Nodes with radio frequency (RF) switching networks and corresponding methods for identifying associated client devices - Patents.com

Abstract

A Data-over-Cable Interface Specification (DOCSIS) node includes a first DOCSIS port and a second DOCSIS port. The node also includes a plurality of radio frequency (RF) ports. A plurality of client devices can be coupled to the RF ports. An RF switching network is coupled between the first DOCSIS port, the second DOCSIS port, and the plurality of RF ports. One or more control circuits can switch the RF switching network between at least a first state and a second state. By switching the RF switching network, the one or more control circuits can identify which client devices are coupled to which RF ports of the node.

Description

[Background technology]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 938,825, filed November 21, 2019.

[0002] Content delivery systems, including those used by cable television providers, distribute content such as video, audio, voice, data, and other content over a network to client devices. Often, this content is distributed over the network from a "headend" or "hub" device to the client devices. When these systems provide data connection services such as interactive video, telephony services, and high-speed data for Internet and World Wide Web communications, high-speed data connections and high data bandwidths can be beneficial. One way to achieve these higher bandwidths is through the use of fiber optic cable. Fiber optic cable can carry orders of magnitude more data than older electrical connections such as coaxial cable.

[0003] Because fiber optic cable installation is expensive, fully converting an older coaxial cable network serving thousands of subscribers to an optical network using current pricing models can be cost-prohibitive. For this reason, many systems employ "hybrid fiber-coaxial" or "HFC" systems, which allow service providers to connect end-user client devices served by coaxial cable with a "headend" or "hub" device that delivers data over fiber optic cable in a cost-effective manner. In HFC systems, centrally located components such as network headends, hub devices, and servers use fiber optic cable to transmit and receive data to and from the network. The termination points, i.e., customers and their corresponding client devices, are served by coaxial cable.

[0004] To bridge between fiber optic cable and coaxial cable, a "node" module is used. This "node" is a device that receives optical signals over the fiber optic network, converts these signals to radio frequency (RF) signals, and distributes the RF signals over the coaxial cable network. Thus, an optical node module receives data over fiber optic on one or more downstream ports, converts that data to RF signals, and distributes these RF signals over one or more RF ports to the legacy coaxial network.

[0005] The Data Over Cable Interface Specification (DOCSIS) is one of many standards that supports such a modular system. One way to achieve the modularity described above is to separate the DOCSIS Medium Access Control (MAC) function from the DOCSIS Physical Layer (PHY) function into two different boxes. In a DOCSIS network using a remote PHY architecture, an Integrated Converged Cable Access Platform (I-CCAP) is separated into a CCAP core located at the headend and a Remote PHY Device (RPD) located at the node. When a node has multiple RF ports, it is difficult or impossible to determine which client device is being served by which RF port. It would be advantageous to have an improved node architecture that allows such a determination to be made. [Brief explanation of the drawings]

[0006] The accompanying drawings, in which like reference numerals refer to identical or functionally similar elements throughout the individual figures, and which, together with the following detailed description, when incorporated into and form a part of this specification, serve to further illustrate various embodiments and explain all of the various principles and advantages in accordance with the present disclosure. [Figure 1] 1 illustrates a prior art remote PHY system architecture. [Figure 2]1 illustrates one illustrative remote PHY system, in accordance with one or more embodiments of the present disclosure. [Figure 3] 1 illustrates a schematic block diagram of one illustrative node, in accordance with one or more embodiments of the present disclosure. [Figure 4] 1 illustrates one illustrative downstream RF switching network in accordance with one or more embodiments of the present disclosure. [Figure 5] 1 illustrates one illustrative upstream RF switching network in accordance with one or more embodiments of the present disclosure. [Figure 6] 1 illustrates one illustrative method according to one or more embodiments of the present disclosure. [Figure 7] 1 illustrates another illustrative method, according to one or more embodiments of the present disclosure. [Figure 8] 1 illustrates one or more method steps according to one or more embodiments of the present disclosure. [Figure 9] 1 illustrates one or more method steps according to one or more embodiments of the present disclosure. [Figure 10] 1 illustrates one or more method steps according to one or more embodiments of the present disclosure. [Figure 11] 1 illustrates one or more method steps according to one or more embodiments of the present disclosure. [Figure 12] 1 illustrates one or more method steps according to one or more embodiments of the present disclosure. [Figure 13] 1 illustrates various embodiments of the present disclosure.

[0007] Those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present disclosure.

[0008] Detailed Description of the Drawings Before describing detailed embodiments according to the present disclosure, it should be observed that the embodiments primarily pertain to combinations of method steps and apparatus elements related to detecting which client devices are being served by which RF ports of a node in a remote PHY system. Any process descriptions or blocks in a flowchart should be understood as representing modules, segments, or portions of code, including one or more executable instructions for implementing specific logical functions or steps in the process. It will be apparent that alternative implementations are included, and functions may be performed out of the order shown or discussed, including substantially simultaneously or in reverse order, depending on the functionality involved. Accordingly, apparatus elements and method steps are represented, where appropriate, by conventional symbols in the drawings, and only those specific details relevant to understanding the embodiments of the present disclosure are shown, so as not to obscure the present disclosure with details that will be readily apparent to those skilled in the art having the benefit of this description.

[0009] It will be understood that the embodiments of the present disclosure described herein may be comprised of one or more conventional processors and unique stored program instructions that control the one or more processors to implement some, most, or all of the functions of detecting which client devices are being served by which RF ports of a node, as described herein, in conjunction with certain non-processor circuitry. The non-processor circuitry may include, but is not limited to, a radio receiver, a radio transmitter, signal drivers, clock circuits, power supply circuits, and user input devices. As such, these functions may be interpreted as method steps for performing a detection process that identifies which client devices are being served by which RF ports of a node. Alternatively, some or all of the functions may be implemented by a state machine without stored program instructions, or in one or more application-specific integrated circuits (ASICs) in which each function or some combination of specific functions is implemented as custom logic. Of course, a combination of the two approaches may be used. Accordingly, methods and means for these functions are described herein. Moreover, it is expected that those skilled in the art will be able to readily generate such software instructions and programs and ASICs with minimal experimentation when guided by the concepts and principles disclosed herein, despite potentially considerable effort and many design choices motivated, for example, by available time, current technology, and economic considerations.

[0010] Embodiments of the present disclosure will now be described in detail. Referring to the drawings, like numerals indicate like parts throughout the views. As used throughout the description and claims herein, the following terms will take the meaning expressly associated therewith, unless the context clearly dictates otherwise, and the meaning of "a," "an," and "the" will include plural references, and the meaning of "in" will include "in" and "on." Relative terms such as first and second, top and bottom, etc. may be used only to distinguish one entity or act from another, without necessarily requiring or implying any actual such relationship or order between such entities or acts.

[0011] As used herein, components may be "operably coupled" if information may be transmitted between such components, even though there may be one or more intermediate or intervening components between or along the connection path. The terms "substantially," "essentially," "approximately," "about," or any other variation thereof, as understood by one of ordinary skill in the art, are defined as close, and in one non-limiting embodiment, the terms are defined as within 10 percent, within 5 percent, within 1 percent, and within 0.5 percent. As used herein, the term "coupled" is defined as connected, but not necessarily directly, and not necessarily mechanically. Also, reference numbers shown in parentheses herein refer to components shown in figures other than the one under discussion. For example, discussing device 10 while discussing Figure A would refer to element 10 shown in figures other than Figure A.

[0012] Referring now to Figure 1, illustrated therein is a prior art remote PHY architecture 100. Remote PHY refers to the technology of moving PHY circuitry from a device, such as a CCAP, and placing the PHY circuitry at the network end of another device, such as a node. Remote PHY builds upon work begun with CableLabs' Modular Cable Modem Termination System (CMTS) (M-CMTS) and Modular Headend Architecture (MHA).

[0013] In a remote PHY architecture, the classic I-CCAP is separated into two separate components. The first component is the CCAP Core 101. This component is typically located at a head-end server. The second component is the Remote PHY Device (RPD) 102. This component is typically located at a node located closer to the client devices 103, 104, 105, 106 that are served by the node via an RF network 107, often comprised of coaxial cable. Data communication between the CCAP Core 101 and the RPD 102 occurs over a fiber optic cable network, denoted here as a Passive Optical Network 108 or (PON), to provide higher bandwidth.

[0014] The CCAP core 101 contains both a CMTS core for DOCSIS and an Edge Quadrature Amplitude Modulator (EQAM) core for video. The CMTS core encompasses the DOCSIS Medium Access Control (MAC) and upper layer DOCSIS protocols. This includes all signaling functions, downstream and upstream bandwidth scheduling, and DOCSIS framing. The DOCSIS functionality of the CMTS core is defined by the existing DOCSIS specifications. The EQAM core encompasses all video processing functions currently provided by EQAM.

[0015] The RPD 102 primarily includes PHY-related circuitry such as a downstream QAM modulator, an upstream QAM demodulator, etc., along with pseudowire logic for connecting to the CCAP core 101. The RPD platform is a physical layer converter, and the function of the physical layer converter includes both converting downstream DOCSIS, Moving Picture Experts Group (MPEG) video, and out-of-band (OOB) signals received from the CCAP core 101 via a digital medium such as Ethernet or PON 108 to analog for transmission over RF over the RF network 107 or other equivalent network, and / or converting upstream DOCSIS and OOB signals received from an analog medium such as RF or linear optical to digital for transmission to the CCAP core 101 via Ethernet or PON 108.

