TECHNOLOGICAL FIELD

The present disclosure is related to but not limited to communication networks. The disclosure in particular pertains to beam management (in particular intra-cell beam management), such as by means of synchronization signal block (SSB) beams, e.g. when performing random access between a first apparatus and a second apparatus.

BACKGROUND

A conventional beam management procedure between a base station (such as gNB) and a terminal device (such as user equipment, UE) is described in third generation partnership project (3GPP) specification. Here, the UE beam management is defined in three phases Phase#l, Phase#2 and Phase#3 as described in 3GPP. These phases are illustrated in the signaling chart 100 Fig. 1 and can be described as follows:

• Phase#l (Pl): The UE uses a broad Rx beam while the gNB is performing SS bursts where SSBs are swept and transmitted in different angular directions covering the cell. The UE measures the reference signal received power (RSRP) for all SSB beams on all UE panels and sends a preamble for random access over the physical random access channel (PRACH) on the random access channel (RACH) Occasion of the best SSB beam to connect to the network with the reciprocal transmit (Tx) beam of the best SSB beam.

• Phase#2 (P2): The UE uses a broad Rx beam to receive the gNB refined Downlink Channel State Information Reference Signal (DL CSI-RS) beam sweeping within the connected SSB beam. The UE measures the RSRP for all CSI-RS beams and reports the best beam ID(s) back to gNB still using the reciprocal broad Tx beam.

• Phase#3 (P3): The gNB transmits a repeated CSI-reference signal with the selected beam based on the UE reporting in Phase#2 and the UE sweeps refined Rx beam settings to identify its best narrow Rx beam. At the end of Phase#3, the alignment between the gNB Tx beam and the UE Rx beam is obtained for maximized directional gain.

The Release 18 New Radio coverage enhancement for PRACH e.g. four step RACH procedures is in consideration. SUMMARY OF SOME EXEMPLARY EMBODIMENTS

However, there is the problem, that the legacy beam management procedure between a gNB and a UE, as described in 3 GPP Technical Report 38.802 and in Technical Specification 38.214, relies on SSB beams for Phase#land CSI-RS for Phase#2 and Phase#3. Phase#l, Phase#2 and Phase#3 are used for Initial Access (IA) but also for e.g. Beam/Link Failure Recovery, Handovers (HO), NR Cell additions and general Beam Management (BM).

One of the significant differences between SSB and CSI-RS is that SSBs are a UE known common periodical transmitted reference signals (RS), while CSI-RSs may be a UE specific periodical or aperiodical RS that is allocated by the gNB whenever its needed and is used for other procedures than BM as well. As such, it would be beneficial if the number of used CSI-RS in the BM procedures could be reduced, as it will also reduce the overhead, improve DL scheduling opportunities and ultimately enhance DL throughput. One way to achieve this is to allocate the same CSI-RS to multiple UEs.

Another disadvantage of using the above described legacy beam alignment procedure is that both the gNB and the UE are using wider beams (beams with less gain than supported be the antenna array) throughout the RACH procedure (i.e. Msgl to Msg4) potentially causing failures due to low link budget. Msg3 (including UE payload) will typically be the message that is lost if the link budget between the gNB and the UE is insufficient.

In other words, the above described approach has the following drawbacks:

• Inherent minimal antenna gain configurations at both gNB and UE side during RACH procedure, potentially causing failures in high path loss environments.

• Higher number of required reference signals (resources) for beam alignment, particularly for busy /loaded networks, since CSI-RS are used for both Phase#2 and hase#3 and configured for each UE.

In view of the above, certain embodiments of the present disclosure may thus have the effect of enable the gNB to enhance the legacy 3 GPP beam management procedure. Certain embodiments may have the effect that a smaller number of transmitted reference signals may be required. Certain embodiments may have the effect of an increased antenna gain, e.g. to ensure successful transmission of the critical Msg#3 and thereby increased coverage.

According to a first exemplary aspect, there is disclosed a first apparatus. The first apparatus may comprise a processor and a transceiver configured for receiving, from a second apparatus, configuration information indicating a first random access channel (RACH) occasion group (ROG) of a first set of synchronization signal block (SSB) beams and a second ROG of a second set of SSB beams. The first apparatus may be further configured for receiving, from the second apparatus, a first SSB beam of the first ROG and/or a second SSB beam of the second ROG. The first apparatus may further be configured for transmitting, to the second apparatus, a random access request on a RACH occasion of the first SSB beam of the first ROG and/or on a RACH occasion of the second SSB beam of the second ROG.

According to a second exemplary aspect, there is disclosed a second apparatus. The second apparatus may comprise a processor and a transceiver configured for transmitting, to a first apparatus, configuration information indicating a first random access channel (RACH) occasion group (ROG) of a first set of synchronization signal block (SSB) beams and a second ROG of a second set of SSB beams. The second apparatus may further be configured for transmitting the first set of SSB beams of the first ROG and the second set of SSB beams of the second ROG. The second apparatus may further be configured for receiving, form the first apparatus, a random access request on a RACH occasion of an SSB beam of the first ROG and/or on a RACH occasion of an SSB beam of the second ROG.

According to each of the exemplary aspects, a respective method is also disclosed.

Thus, according to the first exemplary aspect, there is disclosed a method, at least performed by a first apparatus. The method may comprise receiving, from a second apparatus, configuration information indicating a first random access channel, RACH, occasion group, ROG, of a first set of synchronization signal block, SSB, beams and a second ROG of a second set of SSB beams. The method may further comprise receiving, from the second apparatus, a first SSB beam of the first ROG and/or a second SSB beam of the second ROG. The method may further comprise transmitting, to the second apparatus, a random access request on a RACH occasion of the first SSB beam of the first ROG and/or on a RACH occasion of the second SSB beam of the second ROG.

According to the second exemplary aspect, there is disclosed a method, at least performed by a second apparatus. The method may comprise transmitting, to a first apparatus, configuration information indicating a first random access channel, RACH, occasion group, ROG, of a first set of synchronization signal block, SSB, beams and a second ROG of a second set of SSB beams; The method may further comprise transmitting the first set of SSB beams of the first ROG and the second set of SSB beams of the second ROG. The method may further comprise receiving, form the first apparatus, a random access request on a RACH occasion of an SSB beam of the first ROG and/or on a RACH occasion of an SSB beam of the second ROG.

Any of the disclosed device (first apparatus, second apparatus) may be stationary device or a mobile device. The first apparatus may in particular be a user equipment (UE), e.g. mobile device, such as a smartphone, a tablet, a wearable, a smartwatch, a low power device, an loT device, an IIoT device, a vehicle, a truck, a drone, an airplane, or the like. The first apparatus may in particular be capable of communicating with (transmitting and receiving signals and/or data to/from) a second apparatus, such as a second apparatus of a communication network. Generally, the first apparatus may also be any device enabled for communication with a communication network and/or another first apparatus.

A second apparatus may be understood as a wireless communication station installed at a fixed or mobile location and may in particular be or comprise an entity of the radio access network of the communication system. For instance, the second apparatus may be, comprise, or be part of a second apparatus of a communication network of any generation (e.g. a gNB, eNodeB, NodeB, BTS or the like) of 3GPP standard. Generally, the second apparatus may be or comprise a hardware or software component implementing a certain functionality. In an example, the second apparatus may be an entity as defined by 3GPP 5G or NR standard (also referred to as gNB). Accordingly, while the second apparatus may be understood to be implemented in or be a single device or module, the second apparatus may also be implemented across or comprise multiple devices or modules. As such, the second apparatus may in particular be implemented in or be a stationary device. Multiple second apparatuses of the exemplary aspect may in particular establish a communication system or network, which may in particular be a New Radio (NR) or 5G system (5GS) or any other mobile communications system defined by a past or future standard, in particular successors of the present 3 GPP standards. The second apparatus of the exemplary aspects may be capable of being in direct and/or indirect communication with the exemplary first apparatus.

