The term Coding Scheme (CS) is used in General Packet Radio Service (GPRS), Enhanced Data Service for GSM Evolution (EDGE) and Enhanced General Packet Radio Service (EGPRS) and is directly related to the selected transmission quality. This in turn depends on the network quality, error correction
, packet identification, etc. With GPRS, there are four coding schemes (CS) with which the data transmission rate can be increased, although the transmission quality is directly affected
.kbit/s (CS1), 13.4 kbit/s (CS2), 15.6 kbit/s (CS3) and 21.4 kbit/s for CS4. The error correction (CRC) of CS1, with 40 check bits, is better than that of the other three coding schemes, which use 16 check bits.