[0016] The RPD 102 has one or more RF ports 109, 110, 111, 112 that provide connectivity to client devices 103, 104, 105, 106 belonging to the system's customers. Using the prior art remote PHY architecture 100, it is not possible to determine which client device 103, 104, 105, 106 is being served by which RF port 109, 110, 111, 112. The same is true for a remote medium access control PHY (RMACPHY) device (RMD). This deficiency is highly problematic because the "legs" of the RF network 107 can span significant distances. Furthermore, it is not possible to perform event correlation for a group of customers affected by a failure occurring on a leg of the RF network 107. If something happens to one leg of the RF network 107 in the prior art remote PHY architecture 100, the only way to find out which leg is experiencing the problem is to have someone in a truck drive to each leg to find the problem. This is time consuming and expensive, resulting in very high customer dissatisfaction.

[0017] Advantageously, embodiments of the present disclosure provide methods and systems that can identify which client devices are being served by which RF ports of an RPD or MACPHY. Embodiments of the present disclosure enable users of remote PHY systems configured in accordance with embodiments of the present disclosure, which may include large cable companies, commonly known as multiple system operators (MSOs), that operate several cable communication systems (in some cases up to hundreds of systems), to have a verifiable and consistent method for determining which client devices are being served by each RPD or node. Furthermore, embodiments of the present disclosure enable MSOs to determine which client devices are being served by each RF port, thereby identifying which leg of the RF network any one client device is coupled to.

[0018] Embodiments of the present disclosure contemplate that connections between client devices associated with RF ports of an RPD may become outdated. For this and other reasons, these records may be inaccurate. Furthermore, new records for new client devices are often entered manually, thereby exacerbating error rates. Records may become even more inaccurate when a "node split" occurs due to the fact that additional nodes or RPDs are required to feed the client device base.

[0019] Advantageously, embodiments of the present disclosure provide methods and systems that can be used to determine whether an RPD or RMD has been properly wired to a node's RF tray during the installation process. Embodiments of the present disclosure provide an MSO with the ability to obtain the current network topology for client devices being served by the RPD RF port and the corresponding RF leg of the RF network.

[0020] In one or more embodiments, the RPD, RMD, or node is equipped with an RF switching network coupled between an upstream DOCSIS port, which may be an optical port, and a downstream RF port. As described in more detail below, the RF switching network may be coupled on the downstream path or the upstream path. In other embodiments, the RF switching network may be coupled on both the downstream path and the upstream path. In one or more embodiments, one or more control circuits operable in the RF switching network control the RF switching network during a DOCSIS initialization procedure to determine which client devices are coupled to which RF ports of the RPD, RMD, or node.

[0021] In one or more embodiments, the one or more control circuits cause a client device attached to an RF port of an RPD, RMD, or node to: Distance measurement and Registration The one or more control circuits then cause the RF switching network to change to a different configuration. In one or more embodiments, the one or more control circuits, or optionally one or more processors operable in the RPD, RMD, or node, determine which client devices are: Distance measurement and Registration Determine whether the client device is still identified as having completed the procedure. These client devices may be logged and stored in memory.

[0022] One or more control circuits can then cause the RF switching network to change to yet another configuration, causing previously unreachable client devices to be coupled to other DOCSIS ports, thereby allowing these devices to be identified again. This process can continue for all permutations of ports, such that all client devices coupled to an RF port of an RPD, RMD, or node can be identified as being coupled to that particular RF port and corresponding RF leg of the RF network.

[0023] In one or more embodiments, the client device is rebooted and restarted at the headend. Re-register To avoid causing service interruptions if necessary, this process can be performed using other techniques that do not interrupt service to any of the client devices. Illustratively, by way of example, in one or more embodiments, a subset of the client devices may be instructed to transmit data during the test period. Examples of such instructions include having the client devices coupled to the remaining RF ports broadcast station maintenance, transmit DOCSIS codewords (CWs), transmit pilot transmission probes such as D3.1 probes, etc. Meanwhile, the remaining client devices, i.e., the set comprising the complement of the subset, may be assigned idle grants during the test period.

[0024] In one or more embodiments, one or more control circuits cause the RF switching network to switch between various RF and DOCSIS ports while a subset of client devices transmit data and client devices other than those in the subset are silent. This allows a burst receiver at the headend to identify the RF port and corresponding RF leg to which the client device is attached. These tests can be performed periodically and / or staggered to periodically update the status of the system. They do not need to be performed back-to-back for all client devices, thereby increasing the likelihood of uninterrupted service.

[0025] In one or more embodiments, the DOCSIS node comprises a first DOCSIS port and a second DOCSIS port. The node may further include a plurality of RF ports and an RF switching network coupled between the first DOCSIS port, the second DOCSIS port, and the plurality of RF ports.

[0026] In one or more embodiments, a method for identifying which client devices are coupled to which RF ports of a node includes using one or more control circuits to assign some of the client devices coupled to the node instructions to transmit data. In one or more embodiments, the method includes using the one or more control circuits to assign others of the client devices to idle grants. In one or more embodiments, when the one or more control circuits switch an RF switching network disposed between the RF port and a plurality of optical ports of the node from a first state to a second state, the one or more control circuits assign the data to one of the plurality of optical ports. default identifying one or more client devices among a number of client devices that are delivering to the optical port of the

[0027] Embodiments of the present disclosure contemplate that node splits, node replacements, and other field operations will continue to occur as MSOs work to increase the bandwidth of their RPD systems. Advantageously, embodiments of the present disclosure provide a simple, effective, and low-cost tool for determining which client devices are served by which RF legs of an RF network. Embodiments of the present disclosure also enable an MSO's operations group to determine accurate event correlation for customers affected by a fault occurring on an RF leg. Furthermore, embodiments of the present disclosure also enable an MSO to identify which RF leg coupled to an RPD, RMD, or node RF port is experiencing a technical issue. Embodiments of the present disclosure further enable an MSO to determine the number of client devices served by each RF leg, thereby balancing serving groups within a DOCSIS system.

[0028]

[0013] Embodiments of the present disclosure differ from prior art systems, such as that shown in Figure 1, because previous solutions never implemented an RF switching network that provided flexibility for configuring connections between RF ports and DOCSIS ports of an RPD, RMD, or node. For this reason, prior art solutions are unable to determine which client devices are served by each RF leg of an RPD, RMD, or node. Embodiments of the present disclosure also differ from prior art solutions in that some embodiments of the present disclosure leverage DOCSIS initialization procedures to uniquely determine specific DOCSIS and client device connections with RF ports of an RPD, RMD, or node to accurately identify the system topology and the client devices and corresponding customers served by each RF leg of an RPD, RMD, or node.

[0029] 2, illustrated therein is one illustrative remote PHY system 200 configured in accordance with one or more embodiments of the present disclosure. Remote PHY system 200 may be used to deliver high-definition digital entertainment and telecommunications, such as video, audio, and high-speed Internet services, to one or more client devices, e.g., client devices 205, 206, 207.

[0030] In one or more embodiments, remote PHY system 200 represents the operational or geographic footprint of an entertainment and / or information service franchise that provides entertainment and / or information services to a subscriber base spread across one or more towns, regions, or portions thereof. The particular entertainment and / or information services offered by the franchise, such as entertainment channel lineups, data packages, or other services, may vary from system to system. For example, a large cable company may operate a variety of cable communication systems, which are commonly referred to as an MSO.

[0031] While an HFC network will be used as an exemplary configuration for remote PHY system 200 for illustrative purposes, it should be noted that embodiments of the present disclosure are not so limited. Embodiments of the present disclosure may be used with other network topologies, including all-coax networks, all-fiber networks, fiber-to-the-last-amplifier (FTTA) networks, or other networks. Additionally, while remote PHY system 200 using the DOCSIS protocol will be used as an illustrative example, embodiments of the present disclosure may be used with other types of devices in which headend 201, servers, or other devices are physically separated from node 202, or nodes 202, 203, 204, which feed one or more client devices 205, 206, 207, regardless of whether the DOCSIS protocol is used.

[0032] 2, the remote PHY system 200 comprises an HFC network that combines optical fiber and coaxial cable. In one or more embodiments, this combination advantageously installs fiber nodes to service multiple residences. It should be understood that the systems and methods disclosed herein may be employed in a variety of networks, and that an HFC network is provided merely as a non-limiting example.

[0033] In one or more embodiments, remote PHY system 200 comprises a headend 201 that receives analog video signals and digital bitstreams representing different services, such as video services, audio services, Internet services, or other services, from a variety of digital information sources. For example, headend 201 may receive content from one or more video-on-demand (VOD) servers, Internet Protocol Television (IPTV) broadcast video servers, Internet video sources, or other suitable sources for providing Internet Protocol (IP) content.

[0034] In one or more embodiments, remote PHY system 200 comprises IP network 208, MPEG services 209, and analog services 210. IP network 208 includes web server 211 and data source 212. Web server 211 may comprise a streaming server that distributes video-on-demand, audio-on-demand, and pay-per-view streams to IP network 208 using IP protocols. IP data source 212 may be connected to a regional area or backbone network 213 that transmits IP content. For example, the regional area network may be or include the Internet, or an IP-based network, computer network, web-based network, or any other suitable wired or wireless network or network system.

