abstract: The integration of passive optical networks (PONs) and wireless mesh networks (WMNs) into Fiber-Wireless (FiWi) networks has recently emerged as a promising strategy for providing flexible network services at relative high transmission rates. This work investigates the effectiveness of localized routing that prioritizes transmissions over the local gateway to the optical network and avoids wireless packet transmissions in radio zones that do not contain the packet source or destination. Existing routing schemes for FiWi networks consider mainly hop-count and delay metrics over a flat WMN node topology and do not specifically prioritize the local network structure. The combination of clustered and localized routing (CluLoR) performs better in terms of throughput-delay compared to routing schemes that are based on minimum hop-count which do not consider traffic localization. Subsequently, this work also investigates the packet delays when relatively low-rate traffic that has traversed a wireless network is mixed with conventional high-rate PON-only traffic. A range of different FiWi network architectures with different dynamic bandwidth allocation (DBA) mechanisms is considered. The grouping of the optical network units (ONUs) in the double-phase polling (DPP) DBA mechanism in long-range (order of 100~Km) FiWi networks is closely examined, and a novel grouping by cycle length (GCL) strategy that achieves favorable packet delay performance is introduced. At the end, this work proposes a novel backhaul network architecture based on a Smart Gateway (Sm-GW) between the small cell base stations (e.g., LTE eNBs) and the conventional backhaul gateways, e.g., LTE Servicing/Packet Gateway (S/P-GW). The Sm-GW accommodates flexible number of small cells while reducing the infrastructure requirements at the S-GW of LTE backhaul. In contrast to existing methods, the proposed Sm-GW incorporates the scheduling mechanisms to achieve the network fairness while sharing the resources among all the connected small cells base stations. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2016

As redes de telecomunicações se dividem em redes de longa distância, redes metropolitanas e redes de acesso. As redes de longa distância e metropolitana usufruem a alta capacidade de largura de banda da fibra óptica, enquanto nas redes de acesso há um gargalo de largura de banda por causa do uso de pares de fios e cabo coaxial. Para solucionar este problema e oferecer aos usuários acesso banda larga de baixo custo foram propostas as redes ópticas passivas (passive optical network - PON). A PON é formada por dois elementos básicos, a unidade de rede óptica (optical network unit - ONU), localizada perto dos assinantes, e o terminal de linha óptica (optical line terminal - OLT), localizado próximo ao provedor de serviços. Dentre os padrões disponíveis para redes PON, o Ethernet (EPON), padronizado pelo grupo IEEE 802.3ah, é opção atraente porque ele é bastante difundido nas redes locais. O protocolo de controle multiponto (multipoint control protocol - MPCP), já especificado, é responsável pelo controle de acesso ao meio, fornecendo infra-estrutura de sinalização para transmissão entre OLT e ONUs. Entretanto, o algoritmo de alocação de largura de banda, que realiza o controle de acesso ao meio com base no MPCP, foi considerado fora do escopo de trabalho do grupo de trabalho, permitindo que seja desenvolvido pelos fornecedores de equipamentos. Neste trabalho, arquiteturas de rede EPON e o protocolo MPCP são descritos e algoritmos de alocação de largura de banda são avaliados mediante simulação computacional. São abordados os algoritmos de alocação de largura de banda que integram multiplexação estatística e técnicas para o suporte a classes de serviços diferenciados, com base no esquema de multiplexação por divisão no tempo (time division multiplexing - TDM). Algoritmos que integram a multiplexação por divisão em comprimento de onda (wavelength division multiplexing - WDM) à arquitetura EPON TDM são também investigados. Os algoritmos WDM-TDM permitem a atualização progressiva da EPON que emprega o esquema TDM para WDM. / Telecommunication networks are divided into core, metropolitan and access networks. The core and metropolitan networks use high capacity bandwidth optical fibers, while the access networks have bandwidth bottlenecks because of the use of twisted-pair wires and coaxial cable. To solve this problem and to offers the users broadband access at low cost the use of passive optical networks (PON) is proposed. A PON is formed by two basic elements, the optical network unit (ONU), positioned close to the customers and the optical line terminal (OLT), located close to the service provider. Within the available standards for PON networks, the Ethernet (EPON), standardised by the IEEE group 802.3ah, is an attractive option because it is already widely used in local networks. The multipoint control protocol (MPCP), already specified, is responsible for the media access control, providing signaling infrastructure for transmission between OLT and ONUs. However, the bandwidth allocation algorithm, that controls access based on MPCP, was considered outside the scope of the work group, permitting that this be developed by equipment providers. In this work, EPON architectures and the MPCP protocol are described and bandwidth allocation algorithms are evaluated with computational simulation. Bandwidth allocation algorithms which integrate statistical multiplexing and techniques to support for differentiated classes of service, based on time division multiplexing (TDM) scheme are investigated. Algorithms that integrate wavelength division multiplexing (WDM) to the EPON TDM architecture are also investigated. The WDM-TDM algorithms permit the progressive upgrade of EPON based TDM to WDM schemes.

