140 likes | 244 Views
Presenter: Jae Weon Choi Affiliation: Graduate School of Convergence IT. Considering PCF for WSN. Motivation. Collision worsen Power Waste Issue Delivery Latency Issue Delivery Completion Rate Collision Happen because Contention Based Multi Access Approach has been taken
E N D
Presenter: Jae Weon Choi Affiliation: Graduate School of Convergence IT Considering PCF for WSN
Motivation • Collision worsen • Power Waste Issue • Delivery Latency Issue • Delivery Completion Rate • Collision Happen because Contention Based Multi Access Approach has been taken • In addition, Collision Avoidance has overhead • Using PCF Network can become Collision-Free
PCF Adaptation • 계층 형 WSN • Cycle 분활 형 • Cycle 순례 형
PCF Adaptation(cont.) • Cycle 분활 형 (No Buffer) • Cycle=(Sum((End node Number)*(Node Limit)^N))*2 while N = {0…(Number of Layer-1)} • Retransmission period = Cycle
PCF Adaptation(cont.) • Cycle 분활 형 (With Buffer) • Cycle = (Node Limit) * 3 * (Transmission Time) • Retransmission period = Cycle
PCF Adaptation(cont.) • Cycle 순례 형 • Cycle = 3 * (Transmission Time) • Retransmission period = Cycle * (End Node Number)
Expected Result of PCF • Increase in Delivery Completion Rate • More Accurate estimation of Latency • No Power waste due to collision
Problems Found • Increase in Cycle Time and Delivery Latency • Increase in Idle Listening • Collision Still exist • Complicated Network Initialization
Why do Collision Still Exist? • When 1-1-2 is registered at 1-1-0 and 1-2-1 is registered at 1-2-0 • When 1-1-2 and 1-2-1 was assigned same sending Period • It does not happen at Cycle 순례 형
Conclusion • Currently, not Competent • Adaptive Wakeup Scheduling Used SPEED MAC May Improve it • Utilizing PCF just for Multi-Source Traffic Mode
즐거운 겨울 되세요. 감사합니다.