IEEE 802.11a/b/g/n Indoor Coverage and Performance Comparison Sandra Sendra 1 ,Pablo Fernandez 2 , Carlos Turro 3 , Jaime Lloret 4 Universidad Politécnica de Valencia Camino Vera s/n, 46022, Valencia, Spain 1 asansenco@posgrado.upv.es, 2 pabferm1@epsg.upv.es, 3 turro@dcom.upv.es, 4 jlloret@dcom.upv.es Abstract—Because of the appearance of a great variety of IEEE 802.11 variants, there is a wide range of possibilities. Despite of they use to be chosen based on the bandwidth that they are able to provide and the distance area that they are able to cover, sometimes, there are special cases that the best technology is not the newest one. E.g. when we have devices that are going to transmit a maximum of 1 Mbps, but it is needed the highest signal strength, all of them could be the best choice. In this paper, we are going to compare IEEE 802.11a/b/g/n in indoor environments in order to know which technology fits best our purposes. This comparison will be taken in terms of signal strength inside the coverage area and measuring the interferences between neighboring channels. This study will help the researchers to choose the best technology depending of their deploying case. Keywords-WLAN, IEEE 802.11, Coverage, Interferences, Performance I. INTRODUCTION One of the major issues in WLAN indoor environments is the multipath dispersion due to the influence of many signal reflectors and diffusions. Walls, floors and roofs attenuate the signal highly and provoke great variations in the mean received power. Even the furniture and the metallic structures of the walls and roofs have high impact because they enhance the scattering and diffraction. There has been many studies about the signal propagation in indoors [1][2]. Moreover it has been a big deal when designing WLANs in indoor environments [3]. Because the emitter and the receiver are close, the delay between echoes will enlarge the delay spread. But, temporal variations are slower because of the low mobility of the users. Temporal variations are mainly given by the presence of humans close to the antennas. Moreover, there are other features in indoor environments such as: • Electromagnetic fields provided by electronic devices. Although the reflection and diffraction can be modeled, there are many things inside the building that introduce a certain grade of variability [2]. • Usually people walking in any corridor or facility close to the emitter or the receiver will cause significant variations [4]. • Because the distances are short, any variation of the direction of the antenna will imply high changes in the signal received. • Metallic objects reflect the radio signal. The signal will not cross metallic walls and metallic objects will fade. • Wood, crystal, plastic and bricks reflect part of the signal, but let pass the rest. • The objects with high humidity have more signal absorption. There are several indoor propagation models. They can be classified in empirical models (which are based on the measures taken and predict the signal loss), in deterministic models (that simulate the signal propagation in order to characterize the transmission channel), theoretical models, (which are based in the physical laws of the modeled medium) and stochastic models (they are modes which results have a probability distribution) [5]. The appropriate model must be chosen based in the design necessities. Empirical models are used in network design, while deterministic models are used for high precision applications. The first ones are less complex and need lower input parameters, but they do not predict instantaneous signal fainting [6]. The most well known models are the following ones: • Log-Normal Shadowing Path Loss Model [7] • Loss Model based in COST 231 [8] • Linear Path Attenuation Model [9] • Keenan-Motley Model [10] • ITU-R Model [11] • Dual Slope-Model [12] • Multi-Wall Model [13] Several authors have studied empirically each one of them providing their drawbacks and benefits. But, when we are setting up a WLAN, it is not practical to model all wireless coverage area for each site where the access point is going to be placed, especially when we are talking about large extension areas [14]. Moreover different 802.11 variants (a, b, g and n) provide different coverage areas and even, different signal strength inside the coverage area. In this paper, we are going to show the empirical coverage area, and the signal strength inside the coverage area, in order to know which is the technology that provides better coverage features. Moreover, we are going to compare the interferences between channels for each technology in order to know the number of available channels that can be used to plan the wireless network. The remainder of this paper is organized as follows. Section II shows the related work on WLAN coverage designs. The test bench where our measurements have been performed is shown in Section III. Section IV, the measurements performed and the graphs obtained for each technology. The measurements obtained about the