Dual Sim phones - how do they work?

phases · 21-05-2015, 14:39

Thinking of getting a dual sim phone and have a few questions about it.

I know that a dual sim phone means that you can store 2 sims on one phone, but I want to know that if I have an incoming call, will it indicate on the phone screen which sim it's calling?

As its able to store 2 sims on one phone, does this mean that the battery drains quicker?

Does it allow me to have two different settings for each sim on the phone?

I've been looking around at a few websites and it seems that dual sim phones exists on dumb phones too but most of them say that they don't support 3G and as I'm on the 3 network at the moment, this means that my sim card won't work on those phones. Are there no 3G dual sim phones for sale?

lost boy · 21-05-2015, 15:52

Quote:

Originally Posted by phases

Thinking of getting a dual sim phone and have a few questions about it.

I know that a dual sim phone means that you can store 2 sims on one phone, but I want to know that if I have an incoming call, will it indicate on the phone screen which sim it's calling?

As its able to store 2 sims on one phone, does this mean that the battery drains quicker?

Does it allow me to have two different settings for each sim on the phone?

I've been looking around at a few websites and it seems that dual sim phones exists on dumb phones too but most of them say that they don't support 3G and as I'm on the 3 network at the moment, this means that my sim card won't work on those phones. Are there no 3G dual sim phones for sale?

I have a dual sim, Moto G2, so I'll give your questions a go (disclaimer - these are all 'in my experience', so YMMV). OK:

Quote:

Originally Posted by phases

I know that a dual sim phone means that you can store 2 sims on one phone, but I want to know that if I have an incoming call, will it indicate on the phone screen which sim it's calling?

Yes.

Quote:

Originally Posted by phases

As its able to store 2 sims on one phone, does this mean that the battery drains quicker?

Not necessarily, it depends what sims you have in the phone. Mine drained like **** with Three and Lycamobile (who use O2) sims in it, but happily lasts all day with Three (for data) and Vectone (for calls, runs on EE) sims in it.

Quote:

Originally Posted by phases

Does it allow me to have two different settings for each sim on the phone?

To a degree, yes, mainly for calling and texting. It depends what you specifically want to do.

Quote:

Originally Posted by phases

I've been looking around at a few websites and it seems that dual sim phones exists on dumb phones too but most of them say that they don't support 3G and as I'm on the 3 network at the moment, this means that my sim card won't work on those phones. Are there no 3G dual sim phones for sale?

Yes, there are several dual sim dumb phones about, some very cheap, but as you've found tend not to support 3G.

As for 3G dual sim phones, yes, there's a fair few of them about too (the Moto G2 for example) but they tend to be smart phones I find, and you have to look around a little bit for them. The thing with them is, one sim slot tends to be 3G (which is what data will run off) while the other is 2G, so as a Three user you'll need to make sure your Three sim is in the 3G slot, as it won't work properly in the 2G one, if that makes sense.

Hope that helps.

Stereo Steve · 21-05-2015, 16:10

Some phones can run 3G on both but not many. I don't have any battery issues with mine at all. Concept works well but does vary among handsets eg. some are dual active so you can take or make a call while on a call but most can only use one sim at a time. On mine I can set which sim to make calls on (1,2 or choose each time) and I get 2 send buttons for SMS.

Denco1 · 21-05-2015, 16:18

Quote:

Originally Posted by Stereo Steve

Some phones can run 3G on both but not many. I don't have any battery issues with mine at all. Concept works well but does vary among handsets eg. some are dual active so you can take or make a call while on a call but most can only use one sim at a time. On mine I can set which sim to make calls on (1,2 or choose each time) and I get 2 send buttons for SMS.

Which phones can run 3G on both? I wasn't aware of any.

mbsnr · 21-05-2015, 16:21

My phone can run 3G on either SIM but you have to manually define which one it is active on. Phone is a Wiko Stairway - Sept. '13.

