Using higher gain antennas on WAP?

[Bozz]

Got a wireless network with a Belkin dual-antenna router/WAP/ADSL modem (i'll get model later when I'm there again).

Have one wireless client at the other end of the house who's internet was reliable while it was unsecured however since enabling encryption it drops out almost entirely which was sort of expected.

So we got a high gain 5dbi antenna for the distant computer and it connects with WPA-PSK(TKIP) enabled with a group key renewal of 3600 seconds. It does drop out once every 5-15 minutes though.

The WAP doesn't have a power control in its web interface.

So, firstly teach me about directional antennas - I've tried looking for beam patterns on the net and can't find much useful info.

Is a 6dbi directional antenna going to have the same distance coverage (in its optimal zone of course) as a 6dbi omnidirectional antenna? I understand with the omnidirectional antenna as you increase gain that the beam pattern will shrink on a vertical axis which is acceptable in the situation.

If it is the same coverage, does it mean I should go a higher gain directional antenna, such as 9-12dbi ?

On the other hand, should/can I replace the two tiny (about 10cm) antennas on the WAP with 6dbi or similar omnidirectional antennas?

Thanks everyone.

 

[JackMDS]

In theory you should get the best result by putting on the Wireless Client High Gain (8dbi or more) directional Antenna.

Outside with clear line of sight a good Antenna can be a savior. However, when used indoor any Antenna might not provide a solution.

The best Method to Extend Wireless Coverage depends heavily on the Specific Envioroment.

Look at these pages they describe most of the options that are within the means of Entry Level users, and choose the one that fits you envioroment best.

Link to: Extending the Distance of Entry Level Wireless Network.

Link to: Wirelessly Bridging Home / Network.

Link to: Hi Gain Antenna for Entry Level Wireless.

In general, the best Method involves using multiple units connected with wire to the source.

Or WDS ( Wireless Network - Configuration Modes. ) system using Hardware of one Brand across the board.

 

[Zap]

Originally posted by: Bozz
So, firstly teach me about directional antennas - I've tried looking for beam patterns on the net and can't find much useful info.

You are right about omni antennas and how the vertical axis shrinks as gain goes up. With directional antennas the "beam" gets smaller as gain goes up. This is generally speaking, as you can get "sector" antennas that may be reasonable gain, but have a really wide beam. Also, some designs may beam wider than others with same gain.

Now, you're wanting to compare omni to directional? I'm not sure how that compares, but I'm thinking gain = gain. Perhaps I'm wrong. Never lost any sleep over it though.

Originally posted by: Bozz
On the other hand, should/can I replace the two tiny (about 10cm) antennas on the WAP with 6dbi or similar omnidirectional antennas?

You can and signal should be a bit better.

 

[spidey07]

Before you go making matters worse by using a higher gain antenna..signal quality is more important than strength.

What is your RSSI on the client? Should be shown with net stumbler or your wireless client.
What is the percent of missed beacons and errored frames?

Have you tried changing channels and made sure you have the antennas arranged properly - both pointing straight up? Are you directly above or below the AP antenna as that is the poorest signal you can get?

 

[cparker]

Just go to freeantennas.com. Then find their 9db parabolic reflector template and follow the directions to construct two little reflectors that will slip over your existing antennas on the WAP. (should take all of 20 minutes!) Then aim it to wherever and you will get a dramatic signal increase unless you have too many reflective elements to distort your signal over your desired path. You can also do the same at the other end to have another 9db advantage. Together you will have an 18 db gain (it's additive!). Remember a 10 db gain is equal to 10 times the power level. A 20 db gain is 100 times. 18 db is something like 60-70 times. Does it work? Well, yes. I use it on a close to 1000 foot link using two wap54g units in bridge mode. No problem. But of course it's line of sight.