Smart fiber-to-the-room (FTTR) gateway

Abstract

A method performed by an optical network unit (ONU) gateway connecting an access passive optical network (PON) and a home PON for re-routing home traffic data back to the home PON. The method includes the ONU gateway receiving an access PON downstream optical signal from an optical line terminal (OLT). The access PON downstream optical signal includes access traffic destined for the ONU gateway and access traffic not destined for the ONU gateway. The ONU gateway also receives a home PON upstream optical signal from an ONU of the home PON. The home PON upstream optical signal includes home traffic data and upstream access data. The ONU gateway generates a composite downstream signal including the access traffic destined for the ONU gateway and the home traffic data. The ONU gateway sends the composite downstream signal to all ONUs of the home PON.

Description

Technical Field

[0001] This disclosure generally relates to passive optical networks (PONs), and more specifically, to various systems and methods for providing fiber to the room (FTTR). Background Technology

[0002] A passive optical network (PON) is a fiber optic telecommunications network that provides high-speed access to end customers. PON implements a point-to-multipoint topology, in which a single optical fiber uses a passive fiber optic splitter to divide the fiber bandwidth among multiple access points, thereby providing services to multiple endpoints. Summary of the Invention

[0003] The first aspect relates to an optical network unit (ONU) gateway for connecting an access PON to a home PON. The optical network unit includes: an ONU optical module for receiving access PON downlink optical signals from an optical line terminal (OLT). The access PON downlink optical signals include access traffic destined for the ONU gateway and access traffic not destined for the ONU gateway. The optical module is used to convert the access PON downlink optical signals into access PON downlink electrical signals. The ONU gateway further includes: an OLT optical module for receiving home PON uplink optical signals from the ONU of the home PON. The home PON uplink optical signals include home traffic data and uplink access data. The OLT optical module is used to convert the home PON uplink optical signals into home PON uplink electrical signals. The ONU gateway further includes: an ONU media access control (MAC) chip coupled to the ONU optical module. The ONU MAC chip is used to receive the access PON downlink electrical signals from the ONU optical module. The ONU MAC chip filters the downlink electrical signal of the access PON to remove access traffic not destined for the ONU gateway, thereby generating a filtered access traffic signal. The ONU gateway also includes a time-division multiple access (TDMA) switching module with a first input port and a second input port. The first input port receives the filtered access traffic signal. The second input port receives the uplink electrical signal of the home PON. The TDMA switching module receives one or more control signals from the MAC chip to instruct it to select data from either the first or second input port and generate a composite downlink signal, which includes the access traffic destined for the ONU gateway and the home traffic data. The OLT optical module receives the composite downlink signal, converts it into a composite downlink optical signal, and sends the composite downlink optical signal to all ONUs of the home PON.

[0004] According to the first aspect, in a first implementation of the method, the control signal from the MAC chip is based on bandwidth allocation control information included in the access PON downlink optical signal from the OLT. The control signal from the MAC chip instructs the TDMA switching module to select data from the second input port within the bandwidth slots previously allocated to the access traffic not destined for the ONU gateway in the access PON downlink optical signal, such that the composite downlink signal utilizes the bandwidth slots previously allocated to the access traffic not destined for the ONU gateway to carry the home traffic data.

[0005] According to the first aspect or any of the above implementations of the first aspect, in the second implementation, the MAC chip receives the uplink access data of the home PON uplink electrical signal, generates an access uplink electrical signal including the uplink access data, and outputs the access uplink electrical signal to the ONU optical module. The ONU optical module converts the access uplink electrical signal into an access uplink optical signal and sends the access uplink optical signal to the OLT.

[0006] According to the first aspect or any of the above implementations of the first aspect, in a third implementation, the TDMA switching module is implemented using an electrically controlled multiplexer switch, and the TDMA switching module can electrically connect one of the two input ports to the output port.

[0007] According to the first aspect or any of the above implementations of the first aspect, in a fourth implementation, the TDMA switching module is implemented using a memory buffer having two input ports and one output port, wherein the two input ports can store data in the memory buffer, and the one output port can read data from the memory buffer.

[0008] According to the first aspect or any of the above implementations of the first aspect, in the fifth implementation, the memory buffer is organized over the entire forward error correction (FEC) codeword, storing only the entire FEC codeword and reading from the two input ports of the memory buffer.

[0009] The second aspect relates to a method performed by an ONU gateway connecting an access PON and a home PON for rerouting home traffic data back to the home PON. The method further includes: receiving an access PON downlink optical signal from an OLT. The access PON downlink optical signal includes access traffic destined for the ONU gateway and access traffic not destined for the ONU gateway. The method further includes: receiving a home PON uplink optical signal from an ONU of the home PON. The home PON uplink optical signal includes home traffic data and uplink access data. The method further includes: generating a composite downlink signal, the composite downlink signal including the access traffic destined for the ONU gateway and the home traffic data. The method further includes: sending the composite downlink signal to all ONUs of the home PON.

[0010] According to the second aspect, in a first implementation of the method, generating the composite downlink signal includes: analyzing control information included in the access PON downlink optical signal, and using the control information to generate the composite downlink signal, such that the composite downlink signal uses bandwidth slots previously allocated to the access traffic not sent to the ONU gateway to carry the home traffic data.

[0011] According to the second aspect or any of the above implementations of the second aspect, in the second implementation, generating the composite downlink signal includes: controlling the TDMA switch to generate the composite downlink signal, such that when the TDMA switch is in a first state, the access traffic destined for the ONU gateway is selected; and when the TDMA switch is in a second state, the home traffic data is selected.

