1920 vs 1930 vs 1940 signal level

[filding]

Hi,

We installed 100's of 1920's, 100's of 1930's and also some 1940's already in our project. All Access Points are powered by ADTRAN Netvanta 1534P switches ,around 10 Access Points per switch. Last week I went trough some of live equipment and measured power using WiFi Analyzer app on android  LG NEXUS 4 phone. What I discovered. The 1920's delivered the best signal at -30dBm level, 1930's at -35-40dBm and 1940's at -55dBm. All measurement I made at around 2-3 meters form AP. And now I am completely confused why 1940 with 6 external antennas and ability to deliver 400mW is giving me the worst result. 1940 AP installed at around 6m high is giving me -60dBm in 30meters from AP and -65dBm at around 90meters form AP. I am relay disappointed of signal level delivered by 1940. It is relay more than 20dBm difference between signal level of 1940 and 1920. Do we have something wrong set at controller side or is somewhere hidden option to turn on to get proper signal level?

Does anyone had similar insights?

Regards

Lukasz

[Anonymous]

Two possibilities come to mind.

1) Yes the vWLAN server can set the Transmit power level for the APs as a % of full power.

2) The external antennas are band specific even though they look the same. You should check if they are installed into the correct connectors (see diagram)

Also, you didn't mention which band you were testing. The LG you mention can do both. A good idea during testing is to create 2 SSIDs, one for 2.4G and one for 5G, that way you know what band the test device is connecting to.

[Anonymous]

You should always test further than 3 meters from the AP. The pattern for typical antennas leaves a dead spot near the AP. Also, your tests from 90 meters (~300 feet) look good. You are also testing APs with internal antennas versus an AP which requires external antennas. I would add this to everything from the previous poster.

[Anonymous]

Please also verify you are using 802.3at POE+. 1940s require POE+ not 802.3af POE due to higher power radios for long distant mesh links.