Call blocking probabilities for Poisson traffic under the Multiple Fractional Channel Reservation policy

In this paper, we study the performance of the Multiple Fractional Channel Reservation (MFCR) policy, which is a bandwidth reservation policy that allows the reservation of real (not integer) number of channels in order to favor calls of high channel (bandwidth) requirements. We consider a link of fixed capacity that accommodates Poisson arriving calls of different service-classes with different bandwidth-per-call requirements. Calls compete for the available bandwidth under the MFCR policy. To determine call blocking probabilities, we propose approximate but recursive formulas based on the notion of reserve transition rates. The accuracy of the proposed method is verified through simulation

Contribución al control de admisión en redes móviles celulares multiservicio

El trabajo contenido en esta tesis trata de contribuir en la caracterización, comprensión y desarrollo de mecanismos para la apropiada gestión de los recursos en las redes móviles celulares. En concreto, la aportación que comprende este esfuerzo incluye el desarrollo de modelos, algoritmos y métodos para estudiar el control de admisión desde una perspectiva estacionaria, y el desarrollo de esquemas que optimicen el comportamiento del control de admisión de manera adaptativa con respecto a las situaciones no estacionarias de los sistemas reales.García Roger, D. (2007). Contribución al control de admisión en redes móviles celulares multiservicio [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/1845Palanci

Admission Control Policies in Multiservice Cellular Networks: Optimum Configuration and Sensitivity

Abstract. We evaluate different call admission control policies in various mul-tiservice cellular scenarios. For each of the studied policies we obtain the maximum calling rate that can be offered to the system to achieve a given QoS objective defined in terms of blocking probabilities. We propose an optimiza-tion methodology based on a hill climbing algorithm to find the optimum con-figuration for most policies. The results show that policies of the trunk reserva-tion class outperform policies that produce a product-form solution and the im-provement ranges approximately between 5 and 15 % in the scenarios studied.

Diseño óptimo de políticas de Control de Admisión (CA) del tipo Multiple Fractional Guard Channel (MFGC) para redes móviles multiservicio

[ES] La necesidad de garantizar Calidad de Servicio (QoS) en escenarios móviles multiservicio, lleva a explorar nuevas estrategias que permitan minimizar la probabilidad de terminación forzosa de una conexión debido a un fallo de handover por insuficiencia de recursos en la celda destino. Estas estrategias deben estar coordinadas con los sistemas de Control de Admisión (CA). Las políticas de CA del tipo MFGC son probablemente las que han suscitado un mayor interés pues consiguen unas buenas prestaciones y su implementación es bastante simple. Sin embargo, realizar el ajuste de parámetros de este tipo de políticas de una manera óptima entraña un esfuerzo computacional que puede llegar a ser prohibitivo. Para hacer frente a esta limitaciones computacionales se han propuesto algunos algoritmos basados en aproximaciones numéricas. De los resultados obtenidos, se observa que el coste computacional necesario puede llegar a ser muy elevado en algoritmos previos descritos en la literatura. La aproximación basada en fórmulas recurrentes no ofrece resultados totalmente convincentes, pues la configuración calculada a partir de éste no cumple los objetivos de QoS. Finalmente se propone un algoritmo que mejora los tiempos de cálculo respecto al algoritmo previo y obtiene resultados fiables, pero es mucho más lento que el algoritmo que se basa en la aproximación.[EN] The need to guarantee certain QoS requirements in multiservice cellular networks has led to explore new strategies to minimize blocking probabilities. These strategies must be coordinated with admission control systems (CA). In this paper we study Multiple Fractional Guard Channel (MFGC) policy which provides good results and its implementation is quite simple. Nevertheless, computing the optimal parameters setting of this policy can constitute a high computational cost. To face these computational limitations some algorithms based in numerical approximations are proposed. The obtained results show that the algorithm based in one-dimensional recursion formulas is not a good approximation since the policy configuration obtained do not fulfills the QoS constrains. But this approximation can be useful to accelerate a previous algorithm appeared in the literature. Finally, we propose another algorithm which outperforms this previous algorithm in terms of computational cost and fulfills the QoS constraints, but it is slower than the algorithm based in one-dimensional recursion formulas.Bernal Mor, E. (2008). Diseño óptimo de políticas de Control de Admisión (CA) del tipo Multiple Fractional Guard Channel (MFGC) para redes móviles multiservicio. http://hdl.handle.net/10251/27132.Archivo delegad

DISEÑO ÓPTIMO DE POLÍTICAS DE CONTROL DE ADMISIÓN DEL TIPO MULTIPLE FRACTIONAL GUARD CHANNEL (MFGC) PARA REDES MÓVILES MULTISERVICIO