The means or functionality of any of the disclosed devices or second apparatuses can be implemented in hardware and/or software. They may comprise one or multiple modules or units providing the respective functionality. They may for instance comprise at least one processor for executing computer program code for performing the required functions, at least one memory storing the program code, or both. Alternatively, they could comprise for instance circuitry that is designed to implement the required functions, for instance implemented in a chipset or a chip, like an integrated circuit. In general, the means may comprise for instance one or more processing means or processors.

Thus, according to the respective exemplary aspects of the present disclosure, there is in each case also disclosed a respective apparatus (i.e. a first apparatus and a second apparatus) comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause an apparatus at least to perform a method according to the respective aspect of the present disclosure.

Any of the above-disclosed exemplary aspects may, however, in general be performed by an apparatus, which may be a module or a component for a device, for example a chip. The disclosed apparatus may comprise the disclosed components, for instance means, processor, memory, or may further comprise one or more additional components.

According to the exemplary aspects of the present disclosure, there is in each case also disclosed a computer program, the computer program when executed by a processor of an apparatus causing said apparatus to perform a method according to the respective aspect. The computer program may in each case be stored on computer-readable storage medium, in particular a tangible and/or non-transitory medium. The computer readable storage medium could for example be a disk or a memory or the like. The computer program could be stored in the computer readable storage medium in the form of instructions encoding the computer-readable storage medium. The computer readable storage medium may be intended for taking part in the operation of a device, like an internal or external memory, for instance a Read-Only Memory (ROM) or hard disk of a computer, or be intended for distribution of the program, like an optical disc.

A beam may be generated by a first apparatus or a second apparatus by means of a multiple antennas, multiple antenna ports and/or multiple panels. A beam may be generated by means of analog, hybrid and/or digital beam sweeping architecture.

An SSB may span multiple subcarriers and multiple OFDM symbols. An SSB may carry a primary synchronization signal (PSS), a secondary synchronization signal (SSS) and a physical broadcast channel (PBCH).

An SSB beam may generally be understood as a beam in a certain spatial or angular direction comprising or signaling a certain SSB and thus being identified or associated with said SSB. However, as will be explained in more detail below, different SSB beams may in also be associated with or comprise the same SSB in certain situations.

The SSB of a certain SSB beam may be associated with or indicate a certain RACH occasion (e.g. a certain frequency and/or time instance, such certain OFDM symbols in a certain slot) for the first apparatus. In case the first apparatus uses the respective RACH occasion for communicating with the second apparatus, the second apparatus will know which SSB beam was received by the first apparatus. In the present disclosure it is now suggested the RACH occasions for a first set of SSB beams are grouped into a first ROG and that the RACH occasions for a second set of SSB beams are grouped into a second ROG. While the following disclosure may assume that there are two ROGs with two sets of SSB beams, the present disclosure likewise applies to embodiments with more than two sets of SSB beams and more than two ROGs may be defined. While the exemplary aspects described assume that SSB beams are used, the exemplary embodiments described herein may also be realized with other reference signals than SSB beams.

The first apparatus may now receive the configuration information transmitted by the second apparatus. The configuration information may indicate the first ROG of the first set of SSB beams and the second ROG of the second set of SSB beams in different manners. For instance, the configuration information may explicitly or implicitly indicate the first and the second ROG. In one example, the configuration information may define different RACH occasions (RO) and indicate which of the RACH occasions belong to the first and the second ROG. In one example, the configuration information may indicate which part of a defined set of RACH occasions belong to the first ROG and to the second ROG. For instance, the configuration information may indicate the first ROG and the second ROG by indicating a split or partition between the SSB beams of the first set or RACH occasions belonging to the first ROG and the SSB beams of the second set or RACH occasions belonging the second ROG. For instance, the configuration information may be a number n indicating that the first n RACH occasions of the total number A of RACH occasions belong to the first ROG, while the remaining N-n RACH occasions belong to the second ROG.

The second apparatus may then transmit the first set of SSB beams of the first ROG and the second set of SSB beams of the second ROG. Therein, each of the SSB beams of first set of SSB beams of the first ROG may be sent in a different spatial or angular direction by the second apparatus. Likewise, each of the SSB beams of second set of SSB beams of the second ROG may be sent in a different spatial or angular direction by the second apparatus. Accordingly, the first apparatus will then receive (at least) one of the SSB beams of the first ROG (also referred to as the first SSB beam) and/or (at least) one of the SSB beams of the second ROG (also referred to as the second SSB beam), which is/are sent into the direction of the first apparatus. The other SSB beams of the set of SSB beams of the respective ROG may either not be received or received with lower quality or power at the first apparatus.

Depending on whether the first apparatus is familiar with the approach as described herein, the first apparatus may react differently to the received SSB beams. According to the present disclosure the first apparatus is expected to transmit, to the second apparatus, a random access request (RAR) for each ROG, i.e. a (first) random access request on a RACH occasion indicated by or associate with a received first SSB beam of the first set of SSB beams of the first ROG and a (second) random access request on a RACH occasion indicated by or associate with a received second SSB beam of the second set of SSB beams of the second ROG.

However, as will be explained in more detail below, a legacy first apparatus will only transmit a single random access request for a RACH occasion indicated by or associate with the strongest received SSB beams.

Accordingly, depending on the behavior of the first apparatus, the second apparatus will then receive, form the first apparatus, either one or two random access requests, namely a random access request on a RACH occasion of an SSB beam of the first ROG and/or a random access request on a RACH occasion of an SSB beam of the second ROG.

As the approach described herein only relies on SSB beams (and does not require e.g. CSI- RS) there is a reduced overhead. Moreover, as the second apparatus can obtain random access requests in response to two different SSB beams received by the first apparatus, the second apparatus is enabled to derive beam information from the received random access requests, which may allow to use a refined beam for the further steps of the RACH procedure. In other words, the SSB beams and in particular their spatial coverage or angular direction of the two ROGs may be chosen such that the second apparatus will be enabled to select a refined beam for communicating with the first apparatus. Specifically the management of the SSB beams in different ROGs and the signaling thereof by the second apparatus to the first apparatus will allow for a beam management procedure with a smaller number of transmitted reference signals and an increased antenna gain and thus increased coverage. These and further advantages will become apparent and will be explained in more detail below.

In case the first apparatus receives multiple SSB beams of the same ROG, the first apparatus may transmit the random access requests on respective RACH occasions of SSB beams received e.g. with the highest received power, such as highest reference signal received power (RSRP), the highest signal to noise ratio, SNR, the highest signal to interference plus noise ratio, SINR and/or the highest estimated channel quality. Alternatively, the random access request may be transmitted on a RACH occasions of SSB beams received above a respective configured (e.g. power, RSRP, SNR, SINR or estimated channel quality) threshold. The respective beam may be considered the best or optimal beam from the viewpoint of the first apparatus. Thus, the first apparatus will respond to the second apparatus on those RACH occasions, which are, for each of the ROGs, associated with the SSB beam received with the highest respective rating. Thus, by receiving the respective random access requests, the second apparatus will know for each ROG which beam of the respective ROG is optimally directed towards the first apparatus.

