Koji Kamakura

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This paper indicates a desired scheduler buffer size which minimizes the overall packet blocking probability of optical burst switching (OBS) networks based on forward resource reservation (FRR). A packet is blocked either if it arrives at the edge buffer that is full or if the control packet (CP) corresponding to the burst including the packet arrives to(More)
In image sensor based VLC, transmitter acquisition and tracking are critical issue. However, the fluctuation of the VLC transmitter in the image plane caused by vehicle movement, complicates correct data reception. Therefore, in this paper, we present results of channel fluctuation measurements for infrastructure-to-vehicle VLC (I2V-VLC),(More)
Visible light communication (VLC) using light-emitting diodes (LEDs) is drawing much attention. There are two types of VLC reception devices, a photodiode and an image sensor. VLC using image sensor is called image sensor based VLC. As the receiver only uses the image sensor pixels that sense LED transmission sources and discards other pixels, including(More)
This paper proposes a modified version of vehicular ad hoc network media access control (VeMAC) protocol for further increased throughput. In the modified VeMAC, an additional bit is appended to the field for each time slot in the header used in VeMAC as the collision flag. Upon detecting a collision for a time slot, a node sets the collision flag for that(More)
The present paper considers an optical spatial channel in visible light communication (VLC) using LED and a highspeed camera. In general, the optical spatial channel affects the communication performance. However, the previous studies have not enough discussed the channel for VLC. This study focuses on the communication distance, which is one of channel(More)