1 5 th IEEE Workshop on Wireless Mesh Networks IEEE WiMESH 2010 Boston, 21 June 2010 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs Emmanuel Baccelli Juan Antonio Cordero Philippe Jacquet Équipe Hipercom, INRIA Saclay (France)

2 Agenda Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010  Motivation  Our Proposal: SLO-T  An SLO-T Overlay Example  SLO-T Analysis  Application: SLO-T in OSPF  Motivation

3 Motivation Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Reliable communication of critical data in MANETs Synchronized Overlay

4 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010  MANET link synchronization is costly  Overlay requirements:  Low overlay density  Low overlay link change rate Motivation (2)

5 Agenda Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010  Motivation  Our Proposal: SLO-T  An SLO-T Overlay Example  SLO-T Analysis  Application: SLO-T in OSPF

6 Our Proposal Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Synchronized Link Overlay – Triangular (SLOT) SLOT Uniform Costs SLOT Distance-based Costs Relative Neighborhood Graph (RNG) Synchronized Link Overlay (SLO)

7 Our Proposal Relative Neighbor Graph (RNG) Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010  Mathematical definition u  Intuitive definition v

8 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Our Proposal Synchronized Link Overlay (SLO)  Mathematical definition  Intuitive definition AB C1C1 C2C

9 Distance-based cost (SLOT-D) C A B C A B Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Our Proposal Synchronized Link Overlay – Triangular (SLOT)  Mathematical definition  Intuitive definition SLOT-D SLOT-U Unit cost (SLOT-U)

10 Agenda Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010  Motivation  Our Proposal: SLO-T  An SLO-T Overlay Example  SLO-T Analysis  Application: SLO-T in OSPF

11 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Synchronized Link Overlay – Triangular Example (1)  Network graph  N: 30 nodes  Grid: 400x400m  Radio range: 150 m Network link SLOT-U link SLOT-D link

12 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Synchronized Link Overlay – Triangular Example (2)  SLOT-U subgraph Network link SLOT-U link SLOT-D link

13 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Synchronized Link Overlay – Triangular Example (3)  SLOT-D subgraph Network link SLOT-U link SLOT-D link

14 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Synchronized Link Overlay – Triangular Example (4) Network link SLOT-U link SLOT-D link  SLOT-D subgraph (distance-based metrics)

15 Agenda Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010  Motivation  Our Proposal: SLO-T  An SLO-T Overlay Example  SLO-T Analysis  Application: SLO-T in OSPF

16 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Synchronized Link Overlay – Triangular Analytical Model  Graph model: Unit disk graph  Speed: Constant node speed s  Node distribution:Uniform node density  Mobility: Independent, isotropic random walk

17 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Synchronized Link Overlay – Triangular Analysis 2D (1)  Avg. number of links per node All links SLOT-D SLOT-U  3,60 2,56

18 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Synchronized Link Overlay – Triangular Analysis 2D (2)  Avg. rate of link creation All links SLOT-D SLOT-U for a fixed relative speed  (s)

19 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Synchronized Link Overlay – Triangular Analysis Summary Avg number of overlay links 2 2,56 2,94 2,77 3,60 2,50 Avg rate of link creation 2 2,73 1,02 2 3,60 1,44 dim SLOT-D SLOT-U (  )

20 Agenda Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010  Motivation  Our Proposal: SLO-T  An SLO-T Overlay Example  SLO-T Analysis  Application: SLO-T in OSPF

21 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Application: SLOT in OSPF  OSPF: Link-state routing protocol  MANET extension: RFC 5449  Components: Neighbor sensing (Hello exchange) LSA flooding LSDB synchronization (Adjacencies) SLOT for Unit Cost (SLOT-U)

22 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Application: SLOT in OSPF  Adjacencies (synchronized links)

23 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Application: SLOT in OSPF  Control Traffic Overhead

24 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Application: SLOT in OSPF  Data Delivery Ratio

25 Conclusions & Future Work Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010  Synchronized overlay requirements: low density / low link change rate  SLOT: number of overlay links/node is independent from density  SLOT-OSPF: overhead reduction leads to better behaviors in dense networks  SLOT-D better than SLOT-U (in terms of overlay size)  But requires a distance-based metric  factor in link formation rate

26 Questions ? Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010

27 Backup Slides Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010

28 Analytical Model Formulae (1) Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 SLOT with distance-based metrics

29 Analytical Model Formulae (2) Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 SLOT with unit-cost metrics

30 Analytical Model Formulae (3) Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 Further details  E. Baccelli, J. A. Cordero, P. Jacquet: Optimization of Critical Data Synchronization via Link Overlay RNG in Mobile Ad Hoc Networks. INRIA Research Report RR April (publicly available in the Internet: )

31 The SLO-T Algorithm Relative Neighbor Graph (RNG) AB C1 C2 C3 Synchronized Link Overlay, Triangle elimination AB C SLO-T (unit cost) Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010

32 Documentation of OSPF MANET Extensions  Simulations run over the Georgia Tech Network Simulator (GTNetS)  Implementation based on the Quagga/Zebra OSPFv3 daemon (ospf6d)  Source code for OSPF MANET extensions  Following the IETF RFC 5449 “OSPF Multipoint Relay (MPR) Extension for Ad Hoc Networks” from E. Baccelli, P. Jacquet, D. Nguyen and T. Clausen  SLO-T mechanism following the INRIA Research Report n. 6148, by P. Jacquet.  Implementation provided by INRIA, publicly available in Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010

33 Simulation Environment General Simulation Parameters  20 samples/experiment  Data traffic pattern  Constant Bit Rate UDP flow  Packet size:1472 bytes  Packet rate: 85 pkts/sec  Scenario  Square grid  Grid size: 400x400 m  Node configuration  Radio range:150 m  MAC protocol:IEEE b  Node mobility  Random waypoint model  Pause: 40 sec  Speed: 0, 5, 10, 15 m/s (constant)‏ Performed Experiments  Fixed size grid OSPF Configuration  Standard Parameters  HelloInterval: 2 sec  DeadInterval: 6 sec  RxmtInterval: 5 sec  MinLSInterval: 5 sec  MinLSArrival: 1 sec  RFC 5449  AckInterval:1,8 sec  Adj. persistency:Disabled  SLOT-OSPF  AckInterval:1,8 sec Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010

34 Using Relative Neighborhood Graphs for Reliable Database Synchronization in MANETs IEEE SECON WiMESH 2010 The α parameter