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 Art

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Patent Provisional Application No. 62 / 938,825, filed on November 21, 2019.

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

[0003] Because the installation of fiber optic cables is expensive, it can be prohibitively costly to completely convert an old - style coaxial cable network serving thousands of subscribers to an optical network using current pricing models. For this reason, many systems employ "hybrid fiber - coaxial" or "HFC" systems that allow service providers to connect end - user client devices supplied by coaxial cables to a "head - end" or "hub" device that distributes data over fiber optic cables in a cost - effective manner. In an HFC system, centrally located components such as network head - ends, hub devices, servers, etc., transmit and receive data to and from the network using fiber optic cables. End - points, i.e., customers and their corresponding client devices, are supplied by coaxial cables.

[0004] A "node" module is used to bridge the gap between fiber optic cables and coaxial cables. This "node" is a device that receives optical signals through the fiber optic network, converts these signals into radio frequency (RF) signals, and distributes the RF signals through the coaxial cable network. Thus, an optical node module receives data through the fiber optic cable at one or more downstream ports, converts that data into RF signals, and distributes these RF signals to the older coaxial network at one or more RF ports.

[0005] The Data Over Cable Interface Specification (DOCSIS) is one of many standards that support such modular systems. One way to achieve the modularity described above is to separate the DOCSIS media access control (MAC) function from the DOCSIS physical layer (PHY) function into two different boxes. In a DOCSIS network using a remote PHY architecture, the Integrated Converged Cable Access Platform (I-CCAP) is divided into a CCAP core located at the headend and remote PHY devices (RPDs) located at the nodes. When a node has a large number of RF ports, determining which client device is supplied by which RF port can be difficult or impossible. It would be advantageous to have an improved node architecture that makes such determination possible. [Brief explanation of the drawing]

[0006] The accompanying drawings, where similar reference numerals indicate identical or functionally similar elements throughout the individual drawings, and where these are incorporated into this specification together with the following detailed description and form part of this specification, are useful in further illustrating various embodiments in accordance with this disclosure and in illustrating all of the various principles and advantages. [Figure 1] An example of a prior art remote PHY system architecture is provided. [Figure 2]One or more embodiments of this disclosure illustrate a remote PHY system for one explanation. [Figure 3] A schematic block diagram of nodes for one description is illustrated according to one or more embodiments of the present disclosure. [Figure 4] One or more embodiments of this disclosure illustrate a downstream RF switching network for one explanation. [Figure 5] One or more embodiments of this disclosure illustrate an upstream RF switching network for one explanation. [Figure 6] One or more embodiments of this disclosure illustrate a method for one explanation. [Figure 7] Examples of alternative methods for explanation are provided by one or more embodiments of this disclosure. [Figure 8] One or more method steps according to one or more embodiments of the present disclosure are illustrated. [Figure 9] One or more method steps according to one or more embodiments of the present disclosure are illustrated. [Figure 10] One or more method steps according to one or more embodiments of the present disclosure are illustrated. [Figure 11] One or more method steps according to one or more embodiments of the present disclosure are illustrated. [Figure 12] One or more method steps according to one or more embodiments of the present disclosure are illustrated. [Figure 13] Various embodiments of this disclosure are illustrated below.

[0007] Those skilled in the art will understand that the elements in the figures are illustrative for the sake of brevity and clarity and are not necessarily drawn to an exact scale. For example, the dimensions of some of the elements in the figures may be exaggerated compared to others in order to help improve the understanding of embodiments of the present disclosure.

[0008] Detailed description of the drawing Before describing the detailed embodiments of this disclosure, it should be observed that the embodiments primarily belong to combinations of method steps and apparatus components related to detecting which client device is supplied by which RF port of a node in a remote PHY system. Any process description or block in the flowchart should be understood as representing a module, segment, or part of code containing one or more executable instructions for implementing a particular logical function or step in the process. Alternative implementation examples will be included, and it will become clear that functions may be performed out of the order shown or considered, included substantially simultaneously or in reverse order, depending on the function in question. Accordingly, the apparatus components and method steps are represented by conventional symbols in the drawings where appropriate, and only these specific details relevant to understanding the embodiments of this disclosure are shown so as not to obscure this disclosure with details that would be readily apparent to those skilled in the art who have an interest in the description herein.

[0009] Embodiments of the Disclosure described herein may consist of one or more conventional processors and specific stored program instructions controlling one or more processors, in conjunction with certain non-processor circuits, to implement some, most, or all of the functions of detecting which client devices are supplied by which RF ports of a node, as described herein. The non-processor circuits may include, but are not limited to, wireless receivers, wireless transmitters, signal drivers, clock circuits, power supply circuits, and user input devices. These functions may therefore be interpreted as steps in a method for performing a detection process to identify which client devices are supplied by which RF ports of a node. Alternatively, some or all of the functions may be implemented by a state machine that does not have stored program instructions, or by one or more application-specific integrated circuits (ASICs) in which each function or a combination of certain functions is implemented as custom logic. Of course, a combination of the two approaches may be used. Therefore, methods and means for these functions are described herein. Furthermore, it is expected that a person skilled in the art can easily generate such software instructions and programs, as well as ASICs, with minimal experimentation, guided by the concepts and principles disclosed herein, despite potentially considerable effort and numerous design choices, motivated, for example, by available time, current technology, and economic considerations.

[0010] Embodiments of the present disclosure are described in detail hereby. Referring to the drawings, similar figures indicate similar parts throughout the drawings. As used throughout this description and the claims, the following terms have the meanings expressly associated herein unless the context otherwise clearly indicates: the meanings of “a,” “an,” and “the” include multiple references, and the meaning of “in” includes “in” and “on.” Relational terms such as first and second, top and bottom may be used solely to distinguish one entity or act from another entity or act without necessarily requiring or implying any actual relationship or order between such entities or acts.

[0011] As used herein, components can be “operably linked” if information can be transmitted between them, even if 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 are defined as close as understood by those skilled in the art, and in one non-limiting embodiment, such terms are defined as being within 10 percent, in another embodiment within 5 percent, in yet another within 1 percent, and in yet another within 0.5 percent. As used herein, the term “linked” is defined as being connected, but not necessarily directly or mechanically. Also, reference numbers shown in parentheses herein refer to components shown in figures other than those under consideration. For example, discussing device (10) while considering Figure A means referring to element 10 shown in figures other than Figure A.

