1. The Pulse Protocol: Mobile Ad hoc Network Performance Evaluation Baruch Awerbuch, David Holmer, Herbert Rubens {baruch dholmer herb}@cs.jhu.edu WONS Jan 2005 Johns Hopkins University Department of Computer Science www.cnds.jhu.edu/archipelago/

2. Presentation Overview Pulse Protocol Overview Pulse Protocol Overview Scalable multi-hop ad hoc routing protocol Scalable multi-hop ad hoc routing protocol Based on Tree Routing Based on Tree Routing Tree Routing vs. Direct Routing Tree Routing vs. Direct Routing Performance Evaluation Performance Evaluation Comparison with existing ad hoc wireless routing protocols Comparison with existing ad hoc wireless routing protocols

3. Ad hoc Nodes

4. Network Connectivity

5. Pulse Flood

6. Spanning Tree

7. Source and Destination Need to Establish a Path

8. Pulse Response Sent to Root

9. Destination Paged on Next Pulse

10. Destination Sends Pulse Response

11. Path Option 1: Through the Root Through the Root Path 9 Hops Shortest Path 2 Hops This option is inefficient! It is not necessary to go to the root. Better routes already exist!

12. Path Option 2: Tree Traversal Tree Traversal Path 5 Hops Shortest Path 2 Hops

13. Path Option 3: Tree Shortcut Tree Shortcut Path 3 Hops Shortest Path 2 Hops This is the initially selected path of the Pulse protocol.

14. Path Optimization: Gratuitous Reply Selected Path 2 Hops Shortest Path 2 Hops Node sends gratuitous reply

15. Tree Routing vs. Direct Routing Direct Routing Direct Routing Attempts initially discover the shortest path Attempts initially discover the shortest path Requires large overhead Requires large overhead Link state Link state tracks every link in the network regardless of whether it is used tracks every link in the network regardless of whether it is used a shortest path spanning tree for every node in the network a shortest path spanning tree for every node in the network On-Demand On-Demand floods the network to establish a route floods the network to establish a route re-floods when ever the path breaks re-floods when ever the path breaks a shortest path spanning tree for all nodes transferring data a shortest path spanning tree for all nodes transferring data Tree Routing Tree Routing Proactively rebuilds a single spanning tree on top of the network Proactively rebuilds a single spanning tree on top of the network Boot straps communication off of the tree route Boot straps communication off of the tree route Route are not initially the direct shortest path, but routing mechanism allows the path to converge towards the shortest path Route are not initially the direct shortest path, but routing mechanism allows the path to converge towards the shortest path Active destinations can be reached without flooding the network Active destinations can be reached without flooding the network Efficient operation for realistic traffic patterns Efficient operation for realistic traffic patterns

16. Pulse Concepts Aggregation – for scalability Aggregation – for scalability All nodes have a route to the Pulse Source All nodes have a route to the Pulse Source All communication initiates through Pulse Source All communication initiates through Pulse Source Pulse Source can “Page” multiple nodes on the same Pulse packet, to activate them Pulse Source can “Page” multiple nodes on the same Pulse packet, to activate them Uses a single flood instead of one per source/dest pair Uses a single flood instead of one per source/dest pair De-Aggregation – for efficiency De-Aggregation – for efficiency Routing control packets allow optimized routes to be located using these mechanisms Routing control packets allow optimized routes to be located using these mechanisms Through Root of Tree Through Root of Tree Tree Traversal Tree Traversal Shortcuts Shortcuts Gratuitous Reply Gratuitous Reply

17. Network Traffic Patterns Most existing traffic patterns in networks involve many nodes communicating with a common subset Most existing traffic patterns in networks involve many nodes communicating with a common subset Client Server Model Client Server Model All nodes going to the internet gateways All nodes going to the internet gateways Nodes reporting information to a number of sinks Nodes reporting information to a number of sinks Network Services Network Services Ad hoc DNS Service Ad hoc DNS Service Voice Over IP server Voice Over IP server Local Information Database Local Information Database Nearby restaurants Nearby restaurants Shops/Advertising Shops/Advertising Military Applications Military Applications Blue Force Tracker Blue Force Tracker All soldiers send GPS coordinates to collection node All soldiers send GPS coordinates to collection node Target Identification Target Identification Surveillance Reporting Surveillance Reporting Sensor Network Sensor Network Source  Sink model Source  Sink model

