[Galaxy S III Original Android Development] curiousrom:
Cellular Data Lost After Phone Call?

Hum... you don't give any info about your system setup or what you tried already which makes it very difficult to troubleshoot. See post #1 > Reporting bugs > Phone informations (the Code box).

Try toggling on/off Airplane mode instead of rebooting. Check in Settings > Wireless & networks > More > Cellular networks > if Preferred network type is set to 3G.

Check suggestions in recent post: Network Problems, Internal Storage, Bootloop, Best Kernel & Off Topic especially the part about MatLog & rebooting in Safe Mode.

If you have access to an other phone connected to the same cellular provider you could compare signal strength reception: Data enabled, Wifi & Bluetooth off > Settings > About phone > Status > SIM status > Signal strength (the lower the better) and the other info in that panel like in the attached screenshot. Or use on both phones a free app like Network Cell Info Lite for example. BTW in in this app > 3 dots > System info/feedback > Feedback you can change the email to our own instead of the developer's (screenshot)

I get an excellent -51 dBm outdoor with an unobstructed view of a cell tower @ 700 meters (measured on Google Map). Naturally that may be different for you depending on topography & quality of the cell tower's signal itself. The cellular antenna on the S3 is in the bottom third so don't block it with your hand when checking signal, hold it by the sides or pinch top & bottom.

Settings > About phone > Status > what is your Baseband version (also called modem or radio)? What is your provider? Check the most recent Samsung firmware here for your country/provider combo and open the page then check the modem's name which is under Phone in the firmware pages of this site: https://updato.com/firmware-archive-select-model?q=GT-I9300&rpp=15&order=date&dir=desc&exact=1 and maybe you can find it in this thread: EFSv2 Modem Collection

Or try one of these modems but write down the one you have currently before you do it: Modems: New Zealand + Latin America & Secret Codes

If all the above fails consider installing stock Samsung firmware to rule out a hardware problem: S3 i9300 LineageOS Super Clean Install & Samsung Firmware And/or a super clean stock LineageOS install.

Please report back if you fixed your problem or not. :cool:

BTW [MENTION=7619683]Psycho103[/MENTION] thanks for the Thanks but did you solve your intermittent network connection problem & if so how?

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Thanks for compliment, I think? :confused: The S3 being my daily driver & victim of the Sudden Death Syndrome which brought me to try LineageOS & an old battery forced to learn stuff mostly on XDA so I like to give back to the community plus I like to troubleshoot & fix things & living in a village on top of a mountain in Costa Rica forces you to do it as big stores are a 6 hours round trip at best & a lot of it on dirt roads. :eek:

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Really Cool

My girlfriend is too hot so could you send me 1 liter of that magical thermal paste? Please?

BTW the S3 i9300 does not have a battery thermal sensor so that's why all battery apps report a default placeholder 30° C for it. ;)

Unless you have a temperature gun & what is the name of that test?

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