Reference timing for uplink signaling in a non-terrestrial network
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a serving node associated with a non-terrestrial network (NTN), one or more timing advance (TA) values. The UE may transmit, to the serving node of the NTN, uplink signaling based at least in part on a reference timing for the uplink signaling, wherein the reference timing for the uplink signaling is based at least in part on a reference timing of a downlink signaling and the one or more TA values, wherein the one or more TA values include a UE-specific TA value, and wherein a reference timing of the UE-specific TA value is for: a first propagation delay on a service link between the UE and a satellite associated with the NTN, and a second propagation delay on the service link. Numerous other aspects are described.
1 . An apparatus for wireless communication at a user equipment (UE), comprising:
one or more memories; and
one or more processors, coupled to the one or more memories, configured to cause the UE to:
receive, from a serving node of a non-terrestrial network (NTN), one or more timing advance (TA) values; and
transmit, to the serving node of the NTN, uplink signaling based at least in part on a reference timing for the uplink signaling, wherein the reference timing for the uplink signaling is based at least in part on a reference timing of a downlink signaling, and based at least in part on the one or more TA values, wherein the one or more TA values include a UE-specific TA value, wherein a reference timing of the UE-specific TA value is in accordance with a first propagation delay, wherein the first propagation delay is in accordance with an expected arrival time of the uplink signaling, on a service link between the UE and a satellite associated with the NTN, and wherein a reference timing of the UE-specific TA value is in accordance with a second propagation delay, wherein the second propagation delay is in accordance with an expected arrival time of the downlink signaling, on the service link.
2 . The apparatus of claim 1 , wherein the expected arrival time of the uplink signaling is a slot in which the uplink signaling is expected to arrive at the satellite based at least in part on validated ephemeris information and a reference propagation model.
3 . The apparatus of claim 1 , wherein the expected arrival time of the downlink signaling is a slot in which the downlink signaling, corresponding to a slot of the uplink signaling, is expected to arrive at the satellite based at least in part on validated ephemeris information and a reference propagation model.
4 . The apparatus of claim 3 , wherein the reference timing of the UE-specific TA value is based at least in part on an actual received time of the slot.
5 . The apparatus of claim 1 , wherein the reference timing of the downlink signaling is a downlink slot corresponding to an uplink slot associated with the uplink signaling.
6 . The apparatus of claim 1 , wherein the reference timing for the uplink signaling is the reference timing of the downlink signaling minus a total of the one or more TA values multiplied by a basic time unit (Tc).
7 . The apparatus of claim 1 , wherein the one or more TA values include one or more of a TA value (NTA), a common TA value (NTA,common), or a TA offset value (NTA,offset).
8 . The apparatus of claim 7 , wherein a reference timing of the common TA value is based at least in part on related parameters received from the serving node.
9 . The apparatus of claim 1 , wherein the reference timing of the UE-specific TA value, for the first propagation delay, is a slot in which the uplink signaling is expected to arrive at the satellite based at least in part on a true satellite position of the satellite.
10 . The apparatus of claim 1 , wherein the reference timing of the UE-specific TA value, for the second propagation delay, is a slot in which the downlink signaling corresponding to the reference timing of the downlink signaling is expected to arrive at the satellite based at least in part on a true satellite position of the satellite and an actual received time of the slot.
11 . The apparatus of claim 1 , wherein the reference timing of the UE-specific TA value, for the first propagation delay, is a slot in which the uplink signaling is expected to arrive at the satellite based at least in part on validated ephemeris information and a true satellite position of the satellite.
12 . The apparatus of claim 1 , wherein the reference timing of the UE-specific TA value, for the second propagation delay, is a slot in which the downlink signaling is expected to arrive at the satellite based at least in part on an actual received time of the slot, validated ephemeris information with no error except for quantization, and a reference propagation model.
13 . The apparatus of claim 1 , wherein the one or more processors are configured to cause the UE to:
receive, from the serving node, one or more open-loop TA control related parameters; and
adjust a downlink frame boundary associated with the reference timing of the downlink signaling based at least in part on the one or more open-loop TA control related parameters.
14 . An apparatus for wireless communication at a serving node, comprising:
one or more memories; and
one or more processors coupled to the one or more memories, configured to cause the serving node to:
output one or more timing advance (TA) values; and
obtain uplink signaling based at least in part on a reference timing for the uplink signaling, wherein the reference timing for the uplink signaling is based at least in part on a reference timing of a downlink signaling and based at least in part on the one or more TA values, wherein the one or more TA values include a user equipment (UE)-specific TA value, wherein a reference timing of the UE-specific TA value is in accordance with a first propagation delay, wherein the first propagation delay is in accordance with an expected arrival time of the uplink signaling, on a service link between the UE and a satellite associated with a non-terrestrial network (NTN), and wherein a reference timing of the UE-specific TA value is in accordance a second propagation delay, wherein the second propagation delay is in accordance with an expected arrival time of the downlink signaling, on the service link.
