T-Mobile 5G Bands via OnePlus 8 Pro

  1. B1592018270118
    Cupcake Jul 14, 2020

    B1592018270118 , via OnePlus 8 Pro , Jul 14, 2020 :
    I'm confused with CellMapper app and how to read it.

    Using US version of the OnePlus 8 Pro phone (IN2025) with v10.15.11

    Shows me connected to T-Mobile 5G with speed 90 Mbps on band 2 or band 66. Both T-Mobile LTE bands.

    Am I reading this right?



    Attached Files:

    Last edited: Jul 14, 2020

  2. Stinky_Toe
    Cupcake Jul 15, 2020

    Stinky_Toe , via OnePlus 8 Pro , Jul 15, 2020 :
    Cellmapper can be tricky to interpret plus it does not directly show LTE carrier aggregation. I always use it together with SignalCheck. Here is an example of what it shows for me for T-Mobile 5G on band 66 and aggregated frequencies.

    Let me know if you have any questions.

    Best Regards,


  3. B1592018270118
    Cupcake Jul 15, 2020

    B1592018270118 , via OnePlus 8 Pro , Jul 15, 2020 :
    Isn't it band 66 part of the LTE network, and not 5G? That's what confused me. You're showing me exactly what I'm having, too.

  4. pgrey
    Ice Cream Sandwich Jul 28, 2020

    pgrey , Jul 28, 2020 :
    I'm seeing more or less the same, as well, located in a "Excellent 5G area", according to T-Mobile.
    I think the LTE/5G aggregation is a mess, on the 8/8 Pro, currently. If I enable 5G, my LTE throughput goes to near-zero, particularly the backhaul.
    My 5G, despite being indicated, doesn't appear to be able to handle any data, none, nada, despite the T-Mobile Tier2 engineer saying I'm connected and should be able to use it, effectively.

    My CellMapper data is similar to the above, and my other go-to apps (Network Cell Info Lite & Signal Strength) don't seem to acknowledge the 5G signal, what-so-ever (which kind of makes sense, in the OP-Settings->About, I see "0 dBm and 0 asu", for the 5G, although my LTE signal is strong, even though it's NOT, the aggregate).

    Lots of head-scratching here, lots and lots...

  5. ronnyhawks
    Ice Cream Sandwich Jul 28, 2020

    ronnyhawks , via OnePlus 8 Pro Ultramarine Blue , Jul 28, 2020 :
    You might want to update your sim card with a new one. I'm on T-Mobile and I'm connected to 5G almost 100% of the time and I can pull 300 Mbps average easily just about anywhere

    Amanda W. likes this.
  6. SeaRefractor
    Gingerbread Jul 28, 2020

    SeaRefractor , Jul 28, 2020 :
    Not following here. I asked T-Mobile and the SIM isn't different, would have no impact on 5G at this time.

  7. pgrey
    Ice Cream Sandwich Jul 29, 2020

    pgrey , Jul 29, 2020 :
    Yeah, that's what I'm wondering, too.
    This evening, I was out riding (road cycling), and I stopped, about 1mi due-NE of the TMo main HQ, in Bellvue/Factoria, and I still got 0 dBm and 0 asu values, also tested in several other spots, right along the I-90 corridor.

    @SeaRefractor Yeah, that's my understanding, too, and the Tier2 tech I spoke to today (he's off tomorrow, calling back Thursday), said the same thing, and STILL suggest I go get another SIM, for whatever that's worth (there's a note on my account to not charge)... ;-]

    Either something is really off with my INO2025 OP8 Pro, running build 10.5.12.IN11AA, or something is wonky with an OS config (I did multiple radio-reset yesterday, system cache flush, OP Launcher flush, finally a full factory-reset/restore yesterday as well), or it's my SIM.
    My money's on the SIM at this point, honestly, even if it makes no sense, logically/computationally...
    I'm going to figure out which TMo store is open, nearby, and stop by for a replacement SIM, worst-case, it's a quick trip.

  8. pgrey
    Ice Cream Sandwich Jul 30, 2020

    pgrey , Jul 30, 2020 :
    Hmm, so that was a wasted errand, the trip to T-Mobile.
    They swapped my SIM, and showed me that their S20+ was getting 5G fine, at their store.

    Back to my OP8 Pro, and nix-nada, 5G-indicated, but won't actually connect, still dead-signal (0 dBm, 0 asu values).
    I guess, ultimately, I don't know if it's a provisioning problem with my account, the phone h/w (seems unlikely, but not completely impossible), or some sort of weird provisioning problem.

    Ugh. I'm open to any suggestions on how to test/debug this further...

    @ronnyhawks When you get those metrics, if you go the About->SimStatus, is the NR radio valid, i.e. not 0 dBm and 0 asu values?
    I've seen similar performance to that (more like 250/100) in the greater-Seattle area, on 4G/LTE, so I'm just trying to verify here, thanks.
    Last edited: Jul 30, 2020

  9. Last edited: Jul 30, 2020

  10. pgrey
    Ice Cream Sandwich Jul 30, 2020

    pgrey , Jul 30, 2020 :
    Yep, that's my screenshot, dead-on, except perhaps a slightly different LTE dBm value.
    I'm pretty sure that the NR (New Radio, denotes a 5G radio, exclusively, AFAIK) having zero values is bad news. I'd assume it's as in "it can see the tower, but not actually use the signal for data."
    I guess that part is slightly speculative, but why would the LTE radio be fine (or plenty good enough), in terms of signal-strength, and the NR radio essentially a non-usable signal?
    Maybe it's a bit of a red-herring, I suppose, perhaps it's time to go peruse some Android code and/or specs...

