Oki Electric Industry Co., Ltd.

Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Nippon Sheet Glass Company, Limited

Avanstrate Inc.

Fujikura Limited

Of Networks Co., Ltd.

Satoshi Furusawa

Masaru Fuse

Tsuyoshi Ikushima

Tomokazu Sada

Susumu Morikura

Akiya Suzuki

Tomoaki Ohira

Kuniaki Utsumi

Masahiro Sarashina

Tatsuya Noguchi

Akihiro Takahashi

Kazuyuki Horioka

Jun Hirano

Akihiro Koyama

Yukihito Nagashima

Hideaki Tamai

Toru Shiozaki

Haruki Niida

Kazunori Numata

Hideki Ohashi

Haruki Uchida

Keisuke Kinoshita

Hideaki Takechi

Hideki Ohhashi

Tomihisa Saito

Takashi Muromachi

Toshiaki Mukojima

Masanobu Kimura

Yasuyuki Kuroda

Shozo Yamada

A station-side terminal apparatus comprises terminal devices and a terminal device sorting unit. The terminal devices includes: a buffer unit; a subscriber-side terminal apparatus sorting unit configured to transmit a unicast packet addressed to a switch-target subscriber-side terminal apparatus to the switch queues, and transmit a packet addressed to a plurality of subscriber-side terminal apparatuses to the broadcast queue, and transmit a unicast packet addressed to a non-switch-target subscriber-side terminal apparatus to the through queue; and a scheduler unit configured to read a packet from the switch queues, the broadcast queue, and the through queue. The terminal device sorting unit is configured to transmit a received unicast packet to the terminal device, and transmit a received packet addressed to a plurality of subscriber-side terminal apparatuses, to each of the terminal devices.

Station-side terminal apparatus, and path switching method

The station side terminal device of the present disclosure includes: plural terminal devices, each including a buffer section including a through queue and one or more switch queues that temporarily stores packets, and a subscriber side terminal device assignment section that causes unicast packets addressed to switching target subscriber side terminal devices and packets for switching targets that are addressed to all of the subscriber side terminal devices to be stored in a switch queue, and causes unicast packets addressed to non-switching target subscriber side terminal devices and packets for non-switching targets addressed to all of the subscriber side terminal devices to be stored in the through queue; and a terminal device assignment section that transmits obtained unicast packets and obtained packets addressed to all of the subscriber side terminal devices to the terminal device designated by the packets.

Station side terminal device, subscriber side terminal device, optical communication system, route switching method, non-transitory computer readable medium storing route switching program, and wavelength switching method

The station-side terminal apparatus for the optical access network includes: the station-side terminal apparatus; the subscriber-side terminal apparatuses connected to the station-side terminal apparatus via the optical transmission line; the terminal devices to which mutually different wavelengths are assigned; and the communication failure detecting unit. Each of the terminal devices includes the uplink communication state monitoring unit configured to monitor a state of uplink communication for each registered subscriber-side terminal apparatus, on the basis of the input uplink signal, and the downlink communication failure information extracting unit configured to extract information of a state of downlink communication, which is transmitted from the registered subscriber-side terminal apparatus. The communication failure detecting unit detects a failure of the uplink communication and a failure of the downlink communication, on the basis of the state of the uplink communication and the state of the downlink communication.

Station-side terminal apparatus, optical access network, and communication method

A central-office termination apparatus includes plural termination devices and a termination device distributor. Each termination device includes a buffer, a subscriber-terminal terminator distributor and a scheduler. The buffer has a through queue and one or more switching queues. The subscriber-terminal terminator distributor transfers a packet meant for one subscriber-terminal terminator under switching to the switching queue, and transfers another packet meant for another subscriber-terminal terminator not under switching to the through queue. The scheduler reads out packets from the switching and through queues. The termination device distributor transfers a received packet to a termination device having the subscriber-terminal terminator registered for which that packet is meant.

Central-office termination apparatus of adaptively changing connection to subscriber-terminal terminator and path switching method

A bandwidth allocator for communicating with communication terminals by transmitting and receiving data packets over a line having its communication bandwidth divided into periods of time of a predetermined length. The allocator includes a controller controlling allocation of the bandwidth by using allocation grants as the periods of time. The controller includes a scheduler scheduling the allocation grants so as to cause one allocation grant to partially overlap as a shared grant with another allocation grant adjacent to the one allocation grant. Thus, the bandwidth allocator can minimize allocation loss, otherwise caused by no allocation to an allocation grant, and improve the use efficiency of the bandwidth.

Bandwidth allocator using a shared grant to schedule allocation grants and a method therefor

In an optical communication system that communicates between an optical line terminal (OLT) and a plurality of optical network units (ONU), an ONU can decide an operation time period of communicating with the OLT and an idle time period of reduced or suspended communication with the OLT by using a timer. The OLT can decide a software renewal time period based on the operation time period and the idle time period. Accordingly, the ONU can supply electrical power to its own communication circuit during the operation time period or the software renewal time period, or cut off or reduce the electrical power if a present time does not occur in either the operation time period or the software renewal time period.

Power supply control method, an optical network unit, an optical line terminal and a communication system

In an optical line terminal connectable to optical network units in an optical communication network, an receiver converts an upstream optical signal, received from an optical network unit, into a corresponding upstream electric signal and then derives an upstream control signal controlling the optical line terminal from the upstream electric signal. A controller generates a power control signal switching on or off power supply to the receiver on the basis of the upstream control signal, and a power feeder switches on or off the power supply to the receiver in response to the power control signal. Thus, the optical line terminal can reduce the waste of standby electricity.

