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Politécnico Superior. Universidad de Zaragoza
STUDY OF THE EFFECT OF WIRELESS TRANSMISSIONS ON BIOMEDICAL SIGNALS
· A. Alesanco, “Design and evaluation of coding and transmission methods for electrocardiogram signals in real time telecardiology systems”, PhD Thesis, March 2007.
This thesis is devoted to provide new approaches and solutions suitable for real-time ECG coding, transmission and monitoring in a telecardiology application from a clinical point of view. It is structured in two main chapters: the rst one is dedicated to present and discuss the new approaches in real-time ECG signal compression and the second one presents proposals of new transmission protocols and its eects in the quality of the monitoring process depending on the characteristics of the communication network they have to face in the transmission.
· C. Hernández Ramos, A. Alesanco Iglesias, V. Abadía, J. García Moros. “The Effects of Wireless Channel Errors on the Quality of Real Time Ultrasound Video Transmission" .28th Annual International Conference IEEE Engineering in Medicine and Biology Society (EMBS), New York City, USA, pp. 6457-60. Agosto. 2006.. Agosto. 2006.
In this paper the effect of the conditions of wireless channels on real time ultrasound video transmission is studied. In order to simulate the transmission through a wireless channel, the model of Gilbert-Elliot is used, and the influence of its parameters in transmitted video quality is evaluated. In addition, the efficiency of using both UDP and UDP-Lite as transport protocols has been studied. The effect of using different video compression rates for XviD codec is also analyzed. Based on the obtained results it is observed as the election of the video compression rate depends on the bit error rate (BER) of the channel, since the election of a high compression bit rate for video transmission through a channel with a high BER can degrade the video quality more than using a lower compression rate. On the other hand, it is observed that using UDP as transport protocol better results in all the studied cases are obtained.
· A. Alesanco Iglesias, R. Istepanian, J. García Moros. "Performance Study of Real-Time ECG Transmission in Wireless Networks" .The International Special Topic Conference on Information Technology in Biomedicine (ITAB 2006), Ioannina (Grecia)" . Octubre. 2006.
An ECG coding and transmission methodology for real-time telecardiology applications using wireless networks is presented. The ECG signal is segmented into blocks which are coded and packetized for transmission. The compression method is based on the wavelet transform (WT) and the use of Set Partitioning in Hierarchical Trees (SPIHT) algorithm. Transmission simulations using TCP protocol through wireless channels with different characteristics are presented and discussed. Specific values for relevant parameters in the TCP protocol are proposed to enhance the quality of the communications.
Radio Resource Management in Cellular Broadband
This project proposal is placed within the intense research activity that, in the context of the development of broadband mobile cellular systems, both standardizing boards and research groups in public and private organizations are carrying out.
The project, focused on OFDMA-based systems, has the objective of developing efficient mechanisms to manage radio resources in the air interface, tackling the detailed study of each of them in a reference framework where the relation and coordination among all of these mechanisms are considered in a detailed and explicit way. Specifically, it is focused on the study, proposal, development and evaluation of Medium Access Control (MAC) structures and protocols, capable of providing QoS, and in the coordinated development of dynamic resource scheduling strategies among different users or among traffics of a single user, adaptive selection of modulation and coding, interference control, admission and congestion control, resource management under mobility (handover), that allow to satisfy the demanded requirements regarding quality, coverage and capacity, with the most efficient use of the available resources.
A differentiating aspect of the project is the special emphasis in the search of solutions that provide capacity for supporting multicast/broadcast multimedia services, as well as procedures of coverage and capacity extension, based on the support of the mulihop relay operation mode.
With an orientation towards the use of crosslayer approaches, a key aspect of the project is the explicit consideration of the impact of the architecture over the applicability of the proposals. In a reference framework where the traditional models of a hierarchical architecture are abandoned in order to bet on models with a flatter architecture, the project works on the refinement and the study of the implications of aspects such as the location, relation and coordination of the entities at a multicellular level, of the functions with impact of the resource management and, specifically, of the distribution architecture of the decision points of coordination among cells and of the measurement and distribution of the information that gives support to that coordination.
We are now studying mobility management (location and handover) and we are using OPNET as the simulation tool to evaluate its performance.
We are using OPNET for teaching in three subjects of the Telecommunications Engineering program in the Telematics Area of the Electronics Engineering and Communications Department in the University of Zaragoza (SPAIN).
The courses are the following.
Ángela Hernández Solana (firstname.lastname@example.org)
José Ramón Gállego Martínez (email@example.com)
This subject is a laboratory located in the fourth year of the telecommunications engineering degree. It is focused on the basis of IP networks and WAN interconnection through different technologies. The laboratory is divided into two parts (hardware and software-simulation). The simulation part consists of four different practices that we are developing with OPNET.
José Ramón Gállego Martínez (firstname.lastname@example.org)
Julián Fernández Navajas (email@example.com)
The rapid evolution of the networking industry introduces new exciting challenges that need to be explored by the student. The adoption of Internet as the global network infrastructure places the issue of quality of service among one of the hot topics nowadays: a huge diversity of applications with quite different service requirements must be supported over a basic core of protocols. OPNET is used as main tool to study this new exciting challenges and as laboratory research tool to discover the problems and possible solutions for next generation network design.
Key areas covered by the course are:
- Network Policy
- Quality of Service
- Real Time Applications
- Intelligent Networks
- Performance Evaluation
Antonio Valdovinos Bardají (firstname.lastname@example.org)
The aim of this subject is to show different wireless technologies for accesing networks. By means of OPNET, we have carried out some software-based practices in order to consolidate the student knowledge about GSM and GPRS technologies. We have based these practices on the GSM and GPRS contributed models published at OPNET web site.
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