The wireless network adapter you use to connect a PC to your wireless network transmits data by radio waves. But unlike an FM radio transmitter, your wireless networking equipment sends a signal that can only be picked up for about 300 feet if there are no obstructions (and this kind of performance is usually achieved outside only). As with wired networking technology, such as Ethernet, data is transmitted over a wireless network in pieces, called data packets. Each network adapter has its own unique serial number, called a MAC (media access control) address. You can see the MAC address of your wireless network adapter, as it's usually printed on the underside of the adapter. The data packet contains the data being sent as well as the address of the sender and recipient. Wi-Fi (802.11b) wireless networks, as well as 802.11g equipment, communicate over the unlicensed 2.4-GHz radio band. They share the band with other home electronics, including cordless phones and microwaves . Wi-Fi5 (or 802.11a) wireless networks use the less crowded 5GHz band, and therefore are less affected by home electronics. While operating at up to five times faster than Wi-Fi (802.11b) equipment, the hardware looks just the same (Figure 2.6). Figure 2.6. An 802.11a wireless network adapter for a laptop.
Until newer technologies such as Bluetooth (see sidebar) become more prevalent , wireless networking will mean setting up a Wi-Fi system in most home applications.
Wireless network adapters can communicate directly with each other. Each network adapter acts as a transmitter and receiver, and data is broadcast in a cell. As the cells interlock, the network's range expands. A wireless network in which the network adapters communicate directly with each other is called a peer-to-peer network, or is said to be working in ad-hoc mode. Wireless networks can also work in infrastructure mode, which requires the use of a hardware device that communicates with each network adapter, called an access point (Figure 2.7). Figure 2.7. A simple wireless network.
Once your wireless networking equipment is set up, you can share data and peripherals just as you would over a wired network. |