[0012] Referring to Figure 1, the example shown in the figure is a prior art remote PHY architecture 100. Remote PHY refers to a technique that moves the PHY circuit from a device such as a CCAP and places the PHY circuit at the network termination of another device such as a node. Remote PHY is built upon work that began 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 divided into two distinct components. The first component is the CCAP core 101, which is generally located in the headend server. The second component is the remote PHY device (RPD) 102, which is generally located in a node closer to the client devices 103, 104, 105, and 106, which are supplied by the node via an RF network 107, often consisting of coaxial cable. Data communication between the CCAP core 101 and the RPD 102 takes place via a fiber optic cable network, referred to here as a passive optical network 108 or (PON), to provide higher bandwidth.

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

[0015] The RPD102 primarily comprises PHY-related circuitry, such as a downstream QAM modulator and an upstream QAM demodulator, along with pseudowire logic for connecting to the CCAP core 101. The RPD platform is a physical layer converter, and the physical layer converter's functions include both converting downstream DOCSIS, Moving Picture Expert Group (MPEG) video, and out-of-band (OOB) signals received from the CCAP core 101 to analog for transmission over RF via the RF network 107 or other equivalent network over a digital medium such as Ethernet or PON108, and / or converting upstream DOCSIS and OOB signals received from analog media such as RF or linear optics to digital for transmission to the CCAP core 101 over Ethernet or PON108.

[0016] RPD102 has one or more RF ports 109, 110, 111, 112 that provide connections to client devices 103, 104, 105, and 106 belonging to the system's customers. Using the prior art remote PHY architecture 100, it is not possible to determine which client devices 103, 104, 105, and 106 are supplied by which RF port 109, 110, 111, or 112. The same is true for the Remote Media Access Control PHY (RMACPHY) device (RMD). This deficiency is particularly problematic because the "legs" of the RF network 107 can extend over considerable distances. Furthermore, it is not possible to perform event correlation of groups of customers affected by a failure occurring in 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 having the problem is to put a person in a truck and drive to each leg to find the problem. This process is time-consuming and expensive, resulting in very high customer dissatisfaction.

[0017] Advantageously, embodiments of the present disclosure provide a method and system for identifying which client device is being served by which RF port of an RPD or MACPHY. Embodiments of the present disclosure enable a large cable company, generally known as a multiple system operator (MSO), which operates a number of cable communication systems (in some cases up to hundreds of systems), to have a verifiable and continuous method for determining which client device is being served by each RPD or node. Further, embodiments of the present disclosure enable the MSO to determine which client device is being served by each RF port, thereby identifying which leg of the RF network any one client device is connected to.

[0018] Embodiments of the present disclosure contemplate that the connection between an RF port of an RPD and an associated client device can become old. For this and other reasons, these records can be inaccurate. Further, new records for new client devices are often entered manually, thereby worsening the error rate. The fact that additional nodes or RPDs are required to supply the base of the client device can further make the records even more inaccurate when "node splitting" occurs.

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

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

[0021] In one or more embodiments, by one or more control circuits, a client device attached to an RF port of the RPD, RMD, or node can complete a ranging and registration operation while the RF switching network is in an initial configuration or a default configuration. Thereafter, the one or more control circuits cause the RF switching network to be changed 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 still identified as having completed the ranging and registration procedure. These client devices can be recorded and stored in memory.

[0022] Next, one or more control circuits can be used to change the RF switching network to yet another configuration. This allows client devices that were previously unable to connect to be connected to other DOCSIS ports, thereby making these devices identifiable again. This process can be continued for all port replacements so that all client devices connected to the RF ports of an RPD, RMD, or node can be identified as connected to a particular RF port and the corresponding RF leg of the RF network.

[0023] In one or more embodiments, to avoid service interruptions caused when client devices need to be restarted and repositioned at the headend, this process can be carried out using other techniques that do not interrupt service to any of the client devices. Illustrated by embodiments, in one or more embodiments, a subset of client devices may be instructed to transmit data during the test period. Examples of such instructions include instructing client devices connected to the remaining RF ports to deliver station maintenance, transmit DOCSIS codewords (CW), transmit pilot transmission probes such as D3.1 probes, etc. Meanwhile, the remaining client devices, i.e., 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 switch the RF switching network between various RF ports and DOCSIS ports, while a subset of client devices transmit data, and client devices other than those in the subset remain silent. In this way, the headend burst receiver can identify the RF ports and the corresponding RF legs to which the client devices are connected. These tests can be performed periodically and / or with time delays to periodically update the system status. These do not need to be performed back-to-back for all client devices, thereby increasing the probability that no service interruption will occur.

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

[0026] In one or more embodiments, a method for identifying which client devices are connected to which RF ports of a node includes assigning some of the client devices connected to the node to commands for transmitting data, using one or more control circuits. In one or more embodiments, the method includes assigning the other client devices to idle permission, using one or more control circuits. In one or more embodiments, when one or more control circuits switch an RF switching network arranged between an RF port and a plurality of optical ports of a node from a first state to a second state, one or more control circuits identify one or more of the client devices that are delivering data to a specified optical port among the plurality of optical ports.

[0027] Embodiments of this disclosure assume that node splitting, node swapping, and other field operations will continue to occur as an MSO works to increase the bandwidth of its RPD system. Advantageously, embodiments of this disclosure provide a simple, effective, and low-cost tool for determining which client devices are supplied by which RF leg of the RF network. Embodiments of this disclosure also enable the MSO's operations group to determine accurate event correlations of customers affected by failures occurring in RF legs. Furthermore, embodiments of this disclosure enable the MSO to identify which RF leg is experiencing technical problems in the RPD, RMD, or RF ports of a node. Embodiments of this disclosure further enable the MSO to determine the number of client devices supplied by each RF leg, and thus balance the service delivery groups within the DOCSIS system.

[0028] Embodiments of the Disclosure differ from prior art systems, such as those shown in Figure 1, because previous solutions have never implemented an RF switching network that provides the flexibility to configure connections between the RF ports of an RPD, RMD, or node and the DOCSIS port. For this reason, prior art solutions cannot determine which client devices are supplied by each RF leg of an RPD, RMD, or node. Embodiments of the Disclosure also differ from prior art solutions in that some embodiments of the Disclosure leverage DOCSIS initialization procedures to uniquely determine the connections of client devices to a particular DOCSIS and the RF ports of an RPD, RMD, or node, and to accurately identify the system topology, as well as the client devices and corresponding customers supplied by each RF leg of an RPD, RMD, or node.

