EP4324256A1

EP4324256A1 - Air-to-ground communications

Info

Publication number: EP4324256A1
Application number: EP21739921.1A
Authority: EP
Inventors: Qiaoyu Li; Yu Zhang; Chao Wei; Hao Xu
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2021-04-16
Filing date: 2021-04-16
Publication date: 2024-02-21
Also published as: CN117136597A; WO2022217570A1

Abstract

Certain aspects of the present disclosure provide techniques for air-to-ground (ATG) communications. A method that may be performed by a user equipment (UE) includes determining one or more parameters indicative of movement of the UE relative to the BS. The method also includes updating a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance. The method also includes transmitting an uplink signal over resources determined using the new uplink timing advance.

Description

AIR-TO-GROUND COMMUNICATIONS

BACKGROUND

Field of the Disclosure
Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for determining an uplink timing advance (TA) for air-to-ground (ATG) communications.
Description of Related Art
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts, etc. These wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc. ) . Examples of such multiple-access systems include 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, LTE Advanced (LTE-A) systems, code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems, to name a few.
These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. New radio (e.g., 5G NR) is an example of an emerging telecommunication standard. NR is a set of enhancements to the LTE mobile standard promulgated by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using OFDMA with a cyclic prefix (CP) on the downlink (DL) and on the uplink (UL) . To these ends, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.
However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in NR and LTE technology. These improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.
SUMMARY
The systems, methods, and devices of the disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. After considering this discussion, and particularly after reading the section entitled “Detailed Description” one will understand how the features of this disclosure provide advantages that include enabling air-to-ground (ATG) communications between an airborne user equipment (UE) and a stationary base station (BS) .
Certain aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication by a user equipment (UE) . The method generally includes determining, by the UE, one or more parameters indicative of movement of the UE relative to the BS. The method also includes updating, by the UE, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, the one or more parameters comprising: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory. The method also includes transmitting an uplink signal over resources determined using the new uplink timing advance.
Certain aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication by a user equipment (UE) . The method generally includes receiving, from the BS: a timing advance drift rate data based on UE-specific parameters, the one or more parameters comprising: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory; and a timing advance command. The method also includes updating, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance. The method also includes transmitting an uplink signal over resources determined using the new uplink timing advance.
Certain aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication by a base station (BS) . The method generally includes transmitting, to the UE, one or more parameters indicative of a location of the BS. The method also includes receiving an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters.
Certain aspects of the subject matter described in this disclosure can be implemented in a method for wireless communication by a base station (BS) . The method generally includes receiving UE-specific parameters from the UE, the UE-specific parameters comprising one or more of: an altitude of the UE; a location of the UE; a UE speed; or a UE trajectory. The method also includes determining, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS. The method also includes transmitting, to the UE, the timing advance drift rate.
Certain aspects of the subject matter described in this disclosure can be implemented by a user equipment (UE) . The UE generally includes a memory and a processor communicatively coupled to the memory. The processor and the memory may be configured to determine, by the UE, one or more parameters indicative of movement of the UE relative to the BS. The memory and the processor may be configured to update a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, the one or more parameters comprising: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory. The memory and the processor may also be configured to transmit an uplink signal over resources determined using the new uplink timing advance.
Certain aspects of the subject matter described in this disclosure can be implemented by a user equipment (UE) . The UE generally includes a memory and a processor communicatively coupled to the memory. The processor and the memory may be configured to receive, from the BS: (i) a timing advance drift rate data based on UE-specific parameters, the one or more parameters comprising: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory; and (ii) a timing advance command. The processor and the memory may also update, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance. The memory and the processor may also transmit an uplink signal over resources determined using the new uplink timing advance.
Certain aspects of the subject matter described in this disclosure can be implemented by a base station (BS) . The BS generally includes a memory and a processor communicatively coupled to the memory. The processor and the memory may be configured to transmit, to the UE, one or more parameters indicative of a location of the BS. The processor and the memory may also receive an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters.
Certain aspects of the subject matter described in this disclosure can be implemented by a base station (BS) . The BS generally includes a memory and a processor communicatively coupled to the memory. The processor and the memory may be configured to receive UE-specific parameters from the UE, the UE-specific parameters comprising one or more of: an altitude of the UE; a location of the UE; a UE speed; or a UE trajectory. The processor and the memory may also determine, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS. The processor and the memory may also transmit, to the UE, the timing advance drift rate.
Certain aspects of the subject matter described in this disclosure can be implemented in a user equipment (UE) . The UE generally includes means for determining one or more parameters indicative of movement of the UE relative to the BS. The UE also include means for updating a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, the one or more parameters comprising: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory. The UE also includes means for transmitting an uplink signal over resources determined using the new uplink timing advance.
Certain aspects of the subject matter described in this disclosure can be implemented by a user equipment (UE) . The UE generally includes means for receiving, from the BS: a timing advance drift rate data based on UE-specific parameters, the one or more parameters comprising: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory; and a timing advance command. The UE also includes means for updating, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance. The UE also includes means for transmitting an uplink signal over resources determined using the new uplink timing advance.
Certain aspects of the subject matter described in this disclosure can be implemented in a base station (BS) . The BS includes means for transmitting, to the UE, one or more parameters indicative of a location of the BS. The BS also includes means for receiving an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters.
Certain aspects of the subject matter described in this disclosure can be implemented in a base station (BS) . The BS generally includes means for receiving UE-specific parameters from the UE, the UE-specific parameters comprising one or more of: an altitude of the UE; a location of the UE; a UE speed; or a UE trajectory. The BS also includes means for determining, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS. The BS also includes means for transmitting, to the UE, the timing advance drift rate.
Certain aspects of the subject matter described in this disclosure can be implemented by a non-transitory computer-readable medium having instructions stored thereon that, when executed by a user equipment (UE) , cause the UE to perform operations comprising determining one or more parameters indicative of movement of the UE relative to the BS. The operations also include updating, by the UE, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, the one or more parameters comprising: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory. The operations also include transmitting an uplink signal over resources determined using the new uplink timing advance.
Certain aspects of the subject matter described in this disclosure can be implemented by a non-transitory computer-readable medium having instructions stored thereon that, when executed by a user equipment (UE) , cause the UE to perform operations comprising receiving, from the BS: (i) a timing advance drift rate data based on UE-specific parameters, the one or more parameters comprising: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory; and (ii) a timing advance command. The operations also include updating, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance. The operations also include transmitting an uplink signal over resources determined using the new uplink timing advance.
Certain aspects of the subject matter described in this disclosure can be implemented by a non-transitory computer-readable medium having instructions stored thereon that, when executed by a base station (BS) , cause the BS to perform operations comprising transmitting, to the UE, one or more parameters indicative of a location of the BS. The operations also include receiving an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters.
Certain aspects of the subject matter described in this disclosure can be implemented by a non-transitory computer-readable medium having instructions stored thereon that, when executed by a base station (BS) , cause the BS to perform operations comprising receiving UE-specific parameters from the UE, the UE-specific parameters comprising one or more of: an altitude of the UE; a location of the UE; a UE speed; or a UE trajectory. The operations also include determining, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS. The operations also include transmitting, to the UE, the timing advance drift rate.
To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the appended drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the drawings. It is to be noted, however, that the appended drawings illustrate only certain aspects of this disclosure and the description may admit to other equally effective aspects.
FIG. 1 is a block diagram conceptually illustrating an example wireless communication network, in accordance with certain aspects of the present disclosure.
FIG. 2 is a block diagram conceptually illustrating a design of an example base station (BS) and user equipment (UE) , in accordance with certain aspects of the present disclosure.
FIG. 3 is an example frame format for certain wireless communication systems (e.g., new radio (NR) ) , in accordance with certain aspects of the present disclosure.
FIG. 4A is a block diagram illustrating an example uplink timing advance in a scenario where uplink and downlink slots are time-aligned at a BS.
FIG. 4B is a block diagram illustrating an example uplink timing advance in a scenario where uplink and downlink slots are time-shifted at a BS.
