GSM/GPRS Module Series
M85 Hardware Design
M85_Hardware_Design Confidential / Released 87 / 88
9
Appendix B GPRS Coding Scheme
Four coding schemes are used in GPRS protocol. The differences between them are shown in the
following table.
Table 38: Description of Different Coding Schemes
Scheme
Code
Rate
USF
Pre-coded
USF
Radio
Block
excl.USF
and BCS
BCS
Tail
Coded
Bits
Punctured
Bits
Data
Rate
Kb/s
CS-1
1/2
3
3
181
40
4
456
0
9.05
CS-2
2/3
3
6
268
16
4
588
132
13.4
CS-3
3/4
3
6
312
16
4
676
220
15.6
CS-4
1
3
12
428
16
-
456
-
21.4
Radio block structure of CS-1, CS-2 and CS-3 is shown as the figure below.
Figure 56: Radio Block Structure of CS-1, CS-2 and CS-3
Rate 1/2 convolutional coding
Puncturing
456 bits
USF
BCS
Radio Block
