Method, network nodes and system for sending data in a mobile communication network

A first network node for sending data blocks to a second and third network node in a mobile telecommunications network, wherein said first network node is interfaced with at least said second and third network nodes, wherein said first network node further comprises:

• a data buffer for storing data blocks to be sent to at least one of a second network node and a third network node;
• sending means for sending data blocks to at least one of said second network and said third network node;
• starting means for starting a timer for at least one data block sent to said second network node;
• triggering means for triggering a handover from a cell belonging to said second network node to a cell belonging to said third network node;
• estimating means for estimating based on said timers which data blocks have already been transmitted via said second network node to said mobile terminal;
• and
• transmitting means for transmitting from said data buffer to said third network node said data blocks which are estimated as not being sent to said mobile terminal.

A second network node for sending data blocks to a mobile terminal in a mobile telecommunications network, wherein said second network node is interfaced with at least a first network node and said mobile terminal, wherein said second network node further comprises:

• receiving means for receiving data blocks from a first network node;
• a data buffer for storing data blocks received from said first network node;
• starting means for starting a timer for at least one of a data block to be sent to a mobile terminal when said data blocks arrive at said data block buffer;
• and
• sending means for sending a data block to a mobile terminal before the timer of said data block expires.

A system for sending data to a new network node in a mobile communications network comprising:

• a first network node;
• a second network node connected to said first network node;
• a third network node connected to said first network node;
• a mobile terminal communicating with said second and/or third network node,
• wherein the system further comprises:
• a plurality of data buffers for storing data blocks;
• determining means for determining timer values for said data blocks;
• starting means for starting timers of said data blocks to be sent to said mobile terminal;
• triggering means for triggering a handover from a cell belonging to said second network node to a cell belonging to said third network node;
• estimating means for estimating in said first network node based on said timers which data blocks have already been transmitted via said second network node to said mobile terminal;
• and
• transmitting means for transmitting from said first network node to said third network node said data blocks which are estimated as not being sent to said mobile terminal.