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New Member

Wireless Design Vs. The Client Quantity

Hi everybody,

Currently I'm working on a project for an auditorium which has capacity for up to 2500 people. The auditorium also has Acoustic Design which permits the cancellation of noise (at audible frequencies).

The auditorium works for Conferences and big business meetings.. so the the use of wireless devices is mandatory an so the wireless coverage. I've been talking with the customer and he said that usually about a 10 or 20 percent of the attendants (250 people) bring or use they wireless devices.

I did measures and I had full area coverage with an AIR-LAP1142N-A-K9 assuming about 20 people connect at the whole room. Also I've been looking for the client-per-AP capacity and I found that the max suggested by cisco is 25 clients per AP.

So in this case should I deploy about 10 Lightweight APs for the room? thinking also that there is not enough non-overlaping channels on the 2,4GHz frequency band.

or is there any option to drive the enviroment that I picture before??

Thanks and Regards

3 REPLIES
New Member

Re: Wireless Design Vs. The Client Quantity

The non-overlapping channels in the 2.4 GHz spectrum are 1, 6, and 11. For 802.11a, you have plenty of channels to choose from.

New Member

Re: Wireless Design Vs. The Client Quantity

Yeap... I know the 5GHz spectrum has a lot of non-overlapping channels.. the issue is here at Colombia all the WiFi devices or at least the 90% of them works on 2,4GHz frequency. So by default I have limitation about the non-overlapping channels.

What I really need to know is if there is another way to give service to about 250 clients in a close room but put almost 10 APs at the room (assuming a capacity of 25 clients per AP as cisco recommends).

The picture is:

One room. 2500 people of capacity. About 10% of the people (250) with Wireless devices working at the same time. And Cisco centralized wireless solution using WLC and AIR-LAP1142N-A-K9.

Go.

Thanks and Regards.

Cisco Employee

Re: Wireless Design Vs. The Client Quantity

Hi Jose,

there is no super trick. You can set maybe more than 3 APs if you lower their transmit power to the minimum. So for example 3 APs on one side of the auditorium (1,6,11) and 3 APs on the other side (1,6,11). Hoping the auditorium is big enough so that APs don't disturb each other.

The problem with this is that smart devices like cisco phones (7921) will lower their power too if AP has low power but stupid clients might still send at max power.

So you have your APs whispering to only the clients around but the clients are all shouting in the room and killing each other RF.

However, it's something you can definitely try.

Another possibility is to go with directional antennas. You can then set lower power on APs so that they cover a small area and also give them a directional antenna so that they transmit and hear only in a specific direction. You can then divide your auditorium in "quarters", each quarter covered on all 3 channels. This gives max bandwitdh from AP side (3 channels x 4 quarters = 12x 54Mbps available in the room, given that clients spread evenly in the room).

However the clients are still having omnidirectional antennas and still disturb each other, so this practice has limits.

Regards,

Nicolas

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