF 131 to retain the UE context 459. The UE 102 may use a discontinuous reception (DRX) cycle that alternately switches the interface 1022 between an inactive state and an active state. When operating in the inactive state, the interface 1022 may not be able to receive any signals. For example, an amplifier or an analog-to-digital converter or part of the digital front end may be turned off. On the other hand, when operating in the active state, the interface 1022 is able to receive RX signals, such as paging signals.

[0060] In order to switch from idle connection mode 402 to connected connection mode 401, an RA procedure may be performed. The RA procedure includes transmitting an RA preamble at the RO. Details about the RO are given in Figure 8 Shown in.

[0061] Figure 8 Aspects regarding synchronization signal blocks (SSBs) are schematically shown. Figure 8 BS 101 is shown transmitting multiple SSBs 411 on different resources (eg, time-frequency and / or code resources).

[0062] SSB 411 can facilitate cell search for UE 102 during initial access. SSB 411 can include, for example, a primary synchronization signal (SS) and a secondary SS. The primary and secondary SSs implement RS. SSB 411 can include a physical broadcast channel (PBCH). The PBCH carries master information blocks and uses a specific modulation (typically quadrature phase shift keying) for reliable reception.

[0063] Within the SSB 411, the primary and secondary SSs are used for the UE 102 to lock onto the correct frequency and time. There is also some identification of the transmitting BS 101 encoded into the combined SS. When in sync, the UE 102 can extract information about the associated RA channel allocation from the PBCH.

[0064] The SSB 411 may be transmitted by the BS 101 repeatedly or periodically, for example, on predetermined time-frequency resources of a time-frequency resource grid.

[0065] A burst 410 of SSBs 411 may be transmitted using a beam sweep 360 comprising DL TX beams 361-364. Thus, spatial coverage may be increased. Typically, a burst may have a duration of, for example, up to 5 ms. The period of a transmission burst may be 20 ms to 160 ms.

[0066] The SSBs 411 transmitted on different DL TX beams 361-364 may have different SSB time indices. Therefore, different SSBs 411 (ie, having different SSB time indices) are associated with different ROs 415-418.

[0067] Figure 8 Also shown are aspects regarding RO 415-418. Figure 8 As shown, there is an association 419 between SSB 411 of burst 410 having different SSB time indices and multiple ROs 415-418. Different ROs 415-418 are arranged at different times, frequencies, or use different (eg, orthogonal) codes for RA preambles.

[0068] The association 419 between the SSB 411 and the ROs 415-418 is typically achieved by predetermining a number of SSB time indices for each RO. This number can be greater than the number of SSBs corresponding to a single RO. This number can also be less than the number of SSBs corresponding to multiple ROs. The SSBs are then associated with the ROs first in the frequency domain (e.g., in ascending order of time indices); second, in the time domain within a slot; and third, in the time domain between RA slots.

[0069] According to the reference implementation, by selecting the appropriate RO 415-418, the UE 102 can indicate which DL TX beam 361-364 is the best. This enables the establishment of the appropriate beam pair during initial access.

[0070] The general architecture of beam management during initial access is described above. This framework of beam management during initial access can be enhanced by the inventive concepts related to multi-RO access. These examples are described below.

[0071] exist Figure 8In the example described herein, UE 102 accesses two ROs 415, 418 to establish multiple beam pairs. As a general rule, it is possible for UE 102 to access two or more ROs in the various examples described herein. Multi-beam operation can then be established on wireless link 114 using the BS beams associated with the selected ROs. For DL ​​transmissions, this would include DL TX beams 361, 364; and for UL transmissions, this would include UL RX beams 351* and 354*. UL RX beam 351* corresponds to DL TX beam 361 because it has similar spatial characteristics and / or assumed beam correspondence. For example, the same antenna weights can be used for BS beams 351* and 361.

[0072] Figure 8 Also shown are aspects of beam management at UE 102 for UL TX beams used by UE 102 to access multiple ROs. There are various options available for enabling access to multiple ROs at UE 102. Two of these options are Figure 8 : In the first option (Option I), it is possible for UE 102 to access ROs 415 and 418 using the same UL TX beam (here, UL TX beam 381). In the second option (Option II), it is possible for UE 102 to access ROs 415 and 418 using different UL TX beams (here, UL TX beams 381 and 384). For some ROs, different UL TX beams may be used, while for other ROs, the same UL TX beam may be used.

