Abstract: A packet transfer device including a PoE port includes a power supply unit that controls power supply to the PoE port and measures a power supply amount, a packet switching unit that transfers a packet via the PoE port and another port of the packet transfer device and measures a communication volume of the PoE port, a profile holding unit that holds a profile indicating a normal operation region of a device connected to the PoE port using a map of a correlation of the power supply amount and the communication volume, a correlation analyzing unit that determines whether or not the device is abnormal on the basis of the power supply amount measured by the power supply unit, the communication volume measured by the packet switching unit, and the profile held in the profile holding unit, and a CPU unit that controls the respective units of the packet transfer.

Abstract: It is intended to reduce a power consumption without degrading a communication quality of a packet transfer device. One or more of a receiver, a switch unit, and a transmitter include a QoS control circuit for applying QoS control to received packets. There is provided a power saving operation mode that enables power saving operation by changing a grain size of the QoS control according to a flow rate of the packets, and controlling whether or not to supply an electric power to the QoS control circuit or a part of the QoS control circuit, according to the flow rate of the packets.

Abstract: A transmitter communicates with a receiver and an error corrector corrects bit errors generated during data transmission. The transmitter has a scrambler unit that scrambles data so that a running disparity of 0 and 1 in the input data is substantially zero. A bit-string converting unit 15 that adds bit data for ensuring a maximum run length of a serial bit string of the scrambled data and converts control information to bit data of a fixed value. A synchronization timing generating unit 16 divides the transmitted data by a constant interval and converts the transmission data to a data block. A bit-string converting unit extracts a fixed-value bit pattern of the control data from the bit string of the data block, converts the bit pattern to the control information, and discriminates the data and the control information. A descrambler unit reconverts the data-scrambled data to the data before scrambling.

Abstract: It is intended to reduce a power consumption without degrading a communication quality of a packet transfer device. One or more of a receiver, a switch unit, and a transmitter include a QoS control circuit for applying QoS control to received packets. There is provided a power saving operation mode that enables power saving operation by changing a grain size of the QoS control according to a flow rate of the packets, and controlling whether or not to supply an electric power to the QoS control circuit or a part of the QoS control circuit, according to the flow rate of the packets.

Abstract: A transmitter communicates with a receiver and an error corrector corrects bit errors generated during data transmission. The transmitter has a scrambler unit that scrambles data so that a running disparity of 0 and 1 in the input data is substantially zero. A bit-string converting unit 15 that adds bit data for ensuring a maximum run length of a serial bit string of the scrambled data and converts control information to bit data of a fixed value. A synchronization timing generating unit 16 divides the transmitted data by a constant interval and converts the transmission data to a data block. A bit-string converting unit extracts a fixed-value bit pattern of the control data from the bit string of the data block, converts the bit pattern to the control information, and discriminates the data and the control information. A descrambler unit reconverts the data-scrambled data to the data before scrambling.

Abstract: The objective of the present invention is to improve transmission characteristics by transmitting data through multiple paths in a multihop radio network including multiple paths. In a source node 210 of (a), an encoder 212 performs communication path encoding, and a modulator 216 modulates. Unlike the prior art, however, a packetizing unit 214 designates relay paths and packetizes outputs from the encoder 212 for the respective paths, whereby signals are transmitted to multiple paths (in this case, two paths). A receiver (See (c)) of a destination node 260 demodulates the signals from the multiple paths using a demodulator 262. Thereafter, it depacketizes the packet of binary data hard-decided by a depacketizing/buffering unit 263 and then temporarily stores the depacketized pieces of data for respective paths in a buffer. A reliability data calculator 265 then diversity-combines, taking reliability data into account. A combiner/decoder 267 performs an error correction based on that combined data.