    The problem with 5G being (sort of) new, is that there's very little "frequency/band cheat sheet" type stuff out there, for most of the values, yet, IME ;-]

  11. pgrey
    Ice Cream Sandwich Jul 30, 2020

    pgrey , Jul 30, 2020 :
    Update: I forgot to mention this, but I did a little "5G survey experiment" yesterday, in hopes of resolving this.
    I drove around, and tested it at several locations, the nearby TMo store (full storefront, NOT a auth-retailer), right in front of TMo main HQ (Factoria, WA), several places between I90 and 520, on I405 (this is where the upper-tier tech said there were multiple 5G towers), same deal, always a 0-value signal(s).

    When the tier2-tech called back today (at least that happened), from T-Mobile, they said "there was a 5G tower problem at my closest tower, and a team was dispatched" (hmm, yeah), but they had no idea why I couldn't get signal at the other sites, none, nada. They suggested waiting a week, and testing again, really?

    The other interesting thing (the tech was really surprised by this) is that they tested a couple of Samsung S20+ and Ultra devices, at the store, expecting to see signal, but got the same results, as my OP8 Pro. There were some interesting "eye expressions" there (masks on all of us, of course) at that one, they seemed very confident that they could show me a solid signal, in-store.

    So I'm a bit confused, to put it nicely.
    Additionally, CellMapper says 5G State is "enabled", but 5G Status is "NOT_RESTRICTED", which seems to be pretty murky, if you try to chase that term down, from other posts.

  12. ronnyhawks
    Ice Cream Sandwich Jul 31, 2020

  13. ronnyhawks
    Ice Cream Sandwich Aug 1, 2020

    Last edited: Aug 1, 2020

  14. ronnyhawks
    Ice Cream Sandwich Aug 1, 2020

  15. ronnyhawks
    Ice Cream Sandwich Aug 1, 2020

  16. Kmcshane1
    Cupcake Aug 1, 2020

  17. pgrey
    Ice Cream Sandwich Aug 2, 2020

    pgrey , Aug 2, 2020 :
    Yep, @ronnyhawks same APN as well, exact match on yours (this is the default provisioned APN, for me). I also tried one that's suggested, on for the 7T 5G model, on the TMo site, but same deal, zero-strength signal.

    Maybe (most of) the greater Seattle area has had no 5G (low band obviously) service now, for a week, but I sort of doubt it.
    There's something "odd" with the WiFi radio, too, if it's enabled/connected, the 5G signal (the zero-strength one) goes away, entirely. If you sit there and flip WiFi on/off, or "forget all your networks within range", it will find the zero-strength 5G connection again, weird stuff (doesn't matter if it's a 5GHz or 2.4Ghz one, either, I tried an isolated SSID, for both bands).
    I filed a bug on this one, just need to run the repro and submit logs (the BH team pinged me about it, pretty quick, perhaps a good sign).

    This thing is ALL sorts of buggy/unreliable, that'd be my general experience of the (hopefully just f/w) OP8, so far, at least with regards to connectivity...
    A couple of times I've had my mobile-radio just "disable itself", or go offline, and have had to reboot to get connectivity going again, that's a first, for me, on a OP device.

  18. ronnyhawks
    Ice Cream Sandwich Aug 2, 2020

    ronnyhawks , via OnePlus 8 Pro Ultramarine Blue , Aug 2, 2020 :
    I'm guessing that it just has to do with them upgrading towers in your area. I live around Minneapolis and when I first got my OnePlus 8 it said 5G but it never actually connected to it. Running the Ookla speedtest.net app I would say that I was connected to LTE at all times. About two weeks after getting the phone they must have upgraded the towers in my area because I started to pull 300mbps just about anywhere around me and it actually shows that I am connected to 5G in the speedtest app now. Same with my OnePlus 8 Pro

  19. pgrey
    Ice Cream Sandwich Aug 2, 2020

    pgrey , Aug 2, 2020 :
    Yeah, maybe.
    The last upper-tier tech I talked to said there was one(1) 5G tower with an issue, in my area (that was 3 days ago, and he said a crew was already out to check/fix it, per my report). He also gave me the approximate locations of several others, for testing.
    When I did my "survey experiment", in my above post, that was at 4 of the locations he mentioned, and I got the exact same results. Maybe the tech had no idea, that the entire area was being upgraded/down, which would've been weird, because he seemed to think I should be getting good->excellent signal (from my home, to those sites).
    One spot was literally a couple of blocks in front of T-Mobile HQ, with clear-line-of-sight. If you'd have to bet on a "working location", that sure seems like that would be it (via tower, femtocell, whatever...).

    OnePlus has my logs now, from the WiFi transition test (in my bug report on that issue), and I perused the radio log files, from the same, and you can see where it acquires a 5G signal, and is set to enabled, but that's about it, it just disables itself again, a few milliseconds later on.
    I'm debating on filing a "more general 5G connectivity issue bug", but I'm just not quite sure how they'll receive that.

    For now, my 5G radio is off, because I can't make it through more than a half-day, in terms of battery, if I leave it enabled (it drains about 4-7%/hour, if left COMPLETELY IDLE, no screen, nothing, and very few background apps enabled, mostly just messages, phone and a couple of other essential, like Google Services)...
    It also "handily" shuts itself off (the mobile radio), if left in 5G (I had this happen 3-4 times, when I did leave it enabled). If I can figure out the repro for this one, I'll definitely file it (it needs to be within a reasonable few-minutes window, obviously, for log tracing size and such).

    Something is off/fishy with the whole mess here. I suppose I could dig into the radio code a bit, but I'm really not an Android device-level dev, at all, so I'm hoping OP will dig in here, and come up with some results.
    Best-case, the current OP8 f/w releases sure seem REALLY buggy, making the early days of the OP7 seem fantastically-stable, by comparison, IME/IMO.
    Last edited: Aug 2, 2020

    ronnyhawks likes this.