1 / 22

ROME: Road Monitoring and Alert System through Geo-Cache

ROME: Road Monitoring and Alert System through Geo-Cache. Bin Zan , Tingting Sun, Marco Gruteser , Yanyong Zhang WINLAB, Rutgers University . Road Monitoring in Mobile Sensor Networks. cell phone. Positioning. Communication. GPS. Surface Distress. DSRC. camera. vibration sensor.

shadi
Télécharger la présentation

ROME: Road Monitoring and Alert System through Geo-Cache

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. ROME: Road Monitoring and Alert System through Geo-Cache Bin Zan, Tingting Sun, Marco Gruteser, Yanyong Zhang WINLAB, Rutgers University

  2. Road Monitoring in Mobile Sensor Networks cellphone Positioning Communication GPS Surface Distress DSRC camera vibration sensor rotation sensor Skid Resistance Sensing accelerometer • New road monitoring services are enabled by cars with sensing, communication, computing and storage capabilities. • System Assumption • Location-based interests • Data items are accessed through queries after they are generated. Road Roughness

  3. Data Collection Challenges in Mobile Networks • Query-response • Difficult to locate data source afterwards • Local aggregation • Data are stored around where they are generated by passing cars • Short-ranged radios have larger bandwidth than cellular links • Centralized • Bandwidth (Cellular) • Cost (DSRC) • Storage

  4. Location Aggregation • Three local aggregations. • Aggregation content format

  5. Geo-Cache Concept • Anchor Location: Locations of interest, where sensed results are aggregated. • Geo-Cache • Aggregated information around the Anchor Location. • Geo-Cache Collection Protocol • Protocols to hand over information through inter-vehicle communication as nodes move away.

  6. Geo-Cache Collection Protocol • Broadcast Geo-Cache (Baseline) • Periodically broadcasting Geo-Cache to those closer to the anchor location, until time-to-live timer expires. • High overhead • Relay Geo-Cache • Acknowledgment • Overhearing • Delayed Geo-Cache

  7. Relay Geo-Cache ACK B C A • Relay Protocol • Acknowledgement

  8. Relay Geo-Cache • Relay Protocol • Acknowledgement B C A

  9. Relay Geo-Cache Handoff ACK B C A • Relay Protocol • Acknowledgement

  10. Relay Geo-Cache B C A • Relay Protocol • Overhearing

  11. Relay Geo-Cache • Relay Protocol • Overhearing B C A

  12. Relay Geo-Cache Handoff B C A • Relay Protocol • Overhearing

  13. Delayed Geo-Cache (Boomerang) Detect C B A • Relay protocol incurs high overhead when detection probability is low • Delayed protocol: cars keep their Geo-Cache locally, and later hand off to an opposite collector

  14. Delayed Geo-Cache (Boomerang) C B A D • Relay protocol incurs high overhead when detection probability is low • Delayed protocol: cars keep their Geo-Cache locally, and later hand off to an opposite collector

  15. Delayed Geo-Cache (Boomerang) • Relay protocol incurs high overhead when detection probability is low • Delayed protocol: cars keep their Geo-Cache locally, and later hand off to an opposite collector C B A D

  16. Delayed Geo-Cache (Boomerang) • Relay protocol incurs high overhead when detection probability is low • Delayed protocol: cars keep their Geo-Cache locally, and later hand off to an opposite collector Geo-Cache back to Anchor Location C B A D

  17. When Nobody is Around … • What if the handoff process cannot find a candidate (the current carrier is the only node in the area)? • Infrastructure: cellular, WiFi, road-side DSRC units, etc.

  18. Performance Evaluation • Performance metrics • Communication Overhead • Geo-Cache anchoring delay (the time between when the geo-cache is carried away from the anchor and when it returns) • NJTP Trace • Represents relatively sparse off-peak traffic from 6 to 8 AM, south NJ. • Synthetic workload • 70km two lane road. • Cars’ arrival rate as Poisson distribution. • Average speed: 30 m/s. • Radio range: 100m for dense traffic and 250m for sparse traffic • NS2 • 802.11b as PHY and MAC • Two-ray-ground propagation model

  19. Performance Evaluation • Broadcast Geo-Cache vs. Relay Geo-Cache.

  20. Performance Evaluation • Delayed (Boomerang) vs. Relay Geo-Cache.

  21. Conclusion • New mobile sensing applications are being enabled • Local aggregation through the Geo-Cache structure provides a cost-effective method for mobile sensing • Delayed Geo-Cache protocol can significantly reduce the communication overhead while anchoring the Geo-Cache especially with lower detection probabilities.

  22. Questions & Answers

More Related