Improved linear beam sweeping in high-speed scenarios

Abstract

A measure is provided for improving linear beam sweeping in high speed scenarios, which exemplarily includes setting a second beamwidth characteristic of a second beam of a beam sweep, the setting including calculating the second beamwidth characteristic based on a first beamwidth characteristic of a first beam of the beam sweep and a ratio between a first path loss of the first beam between an antenna and a first position in a linear trajectory covered by the beam sweep and a second path loss of the second beam between the antenna and a second position in the linear trajectory.

Description

[Technical Field]

[0001] Various exemplary embodiments relate to improving linear beam sweeping in high-speed scenarios. More particularly, various exemplary embodiments relate illustratively to approaches (including methods, apparatus, and computer program products) for achieving improved linear beam sweeping in high-speed scenarios. [Background technology]

[0002] This specification relates generally to radio coverage of linear tracks in cellular deployment scenarios, and particularly in high speed scenarios.

[0003] More particularly, this specification relates to the field of wireless communication systems, for example, 5G-NR systems. One promising 5G use case is the high-speed train scenario, which is being discussed in 3GPP. 5G-NR systems face several challenges in supporting such scenarios; one main challenge is caused by the multi-beam operation feature of 5G-NR, as described below.

[0004] High-speed commercial trains are a popular regional transportation option for intercity (typically medium- to long-distance) commuters around the world. For example, Japan's Shinkansen high-speed railway has been in commercial service since 1964 and is used by more than 350 million people annually; each Shinkansen train can carry more than 1,400 passengers. In many countries, high-speed rail networks cover vast geographic areas. For example, China has the world's longest high-speed rail network, reaching a maximum of 29,000 kilometers by the end of 2018 and will be expanded to 38,000 kilometers by 2025. Today's maximum speed of high-speed trains is less than 400 kilometers per hour. In the near future, faster trains (e.g., linear motor or magnetic levitation trains) with speeds of 500 kilometers per hour and above will be deployed. As demand for high-speed rail steadily increases over time, there will be a demand for mobile network operators to provide mobile broadband services to passengers on such trains. Therefore, the 3rd Generation Partnership Project (3GPP) has initiated two work items on 5G New Radio (NR) enhancements targeting mobile speeds of up to 500 kilometers per hour. These work items include "New WID on NR support for high-speed train scenarios in Frequency Range 2" [3GPP RP-202037] and "Revised WID on enhanced NR support for high-speed train scenarios for Frequency Range 1" [3GPP RP-202335]. The former work item addresses high-speed train deployments for 5G NR operating in the mmWave band, while the latter addresses high-speed train deployments for sub-6 GHz.

[0005] Figure 4 (Figure 4(a) and Figure 4(b)) shows schematic diagrams illustrating circular beam sweeping and linear beam sweeping as examples. In particular, Figure 4(a) shows a conventional cellular deployment scenario, and Figure 4(b) shows a high-speed train deployment scenario.

[0006] FIG. 5 shows an exemplary schematic diagram illustrating the relationship between beam radius and beam coverage in linear beam sweeping.

[0007] In a conventional 5G NR cellular deployment scenario, a set of identical beams generated by a gNB is sequentially swept in a circular pattern with a fixed radius, as shown in Figure 4(a); the center of the beam sweeping is the gNB node. Because the beams are identical (i.e., the half-power beam width (HPBW) is fixed), circular beam sweeping results in uniform beam coverage. In a high-speed train deployment scenario, each beam is directed toward a different location along the path of a UE aboard the high-speed train. Typically, the track of a high-speed train is straight, resulting in linear beam sweeping instead of circular, as shown in Figure 4(b). Unlike circular beam sweeping, employing identical beams in a linear beam sweeping procedure leads to non-uniform beam coverage because the radius of each beam is different, as shown in Figure 4(b). It is important to note that beam coverage is proportional to the radius given a fixed HPBW. The problem of uneven beam coverage is further illustrated in Figure 5. A set of five beams is swept and positioned along the trajectory of the UE / CPE. k (k is the beam identification) and directed to a specific position indicated by the beam radius (or beam length) r k This leads to the following inequality for , where the beam radius (or beam length) is the distance between the remote radio head (RRH) and P k This refers to the direct propagation distance between the UE / CPE in the r0>r1>r2>r3>r4 (formula 1)

[0008] The coverage of the kth beam is given by the segment length l along the trajectory. k Using equation (1), similar inequalities can be derived for different beam segment lengths, given by equation (2). l0>l1>l2>l3>l4 (Equation 2)

[0009] The employment of directional antennas (e.g., large antenna arrays) in conjunction with advanced beamforming techniques in gNBs to form very narrow (pencil) beams generally results in small beam coverage in mmWave communication systems. The linear beam sweeping described above can lead to a further reduction in beam coverage. The resulting small coverage poses significant challenges to beam and mobility management procedures. Small coverage implies a short amount of time available to complete the execution of such procedures. In the worst case scenario, a fast UE / CPE will fail to detect a beam before moving into the coverage of an adjacent beam.

[0010] FIG. 6 shows an exemplary schematic diagram of a series of single frequency cells for a high-speed train scenario.

[0011] In particular, Figure 6 shows a typical cellular layout for a high-speed train scenario considered by 3GPP. In this scenario, a series of cells are deployed along the railroad tracks to provide continuous wireless coverage to user equipment (UE) devices on the train. Each cell consists of one baseband unit (BBU) connected to multiple remote radio heads (RRHs), which communicate over the air with the user equipment devices. In the case of a single radio frequency cell, the i-th BBU simultaneously sends the same signal to J remote radio heads; the signal is then transmitted to the UE device by each of the J remote radio heads using the same radio frequency. Alternatively, the UE device communicates with the remote radio heads through a customer premises equipment (CPE), which acts as a relay node and is mounted on the roof of the train car. A cluster of remote radio heads connected to one BBU forms a cell, and within the cell, each remote radio head may transmit one or more beams in a time-sequential manner to cover a spatial area within the cell. This is called beam sweeping.

[0012] During beam sweeping, one synchronization signal (SS) block is transmitted in one direction using one beam, then the next block is transmitted in a different direction using a different beam, and so on. In addition to SS blocks, reference signals such as CSI-RS are also sent using these beams, although possibly narrower than those used for the SS blocks.

[0013] In view of the above, employing identical beams in a linear beam sweeping procedure leads to uneven beam coverage, thereby potentially worsening or even making it impossible to establish and maintain radio links to terminals moving at high speeds.

