# US 12,192,937 B2 · Timing advance for non-terrestrial network communication

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,192,937 B2
- Document ID: US12192937B2
- Status: Granted
- Kind: B2
- Application number: 17/044,586
- Filed: 2019-04-03
- Published: 2021-01-28
- Granted: 2025-01-07
- Earliest claimed: 2018-04-03
- Assignees: InterDigital Patent Holdings, Inc.
- Applicants: Interdigital Patent Holdings, Inc.
- Inventors: Nagi Mahalingam; Anantharaman Balasubramanian; Mihaela Beluri; Ravikumar V. Pragada; Mahmoud Taherzadeh Boroujeni; Shahrokh Nayeb Nazar; Seyed Mohsen Hosseinian; Frank La Sita
- Web page: https://patentgrep.com/patent/US12192937B2

## CPC

- H04W 56/0045: {compensating for timing error by altering transmission time}
- H04B 7/18504: {Aircraft used as relay or high altitude atmospheric platform}
- H04B 7/1851: {Systems using a satellite or space-based relay (H04B7/18508, H04B7/18521 take precedence; providing specific services H04B7/18523 - H04B7/18576)}
- H04B 7/18513: {Transmission in a satellite or space-based system}
- H04W 56/0005: {synchronizing of arrival of multiple uplinks}
- H04W 74/0833: Random access procedures, e.g. with 4-step access
- H04W 74/0836: with 2-step access
- H04W 74/0838: using contention-free random access [CFRA]
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04B: TRANSMISSION

## Abstract

Methods, systems, and devices for addressing timing advance (TA) in non-terrestrial network communication is disclosed herein. A wireless transmit and receive unit (WTRU) may receive system information from a base station attached to an airborne or spaceborne vehicle that indicates a physical random access channel (PRACH) resource. The WTRU may determine a timing offset based on a plurality of information, such as the location information and the system information. The WTRU may transmit a preamble using the timing offset via the PRACH resource. The base station may receive the preamble and send a random access response (RAR) that includes, for example, a TA command. The WTRU may receive the RAR including the TA command and combine the timing offset with the TA command to determine an actual TA, after which the WTRU may use the actual TA for uplink transmissions.

## Claims

### Claim 1

A method performed by a wireless transmit and receive unit (WTRU), the method comprising:
receiving, from a spaceborne communications satellite, system information that includes a position of, and trajectory parameters, including velocity, about, the spaceborne communications satellite;
determining a position of the WTRU using a global navigation satellite system (GNSS);
estimating a propagation delay based on the determined WTRU position and the position of, and the trajectory parameters about, the spaceborne communications satellite;
determining a timing advance (TA) based on the estimated propagation delay; and
transmitting a signal using the determined TA.

### Claim 2 (depends on 1)

The method of claim 1, wherein the system information indicates one or more physical-random-access-channel (PRACH) resources.

### Claim 3 (depends on 2)

The method of claim 2, further comprising:
receiving a random-access response (RAR), wherein the RAR includes a timing-advance (TA) command;
determining an adjusted TA based on the TA command and the estimated propagation delay; and
transmitting a message using the adjusted TA.

### Claim 4 (depends on 3)

The method of claim 3, wherein the RAR further includes at least one of a power correction, an uplink grant, or a temporary identifier.

### Claim 5 (depends on 3)

The method of claim 3, wherein the RAR includes a two-part bitfield, wherein a first part of the two-part bitfield has a high-resolution TA and a second part of the two-part bitfield has a low-resolution TA.

### Claim 6 (depends on 1)

The method of claim 1, wherein the transmitting a signal occurs at a random-access-channel (RACH) opportunity indicated in the system information.

### Claim 7 (depends on 1)

The method of claim 1, wherein the spaceborne communications satellite comprises a relay satellite.

### Claim 8

A wireless-transmit-and-receive unit (WTRU), comprising a processor coupled to a transceiver, the processor and transceiver configured to:
receive, from a spaceborne non-navigation satellite, system information that includes a position of, and trajectory parameters, including velocity, about, the spaceborne non-navigation satellite;
determine a position of the WTRU using a global navigation satellite system (GNSS);
estimate a propagation delay based on the determined WTRU position and the position of, and the trajectory parameters about, the spaceborne non-navigation satellite;
determine a timing advance (TA) based on the estimated propagation delay; and
transmit a signal using the determined TA.

### Claim 9 (depends on 8)

The WTRU of claim 8, wherein the system information indicates one or more physical-random-access-channel (PRACH) resources.

### Claim 10 (depends on 9)

The WTRU of claim 9, the processor and transceiver further configured to:
receive a random access response (RAR), wherein the RAR includes a timing-advance (TA) command;
determine an adjusted TA based on the TA command and the estimated propagation delay; and
transmit a message using the adjusted TA.

### Claim 11 (depends on 10)

The WTRU of claim 10, wherein the RAR further includes at least one of a power correction, an uplink grant, or a temporary identifier.

### Claim 12 (depends on 10)

The WTRU of claim 10, wherein the RAR includes a two-part bitfield, wherein a first part of the two-part bitfield has a high-resolution TA and a second part of the two-part bitfield has a low-resolution TA.

### Claim 13 (depends on 8)

The WTRU of claim 8, wherein the transmitting a signal occurs at a random-access-channel (RACH) opportunity indicated in the system information.

### Claim 14 (depends on 8)

The WTRU of claim 8, wherein the system information further includes timing information.

### Claim 15 (depends on 8)

The WTRU of claim 8, wherein the spaceborne non-navigation satellite is configured to relay signals between the processor and transceiver and a device remote from the processor and transceiver.