[0012] According to the second aspect or any of the above implementations of the second aspect, in a third implementation, the method includes: sending the uplink access data to the OLT.

[0013] For clarity, any of the above implementations can be combined with any other one or more of the above implementations to create new embodiments within the scope of this disclosure. These embodiments and other features will become clearer from the following detailed description taken in conjunction with the accompanying drawings and claims. Attached Figure Description

[0014] To gain a more complete understanding of this disclosure, a brief description is now given below in conjunction with the accompanying drawings and specific embodiments, wherein the same reference numerals denote the same parts.

[0015] Figure 1 A schematic diagram of a short-range PON FTTR network provided in one embodiment of the present disclosure is shown;

[0016] Figure 2 A schematic diagram of an ONU gateway device performing home traffic switching according to an embodiment of this disclosure is shown;

[0017] Figure 3A A schematic diagram of an ONU gateway device performing home traffic switching is shown, according to another embodiment of this disclosure;

[0018] Figure 3B A schematic diagram of a TDM switching module provided in one embodiment of the present disclosure is shown;

[0019] Figure 4 A schematic diagram showing the timing arrangement of four signals being received and transmitted by an ONU gateway device according to an embodiment of the present disclosure is illustrated.

[0020] Figure 5 A flowchart is shown illustrating a process performed by an ONU gateway for intelligent rerouting of home traffic for a home PON, according to an embodiment of this disclosure.

[0021] Figure 6 A schematic diagram of a system provided in one embodiment of this disclosure is shown. Detailed Implementation

[0022] First, it should be understood that although illustrative implementations of one or more embodiments are provided below, the disclosed systems and / or methods can be implemented using any number of techniques, whether currently known or existing. This disclosure is by no means limited to the illustrative implementations, drawings, and techniques described below, including the exemplary designs and implementations illustrated and described herein, but can be modified within the full scope of the appended claims and their equivalents.

[0023] The disclosed embodiments include an intelligent network gateway connecting the access PON and the home PON. The intelligent network gateway provides fiber-to-the-room (FTTR) or floor-to-floor (i.e., a complete home fiber network) while eliminating the inefficiency of routing home traffic (i.e., communication between devices in the home) back to the OLT and then back to the home. According to the disclosed embodiments, the gateway ONU is intelligently controlled such that when an ONU in the home PON needs to access PON traffic, the gateway ONU allows the access PON traffic to pass through. However, when there is no access PON traffic, the gateway ONU can send home traffic from the home PON uplink signal back to the home PON. During these times, one ONU in the home PON can communicate with other ONUs in the home PON. Local home PON traffic essentially preempts downlink signals.

[0024] One problem with PON is that the capacity of the access network is often greater than that of the customer's home or office network (e.g., coaxial and / or Ethernet networks from the optical access network to the customer's premises). Therefore, the customer's home or office network reduces the efficiency of the entire network. One possibility for addressing this deficiency is to apply the concept of Passive Optical Networking (PON) to build an FTTR-style network.

[0025] For example, Figure 1 A schematic diagram of a PON FTTR network 140 provided according to an embodiment of the present disclosure is shown. In the illustrated embodiment, the access PON network 100 provides high-speed access to a customer location 120. The access PON network 100 is an optical fiber network that uses a point-to-multipoint topology and optical splitters to transmit data from a single transmission point to multiple user endpoints. The access PON network 100 can support various PON standards, such as, but not limited to, Gigabit Passive Optical Network (GPON) and Ethernet Passive Optical Network (EPON). The access PON network 100 includes an optical line terminal (OLT) 102 and one or more optical network units (ONUs) 108 (also commonly referred to as optical network terminals (ONTs)) located near the end users (e.g., at customer location 120). The Optical Distribution Network (ODN) provides optical transmission media (e.g., optical cable 122, one or more optional reach extenders (REs) 104, one or more passive fiber optic splitters 106, and cooperating auxiliary components) for physically connecting the ONU 108 to the OLT 102.

[0026] OLT 102 is the starting point for accessing the PON network 100 and is located in the service provider's central office (CO). The primary function of OLT 102 is to convert signals from the service provider, frame the signals, and transmit them downlink to ONU 108 (e.g., distributing data, voice, and video traffic from one or more Internet Protocol (IP) networks to customer location 120). Furthermore, OLT 102 coordinates ONU 108 and performs or controls multiplexing of shared uplink transmissions (e.g., receiving various types of data and / or voice traffic from end users). OLT 102 signals are transmitted to home ONU 108 via the access PON network 100. Depending on the distance between OLT 102 and ONU 108, one or more REs 104 may be used in the access PON network 100. REs 104 are physical layer distance extension devices, such as regenerators or optical amplifiers in the fiber optic link between OLT 102 and ONU 108, and can be used to extend the distance of optical signals. A single downlink signal from OLT 102 is split into multiple signals using passive fiber optic splitter 106, each of which is routed to one of ONUs 108. ONU 108 converts the optical signal received from OLT 102 into an electrical signal. ONU 108 can also optimize and reassemble different types of data from customer location 120 to improve the efficiency of uplink data transmission to OLT 102.

[0027] The OLT 102 notifies the ONU 108 of uplink bandwidth allocation by sending a Bandwidth Map (BWMAP) that indicates the bandwidth allocation (i.e., authorization) for each individual ONU 108. Each bandwidth allocation is an indication sent by the ONU 108 in a defined time slot. The OLT 102 can dynamically calculate the BWMAP to allocate the correct bandwidth to each ONU 108, thereby customizing bandwidth transmission according to service and user requirements. For ITU PON, there is one BWMAP per frame. For IEEE PON, the BWMAP is distributed across control messages.

