Highly efficient, higher loss budget PON transceiver

Abstract

Various example embodiments for supporting optical communication in an optical communication system may be configured to utilize fiber loss characteristics of optical fibers to support improved optical communication in various types of optical communication systems, such as passive optical networks (PONs) or other suitable types of optical communication systems. Various example embodiments for utilizing fiber loss characteristics of an optical fiber to improve optical communication in a PON may be configured to improve arrival and loss characteristics of a PON optical distribution network while enabling the use of a solution that is lower cost and lower power consumption compared to conventional methods for PON systems, based on an apparatus that includes a receiver that receives optical fibers from the PON system. The receiver is configured to operate with a receiver sensitivity specified for a class of optical modules for the passive optical network, and the transmitter is configured to operate with a transmit power less than a transmit power specified for the class of optical modules for the passive optical network.

Description

Technical Field

[0001] Various example embodiments relate generally to optical communication systems, and more particularly, but not exclusively, to supporting communications in a passive optical network (PON). Background Art

[0002] Various communication technologies may be used to support communications in various types of communication systems. Summary of the invention

[0003] In at least some example embodiments, a device includes a receiver configured to operate using a receiver sensitivity specified for a class of optical modules for a passive optical network, and a transmitter configured to operate using a transmit power less than a transmit power specified for the class of optical modules for the passive optical network. In at least some example embodiments, the device is configured to make the dispersion penalty at a specific distance equal to or less than a maximum specified value. In at least some example embodiments, the device is configured to support performing a dispersion penalty test to measure the dispersion penalty at a specific distance. In at least some example embodiments, the dispersion penalty test is configured to confirm that the dispersion at the specific distance is equal to or less than a maximum specified value. In at least some example embodiments, the class of optical modules for the passive optical network includes one of the following: Class A, Class B, Class B+, Class N1, Class N2, Class C, Class C+, Class D, Class E1, or Class E2. In at least some example embodiments, the optical module class for the passive optical network includes class D, the transmit power specified for class D is +8dBm, and the transmitter is configured to operate using a transmit power of +5dBm. In at least some example embodiments, the apparatus includes a passive optical network module. In at least some example embodiments, the passive optical network module is configured to support a single passive optical network. In at least some example embodiments, the passive optical network module is configured to support multiple passive optical networks. In at least some example embodiments, the apparatus includes an optical line terminal for a passive optical network.

[0004] In at least some example embodiments, a non-transitory computer-readable medium stores computer program instructions that, when executed by an apparatus, cause the apparatus to at least perform: receiving an upstream signal from one or more optical network units by a receiver configured to operate using a receiver sensitivity specified for a class of optical modules for a passive optical network, and sending a downstream signal to the one or more optical network units by a transmitter configured to operate using a transmit power less than the transmit power specified for the class of optical modules for a passive optical network. In at least some example embodiments, the dispersion loss at a specific distance is equal to or less than a maximum specified value. In at least some example embodiments, the computer program instructions, when executed by the apparatus, cause the apparatus to at least perform support for performing a dispersion loss test to measure the dispersion loss at a specific distance. In at least some example embodiments, the dispersion loss test is configured to confirm that the dispersion at the specific distance is equal to or less than a maximum specified value. In at least some example embodiments, the class of optical modules for the passive optical network includes one of: Class A, Class B, Class B+, Class N1, Class N2, Class C, Class C+, Class D, Class E1, or Class E2. In at least some example embodiments, the class of optical modules for the passive optical network includes Class D, the transmit power specified for Class D is +8dBm, and the transmit power is +5dBm. In at least some example embodiments, the non-transitory computer-readable medium is disposed within a passive optical network module. In at least some example embodiments, the passive optical network module is configured to support a single passive optical network. In at least some example embodiments, the passive optical network module is configured to support multiple passive optical networks. In at least some example embodiments, the non-transitory computer-readable medium is disposed within an optical line terminal for a passive optical network.

[0005] In at least some example embodiments, a method includes: receiving an upstream signal from one or more optical network units by a receiver configured to operate using a receiver sensitivity specified for an optical module class for a passive optical network, and sending a downstream signal to the one or more optical network units by a transmitter configured to operate using a transmit power less than a transmit power specified for the optical module class for a passive optical network. In at least some example embodiments, the dispersion loss at a specific distance is equal to or less than a maximum specified value. In at least some example embodiments, the method also includes supporting the execution of a dispersion loss test to measure the dispersion loss at a specific distance. In at least some example embodiments, the dispersion loss test is configured to confirm that the dispersion at the specific distance is equal to or less than a maximum specified value. In at least some example embodiments, the optical module class for the passive optical network includes one of the following: Class A, Class B, Class B+, Class N1, Class N2, Class C, Class C+, Class D, Class E1, or Class E2. In at least some example embodiments, the optical module class for the passive optical network includes class D, the transmit power specified for class D is +8dBm, and the transmit power is +5dBm. In at least some example embodiments, the method is performed by a passive optical network module. In at least some example embodiments, the passive optical network module is configured to support a single passive optical network. In at least some example embodiments, the passive optical network module is configured to support multiple passive optical networks. In at least some example embodiments, the method is performed at an optical line terminal for a passive optical network.

