@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}

}

@article{Sarigiannidis201049,

title = {IGFS: A new MAC protocol exploiting heterogeneous propagation delays in the dynamic bandwidth allocation on WDM-EPON},

author = { P.G. Sarigiannidis and S.G. Petridou and G.I. Papadimitriou and M.S. Obaidat},

url = {https://www.researchgate.net/publication/220544845_IGFS_A_new_MAC_protocol_exploiting_heterogeneous_propagation_delays_in_the_dynamic_bandwidth_allocation_on_WDM-EPON},

doi = {10.1109/JSYST.2009.2039886},

year  = {2010},

date = {2010-01-01},

journal = {IEEE Systems Journal},

volume = {4},

number = {1},

pages = {49-56},

abstract = {One of the most challenging issues of the Ethernet passive optical networks' (EPONs) architecture is the bandwidth allocation problem. Various dynamic allocation schemes have been proposed to schedule the subscribers' demands. However, the performance of all these schemes is significantly degraded when the round-trip times (RTTs) of the optical network units (ONUs) are dissimilar, due to the large number of gaps in the transmission schedule. Unfortunately, in real networks, RTTs are usually dissimilar. In this paper a new medium access control (MAC) protocol for multichannel EPONs, namely the Intelligent Gap Filling Strategy (IGFS) is proposed. The IGFS employs two algorithms: the DissimilarityExploitation algorithm, which exploits the RTTs' dissimilarities, and the MinimumLatencyScheduling algorithm, which rearranges the ONUs' service order in order to favor the requests that cause the minimum scheduling latency. © 2010 IEEE.},

keywords = {Passive optical networks, Reservation, Scheduling, WDM-EPONs},

pubstate = {published},

tppubtype = {article}

}

@article{Petridou2008863,

title = {Clustering-based scheduling: A new class of scheduling algorithms for single-hop lightwave networks},

author = { S.G. Petridou and P.G. Sarigiannidis and G.I. Papadimitriou and A.S. Pomportsis},

url = {https://www.researchgate.net/publication/220548025_Clustering-based_scheduling_A_new_class_of_scheduling_algorithms_for_single-hop_lightwave_networks},

doi = {10.1002/dac.929},

year  = {2008},

date = {2008-01-01},

journal = {International Journal of Communication Systems},

volume = {21},

number = {8},

pages = {863-887},

abstract = {In wavelength division multiplexing (WDM) star networks, the construction of the transmission schedule is a key issue, which essentially affects the network performance. Up to now, classic scheduling techniques consider the nodes' requests in a sequential service order. However, these approaches are static and do not take into account the individual traffic pattern of each node. Owing to this major drawback, they suffer from low performance, especially when operating under asymmetric traffic. In this paper, a new class of scheduling algorithms for WDM star networks, which is based on the use of clustering techniques, is introduced. According to the proposed Clustering-Based Scheduling Algorithm (CBSA), the network's nodes are organized into clusters, based on the number of their requests per channel. Then, their transmission priority is defined beginning from the nodes belonging to clusters with higher demands and ending to the nodes of clusters with fewer requests. The main objective of the proposed scheme is to minimize the length of the schedule by rearranging the nodes' service order. Furthermore, the proposed CBSA scheme adopts a prediction mechanism to minimize the computational complexity of the scheduling algorithm. Extensive simulation results are presented, which clearly indicate that the proposed approach leads to a significantly higher throughput-delay performance when compared with conventional scheduling algorithms. We believe that the proposed clustering-based approach can be the base of a new generation of high-performance scheduling algorithms for WDM star networks.},

keywords = {Clustering, prediction, Reservation, Scheduling, WDM star networks},

pubstate = {published},

tppubtype = {article}

}

@article{Sarigiannidis2008525,

title = {Supporting quality-of-service scheduling in a TT-FR WDM system},

author = { P.G. Sarigiannidis and S.G. Petridou and G.I. Papadimitriou and M.S. Obaidat and A.S. Pomportsis},