Depending on the RACH procedure, the random access request may comprise different information. For instance, the first random access request and the second random access request may each comprise a random access preamble. For instance, the first random access request and the second random access request may comprise the same random access preamble. For instance, the first and second random access request may each be a Msgl of a four step or two step RACH procedure.

For instance, the coverage or width of the beams of different sets of beams may be different. For instance, the beams of the first set of beams may have a first width and the beams of the second set of beams may have a second (different) width. In an example, the SSB beams of the first set are beams wider than those of the second set and the SSB beams of the second set are beams narrower than those of the first set. Thus, the SSB beams of the first set may be referred to as wide or wider beams. The SSB beams of the second set may be referred to as narrow, narrower or refined beams. The narrow beams of the second set may be used for refinement of the SSB beams of the first set. However, the described configuration may also be the other way around (i.e. the SSB beams of the first set may also be the narrower beams and the SSB beams of the second set may also be the wider beams). For instance, the term wider may be understood to mean that the half-power beamwidth of the antenna radiation pattern shows a wider angle. For instance, this may be achieved with activating less elements of the antenna array. All beams within a set of SSB beams may have the same or substantially the same width or coverage. However, each beam of a set of beams may be directed in a different spatial or angular direction. Basically, the SSB beams of the second set may be considered to take the place of the CSI-RS beams of the conventional beam refinement procedure of Phase#2 as described above.

Nevertheless, in general, other beam configurations may be used and it may be conceivable to e.g. provide a ROG associated with a set of SSB beams comprising a beams with different widths or spatial coverage, i.e. mixture of wider and narrower SSB beams with one set of beams.

For instance, the configuration information is may be received in a RRC configuration or other higher layer signaling. For instance, the configuration information is may be received in a broadcast message. All first apparatuses in a cell or in a sector or generally served by the second apparatus may receive the configuration information regarding the specified ROGs in this manner without the requirement of any terminal specific signaling. Accordingly, the configuration information may be received by the first apparatus as a common configuration or information. In one example, the configuration information may be received in a system information block, SIB, message, such as a system information block type 2, SIB2, message. As an example, there may be an information element (IE) field in a SIB2 message, which carries the configuration information. For instance, in particular in case the configuration information merely indicates the split or partition between RACH occasions belonging to the first ROG and the RACH occasions belonging the second ROG, the configuration information may only need to be a bit string of x bits, e.g. with x between 1 and 6 bits, in order to indicate the number of RACH occasions belonging to the respective ROG.

The SSB beams of the first set may be transmitted sequentially in different angular directions by the second apparatus. Every SSB beam of the first set may have or be associated with a different SSB. Accordingly, each SSB beam of the first set may be associated with a different RACH occasion of the first ROG. Accordingly, when a first apparatus transmit a random access request on a RACH occasion of the first ROG, the second apparatus may unambiguously identify the respective SSB beam of the first ROG received and used by the first apparatus for this random access request. In an example, certain SSB beams of the first and/or second set of SSB beams, i.e. of the first and/or second ROG, may be transmitted simultaneously in a group-wise manner. In other words, the SSB beams of the first and/or second set may be transmitted in respective multiple common SSB beam configurations. For instance, the SSB beams of the second set may be transmitted simultaneously in respective SSB groups (or respective simultaneous common SSB beam configurations), wherein each SSB beam of a simultaneously transmitted SSB group may have the same SSB identity. In one interpretation such an SSB group of simultaneously transmitted SSB beams may also be considered as a single SSB beam with multiple lobes radiating in different directions.

In an example, each SSB group of simultaneously transmitted SSB beams of the second set comprises (or consists of) a beam for each beam of the first set of SSB beams. More specifically, in an example, each SSB group of simultaneously transmitted SSB beams of the second set comprises (or consists of) a beam for each beam of the first set of SSB beams and having an angular direction within the angular range of the respective beam of the first set of SSB beams. Even if multiple SSB beams of the second set are transmitted with the same SSB identity (as described above), the additional information from a random access request via a RACH occasion based on a received SSB beam of the first set of the first ROG, may unambiguously identify the SSB beam (and thus the angular or spatial direction thereof) of the second set, which has been received (e.g. with the highest RSRP) by the first apparatus, even though multiple SSB beams may be transmitted in the second set in an SSB group or simultaneous common SSB beam configuration with the same SSB identity.

In an example, each SSB group of simultaneously transmitted SSB beams of the second set comprises (or consists of) multiple beams in different angular directions. In other words, each simultaneously transmitted SSB beams of an SSB group has different angular directions. For instance, each SSB beam of the second set of the second ROG may in general have a different angular direction.

In an example, each SSB group of simultaneously transmitted SSB beams of the second set comprises (or consists of) beams which are shifted (e.g. with respect to the angular direction) compared to the beams of the respective other SSB groups. For instance, each beam is shifted by a certain degree (e.g. 5°) from one SSB group to another. Generally, the shift should be such that all SSB beams of the second set together cover substantially the substantially same angular range as the SSB beams of the first set of SSB beams. For instance, the sum of all narrow beams half power beamwidths may equal the respective broad beam beamwidth. For instance, a respective half power beam width (HPBW) may be determined from a 2D cut of a 3D beam radiation pattern. For instance, such a cut may be aligned with an orientation of the antenna, e.g. the horizontal or vertical planes.

In an example, each SSB group of simultaneously transmitted SSB beams of the second set comprises (or consists of) beams which are transmitted using the same physical resource blocks, PRB. However, it is noted that, generally, even though the beams may be sent on the same PRB, at the same time with different spatial filters, they may nevertheless indicate different resources (e.g. PRB) reserved for first apparatus to send a subsequent message (such as a Msg 3).

In an example, each SSB group of simultaneously transmitted SSB beams of the second set comprises (or consists of) beams which are associated with the same RACH occasion. As the beams of an SSB group may transmitted with the same SSB, these SSBs will accordingly be associated with the same RACH occasion.

To provide a non-limiting example, the first set of SSB beams may comprise four (or any other number) wide SSB beams, each having a different SSB (e.g. SSB#1, SSB#2, SSB#3, SSB#4,...) and accordingly the same number of RACH occasions (e.g. one for each SSB) in the first ROG. In the second set of SSB beams there may now be four (or any other number depending on the desired beam refinement) SSB groups. Each SSB group (or simultaneous common SSB beam configuration) has four SSB beams (e.g. one for each SSB beam of the first set) having the same SSB (and are thus associated with the same RACH occasion). That is, in this example, the first SSB group has four narrow SSB beams transmitted simultaneously in different angular directions with SSB#5; the second SSB group has four narrow SSB beams transmitted simultaneously in different angular directions with SSB#6; the third SSB group has four narrow SSB beams transmitted simultaneously in different angular directions with SSB#7; the fourth SSB group has four narrow SSB beams transmitted simultaneously in different angular directions with SSB#8, etc.

The SSB beams of the second set of SSB beams may cover substantially the same angular range as the SSB beams of the first set of SSB beams. For instance, the SSB beams of the second set may be considered to be refined beams of the SSB beams of the first set. However, as multiple beams of the second set for the second ROG may have the same SSB identity, as described above, the number of required reference signals (SSBs) may be kept low.

More specifically, the number of SSBs used for the first and the second set may in particular be independent of the number of connecting first apparatuses. Because multiple SSB beams of the second set may be transmitted simultaneously in different directions with the same SSB identity, the number of used SSBs does not increase with the number of SSB beams in a SSB group of simultaneously transmitted SSB beams. Moreover, because the second set of (refined) SSB beams may substantially cover the same angular range as the (wider) SSB beams of the first set, the number of (refined) SSB beams does also not increase with the number of connective devices from different directions (i.e. from different SSB beams of the first set).

