A wavelength configuration method and device of a wavelength tunable RoF optical module

Abstract

The application discloses a wavelength configuration method and device of a wavelength tunable RoF optical module, and the method comprises the following steps: when a remote node accesses an RoF optical module system, a wavelength division device in the RoF optical module system is used to allocate a default wavelength to the remote node for internal communication and signal diagnosis; power-on initialization is completed; the default wavelength obtains a preset configuration of a near-end node; a given remote node receives a tuning instruction sent by the near-end node, controls the remote node to perform output wavelength tuning according to a selected preset wavelength resource, and performs communication with a predetermined working wavelength; working wavelength communication verification is performed on the remote node, the remote node is instructed to adopt the predetermined working wavelength according to a result of verifying the working wavelength, and normal communication between the remote node and a base station is started. The wavelength signal and the communication quality are ensured.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, and in particular to a wavelength configuration method and apparatus for a wavelength-tunable RoF optical module. Background Technology

[0002] Existing technical solutions typically only adjust the wavelength when adding new equipment or do not adjust it at all, which can easily cause other users on the same network to be affected when the user performs power-on or power-off operations. Furthermore, existing solutions mostly require additional devices to filter the signal when selecting different wavelengths for output, increasing additional costs and the space occupied by physical equipment.

[0003] The existing infrastructure of RoF (Radio over Fiber) systems based on PON (Passive Optical Network) networks is as follows: Figure 1 As shown, this system modulates radio frequency (RF) signals onto an optical carrier and transmits them to remote nodes using a PON network infrastructure. Specifically, at the near end of the RoF, the RF signal is modulated onto the optical carrier and transmitted to the remote node via the optical fiber of the PON network; at the far end of the system, the optical signal is demodulated back into an RF signal and transmitted through an antenna, thereby achieving wireless signal relay amplification. In existing PON-based RoF systems, during the power-on process when a remote node connects to the system, a series of initialization operations are required after startup, and it takes a period of time before the signal is locked to the specified wavelength. Initialization operations include wavelength configuration, laser startup, and temperature stabilization. During this period, the output wavelength of the laser may be unstable and fluctuate within a certain range, causing wavelength disorder in the output optical signal. This, in turn, leads to a large amount of noise generated when the optical signal sent by the remote node is transmitted in the optical fiber. This noise is superimposed on the uplink signal after being demodulated back into an RF signal, severely affecting the reception performance of the base station. Furthermore, uplink signal noise not only affects the communication quality of the current user but may also interfere with the communication of other users and even other remote nodes, leading to a degradation in the overall system performance. Therefore, a reasonable solution is needed to address the signal interference problem when remote nodes power on. The pressing issue is: how to efficiently handle the uplink signal interference of remote nodes powering on the entire system in RoF. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a wavelength configuration method and apparatus for a wavelength-tunable RoF optical module. This effectively improves the user experience. The optical module controls the communication capability between the remote node and the base station system; and it enables a complete tunable wavelength configuration process for the remote node in a PON-based RoF network. This improves the utilization rate of wavelength resources in RoF, effectively avoids the impact of wavelength disturbances caused by the power-on of remote nodes on base station communication, and ensures stable system operation.

[0005] In a first aspect, the present invention provides a wavelength configuration method for a wavelength-tunable RoF optical module, comprising: When a remote node connects to the RoF optical module system, a default wavelength is assigned to the remote node through the wavelength division multiplexing device in the RoF optical module system for internal communication and signal diagnosis; power-on initialization is completed; the default wavelength is obtained from the preset configuration of the near-end node; A given remote node receives a tuning command sent by a near node and controls the remote node to tune its output wavelength according to the selected preset wavelength resources, so as to perform communication at a predetermined working wavelength. Perform a working wavelength communication verification on the remote node, and instruct the remote node to adopt the predetermined working wavelength based on the verification result, thereby enabling normal communication between the remote node and the base station.

[0006] In a second aspect, embodiments of the present invention provide a wavelength configuration device for a wavelength-tunable RoF optical module, comprising: The power-on initialization module is used when a remote node connects to the RoF optical module system. It allocates a default wavelength to the remote node through the wavelength division multiplexing device in the RoF optical module system for internal communication and signal diagnosis; completes power-on initialization; and obtains the default wavelength from the preset configuration of the near-end node. The wavelength tuning configuration module is used to receive tuning commands sent by a near-end node from a given far-end node, and control the far-end node to perform output wavelength tuning according to the selected preset wavelength resources, so as to perform communication at a predetermined working wavelength. A normal transmission module is used to perform working wavelength communication verification on the remote node, and instruct the remote node to adopt the predetermined working wavelength based on the verification result, thereby enabling normal communication between the remote node and the base station. The system monitoring module is used for the remote node and the near-end node connected to the remote node to jointly monitor the communication status of the RoF optical module system; and the near-end node connected to the remote node is responsible for retracting the wavelength, pausing transmission and triggering retuning.