[0014] Therefore, there is a need to provide improved linear beam sweeping in high speed scenarios. Summary of the Invention [Problem to be solved by the invention]

[0015] The various illustrative embodiments aim to address at least some of the above issues and / or problems and drawbacks. [Means for solving the problem]

[0016] Various aspects of the example embodiments are set out in the accompanying claims.

[0017] According to an example aspect, a method for a radio cell control entity is provided, the method including setting a second beamwidth characteristic of a second beam of a beam sweep, the setting including calculating the second beamwidth characteristic based on a first beamwidth characteristic of a first beam of the beam sweep and a ratio between a first path loss of the first beam between an antenna and a first position in a linear trajectory covered by the beam sweep and a second path loss of the second beam between the antenna and a second position in the linear trajectory.

[0018] According to an exemplary aspect, an apparatus for a radio cell control entity is provided, the apparatus including: a setting circuit configured to set a second beamwidth characteristic of a second beam of a beam sweep; and a calculation circuit configured to calculate the second beamwidth characteristic based on a first beamwidth characteristic of a first beam of the beam sweep and a ratio between a first pathloss of the first beam between an antenna and a first position on a linear trajectory covered by the beam sweep and a second pathloss of the second beam between the antenna and a second position on the linear trajectory.

[0019] According to an example aspect, a radio cell control entity apparatus is provided, the apparatus including at least one processor, at least one memory including computer program code, and at least one interface configured to communicate with at least another apparatus, wherein the at least one processor is configured to cause the apparatus to set, using the at least one memory and the computer program code, a second beamwidth characteristic of a second beam of a beam sweep, and in connection with the setting, the at least one processor is configured, using the at least one memory and the computer program code, to cause the apparatus to calculate, based on a first beamwidth characteristic of a first beam of the beam sweep and a ratio between a first pathloss of the first beam between an antenna and a first position on a linear trajectory covered by the beam sweep and a second pathloss of the second beam between the antenna and a second position on the linear trajectory.

[0020] According to an exemplary aspect, a computer program product is provided that includes computer-executable computer program code configured, when the program is executed on a computer (e.g., a computer of an apparatus according to any one of the above-mentioned apparatus-related exemplary aspects of the present disclosure), to cause the computer to perform a method according to any one of the above-mentioned method-related exemplary aspects of the present disclosure.

[0021] Such a computer program product may include (or may be embodied in) a (tangible) computer-readable (storage) medium or the like on which computer-executable computer program code is stored, and / or the program may be directly loadable into the internal memory of the computer or its processor.

[0022] Any one of the above aspects enables efficient linear beam sweeping while avoiding or reducing the adverse effects of distance differences in the case of linear beam sweeping, thereby resolving at least some of the problems and drawbacks identified in connection with the prior art.

[0023] Exemplary embodiments provide improved linear beam sweeping in high-speed scenarios. More specifically, exemplary embodiments provide strategies and mechanisms for achieving improved linear beam sweeping in high-speed scenarios.

[0024] Improvements are therefore achieved by methods, apparatus and computer program products that enable / achieve improved linear beam sweeping in high speed scenarios.

[0025] In the following, the present disclosure will be explained in more detail, by way of non-limiting example, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a block diagram illustrating an apparatus according to an example embodiment. [Figure 2] FIG. 1 is a block diagram illustrating an apparatus according to an example embodiment. [Figure 3] 1 is a schematic diagram of a procedure according to an example embodiment. [Figure 4] (FIGS. 4(a) and 4(b)) show exemplary schematic diagrams illustrating circular and linear beam sweeping. [Figure 5]FIG. 1 shows a schematic diagram exemplarily illustrating the relationship between beam radius and beam coverage in linear beam sweeping. [Figure 6] FIG. 1 shows a schematic diagram illustrating an exemplary series of single-frequency cells for a high-speed train scenario. [Figure 7] 1 shows a schematic diagram illustrating the principle of beam footprint calculation according to an example embodiment; [Figure 8] 1 shows an exemplary schematic diagram of the radiation pattern of an antenna array; [Figure 9] 1 shows a schematic diagram exemplarily illustrating a two-dimensional radiation pattern on a spherical azimuthal plane. [Figure 10] 1 shows a schematic diagram illustrating an exemplary two-dimensional radiation pattern on a spherical elevation plane. [Figure 11] 1 is a schematic diagram of a procedure according to an example embodiment. [Figure 12] 1 is a schematic diagram of a procedure according to an example embodiment. [Figure 13] FIG. 10 is a block diagram illustrating an alternative apparatus according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present disclosure is described herein with reference to certain non-limiting examples and what are presently considered to be possible embodiments. Those skilled in the art will understand that the disclosure is in no way limited to these examples and may be more broadly applicable.

[0028] It should be noted that the following description of the present disclosure and its embodiments primarily refers to specifications used as non-limiting examples of certain exemplary network configurations and deployments. That is, the present disclosure and its embodiments are primarily described in relation to 3GPP specifications used as non-limiting examples of certain exemplary network configurations and deployments. Accordingly, the description of exemplary embodiments provided herein specifically refers to terminology directly related thereto. Such terminology is used only in the context of the presented non-limiting examples and, naturally, does not limit the disclosure in any way. Rather, any other communication or communication-related system deployment, etc., may also be utilized so long as it is compatible with the features described herein.

[0029] In the following, various embodiments and implementations of the present disclosure, as well as aspects or embodiments thereof, will be described using multiple variations and / or alternatives. Generally, it is noted that, according to certain needs and constraints, all of the variations and / or alternatives described may be provided singly or in any conceivable combination (including combinations of individual features of the various variations and / or alternatives).

[0030] Generally speaking, exemplary embodiments provide strategies and mechanisms for improving (enabling / realizing) linear beam sweeping in high-speed scenarios.

[0031] Briefly, in accordance with the illustrative embodiments, methods and mechanisms are provided for overcoming the problem of uneven coverage caused by different beams during beam sweeping.

[0032] Because coverage varies from beam to beam, the exemplary embodiment includes a technique for measuring the coverage of each beam. Unlike traditional hexagonal cell layouts, coverage along the UE / CPE's trajectory is more relevant than coverage area in high-speed deployment scenarios. The technique disclosed herein measures the segment length of the UE / CPE's trajectory covered by a beam based on the beam radius, pointing angle, and HPBW of the RRH antenna array. The beam segment length is required to accurately determine the beam dwell time, an essential quantity in radio resource management, where the beam dwell time is the duration that a UE / CPE traveling at a certain target speed remains within the portion of the trajectory covered by the beam.