[0029] Referring here to Figure 2, illustrated in the figure is a remote PHY system 200 for one description configured according to one or more embodiments of the present disclosure. The 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, for example, client devices 205, 206, and 207.

[0030] In one or more embodiments, the remote PHY system 200 represents the operational or geographical footprint of an entertainment and / or information services franchise that provides entertainment and / or information services to a subscriber base spread across one or more towns, regions, or parts thereof. The specific entertainment and / or information services offered by the franchise, such as a lineup of entertainment channels, data packages, or other services, may vary from system to system. For example, when a major cable company operates a variety of cable communication systems, these are commonly referred to as MSOs.

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

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

[0033] In one or more embodiments, the remote PHY system 200 includes a headend 201 which receives analog video signals and digital bitstreams representing different services, such as video services, audio services, internet services, or other services, from various digital information sources. For example, the 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, the remote PHY system 200 comprises an IP network 208, an MPEG service 209, and an analog service 210. The IP network 208 includes a web server 211 and a data source 212. The web server 211 may comprise a streaming server that uses the IP protocol to deliver video-on-demand, audio-on-demand, and pay-per-view streams to the IP network 208. The 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 other suitable wired or wireless network or network system.

[0035] In one or more embodiments, various services are encoded, modulated, and upconverted to an RF carrier, combined into a single electrical signal, and inserted at the headend 201 into a broadband optical transmitter 214 (indicated as Tx in Figure 1). The optical fiber network 215 extends from the cable operator's master / regional headend 201 to several nodes 202, 203, 204 configured as RPDs in this exemplary embodiment. Nodes 202, 203, 204 may be RMDs or other types of devices in other architectural systems.

[0036] In one or more embodiments, the headend 201 may include an optical transceiver, which may include one or more optical transmitters 214 and optical receivers 216 (indicated by the symbol Rx in Figure 1) for sending and receiving optical communications over the optical fiber network 215. In one or more embodiments, the optical receiver 216 functions as a burst receiver 230 or comprises a burst receiver 230. As will be described in more detail below, in one or more embodiments, the burst receiver 230 may be configured to determine which client devices 205, 206, 207 are delivering data to the DOCSIS ports of nodes 202, 203, 204. In one or more embodiments, the burst receiver 230 receives upstream burst data received from nodes 202, 203, 204, 205 over the optical fiber network 215. In other embodiments, a regional headend and / or neighbor hub site may exist between the headend 201 and one or more nodes 202, 203, 204.

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

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

[0039] As used herein, the terms “forward path” and “downstream” may be used interchangeably to refer to paths from headend 201 to nodes 202, 203, and 204, paths from nodes 202, 203, and 204 to client devices 205, 206, and 207 or to subscribers, or paths from headend 201 to subscribers. Conversely, the terms “return path,” “reverse path,” and “upstream” may be used interchangeably to refer to paths from subscribers or client devices 205, 206, and 207 to nodes 202, 203, and 204, paths from nodes 202, 203, and 204 to headend 201, or paths from subscribers or client devices 205, 206, and 207 to headend 201.

[0040] Furthermore, it should be noted that nodes 202, 203, and 204 may be any analog or digital hubs positioned between the headend 201 and client devices 205, 206, and 207, sending local requests via a system which may be a remote PHY system 200 or other type of system. Forward-path optical communication via the fiber optic network 215 can be converted to RF communication at nodes 202, 203, and 204 for transmission to client devices 205, 206, and 207 via the RF network 217. Conversely, return-path RF communication from client devices 205, 206, and 207 is provided via the RF network 217 and is typically converted to optical signals at nodes 202, 203, and 204 for transmission to the headend 201 via the fiber optic network 215. Each node 202, 203, and 204 may include a return-path transmitter that can relay upstream communication from client devices 205, 206, and 207 to the headend 201.

[0041] In one or more embodiments, each node 202, 203, 204 is supplied to a service group, e.g., service group 218, comprising one or more client devices 205, 206, 207 located at one or more customer locations. Exemplified by embodiments, 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 an embodiment of one exemplary embodiment, node 202 is supplied to any 1 to 2000 customer locations. In an HFC network, node 202 may be connected to multiple client devices 205, 206, 207 via coaxial cable or other routes of the RF network 217. Alternatively, node 202 may be connected to client devices 205, 206, 207 by a combined fiber optic / coaxial cable network. Other network connections suitable for connecting node 202 to client devices 205, 206, 207 will be apparent to those skilled in the art who are interested in this disclosure.

[0042] In one or more embodiments, each node 202, 203, 204 may include a broadband optical receiver that converts downstream optically modulated signals received from the headend 201 or hub into electrical signals for provision to client devices 205, 206, 207 via the RF network 217 of the HFC network. Each node 202, 203, 204 may be connected to many client devices 205, 206, 207 via 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 nodes 202, 203, 204 to client devices 205, 206, 207 via an RF cascade that may comprise one or more amplifiers, e.g., amplifiers 219, 220, 221. The RF cascade may further include other active or passive devices such as cabling, taps, splitters, and inline equalizers. Several RF legs of the RF network 217, e.g., RF leg 222, client device 205 may be connected via amplifiers 219, 220. Other RF legs, e.g., RF leg 223, may not contain an amplifier so that client device 206 does not receive an amplified signal. Each client device 205, 206, 207 may be connected to RF legs 222, 223 of the RF network 217 via one or more taps, e.g., taps 224, 225. The taps are designed with varying values ​​to allow for amplitude consistency along the distributed system.

[0043] In one or more embodiments, client devices 205, 206, and 207 are located at the customer's location, such as the subscriber's home. In one or more embodiments, client devices 205, 206, and 207 are connected to a cable modem termination system (CMTS) 226, or an equivalent component located at the headend 201. Each client device 205, 206, and 207 may be a modem, e.g., a cable modem, a medium terminal adapter (MTA), a set-top box, a terminal device, a television equipped with a set-top box, a DOCSIS terminal device, customer equipment (CPE), a router, or an electronic client device, end device, or terminal device of the subscriber. For example, in one or more embodiments, client devices 205, 206, and 207 comprise a cable modem or IP set-top box that supports data connectivity to the Internet and other computer networks via a cable network, and the cable network provides a bidirectional communication system in which data can be transmitted downstream from the headend 201 to the subscriber and upstream from the subscriber to the headend 201.

