Abstract
Wireless networks’ Operators still face the dual face problem of end to end resource allocation management wile making efficient use of bandwidth. Relative considerations include user mobility, traffic characteristics, Quality of Service (QoS) parameters (throughput, delay, jitter, etc.). The satisfaction of the user depends on subjective parameters related to the rendering of the requested services (end-to-end quality of service). In order to accommodate these parameters, prescriptions have been formulated by the IETF within the framework of the IntServ/DiffServ group which targets network QoS control. The call admission control (CAC) is essential within this mobile communication architecture because the network resources are limited.
The purpose of this work is to specify traffic threshold parameters and the constraints in terms of QoS for a resource allocation based on a call admission control mechanism in a mobile network. In our approach, this mechanism takes place in two stages : the first stage at the level of the New Call acceptation capability by Cell registered at mobile radio Level Agreement Service (SLA), where user mobility is considered as being a major constraint for call acceptance. The second stage takes place at the DiffServ operator network level. QoS acceptance is defined by the SLA contract specifying the parameters of the different levels of acceptance. At a global level, new call or handover call acceptance is based on a collective and consensual decision between the different participating networks. Such a consensus aims at taking a consistent decision to reserve resources according to one of the levels of service predefined by the caller SLA. Then allowing the caller to renegotiate the level of service QoS according to traffic load fluctuation, or to negotiate new resources for new applications requested during the session. The other participating networks can also initiate a renegotiation for the same reasons.