Nippon Telegraph and Telephone Corporation

Hiroko Nomura

Naotaka Shibata

Keita Takahashi

Tomoya Hatano

Tatsuya Shimada

Daisuke Hisano

Hiroyuki Uzawa

Hiroshi Ou

Jun Terada

A bandwidth allocation device is included in a communication system having a terminal station device and a terminal device and relaying upstream data, which is received from a communication terminal by a lower device connected to the terminal device, to an upper device connected to the terminal station device. The bandwidth allocation device includes a transmission-permitted period start position determining unit configured to estimate a start position of an arrival period in which the upstream data arrives at the terminal device from the lower device; a transmission-permitted period length determining unit configured to estimate a length of the arrival period based on an amount of upstream data to be transmitted from the lower device to the terminal device; and a bandwidth allocation unit configured to allocate a bandwidth to the terminal device based on the estimated start position and the estimated length of the arrival period.

Bandwidth allocation device and bandwidth allocation method

Provided is a multiplex transmission system capable of preventing occurrence of a mistake on connection of a client device to a multiplex transmission device. The multiplex transmission system includes: an extraction means configured to extract identification information from a signal inputted to a client port of each of a first multiplex transmission deviceand a second multiplex transmission device; and a switch control unitconfigured to control a switch unitto connect the client port of the first multiplex transmission devicewith the client port of the second multiplex transmission deviceon the basis of a result of collation between identification information extracted from a signal inputted to the client port of the first multiplex transmission deviceand identification information extracted from a signal inputted to the client port of the second multiplex transmission device

Multiplex transmission system and connection method between ports for multiplex transmission system

Provided is a multiplex transmission system capable of preventing occurrence of a mistake on connection of a client device to a multiplex transmission device. The multiplex transmission system includes: a detection means configured to detect new client connection that is new connection of a client device to a client port of each of a first multiplex transmission deviceand a second multiplex transmission device; and a switch control unitconfigured to control a switch unitto connect a client port where new client connection is detected at a first time point in the first multiplex transmission devicewith a client port where new client connection is detected at a second time point in the second multiplex transmission device, when a time interval between the first time point at which new client connection is detected in the first multiplex transmission deviceand the second time point at which new client connection is detected in the second multiplex transmission deviceis within a preset reference time, in a case where new client connection is detected in both the first multiplex transmission deviceand the second multiplex transmission device

One aspect of the present invention is a communication system for a passive optical network that includes: an OLT system including a first OLT (Optical Line Terminal), a second OLT, and an OLT control apparatus that controls the first OLT and the second OLT; a plurality of splitters that are connected between the first OLT and the second OLT using optical communication channels; and ONU systems that are connected to the respective splitters using optical communication channels, and each include a first session establishing unit that establishes a session with the first OLT, a second session establishing unit that establishes a session with the second OLT, and a signal processing unit that executes signal processing of an ONU (Optical Network Unit) based on an optical signal output from the first session establishing unit or the second session establishing unit.

Communication system and ONU system

A communication system of a passive optical communication network includes an optical line terminal (OLT) system including a first OLT, a second OLT, and an OLT control device that controls the first OLT and the second OLT, a plurality of splitters that connects between the first OLT and the second OLT with an optical communication path, and an optical network unit (ONU) that is connected to each of the plurality of splitters with an optical communication path.

Communication system and OLT system

A communication system of a passive optical communication network includes an optical line terminal (OLT) system including a first OLT, a second OLT, and an OLT control device that controls the first OLT and the second OLT, a plurality of splitters that connect the first OLT and the second OLT with an optical communication path, and an ONU that is connected to each of the splitters with an optical communication path. The splitter distributes and outputs an optical signal transmitted from the OLT system to the ONU connected to the splitter and a succeeding device that is another splitter or the OLT system, and the OLT control device determines a distribution ratio at the splitter, the distribution ratio indicating a ratio between the intensity of the optical signal distributed to the succeeding device and the intensity of the optical signal distributed to the ONU.

In a signal transfer system including a signal transfer management apparatus and a plurality of signal transfer apparatuses connected in multiple stages and forming a network between a distribution station apparatus and a central station apparatus, a signal transfer apparatus on an upper side among the plurality of signal transfer apparatuses transmits a timing adjustment request to at least one of a plurality of signal transfer apparatuses on a lower side among the plurality of signal transfer apparatuses upon determining that there is a possibility that a microburst occurs according to mobile scheduling information received from the plurality of signal transfer apparatuses on the lower side, and the signal transfer apparatus on the lower side that has received the timing adjustment request from the signal transfer apparatus on the upper side adjusts opening and closing timings of a gate based on the timing adjustment request. This can prevent the occurrence of a microburst.

Signal transfer system, signal transfer device, signal transfer method and signal transfer program

An optical transmission system includes ground stations; optical-terminating devices; a traffic-monitoring unit that detects a traffic amount of the uplink signal transmitted in a time-division multiplexing manner for each of the optical-terminating devices; and a bandwidth allocation calculation unit that estimates one optical-terminating device of the optical-terminating devices connected to one ground station of the ground stations having a cell where the moving object is positioned on the basis of the traffic amount, and calculates a first allocation amount of a bandwidth allocated to the uplink signal of the one optical-terminating device connected to the one ground station having the cell where the moving object is positioned and a second allocation amount of a bandwidth allocated to the uplink signal of another optical-terminating device of the optical-terminating devices connected to another ground station of the ground stations having a cell adjacent to the cell where the moving object is positioned.

Optical transmission system and bandwidth allocation method

An optical transmission system of an embodiment connects a plurality of wireless communication systems to each other, and includes a wavelength allocation unit that allocates different wavelengths to optical-terminating devices to which the wireless communication systems next to each other are connected, on the basis of the physical arrangement of each of the plurality of wireless communication system.

Growing community of inventors

Yokosuka, Japan

Hiroko Nomura