FIG. 5 is a diagram illustrating an example network comprising an air vehicle UE and a BS, and a corresponding call-flow diagram illustrating example communications between the UE and the BS.
FIG. 6 is a diagram illustrating an example network comprising an air vehicle UE and a BS, and a corresponding call-flow diagram illustrating example communications between the UE and a BS.
FIG. 7 is a diagram illustrating an example network comprising an air vehicle UE and a BS, and a corresponding call-flow diagram illustrating example communications between the UE and the BS.
FIG. 8 is a flow diagram illustrating example operations for wireless communication, in accordance with certain aspects of the present disclosure.
FIG. 9 is a flow diagram illustrating example operations for wireless communication, in accordance with certain aspects of the present disclosure.
FIG. 10 is a flow diagram illustrating example operations for wireless communication, in accordance with certain aspects of the present disclosure.
FIG. 11 is a flow diagram illustrating example operations for wireless communication, in accordance with certain aspects of the present disclosure.
FIG. 12 illustrates a communications device that may include various components configured to perform operations for the techniques disclosed herein, such as the operations illustrated in FIGS. 8 and 9.
FIG. 13 illustrates a communications device that may include various components configured to perform operations for the techniques disclosed herein, such as the operations illustrated in FIGS. 10 and 11.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatus, methods, processing systems, and computer readable mediums for allowing a user equipment (UE) to determine a timing advance for uplink communications using UE-specific information.
The following description provides examples of determining and communicating according to a timing advance in communication systems. Changes may be made in the function and arrangement of elements discussed without departing from the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to, or other than, the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration. ” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.
In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular radio access technology (RAT) and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, an air interface, etc. A frequency may also be referred to as a carrier, a subcarrier, a frequency channel, a tone, a subband, etc. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs.
The techniques described herein may be used for various wireless networks and radio technologies. While aspects may be described herein using terminology commonly associated with 3G, 4G, and/or new radio (e.g., 5G NR) wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems.
NR access may support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth, millimeter wave mmW, massive machine type communications MTC (mMTC) targeting non-backward compatible MTC techniques, and/or mission critical targeting ultra-reliable low-latency communications (URLLC) . These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTI) to meet respective quality of service (QoS) requirements. In addition, these services may co-exist in the same subframe.
NR supports beamforming and beam direction may be dynamically configured. MIMO transmissions with precoding may also be supported. MIMO configurations in the DL may support up to 8 transmit antennas with multi-layer DL transmissions up to 8 streams and up to 2 streams per UE. Multi-layer transmissions with up to 2 streams per UE may be supported. Aggregation of multiple cells may be supported with up to 8 serving cells.
FIG. 1 illustrates an example wireless communication network 100 in which aspects of the present disclosure may be performed. For example, the wireless communication network 100 may be an NR system (e.g., a 5G NR network) . As shown in FIG. 1, the wireless communication network 100 may be in communication with a core network 132. The core network 132 may in communication with one or more base station (BSs) 110a-z (each also individually referred to herein as BS 110 or collectively as BSs 110) and/or user equipment (UE) 120a-y (each also individually referred to herein as UE 120 or collectively as UEs 120) in the wireless communication network 100 via one or more interfaces.
According to certain aspects, the BSs 110 and UEs 120 may be configured for providing information for determining, at a UE 120a, a timing advance for uplink communications with the BS 110a. As shown in FIG. 1, the BS 110a includes a timing advance (TA) manager 112 configured to transmit, to the UE 120a, one or more parameters indicative of a location of the BS 110a, and receive an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters, in accordance with aspects of the present disclosure. In some examples, the TA manager 112 is configured to receive UE-specific parameters from the UE, determine, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS, and transmit, to the UE 120a, the timing advance drift rate.
The UE 120a includes a TA manager 122 that is configured to determine, by the UE 120a, one or more parameters indicative of movement of the UE relative to the BS, update, by the UE, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, and transmit an uplink signal over resources determined using the new uplink timing advance in accordance with aspects of the present disclosure. The TA manager 122 may also be configured to receive, from the BS: a timing advance drift rate data based on UE-specific parameters, and a timing advance command. The TA manager 122 may also be configured to update, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, and transmit an uplink signal over resources determined using the new uplink timing advance.
A BS 110 may provide communication coverage for a particular geographic area, sometimes referred to as a “cell” , which may be stationary or may move according to the location of a mobile BS 110. In some examples, the BSs 110 may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in wireless communication network 100 through various types of backhaul interfaces (e.g., a direct physical connection, a wireless connection, a virtual network, or the like) using any suitable transport network. In the example shown in FIG. 1, the BSs 110a, 110b and 110c may be macro BSs for the macro cells 102a, 102b and 102c, respectively. The BS 110x may be a pico BS for a pico cell 102x. The BSs 110y and 110z may be femto BSs for the femto cells 102y and 102z, respectively. A BS may support one or multiple cells.
The BSs 110 communicate with UEs 120 in the wireless communication network 100. The UEs 120 (e.g., 120x, 120y, etc. ) may be dispersed throughout the wireless communication network 100, and each UE 120 may be stationary or mobile. Wireless communication network 100 may also include relay stations (e.g., relay station 110r) , also referred to as relays or the like, that receive a transmission of data and/or other information from an upstream station (e.g., a BS 110a or a UE 120r) and sends a transmission of the data and/or other information to a downstream station (e.g., a UE 120 or a BS 110) , or that relays transmissions between UEs 120, to facilitate communication between devices.
A network controller 130 may be in communication with a set of BSs 110 and provide coordination and control for these BSs 110 (e.g., via a backhaul) . In aspects, the network controller 130 may be in communication with a core network 132 (e.g., a 5G Core Network (5GC) ) , which provides various network functions such as Access and Mobility Management, Session Management, User Plane Function, Policy Control Function, Authentication Server Function, Unified Data Management, Application Function, Network Exposure Function, Network Repository Function, Network Slice Selection Function, etc.
FIG. 2 illustrates example components of BS 110a and UE 120a (e.g., the wireless communication network 100 of FIG. 1) , which may be used to implement aspects of the present disclosure.
At the BS 110a, a transmit processor 220 may receive data from a data source 212 and control information from a controller/processor 240. The control information may be for the physical broadcast channel (PBCH) , physical control format indicator channel (PCFICH) , physical hybrid ARQ indicator channel (PHICH) , physical downlink control channel (PDCCH) , group common PDCCH (GC PDCCH) , etc. The data may be for the physical downlink shared channel (PDSCH) , etc. A medium access control (MAC) -control element (MAC-CE) is a MAC layer communication structure that may be used for control command exchange between wireless nodes. The MAC-CE may be carried in a shared channel such as a physical downlink shared channel (PDSCH) , a physical uplink shared channel (PUSCH) , or a physical sidelink shared channel (PSSCH) .
The processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols, such as for the primary synchronization signal (PSS) , secondary synchronization signal (SSS) , PBCH demodulation reference signal (DMRS) , and channel state information reference signal (CSI-RS) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) in transceivers 232a-232t. Each modulator in transceivers 232a-232t may process a respective output symbol stream (e.g., for OFDM, etc. ) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from the modulators in transceivers 232a-232t may be transmitted via the antennas 234a-234t, respectively.
At the UE 120a, the antennas 252a-252r may receive the downlink signals from the BS 110a and may provide received signals to the demodulators (DEMODs) in transceivers 254a-254r, respectively. Each demodulator in transceivers 254a-254r may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM, etc. ) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all the demodulators in transceivers 254a-254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120a to a data sink 260, and provide decoded control information to a controller/processor 280.
On the uplink, at UE 120a, a transmit processor 264 may receive and process data (e.g., for the physical uplink shared channel (PUSCH) ) from a data source 262 and control information (e.g., for the physical uplink control channel (PUCCH) from the controller/processor 280. The transmit processor 264 may also generate reference symbols for a reference signal (e.g., for the sounding reference signal (SRS) ) . The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by the modulators in transceivers 254a-254r (e.g., for SC-FDM, etc. ) , and transmitted to the BS 110a. At the BS 110a, the uplink signals from the UE 120a may be received by the antennas 234, processed by the demodulators in transceivers 232a-232t, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by the UE 120a. The receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to the controller/processor 240.
The memories 242 and 282 may store data and program codes for BS 110a and UE 120a, respectively. A scheduler 244 may schedule UEs for data transmission on the downlink and/or uplink.
Antennas 252, processors 266, 258, 264, and/or controller/processor 280 of the UE 120a and/or antennas 234, processors 220, 230, 238, and/or controller/processor 240 of the BS 110a may be used to perform the various techniques and methods described herein. For example, as shown in FIG. 2, the controller/processor 240 of the BS 110a has a TA manager 112 configured to transmit, to the UE 120a, one or more parameters indicative of a location of the BS 110a, and receive an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters, in accordance with aspects of the present disclosure. In some examples, the TA manager 112 is configured to receive UE-specific parameters from the UE, determine, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS, and transmit, to the UE 120a, the timing advance drift rate.