[0006] In at least some example embodiments, a device includes means for: receiving an upstream signal from one or more optical network units by a receiver configured to operate using a receiver sensitivity specified for an optical module class for a passive optical network, and sending a downstream signal to the one or more optical network units by a transmitter configured to operate using a transmit power less than the transmit power specified for the optical module class for a passive optical network. In at least some example embodiments, the dispersion loss at a specific distance is equal to or less than a maximum specified value. In at least some example embodiments, the device also includes means for supporting the execution of a dispersion loss test to measure the dispersion loss at a specific distance. In at least some example embodiments, the dispersion loss test is configured to confirm that the dispersion at the specific distance is equal to or less than a maximum specified value. In at least some example embodiments, the optical module class for the passive optical network includes one of the following: Class A, Class B, Class B+, Class N1, Class N2, Class C, Class C+, Class D, Class E1, or Class E2. In at least some example embodiments, the optical module class for the passive optical network includes class D, the transmit power specified for class D is +8dBm, and the transmit power is +5dBm. In at least some example embodiments, the method is performed by a passive optical network module. In at least some example embodiments, the passive optical network module is configured to support a single passive optical network. In at least some example embodiments, the passive optical network module is configured to support multiple passive optical networks. In at least some example embodiments, the method is performed at an optical line terminal for a passive optical network. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The teachings herein may be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:

[0008] Figure 1 An example embodiment of a passive optical network (PON) configured to support communications between an optical line terminal (OLT) and an optical network unit (ONU) is shown, wherein the OLT is configured to utilize optical fiber loss characteristics to improve optical communications between the OLT and the ONU;

[0009] Figure 2 The inherent loss of silica-based optical fiber at various wavelengths is shown to illustrate the use of optical fiber loss characteristics to improve optical communication between OLT and ONU;

[0010] Figure 3 The asymmetry between the downstream loss and the upstream loss that may exist in the single-mode optical fiber of some PONs is shown to illustrate the use of optical fiber loss characteristics to improve the optical communication between the OLT and the ONU;

[0011] Figure 4The remaining link budget margin for downstream communication in the PON is shown to illustrate the use of fiber loss characteristics to improve the optical communication between the OLT and the ONU;

[0012] Figure 5 An example embodiment of a method for configuring an OLT module to utilize optical fiber loss characteristics to improve optical communications between the OLT and the ONU is shown;

[0013] Figure 6 An example embodiment of a method for supporting communication between an OLT and an ONU using an OLT module configured to utilize optical fiber loss characteristics to improve optical communication between the OLT and the ONU is shown; and

[0014] Figure 7 An example embodiment of a computer suitable for performing the various functions described herein is shown.

[0015] To facilitate understanding, the same reference numerals are used herein as much as possible to represent the same elements in the various figures. DETAILED DESCRIPTION

[0016] Various example embodiments for supporting optical communications in optical communication systems are described herein. Various example embodiments may be configured to utilize optical fiber loss characteristics of optical fiber to support improved optical communications in various types of optical communication systems, such as passive optical networks (PONs) or other suitable types of optical communication systems. Various example embodiments for utilizing optical fiber loss characteristics of optical fiber to improve optical communications in PONs may be configured to improve PON optical distribution network (ODN) reach and loss characteristics while enabling the use of lower cost and lower power consumption solutions compared to traditional approaches to PON systems. Various example embodiments for utilizing optical fiber loss characteristics of optical fiber to improve optical communications in PONs may be configured to utilize the asymmetry between downstream and upstream losses that may exist in single-mode optical fibers when the PON wavelengths are sufficiently separated, as is the case in various types of PONs (e.g., Gigabit-capable PONs (GPONs), XG-PONs, XGS-PONs, etc., and various combinations thereof). Various example embodiments for utilizing the fiber loss characteristics of optical fibers to improve optical communications in PONs may be applied to various types of PONs (e.g., GPON, XGS-PON, etc., and various combinations thereof) to support various types of PON applications (e.g., extended reach PON applications, high margin PON applications, etc., and various combinations thereof). Various example embodiments for utilizing the fiber loss characteristics of optical fibers to improve optical communications in PONs may be used to implement various PON optical distribution network (ODN) classes, including various ODN classes (e.g., Class D, Class E1, Class E2, etc.) that may be standardized by the International Telecommunication Union-Telecommunication Sector (ITU-T) organization, various other ODN classes that may be standardized by standard organizations other than ITU-T, various other ODN classes that may be adopted or accepted by the industry even if not standardized by any standard organization, various other ODN classes that may not be feasible due to OLT transmission power limitations, etc., and various combinations thereof. Various example embodiments for utilizing the fiber loss characteristics of optical fibers to improve optical communications in a PON may be applied to various PON ODN classes that implement various types of PON modules that may be used within a PON (e.g., single PON module (SPM), multi-PON module (MPM), etc.) It should be understood that these and various other example embodiments and advantages or potential advantages may be further understood by reference to the various drawings discussed further below.

[0017] Figure 1 An example embodiment of a passive optical network (PON) configured to support communications between an optical line terminal (OLT) and an optical network unit (ONU) is shown, wherein the OLT is configured to utilize optical fiber loss characteristics to improve optical communications with the ONU.

[0018] The PON 100 is configured to provide broadband network access to end customers using fiber optic telecommunication technology to support communications for the end customers. The PON 100 includes an optical line terminal (OLT) 110 and a group of optical network units (ONUs) 120-1-120-N (collectively referred to as ONUs 120) connected via an optical distribution network (ODN) 130. The PON 100 may be configured to support downstream communications from the OLT 110 to the ONUs 120 via the ODN 130 and upstream communications from the ONUs 120 to the OLT 110 via the ODN 130. The PON 100 may be configured to operate using various types of PON technologies that may be based on various PON standards (e.g., Gigabit PON (GPON), 10 Gigabit Symmetric PON (XGS-PON), etc., and various combinations thereof). It should be appreciated that PON 100 may include various other elements (which have been omitted for clarity), may be based on various other PON technologies and / or standards, etc., as well as various combinations thereof.

