Sharp Kabushiki Kaisha Corporation

Shohei Ohsawa

Koji Sakai

Hitoshi Naoe

Fumihiro Fukae

In a transmitter (), when generating a transmission frame having no limitation to a window size, a batch-transmission-end flag generating circuit () and a sequence number generating circuit () respectively adds a batch-transmission-end flag and a sequence number to the transmission frame. In a receiver, if an omission of a sequence number is detected as a result of analyzing sequence numbers of frames having received from the transmitter (), retransmission request is made when receiving a frame whose batch-transmission-end flag indicates the end. In this way, retransmission is possible in data transmission using UI frames, and the communication efficiency can be improved.

Communication device, non-transitory computer-readable medium storing a communication program

The present invention is a network layer protocol used for free-space optical transmission utilizing an LED or LD as a light source. In order to connect to a device, the network layer issues a connection request command (LAP_con_req) to a lower layer when the network layer has received a connection request command (LM_con_req) from an upper layer. Furthermore, when the network layer has received a connection confirmation command reception notification (LAP_con_conf) from the lower layer, the network layer issues a connection confirmation command reception notification (LM_con_conf) to the upper layer without issuing a data transfer request command to the lower layer. Accordingly, the invention provides a network layer protocol with which time for a connection or disconnection is reduced.

Communication device, communication system, communication method, communication program, and communication circuit

Provided is a communication system including a transmitter and a receiver which carry out communication by establishing connection of their plurality of communication layers. The transmitter generates a connection request containing a command and data required for connecting a number of contiguously adjacent layers among the plurality of communication layers and transmits the connection request to the receiver. The receiver receives a connection request containing a command and data required for connecting a number of contiguously adjacent layers among the plurality of communication layers, extracts the command and data from the connection request, and establishes connection for the plurality of communication layers based on the command and data. In this way, the time taken to establish connection is reduced. Therefore, even when the connection is cut off during the data exchange, the connection can be established again without taking much time, allowing quick recovery of data exchange.

Transmitter, receiver, communication system, communication method, non-transitory computer readable medium

The demodulation circuit of the present invention is a demodulation circuit, connected with a plurality of light-receiving sections each for receiving an optical signal and converting the signal into a binary pulse signal, operable to select and demodulate a pulse signal out of pulse signals that are supplied from the light-receiving sections, respectively, the demodulation circuit including: a judgment and selection section for detecting timing with which High level and Low level of each of the pulse signals are switched and for selecting at least one pulse signal based on the timing; and a demodulation section for demodulating the pulse signal selected by the judgment and selection section. Consequently, the demodulation circuit easily selects and demodulates a signal whose jitter component is small out of a plurality of supplied signals.

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Tenri, Japan

Shohei Ohsawa