Denco1 · 21-05-2015, 16:27

Sorry i should have made it clearer, I'm aware of ones where you can switch the sim, it's just the way Stereo Steve typed it it sounded like you could run both simultaneously which AFAIK isn't the case.

mbsnr · 21-05-2015, 16:32

Quote:

Originally Posted by Denco1

Sorry i should have made it clearer, I'm aware of ones where you can switch the sim, it's just the way Stereo Steve typed it it sounded like you could run both simultaneously which AFAIK isn't the case.

I've not seen them either, although I've not looked. I use the 2nd SIM for data roaming when I'm in the UK, so to have both 3G enabled at the same time hasn't been a requirement.

But I can see the need if you have a Three UK SIM and want to use another operators SIM for data. The Three UK SIM won't necessarily work unless the SIM is "3G" enabled on the phone. Ironically the Three UK SIM works fine on 2G when roaming...

Stereo Steve · 21-05-2015, 17:25

Maybe I'm mistaken then. I thought the Kingzone Z1 could do data on both without selecting but I'm not sure where I read it now. Might have been PC advisor but I can't find it. Problem is with a lot of the Chinese phones is that getting real hard facts is often tricky before you buy. Perhaps having both on 3G at the same time is not possible, as you say.

mbsnr · 22-05-2015, 13:38

Quote:

Originally Posted by Stereo Steve

Maybe I'm mistaken then. I thought the Kingzone Z1 could do data on both without selecting but I'm not sure where I read it now. Might have been PC advisor but I can't find it. Problem is with a lot of the Chinese phones is that getting real hard facts is often tricky before you buy. Perhaps having both on 3G at the same time is not possible, as you say.

Thinking about I can't see how having data active (either 3G or 4G) on both SIMs at once would work at a practical level anyhow. How would the phone (or an app) know which data service to use - unless there was a manual preference set?

Also from a cost perspective, I'd imagine you'd have to have two separate 3G (or 4G) radio components, (extra chipsets at least) not to mention they could be working on different 3G/4G frequencies, plus increased battery use....

As for the Z1 - it's dual SIM standby - one active at one time. See below.

>>>>>>>>>>>
Kingzone Z1 review: Connectivity

Everything you need is covered on the connectivity front. There's GPS and GLONASS, NFC, 4G LTE (although it's supported by only one of the dual-SIM slots, the other maxes out at 3G), dual-band 802.11a/b/g/n/ac Wi-FI, USB OTG support and Bluetooth 4.0. This is a dual-standby dual-SIM phone, for more details on what that means see our dual-SIM phones buying advice and best dual-SIM phones 2015.

>>>>>>>>>>
From http://www.pcadvisor.co.uk/test-cent...advice-uk-may/

Dual-active SIM phones also exist, however, which use two modems and allow you to receive calls on both numbers at once. We've not tested any dual-active phones, but some more recent examples allegedly include the dual-SIM variants of the HTC One M8, Sony Xperia Z3 and Samsung Galaxy S5 mini.

Doesn't say if they are dual data as well as dual voice but again you'd wonder on the benefit of that...

jabbamk1 · 22-05-2015, 20:58

Simultaneous 3G connections on both SIM cards is rare but does exist on some Samsung phones. The Galaxy Duo series has some phones like this.

Most of the time however you're getting 3G/2G in one slot and 2G in the other.

You can have settings set up for each SIM such as the default SIM to send text messages etc... Both SIM cards work at the same time and software enhancements have allowed you to soft swap which SIM is using 3G without physically needing to swap them around.

Stereo Steve · 22-05-2015, 22:23

Thanks.

d123 · 22-05-2015, 22:40

Quote:

Originally Posted by jabbamk1

Most of the time however you're getting 3G/2G in one slot and 2G in the other.

Though a number of the newer releases are now 3G or 4G on sim 1 and 3G on sim 2.

jabbamk1 · 23-05-2015, 13:49

No they're not.

