This is going to be a quick post.
I have used many wireless routers on robots over the years and they have all failed on me. Most of them probably failed due to the vibration, shock, and dust.
The one vendor that I have found so far that has a reliable product is Ubiquiti. Not only is it more reliable and works better then other products I have used it is small and inexpensive. Now its not all good, the website sucks and is not easy to navigate, and the customer support is via email (no phone!!) and can be slow.
When configuring them there are also a few traps that you need to be aware of (everything else is straight forward and similar to other routers). The first trap is that you need to disable AirMax. To get to that you click on the tab (that does not look like a tab) with their logo on it. The second trap is that to connect with standard computers you need to change the channel bandwidth down to 20MHz in the wireless tab.
These devices also let you adjust the output power and change the operating country which are nice features to have.
I have mostly used the Bullet and Rocket products. The bullet is nice as it can connect directly to the antenna using an N connector and is powered over the ethernet cable (POE).
They also recently launched some indoor routers that are nice (lightweight and inexpensive) Click Here for Routers
For more information about increasing your wireless range click here.
Here is a video about how to set up a Ubiquiti device.
Photo source: http://www.ubnt.com/img/products_bullet.png