[0073] In Option 1, BS 101 can coherently combine signals received using multiple UL RX beams with optimized phase shifts and / or amplitudes, thereby achieving higher multi-antenna gain for rank-1 transmission. In Option 1, UL TX beam 381, used to access RO 415 and RO 418, is determined based on DL TX beam 361. For example, UE 102 can determine the angle of arrival of SSB 411 transmitted using DL TX beam 361, for example, based on the reception properties of the corresponding RSs included in SSB 411 (e.g., the amplitude and / or phase at each antenna 1024 of UE 102). UE 102 can then determine appropriate antenna weights to transmit UL signals with the same spatial characteristics, i.e., to reverse the direction of the spatial data streams. This is helpful under the assumption of channel reciprocity.

[0074] On the other hand, UL TX beams 381 and 384 used to access RO 415 and RO 418, respectively, in Option II are determined based on DL TX beams 361 and 364, respectively. DL TX beam 361 is used to transmit SSB 411 associated with RO 415 accessed using UL TX beam 381. DL TX beam 364 is used to transmit SSB 411 associated with RO 418 accessed using UL TX beam 384.

[0075] Thus, according to Option 1, a spatial diversity multi-antenna mode may be configured in which a single DL RX beam (i.e., DL RX beam 381* corresponding to UL TX beam 381) is used at UE 102 (see Figure 5 BS 101 may use DL TX beams 361 and 364 to generate two correlated spatial data streams. In the corresponding device parameters for multi-beam operation, UE 102 may indicate whether it prefers a diversity multi-antenna mode, and / or whether it has coherent decoding / coding capabilities, and / or whether the diversity multi-antenna mode is used for UL transmission and / or DL ​​transmission.

[0076] According to Option II, spatial diversity or spatial multiplexing multi-antenna operation can be used, relying on multiple DL RX beams 381* and 384*. Multiple beam pairs between UE 102 and BS 101 can already be established during initial access; these beam pairs can be used after initial access when transmitting payload data. The UE can indicate in various device parameters for multi-beam operation whether it prefers spatial multiplexing or diversity multi-antenna mode, and / or whether to have coherent or non-coherent operation, and / or whether each multi-antenna mode is used for UL transmission and / or DL ​​transmission.

[0077] Figure 9 It is a signaling diagram of the communication between BS 101 and UE 102. Specifically, Figure 9 Shown according to Figure 8

[0066] Regarding aspects of beam management during initial access. This is an illustrative example; other signal flows are possible.

[0078] Figure 9Aspects of transmitting a configuration regarding access to multiple ROs are shown. This configuration can be transmitted from the communication NW 100 to the UE 102 (see NW configuration 6011) and / or from the UE 102 to the communication NW 100 (see device configuration at 6506). Multi-RO access is based on such a configuration. For example, such a configuration can impose certain constraints on multi-RO access, for example, in terms of the number of ROs accessed and / or in terms of the UL TX beams used by the UE to access the ROs. Multi-beam operation can be set based on this configuration. Specifically, by transmitting this configuration, the communication NW 100 can appropriately configure the multi-beam operation. For example, the UE 102 can indicate that it will use the same UL TX beam to access multiple ROs; the cellular NW can then configure a diversity multi-antenna mode using multiple spatial streams dependent on a single UE beam. The rank of the multi-beam operation can be set based on the number of UL TX beams indicated for use by the UE to access the ROs.

[0079] Initially, at 6501, UE 102 receives a network configuration 6011 transmitted by BS 101 of cellular network 100. Network configuration 6011 indicates network support for UE 102 to access multiple ROs 415-418. Thus, access to more than a single RO 415-418 may be conditional on the respective network support indicated by network configuration 6011. If cellular NW 100 does not support multiple RO access, UE 102 may only access a single RO 415-418 (e.g., except for an escalation policy upon access failure on a given RO 415-418).

[0080] There are various options for providing the NW configuration to the UE 102. For example, when the UE 102 is operating in connected mode 401, the NW configuration 6011 may be received on the PDCCH, or as a control message on the PDSCH (e.g., as an RRC layer 3 control message). The NW configuration 6011 may also be included in a system information block broadcast by the BS 101. In yet another option, the NW configuration 6011 may be received as early data 6012 during the RA procedure, for example, at 6507 (as will be explained in detail below).

[0081] NW configuration 6011 indicates the maximum possible number of ROs 415-418 that can be accessed by UE 102. For example, NW configuration 6011 may indicate that UE 102 is allowed to access four or fewer ROs 415-418. UE 102 may then determine the appropriate number of ROs 415-418 to access based on, for example, its multi-beam operation configuration, reception properties of RSs in SSB 411 transmitted using multiple beams 361-364, and the maximum number of ROs.

