Abstract: A system for performing a local wireless communication using a predetermined frequency band divided into a plurality of channels. The system includes a hub for scanning each channel to identify available one of the plurality of channels and transmitting data over the available channel. The system further includes a sensor set to start to operate when the sensor detects a signal within the predetermined frequency band. The sensor spectrum-senses the signal of the frequency band for each channel, and analyzes a header of packet data for each channel, and receives and processes the packet data if the signal is identified to have a designated code.

Abstract: An apparatus for performing a local wireless communication using a frequency band. At least a part of the frequency band is divided into a plurality of channels. The apparatus includes a plurality of sensors, each sensor scanning each channel to identify whether each channel is used or not, selecting an unused channel as a data transmission channel, and transmitting data through the unused data transmission channel. The apparatus further includes at least one hub receiving and processing the data transmitted from each sensor through each corresponding data transmission channel.

Abstract: A system for performing a local wireless communication using a predetermined frequency band divided into a plurality of channels. The system includes a hub for scanning each channel to identify available one of the plurality of channels and transmitting data over the available channel. The system further includes a sensor set to start to operate when the sensor detects a signal within the predetermined frequency band. The sensor spectrum-senses the signal of the frequency band for each channel, and analyzes a header of packet data for each channel, and receives and processes the packet data if the signal is identified to have a designated code.

Abstract: An antenna is located at the end of a wireless communication system, or other radio system, and more particularly, a wideband planar antenna with linear and circular polarization uses different polarization for transmission or reception to increase the isolation between the transmission and reception by suggestion and using a type of radiation element. The disclosed antenna is more efficient than other similar antennas that can transmit/receive linear or circular polarization. The disclosed invention makes it possible to pr vide an antenna having dual polarization, which has an orthogonal characteristic in both linear and circular polarization, and which can lower the height of the antenna by embodying a micro strip planar antenna which has linear and circular polarization that has high gain over a wide frequency band, and which transmits/receives linear or circular polarization.

Abstract: Provided is an antenna that is located at the end of a wireless communication system, or other radio system, and more particularly, a wideband planar antenna with linear and circular polarization that uses different polarization for transmission or reception to increase the isolation between the transmission and reception by suggesting and using a type of a radiation element. The antenna suggested in this paper is more efficient than other similar antennas that can transmit/receive linear or circular polarization. The solution suggested in the paper makes it possible to provide an antenna having dual polarization, which has an orthogonal characteristic in both linear and circular polarization, and can lower the height of the antenna by embodying a micro strip planar antenna having linear and circular polarization that has high gain over a wide frequency band and transmits/receives linear or circular polarization.