JP2008283536A - Communication system, subscriber terminal, station side device, and communicating method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that an ONU (Optical Network Unit) can not transmit high priority data to an OLT (Optical Line Terminal) after transmitting dying gasp even though having the high priority data because the ONU transmits the dying gasp to the OLT and the OLT disconnects a link with the ONU at that time when the ONU is close to an inoperable state. <P>SOLUTION: When the ONU detects that the ONU itself is close to an inoperable state, the ONU transmits dying gasp to the OLT and also transmits a transmission band request. The OLT receiving them allocates a transmission band of the highest priority for the ONU. The ONU uses the transmission band to transmit the data of the highest priority. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication system, and in particular, when a dicing gasp and a transmission band allocation request are sent from a subscriber terminal to a station side apparatus, the station side apparatus assigns the highest priority band to the subscriber terminal. The allocation and subscriber terminal relates to a communication system for transmitting high priority data using the allocated bandwidth.

  Conventionally, in a network in which one station-side device and a plurality of in-house transmission devices (subscriber terminals) are connected, the in-home transmission device is in a dicing gap when the in-home transmission device is almost inoperable due to a power failure or the like. (DyingGasp) is sent to the station side device. The station side device that has received the diing gasp has taken down the link of the port to which the in-home transmission device that has sent the diing gasp is connected. Such a conventional technique is described in Patent Document 1.

  The above contents will be described with reference to a time chart FIG.

  Conventionally, when a dieing gasp factor is generated in the ONU and the dieing gasp is transmitted from the ONU to the OLT, the OLT disconnects the connection with the ONU even if the ONU is still communicable. Then, after sending the diving gasp, even if the ONU has high priority data with high urgency, the data cannot be transmitted to the OLT. As a result, data that should be sent before the ONU becomes inoperable, such as an emergency call, has also been discarded.

  Here, the station side device in Patent Document 1 corresponds to the Optical Line Terminal (OLT) of the present invention, and the in-home transmission device in Patent Document 1 corresponds to the Optical Network Unit (ONU) of the present invention.

JP 2004-015645 A

In the station side device that has received the above-described conventional diing gasp, since the link with the in-home transmission device that sent the diing gasp after receiving the diing gasp is down (disconnecting the network), the in-home transmission device is Even after the sending, even if the operation is possible using the built-in battery or the like, no data can be sent to the station side device after sending the dieing gasp. For this reason, there is a problem that even when high-priority data with high urgency is present in the in-home transmission device at the time of sending the diving gasp, the data cannot be transmitted.
[Object of invention]
An object of the present invention is to provide a communication system, a subscriber terminal, a station-side device, a communication method, and a program that solve the above-described conventional problems.

  In the communication system of the present invention, when detecting that the state where the inoperable state is close is detected and that the state where the diing gasp factor detecting circuit is inoperable is close, this is indicated. The first signal to be transmitted is transmitted, an uplink transmission band request is transmitted when the first signal is transmitted, and high-priority data is used when the requested transmission band is allocated. A transmission unit that transmits the first signal, and a transmission band with the highest priority to the subscriber terminal that transmitted the first signal when receiving the first signal and the uplink transmission band request. And a station-side device having an OLT control unit for assigning the device.

  When the subscriber terminal according to the present invention detects that the state where the inoperable state is close is detected, and that the state where the diing gasp factor detecting circuit is inoperable is close, that effect is detected. When transmitting the first signal, an uplink transmission band request is transmitted, and the highest priority band is allocated by the station side apparatus connected to the transmission band request. And a transmission unit that transmits data with high priority using this band.

  When the station side apparatus of the present invention receives a first signal and an uplink transmission bandwidth request from the subscriber terminal when it is almost impossible to operate the connected subscriber terminal. It has an OLT control part which allocates the highest priority transmission band to the subscriber terminal which transmitted the said 1st signal.

