SIM900 Hardware Design
(1) The SIM900 does work, but deviations from the GSM specification may occur.
Table
4: Coding schemes and maximum net data rates over air interface
Coding scheme 1 Timeslot 2 Timeslot 4 Timeslot
CS-1: 9.05kbps 18.1kbps 36.2kbps
CS-2: 13.4kbps 26.8kbps 53.6kbps
CS-3: 15.6kbps 31.2kbps 62.4kbps
CS-4: 21.4kbps 42.8kbps 85.6kbps
2.2 SIM900 Functional Diagram
The following figure shows a functional diagram of the SIM900 and illustrates the mainly functional part:
z The GSM baseband engine
z Flash and SRAM
z The GSM radio frequency part
z The antenna interface
z The Other interfaces
Figure 1: SIM900 functional diagram
SIM900_HD_V1.05 06.23.2010
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