Nearly all of the wireless-N adapters on the market today connect through the USB port of your computer. Small and easy to install, most basic adapters are less than $50, as of November 2012. Dual-band adapters can be twenty to thirty percent more, but are capable of faster speeds if they are used with compatible Wi-Fi access points. If you are looking for an adapter to be used at your home or office, look at the manufacturer name on your Wi-Fi access point before purchasing an adapter, as faster speeds may only be available when both are made by the same company.
While wireless-N adapters are capable of speeds up to 300 Mbps, this is dependant on other factors. Distance from the wireless access point, how much other traffic is on the network and your Internet connection speeds can dramatically affect speed. More powerful dual-band adapters are capable of greater speeds because they include additional antennas. For example, the Belkin N750 DB Wireless Dual-Band USB Adapter can get speeds of up to 450 Mbps if it's used with a compatible router.
Size should rarely be a factor with a basic adapter. Although sizes vary, they are usually less than 2 inches long and a half-inch wide. Some models, like the Netgear Micro Adapter is less than a half-inch long. Adapters with multiple antennas can be up to 4 inches long, but bend at a 90-degree angle half-way and can usually swivel to pick up the best signal. At times, more length is beneficial. The Netgear Wireless N 300 USB adapter is on the end of a USB cable and comes with a small cradle, allowing you to reposition it out of the way as needed to get the best signal possible.
Backward compatibility with older Wi-Fi access points, like 802.11g and 802.11b, is a standard feature on nearly all USB adapters. As well, emerging Wi-Fi access points, including home Wi-Fi routers should all be backward compatible with 802.11n adapters. If you have a choice of more than one network to connect to, like at your office or a coffee shop, it's always best to use 802.11n Wi-Fi. Connecting to an 802.11g access point will limit you to 54 Mbps. Even slower is 802.11b, which has a maximum speed of 11 Mbps.
As with backward network compatibility, most USB access points support WEP, WPA and WPA2 security protocols. However, a feature that is not on every access point is Wi-Fi Protected Setup that can be turned on or off with the push of a small button on the adapter. When a WPS adapter is used with a WPS-enabled access point, pushing the button connects it automatically to your network without having to search through any other nearby networks.
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