US-12621706-B2 - Buffering techniques for non-terrestrial networks

US12621706B2US 12621706 B2US12621706 B2US 12621706B2US-12621706-B2

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may be configured to buffer communications with a network node. A buffer size of a buffer used to buffer the communications may be specific to a non-terrestrial network (NTN) via which the UE communicates with the network node. For example, the UE may calculate the buffer size based on a maximum data rate of a connection with the network node via the NTN and a radio link control (RLC) round trip time (RTT). The RLC RTT may be specific to NTNs. The UE may use a buffer having the calculated buffer size to buffer the communications between the UE and the network node over the connection.

Inventors

Toru Uchino
Alberto RICO ALVARINO
Umesh Phuyal
Bharat Shrestha

Assignees

QUALCOMM INCORPORATED

Dates

Publication Date: 20260505
Application Date: 20220201

Claims (20)

1 . An apparatus for wireless communication at a user equipment (UE), comprising: at least one processor; and at least one memory coupled with the at least one processor, with instructions stored in the at least one memory, the instructions being executable by the at least one processor, individually or in any combination, to cause the apparatus to: transmit a capability message indicating a latency of communications that is supported by the UE; establish a connection with a network node via a non-terrestrial network (NTN) based on the capability message; and buffer NTN communications between the UE and the network node over the connection using a buffer having an NTN buffer size that is based at least in part on a radio link control (RLC) layer round trip time (RTT) for the NTN, wherein the RLC RTT for the NTN is associated with the NTN communications between the UE and the network node, wherein the RLC RTT for the NTN is determined based at least in part on an RLC RTT for a terrestrial network associated with the UE and on one or both of an offset for calculating the RLC RTT for the NTN and a scalar for calculating the RLC RTT for the NTN, wherein the RLC RTT for the terrestrial network is selected from a set of RLC RTTs for the terrestrial network based at least in part on a subcarrier spacing of the communications with the network node or a subcarrier spacing group associated with the communications with the network node, and wherein the scalar is selected from a set of scalars for the NTN based at least in part on an orbit of the network node or an orbit group associated with the network node.
2 . The apparatus of claim 1 , wherein the instructions are further executable by the at least one processor, individually or in any combination, to cause the apparatus to: select the RLC RTT for the NTN from a set of RLC RTTs for the NTN based at least in part on the subcarrier spacing of the communications with the network node or the subcarrier spacing group associated with the communications with the network node, wherein the NTN buffer size is determined based at least in part on selecting the RLC RTT for the NTN.
3 . The apparatus of claim 1 , wherein the instructions are further executable by the at least one processor, individually or in any combination, to cause the apparatus to: select the RLC RTT for the NTN from a set of RLC RTTs for the NTN based at least in part on the orbit of the network node or the orbit group associated with the network node, wherein the NTN buffer size is determined based at least in part on selecting the RLC RTT for the NTN.
4 . The apparatus of claim 1 , wherein the instructions are further executable by the at least one processor, individually or in any combination, to cause the apparatus to: select the offset from a set of offsets for the NTN based at least in part on the orbit of the network node or the orbit group associated with the network node; and determine the RLC RTT for the NTN using the RLC RTT for the terrestrial network and the offset, wherein the NTN buffer size is determined based at least in part on determining the RLC RTT for the NTN.
5 . The apparatus of claim 1 , wherein the scalar is associated with a hybrid automatic repeat request RTT associated with the orbit of the network node or the orbit group associated with the network node.
6 . The apparatus of claim 1 , wherein the instructions are further executable by the at least one processor, individually or in any combination, to cause the apparatus to: determine the RLC RTT for the NTN using the RLC RTT for the terrestrial network, the offset, and the scalar.
7 . The apparatus of claim 1 , wherein: the communications between the UE and the network node comprise communications according to a carrier aggregation for a set of serving cells associated with a set of network nodes of the NTN comprising the network node, each network node of the set of network nodes associated with a respective RLC RTT, and the RLC RTT for the NTN used to determine the NTN buffer size corresponds to a largest RLC RTT associated with the set of network nodes.
8 . The apparatus of claim 7 , wherein each serving cell of the set of serving cells is associated with a respective communication latency that is within a first range of communication latencies, each respective RLC RTT is within a second range of RLC RTT, or both.
9 . The apparatus of claim 7 , wherein the capability message further indicates: a restriction of the carrier aggregation to serving cells associated with communication latencies within a first range of communication latencies, RLC RTTs within a second range of RLC RTTs, or both, wherein the carrier aggregation for the set of serving cells is based at least in part on the restriction.
10 . The apparatus of claim 9 , wherein the UE is scheduled to receive data from a second set of serving cells that violate the indicated restriction, and the instructions are further executable by the at least one processor, individually or in any combination, to cause the apparatus to: discard the received data based at least in part on the violation of the indicated restriction; and transmit, to the network node, an indication of the violation of the indicated restriction via a RLC layer negative acknowledgement or a radio link failure message.
11 . The apparatus of claim 1 , wherein the NTN buffer size is further determined based at least in part on a delay associated with communications between base stations in the NTN.
12 . The apparatus of claim 1 , wherein the further indicates that the UE supports the orbit of the network node, the orbit group associated with the network node, or both.
13 . The apparatus of claim 1 , wherein the RLC RTT for the NTN is based at least in part on the orbit of the network node, the orbit of the network node comprising a geosynchronous orbit, a non-geosynchronous orbit, a geostationary earth orbit, a high earth orbit, a medium earth orbit, a low earth orbit, a highly elliptical orbit, or an elevation of a high-altitude platform station.
14 . The apparatus of claim 1 , wherein the NTN buffer size is a layer 2 buffer size and the buffer is a layer 2 buffer.
15 . A method for wireless communication at a user equipment (UE), comprising: transmitting a capability message indicating a latency of communications that is supported by the UE; establishing a connection with a network node via a non-terrestrial network (NTN) based on the capability message; and buffering NTN communications between the UE and the network node over the connection using a buffer having an NTN buffer size that is based at least in part on a radio link control (RLC) layer round trip time (RTT) for the NTN, wherein the RLC RTT for the NTN is associated with the NTN communications between the UE and the network node, wherein the RLC RTT for the NTN is determined based at least in part on an RLC RTT for a terrestrial network associated with the UE and on one or both of an offset for calculating the RLC RTT for the NTN and a scalar for calculating the RLC RTT for the NTN, wherein the RLC RTT for the terrestrial network is selected from a set of RLC RTTs for the terrestrial network based at least in part on a subcarrier spacing of the communications with the network node or a subcarrier spacing group associated with the communications with the network node, and wherein the scalar is selected from a set of scalars for the NTN based at least in part on an orbit of the network node or an orbit group associated with the network node.
16 . The method of claim 15 , further comprising: selecting the RLC RTT for the NTN from a set of RLC RTTs for the NTN based at least in part on the subcarrier spacing of the communications with the network node or the subcarrier spacing group associated with the communications with the network node, wherein the NTN buffer size is determined based at least in part on selecting the RLC RTT for the NTN.
17 . The method of claim 15 , further comprising: selecting the RLC RTT for the NTN from a set of RLC RTTs for the NTN based at least in part on the orbit of the network node or the orbit group associated with the network node, wherein the NTN buffer size is determined based at least in part on selecting the RLC RTT for the NTN.
18 . The method of claim 15 , further comprising: selecting the offset from a set of offsets for the NTN based at least in part on the orbit of the network node or the orbit group associated with the network node; and determining the RLC RTT for the NTN using the RLC RTT for the terrestrial network and the offset, wherein the NTN buffer size is determined based at least in part on determining the RLC RTT for the NTN.
19 . The method of claim 15 , wherein the scalar is associated with a hybrid automatic repeat request RTT associated with the orbit of the network node or the orbit group associated with the network node.
20 . The method of claim 15 , further comprising: determining the RLC RTT for the NTN using the RLC RTT for the terrestrial network, the offset, and the scalar.