They're 4G/3G/2G in SIM 1 and 2G in SIM 2.

I dont think i've see a dual sim 4G phone support 3G in the second SIM card slot yet.

Stereo Steve · 23-05-2015, 21:07

Quote:

Originally Posted by jabbamk1

No they're not.

They're 4G/3G/2G in SIM 1 and 2G in SIM 2.

I dont think i've see a dual sim 4G phone support 3G in the second SIM card slot yet.

Kingzone Z1 I think does.

d123 · 23-05-2015, 21:29

Quote:

Originally Posted by jabbamk1

No they're not.

They're 4G/3G/2G in SIM 1 and 2G in SIM 2.

I dont think i've see a dual sim 4G phone support 3G in the second SIM card slot yet.

I'm just going by a number of reviews/sites that state the phone is 3G compatible on both sims.

(I do like your pedantry about the sim 1 slot being 4G/3G/2G though

).

For example:

Lumia

Quote:

Smart Dual SIM means that both your SIM cards can receive a call at any time, no matter what you’re doing on your phone. And unlike other dual SIM smartphones, your 3G data connection stays on - regardless of what SIM card you’re using.

http://www.microsoft.com/en/mobile/lumia-dual-sim/

The Kingsone Z1

Quote:

There's GPS and GLONASS, NFC, 4G LTE (although it's supported by only one of the dual-SIM slots, the other maxes out at 3G)

http://www.pcadvisor.co.uk/reviews/m...ind-below-200/

HTC one M8 dual sim

Quote:

SIM 1
SIM Type Nano-SIM
GSM/ CDMA GSM
3G Yes
SIM 2
SIM Type Nano-SIM
GSM/ CDMA GSM
3G Yes

http://gadgets.ndtv.com/htc-one-m8-d...5?site=classic

jabbamk1 · 23-05-2015, 21:49

The Lumia does not support 3G in both SIM slots, that quote is just saying you don't lose your data connection when in a call.

The HTC One does not support 3G in both sim slots either.

The Kingone I'm not sure about but I'd imagine it's the same as above.

Basically, if one SIM card is using 4G/3G/2G, the other will always be 2G only. You can soft swap using built in software. It's rare to see a phone that will have dual simultaneous 3G connections and as far as I'm aware there are currently zero, or just a couple, of phones that support 4G/3G in SIM 1 and simultaneous 3G connection in the other SIM.

d123 · 24-05-2015, 11:59

Quote:

Originally Posted by jabbamk1

Basically, if one SIM card is using 4G/3G/2G, the other will always be 2G only. You can soft swap using built in software. It's rare to see a phone that will have dual simultaneous 3G connections and as far as I'm aware there are currently zero, or just a couple, of phones that support 4G/3G in SIM 1 and simultaneous 3G connection in the other SIM.

OK, you've just changed the playing field, I also haven't heard of any phones that offer a simultaneous 3G connection either, I was referring to phones that have been reported to utilise WCDMA 2100Mhz (as opposed to GSM 900/1800) as a voice carrier for sim 2, not as a dual data connection.

jabbamk1 · 24-05-2015, 13:28

Quote:

Originally Posted by d123

OK, you've just changed the playing field, I also haven't heard of any phones that offer a simultaneous 3G connection either, I was referring to phones that have been reported to utilise WCDMA 2100Mhz (as opposed to GSM 900/1800) as a voice carrier for sim 2, not as a dual data connection.

That's the same thing haha. 3G as you know isn't unique to data.

Like I said, the second SIM will NOT connect to 3G network (for voice or data) but will always be on a 2G connection.

Stereo Steve · 24-05-2015, 18:51

Wow, you guys have a talent for making an argument from nothing. Constructive discussion is good and might help somebody who finds this thread on google.

So. The Kingzone and other such phones can do 3G on both sims and 4G on one. I'm not sure where the argument is here. Whether they can do both at the same time is another matter isn't it? Fact is there are phones out there that could for instance run a 4G sim for EE so you had decent data around and about and also a 3G sim to run a VOD sim for 2G calls and maybe Sure signal at home.