[0028] In the illustrated embodiment, at customer location 120, gateway device 110 connects access PON network 100 (via ONU 108) to home PON 140 (via OLT 112). Customer location 120 can be any type of building, such as, but not limited to, single-family homes, multi-family homes (e.g., townhouses, duplexes, and apartment buildings), office buildings, school buildings, or hotels. Home PON 140 is a short-reach (SR) PON fiber-to-the-room (FTTR) or fiber-to-the-floor (FTTF) network. Similar to access PON network 100, home PON 140 includes OLT 112 connected to one or more ONUs 116 via home ODN. Home ODN includes fiber optic lines 124 and one or more passive fiber optic splitters 114. ONUs 116 serve the individual rooms or floors of customer location 120 (as shown by dashed lines), with each room or floor receiving service via a different ONU 116.

[0029] In one embodiment, the home ODN can use single-strand traditional single-mode fiber or multimode fiber for fiber optic line 124. In one embodiment, when customer location 120 has structured cabling, this means there is a central termination block that accepts cables from an external provider and distributes signals directly to each room in the home / building, with all room-entry fiber optics reaching the central termination block where passive fiber splitter 114 is placed. The common fiber optic cable from passive fiber splitter 114 can then be routed to anywhere fixed access services enter customer location 120 (i.e., to gateway device 110). In many locations, the cabling center is not adjacent to the building corridor. For buildings with unstructured cabling (i.e., without a central termination block), home PON 140 can be arranged in various ways: multi-level splitting, tapping, or a combination of both.

[0030] like Figure 1As shown, the most straightforward way to implement gateway device 110 is to connect ONU 108 (to the access PON network 100) to OLT 112 (to the home PON 140). In one embodiment, data traffic received by ONU 108 from the access PON network 100 is decoded and filtered by ONU 108 to isolate traffic destined for ONU 108. The decoded and filtered data is then passed to OLT 112. OLT 112 must then completely repackage the data in the PON protocol to serve the home PON 140. This process creates a rather complex device and requires a significant amount of configuration to activate. Furthermore, the embedded OLT 112 must use existing OLT semiconductor implementations. These devices are often much more expensive than the ONU 108 device. Therefore, constructing gateway device 110 in this way may be economically infeasible.

[0031] In an alternative embodiment, gateway device 110 does not perform the task of decoding and repackaging the data received from OLT 102. Instead, the downlink signal from OLT 102 is simply regenerated and passed to ONU 116, similar to the task performed by the mid-span optical-electrical-optical (OEO) distance extender. ONU 116 performs decoding and filtering tasks to isolate traffic destined for ONU 116. Since ONU 116 typically has to perform signal processing, this does not increase the cost of ONU 116. The uplink repeater in ONU 108 of gateway device 110 must simulate burst-mode operation of ONU 116 by turning on only when its cascaded ONU is on. For example, the uplink repeater can use a power detector to simulate burst-mode operation of ONU 116 to detect when its cascaded ONU is on. Alternatively, in other cases, OLT 102 can command ONU 108 of gateway device 110 when to turn on its transmitter.

[0032] One problem with the alternative embodiments described above is that there is a significant amount of local traffic between rooms within the home PON 140. For example, security cameras, a whole-home DVR system, printers, and other networked devices generate home traffic destined for other devices in the home PON. Because the home PON 140 uses a separate ONU for each room or floor (i.e., eliminating the inefficiency of routers), all home traffic from the home PON 140 travels up the access PON network 100 to the CO, where it is immediately redirected and sent back down to the home PON 140 from which it originated. This process is inefficient, can increase latency, and poses a privacy risk to data that never needs to leave the home PON 140.

[0033] To address this issue, in one embodiment, gateway device 110 performs traffic switching such that traffic originating from home PON 140 destined for other points within home PON 140 (i.e., home traffic, local traffic, or home PON traffic) can remain within home PON 140. In one embodiment, gateway device 110 performs traffic switching based on a bandwidth allocation map or schedule received from OLT 102. The bandwidth allocation map indicates the time period (e.g., start time and duration) during which ONU 116 of home PON 140 and ONU 108 of access PON network 100 can transmit data upstream.

[0034] Figure 2 A schematic diagram of a gateway device 200 performing home traffic switching according to an embodiment of the present disclosure is shown. The gateway device 200 includes an ONU optical module 202, an ONU media access control (MAC) chip 204, a TDM switching module 206, and an OLT optical module 208.

[0035] ONU optical module 202 has a bidirectional access PON connection 201 to access PON network 100 for transmitting and receiving optical signals on access PON network 100 (i.e., transmitting to and receiving from OLT 102). OLT optical module 208 has a bidirectional access PON connection 211 to home PON 140 for transmitting and receiving optical signals on home PON 140 (i.e., transmitting to and receiving from ONU 116).

[0036] GPON employs both downlink and uplink multiplexing mechanisms. In the downlink direction (e.g., from OLT 102 to ONU 108 and ONU 116), data packets are broadcast (i.e., the downlink signal includes data for all downlink devices), but encryption is used to prevent eavesdropping. In the uplink direction (e.g., from the downlink device to OLT 102), data packets are transmitted using time-division multiple access (TDMA) (i.e., based on allocated time slots) to prevent ONU uplink transmissions from colliding.

