1	Quality-of-Service Routing in Ad-Hoc Network Using OLSR Ying Ge¹, Thomas Kunz², Louise Lamont¹ ¹Communications Research Center ²Carleton University
2	Difficulties in QoS Routing Link state metrics should be available and manageable Link quality changes quickly and continuously due to node movement and surrounding changes Computational cost and protocol overhead affect the performance of the QoS routing protocol Protocol performance evaluation is complex
3	Proactive QoS Routing Advantages suitable for the unpredictable nature of Ad-Hoc networks suitable for the requirement of quick reaction to QoS demands makes call admission control possible avoids the waste of network resources Disadvantages introduces additional protocol overhead trade-off between the QoS performance and traditional protocol performance
4	Description of OLSR Selects MPR to cover 2-hop neighbors Exchanges neighbor/MPR information in Hello message Generates and relays TC message to broadcast topology information Reduces control overhead by limiting MPR set In the graph, B selects C as MPR
5	QoS Versions of OLSR OLSR protocol does not guarantee to find the best bandwidth route Three heuristics are proposed to enhance OLSR in bandwidth aspect The heuristics select good bandwidth neighbor as MPR Based on evaluation in static network scenarios, heuristic … is chosen In the previous network topology, B selects A,F as MPRs
6	Simulations in OPNET Implement heuristic in OPNET Define different bandwidth updating threshold to compare the performance (20% OLSR, 40% OLSR, 80% OLSR) Revise Wireless LAN model to compute idle time, which reflects link available bandwidth Piggyback idle time info in Hello and TC messages Computing best bandwidth routes based on available topology
7	Simulation Results I – Basic Performance
8	Simulation Result II – QoS Performance
9	Analysis of Results (Cost Introduced by the QoS Versions of OLSR) More MPRs are selected; more TC messages are generated and relayed The additional control messages increase the Wireless LAN network load The overlap of 2-hop neighbors covered by MPRs causes TC collision
10	Analysis of Results – (Achievement Gained by the QoS Versions of OLSR ) Outperforms the original OLSR protocol in bandwidth aspect In a dense network, the 40% OLSR finds the best bandwidth route In a sparse network, the 20% OLSR finds the best bandwidth route There is a trade-off, so must select routing algorithms based on the request of the data application
11	Thank You! Any Questions?