Jorge Eduardo Ortiz

Modeling and simulation of VDL mode 2 subnet for CPDLC in El Dorado airport

This paper presents the modeling and simulation of a Very High Frequency Data Link Mode 2 (VDL2) sub network to support Controller Pilot Data Link Communication (CPDLC), at El Dorado International Airport in Bogota City. The modeling and simulation were made in order to determine performance characteristics and determine if VDL2 could meet future traffic load increase. The simulation was performed using Network Simulator 2 (NS2). An overview of the technologies currently used for air-ground communication in Colombia is presented. Also this paper shows a glimpse of the features of the VDL Mode 2 protocol and CPDLC service. The VDL Mode 2 subnet model and the subsequent simulation were derived from the characteristics of Colombian airspace and air traffic conditions in the Bogota Terminal Area (TMA). Finally, the simulation results are presented.

RECUPERACIÓN DE INFORMACIÓN UTILIZANDO ECOSISTEMAS DE AGENTES INTELIGENTES

La inteligencia Artificial Distribuida es la ciencia encargada de estudiar conjunta e individualmente los agentes inteligentes con el fin de desarrollar nuevas soluciones a problemas de informacion que generalmente necesitan de una solucion basada en entidades inteligentes. Los Sistemas Multiagente SMA permiten la integracion con otras ciencias de la computacion para desarrollar nuevas soluciones, por ejemplo con la Computacion Bioinspirada. Profundizando en el tema, este trabajo presenta una investigacion de la IAD para aplicarla finalmente en la implementacion de un prototipo recuperador de informacion cuyos resultados se basan en palabras de interes del usuario, los documentos que el sistema busca se encuentran en un directorio local en formato html, la adaptacion e inteligencia del sistema se hace mediante la evolucion de los agentes. El sistema es disenado bajo INGENIAS y su implementacion se hace en JAVA utilizando las libreria de JADE e IR.

A Coalitional Game for Achieving Emergent Cooperation in Ad Hoc Networks Through Sympathy and Commitment

Cooperation among nodes is fundamental for ad hoc networks. In such systems, there is no centralized control, and the network components require self-organize themselves to accomplish their individual and collective goals. These conditions make necessary include cooperation mechanisms during the network operation for improving the system capacity for solving problems through collective actions. In this article, socially inspired computing is used to propose a coalitional game based on the concepts of sympathy and commitment with the purpose of achieving emergent cooperation in ad hoc networks. The results show cooperation may emerge even in scenarios in which agents do not have a cooperative strategy, producing a better network performance and a suitable resources distribution.

Results of a VDL 2 subnet simulation in the approach area to El Dorado Airport

This paper studies air to ground communications in the central sector of the terminal area (TMA) of Bogotas El Dorado Airport. The sector is termed Bogota Arrivals and it is a mandatory way for all aircraft making their final approach to El Dorado Airport. Currently, controller-pilot communications are established using voice messages through the frequency 119.5 MHz. The current capacity of Bogota Arrivals sector, as determined by the Colombian Civil Aviation Authority (UAEAC), is analyzed and compared to the capacity achievable with Controller to Pilot Data Link Communications (CPDLC) environment. To this end CPDLC over a VDL Mode 2 subnet in Bogota Arrivals sector was modeled and simulated using Network Simulator 2 (NS2) software. The capacity study done by the UAEAC was repeated for the CPDLC environment. The results show an increase in the capacity of the Bogota Arrivals sector, if air-ground communications are performed using CPDLC service over the VDL Mode 2 sub network instead of voice messages.

A greener method for content sharing in mobile ad hoc networks

A mobile ad hoc network (MANET) is characterized by its dynamic and decentralized topology, which allows exchanging information between mobile nodes without any pre-existing telecommunications infrastructure. However, mobile devices have constrained resources like memory, energy, bandwidth, etc., that must be optimally used in situations where a MANET is needed. For that reason, we propose a greener method for content sharing in MANETs that reduces energy consumption of nodes. We evaluate our method through simulations using J-Sim environment. Simulation results show that our method uses more efficiently the node resources than a centralized content sharing technique.

SIMULACIÓN DE ENLACES WI-FI Y UMTS CON J-SIM PARA ESTIMAR EL BER Y PER

Este articulo presenta la implementacion de una nueva herramienta de simulacion, desarrollada en J-Sim para las capas fisicas y de enlace de los sistemas Wi-Fi y UMTS, para estudiar el comportamiento de los enlaces de estas dos tecnologias referente al error generado y hacer su respectivo analisis. En particular, aqui se presentan resultados preliminares de las medidas de la tasa de error de bit, BER, y la tasa de error de paquete, PER; ademas se presentan otras simulaciones genericas, independientes de la tecnologia, para mostrar la utilidad de la herramienta desarrollada.

HAND-OFF VERTICAL Y LOS PROTOCOLOS IP COMO FACTORES CLAVE DEL DESARROLLO DE LAS REDES 4G

Este articulo describe lo que son en esencia las redes 4G y muestra un mapa general de su desarrollo tecnologico y se centra principalmente en dos temas principales: el Hand-off Vertical y el uso de IP, porque, como se explica en el articulo, estos dos factores son claves para el desarrollo de este nuevo tipo de redes por lo que sirve como una referencia que expande la vision sobre las redes 4G y muestra el papel del hand-off en su desarrollo para cualquier persona que le interese este tema. Esto es importante, dada la variedad de tecnologias que convergen en el esquema 4G.