Wireless Networking and the Internet

How can I use a wireless network to share an Internet connection?
Once you realise that wireless cards are analogous to ethernet cards and that empty space is analogous to ethernet cabling, the answer to this question becomes clear. To share an Internet connection across a LAN you need two things:

1. an Internet sharing hardware device or software program
   
2. a LAN

If your LAN is wireless, the same criteria apply. You need a hardware or software access point and a wireless LAN. Any computer equipped with a wireless network card running suitable Internet sharing software can be used as a software access point. (See Figure 8) A number of vendors offer hardware access points.

A hardware access point may provide Internet Sharing capabilities to Wired LAN computers, but does not usually provide much flexibility beyond very simple configurations. (See Figure 9)

Figure 8: Software Access Point.
Wireless connected computers using a Software Access Point for shared Internet access.

Figure 9: Hardware Access Point.
Wireless connected computers using a Hardware Access Point for shared Internet access.

If I have more than one hardware access point, how can I share a single Internet connection?
If an existing wired LAN already has an Internet connection, then the hardware access points simply connect to your LAN and allow wireless computers to access the existing Internet connection in the same way as wired LAN computers.

Figure 10: Multiple Access Points.
Wireless connected computers using Multiple Access Points.

If there is no existing Internet connection, then this depends on the access point:

Figure 11: Software Access Point sharing one Internet connection.
Wireless connected computers using Multiple Access Points. All wired and wireless computers access the Internet through a single software access point.

If an access point provides some form of Internet sharing itself, then having multiple such access points connected to a wired LAN may require some special configuration, or possibly may require an additional Internet sharing device or software program.

If I use a wireless network to connect to the Internet does my ISP need a wireless network too?
If you use a wireless network to connect to the Internet, the wireless part only concerns your LAN. The communications link from your LAN to your Internet service provider (ISP) would be identical whether or not you had a wireless network. For example, if you connected an ethernet network to the Internet via a 56K modem, when you upgraded your network to use wireless, you would still use the same 56K modem to connect to the Internet.

Can networking software identify a wireless computer in the same way it can identify an ethernet computer on the network?
Wireless cards look just like ethernet cards to your network drivers. In fact, wireless networking cards have unique MAC hardware addresses that are formatted like ethernet hardware addresses allocated from the same standards organization.