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Networking Research Review SENSIT PI Meeting October 7-8, 1999 Marina Del Rey SCADDS (ISI/W) -- Estrin GRASP (UCLA/CS) -- Zhang DDNC (MIT-LL) -- Van Hook DSN (UCLA/EE-ISI/E) -- Srivastava WINS (Sensorweb) -- Kaiser General Organization (15 minutes per project) Brief overview Detailed progress since last meeting Short term issues encountered (if any) New directions, emphases SCADDS Recent Progress (PI’s: Deborah Estrin, Ramesh Govindan, John Heidemann) Directed diffusion v0 (Intanago) Initial simulation results Initial prototype implementation Experimental platform (Elson, Girod, Kumar, Raghunath, Zhao) Linux and short-range radios Simple hardware assembled to support protocol experiments--rf sensors, tags (in progress), using cots radios Scaffolding for diffusion and application SCADDS: Ongoing activities Preparation for use of WINS ng nodes Detailed discussions of comm API Investigation of current and planned assembly mechanisms(FH and TDMA) Plan to interface ucLinux nodes directly to Sensorweb hardware--run diffusion algorithms on SENSIT testbed Algorithm development and evaluation Directed diffusion design and evaluation (Chalermak Intanagonnowat) Adaptive clustering (Satish Kumar) Timing/Synchronization (Jeremy Elson, Lewis Girod) Adaptive fidelity (Amit Kumar, Ya Xu) Directed Diffusion Version 0.0 of directed diffusion Multi-path delivery Distinct information dissemination Probabilistic forwarding Normalized gradients Initial experiments with one source and one sink per data type Many other “flavors” of diffusion worth exploring Directed Diffusion Preliminary “Indications” Overhead Early indications that average network overhead (data, power, state) grows linearly with network size Overhead per node is constant Traffic dependent Energy Dissipation Low variance of remaining energy across nodes Indicator of effective load balancing and long network lifetime Supplementary: Directed Diffusion Future work Study parameter tuning of the model Cleaner model : Generalization of reinforcement and interest Explore additional flavors of diffusion Redundant information dissemination Absolute gradients Multiple sources and multiple sinks per data type Port to WINS ng nodes, or interface our sensor-controller platform to theirs Adaptive Clustering Original hypothesis: Adaptive clustering allows efficient coordination of local interactions However cluster creation and maintenance can consume significant energy that has to be amortized over gains in application function Soft-state techniques may consume too much energy at low query rates Hard-state techniques perform better but adaptation may be more difficult (work in progress) Adaptation is too energy inefficient if frequency of adaptation not properly controlled Supplementary: Adaptive Clustering: TDMA Master Election Master node assigns TDMA slots to slave nodes Communication between sensors through master to conserve energy Master’s radio powered on all the time and hence consumes more energy than slaves Adapt master selection based on energy to improve network lifetime Supplementary: Adaptive Clustering: TDMA Master Election Adaptation also has a cost: Energy cost of the re-election process Potential data loss during adaptation Potential re-organization of neighbor clusters Change in cluster membership Re-assignment of TDMA slots Some Project Issues Evaluation Platforms uclinux hardware? which radio? Better indoor propagation and power models for use in non-experimental evaluations Interfaces and APIs Interface to WINS ng nodes (i.e., real sensor data and real low-power radio) Interface to applications Interaction of diffusion and radio/mac level behaviors Supplementary: Development Platform ucLinux and ucSimm The Linux Microcontroller project uclinux is a port of the Linux 2.0 to " Features systems without a " 3.5 in x 1 in x 0.25 in, 30pim SIMM Memory Management Unit. " 16Mhz MC68EZ328 DragonBall Target Systems: 3Com Palm III+TRG memory board " " 8Mb RAM, 4Mb FLASHROM I/O Interfaces Other micro-controller such as MC68K series " 18 General Purpose I/O pins ucSimm: specially designed simm module " 10Base-T Ethernet (CS8900A) " Will directly drive a LCD panel 320x240 " RS-232 Serial " Approx $150 per node Supplementary: Pros and Cons Open Source: GNU Public Liciense Good Portability Potential Applications Available worldwide Simple but Flexible I/O Radiometrix Transceiver A/D, D/A converter Standard serial or 10Based wired connection Low Power Consumption 3.3v low voltage, 63mA 108mA Low Price " Still in pre-mature stage " " " Limited Extensibility limited # of I/O pins No Standard AddrBus or DataBus Summary Diffusion experiments underway on prototype testbed Sensors are Librettos or ucSimm running linux with Radiometrics radio as rf-sensor Tags provide data (using small form-factor, semiprogrammable radio beacons) Can be ported or interfaced to WINS ng nodes for SENSIT demo in 2000 Other algorithmic work in design and modeling/simulation phase Diffusion--characterization, comparisons Neighbor identification/coordination/synchronization Clustering Adaptive fidelity
