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Explore the M-LANMAR protocol for efficient team-oriented operations in MANET scenarios, blending unicast tunneling and flooding for high reliability. Learn about LANMAR's proactive routing strategies and how M-LANMAR extends this approach for scalable multicast support with low overhead.
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Scalable Team Multicast in Wireless Ad hoc networks Exploiting Coordinated Motion Mario Gerla University of California, Los Angeles
Introduction • Many team-oriented operations in MANET scenarios • Search and rescue, disaster relief operation, battlefields • Each team tends to move together (affinity team model) a chosen node (e.g., landmark) can represent a team • Often, all nodes or none in a team join a multicast group • Affinity team model simplifies mobility handling, and thus allows a scalable multicast protocol design • LANMAR (Landmark ad hoc routing protocol) works well with affinity team model
Introduction (2) • Proposed idea, two-tier team multicast, called M-LANMAR • Unicast tunneling from the sources to the representative of each subscribed team • Flooding within a team • Advantages of M-LANMAR • High reliability via unicast tunneling and flooding • Easy to manage the large networks based on motion affinity model
LANMAR (Landmark Ad Hoc Routing Protocol) –Background • Proactive Routing • Efficient handling affinity team model • Using the notion of landmarks to keep track of logical subnets (teams) • Using two routing schemes • A local proactive routing: within a limited scope, nodes exchange their routing table each other • A long haul distance vector routing: a landmark of each subnet is propagated to the whole network • Routing Tables • Local routing table • Landmark table
local routing Long haul routing subnetAddr1 LM1 node2 subnetAddr2 LM2 node3 subnetAddr3 LM3 node3 LANMAR-Example LM2 LM1 Landmark Logical Subnet LM3 dest node2 Node3 (src) node1 Landmark Table of node1 (subnet_addr, lm_addr, nextHop, …) Local Routing Table of node1 (destAddr, nextHop, …) Node2 Node2 Node3 Node3 …
M-LANMAR(Multicast-enabled LANMAR) • Extension of LANMAR • Proactive scheme • Supporting both unicast and multicast routing with very low extra overhead • Scalable as the network size and number of groups increase • Join MC group: advertising by piggybacking subscribed multicast groups IDs to landmark broadcast packets • Leave MC group: simply not advertising/timeout • The sources can find joined teams in their landmark table
Scope = 2 Flooding Tunneling Scope = 2 Landmark table of source node Flooding subnetAddr1 LM1 node2 MC1 MC1 subnetAddr2 LM4 node3 subnetAddr3 LM2 node3 … LM2 LM1 LM3 Subscribed Teams Source node (MC1) LM4
Simulation • Compared with • ODMRP (On Demand Multicast Routing Protocol) • Flooding • Environments • QualNet 2.9 • Each source generates data in a CBR fashion • Transmission range: 376m, bandwidth 2Mbits • Network size: 6000 x 6000 m2 • Nodes: 1000 nodes into 36 teams • Mobility: 2 m/s with 10 seconds pause time • Following “Reference Point Group Mobility” • Packet size: 512 bytes
Simulation Results – Static Network (1000 nodes, 3teams for each group, 1pkts/sec) Normalized CTRL OH Delivery Ratio Number of MC Groups(#) Number of MC Groups(#) • As the number of multicast groups increases • ODMRP suffers from large control overhead and collisions • M-LANMAR achieves high delivery ratio (by unicast tunneling and flooding)
1pkt/sec 4pkts/sec ODMRP M-LANMAR FLOOD ODMRP M-LANMAR FLOOD Simulation Results – Mobile Network(1000 nodes, 3teams for each group, 2m/s, 10p)
Simulation Results – Mobile Network(1000 nodes, 3teams for each group, 2m/s, 10p) (2) • As the number of multicast groups increases • With small number of groups, ODMRP outperforms M-LANMAR because of its mesh-based multicast structure (redundant paths); M-LANMAR potentially experiences many link breakages • With large number of groups, flooding suffers due to heavy overhead • With high offered load (right), M-LANMAR outperforms ODMRP (ODMRP suffers from heavy redundant forwarding)
Reliable Multicast Support • Reliable Adaptive Lightweight Multicast (RALM) • Targeting general multicast protocols • NACK-Oriented mechanism • Rate-based congestion control • Send-and-wait mechanism (freeze the sender’s buffer upon receiving a NACK); congestion handling • Round-robin recovery • Sources recover the lost pkts for each NACKER one at a time in a round-robin fashion • Prevent ACK implosion • Combining with M-LANMAR • Only landmarks (say representatives) send feedback (e.g. NACK/ACK) to the source • Prevents unnecessary feedback implosion
Simulation Results with RALM(1000 nodes, 3teams for each group, 2m/s, 10p, 5 multicast groups) –Delivery ratio • Same parameters to • the mobile network • experiment • Increase the offered load (number of pkts/sec) • ODMRP suffers from feedback implosion
Simulation Results with RALM(1000 nodes, 3teams for each group, 2m/s, 10p, 5 multicast groups) –Throughput
Discussions • Possible extensions of M-LANMAR • Efficient resource discovery via content based multicast • Use existing MANET multicast protocols to multicast a packet to all landmarks • Scalable as the number of teams increases • Provide a congestion controlled reliable transport layer like TCP between the sources and the landmarks
Conclusion • Propose a new multicast paradigm • Team multicast • Design M-LANMAR as an example of team multicast • Study the performance of M-LANMAR compared with ODMRP and FLOOD • Flat multicast has scalability limitations • M-LANMAR provides an efficient platform for a reliable and congestion controlled multicast protocol (e.g., TCP) • Apply a reliable transport protocol, RALM over M-LANMAR and ODMRP • M-LANMAR is an efficient platform for a reliable multicast protocol
Thank you Any Questions?