Time Shift Grouping Access in IEEE 802.15.4 MAC Beacon Mode for Layered-Tree Networks. - Yasushi Yamao; Satoru Takagishi (CCNC, 2008)

Multi-code SS-CSMA/CA for cluster-tree wireless ad hoc networks. - Naoto Kobatake; Satoru Takagishi; Yasushi Yamao (ISWCS, 2009)