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  1. Zooty's Avatar
    I am using Telus sim which is voice only, and Rogers sim which is data only. Both sims will work fine but not at the same time. When choosing sim 2(Rogers) in settings as Sim card for data connection I lose cell connection on Sim 1(Telus). So in other words I have to choose the telus Sim as my data Sim in order for voice to work. Kinda strange. Any thoughts. So close to working. The Rogers sim is a flex data plan I had in a tablet.
    12-14-2014 07:55 AM
  2. aleunge's Avatar
    I don't have two sim cards in the phone to know, but if you aren't aware yet, a new update came out for our phones (8.1 update 1). Install that and see if your situation improves? Otherwise, strange behaviour indeed... doesn't make any sense actually. Call Blu?
    12-17-2014 11:59 PM
  3. Michael Castro3's Avatar
    I have a bit of a different issue.
    I have a Bell sim in slot 1 and a wind sim in slot 2. When Bell sim out, Wind works perfectly, when both sims in, Wind will only be in away mode, suggesting that it is picking up the Bell frequencies.

    To me the similarities are in teh fact that dual sim have some peculiarities.
    12-18-2014 06:40 AM
  4. lazybum131's Avatar
    Someone can correct me if I am mistaken, my understanding is as there is only one 3G radio, only one SIM slot can be set to use 3G at a time.

    The issue is that only Rogers (and other carriers that use Rogers' network like Fido, Speakout, etc.) has a 2G GSM voice network, Bell and Telus were CDMA and switched to GSM when they rolled out their 3G networks.

    So in both your situations, you cannot use your SIMs concurrently since they both require the use of the 3G radio of the phone to work.
    RumoredNow likes this.
    12-19-2014 07:26 PM
  5. aleunge's Avatar
    That is indeed strange. Good theory. Anyone knows if all dual sim phones (i.e. android, feature phone) function the same? Seems a little limiting,
    12-20-2014 01:58 AM
  6. Zooty's Avatar
    lazybum..that was my suspicion...but it kind of makes dual sim pointless.
    As soon as I chose sim2 (rogers) as data, sim 1 Telus is not even found if I search for available networks.
    My guess is your on to something.
    12-20-2014 05:35 PM
  7. Zooty's Avatar
    aleunge..I moved to the developer preview builds to try that out ...no luck. Thinking it is a hardware limitation.
    12-20-2014 05:53 PM
  8. Michael Castro3's Avatar
    If it only has one 3g radio then how does that help support a dual sim. Seems it really limits the value of the second sim port.

    If I only want to use one sim ata time though how do I get it to switch to the other sim.
    12-20-2014 06:55 PM
  9. aleunge's Avatar
    Castro3, I think what awesome members here are finding is that both slots can use 2G/GSM concurrently, but only one sim can use 3G at a time (whichever one is set to use data). So if both sims have 2G compatibility, you can call/text and receive calls/text at the same time (the phone has phone 1 and phone 2 as well as message 1 and message 2 stock apps instead of just one each, although you can merge them into one app with a toggle to access each slot). So in this case, you don't need to switch between Sims unless you want to use the other slot's data/3G.

    If one sim only uses 3G for all communication though (Wind Mobile uses calls/text/data via 3G only), you won't be able to access that network unless you set that slot as the default data sim (or go on 2G roam).

    Is that about right? So it looks like this dual sim thing only really works if you have two carriers with both GSM service.....
    RumoredNow likes this.
    12-21-2014 12:46 AM
  10. Michael Castro3's Avatar
    Makes sense and am thankful for the information.
    12-21-2014 06:03 AM
  11. Harrie-S's Avatar
    Furthermore how would the phone know from which SIM he should use the data if both could be enabled. You also can not be connected to 2 Wifi networks in the same time. So to me it is logic that you have to set the 3G to only 1 SIM.
    12-21-2014 06:17 AM
  12. Zooty's Avatar
    Yep ...think i'm out of luck. Live and learn...thanks for the help. I assumed dual sim meant two radios that would work with the frequencies specified for this phone (at the same time).Slightly misleading. If Rogers was my voice sim and Telus data I would have been in business because Rogers still uses 2g(this is my understanding). When I turn 3g off I lose telus connection and can only see Rogers when searching for networks. Makes sense what you guys are saying. I have a cheap grandfathered Telus corporate family plan...without data sharing... I don't want to give up, ( just to explain why I'm doing what I'm doing)
    12-27-2014 11:11 AM
  13. ntsux's Avatar
    So, by this logic, can I safely assume that I can use a 4G/3G carrier in SIM slot 1, and a second carrier that supports the same in SIM slot 2, and then assign SIM 1 to 3G service, and SIM 2 to 4G service? This would eliminate the need for 2G/Rogers.

