for low 3G signal and call drops try this
guide update solution error allowed 3g and drop calls 
download the package here 
https://mega.co.nz/#!Rx0SDapR!P6Mqcl...cSrWuXnCU07upI
extract the contents to a folder on your desktop you will end up with several files 
go in the folder MauiMETA_exe_3G_v6.1216.0 right click on the file Maui META ver 6.1216.0 3G 
compatibility propieta previous versions of windows (with this Win8) 
if you have window7 can directly isattallare the program once installed 
go right icon propieta compatibility win xp service pack3 
this to install the program in this way I was able to install it 
on both Win8 that on win7 both 64-bit and were operated 
open the program installed as an administrator 
to put the phone in recovery mode plug the usb cable 
to go to device manager should see a device named csv sconoscuta update driver 
by selecting the folder on your desktop and then the folder Driver - USB VCOM Driver (binary) 
if you do not find the device go on the phone and still in recovery mode and do rebot now and do not touch it most 
always refer to the guide and images that are in the translation file 
back to the program and select Options --- Conenect smartphone into META mode 
click Reconnect 
select "updata parameter 
Select the button: "change NVRAM DB 
BPLGUInfoCustomAppSrcP_MT6589_S00_MOLY_WR8_W1248_M D_WG_MP_V2 search for the file 
in the folder in the folder on desktopo database 
click " Load from file "and browse for the file zp810.ini always present in the downloaded folder, 
click on Download to flash: You will receive a message from the upgrade program completed did notice all that I have used this procedure.
das ist die erklärung von xda aber blicke da nicht durch 