[0007] Compared with the prior art, the present invention has the following beneficial effects: This invention controls the communication capability between remote nodes and the base station system through optical modules; and realizes a complete wavelength configuration process in a RoF optical module system based on a PON network. This improves the reliability and communication quality of RoF based on PON networks, reduces operation and maintenance costs, and enhances the user experience. Wavelength tunable configuration involves directly adjusting the output wavelength of the laser and then communicating through the PON network after stabilization, while reducing the impact on other nodes and the cost of additional equipment. For example, an optical multiplexer (MUX) is connected to the transmitter of the optical module to filter the transmitted signal. The desired wavelength value is set in the MUX. When the module automatically adjusts the wavelength to the correct value, the signal can pass through; otherwise, the signal will not pass through. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the basic architecture of an existing RoF optical module system based on a PON network. Figure 2 This is a flowchart of the wavelength configuration method for a wavelength-tunable RoF optical module disclosed in this invention; Figure 3 This is a schematic diagram of the power-on initial process of the wavelength configuration method for the wavelength-tunable RoF optical module disclosed in this invention. Figure 4 This is a schematic diagram of the wavelength tuning configuration process of the wavelength tuning RoF optical module disclosed in this invention. Figure 5 This is a normal transmission schematic diagram of the wavelength configuration method of the wavelength-tunable RoF optical module disclosed in this invention; Figure 6 This is a schematic diagram of the wavelength configuration device for the wavelength-tunable RoF optical module disclosed in this invention. Detailed Implementation

[0009] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0010] This invention employs a multi-wavelength wavelength division multiplexing (WDM) mechanism to manage RoF uplink signals. It performs self-adaptation for transmissions at different remote nodes within the same PON network, ensuring that nodes do not interfere with each other during power-on and power-off processes. It also performs self-adaptation for transmissions at a selected remote node on a specific node link within the same PON network, adjusting the laser's output wavelength according to instructions to lock it to a specified operating wavelength, ensuring that nodes do not interfere with each other during power-on and power-off processes. In mobile communication, uplink signals typically refer to the direction of data transmission from a terminal device (e.g., a mobile phone) to the network center (e.g., a base station), while downlink signals refer to the direction of data transmission from the network center to the terminal device.

[0011] Optical carriers (OC-n) are the basic transmission units in the Synchronous Optical Fiber Network (SONET) architecture. Their speeds increase progressively from a base of 51.84 Mbit / s; for example, OC-1 is 51.84 Mbit / s, OC-3 is 155 Mbit / s, and the highest can reach OC-192 at 10 Gbit / s. SONET transmits T-1, E-1, and other services via optical fiber, and is compatible with the international standard Synchronous Digital Hierarchy (SDH), supporting OC and STM speed conversion. Optical carriers use single-mode fiber transmission and are suitable for high-speed, long-distance communication scenarios, such as mobile base station backhaul and cloud computing. Access ring networks typically operate at the OC-3 level, while regional ring networks and backbone ring networks use OC-12 (622 Mbit / s), OC-96 (4.9 Gbit / s), and higher levels, respectively. Data is transmitted via optical pulses, which are converted into electrical signals at the receiving end. Optical carrier modulation mainly employs intensity modulation and phase modulation, with digital modulation based on binary signals to control the on / off state of the optical carrier. Multiplexing techniques are implemented using optical filters or multi-wavelength systems, while demultiplexing methods include direct detection. In wavelength division multiplexing (WDM) systems, the stability of the optical carrier frequency directly affects transmission performance.

[0012] based on Figure 2 Describing a scenario of the technical solution of an embodiment of the present invention, a wavelength configuration method for a wavelength-tunable RoF optical module is provided, including: S1. The near-end node presets a default wavelength. When the far-end node connects to the RoF optical module system, a default wavelength is assigned to the far-end node through the wavelength division multiplexing (WDM) device in the RoF optical module system for internal communication and signal diagnosis; power-on initialization is completed; the default wavelength is obtained from the near-end node's preset configuration. This is used to confirm whether the basic functions of the far-end node and the communication link are normal.

