Maximum PC has rounded up six high-end routers from an assortment of manufacturers. Each router's wireless performance was tested in six different household locations, including an enclosed patio and outdoors at a distance of 85 feet.

If your environment is crowded with wireless access points or your client is at the extreme edge of your router's range, you might be able to increase the router's throughput by reducing its fragmentation threshold. The router will slice up any frames larger than that threshold and send the fragments separately. Since any lost fragments will be smaller than the entire frame, resending them will require less time.

Any changes should be matched by a change to its RTS (Request to Send) threshold. The router will send an RTS signal to the client before sending any frame that's larger than the RTS threshold. The router will then wait until the client sends a CTS (Clear to Send) signal before transmitting the frame. This RTS/CTS exchange minimizes interference and reduces the need to retransmit frames by informing all the stations on the network that a frame exchange is about to occur.

Finding the sweet spot is a trial-and-error process. We significantly boosted TCP throughput from a D-Link DIR-615 router to our client (with 60 feet, one insulated interior wall, and two insulated exterior walls in between) by making incremental changes to these values until TCP throughput stopped increasing and began to go in the other direction.

We eventually increased the router's TCP throughput to the client at that location from 4.4Mb/s to 15.2Mb/s by changing the RTS threshold and fragmentation threshold from their default values of 2,346 bytes to 1,200 bytes each. Bear in mind that settings and results will vary by router. You should also know that changes benefiting a distant client's throughput can be detrimental to the throughput of a client operating closer to the router. When we moved the client back to our kitchen location, for instance, its TCP throughput dropped from 71.4Mb/s with the router's default settings to 21.5Mb/s after our tweaks. That's still plenty fast for web browsing.