Nec Communication Systems, Ltd.

Advanced Telecommunications Research Institute International

Toshiyasu Tanaka

Tetsuya Ito

Hiroyuki Iizuka

Masahito Iwai

Koichi Yoshimura

Yoshihisa Kondo

Sadao Obana

Hiroyuki Yomo

Stefan Aust

Suhua Tang

A wireless communication deviceoperates in either a ROD mode or a non-ROD mode. The non-ROD mode sets the state of the device to an active state that the device can perform wireless communication compliant with a first communication scheme with a communication destination device. The ROD mode: sets the state of the device to either the active state or a sleep state that the device can receive an activation instruction signal compliant with a second communication scheme requiring smaller electric power to receive a signal than the first communication scheme and cannot perform wireless communication compliant with the first communication scheme with the communication destination device; sets the state of the device to the sleep state when a predetermined sleep condition is satisfied; and sets the state of the device to the active state when the device receives the activation instruction signal.

Wireless communication device

A packet interval (a time difference between sequentially received packets) in a certain previous time is calculated and a cumulative distribution function of the calculated packet interval is obtained. Meanwhile, a function value-corresponding to-flow end that is a boundary value of the cumulative distribution function to be considered as a flow end (timeout) in the range of a cumulative distribution function value is stored. From the cumulative distribution function obtained as described above, a value of a packet interval mapped to a cumulative distribution function value that matches the function value-corresponding to-flow end is set as a threshold. That is, the threshold is dynamically set based on a previous packet interval. Therefore, a packet stop period from a last packet reception time to a current time is measured, and it is detected as a flow timeout at a timing when the measured value is equal to or greater than the threshold.

Communication apparatus, communication state detecting method, and communication state detecting program

A terminal devicetransmits a wireless frame having a frame length or amplitude that represents the ID of a wireless base stationto be woken up to the wireless base station. The wireless base stationdetects the wakeup ID from the frame length or amplitude of the wireless frame from the terminal device, and, if the detected wakeup ID is identical with its own ID, transitions from a sleep mode to an operating mode. In this case, the wireless frame is the same wireless frame as that transmitted and received by the wireless communication module of the terminal deviceto and from the wireless base station

Terminal device, wireless base station wirelessly communicating with the same, and wireless communication system using terminal device and wireless base station

Growing community of inventors

Tokyo, Japan

Toshiyasu Tanaka