Nec Corporation

Juniper Networks, Inc.

Hirokazu Ozaki

Satoshi Kamiya

In a redundant system where multiple network interfaces can be switched, an interface switching device includes: a transformer for transforming automatic switch information between a predetermined type used for a predetermined network interface and each of other types used for network interfaces other than the predetermined network interface; a switch controller for performing switch control for automatic switch information of the predetermined type; and a control interface for connecting a first network interface to the switch controller via the transformer when first automatic switch information received from the first network interface is not of the predetermined type.

Interface switching method and device

An exemplary object of the present invention is to accurately reflect allocation requests and increase the bandwidth use efficiency without requiring expensive and fast integrated circuits or CPUs in the control unit even in a large-scale system with a large number of terminal devices. A subscriber station comprises allocating means for determining bandwidth allocation based on a predetermined allocation condition and bandwidth transmitting means for transmitting bandwidth allocation information determined by the allocating means to an optical line terminator. The optical line terminator comprises pipeline transmitting means for transmitting bandwidth allocation information transmitted from the subscriber stations to all subscriber stations to be allocated with bandwidth.

Bandwidth allocation method, optical line terminator, subscriber station, communication system, and recording medium recording program of device

An object of the present invention is to increase the bandwidth use efficiency without requiring costly and fast integrated circuits or CPUs in the control unit even in a large-scale system with a large number of ONUs. An optical network unit includes an allocating unit that determines bandwidth allocation based on a predetermined allocation condition and a bandwidth transmitting unit that transmits bandwidth allocation information determined by the allocating unit to an optical line terminator. The optical line terminator is connected to a plurality of optical network units and includes a pipeline transmitting unit that transmits bandwidth allocation information transmitted from the optical network units to all optical network units to be allocated with bandwidth.

Bandwidth allocation method, optical line terminator, optical network unit, communication system, and recording medium recording program of device

The present invention provides a PON system including a plurality of PONs (passive optical network), a plurality of house devices set in an end user's house, and a station side device including a plurality of PON interface sections connected to the house devices via the plurality of PONs, and a concentrating/distributing section for accommodating the plurality of PONs and concentrating and distributing signals via the plurality of PON interface sections; wherein

PON system, station side device and redundant method used for the same

A scheduler allowing high-speed scheduling scalable with the number of input and output ports of a crosspoint switch and suppressed unfairness among inputs is disclosed. The scheduler includes an M&#xd7;M matrix of scheduling modules, each of which schedules packet forwarding connections from a corresponding input group of input ports to selected ones of a corresponding output group of output ports based on reservation information. A diagonal modulo pattern is used to determine a set of M scheduling modules to avoid coming into collision with each other. Each determined scheduling module performs reservation of packet forwarding connections based on current reservation information and transfers updated reservation information in row and column directions of the M&#xd7;M matrix.

Two-dimensional pipelined scheduling technique

To achieve a station-side apparatus of a wavelength multiplexing PON system, which is capable of saving the wavelength resource through automatically carrying out allotment of the wavelength and the network address to reduce the complicated work for the setting, and through dynamically allotting the wavelength without fixing it in advance. It is a station-side apparatus (OLT) of a wavelength multiplexing PON system that comprises a plurality of in-home apparatuses (ONUs). The station-side apparatus is connected to the in-home apparatuses via transmission paths including an optical multiplexing distributor, and executes allotment of the wavelength in response to wavelength allotment requests from the in-home apparatuses. The station-side apparatus comprises a wavelength/network address allotting device that is provided with a DHCP server in advance, which dynamically allots wavelength and network address to the in-home apparatus in response to the wavelength allotment request from the in-home apparatus.

Station-side apparatus of wavelength multiplexing PON system, wavelength and network address allotting method and program thereof

The present invention provides a bandwidth control apparatus, a bandwidth control method, and a bandwidth control system for effective utilization of bandwidths resource in data transmission. The bandwidth control apparatus measures downstream effective bit rate of own access lines and notifies downstream effective bit rate information of each access line to a remote bandwidth control apparatus which communicates with the bandwidth control apparatus via a network. The bandwidth control apparatus allocates and controls upstream bandwidths of own access lines on the basis of corresponding downstream effective bit rate information of access lines notified from remote bandwidth control apparatus via the networks.

