A method for selectively maintaining compression state and applying a compression technique after a PPP renegotiation on a Um interface of a wireless communicaiton network. A communication device (104) receives packetized data transmitted from a terminal device (102), which is coupled to the communication device via an Rm interface. The communciaiton device determines (S315) whether the received packetized data comprises compressed or uncompressed data. Upon determining that the received packetized data comprises compressed data, the communicaiton device determines (S340) whether connection information exceeds a highest-numbered decompression slot from a plurality of decompression slots on said Um interface. The communciation device sets up (S330) a local decompression slot, int he communicaiton device, which corresponds to the connection information in order to maintain said compressionsate, wherein the local decompression slot is set up in response to determining (S325) that the connection information exceeds the highest-numbered decompression slot. The communication device decompresses (S350) the compressed packetized data when it receives compressed packetized data containing said connection information.