[0035] In one or more embodiments, the various services are encoded, modulated, and upconverted onto RF carriers, combined into a single electrical signal, and inserted into broadband optical transmitter 214 (designated with the symbol Tx in FIG. 1) at headend 201. Optical fiber network 215 extends from the cable operator's master / regional headend 201 to multiple nodes 202, 203, 204, which in this illustrative example are configured as RPDs. Nodes 202, 203, 204 may also be RMDs or other types of devices in other architecture systems.

[0036] In one or more embodiments, headend 201 may contain an optical transceiver, which may include one or more of an optical transmitter 214 and an optical receiver 216 (designated with the symbol Rx in FIG. 1 ), to send and receive optical communications over optical fiber network 215. In one or more embodiments, optical receiver 216 functions as or comprises burst receiver 230. As described in more detail below, in one or more embodiments, burst receiver 230 may be configured to determine which client device 205, 206, 207 is delivering data to the DOCSIS port of node 202, 203, 204. In one or more embodiments, burst receiver 230 accepts upstream burst data received from nodes 202, 203, 204, 205 over optical fiber network 215. In other embodiments, regional headends and / or nearby hub sites may exist between headend 201 and one or more nodes 202, 203, 204.

[0037] In one or more embodiments, the optical fiber network 215 extends from the headend 201 to a regional headend / hub (if included) and / or multiple nodes 202, 203, 204. The optical transmitter 214 converts the electrical signals into downstream optical modulated signals that are transmitted to the nodes 202, 203, 204. The nodes 202, 203, 204 then convert the inbound signals into RF energy for delivery to the client devices 205, 206, 207.

[0038] On the return path, nodes 202, 203, 204 convert the returning RF signal to an optical signal and transmit the optical signal over fiber optic network 215 to optical receiver 216, which can convert the optical signal back to an electrical signal. In one or more embodiments, each node 202, 203, 204 acts as a local digital hub, sending local requests over fiber optic network 215 and back to client devices 205, 206, 207 over RF network 217, which in this example comprises multiple coaxial cables.

[0039] As used herein, the terms "forward path" and "downstream" may be used interchangeably to refer to a path from the head end 201 to a node 202, 203, 204, a path from the node 202, 203, 204 to a client device 205, 206, 207 or subscriber, or a path from the head end 201 to a subscriber. Conversely, the terms "return path," "reverse path," and "upstream" may be used interchangeably to refer to a path from a subscriber or client device 205, 206, 207 to a node 202, 203, 204, a path from the node 202, 203, 204 to the head end 201, or a path from a subscriber or client device 205, 206, 207 to the head end 201.

[0040] Additionally, it should be noted that nodes 202, 203, 204 may be any analog or digital hubs disposed between headend 201 and client devices 205, 206, 207 that route local requests via a system that may be remote PHY system 200 or some other type of system. Forward path optical communications via optical fiber network 215 may be converted to RF communications at nodes 202, 203, 204 for transmission to client devices 205, 206, 207 via RF network 217. Conversely, return path RF communications from client devices 205, 206, 207 are provided via RF network 217 and are typically converted to optical signals at nodes 202, 203, 204 for transmission to headend 201 via optical fiber network 215. Each node 202, 203, 204 may include a return path transmitter capable of relaying upstream communications from client devices 205, 206, 207 to headend 201.

[0041] In one or more embodiments, each node 202, 203, 204 serves a service group, e.g., service group 218, comprising one or more client devices 205, 206, 207 located at one or more customer locations. Illustrating by example, a single node, e.g., node 202, may be connected to thousands of client devices 205, 206, 207, such as cable modems or other network elements including bidirectional RF amplifiers. In one exemplary embodiment, node 202 serves anywhere from 1 to 2,000 customer locations. In an HFC network, node 202 may be connected to multiple client devices 205, 206, 207 via coaxial cable or other routes in RF network 217. Alternatively, node 202 may be coupled to client devices 205, 206, 207 by a combined fiber optic / coaxial cable network. Other network connections suitable for coupling node 202 to client devices 205, 206, 207 will be apparent to those skilled in the art having the benefit of this disclosure.

[0042] In one or more embodiments, each node 202, 203, 204 may include a broadband optical receiver that converts downstream optical modulated signals received from the headend 201 or hub into electrical signals for provision to the client devices 205, 206, 207 over the RF network 217 of the HFC network. Each node 202, 203, 204 may be connected to many of the client devices 205, 206, 207 over a coaxial cable portion of the RF network 217, referred to as an “RF cascade.” In one or more embodiments, signals may be passed from the nodes 202, 203, 204 to the client devices 205, 206, 207 through the RF cascade, which may include one or more amplifiers, e.g., amplifiers 219, 220, 221. The RF cascade may further include other active or passive devices, such as cable connections, taps, splitters, and in-line equalizers. On some RF legs of RF network 217, e.g., RF leg 222, client device 205 may be connected through amplifiers 219, 220. Other RF legs, e.g., RF leg 223, may not include an amplifier so that client device 206 does not receive an amplified signal. Each client device 205, 206, 207 may be coupled to RF legs 222, 223 of RF network 217 via one or more taps, e.g., taps 224, 225. The taps are designed with various values ​​to allow for amplitude consistency along the distribution system.

[0043] In one or more embodiments, client devices 205, 206, 207 reside at customer locations, such as the homes of system subscribers. In one or more embodiments, client devices 205, 206, 207 are connected to a cable modem termination system (CMTS) 226 or equivalent component located at headend 201. Each client device 205, 206, 207 may be a modem, e.g., a cable modem, a media terminal adapter (MTA), a set-top box, a terminal device, a television equipped with a set-top box, a DOCSIS terminal device, a customer premises equipment (CPE), a router, or a subscriber's electronic client, end, or terminal device. For example, in one or more embodiments, client devices 205, 206, 207 comprise a cable modem or IP set-top box supporting data connections to the Internet and other computer networks over a cable network, which provides a two-way communication system through which data may be transmitted downstream from headend 201 to subscribers and upstream from subscribers to headend 201.

[0044] The technology disclosed herein may be applied to DOCSIS-compliant systems. The cable industry developed the international DOCSIS standard or protocol to enable the delivery of IP data packets over cable systems. Generally, DOCSIS defines the communication and operational support interface requirements for data over cable systems. For example, DOCSIS defines the interface requirements for cable modems involved in high-speed data distribution over cable television system networks. However, it will be understood that the technology disclosed herein may be applied to any system for digital service transmission, such as digital video or Ethernet PON over coax (EPOC). Examples that refer to DOCSIS herein are for illustrative purposes and represent the application of the technology to a wide range of services carried over coax.

[0045] In one or more embodiments, the CMTS 226 of the headend 201 comprises components that exchange signals between the headend 201 and the client devices 205, 206, and 207. In one or more embodiments, for example, the CMTS 226 and the client devices 205, 206, and 207 may be endpoints of a DOCSIS protocol, with the remote PHY system 200 transmitting information between these endpoints. It will be understood that the remote PHY system 200 includes one CMTS 226 for clarity of illustration only, as in many embodiments it is common for multiple CMTSs and their connected user devices to be managed by the remote PHY system 200.

[0046] In one or more embodiments, the CMTS 226 hosts downstream and upstream ports and contains a large number of receivers, each handling communications between hundreds of client devices 205, 206, 207 connected to the headend 201. For example, each receiver on the CMTS 226 may be connected to several client devices 205, 206, 207 for many subscribers. Stated differently, a single receiver on the CMTS 226 may be connected to hundreds of client devices 205, 206, 207, each of which may vary widely in communication characteristics. Often, several nodes 202, 203, 204 serve a particular area of ​​a town or city. DOCSIS enables IP packets to be passed between devices on either side of the link between the CMTS 226 and the client devices 205, 206, 207.

[0047] However, it will be understood that the CMTS 226 is one example of a component of the headend 201 that may be used to exchange signals between the headend 201 and the client devices 205, 206, and 207. In other embodiments, a modular CMTS (M-CMTS™) architecture, or CCAP, may function similarly to the CMTS 226, providing more efficient traffic handling through the use of IP routing to replace significant concatenation, segmentation, and cabling components in the CMTS 226. The CCAP design may therefore improve the efficiency of the CMTS design, improving operation, headend maintenance, and equipment lifecycle. The CCAP version of the CMTS 226 may utilize less rack space in the headend 201 and consume less power.

[0048] A quadrature amplitude modulator (QAM) 227 may be present in the headend 201 or a hub device to receive packets of digital content, such as video or data, repacketize the digital content into an MPEG transport stream, and digitally modulate the digital transport stream onto a downstream RF carrier using quadrature amplitude modulation. QAM may be used for both digital broadcast and DOCSIS downstream transmissions. In a CMTS or M-CMTS implementation, data and video QAM may be implemented on separately managed and controlled platforms. In a CCAP implementation, CMTS and edge QAM functions may be combined into a single hardware solution, thereby combining data and video distribution.