Bandwidth control apparatus, bandwidth control method, and bandwidth control system

A bandwidth control apparatus which can reflect current operation states or effective rates of the access lines on bandwidth distribution is realized for effective utilization of bandwidths in a subscriber data transmission system. In a plurality of bandwidth control apparatuses accommodating a plurality of access lines in a bandwidth control system, multiplexed signal lines of respective bandwidth control apparatuses are connected to one another in cascade. Each bandwidth control apparatus acquires a bandwidth state of the access lines in the own apparatus and notifies the other apparatuses of the bandwidth state of the own apparatus having been acquired. Therefore, the bandwidth control apparatus can allocate a transmission bandwidth to be controlled in the own apparatus using a ratio of the bandwidth state occupied by the own apparatus to a total bandwidth states occupied in the bandwidth control system, and can control transmission bandwidths of the respective access lines accommodated in the own apparatus.

Bandwidth control apparatus, bandwidth control method, bandwidth control system, and bandwidth allocating apparatus

A scheduler and method for scheduling packet forwarding operations is provided. Packet forwarding request information associated with a first set of input port/output port combinations is received. Packet forwarding request information associated with a second set of input port/output port combinations different from the first set of input port/output port combinations is received, where the first set of input port/output port combinations and the second set of input port/output port combinations are selected to not conflict with each other. Packet forwarding for both the first set of input port/output port combinations at a first future time slot and the second set of input port/output port combinations at a second future time slot are simultaneously scheduling at a first scheduler and a second scheduler, respectively, based on the received packet forwarding request information. Reservation information for the first set of input port/output port combinations and the second set of input port/output port combinations is transferred to adjacent schedulers based on a module pattern, where the adjacent schedulers are responsible for scheduling additional sets of input port/output port combinations for the first and second future time slots, respectively.

A bandwidth allocation equipment in an optical line terminal, which allocates bandwidth for data to be transmitted from optical network units through an optical splitter, includes a transmit/receive unit and bandwidth allocation units. The transmit/receive unit receives an output request for requesting bandwidth allocation, and sends back a signal sending permission to the respective optical network units for specifying bandwidth to be allowed for transmitting the data in each service cycle. The bandwidth allocation units are connected to one another in a ring. Each bandwidth allocation unit is provided with corresponding to the optical network unit, and outputs the signal sending permission from the bandwidth allocation unit that has performed the last bandwidth allocation processing in the ring connection. The transmit/receive unit specifies the bandwidth allocation unit that performs the first bandwidth allocation processing by shifting one by one for each of the service cycles.

Equipment and method for band allocation

A scheduler allowing high-speed scheduling scalable with the number of input and output ports of a crosspoint switch and suppressed unfairness among inputs is disclosed. The scheduler includes an M&#xd7;M matrix of scheduling modules, each of which schedules packet forwarding connections from a corresponding input group of input ports to selected ones of a corresponding output group of output ports based on reservation information. A diagonal module pattern is used to determine a set of M scheduling modules to avoid coming into collision with each other. Each determined scheduling module performs reservation of packet forwarding connections based on current reservation information and transfers updated reservation information in row and column directions of the M&#xd7;M matrix.

A scheduler allowing high-speed scheduling scalable with the number of input and output ports of a crosspoint switch and suppressed unfairness among inputs is disclosed. The scheduler includes an M&#xd7;M matrix of scheduling modules, each of which schedules packet forwarding connections from a corresponding input group of input ports to selected ones of a corresponding output group of output ports based on reservation information. A diagonal module pattern is used to determine a set or M scheduling modules to avoid coming into collision with each other. Each determined scheduling module performs reservation of packet forwarding connections based on current reservation information and transfers updated reservation information in row and column directions of the M&#xd7;M matrix.

A pipelined scheduling system allowing suppressed unfairness among inputs and reduced fixed delay time is disclosed. Virtual output queues (VOQs) for each input port corresponding to respective ones of the output ports are stored. The VOQs are equally divided into a plurality of groups. Scheduling modules each corresponding to the groups performs a scheduling operation at a single time slot in a round robin fashion such that each of the scheduling modules reserves output ports at a predetermined future time slot for forwarding requests from logical queues of a corresponding group based on a reservation status received from a previous scheduling module, and then transfers an updated reservation status to an adjacent scheduling module. A crossbar switch connects each of the input ports to a selected one of the output ports depending on the reservation status at each time slot.

Pipelined scheduling technique

An information processor includes a CPU, an EEPROM for storing a program for ordinary processing and program download control, and a RAM having a first program storage area for loading the program stored in the EEPROM and a second program storage area for storing a new downloaded program. In an idle time in the ordinary processing program, the CPU executes the download control program to download the new program from an external device into the second program storage area of the RAM and store the downloaded program in the EEPROM, while the CPU is reset after the storage of the program.

Growing community of inventors

Tokyo, Japan

Hirokazu Ozaki