Method for adapting radio random access channel configuration based on air traffic information

Abstract

A method for configuring a radio random access channel adapted to a first base station (gNB) includes: obtaining information at the first gNB about active air corridors and / or about a specific UAM UE associated with it; receiving a connection request from the UAM UE at the first gNB; requesting second information from the UAM UE about the air corridor associated with the UAM UE; receiving a response to the request from the UAM UE; determining a distance range between the UAM UE and the first gNB based on the received information and the known location of the first gNB; and / or determining a mapping between the received information and the radio coverage area above the gNB; and adjusting the PRACH preamble cyclic shift gap configuration, the PRACH-to-SSB resource mapping, and / or the PRACH resource allocation according to the determined distance range and / or mapping.

Description

Technical Field

[0001] This invention relates to random access (RA) procedures in 3GPP-based terrestrial wireless communication networks, and more specifically, to procedures used by mobile nodes (e.g., urban air traffic (UAM) nodes).

[0002] Notation and Definition

[0003] 3GPP, short for "Third Generation Partnership Project," is a collective term for multiple standards organizations that develop mobile telecommunications protocols. In the context of 3GPP, the term "random" emphasizes that user equipment (UE) can request access to network resources at any time, as the UE is not bound by a predetermined or fixed access scheme. The expression "terrestrial wireless communication network" refers to a wireless communication network whose base stations are located on a terrestrial structure, and whose UEs are typically located in or on a terrestrial structure. This document uses the abbreviation "gNB" for base stations, regardless of the naming conventions in various standards, which may use "eNB" or other abbreviations for base stations. Background Technology

[0004] UE access to 3GPP-based terrestrial wireless communication networks is controlled through a corresponding RA procedure. At the start of the existing RA procedure, once the UE detects a Synchronization Signal Block (SSB) transmission from the network (i.e., via a nearby gNB), the UE decodes the System Information Broadcast (SIB) sent from the network. Based on the configuration information carried in the SIB, the UE transmits a preamble on the Physical RA Channel (PRACH) resource indicated by the SIB. Each SSB transmission is associated with its own PRACH timing, which refers to the time-frequency resource received by any UE capable of detecting the SSB transmission and decoding the SIB message (i.e., achieving downlink synchronization), whereby the UE can transmit a PRACH preamble to further achieve uplink synchronization.

[0005] The PRACH preamble is a Zadoff-Chu sequence with a specific indicator length, determined by two parameters: the root sequence index and the index of the Zadoff-Chu sequence. C V 'Represented and indexed' v 'Parameterized cyclic shift values. Although the root sequence index is provided by the network, the cyclic shift values ​​are determined with the help of additional information provided by the network, including the "restricted set" to which the cyclic shift value belongs, and other parameters that the UE can determine based on indications from tables provided by the network and the specification. Specifically, the cyclic shift gap parameter (represented as ' CS ') combined with certain other parameters effectively determined the continuity v The number of unit cyclic shifts between each parameter value.

[0006] Existing 3GPP RA procedures are designed for terrestrial users (i.e., users located on the physical ground) and are not optimized for UAM node access, which typically operates in the air during communication. Within the coverage area, or more precisely, within the coverage space, this added dimension introduces several problems to existing RA procedures: 1. For terrestrial networks, configured by the cell... N CS The set of values ​​can be determined based on the maximum coverage area of ​​the cell, i.e., the maximum coverage area of ​​the gNB serving that cell. However, UAM UEs (i.e., UEs associated with air nodes that may carry passengers or cargo, or UEs associated with passengers transported by such air nodes) can fly quite high above ground-based low-altitude gNBs, even higher than currently commercially available conventional low-altitude unmanned aerial vehicles smaller than UAM aircraft. Furthermore, UAM UEs will fly in active air corridors, which are areas of air designated for traffic use by the Unmanned Air System (UAS) Service Provider (USS) or UAS Traffic Manager (UTM).

[0007] UTM is a system for safely and efficiently integrating unmanned aerial vehicles (UAVs) with other airspace users. It provides a range of functions and services for managing a range of autonomous vehicle operations, such as certifying UAVs, authorizing UAS services, managing UAS policies, and controlling UAS traffic in the airspace.

[0008] USS is an entity that provides services to support the safe and efficient use of airspace by offering services to UAS operators or pilots. The term USS can refer to both USS and USS / UTM.

[0009] While the aviation sector is typically outside the scope of 3GPP, 3GPP networks can communicate with UAVs and UAM UEs via the UAS Network Function (UASNF). The UASNF is a network function implemented via the 3GPP Network Open Function (NEF) to support over-the-air functions related to UAV identification, authentication / authorization, and tracking, and to support remote identification. The NEF is a 3GPP standard node that opens network services to applications. Access to these services enables applications to interact with smart IoT devices such as sensors, instruments, smart vehicles, or televisions. The NEF offers significant flexibility and, among other things, can be used to retrieve the UE's location, set service parameters, and / or broadcast emergency notifications for smart vehicles.

[0010] Figure 1A high-level conceptual block diagram illustrating the decoupling of 3GPP specifications from aviation-related aspects is shown. Information between 3GPP system components and aviation-related components is exchanged through corresponding APIs.

[0011] Figure 2 A high-level example of UAV entity integration in 3GPP Release 17 is shown. In this example, it is clear that the UAS NF 3GPP system component is used to connect the UAV and UAV controller using information from the USS and / or the UTM connected to it.

[0012] Therefore, if the existing configuration has a cyclic shift gap between two consecutive preamble sequences CS If this method is used directly with UAM UE, then there are two options: 1. Network based on terrestrial coverage settings for UAM UE CS The minimum value. It's important to note that due to more favorable line-of-sight propagation conditions, airborne UAM UEs may access the network from distances far exceeding the range available to ground-based UEs. Even if two UAM UEs at different distances from the gNB send preambles with their own different cyclic shifts, if the gap between the cyclic shifts selected according to network settings is insufficient to cover the transmission delay difference between the UAM UEs, the transmissions may arrive at the gNB more or less simultaneously. In this case, the transmissions will collide at the gNB, which may force one of the UAM UEs to retransmit the PRACH preamble.