[0019] The PON 100 may be configured for a variety of different applications. For example, the PON 100 may be configured to operate as an extended reach PON or a high margin PON. For example, an extended reach PON typically strives to reach 60 kilometers (km) while also providing the maximum possible split ratio (maximum possible split ratio) of this extended reach (i.e., achieving the maximum possible value of the number N of ONUs 120). It is worth noting that other distances of reach may also be used, including shorter distances to try to increase the N value (e.g., 50km, 40km, 30km, etc., where shorter lengths may be used to try to increase the N value), or longer distances, where lower N values ​​are acceptable (e.g., 70km, 80km, etc.). For example, a high margin PON is typically a short reach PON (e.g., an extended reach of more than 20 kilometers is typically not required, although longer ranges may be supported) that seeks to achieve a high link budget engineering margin to improve robustness (e.g., robustness to dirty connectors and / or bad splices, which are common in actual PON systems). Note that a single splitter may be used, or multiple splitters may be cascaded. It will be appreciated that PON 100 may be configured in various ways (e.g., using a specific OLT configuration for OLT 110, using a specific ONU configuration for ONU 120, using certain ODN classes for ODN 130, etc., and various combinations thereof) to support such PON applications.

[0020] The OLT 110 is configured to support communication between the ONU 120 and one or more upstream networks (omitted for clarity). The OLT 110 may be located at a central location, such as a central office (CO), an outdoor enclosure, or other suitable location. For example, the one or more upstream networks may include one or more core communication networks configured to support communication of the OLT 110, thereby supporting communication of the ONU 120. For example, the OLT 110 may be configured to forward data received from one or more upstream networks to the ONU 120 downstream through the ODN 130, and forward data received from the ONU 120 upstream through the ODN 130 to one or more upstream networks. The OLT 110 includes a PON module 111 configured to support communication of the OLT 110. The PON module 111 may be a single PON module (SPM) configured to support a single PON (e.g., GPON or XGS-PON), or a multi-PON module (MPM) configured to support two or more PONs (e.g., a combination of GPON and XGS-PON). The PON module 111 may be implemented in various form factors, for example, as a small form-factor pluggable (SFP) transceiver module (e.g., SFP, quad SFP (QSFP), double-density SFP (e.g., SFP-DD or QSFP-DD), etc.), as a module including a transmitter and a receiver, etc. The PON module 111 may be configured in such a manner as to provide improved reach and loss characteristics for the ODN 130 by utilizing the fiber loss characteristics of the optical fiber of the ODN 130, while reducing the cost and power consumption typically required to implement a given ODN class of the ODN 130. It will be appreciated that the OLT 110 may include various other elements for supporting communications with the ONU 120.

[0021] The ONUs 120 are each configured to support communication between the OLT 110 and one or more downstream networks or devices (omitted for clarity). The ONUs 120 may be located at respective user premises or other suitable locations. For example, the one or more downstream networks or devices of the ONUs 120 may include one or more local area networks (LANs) of the customer, one or more communication devices of the customer (e.g., modems, routers, switches, set-top boxes, smart TVs, gaming systems, computers, smart phones, etc., and various combinations thereof). For example, each ONU 120 may be configured to forward data received from the OLT 110 via the ODN 130 downstream to one or more downstream networks or devices, and forward data received from one or more downstream networks or devices upstream to the OLT 110 via the ODN 130. Each ONU 120 may include one or more communication elements 121 (depicted as communication elements 121-1-121-N of ONUs 120-1-120-N, respectively (collectively referred to as communication elements 121)) configured to support communication between the ONU 120 and the OLT 110 (e.g., transceivers, transmitters, receivers, etc., and various combinations thereof). Each ONU 120 may support various PON-related communication functions (e.g., PON-based transmit / receive functions, PON protocol encapsulation, etc., and various combinations thereof). It should be understood that each ONU 120 may include various other elements for supporting communication with the OLT 110.

[0022] The ODN 130 may be a data distribution system configured to support communications between the OLT 110 and the ONUs 120. The ODN 130 is depicted as being arranged in a branching configuration; however, it should be understood that various other P2MP configurations may be used. The ODN 130 may include various passive optical components (e.g., optical fibers, optical couplers, optical splitters, wavelength multiplexers / demultiplexers, etc.) that do not require power to support the distribution of data signals between the OLT 110 and the ONUs 120; however, it should be understood that in some cases, the ODN 130 may also include active components to support communications between the OLT 110 and the ONUs 120 (e.g., optical amplifiers, etc.). The ODN 130 may be configured to support various ODN classes, including ODN classes that may be standardized for PON (e.g., ITU-T standardized ODN classes such as Class A, Class B, Class B+, Class N1, Class N2, Class C, Class C+, Class D, Class E1, Class E2, etc., including other classes currently standardized and other classes that may be developed and standardized in the future (by ITU-T and / or other standards organizations)), ODN classes that have not yet been standardized but are adopted or accepted by the industry (e.g., currently adopted or accepted classes and / or other classes that may be adopted or accepted in the future), etc., and various combinations thereof. It should be understood that the ODN 130 may include various other elements for supporting communication between the OLT 110 and the ONU 120.

