SignalCheck - Android app to monitor your Wi-Fi/2G/3G/4G LTE/5G-NR signal strengths

[ingenium]

You're intermixing how IOS devices and Android devices handle things. Signalcheck cannot show both at the same time properly because it's not possible. The sole reason 1X data is showing while LTE data is showing currently is due to a change in Android 5.0+ that is causing it to report false information or causing stale information to hang around.

I'm not confusing it with iOS, I've never owned an iOS device. But I have watched them both update in LTE Discovery. I don't know how it happens, but it does. SCP is also unable to show GCI and PCI information when it happens, while LTE Discovery does (I've watched it change bands as well).

 

Perhaps the phone "thinks" about switching to 3G for whatever reason (signal quality, congestion, something else?) and is periodically checking 1x quickly before switching back? I don't know.

 

Sent from my Nexus 6

[ingenium]

I'm not confusing it with iOS, I've never owned an iOS device. But I have watched them both update in LTE Discovery. I don't know how it happens, but it does. SCP is also unable to show GCI and PCI information when it happens, while LTE Discovery does (I've watched it change bands as well).

 

Perhaps the phone "thinks" about switching to 3G for whatever reason (signal quality, congestion, something else?) and is periodically checking 1x quickly before switching back? I don't know.

 

Sent from my Nexus 6

 

Case in point, here are 2 screenshots I took seconds apart. Signal levels for both change.

 

Sent from my Nexus 6

[kct1975]

I'm not confusing it with iOS, I've never owned an iOS device. But I have watched them both update in LTE Discovery. I don't know how it happens, but it does. SCP is also unable to show GCI and PCI information when it happens, while LTE Discovery does (I've watched it change bands as well).

 

Perhaps the phone "thinks" about switching to 3G for whatever reason (signal quality, congestion, something else?) and is periodically checking 1x quickly before switching back? I don't know.

 

Sent from my Nexus 6

You are absolutely correct!

 

Since my phone was updated to 6.0 Marshmallow, I have noticed that when I am on my home WiFi, the phone correctly switches from WiFi, to 1x and the SCP doesn't show the LTE signal information while I am on the call. Once the call ends, however, SCP promptly shows the LTE signal information along with the 1x signal information.

[TimS]

You're intermixing how IOS devices and Android devices handle things. Signalcheck cannot show both at the same time properly because it's not possible. The sole reason 1X data is showing while LTE data is showing currently is due to a change in Android 5.0+ that is causing it to report false information or causing stale information to hang around.

 

I don't think it is an Android issue.  My Nexus 5 running Android 5.0 and 6.0 never has had this issue.  My Nexus 5X does have the issue and both LTE and 1x are updating when displayed together.  However, they may not be updating at the same time.

[jefbal99]

SCP is only reporting what it can gather from the Android OS.  I've watched both 1x and LTE signal strengths update in the debug engineering screens.  It is still a bug or our misunderstanding of how the latest generation of mobile devices interact with CDMA, LTE, and eCSFB.  Being these are single path device my assumption and most others are that it is a bug.

[WiWavelength]

The problem is, it is not supposed to work this way. A single radio device (which all tri-band phones are) should not be able to connect to 1x and LTE at the same time. One technology at a time. 

 

I will use just David's post to address this issue, but there are many others on the same topic on this page.

 

To be clear, single RF path means single transmission path.  Think of it just like my analysis of FCC OET filings of ERP/EIRP that covers transmission -- not reception.

 

These single RF path handsets still can have reception from multiple airlinks.  Android bug or not, that is what SignalCheck is displaying.

 

AJ

[bretton88]

Anyone else seeing massive battery drain from signal check? I have the Pro edition on the galaxy Note 5, and it's showing 23-25% battery usage.

 

Sent from my SM-N920P using Tapatalk

[kct1975]

 

 

I will use just David's post to address this issue, but there are many others on the same topic on this page.

 

To be clear, single RF path means single transmission path. Think of it just like my analysis of FCC OET filings of ERP/EIRP that covers transmission -- not reception.

 

These single RF path handsets still can have reception from multiple airlinks. Android bug or not, that is what SignalCheck is displaying.

 

AJ

Thanks AJ!

 

This is what I was trying to say. I think that the Nexus 6, since 6.0, is maintaining multiple reception, so that it can switch from LTE or WiFi to 1x for calls.

[swintec]

Thanks AJ!

 

This is what I was trying to say. I think that the Nexus 6, since 6.0, is maintaining multiple reception, so that it can switch from LTE or WiFi to 1x for calls.

 

Then how come when i cycle airplane mode during this event LTE shows and identifies as it should, with no 1x displayed?  The only reason I think it is doing this is because it does not get the GCI.  That is the only thing missing under signal check during this.

[ingenium]

Then how come when i cycle airplane mode during this event LTE shows and identifies as it should, with no 1x displayed? The only reason I think it is doing this is because it does not get the GCI. That is the only thing missing under signal check during this.

