Method and apparatus for reconfiguring wavelength of optical network unit

Abstract

The invention provides a method and apparatus for reconfiguring wavelength of the ONU. To be specific, the OLT sends a Deactivate_ONU-ID message to the ONU, the Deactivate_ONU-ID message including a reconfiguration flag, a new receive wavelength assigned for the ONU and a new transmit wavelength assigned for the ONU. After receiving the Deactivate_ONU-ID message from the OLT, the ONU discards the TC layer parameters related to the current wavelength channel, and determines whether the reconfiguration flag included in the Deactivate_ONU-ID message indicates the receive wavelength and the transmit wavelength of the ONU are required to be reconfigured. If so, then the ONU replaces its original receive wavelength and original transmit wavelength with its new receive wavelength and the new transmit wavelength included in the Deactivate_ONU-ID message, and enters initial state; and if not, then the ONU enters initial state directly.

Claims

1. A method, in an active optical network unit (ONU),of reconfiguring wavelength of the active ONU, the method comprising the steps of: receiving a reconfiguration message from an optical line terminal (OLT), the reconfiguration message including new receive wavelength and new transmit wavelength assigned for the active ONU; performing, based on the reconfiguration message, both of, discarding transmission convergence layer parameters related to a current wavelength channel and replacing original receive wavelength and original transmit wavelength of the active ONU with the new receive wavelength and the new transmit wavelength included in the reconfiguration message, and subsequently de-activating and re-activating the active ONU, such that a receiver and a transmitter of the re-activated ONU work on the new receive wavelength and the new transmit wavelength.

2. The method according to claim 1, wherein, the reconfiguration message further includes a new ONU-ID of the active ONU used in a new wavelength channel, and the discarding includes replacing an original ONU-ID of the active ONU with the new ONU-ID included in the reconfiguration message, and the de-activating and re-activating omits performance of steps related to obtaining the new ONU-ID.

3. The method according to claim 1, wherein, the reconfiguration message further includes a new equalization delay of the active ONU used in a new wavelength channel, the discarding includes replacing an original equalization delay of the active ONU with the new equalization delay included in the reconfiguration message, and the de-activating and re-activating omits performance of steps related to obtaining the new equalization delay and steps of registration of the active ONU to a XG-PON system corresponding to a wavelength channel, of the active ONU, to be reconfigured.

4. The method according to claim 1, wherein, the reconfiguration message is a Deactivate_ONU-ID message and the Deactivate_ONU-ID message further includes a reconfiguration flag, and the discarding includes determining whether the reconfiguration flag included in the Deactivate_ONU-ID message indicates that a receive wavelength and a transmit wavelength of the active ONU are required to be reconfigured, and based on the determining, performing one of, replacing original receive wavelength and original transmit wavelength of the active ONU with the new receive wavelength and the new transmit wavelength included in the Deactivate_ONU-ID message, and subsequently switching off the transmitter of the active ONU, based on determining that the reconfiguration flag indicates that the receive wavelength and the transmit wavelength of the active ONU are required to be reconfigured, or directly switching off the transmitter of the active ONU, based on determining that the reconfiguration flag does not indicate that the receive wavelength and the transmit wavelength of the active ONU are required to be reconfigured.

5. A method, in an optical line terminal (OLT), of reconfiguring wavelength of an active optical network unit (ONU), the method comprising: sending a reconfiguration message to the active ONU, the reconfiguration message including a new receive wavelength and a new transmit wavelength assigned for the active ONU, such that the reconfiguration message, upon being received by the active ONU, causes the active ONU to perform both of, discarding transmission convergence layer parameters related to a current wavelength channel and replace original receive wavelength and original transmit wavelength of the active ONU with the new receive wavelength and the new transmit wavelength included in the reconfiguration message in a subsequent, de-activation and subsequently de-activating and re-activating the active ONU, such that a receiver and a transmitter of the re-activated ONU are configured to work on the new receive wavelength and the new transmit wavelength.

6. The method according to claim 5, further comprising: assigning a new ONU-ID and/or a new equalization delay of the active ONU used in a new wavelength channel, and registering the active ONU to a XG-PON system corresponding to a wavelength channel, of the active ONU, to be reconfigured; wherein the reconfiguration message further includes the new ONU-ID and/or the new equalization delay of the active ONU used in the new wavelength channel.