隨著智慧家庭技術及物聯網的裝置大幅度地成長，智慧家庭的網路流量亦隨之升高。當大量成長的智慧家庭流量造成網路壅塞時，可能使緊急服務的警告機制失效，或是造成某些應用服務品質低劣而不堪使用。這些問題恐阻礙智慧家庭未來的發展性。 為改善上述問題，本文提出創新的物聯網智慧家庭頻寬配置管理架構。以ISP業者管理數以千計的物聯網智慧家庭為情境，針對智慧家庭多樣化的應用服務，利用具前瞻性的軟體定義網路，提供ISP業者對智慧家庭外部網路頻寬做最佳化的配置。 本研究依改良後的3GPP LTE QoS Class Identifier (QCI)，分類智慧家庭的服務，並考量服務的優先權及延遲程度，提出BASH演算法。透過本研究，ISP業者能依定義好的服務類別，將匯集後的智慧家庭服務流量藉由配置訊務流(traffic flow)的權重，計算出不同服務的最佳頻寬分配量，達到提升QoS及使用者QoE的目的。 為確認本論文所提出之方法的有效性，實驗設計是利用Linux伺服器架設OpenvSwitch、Ryu控制器及Mininet模擬器，建構SDN網路環境。實驗結果顯示，本研究所提出的BASH與ISP所用的傳統頻寬分配方法相比，能有效提高30%的throughput，降低159%的delay time及967%的 jitter time。 / With the increasing number of IoT (Internet of Things) devices and advance of smart home technology, the network traffic of smart home is also raising rapidly. When network congestion occurs due to massive traffic, some emergent alert mechanisms might become invalid or cause some application services performance degraded. All kinds of these will dramatically hamper the future development of smart homes. In order to resolve these problems, we propose an innovative bandwidth allocation smart home management framework for IoT enabled smart homes. The application scope of this research assumes a scenario that an ISP (Internet Service Provider) should support thousands of IoT enabled smart homes for a variety of services. The proposed bandwidth allocation framework is based on the promising software defined networking (SDN) architecture and is responsible for optimizing bandwidth allocation on external Internet traffic. We modify the 3GPP LTE QoS Class Identifier (QCI) to adaptive to the services suitable for smart homes. The proposed bandwidth allocation smart home (BASH) algorithm considers service priority and delay at the same time. With this framework, ISP is able to optimize bandwidth allocation by aggregating thousands of classified services of smart homes and thus effectively enhance Quality of Service (QoS) and user experience (QoE). In order to verify the proposed methods, we implement a SDN environment by using Linux Ubuntu servers with Mininet, Open vSwitch and Ryu controller. The experiment results show that BASH outperforms ISP traditional method in increasing the throughput by 30%, reducing delay and jitter by 159% and 967%, respectively.

Avec l’augmentation du nombre de cœurs, les problèmes de congestion sont commencé avec les interconnexions conventionnelles. Afin de remédier à ces défis, WiNoCoD projet (Wired RF Network-on-Chip Reconfigurable-on-Demand) a été initié par le financement de l’Agence Nationale de Recherche (ANR). Ce travail de thèse contribue à WiNoCoD projet. Une structure de contrôleur de RF est proposé pour l’interconnexion OFDMA de WiNoCoD et plusieurs algorithmes d’allocation de bande passante efficaces (distribués et centralisés) sont développés, concernant les demandes et contraintes très spécifiques de l’environnement sur-puce. Un protocole innovante pour l’arbitrage des sous-porteuses pour des longueurs bimodales de paquets sur-puce, qui ne nécessite aucun signalisation supplémentaire est introduit. Utilisation des ordres de modulation élevés avec plus grande consommation d’énergie est évaluée. / With rapidly increasing number of cores on a single chip, scalability problems have arised due to congestion and latency with conventional interconnects. In order to address these issues, WiNoCoD project (Wired RF Network-on-Chip Reconfigurable-on-Demand) has been initiated by the support of French National Research Agency (ANR). This thesis work contributes to WiNoCoD project. A special RF controller structure has been proposed for the OFDMA based wired RF interconnect of WiNoCoD. Based on this architecture, effective bandwidth allocation algorithms have been presented, concerning very specific requirements and constraints of on-chip environment. An innovative subcarrier allocation protocol for bimodal packet lengths of cache coherency traffic has been presented, which is proven to decrease average latency significantly. In addition to these, effective modulation order selection policies for this interconnect have been introduced, which seeks the optimal delay-power trade-off.