[0033] In relation to the issue of non-uniform coverage, the exemplary embodiment aims to increase the segment length of a beam by widening the HPBW of the RRH antenna array pattern. This means that the original HPBW is widened by a bounded factor. During beam sweeping, a set of beams is swept by the RRH. In the set of beams, the beam with the longest segment length is used as the reference for segment length extension of the other beams. The bounded factor is derived from the difference in free-space path loss between the reference beam and the beam with the extended segment length. Free-space path loss is proportional to the square of the beam radius; this means that the reference beam with the longest beam radius among all beams has the highest free-space path loss. It is important to note that widening the HPBW leads to lower directivity of the RRH antenna array. However, the reduction in antenna directivity is compensated for by the reduction in free-space path loss for the beam, as long as the HPBW widening factor does not exceed the difference in free-space path loss from the reference beam. Therefore, the link quality of the beam does not degrade compared to the reference beam.

[0034] According to an alternative exemplary embodiment, the segment length of a beam is reduced by narrowing the HPBW of the RRH antenna array pattern. This means that the original HPBW is narrowed by a bounding factor. During beam sweeping, a set of beams is swept by the RRH. In the set of beams, the beam with the shortest segment length is used as a reference for segment length reduction of the other beams. Similar principles as described above apply to this alternative.

[0035] Another notable feature of the exemplary embodiment is that it allows fine tuning of the HPBW widening factor in the azimuth or elevation direction, or a combination of the two, to maximize / minimize segment length.

[0036] In brief, therefore, in accordance with an example embodiment, a technique is provided for measuring the segment length covered by a beam along the trajectory of a UE / CPE based on the beam pointing angle, beam radius, and azimuth and elevation HPBW of an RRH antenna array.

[0037] Further, according to an example embodiment, there is provided a method for configuring HPBW of multiple beams transmitted from an antenna array, the configuration depending on at least the beam pointing angle and the beam propagation distance to the orbit of the UE / CPE receiver such that the ratio between the HPBW of different beams among the multiple beams with respect to a reference beam is limited by the ratio of the squares of the beam propagation distances of the reference beam and the respective beams, and such that the coverage lengths of each of the beams along the orbit are substantially equal.

[0038] Exemplary embodiments are identified in more detail below.

[0039] FIG. 1 is a block diagram illustrating an apparatus according to an exemplary embodiment. The apparatus may be a radio cell control entity 10 (e.g., a baseband unit) including a setting circuit 11 and a calculation circuit 12. The setting circuit 11 sets a second beamwidth characteristic of a second beam of a beam sweep. The calculation circuit 12 (which may be part of the setting circuit 11) calculates the second beamwidth characteristic based on a first beamwidth characteristic of a first beam of the beam sweep and a ratio between a first pathloss of the first beam between an antenna and a first position on a linear trajectory covered by the beam sweep and a second pathloss of the second beam between the antenna and a second position on the linear trajectory. FIG. 3 is a schematic diagram of a procedure according to an exemplary embodiment. The apparatus according to FIG. 1 may perform the method of FIG. 3, but is not limited to this method. The method of FIG. 3 may be performed by the apparatus of FIG. 1, but is not limited to being performed by this apparatus.

[0040] As shown in FIG. 3 , a procedure according to an exemplary embodiment includes an operation (S31) of setting a second beamwidth characteristic of a second beam of a beam sweep, the setting (S31) including an operation (S311) of calculating the second beamwidth characteristic based on a first beamwidth characteristic of a first beam of the beam sweep and a ratio between a first path loss of the first beam between an antenna and a first position in a linear trajectory covered by the beam sweep and a second path loss of the second beam between the antenna and a second position in the linear trajectory.

[0041] Figure 2 is a block diagram illustrating an apparatus according to an exemplary embodiment. In particular, Figure 2 illustrates a variant of the apparatus shown in Figure 1. The apparatus according to Figure 2 may therefore further comprise a decision circuit 21, a selection circuit 22, a multiplication circuit 23, a calculation circuit 24, and / or a control circuit 25.

[0042] In embodiments, at least some of the functionality of the apparatus shown in Figure 1 (or Figure 2) may be shared between two physically separate devices forming one operating entity. Thus, the apparatus may be seen to denote an operating entity comprising one or more physically separate devices for performing at least some of the processes described.

[0043] According to a further exemplary embodiment, the first path loss corresponds to a first direct propagation length of the first beam, and the second path loss corresponds to a second direct propagation length of the second beam.

[0044] According to a further exemplary embodiment, the first path loss corresponds to the first direct propagation length between the antenna and the first location in a first antenna boresight direction for the first beam, and the second path loss corresponds to the second direct propagation length between the antenna and the second location in a second antenna boresight direction for the second beam.

[0045] 3, exemplary details of the calculation operations (S311) are provided, which are essentially independent of each other in the sense that they are. Such exemplary calculation operations (S311) according to exemplary embodiments may include determining a factor limit value as the square of the quotient of the first direct propagation length and the second direct propagation length, selecting a factor based on the factor limit value, and multiplying the first beam width characteristic by the factor.

[0046] According to a further exemplary embodiment, the factor is a product of a beamwidth azimuth component factor and a beamwidth elevation component factor.

[0047] According to a further exemplary embodiment, the first direct propagation length of the first beam is longer than the second direct propagation length of the second beam, and the factor limit is an upper limit value for the factor.

[0048] According to a variation of the procedure shown in Figure 3, exemplary details of the calculation operations (S311) are provided, which are essentially independent of each other in the sense that they are. Such exemplary calculation operations (S311) according to exemplary embodiments may include selecting the factors such that the link performance of the second beam is not worse than the link performance of the first beam.

[0049] According to a further exemplary embodiment, the first direct propagation length of the first beam is shorter than the second direct propagation length of the second beam, and the factor limit is a lower limit for the factor.

[0050] According to a variation of the procedure shown in Figure 3, exemplary details of the calculation operations (S311) are provided, which are essentially independent of each other in the sense that they are. Such exemplary calculation operations (S311) according to exemplary embodiments may include selecting the factors such that the link performance of the second beam is not better than the link performance of the first beam.