As shown in FIG. 2, the controller/processor 280 of the UE 120a has a TA manager 122 that is configured to determine, by the UE 120a, one or more parameters indicative of movement of the UE relative to the BS, update, by the UE, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, and transmit an uplink signal over resources determined using the new uplink timing advance in accordance with aspects of the present disclosure. The TA manager 122 may also be configured to receive, from the BS:a timing advance drift rate data based on UE-specific parameters, and a timing advance command. The TA manager 122 may also be configured to update, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, and transmit an uplink signal over resources determined using the new uplink timing advance.
Although shown at the controller/processor, other components of the UE 120a and BS 110a may be used to perform the operations described herein.
NR may utilize orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) on the uplink and downlink. NR may support half-duplex operation using time division duplexing (TDD) . OFDM and single-carrier frequency division multiplexing (SC-FDM) partition the system bandwidth into multiple orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. Each subcarrier may be modulated with data. Modulation symbols may be sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers may be fixed, and the total number of subcarriers may be dependent on the system bandwidth. The minimum resource allocation, called a resource block (RB) , may be 12 consecutive subcarriers. The system bandwidth may also be partitioned into subbands. For example, a subband may cover multiple RBs. NR may support a base subcarrier spacing (SCS) of 15 KHz and other SCS may be defined with respect to the base SCS (e.g., 30 kHz, 60 kHz, 120 kHz, 240 kHz, etc. ) .
FIG. 3 is a diagram showing an example of a frame format 300 for NR. The transmission timeline for each of the downlink and uplink may be partitioned into units of radio frames. Each radio frame may have a predetermined duration (e.g., 10 ms) and may be partitioned into 10 subframes, each of 1 ms, with indices of 0 through 9. Each subframe may include a variable number of slots (e.g., 1, 2, 4, 8, 16, …slots) depending on the SCS. Each slot may include a variable number of symbol periods (e.g., 7, 12, or 14 symbols) depending on the SCS. The symbol periods in each slot may be assigned indices. A sub-slot structure may refer to a transmit time interval having a duration less than a slot (e.g., 2, 3, or 4 symbols) . Each symbol in a slot may be configured for a link direction (e.g., DL, UL, or flexible) for data transmission and the link direction for each subframe may be dynamically switched. The link directions may be based on the slot format. Each slot may include DL/UL data as well as DL/UL control information.
In NR, a synchronization signal block (SSB) is transmitted. In certain aspects, SSBs may be transmitted in a burst where each SSB in the burst corresponds to a different beam direction for UE-side beam management (e.g., including beam selection and/or beam refinement) . The SSB includes a PSS, a SSS, and a two symbol PBCH. The SSB can be transmitted in a fixed slot location, such as the symbols 0-3 as shown in FIG. 3. The PSS and SSS may be used by UEs for cell search and acquisition. The PSS may provide half-frame timing, the SS may provide the CP length and frame timing. The PSS and SSS may provide the cell identity. The PBCH carries some basic system information, such as downlink system bandwidth, timing information within radio frame, SS burst set periodicity, system frame number, etc. The SSBs may be organized into SS bursts to support beam sweeping. Further system information such as, remaining minimum system information (RMSI) , system information blocks (SIBs) , other system information (OSI) can be transmitted on a physical downlink shared channel (PDSCH) in certain subframes. The SSB can be transmitted up to sixty-four times, for example, with up to sixty-four different beam directions for mmWave. The multiple transmissions of the SSB are referred to as a SS burst set. SSBs in an SS burst set may be transmitted in the same frequency region, while SSBs in different SS bursts sets can be transmitted at different frequency regions.
In wireless communication, uplink orthogonality allows a BS 110a to receive uplink transmissions from different UEs 120 within a cell without interference caused between the uplink transmissions. For uplink orthogonality to work, uplink slot boundaries for a given numerology may be time aligned at the BS 110a. In some examples, any timing misalignment between uplink transmissions received by the BS 110a may fall within a cyclic prefix. Thus, to ensure that UE uplink transmissions are time aligned with the BS 110a, a UE 120a may use a transmission timing advance.
Generally, timing advance relates to a negative offset of an uplink transmission by a UE 120a. In some examples, the negative offset is between the start of a downlink slot as observed by the UE 120a and the start of an uplink slot over which an uplink signal is transmitted. If a UE 120a is far from the BS 110a, a larger offset may be required. Therefore, a distant UE 120a may start their uplink transmissions further in advance relative to other UEs that are closer to the BS.
FIG. 4A is a block diagram illustrating an example uplink timing advance 410 in a scenario where uplink and downlink slots are time-aligned at a BS. Here, an nth downlink slot 402 and an nth uplink slot 404 are aligned, from the perspective of the BS. However, because the UE is a distance away from the BS, the UE applies a relatively large timing advance 410 from the nth uplink slot 406 toward the nth downlink slot 408, from the perspective of the UE. That is, the greater the distance between the UE and the BS, the greater the delay between the moment a signal is transmitted from a transmitter and the moment that signal is received by a receiver. Because the slots are aligned at the BS, the UE is responsible for advancing the timing of transmission of the uplink signal so that the nth downlink slot 402 and an nth uplink slot 404 are aligned, from the perspective of the BS.
FIG. 4B is a block diagram illustrating an example uplink timing advance 460 in a scenario where uplink and downlink slots are time-shifted at a BS. Here, an nth downlink slot 452 and an nth uplink slot 454 are time shifted (e.g., separated by, for example, a frame) , from the perspective of the BS. That is, the BS transmits a downlink signal from the nth downlink slot 452 and expects to receive an uplink signal during an nth uplink slot 454 some amount of time 462 later. Accordingly, because of the time shift from the perspective of the BS, the timing advance 460 of the UE’s uplink transmission 456 is reduced toward the nth downlink slot 458 relative to the timing advance 410 of FIG. 4A.
Thus, to achieve proper timing, the UE 120a may advance timing of its uplink transmissions to help ensure synchronized reception timing of the uplink transmissions at the BS 110a. However, issues may arise when determining and applying a timing advance in air-to-ground (ATG) communications between an airborne UE 120a and a stationary BS 110a. For example, in ATG communications, a BS 110a may have a fixed location while the air vehicle UE 120a moves very quickly. This is different from satellite communications, because satellite BSs move much faster than a UE. Moreover, stationary BSs 110a in ATG communications typically have access to little or no information (e.g., location, trajectory, etc. ) regarding the air vehicle UE 120a. Even if such information is available, signaling delay and overhead associated with the ATG communications can reduce the effectivity of such information.
Accordingly, aspects of the disclosure resolve such issues by utilizing UE-specific information to better compensate uplink timing advance by an airborne UE 120a. As described in more detail below, the use of UE-specific information results in relatively lower signaling overhead and reductions in signaling delays.
TIMING ADVANCE BASED ON UE-SPECIFIC AND BS INFORMATION
In certain aspects, a UE 120a may determine and apply a timing advance to its uplink transmissions without requiring a command or other instruction by a BS 110a. That is, the BS 110a may not have to transmit a command or instruction configured to prompt the UE 120a to determine and/or adjust its timing advance of uplink transmissions. Such techniques, as described in more detail below, reduce signaling delays by eliminating specific BS 110a commands and instead providing the UE 120a with the ability to determine and make any appropriate adjustments to the timing advance.
FIG. 5 is a diagram illustrating an example network 500 comprising an air vehicle UE 120a and a BS 110a, and a corresponding call-flow diagram 550 illustrating example communications between the UE 120a and a BS 110a. In this example, the UE 120a is within a range 562 of effective wireless communication with the BS 110a. For example, the range 562 may be any suitable distance (e.g., 300 kilometers (km) or less) that allows for wireless communication between the UE 120a and the BS 110a.
Initially, the UE 120a may engage in a RACH procedure with the BS 110a after receiving a first communication 502 that includes system information block (SIB) and/or random access channel (RACH) messages. The UE 120a may then determine 504 to update or calculate a timing advance for communication with the BS 110a. The UE 120a may determine 506 a timing advance based on the received information (e.g., BS parameters) and/or UE-specific information determined at the UE 120a. The UE may then transmit, in a second communication 508, an uplink transmission according to the determined timing advance. Optionally, the UE 120a may transmit a report 510 to the BS 110a, as discussed in more detail below.
In certain aspects, the UE 120a may automatically (e.g., without command or instruction from the BS 110a) determine an appropriate timing advance 560 for communication with the BS 110a, and update or adjust a previous used timing advance. Because the UE 120a is determining a timing advance 560 on its own, the determination may be based on UE-specific information. For example, the UE 120a may determine an appropriate timing advance 560 based on real-time coordinates and altitude provided by equipment on the UE 120a. In some examples, altitude and other coordinates such as location, speed, trajectory, and any other suitable parameters of the UE 120a may be provided by equipment on the UE 120a, and may be used in real-time to update the timing advance 560. The coordinates may include any geographic coordinate system (GCS) information relating to a location of the UE 120a and/or BS 110a.
In certain aspects, the UE 120a may automatically determine and update timing advance 560 based on the UE specific information and/or one or more BS 110a parameters. The BS 110a parameters may include BS 110a coordinates, BS 110a altitude, and/or a downlink-uplink frame timing shift associated with the BS 110a (e.g., the downlink-uplink frame timing shift illustrated in FIG. 4B) . In some examples, the UE 120a may receive the coordinates and altitude from the BS 110a in a wireless communication, such as a system information broadcast (SIB) or in a RACH message transmitted by the BS 110a.
In a first example, the BS 110a may include one or more of the BS 110a parameters in the SIB message (e.g., SIB 1, SIB 2, etc. ) . In this way, the UE 120a may determine and/or update its timing advance prior to RACH procedure with the BS 110a. Alternatively, or in addition, the BS 110a may provide one or more BS 110a parameters in a RACH message. For example, a second message (msg2) transmitted by the BS 110a during a four-step RACH procedure may include a PDCCH communication providing the BS 110a parameters. In another example, the BS 110a may transmit a random access response (RAR) message (msgB) during a two-step RACH procedure which may provide the UE 120a with the BS 110a parameters. Note that conventional SIB and RACH messaging (e.g., msg2 and msgB) may include timing advance information determined by the BS 110a for the UE 120a. However, because of the speed of an airborne UE 120a, timing advance information provided in this way may become obsolete the moment the UE 120a receives it, or shortly thereafter. As such, SIB and/or RACH messaging may be modified to include an indication of one or more BS 110a parameters instead of a timing advance value determined by the BS 110a. This reduces delays and the amount of time that the BS 110a would otherwise be required to spend determining a UE 120a timing advance, and it also reduces communication overhead.
