2021 |
I.-A. Chousainov; I. Moscholios; P. Sarigiannidis; M. Logothetis , "Multiservice loss models in single or multi-cluster c-ran supporting quasi-random traffic", Applied Sciences (Switzerland), 11 (18), 2021, (cited By 0). Journal Article Περίληψη | BibTeX | Ετικέτες: Cloud-radio access, Cluster, convolution, Product form, Quasi-random, Time congestion | Σύνδεσμοι: @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} } 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. |
2020 |
I. Moscholios; I.A. Chousainov; P. Panagoulias; P. Sarigiannidis; M. Logothetis , "A Multirate System of Quasi-Random Arrivals and a Threshold Call Admission Policy", 2020 12th International Symposium on Communication Systems, Networks and Digital Signal Processing (CSNDSP), IEEE, 2020. Conference Περίληψη | BibTeX | Ετικέτες: blocking, Congestion, convolution, Product form, Quasi-random | Σύνδεσμοι: @conference{Moscholios2020b, title = {A Multirate System of Quasi-Random Arrivals and a Threshold Call Admission Policy}, author = { I. Moscholios and I.A. Chousainov and P. Panagoulias and P. Sarigiannidis and M. Logothetis}, editor = { Networks 2020 12th International Symposium on Communication Systems and Digital Signal Processing ({CSNDSP})}, url = {https://www.researchgate.net/publication/346841887_A_Multirate_System_of_Quasi-Random_Arrivals_and_a_Threshold_Call_Admission_Policy}, doi = {10.1109/CSNDSP49049.2020.9249590}, year = {2020}, date = {2020-07-01}, booktitle = {2020 12th International Symposium on Communication Systems, Networks and Digital Signal Processing (CSNDSP)}, journal = {2020 12th International Symposium on Communication Systems, Networks and Digital Signal Processing, CSNDSP 2020}, publisher = {IEEE}, abstract = {We consider a link that services multirate quasirandom traffic. Calls are distinguished to handover and new calls. New calls compete for the available bandwidth under a threshold call admission policy. In that policy, new calls of a service-class are blocked if the in-service handover and new calls of the same service-class including the new call, exceeds a predefined threshold. Handover calls compete for the available bandwidth under the complete sharing policy. The steady state probabilities in the proposed model have a product form solution which leads to a convolution algorithm for the accurate calculation of congestion probabilities and link utilization. © 2020 IEEE.}, keywords = {blocking, Congestion, convolution, Product form, Quasi-random}, pubstate = {published}, tppubtype = {conference} } We consider a link that services multirate quasirandom traffic. Calls are distinguished to handover and new calls. New calls compete for the available bandwidth under a threshold call admission policy. In that policy, new calls of a service-class are blocked if the in-service handover and new calls of the same service-class including the new call, exceeds a predefined threshold. Handover calls compete for the available bandwidth under the complete sharing policy. The steady state probabilities in the proposed model have a product form solution which leads to a convolution algorithm for the accurate calculation of congestion probabilities and link utilization. © 2020 IEEE. |
I.P. Keramidi; I.D. Moscholios; P.G. Sarigiannidis; M.D. Logothetis , "Performance evaluation of two-link multirate loss models with restricted accessibility", Journal of Telecommunications and Information Technology, (2), pp. 61-69, 2020. Journal Article Περίληψη | BibTeX | Ετικέτες: Accessibility, blocking, Non-product form, Poisson, Quasi-random, Threshold | Σύνδεσμοι: @article{Keramidi202061, title = {Performance evaluation of two-link multirate loss models with restricted accessibility}, author = { I.P. Keramidi and I.D. Moscholios and P.G. Sarigiannidis and M.D. Logothetis}, url = {https://www.researchgate.net/publication/342568028_Performance_Evaluation_of_Two-Link_Multirate_Loss_Models_with_Restricted_Accessibility}, doi = {10.26636/jtit.2020.142320}, year = {2020}, date = {2020-01-01}, journal = {Journal of Telecommunications and Information Technology}, number = {2}, pages = {61-69}, abstract = {We consider a two-link communication system with restricted accessibility that services Poisson arriving calls of many service-classes and propose a multirate teletraffic loss model for its analysis. In a restricted accessibility system, call blocking occurs even if available resources do exist at the time of a call's arrival. In the two-link system under consideration, each link has two thresholds (offloading and support) which express the in-service calls in a link. The offloading threshold represents the point from which a link offloads calls. The support threshold (which is lower than the offloading threshold) defines the point up to which a link supports offloaded calls. The two-link system with restricted accessibility is modeled as a loss system whose steady state probabilities do not have a product form solution. However, approximate formulas for the determination of call blocking probabilities are proposed. In addition, we also provide a corresponding analysis related to the case of quasi-random traffic (i.e. traffic generated by a finite number of users). The accuracy of all formulas is verified through simulation and is found to be quite satisfactory. © 2020 National Institute of Telecommunications. All rights reserved.