1. Patent technology for USN Jinho Son 2006. 4. 13 Real-Time System Lab

2. Contents The method of multicast in ZigBee networks The fire alarm-system Future work in sensor network

3. The method of multicast in ZigBee networks (PN: 10-2005-0081846) Effect of invention –Efficient transmission of data packet for specific group node –Memory size reduction –Overhead reduction Existing transmission method in ZigBee –Unicast transmission –Broadcast transmission

4. The method of multicast in ZigBee networks (PN: 10-2005-0081846) (cont’) Case 2 –Using address bit of broadcast in network layer PAN ID 4 bit12 bit Multicast group1 Multicast group2 Case 1

5. The method of multicast in ZigBee networks (PN: 10-2005-0081846) (cont’) ZigBee Coordinator Sub-Multicast Router Group Coordinator Group Member Non-group Member Multicast Router

6. A general fire alarm-system

7. Initial concept of our fire alarm-system

8. Data flow in case of detecting fire Flame, Smoke, Temperature

9. The wireless fire alarm-system and method (PN: 10-2005-0038068)

10. Future work in sensor network Location problem of mobile node in ZigBee network Reliable routing and data transmission mechanism Energy consumption problem

11. Q & A