I don't want the Kingzone, it's a bit phat but I might be interested in a slimmer phone that could do that.

So, the question is. Can you have a phone that one sim can do 3/4G when it likes (EE) and the other sim can do 2/3G at the same time (VOD)?

I suspect it's all going to be moot in a few months but it's interesting none the less.

jabbamk1 · 24-05-2015, 19:57

Quote:

Originally Posted by Stereo Steve

So, the question is. Can you have a phone that one sim can do 3/4G when it likes (EE) and the other sim can do 2/3G at the same time (VOD)?

That's what we've been discussing and the answer is no.

One SIM will always be 2G only no matter what. The other SIM will have access to 4G/3G/2G.

Of course you can soft swap which SIM is which at any time.

rmervart · 25-09-2015, 17:00

The fact that there are no phones that would support at least 3G on both dual SIM phone slots is annoying. I have Three SIM in one slot that requires 3G even for UK speech calls and I would like to have Vectone for calls abroad and data. However that can be only 2G data which is annoying.

ShaunIOW · 25-09-2015, 19:19

Quote:

Originally Posted by rmervart

The fact that there are no phones that would support at least 3G on both dual SIM phone slots is annoying. I have Three SIM in one slot that requires 3G even for UK speech calls and I would like to have Vectone for calls abroad and data. However that can be only 2G data which is annoying.

I've got the cheap Blu windows phone from Amazon and that has 4G in both SIM card slots, but not at the same time, so you have to select which slot to use for data.

OldHippy53 · 25-09-2015, 21:38

Quote:

Originally Posted by ShaunIOW

I've got the cheap Blu windows phone from Amazon and that has 4G in both SIM card slots, but not at the same time, so you have to select which slot to use for data.

I also have one of these (the smaller one) as a backup phone and yes it is 4g in both SIMS but you do have to swap between them-although I can't check at the moment as there's no credit on the EE SIM.
Off-topic, but it's a great little phone for the price (£69) although not too keen on Windows

Orbitalzone · 25-09-2015, 23:20

I do find my Moto G dual SIM great for work but do wish it could do 3G on both SIMs, not for data on both at the same time but for voice as I often work in places that might have picocells that are 3G only (underground for example) so my main 3G data enabled SIM works but the other SIM for work gets nothing as it's 2G and picocells are 3G (from what I can tell)

The other annoyance is when I tether and take a call on SIM 2 (2G) it cuts out tethering (and data)

But, it's still generally much more convenient that carrying 2 phones.

rmervart · 27-09-2015, 19:03

Quote:

Originally Posted by ShaunIOW

I've got the cheap Blu windows phone from Amazon and that has 4G in both SIM card slots, but not at the same time, so you have to select which slot to use for data.

I would not mind to do software switch of SIMs for data as long as they would both work simultaneously for voice.Do they? With my current phone I can switch which slot is 3G but the other slot becomes 2G. When one of the SIMs is Three and I want to use the other for data then it turns Three off completely.

21-05-2015, 14:39	#1
phases Forum Member Join Date: Mar 2014 Posts: 144	Dual Sim phones - how do they work? Thinking of getting a dual sim phone and have a few questions about it. I know that a dual sim phone means that you can store 2 sims on one phone, but I want to know that if I have an incoming call, will it indicate on the phone screen which sim it's calling? As its able to store 2 sims on one phone, does this mean that the battery drains quicker? Does it allow me to have two different settings for each sim on the phone? I've been looking around at a few websites and it seems that dual sim phones exists on dumb phones too but most of them say that they don't support 3G and as I'm on the 3 network at the moment, this means that my sim card won't work on those phones. Are there no 3G dual sim phones for sale?