In a second example, one or more BS parameters may be pre-loaded and stored on the UE 120a. For example, a database of BSs 110 may be stored and indexed by a BS identifier (ID) that associates one or more BS parameters with a particular BS 110a. In such an example, communication overhead and delays are reduced because the BS 110a does not have to calculate a timing advance for the UE 120a to use, nor does the BS 110a have to communicate the one or more BS parameters to the UE 120a. Instead, the UE 120a may identify the BS 110a based on a SIB, perform a lookup operation to determine the BS parameters associated with the BS 110a, then determine and/or update a timing advance for uplink communications with the BS 110a based on the BS parameters and UE specific information.
As illustrated in the example network 500 of FIG. 5, the UE 120a may optionally receive BS parameters from the BS via a wireless communication 564 (e.g., a SIB or RACH message) . Based on the BS parameters and real-time UE-specific information generated at the UE 120a, the UE 120a may determine a timing advance 560 and transmit an uplink communication 566 according to the determined timing advance. In some examples, the UE 120a may continually update the timing advance based on the BS parameters and the UE-specific information to maintain an appropriate timing advance.
In some examples, the uplink communication 566 may include information indicating the UE-determined timing advance so that the BS 110a may use the timing advance for uplink scheduling. The uplink communication 566 may also, or alternatively, include information regarding the UE’s 120a capabilities to determine UE-specific information. For example, the UE 120a may report 510 information indicating the accuracy of the UE’s 120a GNSS and altimeter information. Based on the information provided in the report 510, the BS 110a may configure the UE 120a with different cyclic prefix (CP) lengths or schedule the US 120a with different time-lines to accommodate the UE’s equipment capabilities or accuracy.
FIG. 6 is a diagram illustrating an example network 600 comprising an air vehicle UE 120a and a BS 110a, and a corresponding call-flow diagram 650 illustrating example communications between the UE 120a and a BS 110a. In this example, the UE 120a is within a range 662 of effective wireless communication with the BS 110a. For example, the range 662 may be any suitable distance (e.g., 300 kilometers (km) or less) that allows for wireless communication between the UE 120a and the BS 110a.
In this example, the UE 120a may provide the BS 110a with UE-specific information so that the BS 110a can determine a timing advance drift rate of the UE 120a. The timing advance drift rate may indicate an estimated rate at which uplink communications from the UE 120a may drift from being synchronized with the timing at the BS 110a, to being outside of a threshold timing value that indicates an unacceptable deviation from the BS 110a timing. Accordingly, the drift rate may indicate whether the UE 120a needs to update its timing advance, and/or the rate at which the UE 120a needs to update its timing advance. The BS 110a may determine the timing advance drift rate of the UE 120a using UE-specific information such as trajectory, location, and speed to predict the drift rate. Because the UE 120a is providing the UE-specific information directly to the BS 110a, the BS does not have to rely on air-traffic control (ATC) or other means to indirectly receive UE-specific information. This reduces latencies and delays introduced into communications by a third party (e.g., ATC) communicating between the US 120a and the BS 110a.
In certain aspects, in a first communication 602, the BS 110a may request UE-specific information from the UE 120a. In one example, the BS 110a may configure the UE 120a to periodically communicate UE-specific information (e.g., one or more of trajectory, location, speed, and any other suitable information calculated or generated at the UE 120a) to the BS 110a. The BS 110a may configure the UE 120a for the periodic communication via RRC messaging comprising an indication of one or more of the type of UE-specific information and the periodicity or frequency of communication of such information. In some examples, the periodicity of the update may be configured via a synchronization signal block (SSB) .
In certain aspects, the first communication 602 may be a downlink control information (DCI) transmitted from the BS 110a. In some examples, the DCI may trigger the UE 120a to communicate UE-specific information to the BS 110a. Accordingly, the BS 110a may aperiodically request the UE-specific information (e.g., in-between periodic communications configured by an RRC, or without any RRC periodic configuration) . In some examples, the DCI may include an indication of the type of UE-specific information requested by the BS 110a.
In another example, the BS 110a request for UE-specific information may be communicated to the UE 120a via a SIB, or in a RAR message (e.g., msg2 of a four-step RACH procedure or msgB of a two-step RACH procedure) . In such an example, the UE 120a may respond to the request by transmitting the UE-specific information via a msg3 of the four-step RACH procedure or msgA of the two-step RACH procedure.
Upon receiving the first communication 602, the UE 120a may respond to the BS 110a with a second communication 604 that includes UE-specific information. Thereafter, the UE 120a may continue to periodically and/or aperiodically transmit UE-specific information to the BS 110a. The BS 110a may then estimate a timing advance drift rate based on the UE-specific information. For example, the BS 110a may predict a rate at which uplink communications from the UE 120a may drift from being synchronized with the timing at the BS 110a, to being outside of a threshold timing value that indicates an unacceptable deviation from the BS 110a timing. The UE 120a may communicate the UE-specific information to the BS 110a via an RRC message, a MAC-CE, or a uplink control information (UCI) .
In a third communication 606, the BS 110a may communicate the determined timing advance drift rate to the UE 120a. In some examples, the drift rate may be communicated via an RRC message, a DCI, or a MAC-CE. In some examples, the third communication 606 may include a time-stamped timing advance command configured to cause the UE 120a to update its timing advance based on the latest drift rate.
In response to one or more of the time-stamped timing advance command or drift rate provided in the third communication 606, in a first process 608, the UE 120a may update its timing advance so that a future uplink transmission 610 is properly synchronized with BS 110a timing. For example, the UE 120a may use the drift rate and the timing advance command to update the timing advance. It should be noted, however, that in some examples, the drift rate may prompt the UE 120a to automatically update its timing advance without a timing advance command.
In a fourth communication 610, the UE 120a may transmit an uplink communication to the BS according to the updated timing advance 660. The UE 120a may optionally transmit a report to the BS 110a in a fifth communication 612. For example, the UE 120a may report information indicating the accuracy of the UE’s 120a GNSS and altimeter information, or any other pieces of equipment used to determine the UE specific information provided to the BS 110a in the second communication 604.
FIG. 7 is a diagram illustrating an example network 700 comprising an air vehicle UE 120a and a BS 110a, and a corresponding call-flow diagram 750 illustrating example communications between the UE 120a and a BS 110a. Here, the UE 120a is within a range 762 of effective wireless communication with the BS 110a. For example, the range 762 may be any suitable distance (e.g., 300 kilometers (km) or less) that allows for wireless communication between the UE 120a and the BS 110a.
In this example, the BS 110a may receive UE-specific information from a source other than the UE 120a itself. For instance, the BS 110a may receive UE-specific information from an ATC, or via automatic dependent surveillance (ADS) (e.g., ADS-A, ADS-B, and/or ADS-C) 764. The BS 110a may then determine a timing advance drift rate for the UE 120a based on the information. Thus, in a first process 702, the BS 110a may determine a timing advance drift rate based on the UE-specific information received from the ADS 764.
Then, in a first communication 704, the BS 110a may communicate the determined timing advance drift rate to the UE 120a. In some examples, the first communication 704 may include a time-stamped timing advance command configured to cause the UE 120a to update its timing advance based on the latest drift rate. In a second process 706, and in response to one or more of the time-stamped timing advance command or drift rate provided in the first communication 704, the UE 120a may update its timing advance 760 so that a future uplink transmission 708 is properly synchronized with BS 110a timing. In a second communication 708, the UE 120a may transmit an uplink communication to the BS 110a according to the updated timing advance 760.
FIG. 8 is a flow diagram illustrating example operations 800 for wireless communication, in accordance with certain aspects of the present disclosure. The operations 800 may be performed, for example, by a UE (e.g., such as the UE 120a in the wireless communication network 100) . The operations 800 may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor 280 of FIG. 2) . Further, the transmission and reception of signals by the UE in operations 800 may be enabled, for example, by one or more antennas (e.g., antennas 252 of FIG. 2) . In certain aspects, the transmission and/or reception of signals by the UE may be implemented via a bus interface of one or more processors (e.g., controller/processor 280) obtaining and/or outputting signals.
The operations 800 may begin, at a first block 802, by determining one or more parameters indicative of movement of the UE relative to the BS.
The operations 800 may proceed to a second block 804 by updating, by the UE, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, the one or more parameters comprising: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory.
The operations 800 may proceed to a third block 806 by transmitting an uplink signal over resources determined using the new uplink timing advance.
In certain aspects, the determining the one or more parameters further comprises receiving, from the BS, the one or more parameters, wherein the one or more parameters are based on information provided by an automatic dependent surveillance –broadcast (ADS-B) .
In certain aspects, the one or more parameters comprise a BS timing shift between an uplink time interval and a downlink time interval, the timing shift indicating whether the uplink time interval is aligned with the downlink time interval at the BS.
In certain aspects, operations 800 may also include receiving a system information broadcast (SIB) from the BS, the SIB indicating one or more of the altitude of the BS, the location of the BS, or the BS timing shift.
In certain aspects, operations 800 may also include receiving one or more of the altitude of the BS, the location of the BS, or the BS timing shift via one of: a message B (MsgB) of a 2-step random access channel (RACH) procedure; or a message 2 (Msg2) of a 4-step RACH procedure.
In certain aspects, a plurality of BS identifiers are stored on the UE, wherein each of the plurality of BS identifiers correspond to a particular BS, and wherein a first BS identifier indicates one or more of the altitude of the BS or the location of the BS.