  In the communication method of the present invention, a diing gasp factor detection step for detecting that the inoperable state is close and a state in which the inoperable state is close in the diing gasp factor detection step are detected. Transmitting a first signal to be transmitted; transmitting an uplink transmission bandwidth request when transmitting the first signal; and receiving the first signal and the uplink transmission bandwidth request Assigning the highest priority transmission band to the subscriber terminal that has transmitted the first signal to the terminal, and transmitting the high priority data using this band when the requested transmission band is assigned; It is characterized by having.

  When the program of the subscriber terminal according to the present invention detects that the inoperable state is close in the diing gasp factor detection process for detecting that the inoperable state is close, and the diing gasp factor detection process is close Transmitting a first signal to that effect, transmitting an uplink transmission band request when transmitting the first signal, and the highest priority band in the station side apparatus connected to the transmission band request And a transmission process for transmitting high-priority data using this band when the data is assigned to the computer.

  The station-side device program of the present invention receives the first signal and the uplink transmission bandwidth request from the subscriber terminal when the connected subscriber terminal is almost impossible to operate. In this case, the computer is caused to execute a process of assigning the highest priority transmission band to the subscriber terminal that has transmitted the first signal.

  In the present invention, when it is detected that the subscriber terminal is almost inoperable, the station side device transmits a first signal informing the station side device and an uplink transmission bandwidth request. The highest priority transmission band is assigned to the subscriber terminal that has transmitted the transmission band request, and the subscriber terminal uses this band to transmit high priority data to the station side device. Therefore, in the present invention, even after the first signal indicating that the subscriber terminal is almost inoperable is transmitted to the station side device, the subscriber terminal transmits the high priority data to the station side. This has the effect that it can be transmitted to the device.

  The present invention relates to a subscriber terminal Optical Network Unit (ONU) and a station side device Optical Line Terminal after sending a diving gasp in a passive optical network (PON), in particular, a Gigabit Ethernet (registered trademark) -passive optical network (GE-PON). The invention relates to transmission and reception of signals between (OLT).

  Prior to the description of the embodiment of the present invention, first, a diing gasp related to the present invention defined in IEEE 802.3ah will be briefly described.

  In the GE-PON standard IEEE 802.3ah, the following contents are defined. The dicing gasp that is sent from the ONU to the OLT when it is almost impossible to operate the terminal due to a power failure or the like is notified in the Flags field of Operations, Administration, and Maintenance Protocol Data Units (OAMPDU), and is sent from the ONU to the OLT. It is sent with the highest priority among the data to be sent. When the ONU deviates from the GE-PON network managed by the OLT, the ONU must continue to operate until the sending of the dieing gasp is completed.

  Further, in the transmission of diing gasp caused by a decrease in the power supply voltage on the ONU side, it is common to guarantee continuous operation for a certain time with a capacitor or a battery.

  Next, a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing the configuration of the first exemplary embodiment of the present invention. As shown in FIG. 1, in the GE-PON in which one optical line 52 is shared by a plurality of subscriber terminals, the first embodiment includes an OLT 30 installed in a center station, an ONU 20 installed in a subscriber's house, 21, 22, optical lines 50, 52, and the like capable of optical communication defined by IEEE 802.3ah, and a coupler 41 that branches the lines for a plurality of subscriber terminals in GE-PON. . The ONU 21 and the ONU 22 are subscriber terminals different from the ONU 20 branched and connected by the coupler 41.

  Communication transmitted from the OLT 30 via the coupler 41 to the ONUs 20, 21, 22 using the optical lines 52, 50, etc. is referred to as downlink communication. Further, the OLT 30 allocates an upstream transmission band to each ONU, and communication transmitted from the ONUs 20, 21, and 22 to the OLT 30 using the allocated band is defined as upstream communication.

  The ONU 20 can be connected to an optical line 50, a communication terminal 40 such as a personal computer, and an emergency notification device 45 such as a fire alarm, and has the following functional blocks.

