Unable to recognize the 3G Data Card

I am now using a 3G Data Card (brand name Huawei) but I used to access the internet using a cable connection through a router (Linksys WRT54G). The problem is my computer is unable to recognize the 3G Data Card and tells me I have no Ethernet connection. Please help me create my wireless network at home. I need to configure my computer or my router to recognize the 3G Data Card. Thanks.
