Patent Application
20090162056
1. Field
Example aspects of this invention relate in general to communication systems, and more particularly to improved methods, systems, apparatuses, and programs for measuring power levels of media signals (voice, data, and/or video) using an optical network terminal (ONT) and a set top box (STB).
2. Related Art
There is a growing demand in the communications industry to find a solution to transmit voice, data, or video from a headend to a subscriber's premises, through a fiber optic network and all the way into an individual home or business. Such fiber optic networks generally are referred to as fiber-to-the-home (FTTH), fiber-to-the-premises (FTTP), fiber-to-the-business (FTTB), fiber-to-the-node (FTTN), or fiber-to-the-curb (FTTC) networks and the like, depending on the specific application of interest. Such types of networks are also referred to herein generally as “FTTx networks”.
Passive Optical Networks (PON) are an emerging broadband, multi-services access technology allowing the benefits of fiber optic transmission to be pushed closer to the customer, including directly to the customer location. A PON is a point-to-multipoint, FTTP network architecture which enables two-way traffic on a single fiber optic cable. Installation costs are reduced by allowing an optical transceiver at the network end of the access system to be shared with many customers and minimizing the number of trunk/feeder fibers toward the customer premises. Operation costs are reduced by the passive nature of the optical distribution network. Such a passive optical network can be utilized to deliver a multitude of media services into the home, such as voice, video, and data services. Delivery of such services can take on a variety of forms after conversion from the Optical Network Terminal (ONT), including but not limited to a radio frequency (RF) signal utilized over coaxial cable.
Service providers typically measure the power level of an RF signal once it has emerged from the ONT to ensure customer satisfaction and to reduce trouble reports post installation. An example of a known approach to measuring the RF power levels for a typical RF overlay application is to individually check the RF power levels for each channel by taking a manual measurement for each channel using a portable, dedicated measuring device on the coaxial cable at two locations: near the ONT and near the Set Top Box (STB) of a particular customer. This involves gaining access to the STB of each customer whose signal must be diagnosed. It can also be extremely time consuming and, in many installations, the check of the RF power levels for every channel is rarely completed.
Furthermore, an ONT is typically only capable of taking a wideband RF power average, which can be very imprecise and cannot measure the power of an individual channel.
Moreover, with manual RF power level measurements at each STB, generally a problem is not detected until the RF power level degradation is visible to the customer and the customer reports this to the service provider, as service providers rarely perform in-home preventative maintenance checks due to scheduling and cost concerns.
Example aspects of the invention include methods, systems, apparatuses, and programs for measuring power levels of media signals in a communications network such as, for example, an FTTx network (e.g., FTTH, FTTP, FTTB, FTTN, FTTC, etc.), using an Optical Network Terminal (ONT) and a Set Top Box (STB).
The term “media signals” as used herein includes, for example, at least one of voice, video, and data signals, such as but not limited to RF signals utilized over a coaxial cable, including those converted at an ONT.
According to an example aspect of the invention, a method for detecting a signal power level of a channel in a communication network includes (1) selecting a channel to be measured, and a corresponding node and user terminal communicatively coupled thereto, on the network, (2) detecting a signal power level of the selected channel at the corresponding node, (3) detecting a signal power level of the selected channel at the corresponding user terminal, (4) performing a comparison involving the detected signal power levels, and (5) providing a notification of a result of performing the comparison if the result exceeds a predetermined threshold.
Further features and advantages, as well as the structure and operation, of various example embodiments of this invention are described in detail below with reference to the accompanying drawings.
The features and advantages of the example embodiments of the invention presented herein will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference numbers indicate identical or functionally similar elements.
Example embodiments of the present invention will next be described; however, it should be clear to those skilled in the art that various modifications, additions, and subtractions can be made without departing from the spirit or scope of the claims.
Example aspects of the invention include methods, systems, apparatuses, and programs for measuring RF power levels for analog and digital television channels on a PON that can be performed quickly, efficiently, and cost effectively while not necessarily requiring technician presence in the end user's place of consumption.
In one example aspect of the invention, there are provided methods, systems, apparatuses, and programs for measuring RF power levels for analog and digital television channels using, for example, an ONT and a STB, or at any suitable location in the network. Measurements can be made substantially without disrupting or detrimentally affecting the signal because they can be taken on a live network.
In a typical FTTx network, equipment at a headend or central office couples the FTTx to external services such as a Public Switched Telephone Network (PSTN) or an external network. Signals received from these services are converted into optical signals and are combined onto a single optical fiber at a plurality of wavelengths, with each wavelength defining a channel within the FTTx network.