[0051] 3, exemplary details of the calculation operation (S311) are provided, which are essentially independent of each other in the sense that they are. Such exemplary calculation operation (S311) according to an exemplary embodiment may include selecting the factor such that a dwell time corresponding to passing with a predetermined velocity a second orbital length of a second orbital portion of the linear orbit covered by the second beam satisfying the second beam width characteristic is longer than a predetermined period.

[0052] According to a further exemplary embodiment, the predetermined period is a minimum period required for a given beam management and mobility procedure.

[0053] 3, exemplary details of the calculating operation (S311) are provided, which are essentially independent of each other in the sense that they are. Such exemplary calculating operation (S311) according to exemplary embodiments may include selecting the factor such that a second dwell time corresponding to passing, with a predetermined velocity, a second orbital length of a second orbital portion of the linear trajectory covered by the second beam satisfying the second beam width characteristic is shorter than a first dwell time corresponding to passing, with the predetermined velocity, a first orbital length of a first orbital portion of the linear trajectory covered by the first beam satisfying the first beam width characteristic.

[0054] According to a further exemplary embodiment, the second beamwidth characteristic of the second beam is selected such that a received power of the second beam exceeds a predetermined threshold.

[0055] According to a further exemplary embodiment, the second beam width characteristic of the second beam is selected such that a link loss of the second beam is below a predetermined threshold.

[0056] 3, exemplary details of the calculation operation (S311) are provided, which are essentially independent of each other in the sense that they are. Such exemplary calculation operation (S311) according to exemplary embodiments may further include selecting the factor such that a second orbit length of a second orbit portion of the linear trajectory covered by the second beam satisfying the second beam width characteristic is substantially equal to a first orbit length of a first orbit portion of the linear trajectory covered by the first beam satisfying the first beam width characteristic.

[0057] According to variations on the procedure shown in Figure 3, exemplary additional operations are provided, which are essentially independent of one another in their nature. According to such variations, an exemplary method according to example embodiments may include an operation of calculating the second orbital length of the second orbital portion based on the second beamwidth characteristic, the second direct propagation length, and at least one of a second azimuth beam pointing angle and a second elevation beam pointing angle corresponding to the second antenna boresight direction for the second beam from the antenna to the second location.

[0058] According to variations of the procedure shown in Figure 3, exemplary additional operations are provided, which are essentially independent of one another in their nature. According to such variations, an exemplary method according to example embodiments may include an operation of calculating the first orbit length of the first orbital portion based on the first beamwidth characteristic, the first direct propagation length, and at least one of a first azimuth beam pointing angle and a first elevation beam pointing angle corresponding to the first antenna boresight direction for the first beam from the antenna to the first location.

[0059] According to variations of the procedure shown in Figure 3, exemplary additional operations are provided, which are essentially independent of one another in their true sense. According to such variations, an exemplary method according to example embodiments may include: calculating, based on the first beamwidth characteristic, a plurality of direct propagation lengths between the antenna and a plurality of positions on the linear trajectory of a plurality of antenna boresight directions for the plurality of beams, and at least one of a plurality of azimuth beam pointing angles and elevation beam pointing angles corresponding to the plurality of antenna boresight directions from the antenna to the plurality of positions on the linear trajectory, a plurality of trajectory lengths of a plurality of trajectory portions of the linear trajectory covered by a plurality of beams that satisfy the first beamwidth characteristic; and selecting, as the first beam, a beam from the plurality of beams having a longest trajectory length among the plurality of trajectory lengths.

[0060] According to variations of the procedure shown in Figure 3, exemplary additional operations are provided, which are essentially independent of one another in their true sense. According to such variations, an exemplary method according to example embodiments may include: calculating, based on the first beamwidth characteristic, a plurality of direct propagation lengths between the antenna and a plurality of positions on the linear trajectory of a plurality of antenna boresight directions for the plurality of beams, and at least one of a plurality of azimuth beam pointing angles and elevation beam pointing angles corresponding to the plurality of antenna boresight directions from the antenna to the plurality of positions on the linear trajectory, a plurality of trajectory lengths of a plurality of trajectory portions of the linear trajectory covered by a plurality of beams that satisfy the first beamwidth characteristic; and selecting, as the first beam, a beam from the plurality of beams having a shortest trajectory length among the plurality of trajectory lengths.

[0061] According to a further exemplary embodiment, each orbit length of the plurality of orbit lengths corresponds to a respective length of a respective intersection point between the linear orbit and a respective ellipse formed by the intersection of the respective beam with a respective plane defined by the linear orbit and a respective horizontal line perpendicular to and intersecting the linear orbit.

[0062] According to a further exemplary embodiment, each orbit length of the plurality of orbit lengths comprises: l k =y2-y1 is calculated as

number

number

[0063] According to a further exemplary embodiment, the first beamwidth characteristic of the first beam is a first fractional-power beamwidth of the first beam and the second beamwidth characteristic of the second beam is a second fractional-power beamwidth of the second beam.

[0064] According to further example embodiments, the first fractional power beamwidth comprises a first fractional power beamwidth azimuth component of the first beam and a first fractional power beamwidth elevation component of the first beam, and the second fractional power beamwidth comprises a second fractional power beamwidth azimuth component of the second beam and a second fractional power beamwidth elevation component of the second beam. In some such embodiments, the fractional power beamwidth may be, for example, half a power beamwidth.

[0065] According to variations of the procedure shown in Figure 3, exemplary additional operations are provided, which are essentially independent of one another in their nature. According to such variations, an exemplary method according to example embodiments may include an operation of controlling an antenna device including the antenna to perform the beam sweep based on the first beamwidth characteristic of the first beam and the second beamwidth characteristic of the second beam.

[0066] According to a further exemplary embodiment, the antenna comprises an antenna array.

[0067] The exemplary embodiments outlined and identified above are described more particularly below.

[0068] In the high-speed train deployment scenario, one important cellular design parameter is the beam coverage provided by different beams emanating from the RRH, which is the segment length l covered by the kth beam along the trajectory of the UE / CPE. k In this specification, l k A mathematical expression for the point G(0,0,h RRH A cellular network model for high-speed train deployment is considered, with one RRH located at h RRH is the height of the RRH in meters.

[0069] FIG. 7 shows a schematic diagram illustrating the beam footprint calculation principle according to an example embodiment.

[0070] The RRH is equipped with a uniform rectangular planar antenna array capable of generating a set of K beams during beam sweeping. For 5G-NR operation in the mmWave frequency range, K is up to 64. All of the beams have equal half-power beamwidths. Example beams can be seen in Figure 8.