  The ONU 20 includes a control unit 1 that controls the operation of the ONU 20, an optical connection unit 2 that can connect the optical line 50, a LAN connection unit 3 that can connect the communication terminal 40 and the emergency call device 45, and a LAN connection unit 3. A transmission priority classifying unit 4 that classifies data frames input via the high priority data frame and the low priority data frame according to a predetermined rule, and the high priority data frame and the low data frame. A priority condition setting unit 5 for setting a condition for classification, a low priority queue 6 for storing data frames classified by the transmission priority classification unit 4 until they are transmitted, and a transmission priority classification It is dynamically allocated by the high priority queue 7 that stores data frames classified by the unit 4 until high priority is transmitted, and GE-PON Dynamic Bandwidth Allocation (DBA). A transmission allocation control unit 8 that stores in the transmission buffer 9 data frames that are actually transmitted according to the allocated upstream band, and stores data frames that are determined to be transmitted using the dynamically allocated upstream band. The transmission buffer 9, the transmission unit 10 that transmits the data frame stored in the transmission buffer 9 to the OLT 30 through the optical connection unit 2, and a diing gasp (Dying Gasp) such as a power supply voltage drop of the ONU 20 need to be transmitted A dicing gasp factor detection circuit 11 for detecting a factor, a receiving unit 12 for receiving a downlink data frame from the optical line 50 via the optical connection unit 2, and a data frame received by the receiving unit 12 are assigned to the ONU 20. And a reception analysis unit 13 for extracting the upstream band.

  The OLT 30 can connect an optical line 52 and a network 51 such as the Internet, and has the following functional blocks.

  An OLT control unit 31 that controls the operation of the OLT 30, an OLT optical connection unit 32 that can connect the optical line 52, an OLT network connection unit 33 that can connect the network 51, and the optical line 52 via the OLT optical connection unit 32. An OLT reception unit 34 that receives an upstream data frame, an OLT reception analysis unit 35 that extracts control information such as information on a bandwidth allocation request from the ONU and dicing gasp from the data frame received by the OLT reception unit 34, OLT transmission band allocation table 36 for storing the status of the uplink transmission band allocated to each ONU 20, 21, 22; OLT transmission control unit 37 for allocating the uplink transmission band for each ONU 20, 21, 22; and transmission control OL for sending control information such as band allocation information from the unit 37 to the optical line 52 And a transmission unit 38.

  Although the configuration of the first embodiment has been described in detail above, the GE-PON defined in IEEE 802.3ah and the DBA that dynamically allocates the upstream bandwidth are well known to those skilled in the art, and the present invention Since the relationship with is thin, detailed description thereof is omitted.

  Next, the operation of the first embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 2 is a flowchart showing an outline of the operation.

  Hereinafter, an operation in which data from the emergency notification device 45 with high urgency is preferentially transmitted to the OLT 30 when the ONU 20 transmits the diving gasp will be described.

  As a premise, in the priority classification condition of the priority condition setting unit 5, it is assumed that the data from the communication terminal 40 is set to a low priority and the data from the emergency call device 45 is set to a high priority. In addition, it is assumed that the cause of occurrence of the dieing gasp is a decrease in the power supply voltage of the ONU 20.

  The operation example of the first embodiment is shown below.

  When the dieing gasp factor detection circuit 11 detects a power supply voltage drop of the ONU 20 due to a power failure or the like (step 101), the control unit 1 transmits the dieing gasp to the OLT 30 via the transmission allocation control unit 8 (step 102).

  After the diving gasp transmission, the control unit 1 of the ONU 20 confirms whether data from the emergency call device 45 exists in the high priority queue 7 (step 103).

  If there is no data in the high priority queue 7 (No in Step 103), the ONU 20 stops its operation as it is (Step 108).

  When data from the emergency call device 45 exists in the high priority queue 7 (Yes in Step 103), the control unit 1 requests the OLT 30 to allocate an upstream band for data transmission (Step 104).

  Further, the control unit 1 discards the data in the transmission buffer 9 in order to preferentially send the data in the high priority queue 7 and stores the data in the high priority queue 7 in the transmission buffer 9 (step 105). ).

