Recovery after packet data convergence protocol packet discard
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a radio bearer may detect, at a packet data convergence protocol (PDCP) layer, expiry of a timer associated with a packet for transmission. The radio bearer may be configured to discard the packet upon expiry of the timer. Accordingly, the radio bearer may re-enqueue, at a modem of the radio bearer or at an application layer of the radio bearer and based at least in part on detecting expiry of the timer, the packet as a new packet for transmission before discarding the packet. Additionally, or alternatively, the radio bearer may retransmit the packet based at least in part on instructions from an application, executed on one or more processors of the radio bearer, that received the packet from the PDCP layer before the packet was discarded. Numerous other aspects are described.
1 . A radio bearer, comprising:
one or more memories; and
one or more processors, coupled to the one or more memories, individually or collectively configured to:
detect, at a packet data convergence protocol (PDCP) layer of the radio bearer, expiry of a timer associated with a packet for transmission;
pass, by the PDCP layer and when the radio bearer is configured to discard the packet upon expiry of the timer, the packet to software associated with a modem of the radio bearer, or an application executed on the one or more processors of the radio bearer; and
re-enqueue the packet, as a new packet for transmission before discarding the packet, based at least in part on:
at least one of: a tuple associated with the packet, traffic patterns associated with the packet, or metadata associated with the packet, and
a type of a protocol of a plurality of protocols, the plurality of protocols including a first subset of protocols associated with re-enqueuing the packet and a second subset of protocols associated with discarding the packet,
wherein:
the packet is re-enqueued as the new packet by the modem based at least in part on passing the packet to the software, or
the packet is re-enqueued as the new packet by the application based at least in part on passing the packet to the application.
2 . The radio bearer of claim 1 ,
wherein a value of the timer is associated with a default radio bearer configuration or a dedicated radio bearer configuration.
3 . The radio bearer of claim 1 ,
wherein the packet is for transmission on an uplink to a network entity.
4 . The radio bearer of claim 3 ,
wherein the one or more processors are further configured to:
receive, from the network entity, a radio bearer configuration that indicates a value of the timer.
5 . The radio bearer of claim 1 ,
wherein the packet is for transmission on a downlink to a user equipment (UE).
6 . The radio bearer of claim 1 ,
wherein at least one of:
the plurality of protocols includes at least one of a transmission control protocol (TCP), a real-time transport protocol (RTP), or a user datagram protocol (UDP), or
the packet is associated with Ethernet, unstructured data, application-specific protocol data, or a combination thereof.
7 . The radio bearer of claim 6 ,
wherein the application-specific protocol data includes extended reality (XR) data, virtual reality (VR) data, or a combination thereof.
8 . The radio bearer of claim 1 ,
wherein the one or more processors are further configured to:
detect, at the PDCP layer, expiry of an additional timer associated with an additional packet for transmission; and
discard the additional packet based at least in part on detecting expiry of the additional timer.
9 . The radio bearer of claim 1 ,
wherein the packet is re-enqueued based at least in part on the tuple associated with the packet.
10 . The radio bearer of claim 1 ,
wherein the packet is passed from the PDCP layer to the software, and the packet is re-enqueued by the software.
11 . The radio bearer of claim 1 ,
wherein the packet is passed from the PDCP layer to the application, and the packet is re-enqueued by the application.
12 . The radio bearer of claim 1 ,
wherein the one or more processors are further configured to:
begin the timer after passing the packet to one or more lower layers of the radio bearer,
wherein expiry of the timer is detected after beginning the timer and at one of:
a failure to receive an acknowledgement during the timer, or
a receipt of a negative acknowledgement during the timer.
13 . The radio bearer of claim 1 ,
wherein the packet is re-enqueued based at least in part on the metadata.
14 . A radio bearer, comprising:
one or more memories; and
one or more processors, coupled to the one or more memories, individually or collectively configured to:
detect, at a packet data convergence protocol (PDCP) layer, expiry of a timer associated with a packet for transmission;
pass, by the PDCP layer and when the radio bearer is configured to discard the packet upon expiry of the timer, the packet to an application executed on the one or more processors of the radio bearer;
duplicate, by the application, the packet before discarding the packet,
wherein the packet is duplicated based at least in part on a type of a protocol of a plurality of protocols, the plurality of protocols including a first subset of protocols associated with duplicating the packet and a second subset of protocols associated with discarding the packet;
send, by the application and based at least in part on duplicating the packet, instructions to the PDCP layer to retransmit the packet; and
retransmit, by the PDCP layer and based at least in part on the instructions, the packet,
wherein the packet is retransmitted based at least in part on a tuple associated with the packet, traffic patterns associated with the packet, or metadata associated with the packet.
