Galaxy J5 Prime Dual SIM performance issues

[meridius]

I bought the Samsung Galaxy J5 Prime Duos (SM-G570M) in August and upgraded to Android 7. Now another phone which is exactly the same model is asking for a software update to Android 9 Oreo but my one isn't and despite my prompts trying to download updates manually there is no option to upgrade.

The main issue though is that I have used one SIM for calls (SIM 1) and another for mobile data (SIM 2 - i.e. browsing only). Both SIMs have different network providers. Despite trying all sorts of different network connections and combinations on each SIM, I just didn't feel that something was working properly i.e. in one part of the flat I would lose mobile data connection on one SIM while the SIM with calls would be fine and vice versa. I was thinking of just having one SIM with both calls and data and am wondering if this would improve things?

At the moment I have moved the calls only SIM to an old Samsung Galaxy Y (with 3G activated) which was my first android phone in 2011. Now there appears to be an improvement in the J5 Prime in operational speed of using the phone and up to a point connection strength for the other data SIM which is now in SIM 1, with SIM 2 empty.

I am trying some tests through speedtest.net and checking out different providers. I don't know how accurate this is. It's not just the speed but the signal strength that's important.

So to summarise my questions:

(a) Why no update for Android 9 on my J5 Prime?

(b) Is it better to have two separate phones and can dual SIM weaken signal strength and download/upload performance in SIM 2 (which I used for data)? If not can any settings improve this?

My understanding is that you can have either:

2G (GSM only) for calls (SIM 1) and 3G (WCDMA only or GSM/WCDMA) for data (SIM 2)
or
3G (WCDMA only or GSM/WCDMA) for calls (SIM 1) and 4G (GSM/WCDMA/LTE) for data (SIM 2)
but not
3G (WCDMA only or GSM/WCDMA) for calls (SIM 1) and 3G (WCDMA only or GSM/WCDMA) for data (SIM 2) which is actually what I am after.

...unless I am wrong and SIM 2 is always condemned to 2G whatever I do...

(c) Is it worth just having one SIM for calls and data using only one provider (obviously the strongest one in this case) or even two SIMs from the same provider: one for calls and the other for data? Or are two separate phones a better option?

(c) Can I reliably check connection strength and upload/download strength using speedtest.net and different servers (i.e. different providers) using the same SIM card from one provider?

 

[meridius]

I noticed that this post got no answers...

Well my technical knowledge on networks isn't that high but the maximum I was able to achieve was SIM1 as 'UMTS' & SIM2 as 'HSDPA' if I set both SIM's to 'WCDMA only' and that did not work well in my flat where reception is poor. I guess 'UMTS' isn't a very powerful 3G either...

I can only see the real solution for me is to have two phones each setting 'WCDMA/GSM' on each one or keep adjusting networks on each SIM as circumstances dictate. Fiddling around with my settings and looking at signal strengths on a dual SIM phone gave me this conclusion unless I am wrong.

So if SIM1 is set to prioritise 4G or 3G, SIM2 will probably only operate well with 2G. LTE is slower than 3G in my area so this isn't an option for me.

I don't know what happens if a single SIM phone is set to calls and mobile data on WCDMA/GSM. I would imagine if a call comes through it re-routes to 2G if mobile data is connected to 3G?? For me the problem is that there are parts of the flat where 2G is completely unavailable...

I wish manufacturers would explain their SIM and network settings more clearly as this is hard work for a novice.

 

[meridius]

One more answer from me.

I think you need to put your hands in your pockets to get dual SIM as 4G or 3G on your second SIM:

https://www.androidcentral.com/what-dual-4g-lte-and-why-should-you-care

Also see the connectivity section of this article on the Nokia 7 Plus:

https://gadgets.ndtv.com/nokia-7-plus-4604

P.S. I answered question (a) in my other post entitled 'Can't upgrade SM-G570M'.

 

[Xavier Black]

I'm sorry you haven't gotten any answer!, ok here are my thoughts:

If you are looking for 3g in SIM2(data) and what ever you get in SIM1(calls & texts)..I can suggest you why not getting a one single SIM in that dual phone of yours..with a provider that gives you the HIGHEST speed for the data..THEN(this is the kicker)..get an app that provides you with a phone number for phone calls and texting..I use TextPlus for years already..it's about $20 a year to own your own number and to have the rights for in & out phone calls..the texting part is partly free(if you don't wanna pay the cost..and you would still reserve the phone number..it used to be totally free but $20 is nothing, though)

I hope I shined some light your way..

 

[meridius]

Many thanks. I'll look into this...

My problem is that SIM1 must be used for incoming calls and sms. I cannot change the phone number or move the number to a different carrier.

SIM1 should not really have a mobile data plan added to it as the provider of SIM1 does not necessarily have the best data plan.

SIM2 can be used for mobile data and used on any carrier.

In any case If I decided to just have one SIM and add data to it, I guess if I am using mobile data on 4G or 3G and a phone call comes in it is immediately 2G and would therefore get cut off in a weak 2G signal area?

 

[meridius]

I really do think that this answers the question: https://www.smartprix.com/bytes/best-dual-sim-dual-volte-phones/

Hopefully Dual SIM Dual VoLTE phones will become more common and cheaper within a year...