21-05-2015, 15:52	#2
lost boy Forum Member Join Date: Sep 2005 Location: Norfolkland Posts: 1,787	Quote: Originally Posted by phases Thinking of getting a dual sim phone and have a few questions about it. I know that a dual sim phone means that you can store 2 sims on one phone, but I want to know that if I have an incoming call, will it indicate on the phone screen which sim it's calling? As its able to store 2 sims on one phone, does this mean that the battery drains quicker? Does it allow me to have two different settings for each sim on the phone? I've been looking around at a few websites and it seems that dual sim phones exists on dumb phones too but most of them say that they don't support 3G and as I'm on the 3 network at the moment, this means that my sim card won't work on those phones. Are there no 3G dual sim phones for sale? I have a dual sim, Moto G2, so I'll give your questions a go (disclaimer - these are all 'in my experience', so YMMV). OK: Quote: Originally Posted by phases I know that a dual sim phone means that you can store 2 sims on one phone, but I want to know that if I have an incoming call, will it indicate on the phone screen which sim it's calling? Yes. Quote: Originally Posted by phases As its able to store 2 sims on one phone, does this mean that the battery drains quicker? Not necessarily, it depends what sims you have in the phone. Mine drained like **** with Three and Lycamobile (who use O2) sims in it, but happily lasts all day with Three (for data) and Vectone (for calls, runs on EE) sims in it. Quote: Originally Posted by phases Does it allow me to have two different settings for each sim on the phone? To a degree, yes, mainly for calling and texting. It depends what you specifically want to do. Quote: Originally Posted by phases I've been looking around at a few websites and it seems that dual sim phones exists on dumb phones too but most of them say that they don't support 3G and as I'm on the 3 network at the moment, this means that my sim card won't work on those phones. Are there no 3G dual sim phones for sale? Yes, there are several dual sim dumb phones about, some very cheap, but as you've found tend not to support 3G. As for 3G dual sim phones, yes, there's a fair few of them about too (the Moto G2 for example) but they tend to be smart phones I find, and you have to look around a little bit for them. The thing with them is, one sim slot tends to be 3G (which is what data will run off) while the other is 2G, so as a Three user you'll need to make sure your Three sim is in the 3G slot, as it won't work properly in the 2G one, if that makes sense. Hope that helps.

21-05-2015, 16:10	#3
Stereo Steve Forum Member Join Date: Jul 2004 Posts: 1,378	Some phones can run 3G on both but not many. I don't have any battery issues with mine at all. Concept works well but does vary among handsets eg. some are dual active so you can take or make a call while on a call but most can only use one sim at a time. On mine I can set which sim to make calls on (1,2 or choose each time) and I get 2 send buttons for SMS.

21-05-2015, 16:18	#4
Denco1 Forum Member Join Date: Mar 2015 Posts: 983	Quote: Originally Posted by Stereo Steve Some phones can run 3G on both but not many. I don't have any battery issues with mine at all. Concept works well but does vary among handsets eg. some are dual active so you can take or make a call while on a call but most can only use one sim at a time. On mine I can set which sim to make calls on (1,2 or choose each time) and I get 2 send buttons for SMS. Which phones can run 3G on both? I wasn't aware of any.

21-05-2015, 16:21	#5
mbsnr Forum Member Join Date: May 2004 Location: Ireland Posts: 284	My phone can run 3G on either SIM but you have to manually define which one it is active on. Phone is a Wiko Stairway - Sept. '13.

21-05-2015, 16:27	#6
Denco1 Forum Member Join Date: Mar 2015 Posts: 983	Sorry i should have made it clearer, I'm aware of ones where you can switch the sim, it's just the way Stereo Steve typed it it sounded like you could run both simultaneously which AFAIK isn't the case.