[0037] ONU optical module 202 receives access PON optical downlink signals from OLT 102, which include downlink headers and access traffic (i.e., downlink data) from one or more ONUs 116 of home PON 140. The access PON optical downlink signals from OLT 102 may also include access traffic from other ONUs 108 of access PON network 100. The downlink header indicates which part of the access PON optical downlink signal is destined for which downlink device. The downlink header also carries an authorization message, including a BWMAP, which grants a specific time slot (e.g., transmitter (T-CONT), start, and end {ALLOC_ID+Start+End}) for each authorized uplink window, during which ONU 108 or ONU 116 can transmit data uplink. OLT 102 calculates the BWMAP almost in real time and can dynamically recalculate it every few milliseconds, allowing the uplink time slots to shrink or expand according to the distribution of uplink traffic load. The allocation ID (ALLOC_ID) is a 12-bit number assigned by OLT 102 to an ONU (e.g., ONU 108 or ONU 116) to identify the traffic bearer entity as the receiver of uplink bandwidth allocation within that ONU. This traffic bearer entity, also known as a T-CONT, is an ONU object representing a group of logical connections that, for the purpose of uplink bandwidth allocation on the PON, appear as a single entity. Each ONU is assigned a default ALLOC_ID equal to its ONU-ID, and additional ALLOC_IDs may be assigned based on the OLT 102's determination. The ONU-ID is an 8-bit identifier assigned by OLT 102 to an ONU via a PLOAM message during ONU activation. The ONU-ID is unique within the PON (both the access PON network 100 and the home PON 140) and remains unchanged until OLT 102 shuts down or deactivates the ONU. The ALLOC_ID field in the downlink header indicates the receiver of the bandwidth allocation (i.e., the specific T-CONT). The ONU optical module 202 converts the access PON optical downlink signal into an electrical signal (i.e., the access PON downlink electrical signal 203).

[0038] The PON downlink electrical signal 203 is sent to the ONU MAC chip 204. The ONU MAC chip 204 analyzes the control information in the downlink header and determines the target ONU (e.g., ...) in the following ways. Figure 1The expected access PON downlink electrical signal 203 of the ONU 108 is filtered, that is, data destined for other ONUs 108 is removed or discarded from the downlink signal to generate filtered access traffic 205. The filtered access traffic 205 is sent to the TDM switching module 206. According to the disclosed embodiment, the ONU MAC chip 204 generates one or more control signals 207 to control the TDM switching module 206.

[0039] On the uplink side, the OLT optical module 208 receives the home uplink optical signal from the ONU 116 via the home PON 140 at the bidirectional access PON connection 211. The home uplink optical signal may include home traffic from other devices in the home PON 140 and uplink access traffic to be sent to the OLT 102. The OLT optical module 208 converts the home uplink optical signal from an optical signal to a home uplink electrical signal 213. The OLT optical module 208 outputs the home uplink electrical signal 213 to the signal splitter 217, where the home uplink electrical signal 213 is copied. One copy of the home uplink signal 213 is sent to the ONU MAC chip 204. A second copy of the home uplink signal 213 is sent to the TDM switching module 206.

[0040] In one embodiment, the TDM switching module 206 is implemented using a dual-port memory buffer 212, where two input ports (one for filtered access traffic 205 and the other for home uplink signal 213) can feed / store data into the buffer 212, and a single output port can read data from the buffer 212. The TDM switching module 206 has two states: a first state and a second state. In the first state, the first input port is selected, and the filtered access traffic 205 (i.e., access PON downlink) is written to the buffer 212. In the second state, the second input port is selected, and the home uplink signal 213 is written to the buffer 212.

[0041] In one embodiment, buffer 212 organizes the entire forward error correction (FEC) codeword, storing and reading only the entire FEC codeword. FEC is a technique used to control errors in data transmission over unreliable or noisy communication channels. The core idea is that the transmitter encodes the original message into a codeword by adding redundant data, most commonly using error-correcting codes. The added redundancy allows the receiver's decoder to detect a limited number of errors that may appear in the message and typically corrects these errors without retransmission, with the goal of successfully recovering the original message at the decoder's output. In one embodiment, to reduce FEC computation, the state of TDM switching module 206 is switched at codeword boundaries. Similarly, in one embodiment, when ONU 116 transmits local traffic (home traffic) using the entire codeword, FEC processing is not required at gateway device 200. Individual output ports read data from buffer 212 in the order data was written to buffer 212 (i.e., first-in, first-out, FIFO) to maintain proper timing of data slots.

[0042] The ONU MAC chip 204 uses one or more control signals 207 to control the state of the TDM switching module 206. The ONU MAC chip 204 determines the state of the TDM switching module 206 (i.e., whether the TDM switching module 206 outputs filtered access traffic 205 or home uplink signal 213 to the OLT optical module 208) based on control information in the downlink header. This control information indicates when there is a gap or available time slot between filtered access traffic 205 (e.g., when data destined for another ONU 116 is allocated). When access downlink data for a specific ONU is available, the ONU MAC chip 204 sends a control signal 207 to the TDM switching module 206 to switch to a first state, thereby outputting the access downlink data to the OLT optical module 208. When no data is available for a specific ONU (e.g., when data is available for other ONUs), the ONU MAC chip 204 sends a control signal 207 to the TDM switching module 206 to switch to a second state, thereby outputting the home traffic from the home uplink signal 213 to the OLT optical module 208. The output of the TDM switching module 206 is a home downlink composite signal 209, which includes the home traffic and the access downlink data of the ONU 116. The home downlink composite signal 209 is received at the input port of the OLT optical module 208.

