The present invention is to provide a network system for transmitting various signals and power, which comprises at least a power sourcing equipment and at least a powered device over a network. Each of the power sourcing equipment and the powered device has at least a port, wherein a first isolated conductor is disposed at one side of the port while a second isolated conductor is disposed at the other side of the port and creates a power circuit for transmitting power in combination with the first isolated conductor. Four differential signal pairs of the port, each with two conductors, are disposed between the first isolated conductor and the second isolated conductor, wherein each of the power sourcing equipment and the powered device transmits Ethernet signals through two of the differential signal pairs of its port and transmits other network signals through the other two differential signal pairs.