CATV AUTOMATED SERVICE PROVISIONING AND CONNECTION STATUS

SYSTEM

FIELD OF THE INVENTION

[0001] The present invention relates generally to cable television networks and physical security.

BACKGROUND OF THE INVENTION

[0002] Most bi-directional cable television systems are designed such that the services provided are always available at all times at the signal tap. Thus, to disconnect the service from a customer requires a maintenance action at the signal tap to physically disconnect the cable linking the customer premises to the feed. To re-establish the service to a customer requires a maintenance action to connect the customer premises cable to the feed. These maintenance actions are often subcontracted by the cable company to a local cable maintenance service provider. Cable operators designate a team of technicians to audit at least 10% of the contractor's disconnect work. Cable operators have experienced unscrupulous subcontractors who report that the maintenance action to disconnect a cable to remove a customer from the network has been complete when, in fact, it has not. When a new customer takes over this customer premises, they will be already connected to the cable signal without having to pay for it. Unfortunately for the cable service provider, this type of theft can only currently be determined through a physical tap audit. Additionally, if a customer figures out how to connect him/her self to the cable feed, the cable signal can be 'stolen' - again resulting in lost revenue to the cable service provider.

[0003] Cable operators experience churns rates up to 60% of its subscribers' base each year highlighting the significant number of transactions that are disconnected daily and

the associated embedded cost to fulfill those disconnects. When those customers are disconnected appropriately, a significant number of those customers return as subscribers. When subscribers are not disconnected appropriately, cable operators lose access to those customers as new subscribers along with the associated revenue.

[0004] Disconnection of service is generally driven by slow or non-paying subscribers and those subscribers who move out of the cable operator's system. Today, those non- pay subscribers are soft disconnected around day 60 from when the bill is due. This applies to only those customers with set top boxes (STB) in the home. From the local office the cable operator is able to disable the STB with a remote command and premium services like HBO and Showtime are not available. Most customers are educated about the vulnerabilities of the cable system and know that if they disconnect the coax cable from the back of the STB and connect directly to the their television, they will have the basic programming tier, about 80 analog channels, until the service is hard disconnected by a technician. The reasons customers can continue to get the service is that the signal is always live at the cable tap irrespective of the condition of the box.

[0005] Addressable taps have been in limited use since 1983. These devices are an attempt to eliminate the need to manually connect and disconnect service by automatically switching the signal being delivered to each subscriber port on or off. The signal used to 'address' the tap is an FM modulated RF signal in the unused portion of the cable frequency spectrum (usually around 100 MHz). This communication capability, however, is only one way: from the control unit to the tap. Thus, there is no verification from the tap electronics that the command was received and acted upon, thus, eliminating the possibility of an electronic audit. Because these taps have the cable connected to them at all times, it is also difficult to physically audit them to make sure that customers are connected properly. Therefore, over time after the installation of the addressable tap, disconnects would be missed based upon the reliability of the communications media and equipment simply because the addressable tap cannot confirm the status of the connection for each port. It is assumed that connections would not be missed because customers would call in due to a lack of service that they were

paying for. Thus, the cable operator is left with an unverifiable and unconfirmed connection status for its non-customers with an erosion of revenue being the result. In addition, cable television offerings have increased in complexity and addressable taps in the marketplace have limited ability (or no ability) to provision services meaning that a manual operation often must be done on the output of the addressable tap to add filtering customized to the service being provisioned. For these reasons, addressable taps have not gained wide range acceptance in the cable television market.

SUMMARY OF THE PRESENT INVENTION

[0006] An object of the present invention is to provide a system for automating customer service provisioning. Another alternate or additional object of the present invention is to transmit connection verification and status information to the cable television (CATV) head-end from the provisioning device. Another alternate or additional object of the present invention is to provide a mechanism for web-based monitoring and measurement of cable system equipment.

[0007] The present invention provides a device for provisioning cable services including a programmable filter for basic cable service.

[0008] The present invention also provides a device for provisioning cable services including a filter module having a programmable circuit for provisioning cable services.

[0009] The present invention also provides a device for controlling cable signals between a network cable and drop cables to customers comprising: an input for receiving cable signals; a first output connector for sending the cable signals to a first customer; a second output connector for sending the cable signals to a second customer; a first filter connecting the input to the first output connector so as to provision cable services to the first customer, and a second filter connecting the input connector to the second output connector so as to provision cable services to the second customer; and a cable modem,

the cable modem capable of receiving instructions for the first and second filters via the input and sending information via the input.