This thesis deal with an analysis of network traffic and its properties. In this thesis are discussed possibilities of prediction network traffic by FARIMA model, theory of chaos with Lyapunov exponent and by neural networks. The biggest attention was dedicated to prediction network traffic by neural networks. In Matlab with using Neural Network Toolbox were created, trained and tested recurrent networks for prediction specific types of network traffics, which was captured on local network. There were choosed Elman network, LRN and NARX network to test the prediction of network traffic, results were discussed. Thesis also introduce area of application ability prediction of network traffic, there is introduce design of system for dynamic allocation bandwidth with particular description of its prediction part. Thesis also states possible use designed system for dynamic allocation of bandwidth.

The aim of this thesis was to study problems of prediction of data in computer networks. Furthermore, this work deals with network traffic and analyzing its properties. In this study were analyzed the possibilities of network traffic prediction using Farima model, the theory of chaos with Lyapunov exponents and neural networks. Possibilities of prediction with the focus on neural network were discussed in detail here, mainly on recurrent neural networks. Prediction was performed in Matlab development environment in Neural Network Toolbox, where they were created, trained and evaluated neural network to predict specific types of network traffic. For testing were selected Elman network NARX network and general LRN recurrent network. The results were clearly organized into tables and plotted in graphical relationships before and after the use of predictive techniques designed to final evaluation.

The research initiatives addressed in this thesis are geared towards improving the performance of passive optical networks (PONs) through the development of advanced dynamic bandwidth allocation (DBA) protocols. In particular, the aim of the research undertaken is to enhance the quality of service (QoS) offered by standard PONs by means of providing subscribers with service level agreement (SLA) to fulfil applications and associated bandwidth requirements on demand. To accomplish the research objectives, a novel service and bandwidth focused DBA protocol is developed for standard time division multiplexing (TDM), gigabit-capable PONs (GPONs) by flexibly assigning a guaranteed minimum bandwidth to each optical network unit (ONU),terminated at subscribers premises. Modelling and simulation of the developed algorithms have displayed a tenfold enhancement in network performance, showing a superior performance to other published DBA protocols, in terms of mean packet delay. To accomplish protocol optimisation, the ONU upstream transmission properties of TDM-PONs have been further analysed and subsequently the ONU data transfer order in each communication cycle has been dynamically configured to increase the network upstream throughput by overlapping the upstream transmission period with parts of the bandwidth request-allocation process between OLT and ONUs. In addition, with the objective of extending the application of the developed protocol to long-reach PONs by means of reducing the augmented propagation delays due to the network’s extensive reach, the concept of virtual communication cycles has been incorporated into the optimised DBA algorithm. This approach demonstrates comparable transmission efficiency in the context of subscriber throughput and packet delay as in a standard PON but at much longer distances from the network exchange. To overcome the inevitably limited communication capacity of single wavelength TDM protocols and with the transportation of the ever increasing, time-sensitive, multi-media services in mind, a novel multi-wavelength DBA protocol is then developed to be applied to a wavelength division multiplexing–PON. With this protocol, both the downstream and upstream network capacity is dynamically adjusted according to subscribers’ service level and bandwidth demand in each polling cycle as opposed to a fixed upstream network capacity in TDM-PONs. It therefore also demonstrates improved upstream transmission efficiency.