In a FTTP network, the optical signals are transmitted through the FTTP network to an optical splitter that splits the optical signals and transmits the individual optical signals over a single optical fiber to a subscriber's premises. At the subscriber's premises, the optical signals are converted into electrical signals using an Optical Network Terminal (ONT). The ONT may split the resultant signals into separate services required by the subscriber such as computer networking (data), telephony and video. In FTTC and FTTN networks, the optical signal is converted to an electrical signal by either an Optical Network Unit (ONU) (FTTC) or a Remote Terminal (RT) (FTTN), before being provided to a subscriber's premises.
A typical FTTx network often includes one or more Optical Line Terminals (OLTs) which each include one or more Passive Optical Network (PON) cards. Such a network is illustrated in
The PON 101 may be deployed for fiber-to-the-business (FTTB), fiber-to-the-curb (FTTC), and fiber-to-the-home (FTTH) applications, for example. The optical feeds 121a-n in PON 101 may operate at bandwidths such as 155 Mb/sec, 622 Mb/sec, 1.25 Gb/sec, and 2.5 Gb/sec or any other desired bandwidth implementations. The PON 101 may incorporate, for example, ATM communications, broadband services such as Ethernet access and video distribution, Ethernet point-to-multipoint topologies, BPON communications, GPON communications, EPON communications, and native communications of data and time division multiplex (TDM) formats. Customer premises equipment (e.g., 110) which can receive and provide communications in the PON 101 may include standard telephones (e.g., Public Switched Telephone Network (PSTN)), Internet Protocol telephones, Ethernet units, and video devices (e.g., 111), computer terminals (e.g., 112), as well as any other type of customer premise equipment, such as Set Top Boxes (STBs) 113a or 113b.
PON 101 can include one or more different types of ONTs (e.g., 106a-n). Each ONT 106a-n, for example, communicates with an ODN device 104a through associated ODN device splitters 105a-n. Each ODN device 104a-n in turn communicates with an associated PON card 120a-n through respective wavelength division multiplexers 103a-n. Wavelength division multiplexers 103a-n are optional components which are used when video services are provided. Communications between the ODN devices 104a-n and the OLT 102 occur over a downstream wavelength and an upstream wavelength. The downstream communications from the OLT 102 to the ODN devices 104a-n may be provided at, for example, 622 megabytes per second, which is shared across all ONTs connected to the ODN devices 104a-n. The upstream communications from the ODN devices 104a-n to the PON cards 120a-n may be provided at, for example, 155 megabytes per second, which is shared among all ONTs connected to ODN devices 104a-n, although the system and method is not limited to those specific types of downstream and upstream communications only, and may also include the types of example communications referred to above or any other suitable types of communications.
The ONT 300 has a device, signal splitter A 302, that converts the optical signal received to a voice signal, a data signal, and/or an electrical RF signal that is carrying the television channels. In an example embodiment, the signal splitter A 302 is a triplexer capable of splitting a signal (e.g., an optical signal) into at least three parts, using technology well known in the art; of course, this is merely an example.
The voice signal propagates to the voice service unit 310 in the ONT 300 by way of system on chip unit 308 and is exported to user voice units (e.g., 316). Such propagation may utilize any suitable protocol well known in the art, such as, for example, Serial Peripheral Interface (SPI). Moreover, such a voice unit 316 may include any device capable of communicating via traditional phone lines, including but not limited to a telephone set, a fax machine, a personal computer modem, etc. The voice service unit 310 provides a physical interface for supporting voice service, and converts a digital voice signal coming from the system on chip unit 308 to an analog voice signal that is supplied to a telephone device (e.g., 316). Conversely, the voice service unit 310 converts an analog voice signal received from a telephone device (e.g, 316) to a digital voice signal which is then supplied to the system on chip unit 308.
Likewise, the data signal propagates through system on chip unit 308 to the ethernet data service unit 312 and is exported to user data units 318. Such propagation may utilize any suitable protocol well known in the art, such as Gigabit Media Independent Interface (GMII). Moreover, such a data unit 318 may include any device capable of utilizing a data stream, including but not limited to a personal computer ethernet card, a wireless router, an ethernet bridge or hub, PDA, etc. Ethernet data service unit 312 provides a physical interface to support ethernet data services, and converts a digital data signal coming from the system on chip unit 308 to an ethernet signal that is supplied to Ethernet-based devices (e.g., 318) such as, for example, home routers, personal computers, etc. Conversely, ethernet data service unit 312 converts an ethernet signal received from an ethernet-based device (e.g., 318) to a digital data signal which is then supplied to the system on chip unit 308.
