CN-121986451-A - Method for non-terrestrial network handoff enhancement in wireless communications

Abstract

Various solutions for non-terrestrial network (NTN) handoff enhancement in wireless communications are described. The device may report Very Small Aperture Terminal (VSAT) User Equipment (UE) capability information to a first network node comprising a first satellite. The device may then receive a handover command from the first network node. The handover command may instruct a handover from the first network node to a second network node comprising a second satellite. The device may also redirect the very small-bore terminal antenna to the second satellite for a very small-bore terminal antenna redirection duration and perform a handoff after the very small-bore terminal antenna redirection duration.

Inventors

• Abdelkard Meadows
• Gilles Chabbit
• CHEN JUNJIA
• FU YIKANG

Assignees

• 联发科技（新加坡）私人有限公司

Dates

Publication Date

20260505

Application Date

20240905

Priority Date

20231004

Claims (20)

1. 1. A method, comprising: Reporting, by a processor of an apparatus, very small bore end user device capability information to a first network node, wherein the first network node includes or is associated with a first satellite; Receiving, by the processor, a handover command from the first network node, wherein the handover command indicates a handover from the first network node to a second network node, the second network node including or being associated with a second satellite; Redirecting, by the processor, a very small aperture terminal antenna to the second satellite for a very small aperture terminal antenna redirection duration, and The switching is performed by the processor after the very small aperture terminal antenna redirection duration.
2. 2. The method of claim 1, wherein the very small-bore end user device capability information comprises at least one of: A very small aperture terminal antenna type indicating that a very small aperture terminal user device uses an electronically or mechanically directional antenna; Capability to simultaneously receive from multiple satellites, and The ability to maintain a link with the first satellite for the duration of the very small aperture terminal antenna reorientation.
3. 3. The method of claim 1, wherein the very small-bore end user device capability information includes a parameter related to the very small-bore terminal antenna redirection duration, and the parameter indicates at least one of: A rotor speed; A value of the minimum aperture terminal antenna reorientation duration; A very small aperture terminal antenna reorientation time scale; A minimum aperture terminal antenna redirection time, and A maximum minimum aperture terminal antenna redirection time.
4. 4. The method of claim 1, further comprising: Starting a redirection timer with a value of the minimum aperture terminal antenna redirection duration upon receipt of the switch command by the processor, and A handover timer is started by the processor upon expiration of the redirection timer and upon initiation of the handover.
5. 5. The method of claim 4 wherein the handover command includes the value of the very small aperture terminal antenna redirection duration.
6. 6. The method of claim 1, further comprising: receiving, by the processor, assistance information from the first network node, wherein the assistance information includes ephemeris information, an epoch time, and a service start time for the second satellite, and A value of the minimum aperture terminal antenna redirection duration is determined by the processor based on the assistance information.
7. 7. The method of claim 6 wherein the assistance information is received in a request message and the value of the minimum aperture terminal antenna redirection duration is reported to the first network node in response to the request message.
8. 8. The method of claim 1, further comprising: And starting a switching timer when the processor receives the switching command, wherein a value configured by the switching timer is larger than the value of the redirection duration of the terminal antenna with the very small caliber.
9. 9. The method of claim 1, wherein the handoff command includes ephemeris information, an epoch time, and a service start time for the second satellite, and the method further comprises: a service stop indication is sent by the processor to the first satellite based on the minimum aperture terminal antenna redirection duration and the service start time prior to performing the handoff.
10. 10. The method of claim 9 wherein the service stop indication is sent in a radio resource control message or a medium access control unit.
11. 11. A method, comprising: Receiving, by a processor of a first network node, very small diameter end user device capability information from a device, wherein the first network node includes or is associated with a first satellite, and A handover command is sent by the processor to the device based on the very small bore end user device capability information, wherein the handover command indicates a handover from the first network node to a second network node, the second network node including or being associated with a second satellite.
12. 12. The method of claim 11, wherein the very small-bore end user device capability information comprises at least one of: A very small aperture terminal antenna type indicating that a very small aperture terminal user device uses an electronically or mechanically directional antenna; Capability to simultaneously receive from multiple satellites, and The ability to maintain a link with the first satellite for the duration of the very small aperture terminal antenna reorientation.
13. 13. The method of claim 11, wherein the very small-bore end user device capability information includes a parameter related to the very small-bore terminal antenna redirection duration, and the parameter indicates at least one of: A rotor speed; A value of the minimum aperture terminal antenna reorientation duration; A very small aperture terminal antenna reorientation time scale; A minimum aperture terminal antenna redirection time, and A maximum minimum aperture terminal antenna redirection time.
14. 14. The method of claim 11, wherein the minimum aperture terminal antenna redirection duration allows the apparatus to redirect a minimum aperture terminal antenna to the second satellite prior to performing the handoff.
15. 15. The method of claim 11 wherein the handoff command comprises a value of the very small aperture terminal antenna redirection duration.
16. 16. The method of claim 11, further comprising: Auxiliary information is transmitted by the processor to the device, wherein the auxiliary information includes ephemeris information, an epoch time, and a service start time for the second satellite, such that the device determines a value for the minimum aperture terminal antenna redirection duration based on the auxiliary information.
17. 17. The method of claim 16 wherein the assistance information is sent in a request message and the value of the minimum aperture terminal antenna redirection duration is received from the device in response to the request message.
18. 18. The method of claim 11 wherein the handoff command includes a handoff timer configured with a value greater than the value of the minimum aperture terminal antenna redirection duration.
19. 19. The method of claim 11, wherein the handoff command includes ephemeris information, an epoch time, and a service start time for the second satellite, and further comprising: a service stop indication is received by the processor for the first satellite, wherein the service stop indication is transmitted by the device based on the minimum aperture terminal antenna redirection duration and the service start time.
20. 20. The method of claim 19 wherein the service stop indication is received in a radio resource control message or a medium access control unit.