  The OLT reception analysis unit 35 of the OLT 30 analyzes data from the ONU 20 received by the reception unit 34. When the OLT reception analysis unit 35 detects the dicing gasp from the ONU 20 (Yes in Step 109), the OLT control unit 31 confirms whether bandwidth allocation is requested from the ONU 20 while maintaining the connection with the ONU 20 ( Step 110).

  When there is no bandwidth allocation request from the ONU 20 (No in Step 110), the OLT control unit 31 disconnects the ONU 20 from the link (Step 114).

  When there is a bandwidth allocation request from the ONU 20 (Yes in Step 110), the OLT control unit 31 receives the request from the ONU 20 at the earliest time among the bandwidths allocated in the uplink direction stored in the OLT transmission bandwidth allocation table 36. Reallocate bandwidth (time) so that data can be transmitted.

  The rearranged bandwidth allocation information is notified to the ONU 20 via the OLT transmission control unit 37 (step 111).

  Here, a recombination example of bandwidth allocation in the transmission bandwidth allocation table 36 will be described with reference to FIG.

  The upper diagram of FIG. 3 shows an example of normal bandwidth allocation in the OLT transmission bandwidth allocation table 36. In this state (the upper diagram in FIG. 3), the ONU 20 can transmit data only after data transmission between the ONU 22 and the ONU 21. For this reason, since it takes a long time until the transmission allocation band (time) of the ONU 20 as it is, there is a possibility that the ONU 20 falls into an inoperable state before sending data.

  In order to avoid this, the OLT control unit 1 of the OLT 30 rearranges the OLT transmission band allocation table 36 so that the ONU 20 can transmit the earliest (the lower diagram in FIG. 3). The state of the OLT transmission band allocation table 36 after this recombination is performed is shown in the lower diagram of FIG.

  Here, the description returns to the flowchart of FIG.

  When the transmission band is allocated from the OLT 30 (Yes in Step 106), the control unit 1 of the ONU 20 transmits the data from the emergency call device 45 stored in the transmission buffer 9 in the designated band (time) (Step S1). 107).

  When receiving data from the ONU 20, the OLT 30 transmits this data to the network 51 through the OLT network connection unit 33 (step 113), and then disconnects the ONU 20 from the link (step 114).

  With the above operation, the data from the emergency call device 45 can be sent to the network 51 before the ONU 20 becomes inoperable due to the cause of the diing gasp.

  Next, the contents of the present embodiment will be described with reference to the time chart FIG.

  In the present embodiment, when a highly urgent data transmission request is generated after a cause of a diing gasp occurs in the ONU, a transmission bandwidth request is transmitted after the diing gasp is transmitted from the ONU to the OLT. The The OLT that has received the transmission bandwidth request assigns the earliest (highest priority) transmission bandwidth to the ONU. Then, the ONU transmits data with high urgency and high priority to the OLT using the earliest transmission band.

  In the present embodiment described above, when a transmission bandwidth request is transmitted after the diving gasp is transmitted from the ONU 20 to the OLT 30, the OLT 30 allocates the earliest transmission bandwidth to the ONU 20, and therefore the ONU 20 transmits the diing gasp. Data can be transmitted even later.

  In addition, since the data to be transmitted at this time is highly urgent and high priority data, the ONU 20 must transmit urgent and high priority data to the OLT 30 even after the diving gasp transmission. Is possible.

  Next, a second embodiment of the present invention will be described with reference to the drawings.

  Since the configuration of the second embodiment is the same as the configuration of the first embodiment (FIG. 1), description thereof is omitted.

  The operation of the second embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 5 is a flowchart showing an outline of the operation.

  Hereinafter, an operation in which high priority data with high urgency from the emergency call device 45 is preferentially transmitted to the OLT 30 when the ONU 20 transmits the diving gasp will be described.

  As a premise, in the priority classification condition of the priority condition setting unit 5, it is assumed that the data from the communication terminal 40 is set to a low priority and the data from the emergency call device 45 is set to a high priority. In addition, it is assumed that the cause of occurrence of the dieing gasp is a decrease in the power supply voltage of the ONU 20.

