1. Distributed P2P Protocols Gabber-Galil overlay network for data storage in sensor networks

2. Overview Background Research goal GG, GPSR, CDA GGC – deterministic “random walk” GROVS Protocol Conclusion

3. SensorNet – Background “Sensors are small, low cost, low power devices equipped with limited computational, storage and communication capabilities” “SensorNet has a substantial capabilities on the aggregate” “Sensors communicate among themselves in order to achieve a higher level task”

4. Problem definition

5. Research Goal Research goal: Design local, simple and efficient protocol for data storage and query retrieval in sensor networks. Experimental design –simulator. GROVS – Gabber Galil Over Voronoi Subdivision

6. Intuitively: A graph for which any “small” subset of vertices has a relatively “large” neighborhood. Fault-tolerance Gabber Galil Expander

7. Explicit construction – Let s i be site {x,y} The Gabber Galil links are: x,y  LE SiSi LN SN SE σ LN {x,y} = {x,x+y} σ LE {x,y} = {x+y,y} σ SN {x,y} = {x+1,y} σ SE {x,y} = {x,y+1}

8. GPSR - Voronoi mosaic Let S be a group of random sites on the unit surface: x,y  1  x,y  0 00.20.40.60.81 0 0.2 0.4 0.6 0.8 1 p A point p lies on V(s i ) iff: ∀ s j ≠ s i dist(p, si)<dist(p, sj) Voronoi diagram is a set regions that satisfy: S T Greedy Perimeter Stateless Routing 1. Greedy routing 2. Perimeter progress S

9. CDA (Continuous Discrete Approach) Random group of sites on the plane forms a Voronoi mosaic A discrete layer on top represent the sites locations and their links Links are calculated by the discrete Gabber – Galil transform

10. Routing algorithm SETS SIMULATION: Begin with primary component Expand by routing at each step

11. Routing algorithm rXY Loc 06 04 Theo 255075100125150175200 20 40 60 80 100 Steps Coverage Primary component 5%, Nx=6400 sites 130140150160170180 190 96 97 98 99 Sets Simulation for 5% primary group 6400 3200 1600 800 400 200 100 50 Theo

12. Gabber Galil Chain (GGC) 00.20.40.60.81 0 0.2 0.4 0.6 0.8 1 GG({X,Y}) GG(GG(GG({X,Y}))) GG(GG({X,Y})) GGC is composed of links: GG NORTH ->GG EAST -> GG NORTH ->GG EAST … GG n ({x,y})= n even {x+y, y} mod 1 n odd {x, y+x} mod 1

13. GROVS Protocol A SET message is sent along GGC in order to STORE FORWARD s1s1 s2s2 s3s3 s4s4 s5s5 s6s6 g1g1 g2g2 ACK is sent to generator in order to update EOC

14. GROVS Protocol Query is sent to S 1 - where an activity was generated s1s1 s2s2 s3s3 s4s4 s5s5 s6s6 g1g1 g2g2 GET Message is sent to the next GGC link S 5 retrieves on the behalf of S 1

15. Experiment

16. Conclusion oDistributed construction of 6-Regular Graph : low diameter (14 hops for 6400 sites). Scales with network size oDeterministic routing algorithm – converges with random walk oSimulations shows that hot spots on GROVS network can generate activities as long as system memory allow

17. [01] Gkantsidis C., Mihail M. and Saberi A. : Random Walks in Peer-to-Peer Networks, College of Computing Atlanta GA, 2004 (http://www.ieee-infocom.org/2004/Papers/03_4.PDF) [02] Manku G S., Naor M. and Wieder U. : Know thy Neighbor’s Neighbor : Power of Look-ahead in Randomized P2P Networks, ACM, 2004 (http://infolab.stanford.edu/~manku/papers/04stoc-nn.pdf) [03] Gabber O. and Galil Z. : Explicit constructions of linear size super-concentrators, Tel Aviv University, 1981 [04] Naor M. and Wieder U. : Novel Architectures for P2P Applications: The continuous-discrete approach (CDA), Weizmann institute of science, 2003 (http://www.ic.unicamp.br/%7Ecelio/peer2peer/debrujin-p2p/novel-architectures-naor.pdf) [05] Karp B., Estrin D., Yin L., Yu F., Rantnasamy S., Shenker S. and Govinadan R. : Data centric storage in SensorNets with GHT, A Geographic Hash Table, MONET, 2003 (http://www.isi.edu/div7/publication_files/data_centric_storage.pdf) [06] Culler D., Estrin D., and Srivastava M. : Overview of Sensor Networks, IEEE, 2004 (http://www.ics.uci.edu/%7Edutt/ics212-wq05/ieeecomput-sensornet-aug04.pdf) [07] Estrin D., Govindan R., Hiedemann J. and Kumar S. : Next century challenges: scalable coordination in sensor network, USC/ Information science institute, 1999 (http://www.isi.edu/~johnh/PAPERS/Estrin99e.pdf) [08] F.L. Lewis, Wireless sensor networks, University of Texas (Arlington), 2004 (http://arri.uta.edu/acs/networks/WirelessSensorNetChap04.pdf) [09] Karp B. and Kung H. T. : GPSR: Greedy Perimeter Stateless Routing for Wireless Networks, Harvard, 2000 (http://www.eecs.harvard.edu/~htk/publication/2000-mobi-karp-kung.pdf) [10] M. de Berg : Computational Geometry, Springer, 2000 (http://books.google.com/) [11] Diestel R. : Graph theory, Springer, 2000 (http://www.math.uni-hamburg.de/home/diestel/books/graph.theory/GraphTheoryIII.counted.pdf) [12] The gnutella protocol specification v0.4 (http://www9.limewire.com/developer/gnutella_protocol_0.4.pdf) [13] Miu A. : Lecture 7, Voronoi diagram presentation, Cambridge, 2001 ( http://nms.lcs.mit.edu/~aklmiu/6.838/L7.ppt ) References