A Call Admission Control Mechanism based both on Queueing and the Probabilistic Bandwidth Reservation Policy in Mobile Hotspots

In this paper we study a mobility-aware call admission control mechanism applied in a mobile hotspot. We consider a vehicle, which can alternate between stop and moving phases and has an access point of a fixed capacity. In the stop phase, the vehicle accommodates both new and handover calls. To prioritize handover calls a probabilistic bandwidth reservation (BR) policy is applied where some of the system’s resources are reserved for handover calls. Based on this policy, new calls may enter the reservation space with a predefined probability. In addition, handover calls can wait in a queue of finite size if there are no available resources at the time of their arrival. In the moving phase, the vehicle services only new calls under the probabilistic BR policy. In both phases, arriving calls follow a Poisson process, require a single bandwidth unit from the system and have an exponentially distributed service time. To analytically determine the most significant performance measures such as call blocking probabilities an efficient iterative algorithm is presented.