15 . The apparatus of claim 14 , wherein the expected arrival time of the uplink signaling is a slot in which the uplink signaling is expected to arrive at the satellite based at least in part on validated ephemeris information and a reference propagation model.
16 . The apparatus of claim 14 , wherein the expected arrival time of the downlink signaling is a slot in which the downlink signaling, corresponding to a slot of the uplink signaling, is expected to arrive at the satellite based at least in part on validated ephemeris information and a reference propagation model.
17 . The apparatus of claim 16 , wherein the reference timing of the UE-specific TA value is based at least in part on an actual received time of the slot.
18 . The apparatus of claim 14 , wherein the reference timing of the downlink signaling is a downlink slot corresponding to an uplink slot associated with the uplink signaling.
19 . The apparatus of claim 14 , wherein the reference timing for the uplink signaling is the reference timing of the downlink signaling minus a total of the one or more TA values multiplied by a basic time unit (Tc).
20 . The apparatus of claim 14 , wherein the one or more TA values include one or more of a TA value (NTA), a common TA value (NTA,common), or a TA offset value (NTA,offset).
21 . The apparatus of claim 20 , wherein a reference timing of the common TA value is based at least in part on related parameters broadcast from the serving node.
22 . The apparatus of claim 14 , wherein the reference timing of the UE-specific TA value, for the first propagation delay, is a slot in which the uplink signaling is expected to arrive at the satellite based at least in part on a true satellite position of the satellite.
23 . The apparatus of claim 14 , wherein the reference timing of the UE-specific TA value, for the second propagation delay, is a slot in which the downlink signaling corresponding to the reference timing of the downlink signaling is expected to arrive at the satellite based at least in part on a true satellite position of the satellite and an actual received time of the slot.
24 . The apparatus of claim 14 , wherein the reference timing of the UE-specific TA value, for the first propagation delay, is a slot in which the uplink signaling is expected to arrive at the satellite based at least in part on validated ephemeris information and a true satellite position of the satellite.
25 . The apparatus of claim 14 , wherein the reference timing of the UE-specific TA value, for the second propagation delay, is a slot in which the downlink signaling corresponding to the reference timing of the downlink signaling is expected to arrive at the satellite based at least in part on an actual received time of the slot, validated ephemeris information with no error except for quantization, and a reference propagation model.
26 . The apparatus of claim 14 , wherein the one or more processors are configured to cause the serving node to:
output one or more open-loop TA control related parameters to adjust a downlink frame boundary associated with the reference timing of the downlink signaling.
27 . A method of wireless communication performed by a user equipment (UE), comprising:
receiving, from a serving node of a non-terrestrial network (NTN), one or more timing advance (TA) values; and
transmitting, to the serving node of the NTN, uplink signaling based at least in part on a reference timing for the uplink signaling, wherein the reference timing for the uplink signaling is based at least in part on a reference timing of a downlink signaling and based at least in part on the one or more TA values, wherein the one or more TA values include a UE-specific TA value, wherein a reference timing of the UE-specific TA value is in accordance with a first propagation delay, wherein the first propagation delay is in accordance with an expected arrival time of the uplink signaling, on a service link between the UE and a satellite associated with the NTN, and wherein a reference timing of the UE-specific TA value is in accordance a second propagation delay, wherein the first second propagation delay is in accordance with an expected arrival time of the downlink signaling, on the service link.
28 . The method of claim 27 , wherein the expected arrival time of the uplink signaling is a slot in which the uplink signaling is expected to arrive at the satellite based at least in part on validated ephemeris information and a reference propagation model.
29 . The method of claim 27 , wherein the expected arrival time of the downlink signaling is a slot in which the downlink signaling, corresponding to a slot of the uplink signaling, is expected to arrive at the satellite based at least in part on validated ephemeris information and a reference propagation mode.
30 . A method of wireless communication performed by a serving node, comprising:
outputting one or more timing advance (TA) values; and
obtaining uplink signaling based at least in part on a reference timing for the uplink signaling, wherein the reference timing for the uplink signaling is based at least in part on a reference timing of a downlink signaling and based at least in part on the one or more TA values, wherein the one or more TA values include a user equipment (UE)-specific TA value, wherein a reference timing of the UE-specific TA value is in accordance with a first propagation delay, wherein the first propagation delay is in accordance with an expected arrival time of the uplink signaling, on a service link between the UE and a satellite associated with a non-terrestrial network (NTN), and wherein a reference timing of the UE-specific TA value is in accordance with a second propagation delay, wherein the second propagation delay is in accordance with an expected arrival time of the downlink signaling, on the service link.