21-05-2015, 16:32	#7
mbsnr Forum Member Join Date: May 2004 Location: Ireland Posts: 284	Quote: Originally Posted by Denco1 Sorry i should have made it clearer, I'm aware of ones where you can switch the sim, it's just the way Stereo Steve typed it it sounded like you could run both simultaneously which AFAIK isn't the case. I've not seen them either, although I've not looked. I use the 2nd SIM for data roaming when I'm in the UK, so to have both 3G enabled at the same time hasn't been a requirement. But I can see the need if you have a Three UK SIM and want to use another operators SIM for data. The Three UK SIM won't necessarily work unless the SIM is "3G" enabled on the phone. Ironically the Three UK SIM works fine on 2G when roaming...

21-05-2015, 17:25	#8
Stereo Steve Forum Member Join Date: Jul 2004 Posts: 1,378	Maybe I'm mistaken then. I thought the Kingzone Z1 could do data on both without selecting but I'm not sure where I read it now. Might have been PC advisor but I can't find it. Problem is with a lot of the Chinese phones is that getting real hard facts is often tricky before you buy. Perhaps having both on 3G at the same time is not possible, as you say.

22-05-2015, 13:38	#9
mbsnr Forum Member Join Date: May 2004 Location: Ireland Posts: 284	Quote: Originally Posted by Stereo Steve Maybe I'm mistaken then. I thought the Kingzone Z1 could do data on both without selecting but I'm not sure where I read it now. Might have been PC advisor but I can't find it. Problem is with a lot of the Chinese phones is that getting real hard facts is often tricky before you buy. Perhaps having both on 3G at the same time is not possible, as you say. Thinking about I can't see how having data active (either 3G or 4G) on both SIMs at once would work at a practical level anyhow. How would the phone (or an app) know which data service to use - unless there was a manual preference set? Also from a cost perspective, I'd imagine you'd have to have two separate 3G (or 4G) radio components, (extra chipsets at least) not to mention they could be working on different 3G/4G frequencies, plus increased battery use.... As for the Z1 - it's dual SIM standby - one active at one time. See below. >>>>>>>>>>> Kingzone Z1 review: Connectivity Everything you need is covered on the connectivity front. There's GPS and GLONASS, NFC, 4G LTE (although it's supported by only one of the dual-SIM slots, the other maxes out at 3G), dual-band 802.11a/b/g/n/ac Wi-FI, USB OTG support and Bluetooth 4.0. This is a dual-standby dual-SIM phone, for more details on what that means see our dual-SIM phones buying advice and best dual-SIM phones 2015. >>>>>>>>>> From http://www.pcadvisor.co.uk/test-cent...advice-uk-may/ Dual-active SIM phones also exist, however, which use two modems and allow you to receive calls on both numbers at once. We've not tested any dual-active phones, but some more recent examples allegedly include the dual-SIM variants of the HTC One M8, Sony Xperia Z3 and Samsung Galaxy S5 mini. Doesn't say if they are dual data as well as dual voice but again you'd wonder on the benefit of that...

22-05-2015, 20:58	#10
jabbamk1 Forum Member Join Date: Jan 2012 Location: London, UK Posts: 8,759	Simultaneous 3G connections on both SIM cards is rare but does exist on some Samsung phones. The Galaxy Duo series has some phones like this. Most of the time however you're getting 3G/2G in one slot and 2G in the other. You can have settings set up for each SIM such as the default SIM to send text messages etc... Both SIM cards work at the same time and software enhancements have allowed you to soft swap which SIM is using 3G without physically needing to swap them around.

22-05-2015, 22:23	#11
Stereo Steve Forum Member Join Date: Jul 2004 Posts: 1,378	Thanks.

22-05-2015, 22:40	#12
d123 Forum Member Join Date: Jul 2007 Posts: 3,993	Quote: Originally Posted by jabbamk1 Most of the time however you're getting 3G/2G in one slot and 2G in the other. Though a number of the newer releases are now 3G or 4G on sim 1 and 3G on sim 2.

23-05-2015, 13:49	#13
jabbamk1 Forum Member Join Date: Jan 2012 Location: London, UK Posts: 8,759	No they're not. They're 4G/3G/2G in SIM 1 and 2G in SIM 2. I dont think i've see a dual sim 4G phone support 3G in the second SIM card slot yet.