[0049] In this exemplary remote PHY system 200, the DOCSIS MAC and PHY layers are moved out of the headend 201 and instead incorporated into each node 202, 203, 204. In some R-CCAP implementations, the entire upper and lower MAC and PHY layer functions are moved to nodes 202, 203, 204, with the CMTS, QAM, and CCAP functions located in nodes 202, 203, 204. When the QAM 227 is physically removed from the integrated CMTS 226 and located downstream, it is known as an edge QAM (EQAM) or downstream PHY device. In some remote node embodiments, nodes 202, 203, 204 are configured as RPDs, and the physical layer ties layer devices, such as the MAC layer, to the physical medium, such as optical fiber or copper cable. In a remote PHY system such as that shown in FIG. 2, the CCAP MAC remains at the headend 201, and Ethernet aggregation is performed by the headend 201.

[0050] Referring now to FIG. 3, illustrated therein is one illustrative node 202 configured in accordance with one or more embodiments of the present disclosure. As previously discussed, in one or more embodiments, node 202 receives optical signals in the downstream direction via an optical fiber network (215) and converts these signals to RF signals. Node 202 then distributes the RF signals via an RF network (217), which in one or more embodiments comprises a coaxial cable network. In the exemplary embodiment of FIG. 3, node 202 receives data via optical fiber at first and second downstream DOCSIS ports 301 and 302, each of which is an optical port. Node 202 converts the data to RF signals and distributes these RF signals to four RF ports 303, 304, 305, and 306, which are coupled by the RF network (217) to one or more client devices (205, 206, and 207). As noted above with respect to FIG. 2, each client device is coupled to a single RF port of node 202. For example, in FIG. 2, client device (205) was coupled to RF port 303, while client devices (206, 207) were coupled to RF port 304, and so on.

[0051] In the upstream direction, node 202 receives RF signals from client devices (205, 206, 207) at RF ports 303, 304, 305, 306. Node 202 converts these signals to optical signals and then distributes the optical signals to first and second upstream DOCSIS ports 307 and 308, each of which is an optical port. The optical signals are then distributed from first and second upstream DOCSIS ports 307 and 308 to the headend (201) via optical fiber network (215).

[0052] To ensure reliability of the components of node 202, these electronic components are generally installed within a housing 318. Because the housing may be exposed to the elements, it should generally be weatherproof. Often, housing 318 is physically configured as a "trunk." The trunk may include a lid pivotally connected to a base by one or more hinges. In one or more embodiments, housing 318 includes one or more openings configured as physical "ports" through which electrical connections to first downstream DOCSIS port 301, second downstream DOCSIS port 302, first RF port 303, second RF port 304, third RF port 305, fourth RF port 306, first upstream DOCSIS port 307, and second upstream DOCSIS port 308 may be made from outside of housing 318.

[0053] In one or more embodiments, node 202 includes one or more electronic components disposed within a housing 318. The electronic components disposed within housing 318 may include a power supply, an RF amplifier, a power distribution board, a fiber optic receiver module, a digital transmitter, one or more processors, or other associated components. For example, in one or more embodiments, the node includes a quad output amplifier module 309, a power supply 310 operable with the quad output amplifier module 309, a control board 311 with one or more control circuits 312, and a node / amplifier determination module 313. These electronic components are for illustrative purposes only. Those skilled in the art with the benefit of this disclosure will understand that other configurations may be more suitable for other applications.

[0054] In one or more embodiments, node 202 includes a downstream RF switching network 314 coupled between the DOCSIS port and the RF port. In the exemplary example of Figure 3, downstream RF switching network 314 is coupled to first downstream DOCSIS port 301 and second downstream DOCSIS port 302, and RF ports 303, 304, 305, and 306. In one or more embodiments, downstream RF switching network 314 enables one or more control circuits 312 of control board 311 to switch connections between first downstream DOCSIS port 301 and second downstream DOCSIS port 302 and RF ports 303, 304, 305, and 306 during operation. To illustrate by way of example, a connection between a first downstream DOCSIS port 301 and a first RF port 303 can be broken simply by switching the downstream RF switching network 314, while another connection between a second downstream DOCSIS port 302 and the first RF port 303 is made.

[0055] Referring briefly to Figure 4, illustrated therein is a schematic block diagram of one embodiment of the downstream RF switching network 314. As shown in Figure 4, the downstream RF switching network 314 includes two input connections 401, 402 and four output connections 403, 404, 405, 406. In one or more embodiments, the first input connection 401 is coupled to the first downstream DOCSIS port (301), while the second input connection 402 is coupled to the second downstream DOCSIS port (302). The first output connection 403 is coupled to the first RF port (303), while the second output connection 404 is coupled to the second RF port (304). The third output connection 405 is coupled to the third RF port (305), while the fourth output connection 406 is coupled to the fourth RF port (306), and so on.

[0056] Coupled between the two input connections 401, 402 and the four output connections 403, 404, 405, 406 is a network of terminated single-pole, double-throw (SPDT) switches 407, 408, 409, 410, 411, 412 and signal splitters 413, 414, 415. By changing the state of the SPDT switches 407, 408, 409, 410, 411, 412, one or more control circuits (312) of node (202) can couple either the first input connection 401 or the second input connection 402 to different combinations of the output connections 403, 404, 405, 406.

[0057] Illustratively, by coupling SPDT 407 and SPDT 411 to connector 416, the first input connection 401 is connected to the first output connection 403 and the second output connection 404. In contrast, by coupling SPDT 407 to SPDT 409, SPDT 410 to signal splitter 413, and both SPDT 411 and SPDT 412 to signal splitter 413, the first input connection 401 is connected to all four output connections 403, 404, 405, 406.

[0058] Similarly, coupling SPDT 408 and SPDT 415 to connector 417 connects the second input connection 402 to the third output connection 405 and the fourth output connection 406. In contrast, coupling SPDT 408 to SPDT 409, SPDT 410 to signal splitter 413, and both SPDT 411 and SPDT 412 to signal splitter 413 connects the second input connection 402 to all four output connections 403, 404, 405, 406, and so on.

[0059] 4 is one illustrative example of how a downstream RF switching network may be configured in accordance with embodiments of the present disclosure to enable switching between input connections 401, 402 and output connections 403, 404, 405, 406. Other configurations, including those using other types of switches, will be apparent to those skilled in the art having the benefit of this disclosure.

[0060] 3 , the one or more control circuits 312 of the control board 311 can switch the downstream RF switching network 314 to a first state in which the first downstream DOCSIS port 301 is connected to the first RF port 303 and the second RF port 304, while the second downstream DOCSIS port 302 is coupled to the third RF port 305 and the fourth RF port 306. Alternatively, the one or more control circuits 312 can switch the downstream RF switching network 314 to a second state in which the first downstream DOCSIS port 301 is coupled to all of the RF ports 303, 304, 305, and 306. Similarly, the one or more control circuits 312 of the control board 311 can switch the downstream RF switching network 314 to a third state in which the second downstream DOCSIS port 302 is coupled to all of the RF ports 303, 304, 305, and 306.

[0061] In one or more embodiments, node 202 also includes an upstream RF switching network 315 similarly coupled between the DOCSIS ports and the RF ports. In the exemplary example of Figure 3, upstream RF switching network 315 is coupled to first and second upstream DOCSIS ports 307 and 308, as well as RF ports 303, 304, 305, and 306. Similar to downstream RF switching network 314, in one or more embodiments, upstream RF switching network 315 enables one or more control circuits 312 of control board 311 to switch connections between first and second upstream DOCSIS ports 307 and 308 and RF ports 303, 304, 305, and 306 during operation. To illustrate by way of example, a connection between a first upstream DOCSIS port 307 and a first RF port 303 can be broken simply by switching the state of the upstream RF switching network 315, while another connection is made between a second upstream DOCSIS port 308 and the first RF port 303.

[0062] Referring briefly to Figure 5, illustrated therein is a schematic block diagram of one embodiment of the upstream RF switching network 315. As shown in Figure 5, the upstream RF switching network 315 includes two output connections 507, 508 and four input connections 503, 504, 505, 506. In one or more embodiments, the first output connection 507 is coupled to the first upstream DOCSIS port (307), while the second output connection 508 is coupled to the second upstream DOCSIS port (308). In one or more embodiments, the first input connection 503 is coupled to the first RF port (303), while the second input connection 504 is coupled to the second RF port (304). The third input connection 505 is coupled to the third RF port (305), while the fourth input connection 506 is coupled to the fourth RF port (306), and so on.

[0063] Coupled between the two output connections 507, 508 and the four input connections 503, 504, 505, 506 are four SPDT switches 509, 510, 511, 512 and two signal combiners 513, 514. By changing the state of the SPDT switches 509, 510, 511, 512, one or more control circuits (312) of the node (202) can couple any of the input connections 503, 504, 505, 506 to any of the output connections 507, 508.

[0064] Illustratively, by coupling SPDT 509 to signal combiner 513, while SPDT 510, SPDT 511, and SPDT 512 to signal combiner 514, the first input connection 503 is coupled to the first output connection 507, while input connection 504, input connection 505, and input connection 506 are coupled to the second output connection 508. By coupling SPDT 509 and SPDT 510 to signal combiner 513, while SPDT 511 and SPDT 512 to signal combiner 514, the first input connection 503 and the second input connection 504 are coupled to the first output connection 507, while the third input connection 505 and the fourth input connection 506 are coupled to the second output connection 508, and so on.