url = {https://www.researchgate.net/publication/224358108_Supporting_quality-of-service_scheduling_in_a_TT-FR_WDM_system},

doi = {10.1109/JSYST.2008.2009207},

year  = {2008},

date = {2008-01-01},

journal = {IEEE Systems Journal},

volume = {2},

number = {4},

pages = {525-535},

abstract = {In this paper, our recent work interval-based orderly scheduling strategy (IOSS) [1] is extended by adding quality-of-service (QoS) provisioning. A revised medium access control (MAC) protocol is introduced, which supports priority-based QoS in wavelength division multiplexing (WDM) networks with star topology. The proposed interval-based prioritized orderly scheduling strategy (IPOSS) operates in a distributed manner, and has the capability of handling channel collision and destinations conflicts in order to provide a collision-free scheduling scheme. Each node in the network is equipped with a tunable transmitter and a fixed receiver, assuring that the scheme is scalable with respect to the number of nodes and channels. Also, each node may accept high- and low-priority packet arrivals. IPOSS favors high-priority packets, without regarding packets' length or packets' destination. Moreover, the proposed scheme differentiates the packet's schedule order by prioritizing the long-length over the short-length packets. It is found that the adopted access control scheme achieves a critically high throughput-delay performance for real-time traffic. Furthermore, IPOSS presents a little bit improved throughput performance than IOSS scheme, since it handles in a different way the case in which two or more requests demand the same amount of transmission time. The traffic involved in the simulation results follows Bernoulli and Poisson distribution, regarding the arrival of the requests. © 2008 IEEE.},

keywords = {Quality-of-service (QoS), Reservation, Scheduling, Wavelength division multiplexing (WDM) star networks},

pubstate = {published},

tppubtype = {article}

}

@article{Petridou20082999,

title = {On the use of clustering algorithms for message scheduling in WDM star networks},

author = { S.G. Petridou and P.G. Sarigiannidis and G.I. Papadimitriou and A.S. Pomportsis},

url = {https://www.researchgate.net/publication/224367225_On_the_Use_of_Clustering_Algorithms_for_Message_Scheduling_in_WDM_Star_Networks},

doi = {10.1109/JLT.2008.926913},

year  = {2008},

date = {2008-01-01},

journal = {Journal of Lightwave Technology},

volume = {26},

number = {17},

pages = {2999-3010},

abstract = {Scheduling algorithms in wavelength division multiplexing (WDM) single-hop networks aim at producing an effective schedule in order to improve the networks' performance. Apart from channel assignment, the message sequencing is an important issue that have to be addressed when designing media access control (MAC) protocols for WDM networks. Up until now, popular approaches have not extensively addressed the order in which the messages are scheduled even though the messages' service order can considerably contribute to the advance of network performance. This paper introduces a new approach to the design of message scheduling algorithms for WDM star networks, which is based on the use of clustering techniques. The proposed clustering oriented - earliest available time scheduling (CO-EATS) creates groups of nodes whose messages are destined to common nodes. The goal of the proposed CO-EATS scheme is to decrease the probability of scheduling messages to the same destination at successive order. The simulation results have shown that the proposed scheme improves channel utilization and as a result it leads to higher network throughput while it keeps mean packet delay at low levels in comparison with conventional scheduling algorithms. © 2008 IEEE.},

keywords = {Clustering, Optical wavelength division multiplexing (WDM) networks, Reservation, Scheduling},

pubstate = {published},

tppubtype = {article}

}

@article{Sarigiannidis200776,

title = {A high performance scheduling priority scheme for WDM star networks},

author = { P. Sarigiannidis and G. Papadimitriou and A. Pomportsis},

url = {https://www.researchgate.net/publication/3417936_A_high_performance_scheduling_priority_scheme_for_WDM_star_networks},

