Optical line terminal device based on optical module standard packaging

Abstract

The invention discloses an optical line terminal device based on optical module standard packaging. The device comprises an optical module shell in the form of SFP, SFP + or XFP and an optical module arranged in the optical module shell. An optical interface of the optical module shell adopts SC or LC, and an electrical interface of the optical module shell adopts a standard SFP, SFP + or XFP interface; the optical module comprises a laser, a photoelectric detector, a laser driving unit, a burst receiving circuit, a G.984 OLT MAC processing unit, an Ethernet exchange processing function unit, a golden finger interface circuit and an equipment control unit. Gigabit passive optical network deployment on equipment meeting IEEE 802.3 can be achieved without traditional optical line terminal equipment, plug-and-play, rapidness and low cost are achieved, and the area and power consumption of a machine room can be saved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber communication, and in particular to an optical line terminal device based on optical module standard packaging. Background Art

[0002] With the rapid development of optical fiber communication technology and the growing demand for bandwidth, the existing optical fiber access network technology can no longer meet the growing demand for broadband services. Therefore, providing higher bandwidth solutions has become the development direction of the next generation of broadband access networks. However, most of the existing OLT (Optical Line Terminal) devices use non-standard packaging and cannot be directly inserted into standard SFP, SFP+ or XFP sockets, resulting in high costs, high power consumption, and inflexible deployment, which restricts the high-quality transmission of high-speed signals. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides an optical line terminal device based on optical module standard packaging.

[0004] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0005] An optical line terminal device based on optical module standard packaging, comprising an optical module housing in the form of SFP, SFP+ or XFP and an optical module arranged inside the housing; the optical interface of the optical module housing adopts SC or LC, and the electrical interface of the optical module housing adopts a standard SFP, SFP+ or XFP interface;

[0006] The optical module includes a laser, a photodetector, a laser driving unit, a burst receiving circuit, a G.984OLT MAC processing unit, an Ethernet switching processing functional unit, a gold finger interface circuit and an equipment control unit; the laser, the photodetector, the laser driving unit, the burst receiving circuit, the G.984OLT MAC processing unit and the Ethernet switching processing functional unit are all bidirectionally connected to the equipment control unit; the input end of the photodetector is connected to a standard LC or FC optical interface, the output end of the photodetector is connected to the input end of the burst receiving circuit, the output end of the burst receiving circuit is connected to the input end of the G.984OLT MAC processing unit, the G.984OLT MAC processing unit is bidirectionally connected to the Ethernet switching processing functional unit, the output end of the G.984OLT MAC processing unit is connected to the input end of the laser driving unit, the output end of the laser driving unit is connected to the input end of the laser, the output end of the laser is connected to the standard LC / FC optical interface, and the Ethernet switching processing functional unit is bidirectionally connected to the gold finger interface circuit.

[0007] Furthermore, the laser uses a 1490nm distributed feedback laser, which is packaged in a TO-56 or TO-38 TO, and is used to convert high-speed electrical signals into NRZ optical signals.

[0008] Furthermore, the photodetector uses a 2.5G APD avalanche diode packaged in a TO-46 TO for converting optical signals into electrical signals.

[0009] Furthermore, the laser and the laser driving unit are connected via direct current coupling.

[0010] Furthermore, the burst receiving unit includes an AC coupling capacitor, a discharge switch network, a burst signal detection circuit indication and a reset circuit, and is used to amplify and shape the burst signal.

[0011] Furthermore, the Ethernet switching processing functional module is used to transmit the CPE data service and control part data Ethernet message mode through GE or 2.5GE after the CPE data service passes through the G.984OLT MAC processing unit.

[0012] The beneficial effects of the present invention are:

[0013] The present invention provides an optical module housing in the form of SFP, SFP+ or XFP and an optical module arranged therein; the optical interface of the optical module housing adopts SC or LC, and the electrical interface of the optical module housing adopts a standard SFP, SFP+ or XFP interface, so that GPON (Gigabit-capable Passive Optical Network) deployment can be achieved on a device that meets IEEE 802.3 (such as a common Ethernet switch) without the need for a traditional OLT device, and the system is plug-and-play, fast and low-cost, thereby achieving the effect of saving computer room area and power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The figure is a schematic diagram of the structure of an optical line terminal device based on standard packaging of optical modules. DETAILED DESCRIPTION

[0015] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0016] like Figure 1As shown, an optical line terminal device based on optical module standard packaging includes an optical module housing in the form of SFP (Small Form Factor Pluggable), SFP+ or XFP (10Gbit pluggable) and an optical module arranged inside the optical module housing; the optical interface of the optical module housing adopts SC (Subscriber Connector, a type of optical fiber connector) or LC (Lucent Connector, a type of optical fiber connector), and the electrical interface of the optical module housing adopts a standard SFP, SFP+ or XFP interface.

