I have a grandfathered contract with T-Mobile that gives me “unlimited” internet on my cell and 6GB of hotspot data. I have been using only cellular internet with my laptop, and can quickly go over the 6GB allotment. Downloads, Video and Audio can eat up a lot of data.
I installed an extension that disables video and audio, which disables preloading and autoplay. As a benefit, it's a reminder that I'm on the hotspot. If I want I can watch the videos on my cell, since it has unlimited.
Tampermonkey / Greasemonkey user script: https://greasyfork.org/en/scripts/8022-disable-audio-video-autoplay
Instead of the default tethering built into Android (of which earlier versions of Android didn't have), you can use a tethering app. Data consumed by the tethering app may show up as regular cell use, rather than hotspot use, as it has for me with Open Garden.
In order for a tethering app to work properly, you may have to adjust battery saver settings on the phone. I already had disabled App Power Monitor, but this was not enough, so I also found the Apps setting below. This was on a Note 9 with Android Oreo. They keep shuffling the settings so your settings locations may be different, and go by different names. They are funny that way.
Settings > Apps > Your Tethering App > Mobile Data > Allow Background Data Use
Settings > Apps > Your Tethering App > Mobile Data > Allow App while Data saver on
Settings > Apps > Your Tethering App > Battery > Allow Background Activity
Settings > Apps > Your Tethering App > Battery > Optimize battery usage (not optimized)
the previous setting is also here: Settings > Apps > | > Special Access > Optimize Battery Usage
This setting is probably not necessary given the previous settings:
Settings > Device Maintenance > Battery > App power monitor > Turn Off
I have a feeling you will get the best results by using a custom ROM. If you have a stock ROM, T-Mobile knows what apps you have installed. If they have that level of control, then they could very well throttle on a per-app basis. Unfortunately for me, the SM-960U1 phone I have cannot be rooted. I am getting unreliable speeds with Open Garden, between not working to 1.0 mbps. I am able to use it, but I don't recommend it as a long term solution. Eventually I will also try SecureTether BT, and see how that goes, to further verify the hypothesis. I can also try the paying for the VPN option that comes with my Blokada, just for the curiosity to see if that makes a difference.
I'm using Open Garden, which is no longer supported and hasn't been updated in forever. In addition to the Android app, I needed the desktop download for MacOS. Open Garden is somewhat flaky. Sometimes I have to reconnect the desktop to the phone by restarting the desktop version of Open Garden. Sometimes I have to restart Open Garden on my phone because it looses internet.
Make sure you remove/unpair your phone/laptop from each other, before connecting via Open Garden. I think the two protocols may interfere with each other. Open Garden does not need pairing to work. If either device asks for pairing, cancel. Also turn off wifi after Open Garden turns it on.
Another hotspot app, using the lower powered Bluetooth for less battery consumption than Wifi. The instructions are easy to follow, but be ready to use the command line. It didn't work for me, because although my laptop and phone would pair, they would only stay connected about 5 seconds, for a reason unknown to me.
note to self: I need to try enabling native bluetooth tethering, just for the sake of having the connection stay permanent to have one of the final commands succeed.
My plan is supposed to give me 6GB Hotspot Data, and when passing this amount, be throttled to a lower speed. However, the documentation makes no mention of what the lower speed is. What I actually get, is 100 Kbps, which is barely, barely usable. Currently, Hotspot Data Plans supposedly throttle to 3G speeds when the limit is reached. What is 3G speed?
So, basic 3G is what I'm being throttled to. But what is T-Mobile's current 3G speed? The 2019 OpenSignal 3G mobile network experience report says the real world T-Mobile 3G speed is 4.2 Mbps, and the slowest is Verizon with 0.9 Mbps. I would be happy with Verizon's 3G, which is 9 times faster than what I'm getting.
So I could call T-Mobile and demand they raise my throttled speed to their actual 3G. Or does their clause say they throttle to the super-old 2001-2002 definition of 3G? The standard of what 3G was *supposed* to deliver is discussed at Wikipedia, which is that there was not really a standard. I have no clue what T-Mobile's current clause is. For my grandfathered plan, the engineer tech read my clause and admitted they didn't know what it meant. I should have written it down so I could look it up.
This may work as well, but I haven't tried it:
Speaking in terms of the United States, but the same could apply elsewhere:
Different frequency bands, and different transmission protocols (2g, 3g, LTE, etc) are used by different carriers (carriers are providers like AT&T, Verizon, or T-Mobile). The antenna in the phone are frequency specific, so in purchasing a phone for a specific carrier, you have to make sure the phone supports all the bands that the carrier uses.
Sometimes, however, there are different model phones that have the same exact internal hardware. The difference in model number is for carrier specific programming. The programming is called firmware.
I'm not sure how optimal it may be, but one carrier's firmware can be just fine working on another carrier's network, which is called “roaming”. Sometimes, you can take the phone you bought from one carrier, and use it with a plan on another carrier. However, no matter what the new carrier will tell you, it is better to use one of their phones. If you are technical and research the technology you can find a definite answer for your specific phone, but don't go by what the sales person says.
There is a specific model of the Samsung Galaxy Note 9 that is not carrier specific. The manufacturer specifications denote that it can work with many of the USA carriers without a change in firmware.
Notice that the non-carrier USA version of the Note 9 is capable of many more band and protocol combinations than the other carrier specific phones. Having more bands could be useful for roaming, and for international travel, where any number of bands might be used. One downside, however, is that the non-carrier specific firmware may not work as well with a particular carrier, as the carrier-specifc firmware? I don't really know what's true at the moment, but Samsung states that the non-carrier-specific firmware works just fine on any carrier, at least based on the FAQ for the Unlocked Galaxy S9/S9+.
Each carrier has radio firmware, or baseband updates. Who makes these updates? For Samsung phones, all updates originate directly from Samsung. The carriers pass them along.
More confusion left to be resolved: https://forum.xda-developers.com/galaxy-note-9/how-to/n960u-tmb-stock-odin-files-firmware-t3833205/post79410606
Carriers deliver updates (known as OTA updates) to your phone automatically, even to the “unlocked” phones. However, if you are using a custom ROM, the updates are up to you. Your baseband can get out of date.
Of particular curiosity to me, is if it is optimal to mix-match a newer baseband radio firmware with an older Android version.
Most people want the latest of everything. However each successive Android version runs slower than the previous, especially if moving away from the prevalent Android version when the hardware is introduced to market. Thus I am prone to want to stay with an older version of Android, but still want the latest baseband so that I have the best radio connectivity with the carrier.
Only if the group SlimRoms puts out a newer version of Android, would I trust it to run smoothly on the phone. Even then, it will not be the latest version of Android. The community needs time to customize Android into something better than the restrictiveness that Google puts out.