[Galaxy Note 4 Android Development (Snapdragon)] tripLr:
radio sim death fix, maybe, please help test.

Based on @tze_vitamin fiddling around to get 4 g, and said he fixed sim death

I am asking to help test this theory

please help test.

I switched from verizion , to straight talk , now to google fi

testing lineageos 14 and varients like ressurection remix

testing lineageos 15 and varients , RR, and @_mone 's AICP

noting @tze_vitamin changed his radio to get 4 g in his home country in eastern Europe and stopped sim death,

and at the same time I was switching to google fi

https://xdaforums.com/note-4-verizon/general/how-to-google-fi-unofficial-support-t3877021

I noticed extreme instability in the changeover process, and some very interesting results.

Google Fi is essentially a " custom named roaming " network as they have at this point NO of their own cell towers.

Steps, Observations, and History

1. @_mone noticed some severe problems with my radio logs, when i was on his AICP using straight talk

2. both @tze_vitamin and other users in different forums said they have less or no sim death by loading an older or different radio. If i read him right tze used a different modem on his device to access 4g, not the one that was for his build. other users have stated an older radio works better than the newest.

3. in my install of Fi, i could not get the network to come up and register, only one time I saw the apns change to Fi. I tried everything last night, apns , reboot, reload, airplane mode, switching back sims, and giving up late.

4. so leaving home this morning, i left the house with my phone fresh clean pico install using the wipe provider data zip in the OP and using the Google Fi app only, and downgraded the radio to CPD1 . As soon as I stepped outside, I logged into Fi!

So, reading more about Fi, i am in a similar case to tze. Fi runs on T-mobile ( which has no good service here ) Sprint, ( same ) , and US Cellular (same bad service). and I have a Verizon device. hmm, both use CDMA, but the radio firmware is different.

Theory test:

1. boot to recovery, flash the wipe provider zip, and custom wipe dalvic and cache
2. power down , remove sim card
3. power up to full, then reboot to recovery.
4. repeat step 1, power down, insert sim and boot up.

watch for sim death,

Case 1 : Is it a no sim detected icon ? looks like sim card with slash

Case 2 : Is it a triangle with no bars and you can make a 911 call ? that's a roaming no service allowed icon.

Then most likely its the radio in the second case, or, what we ( @ripee ) are working on is the ril server issue

my test # 1, flash an older radio for your device from the OEM .

I downgraded to CPD1 for verizon, thanks to @hsbadr thread for verizon

https://xdaforums.com/note-4-verizon/development/firmware-firmware-kernel-modem-recovery-t2942937

use your own manufacturer radio to test

my test #2 ( be careful, have a full backup ready, also you may have to completely reflash oem and re root !!! )

Flash a different manufacture that has the same cell tower band . check your device ( verizon is cdma )

Reason? At the time of manufacture, Qualcomm SOC built the chipset to a spec, here is a link of some specs, cell companies, and what they mean for us ROM users

https://www.whistleout.com/CellPhones/Guides/cell-phone-networks-and-frequencies-explained

So, @tze_vitamin was able to get 4 g , because his flashing a different handset radio allowed access to a different band, and my poor Fi service, means my Verizon radio is only accessing 3 g or "edge" Tmobile, bands. Except one time I must of been on band 2 or 4 of 4 g

On my way to search for a t mobile radio firmware.! and maybe radio firmware compatable with the chipset,

Question does the DUOS international version have dual radios ? or just dual SIMs accessing a dual radio?

either way, the DUOS users cant access the second sim because its a port ( hardware access ) not being seen by the kernel. Its like having dual network cards in a computer made by different companies, and you dont have the driver for the second network card ( i did that once )

In conclusion, the radio firmware allows ONLY access to the network frequencies the device is sold for.

The Snapdragon SOC, was designed/built for ALL the frequencies and specs available at the time of manufacture to Qualcomm , who sold the chipsets to Samsung and other device makers.

The Kernel is compiled at the behest of the device maker for its use ( cell phone, tablet, medical device)

The Rom and radio firmware must configured for the Cell company, and or region. Am i wrong ? let me know please. Project/Google FI is selling handsets configured for all the wireless networks they use, and there are supported Fi handsets tested to work, but there is a huge number of people using apps and software handset "secret codes" to force the radio to change towers

https://play.google.com/store/apps/details?id=com.cheekydevs.fiswitch

there is even a database of "secret codes" in an app

This should be important to developers, because a: roms may not be accessing the radio correctly because b: the radio is not being developed as open source therefor c: its all by guess and by golly.

What we need is the testbed source code for the chipset. testbeds are manufactured ( they look like a raspberry pi ) to plug in different modules on a desktop environment before a handset manufacturer commits to a build. different screens, digitizers, modems, cameras both front and back, bluetooth adaptors, sensors, all can be plugged in and out according to the design.

anyone have a source at Qualcomm?