Jump to content
ReyBanz

Network Vision/LTE - East Michigan Market (Detroit/Flint/Ann Arbor/Tri-Cities)

Recommended Posts

10 hours ago, mikejeep said:

 

I'm still 50/50 on whether or not these are a glitch (scan?) or actual connections (however brief they may be). I kept seeing quick flashes of B17 in an area with no usable Sprint signal so I took my AT&T test phone over there and confirmed the PCI/GCI/TAC of B17 there, and it matched what I was seeing on my Sprint phone. On at least one occasion I did have an active data connection that held for longer than usual as well.

 

My thinking (whatever that's worth) is if you get an actual legitimate GCI, you connected. If not, it was a scan.

 

(Might be worth moving this discussion to the SCP thread or a new one, this isn't specific to MI nor do I want to clog up the thread..)

 

-Mike

The issue for me is that it happens to me regularly in SCP.  But never in NSG or Engineering Screen.  Just SCP.  And I monitor NSG a lot.  And I have never seen it do that once.  And NSG is rapidly updating on the fly.  It's not a slow data refresher.

Robert

Share this post


Link to post
Share on other sites
The issue for me is that it happens to me regularly in SCP.  But never in NSG or Engineering Screen.  Just SCP.  And I monitor NSG a lot.  And I have never seen it do that once.  And NSG is rapidly updating on the fly.  It's not a slow data refresher.
Robert
NSG loads the Qualcomm debug interface and somehow tricks it into outputting locally instead of via USB (possibly some kind of kernel loopback device?). If you connect the phone to your computer and run software such as Actix or TEMS, then load NSG, the computer loses the connection. Likewise, if NSG is running, it prevents Qualcomm diagnostics over USB and the software can't find the phone. As soon as NSG exits, the phone appears.

So NSG is getting its data directly from the modem. The engineering screens may be similar and bypass the Android API? SCP has to wait for Android to refresh its modem data, which seemingly isn't an atomic operation. I'm curious if you see it in other apps that use the Android API, such as Cell Mapper or LTE Discovery?

Sent from my Pixel 2 XL using Tapatalk

  • Like 1

Share this post


Link to post
Share on other sites
9 hours ago, ingenium said:

NSG loads the Qualcomm debug interface and somehow tricks it into outputting locally instead of via USB (possibly some kind of kernel loopback device?). If you connect the phone to your computer and run software such as Actix or TEMS, then load NSG, the computer loses the connection. Likewise, if NSG is running, it prevents Qualcomm diagnostics over USB and the software can't find the phone. As soon as NSG exits, the phone appears.

So NSG is getting its data directly from the modem. The engineering screens may be similar and bypass the Android API? SCP has to wait for Android to refresh its modem data, which seemingly isn't an atomic operation. I'm curious if you see it in other apps that use the Android API, such as Cell Mapper or LTE Discovery?

Sent from my Pixel 2 XL using Tapatalk
 

That's great info.  And coupled with that, it makes me even more convinced there is not an actual connection occurring.  If so, given the way NSG takes directly from the modem, it would be showing that data the instant it was connecting.  Yet it has never happened to me in NSG.  I use Cellmapper a lot in the background.  But I find watching the Cellmapper connection screen difficult to glance at while driving.  So I never monitor it.

Of course, it doesn't seem like it's an SCP error.  The app isn't doing anything wrong, it would just be that these phantom connections are being reported to SCP from Android.  It is contaminating its reporting data when it scans and reports it.  Then SCP populates that data from Android.  Even though a bona fide connection did not actually happen.

Other things that make me think these are not connections...It happens to me with Project Fi SIM too.  If I am connected to Sprint or US Cellular or T-Mobile, it happens to me too and the PLMN ID stays with whomever I was connected to last.  In addition to Sprint, I've seen US Cellular B4, US Cellular B17, US Cellular B41, US Cellular B12 and T-Mobile B5, T-Mobile B26, T-Mobile B41, etc., etc.  I believe Android OS gets some data from these scans, and it doesn't get a new PLMN ID because there was no actual connection.  It reports out the data it received in the scan and mixes stale data that it did not receive, like PLMNID.  Voila.  Of course, all hypothesis on my part.  But it matches what I've seen.

And Project Fi does not roam on AT&T LTE.   And neither does US Cellular nor T-Mobile.  But it freely populates AT&T LTE channel locations all the same.  Because it is in an unlocked every band device and those AT&T channels are being scanned looking for a Sprint, T-Mobile or US Cellular connection.

I am convinced these are other bands scans showing up in the connection data from Android OS.  And the best I can recollect, this only happens when I have a really weak signal and it is actively scanning for anything.  To keep from dropping completely.  And it seems to only affect me when I'm driving and signal intensity and proximity is randomly changing.  Most often in conjunction with band locking in my instances.

The phone is definitely reporting the signals.  And it probably was trying to connect with them.  Much of the information is accurate about what it's reporting, like channel assignment.  Giving us hope that something great is happening.  It's just not a live and usable connection.  Scanning is still ongoing. 

I'm not convinced something good is happening.  We just are seeing a little more behind the scenes of scanning, and misreporting of that data.  I could be wrong.  But I see this error frequently.  Nearly daily.  And sometimes, a dozen times in an hour.  It can be really annoying when trying to locate weak and distant new B26 sites.  Like here in Washington State and over there in Michigan.

Robert

  • Like 4

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×