If you read the infos about A6/A6C/A7 in this pdf: http://wiki.ai-thinker.com/lib/exe/fetch.php/modules/datasheet/a6/ai-thinker_a6_a7_a6c_at_v1.02.pdf you can notice in the title there is also the A20 but i found nothing about this module in internet it’s because they actualy work on it, we can find the information here : http://wiki.ai-thinker.com/lib/exe/fetch.php/modules/datasheet/a6/a6_a6c_a7_datasheet.pdf
So the A20 will combine WIFI/GPRS/GSM/CAMERA, they are the same poeple who made the ESP8266 so maybe they will use this chip for the A20.
There is nothing in the datasheet about the wifi so idk why exacly they added the A20 name, and for the second page they said in chinese “to be updated” and “See full functional test board reference schematics”.
EDIT: I found in a doc here: https://drive.google.com/drive/folders/0B6uNNXJ2z4CxZjZXdy10endmZXM more info about the A20, they will use the 8285 chip for the wifi!
Here is the pin description:
So maybe thx to this chip it will be easiest to find a solution for program the A20 with the Arduino environment… I hope.
The google Drive link come from here: http://www.dx.com/p/gprs-a7-serial-gprs-gps-module-core-developemnt-board-for-arduino-445823#.V9HzFpiLSUk