It's important to note that Asus media bridge mode will use all of the radio's antennae to bridge to the main router. So if it has a 3x3 or 4x4 radio, it'll use all of them to connect to the main router, giving a more stable and higher bandwidth connection. For this reason Asus media bridge mode does not transmit an ssid's or act as a repeater. They have a repeater mode for this instead, which uses some of the radio's to act as a wifi access point and some to connect to the main router. This cuts down on the stability and bandwidth of the connection to the main router. It's a compromised mode.
Other routers have a repeater mode, but you have to be careful to find one with bridge mode.
Some linksys routers have a wireless bridge...