Impact of channel access on localization in cooperative UWB sensor network: A case study

Cooperation in wireless communication networks is nowadays commonly used in order to provide either deeper coverage on those areas where radio signal is usually weak, such as inside complex structures and buildings, or to improve the power efficiency of the whole system. In these networks, client devices act as active parts of the signal transmission: by repeating the signal coming from a device to another they make possible to reach remote locations where the main transmitter signal is too weak or not available. Inspired by this ideas, cooperation in Wireless Sensor Networks (WSNs) is used to achieve better accuracy and to make the localization process possible even if there are not enough anchor nodes available. However, this system has to cope with both synchronization and channel access issues, so some considerations must be taken into account. With this work we want to show a preliminary analysis of these issues, focusing on the channel access problem, when multiple radios must share the medium in order to exchange either ranges and data information about their location, and showing the results we obtained on a real WSN implementation using UWB hardware.