Mine almost always still displays 1x after airplane mode. Or if it doesn't it appears again very quickly. Missing the GCI and PCI is the main reason why the LTE data is incomplete and is what makes it frustrating. There must be some other method to obtain it though, since other apps can get it successfully, just not SCP.

 

AJ, that definitely makes sense that the phones have started keeping track of both.

 

Sent from my Nexus 6

[Jeffrey_J]

I know the problem exists and I'm working on it whenever I can -- literally dozens of hours each week. I've gotten a lot of PMs and e-mails from many of you; it's not unique to you, but it's not being experienced by every device. I'll get back to your messages one of these days, but I'm trying to spend my free time solving the issue instead of replying to 300 unread messages..

 

-Mike

Mike if you can look at the PM I sent to you it may help with the 1X/LTE issue.

[RyanThaDude]

I've seen this on my Nexus 6 on VZW, too, but only in certain areas or when LTE signal was weak and/or switching sites. There is an area not too far where VZW roams on USC for 1X. VZW (or a partner) started putting up LTE sites separate from USC. When these LTE sites were first turned on my N6 would always display both 1X and LTE without GCI. While the signals would appear to be correct, the data reported on LTE seemed stale and didn't update. However, both LTE and voice worked without issue.

 

Now, about a month or so ago this issue of both 1X/LTE displaying in SCP is no longer an issue as it seems VZW might have made a change on their side as nothing changed on my end (I'm still on CM 12.1 Lollipop). With this, I'm making a WAG that part of this issue is not just our phones but the sites as well. Since I don't use Sprint, is this issue happening on certain sites ? Just throwing this observation out there...

[davidtm]

Not that I'm complaining about having LTE, but I miss having the base location/address that I had with CDMA

 

 

Sent from my HTC One M9 on Tapatalk

[RyanThaDude]

Not that I'm complaining about having LTE, but I miss having the base location/address that I had with CDMA

 

 

 

Sent from my HTC One M9 on Tapatalk

While it would be nice to have that feature on LTE or even GSM sites, sadly it's not part of the technology like it is with CDMA. The good news is that you can use the notes feature in SCP to manually add your own location to the site. That, of course, means that you have to locate it as well.

 

Not that m6 carrier, VZW would use it as most of their CDMA sites don't use it, either [emoji53]

 

Sent from my Nexus 6 using Tapatalk

Edited November 21, 2015 by lilotimz

[Trip]

Not that I'm complaining about having LTE, but I miss having the base location/address that I had with CDMA

 

Sent from my HTC One M9 on Tapatalk

 

As Ryan said, LTE doesn't support BSL information like CDMA does. 

 

But with your logs (plus the logs of others!) we could put together a database file that puts the current site information in the Site Note field. 

 

- Trip

[WiWavelength]

Mine almost always still displays 1x after airplane mode. Or if it doesn't it appears again very quickly. Missing the GCI and PCI is the main reason why the LTE data is incomplete and is what makes it frustrating. There must be some other method to obtain it though, since other apps can get it successfully, just not SCP.

 

AJ, that definitely makes sense that the phones have started keeping track of both.

 

I wonder if this could be an e/CSFB issue.  Post Android 5.0, the OS may handle e/CSFB differently.  If LTE signal does not drop completely but falls below a threshold for reliable e/CSFB, then the dual CDMA1X and LTE signal display appears.  At this point, I am not sure of causation, though I am sure of correlation.

 

One experiment to try is with SMS latency.  When the dual CDMA1X and LTE signal display appears, all data still passes via LTE.  However, I have noticed that SMS latency is much higher.  As I commented to Robert a few weeks ago, I suspect that SMS then is passing over CDMA1X, not LTE.  When just LTE, SMS latency is almost instantaneous.  You can try the experiment for yourself.

 

AJ

[Jeffrey_J]

This is just a test app I made to show that all LTE info is still available during the 1X/LTE. If you are curious if your phone shows 1X and LTE info you can test it with this app. That is all it is good for.
https://drive.google.com/file/d/0BwjoW3wFn2LreWV1cVN1Zl92RDg/view?usp=docslist_api

It is based on lordsutch's SignalDetector app.

I am not responsible for any damage caused by the app.

[ingenium]

I wonder if this could be an e/CSFB issue. Post Android 5.0, the OS may handle e/CSFB differently. If LTE signal does not drop completely but falls below a threshold for reliable e/CSFB, then the dual CDMA1X and LTE signal display appears. At this point, I am not sure of causation, though I am sure of correlation.

 

One experiment to try is with SMS latency. When the dual CDMA1X and LTE signal display appears, all data still passes via LTE. However, I have noticed that SMS latency is much higher. As I commented to Robert a few weeks ago, I suspect that SMS then is passing over CDMA1X, not LTE. When just LTE, SMS latency is almost instantaneous. You can try the experiment for yourself.

 

AJ

I've also noticed SMS latency increasing on LTE post 6.0 (when the 1x + LTE issue appeared on the Nexus 6).