  The operation example of the second embodiment is shown below.

  When the diving gasp factor detection circuit 11 detects a power supply voltage drop of the ONU 20 due to a power failure or the like (step 201), the control unit 1 of the ONU 20 determines whether data from the emergency notification device 45 exists in the high priority queue 7 or not. Confirm (step 202).

  When there is no data in the high priority queue 7 (No in Step 202), the control unit 1 of the ONU 20 transmits the diing gasp to the OLT 30 (Step 204), and the ONU 20 stops its operation as it is (Step 208). .

  When data from the emergency call device 45 exists in the high priority queue 7 (Yes in Step 202), the control unit 1 transmits a dicing gasp and an upstream bandwidth allocation request for data transmission to the OLT 30. (Step 203).

  Further, the control unit 1 discards the data in the transmission buffer 9 in order to preferentially send the data in the high priority queue 7 and stores the data in the high priority queue 7 in the transmission buffer 9 (step 205). ).

  The OLT reception analysis unit 35 of the OLT 30 analyzes data from the ONU 20 received by the reception unit 34. When detecting the dicing gasp from the ONU 20 (Yes in Step 209), the OLT reception analysis unit 35 analyzes whether or not bandwidth allocation is requested from the ONU 20 while maintaining the connection with the ONU 20 (Step 210).

  When there is no bandwidth allocation request from the ONU 20 (No in Step 210), the OLT control unit 31 disconnects the ONU 20 from the link (Step 214).

  When there is a bandwidth allocation request from the ONU 20 (Yes in Step 210), the OLT control unit 31 receives the request from the ONU 20 at the earliest time among the bandwidths allocated in the uplink direction stored in the OLT transmission bandwidth allocation table 36. Reallocate bandwidth (time) so that data can be transmitted.

  The reconfigured band allocation information is notified to the ONU 20 via the OLT transmission control unit 37 (step 211).

  When the transmission band is allocated from the OLT 30 (Yes in Step 206), the control unit 1 of the ONU 20 transmits the data from the emergency call device 45 stored in the transmission buffer 9 in the designated band (time) (Step S1). 207).

  When the OLT 30 receives data from the ONU 20 (Yes in step 212), the OLT 30 transmits the data to the network 51 via the OLT network connection unit 33 (step 213).

  With the above operation, the data from the emergency call device 45 can be sent to the network 51 before the ONU 20 becomes inoperable due to the cause of the diving gasp.

  In the second embodiment, since the diving gasp and the transmission band request are transmitted simultaneously, when the transmission band request is sent from the ONU 20 to the OLT 30, the OLT 30 is almost the same as the reception of the diing gasp. At the same time, a transmission bandwidth request is received. For this reason, it is possible to determine whether there is a transmission bandwidth request almost simultaneously with the reception of the diving gasp, so that the processing of the OLT 30 at the time of receiving the diing gasp can be speeded up.

  In the first and second embodiments described above, high-priority data is stored in the high-priority queue. However, even if a dedicated queue such as the high-priority queue is not used, the transmission source and destination IP The priority of data may be determined by referring to identification information or the like included in data stored in an address or payload.

  In the first and second embodiments, after the data stored in the transmission buffer 9 scheduled to be transmitted is discarded, the data in the high priority queue 7 is stored in the transmission buffer 9. However, it is also possible to confirm the priority of the data in the transmission buffer 9 and to transmit without discarding if there is high priority data.

  In the above description, the present invention has been described on the assumption that the present invention is realized in hardware. However, each function of the present invention can be realized by a program read by the CPU.

