Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Modeling power control in WCDMA for multimedia support(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2010-12-01) Pineda Rico, Ulises; PINEDA RICO, ULISES; 179307; ITESMModern Third Generation Wireless Networks demand more and more resources in order to satisfy customers� needs. And these resources can only be provided by a good Power Control. However, power control needs an algorithm in order to work at the margin of the Quality of Service (QoS) requirements. This work is related to this; we propose a power control algorithm modeled under probabilistic criteria. This means, applying a Markovian model to a MAC Protocol (power control algorithm), in order to optimize the power assigment to each user in the system. This protocol is highly interrelated to the power control functionality in order to extract the maximum capacity and flexibility out of the WCDMA scheme. Once it is done, the algorithm is submitted to different scenarios to demonstrate its capabilities and limitations, also thus analyze its behavior under different conditions and viewpoints. At the end, conclusions are listed, together with future work and proposals to strengthen this work.
- A Joint Source Channel Coding Approach to Delivery of Digital Images over CDMA 800 MHz Indoor Wireless Rayleigh Fading Channels(Instituto Tecnológico y de Estudios Superiores de Monterrey, 01/07/2004) Murillo Zolezzi, Jacobo; Rodríguez Cruz, José Ramón; Hinojosa Espinosa, Carlos M.; Vargas Rosales, Cesar; ITESM; Garza Salazar, DavidThe following thesis developed in the area of Electrical Engineering and Telecommunications is aimed at improving current CDMA wireless network capabilities specifically targeting the transmission of JPEG compressed data with the possibility of a continued investigation in the transmission of MPEG video format. The aim or objective is to generate a solution to current transmission problems faced in 3rd generation CDMA networks where band limited transmission limits the capabilities of the network in delivering large data files such as image or video adequately. The rising importance in expanding network capabilities for CDMA networks, in this case for image transmission, is evident because of several factors including the following: � One of these factors is the increasing popularity of CDMA since its creation in 1995. In the cellular branch alone, there are over an estimates 106 million users utilizing a CDMA based network. This rapid increase is due to the fact that CDMA is able to support multiple users on one frequency channel, as will be discussed later. � Secondly and more importantly, the growing demand for image and video transmission generated by increasing multimedia usage has created the recent need to transmit video data over this and other types of wireless networks. In particular, the following thesis is thus aimed at improving the JPEG image compression algorithm for an 800MHz CDMA Cellular wireless network. In order to increase the efficiency of current image transmission over CDMA networks this thesis proposes jointly designing the source and channel code to generate an enhanced image compression algorithm. In order to accomplish this, we will utilize a Rayleigh Fading Model to simulate the channel over which we will be transmitting and then include this information into the compression algorithm; our goal being to manipulate the image compression algorithm to improve image transmission over a specific channel and medium (i.e. An 800MHz wireless network). Furthermore, given that our expected results are met, we can also review the efficiency (bit compression) of our algorithm for transmission and hence review new possibilities for increased error correction in the transmission of image and video data. In addition, as mentioned before, an ongoing investigation in this area using the ideas presented in this paper applied to the MPEG compression algorithm could lead to an enhanced algorithm for video transmission over the same medium.
- Low Overhead Host-Based IDS(Instituto Tecnológico y de Estudios Superiores de Monterrey, 01/07/2004) Aguilar Rodríguez, Ignacio J.; Max Perera, Jorge Carlos; Rodriguez Morales, José Ramón; Aguilar Coutiño, Artemio; ITESMThe area of Intrusion Detection is very important these days. Companies have acquired more interest in having this type of systems beacuse of the importance that information has for them. Machine learning algorithms are being used along with IDSs as an efficient approach. For these reasons we work with this approach in this thesis, presenting from general to specific, the information of the models and types of IDSs, and some machine learning algorithms and some fusion rules for them, that can help achieving a good IDS. In this work, we focus on Host-based intrusion detection, and three machine learning algorithms, which are C4.5, RIPPER and PART. It is showed a method to reduce false alarm rates and with this, increasing the possibility of detecting true alarms when our system trigger them.
- Performance Improvement of Ad-Hoc Networks with ZRP using Route Maintenance(Instituto Tecnológico y de Estudios Superiores de Monterrey, 01/12/2002) Lemus Amezcua, Alejandro A.; Vargas Rosales, César; Martínez Ramírez, Daniel Sergio; Rodríguez Cruz, José Ramón; ITESMZone Routing Protocol (ZRP) is a hybrid routing protocol for Ad-Hoc networks. This protocol divides the network into overlapping routing zones and runs independent protocols that study within and between these zones. Intra-zone protocol (IARP) operates within a zone and learns all possible routes. So, all nodes inside of a zone know about its zone topology very well. This protocol that will run in an intrazone is not defined, but can be any proactive protocol. Different zones may operate with different protocols. Interzone protocol (IERP) is a reactive protocol which consist of a source node by finding a destination node which is not located inside of the same zone by sending RREQ messages to all border nodes until the destination node is found. The routing zone diameter is variable and this should be chosen optimally for a scaled topology. ZRP is based on two procedures: Intrazone Routing Protocol (IARP) and Interzone Routing Protocol (IERP). Through the use of IARP, each node knows the distance which separates it from other node present in its routing zone. The true protocol IARP is not specified and can be implemented starting from various derivated protocols based on “Distance Vector Protocol� such as AODV, for example. In this research, we evaluate and measure using simulation the different maintenance strategies of a route in Ad-Hoc networks with ZRP by employing the Floyd-Warshall algorithm, with the objective of obtaining a better performance.