[0065] 3, one or more control circuits 312 of control board 311 can switch upstream RF switching network 315 into a power of four, or 16, different states. Illustratively, by way of example, in a first state, all RF ports 303, 304, 305, and 306 are coupled to first upstream DOCSIS port 307. In a second state, RF port 303 is coupled to first upstream DOCSIS port 307, while RF ports 304, 305, and 306 are coupled to second upstream DOCSIS port 308. In a third state, RF ports 303 and 304 are coupled to first upstream DOCSIS port 307, while RF ports 305 and 306 are coupled to second upstream DOCSIS port 308. In a fourth state, RF ports 303, 304, and 305 are coupled to a first upstream DOCSIS port 307, while RF port 306 is coupled to a second upstream DOCSIS port 308, and so on.

[0066] As will be described in more detail below, by controlling one or both of the downstream RF switching network 314 and / or the upstream RF switching network 315, the one or more control circuits 312 of the node 202 can advantageously identify which client devices are coupled to which RF ports 303, 304, 305, 306 of the node 202. This technique can further be used during installation to determine whether client devices are also correctly coupled to the RF ports 303, 304, 305, 306. Without the technique described below, it would be impossible to know the event correlation of the group of client devices affected during a fault occurring on the RF leg coupled to the RF ports 303, 304, 305, 306. Advantageously, the technique described below provides an MSO with the ability to obtain current network topology information for customers served by a particular RF port 303, 304, 305, 306 and its corresponding RF leg.

[0067] Referring now to Figure 6, illustrated therein is one illustrative method 600 configured in accordance with one or more embodiments of the present disclosure. The method 600 of Figure 6 utilizes switching the downstream RF switching network 314 and / or the upstream RF switching network 315 with input from a DOCSIS initialization procedure to determine which client devices are coupled to which RF ports 303, 304, 305, 306 of the DOCSIS node 202.

[0068] In one or more embodiments, the method 600 of FIG. 6 allows a client device coupled to the RF ports 303, 304, 305, 306 to receive a QoS notification from the client device while one or both of the downstream RF switching network 314 and / or the upstream RF switching network 315 are in a first state. Distance measurement and Registration In one or more embodiments, the method 600 then changes the state of one or both of the downstream RF switching network 314 and / or the upstream RF switching network 315 to a second state. In this second state, the one or more control circuits 312 of the node 202 determine which client devices are Distance measurement and Registration Determine whether any client devices are still identified as having completed the procedure. Client devices that are no longer in communication with the headend, or alternatively, client devices that are currently connected to other DOCSIS ports, can be identified to determine which client devices are connected to which RF ports 303, 304, 305, 306.

[0069] Although the change in state can occur by switching the state of one or both of the downstream RF switching network 314 and / or the upstream RF switching network 315, for ease of illustration, method 600 is described in terms of changing the state of only the upstream RF switching network 315. However, it should be understood that a method equivalent to method 600 can be achieved by changing the state of the downstream RF switching network 314 while the upstream RF switching network 315 remains in a constant state. In yet other embodiments, a method equivalent to method 600 can be achieved by switching both the downstream RF switching network 314 and the upstream RF switching network 315 to different states. Accordingly, other methods equivalent to method 600 of FIG. 6 will be apparent to those skilled in the art having the benefit of this disclosure.

[0070] Beginning at step 601, the node's one or more control circuits 312 place the downstream RF switching network 314 and the upstream RF switching network 315 in a first state, shown at step 602. In this exemplary embodiment, the first state includes the first downstream DOCSIS port 301 being coupled to the first RF port 303 and the second RF port 304. In this exemplary embodiment, the first state also includes the second downstream DOCSIS port 302 being coupled to the third RF port 305 and the fourth RF port 306.

[0071] As also shown in step 602, in this example, the first state includes first RF port 303 and second RF port 304 being coupled to first upstream DOCSIS port 307. Similarly, third RF port 305 and fourth RF port 306 are coupled to second upstream DOCSIS port 308.

[0072] In step 603, the client devices coupled to the RF ports 303, 304, 305, and 306 (such as the client devices shown in FIG. 2) Distance measurement Operation and Registration In step 604, Distance measurement and Registration Client devices that have completed the process, i.e., client devices that communicate with a headend coupled to a DOCSIS port, are identified. In one or more embodiments, step 604 includes storing these identified client devices in memory 610. While memory 610 is shown as residing within node 202 in FIG. 6, it should be noted that memory 610 and its associated one or more control circuits 312 may reside within a headend coupled to node 202 via optical fiber network (215), or within another electronic device that communicates with either the headend or node 202. Other configurations and arrangements of one or more control circuits 312 and memory 610 will be apparent to those skilled in the art having the benefit of this disclosure.

[0073] By way of example, in one or more embodiments, the one or more control circuits 312 are operable with a DOCSIS MAC control plane. In one or more embodiments, this DOCSIS MAC control plane is sized in different devices as a function of the overall architecture of the system. For example, in an ICCAP device, the DOCSIS MAC control plane is configured as one or more circuit cards located within the chassis. In a CCAP core device, the DOCSIS MAC control plane is configured as one or more circuit cards located within the chassis. In a virtualized core device, the DOCSIS MAC control plane may be configured as an executable software configuration running on the CCAP core. In a remote PHY system (200), such as that shown in FIG. 2 above, the DOCSIS MAC control plane is configured as hardware within the node 202. Therefore, while this exemplary embodiment is used for purposes of explanation, it should be noted that one or more control circuits may reside outside of the node 202, such as in the headend or another electronic device. The same is true for the downstream RF switching network 315 and the upstream RF switching network 315. Although shown as integrated within node 202, they may also be located outside of node 202 within RF network 217. Other configurations equivalent to these exemplary circuit component configurations will be apparent to those skilled in the art having the benefit of this disclosure.

[0074] In step 605, method 600 (in this example) switches upstream RF switching network 315 to a second state, shown in step 606. As shown in step 606, the second state switches RF port 304 and RF port 305. While RF port 303 is still communicating with first upstream DOCSIS port 307, and while RF port 306 is still communicating with second upstream DOCSIS port 308, the connections of RF port 304 and RF port 305 have changed. Instead of communicating with first upstream DOCSIS port 307, as was the case when upstream RF switching network 315 was in the first state, RF port 304 is now coupled to second upstream DOCSIS port 308. In a similar manner, rather than communicating with the second upstream DOCSIS port 308 as it was in the first state, in the second state RF port 304 is now coupled to the first upstream DOCSIS port 307.

[0075] As a result, client devices coupled to first RF port 303 and fourth RF port 306 may experience a loss of connectivity due to the fact that they are still communicating with the same DOCSIS port that they were communicating with when upstream RF switching network 315 was in the first state. Distance measurement and Registration The process can be completed because the client devices are still receiving the correct upstream channel descriptor messages from the downstream communications. However, client devices that are now communicating with different DOCSIS upstream ports may experience issues due to the fact that the upstream channel descriptor messages for these client devices do not match the physical configuration of the upstream RF switching network 315. Distance measurement and Registration The process cannot be completed.

[0076] In step 607, one or more control circuits 312 of node 202 determine which client devices: Distance measurement and Registration In one or more embodiments, the identities of these devices are recorded in memory 610 in step 607. In one or more embodiments, step 607 also includes identifying and recording in memory any client devices that are no longer in communication with the headend.

[0077] Thus, by comparing the client device identities recorded in step 604 with those recorded in step 607, the one or more control circuits 312 can initiate identity associations between the RF ports 303, 304, 305, 306 and the client devices. For example, if client device A and client device B are coupled to the first RF port 303, client device C and client device D are coupled to the second RF port 304, client device E and client device F are coupled to the third RF port 305, and client device G and client device H are coupled to the fourth RF port 306 when the upstream RF switching network 315 is in a first state, each of these client devices would be recorded in step 604. However, in step 607, only client devices A, B, G, and H would be recorded. The one or more control circuits 312 can then conclude that these client devices are coupled to either the first RF port 303 or the fourth RF port 306.

[0078] By repeating the process and making other permutations, further conclusions can be made. For example, if upstream RF switching network 315 is switched to a third state, the devices coupled to first RF port 303 can be accurately identified. If the third state of upstream RF switching network 315 switches between RF port 304 and RF port 306, one or more control circuits 312 will identify client devices A, B, E, and F. Furthermore, one or more control circuits 312 will know that RF ports 303 and 305 are still communicating with the same DOCSIS ports with which they communicated when upstream RF switching network 315 was in the first state. From this, by comparing these client devices with those identified in step 607, one or more control circuits 312 can confidently conclude that client device A and client device B are coupled to first RF port 303. Because client device E and client device F are detected in the third state, these client devices must be connected to third RF port 305. Because client device G and client device H are no longer connected in the third state, these client devices must be coupled to the fourth RF port 306. Because client device C and client device D are not detected at this point, these client devices can only be coupled to the second RF port 304. Thus, in this exemplary embodiment, the one or more control circuits 312 obtain an accurate mapping of the network topology simply by changing the upstream RF switching network 315 between the three states.

