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Multicasting in Ad Hoc Networks. Dewan Tanvir Ahmed University of Ottawa Email: dahmed@discover.uottawa.ca. Recap. Multicasting Group communication One-to-many In Battle field Many-to-many Rescue team communication Why not using existing multicast protocol Resource constraints
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Multicasting in Ad Hoc Networks Dewan Tanvir Ahmed University of Ottawa Email: dahmed@discover.uottawa.ca
Recap • Multicasting • Group communication • One-to-many • In Battle field • Many-to-many • Rescue team communication • Why not using existing multicast protocol • Resource constraints • Frequent tree reorganization • signaling overhead • loss of datagram • Protocol design • robustness vs. efficiency CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Multicasting in MANET • Structure • Tree-based • Shared multicast tree • Vulnerable to high mobility, load and large group • Mesh-based • Quick reconfigurable • Excessive message overhead • Focusing on • Position Based • Energy • Life time improvement • Minimizing TEC • Reliability • QoS, etc. CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Multicast Routing Protocols MAODV AMRoute OLAM L-REMiT WARM MZR AMRIS MCEDAR CAMP S-REMiT ? STMP NSMP PUMA PAST-DM ODMRP DCMP ADMR G-REMiT PBM FGMP MANSI DDR CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
MAODV (Royer and Perkins, 1999) • Each multicast group has a group leader • 1st node joining a group becomes Group Leader • Responsible for maintaining group SN (sequence number) • SN ensures freshness of routing information • A node on becoming a group leader • Broadcasts a Group Hello message CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Group member Multicast Tree member Ordinary node Potential Group member Multicast link Communication link MAODV (Royer and Perkins, 1999) Group Join Process Broadcast - RREQ Multicast Activation Broadcast Group Hello Only GM Responds L CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Group member Multicast Tree member Ordinary node Departing Multicast group Multicast link Communication link MAODV (Royer and Perkins, 1999) Leaving a Multicast Group Non leaf Node Must remain as a Tree member L Leaf Node Send a Prune Again Leaf Node Remove himself from MT CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
MAODV (Royer and Perkins, 1999) • Observation • Similar to unicast AODV • Leader helps in tree maintenance • No alternate path as it forms a tree • Excessive use of RREQ • lead to multicast tree instability CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
X Z Y W ODMRP (Bae, Lee, Su, Gerla, 2000) Join Reply Join Request Forwarding Group Broadcast b Multicast RT s Y, Z s b, c c s s X s a, W s d, e Sender e a d CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
ODMRP (Bae, Lee, Su, Gerla, 2000) Robustness CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
ODMRP (Bae, Lee, Su, Gerla, 2000) • Observation • Sender Forms and Maintains the multicast group • Don’t need to be built on top of a unicast routing protocol • Richer connectivity • May have multiple routes for one particular destination • Helps in case of topology changes and node failures • soft state • Member nodes are refreshed as needed by source • Do not send explicit leave message • Periodic Broadcast of Join Request • Control overhead of route refreshes => Scalability issue. CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
PAST-DM (Chao & Prasant, 2004) • Progressively Adapted Sub-Tree in Dynamic Mesh • Build virtual mesh spanning all members • Use unicast tunneling Concept CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
D C B A Look at Redundancy PAST-DM (Chao & Prasant, 2004) Adapt Virtual Topology Initial Virtual & Physical Topology D B A Same Initial Topology C Physical Topology Changed D D D B C B A B A A C C CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
PAST-DM (Chao & Prasant, 2004) Dynamic Mesh Creation Group Join Request - ERS One of the Group member Respond Not Blind Flooding Send Virtual Link State Packet CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
1 2 A C 0 2 2 6 3 1 2 s 2 E 0 0 3 2 2 2 B D 1 2 0 4 2 PAST-DM (Chao & Prasant, 2004) Data Delivery Tree A C A B C D E B D E CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
PAST-DM (Chao & Prasant, 2004) • Pros • Easy to join to a group • Cons • Link State Table exchange with neighbors (no flooding) • Mandatory GROUP_LEAVE message • Hard to prevent • different unicast tunnels from sharing same physical links • To Construct Data Delivery tree • Whole topology information is required • i.e. Decision is local but information is global CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Neighbor Forwarding node Communication link PBM (Martin et al., 2003) • Position Based Multicast • Forwarding Decision • Based on Geographical Position • Sender has the knowledge (assumptions) • Position of destination(s) • Position of neighbor(s) • It’s own position • + • No Maintenance of distribution structure (Tree/Mesh) • Resorts flooding • Two conflicting minimization goals • Length of path to individual destination • Total hops to forward to all destination CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Neighbor Forwarding node Communication link K Find a set of neighbors Forward the packet next PBM (Martin et al., 2003) Current Forwarding Node Two conflicting Minimization goal Potential Forwarding Node Total