[0010] The present invention also provides a device for connecting a cable signal tap and drop cables to customers comprising: a first input connector for receiving cable signals from a first port of the signal tap; a second input connector for receiving the cable signals from a second port of the signal tap; a first output connector for sending the cable signals to a first customer; a second output connector for sending the cable signals to a second customer; and a circuit connecting the first input connector to the first output connector via a first filter and connecting the second input connector to the second output connector via a second filter.

[0011] The present invention also provides a control system for a cable network comprising: a plurality of electronically-controlled devices, each located between a network cable and a plurality of drop cables for customers and each having an a media access control address and a programmable filter, and a server for controlling the electronically-controlled devices, the server selectively controlling the filters.

[0012] The present invention also provides a system for monitoring a cable network comprising: a plurality of electronically-controlled devices, each located between a network cable and a plurality of drop cables for customers and each having an a media access control address and a programmable filter, and a server for receiving information on the electronic devices, the information providing information on the status of the programmable filters.

[0013] The present invention also provides a method for mapping a cable network comprising the step of sending information regarding a filter status of a plurality of drop cables from an off-premises cable modem.

[0014] The present invention also provides a method for updated an existing cable network comprising attaching controllable filtering devices to existing cable signal taps.

[0015] A fixed frequency filter for provisioning digital services may be provided. Terminating elements for service disconnects, a power measurement circuit to confirm the veracity of the filter module input connection, serial communication ports to communicate with a controlling module or other peripherals, a microprocessor, a DC to DC converter circuit, and other support circuitry may be provided.

[0016] The device may include a controlling module for transmitting and receiving information over a single cable to the cable television network and a filter module which may or may not be co-located with the controlling module.

[0017] The controlling module may contain a cable modem emulator, an AC to DC converter circuit to convert the network power to usable voltages for the cable modem, peripheral devices, and other circuitry, a microprocessor, and serial communication ports to communicate with remote peripheral devices.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A preferred embodiment of the present invention is described below by reference to the following drawings, in which:

[0019] FIGURE 1 shows a typical installation of the present invention located in an existing cable television location, such as a lock box in the distribution network, for a filter module device remotely controlled by the controlling module; and

[0020] FIGURE 2 shows how the filter module is connected to the existing cable network equipment; and

[0021] FIGURE 3 shows a detailed block diagram of the preferred embodiment of the present invention whereby one or more filter modules is remotely controlled by the controlling module; and

[0022] FIGURE 4 shows a description of the possible AC voltages present on the cable television network coaxial cable; and

[0023] FIGURE 5 shows a detailed schematic diagram of an instantiation of the present invention whereby one or more filter modules is remotely controlled by a controlling module.

DETAILED DESCRIPTION

[0024] FIGURE 1 shows an existing lock box 20 in a cable television distribution network which is fed by a coaxial cable 12 from the hybrid fiber coax cable plant 11. Within the lock box 20 is an existing tap 21. Connection to the controlling module 500 is made by connecting a coaxial cable 22 to a power-passing tap 24 on the existing tap 21. The power-passing tap 24 on the existing tap 21 has the property whereby AC power and the cable RF signal are electrically combined and present at the power-passing tap 24 output. The ports 23 of the existing tap 21 may be configured as power-passing taps 24 prior to installation of the controlling module 500. The filter module 1000 is remotely connected to the controller module 500 through a cable 900. The cable 900 carries the analog signals, digital signals, and power from the controlling module 500 to the filter module 1000 necessary to remotely power and control the filter module 1000. Connection to the filter module 1000 is made by connecting a coaxial patch cable 26 between the non-power passing taps 23 on the existing tap 21 and the filter module 1000 ports. The customers to be served from the lock box 20 are connected via their respective coaxial cables 27 to the output ports of the filter module 1000. Also, although only a single filter module 1000 is shown in FIGURE 1, the present invention includes the capability to remotely control more than one filter module 1000 from a single controlling module 500 and also includes the ability to control other peripheral devices as well as the

filter module 1000. The web based software 10 is connected to the hybrid fiber coax cable plant 11 through a standard internet connection from a local or remote location. The web-based software 10 has components which are installed on a local machine, such as a personal computer, and components which are installed on a web-server. The local machine and web-server do not need to be located in the same facility or even in the same geographic vicinity. Finally, the coaxial cable 12 which connects tap 21 to the cable network passes through tap 21 to additional cable lock boxes in the distribution network unless tap 21 is the end of the distribution line.

