Xbee Pro Series2 Multihop Network

Hi All,
I have recently started using Xbee Pro Series 2 . I have interfaced it in AT as well as API mode. now i would like to have multihop network initiated in my Xbee. How shall I start?
I have already used Xbee in API so does changing the broadcast radius help me in having a multihop. ?
I have loaded XBP24-ZB firmware on all my Xbee’s in API mode with one as coodinator and all others as routers.
Thank you for reading.

Regards
kshatriya.