[0013] In one embodiment of the first aspect, such as Figure 3As shown, the current power-on initialization process includes: the optical signal transmitted uplink through the trunk optical cable is divided into multi-wavelength division multiplexing (WDM) analog light by a wavelength division multiplexing (WDM) device. Then, the optical receiver at the near-end node connected to the far-end node of the RoF optical module system receives the optical signal at the default wavelength, converts it into an RF signal, and transmits this signal to the optical receiver of the optical module, terminating the transmission without sending it to the RF combining device. This isolates communication between the far-end node and the base station, preventing uplink signal noise generated during periods of unstable wavelength configuration from affecting the normal operation of the base station. The default wavelength is... Near-end node (Access Unit, or AU for short), far-end node (RU for short).

[0014] The aforementioned RoF components include an optical transmitter, optical cable, and optical receiver. The optical transmitter uses a distributed feedback (DFB) laser or a Fabry-Perot (FP) laser, typically with wavelengths of 1310 nm or 1550 nm. The optical cable usually uses single-mode fiber due to its low dispersion and low loss characteristics. The RoF link is a linear transmission system with advantages such as extremely low loss, ultra-wideband transmission, high signal carrying capacity, and resistance to electromagnetic interference. The RoF optical module is a key component of RoF, combining key technologies of optical fiber and wireless communication to transmit high-frequency wireless signals through optical fiber. It is responsible for converting radio frequency signals into optical signals (wavelength 1310 / 1550 nm) for transmission and converting the optical signals back into radio frequency signals at the receiving end. It utilizes the low loss (<0.2 dB / km) and high bandwidth (up to THz levels) characteristics of optical fiber to achieve long-distance transmission and then restore the wireless signal. Its advantages include resistance to electromagnetic interference (shielding effectiveness ≥60dB), strong scalability (supports multi-band aggregation) and transmission stability (bit error rate <1E-12), making it suitable for complex scenarios such as 5G base station fronthaul and indoor distribution systems.

[0015] S2. Wavelength Tuning Configuration: A given remote node receives a tuning command sent by a near-end node through the internal communication link of the RoF. Based on the selected preset wavelength resources, the remote node controls the output wavelength tuning to perform communication at a predetermined operating wavelength. The remote node adjusts the laser's output wavelength according to the near-end node's command, thus locking the corresponding remote node to the specified operating wavelength. The wavelength resource is the set of wavelength resources currently available to the entire system. In one embodiment of the first aspect, the given remote node receives a tuning command, and the remote node adjusts the output wavelength to the operating wavelength. After stabilization, the system feeds back the status and receives the status information that the working wavelength configuration is complete from the remote node via the PON communication network. The remote node receives the test signal sent by the near node to verify whether the communication between the selected remote node and the near node is normal.

[0016] In one embodiment of the first aspect, selecting a given remote node includes selecting a certain optical fiber node link.

[0017] In one embodiment of the first aspect, the optical signal transmission of a newly added or reactivated remote node in the RoF optical module system, with its wavelength selected as the operating wavelength, terminates at the optical receiver; similarly, the near-end optical module does not transmit to the RF combining device. Specifically, as... Figure 4 As shown, the wavelength of newly added (or reactivated) remote nodes in RoF is selected as... The optical signal transmission terminates at the optical receiver and is not uplinked to the RF combiner by the near-end optical module. Therefore, noise signals generated by remote nodes will not affect the stable operation of the base station system.

[0018] Specifically, RoF uses a PON network for its internal communication links.

[0019] The aforementioned PON (Passive Optical Network) refers to an optical distribution network that contains no electronic components or power supplies, consisting entirely of passive devices such as optical splitters. A PON system comprises an OLT (Optical Line Terminal), ONU (Optical Network Unit), and ODN (Optical Distribution Network). An OLT is a terminal device used to connect optical fiber trunk lines.

[0020] S3. Normal Transmission: Perform working wavelength communication verification on the remote node to verify the working wavelength. The result indicates that the remote node should use the predetermined operating wavelength to establish normal communication between the remote node and the base station. Specifically, this communication verification verifies whether communication is normal at this operating wavelength and whether the noise figure is within an acceptable range.

[0021] Enabling normal communication between the remote node and the base station includes: combining the radio frequency signals of other normally operating remote nodes with the radio frequency signals converted by the optical module of the near node and uplinking them to the base station system, thereby enabling normal communication between the remote user and the base station system.

[0022] The remote node (RU) transmits optical signals of the working wavelength through the RoF optical module system. The optical receiver and RF combiner work together to complete the signal conversion and combining, and the optical signal is transmitted uplink to the base station.

