Abstract: A sound producing apparatus with multi-directivity has two or more speakers to produce music or other types of audio sounds. Each of the speakers can produce audio sounds in a certain direction and at least one speaker is steerable so that its sound propagation direction relative to the others can be changed. Furthermore, one or more speakers can produce audio sounds in an adjustable angular range. One or more of the speakers can be dual-mode speakers, each of which can be operated as a wide-angle speaker or a narrow-angle speaker. With multi-directivity, it is possible to play one type of music in one direction and another type of music in another direction to suit the interests of the audience. The apparatus can be a mobile phone, an audio player, a digital or analog recorder/player, or the like.

Abstract: This invention relates to a method for controlling location distribution of sensing nodes, selection of sensing nodes, control of sensing implementation and process of performing spectrum sensing in cognitive radio networks of open wireless architecture (OWA) systems. Specifically, the invention relates to an efficient and reliable method minimizing time overhead consumed during spectrum sensing with open wireless architecture (OWA).

Abstract: This invention relates to an open wireless architecture (OWA) radio frequency (RF) transceiver architecture including RF front-end system. Specifically, the invention relates to an OWA RF front-end utilizing non-broadband RF hardware to support wide range frequency bands and broad transmission bandwidth for future wireless communications.

Abstract: This invention relates to an open wireless architecture (OWA) radio frequency (RF) transceiver architecture including RF front-end system. Specifically, the invention relates to an OWA RF front-end utilizing non-broadband RF hardware to support wide range frequency bands and broad transmission bandwidth for future wireless communications.

Abstract: This invention relates to a method for controlling location distribution of sensing nodes, selection of sensing nodes, control of sensing implementation and process of performing spectrum sensing in cognitive radio networks of open wireless architecture (OWA) systems. Specifically, the invention relates to an efficient and reliable method minimizing time overhead consumed during spectrum sensing with open wireless architecture (OWA).

Abstract: A sound producing apparatus with multi-directivity has two or more speakers to produce music or other types of audio sounds. Each of the speakers can produce audio sounds in a certain direction and at least one speaker is steerable so that its sound propagation direction relative to the others can be changed. Furthermore, one or more speakers can produce audio sounds in an adjustable angular range. One or more of the speakers can be dual-mode speakers, each of which can be operated as a wide-angle speaker or a narrow-angle speaker. With multi-directivity, it is possible to play one type of music in one direction and another type of music in another direction to suit the interests of the audience. The apparatus can be a mobile phone, an audio player, a digital or analog recorder/player, or the like.