In an example, the number of SSBs used for the first ROG may be 4, 8, 16 or 32. Likewise, the number of SSBs used for the second ROG may be 4, 8, 16 or 32. For instance, the total number of SSBs used for the first and second ROG may be 8 (e.g. in case of 4 SSBs for the first ROG and 4 SSBs for the second ROG), 12 (e.g. in case of 8 SSBs for the first ROG and 4 SSBs for the second ROG), 20 (e.g. in case of 16 SSBs for the first ROG and 4 SSBs for the second ROG) or 36 (e.g. in case of 32 SSBs for the first ROG and 4 SSBs for the second ROG).

Considering now the case that the second apparatus receives a random access request on a RACH occasion of an SSB beam of the first ROG and a random access request on a RACH occasion of an SSB beam of the second ROG, the second apparatus may determine, based on the received random access requests, an aligned second apparatus Tx and/or Rx beam for the first apparatus. The (first) received random access request transmitted by the first apparatus based on the first received (e.g. wide) SSB beam of the first ROG can be compared to the Msg 1 transmitted in Phase# 1 of the conventional beam management procedure described above. The (second) received random access request transmitted by the first apparatus based on the second received (e.g. narrow) SSB beam of the second ROG can be compared to the CSI-RS refinement of Phase#2 of the conventional beam management procedure described above. The combination of the two random access requests (and thus the knowledge at the second apparatus about two received and used SSB beams (one for each ROG) at the terminal side) may allow the second apparatus to unambiguously identify the (narrower) beam of the second set of SSB beams for the first apparatus, even though multiple SSB beams have the same SSB identify in the second set. As a result, the approach according to the present disclosure allows the refinement with fewer reference signals only based on SSB beams with two random access requests.

Moreover, as a beam refinement or alignment at the second apparatus side may already be achieved after the random access request (Msgl), the second apparatus may transmit, to the first apparatus, a Msg2 of a four step RACH procedure with the aligned second apparatus Tx beam. Additionally, this may also allow for the second apparatus to receive, from the first apparatus, a Msg3 of a four step RACH procedure with the aligned second apparatus Rx beam. Additionally, this may further allow for the second apparatus to transmit, to the first apparatus, a Msg4 of a four step RACH procedure with the aligned second apparatus Tx beam.

Considering now the case that the second apparatus receives a random access request on a RACH occasion of a (e.g. narrower) SSB beam of only the second ROG (e.g. because the first apparatus is a legacy device and only sends a single random access request, but not a random access request for each ROG), the second apparatus may transmit random access responses on each SSB beam of the second ROG having the same SSB as the SSB beam on which RACH occasion the random access request was received. These random access responses may be transmitted sequentially. Since multiple SSB beams of the second set of the second ROG may have the same SSB identity, the second apparatus may not be able to unambiguously identify which of the specific SSB beams (and the angular direction thereof) transmitted simultaneously in the SSB group was actually received and considered as optimal (e.g. having the highest power, SNR, SINR, quality etc.) by the first apparatus. This issue can be resolved by the second apparatus by transmitting multiple random access responses on the relevant ambiguous SSB beams. The random access responses may be such that the second apparatus, based on the subsequent message of the first apparatus (e.g. Msg3) to the second apparatus, may determine which of the random access response (and thus which SSB beam) was received and considered optimal by the first apparatus. This may be achieved by allocating different resources for the subsequent message of the first apparatus in each of the random access responses.

In one example, each random access response allocates different bandwidth parts, BWP, for a respective Msg3. However, each random access response may nevertheless allocate the same time instance (e.g. frame, slot or symbol) for a respective Msg3.

As the Msg3 received at the second apparatus allows for determining the SSB considered optimal by the first apparatus, the second apparatus may thus determine, based on the received random access request and a received Msg3, an aligned second apparatus Tx and/or Rx beam for the first apparatus.

However, it is noted that even though the aligned second apparatus beam is only identified after Msg3 is received, the random access response (e.g. Msg2) may nevertheless be already transmitted by the second apparatus on multiple narrow beams, so that also in this case, the random access response (e.g. Msg2) may transmitted by the second apparatus with increased antenna gain compared to Phase#2 of the conventional beam management.

Furthermore, similarly to the above case, it may be that the second apparatus receives a random access request on a RACH occasion of a (e.g. broader) SSB beam of only the first ROG (e.g. because the first apparatus is a legacy device and only sends a single random access request, but not a random access request for each ROG). In that case the second apparatus does not have or cannot derive any information on the optimal narrow SSB beam of the second set or ROG but is only aware of the broad SSB beam of the first set or ROG and the associated RACH occasion used by the first apparatus. This situation is similar to the situation after having received the random access response (Msg2) in Phase#2 of the conventional beam management procedure described at the outset. Thus, the second apparatus may in this case decide to switch to the conventional beam management procedure, continue and complete Phase# 1 with the (broad) SSB beam and then continue in Phase#2 with a beam refinement by means of CSI-RS beams.

It is to be understood that the presentation of the embodiments disclosed herein is merely by way of examples and non-limiting.

Herein, the disclosure of a method step shall also be considered as a disclosure of means for performing the respective method step. Likewise, the disclosure of means for performing a method step shall also be considered as a disclosure of the method step itself.

Other features of the present disclosure will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the present disclosure, for which reference should be made to the appended claims. It should be further understood that the drawings are not drawn to scale and that they are merely intended to conceptually illustrate the structures and procedures described herein.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1 shows a signaling chart of three phases (Phase#l, Phase#2, Phase#3) of a conventional beam alignment for intra-cell beam management with SSB beams and CSI-RS beams;

Fig. 2a shows an exemplary illustration of wide SSB beams, which may be used for the first set of SSB beams of the first ROG;

Fig. 2b-Fig. 2d show exemplary illustrations of narrow CSI-RS beams as used in Phase#2 of the conventional beam alignment for comparison;

Fig. 2e-Fig. 2h show exemplary illustrations of different narrow SSB beams of the second set of SSB beams of the second ROG transmitted simultaneously in groups with the same SSB identity;

Fig. 3 shows an exemplary signaling chart between a base station and a terminal device preforming an exemplary embodiment of the beam management procedure according to the disclosure; Fig. 4 shows an exemplary random access configuration illustrating the concept of ROGs;

Fig. 5a, Fig. 5b shows an exemplary signaling chart between a base station and a legacy terminal device preforming an exemplary embodiment of the beam management procedure according to the disclosure;

Fig. 6 shows the exemplary relation between the Msg2 and the Msg3 of the signaling chart of Fig. 5 in more detail;

Fig. 7 shows a schematic diagram illustrating an example radio environment in which exemplary embodiments of the present disclosure may be performed;

Fig. 8 shows a schematic diagram illustrating a block diagram of an exemplary embodiment of an apparatus according to the present disclosure;

Fig. 9 shows a block diagram of an exemplary embodiment of a base station; and Fig. 10 shows a schematic illustration of examples of tangible and non-transitory computer-readable storage media.

DETAILED DESCRIPTION OF THE FIGURES

The following description serves to deepen the understanding of the present disclosure and shall be understood to complement and be read together with the description of example embodiments of the present disclosure as provided in the above SUMMARY section of this specification.