[0017] The optical module includes a laser, a photodetector, a laser driving unit, a burst receiving circuit, a G.984OLT MAC (Media Access Control) processing unit, an Ethernet switching processing functional unit, a gold finger interface circuit and an equipment control unit; the laser, the photodetector, the laser driving unit, the burst receiving circuit, the G.984OLT MAC processing unit and the Ethernet switching processing functional unit are all bidirectionally connected to the equipment control unit; the input end of the photodetector is connected to a standard LC or FC optical interface, the output end of the photodetector is connected to an input end of the burst receiving circuit, the output end of the burst receiving circuit is connected to an input end of the G.984OLT MAC processing unit, the G.984OLT MAC processing unit is bidirectionally connected to the Ethernet switching processing functional unit, the output end of the G.984OLT MAC processing unit is connected to an input end of the laser driving unit, the output end of the laser driving unit is connected to an input end of the laser, the output end of the laser is connected to a standard LC or FC optical interface, and the Ethernet switching processing functional unit is bidirectionally connected to the gold finger interface circuit.

[0018] In an optional embodiment of the present invention, a standard LC or FC optical port is used to achieve connection with an external optical fiber interface, which may be an LC or FC or other standard optical fiber interface, and the optical port is used to connect with an optical distribution network, and the optical distribution network is connected with CPE (Customer Premise Equipment), thereby achieving optical fiber connection between the device and CPE.

[0019] In an optional embodiment of the present invention, the laser uses a 1490nm distributed feedback laser, which is packaged in a TO (Transistor Outline) of TO-56 or TO-38, and is used to convert high-speed electrical signals into NRZ (Non Return Zero Code) optical signals. In the present invention, a 1490nm distributed feedback laser is used. According to the design requirements and ITU specifications, the wavelength range is required to be 1480-1500nm, the side mode suppression ratio is greater than 30dB, and the -20dB spectrum width is less than 1nm. The optical power has different specifications such as B+, C+ or C++. The laser is packaged in a TO of TO-56 or TO-38. In order to facilitate monitoring of the performance of the laser during the life of the device, an MPD detector (a detection device based on the principle of magnetic field induction) is packaged inside the TO. In order to reduce power consumption, the laser uses a high luminous efficiency chip and is packaged with a non-spherical lens.

[0020] In an optional embodiment of the present invention, the photodetector uses a 2.5G APD (Avalanche PhotoDiod), which is packaged in a TO-46 TO, and is used to convert optical signals into electrical signals. In the present invention, a 2.5G APD is used, which has high sensitivity. The photodetector is packaged in a TO-46 TO. In order to improve the sensitivity, there is also a burst receiving TIA (transimpedance amplifier) ​​in the TO, which is used to convert the burst optical signal generated by the ONU (Optical Network Unit) into a burst electrical signal.

[0021] In an optional embodiment of the present invention, the laser and the laser driving unit are connected by DC coupling to reduce the power consumption of the entire product. The present invention converts high-speed electrical signals into electrical signals suitable for driving the laser. The driving unit includes an input buffer, a pre-driving circuit, a driving output circuit, an automatic power control, a digital control unit, an error alarm unit, etc. The 1.244Gbps CML or LVPECL differential digital signal is coupled to the input buffer through AC. The buffer circuit will amplify and shape the signal, and then the pre-driving circuit drives the output circuit to generate a signal suitable for driving the laser. The signal is a programmable current modulation signal and a bias current, which is provided to the laser. At the same time, the automatic power control circuit monitors the luminous power of the laser through the MPD detector, and controls the size of the modulation signal and the bias current through the digital control unit, so that the optical power is kept within the normal range throughout the product life cycle. At the same time, the error alarm unit generates an alarm signal by monitoring the current and the size of the optical power.

[0022] In an optional embodiment of the present invention, the burst receiving unit includes an AC coupling capacitor, a discharge switch network, a burst signal detection circuit indicator and a reset circuit, which are used to amplify and shape the burst signal. In addition, the burst receiving unit is used to achieve DC component elimination, noise reduction, eye diagram cross point adjustment, CML (Current Mode Logic) output, reset signal pulse widening, reset time adjustment, etc. The signal output from the TIA enters the discharge switch network through AC coupling, and the common mode level is quickly established through the reset signal given by the MAC to achieve DC component elimination. The AC signal with DC component eliminated can generate SD (Secure Digital) and data signals through detection and amplification, and is output to the MAC processing unit through eye diagram cross point adjustment and CML drive current. Since the reset signal time is short, the internal reset signal pulse widening and reset time are reset to improve sensitivity.

