My carrier uses SIM for connection and operates on CDMA 800Mhz and CDMA2000 1x-Ev-DO Rev. A 800Mhz. I have GSM operators with 850 / 900 / 1800 / 1900 Mhz and UMTS 2100 Mhz. Now i want a phone with descent battery life and CPU, GPU power that works on both the bands ( CDMA and GSM) 2G and 3G voice and data. Doesn't matter if dual or single sim. Native video call would be preferable. Any suggestion? Pantech? ZTE? xiaomi? Any other brands?