Optical Transceiver

Abstract

To provide a base station signal monitoring system and a method therefor.SOLUTION: An optical transceiver includes: a reference tunable laser module configured to generate and output light of a reference wavelength; a first general tunable laser module configured to generate and output light of a first wavelength; and a controller configured to control a tuning operation of the first wavelength of the first general tunable laser module, based on information about a relationship between the reference wavelength and the first wavelength.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to optical transceivers, and more particularly to tunable optical transceivers. [Background technology]

[0002] A passive optical network (PON) is a core component of the implementation of FTTH environments and Gigabit Ethernet.

[0003] To realize WDM-PON, multiple light sources with unique wavelengths are required. In order to realize multiple light sources with different wavelengths in WDM-PON, the use of multi-port type wavelength tunable optical transceivers that can simultaneously output multiple optical signals with different wavelengths is gradually increasing recently.

[0004] The above-mentioned wavelength tunable optical transceiver includes a plurality of integrated tunable laser modules, and the integrated tunable laser modules usually have the same configuration and structure. For example, each tunable laser module includes a wavelength locker, a current-to-voltage converter (I / V converter), a thermistor, a thermoelectric cooler (TEC), and the like. However, the wavelength locker, the I / V converter, thermistor, TEC, and the like are not components for generating light of a wavelength required for the tunable laser module (i.e., an assigned wavelength). Nevertheless, the inclusion of these in each tunable laser module causes problems in terms of cost, design, and control complexity of the wavelength tunable optical transceiver. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Korean Patent Publication No. 10-2009-0037195 Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved by the present invention is to provide a tunable optical transceiver capable of outputting a light source having multiple wavelengths while reducing the cost and complexity of the design and control.

[0007] The technical problems that the technical idea of ​​the present invention is intended to solve are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0008] According to one aspect of the present invention, there is provided an optical transceiver comprising: a reference tunable laser module that generates and outputs light of a reference wavelength; a first general tunable laser module that generates and outputs light of a first wavelength; and a controller that controls a tuning operation of the first wavelength of the first general tunable laser module based on information about a relationship between the reference wavelength and the first wavelength.

[0009] According to an exemplary embodiment, the information about the relationship between the reference wavelength and the first wavelength is information indicating a difference between the reference wavelength and the first wavelength.

[0010] According to an exemplary embodiment, the difference between the reference wavelength and the first wavelength is predetermined in consideration of a correlation between the reference wavelength and the first wavelength depending on temperature.

[0011] According to an exemplary embodiment, the optical transceiver further comprises a memory having stored therein a look-up table containing information regarding a relationship between the reference wavelength and the first wavelength.

[0012] According to an exemplary embodiment, the reference wavelength is a wavelength for a data transmission / reception channel or a wavelength for an auxiliary channel.

[0013] According to an exemplary embodiment, of the reference tunable laser module and the first general tunable laser module, only the reference tunable laser module includes at least one of a wavelength locker, a current-voltage converter, a thermoelectric cooler, and a temperature sensor.

[0014] According to an exemplary embodiment, the optical transceiver further includes a second general tunable laser module that generates and outputs light at a second wavelength, and the controller controls a tuning operation of the second general tunable laser module at the second wavelength based on information about a relationship between the reference wavelength and the second wavelength.

[0015] According to another aspect of the present invention, there is provided an optical transceiver comprising: at least one tunable laser module; and a controller that controls wavelength tuning of the at least one tunable laser module by referring to a look-up table containing relationship information between a preset reference wavelength and an output wavelength assigned to the at least one tunable laser module.

[0016] According to an exemplary embodiment, the relationship information is information indicative of a difference between the preset reference wavelength and the assigned output wavelength.

[0017] According to an exemplary embodiment, the difference between the preset reference wavelength and the assigned output wavelength is predetermined in view of a correlation between the preset reference wavelength and the assigned output wavelength with temperature.

[0018] According to an exemplary embodiment, the preset reference wavelength is a wavelength for a data transmission / reception channel or a wavelength for an auxiliary channel.

