declarative sensor networks with applications in landslide detection david chu computer science...
TRANSCRIPT
declarativesensor networks
with applications inlandslide detection
David ChuComputer Science DivisionEECS DepartmentUC Berkeley
iCAST/CMU/TRUSTJoint Conference
9 January 2007
motivation
programming sensor networks is difficult!
building entire sensor systems is even harder!!
inspiration : data management• declarative is widely used in data
management– relational databases– spreadsheets– abstract “what” from “how”
• (Sensor-Network-As-Database)
inspiration : network design• declarative is new idea in networking
– compact– flexible– analyzable, optimizable– Internet Routing, Overlays built declaratively
• (the P2 project)
what we did
• adapted declarative language
• built compiler & runtime for sensornets
• wrote declarative examples
agenda
1. language overview
2. declarative sensornet examples
3. system architecture
4. feasibility assessment
5. application to landslide detection
arch : compiler
Network support
Generated nesC code
store(…) :- prod(…), cons(…). … path(…) :- link(…), dest(…).…
Binary Image
Snlog Compiler/OptimizerSnlog
Program
GenericPredicateTemplate……
nesCTemplates
nesC Backend
Execution Planner
Snlog Frontend
nesC Compiler
Built-in Predicates
Type system
Database Operators
RuntimeComponents
RuntimeTemplate……
DSN Runtime Support
arch : runtime
the network
Join Join Proj
tupleready
Join AggProj Sel
table(compiler generated)
builtin(user’s library)
database operators(compiler’s library)
push interfaces
pull interfaces
thread of control
event signal
Sel Ag Proj
… … …
… …
… …
runtimedaemon
mac daemon
tupleready
tuplereadysendready
tupleready sendready
implementation challenges• predictable execution
→ dynamic vs. static allocation
• memory constraints→ memory footprint optimizations
no temporary tables, join/agg operator choice
• asynchrony→ rule-level atomicity
priorities
[Left] La Conchita, California – a small seaside community along Highway 101 south of Santa Barbara. This landslide and debris flow occurred in the spring of 1995. A reoccurrence in 2005 claimed 4 lives and resulted in 29 missing persons. [Right] Chehalis, Washington - landslides and debris flows during the winter storms of February 1996. Photographs by R.L. Schuster, U.S. Geological Survey.
[Above] The locations of the 2005-2006 and 2006-2007 debris flow deployment sites.[Top Right] Smoke from the Day Fire. [Middle Right] Recently burned hillside in Burbank, CA was the site of two debris flows in 2005-2006 Winter season. [Bottom Right] Base of the channel after debris flow with remaining sediment. [Bottom Left] Burn-resilient vegetation is quickly recovering just a few months after the fires and debris flows.
Harvard Burn Site
Day Fire
[Above] Parshall flume used in conjunction with water level logger at the channel’s choke-point. [Top Right] Custom overland flow sensor for fine-grained detection of water runoff. [Bottom Right] Solar-powered base station for actuating and gathering data from the wireless sensor network, shown here connected to laptop during testing.
conclusion
• sensor networks→ data + communication
• several examples of functional programs
• feasible for today’s hardware platforms
• preparing for landslide deployment