US-12627461-B2 - Signal synchronization and payload extraction in a communication network or other network

Abstract

A method includes obtaining, at a specified device, one or more bandwidth maps contained in communications in a first direction along a transmission medium. Each bandwidth map identifies when one or more other devices are allowed to communicate in a second direction opposite the first direction along the transmission medium. The method also includes using the one or more bandwidth maps to identify expected features of communications from the one or more other devices in the second direction along the transmission medium. The method further includes identifying actual features of the communications from the one or more other devices in the second direction along the transmission medium. In addition, the method includes synchronizing the specified device with the communications from the one or more other devices using the expected and actual features.

Inventors

• Michael H. Grover

Assignees

• RAYTHEON APPLIED SIGNAL TECHNOLOGY, INC.

Dates

Publication Date

20260512

Application Date

20230519

Claims (20)

1. 1 . A method comprising: obtaining, at a specified device, one or more bandwidth maps contained in communications in a first direction along a transmission medium, each bandwidth map identifying when one or more other devices are allowed to communicate in a second direction opposite the first direction along the transmission medium; using the one or more bandwidth maps to identify expected features of communications from the one or more other devices in the second direction along the transmission medium; identifying actual features of the communications from the one or more other devices in the second direction along the transmission medium; synchronizing the specified device with the communications from the one or more other devices using the expected and actual features; and labeling bits associated with the communications from the one or more other devices with tags identifying correct features.
2. 2 . The method of claim 1 , wherein synchronizing the specified device with the communications from the one or more other devices comprises: comparing the expected features to a collection of the actual features; in response to determining that at least some of the expected and actual features do not match, shifting the collection of the actual features; and comparing the expected features to the shifted collection of the actual features.
3. 3 . The method of claim 1 , wherein: each bandwidth map is associated with a frame in the first direction and identifies (i) at least one of the one or more other devices allowed to communicate in a corresponding frame in the second direction and (ii) at least one time slot in which the at least one of the one or more other devices is allowed to communicate in the corresponding frame; and at least some of the expected features are based on the at least one time slot from the one or more bandwidth maps.
4. 4 . The method of claim 1 , wherein labeling the bits comprises generating the tags identifying the correct features after the actual features are aligned with the expected features.
5. 5 . The method of claim 1 , further comprising: performing payload extraction of data contained in the communications from the one or more other devices.
6. 6 . The method of claim 1 , wherein synchronizing the specified device with the communications from the one or more other devices comprises: synchronizing the specified device with the communications from the one or more other devices without using range information from the specified device to the one or more other devices.
7. 7 . The method of claim 1 , wherein: the transmission medium comprises at least one optical fiber; the one or more other devices comprise one or more optical network units configured to communicate with an optical line terminal over the at least one optical fiber; the first direction is associated with transmissions from the optical line terminal to the one or more optical network units; and the second direction is associated with transmissions from the one or more optical network units to the optical line terminal.
8. 8 . An apparatus comprising: at least one interface configured to be coupled to a transmission medium; and at least one processing device configured to: obtain one or more bandwidth maps contained in communications in a first direction along the transmission medium, each bandwidth map identifying when one or more other devices are allowed to communicate in a second direction opposite the first direction along the transmission medium; use the one or more bandwidth maps to identify expected features of communications from the one or more other devices in the second direction along the transmission medium; identify actual features of the communications from the one or more other devices in the second direction along the transmission medium; and synchronize with the communications from the one or more other devices using the expected and actual features; wherein, to synchronize with the communications from the one or more other devices, the at least one processing device is configured to: compare the expected features to a collection of the actual features; in response to determining that at least some of the expected and actual features do not match, shift the collection of the actual features; and compare the expected features to the shifted collection of the actual features.
9. 9 . The apparatus of claim 8 , wherein the at least one processing device is configured to repeatedly compare the expected features to the collection of the actual features, shift the collection of the actual features, and compare the expected features to the shifted collection of the actual features until the actual features align with the expected features.
10. 10 . The apparatus of claim 8 , wherein: each bandwidth map is associated with a frame in the first direction and identifies (i) at least one of the one or more other devices allowed to communicate in a corresponding frame in the second direction and (ii) at least one time slot in which the at least one of the one or more other devices is allowed to communicate in the corresponding frame; and at least some of the expected features are based on the at least one time slot from the one or more bandwidth maps.
11. 11 . The apparatus of claim 8 , wherein the at least one processing device is further configured to label bits associated with the communications from the one or more other devices with tags identifying correct features.
12. 12 . The apparatus of claim 8 , wherein the at least one processing device is further configured to perform payload extraction of data contained in the communications from the one or more other devices.
13. 13 . The apparatus of claim 8 , wherein the at least one processing device is configured to synchronize with the communications from the one or more other devices without using range information from the apparatus to the one or more other devices.
14. 14 . The apparatus of claim 8 , wherein: the transmission medium comprises at least one optical fiber; the one or more other devices comprise one or more optical network units configured to communicate with an optical line terminal over the at least one optical fiber; the first direction is associated with transmissions from the optical line terminal to the one or more optical network units; and the second direction is associated with transmissions from the one or more optical network units to the optical line terminal.
15. 15 . A non-transitory machine readable medium containing instructions that when executed cause at least one processor to: obtain one or more bandwidth maps contained in communications in a first direction along a transmission medium, each bandwidth map identifying when one or more other devices are allowed to communicate in a second direction opposite the first direction along the transmission medium; use the one or more bandwidth maps to identify expected features of communications from the one or more other devices in the second direction along the transmission medium; identify actual features of the communications from the one or more other devices in the second direction along the transmission medium; and synchronize with the communications from the one or more other devices using the expected and actual features; wherein the instructions that when executed cause the at least one processor to synchronize with the communications from the one or more other devices comprise instructions that when executed cause the at least one processor to: compare the expected features to a collection of the actual features; in response to determining that at least some of the expected and actual features do not match, shift the collection of the actual features; and compare the expected features to the shifted collection of the actual features.
16. 16 . The non-transitory machine readable medium of claim 15 , wherein the instructions when executed cause the at least one processor to compare the expected features to the collection of the actual features, shift the collection of the actual features, and compare the expected features to the shifted collection of the actual features until the actual features align with the expected features.
17. 17 . The non-transitory machine readable medium of claim 15 , wherein: each bandwidth map is associated with a frame in the first direction and identifies (i) at least one of the one or more other devices allowed to communicate in a corresponding frame in the second direction and (ii) at least one time slot in which the at least one of the one or more other devices is allowed to communicate in the corresponding frame; and at least some of the expected features are based on the at least one time slot from the one or more bandwidth maps.
18. 18 . The non-transitory machine readable medium of claim 15 , further containing instructions that when executed cause the at least one processor to at least one of: label bits associated with the communications from the one or more other devices with tags identifying correct features; and perform payload extraction of data contained in the communications from the one or more other devices.
19. 19 . The non-transitory machine readable medium of claim 15 , wherein the instructions when executed cause the at least one processor to synchronize with the communications from the one or more other devices without using range information to the one or more other devices.
20. 20 . The non-transitory machine readable medium of claim 15 , wherein: the transmission medium comprises at least one optical fiber; the one or more other devices comprise one or more optical network units configured to communicate with an optical line terminal over the at least one optical fiber; the first direction is associated with transmissions from the optical line terminal to the one or more optical network units; and the second direction is associated with transmissions from the one or more optical network units to the optical line terminal.

