Managing packet duplication
A method for managing uplink packet duplication at an user equipment is described. The example method includes receiving, an indication from a network node, the indication instructing the user equipment (UE) to discard protocol data units (PDUs) that are buffered at one or more associated protocol entities at the user equipment (UE). The method further includes discarding, in response to receiving the indication, the protocol data units (PDUs) that are buffered at the one or more associated protocol entities.
1 . A method of managing uplink packet duplication at a user equipment (UE), the method comprising:
receiving, by a user equipment (UE), a first indication from a first entity via a media access control (MAC) control element (CE), the first indication instructing the user equipment (UE) to activate protocol data unit (PDU) duplication;
transmitting, by the user equipment (UE), in response to receiving the first indication, protocol data units (PDUs) to the first entity and duplicated protocol data units (PDUs) to a second entity;
receiving, by the user equipment (UE) via a first downlink control information (DCI), a second indication from the first entity or the second entity, the second indication instructing the user equipment (UE) to transmit N protocol data units (PDUs) and discard only N duplicated protocol data units (PDUs) that are buffered at the user equipment (UE) while the protocol data unit (PDU) duplication is still activated;
discarding, by the user equipment (UE), in response to receiving the second indication, the N duplicated protocol data units (PDUs);
receiving, by the user equipment (UE), a third indication from the first entity, the third indication instructing the user equipment (UE) to transmit the duplicated protocol data units (PDUs) buffered at the user equipment (UE) to the second entity and also activating an uplink configured grant for uplink transmissions associated with the second entity, and wherein the third indication is transmitted via a second downlink control information (DCI); and
transmitting, by the user equipment (UE), in response to the receiving the third indication, the duplicated protocol data units (PDUs) to the second entity while sending the protocol data units (PDUs) to the first entity.
2 . The method of claim 1 , wherein the protocol data units (PDUs) are packet data convergence protocol (PDCP) protocol data units (PDUs).
3 . The method of claim 1 , wherein the discarding includes:
flushing the duplicated protocol data units (PDUs), or
storing the duplicated protocol data units (PDUs) for transmission.
4 . The method of claim 1 , wherein:
the first entity is a master gNB (MgNB),
the first indication is received from the master gNB (MgNB),
one or more protocol entities include a protocol entity associated with a secondary gNB (SgNB),
the second indication is received from the master gNB (MgNB),
transmitting the N protocol data units (PDUs) comprises transmitting the N protocol data units (PDUs) to the first entity, and
the discarding includes discarding only N duplicated protocol data units (PDUs) buffered at the protocol entity associated with the secondary gNB (SgNB) while sending the N protocol data units (PDUs) to the master gNB (MgNB).
5 . The method of claim 4 , wherein the UE is in a dual connectivity (DC) and/or a carrier aggregation (CA) configuration with the master gNB (MgNB) and the secondary gNB (SgNB) for protocol data unit (PDU) duplication.
6 . The method of claim 5 , wherein the protocol data unit (PDU) duplication is based on new radio (NR) dual connectivity (DC), new radio (NR) carrier aggregation (CA), long term evolution (LTE) dual connectivity, E-UTRA-NR Dual connectivity, or any other form of dual connectivity (DC) or carrier aggregation (CA), as defined in 3GPP standards.
7 . The method of claim 1 , wherein:
the second entity is a secondary gNB (SgNB), wherein the second indication is received from the secondary gNB (SgNB),
one or more protocol entities include a protocol entity associated with a master gNB (MgNB), and
the discarding includes discarding only N duplicated protocol data units (PDUs) buffered at the protocol entity associated with the master gNB (MgNB).
8 . The method of claim 1 , further comprising:
determining, upon the receiving the first indication, by the user equipment (UE), that protocol data unit (PDU) duplication is activated at the user equipment (UE).
9 . The method of claim 8 , wherein the duplication is activated via a media access control (MAC) control element (CE) or downlink control information (DCI).
10 . The method of claim 1 , wherein a 1:1 mapping exists between protocol data units (PDUs) of packet data convergence protocol (PDCP), radio link control (RLC), and media access control (MAC) and corresponding transport blocks (TBs).
11 . The method of claim 10 , wherein the discarding further includes:
flushing the packet data convergence protocol (PDCP) protocol data units (PDUs) buffered at an associated RLC protocol entity, which is transmitted in a received uplink grant in the corresponding transport block.
12 . The method of claim 1 , wherein the discarding is performed at a radio link control (RLC) buffer.
13 . An apparatus comprising:
at least one processor; and
at least one memory including computer program code;
the at least one memory and the computer program code, when executed by the at least one processor, configured to cause the apparatus at least to:
receive, by the apparatus, a first indication from a first entity via a media access control (MAC) control element (CE), the first indication instructing the apparatus to activate protocol data unit (PDU) duplication;
transmit, by the apparatus, in response to receiving the first indication, protocol data units (PDUs) to a first entity and duplicated protocol data units (PDUs) to a second entity;
receive, by the apparatus, a second indication from the first entity or the second entity, the second indication instructing the apparatus to transmit N protocol data units (PDUs) and discard only N duplicated protocol data units (PDUs) that are buffered at the apparatus, the second indication being transmitted via a first downlink control information (DCI) while the protocol data unit (PDU) duplication is still activated;
discard, by the apparatus, in response to receiving the second indication, the N duplicated protocol data units (PDUs);
receiving, by the apparatus from the first entity, a third indication, the third indication instructing the apparatus to transmit the duplicated protocol data units (PDUs) buffered at the apparatus to the second entity and activating an uplink configured grant for uplink transmissions associated with the second entity, and wherein the third indication is transmitted via a second downlink control information (DCI); and
transmitting, by the apparatus while transmitting protocol data units (PDUs) to the first entity, in response to the receiving the third indication, the duplicated protocol data units (PDUs).
14 . The apparatus of claim 13 , wherein the computer program code configured to cause the apparatus to discard comprises the computer program code configured to cause the apparatus to:
flush the duplicated protocol data units (PDUs), or
store the duplicated protocol data units (PDUs) for transmission.
15 . The apparatus of claim 13 , wherein:
the first entity is a master gNB (MgNB),
the first indication is received from the master gNB (MgNB),
one or more protocol entities include a protocol entity associated with a secondary gNB (SgNB),
the second indication is received from the master gNB (MgNB),
transmitting the N protocol data units (PDUs) comprises transmitting the N protocol data units (PDUs) to the first entity, and
the computer program code configured to cause the apparatus to discard comprises the computer program code configured to cause the apparatus to discard only N protocol data units (PDUs) buffered at the protocol entity associated with the secondary gNB (SgNB).
16 . The apparatus of claim 13 , wherein:
the second entity is a secondary gNB (SgNB),
the second indication is received from the secondary gNB (SgNB),
one or more protocol entities include a protocol entity associated with a master gNB (MgNB), and
the computer program code configured to cause the apparatus to discard comprises the computer program code configured to cause the apparatus to discard only N protocol data units (PDUs) buffered at the protocol entity associated with the master gNB (MgNB).
17 . The apparatus of claim 13 , wherein the apparatus is in a dual connectivity (DC) and/or a carrier aggregation (CA) configuration with a master gNB (MgNB) and a secondary gNB (SgNB) for protocol data unit (PDU) duplication.