How to Set Up an Ad Hoc Wireless Network
Using an Ad Hoc network — also called a computer-to-computer network — is a fairly easy thing to accomplish in Mac OS X. Plus, you’re not limited to just Macs: With an Ad Hoc network, you can also swap niceties with PCs and PDAs that have 802.11b/g/n network interface cards (NICs) installed.
This Ad Hoc network is great for setting up an impromptu network in a classroom, exchanging recipes and pictures at a family reunion in a park, or blowing your friend up while gaming across the aisle of a Greyhound bus at 70 mph.
To set up an Ad Hoc network, you first have to create the computer-to-computer network on one of your Macs. This takes advantage of the AirPort Software Base Station that’s built into Lion.
To create a computer-to-computer network, follow these steps:
Click the Wi-Fi status icon on the menu bar.
If you haven’t set Lion to display your Wi-Fi status in the Finder menu bar, follow these steps:
Open the Network pane in System Preferences and choose the Wi-Fi entry in the list at the left of the pane.
Select the Show Wi-Fi Status in Menu Bar check box.
Close the System Preferences window to save your changes.
Click Create Network to display the dialog that you see here.
Enter a name for your network.
Click the Security pop-up menu and choose 128-bit WEP to turn on WEP encryption.
Enter a password for your network and then enter it again to confirm it.
Although you can leave encryption disabled, turn it on and choose a password for that extra bit of security. Note that the password must be an exact length (which is determined by whether you choose a 40-bit [5-character] key or a 128-bit [13-character] key).
In general, channels 1, 6, and 11 are the only ones that don’t overlap other channels — and are therefore the best choices to use. If you’re close to other wireless access points (including Time Capsule devices, AirPort Base Stations, or other Ad Hoc networks), try to find a channel that’s not being used, or performance can be degraded.
(If you have only one access point, it doesn’t matter which channel you select — just allow Lion to automatically select a channel, which is typically Channel 11.)
Creating a computer-to-computer network gives the illusion of having an AirPort Base Station. So for people to join your network, they would follow the same steps as those they would use to join any other AirPort network.