In the following and with reference to Fig. 7 an, an example communication system, in which the present disclosure may be applied, is described. While the specific radio system in the examples below may be for example a 5G system which is only to be considered a non-limiting example.

Fig. 7 shows a 5G communication network as an example, which introduces the New Radio technology and also an architecture for which the different sublayers of the RAN may be split into two logical entities in a communication network control element (like a BS or gNB), which are referred to as distributed unit (DU) and central unit (CU). For example, the CU is a logical node that controls the operation of one or more DUs over a front-haul interface (referred to as Fl interface). The DU is a logical node including a subset of the gNB functions, depending on the functional split option. The communication network control element may be network node. gNB will be used interchangeable with network node in the present disclosure.

As shown in Fig. 7, user equipment (UE) 710, as an example of a first apparatus of the exemplary aspects of the present disclosure, is connected to a cell 1 of a network device or base station (as an example of a second apparatus of the present disclosure), a gNB 720 via a communication beam of the cell 1. In the example shown in Fig. 7, the gNB 730 is provided with a CU 733 and two DUs 731 and 732 being connected to the CU 733 by a Fl interface. Furthermore, as shown in the example of Fig. 7, there is a plurality of further cells to which the UE 710 can connect.

Naturally, in each cell, a plurality of UEs may be present and connected to the respective cell. Similarly to cell 1, cells 2 and 3 are controlled by gNB 725 and 726, respectively, and each provides a plurality of beams 1 to 3, which may be used for beam diversity or beam hopping. As shown in Fig. 7, each base station or gNB of the cells is connected to a core network, such as a 5GC, via respective interfaces, indicated as NG interfaces. Furthermore, each gNB of the cells is connected with each other by means of a specific interface, which is referred to e.g. as an Xn-C interface. Any of these network entities, such as the gNB, gNB-DU, gNB-CU and/or 5GC, may individually or together be an example of a base station or a part thereof according to the present disclosure.

Turning now to Fig. 2, a beam management procedure according to the present disclosure (Fig. 2a and Fig. 2e - Fig. h) will be described in comparison with the legacy or conventional beam management procedure (Fig. 2a - Fig. d). The described example will use four wider beams for the first ROG, where each wider beam of the first ROG is refined by 4 narrower beams of the second ROG. However, the described example is not limited with respect to the specific beam configuration (e.g. number of beams for each ROG) but will likewise apply to other beam configurations and specifically to a different numbers of beams. Also, it shall be noted that the basic idea can be transferred to other combinations of wider and narrower beams. The basic idea of this disclosure is to enable the gNB to map or associate the synchronization signal block (SSB) beams with two different RACH Occasion Groups (ROG). The beamforming behavior of the SSB beams according to the mapped group can be described as follows. The SSBs beams mapped to or associated with to the first ROG are transmitted by the base station sequentially with wider beams as illustrated in Fig. 2a. Up to this point, this is the same as in the conventional procedure. However, the SSB beams mapped to or associated with to the second ROG (R0G#2) will be transmitted with narrower beams (beam refinement) in a sequential narrow beam sweep manner, but simultaneously with one narrower beam per wider beam used in the first ROG (ROG#1). This behavior is exemplarily shown in Fig. 2e-h and will be described in more detail below.

It should be noted that the SSB in the present disclosure may also be another reference signal or a different periodic synchronization signal, for example channel state information reference Signal (CSI-RS)..

In order for the UE to be aware of the different ROGs, the gNB will first indicate to the UE configuration information indicating the first ROG of a first set of SSB beams and a second ROG of a second set of SSB beams e.g. by indicating a split in the SSB and RACH occasion configuration. This allows the gNB to simultaneously send to the UE multiple narrow SSB beams as exemplarily illustrated in each of the groups indicated in Fig. 2e-Fig. h. As will become apparent from the following example, this will speed up the beam alignment and enhance coverage.

From terminal device point of view, a method is provided, and the method includes: receiving, from a base station, configuration information indicating a first random access channel, RACH, occasion group, ROG, of a first set of synchronization signal block, SSB, beams and a second ROG of a second set of SSB beams; and receiving, from the base station, a first SSB beam of the first ROG and/or a second SSB beam of the second ROG; and transmitting, to the base station, a random access request on a RACH occasion of the first SSB beam of the first ROG and/or on a RACH occasion of the second SSB beam of the second ROG. The SSB beams of the first set may be for example beams wider than those of the second set and wherein the SSB beams of the second set are beams narrower than those of the first set.

The SSB beams of the second set may be transmitted simultaneously in SSB groups, each SSB beam of a simultaneously transmitted SSB group having the same SSB identity.

It should be understood that the SSB beams of the first set may be beams narrower than those of the second set and the SSB beams of the second set are beams wider than those of the first set.

Considering the conventional beam management first and referring now to Fig. 2a and Fig. 2b, there is illustrated the situation, in which only one UE is connecting or connected to the gNB. The convention or legacy procedure will use 8 reference signals (RSs) in total for Phase#l and Phase#2, namely the 4 SSB beams of Phase#l (each SSB covering 20° in this example) and the 4 CSI-RS beams of Phase#2 (each CSI-RS beam covering 5° in this example), which is a legacy CSI-RS refinement for one of the SSB beams of Fig. 2a. However, the number of required RSs will increase significantly when the number of connecting or connected UEs increases.

For instance, if there is UE connecting or connected in the beams identified by SSB#1 and SSB#3 already 8 CSI-RS beams are necessary for the beam refinement for both UEs, as illustrated in Fig. 2c, showing a legacy CSI-RS refinement for two SSB beams. If there is a UE in the area of each of the wider SSB beams in Fig. 2a, 16 CSI-RS are required and the total number of reference signals already amounts to 20 RSs, namely 4 SSBs and 16 CSI- RSs as illustrated in Fig. 2a and Fig. 2d, showing a legacy CSI-RS refinement for four SSB beams. This number could in theory increase further for more connecting/connected UEs if the CSI-RSs for UEs in the same SSB beam cannot be shared.

Turning now to an example of the present disclosure, the proposed RACH procedure will, for this example, always use 8 reference signals for the beam alignment of Phase #1 and Phase#2, independently of the number of connecting/connected UEs. First, the wide panel beams for the first ROG as illustrated in Fig. 2a are used, which match the legacy SSB sweep pattern. Instead of the CSI-RS of Fig. 2b - Fig. 2d, the SSB beams of Fig. 2e - Fig. 2h are now used as a second ROG. Therein, Fig.2e - Fig. 2f illustrate SSB beams of the second set transmitted simultaneously in four SSB groups (each comprising four simultaneously transmitted SSB beams). That is, Fig. 2e illustrates a first simultaneously common SSB beam configuration for the second ROG; Fig. 2f illustrates a second simultaneously common SSB beam configuration for the second ROG; Fig. 2g illustrates a third simultaneously common SSB beam configuration for the second ROG; and Fig. 2h illustrates a fourth simultaneously common SSB beam configuration for the second ROG. AS can be noted, all the SSB beams shown in the common configurations are shifted by 5° from configuration to configuration, i.e. SSB group to SSB group in this example.

In order to generate the above described beams the gNB may be a multi-panel gNB or a gNB with hybrid/digital beam sweeping architecture.

Counting the used reference signals, there are the four wider SSB beams in Figure 2a, and the four simultaneously common SSB beam configurations shown in Fig. 2e - Fig. 2h, each only using a single SSB for each group of simultaneously transmitted narrow beams.