In certain aspects, operations 800 further comprise transmitting a report to the BS, the report including an indication of an accuracy of one or more of the UE altitude or the UE coordinates.
FIG. 9 is a flow diagram illustrating example operations 900 for wireless communication, in accordance with certain aspects of the present disclosure. The operations 900 may be performed, for example, by a UE (e.g., such as the UE 120a in the wireless communication network 100) . The operations 900 may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor 280 of FIG. 2) . Further, the transmission and reception of signals by the UE in operations 900 may be enabled, for example, by one or more antennas (e.g., antennas 252 of FIG. 2) . In certain aspects, the transmission and/or reception of signals by the UE may be implemented via a bus interface of one or more processors (e.g., controller/processor 280) obtaining and/or outputting signals.
The operations 900 may begin, at a first block 902, by receiving, from the BS: (i) a timing advance drift rate data based on UE-specific parameters, the one or more parameters comprising: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory; and (ii) a timing advance command.
The operations 900 may proceed to a second block 904 by updating, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance.
The operations 900 may proceed to a third block 906 by transmitting an uplink signal over resources determined using the new uplink timing advance.
In certain aspects, operations 900 include receiving, from the BS, a request for the UE to provide the BS with UE-specific parameters and transmitting the UE-specific parameters to the BS in response to the request.
In certain aspects, operations 900 include determining the UE-specific parameters using equipment integrated into the UE.
In certain aspects, transmitting UE-specific parameters to the BS further comprises transmitting the UE-specific parameters via a radio resource control (RRC) , a media access control (MAC) control element (CE) , or an uplink control information (UCI) .
In certain aspects, the UE-specific parameters comprise information provided by an automatic dependent surveillance –broadcast (ADS-B) .
In certain aspects, the timing advance command comprises a request for the UE to update the previous uplink timing advance.
In certain aspects, the request is received via one or more of a radio resource control (RRC) or a downlink control information (DCI) .
In certain aspects, the timing advance drift rate data is received via a radio resource control (RRC) , a downlink control information (DCI) , or a media access control (MAC) control element (CE) .
FIG. 10 is a flow diagram illustrating example operations 1000 for wireless communication, in accordance with certain aspects of the present disclosure. The operations 1000 may be performed, for example, by a BS (e.g., such as the BS 110a in the wireless communication network 100) . The operations 1000 may be complementary to the operations 800/900 performed by the UE. The operations 1000 may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor 240 of FIG. 2) . Further, the transmission and reception of signals by the BS in operations 1000 may be enabled, for example, by one or more antennas (e.g., antennas 234 of FIG. 2) . In certain aspects, the transmission and/or reception of signals by the BS may be implemented via a bus interface of one or more processors (e.g., controller/processor 240) obtaining and/or outputting signals.
The operations 1000 may begin, at a first block 1002, by transmitting, to the UE, one or more parameters indicative of a location of the BS.
The operations 1000 may begin at a second block 1004 by receiving an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters.
In certain aspects, the one or more parameters comprise an indication of: an altitude of the BS; a location of the BS; or a BS timing shift between an uplink time interval and a downlink time interval, the timing shift indicating whether the uplink time interval is aligned with the downlink time interval at the BS.
In certain aspects, the one or more parameters are transmitted via a system information broadcast (SIB) , a message B (MsgB) of a 2-step random access channel (RACH) procedure, or a message 2 (Msg2) of a 4-step RACH procedure.
In certain aspects, operations 1000 include receiving, from the UE, a report comprising an indication of an accuracy of equipment on the UE, wherein the equipment is configured to provide one or more of an altitude of the UE or a location of the UE.
In certain aspects, operations the timing advance is determined based at least in part on the one or more parameters and one or more UE-specific parameters.
In certain aspects, the BS is a fixed-location terrestrial BS, and wherein the UE is an airborne air vehicle.
FIG. 11 is a flow diagram illustrating example operations 1100 for wireless communication, in accordance with certain aspects of the present disclosure. The operations 1100 may be performed, for example, by a BS (e.g., such as the BS 110a in the wireless communication network 100) . The operations 1100 may be complementary to the operations 800/900 performed by the UE. The operations 1100 may be implemented as software components that are executed and run on one or more processors (e.g., controller/processor 240 of FIG. 2) . Further, the transmission and reception of signals by the BS in operations 1100 may be enabled, for example, by one or more antennas (e.g., antennas 234 of FIG. 2) . In certain aspects, the transmission and/or reception of signals by the BS may be implemented via a bus interface of one or more processors (e.g., controller/processor 240) obtaining and/or outputting signals.
The operations 1100 may begin, at a first block 1102, by receiving UE-specific parameters from the UE, the UE-specific parameters comprising one or more of: an altitude of the UE; a location of the UE; a UE speed; or a UE trajectory.
The operations 1100 may proceed at a second block 1104 by determining, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS.
The operations 1100 may proceed at a third block 1106 transmitting, to the UE, the timing advance drift rate.
In certain aspects, the operations 1100 include transmitting, to the UE, a request for the UE-specific parameters, wherein the UE-specific parameters are received in response to the request.
In certain aspects, the request is transmitted via a radio resource control (RRC) message or a downlink control information (DCI) message.
In certain aspects, the RRC message is configured to cause the UE to periodically transmit UE-specific parameters to the BS; and the DCI message is configured to trigger the UE to transmit a single update of UE-specific information in response to the request.
In certain aspects, operations 1100 include transmitting a timing advance command with the timing advance drift rate, wherein the timing advance command is configured to cause the UE to update a timing advance used for transmitting uplink communications.
In certain aspects, the timing advance command and the timing advance drift rate are communicated via a radio resource control (RRC) message, a media access control (MAC) control element (CE) , or a downlink control information (DCI) message.
In certain aspects, the UE-specific parameters are determined by equipment integrated into the UE.
In certain aspects, operations 1100 include receiving the UE-specific parameters via a radio resource control (RRC) , a media access control (MAC) control element (CE) , or a uplink control information (UCI) .
In certain aspects, operations include receiving the UE-specific parameters via an automatic dependent surveillance –broadcast (ADS-B) .
FIG. 12 illustrates a communications device 1200 that may include various components (e.g., corresponding to means-plus-function components) configured to perform operations for the techniques disclosed herein, such as the operations illustrated in FIGS. 8 and 9. The communications device 1200 includes a processing system 1202 coupled to a transceiver 1208 (e.g., a transmitter and/or a receiver) . The transceiver 1208 is configured to transmit and receive signals for the communications device 1200 via an antenna 1210, such as the various signals as described herein. The processing system 1202 may be configured to perform processing functions for the communications device 1200, including processing signals received and/or to be transmitted by the communications device 1200.
The processing system 1202 includes a processor 1204 coupled to a computer-readable medium/memory 1212 via a bus 1206. In certain aspects, the computer-readable medium/memory 1212 is configured to store instructions (e.g., computer-executable code) that when executed by the processor 1204, cause the processor 1204 to perform the operations illustrated in FIG. 8 and 9, or other operations for performing the various techniques discussed herein for UE updating of timing advance.
In certain aspects, computer-readable medium/memory 1212 stores code 1214 for determining, by the UE, one or more parameters indicative of movement of the UE relative to the BS.
In certain aspects, computer-readable medium/memory 1212 stores code 1216 for updating, by the UE, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance. Alternatively, or in addition, code 1216 may be for updating, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance.
In certain aspects, computer-readable medium/memory 1212 stores code 1218 for transmitting an uplink signal over resources determined using the new uplink timing advance.
In certain aspects, computer-readable medium/memory 1212 stores code 1220 for receiving, from the BS: a timing advance drift rate data based on UE-specific parameters, and a timing advance command.
In certain aspects, the processor 1204 has circuitry configured to implement the code stored in the computer-readable medium/memory 1212. The processor 1204 includes circuitry 1224 for determining, by the UE, one or more parameters indicative of movement of the UE relative to the BS.
The processor 1204 includes circuitry 1226 for updating, by the UE, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance. Alternatively, or in addition, code 1216 may be for updating, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance.
The processor 1204 includes circuitry 1228 for transmitting an uplink signal over resources determined using the new uplink timing advance.
The processor 1204 includes circuitry 1230 for receiving, from the BS: a timing advance drift rate data based on UE-specific parameters, and a timing advance command.
FIG. 13 illustrates a communications device 1300 that may include various components (e.g., corresponding to means-plus-function components) configured to perform operations for the techniques disclosed herein, such as the operations illustrated in FIGS. 10 and 11. The communications device 1300 includes a processing system 1302 coupled to a transceiver 1308 (e.g., a transmitter and/or a receiver) . The transceiver 1308 is configured to transmit and receive signals for the communications device 1300 via an antenna 1310, such as the various signals as described herein. The processing system 1302 may be configured to perform processing functions for the communications device 1300, including processing signals received and/or to be transmitted by the communications device 1300.
The processing system 1302 includes a processor 1304 coupled to a computer-readable medium/memory 1312 via a bus 1306. In certain aspects, the computer-readable medium/memory 1312 is configured to store instructions (e.g., computer-executable code) that when executed by the processor 1304, cause the processor 1304 to perform the operations illustrated in FIG. 10 and 11, or other operations for performing the various techniques discussed herein for UE updating of timing advance.
In certain aspects, computer-readable medium/memory 1312 stores code 1314 for transmitting, to the UE, one or more parameters indicative of a location of the BS. Alternatively, or in addition, code 1314 is for transmitting, to the UE, the timing advance drift rate.