7. The method according to claim 5, wherein the reconfiguration message is a Deactivate_ONU-ID message, and the Deactivate_ONU-ID message further includes a reconfiguration flag to indicate whether a receive wavelength and a transmit wavelength of the active ONU are required to be reconfigured.

8. An apparatus, in an active optical network unit (ONU), for reconfiguring wavelength of the active ONU, the apparatus comprising: communication interface configured to receive a reconfiguration message from an optical line terminal (OLT), the reconfiguration message including new receive wavelength and new transmit wavelength assigned for the active ONU; a memory storing a program of instructions; and processor configured to execute the program of instructions to, based on the reconfiguration message, perform both of, discarding transmission convergence layer parameters related to a current wavelength channel and to replace original receive wavelength and original transmit wavelength of the active ONU with the new receive wavelength and the new transmit wavelength included in the reconfiguration message, and subsequently de-activating and re-activating the active ONU, such that a receiver and a transmitter of the re-activated ONU work on the new receive wavelength and the new transmit wavelength.

9. The apparatus according to claim 8, wherein, the reconfiguration message further includes a new ONU-ID of the active ONU used in a new wavelength channel, the processor is configured to execute the program of instructions to replace an original ONU-ID of the active ONU with the new ONU-ID included in the reconfiguration message, and the de-activating and re-activating includes omitting performance of steps related to obtaining the new ONU ID.

10. The apparatus according to claim 8, wherein, the reconfiguration message further includes a new equalization delay of the active ONU used in a new wavelength channel, the processor is configured to execute the program of instructions to replace an original equalization delay of the active ONU with the new equalization delay included in the reconfiguration message, and the de-activating and re-activating includes omitting performance of steps related to obtaining the new equalization delay and steps of registration of the active ONU to a XG-PON system corresponding to a wavelength channel, of the active ONU, to be reconfigured.

11. The apparatus according to claim 8, wherein, the reconfiguration message is a Deactivate_ONU-ID message and the Deactivate_ONU-ID message further includes a reconfiguration flag, and the discarding includes determining whether the reconfiguration flag included in the Deactivate_ONU-ID message indicates a receive wavelength and a transmit wavelength of the active ONU are required to be reconfigured, and based on determining, performing one of, replacing original receive wavelength and original transmit wavelength of the active ONU with the new receive wavelength and the new transmit wavelength included in the Deactivate_ONU-ID message, and subsequently switching off the transmitter of the active ONU, based on determining that the reconfiguration flag indicates that the receive wavelength and the transmit wavelength of the active ONU are required to be reconfigured, or switching off the transmitter of the active ONU directly, based on determining that the reconfiguration flag does not indicate that the receive wavelength and the transmit wavelength of the active ONU are required to be reconfigured.

12. A system, comprising: active optical network unit (ONU); and an optical line terminal (OLT) configured to reconfigure wavelength of the active ONU, the OLT configured to send a reconfiguration message to the active ONU, the reconfiguration message including new receive wavelength and new transmit wavelength assigned for the active ONU the active ONU configured to, based on the reconfiguration message, perform both of, discarding transmission convergence layer parameters related to a current wavelength channel and replace original receive wavelength and original transmit wavelength of the active ONU with the new receive wavelength and the new transmit wavelength included in the reconfiguration message in a subsequent de-activation, and subsequently de-activating and re-activating the active ONU, such that a receiver and a transmitter of the re-activated ONU work on the new receive wavelength and the new transmit wavelength.

13. The system according to claim 12, the OLT further including, a memory storing a program of instructions; and a processor configured to execute the program of instructions to assign a new ONU-ID and/or a new equalization delay of the active ONU used in a new wavelength channel, and to register the active ONU to a XG-PON system corresponding to a wavelength channel, of the active ONU, to be reconfigured; wherein the reconfiguration message further includes the new ONU-ID and/or the new equalization delay of the active ONU used in the new wavelength channel.

14. The system according to claim 12, wherein the reconfiguration message is a Deactivate_ONU-ID message, and the Deactivate_ONU-ID message further includes a reconfiguration flag to indicate whether a receive wavelength and a transmit wavelength of the active ONU are required to be reconfigured.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The foregoing and other features of the invention will become more apparent upon review of the following detailed description of non-limiting embodiments taken with reference the drawings in which:

(2) FIG. 1 illustrates a flow chart of a method of reconfiguring wavelength of the ONU according to an embodiment of the invention.

