Director: Sheng-Wei Chen

Presenter: Shun-Yun Hu

MMNet IntroMultimedia Networking and Systems

Laboratory Established since 2006.Dr. Sheng-Wei Chen (Associate Fellow)

Postdoc (1), Ph.D (5), RA (10)

Main Research Areas:Internet Quality of Experience (QoE)Network SecurityOnline Gaming

Research Areas• Internet Quality of Experience (QoE)

• User satisfaction index & framework• Packet rate adjustment for efficiency

• Network Security• Quantify info leakage on social networks• Phishing detection

• Online Gaming• Efficient data transmission• Game bots detection

Blizzard, World of Warcraft

America’s Army

Forterra Systems

Can we build a virtual environment with millions of concurrent users?

National Central University

Spatial publish subscribe (SPS)

pub sub

Point publication

Area publication

Point subscription

Area subscription

14

A simple solution (point-to-point)

But…too many irrelevant messagesN * (N-1) connections ≈ O(N2) Not scalable!

Source: [Funkhouser95]

15

A better solution (client-server)

Message filtering at server to reduce trafficN connections = O(N) server is bottleneck

Source: [Funkhouser95]

16

Current solution (server-cluster)

How to partition & balance load?

Source: [Funkhouser95]

Load fluctuations

Density-aware Partitioning

20/

National Central University

Voronoi-based Overlay Network (VON)

Boundary neighbors

New neighbors

Non-overlapped neighbors

Voronoi diagrams identify boundary neighbors for neighbor discovery

Dynamic Load Balancing

Overlap in neighbor regions

root

A

B

C

D

E

F

G

H

I

JK

M

N

O

P

Q

L

ConclusionPotential Applications

Voice communication3D content streamingState management

Future WorksArea publicationsExperiment with millions of entitiesCloud & P2P deployment

References[1] Shun-Yun Hu, Jui-Fa Chen and Tsu-Han

Chen, "VON: A scalable peer-to-peer network for virtual environments," IEEE Network, vol. 20 no. 4, Jul./Aug. 2006, pp. 22-31.

[2] Yeng-Ting Lee and Kuan-Ta Chen, “Is Server Consolidation Beneficial to MMORPG? A Case Study of World of Warcraft,” in Proc. IEEE Cloud, 2010.

[3] Shun-Yun Hu and Kuan-Ta Chen, "VSO: Self-organizing Spatial Publish Subscribe," in Proc. Fifth IEEE Self-Adaptive and Self-Organizing Systems (SASO 2011), Oct. 2011.

Thank You

Q & A

Static vs. dynamic partitioning

Effect of churn on consistency

29

Voronoi Diagram2D Plane partitioned into regions by sites, each

region contains all the points closest to its site

Neighbors

Site

Region

30

Design ConceptsIdentify enclosing and boundary neighborsBoundary neighbors mutually help to discover neighbors

boundary neighbor (B.N.)L. Blue

unknown neighborL. Green

normal AOI neighborGreen

E.N. & B.N.Pink

enclosing neighbor (E.N.)

Yellow

selfWhite

Area of Interest (AOI)Circle

Use Voronoi to solve the neighbor discovery problem