Loading...
6 results
Search Results
Now showing 1 - 6 of 6
- Unified propagation model for Wi-Fi, UMTS and WiMAX planning in mixed scenariosPublication . Varela, Frederico; Sebastião, Pedro; Correia, Americo; Cercas, Francisco; Rodrigues, António; Velez, Fernando J.; Robalo, DanielThis paper presents an unified and empirical propagation model to obtain the received power in mixed scenarios, with outdoor and indoor environments, or in a scenario with only one kind of environment, either for an urban, sub-urban or rural scenario, with or without vegetation. This unified model is called the Lisbon University Institute (LUI) one and can be included into planning tools for wireless communication systems. The developed model is suitable for Path Loss prediction in mobile, as well as fixed wireless network systems, e.g., Wireless Fidelity, Universal Mobile Telecommunications System and Worldwide Interoperability for Microwave Access, considering Line-of-Sight or Non-Line-of-Sight propagation conditions.
- Validation of the unified propagation model for Wi-Fi, UMTS and WiMAX planningPublication . Varela, Frederico; Sebastião, Pedro; Correia, Americo; Cercas, Francisco; Rodrigues, Antonio; Velez, Fernando J.; Robalo, DanielThis paper presents the validation of the unified propagation model, the Lisbon University Institute (LUI) model, which is valid for three wireless technologies: Wireless Fidelity, Universal Mobile Telecommunications System and Worldwide Interoperability for Microwave Access. With this purpose in mind, several experimental trials for those technologies were performed in different scenarios, where mixed environments (outdoor and indoor) were included. This generalized and unified propagation model was tuned by adjusting specific parameters for each different technology, based on the achieved results from the field experiments.
- WLAN planning tool: a techno-economic perspectivePublication . Sebastião, Pedro; Tomé, Ricardo; Velez, Fernando J.; Grilo, António; Cercas, Francisco; Robalo, Daniel; Rodrigues, António; Varela, Frederico F.A simple wireless local area network (WLAN) planning tool was developed to optimize the position and number of access points (APs), as well as the total cost of the required equipment, according to different WLAN suppliers, in indoor and outdoor environments. This planning tool can be distinguished in two mains scopes: technical (defining the number and position of APs) and economic (generating a budget according to all planned equipment and its suppliers). The proposed planning tool enables manual and automatic planning modes. It only needs some inputs, like the digital format of the floor plan, the obstacle types and their positions, the areas to be covered, the user’s most probable position and the applications used by them. The propagation model used in this tool was validated using experimental results for some scenarios. In the manual mode, the APs positions are defined by the network designer. The output of the tool is the received power or the throughput, depending on the chosen option. However, in the automatic mode the tool defines the AP position and minimizes the total amount of APs in a given area. For the implementation of the latter mode, two hot spots position planning algorithms were developed and implemented; they depend on the values of the received power or throughput, while guaranteeing the total coverage or service supply for all users, respectively. This tool also provides an estimation of the budget for the required implementation, and can avoid several days of tedious site-survey work. Except for the lowest distances, experimental values for the received power generally agree with the DP model for the range of distances considered, from the terminal station to the AP, both for outdoor and indoor environments. The differences near the AP are due to different antenna radiation patterns between the tool (omnidirectional isotropic) and the experimental setup (dipole antenna). In the indoor paths, the slight differences between the results of two floors may be due to the interaction of the direct ray with the floor direction itself.
- User capacity based planning tool for Wi-Fi and WiMAX networksPublication . Sebastião, Pedro; Velez, Fernando; Tomé, Ricardo; Costa, Rui; Robalo, Daniel; Grilo, António; Rodrigues, António; Cercas, FranciscoA simple wireless planning tool (WPT) is proposed, which facilitates the design and implementation of wireless fidelity (Wi-Fi), and worldwide microwave access (WiMAX) networks in indoor and outdoor environments. The tool gives to professional planners practical and useful information through quick procedures as the output is the number and position of the access points (APs), or an estimation of the total cost of implementation, based on data provided by different equipment manufacturers. It uses innovative algorithms for computing the best position of each AP. Carrier-to-noise and carrier-tointerference issues are discussed in detail, and a practical deployment of a single WiMAX cell in Covilhã is presented. There is a need of using sectorial antennas to guarantee an adequate coverage and interference mitigation.
- Generalized LUI Propagation Model for UAVs Communications Using Terrestrial Cellular NetworksPublication . Tavares, Tiago; Sebastião, Pedro; Souto, N.; Velez, Fernando J.; Cercas, Francisco; Ribeiro, Marco; Correia, AmericoThis work proposes an empirical propagation model to obtain the path loss, and therefore determine the average received power, of a signal for a specific outdoor urban scenario with UAVs. The proposed 3D propagation model for terrestrial cellular networks generalizes the LUI model and is valid in the frequency ranges from GSM, UMTS and LTE technologies. We report experimental work in 3D space, considering the height, the antennas base station tilt, sectorization, angle and distances profile. The experimental work included in this study appropriately agrees with the proposed theoretical model; hence, the proposed model is adequate for cellular planning tools.
- A WLAN planning tool with a practical approachPublication . Tomé, Ricardo; Lourenço, Pedro; Grilo, António; Cercas, Francisco; Rodrigues, António; Velez, Fernando José; Sebastião, PedroThis paper presents a new planning tool that facilitates the design and implementation of a WLAN (wireless local area network) which not only provides an accurate solution, but it also gives practical and useful information for the professional planner towards a quick implementation, such as the number and position of the access points (AP) or an estimation of the total cost of implementation based on data provided by different equipment manufacturers. The novelty of this tool is a new algorithm for calculating the best position of each AP was used, which is based on the user’s applications and their most probable positions. This tool is user friendly and it interactively helps WLAN designers to properly define all the necessary equipment so as to provide a given coverage, i.e. with a given quality of service, for a given floor plant without to make a site survey in the places where this networks will be implemented.