[0013] 2. The network is based on its ability to set the maximum coverage distance for airborne UAM UEs. CS The minimum value. In this case, a larger value needs to be set to... CS The minimum value is because the propagation delay of airborne UAM UEs can be much larger than that of ground-based UEs, and smaller ranges may be available for ground-based UEs. Large CS The value implies a reduction in the number of orthogonal preambles available for RA, which affects the number of UEs that can perform RA at the same time.

[0014] A major problem with integrating terrestrial and airborne UE communications is that, in terrestrial networks, the PRACH preamble cyclic shift gap to be applied by each UE within a cell is determined based on the round-trip delay corresponding to the cell's maximum coverage. However, if the same principle is followed for UAM UEs, the non-orthogonality at the gNB may increase the chance of preamble collisions due to the large distances between UAM UEs flying in different air corridors and between UAM UEs and the gNB.

[0015] Furthermore, in terrestrial networks, SSBs associated with PRACH resources are typically transmitted across all azimuth beams (i.e., horizontal directions) around the gNB. However, due to the limited number of SSBs in a burst, it may not be possible to scan all elevation directions to assist airborne UAM UEs in RA, as this would create a trade-off with RA performance compared to terrestrial UEs. Therefore, it is important to carefully associate SSBs with appropriate PRACH timings for UAM UEs to perform RA. Additionally, when performing contention-free RA, the allocation of PRACH resources to UAM UEs needs to be optimized.

[0016] Finally, it is necessary to optimize the PRACH resource allocation for non-contact RAs used for ground and UAM UEs to avoid sacrificing their performance.

[0017] While adjustments to the PRACH preamble configuration (including cyclic shifts, SSB-to-PRACH resource allocation, and PRACH resource allocation) are generally known, none of the known methods address the specific requirements of the airborne UAM UE.

[0018] Therefore, the object of the present invention is to propose an improved RA process and / or protocol and / or parameter set that overcomes or at least mitigates the disadvantages of known ground RA processes. Summary of the Invention

[0019] The above objectives are achieved by the methods according to claims 1 and 8, the gNB according to claim 7, the wireless UE according to claim 9, and the computer program product according to claim 8. A corresponding computer-readable storage medium is proposed in claim 10. Advantageous developments and embodiments are provided in the corresponding dependent claims.

[0020] The method according to the present invention improves the RA process for including a UAM UE in a terrestrial communication network by also considering the characteristics and range information of the active air corridor when determining the PRACH configuration, performing PRACH resource allocation, and / or performing SSB-to-PRACH resource allocation. To this end, the present invention addresses the above-mentioned problems through the following operations: 1. Based on the distance of each region to the gNB, a mapping is introduced between the cyclic shift gap parameter and the geographic region above the gNB. Such a mapping can be provided for each gNB, for example, through corresponding simulations or measurements. The geographic region can be represented, for example, as a quantization of the volume around the gNB up to the maximum distance. Each volume quantization can be associated with one or more cyclic shift gap parameters.

[0021] 2. Allow gNBs in the 3GPP system to request information about all active air corridors within their coverage area from Unmanned Air System (UAS) Service Providers (USS) or UAS Traffic Managers (UTMs) (outside the 3GPP system). This can be achieved by introducing new messages / protocols in the interface between the 3GPP system and the USS / UTM system. The request can be periodic, non-periodic, or event-triggered.

[0022] 3. Allow the gNB to request information about the air corridor associated with the UAM UE from the USS / UTM or from the UAM UE itself. This can be achieved by introducing new messages / protocols in the interface between the 3GPP system and the USS / UTM system, or by introducing new information elements in the Media Access Control (MAC) control element (CE) or Radio Resource Control (RRC). The request can be periodic, aperiodic, or event-triggered.

[0023] 4. Allows a gNB to transmit information obtained using the procedures in 2 or 3 to one or more target gNBs to help the target gNBs perform PRACH resource allocation for the RA during handover.

[0024] 5. The gNB can use active air corridor information combined with the mapping in 1 to change the configuration of the cyclic shift gap parameter in System Information Broadcast (SIB) or UE-specific mode.

[0025] 6. The gNB can use active air corridor information to adapt the association between SSB beams and PRACH timing in the SIB or UE-specific mode.

[0026] 7. gNB can use UAM UE air corridor association information to allocate PRACH timing / resources.

[0027] Before discussing the details of this invention, the general RA procedure, also known herein as the Random Access Channel (RACH) procedure, will be discussed in more detail using the 5G New Radio (NR) standard as an example. The RACH plays a crucial role in establishing the initial connection (initial access) between the UE and the network. When a device first wants to connect to the network or after a period of inactivity, it uses the RACH to request access to the network.

[0028] In NR Rel-15, the RACH procedure is triggered when uplink data becomes available at the UE buffer and the UE is in one of the following states: RRC_IDLE / INACTIVE states (for RACH procedures triggered by state transitions) The system is in the RRC_CONNECTED state and the uplink is out of sync (the RACH procedure is used to re-establish uplink synchronization). The UE is in the RRC_CONNECTED state and has no physical uplink control channel (PUCCH) resources available for scheduling requests (SR), or the SR procedure has failed (where the RACH procedure acts as the SR). In addition, the RACH procedure is used for beam failure and recovery, on-demand system information (SI) requests, or it can be explicitly triggered by the network using radio resource control (RRC) for handover.

[0029] RACH resources can be configured for contention-based RA (CBRA) (i.e., for initial access) and contention-free RA (CFRA), i.e., for mobility and beam fault recovery when triggered by the Physical Downlink Control Channel (PDCCH).