hops to forward to all destination Length of path to individual destination CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Neighbor Forwarding node Communication link K No. of neighbors that packet is transmitted to PBM (Martin et al., 2003) Greedy Multicast Forwarding K: Forwarding node N: Set of all neighbors of K W: Set of all subsets of W Z: Set of all destinations d(x,y): distance between x and y Minimize the expression Remaining distance to all destinations CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Neighbor Forwarding node Communication link K PBM (Martin et al., 2003) Perimeter Multicast Forwarding No progress for destination(s) Greedy Multicast Perimeter Multicast Like FACE Traverse the boundaries of the gaps in the network until Greedy can be resumed CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
PBM (Martin et al., 2003) • Observation • Static Environment • Performs well • Dynamic Environment • Create routing loops • Packet loss CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Initial Energy = 480 Unit A 8 12 EU/P B 10 C A A 8 12 8 B B C 10 C L-REMiT (Bin and Gupta, 2003) • Energy Optimization • Total Energy Consumption (TEC) • Network/System Lifetime (NL/SL) Minimum Energy Multicast Tree Maximum Lifetime Multicast Tree TEC = 12 EU/P NL = 480/12 = 40 P TEC = 8+10 = 18 EU/P NL = 480/10 = 48 P CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
L-REMiT (Bin and Gupta, 2003) Energy Cost of a node { Life Time of a node Life Time of MT Bottleneck Node CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Change:changing i’s parent x to y x, y i gain > 0, due to Change x, y i L-REMiT (Bin and Gupta, 2003) Lifetime - Refining Energy efficiency of Multicast Tree gain = LT(Tnew) – LT(Told) CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
L-REMiT (Bin and Gupta, 2003) Bottleneck Node Save 9 2 4.75 8 4 3.3 2.5 1 2.75 2.25 9 6 10 1 2.4 1.5 4.3 2.3 3 7 5 CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Conclusion • State of the Art • MAODV • Low overhead • Low latency • ODPRP • Backup paths • Scalability issues • Holes at Energy Saving CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
References • S. Corson and J. Macker, “Mobile ad hoc networking (MANET): Routing protocol performance issues and evaluation considerations”, RFC 2501, January 1999. • E. Royer, and C. E. Perkins, “Multicast operation of the ad hoc on-demand distance vector routing protocol”, MobiCom, Aug. 1999, pages 207-218. • Sung-Ju Lee, William Su, and Mario Gerla, "On-demand multicast routing protocol (ODMRP) for ad hoc networks", Internet Draft, draft-ietfmanet-odmrp-02.txt, 2000, work in progress. • C. E. Perkins and E. M. Royer. Ad-hoc On-Demand Distance Vector Routing. In Proceedings of 2nd IEEE Wksp. Mobile Comp. Sys. and Apps., pages 90--100, Feb. 1999. • C. Gui and P. Mohapatra, “Efficient Overlay Multicast for Mobile Ad Hoc Networks,” Proc. IEEE WCNC’03, New Orleans, LA, Mar., 2003. • Mauve, M., Füßler, H., Widmer, J., Lang, T., "Poster: Position-Based Multicast Routing for Mobile Ad-Hoc Networks", In Proceedings of Fourth ACM International Symposium on Mobile Ad Hoc Networking and Computing: MobiHoc 2003. Hrsg. • B. Wang and S. K. S. Gupta. S-REMiT: “S-REMiT: A Distributed Algorithm for Source-based Energy Efficient Multicasting in Wireless Ad Hoc Networks ”, In Proceedings of IEEE GlobleCOM, San Francisco, CA, Dec. 2003, pp. 3519-3524 CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
References • B. Wang and S. K. S. Gupta, "G-REMiT: An Algorithm for Building Energy Efficient of Multicast Trees in Wireless Ad Hoc Networks", In Proceedings of IEEE International Symposium on Network Computing and Applications (NCA), Cambridge, MA, April 2003, pp. 265-272. • Bin Wang, Sandeep K. S. Gupta. "On Maximizing Lifetime of Multicast Trees in Wireless Ad hoc Networks," International Conference on Parallel Processing (ICPP'03), 2003. • J. J. Garcia-Luna-Aceves, and E. L. Madruga, "The core-assisted mesh protocol," IEEE Journal on Selected Area in Communications, Special Issue on Ad-Hoc Networks, Vol. 17, No. 8, Aug. 1999. • C. W. Wu, Y. C. Tay, and C-K. Toh, "Ad hoc multicast routing protocol utilizing increasing id-numbers (AMRIS) Functional Specification," Internet draft, IETF, Nov. 1998. • C. Gui and P. Mohapatra, "Efficient Overlay Multicast for Mobile Ad Hoc Networks," Proc. IEEE WCNC'03, New Orleans, LA, Mar., 2003. CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Thank You! CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic
Questions and Answers • Mention two differences between MAODV and ODMRP? • AODV uses a shared bi-directional multicast tree while ODMRP maintains a mesh topology rooted from each source. • ODMRP broadcasts the reply back to the source while MAODV unicast the reply. • MAODV does not activate a multicast route immediately while ODMRP does. • What algorithms are used in Position Based Multicasting (PBM)? When it switches one to other? • Greedy multicast (GM) • Perimeter multicast PM) When there is no progress for one or more destinations, it switches GM to PM for these destination(s) and continues PM until GM can be resumed. • What are the two conflicting goals in designing multicast tree in terms of energy? • Minimum Energy Multicast Tree Optimizes (minimize) total energy consumption of the multicast tree • Maximum Lifetime Multicast Tree Optimizes (maximizes) lifetime of the multicast tree. CSI5140F: Wireless Ad Hoc Networking Ivan Stojmenovic