Proactive switching of V2X communication from sidelink connection to cellular connection

A first terminal device, comprising:

• at least one processor;
• and
• at least one memory including computer program code;
• the at least one memory and the computer program code configured to, with the at least one processor, cause the first terminal device to:
• receive, from a second terminal device via a device-to-device connection, an indication of a decision to switch the device-to-device connection to a connection routed by at least one network device for communication with the second terminal device;
• determine, based on the received indication from the second terminal device, proactive switching from the device-to-device connection to the routed connection to be performed;
• and
• send a request to a first network device of the at least one network device to set up the routed connection, the request indicating a cause for the determined proactive switching,
• wherein the first terminal device is further caused to:
• determine whether a packet data unit session served by a core network is required for the communication via the routed connection;
• and
• in response to determining that the packet data unit session is required, determine the packet data unit session,
• wherein the determining and setup of the packet data unit session is performed after the indication is received and a connection setup is initiated for both the first terminal device and the second terminal device in parallel.