[0023] In an optional embodiment of the present invention, the G.984OLT MAC processing unit is used to implement the MAC processing function of GPON, control the online and offline of CPE, bandwidth allocation, priority allocation and other functions. The GPON MAC complies with the ITU-T G.984.x protocol, supports a downstream rate of 2.48832Gbit / s, an upstream rate of 1.24416Gbit / s, supports a maximum splitting ratio of 1:128, supports 128 ONUs to register online transmission services, supports 1024Tcont, 4096Gemport, and supports bidirectional FEC RS (255,239) error correction coding in order to improve the power budget. It provides PLOAM (Physical Layer OAM, physical layer OAM), OMCI (Optical Network Unit Management and Control Interface, a network protocol), OAM (Operation Administration and Maintenance, operation maintenance management) and Ethernet and other communication interfaces, and manages the internal PLOAM channel through the MCU. In addition, the OMCI channel has two control modes, one is to manage the transmission and reception of the A standard OMCI channel through the MCU internal management, and the other is to control the transmission and reception of the OMCI channel by sending and receiving Ethernet messages in a specific format through the in-band management channel reserved in the uplink port. PON MAC supports ONU-based status statistics, including various alarm indications of ONU, bandwidth management and T-CONT (Transmission Container) allocation, GEM PORT (GEM, a GPON encapsulation method) mapping and other business information and status reporting. PON MAC can monitor the detection of rogue ONUs and report and shut down controllable rogue ONUs, and support fast configuration of AES encryption function based on GEM PORT. PON MAC also has dynamic bandwidth allocation management and software database operation and maintenance control management, and supports the configuration of flexible bandwidth types T1 to T5 in the ITU-T standard protocol.

[0024] In an optional embodiment of the present invention, the Ethernet switching processing function module is used to transmit the CPE data service and control part data Ethernet message mode through GE or 2.5GE after the CPE data service passes through the G.984OLT MAC processing unit. The Ethernet switching processing function module supports the IEEE802.3 standard, supports the HSGMII (2.5GE) interface or the SGMII (GE) interface, supports the auto-negotiation or forced GE mode, supports the Ethernet message length of 64 to 1536Byte, supports the bidirectional link control setting and status query, and supports the bidirectional various message lengths (64 / 65 to 127 / … / 1024 to 1518 / 1519 or more) statistical query.

[0025] In an optional embodiment of the present invention, the gold finger interface circuit meets the SFP, SFP+ or XFP protocol specifications and meets the SGMII, HSGMII or GBIC (Giga Bitrate Interface Converter) interface, thereby realizing power supply / control / service exchange with the switch.

[0026] In an optional embodiment of the present invention, the device control unit is used to control the operation and configuration of the entire product: optical transceiver control, network management configuration. The device can facilitate rapid on-site deployment of the product through the control unit.

[0027] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. An optical line terminal device based on optical module standard packaging, characterized in that: It includes an optical module housing in the form of SFP, SFP+ or XFP and an optical module arranged therein; the optical interface of the optical module housing adopts SC or LC, and the electrical interface of the optical module housing adopts a standard SFP, SFP+ or XFP interface; The optical module includes a laser, a photodetector, a laser driving unit, a burst receiving circuit, a G.984OLT MAC processing unit, an Ethernet switching processing functional unit, a gold finger interface circuit and an equipment control unit; the laser, the photodetector, the laser driving unit, the burst receiving circuit, the G.984OLT MAC processing unit and the Ethernet switching processing functional unit are all bidirectionally connected to the equipment control unit; the input end of the photodetector is connected to a standard LC / FC optical interface, the output end of the photodetector is connected to an input end of the burst receiving circuit, the output end of the burst receiving circuit is connected to an input end of the G.984OLT MAC processing unit, the G.984OLT MAC processing unit is bidirectionally connected to the Ethernet switching processing functional unit, the output end of the G.984OLT MAC processing unit is connected to an input end of the laser driving unit, the output end of the laser driving unit is connected to an input end of the laser, the output end of the laser is connected to a standard LC or FC optical interface, and the Ethernet switching processing functional unit is bidirectionally connected to the gold finger interface circuit.

2. The optical line terminal device based on optical module standard packaging according to claim 1, characterized in that: The laser uses a 1490nm distributed feedback laser, packaged in a TO-56 or TO-38 TO, and is used to convert high-speed electrical signals into NRZ optical signals.

3. The optical line terminal device based on optical module standard packaging according to claim 1, characterized in that: The photodetector uses a 2.5G APD avalanche diode packaged in a TO-46 TO to convert optical signals into electrical signals.

4. The optical line terminal device based on optical module standard packaging according to claim 1, characterized in that: The laser and the laser driving unit are connected via DC coupling.

5. The optical line terminal device based on optical module standard packaging according to claim 1, characterized in that: The burst receiving unit includes an AC coupling capacitor, a discharge switch network, a burst signal detection circuit indication and a reset circuit, and is used to amplify and shape the burst signal.

6. The optical line terminal device based on optical module standard packaging according to claim 1, characterized in that: The Ethernet switching processing functional module is used to transmit the CPE data service and control part data Ethernet message mode through GE or 2.5GE after the CPE data service passes through the G.984OLT MAC processing unit.

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