Javier E. Sierra

Remote locations coverage analysis with wireless mesh networks based on IEEE 802.16 Standard

This article analyzes the wireless coverage problem of remote regions with low user density and propagation problems due to irregular terrain and high tree density. The use of a wireless mesh network is proposed as a solution where user data is transmitted directly to a base station when it is possible or relayed through other nodes in a multi-hop manner when there is not a direct link. The mesh topology uses short links with higher capacity instead of long links with low capacity. We analyze radio propagation and MAC protocols, including random sources, queues, and packet delays. The article is based on the coverage of a realistic rural region near Medellin, a mid size city in Colombia, and it shows that a wireless mesh network is an alternative to a typical cell based solution. It includes propagation analysis and MAC protocol behavior, so it is not limited to a radio coverage problem but also traffic, scheduling, and routing analysis

All-Optical Unicast/Multicast Routing in WDM Networks

Optical transport networks (OTN) must be prepared in terms of better resource utilization, for accommodating unicast and multicast traffic together. Light-trees have been proposed for supporting multicast connections in OTN. Nevertheless when traffic grooming is applied in light-trees, resources can be underutilized as traffic can be routed to undesirable destinations in order to avoid optical-electrical-optical (OEO) conversions. In this paper, a novel architecture named S/G light- tree for supporting unicast/multicast connections is proposed. The architecture allows traffic dropping and aggregation in different wavelengths without performing OEO conversions. A heuristic that routes traffic demands using less wavelengths by taking advantage of the proposed architecture is designed as well. Simulation results show that the architecture can minimize the number of used wavelengths and OEO conversions when compared to light-trees.

ILP model for Greenfield WDM PON network design based on physical layer constraints

One of the main issues in the WDM PON networks design is the optimal dimensioning of the network. The network size usually depends on the traffic demand and the user density, taking in to account the active and passive equipment capacity and some physical layer constraints like the attenuation in the optical path. However, some physical layer limitations related with signal transmission in an optical fiber become more relevant in a WDM transmission and when operating at very high data rates, like 10 Gbps or beyond. In this paper we propose a novel physical layer restrictions based integer linear programming (ILP) model for greenfield next generation 10 Gbps WDM PON network design. The results of the model are validated by means of computational techniques. The proposed ILP model takes into account not only the attenuation of the signal in the optical path but also, through the use of the data obtained by simulation software. We take in to account the restrictions imposed by other phenomena like dispersion, cross talk and some non linear effects typically present in a dense WDM optical transmission.

S/G Light-tree: Multicast grooming architecture for improved resource allocation

Internet traffic demands are constantly increasing and a considerable amount of this increase is expected to be of multicast type. Optical transport networks (OTN)must be prepared in terms of better resource utilization for accommodating multicast traffic. For this purpose multicast traffic grooming has been considered. Light-trees have been proposed for supporting multicast connections in OTN. Nevertheless when light-trees are used with traffic grooming, resources can be overutilized as traffic can be routed to undesirable destinations in order to avoid optical-electrical-optical (OEO)conversions. In this paper a novel architecture named S/G light-tree for supporting multicast connections is proposed. The architecture allows to eliminate and aggregate traffic in different wavelengths without performing OEO conversions.The architecture uses labels supported by generalized multiprotocol label switching (GMPLS). A heuristic that routes traffic demands using less wavelengths by taking advantage of the proposed architecture is designed as well. Simulation results show that the architecture can minimize the number of used wavelengths and OEO conversions when compared to light-trees.

Improvements amplification parameters for radio over fiber of signal 54 MGz

This paper we analyzed three alternatives for optical amplification used to extend the reach of optical fiber link for the transport of RoF (Radio over Fiber) in view of 54 MHz RF signals for wireless applications.

Impact of the number of SAB on architectures that support unicast/multicast traffic in WDM networks

Optical transport networks (OTN) should be prepared to jointly handle both multicast and unicast traffic. Both opaque and transparent architectures are available to handle these types of traffic. Light-trees have been proposed as a way to transport information in a transparent manner. The light-tree however, may route unwanted information through some links while performing grooming of unicast and multicast traffic. To solve this problem we propose S/G light-tree with the goal of optimising the resources from the point of view of the number of wavelengths and available capacity. S/G light-tree uses detection systems (DS) and splitter and amplifier banks (SABs) to determine when unicast traffic should not be routed jointly with a multicast one by eliminating it optically from the link. This article proposes an online heuristic with grooming policies which allows for the analysis of the effects of the number of SABs on the blocking probability in OTN with dynamic traffic.

Design of a prototype remote medical monitoring system for measuring blood pressure and glucose measurement

Escuela de Ciencias Basicas Tecnologia e Ingenieria (ECBTI), Universidad Nacional Abierta y a Distancia; Carrera 27Nro. 40-43. Bucaramanga, Colombia; juan.vesga@unad.edu.co Facultad de Ingenieria, Corporacion Universitaria de Ciencia y Desarrollo UNICIENCIA. Cra. 12 #37-14, Bucaramanga,Colombia; jose.vesga@unicienciabga.edu.co Faculty of Engineering, Universidad de Sucre, Cra 28 # 5-267, Sincelejo, Colombia; javier.sierra@unisucre.edu.co

Analysis in the allocation of bandwidth applied to the concept of flexible optical networks

The continued increase in the capabilities and performance in fiber optic networks today require more robust network designs to allow high consumption of information and thus enable users to have greater capacity and data content. Thats why we in the task of analyzing and implementing the concept of flexible optical networks to optimize the use of bandwidth at high transmission rates and improved spectral efficiency, which represents the industry an effective economy, and energy.

Efficiency analysis on platform over the top (OTT) to deploy content and applications (edutainment) in digital television on optical network link

The convergence of new technologies in the digital world has made devices with internet connectivity such as televisions, smatphone, Tablet, Blu-ray, game consoles, among others, to increase more and more. Therefore the major research centers are in the task of improving the network performance to mitigate the bottle neck phenomenon regarding capacity and high transmission rates in information and data. The implementation of standard HbbTV (Hybrid Broadcast Broadband TV), and technological platforms OTT (Over the Top), capable of distributing video, audio, TV, and other Internet services via devices connected directly to the cloud. Therefore a model to improve the transmission capacity required by content distribution networks (CDN) for online TV, with high-capacity optical networks is proposed.

Impact of green technologies in optical networks case study: green wireless optical broadband access network

This article analyzes the current state of green technologies in optical telecommunications networks, analyzing in detail the basic structure of a hybrid network (Optical-Wireless), taking into account energy consumption by proposing a mathematical model is presented to establish the optimum number of ONUs in a network.