A system for communication via a cellular communication network, the system comprising: a transport control protocol, TCP, source device; and a mobile device including: a TCP layer physical layer circuitry including a transceiver configured to communicate information via the cellular communication network; a modem of the mobile device configured to: control communication according to a first cellular communication protocol standard; detect a change in the communication to a second cellular communication protocol standard different from the first cellular communication protocol standard; and communicate, to an TCP layer of the mobile device, an indication of handover completion indicating completion of the first cellular communication protocol standard to the second cellular communication protocol standard of the change in the cellular communication protocol standard; and characterized in that the TCP layer, configured to initiate transmission of three duplicate acknowledgement, ACK, packets to the TCP source device in response to receiving the indication of handover completion of the change in the cellular communication protocol standard during a download of data to the TCP layer; wherein the TCP layer is further configured to ignore the indication of handover completion if a download of data to the TCP layer is not taking place. a transport control protocol, TCP, source device; and a mobile device including: a TCP layer physical layer circuitry including a transceiver configured to communicate information via the cellular communication network; a modem of the mobile device configured to: control communication according to a first cellular communication protocol standard; detect a change in the communication to a second cellular communication protocol standard different from the first cellular communication protocol standard; and communicate, to an TCP layer of the mobile device, an indication of handover completion indicating completion of the first cellular communication protocol standard to the second cellular communication protocol standard of the change in the cellular communication protocol standard; and characterized in that the TCP layer, configured to initiate transmission of three duplicate acknowledgement, ACK, packets to the TCP source device in response to receiving the indication of handover completion of the change in the cellular communication protocol standard during a download of data to the TCP layer; a TCP layer physical layer circuitry including a transceiver configured to communicate information via the cellular communication network; a modem of the mobile device configured to: control communication according to a first cellular communication protocol standard; detect a change in the communication to a second cellular communication protocol standard different from the first cellular communication protocol standard; and communicate, to an TCP layer of the mobile device, an indication of handover completion indicating completion of the first cellular communication protocol standard to the second cellular communication protocol standard of the change in the cellular communication protocol standard; and control communication according to a first cellular communication protocol standard; detect a change in the communication to a second cellular communication protocol standard different from the first cellular communication protocol standard; and communicate, to an TCP layer of the mobile device, an indication of handover completion indicating completion of the first cellular communication protocol standard to the second cellular communication protocol standard of the change in the cellular communication protocol standard; and characterized in that the TCP layer, configured to initiate transmission of three duplicate acknowledgement, ACK, packets to the TCP source device in response to receiving the indication of handover completion of the change in the cellular communication protocol standard during a download of data to the TCP layer; wherein the TCP layer is further configured to ignore the indication of handover completion if a download of data to the TCP layer is not taking place.