    I am assuming that 3G and 4G would use distinct radios.... just as 3G and 2G, as stated above.

    I think a phone like the BLU 6 HD LTE edition would solve my problem. i really hope so, cuz, I really hate being stuck in this scenario!

    Thoughts?
    04-16-2015 10:17 AM
  14. Peter Cichoszewski's Avatar
    Here is what I found by using a Rogers and Mobilicity within GTA area. The Mobilicity was in the MicroSIM slot and Rogers in the other ( using a SIM adapter since my Rogers was also MicroSIM ). I had to set APN manually for either one to work with data. ( just 1 time setup ).

    Then you select which SIM you want to use for data.... takes a few seconds for the phone to re-initialize ( not reboot, just waiting for connections to establish ) and it worked 80% of the time. If I found it not working, I would just reboot the phone ). You can SMS with your self with dual SIMs, but can't make calls to self (it won't even ring ).
    RumoredNow likes this.
    04-19-2015 09:25 AM
  15. ntsux's Avatar
    I am struggling with Wind and Bell.. Both are HSPA+, and both are fighting for the 3g radio. Bell just will NOT join the 4G/LTE network for some reason with both SIMS in the phone, even when I swap SIM slots.

    I didn't think we were pioneers with this in Canada.... :(
    Last edited by ntsux; 04-22-2015 at 02:41 PM.
    04-22-2015 08:07 AM
  16. Michael Castro3's Avatar
    did you get this to work? It took a while to get the Bell to work on LTE but then the wind sim does not connect at all
    05-04-2015 09:35 AM
  17. RumoredNow's Avatar
    I am struggling with Wind and Bell.. Both are HSPA+, and both are fighting for the 3g radio. Bell just will NOT join the 4G/LTE network for some reason with both SIMS in the phone, even when I swap SIM slots.

    I didn't think we were pioneers with this in Canada.... :(
    It is my impression that only the GSM radio is doubled. If Wind is grabbing the 3G for voice, it is using the sole 3G/LTE radio on board, leaving nothing for Bell.
    05-04-2015 10:45 AM
  18. aleunge's Avatar
    Don't know if this has changed with the Win HD LTE, but best to check in that forum BLU Win HD LTE - Windows Central Forums This forum here is the non-LTE version of the Blu Win HD.

    (although I doubt one SIM can access LTE while the other SIM is accessing 3G)
    RumoredNow likes this.
    05-04-2015 04:25 PM
  19. MassDeduction's Avatar
    I've read a lot of the posts here and want to clear up a few of the misconceptions I read here.

    Like all current dual-SIM Windows Phones, the Blu Win HD has only *one* radio. Not just one 3G radio, just one radio period. This radio is capable of either 2G or HSPA.

    If one SIM is using the radio, then the other cannot. When you SMS yourself, it uses the radio briefly to send, then the other uses it briefly to receive. When one SIM is on the phone, the other can't ring because the radio is in use.

    The Blu Win HD is HSPA for one SIM and 2G-only for the other. This isn't speculation, this is fact. It says it right on Blu's official spec list. So, yes, only a SIM on the Rogers network can use the second SIM in Canada. Bellus, Wind, etc., cannot, as they don't support 2G. Telus has no 2G anymore at all, and Bell only has CDMA2000 2G (which they're in the process of decommissioning).

