1. A method for decompressing a packet header using a processor, the method comprising: determining if decompression of a current packet header failed; determining a difference between a link layer sequence number (LL SN) of a previous correctly decompressed packet and a link layer sequence number (LL SN) of the current packet to provide repair information used for header decompression, if header decompression failed; adding the difference to the LL SN of the current packet to generate a new reference sequence number, if the difference is greater than or equal to (2^k)−p, where k is a number of LL SN bits in the current packet, and p is a shift in an interpretation interval; and decompressing the header of the current packet by the processor using the new reference sequence number as the repair information.