Transmitting data in a mobile communication system
The present invention is related to transmitting data in a mobile communication system. Preferably, the present invention comprises transmitting first data to a receiving side and receiving acknowledgment information for indicating whether the first data was successfully transmitted to the receiving side. If the first data was not successfully transmitted to the receiving side, the method further comprises determining whether an amount of available radio resources is sufficient for retransmitting the first data to the receiving side, retransmitting the first data to the receiving side if the amount of available radio resources is sufficient to retransmit the first data, reconfiguring the first data into at least one second data if the amount of available radio resources is insufficient to retransmit the first data, wherein the at least one second data can be transmitted to the receiving side using the amount of available radio resources, and transmitting the at least one second data to the receiving side.
1. A method for retransmitting a protocol data unit (PDU) to a receiving side by a transmitting side in a mobile communication system, the method comprising:
delivering a first PDU to a lower layer if the first PDU entirely fits within a predetermined size of a PDU;
segmenting the first PDU to form a second PDU which fits within the predetermined size and delivering the second PDU to the lower layer if the first PDU does not fit within the predetermined size; and
transmitting the first PDU or the second PDU to the receiving side,
wherein segmenting the first PDU to form the second PDU comprises:
mapping only a data field of the first PDU to a data field of the second PDU; and
setting a header of the second PDU.
2. The method of claim 1 , wherein the header of the second PDU includes a field indicating a position of the second PDU within the first PDU.
3. The method of claim 1 , wherein the header of the second PDU includes a field indicating a starting position of the second PDU within the first PDU.
4. The method of claim 1 , wherein the header of the second PDU includes a field indicating whether or not the second PDU is a last segmented PDU within the first PDU.
5. The method of claim 1 , wherein the predetermined size is indicated by the lower layer.
6. The method of claim 1 , wherein the header of the second PDU includes a field indicating that the corresponding second PDU is segmented.
7. An apparatus for retransmitting a protocol data unit (PDU) to a receiving side in a mobile communication system, the apparatus comprising:
means for delivering a first PDU to a lower layer if the first PDU entirely fits within a predetermined size of a PDU;
means for segmenting the first PDU to form a second PDU which fits within the predetermined size and delivering the second PDU to the lower layer if the first PDU does not fit within the predetermined size; and
means for transmitting the first PDU or the second PDU to the receiving side,
wherein the means for segmenting the first PDU comprises means for mapping only a data field of the first PDU to a data field of the second PDU and means for setting a header of the second PDU.
8. The apparatus of claim 7 , wherein the header of the second PDU includes a field indicating a position of the second PDU within the first PDU.
9. The apparatus of claim 7 , wherein the header of the second PDU includes a field indicating a starting position of the second PDU within the first PDU.
10. The apparatus of claim 7 , wherein the header of the second PDU includes a field indicating whether or not the second PDU is a last segmented PDU within the first PDU.
11. The apparatus of claim 7 , wherein the predetermined size is indicated by the lower layer.
12. The apparatus of claim 7 , wherein the header of the second PDU includes a field indicating that the corresponding second PDU is segmented.