    It's no more false advertising to advertise a dual-SIM phone that can only use one SIM at a time, than it is to sell a multi-CD changer that can only play one CD at a time. That said, I get the confusion because there are four kinds of dual-SIM handsets:

    - single standby, where only one SIM can access the radio, and you select from a menu which one it is

    - dual-standby, where duplexing is used to let the SIMs rapidly alternate which is listening to the radio (this is what all the dual-SIM Windows Phones from Blu are)

    - dual-standby w/auto-forwarding, where when one SIM is in use on the phone, calls to the other SIM are automatically forwarded to the other (this is what all the dual-SIM Lumias are)

    - dual-active, where there are two radios so both SIMs can do whatever, whenever (this is very, very rare)

    The only downer of the Blu Win HD is that it's not 3G on both radios. A 2G-only SIM is virtually useless for many Canadians.
    RumoredNow and vincentwansink like this.
    05-05-2015 11:43 PM
  20. aleunge's Avatar
    To clarify, you mean if one SIM accesses HSPA, the same SIM/other SIM can only access 2G at any one time. For example, if you have two Rogers SIM, you can have access to one 3G from either cards and 2G from both (rapidly alternating thing). There isn't discretely one 3G SIM slot and one 2G only SIM slot. Otherwise, you can't even use one Rogers SIM and access 2G/3G from that SIM.
    05-06-2015 03:59 PM
  21. ScrubbyXD's Avatar
    Don't mean to be a thread necro but perhaps I can help.

    Sim 1 is voice/sms intended for no data
    Sim 2 is voice/sms/mms/2g/3g/4g intended for Data but can be both.

    Any other arrangement is going to give you grief.
    05-16-2015 08:53 PM
  22. ntsux's Avatar
    Here is the crux of the issue (and maybe it's a re-hash of the last few posts).

    Lots of phones (even some major vendors) claim to have Dual SIM / Full Active (Check the Asus ZenPhone 2 for a great example). And while this is technically true, if you do NOT have one (of your two carriers) who offers GSM service at 2G, it comes with a crippling limitation:

    And this issue is OS-agnostic (I know that this is a Windows forum).

    Trawl (not Troll) the ebay and Asian online mobile phone ads, and you will consistently see the following in the detailed specs for "Dual SIM / Full Active / Dual Active" (yup, no standardized nomenclature yet):

    SIM 1: Micro Sim, LTE/WCDMA/GSM
    SIM 2: Micro Sim, GSM 2G only

    So, if you live in Canada, your choice for SIM slot 2 is pretty much limited to Rogers and its offshoots. Bell, Telus and the minor HSPA+ carriers won't work in SIM slot 2, because they no longer offer 2G service. And even if they do, it's likely not GSM.

    BTW - I really hope to be wrong/misinformed here. I welcome an educated correction!

    Until then, my sad trombone gently weeps....
    Last edited by ntsux; 05-25-2015 at 02:18 PM.
    05-25-2015 12:41 PM
  23. vincentwansink's Avatar
    And in case anybody was wondering if it makes a difference to use two sims from the same carrier, it does not. I just tried two Wind sims in my 950XL and although they both get a signal, I can only send texts and make phone calls from sim 1. Sim 2 is useless with this configuration. (I also tried Wind in sim1, and Telus in sim2, and Telus in sim1 and Wind in sim2). No matter what I do with these three sim cards, I can only get sim1 to work.

    I'm going to try a Fido or Rogers sim in the sim 2 slot (as suggested by MassDeduction "only a SIM on the Rogers network can use the second SIM in Canada"), and hopefully that does the trick.

    If it does work, then my question obviously becomes, for how much longer will Rogers support 2G?
    07-15-2016 06:31 PM
  24. vincentwansink's Avatar
    So I now have a Wind sim in the sim1 slot and a Fido sim in the sim2 slot. Works great! (Lumia 950XL)

    Except for the following:

    1. I can not control the highlight colour for the second sim. Windows 10 seems to pick a random colour that contrasts with my primary highlight colour.
    2. I can not set separate ring tones for the two sims. I can set separate notification tones, but not ring tones.
    3. I don't know how much longer Rogers will support 2G, but hopefully by that time a new dual sim phone will be available that will support higher speeds on the second sim.
    07-19-2016 02:54 PM

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