[0082] NW configuration 6011 may indicate the minimum number of UL TX beams to be used when UE 102 accesses ROs 415-418. For example, NW configuration 6011 may indicate the number of UL TX beams expressed as the number of ROs 415-418 to be used. For example, NW configuration 6011 may indicate that UE 102 will use M UL TX beams when accessing NR ROs 415-418. M may be equal to or less than N. M may be a function of N, i.e., M(N).

[0083] NW configuration 6011 may also indicate a set number of UL TX beams to be used when UE 102 accesses ROs 415-418. That is, NW may set the number of UL TX beams to a certain value. UE 102 may not have any option regarding the number of UL TX beams to be used when accessing ROs 415-418.

[0084] Before initiating the RA procedure 600, the UE 102 monitors the SSB 411 transmitted by the BS 101. Using beam scanning, such as beam scanning 360 (see Figure 8 ) to achieve the transmission. The SSB 411 transmitted at 6502 thus forms a burst 410. Based on the SSB 411, the UE 102 can synchronize with the BS 101.

[0085] The UE 102 may then monitor the paging indication and the paging message (paging signal) 6000. Blind decoding of the PDCCH for receiving the paging indication may be implemented.

[0086] When the paging signal 6000 is received at 6503, the RA process 600 is used in this example to trigger initial access.

[0087] As a general rule, there are other triggering criteria for initial access, such as UE power up or UE originated UL data.As such, the paging signal 6000 is optional.

[0088] At 6504, based on the SSB 411, the UE 102 transmits a RA preamble to the BS 101 in a corresponding RAmsg1 6001. As a result, the UE 102 accesses the RO 415. The RAmsg1 6001 may represent the temporary identity (UE-ID) of the UE 102.

[0089] In response to transmitting RAmsg1 6001, UE 102 receives an RA response message RAmsg2 6002 at 6505. RAmsg2 includes a new temporary identity for UE 102, timing adjustment information, and an UL scheduling grant for time-frequency resources. The UL scheduling grant may be addressed to the RA Radio NW Temporary Identity (RA-RNTI) of UE 102. Using these UL resources indicated by the UL scheduling grant included in RAmsg2 6002, UE 102 transmits an RRC connection request RAmsg3 6003 at 6506. In response to RRC connection request 6003, UE 102 receives a contention resolution message RAmsg4 6004 at 6507 to ensure that the correct UE is addressed. This completes or terminates the establishment of data connection 189. UE 102 then transitions to operating in connected mode 401.

[0090] Early Data (ED) 6012 (e.g., application data or RRC control data) may be included in RAmsg3 6003 and / or RAmsg4 6004. Thus, typically, UL ED and / or DL ​​ED may be included in the RA procedure. For example, ED 6012 may be piggybacked onto RAmsg3 6003 and / or RAmsg4 6004 in the NAS field. ED 6012 may also be included in RAmsg2 or even in RAmsg1 (e.g., by using preamble segmentation). For a two-step RA procedure, ED may be included in RAmsgA and RAmsgB (corresponding to RAmsg1 and RAmsg3, and RAmsg2 and RAmsg4, respectively).

[0091] At 6508, UE 102 transmits another RA preamble 6001, thereby accessing RO 418. It will be appreciated that ROs 415 and 418 can be accessed based on the same measurement result of burst 410 of SSB 411 transmitted by BS 101 at 6502 (in other examples, other bursts 410 of SSB 411 can be monitored). In addition, RO 418 is accessed even if access to RO 415 has been successful, that is, in the case of RO access failure, multiple RO access is not due to an upgrade strategy.

[0092] UL ED 6012 may be used to provide device configuration associated with UE 102 accessing multiple ROs 415-418 to cellular NW 100. UE 102 may access multiple ROs 415-418 according to the device configuration, and BS 101 may monitor access of ROs 415-418 according to the device configuration.

[0093] For example, the device configuration may indicate that the UE accesses multiple ROs. For example, the device configuration may indicate the RO 418 to be accessed later, that is, the RO to be accessed. For example, the device configuration may indicate whether the same or different UL TX beams are used to access multiple ROs 415-418 (see Figure 8 , where the two options I and II are explained as to whether the same UL TX beam 381 is used or different UL TX beams 381, 384 are used. It is possible that the device configuration indicates the number of UL TX beams used by the UE 102 to access the multiple ROs 415-418. Alternatively or additionally, the device configuration may indicate the number of ROs 415-418 accessed by the UE 102.

