In documentation for using VLANS with Cisco Aironet Wireless Equipment it states that it is a misuse of the Infrastructure setting when you are only using wireless laptop cards. We are using both laptop cards and Workgroup bridges on the same ssid/vlan. Should I seperate them to get better performance, and make the SSID for the workgroup bridges the infrastructure SSID? What performance problems occur when you have the infrastructure SSID set and are only using laptop cards?
The difference between Ad Hoc and Infrastructure mode is that Ad Hoc is just what the name says, any client can be the root and control the network. All users in an Ad Hoc network must be able to communicate with all other users ( or 100% coverage). If two users boot up at the same time, they both can become root and will not be able to communicate with each other as there can be only one root per Ad Hoc network, the only way to change this is to reboot the clients. There is no control in the network, the cards make their own decision which role they will play in the network. Ad Hoc networks are mainly for temporary communication between two or three devices that need so share information without a central network (file sharing between users at a meeting for example). Ad Hoc is not supported for more than five users. Infrastructure on the other had is just the opposite. Everything on the network is controlled by the access point. It is always root. It manages associations and traffic and ensures that all clients are able to communicate with the network.
The question was not about the differences between ad-hoc (Independent BSS) and Infrastructure BSS. I would suggest using the infrastructure-client setting for the radio interface to allow reliable broadcast/multicast to the workgroup bridge. Adding a second SSID set to infrastructure-ssid and keeping the laptops on a separate SSID is recommended.