Hardware Guide

6 Appendix
Copyright © Fibocom Wireless Inc. 64
6 Appendix
6.1 GPRS and EGPRS Encoding Scheme
Table 45. GPRS encoding scheme
Encoding Method
CS-1
CS-2
CS-3
CS-4
Rate
1/2
2/3
3/4
1
USF
3
3
3
3
Pre-coded USF
3
6
6
12
Radio Block excl.USF and BCS
181
268
312
428
BCS
40
16
16
16
Tail
4
4
4
- -
Coded Bits
456
588
676
456
Punctured Bits
0
132
220
- -
Data Rate Kb/s
9.05
13.4
15.6
21.4
The GPRS standard stipulates 29 types of GPRS multi-slot modes for mobile stations. The
multi-slot class defines the maximum uplink and downlink rates. The expression is 3+1 or
2+2. The first number indicates the number of downlink timeslots, and the second
number indicates the number of uplink timeslots. Active timeslots indicate the total
number of timeslots that the GPRS device can use for both uplink and downlink
communication.
Table 46. Multislot allocation of different classes
Multislot Class
Downlink Slots
Uplink Slots
Active Slots
1
1
1
2
2
2
1
3