Adaptive Admission Control in Real-Time Systems

André Ferreira, Solange Rito Lima* 

PT INovação, S.A.
Portugal Telecom Group
P-3810-106 Aveiro, Portugal

Universidade do Minho*
Departamento de Informática
P-4710-057 Braga, Portugal

Tel.: +351 253 604436
Fax.: +351 253 604471
E-mail: solange at


In real-time service provisioning platforms the existence of an efficient and flexible admission control mechanism is essential for providing quality of service in a reliable and stable way, avoiding congestion scenarios caused by indiscriminate and uncontrolled service request admission. The capability of modeling and regulating the rate of call acceptance, and provide service differentiation allow indirect control of the load submitted to the platform. This paper presents a service differentiated admission control solution that allows to limit and modulate the rate by which service requests are submitted into a service provisioning platform. The solution is focused on providing a fair level of bandwidth sharing among service classes, in a configurable and dynamic way so that it can adapt the distribution by which service requests are served. To sustain the design decisions of our solution, major scheduling disciplines and rate control mechanisms, some of them proposed recently, are studied and compared. The solution was submitted to unit and charge tests, whose results show its effectiveness and robustness.

Actas da 9ª Conferência de Redes de Computadores (CRC2009), Oeiras, Portugal, Outubro, 2009