LTE Plus / Enhanced LTE (was "Sprint Spark" - Official Name for the Tri-Band Network)

[VW Maverick]

Got this on my Galaxy Nexus.

Mav.

 

Sent telepathically with the ESP App.

Edited November 6, 2012 by VW Maverick

[Chaitu]

OK. I think I have typed this 50 times now in several forums. So I have decided to consolidate this in one thread and direct people here...

 

Did you know that with Sprint LTE Android devices, the signal strength indicator at the top does not show your LTE signal strength? Even if 4G is displayed next to it?

 

This signal displayed here is always your 1x (voice signal), and it is not your 3G EVDO signal strength, nor your LTE signal strength. Regardless of whether it says 3G or 4G next to it. This is the cause of a lot of confusion. Also, third party apps like NetMonitor and CDMA Field Test do not show accurate LTE signal strengths. They also only show the 1x signal strength, even though they may reference being connected to LTE.

 

The purpose of this thread is to help educate the masses, because many people think they have a strong LTE signal, when in fact they do not. And then they are unhappy, thinking that Sprint LTE is really slow, even with a strong signal. LTE performance is very signal strength dependent. So, when you have a weak signal, you can expect much slower than peak results.

 

There is only one accurate way to get your LTE signal strength, and that is from your LTE Engineering screen in your Debug menu. And we will discuss the different ways to get that below.

 

...In the EVO LTE, LG Viper & Motorola Photon Q LTE:

• Go in to your phone app, and dial ##DEBUG#
  
• Select LTE Engineering
  
• Go down to RSRP. The number under RSRP shown in dBm is your LTE signal strength.
  

...In the Galaxy S-III, Victory LTE & Note II:

• Go in to your phone app, and dial ##DEBUG#
  
• Enter 777468 for your lock code
  
• Select LTE Engineering
  
• Go down to RSRP. The number next to RSRP shown in dBm is your LTE signal strength.
  

...In the Galaxy Nexus:

• Go in to your phone app, and dial *#*#DEBUG#*#*
  
• Enter 777468 for your lock code
  
• Select LTE Engineering
  
• Go down to RSRP. The number next to RSRP shown in dBm is your LTE signal strength.
  

The LTE Signal Strength Scale:

 

Now you have determined your actual LTE signal strength in dBms your device is receiving, you can use the following scale below to determine its strength:

• Better than -96dBm is a great signal
  
• Between -97dBm and -107dBm is good
  
• Between -108dBm and -114dBm is fair
  
• Worse than -115dBm is poor
  

Feel free to link people to this thread for explanation. Hopefully, this will clear up some confusion out there!

 

NOTE: It appears that the iPhone 5 does show LTE signal strength in the status bar, when the LTE icon is displayed. So this does not apply to the iPhone.

Also another factor for good download speeds is the latency which determines the time taken to connect to the IP-Backhaul and backbone. The RSRP is good measure to find out the signal quantity but for signal quality SINR value needs to be accounted which shows a clean signal . below are the approx ranges for that metric

22 dbm-30dbm--- excellent

11dbm-22ddm--- decent

0dbm- 11 dbm--- bad

[S4GRU]

Also another factor for good download speeds is the latency which determines the time taken to connect to the IP-Backhaul and backbone. The RSRP is good measure to find out the signal quantity but for signal quality SINR value needs to be accounted which shows a clean signal . below are the approx ranges for that metric

22 dbm-30dbm--- excellent

11dbm-22ddm--- decent

0dbm- 11 dbm--- bad

 

Signal quality is definitely a factor.

 

Robert

[WiWavelength]

The RSRP is good measure to find out the signal quantity but for signal quality SINR value needs to be accounted which shows a clean signal . below are the approx ranges for that metric

22 dbm-30dbm--- excellent

11dbm-22ddm--- decent

0dbm- 11 dbm--- bad

 

True, but LTE also has RSRQ, which is an LTE specific measure of signal quality. Also, SINR (or CINR) should not have dBm appended, just dB, since SINR is a relationship between two variable quantities, not a relationship between one variable quantity and a fixed 1 mW level.

 

Just FYI, for any of our readers who have frequently seen the dBm unit but wondered what it actually represents, it is "decibels relative to 1 milliwatt." So, a typical -90 dBm signal is 90 dB below 1 mW. And -90 dBm is much easier to parse than is 0.000000001 mW or 0.000000000001 W, though all three figures depict the same signal level.

 

AJ

[eSchreibman]

Has anyone used Android Signal Info by Coding Creation

(http://rootzwiki.com...id-signal-info/)

 

It 'seems' to show RSRP/ RSSI RSRQ SNR for LTE.