[0030] The RACH process includes the following steps: Msg1 (RACH preamble, from UE to gNB): - The UE selects the RA preamble from a set of preambles and selects a random sequence number for that preamble. - The UE sends the preamble on the PRACH. - Msg2 (Random access response on PDCCH / PDSCH, from gNB to UE): - Upon receiving Msg1, the gNB sends a response (Msg2), which consists of a time advance (TA) command, a random access preamble ID (RAPID) matching the preamble sent by the UE, and an initial uplink grant for the UE. - The gNB also assigns a temporary identifier to the UE, known as the Random Access Radio Network Temporary Identifier (RA-RNTI). Msg3: - Using the initial uplink clearance provided in Msg2, the UE sends Msg3 on PUSCH (Physical Uplink Shared Channel).

[0031] Msg4 (Competition Resolution): - After processing Msg3, the gNB sends Msg4 to the UE. - Msg4 is MAC data used for race resolution. - The contention resolution message contains the UE's identifier, thus confirming that the gNB has correctly identified the UE and that the contention has been resolved.

[0032] - At this step, the network provides the UE with a C-RNTI (Cell Radio Network Temporary Identifier).

[0033] The above message stream is in Figure 3 The swimming lane diagram is shown.

[0034] Before discussing the details of this invention, various aspects of PRACH will be further discussed. In 5G NR, beamforming and beam tracking features have been introduced into the NRRA process, making the entire process different from the 4G LTE process at frequencies above 6 GHz. In NR RA, the UE needs to detect and select the optimal beam for the RACH process (beam selection process) before the actual PRACH sequence selection and transmission. SI informs the UE of the association between the SSB and RACH resources.

[0035] When is the SSB / PBCH block index mapped to PRACH? - First, in ascending order of the preamble index within a single PRACH timing, - Subsequently, following the ascending order of the frequency resource index at the PRACH frequency reuse timing, Then, following the ascending order of the time resource indexes for time multiplexing PRACH opportunities within a PRACH slot, - Finally, in ascending order of the PRACH slot index.

[0036] Figure 4 A schematic representation of the PRACH timeslot and PRACH structure in the time and frequency domains is shown, as in Chapter 4 - New Radio Access Physical Layer Aspects (Part 2) of "Architecture, Technology, Implementation and Operation of the New Radio Standard for 5G NR-3GPP" (Editor: Sassan Ahmadi, Academic Press, 2019, pp. 411-654).

[0037] Next, we will briefly discuss PRACH sequence generation and random access preamble sets. , ( It should be generated according to the following formula: , ( ) = (( + )mod RA ) ( ) = exp (- ( ( + 1) / RA )), = 0, 1, ... , – 1 Therefore, the frequency domain representation should be generated according to the following formula:

[0038] The PRACH preamble format is given in the table in specifications such as 3GPP TS 38.211 V17.5.0 (2023-06); 3GPP; Radio Access Networks Technical Specification Group; NR; Physical Channels and Modulation (Revision 17) . L RA =839、 L RA =139、 L RA =1151, or L RA =571.

[0039] In each time-frequency PRACH timing, 64 preambles are defined, which are shifted in an incremental cyclic manner according to the first logical root sequence. The logical root sequence is enumerated in ascending order, starting with the index obtained via the higher-level parameter `prach-RootSequenceIndex` or `rootSequenceIndex-BFR`, or via `msgA-PRACH-RootSequenceIndex` (if configured), and the Type 2 random access procedure is initiated as described in Clause 8.1 of TS 38.213. If 64 preambles cannot be generated from a single root Zadoff-Chu sequence, additional preamble sequences are obtained from root sequences with consecutive logical indices until all 64 sequences are found. The logical root sequence order is cyclic; logical index 0 immediately follows... RA -2 onwards. Serial number It is obtained from the logical root sequence index according to Tables 6.3.3.1-3 to 6.3.3.1-4B in TS 38.211. The basic structure of NR random access preamble generation and its placement in the time-frequency domain signal is described in... Figure 5 As shown in the image.

[0040] Next, we will briefly discuss PRACH cyclic shift. Cyclic shift Given by the following formula

[0041] in, CS The parameters are given in Tables 6.3.3.1-5 to 6.3.3.1-7 of the specifications (e.g., 3GPP TS 38.211 V17.5.0 (2023-06); 3GPP; Radio Access Networks Technical Specification Group; NR; Physical Channels and Modulation (Revision 17)). Higher Layer Parameters msgARestrictedSetConfig (If provided) Determine the type of the restricted set (unrestricted, restricted type A, restricted type B). Otherwise, higher-level parameters. restrictedSetConfig Determine the type of the restricted set (unrestricted, restricted type A, restricted type B), and Tables 6.3.3.1-1 and 6.3.3.1-2 show the types of restricted sets supported for different preamble formats.

[0042] For CS Examples of values ​​are shown in the table below:

[0043] Note that the Zadoff-Chu (ZC) sequences generated from cyclic shifts of a single root sequence are orthogonal. Sequences obtained from cyclic shifts of different root sequences are not strictly orthogonal, but have low cross-correlation.

[0044] Circular shift via parameters zeroCorrelationZoneConfig Provided indirectly to the UE. Based on the information provided by the gNB. zeroCorrelationZoneConfig or msgAZeroCorrelationZoneconfig Parameter settings CS The parameter specifies the number of cyclic shifts between the leading sequences.

[0045] Although each UE will utilize a different cyclic shift of the root ZC sequence in the cell, channel delay and delay spread will make the ZC sequence of a UE farther from the gNB appear exactly the same as the ZE sequence of a UE closer to the cyclically shifted gNB. To prevent this, the UE's cyclic shift must remain longer than the round-trip time (RTD) and delay spread. The sum of these must be further apart, meaning the following relationship must be satisfied:

[0046] Figure 6 This illustrates the cyclic shift separation between preamble sequences. CS The illustration.

