Packet Binary Convolution Coding (PBCC) is an optional modulation method recommended in WLANs according to 802.11g. This method is used in combination with Complementary Code Keying( CCK), where CCK is used for the header and PBCC for the payload data.
This measure provides higher data rates and backward compatibility with existing WiFi systems. The PBCC method uses a packet-based convolutional code, unlike CCK, which uses four-bit combinations. This is a mathematical twisting, contorting or convolution of signals, to form a code, based on eight phase shift keying( PSK-8).
A transmission rate of 44 Mbit/s is specified for this method in 802.11b.