An available-spectrum information providing system for mobile terminals

Nowadays a sharing of the UHF bandwidth used as terrestrial broadcasting by cognitive radio, is discussed. For sharing of the UHF bandwidth, cognitive radio terminals have to understand the surrounding radio environment. Then, the database technologies that collect the radio environment information from various sensing equipments are proposed. Nevertheless, their technologies have a drawback that the data-volume of database is enlargement. Accordingly, a generating and providing method of the minimum radio environment information for the terminals is effective. In this paper, we propose an available-spectrum information providing system for mobile terminals. The proposed system generates the Broadcasting Receiving List (BRL) for every area of the cell phone base stations using spectrum sensing results and base station ID in a database. In case that the terminals use TV white space, they carry out the spectrum sensing except the channels that described to the BRL, and use the clear channels. Therefore, this system can control to use the broadcast-wave in the cell, and keep the safety for broadcasting reception. Moreover, in this system, the terminals reduce the number of times of server-access using their time interval of the base station ID registration.