[0047] Next, the airspace as used in this specification will be defined. As described by SIMuna, S. Mukherjee, K. Namuduri, M. Compere, MIAkbas, P. Molnár and R. Subramanian in “Air Corridors: Concept, Design, Simulation, and Rules of Engagement” (Sensors 2021, 21(22), 7536; https: / / doi.org / 10.3390 / s21227536), the airspace comprises several building blocks with corresponding characteristics.

[0048] A geofence defines a specific volume in space whose boundaries cannot be crossed. (Geofence volume) ={ , [], , , , []} is a series of [] on the horizontal plane n vertices [] = [( 1, 1), ( 2, 2), … , ( n , n The definition is as follows: n ≥3, and Indicates the lower limit of altitude. This indicates the upper limit of altitude. Relative to a set of location [] = [ 1, … , Defined by ], where, = ( , , , ),and ≥ 2. Lateral location is represented as a pair of latitude and longitude ( , ). Location of origin i Elevation relative to mean sea level (MSL). It is used for the location of the home region. Activation time, 1 ≤ < . It is used for geofencing g The downtime. The geofence boundary is relative to the location of ownership. = ( , , , Defined by the centroid of the geofence. Vertical lower limit. and upper limit Compared to Defined in meters. The horizontal boundary consists of a series of vertices. = [ 1, … , Definition. Each = ( , ), ∈ [1, [This refers to a local Cartesian coordinate system, defined relative to the local Cartesian coordinate system, whose origin is located at its place of origin given by latitude and longitude. The horizontal vertex and vertical limit are relative to...] The set of two or more home locations defined in brackets [] remains unchanged.

[0049] An aerial cube is a building block for aerial passages in 3D airspace and can be considered as a simplified form of geofencing. It is assumed that all aerial cubes are similar in size and that each aerial cube is specifically reserved for a UAV passing through at any given time. Each aerial cube has a unique identifier. This helps the UAV understand cube occupancy information while moving. center = ( , , ) represents the center point of the air cube, while , , These represent the latitude, longitude, and upper limit of altitude, respectively. (Based on the side length) The center and the direction indicate the direction of traffic flow within the cube.

[0050] [ ] = { , centre, , direction}

[0051] An air passage or track is a designated airspace area for UAVs to pass through. The aircraft must fly within the air passage during its passage. An air passage or track is defined as a volume consisting of several cubes with the same orientation. An entrance gate is used to enter the air passage, and an exit gate is used to exit the air passage.

[0052] [ ] = { , direction, , [ ], } The unique identifier for an air passage is "direction," which indicates one of four travel directions: (east to west), (west to east), (south to north), or (north to south). The length L of the air passage is equal to... ,in, It is the side length of an aerial cube defined in meters, and It represents the number of cubes in the air. Figure 7 The general structure of an air corridor is shown. Boxes with solid outlines represent variables that define data elements within the air corridor. Boxes with dashed outlines represent variables that define the direction of movement of vehicles within the air corridor.

[0053] An intersection is where one airway on a horizontal plane intersects with another airway; that is, the projection of the airway onto the Earth's surface. Within an airway, this is where vehicles can turn or change direction. To avoid collisions, intersections are designed to consist of three levels. The middle level is used for UAVs to temporarily hover before making a planned turn. The vertical airport, or vertical takeoff and landing field (V), is where UAVs take off and land.

[0054] [ ] = { , [ ], , [ ]}

[0055] Each vertical takeoff and landing site has a unique identifier. The volume of the vertical takeoff and landing field is determined by its horizontal apex. [( 1, 1), ( 2, 2), ( 3, 3), ( 4, 4)] and its maximum altitude limit Definition. Array [] is the identification number sequence of UAVs that are permitted to take off or land from a vertical takeoff and landing field.

[0056] The gate is the connection between the air passageway and the vertical takeoff and landing field. It defines the takeoff and landing operations for UAVs. Vehicles need to pass through the gate to enter or leave the air passageway.

[0057] An aerial corridor is a 3D airspace volume reserved for UAS. It is a complete airspace structure that includes all aerial passages, intersections, and gates.

[0058] Figure 8 a) A schematic representation of an aerial walkway in 3D space is shown, and Figure 8 b) shows its projected view. The aerial walkways in Level 1 carry traffic in the east-to-west and west-to-east directions, and the aerial walkways in Level 3 carry traffic in the north-to-south and south-to-north directions. Level 2 is a temporary hovering space for UAV turning. Figure 8 b) shows Figure 8 a) Projection of the air passageway. The black box represents the vertical takeoff and landing field, i.e., the vertical takeoff and landing (VTOL) initiation and landing infrastructure, and the dashed box represents the intersection extending above the third level.

[0059] The invention will now be described with reference to 3GPP wireless communication systems. Note that these procedures can also be used in wireless communication systems operating according to other similar standards.

[0060] In the first step, if the gNB is configured to support UAM UEs, the gNB in ​​the 3GPP system requests information from the USS / UTM, which is not part of the 3GPP communications system, about all active air corridors within its coverage area. This request may include indications of geographic and / or territorial boundaries, within which the gNB requires information about air corridors. Information about the boundaries may represent the coverage hemisphere surrounding the gNB, expressed by center coordinates and radius. Figure 13 An example of the coverage hemisphere surrounding the gNB is shown. This request can be sent periodically, for example, every 30 minutes, or triggered by an event, such as when a UAM UE connects to the gNB, or when the gNB detects that available information has expired.

[0061] This request can be sent by appropriately modifying the existing network protocol between the gNB and the core network, and by introducing additional messages into the interface between the UAS-NF and the USS / UTM in the core network. Upon request from the gNB, the USS / UTM provides information about all active air corridors within the area indicated by the gNB. Active air corridor information may include parameters of the air passages within the air corridors, which are in turn composed of air cubes and their orientations. Similarly, for requests regarding UAM-UE-air corridor associations, the USS / UTM (using a similar mechanism as described above) or the UAM UE itself provides this information directly to the gNB. This information includes appropriate indexes of the air corridors associated with the UAM UE.