[0023] Various example embodiments described herein may be configured to implement higher ODN classes (e.g., Class D, Class E1, Class E2, etc.) for various types of PON modules (e.g., SPM, MPM, etc.) and PON applications (e.g., extended reach PON, high margin PON, etc.) that may be used in various types of PON systems (e.g., XGS, GPON, XG(S)-PON, etc.). Various example embodiments described herein may be configured to implement higher ODN classes for various types of PON modules that may be used in various types of PONs in a manner that tends to improve ODN reach and loss characteristics while enabling the use of lower cost and lower power consumption solutions compared to conventional approaches to PON systems. Various example embodiments described herein may be configured to implement higher ODN classes for various types of PON modules that may be used in various types of PONs by exploiting the asymmetry between downstream and upstream losses that may exist in single mode optical fibers when the PON wavelengths are sufficiently separated, as is the case in various types of PONs (e.g., XGS, GPON, XG(S)-PON, etc.). It should be understood that while the various example embodiments described herein may be used to implement various higher ODN classes in various types of PON modules in various types of PON systems, in order to clearly describe various aspects of the various example embodiments, various example embodiments are primarily described herein in the context of supporting a Class D MPM in the context of an XG(S)-PON system. It should be understood that these and various other example embodiments may be further understood by first considering various aspects of a PON system, including fiber characteristics and ODN classes, more generally.

[0024] In a PON system, various types of OLT optical modules can be used. For example, OLT optical modules can include XGS and GPONOLT transceivers, which can be implemented as single PON modules (SPM) or multi-PON modules (MPM). MPM integrates coexistence filtering in the optical module and provides a single socket to connect to the ODN. Higher loss ODN classes are usually accommodated by improving the specifications of the OLT optical module alone, allowing all ODN classes to use common ONU variants. In a PON system, various link budgets (ODN loss ranges) are defined in the ITU PON standard based on the fiber length and split ratio. The maximum loss of class B+, class C+, and class D ODNs is 28dB, 32dB, and 35dB, respectively. In a PON system, an important performance indicator is the receiver sensitivity, which determines how low a signal can be detected. Based on the various ODN classes, the XGS receiver sensitivity at the OLT for class B+, class C+, and class D ODNs is -25dBm, -29dBm, and -32dBm, respectively. In the PON system, another important performance indicator is the transmit power at the OLT. The minimum transmit power of Class B+, Class C+ and Class D ODNs at the OLT is +1dBm, +5dBm and +8dBm respectively.

[0025] In PON systems, Class D OLT optical modules are often well suited for the extended reach PON and high margin PON applications described above. However, increasing the minimum transmit power of the electro-absorption modulated laser (EML) to achieve Class D presents the following issues: (1) the required +8dBm minimum Tx power at high throughput is difficult to achieve, and (2) the dispersion tolerance of the EML tends to degrade due to the higher chirp as the Tx power increases, resulting in greater dispersion loss for a given distance. To overcome these challenges, the traditional approach is to add an SOA post amplifier. However, the production process required for the EML+SOA results in a larger and more complex device than the EML alone; fewer devices are produced per wafer, increasing the cost. In addition, the SOA requires an additional signal to bias the SOA. Additional pins on the SOA driver and TxTO are required, further increasing the complexity and cost of the module. This results in a more expensive TO package or the TO package includes another TO pin function, such as reusing the laser monitoring photodiode. Like the EML, the SOA must also be cooled, so a TEC with higher cooling capacity is required. The power required for EML+SOA+TEC is usually several hundred milliwatts (mW) higher than that of EML alone, resulting in an increase in the power consumption of the optical module by ~10-15%. Given that the power consumption of the optical module usually accounts for ~50% of the total power consumption of the OLT, when using EML+SOA, the overall OLT power consumption will increase by ~5-8%, resulting in an increase in the operator's operating costs.

[0026] In a PON system, standard single-mode optical fibers (eg, bend-resistant optical fiber types based on G.652, G.657, etc.) are typically used in the ODN. Figure 2 The intrinsic loss of silica-based optical fibers (such as SSMF) at various wavelengths is shown. Figure 2 As shown in Figure 1, the intrinsic loss of the O-band is ~0.15 dB / km higher than that of the C-band or nearby. Therefore, for XGS-PON, the additional loss upstream compared to the downstream loss is approximately 3 dB, 6 dB, and 9 dB at 20 km, 40 km, and 60 km, respectively. Figure 3 As shown. The difference between downstream and upstream losses is due to the physical characteristics of the SSMF and will therefore exist in any SSMF used within the ODN. The GPON wavelengths of 1490 / 1310nm will result in a slightly smaller asymmetry in loss, for example, closer to ~0.1dB / km. It is worth noting that the ITU defines optical path loss (dispersion) masks for DD20 and DD40 in G.9807.1Amd2, while for DD60 it is assumed that up to 3dB of loss is allowed in the (40-60]km range (not standardized). Figure 4 The resulting dispersion mask is shown versus distance, along with the remaining link budget margin that may be defined.

