Timing advance for non-terrestrial network communication

Patent metadata

Field	Value
Publication number	US-2025274891-A1
Application number	US-202519075559-A
Country	US
Kind code	A1
Filing date	Mar 10, 2025
Priority date	Apr 3, 2018
Publication date	Aug 28, 2025
Grant date	—

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.

First claim

1 .- 12 . (canceled)

13 . A method performed by a wireless transmit and receive unit (WTRU), the method comprising:
receiving, from a spaceborne satellite, system information that includes a position of, and trajectory parameters about, the spaceborne satellite; determining a timing advance (TA) based on the system information; and transmitting a signal using the TA.

14 . The method of claim 13 , wherein the system information further includes one or more physical-random-access-channel (PRACH) resources.

15 . The method of claim 14 , further comprising:
receiving a random-access response (RAR) wherein the RAR includes a TA command; determining an adjusted TA based on the TA command and an estimated propagation delay; and transmitting a message using the adjusted TA.

16 . The method of claim 15 , wherein the RAR further includes at least one of a power correction, an uplink grant, or a temporary identifier.

17 . The method of claim 15 , wherein the transmitting the signal occurs at a random-access-channel (RACH) opportunity indicated in the system information.

18 . The method of claim 15 , 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.

19 . The method of claim 13 , wherein the determined TA provides for compensation for a round trip time (RTT) between the WTRU and the spaceborne satellite.

20 . A wireless transmit-and-receive unit (WTRU), the WTRU comprising:
a processor; and a transceiver, wherein the processor and transceiver are configured to:
receive, from a spaceborne satellite, system information that includes a position of, and trajectory parameters about, the spaceborne satellite;
determine a timing advance (TA) based on the determined position of the WTRU and the system information; and
transmit a signal using the TA.

21 . The WTRU of claim 20 , wherein the system information indicates one or more physical-random-access-channel (PRACH) resources.

22 . The WTRU of claim 21 , wherein the processor and transceiver are further configured to:
receive a random-access response (RAR), wherein the RAR includes a TA command; determine an adjusted TA based on the TA command and the estimated propagation delay; and transmit a message using the adjusted TA.

23 . The WTRU of claim 22 , wherein the RAR further includes at least one of a power correction, an uplink grant, or a temporary identifier.

24 . The WTRU of claim 20 , wherein the processor and transceiver are further configured to transmit the signal at a random-access-channel (RACH) opportunity indicated in the system information.

25 . The WTRU of claim 22 , 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.

26 . The WTRU of claim 20 , wherein the determined TA provides for compensation for a round trip time (RTT) between the WTRU and the spaceborne satellite.

Assignees

• Interdigital Patent Holdings Inc

Inventors

• Mahalingam Nagi
• Balasubramanian Anantharaman
• Beluri Mihaela
• Pragada Ravikumar
• Taherzadeh Boroujeni Mahmoud
• Nayeb Nazar Shahrokh
• Hosseinian Seyed Mohsen
• Lasita Frank

Classifications

• H04W74/0836

  with 2-step access · CPC title

• H04W74/0838

  using contention-free random access [CFRA] · CPC title

• H04W74/0833 Primary

  Random access procedures, e.g. with 4-step access · CPC title

• H04W56/0005 Primary

  synchronizing of arrival of multiple uplinks · CPC title

• H04B7/18513

  Transmission in a satellite or space-based system · CPC title