= network interface card. Can be wireless (like your laptop has) or wired (traditional card that uses cables and ends that look like large telephone connectors).
I have zero recent first-hand experience with wireless networking so there may be products I'm not aware of. Not many others on here who do much of it either. So for this you might want to try a forum that deals with lots of wireless issues. A google search for wireless networking forum
will give you quite a few choices.
But in general, you are going to have to buy some additional equipment. How much stuff and how much money depends on the approach you decide on. At the very least, there will have to be some way for the desktop system to send and receive with the wireless laptop.
By far the simplest and least expensive would be a wired card in both desktop and laptop. Then all you'd need is a piece of ethernet cable that was wired "crossover" where the send and receive wires were reversed at either end. For a very valid (but obscure) electronic reason, you connect like devices (nic
, hub-hub/switch) using a crossover cable and unlike devices (nic
-hub) using a straight wired cable.
From the research I did before replying here, I can't find any mention of a way to make a wireless NIC
do crossover. There may be a way but I couldn't find mention of it. And even if it's possible, you still need some device to plug into the desktop that can talk to the wireless, translate, and talk to the desktop.
My guess is you will need a switch to handle traffic between the two PCs and a wireless access point connected to the switch to talk to the laptop. In that case, probably about as cheap to get a router/switch that does wireless. I know you said you didn't want a residential gateway but unless you are willing to put a wired NIC
in the laptop, I'm not sure you can avoid a switch (or a hub - yuck) and at that point, you are spending nearly as much for switch & access point as you would for a gateway device.
So in answer to your question to Train about the point of having a cable between the two devices, simplicity and low cost.