[0027] Figure 4 The remaining link budget margin for downstream communication in a PON is shown to illustrate the use of fiber loss characteristics to improve optical communication between the OLT and the ONU. Figure 4 The step-line 410 in FIG. 4 shows the relationship between the dispersion mask and the distance. Next, assume that the actual dispersion at 60 km is just within the allowed 3 dB limit, such as Figure 4 As shown by point 411 in FIG. 1 , it can be appreciated that although the actual dispersion versus distance relationship will have a convex shape, such as Figure 4 As shown by the curved dot-dash line 420 in FIG. 4 , it can be assumed that the upper limit of the path loss and distance (from the origin (0 dB at 0 distance) and Figure 4 4. The solid straight line 430 anchors the dispersion loss and distance at 0 dB and 3 dB at 0 km and 60 km, respectively, while also accurately intercepting the dispersion mask transition points at 20 km and 40 km (i.e., the transition points of the step-line 410). Figure 4The solid line 440 in shows the downstream excess link budget due to asymmetric losses when the minimum transmit power is reduced by 3dB. Thus, at 0km, the excess link budget starts at -3dB, but then increases with distance due to the asymmetry of losses in the fiber downstream versus upstream. For example, at 20km, the loss asymmetry reaches 3dB, exactly offsetting the effect of reducing the minimum transmit power by 3dB. For the upstream, the maximum loss is always defined by the ODN class, and the OLT receiver sensitivity must meet the specifications of the given class; however, for the downstream, a final remaining link budget margin (RLBM) is defined that takes into account the worst-case bound of asymmetric fiber losses and optical path losses, where the minimum Tx power is reduced by 3dB. This is achieved in Figure 4 Shown as a solid line 450 .

[0028] based on Figure 4 , it will be appreciated that for Class D “lightweight” modules (as opposed to traditional Class D modules) based on the various example embodiments presented herein, at 20 km the RLBM is exactly 0 dB, meaning that the downstream and upstream link budgets are perfectly balanced. For distances above 20 km, there is additional RLBM downstream compared to upstream due to the increased loss asymmetry. Therefore, for distances above 20 km, even higher ODN classes than Class D can be achieved, provided that the OLT receiver sensitivity can be further improved without increasing the OLT minimum transmit power. Below 20 km, the downstream link budget is slightly reduced compared to traditional Class D modules, with the maximum reduction being 2 dB, which occurs at 0 km. However, with respect to Figure 1 For applications in this area, as the fiber distance decreases below 20 km, the physical fiber losses will decrease more than RLBM, giving even more RLBM than achieved at 20 km.

[0029] Based on Figure 4, Class D “light” modules configured to exploit fiber loss characteristics can be calibrated during production, compared to traditional Class D modules, with the following two differences: (1) XGS transmit power is calibrated to meet a minimum of +5dBm, rather than the +8dBm typically specified for Class D ODNs, and (2) the dispersion loss is measured at 60km to confirm that it is less than or equal to 3dB, and based on this test point, the dispersion loss is guaranteed to fall within the step-based dispersion loss mask at all other distances (up to 60km), as described above for Figure 4Thus, a reduced OLT transmit power may be specified for a "Class D" MPM because (1) the applications of actual interest (i.e., extended reach PON and high margin PON) do not require a further increase in OLT transmit power compared to Class C+, and (2) the reduced OLT transmit power avoids the need for an SOA post-amplifier and the resulting disadvantages described herein (e.g., larger footprint, higher power consumption, higher cost, etc.).

[0030] Reference again Figure 1 , and based on Figure 4 For extrapolation of various ODN classes that ODN 130 may support, PON module 111 of OLT 110 may be configured in a manner that exploits the fiber loss characteristics of the optical fiber of ODN 130 to provide improved reach and loss characteristics for ODN 130 while reducing the cost and power consumption typically required to implement a given ODN class of ODN 130. PON module 111 may include a receiver 112 configured to operate using a receiver sensitivity specified for the class of optical modules used for PON (e.g., specified by one or more ITU-T standards and / or other suitable standards, not standardized but adopted or accepted by the industry, or similar standards), and a transmitter 113 configured to operate using a transmit power less than the transmit power specified for the class of optical modules used for PON (e.g., specified by one or more ITU-T standards and / or other suitable standards, not standardized but adopted or accepted by the industry, or similar standards). The PON module 111 may be configured to make the dispersion loss at a specific distance meet a specific threshold (e.g., the dispersion loss at 60 km is less than or equal to 3 dB), and may be configured to support the execution of a dispersion loss test to ensure that the dispersion loss at a specific distance meets the specific threshold. It is understood that, based on further consideration of various specific ODN classes that the ODN 130 may support, it is further understood that the configuration of the PON module 111 supports such features.

[0031] In the case of Class D specified by the ITU-T standard for multiple PON modules, the PON module 111 may, for example, include: a receiver 112 configured to use the receiver sensitivity specified by the ITU-T standard for Class D; and a transmitter 113 configured to use a transmit power that is less than the transmit power specified by the ITU-T standard for Class D (e.g., using a transmit power of +5dBm specified by the ITU-T standard for Class C+ instead of a transmit power of +8dBm specified by the ITU-T standard for Class D). It should be understood that the transmit power does not necessarily need to correspond to the transmit power of the next lower ODN class in the ODN class hierarchy, but will be less than the transmit power specified by the ITU-T standard for Class D (e.g., the transmit power may correspond to the transmit power of a different lower ODN class (e.g., Class C) in the ODN class hierarchy, a transmit power that is not necessarily specified for a particular ODN class in the ITU-T standard (e.g., a lower transmit power adopted or accepted by the industry or any other suitable lower transmit power), etc.). It should be noted that such a PON module 111 may be referred to as a Class D "lightweight" module.