23-05-2015, 21:07	#14
Stereo Steve Forum Member Join Date: Jul 2004 Posts: 1,378	Quote: Originally Posted by jabbamk1 No they're not. They're 4G/3G/2G in SIM 1 and 2G in SIM 2. I dont think i've see a dual sim 4G phone support 3G in the second SIM card slot yet. Kingzone Z1 I think does.

23-05-2015, 21:29	#15
d123 Forum Member Join Date: Jul 2007 Posts: 3,993	Quote: Originally Posted by jabbamk1 No they're not. They're 4G/3G/2G in SIM 1 and 2G in SIM 2. I dont think i've see a dual sim 4G phone support 3G in the second SIM card slot yet. I'm just going by a number of reviews/sites that state the phone is 3G compatible on both sims. (I do like your pedantry about the sim 1 slot being 4G/3G/2G though ). For example: Lumia Quote: Smart Dual SIM means that both your SIM cards can receive a call at any time, no matter what you’re doing on your phone. And unlike other dual SIM smartphones, your 3G data connection stays on - regardless of what SIM card you’re using. http://www.microsoft.com/en/mobile/lumia-dual-sim/ The Kingsone Z1 Quote: There's GPS and GLONASS, NFC, 4G LTE (although it's supported by only one of the dual-SIM slots, the other maxes out at 3G) http://www.pcadvisor.co.uk/reviews/m...ind-below-200/ HTC one M8 dual sim Quote: SIM 1 SIM Type Nano-SIM GSM/ CDMA GSM 3G Yes SIM 2 SIM Type Nano-SIM GSM/ CDMA GSM 3G Yes http://gadgets.ndtv.com/htc-one-m8-d...5?site=classic

23-05-2015, 21:49	#16
jabbamk1 Forum Member Join Date: Jan 2012 Location: London, UK Posts: 8,759	The Lumia does not support 3G in both SIM slots, that quote is just saying you don't lose your data connection when in a call. The HTC One does not support 3G in both sim slots either. The Kingone I'm not sure about but I'd imagine it's the same as above. Basically, if one SIM card is using 4G/3G/2G, the other will always be 2G only. You can soft swap using built in software. It's rare to see a phone that will have dual simultaneous 3G connections and as far as I'm aware there are currently zero, or just a couple, of phones that support 4G/3G in SIM 1 and simultaneous 3G connection in the other SIM.

24-05-2015, 11:59	#17
d123 Forum Member Join Date: Jul 2007 Posts: 3,993	Quote: Originally Posted by jabbamk1 Basically, if one SIM card is using 4G/3G/2G, the other will always be 2G only. You can soft swap using built in software. It's rare to see a phone that will have dual simultaneous 3G connections and as far as I'm aware there are currently zero, or just a couple, of phones that support 4G/3G in SIM 1 and simultaneous 3G connection in the other SIM. OK, you've just changed the playing field, I also haven't heard of any phones that offer a simultaneous 3G connection either, I was referring to phones that have been reported to utilise WCDMA 2100Mhz (as opposed to GSM 900/1800) as a voice carrier for sim 2, not as a dual data connection.

24-05-2015, 13:28	#18
jabbamk1 Forum Member Join Date: Jan 2012 Location: London, UK Posts: 8,759	Quote: Originally Posted by d123 OK, you've just changed the playing field, I also haven't heard of any phones that offer a simultaneous 3G connection either, I was referring to phones that have been reported to utilise WCDMA 2100Mhz (as opposed to GSM 900/1800) as a voice carrier for sim 2, not as a dual data connection. That's the same thing haha. 3G as you know isn't unique to data. Like I said, the second SIM will NOT connect to 3G network (for voice or data) but will always be on a 2G connection.

