[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] pawadca:
Canadian LTE & Dandroid & Losing Data connection

I've spent the last two weeks chasing a gremlin. Randomly losing data connection. Not cellular connection loss, just data only. Still saw full bars.

--DISCLAIMER--

This is by no means an exhaustive diagnosis or an engineering solution. Just notes from my experiences and I only guarantee that you might think about trying it and warrant no particular results.

--/DISCLAIMER--

A few weeks ago I started seeing data loss on my Dandroid. I would be scrolling twitter or facebook and suddenly there was nothing coming up. The Signal icon would show full bars but no indicator of data speed (3G/LTE/etc).

I tried flashing a few different modems. No improvement.

I downgraded to an earlier Dandroid. No improvement.

I upgraded back to the latest Dandroid. No improvement.

I then remembered a post by Dan "Have you recently tried Odin back to stock..." SO I figured maybe I was due.

I grabbed the Toolbox and did an Odin back to stock. No improvement.

Now I was getting annoyed. Maybe a previous over heating had buggered up the modem. I jumped on the Rogers website and checked warranty. I was in luck. 8 weeks left. I called Rogers and we did some tests ( note I can see the tower 4 blocks away from my bedroom window) and the tech was impressed at how strong the signal was, but even on the phone we were able to reproduce the data loss. They did some network resets and I did a power cycle and it seemed to be working.

Or at least it worked for about 2 hours. Call Rogers again. Did some more tests. Disabled LTE. Seems to be working again. Tech advised I should probably take it in and have it fixed.

Now for the Samsung stinger; the flash counter and modified flag. I used the counter reset tool and did another odin back to stock. Hmmmm still says modified. Repeat the steps again. Flash counter zero and modified flag cleared.

I then spent a week with the phone just to see if the problem would reoccur in stock. 1 week later I was happy that the problem could not be reproduced.

Today I decided it was time for some more Dandroid. Installed the latest TWRP, rooted, flashed Dandroid. After the reboot I didn't setup an account, just confirmed everything till I was at the desktop. Let it sit for an hour. Then setup 1 google account and started installing some of the missing gApps. DATA LOSS AGAIN.

Not about to jump in the forms and ask dumb questions I did some more tests. I noticed that Dandroid comes with 4 APNs. What if I eliminated some of them. I found a post on Rogers website that says the only APN you need for LTE networking is

If you have a LTE device, use the following settings:

APN: LTEMOBILE.APN

MMS (Picture Messaging) Settings:

MMSC: http://mms.gprs.rogers.com

MMS Proxy: 10.128.1.69

MMS Port: 80

5. Leave the followings fields blank: Proxy, Port, User Name, Password, server

So I deleted all of the existing APNs and made one new one.

Now more testing. Facebook, Twitter, Gplay, sms, mms. Everything seems to work. Can't get the data to drop at all.

So far I can't get the data to drop off. But as I said at the top of the post. There is no guarantee that this is going to work for me or you. I haven't tried going any where there is no LTE. But I figured I can't be the only one having this issue so I thought I would share what I have figured out.