You need a WWAN card that's compatible with your service provider's network - - the card requires the driver. The SIM card by itself is not functional - you need the WWAN card to make the connection to your provider network.
Not unless you ordered the system with a WWAN card - and even if you did, chances are that any card that dates from when this system was new (probably somewhere between 7-8 years ago) would likely need to be replaced to work with a wireless PCS data network at this point.
WWAN cards were/are not standard - they are optional in some markets at purchase. I don't think Dell even offers the cards in the US market at this time, since the data providers generally supply their own hardware for their networks when you sign a data contract with Verizon, AT&T, etc.
thanks again, actually i bought my laptop from second hand shop in UK for that i am asking 🙂
and i have a new one (laptop) with more resources but i like work on E5400 yes its old now but still super:) and better than my new for me :0, and i read that WWAN it support until HSPA not 4G/LTE
i have wireless PCS but come too hot after half an hour 😞