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Permit simultaneous LTE and 2G connection (for places where 3G frequency is not accessible)

asked 2014-06-11 00:12:19 +0300

shallimus gravatar image

updated 2014-07-22 09:50:29 +0300

jiit gravatar image

Due to the less-than-total frequency coverage by the Jolla radio hardware, some people (e.g. in Canada) are now in the odd situation of being able to have LTE or 2G calling, but no 3G.

This means that the device is usable either as a small tablet with fast internet but no phone calls (LTE) or as a cellphone with poor reception and terribly slow internet (2G).

Since the update, it is now possible to place a call: the device slooowly switches from LTE to 2G (or rather, non-detectable 3G coverage to detectable 2G coverage), switching off LTE in the process.

Since the update, it It is now possible to make phone calls from my Jolla but not to receive them (unless I force 2G mode and give up on modern internet usage). This is a bit of a problem, obviously.

So: is it possible to force the Jolla to use LTE for data but at the same time always try to be on a 2G network for phone calls? 2G is a lot better than nothing!

Assuming something is possible in software, I realise that this will probably cause a battery drain, but at this point I am OK with charging more often if it means people can call me.

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This could achieved by enabling allow/deny configuration for 2G, 3G and 4G separately. Btw, this is not affecting only those brave enthusiasts who have bought phone from Finland to be shipped to Canada or USA even when it was known that all local frequencies won't be supported. This affects also those travelling in Canada or USA.

Penguin ( 2014-06-11 00:17:53 +0300 )edit

True. I know I am not the only one affected by this. I give myself and my location only as an example.

Is there a separate 2/3/4G allow/deny question already? Perhaps I'm not searching for the right thing, but I don't see it. I suppose this is in the same area as your question: https://together.jolla.com/question/45764/4g-selection-logic-when-mobile-data-disabled/ but not the same.

shallimus ( 2014-06-11 00:22:18 +0300 )edit

2 Answers

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answered 2014-06-11 01:12:30 +0300

tigeli gravatar image

@shallimus The phone should do cs-fallback from LTE to both UTMS/GSM during incoming call and this has been tested. However I've personally seen networks which have been "broken" and not signaling the LTE-supported devices correctly during CS-fallback. Can you do test call to your Jolla while it's in LTE-network to see if it switches to GSM-network at any point during incoming call?

Unfortunately doing simultaneous GSM/UMTS & LTE is not possible.

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hello ! I have the same situation. I made some tests with lte. While I m connected to lte : - If I made a call from my Jolla, I have to wait until the 2g connection is established and sometimes this take too much time and the call is canceled. - If I wait a call to my jolla, the caller think I m not online. ( I don t have voice mail). My jolla doesn t change network to receive a call... So i just miss calls ... which is really not coool ... My provider isn t compatible with 3G, i can only have 2G and 4g. btw, the 4g is really impressive, I get 92Mb/s dl and 10Mb/s up !

Thnaks for your answer.

titilambert ( 2014-06-11 03:39:43 +0300 )edit

I have issue with 4G. when it is enabled and there is no 4G coverage, the signal drops and there is no network. I'm forced now to switch the phone to 3G in order to receive and make calls.

Kindly Jolla, fix this issue.

Rashed Albloushi ( 2014-06-11 07:25:37 +0300 )edit

If it would help the developers, I have a second Jolla (my first one with a demolished screen) here in Canada that I could leave powered on and give remote access to for testing. I will even donate (in the form of paying for an active LTE subscription) if it will help in addressing the issue facing the few, but loyal, Canadian Jolla users.

CraigA ( 2014-06-11 07:42:26 +0300 )edit

@tigeli Thank you for this useful response. Certainly other people on my network (Fido in Canada, for what it's worth) use LTE and receive phone calls with other LTE-compatible devices fine (tested just now with my friend's iPhone 5 on the same operator). I can't think of any way of testing like-for-like with another device, though: I'm not sure how I could get that iPhone 5 to not see 3G signal and thus be forced to fall back from LTE to 2G when receiving a call.

I called my phone a number of times while it was connected to LTE in an area where 2G signal is also available. Voicemail every time. I will see if it is possible to make my VM wait longer before picking up - perhaps the switching is too slow and the VM is answering before the switch is possible.

shallimus ( 2014-06-11 16:11:12 +0300 )edit

@shallimus I've found the same thing on Rogers (Fido's backbone for those who are unaware). On 4G all my calls go to voicemail :(

CraigA ( 2014-06-12 19:42:50 +0300 )edit

answered 2014-06-11 12:35:37 +0300

jalyst gravatar image

updated 2014-06-11 12:38:23 +0300

Read 1st paragraph here: http://en.wikipedia.org/wiki/4G#History_of_4G_and_pre-4G_technologies

And see here... http://lteworld.org/ltefaq/what-cs-fallback-lte

But alas, some telcos may not do fall-back gracefully, or at all.

It's put best by neildk here: http://talk.maemo.org/showthread.php?p=1429133#post1429133

UPDATE: Already answered it seems!!!

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While it is interesting to learn more about the background, I'm less interested in the underlying historical/technological standards/constraints than in the clear practical requirement:

I need to use fast (non-2G!) internet, but also need to be able to receive phone calls.

shallimus ( 2014-06-11 16:13:25 +0300 )edit

Then you need a 3G connection/operator or a second device.

cocof2001 ( 2014-06-11 16:18:52 +0300 )edit

Perhaps I'm misunderstanding something, but as far as I can tell from what tigeli says above, Jolla should be capable of switching down to 2G.

I have already changed from one network operator to another to be able to get any signal at all for my Jolla here in Canada. In terms of frequency match with the Jolla's radio hardware, there is no better alternative to the network I am on right now, so getting a 3G connection/operator as you suggest is unfortunately not an option.

shallimus ( 2014-06-11 16:27:34 +0300 )edit

I agree that for calls it should fall back to 2G, but you said you want fast internet. So... in 2G it will not be that fast. That's why a posted that comment. To see why it is not falling back you will need some network/operator traces.

cocof2001 ( 2014-06-11 16:33:00 +0300 )edit

I can handle having slow internet during a phone call, but not all the time, which is my only option right now if I want to be reachable via phone.

I do realise that the problem here is likely to be an operator issue rather than a device/software issue, so perhaps I was too hasty in assessing this answer-thread as less useful. Still, my point remains that it is not a great choice: "no phone calls but fast internet" or "phone calls but internet from 1997".

shallimus ( 2014-06-11 16:35:53 +0300 )edit
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Asked: 2014-06-11 00:12:19 +0300

Seen: 1,807 times

Last updated: Jun 11 '14