Las políticas de CA MFGC son probablemente las que han suscitado un mayor interés en el entorno móvil. Sin embargo, realizar el ajuste de parámetros de este tipo de políticas entraña un esfuerzo computacional que puede llegar a ser prohibitivo. Para hacer frente a esta limitaciones se proponen algunos algoritmos basados en aproximaciones númerica. Abstract: Multiple Fractional Guard Channel (MFGC) policy provides good results and its implementation is quite simple. Nevertheless, computing the optimal parameters setting of this policy can constitute a high computational cost. To face these computational limitations some algorithms based in numerical approximations are proposed.Bernal Mor, E. (2007). DISEÑO ÓPTIMO DE POLÍTICAS DE CONTROL DE ADMISIÓN DEL TIPO MULTIPLE FRACTIONAL GUARD CHANNEL (MFGC) PARA REDES MÓVILES MULTISERVICIO. http://hdl.handle.net/10251/12625Archivo delegad

Contribución a la gestión de recursos en redes de acceso celulares. Modelos analíticos y evaluación de prestaciones

Desde sus inicios hace algo más de veinte años, la telefonía móvil celular ha experimentado un enorme crecimiento e importantes transformaciones y, todavía hoy, se encuentra en una fase de cambio y crecimiento. A diferencia de lo que ocurre en una red fija, en la que la enorme capacidad de transmisión que aporta la fibra óptica relega a un segundo plano la gestión eficiente de esta capacidad, el medio de transmisión en la interfaz radio de las redes móviles es un bien escaso. Aunque los avances tecnológicos permiten ampliar el rango de frecuencias utilizables y conseguir una mayor eficiencia espectral, el aumento del tráfico junto a la aparición de nuevos usos y servicios hacen que la gestión eficiente de los recursos radio continúe siendo de gran importancia. El control de admisión (CA) es un mecanismo importante para la gestión de los recursos radio. Aunque el estudio de las técnicas de CA recibió un impulso importante en el contexto de la red digital de servicios Integrados de banda ancha (RDSI-BA), las redes móviles tienen ciertas características específicas que hacen que el CA sea más complejo: las ya referidas limitaciones del espectro, las características propias del canal radio que resultan en un comportamiento aleatorio y, sobre todo, la movilidad de los terminales. En este trabajo se estudia el CA en relación con la movilidad: para admitir una nueva sesión se deben tener ciertas garantías -al menos en un sentido estadístico- de que la red tendrá recursos suficientes para mantener, con la calidad de servicio (QoS) requerida, tanto esa nueva sesión como las ya existentes en ese momento, y ello teniendo en cuenta que durante la vida de una sesión, ésta -el terminal- puede cambiar de área de cobertura (célula), y los recursos deberán estar disponibles allí donde vaya el terminal. Aunque el interés por este tema no es nuevo, continúa vigente, pues para atender la creciente demanda de capacidad, una de las formas pasa por reducir el tamaño de las células....Pla Boscà, V. (2005). Contribución a la gestión de recursos en redes de acceso celulares. Modelos analíticos y evaluación de prestaciones [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/2001Palanci

On the Merits of Deploying TDM-based Next-Generation PON Solutions in the Access Arena As Multiservice, All Packet-Based 4G Mobile Backhaul RAN Architecture

The phenomenal growth of mobile backhaul capacity required to support the emerging fourth-generation (4G) traffic including mobile WiMAX, cellular Long-Term Evolution (LTE), and LTE-Advanced (LTE-A) requires rapid migration from today\u27s legacy circuit switched T1/E1 wireline and microwave backhaul technologies to a new fiber-supported, all-packet-based mobile backhaul infrastructure. Clearly, a cost effective fiber supported all-packet-based mobile backhaul radio access network (RAN) architecture that is compatible with these inherently distributed 4G RAN architectures is needed to efficiently scale current mobile backhaul networks. However, deploying a green fiber-based mobile backhaul infrastructure is a costly proposition mainly due to the significant cost associated with digging the trenches in which the fiber is to be laid. These, along with the inevitable trend towards all-IP/Ethernet transport protocols and packet switched networks, have prompted many carriers around the world to consider the potential of utilizing the existing fiber-based Passive Optical Network (PON) access infrastructure as an all-packet-based converged fixed-mobile optical access networking transport architecture to backhaul both mobile and typical wireline traffic. Passive Optical Network (PON)-based fiber-to-the-curb/home (FTTC/FTTH) access networks are being deployed around the globe based on two Time-Division Multiplexed (TDM) standards: ITU G.984 Gigabit PON (GPON) and IEEE 802.ah Ethernet PON (EPON). A PON connects a group of Optical Network Units (ONUs) located at the subscriber premises to an Optical Line Terminal (OLT) located at the service provider\u27s facility. It is the purpose of this thesis to examine the technological requirements and assess the performance analysis and feasibility for deploying TDM-based next-generation (NG) PON solutions in the access arena as multiservice, all packet-based 4G mobile backhaul RAN and/or converged fixed-mobile optical networking architecture. Specifically, this work proposes and devises a simple and cost-effective 10G-EPON-based 4G mobile backhaul RAN architecture that efficiently transports and supports a wide range of existing and emerging fixed-mobile advanced multimedia applications and services along with the diverse quality of service (QoS), rate, and reliability requirements set by these services. The techno-economics merits of utilizing PON-based 4G RAN architecture versus that of traditional 4G (mobile WiMAX and LTE) RAN will be thoroughly examine and quantified. To achieve our objective, we utilize the existing fiber-based PON access infrastructure with novel ring-based distribution access network and wireless-enabled OLT and ONUs as the multiservice packet-based 4G mobile backhaul RAN infrastructure. Specifically, to simplify the implementation of such a complex undertaking, this work is divided into two sequential phases. In the first phase, we examine and quantify the overall performance of the standalone ring-based 10G-EPON architecture (just the wireline part without overlaying/incorporating the wireless part (4G RAN)) via modeling and simulations. We then assemble the basic building blocks, components, and sub-systems required to build up a proof-of-concept prototype testbed for the standalone ring-based EPON architecture. The testbed will be used to verify and demonstrate the performance of the standalone architecture, specifically, in terms of power budget, scalability, and reach. In the second phase, we develop an integrated framework for the efficient interworking between the two wireline PON and 4G mobile access technologies, particularly, in terms of unified network control and management (NCM) operations. Specifically, we address the key technical challenges associated with tailoring a typically centralized PON-based access architecture to interwork with and support a distributed 4G RAN architecture and associated radio NCM operations. This is achieved via introducing and developing several salient-networking innovations that collectively enable the standalone EPON architecture to support a fully distributed 4G mobile backhaul RAN and/or a truly unified NG-PON-4G access networking architecture. These include a fully distributed control plane that enables intercommunication among the access nodes (ONUs/BSs) as well as signaling, scheduling algorithms, and handoff procedures that operate in a distributed manner. Overall, the proposed NG-PON architecture constitutes a complete networking paradigm shift from the typically centralized PON\u27s architecture and OLT-based NCM operations to a new disruptive fully distributed PON\u27s architecture and NCM operations in which all the typically centralized OLT-based PON\u27s NCM operations are migrated to and independently implemented by the access nodes (ONUs) in a distributed manner. This requires migrating most of the typically centralized wireline and radio control and user-plane functionalities such as dynamic bandwidth allocation (DBA), queue management and packet scheduling, handover control, radio resource management, admission control, etc., typically implemented in today\u27s OLT/RNC, to the access nodes (ONUs/4G BSs). It is shown that the overall performance of the proposed EPON-based 4G backhaul including both the RAN and Mobile Packet Core (MPC) {Evolved Packet Core (EPC) per 3GPP LTE\u27s standard} is significantly augmented compared to that of the typical 4G RAN, specifically, in terms of handoff capability, signaling overhead, overall network throughput and latency, and QoS support. Furthermore, the proposed architecture enables redistributing some of the intelligence and NCM operations currently centralized in the MPC platform out into the access nodes of the mobile RAN. Specifically, as this work will show, it enables offloading sizable fraction of the mobile signaling as well as actual local upstream traffic transport and processing (LTE bearers switch/set-up, retain, and tear-down and associated signaling commands from the BSs to the EPC and vice-versa) from the EPC to the access nodes (ONUs/BSs). This has a significant impact on the performance of the EPC. First, it frees up a sizable fraction of the badly needed network resources as well as processing on the overloaded centralized serving nodes (AGW) in the MPC. Second, it frees up capacity and sessions on the typically congested mobile backhaul from the BSs to the EPC and vice-versa

Quality of service technologies for multimedia applications in next generation networks

Next Generation Networks are constantly evolving towards solutions that allow the operator to provide advanced multimedia applications with QoS guarantees in heterogeneous, multi-domain and multi-services networks. Other than the unquestionable advantages inherent the ability to simultaneously handle traffic flows at different QoS levels, these architectures require management systems to efficiently perform quality guarantees and network resource utilization. These issues have been addressed in this thesis. DiffServ-aware Traffic Engineering (DS-TE) has been considered as reference architecture for the deployment of the quality management systems. It represents the most advanced technology to accomplish either network scalability and service granularity goals. On the basis of DS-TE features, a methodology for traffic and network resource management has been defined. It provides some rules for QoS service characterization and allows to implement Traffic Engineering policies with a class-based approach. A set of basic parameters for quality evaluation has been defined, that are the Key Performance Indicators; some mathematical model to derive the statistical nature of traffic have been analyzed and an algorithm to improve the fulfillment of quality of service targets and to optimize network resource utilization. It is aimed at reducing the complexity inherent the setting of some of the key parameters in the NGN architectures. Multidomain scenarios with technologies different from DS-TE have been also evaluated, defining some methodologies for network interoperability. Simulations with Opnet Modeler confirmed the efficacy of the proposed system in computing network configurations with QoS targets. With regard to QoS performance at the application level, video streaming applications in wireless domains have been particularly addressed. A rate control algorithm to adjust the rate on a per-window basis has been defined, making use of a short-term prediction of the network delay to keep the probability of playback buffer starvation lower than a desired threshold during each window. Finally, a framework for mutual authentication in web applications has been proposed and evaluated. It integrates an IBA password technique with a challenge-response scheme based on a shared secret key for image scrambling. The wireless environment is mainly addressed by the proposed system, which tries to overcome the severe constraints on security, data transmission capability and user friendliness imposed by such environment