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A NOVEL SOCIAL CLUSTER-BASED P2P FRAMEWORK FOR INTEGRATING VANETS WITH THE INTERNET. Chien-Chun Hung CMLab, CSIE, NTU, Taiwan. OUTLINE. Introduction Social cluster-based overlay structure Lifetime-aware flooding scheme Connectivity-aware retrieval scheme Performance Evaluation Conclusions.
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A NOVEL SOCIAL CLUSTER-BASED P2P FRAMEWORK FOR INTEGRATING VANETS WITH THE INTERNET Chien-Chun Hung CMLab, CSIE, NTU, Taiwan
OUTLINE • Introduction • Social cluster-based overlay structure • Lifetime-aware flooding scheme • Connectivity-aware retrieval scheme • Performance Evaluation • Conclusions
INTRODUCTION • Non-safety related applications in VANETs • Improve driving comfort • Provide interesting entertainment services • Two different types of communications: • Inter-Vehicle Communication • Roadside-to-Vehicle Communication • Two important elements defined in VII (Vehicle Infrastructure Integration): • RSU(Road Side Unit) • OBU(On Board Unit)
INTRODUCTION • Peer-to-peer(P2P) system: • Efficiently access different types of data • Leverage each peer’s resource • Reduce the load of original content provider • Main components of P2P system: • Resource discovery scheme • Resource retrieval scheme
INTRODUCTION • Goal: To design a P2P framework for hybrid network(VANET and Internet) • Fixed peer: original peers in thee Internet • Mobile peer: moving vehicles • Challenge: Enable mobile peers to request and retrieve resource efficiently according to connectivity and environment
INTRODUCTION • Framework: Interest-based clustering to group similar peers into a cluster: • Social cluster-based overlay structure • To eliminate discovering overhead through the RSU • Lifetime-aware flooding scheme • To eliminate request storm among mobile peers • Connectivity-aware retrieval scheme • Take lifetime and bandwidth into consideration to select the best peer
OUTLINE • Introduction • Social cluster-based overlay structure • Lifetime-aware flooding scheme • Connectivity-aware retrieval scheme • Performance Evaluation • Conclusions
SOCIAL CLUSTER-BASED OVERLAY STRUCTURE • Goal: to eliminate the overhead of finding mobile peers. • Group mobile peers and fixed peers into clusters. • Peers with similar interests are group into a cluster. ______
SOCIAL CLUSTER-BASED OVERLAY STRUCTURE • Interest-based intra-cluster construction • One fixed peer and several mobile peers • Mobile peer picks the cluster whose cluster head has the most similar interest with it • Fixed peer acts as the cluster head and maintains file indexes of its cluster
SOCIAL CLUSTER-BASED OVERLAY STRUCTURE • Small-world-based inter-cluster construction • Random walk to reach into different clusters • To increase the ratio of resources that can be found • Peers can use overlay to effectively discover resources by requesting the cluster.
OUTLINE • Introduction • Social cluster-based overlay structure • Lifetime-aware flooding scheme • Connectivity-aware retrieval scheme • Performance Evaluation • Conclusions
LIFETIME-AWARE FLOODING SCHEME • Social cluster-based overlay • Enable mobile peers to discover resources in clusters (through RSUs) • Lifetime-aware flooding scheme • Help mobile peers to efficiently discover resources through VANETS • Connection lifetime must be taken into consideration.
OUTLINE • Introduction • Social cluster-based overlay structure • Lifetime-aware flooding scheme • Connectivity-aware retrieval scheme • Performance Evaluation • Conclusions
CONNECTIVITY-AWARE RETRIEVAL SCHEME • If a mobile peer requests too many blocks at once, it might waste bandwidth. • The path quality between two peers must be considered in order to decide how to retrieve data. • Path lifetime • Path bandwidth
OUTLINE • Introduction • Social cluster-based overlay structure • Lifetime-aware flooding scheme • Connectivity-aware retrieval scheme • Performance Evaluation • Conclusions
PERFORMANCE EVALUATION • Network simulator 2 (NS2) • Geographic Information System (GIS) • 200 fixed nodes in 3000m * 3000m • 802.11n standard MAC protocol • Transmission range: 250m • Transmission rate: 27 Mb/sec • 83 kinds of data, 31005 files
PERFORMANCECOMPARISON SCHEMES • Gnutella • Interest-based P2P scheme • Network-based P2P scheme • CarTorrent • Social Cluster-based P2P scheme
PERFORMANCE EVALUATIONQUERY HIT RATIO VS. RSU NUMBERS • 200 mobile peers • Each has 50 cached files
PERFORMANCE EVALUATIONRATIO OF RETRIEVING FILES VS. NUMBER OF RSUS
OUTLINE • Introduction • Social cluster-based overlay structure • Lifetime-aware flooding scheme • Connectivity-aware retrieval scheme • Performance Evaluation • Conclusions
CONCLUSIONS • Design a P2P system that can integrate VANETs and the Internet • Social cluster-based overlay structure • Lifetime-aware flooding scheme • Connectivity-aware retrieval scheme • Our work achieves higher discovering rate and retrieving speed than existing schemes.