Abstract: An optical line terminal performs transmission to optical network units using a light signal having a wavelength different for each of systems, allocates communication time to data, which is transmitted from the optical network units, in a time division manner for each of the systems, selects, for each of the optical network units, a system for performing data transmission, and transmits the data using a wavelength corresponding to the selected system. The optical network unit includes: ith blocking filter that removes a component other than a component in a predetermined wavelength band, which is set to correspond to an ith system, from a received light signal; and ith PON processing unit that applies termination processing to signals and transmitting the data based on an allocation result of the optical line terminal. The PON system includes n optical network units corresponding to i=1 to i=n.

Abstract: A communication control method performing Discovery processing, which is a procedure at an OLT to detect an ONU newly connected, in a PON system, the method includes: a transmission-permission-signal transmitting step of transmitting, by the OLT, a transmission permission signal for discovery, which includes an individual number of an ONU that is permitted to respond and mask information for designating a match-detection target bit for the individual number; and a registration-request-signal transmitting step of comparing, by an ONU, which is not registered in the OLT, a match-detection target bit for the individual number designated in the mask information with an individual number of the ONU based on a received transmission permission signal, and when the target bit and the individual number match each other, transmitting a registration request signal to the OLT.

Abstract: An allocation determining unit determines a bandwidth allocation for each of a plurality of subscriber devices in each data-collection cycle. A history managing unit takes a history of a request increment from a bandwidth request amount acquired from more than one time of data collections and an allocation amount allocated by the allocation determining unit for the bandwidth request amount, and presents a bandwidth request amount for the allocation determination to the allocation determining unit by dividing the bandwidth request amount into a plurality of request increments indicated by the history.

Abstract: A primary station equipment unit transmits, to a secondary station equipment unit, a message transmission enable signal granting transmission of a PST message from the secondary station equipment unit, when a predetermined period of time defined for transmission elapses after the primary station equipment unit transmitted a downstream PST message in a redundancy switching process corresponding to the secondary station equipment unit.

Abstract: According to an aspect of this invention, dynamic bandwidth assignment (DBA) can be performed without interrupting communication of a regular cell and interfering with communication between child stations. In a passive optical network including a parent station and a plurality of child stations, a maintenance signal for a mini slot signal is provided. Each of the child stations sends a corresponding maintenance signal if necessary, and the parent station controls state transition by using the maintenance signal concerning on the mini slot signal for each of the child stations. By controlling the state transition, the dynamic bandwidth assignment can be performed.

Abstract: In a passive optical network system, upon detecting a connection with one of a plurality of optical network units at the time of performing autonomous ranging, an optical line termination requests for subscriber recognition information from the connected optical network unit, searches a database, to thereby specify the subscriber and the service details, and performs bandwidth setting and connection setting based on specified service details. The optical network unit stores the subscriber recognition information input by a subscriber, in association with the subscriber information.

Abstract: An OLT 1 sequentially allocates transmission permission of a packet on an upstream transmission line to a plurality of ONUs 2 registered, and performs packet communication in a simplified method with control by using a first timer for detecting a packet signal and a second timer for controlling transmission permission time, in order to transmit an IP packet of variable length without mounting a function of complex processing for analyzing an upstream packet in the OLT 1.

Abstract: According to an aspect of this invention, dynamic bandwidth assignment (DBA) can be performed without interrupting communication of a regular cell and interfering with communication between child stations. In a passive optical network including a parent station and a plurality of child stations, a maintenance signal for a mini slot signal is provided. Each of the child stations sends a corresponding maintenance signal if necessary, and the parent station controls state transition by using the maintenance signal concerning on the mini slot signal for each of the child stations. By controlling the state transition, the dynamic bandwidth assignment can be performed.

Abstract: Dynamic up-link bandwidth allocation is realized in a optical communication system in which a plurality of subscriber devices with mutually different device configurations are connected to a station unit, by configuring the station unit to consider device configurations of the subscriber devices in performing up-link bandwidth allocation.

Abstract: In a communications system in which a plurality of subscriber apparatuses and a station apparatus are connected to the same transmission channel for bidirectional communication, a bandwidth allocated in a direction from subscriber apparatuses to a station apparatus is dynamically updated. More specifically, a bandwidth usage rate is calculated from a bandwidth allocated in a updating period and a bandwidth actually used in the updating period. A bandwidth to be allocated in a subsequent period is determined based on the bandwidth usage rate thus calculated. With this construction, the station apparatus is capable of allocating the bandwidth required by the subscriber apparatuses or subscriber terminal apparatuses so that the bandwidth is efficiently used.

Abstract: An allocation determining unit determines a bandwidth allocation for each of a plurality of subscriber devices in each data-collection cycle. A history managing unit takes a history of a request increment from a bandwidth request amount acquired from more than one time of data collections and an allocation amount allocated by the allocation determining unit for the bandwidth request amount, and presents a bandwidth request amount for the allocation determination to the allocation determining unit by dividing the bandwidth request amount into a plurality of request increments indicated by the history.

Abstract: An OLT 1 sequentially allocates transmission permission of a packet on an upstream transmission line to a plurality of ONUs 2 registered, and performs packet communication in a simplified method with control by using a first timer for detecting a packet signal and a second timer for controlling transmission permission time, in order to transmit an IP packet of variable length without mounting a function of complex processing for analyzing an upstream packet in the OLT 1.

Abstract: In a communications system in which a plurality of subscriber apparatuses and a station apparatus are connected to the same transmission channel for bidirectional communication, a bandwidth allocated in a direction from subscriber apparatuses to a station apparatus is dynamically updated. More specifically, a bandwidth usage rate is calculated from a bandwidth allocated in a updating period and a bandwidth actually used in the updating period. A bandwidth to be allocated in a subsequent period is determined based on the bandwidth usage rate thus calculated. With this construction, the station apparatus is capable of allocating the bandwidth required by the subscriber apparatuses or subscriber terminal apparatuses so that the bandwidth is efficiently used.

Abstract: A primary station equipment unit 51 transmits, to a secondary station equipment unit 52, a message transmission enable signal granting transmission of a PST message from the secondary station equipment unit 52, when a predetermined period of time defined for transmission elapses after the primary station equipment unit 51 transmitted a downstream PST message in a redundancy switching process corresponding to the secondary station equipment unit 52.

Abstract: According to an aspect of this invention, dynamic bandwidth assignment (DBA) can be performed without interrupting communication of a regular cell and interfering with communication between child stations. In a passive optical network including a parent station and a plurality of child stations, a maintenance signal for a mini slot signal is provided. Each of the child stations sends a corresponding maintenance signal if necessary, and the parent station controls state transition by using the maintenance signal concerning on the mini slot signal for each of the child stations. By controlling the state transition, the dynamic bandwidth assignment can be performed.

Abstract: Dynamic up-link bandwidth allocation is realized in a optical communication system in which a plurality of subscriber devices with mutually different device configurations are connected to a station unit, by configuring the station unit to consider device configurations of the subscriber devices in performing up-link bandwidth allocation.

Abstract: A counter of a transmission permitting signal counts a number of the transmission permitting signal which was not sent to a subscriber-side apparatus due to the opening of ranging window. A band controller allocates a band to the transmission permitting signal which was not sent so that the transmission permitting signal which was not sent and counted by the counter of the transmission permitting signal is sent prior to other signals in a next sending opportunity (next time frame for updating the band).