[0094] Although Figure 9 An example is shown in which the device configuration is transmitted in the RA process 600 associated with the RO 415, but in other examples, the device configuration may be provided to the cellular NW 100 in other manners (eg, after transitioning to the connected connection mode 401).

[0095] The device configuration may be determined based on the NW configuration 6011 received at 6501. For example, the number of ROs 415-418 accessed by UE 102 may be selected to be equal to or less than the maximum number of ROs to be accessed indicated by NW configuration 6011.

[0096] As an alternative or in addition to transmitting the device configuration for the access of multiple ROs 415, 418, the ED 6012 may also be used to provide device parameters for multi-beam operation to the cellular NW 100. The multi-beam operation may then be subsequently established based on the device parameters. The device parameters may represent one or more UE capability limitations related to the multi-beam operation. For example, the UE capability limitation may specify that the UE 102 cannot coherently receive and / or transmit on multiple beams. The UE capability limitation may specify that the UE 102 cannot perform bidirectional communication on some beams, for example, single UL, single DL, bidirectional. For example, the device parameters may represent a preferred multi-beam operation mode, such as diversity or spatial multiplexing or beam scanning. It is possible that the device parameters include analog and / or digital front-end capabilities of the interface 1022 of the UE 102, for example, whether the UE 102 supports digital beamforming, the number of receive chains, the number of transmit chains, etc. Alternatively or additionally, the device parameters may include the parameters used by the BS 101 to transmit the datagram associated with the selected RO 415, 418 (see Figure 8) beam priorities of DL TX beams 361 and 364 of SSB 411 associated with DL TX beam 364. The beam priority may be set, for example, based on the reception quality of each RS included in SSB 411. For example, the reception quality may be determined based on the reception amplitude. For example, if the RS included in SSB 411 transmitted using DL TX beam 361 is received at a higher signal-to-noise ratio level than the RS included in SSB 411 transmitted using DL TX beam 364, the beam priority may indicate that DL TX beam 361 has a higher priority than DL TX beam 364. This may be taken into account when establishing, for example, spatial multiplexing multi-antenna operation, so that data is routed at a lower data rate via the spatial data stream associated with DL TX beam 364 than the spatial data stream associated with DL TX beam 361. The device parameter may indicate whether UE 102 uses multiple beams to access multiple ROs. The device parameter may indicate the number of beams used by UE 102 to access multiple ROs.

[0097] Although Figure 9 An example of transmitting device parameters in the RA process 600 associated with the RO 415 is shown, but in other examples, the device parameters may be provided to the cellular NW 100 in other manners (eg, after transitioning to the connected connection mode 401).

[0098] For example, the beam priority as described above may also be implicitly indicated to the cellular NW 100 based on the order in which the ROs 415-418 are accessed. Figure 8 and Figure 9 In the case of RO 415, RO 415 is accessed before RO 418. This means that DL TX beam 361 has a higher priority than DL TX beam 364 because DL TX beam 361 is used to transmit SSB 411 associated with RO 415, while DL TX beam 364 is used to transmit SSB 411 associated with RO 418.

[0099] exist Figure 9 In the example of FIG4 , a DLED 6012 can be used to indicate at 6508 which RA preamble 6001 the UE 102 will use to access the RO 418. Thus, the other RA preamble 6001 transmitted at 6508 can be contention-free. The contention-free RA preamble can be provided as part of the DLED 6012. In contrast, the RA preamble 6001 transmitted at 6504 when accessing the RO 415 can be contention-based.

[0100] As a general rule, multiple ROs 415-418 will likely be accessed using (i) only contention-based random access preambles, (ii) only contention-free RA preambles, or (iii) a mix of contention-based and contention-free RA preambles, e.g. Figure 9 Details of (i)-(iii) are shown in Table 1.

[0101]

[0102] Tag 1: Option to select RA preamble when accessing multiple ROs

[0103] Although Figure 9 An example of a 4-step RA process 600 is shown, but similar techniques can be readily used for a 2-step RA process.

[0104] Figure 10 is a flow chart of a method according to various examples. Figure 10 The method may be performed by a UE that can be connected to a cellular NW. For example, Figure 10 The method may be performed by UE 102. More specifically, when the program code is loaded from memory 1025, the processor 1021 of UE 102 may execute Figure 10 method.

[0105] Optional box in Figure 10 Indicated by dotted line.

[0106] In block 3001, the UE receives an NW configuration from a cellular NW. The NW configuration indicates NW support for the UE to access multiple ROs in order to configure multi-beam operation. Specifically, the NW configuration may be received from a BS of a cell of the cellular NW, thereby indicating its support for the UE to access multiple ROs. Alternatively or additionally, the NW configuration may also be received from an anchor node associated with the UE (e.g., such as AMF 131 (see Figure 6 )'s mobility control node) receives the NW configuration.