The electrical RF signal typically has a power level at an average of 18 dmv+/−3 dbmv; however, field experience has shown that individual RF channels can vary by up to approximately 8 db when compared against each other. The electical RF power signal is fed from the signal splitter A 302 into signal splitter B 304. In an example embodiment, signal splitter B 304 is a diplexer capable of splitting an optical signal into at least two parts using technology well known in the art. Signal splitter B 304 splits the electrical RF power signal into multiple signals, sending one signal out to the home video unit 314 and sending one to the tuner 306. In an example embodiment, the home video unit 314 is the STB 400 of
The tuner 306 tunes the electrical RF signal to a specific channel (or channels). Many different types of tuners can be used, with an example aspect of the invention utilizing an Analog and QAM Tuner based on a traditional silicon tuner chip. The specific channel is then sent to the system on chip unit 308.
The system on chip unit 308 carries out many of the higher level functions of the ONT device, such as processing of incoming data, storing of variables, and management of communications and signal flows. The system on chip unit 308 measures the RF power level of the single channel signal (or plural selected channels) sent from the tuner 306 using measurement techniques known in the art, and stores the measured value locally at the ONT. This measurement is retained for a later comparison, as further explained herein.
The tuner 404 selects a particular channel (or channels) of the RF video signal, as described below, and splits that channel-specific video signal (i.e., the particular channel selected) and provides part to the end user video device 408, which may be, for example, a television, digital video recorder, a video cassette recorder, a personal computer, etc.
At least one other channel-specific video signal from the tuner 404 is fed to the system on chip unit 406 (which may, for example, be similar to the system on chip unit 308 in the ONT 300 shown in
The selected ONT (
In an example embodiment of the invention, such a comparison takes place within the system on chip unit 308 within the ONT 300 as shown in
It is then determined, for example by the EMS 130, whether the result of the comparison merits an external communication such as an alarm to be declared. This determination can be based on various criteria deemed by the service provider as notable for raising an alarm condition, or based on other predetermined criteria. For example, one such alarm condition can include (1) an RF channel (of an ONT and/or STB) exceeding/being less than a predefined tolerance from an established optimal power level (e.g., high or low RF power levels on a per channel basis), (2) a differential between the power levels detected in the STB(s) and ONT(s) exceeding and/or being below a predetermined threshold, and/or (3) any other criteria established during the initiation. Of course, these examples are not meant to be limiting in any way, and any other desired comparison can be made. For example, in other embodiments, a condition for declaring an alarm can be deemed present if one or more of the foregoing criteria (1) to (3) are determined to be present over a predetermined time period or at predetermined times.
In one embodiment, upon receipt of the RF channel power levels reported by the ONT 300 and the STB 400, the ONT 300 can perform a comparative analysis of the information received, and from this analysis, the ONT 300 can determine if an RF channel power level problem exists and can isolate the location of the problem (e.g., in the home coaxial network). The ONT 300 can perform a comparison involving the reported RF channel power levels at the ONT 300 and the STB 300 in any of the foregoing manners. In one example embodiment, since the ONT 300 has been programmed as to the acceptable limits of an RF power level for a channel (e.g., both high and low limits), if the ONT 300 level is deemed acceptable but the STB 400 level is not, then an alarm can be generated (as explained below) reporting that problem is in the coaxial network feeding that particular STB 400. Since many customer premises have multiple STBs, the ONT 300 can perform one or more comparisons based on the levels being received by all STBs and determine which leg of the coaxial network may be problematic. If, for example, the ONT 300 level is low (below a threshold), this could indicate that all STBs will also see a problematic RF power level for a particular channel. If, for example, the RF channel power levels reported by STBs to the ONT 300 levels are high (above a threshold), the ONT 300 could then notify that additional RF power level attenuation may be needed.
It is noted that the components and communication channels of
In block 202 an RF power signal check is initiated. In an example aspect of the invention, this check is initiated by a scheduled process within the Element Management System (such as EMS 130 of
Utilizing a scheduled approach, a service provider can run routing diagnostics at any time including, for example, opportune times such as off-peak hours when system utilization is otherwise low (for example at 4 am). Such an automated diagnostics approach can over time build a statistical pattern representing signal power performance of the system. Such pattern can, for example, show overall decline and predict failure of a particular ONT before such a failure has actually occurred or is visible to the user. This method can thus aid in preventative maintenance by scheduling periodic tests of the overall RF overlay network, allowing service providers to detect early warning signs that a user's television signal quality is beginning to degrade. Proactive steps can then be taken by the operator to dispatch a technician prior to the homeowner even noticing a degradation in service.