[0043] In one embodiment, the timing of when the home uplink signal 213 containing home traffic arrives at the TDM switching module 206 is controlled based on control information initiated by the OLT 102 (e.g., using BWMAP). The control information from the OLT 102 ensures that the home traffic portion of the home uplink signal 213 arrives at the TDM switching module 206 almost simultaneously with the available time slots of the filtered access traffic 205, in order to minimize data buffering (i.e., BWMAP controls when each of the ONUs 116 can send uplink data). The OLT optical module 208 converts the home downlink composite signal 209 from an electrical signal to an optical signal and sends the optical signal to the intended ONU 116 of the home PON 140.

[0044] Similarly, in one embodiment, the timing of when a copy of the home uplink signal 213 arrives at the ONU MAC chip 204 is controlled based on control information initiated by the OLT 102. The control information from the OLT 102 ensures that the ONU MAC chip 204 minimizes any buffering of the home uplink signal 213. Based on the control information, the ONU MAC chip 204 removes the home traffic portion of the home uplink signal 213 to generate an access uplink signal 215. The access uplink signal 215 is output to the ONU optical module 202. The ONU optical module 202 converts the access uplink signal 215 from an electrical signal to an optical signal. The ONU optical module 202 transmits the access uplink signal 215 to the OLT 102 via the bidirectional access PON connection 201 according to the time slot allocated to the gateway device 200.

[0045] Therefore, OLT 102 can use its authorized scheduling to coordinate the timing of all signals to avoid conflicts and reduce buffering at gateway device 110. For example, authorized scheduling can instruct ONU optical module 202 when to send an access PON optical uplink signal, instruct ONU MAC chip 204 when to initiate control signal 207 to change the state of TDM switching module 206, and instruct ONU 116 when to send uplink data. When all signals are properly coordinated, conflicts can be avoided, and gateway device 110 does not need to store too much data. In one embodiment, authorized scheduling enables "just-in-time" operation. For example, when access uplink signal 215 arrives at ONU optical module 202, ONU optical module 202 receives authorization to send access uplink signal 215 to access PON network 100. In this way, access uplink signal 215 can pass directly through ONU optical module 202 with minimal or no delay or buffering. According to the disclosed embodiments, timing coordination is very fine-grained / precise (e.g., on the order of approximately nanoseconds).

[0046] Figure 3AA schematic diagram of a gateway device 300 performing home traffic switching according to another embodiment of this disclosure is shown. The gateway device 300 includes, as... Figure 2 The ONU optical module 202, ONU MAC chip 204, and OLT optical module 208 are shown, but a TDM switching module 216 is used to control the home uplink signal 213. The TDM switching module 216 uses an electrically controlled multiplexer switch, which can electrically connect one of the two input ports to an output port. For example, in the illustrated embodiment, the TDM switching module 216 includes a downlink input switch 218 and an uplink output switch 220. The downlink input switch 218 can electrically connect one of the two input ports to a downlink output port, which feeds into the OLT optical module 208. The uplink output switch 220 can route the home uplink signal 213 to one of the input ports or to the uplink output port of the TDM switching module 216.

[0047] As described above, the ONU MAC chip 204 uses control signal 207 to control the state of the downlink input switch 218 and the uplink output switch 220 based on control information (e.g., BWMAP) in the header of the access downlink signal received from the OLT 102. In the illustrated embodiment, when both the downlink input switch 218 and the uplink output switch 220 are in the up position, the TDM switching module 216 outputs the filtered access traffic 205 (i.e., the access downlink signal for a specific ONU 116) to the OLT optical module 208 and outputs the home uplink signal 213 to the ONU MAC chip 214. According to the control information, when there is no data for a specific ONU 116 in the filtered access traffic 205 and home traffic data in the home uplink signal 213, the ONU MAC chip 204 can send control signal 207 to the TDM switching module 216 to switch both the downlink input switch 218 and the uplink output switch 220 to the down position. In the down position, uplink output switch 220 directs the home uplink signal 213 to the second input port of TDM switching module 216; with downlink input switch 218 in the down position, home traffic data in the home uplink signal 213 is output to OLT optical module 208. In the illustrated embodiment, downlink input switch 218 and uplink output switch 220 are connected together by a dashed line to indicate that they switch uniformly. That is, both switches go up or down together. In some embodiments, TDM switching module 216 may include a small FIFO-like memory buffer (not shown) to temporarily store any data, thereby compensating for any data misalignment.

[0048] In an alternative embodiment, the TDM switching module 216 can be redesigned such that the downlink input switch 218 and the uplink output switch 220 switch from left to right, as follows: Figure 3B As shown, instead of switching up and down. In this embodiment, when both the downlink input switch 218 and the uplink output switch 220 are in the left position (i.e., pointing to the left), the TDM switching module 216 outputs the filtered access traffic 205 to the OLT optical module 208 and outputs the home uplink signal 213 to the ONU MAC chip 214. When there is no data for a specific ONU 116 in the filtered access traffic 205 and home traffic data is present in the home uplink signal 213, the ONU MAC chip 204 can send a control signal 207 to the TDM switching module 216 to switch the downlink input switch 218 and the uplink output switch 220 to the correct position (as shown by the dashed arrow). In the right position, the uplink output switch 220 redirects the home uplink signal 213 to the second input port of the TDM switching module 216; when the downlink input switch 218 is in the right position, the home traffic data in the home uplink signal 213 is output to the OLT optical module 208.

[0049] One advantage of gateway device 300 compared to gateway device 200 is that it does not require duplication of the home uplink signal 213. Another advantage is that the ONU MAC chip 204 can use the TDM switching module 216 to filter home traffic from the home uplink signal 213, instead of filtering home traffic from the home uplink signal 213 at the ONU MAC chip 204 itself. A disadvantage of gateway device 300 compared to gateway device 200 is that the implementation of the TDM switching module 216 may be more complex and costly than that of the TDM switching module 206.

