Add Wireless Support to Internet Sharing
You can add wireless capabilities to your shared Internet party. Basically, you can encounter a couple of situations when trying to add wireless capabilities into the mix. Either you already have an Internet connection-sharing mechanism in place (either hardware or software), or you don’t yet have your Internet connection shared.
If you already have a cable/DSL router or are using software Internet sharing
If you already have a cable/DSL router or if you’re using software Internet sharing, like that built into Lion, you can simply buy a WAP (short for Wireless Access Point) and connect it to your LAN. Adding a WAP enables anyone using wireless Ethernet access to your network and thus to your shared Internet connection.
You can buy many WAPs to add wireless to your network. AirPort Extreme is a good example; however, because AirPort Extreme also can do Internet sharing, make sure that you don’t enable Internet sharing through software on your MacBook! (In this case, you don’t want or need this feature because it can conflict with your cable/DSL router operation.)
If you do not have a cable/DSL router or an AirPort Extreme Base Station
If you don’t have a cable/DSL router or an AirPort Extreme Base Station or Time Capsule for Internet sharing, you have a few options. Each option has an upside and a downside.
One option is to get either an AirPort Extreme Base Station or a Time Capsule. Both of these devices provide wireless access (for computers with Wi-Fi hardware) and Internet sharing for the entire network!
Because both the AirPort Extreme Base Station and the Time Capsule device also feature three built-in Ethernet ports for wired connections, you won’t need an additional switch to connect up to three Macs (or PCs, or printers, or even network file servers) using Ethernet cables.
The other option is to buy a combination cable/DSL router, which has a built-in WAP. Most cable/DSL routers — including the ones that have wireless built in — also have multiple Ethernet ports on them, so connecting computers by using wired Ethernet can be done without buying an external switch.
The final option is that you can use the AirPort software built into Lion to turn your MacBook into an Airport/AirPort Extreme Base Station. This is a great, low-cost way to add wireless and Internet sharing to your network, but remember that the software will still eat up processor time and memory, and your MacBook must remain turned on to supply the connection to your network.