[0019] According to an exemplary embodiment, the optical transceiver further comprises a reference tunable laser module that generates and outputs light at the preset reference wavelength, but only the reference tunable laser module comprises at least one of a wavelength locker, a current-to-voltage converter, a thermoelectric cooler, and a temperature sensor. Effect of the Invention

[0020] According to an embodiment of the present invention, when implementing a wavelength-tunable optical transceiver capable of outputting light sources with multiple wavelengths by integrating multiple tunable laser modules, it is possible to reduce costs and reduce the complexity of design and control by simplifying some of the components of the tunable laser modules.

[0021] The effects obtained by the embodiments according to the technical concept of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description. [Brief description of the drawings]

[0022] [Figure 1] 1 is a configuration diagram of an optical communication system according to an embodiment of the present invention. [Diagram 2] 1 is a block diagram of an optical transceiver according to an embodiment of the present invention; [Diagram 3] 1 is a block diagram of a reference tunable laser module according to an embodiment of the present invention; [Figure 4] 1 is a block diagram of a general tunable laser module according to an embodiment of the present invention; [Diagram 5] FIG. 2 is an illustrative diagram of a wavelength lookup table according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The technical idea of ​​the present invention can be modified in various ways and can have various embodiments, and therefore, specific embodiments are illustrated in the drawings and will be described in detail. However, this is not intended to limit the technical idea of ​​the present invention to the specific embodiments, and it should be understood that the technical idea of ​​the present invention includes all modifications, equivalents, and alternatives included in the scope of the technical idea of ​​the present invention.

[0024] In describing the technical concept of the present invention, if a detailed description of the related known art is deemed to unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, numbers (e.g., 1, 2, etc.) used in the description of this specification are merely identification symbols for distinguishing one component from another.

[0025] In addition, when a component is referred to as being "coupled" or "connected" to another component in this specification, it should be understood that the component may be directly coupled or connected to the other component, but unless specifically stated to the contrary, it may also be coupled or connected via another component in between.

[0026] In addition, terms such as "module", "device" and "child" used in this specification refer to a unit that processes at least one function or operation, and this is embodied as hardware or software, or a combination of hardware and software, such as a processor, microprocessor, microcontroller, CPU (Central Processing Unit), GPU (Graphics Processing Unit), APU (Accelerate Processor Unit), DSP (Drive Signal Processor), ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

[0027] It is to be understood that the division of components in this specification is merely a division according to the main function of each component. That is, two or more components described below may be combined into one component, or one component may be divided into two or more components according to further subdivided functions. It goes without saying that each component described below may perform some or all of the functions of other components in addition to its own main function, and some of the main functions of each component may be exclusively performed by other components.

[0028] Hereinafter, various embodiments according to the technical concept of the present invention will be described in detail.

[0029] FIG. 1 is a configuration diagram of an optical communication system according to an embodiment of the present invention.

[0030] Referring to FIG. 1, an optical communication system 100 according to an embodiment of the present invention includes an optical communication device 110, a demultiplexer (DeMUX) 120 that receives an optical signal transmitted from the optical communication device 110, and an optical transceiver 130 at a remote location that is connected to the DeMUX 120 and receives the separated individual optical signals.

[0031] The optical communication device 110 includes n optical transceivers 112-1 to 112-n (where n is a natural number equal to or greater than 2) that generate individual optical signals, and a multiplexer (MUX) 111 that multiplexes the n optical signals input from the n optical transceivers 112-1 to 112-n. Depending on the embodiment, the MUX 111 may be separate from the optical communication device 110.