[0050] Figure 4 An embodiment of this disclosure illustrates an access smart gateway (e.g., Figure 2 The timing arrangement of the four signals of the gateway device 200 in Figure 200 or the gateway device 300 in Figure 3. In the illustrated embodiment, the smart gateway operates as ONU#1 on the access PON (e.g., ONU#1 could be...). Figure 1 (Any ONU 108 in the PON network 100).

[0051] like Figure 4 As shown, these four signals are access uplink signal 402, access downlink signal 404, home uplink signal 406, and home downlink composite signal 408. These four signals are plotted relative to the gateway's time (as indicated by the horizontal arrows). There is no significant propagation delay between these four signals because all four signals are physically located at the gateway.

[0052] The access downlink signal 404 is a signal received from the OLT 102 at the ONU of the gateway. The access downlink signal 404 is a normal PON signal, which has a downlink (DS) header 410 and data destined for various ONUs 108 in each frame (shown in the access downlink signal 404 as data for other ONUs 412 and data for ONU#1 414). Figure 4 The dashed arrows in the diagram illustrate how data is forwarded from one signal to another, controlled by the information in the DS header 410. The DS header 410 contains a bandwidth map that provides timing allocation to the gateway and all cascaded home ONUs. The bandwidth map in the DS header 410 controls the timing of when the DS header 410 from the access downlink signal 404, home data 416 from the home uplink signal 406, and data for ONU#1 414 are transmitted from the access downlink signal 404 to the home downlink composite signal 408. Furthermore, the bandwidth map in the DS header 410 controls the timing of when data destined for OLT 418 is transmitted from the home uplink signal 406 to the access uplink signal 402.

[0053] For example, such as Figure 4 As shown, based on bandwidth mapping, when the access downlink signal 404 is received by ONU#1, the DS header 410 is transmitted through the TDM switching module to become part of the home downlink composite signal 408. The access downlink signal 404 contains data for other ONUs 412 (e.g., not sent to...). Figure 1 During the period when the data from customer location 120 is transmitted, the TDM switching module switches states, and home data 416 from home uplink signal 406 is transmitted through the TDM switching module to become part of home downlink composite signal 408. When access downlink signal 404 contains data for ONU#1 414, the TDM switching module switches states, and data for ONU#1 414 is transmitted from access downlink signal 404 through the TDM switching module to become part of home downlink composite signal 408. Any data in home uplink signal 406 destined for OLT 418 becomes part of access uplink signal 402. The timing of data destined for OLT 418 is also controlled by control information in DS header 410 to avoid any collisions when sending access uplink signal 402 to OLT.

[0054] like Figure 4As shown, there are two types of allocations in this scheme. There is an allocation that can realize home data 416, and an allocation that can realize data destined for OLT 418. The allocations of home data 416 are arranged so that they do not conflict with the DS header 410 or the incoming data for ONU#1 414. Due to these restrictions, home data 416 can then be fixed (i.e., U-turn) at the smart gateway and rerouted from home uplink signal 406 to home downlink composite signal 408 without buffering or delay. The allocations of data destined for OLT 418 are arranged so that they do not conflict with any of the home data 416 transmissions or with any transmissions from other ONUs. Due to these restrictions, data destined for OLT 418 can be forwarded from home uplink signal 406 to ONU#1 access uplink signal 402 without buffering or delay.

[0055] Figure 5 An embodiment of the present disclosure provides an ONU gateway (e.g., Figure 1 The flowchart below shows the process 500 performed by the gateway device 110 in the OLT for intelligent rerouting of home traffic in the home PON. The ONU gateway is a gateway or bridge between the access PON and the home PON. In step 502, the ONU gateway receives access downlink signals from the OLT. These access downlink signals include control information (e.g., BWMAP in the header), access traffic destined for the ONU gateway, and access traffic not destined for the ONU gateway.

[0056] In step 504, the ONU gateway receives the home PON uplink optical signal from the ONU of the home PON. The home PON uplink optical signal includes home traffic data (i.e., data intended for communication between devices in the home PON) and uplink access data (i.e., data sent to the OLT).

[0057] In step 506, the ONU gateway generates a composite downlink signal, which includes access traffic destined for the ONU gateway and home traffic data. In one embodiment, the ONU gateway analyzes control information in the downlink header to control the TDMA switch to generate the composite downlink signal, such that when the TDMA switch is in a first state, it selects access traffic destined for the ONU gateway; and when the TDMA switch is in a second state, it selects home traffic data. In one embodiment, the ONU gateway utilizes bandwidth time slots previously allocated to access traffic not destined for the ONU gateway to insert home traffic data into the composite downlink signal.

[0058] In step 508, the ONU gateway sends the composite downlink signal to all ONUs of the home PON. In step 510, the ONU gateway sends the uplink access data from the home uplink signal to the OLT via the access PON.

[0059] Therefore, the disclosed embodiments provide various systems and methods for providing an intelligent network gateway between the access PON and the home PON, capable of providing fiber to the room or floor (i.e., a complete home fiber network) while eliminating the inefficiency of routing home traffic all the way back to the OLT and then back to the home. According to the disclosed embodiments, the gateway ONU is intelligently controlled such that when an ONU in the home PON needs to access PON traffic, the gateway ONU allows the access PON traffic to pass through. However, when there is no access PON traffic, the gateway ONU can send home traffic from the home PON uplink signal back to the home PON. During these times, one room ONU in the home PON can communicate with other ONUs in the home PON. Local home PON traffic essentially preempts downlink signals.

