I recently purchased Galaxy S4 from Verizon - unlocked and with a Global option.
1. It is working fine in the US - both data and voice.
2. I am in China now and purchase a SIMM card from China Unicom. My China Unicom plan includes voice and data.
3. I can make and receive calls with my phone when in China using SIMM card from China Unicom but I cannot access the data.
4. I can access the data while in China using China Unicom SIMM card only when there is a WiFi service.
5. I tried all possible combination of options on my phone but still no success with accessing the data.
6. Is there some setting I am missing?