doi = {10.1109/LCOMM.2007.060824},

year  = {2007},

date = {2007-01-01},

journal = {IEEE Communications Letters},

volume = {11},

number = {1},

pages = {76-78},

abstract = {A novel scheduling scheme for local area wavelength division multiplexing (WDM) single hop networks is introduced. The proposed protocol provides pre-transmission coordination schedule without collisions. It is based on a broadcast and select star architecture and uses a timeslot based access protocol. The proposed scheme incorporates a prediction based system, in order to reduce the amount of time spend in computing the schedule by predicting traffic requests. A series of simulation results is presented which indicates that when a specific schedule order is followed, starting from the node with the greatest demand, and completing to the node with the least demand (in transmission time) then a better network performance is achieved. Furthermore, the network throughput is higher, while the mean time packet delay at the waiting queues seems to be lower. © 2007 IEEE.},

keywords = {Optical WDM networks, Reservation, Scheduling, Traffic prediction},

pubstate = {published},

tppubtype = {article}

}

@article{Sarigiannidis2006211,

title = {CS-POSA: A high performance scheduling algorithm for WDM star networks},

author = { P.G. Sarigiannidis and G.I. Papadimitriou and A.S. Pomportsis},

url = {https://www.researchgate.net/publication/225152613_CS-POSA_A_high_performance_scheduling_algorithm_for_WDM_star_networks},

doi = {10.1007/s11107-005-6024-x},

year  = {2006},

date = {2006-01-01},

journal = {Photonic Network Communications},

volume = {11},

number = {2},

pages = {211-227},

abstract = {In this paper a new packet scheduling algorithm for WDM star networks is introduced. The protocol adopted is pre-transmission coordination-based and packet collisions have been eliminated due to predetermination of the timeslots each node transmits in a demand matrix. The requests of the transmitted packets are predicted through Markov chains in order to reduce the calculation time of the final scheduling matrix. This is accomplished by pipelining the schedule computation. The innovation that this algorithm introduces is to modify the service sequence of the node. The proposed algorithm is studied via extensive simulation results and it is proved that changing the sequence that nodes transmit, from the node with the largest number of requests to the node with the fewest requests, that there is an increase in the throughput of the network, with a minimum (almost zero) cost in mean time delay and in delay variance. © Springer Science + Business Media, Inc. 2006.},

keywords = {Optical WDM networks, Reservation, Scheduling, Star topology, Traffic prediction},

pubstate = {published},

tppubtype = {article}

}

@article{Sarigiannidis20064811,

title = {A high-throughput scheduling technique, with idle timeslot elimination mechanism},

author = { P.G. Sarigiannidis and G.I. Papadimitriou and A.S. Pomportsis},

url = {https://www.researchgate.net/publication/3243752_A_High-Throughput_Scheduling_Technique_With_Idle_Timeslot_Elimination_Mechanism},

doi = {10.1109/JLT.2006.884992},

year  = {2006},

date = {2006-01-01},

journal = {Journal of Lightwave Technology},

volume = {24},

number = {12},

pages = {4811-4827},

abstract = {A new media-access-control protocol is introduced in this paper. The authors consider a wavelength-division-multiplexing (WDM) network with star topology. A single-hop WDM system is considered, so that there is a full connectivity between every node-pair in just one hop. The protocol adopted is pretransmission coordination-based, so the protocol coordinates nodes before the actual transmission. The coordination is achieved with one demand (or traffic) matrix, which saves the predetermination of the timeslots each node transmits. Each transmission frame (or cycle) has two phases: the control phase and the data phase. In order to eliminate the possible delay added by the schedule computation between the two phases of each frame, they consider a traffic prediction scheme, which is based upon the hidden Markov chain model. The control phase functions as a learning period in which the predictor is trained. The training is based on the traffic of the network. During the data phase, each station transmits its packets based on the predicted reservations, which are the predictor's output. In the same frame, the predictor computes the reservations for the next frame. They show that their protocol, although suffering from small packet delay loss, introduces a new method of computing the reservations of the demand matrix and brings some performance improvement in terms of channel utilization and results in higher network throughput, which is proven by extensive simulations. © 2006 IEEE.},

keywords = {Demand matrix, Optical wavelength-division-multiplexing (WDM) networks, Reservation, Scheduling, Traffic prediction},

pubstate = {published},

tppubtype = {article}

}