The use of asynchronous duty-cycling in wireless sensor network (WSN) MAC protocols is common, since it can greatly reduce energy consumption and requires no clock synchronization. However, existing systems using asynchronous duty- cycling do not efficiently support broadcast-based communication that may be used, for example, in route discovery or in network-wide queries or information dissemination. ADB (Asynchronous Duty-cycle Broadcasting), is a new protocol for efficient multihop broadcast in WSN using asynchronous duty-cycling. The seminar presents the protocol and the experimental results obtained by implementing ADB on a testbed network of MICAz mote sensors.