一個傳感器網絡調查 Ian F. Akyildiz, Weilian Su, Yogesh Sankarasubramaniam, and Erdal Cayirci Georgia Institute of Technology From:IEEE Communications Magazine • August 2002. Report： yan yi li 2018/7/29

大綱 Introduction 感測網路的通訊體系架構 結論 Physical, Data link, Network, Transport, Application 結論 2018/7/29

Introduction Application areas: Health, military, home, and commercial The differences between sensor networks and ad hoc networks: The number of sensor nodes in a sensor network can be several orders of magnitude higher than the nodes in an ad hoc network. Density of deployment Probability of failure Change of topology Hardware constraint 2018/7/29

感測網路的通訊架構 這些分散的每一個感測器節點都有能力去收集數據資料並且回傳路由數據到接收端. 感測器節點通常分散於感測領域 接收端可以通過網路或是衛星和事件管理者做通訊. 2018/7/29

including fault tolerance Scalability production costs 感測網路設計的影響因素 including fault tolerance Scalability production costs operating environment sensor network topology hardware constraints transmission media power consumption 2018/7/29

硬體的限制 2018/7/29

感測網路通訊架構 Used by the sink and sensor nodes 2018/7/29

實體層 頻率選擇，載波頻率的產生，信號檢測，調變以及數據加密 915 MHz ISM頻帶已被廣泛提出的感測網路 追求的能量使用效率 Industrial, scientific,medical 追求的能量使用效率 二進制和多進制調變 (超寬頻) UWB 無線電脈衝 (IR) 基頻 不需要媒介或者是載波頻率 脈衝位置調變(PPM) 較低的傳輸電力和簡單的收發器 2018/7/29

實體層 Open research issues: Modulation schemes Simple and low-power Strategies to overcome signal propagation effects Hardware design Tiny, low-power, low-cost transceiver, sensing, and processing units need to be designed. 2018/7/29

資料鏈結層 Responsibility: Multiplexing of data streams Data frame detection Medium access control Error control 2018/7/29

資料鏈結層 Open research issues: MAC for mobile sensor networks SMACS and EAR Determination of lower bounds on the energy required for sensor network self-organization Error control coding schemes Power-saving modes of operation Turn the transceiver off when idle Using short data packets 2018/7/29

網路層 Designed according to the following principles: Power efficiency Data-centric No hinder the collaborative effort An ideal sensor network has attribute-based addressing and location awareness 2018/7/29

網路層 Maximum PA route: Minimum energy (ME) route: Sink-D-T, total PA=3, total α=4, Route 1: Sink-A-B-T, total PA=4, total α=3, Maximum PA route: Route 4 Minimum energy (ME) route: Route 1 Minimum hop (MH) route: Route 3 Route 1: Sink-A-B-T, total PA=4, total α=3 Route 2: Sink-A-B-C-T, total PA=6, total α=6 Route 3: Sink-D-T, total PA=3, total α=4 Route 4: Sink-E-F-T, total PA=5, total α=6 Route 4: Sink-E-F-T, total PA=5, total α=6 Route 2: Sink-A-B-C-T, total PA=6, total α=6, 2018/7/29

網路層 DATA REQ ADV Source Sink REQ DATA ADV Step 3: send data Flooding Gossiping Sensor protocols for information via negotiation (SPIN) Directed diffusion DATA REQ ADV Source Sink REQ DATA ADV Step 3: send data Step 2: set up gradient Step 1: propagate interest 2018/7/29

網路層 Open research issues Improved or new protocols to address higher topology changes and higher scalability. 2018/7/29

傳輸層 Need when system is planned to be accessed through the Internet or other external networks Between sensor node and sink node: UDP Between sink node and user: UDP or TCP ? TCP/UDP 2018/7/29

傳輸層 Open research issues Hardware constraints such as limited power and memory. Each sensor node cannot store large amounts of data like a server in the internet. may be needed where UDP-type protocols are used in the sensor network and TCP/UDP protocols in the internet or satellite network. 2018/7/29

應用層 Potential application layer protocols for sensor networks remains a largely unexplored region. three possible application layer protocols Sensor management protocol (SMP) task assignment and data advertisement protocol (TADAP), Sensor query and data dissemination protocol (SQDDP) 2018/7/29

應用層 Open research issues Although SQTL is proposed, other application layer protocols still need to be developed to pride a greater level of services Research developments should also focus on TADAP and SQDDP 2018/7/29

Conclusion Wide range of application areas New sensor networking techniques are required Intend to motivate a search for solutions to the open research issues 2018/7/29