High Gain Omni Antenna

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One of my favorite things about Wifi as a hobby is that it I never stop learning stuff, and finding new and better and cheaper ways to do things. My favorite thing about wireless networks are the antennas, but owing to a lot of variables they are the hardest things to write about. Until now, my tests have indicated that to make a wireless link over 200 to 300 metres directional antennas were a requirement. Generally the cost of directional antennas was about the same as omni directional antennas, making them bang for buck the best way to go. Today, we acomplished a flawless 250 meter link using two omnidirectional antennas in the most adverse conditions using 2 omnidirectional antennas. Costing around one quarter of what we have been spending until now, these little omnidirectional antennas out perform their commercial rivals hands down, causing us to rethink some of our basic network design for client equipment and short range links.

I have two omnidirectional antennas that I paid $120.00 each for, sitting in my cupboard with my sparklan PCI cards, and a gaggle of cheap ethernet switches - things that I have tried out and found to be poor performers. With this in mind I didn't have high expectations for these little $30.00 omni's but still at this price I just had to try them.

I have a standard test range up the street that my balcony overlooks. Its about 250 meters long, has some trees, and crosses a busy highway at it's far end. To make things even more interesting because of the high population density, it has a high noise floor at 2.4 GHz. In short - a pretty harsh testing ground. It is on this testing ground that I have performed trials on every antenna and access point that I have bought or made, and so I have a pretty good idea of what kind of performance to expect. Over time I have developed methods of testing that provide real indications of useful performance. Beyond simple signal strength measurements, I perform the "can I still surf the web test", and the file transfer speed test. The reason that I don't use signal strength measurement as my only method of testing antennas and access points is that the signal strength indications can be quite variable depending upon your software and hardware combinations - thus bringing into light that the proof really is in the pudding. The "does it work" and "how well does it work" tests of web surfing and file transfer speeds are the best indicators of real life network conditions that I have found.

Todays testing was done using a minitar access point on my verandah as the access point, and my laptop. The tests were conducted in 3 stages. First we established a baseline using the access point's standard antenna. We measured signal strengths and usability along the test range and took particular note of the locations where we were at the fringe of its usable area. Next we attached one of these new antennas to the access point. We conducted the same signal and usability tests as we did with the standard antenna and noted the improvement on the edges of the wireless link. We did all the same tests again but with one of these new antennas connected to the laptop. Comparing again the signal strenght and connectivity to the netowork all along the testing range. These are the same tests that I have repeated time and time again with cantennas, and cap antennas, commercial omnidirectional antennas, dishes and grid antennas.

As I type this, I am just busting out of my skin to share how damn well adding these omnidirectional antennas improved the performance between the laptop and the access point. What I really want to do is jump up and down and and wave my hands in the air and tell everyone that I have found the best antenna that I have tested in ages - one that has provided test results that bettered those of my much loved vagi over the distance at a quarter of the price.

When we added the first omni antenna and tested it's operation using net stumbler, the increase in signal strength indication at the 50 and 100 meter marks was about 10Db - which appeared to be unusually high, but gave us confidence that we could expect a significant result. We next went to the points along the range where connectivity with the standard antenna had become marginal and finally had dropped out. The result was that in the marginal areas, connectivity was restored to 100 percent, and in the dropout areas usable signal was achieved. Finally in the last test with these antennas fitted to both the access point and to the laptop, the now greatly extended marginal zones became 100 percent zones, and there were no dropout zones all the way up the testing range.

I have never seen the whole street blanketed with 2.4 GHz 802.11B. It's that simple - I was able to get WiFi coverage from a laptop to an access point up the entire length of the street. Even directly behind the willow trees that normally kill WiFi dead. There was one test left to be done - to try and lose connection with the access point. I crossed the Grand Parade and went down to the bus shelter near the beach where I have never made 2.4 GHz work before - to push the wireless where no wireless had gone before. On this test I removed this antenna from the laptop, and tried to connect to the access point, and it simply didn't work at all - the access point didn't even appear on the available access points list. Then I reconnected the external omni, and not only was I able to connect to the access point, it connected firmly at full speed. This is why I am so excited about these results - not since our 802.11A tests with directonal antennas have I seen WiFi work at the bus shelter. Between myself and the access point there was 250 meters of distance, one very dense willow tree, and four lanes of peek hour traffic!!

As such a strong performer over these distances, I expect that these antennas would continue to operate well out toward a kilometer. They will see a lot of use on the community wireless network as they are one quarter of the price of their nearest competiter. In broader terms, I simply could not recommend these antennas too highly for people who want to improve the performance of their wireless network equipment, or create local hotspots and wireless links. The antennas have a magnetic base that is strong enough for all situations, whilst small enough not to be a pain in the bum, and come standard with a choice of RP-TNC or RP-SMA connectors.

.I now have one of these antennas in my laptop bag for stumbling / wardriving (war driving ?), replacing the somewhat more bulky and less efficient Hills antenna that cost me $80.00.

The antennas are made by WiFi-Tech and retail for around $30.00 each.