18. Common Destination All of these reverse routes are established with a single unicast packet!

19. Node wants to sent packets

20. Doesn’t currently have a route Must forward the packet to the Pulse Source.

21. Parent however DOES have route! Can send packet directly to the destination. No paging involved.

22. Multiple Sources Send Data

23. Route initially twice the length of shortest path!

24. Properties Pulse flood proactively maintains a routing tree across the network Pulse flood proactively maintains a routing tree across the network Active destinations unicast a pulse response to maintain reverse routes Active destinations unicast a pulse response to maintain reverse routes All nodes can route to all active destinations without flooding All nodes can route to all active destinations without flooding Paging of inactive destinations is aggregated to limit impact on network Paging of inactive destinations is aggregated to limit impact on network

25. NS2 General Simulation Setup All nodes use random way-point mobility including the Pulse Source All nodes use random way-point mobility including the Pulse Source Exponential on/off traffic model Exponential on/off traffic model Many randomly changing CBR flows (different sources & destinations over time) Many randomly changing CBR flows (different sources & destinations over time) Average flow duration of 10 seconds Average flow duration of 10 seconds Each flow offers 0.01 Mbps w/ 512 byte packets Each flow offers 0.01 Mbps w/ 512 byte packets Total load controlled by the number of flows Total load controlled by the number of flows Energy efficient version of protocol (INFOCOM 2004) Energy efficient version of protocol (INFOCOM 2004) No gratuitous reply mechanism No gratuitous reply mechanism 10% of bandwidth wasted on power saving mechanism 10% of bandwidth wasted on power saving mechanism Randomized traffic model is worst case for protocol Randomized traffic model is worst case for protocol

26. Delivery Ratio at 10m/s 1k x 1k 50 Nodes Low Density 1k x 1k 100 Nodes Medium Density 1k x 1k 200 Nodes High Density DSRPulse

27. Delivery Ratio at 20m/s 1k x 1k 50 Nodes Low Density 1k x 1k 100 Nodes Medium Density 1k x 1k 200 Nodes High Density DSRPulse

28. Pulse Protocol Conclusion Excellent performance compared with existing ad hoc routing protocols Excellent performance compared with existing ad hoc routing protocols High delivery ratio under High delivery ratio under High Mobility High Mobility High Density High Density Large number of flows Large number of flows Scalable routing solution for multi-hop ad hoc peer-to-peer networks Scalable routing solution for multi-hop ad hoc peer-to-peer networks

29. Real World Implementation Completed Features Completed Features Linux Kernel Module 2.4 and 2.6 compatibility Linux Kernel Module 2.4 and 2.6 compatibility Operates at layer 2 Operates at layer 2 Distributed virtual switch architecture provides seamless bridging Distributed virtual switch architecture provides seamless bridging Pulse Protocol Pulse Protocol Shortcuts and gratuitous reply Shortcuts and gratuitous reply Instantaneous loop freedom Instantaneous loop freedom Fast parent switching (with loop freedom) Fast parent switching (with loop freedom) Medium Time Metric route selection metric (WONS 2004) Medium Time Metric route selection metric (WONS 2004) 50 Nodes deployed across JHU Campus 50 Nodes deployed across JHU Campus Internet Access, Ad hoc Access Points, Voice over IP Internet Access, Ad hoc Access Points, Voice over IP Mobility testing from automobiles Mobility testing from automobiles Leader Election Algorithm Leader Election Algorithm Fault tolerance, switches pulse source to most accessed destination Fault tolerance, switches pulse source to most accessed destination Handle merge and partition Handle merge and partition In Progress In Progress Efficient Tree Flooding Efficient Tree Flooding Similar to expanding ring search but with no duplicates Similar to expanding ring search but with no duplicates Security – (NDSS 2005) Security – (NDSS 2005) Flood Rushing, Wormholes, Blackholes, any NON-Byzantine attack Flood Rushing, Wormholes, Blackholes, any NON-Byzantine attack