[0062] Based on information about the air corridors within its area of ​​interest, the gNB adapts its PRACH configuration in three ways: 1. Configure the cyclic shift gap parameters in gNB To accommodate varying round-trip delays caused by UAM UEs transmitting PRACH preambles from different air corridors. Potential cyclic shifts may be associated with different aerogeographic volumes within the gNB's coverage area and can be hard-coded in the specification. For example, hemispherical coverage areas can be quantized as concentric shells, which can be associated with different cyclic shift gap parameter values. Figure 14 An exemplary configuration following this concept is shown, in which different shells are referred to as areas numbered from 1 to 4.

[0063] The association between geographic areas and active air corridors is established by the gNB, and the corresponding cyclic shift indication is provided in the PRACH configuration within the System Information Block (SIB). If the active air corridor configuration changes, the NB adapts the PRACH configuration in the SIB accordingly. When an active air corridor extends across multiple areas, the gNB can use multiple PRACH configurations. Figure 15 Examples of multiple active air corridors extending across multiple areas are shown. Active air corridor 1, shown as running at an angle to the ground, extends specifically through area 4, while active air corridor 2, running parallel to the ground, extends through areas 3 and 4. Note that active air corridor 2, running parallel to the ground, is perpendicular to the plane shown in the figure.

[0064] 2. The gNB also adapts the SSB beam associated with PRACH resources based on air corridor information. Specifically, the gNB will match the SSB beam pointing in the direction of the air corridor with a suitable... CS The configured PRACH resources are associated. An example of using SSB beam pointing to cover different sectors of the hemisphere and associating them with the corresponding different PRACH resources is shown in... Figure 16 As shown in the attached figure, it is assumed that the gNB obtains information from the USS / UTM regarding the existence of two active air corridors 1 and 2. Based on its own coverage area classification and required cyclic shift separation, the gNB transmits data with appropriate cyclic shift gap parameters. and The RACH configuration. Furthermore, it associates the SSB beams pointing in these directions with the corresponding PRACH resources; for example, beams 1 and 2 are associated with the resources configured with… Associated with PRACH resources, beam 3 is configured with and It is associated with RACH resources.

[0065] 3. The gNB uses the association information between the air corridor and the UAM UE to measure congestion in the air corridor and allocates PRACH resources to the UAM UE accordingly during handover and other contention-free RACH procedures. To this end, the source gNB may, for example, exchange the association information between the air corridor and the UAM UE with the target gNB in ​​a handover request. The target gNB then uses this information to configure contention-free RACH resources and appropriate PRACH resources. Figure 17 The diagram illustrates an exemplary swimlane diagram of the message flow between the source gNB, the target gNB, and the UAM UE for contention-free RA using UAM UE-Air Corridor Information.

[0066] Next, after the UAM UE (e.g., an air taxi) connects to the gNB, the gNB requests information about the air corridor associated with the UAM UE from the USS / UTM or from the UAM UE itself. Note that both of these requests can be periodic or event-triggered. In response to the request, the USS / UTM and / or the UAM UE itself provides the requested information to the gNB.

[0067] Figure 9 A swimlane diagram illustrating the message flow between the gNB, UAS NF, and USS or UTM for retrieving active air corridor and / or specific UAM UE association information from the USS / UTM according to this method is shown.

[0068] The gNB uses air corridor information and air corridor-UAM UE association, as well as the mappings mentioned above in the specification, to adjust the PRACH preamble cyclic shift gap configuration, PRACH to SSB resource mapping, and PRACH resource allocation.

[0069] The above information is used to adapt the PRACH preamble cyclic shift gap configuration and PRACH-to-SSB resource mapping in both contention-based and contention-free RA mechanisms. PRACH resource allocation can be performed for contention-free RA. These optimizations apply to both 4-step and 2-step RA mechanisms.

[0070] For contention-based RAs, the RA configuration can be modified by changing the parameters broadcast in the system information; for contention-free RAs, the RA configuration can be modified by changing the parameters via UE-specific messages.

[0071] Figure 10 A swimlane diagram of the message flow between the gNB and the UAM UE for retrieving UAM UE-air corridor association information from the UAM UE is shown.

[0072] Figure 11 A flowchart is shown for an exemplary basic method for retrieving and using active air corridor information by a gNB.

[0073] Figure 12 A flowchart is shown for an exemplary basic method for UAM UE-active air corridor association by gNB.

[0074] According to a first aspect of the present invention, a method for adapting a wireless random access channel configuration is provided. Method 100 (an exemplary flowchart thereof is shown in...) Figure 21(As shown in the diagram) includes obtaining, in step 110, first information at the first gNB regarding an active air corridor and / or a specific UAM UE associated therewith. The first information may be limited to air corridors within the radio coverage area above the gNB. Optionally, corresponding information related to neighboring gNBs having radio coverage areas adjacent to or overlapping with the first gNB's radio coverage area may also be obtained. The method further includes receiving a connection request from the UAM UE at the first gNB in ​​step 120. In response to the connection request, in step 130, the first gNB requests second information from the UAM UE regarding the air corridor associated with the UAM UE, and in step 140, receives a response to the request from the UAM UE. The received first and / or second information is then used in the first gNB to determine, in step 150a, the distance range between the UAM UE and the first gNB based on the received first and / or second information and the known location of the first gNB, and / or in step 150b, to determine a mapping between the received information and the radio coverage area above the gNB. This mapping can include the association of a corresponding gNB with a volume in the space surrounding each corresponding gNB. This volume can be represented by multiple quantized sub-volumes. For this purpose, the positions of multiple quantized sub-volumes in the space surrounding each gNB can be determined by measurement or simulation, up to a maximum distance. The corresponding mapping for each gNB can be stored in the gNB. Finally, in step 160, the PRACH preamble cyclic shift gap configuration, the PRACH to SSB resource mapping, and / or the PRACH resource allocation according to the determined distance range are adjusted based on the determined distance range or mapping.

