Читать книгу Networking All-in-One For Dummies - Lowe Doug, Doug Lowe - Страница 46

As I mention in Chapter 1 of this minibook, a wireless network is a network in which radio signals are used to connect devices to the network rather than physical cables. You learn much more about wireless networks in Book 2, Chapter 1, as well as Book 4, Chapter 2. But for now, I want you to keep the following points in mind:

 Just like a wired network, a device connecting to a wireless network does so via a network interface. A wireless interface, also known as a wireless adapter, includes a radio transmitter and receiver rather than a physical cable connection.

 Every wireless network adapter has a MAC address.

 Rather than a switch or a hub, wireless devices connect to a wireless access point (WAP).

 Collisions are possible (likely, actually) on a WAP, just as they are on a hub. Unfortunately, there is no equivalent to a wireless switch that reduces the collision problem. WAPs are essentially hubs in that every device that connects to the access point is competing for the same bandwidth. Whenever the WAP sends a packet, all devices connected to the access point must inspect the packet to determine the MAC address destination. And if two devices try to send packets at the same time, a collision will occur. This is one of the inherent reasons that wireless networking is slower than wired networking.