Block diagram of a communication system in the first and second embodiments The flowchart which shows operation | movement of 1st Embodiment. The conceptual diagram which shows the change condition of the OLT transmission bandwidth allocation table of 1st Embodiment Time chart showing the operation of the first embodiment The flowchart which shows operation | movement of 2nd Embodiment. Time chart showing operation of background technology

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control part 2 Optical connection part 3 LAN connection part 4 Transmission priority classification | category part 5 Priority condition setting part 6 Low priority queue 7 High priority queue 8 Transmission allocation control part 9 Transmission buffer 10 Transmission part 11 Dying gasp factor detection circuit 12 receiving unit 13 receiving analyzing unit 20 ONU
21 ONU
22 ONU
30 OLT
31 OLT control unit 32 OLT optical connection unit 33 OLT network connection unit 34 OLT reception unit 35 OLT reception analysis unit 36 OLT transmission bandwidth allocation table 37 OLT transmission control unit 38 OLT transmission unit 40 communication terminal 41 coupler 45 emergency call device 50 optical line 51 Network 52 Optical line

Claims (14)

A diving gasp factor detection circuit for detecting that the state of being inoperable is near,
When it is detected that the state in which the diving gasp factor detection circuit is inoperable is close, a first signal is transmitted to that effect, and when transmitting the first signal, an uplink transmission bandwidth request is transmitted. A transmission unit that transmits high-priority data using the band when the requested transmission band is allocated; and
A subscriber terminal having
A station-side apparatus having an OLT control unit that allocates a highest-priority transmission band to a subscriber terminal that has transmitted the first signal when receiving the first signal and the uplink transmission band request;
A communication system comprising:   The communication system according to claim 1, wherein the uplink transmission band request is transmitted after the transmission of the first signal.   The communication system according to claim 1, wherein the uplink transmission band request is transmitted simultaneously with the transmission of the first signal.   The communication system according to any one of claims 1 to 3, wherein the high priority data is stored in a high priority queue of a subscriber terminal.   The communication system according to any one of claims 1 to 4, wherein it is determined whether or not the data is high priority data based on the identification information of the data. A diving gasp factor detection circuit for detecting that the state of being inoperable is near,
When detecting that the state in which the diving gasp factor detection circuit becomes inoperable is close, a first signal is transmitted to that effect, and when transmitting the first signal, an uplink transmission bandwidth request is transmitted. A transmitting unit that transmits high-priority data using this band when a highest-priority band is allocated in a station-side device connected to the transmission band request;
A subscriber terminal.   When the connected subscriber terminal is in a state where it is almost impossible to operate, the first signal is transmitted from the subscriber terminal and the first signal is transmitted when an uplink transmission bandwidth request is received from the subscriber terminal. A station-side apparatus comprising an OLT control unit that allocates a highest priority transmission band to a subscriber terminal. Dying gasp factor detection step for detecting that the state where the operation becomes impossible is near,
Sending a first signal to that effect when detecting that the inoperable state is near in the dicing gasp factor detection step;
Transmitting an uplink transmission bandwidth request when transmitting the first signal;
Assigning a highest priority transmission band to a subscriber terminal that has transmitted the first signal when receiving the first signal and the uplink transmission band request;
And a step of transmitting high-priority data using the band when the requested transmission band is allocated.   The communication method according to claim 8, wherein the uplink transmission band request is transmitted after the transmission of the first signal.   9. The communication method according to claim 8, wherein the uplink transmission band request is transmitted simultaneously with the transmission of the first signal.   The communication method according to any one of claims 8 to 10, wherein the high priority data is stored in a high priority queue of a subscriber terminal.   12. The communication method according to claim 8, wherein whether or not the data is high priority data is determined based on the data identification information. Dying gasp factor detection process for detecting that the state where the operation becomes impossible is near,
When it is detected that the inoperable state is close in the dicing gasp factor detection process, a first signal is transmitted to that effect, and when transmitting the first signal, an uplink transmission bandwidth request is transmitted. A transmission process for transmitting high-priority data using this band when the highest-priority band is allocated in the station-side apparatus connected to the transmission band request;
A program for a subscriber terminal, which causes a computer to execute.   When the connected subscriber terminal is in a state where it is almost impossible to operate, the first signal is transmitted from the subscriber terminal and the first signal is transmitted when an uplink transmission bandwidth request is received from the subscriber terminal. A program for a station-side apparatus, which causes a computer to execute a process of assigning a highest priority transmission band to a subscriber terminal.

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