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MultiNetwork Information Dissemination

MultiNetwork Information Dissemination. Nalini Venkatasubramanian Dept. of Computer Science CERT/ UC Irvine UCI: Valentina Bonsi, Mayur Deshpande, Hojjat Jafarpour, Kyungbaek Kim, Sharad Mehrotra, Do Minh Ngoc, Mirko Montanari, J eanettte Sutton, Kathleen Tierney, Bo Xing……. &

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MultiNetwork Information Dissemination

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  1. MultiNetwork Information Dissemination Nalini Venkatasubramanian Dept. of Computer Science CERT/ UC Irvine UCI: Valentina Bonsi, Mayur Deshpande, Hojjat Jafarpour, Kyungbaek Kim, Sharad Mehrotra, Do Minh Ngoc, Mirko Montanari, Jeanettte Sutton, Kathleen Tierney, Bo Xing……. & City of LA Emergency Preparedness Dept. City of Ontario, CA

  2. Center for Emergency Response Technologies • CERT Mission • lead research, technology development IT to improving emergency response. • forum for collaboration between academia, industry, and government • Interdisciplinary researchers • Computer Science, Social Science, Engineering • Close partnerships with local & state agencies, industry. • Cities of LA/SD/Ontario/Rancho, OCFA, LA County Fire… • Responsphere – A campus-wide testbed for technology testing 2

  3. Next Generation Alerting and Warning Project

  4. Scenario: Earthquake Dissemination Timeline • Warning • Damage Analysis & Response • Disseminating Public Information T: 0 45 secs 2-5 mins 5-60 mins

  5. Flash Dissemination in Wired Networks • Early Earthquake Warning Systems (0-45 seconds) • Sound sirens, backup data, avoid bridges • Goals: Speed and reliability • USGS Shakecast (2-5 minutes) • Highly Detailed GIS data • Partial infrastructure availability • Information Portals(>1 hour) • Up-to-date Information from authoritative sources • Website under heavy load: Spikes  crash

  6. Flash Dissemination in the Large (Wired Networks) • Early Earthquake Warning Systems (0-45 seconds) • Sound sirens, backup data, avoid bridges • Goals: Speed and reliability • Approach: Reliable ALM Protocols over P2P Networks (FareCAST) • USGS Shakecast (2-5 minutes) • Highly Detailed GIS data • Partial infrastructure availability • Approach: Gossip-Based Random Walker Protocols on P2P Networks (CREW) • Information Portals(>1 hour) • Up-to-date Information from authoritative sources • Website under heavy load: Spikes  crash • Approach: P2P WebServers (Flashback)

  7. FaReCast : Fast and Reliable Application Layer Multicast • Traditional Tree : Multiple Fan-Out • Efficient and Fast,Single Point of Failure • No time to recover, ack/resend • 1. Forest-Based M2M ALM Structure • Multiple Fan-In – for reliability • Multiple Fan-Out – for speed • ↑Path Diversity, ↑reliability,↑speed • 2. Multidirectional Multicasting • Don’t fix, trigger sends judiciously • Backup Dissemination • L2L (Leaf-to-Leaf) Dissemination

  8. FaReCast: Fast Reliable Appl. Layer Multicast Simulation with 100,000 nodes 100% reliability under 40% of failed nodes No significant increase in latency for over 99% of nodes

  9. Richer Information (2-5 minutes)CREW (Concurrent Random Expanding Walkers) Protocol • Basic Idea: Servers ‘serve’ data to only a few clients • Who In turn become servers and ‘recruit’ more servers • Split data into chunks • Chunks are concurrently disseminated through random-walks • Self-scaling and self-tuning to heterogeneity 2 2 3 1 1 1 3 3 2 4 5 4 5 6 6

  10. CREW Protocol: Latency, Reliability

  11. An Hour and Beyond…Flashback: Scalable Dissemination of Web Pages Spike loads crash Web sites • Slashdot, Disaster-Portals • A Distributed Web Server • Browsers that want the web-page are now collectively behaving as a P2P webserver • No intermediaries, setup • Medium Size Content • 100KB – 1-2MBs • Repeated catastrophes!!! • 10 secs – user interaction, peer download times • Roulette Protocol • Grandma-proof! • Setup/configure, firewalls • Diverse OS, browsers

  12. Performance Measurement: Basic Scalability • Test Setup • Web-server hit with a “one-shot” number of clients; server 800Kbps BW • Average time for a client to get the whole file measured • Flashback is highly scalable • HTTP download time is linear in number of nodes • Flashback download time is Log in number of nodes