[0071] FIG. 8 shows an exemplary radiation pattern of an antenna array, and in particular a schematic diagram illustrating a typical antenna array pattern.

[0072] The RRH antenna array lies in the yz plane at the origin of the spherical coordinate system. The beam direction is governed by the maximum radiation direction in the antenna array pattern, which is also known as the antenna array boresight. Boresight is defined by an ordered pair of spherical coordinates (φ, θ); φ is the azimuth angle between the positive x-axis and the vertical projection of the boresight on the xy plane, and θ is the elevation angle that the boresight makes with the positive z-axis. The antenna array half-power beamwidth (HPBW), measured in degrees (as an example of a fractional power beamwidth), is the angular separation between the two directions at which the radiated intensity is reduced by half relative to its peak value at the boresight. As shown in Figures 9 and 10, respectively, the HPBW defined in the spherical azimuth plane is expressed as φ HPBW and the HPBW in the spherical elevation plane is given by θ HPBW Fig. 9 shows a schematic diagram exemplarily illustrating a two-dimensional radiation pattern on a spherical azimuth plane, and Fig. 10 shows a schematic diagram exemplarily illustrating a two-dimensional radiation pattern on a spherical elevation plane.

[0073] The array antenna boresight for the kth beam is at point P k (u,y k ,h) and point P k is along the trajectory of the UE / CPE, where k is 1≦k≦K. Therefore, beam k is the vector

number

number

number

[0074] Vector

number

number

number

number

number

number

number

number

[0075] φ k To determine the vector

number

number

number

number

number

number

number

number

number

number

number

[0076] In short, the vector

number

[0077] In general, the footprint of the beam k projected onto the plane of the trajectory of the UE / CPE (i.e., the xy plane z=h in FIG. 7) has a center C(x c ,y c ,z c ), has an elliptical shape with a semimajor axis a and a semiminor axis b. The equation of such an ellipse is:

number

number

[0078] From trigonometry,

number

number

number

[0079] In the semiminor axis formula (equation (5c)), θ' c is a vector

number

number

number

[0080] Referring to Figure 7, the segment length of the UE / CPE's trajectory covered by the footprint of beam k is the line segment connecting points P1(u,y1,h) and P2(u,y2,h), where points P1 and P2 are the intersections of the ellipse with lines x=u, z=h. In determining these two points, substituting x=u into equation (5a) and rewriting it as a quadratic equation in y gives: αy 2 +βy+γ=0 (Equation 8a) where the coefficients are α=a 2 cos 2 φ k +b 2 sin 2 φ k (Formula 8b) β=2[y c (-a 2 cos 2 φ k -b 2 sin 2 φ k )+(ux c )(b 2 cosφ k sinφ k -a 2 cosφ k sinφk )] (Equation 8c)

number

[0081] The two solutions to the quadratic equation are

number

[0082] The segment length l of the UE / CPE's trajectory covered by beam k k (units of meters) is l k =y2-y1 (Equation 10) is given by

[0083] Therefore, the residence time t for beam k k (in seconds) is

number

[0084] To determine the width of the footprint produced by beam k, it is calculated by dividing the x-axis by the x-axis perpendicular to the line x=u, z=h. k (u,y k ,h) is the intersection of the line and the ellipse. k Using the same method as in the derivation of y=y k Substituting into equation (5a) we obtain a quadratic equation in x. α'x 2 +β'x+γ'=0 (Equation 12a) Here, the coefficients are α'=a 2 sin 2 φ k +b 2 cos 2 φ k (Formula 12b) β'=2[x c (-a 2 sin 2 φ k -b2 cos 2 φ k )+(y k -y c )(b 2 cosφ k sinφ k -a 2 cosφ k sinφ k )] (Equation 12c)

number

[0085] The two solutions to the quadratic equation are

number

[0086] The width w of the footprint defined by the beam k k (unit: meters) w k =x2-x1 (equation 14) It is expressed as:

[0087] 11 is a schematic diagram of a procedure according to an example embodiment, and in particular a flowchart illustrating a method for calculating beam segment length, width, and dwell time according to an example embodiment. More specifically, FIG. 11 illustrates applying the above formulas according to an example embodiment to calculate the segment length, l k , width w k , and residence time t k 1 shows a flowchart of an exemplary method for measuring

[0088] As shown in Fig. 11, first, the RRH antenna array parameters, azimuth angle HPBWφ HPBW , elevation angle HPBWθ HPBW , and height h RRH is decided.

[0089] Additionally, the UE / CPE parameters, distance u from the RRH, height h, speed and direction of movement are determined.

[0090] Furthermore, the required number of sweeping beams, K, is determined.

[0091] Furthermore, the segment length l for beam k k , width w k , and residence time t k is calculated according to equations (3)-(14).

[0092] When calculations have been performed for all beams, the processing in FIG. 11 ends.

[0093] If not, the next beam is selected and the calculations are performed on the newly selected beam.

[0094] The following table (showing exemplary beam coverage lengths, widths, and dwell times for different beam radii) gives the segment lengths, widths, and beam dwell times for different beam radii for an example high speed train deployment: k and w k , u=10m, θ HPBW =12.6°, φ HPBW = 12.6°, and 0 <y k < 90 meters, calculated using equations (10) and (14), respectively. k As decreases, the segment length l k is the beam coverage width w k When the UE / CPE speed is 500 km / h, the dwell time of beams 2-5 is t k is shorter than the minimum time required by the beam and mobility management procedures. As a result, such a short beam segment length l k These beams with .gtoreq..times ...