[0032] For example, in the case of a D+ class that is not specified by the ITU-T standard but may be developed and adopted by the industry, the PON module 111 may include a receiver 112 that is configured to use a receiver sensitivity specified or adopted by the industry for the D+ class, and a transmitter 113 that is configured to use a transmit power that is less than the transmit power specified or adopted by the industry for the D+ class (e.g., using a transmit power of +8 dBm specified or adopted by the industry for the D class instead of using a higher transmit power specified or adopted by the industry for the D+ class). It should be understood that the transmit power does not necessarily need to correspond to the transmit power of the next lower ODN class in the ODN class hierarchy, but will be less than the transmit power specified for the D+ class (e.g., the transmit power may correspond to the transmit power of a different lower ODN class in the ODN class hierarchy (e.g., Class C+, Class C, etc.), not necessarily the transmit power specified by a particular ODN class in the ITU-T standard (e.g., a lower transmit power adopted or accepted by the industry or any other suitable lower transmit power), etc.). Note that such a PON module 111 may be referred to as a D+ class "lightweight" module.

[0033] For example, in the case of the E1 class specified by the ITU-T standard, the PON module 111 may include a receiver 112 configured to use the receiver sensitivity specified by the ITU-T standard for the E1 class, and a transmitter 113 configured to use a transmit power that is less than the transmit power specified by the ITU-T standard for the E1 class (e.g., using the transmit power specified by the ITU-T standard for the N1 class or the N2 class, rather than using the higher transmit power specified by the ITU-T standard for the E1 class). It should be understood that the transmit power does not necessarily need to correspond to the transmit power of the next lower ODN class in the ODN class hierarchy, but will be less than the transmit power specified by the ITU-T standard for the E1 class (e.g., the transmit power may correspond to the transmit power of a different lower ODN class in the ODN class hierarchy (e.g., the N1 class or the N2 class), not necessarily the transmit power specified by a particular ODN class in the ITU-T standard (e.g., a lower transmit power adopted or accepted by the industry or any other suitable lower transmit power), etc.). Note that such a PON module 111 may be referred to as an E1 class "lightweight" module.

[0034] For example, in the case of class E2 specified by the ITU-T standard, the PON module 111 may include a receiver 112 configured to use the receiver sensitivity specified by the ITU-T standard for class E2, and a transmitter 113 configured to use a transmit power that is less than the transmit power specified by the ITU-T standard for class E2 (e.g., using the transmit power specified by the ITU-T standard for class E1, rather than using the higher transmit power specified by the ITU-T standard for class E2). It should be understood that the transmit power does not necessarily need to correspond to the transmit power of the next lower ODN class in the ODN class hierarchy, but will be less than the transmit power specified by the ITU-T standard for class E1 (e.g., the transmit power may correspond to the transmit power of a different lower ODN class (e.g., class N1 or class N2) in the ODN class hierarchy, not necessarily the transmit power specified by a particular ODN class in the ITU-T standard (e.g., a lower transmit power adopted or accepted by the industry or any other suitable lower transmit power), etc.). Note that such a PON module 111 may be referred to as a class E2 "lightweight" module.

[0035] Although the PON module 111 is mainly described as utilizing the fiber loss characteristics of the optical fiber of the ODN 130 to support a specific ODN class, it can be configured to utilize the fiber loss characteristics of the optical fiber of the ODN 130 to support various other ODN classes, including various other ODN classes standardized by the ITU-T (Class A, Class B, Class B+, Class C, Class C+, etc., and various combinations thereof), various other ODN classes that can be standardized by standard organizations other than the ITU-T, various other ODN classes that may be adopted or accepted by the industry even if they are not standardized by any standard organization, etc., and various combinations thereof.

[0036] As described above, the PON module 111 can be configured to utilize the fiber loss characteristics of the optical fiber of the ODN 130 to support various ODN classes that can utilize various transmission powers and receiver sensitivities. The configuration of the PON module 111 can include the configuration or calibration of the transmitter 113 of the PON module 111 and the configuration or calibration of the receiver 112 of the PON module 111. The transmitter 113 can be calibrated so that the chirp properties of the transmitted signal allow the transmission of dispersion losses over long fiber distances. For example, in the case of XGS using an externally modulated laser (EML), the chirp properties of the transmitter 113 are related to the voltage applied to the electrical absorption (EA) portion of the EML. At the same time, the higher the EA voltage is set, the lower the output power of the EML. Therefore, during calibration, the EA voltage will be set to the maximum possible negative value while transmitting the minimum output power required for power delivery. The receiver 112 can be configured or calibrated so that the receiver operates using the receiver sensitivity specified for the optical module class used for the PON module 111. It is understood that the configuration of the PON module 111 may be performed in other ways to take advantage of the fiber loss characteristics of the optical fibers of the ODN 130 to support various ODN types.

[0037] It will be appreciated that although PON 100 is described primarily with respect to a particular type, number, and arrangement of components, it may be implemented using various other types of components, various other numbers of components, various other arrangements of components, etc., and various combinations thereof.

