No, the WiFi card sends a connection request to the wireless access point, the wireless access point then sends this preamble before every packet of data so that the WiFi clients know which data info is for them. The preamble byte is like a little robot before the data the shoves the data along to the correct device. It happens seamlessly, and it happens on EVERY kind of data connection, from Wired LANs, to 56k modems. Here's the data train:
P[DATA] *chugga, chugga ... wooo, wooooo*
P is the preamble moving the Data which is a webpage or a file, anything, to the correct device.
But I have that exact same card built into my Dell laptop. It's a good card, great range. I'd recommend it, ESPECIALLY at that price!