I originally flashed an older rom onto my phone in order to unlock it, then it did the OTA update to 4.3, following which I used CF auto root to successfully root it. Now this is what I have:
AT&T Galaxy S3
Android version 4.3
Baseband version I747UCUEMJB
Build Number JSS15J.I747UCUEMJB
SE Android Status Enforcing SEPF_SMSUNG-SGH-I747_4.3_0024
When I try to enable wifi tethering, either natively or through Portable Wifi Hotspot or other apps then I get the message that "Mobile data is not available or invalid SIM", neither of which is true. I have been able to get FoxFi/PDANet to work for bluetooth tethering, but not WiFi which I need for some of the devices I have with me.
I have seen that perhaps there are some modem/bootloader files that can be flashed over, but those seem to be specific to the leaked version of 4.3 , and I dont know if they would work for the UCUEMJB.
Is there any way I can do a simple mod to enable the wifi teathering? Would prefer to avoid flashing another rom bc Im traveling through Latin America and access to decent internet is a big issue (hence the need to tether).