Abstract: A long-distance PoE power sourcing equipment includes a PoE local power supply, a PoE remote switch, and a link cable linked therebetween. The PoE local power supply serves as a conversion medium between a network signal and a first transmission signal and sources a first DC power to the PoE remote switch through the link cable. The PoE remote switch serves as a conversion medium between the first transmission signal and a second transmission signal and converts the first DC power into a second DC power supplied to a PoE power device through an Ethernet cable. The power transmission implemented by the PoE local power supply and the link cable allows the data and power transmission distance of the PoE system to exceed the distance limitation of the Ethernet specification.

Abstract: In a signal converter and a multimedia system using the same, the multimedia system includes an image capture device, a first signal converter, a second signal converter. The image capture device is configured for capturing images, converting the images into a first electronic signal, and transmitting the first electronic signal through a first type transmission interface. The first signal converter is configured for receiving the first electronic signal, modulating the first electronic signal by the orthogonal frequency-division multiplexing (OFDM) technology to obtain a second electronic signal suited for a second type transmission interface. The second signal converter is configured for receiving and modulating the second electronic signal through the second type transmission interface. The first type transmission interface is different from the second type transmission interface.