[0044] The technologies disclosed herein may be applied to DOCSIS-compliant systems. The cable industry has developed the international DOCSIS standard or protocol to enable the distribution of IP data packets over cable systems. Generally, DOCSIS defines the requirements for communication and operational support interfaces for data traversing 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 technologies disclosed herein may be applied to any system for digital service transmission, such as digital video or Ethernet PON over coaxial (EPOC). The embodiments that refer to DOCSIS herein are for illustrative purposes only and represent the application of the technology to a wide range of services carried over coaxial.

[0045] In one or more embodiments, the CMTS226 of the headend 201 includes components for exchanging signals between the headend 201 and client devices 205, 206, and 207. In one or more embodiments, for example, the CMTS226 and client devices 205, 206, and 207 may also be endpoints of the DOCSIS protocol, and the remote PHY system 200 transmits information between these endpoints. It will be understood that the remote PHY system 200 includes only one CMTS226 for illustrative purposes, as in many embodiments, a number of CMTS and their connected user devices are typically managed by the remote PHY system 200.

[0046] In one or more embodiments, the CMTS226 hosts downstream and upstream ports and includes numerous receivers, each receiver handling communication between hundreds of client devices 205, 206, and 207 connected to the headend 201. For example, each receiver of the CMTS226 may be connected to several client devices 205, 206, and 207 of many subscribers. In other words, a single receiver of the CMTS226 may be connected to hundreds of client devices 205, 206, and 207, each of which may vary considerably in terms of communication characteristics. Often, several nodes 202, 203, and 204 correspond to specific areas of a town or city. DOCSIS enables IP packets to be passed between devices on both sides of the link between the CMTS226 and the client devices 205, 206, and 207.

[0047] However, it will be understood that the CMTS226 is one embodiment of the components of the headend 201, which can be used to exchange signals between the headend 201 and client devices 205, 206, and 207. In other embodiments, a modular CMTS (M-CMTS™) architecture or CCAP can function similarly to the CMTS226, replacing key coupling, splitting, and cabling components in the CMTS226 by providing more efficient traffic handling through the use of IP routing. Thus, a CCAP design can improve the efficiency of the CMTS design and improve operation, headend maintenance, and the equipment lifecycle. The CCAP version of the CMTS226 can take advantage of the less rack space of the headend 201 and reduce power consumption.

[0048] The quadrature amplitude modulator (QAM) 227 may be located in the headend 201 or a hub device to receive packets of digital content, such as video or data, repacket the digital content into an MPEG transport stream, and digitally modulate the digital transport stream to a downstream RF carrier using quadrature amplitude modulation. QAM can be used for both digital broadcast and DOCSIS downstream transmission. In a CMTS or M-CMTS implementation example, data and video QAM may be implemented on separately managed and controlled platforms. In a CCAP implementation example, CMTS and edge QAM functions can 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 integrated into each node 202, 203, and 204. In some R-CCAP implementations, the entire functionality of the upper and lower MAC and PHY layers is moved to nodes 202, 203, and 204, and the CMTS, QAM, and CCAP functions are located in nodes 202, 203, and 204. When the QAM 227 is physically removed from the integrated CMTS 226 and installed downstream, it is known as edge QAM (EQAM) or downstream PHY device. In some remote node embodiments, nodes 202, 203, and 204 are configured as RPDs, where the physical layer connects layer devices such as the MAC layer to a physical medium such as optical fiber or copper cable. In a remote PHY system as shown in Figure 2, the CCAP MAC remains in the headend 201, and Ethernet aggregation is performed by the headend 201.

[0050] Referring here to Figure 3, the node 202 illustrated in the figure is a node 202 for one description configured according to one or more embodiments of the present disclosure. As previously stated, in one or more embodiments, the node 202 receives optical signals downstream via an optical fiber network (215) and converts these signals into RF signals. The node 202 then distributes the RF signals via an RF network (217) comprising a coaxial cable network in one or more embodiments. In the exemplary embodiment of Figure 3, the node 202 receives data via optical fiber at a first downstream DOCSIS port 301 and a second downstream DOCSIS port 302, each of which is an optical port. The node 202 converts the data into RF signals and distributes these RF signals to four RF ports 303, 304, 305, and 306 connected by the RF network (217) to one or more client devices (205, 206, and 207). As shown above with respect to Figure 2, each client device is connected to a single RF port of the node 202. For example, in Figure 2, client device (205) was connected to RF port 303, while client devices (206, 207) were connected to RF port 304 (and so on).

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

[0052] To ensure the reliability of the components of node 202, these electronic components are generally housed within a housing 318. The housing may be exposed to elements and therefore needs to be weather-resistant overall. Often, the housing 318 is physically configured as a “trunk.” The trunk may include a lid pivotably connected to a base by one or more hinges. In one or more embodiments, the housing 318 includes one or more openings configured as physical “ports” from which electrical connections to a first downstream DOCSIS port 301, a second downstream DOCSIS port 302, a first RF port 303, a second RF port 304, a third RF port 305, a fourth RF port 306, a first upstream DOCSIS port 307, and a second upstream DOCSIS port 308 can be made from outside the housing 318.

[0053] In one or more embodiments, the node 202 includes one or more electronic components located within a housing 318. These electronic components may include a power supply, an RF amplifier, a switchboard, 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 capable of operating 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 illustrative only. Those skilled in the art who are interested in this disclosure will understand that other configurations may be better suited to other applications.

[0054] In one or more embodiments, node 202 includes a downstream RF switching network 314 connected between the DOCSIS ports and the RF ports. In the exemplary embodiment of Figure 3, the downstream RF switching network 314 is connected to a first downstream DOCSIS port 301 and a second downstream DOCSIS port 302, as well as RF ports 303, 304, 305, and 306. In one or more embodiments, the downstream RF switching network 314 allows one or more control circuits 312 of the control board 311 to switch the connections between the first downstream DOCSIS port 301 and the second downstream DOCSIS port 302 and the RF ports 303, 304, 305, and 306 during operation. As illustrated by the embodiment, the connection between the first downstream DOCSIS port 301 and the first RF port 303 can be disconnected simply by switching the downstream RF switching network 314, while another connection is in place between the second downstream DOCSIS port 302 and the first RF port 303.

[0055] Referring briefly to Figure 4, the diagram illustrates a schematic block diagram of one embodiment of a 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 connected to a first downstream DOCSIS port (301), while the second input connection 402 is connected to a second downstream DOCSIS port (302). The first output connection 403 is connected to a first RF port (303), while the second output connection 404 is connected to a second RF port (304). The third output connection 405 is connected to a third RF port (305), while the fourth output connection 406 is connected to a fourth RF port (306), and so on.

