Admission control and handover management for high‐speed trains in vehicular geostationary satellite networks with terrestrial gap‐filling

Abstract

Following a recent upgrade, the Digital Video Broadcasting—Return Channel Satellite (DVB-RCS) standard sets up to support terminal mobility. In this scenario, integration with terrestrial systems becomes a primary concern to ensure network connectivity in urban areas. This article proposes an integrated satellite–terrestrial architecture for the provision of broadband services onboard high-speed trains, in which terrestrial cellular networks are seen as viable gap-fillers for discontinuous satellite coverage. We derive an analytical model of the hybrid DVB-RCS-cellular system by exploiting analogies between the mobility pattern predictability of LEO constellations and that of high-speed trains. Terminals whose QoS cannot be guaranteed by the satellite segment are proposed to temporarily divert the connections towards the terrestrial infrastructure, where available. Using an iterative approach based on the Erlang fixed-point approximation, we show performance improvements with respect to stand-alone satellite systems in terms of handover failure probability and overall resource utilization. The analytical model is also validated via our ns2-based DVB-RCS packet-level simulator. Detailed modelling of synchronization and signalling mechanisms confirms the accuracy of the analytical results, and shows that topology and mobility information can contribute to refine radio resource utilization optimality when used jointly

A survey on high-speed railway communications: A radio resource management perspective

“…By means of Markov chains, the proposed algorithm is evaluated in terms of new-call blocking March 18, 2016 DRAFT probability, handover-call dropping probability, handover-call waiting time in the queue, and channel utilization. The literature [69] proposes joint admission control and handover policies in an integrated satellite-terrestrial architecture, and the proposed policies aim to increase both the user satisfaction and the resource utilization. Another handoverbased admission control scheme is proposed in [70], where a position-based factor is introduced to reserve more resources to accept handover calls.…”

“…Based on the admission level, the admission control schemes can be classified into the call-level admission control and the packet-level admission control. Traditional admission control schemes only consider call-level performance and are mainly designed for circuit-switched GSM-R system [43,[67][68][69][70][71][72]. Since LET-R will become a packet-switched system, the packet-level features could be explored to improve the system performance [26].…”

“…In the above schemes [67][68][69][70], the handover services and new services are considered when making admission control decisions. Actually, the services can dynamically change their modulation and coding schemes (MCS) in HSR wireless communications.…”