Providing Group Tour Guide by RFIDs and WSNs Yu-Chee Tseng, CS.NCTU (a joint work with NTHU) (in IEEE Trans. on Wireless Comm.) ( 中華民國專利 : " 使用無線感測網路提供群組導引 服務之方法及系統 ", I319947)

Motivation Traditional tour guide:  personalized guiding  by portable audio/mobile devices  They do not consider tourists as a group. Our goals:  a group guiding framework Feasible Low management effort  group guiding protocol with a prototype

System overview & Services Leader tracking Help service Member recall

Group guiding services 1. Leader tracking Sensors cooperate to track the locations of group leaders. 2. Help service Help lost members to find their leaders. 3. Member recall A leader can call his/her members. 4. Push message A leader can push information to his/her members.

Group guiding protocol (1/2) How to track a group leader  a signal-strength based method by “bidding”

Group guiding protocol (2/2) Mobility management A potential-based method is adopted for sensors to trace the locations of leaders. A local update is proposed to reduce update messages.

System Architecture (WSN + RFID system)

Leader badge & direction board

Help (Information) Center

Help service & GUI

Prototyping system & Member-recall

Simulation results Area: 100m*100m Nodes: 10*10, 30*30, and 50*50 Transmission range: 15m Trans. Data rate: 256 kbps Obstacles: 2*4 or 4*2 Pkt. Loss: 0% ~ 20% Each group has one leader and multiple members.

Performance metrics Message overhead  Tracking leader  Support group guiding services Scalability Length of guiding path  Routing property

Message overhead & Scalability Message overhead vs. Leader mobility Impact of obstacles on message overhead

Length of guiding path AEH: Avg. excess hops

Response time vs. Packet loss

Overall message overhead

Conclusions a feasible GROUP tour guide system  based on RFID  ease of management Future work:  integrating with real tour information  realization in mobile devices, such as iPhone or gPhone