Alimentation GSM Shield / Arduino UNO

Hi.

I never used Arduino before, but I got a new job on Arduino.
In a simple way, I need to use GPRS with my Arduino UNO. After a look on the products, the GSM Shield could provides GPRS so I decide to choose this one.
Before ordering all the material I just want to know if I will need an external alimentation for the GSM Shield ? And which kind ?

Thank you in advance.

Use an external AC/DC is very recommendable. 110/220v AC (depends on your country) to 5v DC.