24-05-2015, 18:51	#19
Stereo Steve Forum Member Join Date: Jul 2004 Posts: 1,378	Wow, you guys have a talent for making an argument from nothing. Constructive discussion is good and might help somebody who finds this thread on google. So. The Kingzone and other such phones can do 3G on both sims and 4G on one. I'm not sure where the argument is here. Whether they can do both at the same time is another matter isn't it? Fact is there are phones out there that could for instance run a 4G sim for EE so you had decent data around and about and also a 3G sim to run a VOD sim for 2G calls and maybe Sure signal at home. I don't want the Kingzone, it's a bit phat but I might be interested in a slimmer phone that could do that. So, the question is. Can you have a phone that one sim can do 3/4G when it likes (EE) and the other sim can do 2/3G at the same time (VOD)? I suspect it's all going to be moot in a few months but it's interesting none the less.

24-05-2015, 19:57	#20
jabbamk1 Forum Member Join Date: Jan 2012 Location: London, UK Posts: 8,759	Quote: Originally Posted by Stereo Steve So, the question is. Can you have a phone that one sim can do 3/4G when it likes (EE) and the other sim can do 2/3G at the same time (VOD)? That's what we've been discussing and the answer is no. One SIM will always be 2G only no matter what. The other SIM will have access to 4G/3G/2G. Of course you can soft swap which SIM is which at any time.

25-09-2015, 17:00	#21
rmervart Forum Member Join Date: Oct 2005 Posts: 34	The fact that there are no phones that would support at least 3G on both dual SIM phone slots is annoying. I have Three SIM in one slot that requires 3G even for UK speech calls and I would like to have Vectone for calls abroad and data. However that can be only 2G data which is annoying.

DS Forums

Dual Sim phones - how do they work?

25-09-2015, 19:19	#22
ShaunIOW Forum Member Join Date: Jun 2006 Location: Isle of Wight Posts: 7,828	Quote: Originally Posted by rmervart The fact that there are no phones that would support at least 3G on both dual SIM phone slots is annoying. I have Three SIM in one slot that requires 3G even for UK speech calls and I would like to have Vectone for calls abroad and data. However that can be only 2G data which is annoying. I've got the cheap Blu windows phone from Amazon and that has 4G in both SIM card slots, but not at the same time, so you have to select which slot to use for data.

25-09-2015, 21:38	#23
OldHippy53 Forum Member Join Date: Jan 2007 Location: In a world of my own... Posts: 221	Quote: Originally Posted by ShaunIOW I've got the cheap Blu windows phone from Amazon and that has 4G in both SIM card slots, but not at the same time, so you have to select which slot to use for data. I also have one of these (the smaller one) as a backup phone and yes it is 4g in both SIMS but you do have to swap between them-although I can't check at the moment as there's no credit on the EE SIM. Off-topic, but it's a great little phone for the price (£69) although not too keen on Windows

25-09-2015, 23:20	#24
Orbitalzone Forum Member Join Date: Oct 2000 Location: Sussex Posts: 12,173	I do find my Moto G dual SIM great for work but do wish it could do 3G on both SIMs, not for data on both at the same time but for voice as I often work in places that might have picocells that are 3G only (underground for example) so my main 3G data enabled SIM works but the other SIM for work gets nothing as it's 2G and picocells are 3G (from what I can tell) The other annoyance is when I tether and take a call on SIM 2 (2G) it cuts out tethering (and data) But, it's still generally much more convenient that carrying 2 phones.

27-09-2015, 19:03	#25
rmervart Forum Member Join Date: Oct 2005 Posts: 34	Quote: Originally Posted by ShaunIOW I've got the cheap Blu windows phone from Amazon and that has 4G in both SIM card slots, but not at the same time, so you have to select which slot to use for data. I would not mind to do software switch of SIMs for data as long as they would both work simultaneously for voice.Do they? With my current phone I can switch which slot is 3G but the other slot becomes 2G. When one of the SIMs is Three and I want to use the other for data then it turns Three off completely.