1. SAP: STORAGE AWARE PROTOCOLS FOR HETEROGENEOUS NETWORKS Shweta Jain Assistant Professor Mathematics and Computer Science York College CUNY

2. Outline Background and Motivation Overview of network architectures --Applications, Goals, Challenges and Proposed solutions Seamless communication Work in progress Next steps and future directions

3. BACKGROUND AND MOTIVATION

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5. Source: www.Caida.org

6. Some Statistics Mobile broadband users worldwide 1.2 billion estimated by the ITU in 2011 Growth rate 45% annually over last 4 years Mobile broadband subscriptions outnumber fixed subscriptions 2:1 Top Mobile broadband Usage (survey 2010 by Keynote/Adobe) Media and entertainment Social networking, (76%) local information (73%), news (68%), music (63%), games (61%), video (56%) Travel Maps (81%), Research travel (47%)

7. Analysis of Usage Users prefer to be mobile People want their content NOW Mostly “Delay Intolerant” usage Delay tolerant applications – not so much? Ebooks,. Podcast, etc Why do anything different with the delay tolerant traffic?

8. Google Search Trends – Wimbledon, Olympics, Podcasts and Ebooks Wimbeldon Olympics Podcasts eBooks

9. Analysis of Usage Users prefer to be mobile People want their content NOW Mostly “Delay Intolerant” usage Delay tolerant applications – not so much ebooks,. Podcast Google trend shows searches including the terms ebooks and podcasts Similar traffic all year round! Why do anything different with the delay tolerant traffic? Need to make way for live streaming during the surge! Historically when a service improves, demand for service also increases and vice-versa

10. Key Motivation Internet has evolved Needs new protocols for efficient delivery of content Mobile internet access is highly popular Need a variety of mobile broadband infrastructures Mesh and Manet free/low cost services Sensors, IoT, VANET secure, niche applications for utilities and services Need protocols that enable seamless communication across these networks Delay tolerant applications need to be served differently from “delay intolerant” Podcasts, eBooks, sensors, Internet of Things create traffic all year round

11. OVERVIEW OF NETWORK ARCHITECTURES Applications, Communication Goals, Communication Challenges and Proposed solutions

12. NetworkKey ApplicationCommunication Goals Communicatio n Challenges Proposed Solutions Wireless mesh and MANET Wireless and mobile communication in disaster zone, military, civilian settings Provide peer-to- Peer, multicast, and broadcast communication Load balancing, energy efficiency, fast routing updates Distance vector, link- state and hierarchical routing protocols Wireless sensor networks Remote monitoring of the environment Forests, volcanos, buildings/home, war zone Data aggregation from group/type of sensors rather than specific nodes Prolong network lifetime by reducing communication overhead In-network processing, local data aggregation Internet of Things Remote monitoring and control: smart grid, smart utility meters Bi-directional communication between devices or groups Communication Storm, ensure quality of service for time sensitive/missio n critical applications Several sensor network solutions are applicable Network architecture research – Key points

13. NetworkKey ApplicationCommunication Goals Communicatio n Challenges Proposed Solutions Delay Tolerant Networks Data delivery to remote areas: Rural areas, forest camp, army base, Enable communication in networks that may not have end-to- end connectivity Long periods of disconnection, no end-o-end route, traditional routing not applicable Flooding, opportunistic transport, prediction based routing Cognitive Radio Networks Improve spectrum utilization: Public safety, military communication, consumer applications Programmable radios communicating over licensed bands with minimum impact on primary users’ quality of service Detect primary users, estimate spectrum availability and measure impact on primary user spectrum sensing for user detection, database of primary user activity to predict spectrum availability Network architecture research – Key points

14. Key Features Routing technique: Control state or Data state based Cost metrics: Link cost or Historical connectivity information Transport End-to-end TCP/UDP or Opportunistic transport, send data as soon as a candidate forwarding node is available

15. SEAMLESS COMMUNICATION Storage aware protocols (Network and Transport)

16. Key Observations From an application standpoint: All networks are in general prone to varying degree of disconnections 1) Mobile devices lose connectivity for long or short time periods 2) Mobility triggers new route discovery, causing disconnection until a new end-to-end path is discovered 3) Sensor networks re-configure routes to avoid network partition due to battery depletion 4) IoT are struggling with communication storms which may be inferred as disconnection by the application 5) Cognitive radios stop transmitting when a primary user is detected

17. Generalized Delay Tolerant Networks: gDTN Observation: In general all network architectures have properties similar to the Delay Tolerant Networks Wireless characteristics Intermittent connectivity – Cognitive Radio, MANET, VANET Variable link speed – Bluetooth, WiMAX, WiFi, Cellular Internet Long term disconnection – Mobility Every vertical handoff changes the link speed These are similar to Disruption Tolerant network (DTN) features DTN is the extreme case of challenged networks Wired is the other extreme case of well provisioned networks Other wireless networks are somewhere between this red and green 17

18. gDTN: Generalized DTN ??: Can a storage and prediction based approach be the one-size fit all solution to the problem of seamless interconnection? Can we combine features of wireless routing with history and storage based DTN routing? Proposal SAP: Storage Aware Protocols for seamless integration of heterogeneous network architectures

19. WORK IN PROGRESS Storage Aware Protocols (SAP) 19

20. Components of SAP Storage Aware Routing (STAR) Use history based routing metric Use storage to delay data delivery while the network searches for “better” paths Better {Energy efficient, most storage, fastest, higher probability of success,…} Disruption tolerant transport End-to-end transport with proxy and feedback for disconnection 20

21. STAR: Storage Aware Routing Compute multiple paths to the destination using the hop count based routing metric- breadth first topology search Maintain long and short term “expected link rates” to describe the temporal/variable cost component of the routes Choose to store when the best path is Worse than usual or Downstream routers have low available storage (network layer backpressure flow control) (Future routers will have storage space for caching and temporary storage) (storage is getting cheaper by the year) Forwarding Algorithm

22. Storage Router 22

23. Applicable to all networks? Applicability: Long term cost: Time scale of variation depends upon the network type Storage space: Indicates congestion in wired, wireless, DTN (congestion is a measure of storage space) Storage aware routing concept for all networks Unifies and generalizes the routing scheme across networks Support for mobility Allows policy and price based store or forward Avoid expensive 3G Store if the Wi-Fi data rate is lower than usual

24. End to End Transport Send feedback to sender or sender’s agent when data forwarding is interrupted Sender keeps the route alive by sending 1 byte packets– similar to flow control in TCP Data is stored at the last router that detected disconnection If route becomes available, transmission resumes If it takes too long…. The end host will need to retry 24

25. NEXT STEPS AND FUTURE DIRECTIONS 25

26. Next Steps Implementation and evaluation Simulation and emulation of network and transport on wired- wireless mesh and DTN testbeds Tying the lose ends How much state to maintain? Proxy placement How long and how much to store? 26

27. Future Directions Integration of networks is necessary but difficult Several lose ends and unanswered questions Security, data integrity and privacy

28. THANKS FOR LISTENING! Questions and feedback please?