(3) Identical or similar reference numerals in the drawings denote identical or similar components.

DETAILED DESCRIPTION OF EMBODIMENTS

(4) Embodiments of the invention will be described below using the extension of the current standard Deactivate_ONU-ID PLOAM message as an example.

(5) The PLOAM channel supports XG-PON TC layer management functions. It is based upon exchange of 48-byte messages that are transported in the PLOAM partition of the downstream XGTC frame header and in the upstream XGTC burst header. The PLOAM channel supports the following functions of Burst profile communication, ONU activation, ONU registration, Encryption key update exchange, Protection switching signaling and power management.

(6) To reconfigure the active ONU to work on another wavelengths, the ONU must be stopped from sending upstream traffic on the current working transmit wavelength, thus it must be deactivated, and then activate on the target wavelengths.

(7) The standard Deactivate_ONU-ID message defined in G.987.3 is a downstream PLOAM message, as shown in table 1.

(8) TABLE-US-00001 TABLE 1 Message type ID Message name Function Trigger Effect of receipt 0x05 Deactivate_ONU-ID To instruct a At the OLT's The ONU with this ONU-ID specific ONU to discretion. switches off its laser. The stop sending ONU-ID, default and explicit upstream traffic Alloc-IDs, default XGEM and reset itself. It Port-ID, burst profiles, and can also be a equalization delay are broadcast message. discarded. The ONU moves to the Initial state. No Acknowledgement.

(9) The format of the standard Deactivate_ONU-ID message is as shown in table 2.

(10) TABLE-US-00002 TABLE 2 Octet Content Description 1-2 ONU-ID Directed message to one ONU or broadcast message to all ONUs. As a broadcast to all ONUs, ONU-ID = 0x03FF. 3 0x05 Message type ID “Deactivate_ONU-ID”. 4 SeqNo Unicast or broadcast PLOAM sequence number, as appropriate.  5-40 Padding Set to 0x00 by the transmitter; treated as “don't care” by the receiver. 41-48 MIC Message integrity check.

(11) The extended Deactivate_ONU-ID message of the technical solution of the present invention is as defined in table 3.

(12) TABLE-US-00003 TABLE 3 Message Type ID Message Name Function Trigger Effect of receipt 0x05 Deactivate_ONU-ID To instruct a At the If the reconfiguration-flag is specific ONU to OLT's not set, the ONU with either stop discretion. this ONU-ID switches sending off its laser. The upstream traffic ONU-ID, default and and reset itself, explicit Alloc-IDs, or stop sending burst profiles, and upstream traffic equalization delay are and reconfigure discarded. The ONU the ONU's moves to the Initial state. receive/transmit If the reconfiguration-flag is wavelength and set, the ONU with this then reset itself. ONU-ID not only It can also be a performs the broadcast deactivation process message. defined in G.987.3, but also reconfigures the ONU's receive/transmit, and then moves to the Initial state. No Acknowledgement.

(13) The extended Deactivate_ONU-ID message has ONU wavelength reconfiguration sub-function, which can be used by the OLT to change/reconfigure the wavelength of the active ONU.

(14) The format of the extended Deactivate_ONU-ID message is as shown in table 4.

(15) TABLE-US-00004 TABLE 4 Octet Content Description 1-2 ONU-ID Directed message to one ONU or broadcast message to all ONUs. As a broadcast to all ONUs, ONU-ID = 0x03FF. 3 0x05 Message type ID “Deactivate_ONU-ID”. 4 SeqNo Unicast or broadcast PLOAM sequence number, as appropriate. 5 Reconfigure- 0- ONU directly performs the deactivation Flag process defined in G.987.3 1- ONU firstly performs the deactivation process defined in G.987.3, and then enters ONU activation process to work on the wavelengths indicated in this Deactivate_ONU-ID message. 6-9 Receive- The wavelength to be used by the ONU's Wavelength receiver 10-13 Transmit- The wavelength to be used by the ONU's Wavelength transmitter 14-40 Padding Set to 0x00 by the transmitter; treated as “don't care” by the receiver 41-48 MIC Message integrity check

(16) As can be seen from table 4 and table 2, the extended Deactivate_ONU-ID message further includes a Reconfigure-Flag field, a Receive-Wavelength field, and a Transmit-Wavelength field.

