I have Thinkpad T410 2537-BU1 and from lenovo support it is stated "WWAN upgradeable" .
I've already opened the laptop and there's no WWAN card so my newbie questions are:
Does the antenna already exist within the laptop and I only need to buy a WWAN card? If so are all these cards compatible (Ericsson F3507g, Ericsson F3607gw,HUAWEI EM660) and I can buy anyone of the them plugin and get drivers and that's all?
If no, then how can I upgrade the laptop for WWAN?
WWAN upgradeable means that the machine was built / shipped with the corresponding WWAN antenna and simcard reader. Proof for that should lie in the fact that in the spot where the WWAN card needs to be fitted, two wires (blue and red) are available to connect to the card. Their connectors are fitted with rubber caps to prevent a short-circuit when not in use.
You can only use original Lenovo WWAN cards. For WWAN cards the Lenovo BIOS contains a whitelist that limits the number of cards you can use.
To find out which card you need you can check the following link: