LTE-advanced self-organizing network conflicts and coordination algorithms

Self-organizing network (SON) functions have been introduced in the LTE and LTEAdvanced standards by the Third Generation Partnership Project as an excellent solution that promises enormous improvements in network performance. However, the most challenging issue in implementing SON functions in reality is the identification of the best possible interactions among simultaneously operating and even conflicting SON functions in order to guarantee robust, stable, and desired network operation. In this direction, the first step is the comprehensive modeling of various types of conflicts among SON functions, not only to acquire a detailed view of the problem, but also to pave the way for designing appropriate Self-Coordination mechanisms among SON functions. In this article we present a comprehensive classification of SON function conflicts, which leads the way for designing suitable conflict resolution solutions among SON functions and implementing SON in reality. Identifying conflicting and interfering relations among autonomous network management functionalities is a tremendously complex task. We demonstrate how analysis of fundamental trade-offs among performance metrics can us to the identification of potential conflicts. Moreover, we present analytical models of these conflicts using reference signal received power plots in multi-cell environments, which help to dig into the complex relations among SON functions. We identify potential chain reactions among SON function conflicts that can affect the concurrent operation of multiple SON functions in reality. Finally, we propose a selfcoordination framework for conflict resolution among multiple SON functions in LTE/LTEAdvanced networks, while highlighting a number of future research challenges for conflict-free operation of SON

Context-Aware Handover Policies in HetNets

Next generation cellular systems are expected to entail a wide variety of wireless coverage zones, with cells of different sizes and capacities that can overlap in space and share the transmission resources. In this scenario, which is referred to as Heterogeneous Networks (HetNets), a fundamental challenge is the management of the handover process between macro, femto and pico cells. To limit the number of handovers and the signaling between the cells, it will hence be crucial to manage the user's mobility considering the context parameters, such as cells size, traffic loads, and user velocity. In this paper, we propose a theoretical model to characterize the performance of a mobile user in a HetNet scenario as a function of the user's mobility, the power profile of the neighboring cells, the handover parameters, and the traffic load of the different cells. We propose a Markov-based framework to model the handover process for the mobile user, and derive an optimal context-dependent handover criterion. The mathematical model is validated by means of simulations, comparing the performance of our strategy with conventional handover optimization techniques in different scenarios. Finally, we show the impact of the handover regulation on the users performance and how it is possible to improve the users capacity exploiting context information

Planificación en redes de área local inalámbricas en escenarios internos: elementos, herramientas y cuestiones prácticas

En la actualidad unas de las dificultades que presentan las redes inalámbricas de área local (WLAN) en espacios internos, por ejemplo, edificios, oficinas, distribución de cubículos entre pisos, es la adecuada cobertura a la cual tiene acceso diversos tipos de artefactos como son los celulares, laptops, computadoras, a través de la conexión inalámbrica que provee los diversos puntos de acceso (AP) distribuidos en diversos espacios por dónde transitan o trabajan las personas. En este artículo presentamos un análisis de los escenarios internos, al considerar una serie de elementos básicos, características, herramientas y cuestiones prácticas en el momento de la planificación de una red inalámbrica. Existen una serie de herramientas como inSSIDer, NetSurveyor, NetSpot y Vistumbler orientados a la planificación y diseño de redes LAN inalámbricas 802.11 a/b/g/n/ac en la obtención de rendimiento, seguridad y cumplimiento óptimo de la red. Los resultados obtenidos mediante experimentación permiten obtener información relevante para el planificador de la red encargado de diseñar e implementar la red LAN inalámbrica. De igual modo, se hace uso de una serie de escenarios para la simulación, los cuales están configurados con ciertas características, lo que permite la verificación de la velocidad de conexión, frecuencia de la señal y capacidad de transmisión afrontando las etapas de congestión de la red