[0023] In one embodiment of the first aspect, such as Figure 5 As shown, this remote node operates at a wavelength... The optical signal transmitted to the near-end node is converted into a radio frequency (RF) signal by the optical receiver in the optical module of the near-end node. The converted RF signal is then combined with the RF signals of other normally operating remote nodes and transmitted uplink to the base station system, thereby enabling normal communication between the remote user and the base station system.

[0024] S4. System Monitoring: The remote node (RU) and the near-end node (AU) connected to the remote node jointly monitor the communication status of the RoF optical module system. The near-end node connected to the remote node is responsible for reclaiming wavelengths, pausing transmission, and triggering retuning. This ensures the stability of wavelength signals and communication quality.

[0025] In one embodiment of the first aspect, monitoring the communication status of the RoF optical module system includes: if a remote node adjusts its transmission wavelength, suspending data transmission between the remote node and the corresponding near node, retracting the operating wavelength transmitted by the remote node to cut off communication between the remote node and the base station system, and switching to the remote node wavelength tuning configuration.

[0026] In summary, this invention controls the communication capability between remote nodes and the base station system through optical modules; and realizes a complete wavelength configuration process in RoF based on PON networks. It achieves tunable wavelength configuration of remote nodes in RoF based on PON networks, while simultaneously solving the interference problem caused by remote nodes powering on to the entire system. This improves the utilization rate of wavelength resources in RoF, effectively avoids the impact of wavelength disorder caused by remote nodes powering on base station communication, and ensures stable system operation.

[0027] Example 2: Based on all client terminal scenarios with switching enabled, this invention, building upon Example 1, further proposes a wavelength configuration device for a wavelength-tunable RoF optical module, such as... Figure 6 As shown, it includes: The power-on initialization module 01 is used to allocate a default wavelength to the remote node through the wavelength division multiplexing device in the RoF optical module system for internal communication and signal diagnosis when the remote node accesses the RoF optical module system; complete the power-on initialization; obtain the default wavelength from the preset configuration of the near-end node; and confirm whether the basic functions and communication link of the remote node are normal.

[0028] The wavelength tuning configuration module 02 is used to receive tuning commands sent by a near-end node from a given far-end node, and control the far-end node to perform output wavelength tuning according to the selected preset wavelength resources, so as to perform communication at a predetermined working wavelength. Normal transmission module 03 is used to perform working wavelength communication verification on the remote node, and instruct the remote node to adopt the predetermined working wavelength based on the verification result of the working wavelength, so as to open normal communication between the remote node and the base station. The system monitoring module 04 is used for the remote node (RU) and the near-end node (AU) connected to the remote node to jointly monitor the communication status of the RoF optical module system; and the near-end node connected to the remote node is responsible for retracting the wavelength, pausing transmission and triggering retuning.

[0029] In one embodiment of the second aspect, the current power-on initialization module includes: the optical signal transmitted uplink from the trunk optical cable is divided into multi-wavelength division analog light by a wavelength division device, and the optical receiver of the near-end node connected to the far-end node of the RoF optical module system receives the optical signal of the default wavelength and converts it into a radio frequency signal. The optical signal is then transmitted to the optical receiver of the optical module and terminated, without being transmitted to the RF combining device.

[0030] In one embodiment of the second aspect, the given remote node acquires a tuning command, and the remote node adjusts the output wavelength to the operating wavelength. After stabilization, the system feeds back the status and receives the status information that the working wavelength configuration is complete from the remote node via the PON communication network. The remote node receives the test signal sent by the near node to verify whether the communication between the selected remote node and the near node is normal.

[0031] In one embodiment of the second aspect, the given remote node is a remote node selected for a certain optical cable node link. Specifically, in the RoF optical module system, the optical signal transmission of a newly added or reactivated remote node with a wavelength selected as the operating wavelength terminates at the optical receiver, and similarly, the near-end optical module does not transmit to the RF combining device.

[0032] In one embodiment of the second aspect, the remote node (RU) transmits optical signals of the working wavelength through the RoF optical module system, and the optical receiver and RF combiner cooperate to complete signal conversion and combining, and the optical signals are transmitted uplink to the base station.

[0033] In one embodiment of the second aspect, the remote node operates via a working wavelength. The optical signal transmitted to the near-end node is converted into a radio frequency (RF) signal by the optical receiver in the optical module of the near-end node. The converted RF signal is then combined with the RF signals of other normally operating remote nodes and transmitted uplink to the base station system, thereby enabling normal communication between the remote user and the base station system.

[0034] In one embodiment of the second aspect, monitoring the communication status of the RoF optical module system includes: if a remote node adjusts its transmission wavelength, suspending data transmission between the remote node and the corresponding near node, retracting the operating wavelength of the remote node to cut off communication between the node and the base station system, and switching to the remote node wavelength tuning configuration.