[0095] [Table 1]

[0096] The short beam segment length l mentioned abovek is due to the reduction in the footprint size of the beam k. Analyzing equation (5a), the beam footprint size is a function of the semimajor axis a and semiminor axis b of the ellipse. From equations (5a) and (5b), one important parameter that affects the magnitude of a and b is the elevation angle HPBWθ HPBW and azimuth angle HPBWφ HPBW Here, in linear beam sweeping, θ HPBW and φ HPBW is fixed for all K beams. To this end, according to an exemplary embodiment, those beams with short segment lengths may be increased by using a wider HPBW. According to an alternative exemplary embodiment, those beams with long segment lengths may be decreased by using a narrower HPBW. However, it is important to note that the antenna array directivity is inversely proportional to the HPBW; i.e., a wider HPBW leads to lower antenna array directivity, and a narrower HPBW leads to higher antenna array directivity. Mathematically, the two quantities are:

number

[0097] Since RRHs typically employ uniform rectangular antenna arrays, equation (15) becomes:

number

[0098] θ HPBW and φ HPBW are respectively σ θ,k and σ φ,kFor a beam k obtained using equation (16), if the beam is broadened (or narrowed, i.e., more generally, modified) by a factor of k teeth,

number

[0099] Let D0 denote the original directivity in equation (16), then by dividing it by equation (17),

number

[0100] Compared with D0, D k where σ φ,k and σ θ,k and both terms are real. To ensure that the link performance of beam k is no worse than beam 0 as a result of its lower directivity, the product (σ φ,k σ θ,k ) is a condition

number

number

[0101] Alternatively, compared to D0, D k where σ φ,k and σ θ,k and both terms are real. To ensure that the link performance of beam k is not better than beam 0 as a result of higher directivity, or that the residence time of beam k is not shorter than beam 0, the product (σ φ,k σθ,k ) is a condition

number

[0102] The free space propagation loss for beam 0 and beam k is:

number

[0103] Since all beams use the same carrier frequency for beam sweeping, the free space propagation loss ratio is

number

[0104] Equation (18) and (22)

number

number

[0105] Equation (23) is the product (σ φ,k σ θ,k )but

number

number

[0106] Expanded azimuth angle HPBWσ φ,k φ HPBW and elevation angle HPBWσ θ,k θ HPBW Using the segment length l k , width w k , and residence time t k is recalculated for beam k using equations (5)-(14). As the beam segment length increases, the number of beams required to provide the same coverage decreases.

[0107] 12 is a schematic diagram of a procedure according to an example embodiment, and in particular, a flowchart illustrating a method for increasing beam segment length and width according to an example embodiment. More specifically, FIG. 12 shows a flowchart of an example method for increasing beam coverage by widening HPBW.

[0108] As shown in FIG. 12, first, a beam k is selected for coverage expansion.

[0109] Furthermore, the free space propagation loss ratio

number

[0110] Furthermore, the widening factor σ θ,k and σ φ,k is determined.

[0111]

number

[0112] If not, i.e.

number

[0113] If the most recently processed beam is the last beam, the process of FIG. 12 ends.

[0114] If not, the next beam is selected and calculations and decisions are made on the newly selected beam.

[0115] The above procedures and functions may be implemented by the respective functional elements, processors, etc. described below.

[0116] In the above exemplary description of the network entity, only units that are relevant for understanding the principles of the disclosure are described using functional blocks. The network entity may include additional units necessary for its respective operations. However, descriptions of these units are omitted herein. The functional block configuration of the device should not be construed as limiting the disclosure, and a function may be performed by one block or further divided into sub-blocks.

[0117] In the foregoing description, when it is stated that an apparatus, i.e., a network entity (or some other means), is configured to perform some functions, this should be interpreted as being equivalent to stating that a (i.e., at least one) processor or corresponding circuitry, potentially in cooperation with computer program code stored in a memory of the respective apparatus, is configured to cause the apparatus to perform at least the functions so described. Also, such functions should be interpreted as being equivalently implementable by circuits or means specifically configured to perform the respective functions (i.e., the expression "a unit configured to" should be interpreted as being equivalent to expressions such as "means for").

[0118] An alternative diagram of an apparatus according to an exemplary embodiment is shown in Figure 13. As shown in Figure 13, according to the exemplary embodiment, an apparatus (network entity, e.g., radio cell control entity) 10' (corresponding to the network entity, e.g., radio cell control entity 10) comprises a processor 131, a memory 132, and an interface 133, which are connected by a bus 134 or the like, and the apparatus may be connected to another apparatus 139, e.g., an interface of another apparatus 139, via a link 135.

[0119] The processor 131 and / or the interface 133 may each include a modem or the like to facilitate communication over a link (wired or wireless). The interface 133 may each include a suitable transceiver coupled to one or more antennas or communication means for communication (wired or wireless) with a linked or connected device. The interface 133 is generally configured to communicate with at least one other device, i.e., its interface.

[0120] The memory 132 may store respective programs that, when executed by the respective processors, are responsible for including program instructions or computer program code that enable the respective electronic device or apparatus to operate according to the exemplary embodiments.

[0121] Generally speaking, each device / apparatus (and / or part thereof) may represent a means for performing a respective operation and / or exhibiting a respective functionality, and / or each device (and / or part thereof) may have functionality for performing a respective operation and / or exhibiting a respective functionality.

[0122] In the following description, when it is stated that a processor (or some other means) is configured to perform some functions, this should be interpreted as equivalent to stating that at least one processor is configured, potentially in cooperation with computer program code stored in the memory of the respective device, to cause the device to perform at least the functions so stated. Also, it should be interpreted that such functions can be equivalently implemented by means specifically configured to perform the respective functions (i.e., the phrases "a processor configured to cause xxx to do something" and "a processor configured to cause an device to do xxx" should be interpreted as equivalent to phrases such as "means for xxx").

[0123] According to an exemplary embodiment, an apparatus representing a network entity, e.g., a radio cell control entity 10, includes at least one processor 131, at least one memory 132 containing computer program code, and at least one interface 133 configured for communication with another apparatus. The processor (i.e., the at least one processor 131 using the at least one memory 132 and the computer program code) is configured to: set (thus, the apparatus comprising corresponding means for setting) a second beam-width characteristic of a second beam of a beam sweep; and calculate (thus, the apparatus comprising corresponding means for calculating) the second beam-width characteristic based on a first beam-width characteristic of a first beam of the beam sweep and a ratio between a first path loss of the first beam between an antenna and a first position on a linear trajectory covered by the beam sweep and a second path loss of the second beam between the antenna and a second position on the linear trajectory.

[0124] For further details regarding the operability / functionality of the individual devices, reference is made to the above description in relation to any one of Figures 1-14 respectively.