O crescente aumento da demanda de tráfego nas redes celulares vem aumentando a necessidade de uma melhor utilização dos recursos do sistema, já que sua expansão é custosa. Nas estações rádio base (ERB), a disponibilidade de largura de faixa de freqüências é limitada e desta maneira, em uma rede de comunicação móvel celular, o controle de admissão de chamadas exerce grande influência no desempenho do sistema, pois determina a utilização de banda das ERBs e se uma determinada quantidade de recursos (banda) será alocado ou não para uma determinada chamada. O desempenho da rede pode ser atrelado a determinados parâmetros, como a probabilidade de bloqueio de novas chamadas, probabilidade de bloqueio de chamadas handoff e a utilização de banda da rede. Este trabalho propõe um controle de admissão de chamadas que, no atendimento de uma chamada, faz o empréstimo de banda de chamadas em andamento na célula no caso de banda insuficiente. O sistema adota um mecanismo heurístico que determina a banda disponível para novas chamadas conforme os valores de certos parâmetros do sistema. O empréstimo de banda é realizado em chamadas em andamento nas células até níveis mínimos estabelecidos para cada tipo de chamada, que se diferenciam pelas necessidades de banda de cada uma. O algoritmo foi aplicado às bandas e características de uma rede de terceira geração (3G), que possui chamadas de voz, videoconferência, interação multimídia, e-mail, downloads e transferência de arquivos e a uma rede GSM/GPRS (global system for mobile communications/ general packet radio service), que possui chamadas de voz e de dados. Os resultados mostram melhorias na probabilidade de bloqueio de novas chamadas, probabilidade de bloqueio de handoff e na utilização de banda do sistema. / The recent growth in traffic loads in cellular networks has seen the need for a better use of system resources as its expansion is expensive. In the base transceiver station (BTS), the bandwidth availability is limited. Thus, in cellular networks the call admission control greatly influences the system performance because it determines the bandwidth use of the BTSs and if an amount of resources will or will not be allocated to a call. The network performance can be evaluated by parameters such as blocking probability of new calls, dropping probability of handoff calls and bandwidth use. This work proposes a call admission control that carries out the bandwidth borrowing when a call arrives and there is not enough bandwidth. The system makes use of a heuristic mechanism that determines the available bandwidth for the new calls according to some parameter values of the system. The bandwidth borrowing is applied to the cell ongoing calls until the minimum levels for each type are met. The algorithm was applied to the bandwidths and characteristics of a third generation cellular network, which supports voice calls, videoconference, multimedia interaction, e-mails, downloads and file transfers. It was also applied to a GSM/GPRS (global system for mobile communications/ general packet radio service), which supports voice and data calls. The results show improvements in the blocking probability of new calls, dropping probability of handoff calls and in the bandwidth use of the system.

O crescente aumento da demanda de tráfego nas redes celulares vem aumentando a necessidade de uma melhor utilização dos recursos do sistema, já que sua expansão é custosa. Nas estações rádio base (ERB), a disponibilidade de largura de faixa de freqüências é limitada e desta maneira, em uma rede de comunicação móvel celular, o controle de admissão de chamadas exerce grande influência no desempenho do sistema, pois determina a utilização de banda das ERBs e se uma determinada quantidade de recursos (banda) será alocado ou não para uma determinada chamada. O desempenho da rede pode ser atrelado a determinados parâmetros, como a probabilidade de bloqueio de novas chamadas, probabilidade de bloqueio de chamadas handoff e a utilização de banda da rede. Este trabalho propõe um controle de admissão de chamadas que, no atendimento de uma chamada, faz o empréstimo de banda de chamadas em andamento na célula no caso de banda insuficiente. O sistema adota um mecanismo heurístico que determina a banda disponível para novas chamadas conforme os valores de certos parâmetros do sistema. O empréstimo de banda é realizado em chamadas em andamento nas células até níveis mínimos estabelecidos para cada tipo de chamada, que se diferenciam pelas necessidades de banda de cada uma. O algoritmo foi aplicado às bandas e características de uma rede de terceira geração (3G), que possui chamadas de voz, videoconferência, interação multimídia, e-mail, downloads e transferência de arquivos e a uma rede GSM/GPRS (global system for mobile communications/ general packet radio service), que possui chamadas de voz e de dados. Os resultados mostram melhorias na probabilidade de bloqueio de novas chamadas, probabilidade de bloqueio de handoff e na utilização de banda do sistema. / The recent growth in traffic loads in cellular networks has seen the need for a better use of system resources as its expansion is expensive. In the base transceiver station (BTS), the bandwidth availability is limited. Thus, in cellular networks the call admission control greatly influences the system performance because it determines the bandwidth use of the BTSs and if an amount of resources will or will not be allocated to a call. The network performance can be evaluated by parameters such as blocking probability of new calls, dropping probability of handoff calls and bandwidth use. This work proposes a call admission control that carries out the bandwidth borrowing when a call arrives and there is not enough bandwidth. The system makes use of a heuristic mechanism that determines the available bandwidth for the new calls according to some parameter values of the system. The bandwidth borrowing is applied to the cell ongoing calls until the minimum levels for each type are met. The algorithm was applied to the bandwidths and characteristics of a third generation cellular network, which supports voice calls, videoconference, multimedia interaction, e-mails, downloads and file transfers. It was also applied to a GSM/GPRS (global system for mobile communications/ general packet radio service), which supports voice and data calls. The results show improvements in the blocking probability of new calls, dropping probability of handoff calls and in the bandwidth use of the system.

