PROTOCOL DATA UNIT SYSTEMS AND METHODS

1 . A method of transferring traffic to a client device from a first access network to a second access network in a multi-access protocol data unit (PDU) (MA-PDU) session, comprising the steps of:

establishing the MA-PDU session over the first access network and the second access network;

setting a first priority level for the first access network and a second priority level for the second access network, wherein the first priority level has a higher value than the second priority level;

transmitting one or more PDU packets of the MA-PDU session over the first access network based on the set first priority level;

receiving, from the client device, a congestion indication regarding the first access network; and

controlling, based on the received congestion indication, transmission of the one or more PDU packets from the first access network to the second access network.

2 . The method of claim 1 , wherein the congestion indication includes a low latency low loss scalable throughput (L4S) standard explicit congestion notification (ECN) field.

3 . The method of claim 1 , further comprising a step of notifying a policy control function (PCF) of the congestion indication and an access type of the first access network.

4 . The method of claim 3 , further comprising a step of providing, by the PCF, an enhanced switching rule for the MA-PDU session based on the step of notifying.

5 . The method of claim 1 , wherein the first access network is a 3GPP access type, and wherein the second access network is a non-3GPP access type.

6 . The method of claim 1 , wherein the first access network is a non-3GPP access type, and wherein the second access network is a 3GPP access type.

7 . The method of claim 1 , wherein the step of controlling comprises a substep of switching, splitting, or steering the traffic from the first access network.

8 . A method of providing redundancy for traffic to a client device from a first access network and a second access network in a multi-access protocol data unit (PDU) (MA-PDU) session, comprising the steps of:

establishing the MA-PDU session over the first access network and the second access network;

enabling a dropping policy for a PDU set of the MA-PDU session, wherein the PDU set includes a plurality of PDU packets;

transmitting a first PDU packet of the plurality of PDU packets to the client device over the first access network;

transmitting the first PDU packet to the client device over the second access network;

dropping, by the first access network, a second PDU packet of the plurality of PDU packets transmitted subsequently to the first PDU packet; and

transmitting, based on the enabled dropping policy, the second PDU packet to the client device over the second access network.

9 . The method of claim 8 , wherein the first access network is a 3GPP access type, and wherein the second access network is a non-3GPP access type.

10 . The method of claim 8 , wherein the first access network is a non-3GPP access type, and wherein the second access network is a 3GPP access type.

11 . The method of claim 8 , wherein the first access network includes a local data network, and wherein the second access network includes a central data network.

12 . The method of claim 8 , further comprising the steps of:

dropping, by the first access network, a third PDU packet of the plurality of PDU packets transmitted subsequently to the first PDU packet;

dropping, by the second access network, the third packet of the plurality of PDU packets transmitted subsequently to the first PDU packet; and

instructing, based on the enabled dropping policy, the first and second access networks to drop all PDU packets of the plurality of PDU packets transmitted subsequently to the third PDU packet.

13 . The method of claim 8 , wherein the redundancy for the traffic is one of partial redundancy and full redundancy.