[0125] For purposes of the present disclosure set forth herein above: - the steps of the method, which may be implemented as software code portions and executed using a processor in a network server or a network entity (as an example of a device, apparatus and / or modules thereof, or as an example of an entity comprising an apparatus and / or modules therefor), can be specified using any known or future developed programming language, as long as the functionality defined by the steps of the method is preserved without relying on software code; - in general, any method step is suitable to be implemented as software or by hardware without changing the idea of the embodiment and its modifications in terms of the functionality implemented; - the method steps and / or devices, units or means likely to be implemented as hardware components in the apparatus defined above, or any modules thereof (e.g. a device performing the functions of the apparatus according to the above-mentioned embodiments), are hardware-independent and may be implemented using any known or future developed hardware technology such as MOS (Metal Oxide Semiconductor), CMOS (Complementary Metal-Oxide Semiconductor), BiMOS (Bipolar Metal-Oxide Semiconductor), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), TTL (Transistor Transistor Logic), or any hybrid thereof, for example using ASIC (Application Specific IC (Integrated Circuit)) components, FPGA (Field Programmable Gate Array) components, CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components; - devices, units or means (e.g. a network entity or network register as defined above or any one of their respective units / means) may be implemented as individual devices, units or means, but this does not exclude them being implemented in a distributed manner throughout the system, as long as the functionality of the device, unit or means is preserved; - devices such as user equipment and network entities / network registers may be represented by semiconductor chips, chipsets or (hardware) modules comprising such chips or chipsets; however, this does not exclude the possibility that the functionality of a device or module is not implemented in hardware but is implemented as software within a (software) module, such as a computer program or computer program product comprising executable software code portions for execution / running on a processor; - A device may be considered as an apparatus or as an assembly of one or more devices, whether functionally cooperating with each other or functionally independent of each other but within the same device housing; It should be noted that:

[0126] In general, it should be noted that each functional block or element according to the above-described aspects can be implemented by any known means, either hardware and / or software, when it is merely configured to perform the described function of the respective part. The described method steps may be realized by individual functional blocks or individual devices, or one or more of the method steps may be realized by a single functional block or a single device.

[0127] Generally, any method step is suitable for implementation as software or by hardware without changing the idea of the present disclosure. Devices and means may be implemented as individual devices, but this does not exclude them being implemented in a distributed manner throughout the system, as long as the functionality of the device is preserved. Such principles and similar principles should be considered known to those skilled in the art.

[0128] Software in the sense of this description includes the software code itself, including code means or portions, or computer programs or computer program products, for performing the respective functions, as well as the software (or computer programs or computer program products) embodied on tangible media such as computer readable (storage) media on which the respective data structures or code means / portions are stored, or potentially during their processing, embodied in signals or chips.

[0129] This disclosure covers any conceivable combination of the above-described method steps and operations, and any conceivable combination of the above-described nodes, devices, modules, or elements, so long as the above-described concepts of methodology and structural configuration are applicable.

[0130] In view of the above, a method for improving linear beam sweeping in high-speed scenarios is provided, which illustratively includes setting a second beamwidth characteristic of a second beam of a beam sweep, where the setting includes calculating the second beamwidth characteristic based on a first beamwidth characteristic of a first beam of the beam sweep and a ratio between a first path loss of the first beam between an antenna and a first position on a linear trajectory covered by the beam sweep and a second path loss of the second beam between the antenna and a second position on the linear trajectory.

[0131] While the disclosure has been described above with reference to examples and according to the accompanying drawings, it is to be understood that the disclosure is not limited thereto. Rather, it will be apparent to those skilled in the art that the disclosure can be modified in many ways without departing from the scope of the inventive ideas disclosed herein.

[0132] List of acronyms and abbreviations 3GPP 3rd Generation Partnership Project BBU Baseband Unit CPE Customer Premises Equipment HPBW Half Power Beam Width NR New Radio RRH Remote Radio Head SS Sync Signal UE User Equipment

Claims

1. 1. An apparatus comprising: at least one processor; at least one memory containing computer program code; at least one interface configured to communicate with at least another device; Equipped with At least one processor, using at least one memory and computer program code, configured to cause the apparatus to set a second beam width characteristic of a second beam of the beam sweep; In connection with the configuring, at least one processor, using at least one memory and computer program code, calculating the second beamwidth characteristic based on a first beamwidth characteristic of a first beam of the beam sweep and a ratio between a first path loss of the first beam between an antenna and a first position on a linear trajectory covered by the beam sweep and a second path loss of the second beam between the antenna and a second position on the linear trajectory; The apparatus is configured to cause the apparatus to execute the

2. 2. The apparatus of claim 1, wherein a first path loss corresponds to a first direct propagation length of the first beam and a second path loss corresponds to a second direct propagation length of the second beam.

3. 3. The apparatus of claim 2, wherein the first path loss corresponds to the first direct propagation length between the antenna and the first location in a first antenna boresight direction for the first beam, and the second path loss corresponds to the second direct propagation length between the antenna and the second location in a second antenna boresight direction for the second beam.

4. In connection with the calculating, at least one processor, using at least one memory and computer program code, determining a factor limit as the square of the quotient of the first direct propagation length and the second direct propagation length; selecting a factor based on the factor limit values; multiplying the first beamwidth characteristic by the factor; The apparatus of claim 2 , configured to cause the apparatus to perform the following:

5. The apparatus of claim 4 , wherein the factor is a product of a beamwidth azimuth component factor and a beamwidth elevation component factor.

6. the first direct propagation length of the first beam is longer than the second direct propagation length of the second beam; The apparatus of claim 4 , wherein the factor limit is an upper limit value for the factor.

7. In connection with the calculating, at least one processor, using at least one memory and computer program code, selecting the factor such that link performance of the second beam is no worse than link performance of the first beam. The apparatus of claim 6 , configured to cause the apparatus to perform the following:

8. In connection with the calculating, at least one processor, using at least one memory and computer program code, selecting the factor such that a dwell time corresponding to passing through a second orbit length of a second orbit portion of the linear orbit covered by the second beam satisfying the second beam width characteristic having a predetermined velocity is longer than a predetermined period. The apparatus of claim 6 , configured to cause the apparatus to perform the following:

9. The apparatus of claim 8 , wherein the predetermined period is a minimum period required for a given beam management and mobility procedure.

10. At least one processor, using at least one memory and computer program code, calculating the second orbit length of the second orbital portion based on the second beamwidth characteristic, the second direct propagation length, and at least one of a second azimuth beam-pointing angle and a second elevation beam-pointing angle from the antenna to the second location; The apparatus of claim 8 , configured to cause the apparatus to perform the following:

11. In connection with the calculating, at least one processor, using at least one memory and computer program code, selecting the factor such that a second dwell time corresponding to traversing a second orbit length of a second orbit portion of the linear orbit covered by the second beam satisfying the second beam width characteristic with a predetermined velocity is not shorter than a first dwell time corresponding to traversing a first orbit length of a first orbit portion of the linear orbit covered by the first beam satisfying the first beam width characteristic with the predetermined velocity. The apparatus of claim 6 , configured to cause the apparatus to perform the following:

12. the first direct propagation length of the first beam is shorter than the second direct propagation length of the second beam; The apparatus of claim 4 , wherein the factor limit is a lower limit for the factor.

