[原] [kernel]Using UMTS stick on nexus7(2013)

I want to use UMTS stick on nenus7(2013) a while. But I can not find exact directions.
So I make this thread to summarize my experience collected form internet to help someone like me.

first setp:
I made a kernel based on bulletproof v1.2 that adding some necessary driver.

Thanks bulletproof developers a lot for open kernel source.
Link: http://forum.xda-developers.com/showthread.php?t=2427162

You can flash it form recovery mode.

second setp:
I slove usb host bug following below thread.
link: nexususb.blogspot.fr/2013/07/android-4.html


My devices infomation:
bootloader unlock and Rom rooted

My Rom: stock ROM(JSS15Q)
Recovery: TWRP 2.6
kernel: bulletproof modified