Gonzalo Olmedo

Data transmission efficiency over CDMA systems employing RLP and FEC error control strategies on the radio link layer

In this article, the normalized throughput and the normalized average delay for the transport layer at the reverse link of multicellular CDMA systems are obtained. For the transport layer the Transport Control Protocol (TCP) with consecutive retransmissions control is employed. On the radio link layer three TCP error control strategies are evaluated and compared. The first strategy is based on the radio-link-protocol (RLP), which breaks down the TCP packets into smaller blocks and uses an error detecting procedure to protect those RLP blocks. The second strategy uses forward-error-control (FEC) procedure at the radio link layer. In this case, two kinds of FEC are compared: convolutional and turbo coding. The third one is a hybrid between the first and second strategies with coding at the RLP layer. A frequency-selective Rayleigh fading channel with shadowing and power control loop error is considered.

Designing a system for monitoring and broadcasting early warning signs of natural disasters for Digital Terrestrial Television

This paper deals with the design of a monitoring system and the broadcast of warning signals for Digital Terrestrial Television. A graphical user interface will be created in specialized software as it is Netbeans. Area codes will be used to generate the corresponding transport stream files which will be sent through Stream Xpress software in order to broadcast the signal. Finally, the warning will be displayed in an equipment of ISDB-T INTERNACIONAL. The main aim of this work is to show the Emergency Warning Broadcast System signal to prevent people from any natural disaster that might happen.

Analytical performance of modulation and error correcting codes for the ISDB-T system over AWGN channels

This article presents on analytical performance analyzes about QPSK, 16QAM and 64 QAM modulations and error correcting codes defined in ISDB-T system over AWGN channels. Simple and precise close-form analytic expressions related to byte error probability for the transport stream layer, as a function of the energy per modulated symbol for Viterbi hard and soft decision decoding are derived. The proposed expressions of the analytic model developed to evaluate the performance of the ISDB-T system are verified by the results of computer simulations.

Voice — TOUCH GPS: Navegation and mobility assistant for people with visual disability in Ecuador

This article presents a mobility application of navegation directed to people with visual deficiency and disability. Visually disabled people cope with daily challenges in mobility and in their automony. VOICE-TOUCH GPS is an application that has two forms in order to interact with them. The first one lets the person use a smartphone with touch screen to have an auditory feedback. The second one interacts by means of a synthesizer which generates a text by voice and vice-versa. The application presents a graphic interface easy to use along with the help of a GPS. It will help the user know the latest location, the nearest bus stop, buses routes, make phone calls and send messages predetermined to the location. Furthermore, this article presents the functions of the application, requirements of functioning, social impact and the results obtained in people with total and partial visual deficiency in Ecuador.

MPEG-2 transport stream analyzer for digital television

The present article describes the creation of a MPEG-2 Transport Stream (TS)/Broadcast Transport Stream (BTS) Analyzer for Digital Television. This analyzer recognizes TS and BTS files in a decimal or hexadecimal format and it shows the components of the PSI (Program Service Information)/SI (Service Information) Tables, such as: Program Association Table (PAT), Program Map Table (PMT), Network Information Table (NIT), and Service Descriptor Table (SDT); in the case of the BTS files it also shows the content of the Transmission and Multiplexing Configuration (TMCC) table. The software has a package search system where you can look for a package through his PID (Program Identification) number or his package number. It also allows surfing between all the packages or the packages with the same PID number.

Design, implementation and evaluation of data carrousel extractor algorithm on MPEG-2 TS for digital terrestrial television

This paper shows the design, implementation and evaluation of an algorithm that allows the extraction of Transport Streams (TS) data section for Digital Terrestrial Television (DTT), with the organization in a hierarchical file system and directories based on MPEG-2 standard ISO-13818-6: Extension for Digital Storage Media Command and Control (DSM-CC), in order to fully recover the media from interactive applications contained by the MPEG-2 TS stream. To check the validity of the algorithm, it was implemented in a software to evaluate the application extraction of different TS, verifying its correct operation, as it successfully recovered all directories and files from interactive applications.

Towards to a Usable and Accessible Mixed Global Standard DTT-IPTV

This proposal includes the establishment of a joint standard for the integration of interactive open platforms: GINGA for interactive service on ISDB-T and Hybrid European standard HbbTV with SiestaCloud ecosystem for IPTV together. In addition, this standard will be interoperable with close or half open Smart-TV standards like, AndroidTV, AppleTV, AmazonTV, etc.; the incompatibility that actually exists between these platforms will be solved by this project. Our proposal also includes development of interactive applications on DTT and IPTV which assumes usability (SIMPLIT) and accessibility (W3C) rules. The authoring tool implementation is also contemplated for the development of interactive applications, under the concept of open existing access repositories templates and an extension of Unity framework for interactive 3D content development without having to program a single code line. Finally, a production methodology of audiovisual content (i-standardized, accessible and usable) in cultural, health, educational and commercial context will also be proposed.

Performance analysis on return channel for interactive digital TV ISDB-Tb system

This article describes the analysis of return channel for digital terrestrial television (DTT), through the development of interactive application called Shopping Car buying and selling. Using the middleware Ginga-NCL, Lua and MySQL, to get evidence of the return path for the interactive application and determines the capacity of server performance.