Description

FIELD OF TECHNOLOGY The following relates to wireless communications, including buffering techniques for non-terrestrial networks (NTNs). BACKGROUND Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). In some wireless communications systems, a UE may buffer data communicated between the UE and a network node. In some examples, the UE may communicate with the network node via a non-terrestrial network (NTN). Improved techniques for buffering data communicated via an NTN may be desired. SUMMARY The described techniques relate to improved methods, systems, devices, and apparatuses that support buffering techniques for non-terrestrial networks (NTNs). Generally, the described techniques enable buffer management for data communicated between a UE and a network node via an NTN. For example, a UE may establish a connection with a network node via an NTN (e.g., establish the connection via an NTN node, such as a satellite or a high-altitude platform station (HAPS), among other types of NTN nodes). The UE may be configured to buffer NTN communications between the network node and the UE over the connection using a buffer, such as a layer 2 buffer. A size of the buffer may be specific to NTNs to support buffering of the NTN communications. For example, the UE may calculate the buffer size using a maximum data rate of the connection and a radio link control (RLC) round trip time (RTT) that is specific to NTNs. In some examples, the RLC RTT specific to NTNs may be greater than an RLC RTT that is specific to terrestrial networks (e.g., terrestrial network communications between a UE and a terrestrial base station). Using the RLC RTT specific to NTNs may result in a larger buffer size compared to a buffer size calculated using the RLC RTT specific to terrestrial networks, which may prevent or reduce memory overflow of buffered NTN communications. A method for wireless communication at a UE is described. The method may include establishing a connection with a network node via a NTN, calculating a buffer size for communications with the network node via the connection based on a maximum data rate of the connection and an RLC layer RTT, where the buffer size is specific to NTNs, and buffering communications between the UE and the network node over the connection using a buffer in accordance with the calculated buffer size. An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to establish a connection with a network node via a NTN, calculate a buffer size for communications with the network node via the connection based on a maximum data rate of the connection and an RLC layer RTT, where the buffer size is specific to NTNs, and buffer communications between the UE and the network node over the connection using a buffer in accordance with the calculated buffer size. Another apparatus for wireless communication at a UE is described. The apparatus may include means for establishing a connection with a network node via a NTN, means for calculating a buffer size for communications with the network node via the connection based on a maximum data rate of the connection and an RLC layer RTT, where the buffer size is specific to NTNs, and means for buffering communications between the UE and the network node over the connection using a buffer in accordance with the calculated buffer size. A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to establish a connection with a network node via a NTN, calculate a buffer size for communications with the network node via the connection based on a maximum data rate of the connection and an RLC layer RTT, where the buffer size is speci