Step 1: DD-WRT
If your hardware is supported and you feel comfortable with carrying out a moderately advanced software update, you may want to consider replacing your router's firmware with DD-WRT. DD-WRT is open-source firmware for most major brands of wireless APs for the home, providing lots of additional functionality and configurable parameters.
Step 2: Channels/Frequencies
Download IPerf for testing network performance. Strongest signal (i.e. more bars or a higher number on your client's wifi status window) does not necessarily mean best throughput, as interference and other wireless networks can reduce your network's throughput, which is why testing with a tool like IPerf is so important. For example, I found that while I had a stronger signal at 2.4GHz compared to 5GHz, my actual throughput measured with IPerf was lower as there was more traffic and I was getting interference from my LCD TV in the 2.4GHz range. Furthermore, it is very important to experiment with various channel/frequency settings, as the factory defaults are almost never optimal for your situation.
Run IPerf in client mode on one computer connected via wireless to your router, and in server mode on another computer connected by wire to the router. Systematically test all channels/frequencies on your router, each time running the following command on your client:
iperf -c your-server-IP-address -w 8m -r
This does a reciprocal throughput test from client to server using an 8MB window. During the course of the systematic testing, do not change your client's antennae position, and make sure you are not blocking the signal. Test it a few times for each channel, and note the results. Once you've tested all the channels, you'll likely see significant differences in throughput. Select the channels which work best for your situation.
You can also test the effects of other settings in this way. For example, N-only versus mixed, afterburner, wide/standard channel, etc. In general, I would recommend restricting wifi standards to those which you actually use/need (e.g. N-only, NG-only), enabling afterburner and frameburst, reducing the sensitivity range to suit your situation, and selecting auto/wide channel (if your clients support this - wide-channel simply allows for channel aggregation, i.e. using two adjacent channels to effectively double the bandwidth).
Remember to backup your router's configuration when you're done, so you can restore it later if necessary.
Here are snapshots of settings I use on my WRT610Nv1:
(In addition to the above settings, wireless security is set to WPA2 Personal/AES, and a webserver is in the DMZ. )
Step 3: Antenna Position/Direction
The position and direction of your antenna significantly affects your throughput. For example, the antennas in USB sticks are etched onto the circuitry and the broad/flat side of the USB stick needs to face towards the signal for maximum reception. The position of the antenna in relation to reflecting objects will also affect throughput.
Note that I wrote "face towards the signal" and not "face towards the router". If your client does not have line-of-sight to the router, then, depending upon the objects blocking the line-of sight (e.g. concrete versus dry-wall), you may need to direct your antenna towards a reflected signal rather than in the direction of the router.
First, using the server's wifi signal status, adjust its position until you get the strongest signal (most bars).
Now, use IPerf again:
iperf -c your-server-IP-address -w 8m -t 300 -i 10
This will test continuously for 5 minutes (300 seconds) reporting every 10 seconds.
Now, try the antenna in various positions/directions, each time backing away at least a metre and out of the path of the signal. Note that if you hold the antenna, your body will act as an antenna and influence the results. Note the results for each position/direction, marking it on the surface so you can easily find it again.
Step 4: Transmit Power
If you have a weak signal, you may want to consider adjusting your transmit power settings. You do this . I advise you to be very careful, as you don't want to burn out your router/adapter. Ensure your hardware is properly cooled/ventilated and check out various wiki's for recommendations/limits for settings for your hardware and country/region.
You can check your wifi adapter's settings to see if you can adjust the transmit power. You probably can't via the control panel, but sometimes you can find undocumented registry settings, as I did for my WUSB600N USB adapters.
Using DD-WRT on the router, you can adjust your router's transmit power. The default was 71mW for my router, and I upped it to 84mW. I tried a setting in the 90s, but it didn't make a significant difference with respect to 84, and a lower setting is better for radio-life and heat generation. Personally, I wouldn't even consider going above 100mW.
Again, if you decide to change the power settings, you do so entirely at your own risk, as doing so may result in you burning out your hardware or going above regulatory limits for your country.
Step 5: Focus the Signal
Increase wifi signal strength and throughput significantly, for less than 2 euro, with this parabolic trough:
I have a media server connected by a Linksys WUSB600N dual-frequency 802.11n USB stick to our Linksys WRT610N router. The signal had to go through walls and/or bounce down our hallway, so it was a bit weak by the time it got to the TV around the corner in our livingroom. The best I was getting was 54Mbps "poor" (1 bar) signal. I searched online for solutions, and ran across the Free Antennas site with a whole set of designs for home-made parabolic dishes and troughs. The problem was, none of them was particularly well-suited for thicker paper (e.g. cardstock or cardboard), and I wanted something a bit sturdier.
So I designed my own, which I'm making available to you for a limited time for the incredible low price of nil, that's right nil euro! Here's the design:
right-click and select save
to download
Other than a sheet of cardstock which I bought from a local art store (because I wanted it to look reasonably good in our living-room), the rest of the supplies are things you probably already have at home.
Supplies
- cardstock (the heavier the weight, the better)
- aluminium foil
- exacto knife
- scissors
- glue stick
- tape
Instructions
- Print the template on cardstock (or on paper, then transfer to cardstock)
- You may scale the diagram to fit your needs, but make sure you maintain the horizontal/vetical scale (i.e. scale the horizontal and vertical dimensions by the same percentage)
- I printed this template at 100% on two pieces of A4-paper, then transfered to my cardstock
- Using the exacto knife, lightly score the dotted lines for easier folding
- Cut the reflector slots with the exacto knife
- The centre of the “X” in the two rectangles in the support part marks the focal point of the parabola
- If making for a USB stick, X-cut the two rectangles in the support part (do not cut the rectangle out or the support may slide off the USB stick). If you have scaled the diagram, you'll need to adjust the dimensions (but not the centre!) of the rectangles
- If making for an antenna, X-cut the dots in the two rectangles in the support part (do not cut a circular hole or the support will slide off the antenna)
- Cut out the support and reflector
- Apply glue thinly and evenly to the back of the reflector and apply aluminium foil, smooth out wrinkles, allow to dry
- Fold the support part along the scored lines
- Insert the middle tabs of the support part into the middle slots on the front of the reflector
- Centre the support on the reflector, then glue and/or tape the tabs in place
- Carefully bend the reflector and insert the other tabs of the support part, then glue and/or tape in place
- Poke the antenna through the X holes, or push the USB stick through the X-rectangles
- Point the reflector in the direction of the target (e.g. wifi client, AP) signal (either towards the target if you have line-of-sight or towards the bounced signal)
Note 1: Do not use reflective material for the support part as this will shield your antenna and defeat the purpose. Use only cardstock for the support part so the radio signal can pass freely through to the parabola to be reflected and focussed on the antenna.
Note 2: As mentioned above, the antennas in USB sticks are etched onto the circuitry and the broad/flat side of the USB stick needs to
face towards the signal for maximum reception. Hence (and extensive testing confirms) dish/trough designs which point the top or edge of the USB stick
towards the signal are far less effective.
Here's the result:
Here's the view from the back, showing the aluminium foil
(tabs from the support are folded over the foil):
I aimed reflector in the direction of the WRT610N AP signal, which in my case was not passing through the reinforced concrete walls but, rather, being reflected down the hallway.
Conclusion
The result of employing all the above steps is that I now get a "excellent" (4 bar) signal, and actual throughput has gone up by a factor of six. All that for less than 2 euro in materials (including the cardstock from the art store).