In certain aspects, computer-readable medium/memory 1312 stores code 1316 for receiving an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters. Alternatively, or in addition, code 1316 may be for receiving UE-specific parameters from the UE.
In certain aspects, computer-readable medium/memory 1312 stores code 1318 for determining, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS.
In certain aspects, the processor 1304 has circuitry configured to implement the code stored in the computer-readable medium/memory 1312. The processor 1304 includes circuitry 1324 for transmitting, to the UE, one or more parameters indicative of a location of the BS. Alternatively, or in addition, circuitry 1324 is for transmitting, to the UE, the timing advance drift rate.
In certain aspects, the processor include circuitry 1326 for receiving an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters. Alternatively, or in addition, circuitry 1326 may be for receiving UE-specific parameters from the UE.
In certain aspects, the processor include circuitry 1328 for determining, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS.
In some examples, means for transmitting (or means for outputting for transmission) may include a transmitter and/or an antenna (s) 234 or the BS 110a or the transmitter unit 254 and/or antenna (s) 252 of the UE 120a illustrated in FIG. 2. Means for receiving (or means for obtaining) may include a receiver and/or an antenna (s) 234 of the BS 110a or a receiver and/or antenna (s) 252 of the UE 120a illustrated in FIG. 2. Means for communicating may include a transmitter, a receiver or both. Means for generating, means for performing, means for determining, means for taking action, means for determining, means for coordinating may include a processing system, which may include one or more processors, such as the transmit processor 220, the TX MIMO processor 230, the receive processor 238, and/or the controller/processor 240 of the BS 110a or the receive processor 258, the transmit processor 264, the TX MIMO processor 266, and/or the controller/processor 280 of the UE 120a illustrated in FIG. 2 and/or the processing system.
EXAMPLE ASPECTS
Implementation examples are described in the following numbered clauses:
1. A method for wireless communications by user equipment (UE) to a base station (BS) , comprising: determining, by the UE, one or more parameters indicative of movement of the UE relative to the BS; updating, by the UE, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance; and transmitting an uplink signal over resources determined using the new uplink timing advance.
2. The method of aspect 1, wherein the determining the one or more parameters further comprises receiving, from the BS, the one or more parameters, wherein the one or more parameters are based on information provided by an automatic dependent surveillance –broadcast (ADS-B) .
3. The method of any of aspects 1 and 2, wherein the one or more parameters comprise: an altitude of the UE or BS; a location of the UE or BS; a UE speed; a UE trajectory; or a BS timing shift between an uplink time interval and a downlink time interval, the timing shift indicating whether the uplink time interval is aligned with the downlink time interval at the BS.
4. The method of any of aspects 1-3, further comprising receiving a system information broadcast (SIB) from the BS, the SIB indicating one or more of the altitude of the BS, the location of the BS, or the BS timing shift.
5. The method of any of aspects 1-4, further comprising receiving one or more of the altitude of the BS, the location of the BS, or the BS timing shift via one of: a message B (MsgB) of a 2-step random access channel (RACH) procedure; or a message 2 (Msg2) of a 4-step RACH procedure.
6. The method of any of aspects 1-5, wherein a plurality of BS identifiers are stored on the UE, wherein each of the plurality of BS identifiers correspond to a particular BS, and wherein a first BS identifier indicates one or more of the altitude of the BS or the location of the BS.
7. The method of any of aspects 1-6, further comprising transmitting a report to the BS, the report including an indication of an accuracy of one or more of the UE altitude or the UE coordinates.
8. A method for wireless communications by user equipment (UE) to a base station (BS) , comprising: receiving, from the BS: a timing advance drift rate data based on UE-specific parameters, and a timing advance command; updating, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance; and transmitting an uplink signal over resources determined using the new uplink timing advance.
9. The method of aspect 8, further comprising: receiving, from the BS, a request for the UE to provide the BS with UE-specific parameters; and transmitting the UE-specific parameters to the BS in response to the request.
10. The method of any of aspects 8 and 9, wherein the UE-specific parameters comprises one or more of a trajectory of the UE, a location of the UE, or a speed of the UE.
11. The method of any of aspects 8-10, wherein transmitting UE-specific parameters to the BS further comprises transmitting the UE-specific parameters via a radio resource control (RRC) , a media access control (MAC) control element (CE) , or an uplink control information (UCI) .
12. The method of any of aspects 8-11, wherein the UE-specific parameters comprise information provided by an automatic dependent surveillance –broadcast (ADS-B) .
13. The method of any of aspects 8-12, wherein the timing advance command comprises a request for the UE to update the previous uplink timing advance.
14. The method of any of aspects 8-13, wherein the request is received via one or more of a radio resource control (RRC) or a downlink control information (DCI) .
15. The method of any of aspects 8-14, wherein the timing advance drift rate data is received via a radio resource control (RRC) , a downlink control information (DCI) , or a media access control (MAC) control element (CE) .
16. A method for wireless communications by base station (BS) to a user equipment (UE) , comprising: transmitting, to the UE, one or more parameters indicative of a location of the BS; and receiving an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters.
17. The method of aspect 16, wherein the one or more parameters comprise an indication of: an altitude of the BS; a location of the BS; or a BS timing shift between an uplink time interval and a downlink time interval, the timing shift indicating whether the uplink time interval is aligned with the downlink time interval at the BS.
18. The method of any of aspects 16 or 17, wherein the one or more parameters are transmitted via a system information broadcast (SIB) , a message B (MsgB) of a 2-step random access channel (RACH) procedure, or a message 2 (Msg2) of a 4-step RACH procedure.
19. The method of any of aspects 16-18, further comprising receiving, from the UE, a report comprising an indication of an accuracy of equipment on the UE, wherein the equipment is configured to provide one or more of an altitude of the UE or a location of the UE.
20. The method of any of aspects 16-19, wherein the timing advance is determined based at least in part on the one or more parameters and one or more UE-specific parameters.
21. The method of any of aspects 16-20, wherein the BS is a fixed-location terrestrial BS, and wherein the UE is an airborne air vehicle.
22. A method for wireless communications by base station (BS) to a user equipment (UE) , comprising: receiving UE-specific parameters from the UE; determining, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS; and transmitting, to the UE, the timing advance drift rate.
23. The method of aspect 22, further comprising transmitting, to the UE, a request for the UE-specific parameters, wherein the UE-specific parameters are received in response to the request.
24. The method of any of aspects 22 and 23, wherein the request is transmitted via a radio resource control (RRC) message or a downlink control information (DCI) message.
25. The method of any of aspects 22-24, wherein: the RRC message is configured to cause the UE to periodically transmit UE-specific parameters to the BS; and the DCI message is configured to trigger the UE to transmit a single update of UE-specific information in response to the request.
26. The method of any of aspects 22-25, further comprising transmitting a timing advance command with the timing advance drift rate, wherein the timing advance command is configured to cause the UE to update a timing advance used for transmitting uplink communications.
27. The method of any of aspects 22-26, wherein the timing advance command and the timing advance drift rate are communicated via a radio resource control (RRC) message, a media access control (MAC) control element (CE) , or a downlink control information (DCI) message.
28. The method of any of aspects 22-27, wherein the UE-specific parameters include one or more of a trajectory of the UE, a location of the UE, or a speed of the UE.
29. The method of any of aspects 22-28, further comprising receiving the UE-specific parameters via a radio resource control (RRC) , a media access control (MAC) control element (CE) , or a uplink control information (UCI) .
30. The method of any of aspects 22-29, further comprising receiving the UE-specific parameters via an automatic dependent surveillance –broadcast (ADS-B) .
31. A method for wireless communications by user equipment (UE) to a base station (BS) , comprising: determining, by the UE, one or more parameters indicative of movement of the UE relative to the BS; updating, by the UE, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, the one or more parameters comprising: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory; and transmitting an uplink signal over resources determined using the new uplink timing advance.
32. The method of aspect 31, wherein the determining the one or more parameters further comprises receiving, from the BS, the one or more parameters, wherein the one or more parameters are based on information provided by an automatic dependent surveillance –broadcast (ADS-B) .
33. A method for wireless communications by user equipment (UE) to a base station (BS) , comprising: receiving, from the BS: a timing advance drift rate data based on UE-specific parameters, the one or more parameters comprising: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory; and a timing advance command; updating, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance; and transmitting an uplink signal over resources determined using the new uplink timing advance.
34. The method of aspect 33, further comprising determining the UE-specific parameters using equipment integrated into the UE.
35. A method for wireless communications by base station (BS) to a user equipment (UE) , comprising: receiving UE-specific parameters from the UE, the UE-specific parameters comprising one or more of: an altitude of the UE; a location of the UE; a UE speed; or a UE trajectory; determining, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS; and transmitting, to the UE, the timing advance drift rate.
36. A user equipment (UE) , comprising: a memory; and a processor coupled to the memory, the processor and the memory configured to: determine one or more parameters indicative of movement of the UE relative to the BS; update a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, the one or more parameters comprising at least one of: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory; and transmit an uplink signal over resources determined using the new uplink timing advance.
37. A user equipment (UE) , comprising: a memory; and a processor coupled to the memory, the processor and the memory configured to: receive, from the BS: a timing advance drift rate data based on UE-specific parameters, the one or more parameters comprising at least one of: an altitude of the UE or BS; a location of the UE or BS; a UE speed; or a UE trajectory; or a timing advance command; update, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance; and transmit an uplink signal over resources determined using the new uplink timing advance.