Description

GOVERNMENT RIGHTS This invention was made with government support under contract number XX-21112200001 awarded by the United States government. The government has certain rights in the invention. TECHNICAL FIELD This disclosure relates generally to communication systems. More specifically, this disclosure relates to signal synchronization and payload extraction in a communication network, such as a gigabit passive optical network (GPON), or other network. BACKGROUND Gigabit passive optical networks (GPONs), which are detailed in ITU-T Recommendation G.984.3 (referred to as the “GPON specification”), typically include multiple optical network units (ONUs) that communicate with an optical line terminal (OLT) over one or more common optical fibers. Optical transmissions from the optical network units occur in tightly-scheduled bursts in order to keep the optical network units from simultaneously transmitting optical signals and interfering with each other. To support this, the optical line terminal periodically communicates a schedule and burst frame format to the optical network units so that the optical network units are able to determine when and how their communications to the optical line terminal should occur. Orderly scheduling of the communications from the optical network units typically involves knowledge of the range (distance) between the optical line terminal and each optical network unit. This allows the optical line terminal to schedule communications from the optical network units while accounting for various delays associated with propagation of optical signals through different lengths of optical fibers between the optical line terminal and the optical network units. SUMMARY This disclosure relates to signal synchronization and payload extraction in a communication network, such as a gigabit passive optical network (GPON), or other network. While the following discussion often focuses on GPON networks to explain various aspects of the methods, devices, and systems of this disclosure, it should be appreciated that the scope of this disclosure is not limited to GPON networks, and those skilled in the art will appreciate that the disclosed techniques may be implemented in many suitable communication networks or other networks. For example, the methods, devices, and systems of this disclosure are suitable for use with many wired and wireless networks, such as optical and radio frequency (RF) communication networks, which may leverage time division multiplexing (TDM) schemes and/or other shared medium access protocols to facilitate communications. In a first embodiment, a method includes obtaining, at a specified device, one or more bandwidth maps contained in communications in a first direction along a transmission medium. Each bandwidth map identifies when one or more other devices are allowed to communicate in a second direction opposite the first direction along the transmission medium. The method also includes using the one or more bandwidth maps to identify expected features of communications from the one or more other devices in the second direction along the transmission medium. The method further includes identifying actual features of the communications from the one or more other devices in the second direction along the transmission medium. In addition, the method includes synchronizing the specified device with the communications from the one or more other devices using the expected and actual features. In a second embodiment, an apparatus includes at least one interface configured to be coupled to a transmission medium. The apparatus also includes at least one processing device configured to obtain one or more bandwidth maps contained in communications in a first direction along the transmission medium. Each bandwidth map identifies when one or more other devices are allowed to communicate in a second direction opposite the first direction along the transmission medium. The at least one processing device is also configured to use the one or more bandwidth maps to identify expected features of communications from the one or more other devices in the second direction along the transmission medium. The at least one processing device is further configured to identify actual features of the communications from the one or more other devices in the second direction along the transmission medium. In addition, the at least one processing device is configured to synchronize with the communications from the one or more other devices using the expected and actual features. In a third embodiment, a non-transitory machine readable medium contains instructions that when executed cause at least one processor to obtain one or more bandwidth maps contained in communications in a first direction along a transmission medium. Each bandwidth map identifies when one or more other devices are allowed to communicate in a second direction opposite the first direction along the transmission medium. The non-tran