M ODELING R ESOURCE S HARING D YNAMICS OF V O IP USERS OVER A WLAN U SING A G AME -T HEORETIC A...
-
Upload
anne-nelson -
Category
Documents
-
view
214 -
download
0
Transcript of M ODELING R ESOURCE S HARING D YNAMICS OF V O IP USERS OVER A WLAN U SING A G AME -T HEORETIC A...
MODELING RESOURCE SHARING DYNAMICS OF VOIP USERS OVER A WLAN USING A GAME-THEORETIC APPROACHINFOCOM 2008
Edson H. Watanabe, Daniel S. Menasch´e, Edmundo de Souza e Silva, Rosa M. M. Le˜ao
Systems Engineering and Computer Science Department
COPPE - Federal University of Rio de Janeiro, 21941-590 - Rio de Janeiro, RJ, Brazil
Presenter: Po-Jung Wang
OUTLINE
Scenario Introduction Game-theoretic model Simulation Experiment Result Conclusion
SCENARIO – COFFEE SHOP
AIRPORT
USING VOIP THROUGH THE WIFI
NOW WE HAVE TWO QUESTIONS
What are the performance consequences of letting the users to freely choose their rates?
How to explain the adaptation process of the users?
MODELING
GAME THEORY EQUATION
SYMMETRIC STRATEGIC GAME
N is the number of users that share the access point. S is the discrete set of strategies available, that is, the set of joint codec plus FEC mechanisms that any application user can select from. U is the utility function.
WHAT IS MOS?
Mean opinion score (MOS)
MOS Quality Impairment
5 Excellent Imperceptible
4 Good Perceptible but not annoying
3 Fair Slightly annoying
2 Poor Annoying
1 Bad Very annoying
PERSPECTIVE FROM ONE USER
low, 20 kbps (Speex 6 kpbs, FEC 1:2::3:6);
medium, 33.6 kbps (Speex 14.2 kbps, FEC 1:2)
high, 47.5 kbps (Speex 14.2 kps, FEC 1:2::3:6).
SYSTEM SATURATION THROUGHPUT TESTING
EQUILIBRIUM STATES FOR THE MODEL AND THE EXPERIMENT
TRANSIENT PROBABILITY
PROBABILITY FORM ONE STATE TO ANOTHER
LETTING USER EXIT THE SYS IF MOS IS TO LOW
SUMMARY AND CONCLUSION
Free users with local information can reach an equilibrium which is close to optimal from the system perspective. However, the equilibrium can be unfair.
Using a game-theoretic model and propose a methodology to parameterize it.
Strength and weekness
Discovery the phenomena of letting user to freely choose
Need more scalable experiments