[0038] Figure 5 An example embodiment of a method for configuring an OLT module to utilize optical fiber loss characteristics to improve optical communication between the OLT and the ONU is shown. It is understood that although primarily presented as being performed sequentially, at least a portion of the functions of method 500 may be performed simultaneously or in parallel. Figure 5The method 500 is performed in a different order than the order shown. At block 501, the method 500 begins. At block 510, the OLT module is configured so that the receiver of the OLT module is configured to operate using a receiver sensitivity specified for the class of optical modules for the passive optical network, and the transmitter of the OLT module is configured to operate using a transmit power less than the transmit power specified for the class of optical modules for the passive optical network. At block 520, a dispersion loss test is performed on the OLT module to measure the dispersion loss of the OLT module at a specific distance. At block 599, the method 500 ends. It should be understood that the present invention is not limited to the following. Figure 1 The various functions introduced can be incorporated into Figure 5 In the context of method 500 .

[0039] Figure 6 An example embodiment of a method for supporting communication between an OLT and an ONU using an OLT module configured to utilize optical fiber loss characteristics to improve optical communication between the OLT and the ONU is shown. It should be understood that although the main functions of method 600 are presented as being performed continuously, at least a portion of the functions of method 600 may be performed simultaneously or in parallel. Figure 6 The method 600 may be performed in a different order than the order shown. At block 601, the method 600 begins. At block 610, an upstream signal from one or more optical network units is received by a receiver configured to operate using a receiver sensitivity specified for the optical module class for the passive optical network. At block 620, a downstream signal is sent to one or more optical network units by a transmitter configured to use a transmission power less than the transmission power specified for the optical module class for the passive optical network. At block 699, the method 600 ends. It should be understood that the present invention is not limited to the embodiments of the present invention. Figure 1 The various functions shown can be incorporated into Figure 6 In the context of method 600 .

[0040] Various example embodiments for supporting optical communications using optical modules configured based on developments in optical fiber loss characteristics may provide various advantages or potential advantages. For example, various example embodiments for supporting optical communications using optical modules configured based on developments in optical fiber loss characteristics may be configured to support improved ODN reach and loss characteristics using lower cost and lower power consumption solutions compared to conventional solutions for PON systems. For example, various example embodiments for supporting optical communications using optical modules configured based on developments in optical fiber loss characteristics may be configured to achieve higher loss ODN classes by only increasing the receiver sensitivity of the OLT receiver without increasing the transmitter output power of the OLT transmitter, thereby being able to significantly reduce the power dissipation and cost of the OLT optical module. For example, various example embodiments for supporting optical communications using optical modules configured based on developments in optical fiber loss characteristics can be configured to achieve higher loss ODN classes by only increasing the receiver sensitivity of the OLT receiver and maintaining the transmitter output power of the OLT transmitter of the lower loss ODN class (e.g., the OLT transmit power specification of a class D ODN can remain the same as a class C+ to provide a class D "lightweight" optical module, the OLT transmit power specification of a class E1 ODN or a class E2 ODN can remain the same as a class N1 ODN or a class N2 ODN to provide a class E1 "lightweight" optical module or a class E2 "lightweight" optical module, and so on), thereby significantly reducing the power dissipation and cost of the OLT optical module. For example, various example embodiments for supporting optical communications using optical modules configured based on utilization of optical fiber loss characteristics may be configured to achieve higher ODN classes (e.g., Class D, Class E2, or other ODN classes with relatively higher ODN losses) for various types of PON modules (e.g., SPM, MPM, etc.) and PON applications (e.g., extended reach PON, high margin PON, etc.), which may be used in various types of PON systems (e.g., XGS, GPON, XG(S)-PON, etc.) while using lower cost and lower power consumption solutions compared to traditional approaches (e.g., no need to increase transmit power and no need for SOA post-amplifiers). For example, various example embodiments for supporting optical communications using optical modules configured based on fiber loss characteristics development can be configured to exploit the asymmetry between downstream and upstream losses that may exist in single-mode optical fibers when the PON wavelengths are sufficiently separated, which may be the case for GPON and XG(S)-PON, making the approach suitable for improving ODN reach and loss for various types of PON modules that may be deployed in various types of PONs (e.g., XG(S) and / or GPON single PON modules, XG(S)+GPON MPMs, potential future MPMs that may integrate GPON and / or XG(S)-PON with future higher speed PONs (e.g., 25G PON or 50GPON), etc., and various combinations thereof).It should be appreciated that various example embodiments for supporting optical communications using optical modules configured based on optical fiber loss characteristic exploitation may provide various other advantages or potential advantages.

[0041] Figure 7 An example embodiment of a computer suitable for performing the various functions presented herein is shown.

[0042] The computer 700 includes a processor 702 (e.g., a central processing unit (CPU), a processor, a processor having a set of processor cores, a processor core of a processor, etc.) and a memory 704 (e.g., a random access memory (RAM), a read-only memory (ROM), etc.). In at least some example embodiments, the computer 700 may include at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the computer to perform various functions presented herein.

[0043] The computer 700 may also include a cooperating element 705. The cooperating element 705 may be a hardware device. The cooperating element 705 may be a process that may be loaded into the memory 704 and executed by the processor 702 to implement the various functions presented herein (in which case, for example, the cooperating element 705 (including associated data structures) may be stored on a non-transitory computer-readable medium, such as a storage device or other suitable type of storage element (e.g., non-volatile memory (e.g., flash memory, erasable programmable read-only memory (EPROM)), disk drive, optical drive, etc.)).

[0044] The computer 700 may also include one or more input / output devices 706. The input / output devices 706 may include one or more of a user input device (e.g., a keyboard, a keypad, a mouse, a microphone, a camera, etc.), a user output device (e.g., a display, a speaker, etc.), one or more network communication devices or elements (e.g., an input port, an output port, a receiver, a transmitter, a transceiver, etc.), one or more storage devices (e.g., a tape drive, a floppy disk drive, a hard disk drive, a high-density disk drive, etc.), etc., and various combinations thereof.