[0079] Decision 608 determines whether the appropriate number of combinations have been made to obtain this network mapping. In the example of the preceding paragraph, only three states of the upstream RF switching network 315 were required to map the four RF ports 303, 304, 305, and 306. This is despite the fact that the upstream RF switching network 315 can be switched to 16 different states. In one or more embodiments, decision 608 includes determining whether the minimum number of states have been reached to determine which client devices are coupled to which RF ports 303, 304, 305, and 306. In other embodiments, for completeness, decision 608 includes first identifying all permutations of the state of the upstream RF switching network 315, and then, by redundancy, determining whether it has been completed to ascertain which client devices are coupled to which RF ports 303, 304, 305, and 306. Step 609 then performs the comparison described in the immediately preceding paragraph to obtain the network mapping.

[0080] The method 600 of FIG. 6 is implemented by various client devices. Distance measurement and Registration Note that this is done while the process is running. This method 600 works well in practice, but during the testing process, it may be possible to determine if a particular client device Distance measurement and Registration This can cause network disruptions due to the inability to complete the process, and therefore these client devices will need to repeat the process to get back online when the testing process is complete.

[0081] To allow a node to determine which client devices are associated with which RF ports without interrupting any service, in another embodiment, some client devices are delivered idle grants and other client devices are instructed to transmit data. Tests can then be performed during these idle grant / data transmissions to allow for the determination of which client devices are associated with which RF ports without any interruption to service. Referring now to Figure 7, illustrated therein is one method 700 by which this process can be performed.

[0082] Similar to the method (600) of Figure 6, the method 700 of Figure 7 may be performed by switching the state of one or both of the downstream RF switching network (314) and / or the upstream RF switching network (315). However, for ease of illustration, the method 700 will also be described in terms of changing the state of only the upstream RF switching network (315). As mentioned above, other methods equivalent to the method 700 of Figure 7, including switching the downstream RF switching network (314) or a combination of the downstream RF switching network (314) and the upstream RF switching network (315), will be apparent to those skilled in the art having the benefit of this disclosure.

[0083] Beginning at step 701, the downstream RF switching network (314) and the upstream RF switching network (315) are switched to a default configuration. Then, each client device coupled to the node's RF ports (303, 304, 305, 306) Distance measurement and Registration The process is completed and in step 702, communication begins with a headend coupled to the node (202).

[0084] In step 703, a subset of the client devices are instructed to transmit data during the test period. Examples of such instructions include instructing the client devices coupled to the remaining RF ports to broadcast station maintenance, transmit DOCSIS codewords (CW), transmit pilot transmission probes such as D3.1 probes, etc. In step 704, the remaining client devices are assigned idle grants during the test period.

[0085] In step 705, method 700 switches the upstream RF switching network (315) to a state different from a default state. For example, in one or more embodiments, step 705 includes using one or more control circuits 312 to switch the upstream RF switching network (315) disposed between the RF ports (303, 304, 305, 306) and multiple optical ports (e.g., the first upstream DOCSIS port 307 or the second upstream DOCSIS port 308) of the node (202) from a first state to a second state. In one or more embodiments, this second state connects one RF port to one DOCSIS port while coupling the remaining RF ports to another DOCSIS port. Decision 706 determines whether a burst receiver of a headend coupled to the node (202) detects data.

[0086] If, for some reason, no client devices are detected as transmitting data, step 707 switches the upstream RF switching network (315) to a different state. When the headend burst receiver detects data, those client devices transmitting data are identified in step 708 as being connected to an RF port coupled to the selected DOCSIS port. In other words, in one or more embodiments, step 708 uses one or more control circuits (312) to route data to one of a plurality of optical ports. defaultThis includes identifying one or more client devices streaming to the optical port(s). This information is recorded in memory in step 709. Decision 710 determines whether all RF ports have been tested. If not, method 700 returns to step 703, where the upstream RF switching network (315) is switched to yet another state. Once all RF ports have been tested, the testing process ends in step 711, and all client devices have been correctly and reliably identified as being connected to the particular RF port. Method 700 can then be repeated, with other client devices receiving idle grants and other client devices being instructed to transmit data, and so on.

[0087] This method 700 is illustrated by the examples in Figures 8-12. Referring now to Figure 8, in step 701, one or more control circuits 312 of node 202 place downstream RF switching network 314 and upstream RF switching network 315 in a first state, as shown in step 801. In this exemplary embodiment, the first state includes first downstream DOCSIS port 301 being coupled to first RF port 303 and second RF port 304. In this exemplary embodiment, the first state also includes second downstream DOCSIS port 302 being coupled to third RF port 305 and fourth RF port 306.

[0088] As also shown in step 801, in this embodiment, the first state includes first RF port 303 and second RF port 304 being coupled to first upstream DOCSIS port 307. Similarly, third RF port 305 and fourth RF port 306 are coupled to second upstream DOCSIS port 308.

[0089] In this example, two client devices are coupled to each RF port 303, 304, 305, and 306. Client device A and client device B are coupled to RF port 303, while client device C and client device D are coupled to RF port 304. Client device E and client device F are coupled to RF port 305, while client device G and client device H are coupled to RF port 306.

[0090] In step 702, client devices A, B, C, D, E, F, G, and H coupled to RF ports 303, 304, 305, and 306 are Distance measurement Operation and Registration In one or more embodiments, step 702 includes: Distance measurement and Registration Step 702 includes identifying client devices A, B, C, D, E, F, G, and H that have completed the process. In one or more embodiments, step 702 includes storing these identified client devices in memory 610.

[0091] In step 703, a subset of the client devices is instructed to transmit data. For purposes of illustration, in this example, the subset of client devices includes client device A, client device C, client device E, and client device G. At this point, the one or more control circuits 312 do not know which RF ports 303, 304, 305, 306 are coupled to these client devices A, C, E, and G.

[0092] In step 704, the complement of the subset of client devices is assigned an idle grant. In this example, the complement of the subset of client devices A, C, E, and G would include client device B, client device D, client device F, and client device H. Each would be assigned an idle grant in step 705. In step 705, the one or more control circuits 312 switch the upstream RF switching network 315 to switch to the second state shown in FIG. 9.

[0093] 9, step 901 illustrates a second state of upstream RF switching network 315 in this exemplary embodiment. As illustrated in step 901, the second state leaves RF port 303 in communication with first upstream DOCSIS port 307. While RF port 303 is still in communication with first upstream DOCSIS port 307, the connection of RF port 304, RF port 305, and RF port 306 is now to second upstream DOCSIS port 308. Thus, step 901 switches one of the RF ports, which in this example is first upstream DOCSIS port 307, to a second upstream DOCSIS port 308. default However, the remaining RF port is coupled to another optical port, which in this example is the second upstream DOCSIS port 308.

[0094] In one or more embodiments, determining 706 then includes a burst receiver at a headend coupled to node 202 receiving the data received on first upstream DOCSIS port 307. Stated another way, the burst receiver at the headend determines which client device of the plurality of client devices is delivering data to first upstream DOCSIS port 307. In this example, client device A will transmit data to first upstream DOCSIS port 307. Thus, step 708 will identify that client device A is coupled to RF port 303, and that conclusion is recorded in memory 610 in step 709. Client device B will not yet be identified as coupled to RF port 303 because it has been assigned an idle grant.

[0095] Decision 710 determines whether all RF ports have been tested. In Figure 9, no, because only the first RF port 303 has been tested. Therefore, step 703 switches the switched upstream RF switching network 315 to yet another state, shown in Figure 10.

[0096] 10, step 1001 illustrates a second state of upstream RF switching network 315 in this exemplary embodiment. As shown in step 1001, in the second state, RF port 304 is placed in communication with first upstream DOCSIS port 307, while the connections of RF port 303, RF port 305, and RF port 306 are now connections to second upstream DOCSIS port 308.

[0097] In one or more embodiments, determining 706 then includes a burst receiver at a headend coupled to node 202 receiving the data received on first upstream DOCSIS port 307. In this example, client device C will transmit data to first upstream DOCSIS port 307. Thus, step 708 will identify client device C as being coupled to RF port 304, and that conclusion is recorded in memory 610 in step 790. Client device D will not yet be identified as being coupled to RF port 304 because it has been assigned an idle grant. Thus, in this example, step 708 will determine using one or more control circuits to transmit the data to one of a plurality of optical ports. default and identifying one or more other client devices among some of the client devices that are serving to the optical port of the other client device.

[0098] Decision 710 again determines whether all RF ports have been tested. In Figure 10, no, because only first RF port 303 and second RF port 304 have been tested. Therefore, step 703 switches the switched upstream RF switching network 315 to yet another state, shown in Figure 11.

[0099] 11, step 1101 illustrates a third state of upstream RF switching network 315 in this exemplary embodiment. As shown in step 1101, in the third state, RF port 305 is placed in communication with first upstream DOCSIS port 307, while the connections of RF port 303, RF port 304, and RF port 306 are now connections to second upstream DOCSIS port 308.

[0100] In one or more embodiments, determining 706 then includes a burst receiver at a headend coupled to node 202 receiving the data received on first upstream DOCSIS port 307. In this example, client device E will transmit data to first upstream DOCSIS port 307. Thus, step 708 will identify that client device E is coupled to RF port 305, a conclusion that is recorded in memory 610 in step 709. Client device F will not yet be identified as coupled to RF port 305 because it has been assigned an idle grant.

[0101] Decision 710 again determines whether all RF ports have been tested. In Figure 11, only three RF ports 303, 304, and 305 have been tested. Therefore, step 703 switches the switched upstream RF switching network 315 to yet another state, shown in Figure 12.

