help me to figure this out

Actually i am doing a project based on GPS AND GSM technologies for which i need a gsm module.
but i want to design the module myself instead of buying a readily available one in the market.
so is it possible.as i have no clue of how to design.........plzzzz can any one help me

Here's a datasheet for a suitable GSM modem chip that I'm currently using, you can easily build your own devices using it.