[0045] It should be understood that the computer 700 may represent a general architecture and functionality suitable for implementing the functional elements described herein, portions of the functional elements described herein, etc., and various combinations thereof. For example, the computer 700 may provide a general architecture and functionality suitable for implementing one or more elements described herein. For example, the computer 700 may provide a general architecture and functionality suitable for implementing at least one of the following: an OLT or a portion thereof, an OLT optical module or a portion thereof, an ONU or a portion thereof, etc., and various combinations thereof.

[0046] It should be understood that at least some of the functionality presented herein may be implemented in software (e.g., by implementing the software on one or more processors for execution on a general-purpose computer (e.g., by execution by one or more processors) to provide a special-purpose computer, etc.) and / or may be implemented in hardware (e.g., using a general-purpose computer, one or more application-specific integrated circuits and / or any other hardware equivalents).

[0047] It should be understood that at least some of the functions presented herein can be implemented in hardware, for example, as circuits that cooperate with a processor to perform various functions. Some of the functions / elements described herein can be implemented as a computer program product, in which computer instructions, when processed by a computer, adjust the operation of the computer to invoke or otherwise provide the methods and / or techniques described herein. Instructions for invoking various methods can be stored in fixed or removable media (e.g., non-transitory computer-readable media), transmitted via a data stream in a broadcast or other signal-bearing medium, and / or stored in a memory within a computing device that operates according to the instructions.

[0048] It should be understood that the term "non-transitory" as used herein is a limitation of the medium itself (ie, tangible, not a signal), rather than a limitation of data storage persistence (eg, RAM vs. ROM).

[0049] It should be understood that, as used herein, “at least one of: ” and “at least one of ” and similar expressions, where a list of two or more elements is connected by “and” or “or”, mean at least any one element, or at least any two or more elements, or at least all elements.

[0050] It should be understood that, as used herein, the term "or" refers to a non-exclusive "or" unless otherwise indicated (eg, with use of "or else" or "or alternatively").

[0051] It should be understood that although various embodiments that incorporate the teachings presented herein have been shown and described in detail, those skilled in the art can readily devise many other varied embodiments that still incorporate these teachings.

Claims

1. A device comprising: a receiver configured to operate using a receiver sensitivity specified for a class of optical modules for use in a passive optical network; as well as A transmitter is configured to operate using a transmit power less than a transmit power specified for the class of optical modules for use in a passive optical network.

2. The device according to claim 1, wherein: The apparatus is configured so that the dispersion loss at a certain distance is equal to or less than a maximum specified value.

3. The device according to any one of claims 1 to 2, wherein: The apparatus is configured to support performing a dispersion loss test to measure dispersion loss at a specific distance.

4. The device according to claim 3, wherein: The dispersion loss test is configured to confirm that the dispersion at the particular distance is equal to or less than a maximum specified value.

5. The device according to any one of claims 1 to 4, wherein: The optical module class used for the passive optical network includes one of the following: Class A, Class B, Class B+, Class N1, Class N2, Class C, Class C+, Class D, Class E1, or Class E2.

6. The device according to any one of claims 1 to 4, wherein: The optical module class for the passive optical network includes class D, wherein the transmit power specified for class D is +8 dBm, wherein the transmitter is configured to operate using a transmit power of +5 dBm.

7. The device according to any one of claims 1 to 6, wherein: The device includes a passive optical network module.

8. The device according to claim 7, wherein: The passive optical network module is configured to support a single passive optical network.

9. The device according to claim 7, wherein: The passive optical network module is configured to support a plurality of passive optical networks.

10. The device according to any one of claims 1 to 9, wherein: The apparatus comprises an optical line terminal for a passive optical network.

11. A method comprising: receiving, by a receiver configured to operate using a receiver sensitivity specified for a class of optical modules for use in a passive optical network, upstream signals from one or more optical network units; as well as Downstream signals are sent to the one or more optical network units by a transmitter configured to operate using a transmit power that is less than a transmit power specified for the class of optical modules for use in a passive optical network.

12. The method according to claim 11, wherein: The dispersion loss at a specific distance is equal to or less than the maximum specified value.

13. The method according to any one of claims 11 to 12, further comprising: Supports dispersion loss testing to measure the dispersion loss at a specific distance.

14. The method according to claim 13, wherein: The dispersion loss test is configured to confirm that the dispersion at the particular distance is equal to or less than a maximum specified value.

15. The method according to any one of claims 11 to 14, wherein: The optical module class used for the passive optical network includes one of the following: Class A, Class B, Class B+, Class N1, Class N2, Class C, Class C+, Class D, Class E1, or Class E2.

16. The method according to any one of claims 11 to 14, wherein: The optical module class for the passive optical network includes class D, wherein the transmit power specified for class D is +8dBm, wherein the transmit power is +5dBm.

17. The method according to any one of claims 11 to 16, wherein: The method is performed by a passive optical network module.

18. The method according to claim 17, wherein: The passive optical network module is configured to support a single passive optical network.

19. The method according to claim 17, wherein: The passive optical network module is configured to support a plurality of passive optical networks.

20. The method according to any one of claims 11 to 19, wherein: The method is performed at an optical line terminal for a passive optical network.

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