Description

Method for non-terrestrial network handoff enhancement in wireless communications Cross reference The present disclosure is part of a non-provisional application claiming the priority benefits of U.S. provisional patent application No. 63/587,760 (filed on 4/10 at 2023), the entire contents of which are incorporated herein by reference. Technical Field The present disclosure relates generally to wireless communications, and more particularly to handoff enhancements for very small bore terminals (VERY SMALL aperture terminal, VSAT) User Equipment (UE) and network nodes in non-terrestrial networks (non-TERRESTRIAL NETWORK, NTNs) in wireless communications. Background Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims and are not admitted to be prior art by inclusion in this section. In release 17 of the 3 rd generation partnership project (3 rd Generation Partnership Project, 3GPP for short), non-terrestrial networks (NTNs) were introduced as a terminal-to-satellite direct communication technology based on a New Radio (NR) interface. With the convergence of satellite networks with terrestrial cellular networks (e.g., 5 th Generation 5G networks), NTNs are able to provide ubiquitous coverage that is not limited by topography and topography. With the continued evolution of NTN in the 5G-Advanced stage, NTN has become an important component of the 3GPP release 18 working plan. Currently, NTNs may include two working groups, internet of things (IoT-Things, ioT for short) NTNs and New Radio (NR) NTNs. IoT NTN is focused on satellite internet of things services supporting low complexity enhanced machine type communications (ENHANCED MACHINE-type communication, eMTC for short) and narrowband internet of things (NB-IoT) user equipment. NR NTN utilizes a 5G NR framework to realize direct connection between satellites and smart phones to provide voice and data services. For satellite communications, a large antenna or large phased array may be required at the user equipment end to meet the link budget, such user equipment may be referred to as very small caliber end user equipment (VSAT UE). In non-terrestrial networks, since the satellites are in motion, very small bore end user devices may need to perform a handoff (e.g., from a source satellite to a target satellite) to ensure proper transceiving over long connection times and avoid radio link failure. For example, redirecting a very small aperture terminal antenna to a target satellite may introduce significant delays in seconds or even tens of seconds. However, in the current release 18 3GPP standard, the design of the handover mechanism does not take into account the redirection delay. Therefore, physical Random Access Channel (PRACH) resources of the ue at the initial access of the target satellite will be reserved for a long time. Furthermore, since the timer associated with the handover is not adapted for the satellite scenario, the operation of the user equipment during the handover may not be performed correctly (e.g., the user equipment may not have enough time to complete the handover). Therefore, how to optimize the handoff mechanism for satellite scenarios is an important issue for modern wireless communication systems. Accordingly, it is necessary to provide an appropriate solution to the above-described problems. Accordingly, it is necessary to provide an appropriate scheme and design for a procedure for allowing a user equipment and a network to perform satellite handoff in mobile communication. Disclosure of Invention The following is for illustration only and is not intended to be limiting in any way. That is, the following is intended to introduce the concepts, emphasis, benefits, and advantages of the novel and nonobvious techniques described herein. Some embodiments will be further elucidated in the following detailed description. Thus, the following is not intended to identify key features of the claimed subject matter, nor is it intended to be used to determine the scope of the claimed subject matter. It is an object of the present disclosure to propose a solution, a concept, a design, a system, a method and an apparatus related to non-terrestrial network (NTN) handover enhancements in wireless communication. It is believed that the foregoing problems can be avoided or alleviated by practice of one or more of the proposed solutions described herein. In one aspect, a method may involve an apparatus reporting very small bore end user device capability information to a first network node, wherein the first network node includes or is associated with a first satellite. The method may also involve the apparatus receiving a handover command from the first network node, wherein the handover command indicates a handover from the first network node to a second network node that includes or is associated with the second satellite. The method may also involve the apparatus redirecting the very small