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Passive optical network (PON) systems are rapidly becoming the most promising and cost-effective class of fiber access systems. In this paper we investigate the performance of a simple PON configuration, in respect of the end-to-end packet delay. The network supports multiple service-classes with priorities, in terms of the number of packets that can be transmitted in each transmission period. We...
We study the call-level performance behavior of two Passive Optical Network (PON) configurations in the upstream direction: an Optical Code Division Multiple Access (OCDMA) PON and a hybrid Wavelength Division Multiplexing (WDM)-OCDMA PON. Each PON accommodates 2K service-classes, which are grouped in two service priorities. The latter are denoted by thresholds in accessing the PON resources. The...
We investigate the performance of the IEEE 802.11e in respect of end-to-end delay, which is estimated by the sum of queuing delay and MAC delay. The MAC delay analysis is performed based on elementary probability theory (conditional probabilities) while avoiding the complex Markov Chain method. A comprehensive study of the MAC delay is presented by providing higher moments of the MAC delay distribution...
The call-level performance modelling and evaluation of 3G cellular networks is important for the proper network dimensioning and efficient use of the network resources, such as bandwidth and power. In the case of the wideband code division multiple access (W-CDMA) cellular networks, this task is complicated, not only because of the so called soft blocking, the multiple access interference (MAI) and...
This paper focuses on the call blocking probabilities calculation in a W-CDMA cell with fixed number of channels and finite number of traffic sources. To this end, the use of the Engset multirate loss model (EnMLM) is proposed in the uplink direction. To apply the EnMLM we need to extend it by incorporating the so called localblockings. Arriving calls compete for their successful admission to a W-CDMA...
The performance evaluation of wavelength division multiplexing (WDM) all-optical networks becomes an exceptionally important research topic, especially when the traffic grooming technique is used. In this paper we develop analytical loss models for calculating route establishment failure probabilities and call blocking probabilities in traffic-groomed WDM networks. We consider both single optical...
In this paper, we evaluate a call admission control (CAC) scheme suitable for W-CDMA cellular networks accommodating multiple service-classes. In such networks, the distinction between the new and the handoff traffic is very important. A simple CAC scheme can distinguish the calls between the two traffic types by setting different thresholds for call admission. This simple CAC scheme is evaluated...
The passive optical network (PON) is an attractive solution for delivering services with numerous applications, such as high-definition video, video conferencing and data traffic. In this paper we develop teletraffic loss models for calculating connection failure probabilities (due to unavailability of a wavelength) and call blocking probabilities (due to the restricted bandwidth capacity of a wavelength)...
In this paper, we investigate the call blocking probability calculations in the uplink of W-CDMA mobile cellular networks. In these networks, we distinguish two types of blocking, the new-call blocking, which concerns the initial call establishment request, and the handoffcall blocking, due to the users' mobility from one cell to the other. To analyze the system, we describe it by a Discrete Time...
We study a hybrid WDM-OCDMA Passive Optical Network (PON) with dynamic wavelength allocation, and propose analytical models for calculating connection failure probabilities (due to unavailability of a wavelength) and call blocking probabilities (due to interference of neighboring calls). The PON accommodates multiple service-classes with infinite number of traffic sources. The springboard of our analysis...
We present a new model, named Wireless Finite Connection-Dependent Threshold Model, for the call-level analysis of W-CDMA networks that support both elastic and stream traffic. Calls generated by service-classes of finite source population (quasi-random call arrival process) compete for their acceptance to a W-CDMA cell, under the complete sharing policy. An arriving call can be accepted with one...
The authors present an extensive investigation of the performance of the IEEE 802.11 medium access control (MAC) protocol, with respect to throughput and delay. For the protocol analysis, a new model, which describes the protocol's behaviour to a great extent by incorporating and extending the existing models, is proposed. The authors also present a detailed analysis of the end-to-end delay through...
Traffic grooming in Wavelength Division Multiplexing (WDM) optical networks is a promising technology for improving the performance and reducing the network cost. We study the blocking performance of a single-hop WDM traffic groomed optical network, by considering that different connections request service through a single optical link. In each connection the generated calls may come from a single...
The IEEE 802.11 protocol is the dominant standard for wireless local area networks (WLANs) and has generated much interests in investigating and improving its performance. The IEEE 802.11 medium access control (MAC) is mainly based on the distributed coordination function (DCF). DCF uses a carrier sense multiple access with collision avoidance (CSMA/CA) protocol in order to resolve contention between...
We propose a new teletrafflc model for the calculation of link occupancy distribution and determine the call blocking probabilities and link utilization in a single-link multi-rate loss system. We consider K different service-classes, either of elastic or of adaptive type, that compete for the available link bandwidth under the complete sharing policy. Calls arrive to the link with several contingency...
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