What is GPRS?
GPRS (General Packet Radio Service) is a service within the GSM network, just like the two most popular services SMS and voice connections. GPRS is used for transmitting data in the GSM network in from of packets. The connection to the remote station is not reserved and left open during the entire connect time, but is occupied only at the time of actual data transmission.
8 time slots and 4 coding schemes (CS) with different data transmission rates are available CS1 with 9,05 kbit/s, CS2 with 13,4 kbit/s, CS3 with 15,6 kbit/s, CS4 with 21,4 kbit/s.
This results a theoretical total data rate of 171,2 kbit/s when bundling all eight time slots with coding scheme 4. The effort for the error correction will be reduced with this and longer data blocks are transmitted. The adjustment of the transmission speed is made dynamically depending on the HF transmission characteristics by switching between the coding schemes. Average data rates of 58, which are bases on four time slots, can be expected in practice.