With the above described procedure, the gNB simultaneously transmits multiple SSBs in different angular directions in the second ROG using the same Physical Resource Blocks (PRBs), whereby those SSBs will be allocated with the same RACH Occasion (RO). In response, the UE transmits identical preambles for the best RO per allocated ROG. A high- level overview of the beam alignment steps, can be summarized as follows: The gNB uses 2 ROGs, while the first ROG (ROG#1) is configured with broad beams (SSB#l-4), the second ROG (R0G#2) with narrow beams (SSB#5-11).

The gNB sequentially send SSB beams with SSB# 1-4 in different angular directions as part of R0G1 (Fig. 2a). The gNB then simultaneously send SSB beams each with the same SSB#5 from all panels for a multi-panel gNB or from the same panel for a hybrid/digital gNB in multiple angular directions as part of R0G2 (Fig. 2e). This is repeated for SSB#6 and SSB#7, each time with beams of shifted angular directions, until the gNB simultaneously sends SSB beams with SSB#8 from all panels for a multi-panel gNB or from the same panel for a hybrid/digital gNB in multiple angular directions as part of R0G2 (Figure 2h).

In turn, the UE sends a first random access request or RACH preamble (Msgl) on the optimal SSB (associated with the beam of e.g. highest received power) from R0G1. The UE also sends a second random access request or RACH preamble (Msgl) on an SSB (associated with the beam of e.g. highest received power) from R0G2. For this, the gNB can derive which narrow beam the UE is detecting and connecting to.

It is noted that a legacy UE is expected to only send one preamble for the received SSB considered best and will most likely report an SSB transmitted with a narrow beam (as it will have higher antenna gain and thereby might have a higher EIRP), i.e. one of the SSB beams in Fig. 2e - Fig. 2f, whereby the gNB will not know the exact angular direction of that UE, as the RO is monitored simultaneously with narrower beams in different angular directions. A procedure for a gNB to overcome this issue is described in further detail below.

As illustrated in the above procedure, when a UE sends one preamble for each of the two RACH Occasion Groups, the first received preamble will inform the gNB of the best wider beam and the second preamble will inform the gNB of the best narrower beam. This will enable the gNB to perform a narrow beam alignment (corresponding to Phase# 1 and Phase#2), but based on few SSB signals only.

The advantage of using SSBs for Phase#2 (compared to CSI-RS in the conventional beam alignment procedure) is that they are common for all the UEs in the coverage area of that gNB sector, so the gNB uses only eight SSBs irrespective of the number of UEs in the coverage area of that sector. In addition, the coverage area of the gNB will also be increased, as Msg2, Msg3 and Msg4 of the four step RACH procedure will be received and transmitted by the gNB with higher antenna gain. The gain improvement will depend on how many beams are used for refinement of the wider legacy SSB beams. For instance, a 3dB gain improvement is possible with a refinement of 2 to 4 beams, while a 6 dB gain improvement is possible with a refinement of 8 to 16 beams. Examples of the obtained reductions of used reference signals for the example of a refinement of 4 beams for the proposed approach compared to the legacy beam management procedure is illustrated in the below Table 1. It is assumed that at least one UE is connecting via a RACH procedure to each SSB (so that a refinement of each SSB beam is required)

Table 1: Number of required RS for the legacy BM procedure compared to the BM procedure proposed herein

A significant reduction of the number of needed RSs for beam management is observed for the proposed procedure (namely between a factor of 20/8=2.5 to 160/36=4.4 in these examples). The optimal balance or split between the number of wider SSBs in the first ROG and the number on narrower SSBs in the second ROG depends on the total number of needed RS and the hardware capabilities of the gNB.

For the above described procedure an additional Information Element (IE), which may be termed “ROGroup-Splif may be used in order to inform the UE of the utilization of multiple ROGs. This IE may be broadcast and e.g. implemented as an optional part of the SIB2 message.

Turning now to Fig. 3, there is illustrated a signaling chart 300 between a gNB and a UE being configured to process such a signaled configuration regarding the RO-Group-Split.

With the first ROG, the gNB sequentially transmits x wider SSB beams with different SSB each at a time (x SSBs in total) with in different angular directions (each beam is 20° shifted in this example), which can be considered to correspond to the legacy SSB procedure, action 301. With the second ROG, the gNB sequentially transmits y groups of simultaneously transmitted narrow SSB beams with the same SSB identity, with one narrow SSB beam in each of the angular directions covered by the wider SSB beams belonging to the first ROG (y SSBs in total). From SSB group to SSB group the narrow beams are shifted by 5° in this example. This is sequentially repeated for all the narrow beams used for refinement of the wider SSB beam, action 302.

The gNB is then listening for RACH preambles in the first ROG and will receive a first Msgl with a preamble in a RACH occasion of the first ROG and associated with the SSB of the best SSB beam from the UE, action 303. Based thereon the gNB can determine the best wider SSB beam.

The gNB will also listen for RACH preambles in the second ROG with the associated beam configurations used in action 302 for each assigned RO and will receive a second Msgl with a preamble in a RACH occasion of the second ROG and associated with the SSB of the best SSB beam from the UE, action 304. Based thereon the gNB can determine the best (group of) narrow beams.

Based on both of the received preambles the gNB can unambiguously identify the best narrow Tx/Rx SSB beam.

Accordingly, the further messages can be exchanged with increased antenna gain on the gNB side, i.e. the gNB sends Msg2 with increased antenna gain, action 305, the gNB receives Msg3 with increased antenna gain, action 306, and the gNB sends Msg4 with increased antenna gain, action 307.

Compared to the conventional beam management procedure, the proposed approach in particular introduces the new IE (“RO-Group-Splif ’) allowing a gNB indication to the UE of a switch of the SSB/RO spatial filters for Tx ROG1 vs Tx ROG2, and Rx Msgl in ROG1 vs Rx Msgl in ROG2, so that a RACH procedure is provided with two consecutive preambles received by two different spatial filters (gNB Beams). The described example thus allows for a Phase#2 beam alignment using common SSBs only. Due to the use of only a few SSBs, the overhead can be reduced by a factor of between 2.5 to 4.4. Furthermore, the alignment time to reach the gNB narrow beam is reduced. Moreover, only a low and fixed number of SSBs is needed to perform Phase#l and Phase#2 independent of the number of UEs in the coverage area of the gNB. The benefit scales the higher the cell load. As Msg2 to Msg4 can be transmitted and received with increased antenna gain at the gNB, this increases the coverage of the gNB. As will be explained in more detail below, the suggested approach is also backwards compatible for legacy UEs.

As already mentioned above, the UE may be informed of the actual SSB scan method currently utilized by the gNB. Such signaling can be part of a System Information Block (SIB) message to enable this feature for RACH in Initial Access (Al) and in connected mode (RRC). In the following an example of how the signaling can be implemented into the SIB2 message is described.

The implementation can be achieved by adding 1 to 6 bits to an optional new field in the SIB2 message, as illustrated below where the red bold text highlights how the new field called “RO-Group-Split” could be added to the SIB2 message of 3GPP TS 38.331 V15.10.0 (2020-07). It should be noted that even that there are only a few bits reserved in the field, the optionality indication is another state, as it will indicate legacy behavior.