[0032] The optical communication device 110 converts input data or data received from other devices into optical signals and transmits them to the DeMUX 120. The DeMUX 120 is a device connected to the optical communication device 110 through an optical cable, and transmits individual optical signals assigned to the corresponding optical transceivers 130 at the remote site. The optical transceivers 130 at the remote site are connected to a predetermined device. In some embodiments, the optical communication system 10 is applied to an optical subscriber network. In this case, the optical communication device 110 is an optical line terminal (OLT) at the central office. The optical transceiver 130 at the remote site is connected to one of a remote terminal (RT), an optical network terminal (ONT) at the subscriber, and an optical network unit. In another embodiment, the optical communication system 100 constitutes an optical transmission network, which is a sub-network constituting a fronthaul segment of a radio access network architecture. In this case, the optical communication device 110 is a longitudinal device on the side of a digital unit (DU) or a baseband unit (BBU) on the side of a central office. And, the optical transceiver 130 on the side of a remote site is connected to a remote unit (RU) or a remote radio head (RRH). However, the present invention is not limited thereto, and the technical idea of ​​the present invention can also be applied to a midhaul and backhaul segment of the radio access network architecture.

[0033] In yet another embodiment, the optical communication system 100 is applied to a distributed antenna system (DAS) for eliminating shadow areas of a base station, in which the optical communication device 110 is a head-end unit and the optical transceiver 130 at the remote site is connected to an extension unit or a remote unit.

[0034] As described above, the optical communication system 100 according to the technical concept of the present invention can be applied to various optical communication networks implemented by optical communication devices located at remote locations and transmitting and receiving optical signals through corresponding optical transceivers.

[0035] Hereinafter, the specific operation of the components of the optical communication device 110, particularly the optical transceiver 112, will be described with reference to FIG. 2 to FIG.

[0036] FIG. 2 is a block diagram of an optical transceiver 112 according to an embodiment of the present invention, FIG. 3 is a block diagram of a reference tunable laser module 240 according to an embodiment of the present invention, FIG. 4 is a block diagram of a general tunable laser module 230 according to an embodiment of the present invention, and FIG. 5 is an exemplary diagram of a wavelength look-up table according to an embodiment of the present invention.

[0037] 2 to 4, an optical transceiver 112 according to an embodiment of the present invention includes a controller (MCU, Main Control Unit) 210, a memory 220, m general tunable laser modules 230-1, 230-2 through 230-m (where m is a natural number equal to or greater than 3), and a reference tunable laser module 240. Depending on the embodiment, the optical transceiver 112 may further include a MUX 250.

[0038] First, the standard tunable laser module 240 and the general tunable laser module 230 will be described.

[0039] The reference tunable laser module 240 according to an embodiment of the present invention includes a temperature sensor 300, a thermoelectric cooler (TEC) 310, a wavelength locker 320, a laser controller 330, and a laser diode 340. Although not shown, the reference tunable laser module 240 further includes a current-to-voltage converter (I / V converter) that converts a current signal into a corresponding voltage signal, a thermistor whose resistance value changes depending on temperature, and the like.

[0040] The general tunable laser modules 230-1 to 230-m according to an embodiment of the present invention include a laser controller 410 and a laser diode 420. Unlike the standard tunable laser module 240, the general tunable laser module 230 does not include a TEC, a wavelength locker, an I / V converter, a thermistor, etc.

[0041] The reference tunable laser module 240 outputs an optical signal of a preset n-th wavelength λn. Hereinafter, the n-th wavelength λn is referred to as a reference wavelength. The reference wavelength is preset, and depending on the embodiment, a wavelength for a data transmission / reception channel or a wavelength for an auxiliary channel (wavelength for wavelength locking, etc.) is set as the reference wavelength. The operation of the reference tunable laser module 240 is similar to that of a conventional tunable laser module, and therefore a detailed description thereof will be omitted.

[0042] The first general tunable laser module 230-1 outputs an optical signal of a first wavelength λ1 under the control of the controller 210. Also, the second general tunable laser module 230-2 outputs an optical signal of a second wavelength λ2 under the control of the controller 210. Also, the mth general tunable laser module 230-m outputs an optical signal of an mth wavelength λm under the control of the controller 210. Here, the first wavelength λ1, the second wavelength λ2 through the mth wavelength λm, and the reference wavelength λn are all different wavelengths.

