What are these things on the ceiling?

November 6, 2017 12:26 PM

I saw these devices on the ceiling of a tech firm I visited. What are they? Are they Alexa-style "eavesdrop on everything" listening devices?
posted by Borborygmus to Computers & Internet (12 answers total)

Wifi hotspot, i think!
posted by thejoshu at 12:29 PM on November 6, 2017

Possibly a white noise generator? To measure the ambient sound in order to trigger the right amount of white noise, to compensate?
posted by I_Love_Bananas at 12:42 PM on November 6, 2017

No visible slots for sound waves to enter. Unit is labelled ANT151. Coax-type cable that doesn't look it's carrying any power but taps into a master coax cable.

I'm going with a wifi antenna here.
posted by JoeZydeco at 12:46 PM on November 6, 2017

The black cone labeled "ANT151" looks like an indoor ceiling mount antenna for Wi-Fi or cellular (GSM/3G/LTE/etc) purposes.

Solwise has a few similar antennas on their site here.

My first guess would be that this is part of a cellular network repeater designed to address poor cellular signal quality in these offices. Potentially maintained by the tech firm in question, the building owner, or through an agreement with the cellular provider in the area.
posted by ffej at 12:46 PM on November 6, 2017

Definitely network antenna of some kind. Given the coax I'd assume Wifi but I don't work with the actual physical items like this, just their listings in a database.
posted by dust.wind.dude at 12:56 PM on November 6, 2017

I'd agree with others that it looks like a standard cell phone repeater.
posted by mikeh at 1:29 PM on November 6, 2017

ANT151 is an Omni High Gain Antenna. It looks just like part of what you have pictured.
posted by ubiquity at 1:31 PM on November 6, 2017

If they had stuff exposed like that and you didn't see anything ELSE that you'd readily identify as wifi, I'd say it's almost certainly wifi. Most places with it building-wide have a ton of things but they're usually hidden by ceiling tiles and the like. I don't think ANT151 is the model number, though--I think that's telltale signs of a label maker right there, and I think it's a device that's been labeled ANT151 because it's one of a large series of antennas that this firm has that all have IDs in the software that keeps track of all their equipment so they know what's where.
posted by Sequence at 2:18 PM on November 6, 2017

I don't know much about the equipment, but a repeater antenna sounds likely. The building is made of steel, or at least steel floor deck with concrete on it, which is usually done in a steel structure.
posted by rudd135 at 4:01 PM on November 6, 2017

Some office buildings have what are called distributed antenna systems, which are designed to enhance wireless connectivity within a space that might otherwise not have good penetration (e.g. steel buildings). They're commonly used for 3G/4G. These might also be wireless access points with the antennas as the only protruding element, though that's not as common.
posted by arimathea at 5:15 PM on November 6, 2017

arimathea is correct, it's an indoor repeater. Used for either cellular or wifi.

Here is an identical example (except the color) - same N-connector as your picture.
posted by SquidLips at 5:55 PM on November 6, 2017

Thanks all!
posted by Borborygmus at 10:00 AM on November 10, 2017