Here are the pointers to the piece of software I coded.
Openwsn: an opensource stack for 6TiSCH (https://github.com/openwsn-berkeley/openwsn-fw for the main repository I forked)
I used Opnet to evaluate IEEE 802.11 networks in the past (opnet->http://www.opnet.com):
I used the wsnet simulator to evaluate in simulations WSN toplogies: