Enhanced multi-access protocol data unit (PDU) session

A method comprising:

• sending, by a wireless device, a first protocol data unit (PDU) session establishment request to a first network, wherein the first PDU session establishment request indicates:
• a PDU session type being an enhanced multi-access PDU (eMA-PDU) session across a plurality of access networks which includes a first access network and a second access network;
• an anchor network of the eMA-PDU session being the first network;
• and
• a PDU session identifier;
• receiving, via the first access network, a first response indicating a successful first establishment of a first PDU session, the first access network being a new radio access network;
• sending, by the wireless device and based on receiving the first response, a second PDU session establishment request to a second network indicating:
• the PDU session type;
• the anchor network of the eMA-PDU session being the first network;
• and
• the PDU session identifier;
• receiving, via the second access network, a second response indicating a successful second session establishment of a second PDU session, the second access network being a long-term evolution access network, wherein the second response indicating the successful second session establishment is based on a session management function (SMF) of the second network forwarding the second PDU session establishment request to an SMF of the first network as the anchor network of the eMA-PDU session, the anchor network managing the eMA-PDU session, and the SMF of the first network forwarding the second PDU session establishment to a user plane function (UPF) of the first network for establishment of the second PDU session, wherein the second response is based on the establishment of the second PDU session by the UPF of the first network;
• and
• communicating with at least one of the first access network or the second access network based on the second PDU session, wherein data communicated to the long-term evolution access network of the second access network from the wireless device is forwarded from the UPF of the second network to the UPF of the new radio access network of the first network as the anchor network of the eMA-PDU session managed by the anchor network.

A method comprising:

• receiving, by a first session management function (SMF) of a first network, a protocol data unit (PDU) session establishment request from a wireless device, wherein the PDU session establishment request indicates:
• a PDU session type being an enhanced multi-access (eMA-PDU) session across a plurality of access networks comprising a first access network of the first network and a second access network of a second network;
• an anchor network being the second network;
• and
• a PDU session identifier;
• determining a second SMF of the second network in response to the anchor network being the second network, the anchor network managing the eMA-PDU session;
• sending a forwarded request of the PDU session establishment request to the second SMF of the second network to establish a second of the eMA-PDU session, the SMF of the first network forwarding the PDU session establishment to a user plane function (UPF) of the first network for establishment of the eMA-PDU session;
• receiving a response of the forwarded request of the PDU session establishment request from the second SMF, wherein the response is based on the establishment of the eMA-PDU session by the UPF of the first network;
• and
• transmitting, at least partly based on the response, a forwarded response of the PDU session establishment to the wireless device.