[0043] More specifically, the operation of the controller 210 to control the optical signal output based on the relationship between a preset reference wavelength λn and the assigned wavelength required for each of the m individual general tunable laser modules 230-1 to 230-m will be described.

[0044] First, information on a reference wavelength λn is stored in the memory 220, and information on the relationship between the reference wavelength λn and each of the first to m-th wavelengths λ1 to λm is stored in the form of a look-up table. Meanwhile, in FIG. 2, the memory 220 is illustrated as being separate from the controller 210, but may be included in the controller 210.

[0045] The controller 210 controls the laser controller 410 provided in the first general tunable laser module 230-1 based on information about the relationship between the reference wavelength λn and the first wavelength λ1 stored in the look-up table of the memory 220, and the laser controller 410 outputs a first optical signal corresponding to the first wavelength λ1 from the laser diode 420.

[0046] In the same manner, the controller 210 controls the laser controller 410 provided in the mth general tunable laser module 230-m based on the information about the relationship between the reference wavelength λn and the mth wavelength λm stored in the look-up table, and the laser controller 410 outputs the mth optical signal corresponding to the mth wavelength λm from the laser diode 420.

[0047] 5 illustrates a wavelength lookup table according to an embodiment of the present invention, which includes information on the relationship between a first wavelength λ1 and a reference wavelength λn, information on the relationship between a second wavelength λ2 and a reference wavelength λn, and information on the relationship between an m-th wavelength λm and a reference wavelength λn.

[0048] The information on the relationship between the wavelengths and the reference wavelengths is information indicating the difference between the wavelengths. For example, as shown in FIG 5, the wavelength lookup table includes information indicating that the first wavelength is greater than the reference wavelength by a (λ1=λn+a), the second wavelength is greater than the reference wavelength by b (λ2=λn+b), and the m-th wavelength is greater than the reference wavelength by k (λm=λn+k).

[0049] The wavelength differences (a, b, etc.) are values ​​that are predefined in consideration of correlation with temperature, for example, and the wavelength lookup table also includes information related to the temperature. For example, the wavelength lookup table may be predefined as a=αΔT+x1, b=αΔT+x2, and k=αΔT+xm. Here, α is a predefined correlation coefficient. Also, ΔT is a difference value from a predefined reference temperature. Information about the reference temperature is predefined in the memory 220, the reference tunable laser module 240 senses a current temperature through the temperature sensor 300 provided therein, and the controller 210 generates a difference value (ΔT) between the sensed temperature and the reference temperature. Also, x1 to xm are predefined offsets. Such information related to temperature is also included in the wavelength lookup table and is predefined in the memory 220. Also, information about the size of the reference wavelength may be predefined in the memory 220.

[0050] Therefore, the controller 210 refers to the wavelength lookup table to read information stored in the memory 220 regarding the relationship between the reference wavelength and the wavelength required for the general tunable laser module, and based on the read information, controls the wavelength tuning of the optical signal so that each of the first general tunable laser module 230-1 to the mth general tunable laser module 230-m has the wavelength required.

[0051] In other words, the controller 210 controls each laser controller 410 of the general tunable laser module, and each laser controller 410 sets the output light wavelength value of the general laser diode to have an output light wavelength value set (or assigned) by the control of the controller 210.

[0052] The nth optical signal output from the reference tunable laser module 240 is combined with transmission data by a corresponding modulator to be converted into modulated nth optical data, which is then input to the MUX 250 .

[0053] Similarly, the first optical signal output from the first general tunable laser module 230-1 through the mth optical signal output from the mth general tunable laser module 230 are converted into first optical data through mth optical data modulated by combining with transmission data by corresponding modulators, respectively, and the first optical data through the mth optical data are input to the MUX 250, respectively.

[0054] The MUX 250 of the optical transceiver 112 multiplexes the first optical data through the n-th optical data and outputs the multiplexed data to the MUX 111 of the optical communication device 110. The MUX 111 of the optical communication device 110 multiplexes the optical signals input from the multiple optical transceivers 112-1 through 112-n, and transmits the multiplexed data through the optical cable via the DeMUX 120 to the corresponding optical transceiver 130 at the remote location.