13. In connection with the calculating, at least one processor, using at least one memory and computer program code, The apparatus of claim 12 , configured to cause the apparatus to select the factor such that link performance of the second beam is no better than link performance of the first beam.

14. In connection with the calculating, at least one processor, using at least one memory and computer program code, selecting the factor such that a second orbit length of a second orbit portion of the linear orbit covered by the second beam satisfying the second beam width characteristic is substantially equal to a first orbit length of a first orbit portion of the linear orbit covered by the first beam satisfying the first beam width characteristic. The apparatus of claim 4 , configured to cause the apparatus to perform the following:

15. At least one processor, using at least one memory and computer program code, calculating the first orbit length of the first orbital portion based on the first beamwidth characteristic, the first direct propagation length, and at least one of a first azimuth beam-pointing angle and a first elevation beam-pointing angle from the antenna to the first location; The apparatus of claim 14 , configured to cause the apparatus to perform the following:

16. The apparatus of claim 1 , wherein a second beamwidth characteristic of the second beam is selected such that a received power of the second beam exceeds a predetermined threshold.

17. The apparatus of claim 1 , wherein a second beamwidth characteristic of the second beam is selected such that a link loss of the second beam is below a predetermined threshold.

18. At least one processor, using at least one memory and computer program code, calculating a plurality of track lengths of a plurality of track portions of the linear track covered by a plurality of beams that satisfy the first beamwidth characteristic based on the first beamwidth characteristic, a plurality of direct propagation lengths between the antenna and a plurality of positions on the linear track in a plurality of antenna boresight directions for the plurality of beams, and at least one of a plurality of azimuth beam pointing angles and elevation beam pointing angles corresponding to the plurality of antenna boresight directions from the antenna to the plurality of positions on the linear track; selecting a beam from the plurality of beams that has the longest orbital length among the plurality of orbital lengths as the first beam; The apparatus of claim 1 , configured to cause the apparatus to perform the following:

19. 20. The apparatus of claim 18, wherein each orbit length of the plurality of orbit lengths corresponds to a respective length of a respective intersection point between the linear orbit and a respective ellipse formed by an intersection of the respective beam with a respective plane defined by the linear orbit and a respective horizontal line perpendicular to and intersecting the linear orbit.

20. Each of the plurality of orbit lengths is l ｋ =y ２ -y １ is calculated as [Equation 1] year, a = a ２ አማርስ ２ f ｋ +b ２ sin ２ f ｋ β=2[y ｃ (-A) ２ አማርስ ２ f ｋ -A ２ sin ２ f ｋ )+(u-+ ｃ )(b ２ Ọsố ｋ class ｋ -a ２ Ọsố ｋ class ｋ )] [Equation 2] where, a is the semimajor axis of each of said ellipses; b is the semi-minor axis of each of said ellipses; φ ｋ is a respective azimuth beam pointing angle corresponding to the respective antenna boresight direction from the antenna to the respective position on the linear trajectory, x ｃ are the respective distance components from the antenna to the respective centers of the respective ellipses in a direction perpendicular to the linear trajectory, y ｃ are the respective distance components from the antenna to the respective centers of the respective ellipses in a direction parallel to the linear trajectory, u is a distance component from the antenna to each of the positions on the linear trajectory in a direction perpendicular to the linear trajectory; 20. The apparatus of claim 19.

21. At least one processor, using at least one memory and computer program code, calculating a plurality of track lengths of a plurality of track portions of the linear track covered by a plurality of beams that satisfy the first beamwidth characteristic based on the first beamwidth characteristic, a plurality of direct propagation lengths between the antenna and a plurality of positions on the linear track in a plurality of antenna boresight directions for the plurality of beams, and at least one of a plurality of azimuth beam pointing angles and elevation beam pointing angles corresponding to the plurality of antenna boresight directions from the antenna to the plurality of positions on the linear track; selecting a beam from the plurality of beams that has the shortest orbital length among the plurality of orbital lengths as the first beam; The apparatus of claim 1 , configured to cause the apparatus to perform the following:

22. the first beamwidth characteristic of the first beam is a first fractional power beamwidth of the first beam; the second beam width characteristic of the second beam is a second fractional power beam width of the second beam; 10. The apparatus of claim 1.

23. the first fractional beamwidth comprises a first fractional beamwidth azimuth component of the first beam and a first fractional beamwidth elevation component of the first beam; 23. The apparatus of claim 22, wherein the second fractional beamwidth comprises a second fractional beamwidth azimuth component of the second beam and a second fractional beamwidth elevation component of the second beam.

24. At least one processor, using at least one memory and computer program code, controlling an antenna device including the antenna to perform the beam sweep based on the first beamwidth characteristic of the first beam and the second beamwidth characteristic of the second beam, optionally the antenna includes an antenna array.

24. An apparatus according to any preceding claim, configured to cause the apparatus to perform

25. 1. A method comprising: setting a second beam width characteristic of a second beam of the beam sweep; The setting calculating the second beamwidth characteristic based on a first beamwidth characteristic of a first beam of the beam sweep and a ratio between a first path loss of the first beam between an antenna and a first position on a linear trajectory covered by the beam sweep and a second path loss of the second beam between the antenna and a second position on the linear trajectory; method.

26. 1. An apparatus comprising: a setting circuit configured to set a second beam width characteristic of a second beam of the beam sweep; a calculation circuit configured to calculate the second beamwidth characteristic based on a first beamwidth characteristic of a first beam of the beam sweep and a ratio between a first path loss of the first beam between an antenna and a first position on a linear trajectory covered by the beam sweep and a second path loss of the second beam between the antenna and a second position on the linear trajectory; An apparatus comprising:

27. When the program is run on a computer, the computer 1. A computer program product comprising computer-executable computer program code configured to cause setting a second beam width characteristic of a second beam of a beam sweep, the computer program product comprising: The setting calculating the second beamwidth characteristic based on a first beamwidth characteristic of a first beam of the beam sweep and a ratio between a first path loss of the first beam between an antenna and a first position in a linear trajectory covered by the beam sweep and a second path loss of the second beam between the antenna and a second position in the linear trajectory.

Images