  13. Fast, Reliable Dissemination in Wireless Networks The problem: Broadcast of rich content data over wireless networks at crisis site Instant Dissemination in Connected Networks Reliability Cellular, WiFi, MANETS, DTNs, Mesh Delayed Dissemination in Disconnected Networks Goals Timeliness Hybrid Networks for Reachability and Scalability Message Efficiency

  14. RADCAST: Flash Broadcast in MANETS • Concurrent dissemination of awareness and content • Data diffusion: based on a mix of push/pull (Pryer) • Awareness assurance: network traversal using walkers (Peddler) • Problem: fast network traversal • Minimizing cover time, termination time and transmission overhead Assures reception { Walker Metadata { Awareness Assurance concurrent Reliable Content Dissemination Walker Guides Fragmentation Retrieves missing concurrent { Pull Content Data Data Diffusion concurrent Push Spreads

  15. Sticker: A Protocol for Spatial Dissemination in Disconnected Networks Problem: Post messages to a geographic location without infrastructure support h { Fixed Number of Distinct Copies Devices cache and carry messages for others, Messages exchanged during encounters Replication Context Sens- ing & Collection Location- Closeness Based Forwarding Aliveness-Signi- ficance Based Purging

  16. Instant Mesh Networks Dynamically deployed mesh networks for providing short-term infrastructure coverage at incident/event sites • Fast, easy deployment • Expanded coverage • External information Network Backhaul Backbone Latency Gateway Mesh Backbone Client Latency Mobile Clients Data Network

  17. Gateway Designation in Instant Mesh Networks The Problem: To determine which mesh router in a given mesh backbone should serve as the gateway, so that backbone latency is minimized. Given: • A connected network formed by stationary mesh routers • An initiator mesh router Goal: • Distributedly find the mesh router with maximum centrality and report it to the initiator mesh router Optimize: • Transmission Efficiency: least number of transmissions • Time Efficiency: least execution time Closeness Centrality: -- Capturing average backbone latency -- Capturing max backbone latency Graph Centrality: Measured based on link quality metrics

  18. FACE: An Approximation Algorithm Centrality Approximation using spanning tree root/leaves as sample points Centrality Measuring { FACE Distance Notification through Spanning trees (SSTs) for centrality calculation Gateway Designation Popping up the maximum centrality along a spanning tree rooted at initiator (PST) Extrema Finding Centrality Approximation: Using randomly picked nodes as sample points to approximate centrality [Eppstein SODA 2001] - additive error based on number of sample points

  19. Some Performance Results Impact of FACE on Inbound dissemination latencies (32KB data) The FACE-designated gateways significantly enhances the timeliness of disseminations of external information.

  20. Mesh Network Deployments Commercial mesh routers not good enough • 5X improvement with • new antenna technology • Better signal coverage better building penetration • Some Setup effort required • Not always feasible • Vulnerable to hardware failures

  21. In the future • Research • Geographically Correlated Failures • Uncertainty and Correlations in Information Dissemination • Understanding/Incorporating Social Media dissemination • Twitter, Facebook, rimoftheworld.net • Multinetwork messaging • Towards a Unified Warning Model and System • Implementation • Standards, Multihazard warning • Testing and Deployment • Partnerships, Pilot Studies • Training

  22. BACKUPS

  23. Organization Policy Specifications Crisis Policy Specifications Crisis Alert CrisisAlert – A Meta Alerting System for Organizations Automatic notification systems (USGS, EDIS, CAP based systems. ..) Crisis Information from Emergency Operations Center • Which messages to send? • Who should receive them? • Personalization and Customization • Who will receive the notifications? • What modalities will be used? • School Principal: • Receives updates • Makes decisions • Communicates decision to others • All Staff • Receives messages Proprietary delivery mechanism used by the organization/school

  24. Applications Implementation on Mobile Devices Middleware Operating System Symbian DTN-Based Flash Broadcast Spatial Dissemination RADcast Maemo

  25. $ Short & Long Term Warning • Part of the Disaster Portal Project: in use by the City of Ontario • Earthquake Scenario Earthquake hits the area Timeline Earthquake Early Warning Shakecast Information Detailed Information People close to the epicenter Detailed map of the damages Location of shelters People close to chemical facilities Map of the damaged area, Location of the dangerous chemical facilities Information about the chemical People in safe areas Hospital information General information about the emergency Visual and sound notifications of “Duck and Cover” Map of the affected area Generic first-aid information

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