30. Thank You! Questions?? http://www.cnds.jhu.edu/archipelago/ (baruch,dholmer,herb)@cs.jhu.edu Wave Relay Ad hoc Networking Test-bed http://www.cnds.jhu.edu/research/networks/archipelago/testbed/testbed.html Secure Ad hoc Networking for Industrial Process Control http://www.cnds.jhu.edu/research/networks/archipelago/industrial/industrial.html Baruch Awerbuch, David Holmer, Herbert Rubens

31. SNS Scalability Simulation Size: 10 km x 10 km Size: 10 km x 10 km Nodes: 5,000 Nodes: 5,000 Speed: 1 m/s Speed: 1 m/s Traffic: 5 Mbps Traffic: 5 Mbps Delivery Ratio: 97.2% Delivery Ratio: 97.2% 10 km 100 stationary backbone nodes were arranged in a 10 by 10 grid 5000 nodes were randomly placed and moved randomly Exponential random traffic pattern was used

32. Density Performance Low Traffic 0.10 Mbps Medium Traffic 0.15 Mbps High Traffic 0.20 Mbps DSRPulse 1km x 1km with 5 m/s Max Speed

33. Routing Methods Pulse Source SourceDestination

34. Through the Root Pulse Source SourceDestination

35. Through the Root Pulse Source SourceDestination

36. Tree Traversal Pulse Source SourceDestination

37. Tree Short Cuts Pulse Source SourceDestination

38. Gratuitous Reply Pulse Source SourceDestination

39. Ad hoc Nodes

40. Network Connectivity

41. Spanning Tree

42. Source and Destination Need to Establish a Path

43. Reservation Sent to Root of Tree

44. Routes to Source Installed at Adjacent Nodes

45. Destination Paged on Next Pulse

47. Communication Begins

48. Gratuitous Reply

49. Pulse Protocol Multi-hop tree routing protocol Multi-hop tree routing protocol High Scalability High Scalability Mobility Mobility Number of nodes Number of nodes Number of flows Number of flows Periodic “pulse” flood initiated by pulse source Periodic “pulse” flood initiated by pulse source Flood propagation creates high throughput network wide spanning tree Flood propagation creates high throughput network wide spanning tree Reservations sent in response to pulse flood Reservations sent in response to pulse flood Nodes who wish to transfer data send a reservation up the tree to create reverse route entries Nodes who wish to transfer data send a reservation up the tree to create reverse route entries

50. Properties Local communication remains local Local communication remains local Nodes track their neighbors by overhearing Pulse Packets Nodes track their neighbors by overhearing Pulse Packets Distant communication efficiently traverses tree Distant communication efficiently traverses tree If all nodes have a route to Pulse Source, then all nodes have a route to all nodes through Pulse Source If all nodes have a route to Pulse Source, then all nodes have a route to all nodes through Pulse Source Optimized for data collection (many-to-one) Optimized for data collection (many-to-one) If the Pulse Source is the Internet Gateway, then routing to the Internet is already provided just off of Pulse tree If the Pulse Source is the Internet Gateway, then routing to the Internet is already provided just off of Pulse tree Routing information propagates on data packets Routing information propagates on data packets Rapid tracking of active routes Rapid tracking of active routes Routing information tracking remains localized Routing information tracking remains localized

51. Pulse Protocol Operation Periodic “pulse” flood initiated by pulse source Periodic “pulse” flood initiated by pulse source Flood propagation creates network wide spanning tree Flood propagation creates network wide spanning tree Proactively updates all routes to pulse source Proactively updates all routes to pulse source Active nodes send Pulse Response packet Active nodes send Pulse Response packet Nodes currently transferring data unicast a Pulse Response up the tree to the pulse source Nodes currently transferring data unicast a Pulse Response up the tree to the pulse source Pulse Response packets create reverse route entries Pulse Response packets create reverse route entries Data Packets Data Packets Data packets carry routing information to populate routing tables of nodes along path Data packets carry routing information to populate routing tables of nodes along path Gratuitous Reply mechanisms allow protocol to track the best route under mobility Gratuitous Reply mechanisms allow protocol to track the best route under mobility