— ASN1 START

— TAG-S IB2-START

S IB2 : : = SEQUENCE { cel IReselect ionlnfoCommon SEQUENCE { ... } cel IReselect ionServingFreqlnfo SEQUENCE { ... } , IntraFreqCellRe select! on Info SEQUENCE { q-RxLevMin Q-RxLevMin, q-RxLevMinSUL Q-RxLevMin

OPTIONAL, — Need R q-QualMin Q-QualMin

OPTIONAL, — Need S s- IntraSearchP Reselect ionThreshold, s- IntraSearchQ Reselect ionThresholdQ

OPTIONAL, — Need S t-ReselectionNR T-Re select! on, f requencyBandList MultiFrequencyBandListNR-

SIB OPTIONAL, — Need S f requencyBandList SUL MultiFrequencyBandListNR-

SIB OPTIONAL, — Need R p-Max P-Max

OPTIONAL, — Need S smtc SSB-MTC

OPTIONAL, — Need S ss -RS SI -Measurement SS -RS SI -Measurement

OPTIONAL, — Need R ssb-ToMeasure SSB-ToMeasure

OPTIONAL, — Need S deriveSSB-IndexFromCell BOOLEAN,

RO -Group -Split BIT STRING (SIZE [1 to 6] )

OPTIONAL,

The interpretation of this optional IE field and the associated bit could be as follow: In case the field is absent, legacy behavior of the gNB is assumed. In case the IE field is present, the bit value will represent the number of SSBs in the first RO Group (ROG).

In the following and with reference to Fig.4 an example for an exemplary random access configuration is provided. In this example, a random access configuration, index=45 (see below Table 2), is used to further illustrate the division or split of RACH occasions into ROG’s as proposed in this disclosure.

Table 2: Random access configurations for FR2 and unpaired spectrum assuming PRACH Config.

Index = 45 [see Table 6.3.3.2-4; 3GPP 38.211], The random-access configuration, index=45, is shown in Figure 4 for a Sub Carrier Spacing (SCS) of 120 kHz, with an indication that the first 4 RACH occasions belong to the first ROG, i.e. RO-Group-Split = 4. The UE will interpret this the following way:

• SSB#1 to SSB#4 are part of ROG# 1 and the UE will send one preamble at the RO associated with the SSB (any of SSB#1 to SSB#4) received with the highest RSRP level (or based on another suitable evaluation of the beam quality).

• SSB#5 to SSB# 12 are part of ROG#2 and the UE will send one preamble at the RO associated with the SSB (any of SSB#5 to SSB# 12) received with the highest RSRP level (or based on another suitable evaluation of the beam quality).

For instance, considering the case where the gNB receives the same preamble at RO#2 and RO#8 it will interpretate this as narrow beam configuration #4 (SSB#8 is the fourth beam configuration in ROG#2) associated to wide beam configuration #2 and can now configure a narrow beam with increases antenna gain for the remaining IA messages (Msg#2 to Msg#4).

The example just illustrated in Figure 4 uses the wider SSB beam in the first ROG and the narrower SSB beams in the second ROG. However, generally, the gNB could reverse this and use the first ROG for the narrower SSB beams and the second ROG for the wider SSB beams. The gNB would just need to change the value of RO-Group-Split from 4 to 8 in this example. This will be transparent for the UE, as it just needs to know the split and not which beam configurations the gNB utilizes in the different ROGs.

Turning now to Fig. 5a and Fig. b, there is shown a signaling diagram 500 for the case when only the gNB is utilizing the proposed signaling (i.e. the IE “RO-Group-Split”), but the UE is not configured to use ROGs.

More specifically, a legacy UE will not understand the suggested ROG signaling (i.e. the IE “RO-Group-Split”) and will only send a single preamble for the SSB received with the highest RSRP, which could be either in the first ROG or the second ROG. If the gNB only receives a preamble in the ROG for the wider SSB beams (i.e. of the first ROG in the above examples), it will revert to the conventional or legacy procedure as illustrated in Figure 1 for that specific UE. However, in case the gNB will only receive a single Msgl on a RO associated to a narrow beam (i.e. of the second ROG in the above examples), the gNB will not be able to unambiguously identify the exact angular direction of the beam and the UE, since the RO was provided simultaneously with narrow beams in multiple angular directions. Thus, the gNB will initiate the procedure as shown in Fig. 5a, b to ensure a successful RACH procedure for UE.

The first part of the signaling corresponds to the signaling described with respect to Fig. 3, i.e. actions 501, 502, 504 correspond to actions 301, 302, 304.

Thus, in the first ROG, the gNB sequentially transmits SSBs in different angular directions (which can be considered as the being the legacy SSB procedure), action 501.

In the second ROG, the gNB will simultaneously transmit one SSB with a narrow beam in each of the angular directions covered by the wider SSB beam belonging to the first ROG, which is sequentially repeated for all the narrow beams used for refinement of the wider SSB beams, action 502.

However, while the gNB is listening for preambles in the first ROG to determine the best wider SSB beam, the gNB will not receive any preambles for this ROG, as the UE is not configured to interpret the signaled ROG-split and thus does not send a preamble for this first ROG, crossed out action 503.

The gNB may listen for preambles in the second ROG with the associated beam configuration used in action 502 and will receive a corresponding Msgl based on the RACH occasion associated with the narrow SSB beam received at the UE, action 504. The gNB can thus determine the best narrow beam. While the gNB may now know the best narrow beam, it may still not know the corresponding best wide SSB beam.

The gNB may thus change its behavior compared to the procedure illustrated in Fig. 3. The gNB may now send sequentially (or alternatively simultaneously) one Msg2, action 505, with each of the narrow beams already identified based on the received Msgl in action 504 (i.e. the SSB beams of an SB group with the same SSB). The respective Msg2 messages will be configured such that the associated Msg3 messages for the Msg2 messages will be allocated in the same time instance (e.g. slot), but with different Band-Width Parts (BWP), whereby the gNB only have to configure multiple narrow SSB beam for recption a single time, independent on which narrow SSB beam (angular direction) the UE is responding to. This concept is illustrated in Fig. 6. These Msg2 will advantageously still be transmitted with increased antenna gain.

The UE may only receive the Msg2 transmitted into the direction of the UE (the other Msg2 will either not be received or only with lower power or quality) and transmit a Msg3 according to the resource allocation in the Msg2, action 506. The gNB may then receive the Msg3 using the simultaneously multiple narrow beam configuration identified in action 504. The BWP location of the received Msg3 may be used by the gNB to identify the best narrow beam fort that UE.

The gNB may then send a Msg4 with a single narrow beam with increased antenna gain, action 507.

A legacy UE may send its preamble on a RO corresponds to or associates with the best received SSB beam, which will depend on the EIRP level of the SSB beams in the different ROGs. The EIRP levels of the two ROGs can in some cases be at the same level even though the narrow SSB beams have a higher antenna gain that the wider SSB beams. This is due to potential hardware limitations at the gNB, where the available PA power level must be divided between the simultaneously transmitted narrow SSB beams. As such, the gain in antenna gain is reduced by the reduced Tx power level. Other gNBs implementations may be capable of transmitted the narrow SSB beams with an increased EIRP equal to the increased antenna gain.

Compared to the conventional beam management and the situation in which the UE utilizes the configuration information regarding the ROGs, in the just described example the gNB only receives a single Msgl on one ROG. Therefore, the gNB assigns Msg3 resources in same time instance but in different BWPs to be able to differentiate among different narrow SSB beams. The gNB listens for a Msg3 with narrow beams simultaneously on all panels and relates a received Msg3 in a specific BWP to a specific narrow beam. Turning now to Fig. 8, there is shown a block diagram of an exemplary embodiment of a first or second terminal device or UE 800 according to the present disclosure. For example, UE 800 may be one of a smartphone, a tablet computer, a notebook computer, a smart watch, a smart band, an loT device or a vehicle or a part thereof.