[0075] In one or more embodiments of the method, obtaining includes sending a request for such information to a UAS NF implemented in the core network, by Figure 21 As shown in step 110-1, the UAS NF receives the information from the USS or UTM in response to the corresponding request, and receives a response to the request from the UAS NF. Figure 21 Step 110-2 is shown.

[0076] In one or more embodiments, the method further includes Figure 21 In step 170, the adjusted parameters are broadcast in the System Information Broadcast (SIB), or in Figure 21 Step 172 involves sending the adjusted data in a message for a specific UAM UE.

[0077] In one or more embodiments, the method further includes sending a handover request from the first gNB to the second gNB when a handover of the UAM UE's network connection occurs from the first gNB to the second gNB. Figure 21Step 174), and receiving handover confirmation from the second gNB and optimized PRACH resource configuration for remote access (RA) for the UAM UE (in step 174), and optimizing PRACH resource configuration for remote access (RA) for the UAM UE. Figure 21 Step 176). Then, the first gNB sends a radio resource configuration (RRC) to the UAM UE, which includes the previously received optimized PRACH resource configuration (...). Figure 21 Step 178 in the middle.

[0078] In one or more embodiments, the method further includes adapting the SSB beam associated with the PRACH source based on the obtained first and / or second information and / or the information determined therefrom. Figure 21 Step 180 in the middle.

[0079] In one or more embodiments, the method further includes using the obtained first and / or second information and / or the information determined therefrom for measuring congestion to measure or determine congestion in the air corridor. Figure 21 Step 182 in the process, and accordingly allocate PRACH resources to the UAM UE during handover and other contention-free RACH procedures. Figure 21 Step 184).

[0080] According to a second aspect of the present invention, a gNB for a wireless communication network is proposed. gNB 500 (an exemplary block diagram of which is shown in...) Figure 18 The gNB 500 (shown in the figure) includes one or more first wireless interfaces 501 configured to wirelessly communicate with a ground UE and / or an air UE according to a predetermined communication standard. The one or more first wireless interfaces 501 may include one or more antennas and associated RF circuitry for transmitting and / or receiving processed radio frequency signals (not shown in the figure). The gNB 500 further includes a second communication interface 502 configured to communicate with a network backbone and / or a network management unit, and further configured to communicate with a UAM NF (network component not shown in the figure) implemented using the network backbone or network management unit. The gNB 500 further includes one or more microprocessors 503 and associated volatile and non-volatile memories 504, 505. The above-mentioned components of the gNB 500 are communicatively connected via one or more data and / or signal lines and / or buses 506. Non-volatile memory 505 stores computer program instructions that, when executed by one or more microprocessors 503, configure gNB 500 to perform, implement, or carry out embodiments of the method according to the first aspect of the invention, and accordingly control the hardware and / or software elements and / or components of gNB 500.

[0081] According to a third aspect of the present invention, a method for operating a Wireless Urban Air Traffic User Equipment (UAM UE) is provided. Method 200 (an exemplary flowchart of which is shown in...) Figure 19 (As shown in the figure) includes: sending a connection request to the base station gNB500 of the wireless communication network in step 210, receiving a request from gNB500 in step 220 for providing second information about the air corridor currently associated with the UAS UE, providing a response to the request in step 230, receiving an SSB / PRACH resource allocation from gNB500 in step 240, and subsequently operating radio communication according to the received SSB / PRACH resource allocation, as shown in step 250.

[0082] According to a fourth aspect of the present invention, a wireless UE 600 for a UAS is provided. The wireless UE 600 (an exemplary block diagram of which is shown in...) Figure 20 The wireless UE 600 (shown in the figure) includes one or more first wireless interfaces 601 (configured for wireless communication with the gNB 500), one or more microprocessors 603, and associated volatile and non-volatile memories 604, 605. The one or more first wireless interfaces 601 may include one or more antennas and associated RF circuitry for transmitting and / or receiving processed radio frequency signals (not shown in the figure). The aforementioned components of the wireless UE 600 are communicatively connected via one or more data and / or signal lines and / or buses 606. The non-volatile memory 605 stores computer program instructions that, when executed by one or more microprocessors 603, configure the wireless UE 600 to perform, implement, or carry out embodiments of the method according to the third aspect of the invention, and accordingly control the hardware and / or software elements and / or components of the wireless UE 600.

[0083] The methods described above can be represented by computer program instructions. Therefore, according to a fifth aspect of the invention, a computer program product includes computer program instructions that, when executed by a microprocessor of a gNB according to a second aspect of the invention or a microprocessor functionally coupled to a gNB according to a second aspect of the invention, cause the processor to perform the methods according to a first aspect of the invention, and / or correspondingly control the hardware and / or software blocks or modules of the gNB; or, when executed by a microprocessor of a wireless UE of a UAS according to a fourth aspect of the invention or a microprocessor functionally coupled to a wireless UE of a UAS according to a fourth aspect of the invention, cause the processor to perform the methods according to a third aspect of the invention, and / or correspondingly control the hardware and / or software blocks or modules of the wireless UE.

[0084] The computer program instructions or code used to perform the operations for the embodiments can be any number of lines and can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Python, Ruby, Java, Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" programming language, etc., and / or machine languages ​​such as assembly language. The code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN), wireless local area network (WLAN), or wide area network (WAN), or can be connected to the external computer via the Internet, for example, using an Internet service provider (ISP).

[0085] Computer program instructions may be retrievably stored on or transmitted on a computer-readable medium or data carrier. This medium or data carrier may be physically embodied, for example, in the form of a hard disk, solid-state drive, flash memory device, etc. However, the medium or data carrier may also include modulated electromagnetic, electrical, or optical signals that are received by the computer via a corresponding receiver, and transmitted and stored in the computer's memory.

