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High Gain antenna

If I have a 100foot ceiling and do not want to turn up my transmit power high cuz my clients cannot transmit that high, will a high gain antenna allow my client to connect to the high gain antenna 100feet high at a reasonable power?

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Hall of Fame Super Gold

Re: High Gain antenna

will a high gain antenna allow my client to connect to the high gain antenna 100feet high at a reasonable power?

No because your clients won't have a high gain antenna to send the return traffic back to the AP.

If you have a power point in the vicinity of the clients, get another AP and do a wireless point-to-point bridge.

You stick a high-gain antenna to point at teach AP and then use the second radio to provide wireless service to the clients.

8 REPLIES
Hall of Fame Super Silver

Re: High Gain antenna

High gain adds to the total EIRP so it's just like bumping up the power. Every 3dbi gain is double the tx power. So if you set the tx power to 25mw and your using a 3dbi gain antenna your total EIRP is 50mW. You might look at a low gain patch antenna.

Sent from Cisco Technical Support iPhone App

-Scott
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New Member

Re: High Gain antenna

would a low gain directional from 100feet away work and still give me a nice cell size not greater than -70dBm?

Hall of Fame Super Gold

Re: High Gain antenna

will a high gain antenna allow my client to connect to the high gain antenna 100feet high at a reasonable power?

No because your clients won't have a high gain antenna to send the return traffic back to the AP.

If you have a power point in the vicinity of the clients, get another AP and do a wireless point-to-point bridge.

You stick a high-gain antenna to point at teach AP and then use the second radio to provide wireless service to the clients.

New Member

Re: High Gain antenna

The only there is that, I have to use one of my radios for backhaul, and so if i use 5ghz I will be left with 2.4 and 3non-overlapping channels, and if I use 2.4 for backhaul, I will eliminate a lot of clients.

Hall of Fame Super Gold

Re: High Gain antenna

Thanks for the ratings.

That is correct.  5.0 Ghz backhaul would be good because there would be little chances of your backhaul falling into channel interferrence issues.  Then your issue would be channel interferrence on the 2.4 Ghz which, in my humble opinion, be tolerable. 

Hall of Fame Super Silver

Re: High Gain antenna

It depends on the antenna pattern but you should be able to tweak the signal. The best way is to actually sample/test with the antenna to determine your coverage.

Sent from Cisco Technical Support iPhone App

-Scott
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New Member

Re: High Gain antenna

I dont think the elevation or azimuth of low gain antenna can push the signal 100feet down, and that's why I was considering a high gain, but there again, I'm worried about my clients matching that power requirement. I've tested several HG at 30feet and meeting an rssi 0f -70dBm or greater is a challenge, let alone 100feet. I doubt it test but I  will test it. Any other suggestions for contigency?

Hall of Fame Super Silver

Re: High Gain antenna

Yes it will... You need to test as you can use a high gain but lower the tx power to determine your EIRP. It the same for stadium ap's and antennas, but the EIRP is higher. 100 feet is nothing even with a low gain patch.

Sent from Cisco Technical Support iPhone App

-Scott
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