@article{Chousainov2021b,

title = {Multiservice loss models in single or multi-cluster c-ran supporting quasi-random traffic},

author = { I.-A. Chousainov and I. Moscholios and P. Sarigiannidis and M. Logothetis},

url = {https://www.researchgate.net/publication/354616239_Multiservice_Loss_Models_in_Single_or_Multi-Cluster_C-RAN_Supporting_Quasi-Random_Traffic},

doi = {10.3390/app11188559},

year  = {2021},

date = {2021-01-01},

journal = {Applied Sciences (Switzerland)},

volume = {11},

number = {18},

abstract = {In this paper, a cloud radio access network (C-RAN) is considered where the baseband units form a pool of computational resource units and are separated from the remote radio heads (RRHs). Based on their radio capacity, the RRHs may form one or many clusters: a single cluster when all RRHs have the same capacity and multi-clusters where RRHs of the same radio capacity are grouped in the same cluster. Each RRH services the so-called multiservice traffic, i.e., calls from many service classes with various radio and computational resource requirements. Calls arrive in the RRHs according to a quasi-random process. This means that new calls are generated by a finite number of mobile users. Arriving calls require simultaneously computational and radio resource units in order to be accepted in the system, i.e., in the serving RRH. If their requirements are met, then these calls are served in the (serving) RRH for a service time which is generally distributed. Otherwise, call blocking occurs. We start with the single-cluster C-RAN and model it as a multiservice loss system, prove that the model has a product form solution, and determine time congestion probabilities via a convolution algorithm whose accuracy is validated with the aid of simulation. Furthermore, the previous model is generalized to include the more complex case of more than one clusters. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.},

note = {cited By 0},

keywords = {Cloud-radio access, Cluster, convolution, Product form, Quasi-random, Time congestion},

pubstate = {published},

tppubtype = {article}

}

@article{Moscholios202051,

title = {Performance evaluation of the threshold call admission policy in multi-rate loss systems},

author = { I.D. Moscholios and I.-A. Chousainov and P.I. Panagoulias and P.G. Sarigiannidis and M.D. Logothetis},

url = {https://www.researchgate.net/publication/342568954_Performance_Evaluation_of_the_Threshold_Call_Admission_Policy_in_Multi-rate_Loss_Systems},

doi = {10.26636/jtit.2020.142120},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Telecommunications and Information Technology},

number = {2},

pages = {51-60},

abstract = {In this paper we consider a link, characterized by specific capacity, that services multi-rate random or quasirandom traffic. Random traffic is generated by an infinite number of traffic sources, while quasi-random traffic is generated by a finite population of traffic sources. The link is modeled as a multi-rate loss system. Handover and new calls are distinguished. New calls compete for the available bandwidth under a threshold call admission policy. In that policy, a new call of a particular service-class is not allowed to enter the system if the in-service handover and new calls of the same service-class plus the new call, exceed a predefined threshold (which can be different for each service-class). On the other hand, handover calls compete for the available bandwidth based on the complete sharing policy. We show that the steady state probabilities in the proposed models have a product form solution (PFS). The PFS leads to a convolution algorithm for accurate calculation of congestion probabilities and link utilization. © 2020 National Institute of Telecommunications. All rights reserved.},

keywords = {blocking, Congestion, convolution, Product form, Quasi-random, Rando},

pubstate = {published},

tppubtype = {article}

}

@article{Chousainov20201,

title = {Congestion probabilities in a multi-cluster c-ran servicing a mixture of traffic sources},

author = { I.-A. Chousainov and I.D. Moscholios and P.G. Sarigiannidis},

url = {https://www.researchgate.net/publication/347616523_Congestion_Probabilities_in_a_Multi-Cluster_C-RAN_Servicing_a_Mixture_of_Traffic_Sources},

doi = {10.3390/electronics9122120},

year  = {2020},

date = {2020-01-01},

journal = {Electronics (Switzerland)},

volume = {9},

number = {12},

pages = {1-18},

abstract = {A multi-cluster cloud radio access network (C-RAN) is considered in this paper where the remote radio heads (RRHs) form different clusters. A cluster includes RRHs that have the same radio resource unit capacity. In addition, all RRHs are separated from the common pool of computational resource units named baseband units. Each RRH accommodates calls whose arrival process can be random, quasi-random, or even bursty. The latter is modeled according to the compound Poisson process where calls arrive in the C-RAN in the form of batches whose size (in calls) is generally distributed. An arriving call requires a radio and a computational resource unit so as to be accepted in the C-RAN. If at least one of these units is not available, the call is blocked. To analyze the proposed multi-cluster C-RAN we model it as a loss system, show that the steady-state probabilities have a product form solution and propose an algorithm for the computation of congestion probabilities. The accuracy of the proposed algorithm is verified via simulation. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.},

keywords = {Bursty, Cloud-radio access, Cluster, Congestion, Poisson, Probability, Product form, Quasi-random},

pubstate = {published},

tppubtype = {article}

}