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

[0057] As illustrated by the embodiment, the first input connection 401 is connected to the first output connection 403 and the second output connection 404 by connecting SPDT407 and SPDT411 to connector 416. In contrast, the first input connection 401 is connected to all four output connections 403, 404, 405, and 406 by connecting SPDT407 to SPDT409, SPDT410 to signal splitter 413, and both SPDT411 and SPDT412 to signal splitter 413.

[0058] Similarly, by connecting SPDT408 and SPDT415 to connector 417, the second input connection 402 is connected to the third output connection 405 and the fourth output connection 406. In contrast, by connecting SPDT408 to SPDT409, SPDT410 to signal splitter 413, and both SPDT411 and SPDT412 to signal splitter 413, the second input connection 402 is connected to all four output connections 403, 404, 405, and 406 (and so on).

[0059] It should be noted that the downstream RF switching network 314 in Figure 4 is an embodiment for one explanation of how a downstream RF switching network may be configured according to embodiments of the present disclosure, in order to enable switching of connections 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 who are interested in the present disclosure.

[0060] Returning to Figure 3, one or more control circuits 312 of the control board 311 can switch the downstream RF switching network 314 to a first state. In the first state, 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 connected to the third RF port 305 and the fourth RF port 306. Alternatively, 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 connected to all of RF ports 303, 304, 305, and 306. Similarly, 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 connected to all of RF ports 303, 304, 305, and 306.

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

[0062] Referring briefly to Figure 5, the diagram illustrates 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 connected to the first upstream DOCSIS port (307), while the second output connection 508 is connected to the second upstream DOCSIS port (308). In one or more embodiments, the first input connection 503 is connected to the first RF port (303), while the second input connection 504 is connected to the second RF port (304). The third input connection 505 is connected to the third RF port (305), while the fourth input connection 506 is connected to the fourth RF port (306), and so on.

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

[0064] As illustrated by the embodiment, by connecting SPDT509 to signal combiner 513, and SPDT510, SPDT511, and SPDT512 to signal combiner 514, the first input connection 503 is connected to the first output connection 507, while input connections 504, 505, and 506 are connected to the second output connection 508. By connecting SPDT509 and SPDT510 to signal combiner 513, and SPDT511 and SPDT512 to signal combiner 514, the first input connection 503 and the second input connection 504 are connected to the first output connection 507, while the third input connection 505 and the fourth input connection 506 are connected to the second output connection 508 (and so on).

[0065] Returning to Figure 3, one or more control circuits 312 of the control board 311 can switch the upstream RF switching network 315 to 4 squared, or 16 different states. Illustrated by an embodiment, in the first state, all RF ports 303, 304, 305, and 306 are connected to the first upstream DOCSIS port 307. In the second state, RF port 303 is connected to the first upstream DOCSIS port 307, while RF ports 304, 305, and 306 are connected to the second upstream DOCSIS port 308. In the third state, RF ports 303 and 304 are connected to the first upstream DOCSIS port 307, while RF ports 305 and 306 are connected to the second upstream DOCSIS port 308. In the fourth state, RF ports 303, 304, and 305 are connected to the first upstream DOCSIS port 307, while RF port 306 is connected to the second upstream DOCSIS port 308 (and so on).

[0066] As will be shown in more detail below, by controlling one or both of the downstream RF switching network 314 and / or the upstream RF switching network 315, one or more control circuits 312 of node 202 can advantageously identify which client devices are connected to which RF ports 303, 304, 305, and 306 of node 202. This technique may be further used during installation to determine whether client devices are also correctly connected to RF ports 303, 304, 305, and 306. Without the techniques described below, it would be impossible to know the event correlation of groups of client devices affected during a failure occurring in the RF legs connected to RF ports 303, 304, 305, and 306. Advantageously, the techniques described below provide the MSO with the ability to obtain current network topology information for customers supplied by specific RF ports 303, 304, 305, and 306 and their corresponding RF legs.

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

[0068] In one or more embodiments, Method 600 in Figure 6 allows client devices connected to RF ports 303, 304, 305, and 306 to complete the ranging and alignment operations of the client devices while one or both of the downstream RF switching network 314 and / or the upstream RF switching network 315 are in a first state. In one or more embodiments, 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, one or more control circuits 312 of node 202 determine which client devices are still identified as having completed the ranging and alignment procedures. By identifying client devices that are no longer communicating with the headend, or alternatively, client devices currently connected to other DOCSIS ports, it is possible to determine which client devices are connected to which RF ports 303, 304, 305, and 306.

[0069] The change in state may be achieved by switching the state of one or both of the downstream RF switching network 314 and / or the upstream RF switching network 315, but for the sake of simplicity of illustration, method 600 is described in a form in which only the state of the upstream RF switching network 315 is changed. 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 another embodiment, 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. Thus, other methods equivalent to method 600 in Figure 6 will be obvious to those skilled in the art who are interested in this disclosure.

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

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

[0072] In step 603, client devices connected to RF ports 303, 304, 305, and 306 (such as the client devices shown in Figure 2) perform ranging and alignment operations. In step 604, client devices that have completed the ranging and alignment process, i.e., client devices that communicate with the headend connected to the DOCSIS port, are identified. In one or more embodiments, step 604 includes storing these identified client devices in memory 610. Although memory 610 is shown as residing within node 202 in Figure 6, it should be noted that memory 610 and one or more control circuits 312 relating thereto may reside in the headend connected to node 202 via the optical fiber network (215), or in another electronic device communicating 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 who are interested in this disclosure.

[0073] As illustrated by the embodiments, in one or more embodiments, one or more control circuits 312 can operate on the DOCSIS MAC control plane. In one or more embodiments, this DOCSIS MAC control plane is resized in different devices as a feature of the overall system architecture. 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 operating on the CCAP core. In a remote PHY system (200) as shown in Figure 2 above, the DOCSIS MAC control plane is configured as hardware within node 202. Therefore, while this exemplary embodiment is used for illustrative purposes, it should be noted that one or more control circuits may reside outside node 202, such as within the headend or within another electronic device. The same applies to the downstream RF switching network 315 and the upstream RF switching network 315. Although shown as being integrated within node 202, these may also be located outside node 202 in the RF network (217). Other configurations corresponding to these exemplary circuit component configurations will be apparent to those skilled in the art who are interested in this disclosure.

