Call Blocking Probabilities under a Probabilistic Bandwidth Reservation Policy in Mobile Hotspots

Abstract

In this paper we study a mobility-aware call admission control algorithm in a mobile hotspot. To this end, a vehicle is considered which has an access point with a fixed capacity. The vehicle alternates between stop and moving phases. When the vehicle is in the stop phase, it services new and handover calls by prioritizing them via a probabilistic bandwidth reservation (BR) policy. Based on this policy, new handover calls may enter the reservation space with a predefined probability. When the vehicle is in the moving phase, it services new calls only. In that phase, two different policies are considered: (a) the classical complete sharing (CS) policy, where new calls are accepted in the system whenever there exists available bandwidth, and (b) the probabilistic BR policy. Depending on the selected policy in the moving phase, we propose the probabilistic BR loss model (if the CS policy is selected) and the generalized probabilistic BR loss model (if the probabilistic BR policy is selected). In both stop and moving phases, where the call arrival process is Poisson, calls require a single bandwidth unit in order to be accepted in the system, while the service time is exponentially distributed. To analytically determine call blocking probabilities and the system’s utilization, we propose efficient iterative algorithms based on two-dimensional Markov chains. The accuracy of the proposed algorithms is verified via simulation.

Performance evaluation of a mobile hotspot supporting quasi‐random traffic

“…[25], the prioritisation of handover calls is studied in the case of high‐speed railway mobile communications. In such a case, handovers are more frequent compared to the scenario studied in our paper and in Refs [11, 13]. More specifically, in Ref.…”

“…Regarding the vehicle's moving phase whose duration is also exponentially distributed with mean $${\theta }_{m}^{-1}$$, we assume that only new calls are generated [11, 13]. Based on this, the CAC of new calls is based on the CS policy.…”

“…of a finite first-in-first-out (FIFO) queue. Following Refs [11,13], we consider two CAC phases for the vehicle: a stop and a moving phase.…”

“…Note that the probabilistic BR policy has been proposed for pure loss systems in Ref. [13] and for loss/ queueing systems in Ref. [14] which serve random traffic (traffic generated via an infinite number of users).…”

Analytical Model of the Connection Handoff in 5G Mobile Networks with Call Admission Control Mechanisms

“…It is assumed that the offered traffic is generated by multi-service sources [ 13 , 23 ], i.e., it is assumed that each source can generate streams of different traffic classes. In the article, the authors focused on the two most popular CAC mechanisms: the resource reservation mechanism and the threshold mechanism [ 24 , 25 , 26 , 27 ].…”