Optical line terminal for optoelectrically converting a signal and a method therefor

The present invention provides a station-side terminal device including a control signals reading/generating section that receives a requested bandwidth which the subscriber-side terminal devices require for the communication, from each of the subscriber-side terminal devices, and an uplink band allocating section including a first calculation section that allocates a usable communication bandwidth to each of the subscriber-side terminal devices based on a ratio of a service level parameter predetermined for each of the subscriber-side terminal devices, and a second calculation section that obtains an updated usable communication bandwidth updated by subtracting a sum of the allocated bandwidths from the usable communication bandwidth, and obtains an updated requested bandwidth updated by subtracting the allocated bandwidth from the requested bandwidth, to allocate the updated usable communication bandwidth to each of the subscriber-side terminal devices based on a ratio of the updated requested bandwidth.

Dynamic communication bandwidth allocation method, computer-readable medium storing dynamic communication bandwidth allocation program, semiconductor chip, and PON system

Provided is a subscriber-side communication device including a subscriber-side processing unit that continuously performs signal processing regardless of computer restart and includes a transmission processing unit that performs a data transmission process according to transmission control information contained in a received signal from the office-side communication device. Also provided is an office-side communication device including an office-side processing unit that continuously performs signal processing regardless of computer restart, and a transmission control information computing unit that computes transmission control information for each subscriber-side communication device, the office-side processing unit including a transmission control information storing unit that stores transmission control information of each subscriber-side communication device computed by the transmission control information computing unit, and a transmission control processing unit that performs a transmission control process with each subscriber-side communication device by using the transmission control information of each subscriber-side communication device stored in the transmission control information storing unit.

Transmission control system, subscriber-side communication device, and office-side communication device

A bandwidth allocating control apparatus for use in an optical communication base station has its reception bandwidth divided into a bandwidth for short distance and a bandwidth for long distance. A residual bandwidth calculator calculates a residual bandwidth remaining unallocated in the bandwidth for short distance after having allocated the reception bandwidth to short-distance subscriber terminal units. A middle-distance subscriber terminal classifier uses a middle-distance boundary calculation model representing the relationship between the residual bandwidth and a communication distance from the base station to the subscriber terminal units to further classify long-distance subscriber terminal units into a middle-distance subscriber terminal unit and a long-distance subscriber terminal unit. A middle-distance bandwidth allocator further allocates the residual bandwidth to the middle-distance subscriber terminal unit in addition to a predetermined bandwidth allocated thereto.

Dynamic bandwidth allocating control apparatus with bandwidth usability improved

A glass composition which is reduced in the amount of residual bubbles and is produced using smaller amounts of an environmentally unfriendly component such as arsenic oxide and antimony oxide. This glass composition comprises, in terms of mass %; 40-70% SiO; 5-20% BO; 10-25% AlO; 0-10% MgO; 0-20% CaO; 0-20% SrO; 0-10% BaO; 0.001-0.5% LiO; 0.01-0.5% NaO; 0.002-0.5% KO; and 0-1.0%, excluding 0%, Cl.

Glass composition

A data communication apparatus is highly concealable and significantly increases time necessary for an eavesdropper to analyze cipher text. A multi-level code generation section generates, by using predetermined key information, a multi-level code sequence in which a signal level changes so as to be random numbers. The multi-level processing section combines a multi-level code sequence and information data, and generates a multi-level signal having a level corresponding to a combination of the multi-level code sequence and the information data. In the multi-level code generation section, a random number sequence generation section generates a binary random number sequence by using the predetermined key information. A multi-level conversion section generates a multi-level code sequence from the binary random number sequence in accordance with a predetermined encoding rule.

Data transmitting apparatus, data receiving apparatus and data communication apparatus

A data communication apparatus wherein stealthiness is enhanced by significantly increasing the time required for a wiretapper to decrypt an encrypted text. The data communication apparatus is constituted by connecting a data transmitting apparatus and a data receiving apparatus via a transmission path. The data transmitting apparatus receives a first predetermined initial value (key information) and information data, generates a multi-valued signal, the level of which varies substantially in a random number manner, and converts the multi-valued signal to a modulated signal of a predetermined modulation format for transmission. The data receiving apparatus demodulates the modulated signal to output the multi-valued signal, and then reproduces the information data from the multi-valued signal and a received second predetermined initial value (key information).

Data communication apparatus

A data communication apparatus, performing a secret communication, is provided to reduce a random number generation speed using a plurality of random number generators. The data communication apparatus includes random number generation sections generating random numbers, which are each a multi-level pseudo random number, using predetermined key information includes a multi-level signal modulation section selecting a level, from among multi-levels previously prepared, selected level corresponding to information data and a multi-level sequence, which is composed of a combination of values of the random numbers and generating a multi-level modulated signal including a noise having a predetermined noise level using the selected level. Levels of a multi-level signal are in a range of the noise level, and a signal point allocation is set such that all values which are possibly taken by each of the random numbers are allocated to the plurality of levels of the multi-level signal.

Data transmitting apparatus and data receiving apparatus

A data transmitting apparatus has improved security against eavesdropping for secret communication using Y-00 protocol. The multi-level code generation section generates, based on key information, a multi-level code sequence in which a signal level changes so as to be approximately random numbers. The multi-level processing section generates a multi-level signal having a level which corresponds to a combination between information data and the multi-level code sequence. The error signal generation section generates an error signal which changes randomly. The accumulation section accumulates the error signal, and outputs an accumulated error signal. The adding section adds the accumulated error signal to the multi-level signal, and outputs a variable multi-level signal. The modulator section modulates the variable multi-level signal, and outputs a modulated signal.

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Osaka, Japan

Satoshi Furusawa