[0074] In step 605, the upstream RF switching network 315 is switched to a second state, as shown in step 606, by method 600 (in this embodiment). As shown in step 606, the second state switches RF ports 304 and 305. The connections of RF ports 304 and 305 are changed while RF port 303 is still communicating with the first upstream DOCSIS port 307 and RF port 306 is still communicating with the second upstream DOCSIS port 308. Instead of communicating with the first upstream DOCSIS port 307, as it would have been when the upstream RF switching network 315 was in the first state, RF port 304 is now connected to the second upstream DOCSIS port 308. Similarly, instead of communicating with the second upstream DOCSIS port 308 in the same way as when the upstream RF switching network 315 was in the first state, in the second state, RF port 304 is connected to the first upstream DOCSIS port 307.

[0075] As a result, client devices connected to the first RF port 303 and the fourth RF port 306 can complete the ranging and alignment process because they are still communicating with the same DOCSIS port they were communicating with when the upstream RF switching network 315 was in the first state. This is because the client devices are still receiving the correct upstream channel descriptor messages from the downstream communications. However, client devices that are currently communicating with different DOCSIS upstream ports cannot complete the ranging and alignment process because the upstream channel descriptor messages of these client devices do not match the physical configuration of the upstream RF switching network 315.

[0076] In step 607, one or more control circuits 312 of node 202 determine which client devices are still identified as having completed the ranging and alignment procedure. 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 client devices that have stopped communicating with the headend.

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

[0078] Further conclusions can be drawn by repeating the process and performing different substitutions. For example, if the upstream RF switching network 315 is switched to a third state, the devices connected to the first RF port 303 can be accurately identified. If the third state of the upstream RF switching network 315 switches RF ports 304 and 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 that the upstream RF switching network 315 was communicating with when it 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 devices A and B are connected to the first RF port 303. Since client devices E and F are detected in the third state, these client devices must be connected to the third RF port 305. Since client devices G and H are no longer connected in the third state, these client devices must be connected to the fourth RF port 306. Since client devices C and D are not detected at this point, these client devices can only be connected to the second RF port 304. Thus, in this exemplary embodiment, one or more control circuits 312 obtain the exact mapping of the network topology simply by changing the upstream RF switching network 315 between the three states.

[0079] Decision 608 determines whether a suitable number of combinations have been made to obtain this network mapping. In the embodiments 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 occurred to determine which client devices are connected to which RF ports 303, 304, 305, and 306. In other embodiments, for completeness, decision 608 includes determining whether all substitutions of the states of the upstream RF switching network 315 have been identified first, and then, by redundancy, whether it has been completed to determine which client devices are connected to which RF ports 303, 304, 305, and 306. Step 609 then performs the comparison described in the preceding paragraph to obtain the network mapping.

[0080] It should be noted that Method 600 in Figure 6 is performed while various client devices are undergoing the ranging and alignment process. While Method 600 works well in practice, during the testing process, certain client devices may cause network interruptions by being unable to complete the ranging and alignment process. Therefore, these client devices need to repeat the process to come back online when the testing process is complete.

[0081] In another embodiment, to enable a node to determine which client device is connected to which RF port without interrupting any service provision, some client devices are given idle permission, while others are instructed to transmit data. Tests can then be performed during these idle permission / data transmissions to enable the determination of which client device is connected to which RF port without interrupting any service provision. Referring now to Figure 7, one method 700 is illustrated in the figure, and this process can be carried out by method 700.

[0082] Similar to method (600) in Figure 6, method 700 in 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 the sake of simplicity of illustration, method 700 is also described in a form in which only the state of the upstream RF switching network (315) is changed. As stated above, other methods equivalent to method 700 in 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 who are interested in this disclosure.

[0083] Starting in step 701, the downstream RF switching network (314) and the upstream RF switching network (315) are switched to their default configurations. Then, each client device connected to the RF ports (303, 304, 305, 306) of the node completes the ranging and alignment process and, in step 702, begins communicating with the headend connected to node (202).

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

[0085] In step 705, method 700 switches the upstream RF switching network (315) to a state different from the 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), which is located between the RF ports (303, 304, 305, 306) and a plurality of optical ports of node (202) (e.g., a first upstream DOCSIS port 307 or a second upstream DOCSIS port 308), from a first state to a second state. In one or more embodiments, this second state causes one RF port to be connected to one DOCSIS port, while the remaining RF ports are connected to another DOCSIS port. Decision 706 determines whether the burst receiver of the headend connected to node (202) detects data.

[0086] If, for any reason, a client device is not detected as transmitting data, step 707 switches the upstream RF switching network (315) to a different state. When the headend burst receiver detects data, these client devices transmitting data are identified in step 708 as being connected to the RF ports coupled to the selected DOCSIS ports. In other words, in one or more embodiments, step 708 includes using one or more control circuits (312) to identify one or more client devices that are distributing data to a given optical port among a plurality of optical ports. 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 are correctly and reliably identified as being connected to a particular RF port. Method 700 can then be repeated, in which other client devices receive an idle permission and are instructed to transmit data (and so on).

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

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

[0089] In this embodiment, two client devices are connected to RF ports 303, 304, 305, and 306, respectively. Client devices A and B are connected to RF port 303, while client devices C and D are connected to RF port 304. Client devices E and F are connected to RF port 305, while client devices G and H are connected to RF port 306.

[0090] In step 702, client devices A, B, C, D, E, F, G, and H connected to RF ports 303, 304, 305, and 306 perform ranging and alignment operations. In one or more embodiments, step 702 includes identifying client devices A, B, C, D, E, F, G, and H that have completed the ranging and alignment process. In one or more embodiments, step 702 includes storing these identified client devices in memory 610.

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

[0092] In step 704, the complement of a subset of client devices is assigned to idle permission. In this embodiment, 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 of these will be assigned to idle permission in step 705. In step 705, one or more control circuits 312 switch the upstream RF switching network 315 to switch to the second state shown in Figure 9.

[0093] Referring now to Figure 9, step 901 represents a second state of the upstream RF switching network 315 in this exemplary embodiment. As shown in step 901, the second state leaves RF port 303 communicating with the first upstream DOCSIS port 307. While RF port 303 is still communicating with the first upstream DOCSIS port 307, the connections of RF ports 304, 305, and 306 are, here, connections to the second upstream DOCSIS port 308. Thus, step 901 includes coupling one of the RF ports to a specified optical port, which in this embodiment is the first upstream DOCSIS port 307. However, the remaining RF ports are coupled to another optical port, which in this embodiment is the second upstream DOCSIS port 308.

