1 / 10

Usable Sensor Neworks

Usable Sensor Neworks. Kay Römer ETH Zurich. Programming a dynamic ensemble of sensor nodes. Setting up a working system in the field. Make information accessible to humans. Sensor Nets are Hard to Use. Tool for scientists, not for end users Real world embedding Resource constraints

rae-miranda
Download Presentation

Usable Sensor Neworks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. UsableSensor Neworks Kay Römer ETH Zurich

  2. Programming a dynamic ensemble of sensor nodes Setting up a working system in the field Make information accessible to humans Sensor Nets are Hard to Use • Tool for scientists, not for end users • Real world embedding • Resource constraints • Complex, uncertain distr. system • Mission: concepts and tools to enhance ease of use Design Implementation Test Deployment Use

  3. Implementation • Sensor networks are complex and dynamic distributed systems • Hard to program correctly • Programming abstractions • Hide certain system properties from the developer • Declarative: specify what rather than how • Global: whole network rather than single nodes

  4. Role Assignment ON :: { battery >= 50%AND count(2 meters) { role == ON } <= 1} OFF :: else • Assign functions to sensor nodes based on node properties • New abstraction: “roles” • Generic specification language • Ex. “Coverage”: determine few ON nodes that cover whole area with their sensors, others OFF • Compiled offline • Distributed algorithm to findand maintain role assignment

  5. Deployment • Real-word can easily break a sensor network • Frequent node and communication failures • Unsatisfactory quality of service (lifetime, latency, data yield) • Passive inspection • Monitor sensor network • Without instrumentation of sensor nodes

  6. Sensor Net Inspection Framework • Overhear and decode network traffic • Analyze to find bugs • Node crash, reboot, no route, partition, ... • Main challanges • Incomplete information • Genericity

  7. struct TOS_Msg { uint16_t addr; uint8_t type; uint8_t group; uint8_t length; int8_t data [29]; uint16_t crc; }; Packet Description Packet Decoder Operator Graph Data StreamProcessing Decision Tree Node State SNIF Architecture cc.freq = 868000000; cc.sop = 0x55aa; cc.crc = 0xA001; Radio Configuration Sniffer

  8. Use • Make sensor information accessible to non-expert users • Simple and intuitive • Not: complex db queries

  9. Google for the Real World • Things and places have Web pages • Contain dynamic information derived from sensors • E.g. room page contains occupancy and temperature • Make these dynamic pages searchable ala Google • Main challenge • Cannot index dynamic content in real time • Large scale

  10. GoForReal Architecture room IFW sensor:occupied=empty IFWD42.html Room IFW D42 Occupied: Empty Occupied Model: Empty (80%), Full (20%) Search Engine Room IFW D42 Motion: False Index IFWD42.html Occupied Cache: Empty Occupied Model: Empty (80%), Full (20%) Internet Inference Model

More Related