[0107] Next, at block 3002, the UE checks whether it is to perform initial access. If so, the method proceeds to block 3003.

[0108] In block 3003, the UE monitors SSBs. The UE receives one or more SSBs that may have different time indices. Different SSBs within a burst are transmitted using different DL TX beams. The SSBs include DL RSs. Each SSB is associated with a corresponding RO.

[0109] Then, at block 3004, the UE may select at least two of the ROs. The selected at least two ROs are associated with at least two DL RSs included in the received SSB, which are selected by the UE based on the monitoring at block 3003. For example, the N strongest DL RSs (i.e., received with the highest signal-to-noise ratio) may be selected.

[0110] At block 3005, access is performed on the selected at least two ROs. That is, RA preambles are transmitted at the selected at least two ROs. Contention-free and / or contention-based RA preambles may be used.

[0111] Optionally, at block 3006, the accessed device configurations and / or device parameters for subsequent multi-beam operation of the at least two ROs may be transmitted to the cellular NW. For example, this may be accomplished using an ED piggybacked onto RAmsg3 or RAmsgA.

[0112] Note that block 3006 may be performed before access to multiple ROs is completed at block 3005 .

[0113] At block 3007, multi-beam operation of the wireless link between the UE and the cellular NW is established. At block 3005, multi-beam operation is established based on access to multiple ROs. For example, multiple DL TX beams may be used for multi-beam operation, where the multiple DL TX beams are associated with the ROs accessed at block 3005. More specifically, the multiple DL TX beams used for the multi-beam operation established at block 3007 may be used to transmit SSBs associated with the at least two ROs selected at block 3004. These beams may also be refined, for example, using sub-beams.

[0114] Multi-beam operation can be used after the RA process is completed.

[0115] For example, based on access to multiple ROs at block 3005, a selection may be made between a diversity multi-antenna mode and a spatial multiplexing multi-antenna mode of operation.

[0116] At block 3008, a wireless link may be established between the UE and the cellular NW, for example, by completing an RA procedure triggered by access to one of the ROs accessed at block 3005. The RA procedure may be completed using the multi-beam operation established at block 3007. Further, subsequent communications over the established wireless link may then be achieved using the multi-beam operation established at block 3007.

[0117] The order of blocks 3001-3008 is merely an example. For example, the NW configuration may be received as part of a RA procedure triggered by the RO access of block 3005 (so that block 3001 may be performed after block 3005).

[0118] Figure 11 is a flow chart of a method according to various examples. Figure 11 The method can be performed by an access node of a communication NW. For example, Figure 11 The method may be performed by a BS of a cellular NW (eg, BS 101 of cellular NW 100). More specifically, when the program code is loaded from the memory 1015, Figure 11 The method may be executed by the processor 1011 of the BS 101 .

[0119] Figure 11 Methods and Figure 10 The methods are related to each other. Figure 10 and Figure 11 When using the method, BS 101 and UE 102 interact.

[0120] exist Figure 11 Optional boxes are shown with dotted lines.

[0121] The method begins at block 3101. Here, a NW configuration is transmitted to a UE communicating with an access node. Block 3101 is associated with block 3001. The NW configuration may indicate whether the access node supports the UE accessing multiple ROs to establish multi-beam operation during initial access. Block 3101 is associated with block 3001.

[0122] In block 3103, multiple SSBs are transmitted using beams. In particular, beam scanning can be used to transmit bursts of SSBs. The SSBs include RSs. The UE can perform channel sounding based on the RSs. Each SSB is associated with a corresponding RO. Block 3103 is interrelated with block 3003.

[0123] In block 3105, the RO is monitored. That is, the access node attempts to receive RA messages on the RO. For example, the BS of the cellular NW may attempt to receive RAmsg1 or RAmsgA on the RO. Block 3105 is associated with block 3005.

[0124] By receiving RAmsg1 or RAmsgA on multiple ROs, the BS can determine that the same UE has accessed two RAs.

[0125] In some examples, based on the reception properties (ie, amplitude and / or phase) of the RS associated with the RA message, it may be possible for the BS to acquire channel state information. Subsequent multi-beam operations may be configured based on such channel sounding.

[0126] At block 3106 , device configuration for multi-RO access of the UE and / or device parameters for subsequent multi-beam operation may be received. Block 3106 is interrelated with block 3006 .

