A method of processing data frames for transmission on a wireless access interface of a wireless communications system, the method comprising receiving a first data frame comprising a first protocol header, the first protocol header associated with a medium access control, MAC, frame format for data transmission within a local area network, LAN, applying header compression in accordance with a header compression context to the first data frame by compressing one or more protocol header fields of the first protocol header to form a first compressed data frame for transmission on the wireless access interface, transmitting the first compressed data frame on the wireless access interface, receiving a second data frame comprising a second protocol header associated with the MAC frame format, determining that none of the fields of the second protocol header are to be compressed in accordance with the header compression context before the second data frame is transmitted on the wireless access interface, transmitting the second data frame on the wireless access interface, establishing another header compression context based on the second data frame for compressing the one or more protocol header fields associated with the MAC frame format for one or more subsequent data frames, receiving a third data frame comprising a third protocol header associated with the MAC frame format, and applying the other header compression to the third data frame by compressing one or more protocol header fields of the second protocol header to form a third compressed data frame for transmission on a wireless access interface of the wireless communications network, the header compression being in accordance with the other header compression context, the method being characterized in that the determining that none of the fields of the second protocol header are to be compressed in accordance with the header compression context before the second data frame is transmitted comprises receiving within a receive window, a first number of feedback packets for every header that has been correctly decompressed by a peer decompressor, comparing the first number with a second number, the second number representing a number of frames transmitted during a corresponding transmit window, the headers of the frames having been compressed in accordance with the context, and determining that none of the fields of the second protocol header are to be compressed in accordance with the header compression context comprises determining that the first number is lower than the second number receiving a first data frame comprising a first protocol header, the first protocol header associated with a medium access control, MAC, frame format for data transmission within a local area network, LAN, applying header compression in accordance with a header compression context to the first data frame by compressing one or more protocol header fields of the first protocol header to form a first compressed data frame for transmission on the wireless access interface, transmitting the first compressed data frame on the wireless access interface, receiving a second data frame comprising a second protocol header associated with the MAC frame format, determining that none of the fields of the second protocol header are to be compressed in accordance with the header compression context before the second data frame is transmitted on the wireless access interface, transmitting the second data frame on the wireless access interface, establishing another header compression context based on the second data frame for compressing the one or more protocol header fields associated with the MAC frame format for one or more subsequent data frames, receiving a third data frame comprising a third protocol header associated with the MAC frame format, and applying the other header compression to the third data frame by compressing one or more protocol header fields of the second protocol header to form a third compressed data frame for transmission on a wireless access interface of the wireless communications network, the header compression being in accordance with the other header compression context, the method being characterized in that the determining that none of the fields of the second protocol header are to be compressed in accordance with the header compression context before the second data frame is transmitted comprises receiving within a receive window, a first number of feedback packets for every header that has been correctly decompressed by a peer decompressor, comparing the first number with a second number, the second number representing a number of frames transmitted during a corresponding transmit window, the headers of the frames having been compressed in accordance with the context, and determining that none of the fields of the second protocol header are to be compressed in accordance with the header compression context comprises determining that the first number is lower than the second number