In an alternative example embodiment, the RF power signal check initiated in block 202 can be effected manually by a service provider representative or technician. Such initiation can take place, for example, via a physical input into the hardware running the EMS 130 or via a remote signal into the EMS 130, such as an e-mail, a proprietary signal, a phone call, an SMS text message, etc. For example, this mode can be used by an operator or technician to troubleshoot reported video problems from a homeowner or customer, e.g., if the user were to contact the service provider after seeing a disruption in service. The results of the check, as described below, can assist the service provider and user in isolating the problem and determining whether to dispatch a technician to repair the problem.
This is notable in part because under certain regulations, the homeowner or customer is responsible for inside cabling beyond the so-called “demarcation point,” i.e., the point where the signal leaves the ONT and enters the home or customer premises. Under existing systems, the problem cannot be diagnosed until the service provider has already dispatched a technician to the user's location. Therefore, even though the user is responsible for paying for such repairs, the service provider will often not charge them for the repairs in order not to impose an unexpected fee on the customers.
Accordingly, in example embodiments of the invention, an automated process enables proactive measures to be taken, and, in other examples, a manual process can be initiated to assist in troubleshooting reported problems. Further, a check on any channel can be initiated by a technician without the need for test equipment or for physically going to every RF end point to take an actual measurement.
In block 204, a particular ONT, STB, and RF channel are selected, to check the RF power levels on. The reason for this procedure is that each Element Management System is capable of managing a plurality of ONTs on a plurality of PONs, and each ONT is capable of sending RF signals to a plurality of STBs. Moreover, contained in the RF signal between each ONT and each STB is a plurality of RF channels, each of which can have variations in signal strength. A particular ONT, STB, and RF channel (or more than one of each such items) may be selected, for example, based on a manual initiation via the EMS operator for immediate trouble shooting, or based on a preventative maintenance schedule that is initiated by an automated inspection function from the EMS 130 on pre-selected channels or on all channels, etc. Of course, these are merely examples and are not meant to be limiting in any way.
In block 206, a measurement is taken of the signal strength of the selected RF channel(s) within the selected ONT, and the signal strength value is stored locally in the ONT for later comparison, as described above in connection with
In block 210, the STB communicates the signal strength reading of the selected RF channel(s) within the selected STB (determined in block 208) back to the selected ONT for the comparison in block 212. This communication can be accomplished in various ways, including but not limited to a conventional ethernet transmission or a Media Over Cable Alliance (MOCA) protocol utilized over the attached coaxial cable that runs to the STB from the ONT (see
In block 212, the selected ONT performs one or more comparisons involving the signal strength reading of the selected RF channel(s) within the selected ONT (taken internally at block 206) and the signal strength reading of the selected RF channel(s) within the STB (taken internally at block 208). Such a comparison, the result of which is used in block 216, can be undertaken, for example, in accordance with any of the techniques described above. In an example embodiment of the invention, such a comparison takes place within the system on chip unit 308 within the ONT 300 shown in
In block 214, a determination is made as to (1) whether there are more RF channels on this particular STB to measure, (2) whether there are more STBs on this particular ONT to measure, or (3) whether there are more ONTs on this particular PON to measure. In an example embodiment of the invention, this determination is carried out by the EMS 130, based on predetermined operating criteria or the like, such as whether a predetermined number of channels, STBs, and/or ONTs, have been checked, etc. If further measurements are required (“YES” block 214), then, in block 204, at least one other combination ONT/STB/RF channel can be chosen to be checked.
Accordingly, a wide variety of combinations can be checked, including every channel on the PON 101, all channels for one user experiencing problems, one problematic channel across a variety of users, etc. The results of all comparisons (e.g., the RF power levels) can be consolidated and communicated to (for example) the EMS 130, and stored therein or in any other suitable location, and displayed to the operator.
If in block 214 it is determined that no further measurements are required (“NO” at block 214), then in block 216 it is determined, for example by the EMS 130, whether the result of the comparison(s) in block 212 merits an external communication such as an alarm to be declared. This determination can be based on various criteria deemed by the service provider as notable for raising an alarm condition, such as, for example, any of the criteria (1) through (3) described above.
