Method and apparatus for switching UPFs

A method, performed by a Wireless Device, WD, connected to a wireless communications network, the wireless communications network comprising a core network node, a first gNB and a second gNB, the WD is connected to the first gNB, and there is a first Packet Data Unit, PDU, session established between the WD and a Data Network, DN, over a first User Plane Function, UPF, the DN comprising an application server, AS, the PDU session enabling transmission of data between the WD and the AS, the method comprising:

• receiving an instruction to establish a second PDU session between the WD and the DN over a second UPF, the instruction being received in response to a predicted positional change of the WD indicating a new future position in which the second UPF is more suitable than the first UPF for transmission of data between the AS and the WD;
• in response to the receiving, establishing the second PDU session over the second UPF between the WD and the DN, the establishing the second PDU session over the second UPF including establishing the second PDU session over the second UPF via the second qNB, the establishing the second PDU session over the second UPF via the second qNB including establishing the second PDU session over the second UPF via the first gNB;
• in response to the establishing the second PDU session over the second UPF via the first qNB, transferring the second PDU session from the first qNB to the second gNB;
• and
• in response to the establishing (304) the second PDU session over the second UPF between the WD and the DN, initiating a first move of packet flows from the first PDU session over the first UPF to the second PDU session over the second UPF.

A method, performed by a first gNB of a wireless communications network, the wireless communications network further comprising a core network node and a second gNB, a WD is connected to the first gNB, and there is a first Packet Data Unit, PDU, session established between the WD and a Data Network, DN, over a first User Plane Function, UPF, the DN comprising the AS, the PDU session enabling transmission of data between the WD and the AS, the method comprising:

• receiving a request for establishing a second PDU session over a second UPF, based on a predicted new position of the WD;
• obtaining an indication that the second PDU session should be established via the most suitable gNB for the second UPF, the indication including an indication that the second PDU session should be via the qNB that has the shortest packet transmission delay for the predicted new position;
• and
• based on the received indication and the received request, ensuring that the second PDU session is established via the second gNB.

A core network node operable in a wireless communications network, the wireless communications network comprising a first gNB and a second gNB, a wireless device, WD, is connected to the first gNB, and there is a first Packet Data Unit, PDU, session established between the WD and a Data Network, DN, over a first User Plane Function, UPF, the DN comprising an application server, the core network node comprising:

• processing circuitry;
• and
• a memory, the memory containing instructions executable by the processing circuitry, to configure the core network node for:
• obtaining information regarding a predicted positional change of the WD indicating a new future position of the WD;
• selecting a second UPF which is more suitable than the first UPF for transmission of data between the application server and the WD for the new future position;
• triggering establishment of the second PDU session over the second UPF, the triggering establishment of the second PDU session over the second UPF including triggering establishment of the second PDU session over the second UPF via the second qNB, the triggering establishment of the second PDU session over the second UPF via the second qNB including triggering establishment of the second PDU session over the second UPF via the first gNB;
• in response to the establishment of the second PDU session over the second UPF via the first qNB, facilitating a transfer of the second PDU session over the second UPF from the first qNB to the second gNB;
• and
• in response to the triggering establishment of the second PDU session over the second UPF, triggering a first move of packet flows from the first PDU session to the second PDU session.

A wireless device, WD, operable for communication with a wireless communications network, the wireless communications network comprising a core network node, a first gNB and a second gNB, the WD is operable to be connected to the first gNB, and operable to have a first Packet Data Unit, PDU, session established between the WD and a Data Network, DN, over a first User Plane Function, UPF, the DN comprising an application server, AS, the PDU session enabling transmission of data between the WD and the AS, the WD comprising:

• processing circuitry;
• and
• a memory, the memory containing instructions executable by the processing circuitry, to configured the wireless device for:
• receiving an instruction to establish a second PDU session between the WD and the DN over a second UPF, the instruction being received in response to a predicted positional change of the WD indicating a new future position in which the second UPF is more suitable than the first UPF for transmission of data between the AS and the WD;
• in response to the receiving, establishing the second PDU session over the second UPF between the WD and the DN, the establishing the second PDU session over the second UPF including establishing the second PDU session over the second UPF via the second qNB, the establishing the second PDU session over the second UPF via the second qNB including establishing the second PDU session over the second UPF via the first gNB;
• in response to the establishing the second PDU session over the second UPF via the first qNB, transferring the second PDU session from the first qNB to the second gNB;
• and
• in response to the establishing the second PDU session over the second UPF between the WD and the DN, initiating a first move of packet flows from the first PDU session over the first UPF to the second PDU session over the second UPF.

A first gNB operable in a wireless communications network, the wireless communications network further comprising a core network node and a second gNB, the first gNB is operable to have a connection to a WD, and the first gNB is operable to have a first Packet Data Unit, PDU, session established between the WD and a Data Network, DN, over a first User Plane Function, UPF, the DN comprising the AS, the PDU session enabling transmission of data between the WD and the AS, the first gNB comprising:

• processing circuitry;
• and
• a memory, the memory containing instructions executable by the processing circuitry to configured the first gNB for:
• receiving a request for establishing a second PDU session over a second UPF, based on a predicted new position of the WD;
• obtaining an indication that the second PDU session should be established via the most suitable gNB for the second UPF, the indication including an indication that the second PDU session should be via the qNB that has the shortest packet transmission delay for the predicted new position;
• and
• based on the received indication and the received request, ensuring that the second PDU session is established via the second gNB.