(17) If the Reconfigure-Flag field is 0, the Receive-Wavelength field and the Transmit-Wavelength field must set to 0. Now this means the message is a standard Deactivate_ONU-ID PLOAM message defined in G.987.3

(18) If the Reconfigure-Flag field is 1, the Receive-Wavelength field and the Transmit-Wavelength field contain the wavelength information which will be used by this deactivated ONU.

(19) It is to be noted that, in practical application, alternatively, “1” could represent that ONU directly performs the deactivation process defined in G.987.3, and “0” could represent that ONU firstly performs the deactivation process defined in G.987.3 and then enters ONU activation process to work on the wavelengths indicated in this Deactivate_ONU-ID message.

(20) Hereafter, the method of reconfiguring wavelength of the ONU according to one embodiment of the invention will be described in details, based on the above extended Deactivate_ONU-ID message.

(21) First, in step S11, the OLT sends a Deactivate_ONU-ID message to the ONU, the Deactivate_ONU-ID message including a reconfiguration flag (reconfigure flag), a new receive wavelength assigned for the ONU and a new transmit wavelength assigned for the ONU.

(22) After receiving the Deactivate_ONU-ID message from the OLT, in step S12, the ONU determines whether the reconfiguration flag included in the Deactivate_ONU-ID message indicates the receive wavelength and the transmit wavelength of the ONU are required to be reconfigured.

(23) If the reconfiguration flag does not indicate that the receive wavelength and the transmit wavelength of the ONU are required to be reconfigured, then the ONU enters the initial state directly, that is, switches off its transmitter, discard TC layer configuration parameters, etc. Then, ONU goes into activation process to listen to downstream transmission, obtain PSync and subframe synchronization, etc, which are existing steps in prior art and will not be repeated herein.

(24) If the reconfiguration flag indicates that the receive wavelength and the transmit wavelength of the ONU are required to be reconfigured, then the ONU discards TC layer parameters related to the current wavelength channel, replace the original receive wavelength and original transmit wavelength of the ONU with the new receive wavelength and the new transmit wavelength included in the Deactivate_ONU-ID message, and goes to the initial state. Then, the ONU performs a plurality of standard procedures orderly in the activation process. Since the original receive wavelength and original transmit wavelength of the ONU are replaced with the new receive wavelength and the new transmit wavelength, the ONU will work the new working wavelengths later.

(25) Advantageously, the Deactivate_ONU-ID message can be further extended to include other essential parameters of the ONU, for example, the new ONU-ID of the ONU used in the new wavelength channel, the new equalization delay of the ONU used in the new wavelength channel, etc.

(26) In this embodiment, the OLT needs to assign the new ONU-ID and/or the new equalization delay of the ONU used in the new wavelength channel, and register the ONU to a XG-PON system corresponding to a wavelength channel, of the ONU, to be reconfigured. After receiving the Deactivate_ONU-ID message from the OLT, besides the ONU replaces the original receive wavelength and original transmit wavelength with the new receive wavelength and new transmit wavelength, it could also replace the original ONU-ID with the new ONU-ID and the original equalization delay with the new equalization delay.

(27) Since the ONU obtains its new ONU-ID and new equalization delay used in the new wavelength channel through the Deactivate_ONU-ID message, the steps related to obtaining these parameters and related to registration could be omitted in the subsequent ONU activation process. That is, after synchronization and obtaining profile information, the ONU will skip to operational state directly. As a result, the subsequent ONU activation process is simplified.

(28) Those skilled in the art shall appreciate that the invention apparently will not be limited to the foregoing exemplary embodiments and can be embodied in other specific forms without departing from the spirit or essence of the invention. Accordingly the embodiments shall be construed anyway to be exemplary and non-limiting. Any reference numerals in the claims shall not be construed as limiting the scope of the invention. Moreover apparently the term “comprising” will not preclude another element(s) or step(s), and the term “a” or “an” preceding an element will not preclude a plurality of this element. A plurality of elements stated in an apparatus claim can alternatively be embodied as a single element in software or hardware. The terms “first”, “second”, etc., are intended to designate a name but not to suggest any specific order.