}, keywords = {Accessibility, blocking, Non-product form, Poisson, Quasi-random, Threshold}, pubstate = {published}, tppubtype = {article} } We consider a two-link communication system with restricted accessibility that services Poisson arriving calls of many service-classes and propose a multirate teletraffic loss model for its analysis. In a restricted accessibility system, call blocking occurs even if available resources do exist at the time of a call's arrival. In the two-link system under consideration, each link has two thresholds (offloading and support) which express the in-service calls in a link. The offloading threshold represents the point from which a link offloads calls. The support threshold (which is lower than the offloading threshold) defines the point up to which a link supports offloaded calls. The two-link system with restricted accessibility is modeled as a loss system whose steady state probabilities do not have a product form solution. However, approximate formulas for the determination of call blocking probabilities are proposed. In addition, we also provide a corresponding analysis related to the case of quasi-random traffic (i.e. traffic generated by a finite number of users). The accuracy of all formulas is verified through simulation and is found to be quite satisfactory. © 2020 National Institute of Telecommunications. All rights reserved. |
I.D. Moscholios; I.-A. Chousainov; P.I. Panagoulias; P.G. Sarigiannidis; M.D. Logothetis , "Performance evaluation of the threshold call admission policy in multi-rate loss systems", Journal of Telecommunications and Information Technology, (2), pp. 51-60, 2020. Journal Article Περίληψη | BibTeX | Ετικέτες: blocking, Congestion, convolution, Product form, Quasi-random, Rando | Σύνδεσμοι: @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} } 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. |
I.-A. Chousainov; I.D. Moscholios; P.G. Sarigiannidis , "Congestion probabilities in a multi-cluster c-ran servicing a mixture of traffic sources", Electronics (Switzerland), 9 (12), pp. 1-18, 2020. Journal Article Περίληψη | BibTeX | Ετικέτες: Bursty, Cloud-radio access, Cluster, Congestion, Poisson, Probability, Product form, Quasi-random | Σύνδεσμοι: @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} } 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. |
2019 |
P.I. Panagoulias; I.D. Moscholios; P.G. Sarigiannidis; M. Glabowski; M.D. Logothetis , "An analytical framework in OFDM wireless networks servicing random or quasi-random traffic", Applied Sciences (Switzerland), 9 (24), 2019. Journal Article Περίληψη | BibTeX | Ετικέτες: Complete sharing, Congestion, OFDM, Quasi-random, Random, Recursive, Reservation, Restricted | Σύνδεσμοι: @article{Panagoulias2019b, title = {An analytical framework in OFDM wireless networks servicing random or quasi-random traffic}, author = { P.I. Panagoulias and I.D. Moscholios and P.G. Sarigiannidis and M. Glabowski and M.D. Logothetis}, url = {https://www.researchgate.net/publication/337850639_An_Analytical_Framework_in_OFDM_Wireless_Networks_Servicing_Random_or_Quasi-Random_Traffic}, doi = {10.3390/app9245376}, year = {2019}, date = {2019-01-01}, journal = {Applied Sciences (Switzerland)}, volume = {9}, number = {24}, abstract = {We consider the downlink of an orthogonal frequency division multiplexing (OFDM)-based cell that services calls from many service-classes. The call arrival process is random (Poisson) or quasi-random, i.e., calls are generated by an infinite or a finite number of sources, respectively. In order to determine congestion probabilities and resource utilization, we model the cell as a multirate loss model. Regarding the call admission, we consider the restricted accessibility, the bandwidth reservation (BR), and the complete sharing (CS) policies. In a system of restricted accessibility, a new call may be blocked even if resources do exist. In a BR system, subcarriers can be reserved in favor of calls of high subcarrier requirements. Finally, in a CS system, a new call is blocked due to resource unavailability. In all three policies, we show that there exist recursive formulas for the determination of the various performance measures. Based on simulation, the accuracy of the proposed formulas is found to be quite satisfactory. © 2019 by the authors.}, keywords = {Complete sharing, Congestion, OFDM, Quasi-random, Random, Recursive, Reservation, Restricted}, pubstate = {published}, tppubtype = {article} } We consider the downlink of an orthogonal frequency division multiplexing (OFDM)-based cell that services calls from many service-classes. The call arrival process is random (Poisson) or quasi-random, i.e., calls are generated by an infinite or a finite number of sources, respectively. In order to determine congestion probabilities and resource utilization, we model the cell as a multirate loss model. Regarding the call admission, we consider the restricted accessibility, the bandwidth reservation (BR), and the complete sharing (CS) policies. In a system of restricted accessibility, a new call may be blocked even if resources do exist. In a BR system, subcarriers can be reserved in favor of calls of high subcarrier requirements. Finally, in a CS system, a new call is blocked due to resource unavailability. In all three policies, we show that there exist recursive formulas for the determination of the various performance measures. Based on simulation, the accuracy of the proposed formulas is found to be quite satisfactory. © 2019 by the authors. |
Διεύθυνση
Internet of Things and Applications Lab
Department of Electrical and Computer Engineering
University of Western Macedonia Campus
ZEP Area, Kozani 50100
Greece
Πληροφορίες Επικοινωνίας
tel: +30 2461 056527
Email: ithaca@uowm.gr