Methods for WiFi integration in cellular systems

A wireless transmit/receive unit (WTRU) comprising:

• first transceiver;
• a second transceiver;
• and
• at least one processor operatively coupled to the first transceiver and the second transceiver;
• wherein:
• the at least one processor and the first transceiver are configured to receive information using a first radio access technology (RAT);
• the at least one processor is further configured to process bearers at a packet data convergence protocol (PDCP) layer, wherein the bearers include a first bearer for transmission using the first RAT, a second bearer for transmission using a second RAT, and a split bearer for split transmission using the first RAT and using the second RAT, wherein the PDCP layer supports in-sequence delivery of protocol data units (PDUs) to upper layers, wherein the first RAT is a cellular technology and the second RAT is a WiFi technology;
• the at least one processor is further configured to provide PDCP processed bearer data to a corresponding one of the first transceiver or the second transceiver;
• the first transceiver is further configured to transmit the PDCP processed bearer data for the first bearer and a first portion of the PDCP processed bearer data for the split bearer using the first RAT;
• the second transceiver is configured to transmit the PDCP processed bearer data for the second bearer and a second portion of the PDCP processed bearer data for the split bearer using the second RAT;
• the at least one processor is further configured to steer the PDCP processed bearer data corresponding to the first transceiver to the second transceiver for transmission using the second RAT based on measurements related to the second RAT;
• and
• the at least one processor is further configured to send a first status report associated with the first RAT and a second status report associated with the second RAT, wherein the first status report is a PDCP status report, and wherein the second status report includes missing PDCP PDUs associated with the second RAT, and wherein the second status report triggers a network to retransmit the missing PDCP PDUs associated with the second RAT using the first RAT.