[0102] 12, step 1201 illustrates a fourth state of upstream RF switching network 315 in this exemplary embodiment. As shown in step 1201, in the fourth state, RF port 306 is placed in communication with first upstream DOCSIS port 307, while the connection of RF port 303, RF port 304, and RF port 305 is now to second upstream DOCSIS port 308.

[0103] In one or more embodiments, determination 706 then includes a burst receiver at a headend coupled to node 202 receiving the data received on first upstream DOCSIS port 307. In this example, client device G will transmit data to first upstream DOCSIS port 307. Thus, step 708 will identify that client device E is coupled to RF port 306, a conclusion that is recorded in memory 610 in step 709. Client device H will not yet be identified as coupled to RF port 306 because it has been assigned an idle grant.

[0104] Once all RF ports have been tested, the testing process ends at step 711, and all client devices have been correctly and positively identified as being connected to a particular RF port. Method 700 may then be repeated, with other client devices receiving idle permission and other client devices being instructed to transmit data, and so on. By way of example, the method steps shown in Figures 8-12 may be repeated, with client device B, client device D, client device F, and client device H being instructed to transmit data, while client device A, client device C, client device E, and client device G are given idle permission.

[0105] In doing so, the burst receiver at the headend can identify the RF port and corresponding RF leg to which the client device is attached. These tests can be performed periodically and / or staggered to periodically update the state of the system. They do not need to be performed back-to-back for every client device, thereby increasing the likelihood of no interruption in service delivery.

[0106] Embodiments of the present disclosure contemplate that node splits, node replacements, and other field operations will continue to occur as MSOs work to increase the bandwidth of their RPD systems. Advantageously, embodiments of the present disclosure provide a simple, effective, and low-cost tool for determining which client devices are served by which RF legs of an RF network. Embodiments of the present disclosure also enable an MSO's operations group to determine accurate event correlation for customers affected by a fault occurring on an RF leg. Furthermore, embodiments of the present disclosure also enable an MSO to identify which RF leg coupled to an RPD, RMD, or node RF port is experiencing a technical issue. Embodiments of the present disclosure further enable an MSO to determine the number of client devices served by each RF leg, thereby balancing serving groups within a DOCSIS system.

[0107] 13, illustrated therein are various embodiments of the present disclosure. At 1301, a method for identifying which client devices are coupled to which RF ports of a node includes assigning, using one or more control circuits, some of the client devices to instructions to transmit data. At 1301, the method includes assigning, using one or more control circuits, others of the client devices to idle grants. At 1301, the method includes switching, using one or more control circuits, an RF switching network disposed between the RF port and a plurality of optical ports of the node from a first state to a second state. At 1301, the method includes assigning, using one or more control circuits, some of the client devices to instructions to transmit data. default identifying one or more client devices among the number of client devices that are serving to the optical port of the

[0108] In 1302, the RF switching network of 1301 comprises an upstream RF switching network. In 1302, the plurality of optical ports of 1301 comprises a plurality of upstream optical ports.

[0109] In 1303, in the second state of 1301, one of the RF ports is default In 1304, in the second state of 1303, the remaining RF ports other than one RF port are coupled to the optical ports of default At 1305, the method of 1304 further includes identifying, with the one or more control circuits, the at least one client device as being coupled to an RF port.

[0110] At 1306, the method of 1305 further includes switching the RF switching network from the second state to a third state using one or more control circuits. At 1306, the method includes switching the RF switching network from the second state to a third state using one or more control circuits. default identifying one or more client devices among the number of client devices that are serving to the optical port of the

[0111] At 1307, in a third state of 1306, another of the RF ports is default In 1308, in the third state of 1307, an RF port other than the other RF port is coupled to the optical port of default At 1309, the method of 1308 further includes identifying, with the one or more control circuits, one or more other client devices as being coupled to another RF port.

[0112] In 1310, the DOCSIS node comprises a first DOCSIS port and a second DOCSIS port. In 1310, the DOCSIS node comprises a plurality of radio frequency (RF) ports. In 1310, the DOCSIS ports comprise an RF switching network coupled between the first DOCSIS port, the second DOCSIS port, and the plurality of RF ports.

[0113] In 1311, the DOCSIS node of 1310 further comprises one or more control circuits configured to switch the RF switching network between at least a first state in which a first RF port of the plurality of RF ports is coupled to a first DOCSIS port and a second RF port of the plurality of RF ports is coupled to a second DOCSIS port, and a second state in which a first RF port of the plurality of RF ports is coupled to a second DOCSIS port and a second RF port of the plurality of RF ports is coupled to the first DOCSIS port.

[0114] At 1312, the one or more control circuits of 1311 are further configured to switch the RF switching network to a third state in which a third RF port of the plurality of RF ports is coupled to the first DOCSIS port, and the first RF port of the plurality of RF ports and a second RF port of the plurality of RF ports are coupled to a second DOCSIS port. At 1313, the one or more control circuits of 1312 are further configured to switch the RF switching network to a fourth state in which a fourth RF port of the plurality of RF ports is coupled to the first DOCSIS port, and the first RF port of the plurality of RF ports, the second RF port of the plurality of RF ports, and a third RF port of the plurality of RF ports are coupled to the second DOCSIS port.

[0115] At 1314, the first DOCSIS port and the second DOCSIS port of 1313 comprise upstream DOCSIS ports. At 1315, the DOCSIS node of 1313 further comprises a plurality of client devices coupled to the plurality of RF ports. At 1315, the one or more control circuits distribute idle grants to some of the plurality of client devices and instructions to transmit data to other of the plurality of client devices.

[0116] At 1316, the DOCSIS node of 1315 further comprises a headend, the headend comprising a burst receiver coupled to the first DOCSIS port, wherein the burst receiver is configured to determine whether the RF switching network is in a first state, a second state, a third state, and a Fourth determine which client device of the plurality of client devices is delivering data to the first DOCSIS port when in each of the states.

[0117] At 1317, a method for identifying which client devices are coupled to which RF ports of a node includes switching, with one or more control circuits, an RF switching network disposed between the RF ports and a plurality of optical ports of the node from a first state to a second state. At 1317, the method includes identifying, with the one or more control circuits, the plurality of client devices coupled to the RF ports; Distance measurement and Registration This includes starting the process.

[0118] At 1317, the method includes switching, with the one or more control circuits, the RF switching network from the first state to the second state. At 1317, the method includes, with the one or more control circuits, identifying a subset of the plurality of client devices to: Distance measurement and Registration This includes continuing the process.

[0119] At 1318, the method of 1317 further includes associating, with the one or more control circuits, a subset of the plurality of client devices with at least one RF port of the RF ports when the RF switching network is in the second state. At 1319, the method of 1318 further includes switching, with the one or more control circuits, the RF switching network from the second state to a third state. At 1319, the method includes associating, with the one or more control circuits, at least some client devices from the subset of the plurality of client devices with a single RF port of the RF ports. At 1320, the method of 1319 further includes switching, with the one or more control circuits, the RF switching network from the third state to the first state.

[0120] In the foregoing specification, particular embodiments of the present disclosure have been described. However, those skilled in the art will understand that various modifications and changes can be made without departing from the scope of the present disclosure, as set forth in the following claims. Thus, while preferred embodiments of the present disclosure have been illustrated and described, it will be clear that the disclosure is not so limited. Numerous modifications, changes, variations, substitutions, and equivalents will occur to those skilled in the art without departing from the spirit and scope of the present disclosure, as defined by the following claims.

[0121] For example, if different RF ports are present on an RPD, RMD, or node, or alternatively, an Upstream Cable Access Module (UCAM), prior art systems would be unable to identify which RF port connects to a particular client device. Advantageously, embodiments of the present disclosure enable accurate identification of each client device coupled to each RF port of each RPD, RMD, or node. This identification, in one or more embodiments, is accomplished by operation of an RF switching network(s) that connects burst receivers to different RF ports at different times. This switching is accomplished by the operation of an RF switching network(s) that connects burst receivers to different RF ports at different times. Distance measurementIn combination with the scheduling process, and / or scheduling, targeted client devices can be granted instructions to transmit data, while other client devices are given idle permission to identify the RF port and RF leg mapping. Thus, embodiments of the present disclosure are novel over prior art solutions because they advantageously identify the RF port hosting a particular client device. This may help avoid sounding in full-duplex (FDX) operation, find leg obstructions, provide recommendations on when to split the RF leg, etc. Other features and benefits will be apparent to those skilled in the art having the benefit of this disclosure.