[0055] As described above, the controller 210 uses the wavelength look-up table stored in the memory 220 to set the wavelength values ​​of the optical signals output from the general tunable laser modules 230-1 to 230-m.

[0056] As a result, each of the multiple general tunable laser modules 230-1 to 230-m does not need to include any other components (e.g., TEC, wavelength locker, thermistor, etc.) other than the laser controller 410 and the laser diode 420 for generating an optical signal.

[0057] As a result, it is clear that the optical transceiver according to the embodiment of the present invention can have a simple configuration and can also reduce costs.

[0058] In the above, it has been assumed that the reference tunable laser module 240 outputs an optical signal of a preset reference wavelength, but the reference tunable laser module 240 can also generate and output light of a corresponding wavelength under the control of the controller 210.

[0059] For example, the wavelength lookup table in the memory 220 contains information about the relationship between the reference wavelength and the wavelength (i.e., the nth wavelength) to be output from the reference tunable laser module 240. In this case, the controller 210 can tune the reference wavelength using the information stored in the wavelength lookup table in the memory 220. That is, the controller 210 controls the laser controller 330, which sets the output light wavelength value of the reference laser diode 340 under the control of the controller 210.

[0060] Although the technical concept of the present invention has been described in detail above with reference to various embodiments, the technical concept of the present invention is not limited to the above embodiments and may be modified or changed in various ways by those skilled in the art. [Explanation of symbols]

[0061] 100: Optical communication systems 110: Optical communication equipment 120: Demultiplexer (DeMUX) 112, 130: Optical transceiver

Claims

1. An optical transceiver, comprising: a reference tunable laser module for generating and outputting light of a reference wavelength; a first conventional tunable laser module for generating and outputting light at a first wavelength; a controller for controlling a tuning operation of the first wavelength of the first general tunable laser module based on information about a relationship between the reference wavelength and the first wavelength; the information about the relationship between the reference wavelength and the first wavelength is information indicative of a difference between the reference wavelength and the first wavelength, The difference between the reference wavelength and the first wavelength is determined in advance in consideration of a correlation between the reference wavelength and the first wavelength depending on temperature. Optical transceiver.

2. 10. The optical transceiver of claim 1, further comprising a memory having a look-up table stored therein that contains information about a relationship between the reference wavelength and the first wavelength.

3. 2. The optical transceiver of claim 1, wherein the reference wavelength is a wavelength for a data transmission / reception channel or a wavelength for an auxiliary channel.

4. 2. The optical transceiver of claim 1, wherein among the reference tunable laser module and the first general tunable laser module, only the reference tunable laser module includes at least one of a wavelength locker, a current-to-voltage converter, a thermoelectric cooler, and a temperature sensor.

5. and a second general tunable laser module for generating and outputting light at a second wavelength, 2. The optical transceiver of claim 1, wherein the controller controls a tuning operation of the second wavelength of the second general tunable laser module based on information about a relationship between the reference wavelength and the second wavelength.

6. An optical transceiver, comprising: at least one tunable laser module; a controller for controlling wavelength tuning of the at least one tunable laser module by referring to a look-up table containing information about a relationship between a preset reference wavelength and an output wavelength assigned to the at least one tunable laser module; the information about the relationship is information indicating a difference between the preset reference wavelength and the assigned output wavelength, the difference between the preset reference wavelength and the assigned output wavelength is predetermined in consideration of a correlation between the preset reference wavelength and the assigned output wavelength with temperature; Optical transceiver.

7. 7. The optical transceiver according to claim 6, wherein the preset reference wavelength is a wavelength for a data transmission / reception channel or a wavelength for an auxiliary channel.

8. Further comprising a reference tunable laser module for generating and outputting light of the preset reference wavelength; The optical transceiver of claim 6, wherein only the reference tunable laser module includes at least one of a wavelength locker, a current-to-voltage converter, a thermoelectric cooler, and a temperature sensor.

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