15 . The radio bearer of claim 14 ,
wherein a value of the timer is associated with a default radio bearer configuration or a dedicated radio bearer configuration.
16 . The radio bearer of claim 14 ,
wherein the packet is for transmission on an uplink to a network entity.
17 . The radio bearer of claim 14 ,
wherein the packet is for transmission on a downlink to a user equipment (UE).
18 . The radio bearer of claim 14 ,
wherein:
the protocol is a transmission control protocol (TCP), a real-time transport protocol (RTP), or a user datagram protocol (UDP), or
the packet is associated with Ethernet, unstructured data, application-specific protocol data, or a combination thereof.
19 . The radio bearer of claim 14 ,
wherein the one or more processors are further configured to:
detect, at the PDCP layer, expiry of an additional timer associated with an additional packet for transmission; and
discard the additional packet based at least in part on detecting expiry of the additional timer.
20 . The radio bearer of claim 14 ,
wherein the packet is retransmitted based at least in part on the tuple associated with the packet.
21 . The radio bearer of claim 14 ,
wherein the PDCP layer is configured to retransmit after a threshold quantity of negative-acknowledgement (NACK) signals, and the packet is retransmitted based at least in part on fewer NACK signals than the threshold quantity.
22 . A method of wireless communication performed by a radio bearer, comprising:
detecting, at a packet data convergence protocol (PDCP) layer of the radio bearer, expiry of a timer associated with a packet for transmission;
passing, by the PDCP layer and when the radio bearer is configured to discard the packet upon expiry of the timer, the packet to software associated with a modem of the radio bearer, or an application executed on the radio bearer; and
re-enqueuing the packet, as a new packet for transmission before discarding the packet, based at least in part on:
at least one of: a tuple associated with the packet, traffic patterns associated with the packet, or metadata associated with the packet, and
a type of a protocol of a plurality of protocols, the plurality of protocols including a first subset of protocols associated with re-enqueuing the packet and a second subset of protocols associated with discarding the packet,
wherein:
the packet is re-enqueued as the new packet by the modem based at least in part on passing the packet to the software, or
the packet is re-enqueued as the new packet by the application based at least in part on passing the packet to the application.
23 . The method of claim 22 ,
wherein the packet is passed from the PDCP layer to the software, and the packet is re-enqueued by the software.
24 . The method of claim 22 ,
wherein the packet is passed from the PDCP layer to the application, and the packet is re-enqueued by the application.
25 . A method of wireless communication performed by a radio bearer, comprising:
detecting, at a packet data convergence protocol (PDCP) layer, expiry of a timer associated with a packet for transmission;
passing, by the PDCP layer and when the radio bearer is configured to discard the packet upon expiry of the timer, the packet to an application executed on the radio bearer;
duplicating, by the application, the packet before discarding the packet,
wherein the packet is duplicated based at least in part on a type of a protocol of a plurality of protocols, the plurality of protocols including a first subset of protocols associated with duplicating the packet and a second subset of protocols associated with discarding the packet;
sending, by the application and based at least in part on duplicating the packet, instructions to the PDCP layer to retransmit the packet; and
retransmitting, by the PDCP layer and based at least in part on the instruction, the packet,
wherein the packet is retransmitted based at least in part on a tuple associated with the packet, traffic patterns associated with the packet, or metadata associated with the packet.
26 . The method of claim 25 ,
wherein the packet is retransmitted based at least in part on the tuple associated with the packet.
27 . The method of claim 25 ,
wherein the PDCP layer is configured to retransmit after a threshold quantity of negative-acknowledgement (NACK) signals, and the packet is retransmitted based at least in part on fewer NACK signals than the threshold quantity.
28 . The method of claim 22 ,
wherein a value of the timer is associated with a default radio bearer configuration or a dedicated radio bearer configuration.
29 . The method of claim 25 ,
wherein a value of the timer is associated with a default radio bearer configuration or a dedicated radio bearer configuration.