[0122] Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present disclosure. Benefits, advantages, solutions to problems, and any elements that may result in any benefit, advantage, or solution occurring or becoming more pronounced should not be construed as critical, necessary, or essential features or elements of any or all claims. The present disclosure is defined solely by the appended claims, including any amendments made during the pendency of this application, and all equivalents of those claims as issued. The invention disclosed in this specification includes the following aspects. <Aspect 1> 1. A method for identifying which client devices are coupled to which radio frequency (RF) ports of a node, the method comprising: assigning, using one or more control circuits, some of the client devices with instructions to transmit data; assigning idle permits to others of the client devices using the one or more control circuits; and switching, using the one or more control circuits, an RF switching network disposed between the RF port and a plurality of optical ports of the node from a first state to a second state; and identifying, with the one or more control circuits, one or more client devices of the some of the client devices that are delivering the data to a defined optical port of the plurality of optical ports. <Aspect 2> 2. The method of embodiment 1, wherein the RF switching network comprises an upstream RF switching network, and the plurality of optical ports comprises a plurality of upstream optical ports. <Aspect 3> 2. The method of claim 1, wherein in the second state, one of the RF ports is coupled to the defined optical port. <Aspect 4> Aspect 4. The method of aspect 3, wherein in the second state, remaining RF ports other than the one RF port are coupled to optical ports other than the specified optical port. <Aspect 5> 5. The method of embodiment 4, further comprising: identifying, with the one or more control circuits, at least one client device as being coupled to the one RF port. <Aspect 6> 6. The method of claim 5, further comprising: using the one or more control circuits to switch the RF switching network from the second state to a third state; and using the one or more control circuits to identify one or more other client devices among the some of the client devices that are delivering the data to the specified optical port of the plurality of optical ports. <Aspect 7> 7. The method of claim 6, wherein in the third state, another of the RF ports is coupled to the defined optical port. <Aspect 8> Aspect 8. The method of aspect 7, wherein in the third state, an RF port other than the another RF port is coupled to an optical port other than the specified optical port. <Aspect 9> 9. The method of embodiment 8, further comprising: identifying, with the one or more control circuits, the one or more other client devices as being coupled to the other RF port. <Aspect 10> 1. A Data Over Cable Interface Specification (DOCSIS) node, comprising: a first DOCSIS port; a second DOCSIS port; and Multiple radio frequency (RF) ports and a Data-over-Cable Interface Specification (DOCSIS) node comprising: an RF switching network coupled between the first DOCSIS port and the second DOCSIS port and the plurality of RF ports; <Aspect 11> 11. The DOCSIS node of aspect 10, further comprising: one or more control circuits configured to switch the RF switching network between at least a first state in which a first RF port of the plurality of RF ports is coupled to the first DOCSIS port and a second RF port of the plurality of RF ports is coupled to the second DOCSIS port, and a second state in which the first RF port of the plurality of RF ports is coupled to the second DOCSIS port and a second RF port of the plurality of RF ports is coupled to the first DOCSIS port. <Aspect 12> 12. The DOCSIS node of claim 11, wherein the one or more control circuits are further configured to switch the RF switching network to a third state in which a third RF port of the plurality of RF ports is coupled to the first DOCSIS port, and the first RF port of the plurality of RF ports and the second RF port of the plurality of RF ports are coupled to the second DOCSIS port. <Aspect 13> 13. The DOCSIS node of aspect 12, wherein the one or more control circuits are further configured to switch the RF switching network to a fourth state in which a fourth RF port of the plurality of RF ports is coupled to the first DOCSIS port, and the first RF port of the plurality of RF ports, the second RF port of the plurality of RF ports, and the third RF port of the plurality of RF ports are coupled to the second DOCSIS port. <Aspect 14> 14. The DOCSIS node of aspect 13, wherein the first DOCSIS port and the second DOCSIS port each comprise an upstream DOCSIS port. <Aspect 15> 14. The DOCSIS node of claim 13, further comprising: a plurality of client devices coupled to the plurality of RF ports, wherein the one or more control circuits distribute idle grants to some of the plurality of client devices and instructions to transmit data to other of the plurality of client devices. <Aspect 16> 16. The DOCSIS node of claim 15, further comprising: a head end; wherein the head end comprises a burst receiver coupled to the first DOCSIS port; and the burst receiver determines which of the plurality of client devices is delivering the data to the first DOCSIS port when the RF switching network is in each of the first state, the second state, the third state, and the second state. <Aspect 17> 1. A method for identifying which client devices are coupled to which radio frequency (RF) ports of a node, the method comprising: switching, using one or more control circuits, an RF switching network disposed between the RF port and a plurality of optical ports of the node to a first state; using the one or more control circuits to identify a plurality of client devices coupled to the RF ports and initiate a ranging and alignment process; switching the RF switching network from the first state to a second state using the one or more control circuits; and using the one or more control circuits to identify a subset of the plurality of client devices to continue the ranging and alignment process. <Aspect 18> 18. The method of aspect 17, further comprising associating, by the one or more control circuits, the subset of the plurality of client devices with at least one RF port of the RF ports when the RF switching network is in the second state. <Aspect 19> 19. The method of embodiment 18, further including: switching the RF switching network from the second state to a third state with the one or more control circuits; and associating, by the one or more control circuits, at least some client devices from the subset of the plurality of client devices with a single RF port among the RF ports. <Aspect 20> 20. The method of embodiment 19, further comprising switching the RF switching network from the third state to the first state with the one or more control circuits.

Claims

1. 1. A method for identifying which client devices are coupled to which radio frequency (RF) ports of a node, the method comprising: assigning, using one or more control circuits, some of the client devices with instructions to transmit data; assigning idle permits to others of the client devices using the one or more control circuits; and switching, using the one or more control circuits, an RF switching network disposed between the RF port and a plurality of optical ports of the node from a first state to a second state; and identifying, with the one or more control circuits, one or more client devices of the some of the client devices that are delivering the data to a default optical port of the plurality of optical ports.

2. The method of claim 1 , wherein the RF switching network comprises an upstream RF switching network, and the plurality of optical ports comprises a plurality of upstream optical ports.

3. The method of claim 1 , wherein in the second state, one of the RF ports is coupled to the predetermined optical port.

4. The method of claim 3 , wherein in the second state, the remaining RF ports other than the one RF port are coupled to optical ports other than the default optical port.

5. The method of claim 4 , further comprising identifying, with the one or more control circuits, at least one client device as being coupled to the one RF port.

6. 6. The method of claim 5, further comprising: switching, with the one or more control circuits, the RF switching network from the second state to a third state; and identifying, with the one or more control circuits, one or more other client devices of the some of the client devices that are delivering the data to the default optical port of the plurality of optical ports.

7. The method of claim 6 , wherein in the third state, another of the RF ports is coupled to the predetermined optical port.

8. 8. The method of claim 7, wherein in the third state, an RF port other than the another RF port is coupled to an optical port other than the default optical port.

9. 10. The method of claim 8, further comprising identifying, with the one or more control circuits, the one or more other client devices as being coupled to the other RF port.

10. A Data Over Cable Interface Specification (DOCSIS) node for connecting a client device to a radio frequency (RF) port, comprising: a first DOCSIS port; and a second DOCSIS port; and a plurality of radio frequency (RF) ports; an RF switching network coupled between the first and second DOCSIS ports and the plurality of RF ports; and one or more control circuits configured to switch the RF switching network between at least a first state in which a first RF port of the plurality of RF ports is coupled to the first DOCSIS port and a second RF port of the plurality of RF ports is coupled to the second DOCSIS port, and a second state in which the first RF port of the plurality of RF ports is coupled to the second DOCSIS port and a second RF port of the plurality of RF ports is coupled to the first DOCSIS port.

11. 11. The DOCSIS node of claim 10, wherein the one or more control circuits are further configured to switch the RF switching network to a third state in which a third RF port of the plurality of RF ports is coupled to the first DOCSIS port, and the first RF port of the plurality of RF ports and the second RF port of the plurality of RF ports are coupled to the second DOCSIS port.

12. 12. The DOCSIS node of claim 11 , wherein the one or more control circuits are further configured to switch the RF switching network to a fourth state in which a fourth RF port of the plurality of RF ports is coupled to the first DOCSIS port, and the first RF port of the plurality of RF ports, the second RF port of the plurality of RF ports, and the third RF port of the plurality of RF ports are coupled to the second DOCSIS port.

13. The DOCSIS node of claim 12 , wherein the first DOCSIS port and the second DOCSIS port each comprise an upstream DOCSIS port.

14. 13. The DOCSIS node of claim 12, further comprising a plurality of client devices coupled to the plurality of RF ports, wherein the one or more control circuits distribute idle grants to some of the plurality of client devices and instructions to transmit data to other of the plurality of client devices.

15. 15. The DOCSIS node of claim 14, further comprising a headend, the headend comprising a burst receiver coupled to the first DOCSIS port, the burst receiver determining which client device of the plurality of client devices is delivering the data to the first DOCSIS port when the RF switching network is in each of the first state, the second state, the third state, and the fourth state.

16. 1. A method for identifying which client devices are coupled to which radio frequency (RF) ports of a node, the method comprising: switching, using one or more control circuits, an RF switching network disposed between the RF port and a plurality of optical ports of the node to a first state; using the one or more control circuits to identify a plurality of client devices coupled to the RF ports and initiate a ranging and registration process; switching the RF switching network from the first state to a second state using the one or more control circuits; and using the one or more control circuits to identify a subset of the plurality of client devices to continue the ranging and registration process.

17. 17. The method of claim 16, further comprising associating, by the one or more control circuits, the subset of the plurality of client devices with at least one of the RF ports when the RF switching network is in the second state.

18. 18. The method of claim 17, further comprising: switching the RF switching network from the second state to a third state with the one or more control circuits; and associating, by the one or more control circuits, at least some client devices from the subset of the plurality of client devices with a single one of the RF ports.

19. 20. The method of claim 18, further comprising switching the RF switching network from the third state to the first state with the one or more control circuits.

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