(figure from dd-wrt web site)
However, with a dual band (2.4GHz and 5GHz) router, it can be used to boost wifi performance. The idea is that, at location where wifi is weak, the secondary router can be configured as bridge to connect to primary router using 2.4GHz (as it has better penetration through walls than 5GHz). Not to mention that with DD-WRT, the TX power can be configured to be much higher than your portable devices.
At the same time, the 5GHz channel of the secondary router can provide a strong and non-interfered signal to local devices. Internet traffic will be bridged to primary router via the 2.4GHz channel.
I recently moved back to Canada and now living in a house sharing the existing Telus internet connection with others :(. There are some tricks that can be done on the crappy V1000H router provided by Telus, but that will be another story.
Since the internet router is located in another floor, the wifi connection is not optimal for me. So I reconfigured my DD-WRT-ed Asus RT-N66U as the diagram shown above. Steps are clearly stated on DD-WRT web site on how to setup router as bridge. The only different is that since my router is dual band, the 5GHz channel can be used to serve my devices while 2.4GHz is used as bridge.
Here are some speed tests ran on my Dell Inspiron 13 (Intel AC7265):
2.4GHz directly to the primary router:
5GHz to secondary router, bridged to primary router via 2.4GHz:
- latency is higher when there is one more hop
- improvement on both download and upload speed is significant