Wireless Network Cards
As we mentioned, you will need to buy one wireless network card for each computer that you want to connect to your wireless network. Wireless network cards are compatible with at least one IEEE 802.11 protocol. There are several protocols and the most common are IEEE 802.11b, 802.11g, 802.11a and 802.11n. From now one we will refer to these protocols simply as b, g, a and n, respectively. The main difference between them is speed: b can transfer data up to 11 Mbps, while g and a can transfer data up to 54 Mbps (the difference between g and a is the frequency of the spectrum that they operate). IEEE 802.11n allows several different speeds starting from 65 Mbps and going all the way up to 600 Mbps. The actual speed depends on the number of antennas, the frequency from the spectrum used and the channel size. The most common speeds for this standard are 130 Mbps, 150 Mbps, 270 Mbps and 300 Mbps, and both the router and the wireless cards must be compatible with the intended speed.
Some network cards are rated as 108 Mbps, but they are in fact 54 Mbps cards using data compression technique and in order for them to achieve this speed your broadband router and the card installed on the computer must have this technology and must be from the same manufacturer, otherwise they will work as a regular b, g or a card. This technology doesn’t work on ad-hoc networks, i.e., networks not using a broadband router.
In theory the best scenario is to have all your computers using 54 Mbps or faster cards. However, you are limited by the speed of your Internet connection. So if you don’t use your network for transferring files between the computers, buying 54 Mbps cards doesn’t make sense, simply because the speed of your Internet connection will be far lower. For example, if you have a 1 Mbps connection, you will have a network capable of transferring data 54 times faster than your Internet connection. An 11 Mbps network will work just fine for you (and it will still be 11 times faster than your Internet connection). So you can save some bucks buying 11 Mbps cards – they will work just fine for the average user. Also, ad-hoc networks are not capable of transferring data above 11 Mbps, so using 54 Mbps cards on this type of network is simply a waste of money. If you really want to have 54 Mbps (or faster) capability, you will need to build your wireless network using a router.
Just to clarify, if you have a 1 Mbps or even a 2 Mbps Internet connection, you will still navigate at this speed using 11 Mbps or 54 Mbps wireless cards.
If even with our tip you decided to buy a 54 Mbps or faster wireless card, make sure to buy one that is compatible with 802.11b standard, so you can build your wireless network without using a router, since ad-hoc networks only work at 11 Mbps. It is also interesting that you buy all cards using the same 54 Mbps standard (a or g), so if in the future you decide to upgrade your network by installing a wireless router all cards will be capable of transferring data at 54 Mbps.
There are two types wireless network cards available: USB and add-on. Usually add-on cards are more stable. Add-on cards for desktops are provided for the PCI slot (and probably for the PCI Express x1 slot in the future) and add-on cards for laptops are provided for the PC Card (a.k.a. PCMCIA) slot or for the Express Card slot. If your laptop does not have an embedded wireless card, you will need to check whether it has an expansion slot (PC Card or Express Card) and buy one add-on network wireless for it (PC Card will probably be the choice, as Express Card slots also accept PC Card devices).
In Figure 1, you can see a PCI add-on wireless network card for desktops, in Figure 2 a USB wireless network card, which can be used by desktops and laptops, and in Figure 3 a PC Card add-on wireless network card for laptops.
The installation of the card should be done following the card manual. Usually it is very simple step: just connect the device to your computer (if you are installing a PCI card on a desktop computer, you will need to turn it off and open its case), turn it on and install its drivers.
Just a tip, with our PCI card portrayed in Figure 1 (a D-Link DWL-G510) we needed to install the drivers before installing the card to the PC.
Install the wireless network card to the computers that will be connected to your wireless network. The next step is configuring the host computer, i.e., the computer that has the broadband Internet connection. If you are sharing your Internet connection using a regular broadband router (i.e., without wireless capability) any computer connected to the router can be configured as host. In this case just remember what we’ve said earlier: you will need to change the IP address range of your network if it is configured to use the 192.168.0.x range to 192.168.1.x because the Windows Internet sharing service also uses the 192.168.0.x range and you will have conflicting IP addresses on your network. This configuration is done by entering the router’s setup program (usually by opening http://192.168.0.1 from any computer connected to it).