phone in full strength on top floor but zero in 1st

There is a ATT & t-mobile phones.. both give 5 bars in the 10th floor but on the ground floor one has 3 bars, other has zero... how that be? Is that a phone issue or signal strength issue?
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Colleen KayterConnect With a Mentor 4D AssetsCommented:
You said one is AT&T and one is T-mobile. I can't tell you what AT&T invests in their towers that T-mobile doesn't, but it seems the AT&T network is more comprehensive.

Go to the coverage maps for both services. Drill down to the address and check both 4G and voice services for both companies. I'm willing to bet you'll find T-mobile coverage is not in the excellent range...
d-glitchConnect With a Mentor Commented:
The top floor can probably see the cell tower.
If you are surrounded by 10-story buildings, you may have no signal at all on the first floor.
It could also be just a small, local dead spot.

The phone is fine.

You might be able to get a local repeater -- receive antenna on the roof linked to a little transmitter on ground.
Anthony RussoConnect With a Mentor Commented:
This company also specializes in increasing cell phone signals in buildings and other dead zones:

XG-Wireless :
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Thibault St john Cholmondeley-ffeatherstonehaugh the 2ndConnect With a Mentor Commented:
Phone antennae are directional both horizontally and vertically. This property is used to prevent interference with nearby antennae possibly of a different network provider. So the signal could be aimed higher at your building so as not to affect something nearer ground level. Buildings do attenuate signals so it is also quite likely that nearby buildings are causing a shadow over your lower floors.
viki2000Connect With a Mentor Commented:
If I understand right you have 2 mobiles phones. And you ask how come at the ground floor one mobile phone has 3 bars and the other one zero.

If you are on the same network (ATT & t) with both SIM cards in the mobile phones then is quite clear and logic that the mobiles phones do not have the same sensitivity in detection the GSM signal, even if they are the same brand.

By curiosity I would switch the SIM cards between them to see if is any difference.
If it is not, meaning the same mobile phone has zero bars at ground floor, then is worse quality than the other one or in the best case has a defect - maybe was dropped and has a connection problem to the internal antenna.
Of course, may be also the chance that is a bad production lot where the standards are met, but at the limit.
dhsindyConnect With a Mentor Retired considering supplemental income.Commented:
The steel frames of buildings are grounded to the earth with copper cables which makes the frame act like a Faraday Cage interfering with the RF signal.  To improve reception try moving to an outside wall between columns.

Also, note that concrete reinforced building have the reinforcing steel grounded.  In our office, everyone has a cell phone it seems.  But, everyone also has a desk phone on our digital phone system.
deightonConnect With a Mentor progCommented:
even if the phones are an identical model, one might have benefited from some better part in manufacture, either by chance or manufacturers upgrade.
PCableGuyConnect With a Mentor Commented:
If the phones are identical, a simple thing to try is swap the batteries between the phones to see what happens, you never know it could be related to the battery.
Colleen KayterConnect With a Mentor 4D AssetsCommented:
I don't live near any tall buildings, but my t-mobile phone is constantly trying to connect to the AT&T network. It seems AT&T has better positioned towers, stronger signal, i don't know, but I'm going to be switching to AT&T next month in hopes of being able to have a phone convo while in my living room. I've recently switched from Sprint, which uses CDMA, to T-Mobile, which uses GSM. I've learned a lot in the process.

Both T-Mobile and AT&T use GSM (SIM cards). The phone identifies itself with a nearby tower and you're ready to go. The problem is, GSM saturation can occur. Too many phones glomming onto the same tower. When you're 10 stories up, your phone may be glomming onto a different tower than the one visible to all the phones at street level. CDMA phones don't have the saturation problem, but you can't switch carriers and you can't roam (particularly internationally) with them.

That said, I did check out signal boosters. T-mobile will supply one free if you're on a contract and meet certain requirements...

otherwise, you can buy one directly from the manufacturer.

AT&T doesn't work with the Cel-Fi device, but offers a device they call MICROCELL.

There are no monthly charges. It hooks into your internet. Seems to work similar to skype, but uses your cell minutes. I tried to scare up some pricing on this, but it seems to only be offered at AT&T stores, though there is more information available at the AT&T website.
viki2000Connect With a Mentor Commented:
There is very helpful information what you posted above - at least for me as learning material.
But I do not think it explains why 2 identical mobile phones with similar SIM cards have in the same space point different signal strength.
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