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Sector antenna for Cisco 1524

We have some Cisco aironet 1524 AP's. Can I connect these AP's to a 21 dBi Sector Antenna and use it for Wi-Fi Broadcasting. Maybe even for indoor penetration for a distance of 150 to 200 meters?

8 REPLIES
Hall of Fame Super Silver

Re: Sector antenna for Cisco 1524

If you are trying to provide more coverage than usual, then it's not a good idea. You can search the forum as others have tried suggesting if they should do that. The issue with using a very high gain is that you overpower the client devices. If your trying to do point to point bridging, then yes that's a good idea to get the signal from one point to another with a good RSSI and SNR. For wireless end users, its not a good idea. The proper way is to add access points.

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-Scott
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Sector antenna for Cisco 1524

I am not trying more coverage, As indoor penetration with 8 dBi omni antenna is not good, and adding to this site acquisition for increasing the density of AP's is another problem we face here, my approach is to provide the same 100 to 150 meters coverage, but not just outdoor, but indoor as well.  I would like to know if there is a suggestion to do something else if not using a high power antenna?

Hall of Fame Super Silver

Re: Sector antenna for Cisco 1524

You are trying to increase coverage per say. No it's not a good idea because your client devices will not be able to penetrate the same structure. The signal from the client will not reach the AP. you have to look a both directions.

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-Scott
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New Member

Re: Sector antenna for Cisco 1524

Scott,

If by "over-powering of the client" you mean pumping more EIRP from the AP than from the client than I would object your statement. Antenna gain doesn't lead to over-powering the client, antenna gain is symmetrical in transmitting and receiving parts of the equation. You can use a high gain antenna at the AP and use clients with weak antennas and achieve better range of coverage. You also can penetrate structures and increase the effective "listening" capabilities at the AP while clients are still "whispering" their signals through the obstruction.

However it is indeed a bad idea to use high gain antennas indoors to penetrate through obstructions. High gain directional antenna will receive clients signals from larger distances increasing the cell radius - true. But this, in its turn, will lead to other RF issues, such as Hidden Nodes and Near-Far situations. As Scott mentioned this is not a common strategy of increasing the coverage indoor.

1524 access points also have more available transmit power - and that can lead to over-powering of the client. At Level 1 they transmit 28 dBm (while normal laptop trasmits at 17 dBm). While antennas can be mismatched the transmit power must be set to same or lower than wireless clients.

Re: Sector antenna for Cisco 1524

My actual approach was to make the Cisco 1524 AP work as sectors where I was planning to fix the AP and antenna on a tower and set the tilt with a cell size not exceeding more than 170 meters. Maximum 200 meters. Regarding the level 1 Transmit power level, as I am working in middle east region where the -M regulatory domain only allows me to transmit at 14 dBm . Based on what Scott said, i was thinking if I could use a small repeater at the customer end indoor which recieves and broadcasts back a stronger signal, if my concept could work. I am right now in thetesting phase before I come to any conclusion. I would like to know both Vlad's and Scott's opinion if using a repeater can take this concept ahead?  I am still in the  learning stages as a wireless engineer , so both your inputs in this case would be very valueble in this case. Another point I want to ask is how much will the Diversity function (Rx & Rx-Tx) in the AP help in smooth transmission and reception of data at the AP?

New Member

Re: Sector antenna for Cisco 1524

You could use the 1524s to to create 5GHz link to the repeater (mesh node in such case) and have 2.4GHz broadcasted inside of the building. As for the Diversity check the APs documentation. I think with all the antennas installed you can gain up to 3-4 dB increase in sensitivty but this is from the top of my head - worth while checking this information.

Re: Sector antenna for Cisco 1524

My actual approach was to make the Cisco 1524 AP work as sectors where I was planning to fix the AP and antenna on a tower and set the tilt with a cell size not exceeding more than 170 meters. Maximum 200 meters. Regarding the level 1 Transmit power level, as I am working in middle east region where the -M regulatory domain only allows me to transmit at 14 dBm . Based on what Scott said, i was thinking if I could use a small repeater at the customer end indoor which recieves and broadcasts back a stronger signal, if my concept could work. I am right now in the testing phase before I come to any conclusion. I would like to know both Vlad's and Scott's opinion if using a repeater can take this concept ahead?  I am still in the  learning stages as a wireless engineer , so both your inputs in this case would be very valueble in this case. Another point I want to ask is how much will the Diversity function (Rx & Rx-Tx) in the AP help in smooth transmission and reception of data at the AP?

Re: Sector antenna for Cisco 1524

Yes, you can do that. You can connect the AP’s to a 21 dBi Sector Antenna and use it for W-Fi Broadcasting but it is not recommended as the strength of the signal will be more focused.

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