[0094] In one or more embodiments, decision 706 then includes a burst receiver in a headend connected to node 202 receiving data received at the first upstream DOCSIS port 307. In other words, the burst receiver in the headend determines which of the multiple client devices is delivering data to the first upstream DOCSIS port 307. In this embodiment, client device A will transmit data to the first upstream DOCSIS port 307. Therefore, step 708 will identify that client device A is connected to RF port 303, and this conclusion is recorded in memory 610 in step 709. Client device B is assigned to idle permission and will not yet be identified as connected to RF port 303.

[0095] Decision 710 determines whether all RF ports have been tested. In Figure 9, they have not been tested. This is 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] Referring now to Figure 10, step 1001 shows a second state of the upstream RF switching network 315 in this exemplary embodiment. As shown in step 1001, in the second state, RF port 304 is in communication with the first upstream DOCSIS port 307. Meanwhile, the connections of RF ports 303, 305, and 306 are, here, connections to the second upstream DOCSIS port 308.

[0097] In one or more embodiments, decision 706 then includes the fact that a burst receiver in a headend connected to node 202 receives data received at the first upstream DOCSIS port 307. In this embodiment, client device C will transmit the data to the first upstream DOCSIS port 307. Therefore, step 708 will identify that client device C is connected to RF port 304, and this conclusion is recorded in memory 610 in step 790. Client device D is assigned to idle permission and therefore will not yet be identified as connected to RF port 304. Therefore, in this embodiment, step 708 will include identifying one or more other client devices among several client devices that are distributing data to a specified optical port among a plurality of optical ports using one or more control circuits.

[0098] Decision 710 also determines whether all RF ports have been tested. In Figure 10, they have not been tested. This is because only the first RF port 303 and the 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] Referring now to Figure 11, step 1101 shows a third state of the upstream RF switching network 315 in this exemplary embodiment. As shown in step 1101, in the third state, RF port 305 is in communication with the first upstream DOCSIS port 307. Meanwhile, the connections of RF ports 303, 304, and 306 are, in this case, connections to the second upstream DOCSIS port 308.

[0100] In one or more embodiments, decision 706 then includes the burst receiver of the headend connected to node 202 receiving the data received at the first upstream DOCSIS port 307. In this embodiment, client device E will transmit the data to the first upstream DOCSIS port 307. Therefore, step 708 will identify that client device E is connected to RF port 305, and this conclusion is recorded in memory 610 in step 709. Client device F is assigned to idle permission and will therefore not yet be identified as connected to RF port 305.

[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] Referring now to Figure 12, step 1201 shows a fourth state of the 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 the first upstream DOCSIS port 307. Meanwhile, the connections of RF ports 303, 304, and 305 are, here, connections to the second upstream DOCSIS port 308.

[0103] In one or more embodiments, decision 706 then includes the burst receiver of the headend connected to node 202 receiving the data received at the first upstream DOCSIS port 307. In this embodiment, client device G will transmit the data to the first upstream DOCSIS port 307. Thus, step 708 will identify that client device E is connected to RF port 306, and this conclusion is recorded in memory 610 in step 709. Client device H is assigned to idle permission and therefore will not yet be identified as connected to RF port 306.

[0104] Once all RF ports have been tested, the testing process ends in step 711, and all client devices are correctly and positively identified as being connected to a particular RF port. Method 700 can then be repeated, with other client devices receiving idle permission and other client devices being commanded to transmit data (and so on). To illustrate by embodiment, the method steps shown in Figures 8 to 12 can be repeated, this time with client devices B, D, F, and H being commanded to transmit data, while client devices A, C, E, and G are given idle permission.

[0105] By doing so, the headend burst receiver can identify the RF port and the corresponding RF leg to which the client device is connected. These tests can be performed periodically and / or at staggered intervals to periodically update the system status. These do not need to be done back-to-back for all client devices, thereby increasing the probability that no service interruption will occur.

[0106] Embodiments of this disclosure assume that node splitting, node swapping, and other field operations will continue to occur as an MSO works to increase the bandwidth of its RPD system. Advantageously, embodiments of this disclosure provide a simple, effective, and low-cost tool for determining which client devices are supplied by which RF leg of the RF network. Embodiments of this disclosure also enable the MSO's operations group to determine accurate event correlations of customers affected by failures occurring in RF legs. Furthermore, embodiments of this disclosure enable the MSO to identify which RF leg is experiencing technical problems in the RPD, RMD, or RF ports of a node. Embodiments of this disclosure further enable the MSO to determine the number of client devices supplied by each RF leg, and thus balance the service delivery groups within the DOCSIS system.

[0107] Referring now to Figure 13, the figures illustrate various embodiments of the present disclosure. 1301 A method for identifying which client devices are connected to which RF port of a node includes using one or more control circuits to assign some of the client devices to commands for transmitting data. 1301 A method also includes using one or more control circuits to assign the other of the client devices to idle permission. 1301 A method also includes using one or more control circuits to switch an RF switching network located between an RF port and multiple optical ports of a node from a first state to a second state. 1301 A method also includes using one or more control circuits to identify one or more of several client devices that are distributing data to a specified optical port among multiple optical ports.

[0108] In the 1302, the RF switching network of the 1301 is provided with an upstream RF switching network. In the 1302, the multiple optical ports of the 1301 are provided with multiple upstream optical ports.

[0109] In 1303, in the second state of 1301, one of the RF ports is connected to a specified optical port. In 1304, in the second state of 1303, the remaining RF ports, excluding one RF port, are connected to optical ports other than the specified optical port. In 1305, the method of 1304 further includes using one or more control circuits to identify at least one client device as being connected to one RF port.

[0110] In 1306, the method of 1305 further includes using one or more control circuits to switch the RF switching network from a second state to a third state. In 1306, the method includes using one or more control circuits to identify one or more client devices among several client devices that are distributing data to a specified optical port among a plurality of optical ports.

[0111] In 1307, in the third state of 1306, another RF port among the RF ports is connected to the specified optical port. In 1308, in the third state of 1307, an RF port other than the specified RF port is connected to an optical port other than the specified optical port. In 1309, the method of 1308 further includes using one or more control circuits to identify one or more other client devices as being connected to another RF port.