 

Sent from my Nexus 6

[Trip]

Mike,

 

Two things:

 

1)  My MetroPCS phone won't roam on AT&T, but does connect to AT&T GSM when all else fails in case it needs to make a 911 call.  However, when it makes those connections, it doesn't report the Provider information.  Despite this, it shows the text about adding a site note, but if you tap it, it says it can't add one.  Would it be possible to either have it log sites without provider information, or have it not show the text about adding a site note if it's just going to fail when I tap it? 

 

2)  Do you happen to know what phones people are using on Verizon (13/4), AT&T (2/4/5/17), and US Cellular (5/12) with SignalCheck that properly show GCI/PCI?  I'm trying to buy cheapie phones to be able to track/map all carriers, like I've already done with my MetroPCS phone for T-Mobile, but SCP compatibility is obviously not something that is regularly reported in reviews. 

 

Thanks.

 

- Trip

[RyanThaDude]

 

 

2) Do you happen to know what phones people are using on Verizon (13/4), AT&T (2/4/5/17), and US Cellular (5/12) with SignalCheck that properly show GCI/PCI? I'm trying to buy cheapie phones to be able to track/map all carriers, like I've already done with my MetroPCS phone for T-Mobile, but SCP compatibility is obviously not something that is regularly reported in reviews.

My Nexus 6 had displayed both PCI and GCI on VZW, TMO, Sprint (Project Fi), and AT&T for LTE. I can only assume it will do the same on other carriers as well. What's nice is that ever since the Nexus 6P & 5X were released the 6's price has plummeted. Plus, it's a great phone, too.

 

 

Sent from my Nexus 6 using Tapatalk

[Trip]

My Nexus 6 had displayed both PCI and GCI on VZW, TMO, Sprint (Project Fi), and AT&T for LTE. I can only assume it will do the same on other carriers as well. What's nice is that ever since the Nexus 6P & 5X were released the 6's price has plummeted. Plus, it's a great phone, too.

 

 

Sent from my Nexus 6 using Tapatalk

 

The Nexus 6 is, unfortunately, a bit pricey for a cheapie phone.  (My MetroPCS phone was almost exactly $100.)  I have been considering a Nexus 5 though.  I am just curious if there's anything cheaper, since I'm not planning to actually use the phone as a phone, but rather, to look for GCI/PCI for map-making purposes.  If I can get it to connect to LTE without service, like my MetroPCS phone does, that would be a bonus.

 

- Trip

[Fraydog]

I'm on the Verizon Galaxy Note 5 and that definitely shows the PCI and GCI correctly.

 

Sent from my SM-N920V using Tapatalk

[DrJason]

I have both SignalCheck Pro and LTE Discovery on a Nexus 6p.  Most of the time they both show the same info.  Sometimes they show that I'm connected to different bands.

 

For example today SCP said that I was on B41 while LTE Discovery said that I was on B25.

Last week LTE Discovery said I was on B26 while SCP said I was on B25.

 

Not sure which app is showing the correct data when they disagree.  Any suggestions?

[ingenium]

I have both SignalCheck Pro and LTE Discovery on a Nexus 6p. Most of the time they both show the same info. Sometimes they show that I'm connected to different bands.

 

For example today SCP said that I was on B41 while LTE Discovery said that I was on B25.

Last week LTE Discovery said I was on B26 while SCP said I was on B25.

 

Not sure which app is showing the correct data when they disagree. Any suggestions?

Did they show the same GCI? Both apps determine the band based on GCI (to my knowledge anyway), so it could be one of them has an incorrect mapping.

 

As a side note, I've found that the Nexus 6p works much better with SCP than the Nexus 6 post Marshmallow. It's actually usable again for logging, though the 1x + LTE "bug" still occurs, but much less frequently and eventually corrects itself (or airplane mode fixes it immediately).

 

Sent from my Nexus 6P

[JWMaloney]

I wonder if this could be an e/CSFB issue.  Post Android 5.0, the OS may handle e/CSFB differently.  If LTE signal does not drop completely but falls below a threshold for reliable e/CSFB, then the dual CDMA1X and LTE signal display appears.  At this point, I am not sure of causation, though I am sure of correlation.

 

One experiment to try is with SMS latency.  When the dual CDMA1X and LTE signal display appears, all data still passes via LTE.  However, I have noticed that SMS latency is much higher.  As I commented to Robert a few weeks ago, I suspect that SMS then is passing over CDMA1X, not LTE.  When just LTE, SMS latency is almost instantaneous.  You can try the experiment for yourself.

 

AJ

 

AJ, I think you're on the right path, but my interpretation is slightly different. I suspect SMS is still passing over LTE, which is precisely the reason for the delay: e/CSFB devices will still periodically scan both networks in-between the LTE paging interval to report back to the eNB, so there's a chance what you're seeing is related to being in a connection state in which an active session must be re-established (such as idle, TAU, etc.).