1. A Survey on Sensor Networks Hussein Alzoubi Hussein_alzoubi@hotmail.com Rami Alnamneh Ramir11@yahoo.com

2. Outline Introduction Communication architecture Protocol stack Conclusion

3. Introduction Sensor Networks … low-cost, rapid deployment, self-organizing, and fault tolerance. Application areas: heath, military, and home. Large number of sensor nodes that are densely deployed. Nodes use their processing abilities to locally carry out simple computations and transmit the required and partially processed data. Ad hoc networks are not suitable for the sensor networks because of their unique features and application requirements.

4. Communication Architecture Internet and Satellite Sink Task manager node User Sensor nodes Sensor field A B C D E

5. Design Factors Fault Tolerance the ability to sustain sensor network functionalities without any interruption due to sensor node failures because of lack of power, physical damage, or environmental interference. Scalability the density of sensor nodes can range from few sensor nodes to few hundred sensor nodes in a region. Production Costs the cost of sensor node should be much less than $1 in order for the sensor network to be feasible

6. Hardware Constraints Power Unit Power generator Location finding systemMobilizer Transceiver SensorADC Sensing Unit Processing Unit Processor Storage Continue.. Design Factors

7. Sensor Network Topology - Predeployment and deployment phase - Post-deployment phase - Redeployment of additional nodes phase Environment can work in different environments. Transmission Media links between nodes can be formed by radio, infrared, or optical media. Power Consumption battery lifetime design of power-aware protocols and algorithms Power consumption: sensing, communication, and data processing Continue.. Design Factors

8. Protocol Stack Application layer Transport layer Network layer Data link layer Physical layer Power management plane Mobility management plane Task management plane

9. The Physical Layer Frequency selection. Carrier frequency generation. Signal detection. Modulation Binary and M-ary modulation schemes the binary modulation scheme is more energy- efficient Low transmission power and simple transceiver circuitry make Ultra wideband (UWB) an attractive candidate.

10. The Data Link Layer Multiplexing of data streams. Data frame detection. Medium access and error control. Ensures reliable point-to-point and point- to-multipoint connections in a communication network.

11. Medium Access Control Must achieve two goals - the creation of the network infrastructure - share communication resources between sensor nodes fairly and efficiently. Can ’ t be adopted into sensor networks, because - there is no central controlling agent like the base station. - power efficiency directly influences network lifetime in sensor network. Continue.. The Data Link Layer

12. Some of the proposed MAC protocols MAC protocolPower conservation SMACS and EARRandom wakeup during setup and turning off while idle Hybrid TDMA/FDMAHardware-based approach for system energy minimization CSMA-basedConstant listening time for energy efficiency Continue.. The Data Link Layer

13. Power saving modes of operation Turning the transceiver off during idling may not always be efficient due to energy spent in turning it back on each time. Error control Two modes of error control: - Forward Error Correction, decoding complexities. -Automatic Repeat Request (ARQ), additional retransmission energy cost and overhead. Best solutions: simple error control codes with low- complexity encoding and decoding Continue.. The Data Link Layer

14. Network Layer Task: energy efficient routes Sink A (PA=2) B (PA=2) C (PA=2) T D (PA=3) E (PA=1) F (PA=4) α 1 =1 α α α α α α α α α 5 =2 3 =2 4 =2 2 =1 6 =2 7 =1 8 =2 9 =2 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 Approaches: Minimum PA route: route 4 Minimum Energy (ME) route: route 1 Minimum hop (MH) route: route 3 Maximum minimum PA node route: route 3

15. Data Aggregation, data fusion A B C D E F G Sink Continue.. Network Layer

16. Routing techniques Flooding each node receiving a data or management packet repeats it by broadcasting. Gossiping send the incoming packets to a randomly selected neighbor. Continue.. Network Layer

17. Sensor Protocols for Information via Negotiation (SPIN) Step 1 ADV Step 2 REQ Step 3 DATA Step 4 ADVREQ Step 5Step 6 DATA Continue.. Network Layer

18. Sequential Assignment Routing (SAR) Creates multiple trees where the root of each tree is a one-hop neighbor from the sink. Low-Energy Adaptive Clustering Hierarchy (LEACH) Forms clusters to minimize energy dissipation. Directed diffusion Sets up gradients for data to flow from source to sink during interest dissemination. Continue.. Network Layer

19. Transport Layer Transport layer protocols are still unexplored: they may be purely UDP- type protocols, because each sensor node has limited memory and power.

20. The Application Layer Sensor Management Protocol (SMP) makes the hardware and software of the lower layers transparent to the sensor network management applications. System administrators interact with sensor networks using SMP. Task Assignment And Data Advertisement Protocol (TADAP) provides the user software with efficient interfaces for interest dissemination. Sensor Query and Data Dissemination Protocol (SQDDP) provides user applications with interfaces to issue queries, respond to queries and collect incoming replies.

21. Conclusion The flexibility, fault tolerance, high sensing fidelity, low cost, and rapid deployment characteristics of sensor networks create new and exciting application areas for remote sensing.

22. Questions? Thank you!