How to connect two wireless routers together wirelessly

Software (3rd party firmware)

You can use the following software / firemware to get the addition features which are not typically included in a manufacturer’s router firmware such as client mode wireless bridge. You can either setup a full WAP or just bridge your LAN so that wireless devices can get access to all LAN resources transparently.

1. DD-WRT : Linux-based alternative OpenSource firmware for wireless routers. It works for several routers, most notably the Linksys. It works great with variety of wireless routers and embedded systems. This is recommend for new users as it comes with easy to use web-gui.
2. Tomato : Another simple and easy to use replacement firmware for Linksys’ WRT54G/GL/GS, Buffalo WHR-G54S/WHR-HP-G54, Asus and other Broadcom-based routers. It features a new easy to use GUI, a new bandwidth usage monitor, more advanced QOS and access restrictions, enables new wireless features such as WDS and wireless client modes, raises the limits on maximum connections for P2P, allows you to run your custom scripts or telnet/ssh in and do all sorts of things like re-program the SES/AOSS button, adds wireless site survey to see your wifi neighbors, and more. This is recommend for new users as it comes with easy to use web-gui.
3. OpenWrt : OpenWrt is not just firmware but it is often described as a complete Linux distribution for embedded devices. Instead of trying to create a single, static firmware, OpenWrt provides a fully writable filesystem with package management. This frees you from the application selection and configuration provided by the vendor and allows you to customize the device through the use of packages to suit any application. This firmware is recommend for advanced users only.
4. DIY option – You can install Linux or FreeBSD/OpenBSD based operating systems and create a full WAP or just a bridge. This option requires good understanding of Unix, networks and embedded devices.