LTE band preference (Unlocked S8)

[TylerLV76]

This is a curiosity question for the experts.

I was reading through the forums when I saw my signal bars go nuts for a second so I installed LTE discovery to see what my true signal was. In doing so I saw my S8 doing things no other phone I have has done. It was going from Band 12 with a -89db to band 4 with a -108 and as high as a -120db. I decided to throw my sim in my T-Mobile branded G6 and see what it shows and it stays on band 4 with a -108db and doesn't budge.

My question is pretty simple. If band 12 is getting that good of signal, why is the phone swapping back to band 4 after a little while since that bands signal is bouncing around like crazy? Shouldn't it stays on band 12 or is the S8 doing something it shouldn't by going back to band 4.

Lastly, this is the first phone I've had to actually use band 12. No other T-Mobile device has connected to it including my G6 and other S8's and S8+. Could the unlocked variant be a little more aggressive about choosing the best band?

 

[nguyening]

This is a curiosity question for the experts.

I was reading through the forums when I saw my signal bars go nuts for a second so I installed LTE discovery to see what my true signal was. In doing so I saw my S8 doing things no other phone I have has done. It was going from Band 12 with a -89db to band 4 with a -108 and as high as a -120db. I decided to throw my sim in my T-Mobile branded G6 and see what it shows and it stays on band 4 with a -108db and doesn't budge.

My question is pretty simple. If band 12 is getting that good of signal, why is the phone swapping back to band 4 after a little while since that bands signal is bouncing around like crazy? Shouldn't it stays on band 12 or is the S8 doing something it shouldn't by going back to band 4.

Lastly, this is the first phone I've had to actually use band 12. No other T-Mobile device has connected to it including my G6 and other S8's and S8+. Could the unlocked variant be a little more aggressive about choosing the best band?

Not an expert, but I have done a lot of research since I own the s8+ on TMo. Band 12 is meant for better building penetration (low frequency) as opposed to Band 4. Band 4 carries data at 20Mhz, and I think Band 12 carries less (I haven't personally witnessed Band 12 often enough to pay attention). I presume the phone prefers to connect to a faster band when available to give you the best signal/speed possible. Otherwise, TMo might lose to BigRed on the speed test.

 

[Almeuit]

This is a curiosity question for the experts.

I was reading through the forums when I saw my signal bars go nuts for a second so I installed LTE discovery to see what my true signal was. In doing so I saw my S8 doing things no other phone I have has done. It was going from Band 12 with a -89db to band 4 with a -108 and as high as a -120db. I decided to throw my sim in my T-Mobile branded G6 and see what it shows and it stays on band 4 with a -108db and doesn't budge.

My question is pretty simple. If band 12 is getting that good of signal, why is the phone swapping back to band 4 after a little while since that bands signal is bouncing around like crazy? Shouldn't it stays on band 12 or is the S8 doing something it shouldn't by going back to band 4.

Lastly, this is the first phone I've had to actually use band 12. No other T-Mobile device has connected to it including my G6 and other S8's and S8+. Could the unlocked variant be a little more aggressive about choosing the best band?

Mainly because the phone was programmed how to handle the different frequencies and when to "swap" at the varying -dBm levels. T-Mobile variants may be more forgiving and will hold onto something like band 4 at a higher -dBm then what Samsung would program the unlocked one to do. This could cause the phone to hop around more.

I noticed this when on my Pixel XL on VZW. It would hop bands more frequently then the S8+ on VZW does.

 

[torbach1]

Odd. I found the exact opposite. My T-Mobile S7 Edge would routinely find and stick to Band 12 giving me excellent signal strength and speed, while my unlocked variant would continuously switch to other bands, get very hot trying to get a decent signal, etc.