# Question on cell phone signal strength

**URL:** <https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057>\
**Category:** Factual Questions\
**Created:** [September 11, 2019, 5:58pm UTC](https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057 "2019-09-11T17:58:37Z")\
**Posts on this page:** 11\
**Page:** 1

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**Author:** ![The\_Man\_In\_Black](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@The\_Man\_In\_Black](https://boards.straightdope.com/u/The_Man_In_Black)\
**Post date:** [September 11, 2019, 5:58pm UTC](https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057/1 "2019-09-11T17:58:37Z")

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So I was doing some reading about signal strength and how to actually see it on the phone. So when I get to the screen, I see that it bounces from -101dBm to -108dBm. From what I read, at those numbers I have almost no signal. But I have 4 to 5 bars and I don’t think I have any signal problem. So any idea what’s up with that?

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**Author:** ![swampspruce](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/swampspruce/32/261_2.png) [@swampspruce](https://boards.straightdope.com/u/swampspruce)\
**Post date:** [September 11, 2019, 9:38pm UTC](https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057/2 "2019-09-11T21:38:44Z")

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That’s pretty typical, actually. This[link](https://usatcorp.com/faqs/understanding-lte-signal-strength-values/) gives you the normal ranges.

“RSRP – The average power received from a single Reference signal, and Its typical range is around -44dbm (good) to -140dbm(bad).” 101-108 is a fair signal. Keep in mind your phone will have a variable sensitivity compared to others.

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**Author:** ![The\_Man\_In\_Black](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@The\_Man\_In\_Black](https://boards.straightdope.com/u/The_Man_In_Black)\
**Post date:** [September 13, 2019, 12:21am UTC](https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057/3 "2019-09-13T00:21:35Z")

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Thank you. That explains it then.

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**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\
**Post date:** [September 13, 2019, 1:09am UTC](https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057/4 "2019-09-13T01:09:16Z")

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Note, the available signal strength naturally depends on the radio network/standard in use. Based on your post you are using LTE; if you were hypothetically using GSM or 3G then at -100 dBm (RSSI) your call would probably get poor or dropped. RSRP is Reference Signal Received Power, more of a narrow-band measurement, which explains why your LTE phone still works down to -120 or whatever (while the RSSI is much higher). In other words, you should check what your signal strength screen is actually displaying to be able to interpret the power level correctly.

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**Author:** ![enipla](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@enipla](https://boards.straightdope.com/u/enipla)\
**Post date:** [September 13, 2019, 2:13am UTC](https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057/5 "2019-09-13T02:13:23Z")

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If I may tag along…

We live in an area with very, very poor signal. 2-3 bars, 1x. You could make a call, but you had best not move. If you went outside, it was better.

I installed a yagi directional antenna on the roof and pointed it at our closest cell phone antenna about 14 miles away. Coax runs from the yagi to a booster in the house that ‘repeats’ the signal.

We now get 1 bar of 4g. But it’s -120db. But, we can talk on the cell phone anywhere in the house without losing the signal. :shrug: beats me. Seems to be better.

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**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\
**Post date:** [September 13, 2019, 3:15am UTC](https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057/6 "2019-09-13T03:15:49Z")

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Can you read the other parameters, eg RSSI, RSRQ and similar in addition to RSRP? Not sure why 2-3 “bars” would sound worse than 1 “bar”, nor what the bars in fact represent on your phone.

-120 dBm RSRP is close to the edge of usable LTE coverage according to **swampspruce** ’s link, but evidently it works. Yours might be -120 dBm from your booster, though, not from the cell tower. I guess in that case the question is how much power is coming from the Yagi antenna before it gets amplified, and/or what is the RSRQ value, which is proportional to RSRP divided by RSSI and therefore is some indication of the quality of the signal.

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**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\
**Post date:** [September 13, 2019, 10:08am UTC](https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057/7 "2019-09-13T10:08:56Z")

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I read a long time ago that the ‘bars’ mean very little:

> [@](#):
>
> if an algorithm of your phone says that for every 10 db you will see a bar and your friend’s phone manufacturer has set it such that for every 15 db a bar will appear, their signal will always appear to be weaker even though they may be receiving more dbs (40 dbs which would be 2 bars as opposed to 30 which would show 3 bars). Bars could be compared to a gas gauge where they give you a general idea of what the signal strength is, but not the actual strength.
> 
> [What Do Signal Bars on a Cell Phone REALLY Mean?](https://www.signalbooster.com/pages/what-do-signal-bars-on-a-cell-phone-really-mean)

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**Author:** ![swampspruce](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/swampspruce/32/261_2.png) [@swampspruce](https://boards.straightdope.com/u/swampspruce)\
**Post date:** [September 13, 2019, 9:14pm UTC](https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057/8 "2019-09-13T21:14:08Z")

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> [@enipla](#):
>
> If I may tag along…
> 
> We live in an area with very, very poor signal. 2-3 bars, 1x. You could make a call, but you had best not move. If you went outside, it was better.
> 
> I installed a yagi directional antenna on the roof and pointed it at our closest cell phone antenna about 14 miles away. Coax runs from the yagi to a booster in the house that ‘repeats’ the signal.
> 
> We now get 1 bar of 4g. But it’s -120db. But, we can talk on the cell phone anywhere in the house without losing the signal. :shrug: beats me. Seems to be better.

If you add a commercial booster you’ll see better results. we’ve had to do that on our remote sites that sit about the same or more distance from the towers.

[https://www.repeaterstore.com/products/wilson-pro-70?variant=23478804615](https://www.repeaterstore.com/products/wilson-pro-70?variant=23478804615) Pricy but you’ll be able to sit outside with your laptop…😃 Until the snow drops!

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**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\
**Post date:** [September 13, 2019, 10:00pm UTC](https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057/9 "2019-09-13T22:00:53Z")

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Note that, by amplifying the signal, the basic repeater/booster makes it stronger, but more noisy. Unless I misunderstood something. But it is useful for rebroadcasting a weak outdoor signal indoors.

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**Author:** ![enipla](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@enipla](https://boards.straightdope.com/u/enipla)\
**Post date:** [September 14, 2019, 7:32pm UTC](https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057/10 "2019-09-14T19:32:05Z")

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> [@DPRK](#):
>
> Note that, by amplifying the signal, the basic repeater/booster makes it stronger, but more noisy. Unless I misunderstood something. But it is useful for rebroadcasting a weak outdoor signal indoors.

That seems to be he case for us. We can actually use our cell phones at home, inside. We are trying to get rid of our land line as we are the only ones on the wire. It gets knocked out by weather and snow plows about 3 times a year. Um… this makes no sense for anyone. Just pisses me off and it’s basically a waste of resources to have them fix it.

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**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\
**Post date:** [September 15, 2019, 12:53pm UTC](https://boards.straightdope.com/t/question-on-cell-phone-signal-strength/840057/11 "2019-09-15T12:53:33Z")

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I dropped my landline years ago when I figured out I was paying about a buck a day for the privilege of receiving commercial calls.\* Everybody I knew called the cell number instead.

“We will clean the carpet in three rooms for $100! Solongasthethreeroomsdonotexceed100squarefeettotal.”
