Before the introduction of wireless network technology, accessing the Internet required connecting some sort of cable from your computer to a modem or router. Modern Wi-Fi adapters, though, enable you to connect to high-speed broadband networks from your home or at many hotspots on the road. Wi-Fi technology transmits data between computers and other Internet-capable devices using radio-wave signals rather than cables. Several types of wireless network adapters exist for desktop and laptop computers. Choosing the wireless adapter that best suits your needs depends on several factors such as the type of computer you have, where you usually connect to the Internet and your own privacy and security concerns.
In 1997, the Institute of Electrical and Electronics Engineers released the original IEEE 802.11-1997 standard for wireless networks, which never saw implementation. In 1999, IEEE released the 802.11b standard, which was the first wireless protocol to see widespread acceptance and use. Equipment using the 802.11b protocol transmits data up to 11Mbps over the unregulated 2.4GHz band -- the same one used by most cordless telephone. 802.11b was actually the second revision of the original 802.11-1997 wireless standard. Engineers at the IEEE began working on 802.11a a few months before starting on 802.11b, but did not release it until a few months later than the second revision. 802.11a supports wireless bandwidths up 54Mbps over the 5GHz spectrum, which results in much faster data transmissions. However, 802.11a never saw major support from consumers and manufacturers because of its limited range when compared to 802.11b. Because 802.11a and 802.11b use different frequency spectrums, they are not compatible with each other. In late 2002, 802.11g adapters and routers began to appear on the market. 802.11g combines the 54Mbps transmission rate of 802.11a and the 2.4GHz band spectrum of 802.11b to create a protocol that provides increased speed, range and penetration through walls and obstacles. 802.11g equipment is backwards compatible with 802.11b equipment and transmits and receives data at the slower 11Mbs rate if needed.
IEEE released the latest official wireless standard, 802.11n, in 2009 and the protocol is backward compatible with 802.11b/g network equipment. Most modern wireless networking gear supports 802.11n, which provides transmission rates of over 100Mbps on both the 2.4GHz and 5GHz frequency bands. The IEEE 802.11ac standard is emerging as of 2012; most experts expect ratification in 2013. There are already routers and network adapters available that support the potential 1Gbps throughput over the 5GHz band that the new standard promises. If the expected standard for 802.11ac changes before final ratification, equipment sold today may or may not be compatible.
Ease of Installation
Depending on whether you want to connect a desktop or laptop computer to a Wi-Fi network, you may have couple of options for installing a wireless network adapter. If you own a laptop computer, your only real option is to use an adapter or dongle that connects to an empty USB port on the machine. If you have a desktop computer, you can choose to install an internal PCI wireless card inside the computer or connect a USB wireless adapter. USB adapters and dongles are much easier to install and use because installing an internal PCI wireless adapter requires that you open the computer case and plug the card into the motherboard. Installing an internal PCI wireless card is not difficult, but don't attempt it if you are uncomfortable working with electrostatic sensitive components inside your computer. Opening the case of your computer could void the manufacturer warranty -- so check your warranty documentation first. There is an upside to an internal wireless adapter, though: PC wireless cards generally have much greater signal range than plugin USB adapters or dongles.
If you anticipate having to use your computer far away from a network router or access point, consider the range of the adapter. When connecting to a router less than 10 meters away from your computer, the type of adapter you use doesn’t really matter. At short distances, USB adapters or dongles should perform as well as internal PCI wireless cards. However, as you move away from an wireless access pointer or router, the type of antenna -- and the signal strength it provides -- plays a major role in how well the adapter performs and how fast it can transmit data. Thus, internal PIC wireless cards have an advantage over most USB adapters because they have external antennas, though a few USB adapters do ship with small antennas. Nevertheless, even the antennas attached to PCI cards can provide varying levels of wireless signal strength. Cards with two or three antennas usually perform better than do ones with a single antenna when placed far away from the access point or router. Likewise, cards with positional antennas -- ones you can move or adjust -- generally perform better than models with fixed-position antennas.
Your Primary Network
While several factors will play into your decision on the type of wireless adapter you buy, your primary concern should be purchasing one that is compatible with the Wi-Fi network you use most. Therefore, if your school or workplace uses an older 802.11a router, you won't be able to use newer adapters that support 802.11b/g/n protocols. If you are purchasing an add-on adapter to add to an older notebook, choosing an 802.11n dongle or corded adapter should serve you well in most hotspots at airports, coffee shops, hotels and other public Wi-Fi zones. If you want to create a wireless network in your home and connect a desktop computer, you might want to consider purchasing a router and adapter that are both made by the same manufacturer, as this will usually simply setup and configuration. Companies such as Belkin and Linksys produce wireless adapters and routers designed to work with each other and require only minimal setup or configuration.
- NPR: The Zombie Network - Beware 'Free Public WiFi'
- University of Pittsburgh Information Technology: Wireless Network Standard
- PCWorld: The Desktop Wireless Adapter Difference USB vs. PCI
- University of Virginia Information Technology Services: Recommended Wireless Adapters
- Intellinet Knowledge Base: How Do I Choose the Right Network Adapter?
- Microsoft at Home: 10 Tips to Help Improve Your Wireless Network
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