38. A base station (BS) , comprising: a memory; and a processor coupled to the memory, the processor and the memory configured to: transmit, to the UE, one or more parameters indicative a location of the BS, the one or more parameters including at least one of an altitude of the BS or coordinates of the BS; and receive an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters.
39. A base station (BS) , comprising: a memory; and a processor coupled to the memory, the processor and the memory configured to: receive UE-specific parameters from the UE, the UE-specific parameters comprising at least one of: an altitude of the UE; a location of the UE; a UE speed; or a UE trajectory; determine, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS; and transmit, to the UE, the timing advance drift rate.
40. An apparatus comprising means for performing the method of any of aspects 1-36.
38. An apparatus comprising at least one processor and a memory coupled to the at least one processor, the memory comprising code executable by the at least one processor to cause the apparatus to perform the method of any of aspects 1-36.
39. A computer readable medium storing computer executable code thereon for wireless communications that, when executed by at least one processor, cause an apparatus to perform the method of any of aspects 1-36.
The techniques described herein may be used for various wireless communication technologies, such as NR (e.g., 5G NR) , 3GPP Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , single-carrier frequency division multiple access (SC-FDMA) , time division synchronous code division multiple access (TD-SCDMA) , and other networks. The terms “network” and “system” are often used interchangeably. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA) , cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. CdMA2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM) . An OFDMA network may implement a radio technology such as NR (e.g. 5G RA) , Evolved UTRA (E-UTRA) , Ultra Mobile Broadband (UMB) , IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS) . LTE and LTE-A are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP) . CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . NR is an emerging wireless communications technology under development.
In 3GPP, the term “cell” can refer to a coverage area of a Node B (NB) and/or a NB subsystem serving this coverage area, depending on the context in which the term is used. In NR systems, the term “cell” and BS, next generation NodeB (gNB or gNodeB) , access point (AP) , distributed unit (DU) , carrier, or transmission reception point (TRP) may be used interchangeably. A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or other types of cells. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having an association with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG) , UEs for users in the home, etc. ) . A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS.
A UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, a Customer Premises Equipment (CPE) , a cellular phone, a smart phone, a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, an appliance, a medical device or medical equipment, a biometric sensor/device, a wearable device such as a smart watch, smart clothing, smart glasses, a smart wrist band, smart jewelry (e.g., a smart ring, a smart bracelet, etc. ) , an entertainment device (e.g., a music device, a video device, a satellite radio, etc. ) , a vehicular component or sensor, a smart meter/sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium. Some UEs may be considered machine-type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., that may communicate with a BS, another device (e.g., remote device) , or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.
In some examples, access to the air interface may be scheduled. A scheduling entity (e.g., a BS) allocates resources for communication among some or all devices and equipment within its service area or cell. The scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, subordinate entities utilize resources allocated by the scheduling entity. Base stations are not the only entities that may function as a scheduling entity. In some examples, a UE may function as a scheduling entity and may schedule resources for one or more subordinate entities (e.g., one or more other UEs) , and the other UEs may utilize the resources scheduled by the UE for wireless communication. In some examples, a UE may function as a scheduling entity in a peer-to-peer (P2P) network, and/or in a mesh network. In a mesh network example, UEs may communicate directly with one another in addition to communicating with a scheduling entity.
The methods disclosed herein comprise one or more steps or actions for achieving the methods. The method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified.
As used herein, a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c) .
As used herein, the term “determining” encompasses a wide variety of actions. For example, “determining” may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure) , ascertaining and the like. Also, “determining” may include receiving (e.g., receiving information) , accessing (e.g., accessing data in a memory) and the like. Also, “determining” may include resolving, selecting, choosing, establishing and the like.
The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” Unless specifically stated otherwise, the term “some” refers to one or more. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112 (f) unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for. ”
The various operations of methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include various hardware and/or software component (s) and/or module (s) , including, but not limited to a circuit, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , or a processor (e.g., a general purpose or specifically programmed processor) . Generally, where there are operations illustrated in figures, those operations may have corresponding counterpart means-plus-function components with similar numbering.
The various illustrative logical blocks, modules and circuits described in connection with the present disclosure may be implemented or performed with a general purpose processor, a DSP, an ASIC, a field programmable gate array (FPGA) or other programmable logic device (PLD) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
If implemented in hardware, an example hardware configuration may comprise a processing system in a wireless node. The processing system may be implemented with a bus architecture. The bus may include any number of interconnecting buses and bridges depending on the specific application of the processing system and the overall design constraints. The bus may link together various circuits including a processor, machine-readable media, and a bus interface. The bus interface may be used to connect a network adapter, among other things, to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In the case of a user terminal (see FIG. 1) , a user interface (e.g., keypad, display, mouse, joystick, etc. ) may also be connected to the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further. The processor may be implemented with one or more general-purpose and/or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuitry that can execute software. Those skilled in the art will recognize how best to implement the described functionality for the processing system depending on the particular application and the overall design constraints imposed on the overall system.
If implemented in software, the functions may be stored or transmitted over as one or more instructions or code on a computer readable medium. Software shall be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Computer-readable media include both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. The processor may be responsible for managing the bus and general processing, including the execution of software modules stored on the machine-readable storage media. A computer-readable storage medium may be coupled to a processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. By way of example, the machine-readable media may include a transmission line, a carrier wave modulated by data, and/or a computer readable storage medium with instructions stored thereon separate from the wireless node, all of which may be accessed by the processor through the bus interface. Alternatively, or in addition, the machine-readable media, or any portion thereof, may be integrated into the processor, such as the case may be with cache and/or general register files. Examples of machine-readable storage media may include, by way of example, RAM (Random Access Memory) , flash memory, ROM (Read Only Memory) , PROM (Programmable Read-Only Memory) , EPROM (Erasable Programmable Read-Only Memory) , EEPROM (Electrically Erasable Programmable Read-Only Memory) , registers, magnetic disks, optical disks, hard drives, or any other suitable storage medium, or any combination thereof. The machine-readable media may be embodied in a computer-program product.
A software module may comprise a single instruction, or many instructions, and may be distributed over several different code segments, among different programs, and across multiple storage media. The computer-readable media may comprise a number of software modules. The software modules include instructions that, when executed by an apparatus such as a processor, cause the processing system to perform various functions. The software modules may include a transmission module and a receiving module. Each software module may reside in a single storage device or be distributed across multiple storage devices. By way of example, a software module may be loaded into RAM from a hard drive when a triggering event occurs. During execution of the software module, the processor may load some of the instructions into cache to increase access speed. One or more cache lines may then be loaded into a general register file for execution by the processor. When referring to the functionality of a software module below, it will be understood that such functionality is implemented by the processor when executing instructions from that software module.
Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared (IR) , radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk, and disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Thus, in some aspects computer-readable media may comprise non-transitory computer-readable media (e.g., tangible media) . In addition, for other aspects computer-readable media may comprise transitory computer-readable media (e.g., a signal) . Combinations of the above can also be considered as examples of computer-readable media.
Thus, certain aspects may comprise a computer program product for performing the operations presented herein. For example, such a computer program product may comprise a computer-readable medium having instructions stored (and/or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein, for example, instructions for performing the operations described herein and illustrated in FIGs. 8-11.
Further, it should be appreciated that modules and/or other appropriate means for performing the methods and techniques described herein can be downloaded and/or otherwise obtained by a user terminal and/or base station as applicable. For example, such a device can be coupled to a server to facilitate the transfer of means for performing the methods described herein. Alternatively, various methods described herein can be provided via storage means (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or floppy disk, etc. ) , such that a user terminal and/or base station can obtain the various methods upon coupling or providing the storage means to the device. Moreover, any other suitable technique for providing the methods and techniques described herein to a device can be utilized.
It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above.

