Wireless Access

Hi everyone,

I try to improve some 2.4Ghz coverage holes in my hospital by following the RF and Roaming Omtimization and I would like your opinions.

5Ghz performances are quite good but I got some holes in 2.4Ghz especially with old smartphones Intermec CS40 (Windows Mobile 6.5 !) used by a delivery application.

Current configuration :
- Two 7220 Master/local AOS6.4.2.12 with 700 AP (AP105 and AP103)
- 5Ghz = work SSID
- 2.4Ghz = Guests/Patients SSID +  old delivery work app
- Two differents AP Group, one with 5Ghz + 2.4Ghz enable and one with only 5Ghz.
- 2.4 is enable on roughly 50% of AP
- ARM profile for 5Ghz : 20Mhz  width; Min TX 9 ; Max TX 18
- ARM profile for 2.4Ghz : 20Mhz width;  Min TX 9 ; Max TX 15
- DFS channel are enable
- No band steering
- The wifi coverage study was conducted in 5Ghz.

My idea is to change 2.4Ghz ARM profile to Min TX 6 ; Max TX 9, maybe enable Mode Aware ARM and then to enable 2.4Ghz on all my AP.

Good idea ? Bad idea ? Better idea ?  ;-)

I know that the right thing to do is to trash this old devices, but my boss don’t think so …

Why do you say you have coverage holes?  Typically the 2.4ghz frequency travels further than the 5ghz frequency, so for the same transmit power, you should expect bettter, not worse coverage. 

Have you done a 2.4ghz site survey to see your actual coverage?

How high are the access points mounted?  Are they mounted in the rooms or in the halls?  How far apart are they mounted?

Access Points are mounted at about 2.5m (8.2 ft) above ground, always visible and not inside celling. Always in corridors and never in patient rooms. We have up to 8 floors with Wifi in some buildings.

I know that the coverage is better with 2.4Ghz but we have a lots of noises in this band (Bluetooth, Microwave ovens, Smartphone share connection, etc) and only three channel (1,6,11) so work SSID are on 5Ghz frequency.

We don't have 2.4ghz site survey, I just use Airwave Visual RF to enable or disable 2.4 AP.

It's clearly not the right method so I would like to enable all AP with 5Ghz + 2.4Ghz.

It is difficult to optimize 2.4ghz because whatever interference there is we must accept.  The other difficulty is that it can be hard to get coverage into rooms when all of the access points are mounted in the hallways.  Do you have Microwave ovens in use in the hospital?