| Wireless equipment based on IEEE 802.11 standard has been increasingly successful during the recent years. The popularity of wireless LAN hardware, and increasing use of different applications has brought challenges and competition among different vendors of IEEE 802.11 standards. Traditionally, such equipment has mainly been used indoors to allow users to wirelessly connect to the Internet or to a LAN.; In this thesis we evaluate wireless equipment of the 802.11b standard. We consider typical scenarios and also consider typical transport protocols (i.e. TCP and UDP) in order to observe the performance of the system in real settings.; Although the performance of a system mainly depends on the following metrics: throughput, packet loss, delay and jitter, in this thesis we take into consideration a large number of metrics of performance in order to obtain a better understanding of the way diverse factors impact performance in real wireless LANs. Indeed, we perform a large set of tests and measurements with different hardware. This let us obtain a more complete view of the performance of the system. Such parameters are important in real networks since its interrelation affect the quality of service perceived by various services carried by the network.; We observe that real throughput of WLANs is sensibly lower than the raw amount usually advertised by the manufacturers. From the obtained results we conclude that in addition to the lack of efficiency of the MAC layer, this situation is also due to the combination of other factors that are detailed in the thesis. We found that one of the most important factor affecting the performance is a corner in the signal path between the sender and the receiver, which significantly affects the performance. We also describe some different hardware and software tools that are useful to carry out the tasks required for a performance study in a wireless LAN. |