UE 800 comprises a processor 801. Processor 801 may represent a single processor or two or more processors, which are for instance at least partially coupled, for instance via a bus. Processor 801 may execute a program code stored in program memory 802 for instance program code causing mobile device 800 in connection with base station 800 to perform one or more of the embodiments of a method according to the present disclosure or parts thereof, when executed on processor 801, and interfaces with a main memory 803. Program memory 802 may also contain an operating system for processor 801. Some or all of memories 802 and 803 may also be included into processor 801.

One of or both of a main memory and a program memory of a processor (e.g. program memory 802 and main memory 803) could be fixedly connected to the processor (e.g. processor 801) or at least partially removable from the processor, for instance in the form of a memory card or stick.

A program memory (e.g. program memory 802) may for instance be a non-volatile memory. It may for instance be a FLASH memory (or a part thereof), any of a ROM, PROM, EPROM, MRAM or a FeRAM (or a part thereof) or a hard disc (or a part thereof), to name but a few examples. For example, a program memory may for instance comprise a first memory section that is fixedly installed, and a second memory section that is removable from, for instance in the form of a removable SD memory card.

A main memory (e.g. main memory 803) may for instance be a volatile memory. It may for instance be a DRAM memory, to give non-limiting example. It may for instance be used as a working memory for processor 801 when executing an operating system, an application, a program, and/or the like.

Processor 801 may further control a communication interface 804 (e.g. radio interface) configured to receive and/or transmit data and/or information. For instance, communication interface 804 may be configured to transmit and/or receive radio signals from a radio node, such as a base station, in particular as described herein. It is to be understood that any computer program code based processing required for receiving and/or evaluating radio signals may be stored in an own memory of communication interface 804 and executed by an own processor of communication interface 804 and/or it may be stored for example in memory 803 and executed for example by processor 801.

Communication interface 804 may in particular be configured to communicate according to a cellular communication system like a 2G/3G/4G/5G or future generation cellular communication system. Terminal device 800 may use radio interface 804 to communicate with a base station.

For example, the communication interface 804 may comprise a BLE and/or Bluetooth radio interface including a BLE transmitter, receiver or transceiver. For example, radio interface 804 may additionally or alternatively comprise a WLAN radio interface including at least a WLAN transmitter, receiver or transceiver.

The components 802 to 804 of terminal device 800 may for instance be connected with processor 801 by means of one or more serial and/or parallel busses.

It is to be understood that terminal device 800 may comprise various other components. For example, terminal device 800 may optionally comprise a user interface (e.g. a touch- sensitive display, a keyboard, a touchpad, a display, etc.).

Fig. 9 is a block diagram of an exemplary embodiment of a network entity, such as a base station or gNB. For instance, network device 900 may be configured for scheduling and/or transmitting signals to the UE, as described above.

Network device 900 comprises a processor 901. Processor 901 may represent a single processor or two or more processors, which are for instance at least partially coupled, for instance via a bus. Processor 901 executes a program code stored in program memory 902 (for instance program code causing network device 900 to perform alone or together with terminal device 800 embodiments according to the present disclosure or parts thereof), and interfaces with a main memory 903.

Program memory 902 may also comprise an operating system for processor 901. Some or all of memories 902 and 903 may also be included into processor 901.

Moreover, processor 901 controls a communication interface 904 which is for example configured to communicate according to a cellular communication system like a 2G/3G/4G/5G cellular communication system. Communication interface 904 of apparatus

900 may be realized by radio heads for instance and may be provided for communication between network device and terminal device.

The components 902 to 904 of apparatus 900 may for instance be connected with processor

901 by means of one or more serial and/or parallel busses.

It is to be understood that apparatuses 800, 900 may comprise various other components.

Fig. 10 is a schematic illustration of examples of tangible and non-transitory computer- readable storage media according to the present disclosure that may for instance be used to implement memory 802 of Fig. 8 or memory 902 of Fig. 9. To this end, Fig. 10 displays a flash memory 1000, which may for instance be soldered or bonded to a printed circuit board, a solid-state drive 1001 comprising a plurality of memory chips (e.g. Flash memory chips), a magnetic hard drive 1002, a Secure Digital (SD) card 1003, a Universal Serial Bus (USB) memory stick 1004, an optical storage medium 1005 (such as for instance a CD- ROM or DVD) and a magnetic storage medium 1006.

Any presented connection in the described embodiments is to be understood in a way that the involved components are operationally coupled. Thus, the connections can be direct or indirect with any number or combination of intervening elements, and there may be merely a functional relationship between the components.

Further, as used in this text, the term ‘circuitry’ refers to any of the following: (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry)

(b) combinations of circuits and software (and/or firmware), such as: (i) to a combination of processor(s) or (ii) to sections of processor(s)/ software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone, to perform various functions) and

(c) to circuits, such as a microprocessor s) or a section of a microprocessor s), that require software or firmware for operation, even if the software or firmware is not physically present.

This definition of ‘circuitry’ applies to all uses of this term in this text, including in any claims. As a further example, as used in this text, the term ‘circuitry’ also covers an implementation of merely a processor (or multiple processors) or section of a processor and its (or their) accompanying software and/or firmware. The term ‘circuitry’ also covers, for example, a baseband integrated circuit or applications processor integrated circuit for a mobile phone.

Any of the processors mentioned in this text, in particular but not limited to processors 801 and 901 of Figs. 8 and 9, could be a processor of any suitable type. Any processor may comprise but is not limited to one or more microprocessors, one or more processor(s) with accompanying digital signal processor(s), one or more processor(s) without accompanying digital signal processor(s), one or more special-purpose computer chips, one or more field- programmable gate arrays (FPGAS), one or more controllers, one or more applicationspecific integrated circuits (ASICS), or one or more computer(s). The relevant structure/hardware has been programmed in such a way to carry out the described function.

Moreover, any of the actions or steps described or illustrated herein may be implemented using executable instructions in a general-purpose or special-purpose processor and stored on a computer-readable storage medium (e.g., disk, memory, or the like) to be executed by such a processor. References to ‘computer-readable storage medium’ should be understood to encompass specialized circuits such as FPGAs, ASICs, signal processing devices, and other devices. Moreover, any of the actions described or illustrated herein may be implemented using executable instructions in a general-purpose or special-purpose processor and stored on a computer-readable storage medium (e.g., disk, memory, or the like) to be executed by such a processor. References to ‘computer-readable storage medium’ should be understood to encompass specialized circuits such as FPGAs, ASICs, signal processing devices, and other devices.

The wording “A, or B, or C, or a combination thereof’ or “at least one of A, B and C” may be understood to be not exhaustive and to include at least the following: (i) A, or (ii) B, or (iii) C, or (iv) A and B, or (v) A and C, or (vi) B and C, or (vii) A and B and C.

It will be understood that the embodiments disclosed herein are only exemplary, and that any feature presented for a particular exemplary embodiment may be used with any aspect of the present disclosure on its own or in combination with any feature presented for the same or another particular exemplary embodiment and/or in combination with any other feature not mentioned. It will further be understood that any feature presented for an example embodiment in a particular category may also be used in a corresponding manner in an example embodiment of any other category.

Abbreviations

SSB Synchronization Signal Block

CSI-RS Channel State Information Reference Signal

RS Reference Signals

BM Beam Management

RSPR Reference Signal Received Power

MIB Master Information Block

SIB System Information Block

UE User Equipment gNB next Generation Node B

RO RACH Occasion

ROG RACH Occasion Group

IE Information Element

EIRP Equivalent Isotropic Radiation Power BWP Band Width Part