[Todos] [Kolmogorov] Seminario de Estadistica, Modelizacion Estocastica y Aplicaciones

[Pablo Ferrari]

Un poco tarde pero aqui va la charla de hoy.


Seminario de Estadística, Modelización Estocástica y Aplicaciones (SEMEA)

PROXIMO ENCUENTRO: Miércoles 2 de junio, 10:30hs.

LUGAR: Sala de Seminario Pabellon 1 (DM)



Matthieu  Jonckheere,
Differentiation of service and traffic surges in
telecommunication networks

In a large variety of communication networks, traffic
surges due to one class of users can significantly degrade the
performance of other classes. During these transient periods, it
is thus of crucial importance to implement priority mechanisms
allowing the conservation of the quality of service experienced
by the affected classes while ensuring at the same time that the
temporarily unstable class is not completely neglected.
 We examine for a suitably-scaled set of parameters the
complex interaction occurring between several classes of traffic
when an unstable class is penalized in function of its congestion.
 We characterize the evolution of the performance
measures of the network from the moment the initial surge
takes place until the system reaches its equilibrium. We show
that, using a time-space-transition-scaling, the trajectory of the
temporarily unstable class can be described by a differential
equation while that of the stable classes retain their stochastic
nature. In particular, we show that the temporarily unstable class
evolves at a time-scale which is much slower that of the stable
classes. Although the time-scales decouple, the dynamics of the
temporarily unstable and the stable classes continue to influence
one another. We further proceed to characterize the obtained
differential equations for several simple network examples. In
particular, the macroscopic asymptotic behavior of the unstable
class allows us to gain important qualitative insights on how the
bandwidth allocation affects performance.