If an external communication is deemed appropriate (“YES” at block 216), then an alarm is declared in block 216 and in block 218, an external communication (alarm) is delivered from, e.g., the EMS, to at least one predetermined destination to signal the condition. Such communication may be of various forms, including but not limited to a warning light on the apparatus running the Element Management System 130, an e-mail concerning the details of the alarm, a paper report being generated, etc., and can be sent to the ONT(s) and/or STB(s) for which measurements were made and/or to other predetermined destinations.
If in block 216 an external communication is deemed not appropriate (“NO” of block 216), then the method will stop.
In either case, at conclusion of the method a report can be generated with information, including but not limited to the fact that a check was conducted, the ONT/STB/channel combinations checked, the date and time of the check, and the results thereof, etc. Any such report can then be outputted to a technician and/or provided to another network component.
The input/output user interface 618 may include, for example, at least one of a keyboard, a mouse, a trackball, touch screen, a keypad, and/or any other suitable type of user-operable input device(s), and at least one of a video display, a liquid crystal or other flat panel display, a speaker, a printer, and/or any other suitable type of output device for enabling a user to perceive outputted information.
Storage device 610 having a computer readable medium is coupled to the processor 602 via a storage device controller 612 and the I/O bus 608 and the system bus 606. The storage device 610 is used by the processor 602 and controller 612 to store and read/write data 610a, and to store program instructions 610b used to implement at least part of the procedures described herein and shown in
In operation, processor 602 loads the program instructions 610b from the storage device 610 into the memory 604. Processor 602 then executes the loaded program instructions 610b to perform any of the example methods described herein, for operating the system 600 (which forms individual ones of the components 102, 104a-n, 106a-n, 110, 113a, 113b, and 130 of
Although described in reference to a passive optical network, the same or other example embodiments of the invention may be employed in any communications network, such as an active optical network, data communications network, or wireless network (e.g., between handheld communications units and a base transceiver station). Furthermore, example embodiments of the invention may be employed in all types of passive optical networks, such as APON, BPON, GPON, WDM-PON, EPON, or any PON derivative. Example embodiments of this invention can be incorporated in networks that utilize RF overlay architectures.
Those of ordinary skill in the art should recognize that example methods of the invention may be embodied in hardware, software or firmware, a combination of hardware, software and/or firmware, or software that includes a computer usable medium. Such a computer usable medium can include, but is not limited to, a readable memory device, such as a solid state memory device, a hard drive device, a CD-ROM, a DVD-ROM, an optical disk, a magneto-optical disk, or a computer diskette, having stored computer-readable program code segments. The computer readable medium can also include a communications or transmission medium, such as a bus or a communications link, either optical, wired, or wireless, carrying program code segments as digital or analog data signals.
Software example embodiments of the present invention may be provided as a computer program product, or software, that may include an article of manufacture on a machine accessible or machine (or computer) readable medium (memory) having instructions. The instructions on the machine accessible or machine readable medium may be used to program a computer system or other electronic device. The machine-readable medium may include, but is not limited to, floppy diskettes, optical disks, CD-ROMs, and magneto-optical disks or other types of media/machine-readable medium suitable for storing or transmitting electronic instructions. The techniques described herein are not limited to any particular software configuration. They may find applicability in any computing or processing environment. The terms “machine accessible medium,” “machine readable medium,” or “computer readable medium” used herein shall include any medium that is capable of storing, encoding, or transmitting a sequence of instructions for execution by the machine and that cause the machine to perform any one of the methods described herein. Furthermore, it is common in the art to speak of software, in one form or another (e.g., program, procedure, process, application, module, unit, logic, and so on) as taking an action or causing a result. Such expressions are merely a shorthand way of stating that the execution of the software by a processing system causes the processor to perform an action to produce a result.
While the inventions has been particularly shown and described with respect to example embodiments thereof, it should be understood that it has been presented as such by way of example, and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the example aspects of the invention should not be limited by any above-described example embodiments, but should be defined only in accordance with the following claims and their equivalents.
In addition, it should be understood that the figures illustrated in the attachments, which highlight the functionality and advantages of the present system, are presented for example purposes only. The architecture of the present system is sufficiently flexible and configurable, such that it may be utilized (and navigated) in ways other than that shown in the accompanying figures.
Furthermore, the purpose of the foregoing Abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is not intended to be limiting as to the scope of the present system in any way. It is also to be understood that the steps and processes recited in the claims need not be performed in the order presented.