[0086] The features, structures, or characteristics of the described embodiments can be combined in any suitable manner. Numerous specific details, such as examples of programming, software modules, user selection, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., are provided in this specification to provide a comprehensive understanding of the embodiments. However, those skilled in the art will recognize that the embodiments can be practiced without one or more specific details, or using other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the embodiments. In this specification, references to “an embodiment,” “embodiment,” or similar language mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Therefore, unless expressly stated otherwise, the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, refer to the same embodiment, but rather to “one or more, but not all, embodiments.” Unless expressly stated otherwise, the terms “comprising,” “including,” “having,” and variations thereof mean “including, but not limited to,” “including.” Unless expressly stated otherwise, the list of items does not imply that any or all items are mutually exclusive. Unless otherwise expressly stated, the terms “a,” “an,” and “the” also mean “one or more.”

[0087] In describing aspects of embodiments in this specification with reference to schematic flowcharts and / or schematic block diagrams of methods, apparatus, systems, and program products according to embodiments, it will be understood that each block in the schematic flowcharts and / or schematic block diagrams, and combinations of blocks in the schematic flowcharts and / or schematic block diagrams, can be implemented by code. This code can be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine, such that instructions executable via the processor of the computer or other programmable data processing apparatus create components for implementing the functions / actions specified in the flowcharts and / or block diagrams.

[0088] It should be noted that in some implementations or embodiments, the functions indicated in the exemplary embodiments shown in the accompanying drawings may not appear in the order shown in the drawings. For example, depending on the functions involved, two consecutively shown blocks may actually be executed substantially simultaneously, or these blocks may sometimes be executed in reverse order. Other steps and methods that are functionally, logically, or effectively equivalent to one or more blocks or portions thereof shown in the accompanying drawings are conceivable.

[0089] The proposed mapping between the cyclic shift gap parameter and the coverage area above the gNB helps to achieve a better trade-off between the number of orthogonal preambles available for the RA and the probability of collision between two orthogonal preambles arriving simultaneously.

[0090] The air corridor information obtained from the USS / UTM helps the gNB identify whether there are any active air corridors that a UAM UE may fly over, and configure PRACH resources accordingly, because the PRACH configuration needs to be adapted to obtain better RA performance for the UAM UE.

[0091] The air corridor association information obtained from the UAM UE or USS / UTM helps the gNB determine the congestion level and movement direction of the UAM UE in each air corridor and adapt the PRACH resource configuration accordingly.

[0092] This invention can be very advantageously used in cellular networks, particularly wireless communication systems, such as 5G+ and 6G, where artificial intelligence and machine learning concepts are envisioned for optimizing the performance of radio access networks. Attached Figure Description

[0093] The invention has been described above with reference to the accompanying drawings, in which: Figure 1 This diagram illustrates a high-level concept block diagram demonstrating the decoupling of 3GPP specifications from aviation-related aspects. Figure 2 This shows a high-level example of UAV entity integration in 3GPP Release 17. Figure 3 The diagram shows a schematic swimlane representation of the RACH process message flow. Figure 4 The diagram illustrates schematic representations of the PRACH time slots and PRACH structure in the time and frequency domains. Figure 5 This illustrates the basic structure for generating NR random access preambles. Figure 6 This illustrates the cyclic shift separation between preamble sequences. CS The illustration, Figure 7 The general structure of the air passage is shown. Figure 8 A schematic representation of the skywalk and its projected view are shown. Figure 9 This diagram illustrates the swimlane layout of the message flow between the gNB, UASNF, and the USS or UTM for retrieving active air corridor and / or specific UAM UE association information from the USS / UTM. Figure 10 The diagram illustrates the swimlane layout of the message flow between the gNB and the UAM UE used to retrieve UAM UE-air corridor association information from the UAM UE. Figure 11 A flowchart illustrating an exemplary basic method for retrieving and using active air corridor information by a gNB is shown. Figure 12 A flowchart illustrating an exemplary basic method for UAM UE-active air corridor association by gNB is shown. Figure 13 An example of a hemispherical coverage area around the gNB is shown. Figure 14 An exemplary configuration of a hemispherical coverage area quantized as a concentric shell is shown. Figure 15 Examples of multiple active air corridors extending across multiple regions are shown. Figure 16 Examples are shown of different sectors for SSB beam pointing covering the hemisphere and associated with corresponding different PRACH resources. Figure 17 This diagram illustrates an exemplary swimlane diagram of the message flow between the source gNB, the target gNB, and the UAM UE for contention-free RA using UAM UE-Air Corridor Information. Figure 18 An example block diagram of a gNB (gard network) configured to perform methods according to aspects of the present invention is shown. Figure 19An exemplary flowchart illustrating a method for operating a wireless UE using a UAS according to various aspects of the present invention is shown. Figure 20 An exemplary block diagram of a wireless UE of a UAS configured to perform methods according to aspects of the present invention is shown, and Figure 21 An exemplary flowchart illustrating a method for operating a gNB of a wireless communication network according to a first aspect of the present invention is shown.

[0094] In the accompanying drawings, the same or similar elements may be referenced using the same reference numerals.

[0095] Reference number list (part of the instruction manual)

[0096] 100 methods

[0097] 110 received the first information

[0098] 110-1 sends a request for the first message.

[0099] 110-2 receives the first message

[0100] 120 receives connection request

[0101] 130 Request Second Information

[0102] 140 received response

[0103] 150a determines the distance range

[0104] 150b determines the mapping

[0105] 160 Adjust PRACH resources / parameters

[0106] Parameters adjusted for 170 broadcast

[0107] 172 sends the adjusted parameters

[0108] 174 Sends a handover request

[0109] 176 Receive Switching Confirmation

[0110] 178 sent RRC

[0111] 180 compatible with SSB beam

[0112] 182 Measuring air corridor congestion

[0113] 184 allocates PRACH resources

[0114] 200 methods

[0115] 210 Send connection request

[0116] 220 Receives a request for the second information

[0117] 230 provides a response to the request for second information.