[0127] Then, at block 3107, multi-beam operation is established. For example, a diversity multi-antenna mode or a spatial multiplexing multi-antenna operation mode may be activated. At block 3105, the beams used for multi-beam operation may be determined based on the RO to which the UE is accessed. For example, each RO may be associated with a corresponding DL TX beam that has been used to transmit the corresponding SSB. These DL TX beams may then be used for multi-beam operation or further refined. For example, if the multi-beam operation involves UL transmission, UL RX beams corresponding to these DL TX beams may be used, for example, using the same antenna weights and / or having corresponding spatial characteristics.

[0128] As part of block 3105, the multi-beam operation established at block 3107 may be used to complete RA on the additional accessed RO. The multi-beam operation may also be used to transmit data on the wireless link subsequently established at block 3108. Block 3107 corresponds to block 3007. Block 3108 corresponds to block 3008.

[0129] In summary, the above techniques have been described for facilitating multi-beam operation, such as using diversity multi-antenna and / or spatial multiplexing multi-antenna operation. Techniques have been described for facilitating UE access to multiple ROs. A cellular NW can indicate whether it supports such multi-RO access. For example, such NW configuration can be signaled as part of broadcast system information.

[0130] The UE may access a first RO and, for example, report its intention to access one or more additional ROs using an ED transmitted as part of the RA procedure associated with access to the first RO. As a general rule, the UE may provide the cellular NW with device configuration for multi-RO access and / or device parameters for multi-beam operation, such as ED. The UE may indicate the intended number of ROs to access and / or the number of UL TX beams to use for this purpose. For example, the UE may use the same UL TX beam to access two or more of the multiple ROs.

[0131] The BS may allocate an RA preamble for one or more additional ROs as part of a DL ED (transmitted to the UE as part of the RA procedure associated with access of the first random access opportunity). Contention-free access is then possible in at least one additional RA procedure associated with the one or more additional ROs.

[0132] By such a technique, low delay of spatial diversity and / or multiplexing is already possible during initial access. The overall control signaling overhead can be limited.

[0133] Although the invention has been shown and described with respect to certain preferred embodiments, equivalents and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such equivalents and modifications.

[0134] For illustration purposes, various techniques using a 4-step RA process have been described above. Similar techniques can also be applied to a 2-step RA process. As a general rule, a 2-step RA process relies on a combination of RAmsg1 and RAmsg3 through RAmsgA, and a combination of RAmsg2 and RAmsg4 through RAmsgB.

[0135] For further explanation, various examples have been described where UL ED is piggybacked onto RAmsg3. At least a portion of this information may be provided via RAmsg1 (eg, using preamble partitioning).

[0136] For further explanation, various examples in which the DL RS is implemented by SSB have been described. In other examples, other kinds and types of DL RSs may be used.

[0137] For further explanation, various examples have been described in which the UE selects the strongest DL TX beam. In other examples, other and / or additional quality metrics may be considered, such as signal-to-noise ratio.

[0138] For further explanation, various scenarios are described above where a single BS receives RAmsg1 or RAmsgA on multiple ROs accessed by a UE and monitored by the single BS. Similar techniques can be applied to scenarios where multiple ROs associated with a burst of SSBs and accessed by a UE are monitored by different BSs (e.g., via TRPs).

Claims

1. A method of operating a wireless communication device (102), the wireless communication device being configured to connect to a communication network (100), the method comprising: - monitoring a plurality of downlink reference signals (411) transmitted by at least one access node of the communication network (100) using a plurality of downlink transmission beams (361-364), each downlink reference signal of the plurality of downlink reference signals (411) being associated with a respective at least one random access opportunity of a plurality of random access opportunities (415-418), - accessing at least two random access opportunities (415, 418) of the plurality of random access opportunities (415-418), the at least two random access opportunities (415, 418) being associated with at least two downlink reference signals (411) selected from the plurality of downlink reference signals (411) based on the monitoring, and - establishing a multi-beam operation between the wireless communication device (102) and the communication network (100), wherein the multi-beam operation is established based on at least two downlink transmission beams (361, 364) for transmitting the selected at least two downlink reference signals (411).

2. The method according to claim 1, in, The accessing of the at least two random access opportunities (415, 418) is based on at least one configuration (6011) communicated between the wireless communication device (102) and the communication network (100).

3. The method according to claim 1 or 2, further comprising: - receiving a network configuration (6011) from said communication network (100), The at least two random access opportunities (415, 418) are accessed according to the network configuration (6011).