As a bonus, the dev has a neat graphic that helped me get my head around a couple of these terms:

 

[WiWavelength]

Has anyone used Android Signal Info by Coding Creation (http://rootzwiki.com...id-signal-info/) It 'seems' to show RSRP/ RSSI RSRQ SNR for LTE.

 

Yes, I found the Android Signal Info app and RootzWiki thread about six months ago -- back when the app still had to be side loaded. I have mixed feelings about it. I am not a programmer, so I respect the effort "yarly" put in to create an app himself. However, the app has some shortcomings.

 

Its RSRP and RSRQ figures are already available via the internal debug screens on various handsets. And its RSSI calculation, which uses a questionable (RSRP − RSRQ + 17) formula, is predicated entirely on one particular LTE carrier bandwidth: 10 MHz FDD (e.g. VZW in all markets, AT&T in some markets), but not 5 MHz FDD (e.g. Sprint in all markets, AT&T in some markets). So, the app purports to be carrier agnostic, but it really is not. For LTE, it is geared toward VZW, as "yarly" is a VZW user.

 

Additionally, "yarly" seems to misunderstand the SNR (signal to noise ratio) metric, as he quotes in the RootzWiki thread SNRs on the order of 300 dB. For a radio link, a 300 dB SNR is basically impossible -- that is a 10^30:1 ratio. "yarly" does not seem to get that the SNR reported is multiplied by 10. So, that "300 dB" SNR is actually a 30 dB SNR, which is extremely good.

 

AJ

[Troyhe98]

Not sure why my phone keeps switching to 4g and back to 3g but at exit 5 on I4 it switched to 4g and back to 3g as I neared exit 1. I didn't get the 4g signal at my office today. I tried debugging my phone to check the signal as described in the article but it didn't work. There must be a different way, or I am doing something wrong..

[nahum365]

What I don't understand is the iPhone's choice of how many bars to display. For example, a -88dBm signal is considered a 4 bar (very good) signal. But a -92dBm is considered a 1 bar (horrible) signal. But that's only when I'm using 1X or EVDO. The LTE signal strength bars are usually spot on. Right now I have a -101dBm signal and its considering it as a 1 bar. That's odd too, considering I had a -79dBm signal 2 minutes ago. And I haven't moved the phone. I'm not even holding it. Just tapping on it as its propped up on my computer monitor.

[WiWavelength]

What I don't understand is the iPhone's choice of how many bars to display. For example, a -88dBm signal is considered a 4 bar (very good) signal. But a -92dBm is considered a 1 bar (horrible) signal. But that's only when I'm using 1X or EVDO.

 

Those CDMA1X RSSI figures are relatively similar. But I doubt that the iPhone is using RSSI to drive the signal bars. Rather, it is probably using Ec/Io. And due to loading, Ec/Io can vary considerably with the same RSSI.

 

AJ

[nahum365]

 

 

Those CDMA1X RSSI figures are relatively similar. But I doubt that the iPhone is using RSSI to drive the signal bars. Rather, it is probably using Ec/Io. And due to loading, Ec/Io can vary considerably with the same RSSI.

 

AJ

 

Ah. So the signal strength isn't always exactly accurate? Like when there are a lot of people on the tower?

[Marty]

I've read through this thread but perhaps I missed the answer to a question I have. I understand that the bars displayed represent 1x strength, not 3G or 4G. However, when my Optimus G picks up a 4G signal when I am at home (the only place where I can currently get a 4G signal), the signal meter shows 0 bars. If I tell the phone to use 3G only, I get 4 bars. I am not doubting that the bars reflect 1X but why do they switch between 0 and 4 bars when going between 4G and 3G?

[WiWavelength]

I've read through this thread but perhaps I missed the answer to a question I have. I understand that the bars displayed represent 1x strength, not 3G or 4G. However, when my Optimus G picks up a 4G signal when I am at home (the only place where I can currently get a 4G signal), the signal meter shows 0 bars. If I tell the phone to use 3G only, I get 4 bars. I am not doubting that the bars reflect 1X but why do they switch between 0 and 4 bars when going between 4G and 3G?

 

I believe it has been shown that LG handsets are outliers. They display the signal strength of the highest connected airlink protocol.

 

AJ

[jamesinclair]

I was looking at my gfs verizon samsung galaxy 3, and under her settings, status, it said she was at -115db with 2-3 bars. 4G was indicated at the top of the phone. I was surprised because I was under the impression anything worse than 110 was no service. I read this thread to see that for LTE its different.

 

Does that mean verizon phones show the lte signal strength while sprint phones show the voice strength?