[0118] 240 Receive SSB / PRACH Resource Allocation

[0119] 250 Operates radio communications according to the received SSB / PRACH resource allocation.

[0120] 500 base stations / gNB

[0121] 501 First Wireless Interface

[0122] 502 Second Communication Interface

[0123] 503 microprocessor

[0124] 504 volatile memory

[0125] 505 non-volatile memory

[0126] 506 Data / Signal Lines / Bus

[0127] 600 UE

[0128] 601 Third Wireless Interface

[0129] 603 microprocessor

[0130] 604 volatile memory

[0131] 605 Non-volatile Memory

[0132] 606 Data / Signal Line / Bus

Claims

1. A method (100) for adapting the wireless random access channel configuration of a first base station, i.e., a first gNB, comprising: - Obtain (110) first information at the first gNB regarding active air corridors and / or regarding the association of a specific city air traffic user equipment (UAM) UE. - Receive (120) a connection request from the UAM UE at the first gNB. - Request (130) second information about the air corridor associated with the UAM UE from the UAM UE, and receive (140) a response to the request from the UAM UE. - Based on the received first and / or second information and the known location of the first gNB, determine (150a) the distance range between the UAM UE and the first gNB, and / or determine (150b) the mapping between the received information and the radio coverage area above the gNB, and - Adjust (160) the physical random access channel PRACH preamble cyclic shift gap configuration, the PRACH to synchronization signal block SSB resource mapping and / or PRACH resource allocation according to the determined distance range and / or mapping.

2. The method (100) according to claim 1, wherein, Obtaining (110) includes: sending (110-1) a request for such information to an Unmanned Air System Network Function (UAS NF) implemented in the core network, the UAS NF receiving the information from an Unmanned Air System Service Provider (USS) or an Unmanned Air System Traffic Manager (UTM) in response to the corresponding request, and receiving (110-2) a response to the request from the UAS NF.

3. The method (100) according to claim 1 or 2, further comprising: The adjusted parameters are broadcast in the System Information Broadcast (SIB) (170) or sent in a message for a specific UAM UE (172).

4. The method (100) according to any one of claims 1 to 3, further comprising: When the UAM UE's network connection is switched from the first gNB to the second gNB: - The first gNB sends a (174) handover request to the second gNB. - The first gNB receives (176) a handover confirmation and an optimized PRACH resource configuration for the remote access RA of the UAM UE from the second gNB, and - The first gNB sends a (178) radio resource configuration RRC to the UAM UE, the RRC including the previously received optimized PRACH resource configuration.

5. The method (100) according to any one of claims 1 to 4, further comprising: The gNB adapts (180) the SSB beam associated with the PRACH resource based on the first and / or second information and / or the information determined therefrom.

6. The method (100) according to any one of claims 1 to 5, further comprising: The gNB uses the first and / or second information and / or the information determined therefrom to measure (182) congestion in the air corridor and accordingly allocate (184) PRACH resources to the UAM UE during handover and other contention-free RACH procedures.

7. A base station gNB (500) for a wireless communication network, the gNB comprising one or more first wireless interfaces (510) and second communication interfaces (502), the first wireless interfaces (510) being configured to wirelessly communicate with a ground UE and / or an air UE (600) according to a predetermined communication standard, the second communication interfaces (502) being configured to communicate with a network backbone and / or a network management unit, and further configured to communicate with a UAM NF implemented using the network backbone or the network management unit, the gNB further comprising one or more microprocessors (503) and associated volatile memory (504) and non-volatile memory (505), the aforementioned components or elements of the gNB (500) being communicatively connected via one or more signal and / or data lines and / or buses (506), wherein, The non-volatile memory (505) stores computer program instructions that, when executed by the one or more microprocessors (503), configure the gNB (500) to perform the method according to one or more of claims 1 to 6, and accordingly control the hardware and / or software elements and / or components of the gNB (500).

8. A method (200) for operating an Urban Air Traffic System Radio User Equipment (UAM UE) (600), comprising: - Send a (210) connection request to the base station gNB (500) of the wireless communication network. - Receive (220) a request from the gNB (500) for providing second information about the air corridor associated with the UAM UE (600), - Send (230) the second information to the gNB (500), - Receive (240) synchronization signal block SSB / physical random access channel PRACH resource allocation from the gNB (500), and - Operate (250) radio communication according to the received SSB / PRACH resource allocation.

9. A wireless user equipment (UE) (600) comprising a third wireless interface (601) configured to wirelessly communicate with a base station gNB (500) of a wireless communication network according to a predetermined communication standard, the wireless UE further comprising one or more microprocessors (603) and associated volatile memory (604) and non-volatile memory (605), the aforementioned components or elements of the wireless UE (600) being communicatively connected via one or more signal and / or data lines and / or buses (606), wherein, The non-volatile memory (605) stores computer program instructions that, when executed by the one or more microprocessors (603), configure the wireless UE (600) to perform the method according to claim 8 and accordingly control the hardware and / or software elements and / or components of the wireless UE (600).

10. A computer program product comprising computer program instructions that, when executed by a microprocessor (503) of a base station gNB (500) according to claim 7 or a microprocessor (503) functionally coupled to the base station gNB (500) according to claim 7, cause the processor (503) and / or the gNB (500) to perform the method according to one or more of claims 1 to 6, or when executed by a microprocessor (603) of a wireless user equipment UE (600) according to claim 9 or a microprocessor (603) functionally coupled to the wireless user equipment UE (600) according to claim 9, cause the processor (603) and / or the UE (600) to perform the method according to claim 8.

11. A computer-readable medium or data carrier for retrievably transmitting or storing a computer program product according to claim 10.

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