4. The method according to claim 3, in, The network configuration (6011) indicates a maximum number of random access opportunities (415-418) to be accessed by the wireless communication device (102).

5. The method according to claim 3, in, The network configuration (6011) indicates whether the wireless communication device is to use the same or different uplink transmission beams (381, 384) for the access of the at least two random access opportunities.

6. The method according to claim 3, in, The network configuration (6011) indicates a minimum number of uplink transmission beams (381, 384) to be used by the wireless communication device (102) for the access of the at least two random access opportunities, The minimum number of uplink transmission beams (381, 384) optionally depends on the number of the at least two random access opportunities.

7. The method according to claim 3, in, The network configuration (6011) indicates network support for accessing multiple random access opportunities (415-418).

8. The method according to claim 1 or 2, further comprising: - transmitting the accessed device configuration of the at least two random access occasions to the communication network (100), The accessing of the at least two random access opportunities is configured according to the device.

9. The method according to claim 8, in, The device configuration indicates whether the same or different uplink transmission beams (381, 384) are used for the access of the at least two random access opportunities.

10. The method according to claim 8, in, The device configuration indicates a number of random access opportunities (415-418) accessed by the wireless communication device (102).

11. The method according to claim 8, in, The device configuration is transmitted in a random access procedure (600) associated with at least one of the at least two random access opportunities (415, 418).

12. The method according to claim 8, in, The device configuration indicates the number of uplink transmission beams (381, 384) used for the access of the at least two random access opportunities.

13. The method according to claim 8, further comprising: - receiving a network configuration (6011) from said communication network (100), The device configuration is determined based on the network configuration.

14. The method according to claim 1 or 2, further comprising: - transmitting device parameters of said multi-beam operation to said communication network (100), Wherein, the multi-beam operation is established according to the device parameters.

15. The method according to claim 14, in, The device parameters include a mode of multi-beam operation selected from the group consisting of: diversity; and spatial multiplexing.

16. The method according to claim 14, in, The device parameters include front-end capabilities of a wireless interface of the wireless communication device (102).

17. The method according to claim 14, in, The device parameters include beam priorities of the at least two downlink transmission beams (361, 364), wherein the beam priorities are dependent on reception properties of the at least two downlink reference signals (411).

18. The method according to claim 14, in, The device parameters are transmitted in a random access procedure (600) associated with the access of the at least two random access opportunities (415, 418).

19. The method according to claim 1 or 2, in, The at least two random access opportunities are accessed using the same uplink transmission beam (381, 384).

20. The method according to claim 1 or 2, in, The at least two random access opportunities (415, 418) are accessed in an order determined according to a beam priority order of the at least two downlink transmission beams (361, 364), the beam priority order being dependent on reception properties of the at least two downlink reference signals (411), The multi-beam operation is established according to the beam priority.

21. The method according to claim 1 or 2, further comprising: - determining an uplink transmission beam (381) based on a downlink transmission beam (361) of the plurality of downlink transmission beams (361-364) used for transmitting a first downlink reference signal (411) of the at least two downlink reference signals (411), the first downlink reference signal (411) being associated with a first random access opportunity of the at least two random access opportunities (415), wherein a first random access opportunity (415) of the at least two random access opportunities (415, 418) is accessed using the uplink transmission beam (381), The second random access opportunity (418) of the at least two random access opportunities (415, 418) is accessed using the uplink transmission beam (381).

22. The method according to claim 21, in, The multi-beam mode of operation is spatial diversity using a single downlink receive beam (381*) at the wireless communication device (102), the single downlink receive beam (381*) corresponding to the uplink transmit beam (381).

23. The method according to claim 1 or 2, further comprising: - determining a first uplink transmission beam (381) based on a first downlink transmission beam (361) of the plurality of downlink transmission beams (361-364) used for transmitting a first downlink reference signal (411) of the at least two downlink reference signals (411), the first downlink reference signal (411) being associated with a first random access opportunity (415) of the at least two random access opportunities (415, 418), - determining a second uplink transmission beam (384) based on a second downlink transmission beam (364) of the plurality of downlink transmission beams (361-364) used for transmitting a second downlink reference signal (411) of the at least two downlink reference signals (411), the second downlink reference signal (411) being associated with a second random access opportunity of the at least two random access opportunities (418), The first random access opportunity (415) of the at least two random access opportunities (415, 418) is accessed using the first uplink transmission beam (381), The second random access opportunity (418) among the at least two random access opportunities (415, 418) is accessed using the second uplink transmission beam (384).