[0112] In the 1310, a DOCSIS node has a first DOCSIS port and a second DOCSIS port. In the 1310, a DOCSIS node has multiple radio frequency (RF) ports. In the 1310, a DOCSIS port has an RF switching network connected between the first DOCSIS port and the second DOCSIS port and the multiple RF ports.

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

[0114] In 1312, 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 connected to a 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 connected to a second DOCSIS port. In 1313, 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 connected to a 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 connected to a second DOCSIS port.

[0115] In 1314, the first and second DOCSIS ports of 1313 are equipped with upstream DOCSIS ports. In 1315, the DOCSIS node of 1313 further comprises multiple client devices connected to multiple RF ports. In 1315, one or more control circuits distribute idle permission to some of the multiple client devices and distribute commands to transmit data to the other client devices.

[0116] In 1316, the DOCSIS node of 1315 further comprises a headend, the headend comprising a burst receiver connected to the first DOCSIS port. In 1316, the burst receiver determines which of the multiple client devices is distributing data to the first DOCSIS port when the RF switching network is in each of the first, second, third, and second states.

[0117] In 1317, a method for identifying which client device is connected to which RF port of a node includes using one or more control circuits to switch an RF switching network, which is located between the RF port and multiple optical ports of the node, from a first state to a second state. In 1317, the method includes using one or more control circuits to identify multiple client devices connected to an RF port and to initiate a ranging and alignment process.

[0118] In 1317, the method includes using one or more control circuits to switch an RF switching network from a first state to a second state. In 1317, the method also includes using one or more control circuits to identify a subset of multiple client devices and subsequently perform ranging and alignment processes.

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

[0120] The aforementioned specification describes specific embodiments of the present disclosure. 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 are illustrated and described, it is clear that the present disclosure is not limited in that way. Without departing from the spirit and scope of the present disclosure as defined by the following claims, numerous modifications, changes, variations, substitutions, and equivalents will arise for those skilled in the art.

[0121] For example, if different RF ports reside on an RPD, RMD, or node, or alternatively, an upstream cable access module (UCAM), prior art systems make it impossible to identify which RF port is connected to a particular client device. Advantageously, embodiments of the present disclosure enable precise identification of each client device connected to each RF port on each RPD, RMD, or node. This identification can be achieved in one or more embodiments by the operation of an RF switching network(s) connecting burst receivers to different RF ports at different times. This switching, combined with the ranging and / or scheduling processes of client devices, can allow commands to transmit data to the target client device, while other client devices are given idle permission to identify the RF ports and RF leg mappings. Thus, embodiments of the present disclosure are novel to prior art solutions for identifying the RF port hosting a particular client device. This may help avoid sounding in full-duplex (FDX) operation, find leg failures, and provide recommendations regarding the timing of RF leg splitting. Other features and benefits will be apparent to those skilled in the art who are interested in the present disclosure.

[0122] Accordingly, this specification and the figures should be considered illustrative rather than restrictive, and all such modifications are intended to be within the scope of this disclosure. Any benefit, advantage, or solution that may result in or become more prominent, and any element, should not be construed as an important, necessary, or essential feature or element of any one or all of the claims. This disclosure is defined solely by the appended claims, including any amendments made during the pendency of this application, and all equivalents of these claims issued.

Claims

**Claim 1** A method for identifying which client device is connected to which radio frequency (RF) port of a node, the method comprising: using one or more control circuits to assign some of the client devices to commands for transmitting data; using the one or more control circuits to assign the others of the client devices to idle permissions; using the one or more control circuits to 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; using the one or more control circuits to identify one or more of the some of the client devices that are distributing the data to a predetermined optical port among the plurality of optical ports. **Claim 2** The method according to claim 1, wherein the RF switching network comprises an upstream RF switching network, and the plurality of optical ports comprise a plurality of upstream optical ports. **Claim 3** The method according to claim 1, wherein in the second state, one of the RF ports is connected to the predetermined optical port. **Claim 4** The method according to claim 3, wherein in the second state, the remaining RF ports other than the one RF port are connected to optical ports other than the predetermined optical port. **Claim 5** The method according to claim 4, further comprising using the one or more control circuits to identify at least one client device as being connected to the one RF port. **Claim 6** The method according to 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 distributing the data to the predetermined optical port among the plurality of optical ports. **Claim 7** The method according to claim 6, wherein in the third state, another one of the RF ports is connected to the predetermined optical port. **Claim 8** The method according to claim 7, wherein in the third state, RF ports other than the other RF port are connected to optical ports other than the predetermined optical port.

9. The method according to claim 8, further comprising identifying, using the one or more control circuits, the one or more other client devices as being connected to the other RF port.

10. A Data Over Cable Interface Specification (DOCSIS) node, which is a node for connecting a client device to a radio frequency (RF) port, a first DOCSIS port, a second DOCSIS port, a plurality of radio frequency (RF) ports, an RF switching network connected between the first DOCSIS port, the second DOCSIS port, and the plurality of RF ports, 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 connected to the first DOCSIS port and a second RF port of the plurality of RF ports is connected to the second DOCSIS port, and a second state in which the first RF port of the plurality of RF ports is connected to the second DOCSIS port and the second RF port of the plurality of RF ports is connected to the first DOCSIS port; A Data Over Cable Interface Specification (DOCSIS) node comprising:

11. The DOCSIS node according to 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 connected to the first DOCSIS port and the first RF port and the second RF port of the plurality of RF ports are connected to the second DOCSIS port.

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

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

14. The DOCSIS node according to claim 12, further comprising a plurality of client devices connected to the plurality of RF ports, wherein the one or more control circuits distribute idle permissions to some of the plurality of client devices and distribute instructions for transmitting data to other client devices among the plurality of client devices.

15. The DOCSIS node according to claim 14, further comprising a head end, the head end including a burst receiver connected to the first DOCSIS port, and the burst receiver determining 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 fourth state.

16. A method for identifying which client device is connected to which radio frequency (RF) port of a node, the method comprising: using one or more control circuits to switch 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 connected to the RF port and initiate a distance measurement and registration process; using the one or more control circuits to switch the RF switching network from the first state to a second state; A method comprising using the one or more control circuits to identify a subset of the plurality of client devices and continue the distance measurement and registration process. **Claim 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. **Claim 18** The method of claim 17, further comprising using the one or more control circuits to switch the RF switching network from the second state to a third state 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. **Claim 19** The method of claim 18, further comprising using the one or more control circuits to switch the RF switching network from the third state to the first state.

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