From what I've seen, it seems that you are trying to use a mobile card (hspa/gprs) as a wireless 802.11 device. This won't obviously work, that kind of card is supposed to run with a SIM card and connect to mobile phone networks, not wireless AP's/hotspots. Here's an excerpt from their site:
Sierra Wireless’s newly unveiled HSUPA-capable product line includes the AirCard® 881 Data Card. This card offers tri-band UMTS/HSPA and quad-band GPRS/EDGE for global connectivity and worldwide roaming.