Abstract: A method of segmenting a re-ordering buffer comprises: dividing the re-ordering buffer into multiple segments; dividing each segment into multiple blocks such that blocks within the same segment have the same size while the sizes of blocks located in separate segments are integer multiples of each other. A method of mapping TTI data to the re-ordering comprises: determining a size category of the TTI data; comparing the size category of the TTI data with sizes of the blocks of the segments to find a matching block for storing the TTI data; storing the TTI data in the matching block if an empty matching block is found, but if no empty matching block is found: storing the TTI data in a block with a size larger than the size category of the TTI data; storing the TTI data in adjacent blocks, if such a block with a larger size is unavailable.