Sunday, February 6, 2011

Improving Wireless Reception - Part 3

Introduction
I will assume at this point, you are still suffering wireless connectivity issues in your home even after applying suggestions from Part 1 and Part 2 of this blog series.  Don't worry!  There are still solutions that will resolve your issue.  They just take a little more money, some technical expertise, and time.

Fastest Fix
The fastest and easiest fix to improve your wireless signal strength is to use high gain antennas.  For example, let's say your router/access point is located on the outside wall of your home (versus the middle of the home).  As a result, half your wireless signal is going through your wall to the outside.  Recall the stock antennas that router/access points come with have very low dbi and the signal pattern is a large doughnut shape.  If your router/access point resides near the outside wall of your home, we need to redirect that wasted signal going outside and make use of it in the house.  You can't increase the power output of your router/access point (well you can, but this is a different discussion), in fact it can make things worse.  However, we can substantially increase the signal strength by using directional antennas to send the majority of the transmitted signal in a particular direction.  So, in effect we are increasing signal strength but we are not changing the actual power output of the transmitter.

Removable Antennas?
Now we have a caveat.  Not every router/access point will have removable antennas.  This is why I always recommend that when buying any wireless device, assure it has removable antennas to permit the use of third party antennas.  If your router/access point has fixed antenna, or worse yet, no antennas on the outside, it is time to buy a new router/access point with removable antennas.

Third Party Antennas
There are a handful of manufactures that make third party antennas for wifi devices.  I have personally only used the directional antennas from Hawking Technologies and have been pleased with their performance.  I have used omni-directional antennas from a number of brands and have also been pleased with their performance as well.

Antenna Types
There are two planes to consider when focusing wireless signals.  One option is to flatten the doughnut and increase signal strength in all directions.  These are called high gain omni directional antennas.  This type of antenna would be appropriate if you are trying to increase the signal strength on one floor of your home.  In this scenario, there will be almost no wifi signal going vertically and all the wireless signal is radiated horizontally.  I would recommend this type of antenna if your router/access point was located near the center of your home.  You can find several examples of this antenna on amazon from different manufactures.  Go with the highest gain you can find,  which is usually 9 dbi.

Alternatively, Hawking Technologies for example, sells a "corner" antenna.  This antenna would be a great solution if your router access point is located in a corner of your house.  The antenna I am referring to is located at Amazon Hawking HiGain Directional Corner Antenna.  It will focus the signal out in an approximately 90 degree angle horizontally.  I have also used this antenna for client computers that are some distance from the router/access point to increase throughput with great success.

Your Last Resort
If you continue to have wireless connectivity issues in your home even after exploring/testing third party antennas, your last resort is to just run multiple access points.  I do this in my home because my house (old rancher) is 60+ years old and the walls were made with a concrete based board and plaster.  Based on my testing, these type walls attenuate the signal at least 12 dbi.  As a result, I run 4 access points in my home.  I have two on the main floor and two in the basement.

Running multiple access points requires some technical expertise so you do not bring down your whole home network  You may want to seek out a friend or colleague that is knowledgeable in wireless networking to set this up for you.  The way I do this is the following:

  • Run each access point on a different IP (of course) but put them on same network, aka a flat network.
  • Only run one DHCP server and make sure it points to the correct default gateway and DNS server(s).
  • Put each access point on a unique channel
  • Assign separate SSIDs for each access point.  Ideally, you should actually run all the access points on the same SSID.  However, I find wireless clients are sticky to the access point they originally connect to.  For example:
    • I am upstairs with my laptop and it connects to upstairs access point A.  Then I go downstairs with my laptop and in a perfect scenario it would connect the downstairs access point which now has the stronger signal.  However, I find this does not happen.  Therefore, I just disconnect from the upstairs SSID and then connect to the downstairs SSID that now has the strongest signal.
  • All the access points need to be connected to your inside network via a wired connection.  Consider them just clients on your wired network and each access point will bridge wireless clients.
  • I actually buy router/access points and don't use the "router" part when they are acting as access points.  Note:  there are manufactures that sell just an access point.  However, I find these are more expensive than the router/access points.
This configuration has worked very well for me.  Note:  only pursue this if you know what you are fairly familiar with networking.  If you start putting multiple access points on your network without probably configuring them, you will break your network without question.

Conclusion
I hope these three blog entries help you improve your wireless network in your home.  These steps have certainly helped me and others that I have helped in the past.  If you have questions or comments please post them.  If you wish to contact me privately, please do:  john@mysnmp.org.