24. The method according to claim 23, in, The multi-beam operation mode is spatial diversity or spatial multiplexing.

25. The method according to claim 1 or 2, in, A first random access opportunity (415) of the at least two random access opportunities (415, 418) is accessed using a contention-based random access preamble, The second random access opportunity of the at least two random access opportunities is accessed using a contention-free random access preamble code, The method further comprises: - receiving an indication of said contention-free random access preamble in a random access procedure (600) associated with said contention-based random access preamble.

26. The method according to claim 1 or 2, in, A first random access opportunity of the at least two random access opportunities is accessed using a first contention-based random access preamble, The second random access opportunity among the at least two random access opportunities is accessed using a second contention-based random access preamble code.

27. The method according to claim 1 or 2, in, A first random access opportunity of the at least two random access opportunities is accessed using a first contention-free random access preamble, The second random access opportunity among the at least two random access opportunities is accessed using a second contention-free random access preamble code.

28. A method of operating at least one access node of a communication network (100), the method comprising: - transmitting a plurality of downlink reference signals (411) using a plurality of downlink transmission beams, each downlink reference signal of the plurality of downlink reference signals (411) being associated with a respective at least one random access opportunity of a plurality of random access opportunities (415-418), - monitoring access by a wireless communication device (102) to at least two random access opportunities associated with at least two downlink reference signals (411) of the plurality of downlink reference signals (411), and - Based on the monitoring of the access, establishing a multi-beam operation between the wireless communication device (102) and the communication network (100), wherein the multi-beam operation is established based on at least two downlink transmission beams of the plurality of downlink transmission beams used for transmitting the at least two downlink reference signals (411).

29. The method according to claim 28, in, The multi-beam operation is established after completing a random access procedure associated with the wireless communication device (102) accessing the at least two random access opportunities.

30. The method according to claim 28 or 29, in, The multi-beam operation is further established based on at least one configuration (6011) communicated between the wireless communication device (102) and the communication network (100), and / or Therein, the access is monitored according to the at least one configuration.

31. The method according to claim 28 or 29, further comprising: - transmitting a network configuration (6011) to the wireless communication device (102), the network configuration (6011) indicating network support for the access of a plurality of random access opportunities (415-418).

32. The method according to claim 28 or 29, further comprising: - receiving a device configuration for access to the at least two random access opportunities, Wherein, the access is monitored according to the device configuration.

33. The method of claim 32, further comprising: - receiving device parameters for said multi-beam operation from said wireless communication device (102), Wherein, the multi-beam operation is established according to the device configuration.

34. The method according to claim 28 or 29, further comprising: - determining an order of accessing the at least two random access opportunities (415, 418) based on the monitoring, and - determining a beam priority of the at least two downlink transmission beams (361, 364) based on the order, The multi-beam operation is established according to the beam priority.

35. A wireless communication device (102) configured to connect to a communication network (100), the wireless communication device (102) comprising a control circuit configured to: - monitoring a plurality of downlink reference signals (411) transmitted by at least one access node of the communication network (100) using a plurality of downlink transmission beams (361-364), each downlink reference signal of the plurality of downlink reference signals (411) being associated with a respective at least one random access opportunity of a plurality of random access opportunities (415-418), - accessing at least two random access opportunities (415, 418) of the plurality of random access opportunities (415-418), the at least two random access opportunities (415, 418) being associated with at least two downlink reference signals (411) selected from the plurality of downlink reference signals (411) based on the monitoring, and - establishing multi-beam operation between the wireless communication device (102) and the communication network (100), wherein The multi-beam operation is established based on at least two downlink transmission beams (361, 364) for transmitting at least two selected downlink reference signals (411).

36. The wireless communication device (102) of claim 35, wherein: The control circuit is configured to perform the method according to any one of claims 1 to 27.

37. At least one access node of a communication network (100), the at least one access node comprising a control circuit, the control circuit being configured to: - transmitting a plurality of downlink reference signals (411) using a plurality of downlink transmission beams, each downlink reference signal in the plurality of downlink reference signals (411) being associated with a respective at least one random access opportunity in a plurality of random access opportunities (415-418), - monitoring access by a wireless communication device (102) to at least two random access opportunities associated with at least two downlink reference signals (411) of the plurality of downlink reference signals (411), and - establishing multi-beam operation between the wireless communication device (102) and the communication network (100) based on the monitoring of the access, wherein The multi-beam operation is established based on at least two downlink transmission beams among a plurality of downlink transmission beams being used to transmit the at least two downlink reference signals (411).

38. The at least one access node according to claim 37, wherein: The control circuit is configured to perform the method of any one of claims 28 to 34.

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