Claims

A method for wireless communications by user equipment (UE) to a base station (BS) , comprising:

determining, by the UE, one or more parameters indicative of movement of the UE relative to the BS;

updating, by the UE, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, the one or more parameters comprising at least one of:

an altitude of the UE or BS;

a location of the UE or BS;

a UE speed; or

a UE trajectory; and

transmitting an uplink signal over resources determined using the new uplink timing advance.
The method of claim 1, wherein the determining the one or more parameters further comprises receiving, from the BS, the one or more parameters, wherein the one or more parameters are based on information provided by an automatic dependent surveillance –broadcast (ADS-B) .
The method of claim 1, wherein the one or more parameters comprise a BS timing shift between an uplink time interval and a downlink time interval, the timing shift indicating whether the uplink time interval is aligned with the downlink time interval at the BS.
The method of claim 3, further comprising receiving a system information broadcast (SIB) from the BS, the SIB indicating one or more of the altitude of the BS, the location of the BS, or the BS timing shift.
The method of claim 3, further comprising receiving one or more of the altitude of the BS, the location of the BS, or the BS timing shift via one of:

a message B (MsgB) of a 2-step random access channel (RACH) procedure; or

a message 2 (Msg2) of a 4-step RACH procedure.
The method of claim 3, wherein a plurality of BS identifiers are stored on the UE, wherein each of the plurality of BS identifiers correspond to a particular BS, and wherein a first BS identifier indicates one or more of the altitude of the BS or the location of the BS.
The method of claim 3, further comprising transmitting a report to the BS, the report including an indication of an accuracy of one or more of the UE altitude or the UE coordinates.
A method for wireless communications by user equipment (UE) to a base station (BS) , comprising:

receiving, from the BS:

a timing advance drift rate data based on UE-specific parameters, the one or more parameters comprising at least one of:

an altitude of the UE or BS;

a location of the UE or BS;

a UE speed; or

a UE trajectory; or

a timing advance command;

updating, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance; and

transmitting an uplink signal over resources determined using the new uplink timing advance.
The method of claim 8, further comprising:

receiving, from the BS, a request for the UE to provide the BS with UE-specific parameters; and

transmitting the UE-specific parameters to the BS in response to the request.
The method of claim 9, further comprising determining the UE-specific parameters using equipment integrated into the UE.
The method of claim 9, wherein transmitting UE-specific parameters to the BS further comprises transmitting the UE-specific parameters via a radio resource control (RRC) , a media access control (MAC) control element (CE) , or a uplink control information (UCI) .
The method of claim 8, wherein the UE-specific parameters comprise information provided by an automatic dependent surveillance –broadcast (ADS-B) .
The method of claim 8, wherein the timing advance command comprises a request for the UE to update the previous uplink timing advance.
The method of claim 13, wherein the request is received via one or more of a radio resource control (RRC) or a downlink control information (DCI) .
The method of claim 8, wherein the timing advance drift rate data is received via a radio resource control (RRC) , a downlink control information (DCI) , or a media access control (MAC) control element (CE) .
A method for wireless communications by base station (BS) to a user equipment (UE) , comprising:

transmitting, to the UE, one or more parameters indicative a location of the BS, the one or more parameters including at least one of an altitude of the BS or coordinates of the BS; and

receiving an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters.
The method of claim 16, wherein the one or more parameters comprise an indication of a BS timing shift between an uplink time interval and a downlink time interval, the timing shift indicating whether the uplink time interval is aligned with the downlink time interval at the BS.
The method of claim 16, wherein the one or more parameters are transmitted via a system information broadcast (SIB) , a message B (MsgB) of a 2-step random access channel (RACH) procedure, or a message 2 (Msg2) of a 4-step RACH procedure.
The method of claim 16, further comprising receiving, from the UE, a report comprising an indication of an accuracy of equipment on the UE, wherein the equipment is configured to provide one or more of an altitude of the UE or a location of the UE.
The method of claim 16, wherein the timing advance is determined based at least in part on the one or more parameters and one or more UE-specific parameters.
The method of claim 16, wherein the BS is a fixed-location terrestrial BS, and wherein the UE is an airborne air vehicle.
A method for wireless communications by base station (BS) to a user equipment (UE) , comprising:

receiving UE-specific parameters from the UE, the UE-specific parameters comprising at least one of:

an altitude of the UE;

a location of the UE;

a UE speed; or

a UE trajectory;

determining, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS; and

transmitting, to the UE, the timing advance drift rate.
The method of claim 22, further comprising transmitting, to the UE, a request for the UE-specific parameters, wherein the UE-specific parameters are received in response to the request.
The method of claim 23, wherein the request is transmitted via a radio resource control (RRC) message or a downlink control information (DCI) message.
The method of claim 24, wherein:

the RRC message is configured to cause the UE to periodically transmit UE-specific parameters to the BS; and

the DCI message is configured to trigger the UE to transmit a single update of UE-specific information in response to the request.
The method of claim 22, further comprising transmitting a timing advance command with the timing advance drift rate, wherein the timing advance command is configured to cause the UE to update a timing advance used for transmitting uplink communications.
The method of claim 26, wherein the timing advance command and the timing advance drift rate are communicated via a radio resource control (RRC) message, a media access control (MAC) control element (CE) , or a downlink control information (DCI) message.
The method of claim 22, wherein the UE-specific parameters are determined by equipment integrated into the UE.
The method of claim 22, further comprising receiving the UE-specific parameters via a radio resource control (RRC) , a media access control (MAC) control element (CE) , or a uplink control information (UCI) .
The method of claim 22, further comprising receiving the UE-specific parameters via an automatic dependent surveillance –broadcast (ADS-B) .
A user equipment (UE) , comprising:

a memory; and

a processor coupled to the memory, the processor and the memory configured to:

determine one or more parameters indicative of movement of the UE relative to the BS;

update a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the one or more parameters, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance, the one or more parameters comprising at least one of:

an altitude of the UE or BS;

a location of the UE or BS;

a UE speed; or

a UE trajectory; and

transmit an uplink signal over resources determined using the new uplink timing advance.
A user equipment (UE) , comprising:

a memory; and

a processor coupled to the memory, the processor and the memory configured to:

receive, from the BS:

a timing advance drift rate data based on UE-specific parameters, the one or more parameters comprising at least one of:

an altitude of the UE or BS;

a location of the UE or BS;

a UE speed; or

a UE trajectory; or

a timing advance command;

update, in response to the timing advance command, a previous uplink timing advance to a new uplink timing advance, wherein the update is based on the timing advance drift rate, and the new uplink timing advance is a change of uplink transmission timing relative to the previous uplink timing advance; and

transmit an uplink signal over resources determined using the new uplink timing advance.
A base station (BS) , comprising:

a memory; and

a processor coupled to the memory, the processor and the memory configured to:

transmit, to the UE, one or more parameters indicative a location of the BS, the one or more parameters including at least one of an altitude of the BS or coordinates of the BS; and

receive an uplink communication from the UE, the uplink communication transmitted according to a timing advance determined based at least in part on the one or more parameters.
A base station (BS) , comprising:

a memory; and

a processor coupled to the memory, the processor and the memory configured to:

receive UE-specific parameters from the UE, the UE-specific parameters comprising at least one of:

an altitude of the UE;

a location of the UE;

a UE speed; or

a UE trajectory;

determine, based at least in part on the UE-specific parameters, a timing advance drift rate indicating a rate at which uplink transmissions from the UE are drifting out of timing synchronization with the BS; and

transmit, to the UE, the timing advance drift rate.