Supporting network transmissions using unicast sidelink communications
This disclosure provides systems, methods, and apparatuses for supporting network transmissions using unicast sidelink communications. A base station (BS) may transmit a set of encoded packets to a number of user equipment (UEs) and receive feedback messages from the UEs that indicate sets of decoded packets. Based on the feedback messages, the BS may transmit an updated set of encoded packets based on a difference between the set of encoded packets and the union of decoded packets. The BS may transmit an instruction to a first UE to transmit a unicast sidelink communication to a second UE that includes a set of missed packets that includes one or more decoded packets that were decoded by the first UE but were not decoded by the second UE. The first UE may transmit the unicast sidelink communication to the second UE.
1. An apparatus for wireless communication at a first user equipment (UE), comprising:
one or more memories storing processor-executable code; and
one or more processors coupled with the one or more memories, at least one processor of the one or more processors configured to cause the first UE to:
receive, from a base station (BS), a set of encoded packets;
transmit, to the BS, a feedback message that indicates a first set of decoded packets;
transmit, to a second UE, a first unicast sidelink communication comprising a first set of missed packets, the first set of missed packets including one or more decoded packets of the first set of decoded packets; and
receive, from the second UE, a second unicast sidelink communication comprising a second set of missed packets, the second set of missed packets including one or more decoded packets of a second set of decoded packets that are not included in the first set of decoded packets.
2. The apparatus of claim 1 , wherein at least one processor of the one or more processors is configured to cause the first UE to:
receive, from the BS, an updated set of encoded packets responsive to the feedback message.
3. The apparatus of claim 2 , wherein at least one processor of the one or more processors is configured to cause the first UE to:
decode the set of encoded packets using a decoding function corresponding to an encoding function used to generate the set of encoded packets; and
decode the updated set of encoded packets using the decoding function.
4. The apparatus of claim 3 , wherein the encoding function comprises a random matrix, and wherein at least one processor of the one or more processors is configured to cause the first UE to:
receive an indication of the random matrix from the BS.
5. The apparatus of claim 2 , wherein at least one processor of the one or more processors is configured to cause the first UE to:
transmit, to the BS, an additional feedback message that indicates a third set of decoded packets including a subset of the updated set of encoded packets.
6. The apparatus of claim 1 , wherein, to receive the set of encoded packets, at least one processor of the one or more processors is configured to cause the first UE to:
receive the set of encoded packets using an access link between the BS and the first UE.
7. The apparatus of claim 1 , wherein at least one processor of the one or more processors is configured to cause the first UE to:
receive, from the BS, a sidelink configuration.
8. The apparatus of claim 7 , wherein the sidelink configuration indicates at least one of:
a sidelink transmission resource,
a frequency configuration, or
a modulation and coding scheme (MCS) pool.
9. The apparatus of claim 7 , wherein the first unicast sidelink communication and the second unicast sidelink communication are associated with the sidelink configuration.
10. The apparatus of claim 1 , wherein at least one processor of the one or more processors is configured to cause the first UE to:
receive, from the BS, a network coding configuration comprising a set of network coding parameters.
11. The apparatus of claim 10 , wherein the set of network coding parameters indicate at least one of:
a network coding algorithm,
an encoding function,
an encoding matrix, or
a maximum number of decoding iterations.
12. The apparatus of claim 10 , wherein the network coding configuration is carried in at least one of:
a medium access control (MAC) control element (MAC-CE),
downlink control information (DCI), or
a radio resource control (RRC) message.
13. The apparatus of claim 10 , wherein at least one processor of the one or more processors is configured to cause the first UE to:
transmit, to the BS, a network coding parameter change request in response to a performance of the first UE associated with the set of network coding parameters satisfying an underperformance threshold.
14. The apparatus of claim 13 , wherein the network coding parameter change request is carried in at least one of:
a medium access control (MAC) control element (MAC-CE), or
uplink control information (UCI).
15. The apparatus of claim 13 , wherein at least one processor of the one or more processors is configured to cause the first UE to:
receive an additional set of network coding parameters from the BS responsive to the network coding parameter change request.
16. The apparatus of claim 15 , wherein the additional set of network coding parameters is carried in at least one of:
a medium access control (MAC) control element (MAC-CE), or
downlink control information (DCI).
17. The apparatus of claim 13 , wherein at least one processor of the one or more processors is configured to cause the first UE to:
receive an additional set of network coding parameters from the BS;
receive a network coding parameter switch indication from the BS responsive to the network coding parameter change request; and
instantiate, in accordance with the network coding parameter switch indication, the additional set of network coding parameters.
18. The apparatus of claim 1 , wherein the feedback message comprises at least one of:
a packet data convergence protocol (PDCP) status report,
a radio link control (RLC) status report,
a medium access control (MAC) hybrid automatic repeat request (HARQ) feedback message, or
a dedicated decoding feedback message.
19. A method for wireless communication at a first user equipment (UE), comprising:
receiving, from a base station (BS), a set of encoded packets;
transmitting, to the BS, a feedback message that indicates a first set of decoded packets;
transmitting, to a second UE, a first unicast sidelink communication comprising a first set of missed packets, the first set of missed packets including one or more decoded packets of the first set of decoded packets; and
receiving, from the second UE, a second unicast sidelink communication comprising a second set of missed packets, the second set of missed packets including one or more decoded packets of a second set of decoded packets that are not included in the first set of decoded packets.
20. A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising:
one or more instructions that, when executed at a first user equipment (UE), cause the first UE to:
receive, from a base station (BS), a set of encoded packets;
transmit, to the BS, a feedback message that indicates a first set of decoded packets;
transmit, to a second UE, a first unicast sidelink communication comprising a first set of missed packets, the first set of missed packets including one or more decoded packets of the first set of decoded packets; and
receive, from the second UE, a second unicast sidelink communication comprising a second set of missed packets, the second set of missed packets including one or more decoded packets of a second set of decoded packets that are not included in the first set of decoded packets.