how to do international to international transfer in beijing airport both flights are airchina

I have flight from lax to mumbai through beijing. I have only 1.5 hts to transfer on beijing airport.
I am very worry how i will do it as very few people spead in beijing.
How airchina will help me in transfer after i land in beijing did they provide bus and did they have any special notification on bus about where the passanger will go.
If anyone has done international to international transfer please let me know the detail procedure with airchina.
Thanks