[0035] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0036] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0037] The above description is merely illustrative of the embodiments of the present invention and is not intended to limit the present invention. For those skilled in the art, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wavelength configuration method for a wavelength-tunable RoF optical module, comprising: When a remote node connects to the RoF optical module system, a default wavelength is assigned to the remote node through the wavelength division multiplexing device in the RoF optical module system for internal communication and signal diagnosis; power-on initialization is completed; the default wavelength is obtained from the preset configuration of the near-end node; A given remote node receives a tuning command sent by a near node and controls the remote node to tune its output wavelength according to the selected preset wavelength resources, so as to perform communication at a predetermined working wavelength. Perform a working wavelength communication verification on the remote node, and instruct the remote node to adopt the predetermined working wavelength based on the verification result, thereby enabling normal communication between the remote node and the base station.

2. The wavelength configuration method for the wavelength-tunable RoF optical module according to claim 1, characterized in that: Also includes: The remote node and the near-end node connected to the remote node jointly monitor the communication status of the RoF optical module system. The near-end node connected to the far-end node is responsible for retrieving the wavelength, pausing transmission, and triggering retuning.

3. The wavelength configuration method for the wavelength-tunable RoF optical module according to claim 2, characterized in that: The current power-on initialization process includes: After the optical signal transmitted uplink from the trunk optical cable is divided into multiple wavelength division multiplexing analog light by the wavelength division device, the optical module of the near-end node connected to the remote node of the RoF optical module system controls the optical module to convert the optical signal of the default wavelength into an radio frequency signal, and the optical signal is transmitted to the optical receiver of the optical module and terminated, and is not sent to the RF combining device.

4. The wavelength configuration method for the wavelength-tunable RoF optical module according to claim 3, characterized in that: The remote node receives the tuning command, adjusts the output wavelength to the working wavelength, and after stabilizing, feeds back the status. It also receives the status information that the working wavelength configuration is completed from the remote node via the PON communication network. The remote node receives the test signal sent by the near node to verify whether the communication between the selected remote node and the near node is normal.

5. The wavelength configuration method for the wavelength-tunable RoF optical module according to claim 4, characterized in that: The remote node transmits optical signals of the working wavelength through the RoF optical module system. The optical receiver and RF combiner work together to complete the signal conversion and combining, and the optical signal is transmitted uplink to the base station.

6. The wavelength configuration method for the wavelength-tunable RoF optical module according to claim 5, characterized in that: Selecting a given remote node means selecting a remote node that includes a certain optical fiber node link.

7. The wavelength configuration method for the wavelength-tunable RoF optical module according to claim 6, characterized in that: In the RoF optical module system, the optical signal transmission of the newly added remote node with the selected operating wavelength terminates at the optical receiver, and similarly, the optical module at the near end does not transmit to the RF combining device.

8. The wavelength configuration method for the wavelength-tunable RoF optical module according to claim 7, characterized in that: The wavelength of the remote node reactivated in the RoF optical module system is selected as the operating wavelength. The optical signal transmission terminates at the optical receiver, and similarly, the optical module at the near end does not transmit to the RF combining device.

9. The wavelength configuration method for the wavelength-tunable RoF optical module according to claim 8, characterized in that: Enabling normal communication between the remote node and the base station includes: combining the radio frequency signals of other normally operating remote nodes with the radio frequency signals converted by the optical module of the near node and uplinking them to the base station system, thereby enabling normal communication between the remote user and the base station system.

10. A wavelength configuration device for a wavelength-tunable RoF optical module, characterized in that, include: The power-on initialization module is used to preset the default wavelength for near-end nodes. When a far-end node connects to the RoF optical module system, it allocates a default wavelength to the far-end node through the wavelength division multiplexing device in the RoF optical module system for internal communication and signal diagnosis; completes power-on initialization; and obtains the default wavelength preset configuration of the near-end node. The wavelength tuning configuration module is used to receive tuning commands sent by a near-end node from a given far-end node, and control the far-end node to perform output wavelength tuning according to the selected preset wavelength resources, so as to perform communication at a predetermined working wavelength. The normal transmission module is used to perform working wavelength communication verification on the remote node, and instruct the remote node to adopt the predetermined working wavelength based on the verification result, so as to enable normal communication between the remote node and the base station. The system monitoring module is used for the remote node and the near-end node connected to the remote node to jointly monitor the communication status of the RoF optical module system; The near-end node connected to the far-end node is responsible for retrieving the wavelength, pausing transmission, and triggering retuning.

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