[WiWavelength]

I was looking at my gfs verizon samsung galaxy 3, and under her settings, status, it said she was at -115db with 2-3 bars. 4G was indicated at the top of the phone. I was surprised because I was under the impression anything worse than 110 was no service. I read this thread to see that for LTE its different.

 

Guaranteed, the -115 dBm reading was LTE RSRP. The 2-3 signal bars, however, could have been and probably were based on CDMA1X RSSI. So, all bets are off. Engineering screens (or apps that pull from the same) are the only worthwhile sources of signal data.

 

AJ

[jamesinclair]

I dont understand why they dont have two signal bar. Wimax with a separate 4G signal bar was perfect.

[WiWavelength]

I dont understand why they dont have two signal bar. Wimax with a separate 4G signal bar was perfect.

 

TMI. Too much information for the commoners. And that is probably for the best. Nearly all mobile phone users need info on the level of a one bit binary value. Will the device work at this time in this location? Yes/no? Any info more granular than that just causes them needless agita.

 

AJ

[Sgt. Slaughter]

I dont understand why they dont have two signal bar. Wimax with a separate 4G signal bar was perfect.

 

WiMax devices also had a completely separate radio chip for wimax only... Might have something to do with them displaying the two signal bars then...

 

Might pose more difficult with the integrated radios....but I honestly don't see why that would be the case since they display the signal levels on the ENG screens already, so it shouldn't be much of an issue to map that value to a signal meter really....

 

See if I can get a developer over on xda to tackle that possibly...

 

 

 

Sent from my EVO using Tapatalk 2

 

 

[jamesinclair]

TMI. Too much information for the commoners. And that is probably for the best. Nearly all mobile phone users need info on the level of a one bit binary value. Will the device work at this time in this location? Yes/no? Any info more granular than that just causes them needless agita.

 

AJ

 

I dont think its too much information at all.

 

I think not knowing why voice works but data doesnt is a bigger deal.

[Zman1369]

 

I mentioned it in another thread, but you can make a shortcut instead of entering dialer codes to get to this screen.

Download "QuickShortcutMaker" from the Play Store, run it and enter "field" in the search box. It should find Field Trial. Click on it and it will create a shortcut to use instead of the codes.

this was perfect, thanks.

 

EVO-LUTION 4G LTE

 

 

[WiWavelength]

I dont think its too much information at all.

 

I think not knowing why voice works but data doesnt is a bigger deal.

 

Good grief, you, too, are missing my point.

 

Do you understand that you may not represent most cellphone users? And do you understand that many cellphone users think that they cannot effectively use their devices if their signal bars are low?

 

Heck, I would like for engineering screen readouts to be standard on the home screen, but that does not mean my wish is appropriate for all users.

 

AJ

[S4GRU]

I get a -102dBm EVDO/1x signal in my work office and I will get pings of 90-120ms and 1.2Mbps speeds. And my phone calls are crisp and clear. Low signal does not always equal low performance.

 

Robert via Samsung Note II via Tapatalk

 

 

[jamesinclair]

Good grief, you, too, are missing my point.

 

Do you understand that you may not represent most cellphone users? And do you understand that many cellphone users think that they cannot effectively use their devices if their signal bars are low?

 

Heck, I would like for engineering screen readouts to be standard on the home screen, but that does not mean my wish is appropriate for all users.

 

AJ

 

I worked at a cell phone customer care call center. I think I have a pretty good understanding of what the average cell phone user thinks, considering I talked to 70 of them a day.

[EvoMania]

I get a -102dBm EVDO/1x signal in my work office and I will get pings of 90-120ms and 1.2Mbps speeds. And my phone calls are crisp and clear. Low signal does not always equal low performance.

 

Robert via Samsung Note II via Tapatalk

 

What offsets that low signal? Is it low noise and the quality of the signal even though its a low signal? Can you explain in depth?

[WiWavelength]

What offsets that low signal? Is it low noise and the quality of the signal even though its a low signal? Can you explain in depth?

 

CDMA1X does not require great signal strength. Remember, it is using the full 1.25 MHz channel bandwidth to deliver a voice signal that averages about 5-6 kbps.

 

AJ

[EvoMania]

CDMA1X does not require great signal strength. Remember, it is using the full 1.25 MHz channel bandwidth to deliver a voice signal that averages about 5-6 kbps.

 

AJ

 

Thanks but I was already somewhat aware that 1x works well at low signals. I should have said been more precise with my question. I want to know how he is able to get great data speeds with such a low signal. In my experience, having a signal of -100+ is almost always handcuffed to dismal or decent speeds not 1mbps+