Md. Abdul Hamid, Muhammad Mahbub Alam, and Choong Seon Hong Networking Lab, Department of Computer Engineering, Kyung Hee University, Korea Presenter : Jiun-Kuei Shiung IEEE "GLOBECOM" 2008 proceedings.

 Key points in WSN  Energy efficiency  In WMSN  QoS – real-time + energy  Contribution  Multi-channel multi-path  Dynamic routing mechanism 2

IntroductionRelated workNetwork model and assumptionsQoS-aware routing protocolPerformance evaluationConclusion 3

 Novel app let the problem occur.  Hardware is weak in sensor networks.  How to do that?  Load balance.  Monitor path condition.  Contributions  Multiple channels Multiple paths. ▪ Main reasons : load balancing, reliable.  PPDD(path-length-based proportional delay differentiation) 4

 Before research MRTP: a multiflow real-time transport protocol for ad hoc networks,2006 Split packetCareless energy TDMA scheduling design of multihop packet radio networks based on latin square,2004 Trade of energy & delay Energy aware routing for low energy ad hoc sensor networks,2002 Multi-path(2 line used by energy) MMSPEED,2006Multi-path and multi-speed routing. An energy-aware QoS routing protocol for wireless sensor networks,2003 Class-based queuing model （ r-value ） Fix set up Energy and QoS aware routing in wireless sensor networks,2005 Different r-valuebig overhead. 5 Locally adjusts the bandwidth and delay requirement based on PPDD

Homogenous Processing hubs for in-network. Single radio interface and multi-channel. 6

 Multi-path Multi-channel Network Topology 7

8 (MOLS)Mutually Orthogonal Latin Square

 QoS-aware Packet Scheduling  Classification 9

 QoS assurance ▪ Dynamic Bandwidth Adjustment B : bandwidth H: hop count of node. a: factor 10

▪ PPDD(Path-length-based Proportional Delay Differentiation) ▪ Extension from PDD(proportional delay differentiation )  WTP(Waiting Time Priority) algorithm 11 d H k : average queuing delay of a packet at node k that is H hops away from sink. δ: 1= δH+1 >δH > ··· >δ1 > 0

 Routing ▪ Source : ▪ Choose paths/channels that meet the bandwidth and delay requirements ▪ Each node : ▪ Adjusts bandwidth and delay. ▪ Data : ▪ Not meet the deadline are discarded. ▪ Best effort traffics are routed through the alternative paths 12

 Environment  100 node in 500m x 500m square area  Sink at [500, 250]  25 multimedia processing hubs  7 channels and take 250us as the channel switching delay  Other [14] 13

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 Improve  Average delay, lifetime and throughput  Now  Minimize switching delay, focus on selection of routes do not require frequent switching.  The next  Import the issues of mobile and multiple sinks. 15