[0060] In one embodiment, for the network to function properly, the TDM switching module of the ONU gateway coordinates with the access PON traffic and all home ONUs. This coordination is performed at the OLT during the calculation of bandwidth allocation for each of the downlink ONUs. In one embodiment, the OLT can use common BWMAP messages found in all TDMA PONs to control the ONU gateway and home ONUs. This keeps the ONU gateway fairly simple and avoids almost all common OLT processing functions.

[0061] Some embodiments may be implemented as a system, apparatus, method, and / or computer program product. The computer program product may include one or more computer-readable storage media having computer-readable program instructions that cause a processor to perform various aspects of this disclosure. The computer-readable storage medium may be a tangible device capable of retaining and storing instructions for use by an instruction execution device.

[0062] Figure 6 A schematic diagram of a system 600 provided in one embodiment of this disclosure is shown. System 600 or portions thereof can be used to implement various embodiments of the intelligent ONU gateway disclosed herein, or one or more components of an intelligent ONU gateway, such as, but not limited to, an ONU optical module, an OLT optical module, and / or a MAC chip. In some embodiments, system 600 can be integrated on a single chip, such as a system on a chip (SOC).

[0063] System 600 includes a receiving unit (RX) 620 or receiving device for receiving data via one or more input ports 610. System 600 also includes a transmitting unit (TX) 640 or transmitting device for transmitting or forwarding data from one or more output ports 650. In some embodiments, RX 620 and TX 640 may be combined into a single transceiver unit. Furthermore, input 610 and output port 650 may be combined into a bidirectional port.

[0064] System 600 includes a memory 660 or data storage device for storing instructions and various types of data. Memory 660 can be any type or combination of memory components capable of storing data and / or instructions. For example, memory 660 may include volatile and / or non-volatile memory, such as read-only memory (ROM), random access memory (RAM), ternary content-addressable memory (TCAM), and / or static random-access memory (SRAM). Memory 660 may also include one or more disk drives, tape drives, and solid-state drives. In some embodiments, memory 660 may be used as an overflow data storage device or buffer to store such programs used when selecting an execution program and to store instructions and data read during program execution.

[0065] System 600 has one or more processors 630 or other processing means to process instructions. In some embodiments, processor 630 may be a central processing unit (CPU) chip, a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), and / or a digital signal processor (DSP) having one or more processing cores. Processor 630 is communicatively coupled to ingress port 610, RX 620, TX 640, egress port 650, and memory 660 via a system bus. Processor 630 may be used to execute instructions stored in memory 660. Therefore, processor 630 provides an means for performing any calculation, comparison, determination, initiation, configuration step, or any other action corresponding to the claims when the processor executes appropriate instructions. In some embodiments, memory 660 may be memory integrated with processor 630.

[0066] Although not shown, in some embodiments, system 600 may include, in addition to Figure 6 Other than or in place of one or more components shown Figure 6 Other components of one or more of the components shown. For example, in some embodiments, system 600 may include a light-to-electrical signal converter and / or an electrical-to-light signal converter. Additionally, system 600 may include one or more multiplexer switches for redirecting signal flow.

[0067] In one embodiment, memory 660 stores ONU gateway home rerouting module 670. ONU gateway home rerouting module 670 includes data and executable instructions for implementing the disclosed embodiments. For example, ONU gateway home rerouting module 670 may include instructions for implementing... Figure 5 The instructions for the method described herein include the ONU gateway home rerouting module 670, which provides a technical improvement to the functionality of system 600 by enabling system 600 to reroute home traffic from home PON back to home PON without further uplink transmission of home traffic, thereby improving the efficiency and security of the entire network.

[0068] In one exemplary embodiment, system 600 includes: a downlink receiving module for receiving access PON downlink optical signals from an optical line terminal (OLT), the access PON downlink optical signals including access traffic destined for an ONU gateway and access traffic not destined for an ONU gateway; an uplink receiving module for receiving home PON uplink optical signals from ONUs of the home PON, the home PON uplink optical signals including home traffic data and uplink access data; a compositing module for generating a composite downlink signal, the composite downlink signal including access traffic destined for an ONU gateway and home traffic data; and a transmitting module for transmitting the composite downlink signal to all ONUs of the home PON. In some embodiments, system 600 may include other or additional modules for performing any or a combination of the steps described in the embodiments. Furthermore, as shown in any of the figures or described in any claim, any additional or alternative embodiments or aspects of the method are contemplated to include similar modules.

[0069] While several embodiments have been provided in this disclosure, it should be understood that the systems and methods disclosed herein may be embodied in many other specific forms without departing from the spirit or scope of this disclosure. These examples are intended to be illustrative rather than limiting and are not intended to be limited to the details given herein. For example, various elements or components may be combined or integrated into another system, or certain features may be omitted or not implemented.

[0070] Furthermore, without departing from the scope of this disclosure, the technologies, systems, subsystems, and methods described and illustrated as discrete or separate in the various embodiments may be combined or integrated with other systems, modules, technologies, or methods. Other items shown or described as coupled to each other, or directly coupled, or communicating with each other, may be indirectly coupled or communicated through some interface, device, or intermediate component, electrically, mechanically, or otherwise. Those skilled in the art can identify other examples of changes, substitutions, and modifications, and may make changes, substitutions, and modifications without departing from the spirit and scope of this disclosure.