本論文針對隨機數位網路提出一套可行的計算機制，以提供網路管理者進行資源分配與壅塞管理的分析工具。我們研究兩種利潤最佳化模型，探討在預算控制下的頻寬分配方式。因為資源有限，網路管理者無法隨時提供足夠頻寬以滿足隨機的網路需求，而量測網路連結成功與否的阻塞機率(Blocking Probability)為評估此風險之一種指標。我們利用頻寬分配、網路需求量和虛擬端對端路徑的數量等變數，推導阻塞機率函數，並證明阻塞機率的單調性(Monotonicity)和凸性(Convexity)等數學性質。在不失一般性之假設下，我們驗證阻塞機率是(1)隨頻寬增加而變小；(2)在特定的頻寬分配區間內呈凸性；(3)隨網路需求量增加而變大；(4)隨虛擬路徑的數量增加而變小。 本研究探討頻寬分配與阻塞機率之關係，藉由推導單調性和凸性等性質，提供此兩種利潤模型解的最適條件與求解演算法。同時，我們引用經濟學的彈性概念，提出三種模型參數對阻塞機率變化量的彈性定義，並分別進行頻寬分配、網路需求量和虛擬路徑數量對邊際利潤函數的敏感度分析。當網路上的虛擬路徑數量非常大時，阻塞機率的計算將變得複雜難解，因此我們利用高負荷極限理論(Heavy-Traffic Limit Theorem)提供阻塞機率的估計式，並分析其漸近行為(Asymptotic Behavior)。本論文的主要貢獻是分析頻寬分配與阻塞機率之間的關係及其數學性質。網路管理者可應用本研究提出的分析工具，在總預算限制下規劃寬頻網路的資源分配，並根據阻塞機率進行網路參數的調控。 / This thesis considers the problem of bandwidth allocation on communication networks with multiple traffic classes, where bandwidth is determined under the budget constraint. Due to the limited budget, there exists a risk that the network service providers can not assert a 100% guaranteed availability for the stochastic traffic demand at all times. We derive the blocking probabilities of connections as a function of bandwidth, traffic demand and the available number of virtual end-to-end paths for all service classes. Under general assumptions, we prove that the blocking probability is directionally (i) decreasing in bandwidth, (ii) convex in bandwidth for specific regions, (iii) increasing in traffic demand, and (iv) decreasing in the number of virtual paths. We also demonstrate the monotone and convex relations among those model parameters and the expected path occupancy. As the number of virtual paths is huge, we derive a heavy-traffic queueing model, and provide a diffusion approximation and its asymptotic analysis for the blocking probability, where the traffic intensity increases to one from below. Taking the blocking probability into account, two revenue management schemes are introduced to allocate bandwidth under budget control. The revenue/profit functions are studied in this thesis through the monotonicity and convexity of the blocking probability and expected path occupancy. Optimality conditions are derived to obtain an optimal bandwidth allocation for two revenue management schemes, and a solution algorithm is developed to allocate limited budget among competing traffic classes. In addition, we present three elasticities of the blocking probability to study the effect of changing model parameters on the average revenue in analysis of economic models. The sensitivity analysis and economic elasticity notions are proposed to investigate the marginal revenue for a given traffic class by changing bandwidth, traffic demand and the number of virtual paths, respectively. The main contribution of the present work is to prove the relationship between the blocking probability and allocated bandwidth under the budget constraint. Those results are also verified with numerical examples interpreting the blocking probability, utilization level, average revenue, etc. The relationship between blocking probability and bandwidth allocation can be applied in the design and provision of broadband communication networks by optimally choosing model parameters under budget control for sharing bandwidth in terms of blocking/congestion costs.