SIMCom presents a  compact and reliable wireless module-SIM900B which is compatible with the module-SIM300/340 and SIM340E.This is a complete  Quad-band GSM/GPRS module is a B2B type and designed with a very powerful single-chip processor integrating AMR926EJ-S CORE, allowing you to benefit from small dimensions and cost-effective solutions.
 
Featuring an industry-standard interface, the SIM900 delivers GSM/GPRS 850/900/1800/1900MHz performance for voice, SMS, Data, and Fax in a small form factor and with low power consumption. With a tiny configuration of 24mm x 24mm x 3 mm, SIM900 can fit almost all the space requirements in your M2M application, especially for slim and compact demand
of design.
 
 
General features
Quad-Band 850/ 900/ 1800/ 1900 MHz
GPRS multi-slot class 10/8
GPRS mobile station class B
Compliant to GSM phase 2/2+
  – Class 4 (2 W @850/ 900 MHz)
  – Class 1 (1 W @ 1800/1900MHz)
Dimensions: 40* 33* 3 mm
Weight: 7g
Control via AT commands (GSM 07.07 ,07.05 and  
  SIMCOM enhanced AT Commands)
SIM application toolkit
Supply voltage range 3.4 ... 4.5 V
Low power consumption
Normal Operation temperature: -30 °C to +80 °C
 
Specifications for Fax
Group 3, class 1
 
Specifications for Data
GPRS class 10: max. 85.6 kbps (downlink)
PBCCH support
Coding schemes CS 1, 2, 3, 4
CSD up to 14.4 kbps
USSD
Non transparent mode
PPP-stack
 
Specifications for SMS via GSM/GPRS
 Point to point MO and MT
SMS cell broadcast
Text and PDU mode 
 
Software features
0710 MUX protocol
FTP/HTTP(available at July.2010)
Specifications for Voice
Tricodec
– Half rate (HR)
– Full rate (FR)
– Enhanced Full rate (EFR)
Hands-free operation
(Echo suppression)
 
Interface
60 PIN Board-to-hoard connector
Interface to external SIM 3V/ 1.8V
Two analog audio interface
RTC backup
SPI interface
Serial interface
Embedded SIM(option)
Embedded SIM Holder (option)
GPIO
PWM 
ADC
Antenna connector