Claims

1. An optical network unit (ONU) gateway for connecting a passive optical network (PON) to a home PON, characterized in that, The ONU gateway includes: An ONU optical module is used to convert access PON downlink optical signals into access PON downlink electrical signals. The access PON downlink electrical signals include access traffic destined for the ONU gateway and access traffic not destined for the ONU gateway. OLT optical module is used to convert home PON uplink optical signal into home PON uplink electrical signal, the home PON uplink electrical signal including home traffic data and uplink access data; The ONU MAC chip is coupled to the ONU optical module. The ONU MAC chip is used to filter the access PON downlink electrical signal to remove the access traffic that is not sent to the ONU gateway, thereby generating a filtered access traffic signal. A Time Division Multiple Access (TDMA) switching module is used to receive one or more control signals from the ONU MAC chip to instruct the TDMA switching module to generate a composite downlink electrical signal, the composite downlink electrical signal including the access traffic to the ONU gateway and the home traffic data; The OLT optical module is used to convert the composite downlink electrical signal into a composite downlink optical signal and send the composite downlink optical signal to all ONUs of the home PON.

2. The ONU gateway according to claim 1, characterized in that, The TDMA switching module includes a first input port and a second input port. The first input port is used to receive the filtered access traffic signal, and the second input port is used to receive the home PON uplink electrical signal.

3. The ONU gateway according to claim 2, characterized in that, The TDMA switching module selects data from the first input port or the second input port according to one or more control signals to generate the composite downlink electrical signal.

4. The ONU gateway according to any one of claims 1 to 3, characterized in that, The one or more control signals from the ONU MAC chip are based on bandwidth allocation control information included in the access PON downlink optical signal from the OLT.

5. The ONU gateway according to claim 3, characterized in that, The one or more control signals from the ONU MAC chip instruct the TDMA switching module to select data from the second input port within the bandwidth time slot previously allocated to the access traffic not destined for the ONU gateway in the access PON downlink optical signal, such that the composite downlink electrical signal carries the home traffic data using the bandwidth time slot allocated to the access traffic not destined for the ONU gateway.

6. The ONU gateway according to any one of claims 1 to 3, characterized in that, The ONU MAC chip receives a copy of the home PON uplink electrical signal, which includes the home traffic data and the uplink access data. The ONU MAC chip is used to remove the home traffic data from the copy of the home PON uplink electrical signal to generate an access uplink electrical signal that includes the uplink access data.

7. The ONU gateway according to claim 6, characterized in that, The ONU optical module converts the access uplink electrical signal into an access uplink optical signal and sends the access uplink optical signal to the OLT.

8. The ONU gateway according to claim 6, characterized in that, The OLT optical module is used to receive the uplink optical signal of the home PON from the ONU of the home PON.

9. The ONU gateway according to any one of claims 1 to 3, characterized in that, The TDMA switching module uses an electrically controlled multiplexer switch, which electrically connects one of the two input ports to the output port.

10. The ONU gateway according to any one of claims 1 to 3, characterized in that, The TDMA switching module is implemented using a memory buffer with two input ports and one output port. The two input ports store data in the memory buffer, and the one output port reads data from the memory buffer.

11. The ONU gateway according to claim 10, characterized in that, The memory buffer is organized over the entire forward error correction (FEC) codeword, storing only the entire FEC codeword and reading from the two input ports of the memory buffer.

12. A method for rerouting home traffic data back to the home PON, performed by an optical network unit (ONU) gateway connecting an access passive optical network (PON) and a home PON, characterized in that, The method includes: The system receives downlink optical signals for accessing the PON from the optical line terminal (OLT), wherein the downlink optical signals for accessing the PON include access traffic destined for the ONU gateway and access traffic not destined for the ONU gateway. Receive home PON uplink optical signal from the ONU of the home PON, the home PON uplink optical signal including home traffic data and uplink access data; Generate a composite downlink signal, the composite downlink signal including the access traffic sent to the ONU gateway and the home traffic data; The composite downlink signal is sent to all ONUs of the home PON.

13. The method according to claim 12, characterized in that, Generating the composite downlink signal includes: analyzing the control information included in the access PON downlink optical signal, and using the control information to generate the composite downlink signal.

14. The method according to claim 13, characterized in that, The composite downlink signal uses bandwidth slots allocated to the access traffic that is not sent to the ONU gateway to carry the home traffic data.

15. The method according to any one of claims 12 to 14, characterized in that, Generating the composite downlink signal includes controlling a Time Division Multiple Access (TDMA) switch to generate the composite downlink signal.

16. The method according to claim 15, characterized in that, When the TDMA switch is in the first state, the access traffic destined for the ONU gateway is selected; when the TDMA switch is in the second state, the home traffic data is selected.

17. The method according to claim 16, characterized in that, The method further includes sending the uplink access data to the OLT.

18. A system for providing an optical network unit (ONU) gateway between a passive optical network (PON) and a home PON to reroute home traffic data back to the home PON, characterized in that, The system includes: Memory, used to store instructions; A receiver is used to receive signals. A transmitter is used to send signals; A processor coupled to the memory, the processor being configured to execute the instructions to cause the system to: Receive access PON downlink optical signals, wherein the access PON downlink optical signals include access traffic destined for the system; Receive home PON uplink optical signal, wherein the home PON uplink optical signal includes home traffic data; Generate a composite downlink signal, the composite downlink signal including the access traffic and the household traffic data; Send the composite downlink signal.

19. The system according to claim 18, characterized in that, Generating the composite downlink signal includes: analyzing the control information included in the access PON downlink optical signal, and using the control information to generate the composite downlink signal.

20. The system according to claim 18 or 19, characterized in that, The composite downlink signal uses bandwidth slots allocated to access traffic not destined for the system to carry the home traffic data.

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