Useful Link: SIM800H_Hardware_Design_V1.01,SIM800 Series_AT Command Manual_V1.01.

Datasheet:SIM800H.

General features
•Quad-band 850/900/1800/1900MHz
•GPRS multi-slot class 12/10
•GPRS mobile station class B
•Compliant to GSM phase 2/2+
    – Class 4 (2 W @ 850/900MHz)
    – Class 1 (1 W @ 1800/1900MHz)
•Bluetooth: compliant with 3.0+EDR
•FM: 76~109MHz worldwide bands with 50KHz tuning step
•Dimensions: 15.8*17.8*2.4mm
•Weight: 1.35g
•Control via AT commands (3GPP TS 27.007, 27.005 and SIMCOM enhanced AT Commands)
•Supply voltage range 3.4 ~ 4.4V
•Low power consumption
•Operation temperature:-40℃ ~85℃

Specifications for GPRS Data 
•GPRS class 12: max. 85.6 kbps (downlink/uplink)
•PBCCH support
•Coding schemes CS 1, 2, 3, 4
•PPP-stack
•CSD up to 14.4 kbps
•USSD
•Non transparent mode

Specifications for SMS via GSM/GPRS
•Point to point MO and MT
•SMS cell broadcast
•Text and PDU mode

 Software features
•0710 MUX protocol
•Embedded TCP/UDP protocol 
•FTP/HTTP
•MMS
•E-MAIL
•DTMF
•Jamming  Detection
•Audio Record
•TTS
•Embedded AT (optional)

Specifications for voice
•Tricodec
     – Half rate (HR)
     – Full rate (FR)
     – Enhanced Full rate (EFR)
•AMR
     – Half rate (HR)
     –  Full rate (FR)
•Hands-free operation
   （Echo suppression）

Interfaces
•88 LGA pads including:
•Analog audio interface
•PCM interface
•RTC backup
•Serial interface
•USB interface
•Interface to external SIM 3V/1.8V
•Keypad interface
•GPIO
•ADC
•GSM Antenna pad
•FM Antenna pad
•Bluetooth Antenna pad

Compatibility
•AT cellular command interface

Certifications(Plan)
•CE
•GCF
•FCC
•ROHS
•REACH