network adapter -
interfaces a computer to a network. The term "adapter" was popularized originally by Ethernet add-in cards for PCs.
Modern network adapter hardware exists in several forms. Besides traditional PCI Ethernet cards, some network adapters are PCMCIA devices (also know as "credit card" or "pc Card" adapters) or USB devices. Some wireless network adapter gear for laptop computers are integrated circuit chips pre-installed inside the computer.
Windows and other operating systems support both wired and wireless network adapters through a piece of software called a "device driver." Network drivers allow application software to communicate with the adapter hardware.
Wireless Routers -
The centerpiece product of many home computer networks is a wireless router. These routers support all home computers configured with wireless network adapters (see below). They also contain a network switch to allow some computers to be connected with Ethernet cables.
Wireless routers allow cable modem and DSL Internet connections to be shared. Additionally, many wireless router products include a built-in firewall that protects the home network from intruders.
Illustrated above is the Linksys WRT54G (compare prices). This is a popular wireless router product based on the 802.11g Wi-Fi network standard. Wireless routers are small box-like devices generally less than 12 inches (0.3 m) in length, with LED lights on the front and with connection ports on the sides or back. Some wireless routers like the WRT54G feature external antennas that protrude from the top of the device; others contain built-in antennas.
Wireless router products differ in the network protocols they support (802.11g, 802.11a, 802.11b or a combination), in the number of wired device connections they support, in the security options they support, and in many other smaller ways. Generally only one wireless router is required to network an entire household.
Wireless Access Points -
A wireless access point (sometimes called a WAP) serves to join or "bridge" wireless clients to a wired Ethernet network. Access points centralize all Wi-Fi clients on a local network in so-called "infrastructure" mode. An access point in turn may connect to another access point, or to a wired Ethernet router.
Wireless access points are commonly used in large office buildings to create one compare prices) shown above, wireless access points appear physically similar to wireless routers. Wireless routers actually contain a wireless access point as part of the overall package. Like wireless routers, access points are available with support for 802.11a, 802.11b, 802.11g or combinations.
Wireless Network Adapters -
A wireless network adapter allows a computing device to join a wireless LAN. Wireless network adapters contain a built-in radio transmitter and receiver. Each adapter supports one or more of the 802.11a, 802.11b, or 802.11g Wi-Fi standards.
Wireless network adapters also exist in several different form factors. Traditional PCI wireless adapters are add-in cards designed for installation inside a desktop computer having a PCI bus. USB wireless adapters connect to the external USB port of a computer. Finally, so-called pc Card or PCMCIA wireless adapters insert into a narrow open bay on a notebook computer.
Each type of wireless network adapter is small, generally less than 6 inches (0.15 m) long. Each provides equivalent wireless capability according to the Wi-Fi standard it supports.
Some notebook computers are now manufactured with bulit-in wireless networking. Small chips inside the computer provide the equivalent functions of a network adapter. These computers obviously do not require separate installation of a separate wireless network adapter.
Wireless Print Servers -
A wireless print server allows one or two printers to be conveniently shared across a Wi-Fi network. Wireless print servers for home networks generally are available in both 802.11b and 802.11g varieties.
Wireless print servers offer the following advantages:
- Allows printers to be conveniently located anywhere within wireless network range, not tied to the location of computers
- Does not require a computer be always turned on in order to print
- Does not require a computer to manage all print jobs, that can bog down its performance
- Allows administrators to change computer names and other settings without having to re-configure the network printing settings.
A wireless print server must be connected to printers by a network cable, normally USB 1.1 or USB 2.0. The print server itself can connect to a wireless router over Wi-Fi, or it can be joined using an Ethernet cable.
Most print server products include setup software on a CD-ROM that must be installed on one computer to complete the initial configuration of the device. As with network adapters, wireless print servers must be configured with the correct network name (SSID) and encryption settings. Additionally, a wireless print server requires client software be installed on each computer needing to use a printer.
Wireless Game Adapters -
A wireless game adapter connects a video game console to a Wi-Fi home network to enable Internet or head-to-head LAN gaming. Wireless game adapters for home networks are available in both 802.11b and 802.11g varieties. An example of an 802.11g wireless game adapter appears above, the Linksys WGA54G
Wireless game adapters can be connected either to a wireless router using an Ethernet cable (for best reliability and performance) or over Wi-Fi (for greater reach and convienence). Wireless game adapter products include setup software on a CD-ROM that must be installed on one computer to complete initial configuration of the device. As with generic network adapters, wireless game adapters must be configured with the correct network name (SSID) and encryption settings.
Wireless Internet Video Cameras -
A wireless Internet video camera allows video (and sometimes audio) data to be captured and transmitted across a Wi-Fi computer network. Wireless Internet video cameras are available in both 802.11b and 802.11g varieties.
Wireless Internet video cameras work by serving up data streams to any computer that connects to them. Cameras like the one above contain a built in Web server. Computers connect to the camera using either a standard Web browser or through a special client user interface provided on CD-ROM with the product. With proper security information, video streams from these cameras can also be viewed across the Internet from authorized computers.
Wi-Fi Internet video cameras can be connected to a wireless router using either an Ethernet cable or wirelessly. These products include setup software on a CD-ROM that must be installed on one computer to complete initial Wi-Fi configuration of the device.
Wireless Range Extender -
A wireless range extender increases the distance over which a WLAN signal can spread, overcoming obstacles and enhancing overall network signal quality. Several different forms of wireless range extenders are available. These products are sometimes called "range expanders" or "signal boosters." The Linksys WRE54G (compare prices) 802.11g Wireless Range Expander is shown above.
A wireless range extender works as a relay or network repeater, picking up and reflecting WiFi signals from a network's base router or access point. The network performance of devices connected through a range extender will generally be lower than if they were connected directly to the primary base station.
A wireless range extender connects wirelessly to a WiFi router or access point. However, due to the nature of this technology, most wireless range extenders work only with a limited set of other equipment. Check the manufacturer's specifications carefully for compatiblity information.
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