[0025] FIGURE 2 shows the connection between the existing tap 21 and the filter module 1000 in greater detail. The coaxial cable 12 feeds the existing tap 21 where the RF signal is split from the power with a portion of the RF signal presented at each of the existing tap 21 output ports. The existing tap 21 output ports are connected to the filter module 1000 input ports via a coaxial patch cable 26. Each of the filter module 1000 output ports are then connected to an individual subscriber via the coaxial cables 27. The connections to the existing tap 21 output ports, filter module 1000 input ports and filter module 1000 output ports may be made using locking connectors to help ensure the integrity of the system connections.

[0026] FIGURE 3a shows a detailed block diagram of the controlling module 500 with an attached filter module as depicted in FIGURE 1. The controlling module 500 input connector 101 is a connector that is compatible with existing cable television network patch cables, such as an F connector jack. The input connector 101 must be capable of passing AC power as well as the RF spectrum allocated within the cable network for modem operations (5 MHz to 50 MHz and 550 MHz to 850 MHz). The output of the input connector 101 carrying the composite RF + AC power signal feeds a signal splitter 1 10 designed to separate the AC signal and the RF signal. The AC signal is routed to an AC to DC converter circuit 120 to provide DC power for the controlling module 500 and one or more security devices 1000 while the RF signal is routed to an optional RF Power Sensor 270 and the cable modem emulation electronics 200. The signal splitter 110 is designed such that the AC power signal is heavily attenuated when viewed at the signal

splitters' 1 10 RF port output and the RF signal is heavily attenuated when viewed at the signal splitters' 110 AC port output. The AC to DC converter 120 is designed to convert a 60V to 90V, 60 Hz AC square wave, quasi-square wave, or sine wave input to a DC voltage necessary to support the cable modem emulation electronics 200 and peripheral security devices 1000, such as +12V DC. The resulting DC power signal is used to power various functions in the controlling module 500 and filter module 1000 as indicated in FIGURE 3a. The DC to DC converter 250 is designed to convert the output of the AC to DC converter 120 to an alternate voltage level compatible with TTL electronics assuming that the AC to DC converter 120 output voltage is incompatible with these devices. The optional RF power sensor 270 samples and measures the output power from the cable modem emulation electronics 200. The output of the optional RF power sensor 270 may be either in a digital form or an analog voltage. In the diagram of FIGURE 3a, the optional RF power sensor 270 output is assumed to be digital and is directly connected to the microprocessor 310 bus. If the output of the optional RF power sensor were an analog voltage, it would require connection to an analog to digital conversion port within the microprocessor 310 or to an external analog to digital converter whose digital output would then be connected to the microprocessor 310 bus. The RF power level measured by the optional RF power sensor 270 is useful diagnostic information for testing the controlling module 500 and may be sent to the web based software 10, represented in FIGURE 1, to use for diagnostic or other purposes.

[0027] The cable modem emulation electronics 200 offer the full functionality of a standard cable modem with respect to the cable network interface. However, the cable modem emulation electronics 200 are not necessarily required to support the full functionality required to connect to a standard personal computer. In FIGURE 3a, the cable modem emulation electronics 200 are connected to an optional communication controller 290. The optional communication controller 290 could be a universal serial bus (USB) controller or Ethernet controller as examples. This allows the freedom to either directly connect the cable modem emulation electronics 200 to the microprocessor 310 bus or through an optional communication controller 290. Existing cable modem systems are considered to be mature systems with respect to both hardware and software

performance and reliability. Thus, connecting the microprocessor 310 through an optional communication controller 290 offers the advantage that existing cable modem technology may be used to implement the cable modem emulation electronics 200 function. Alternately, the cable modem emulation electronics 200 may be connected directly to the microprocessor 310 bus which has the advantage of eliminating unnecessary cable modem hardware functions used to support a personal computer interface with the potential penalty of increased software development.

[0028] The microprocessor 310 function provides for a programmable means of supporting the controlling module 500 device tasks. The microprocessor 310 acts as the primary communication hub between the controlling module 500 and the web-based software 10 of FIGURE 1. Messages or data sent from the web-based software 10 of FIGURE 1 to the controlling module 500 are received by the microprocessor 310, decoded, acknowledged, and acted upon. Messages or data sent from the web-based software 10 of FIGURE 1 may be commands, requests for status, downloads of updated software, digitized speech, or other requests and commands. Similarly, messages or data to be sent to the web-based software 10 of FIGURE 1 from the controlling module 500 are initiated by the microprocessor 310. Messages to the web-based software 10 of FIGURE 1 may be status updates or other requests and commands.

[0029] The microprocessor support electronics 350 includes the power-up reset logic for the microprocessor 310, LED's, crystal oscillator circuits to provide a time reference for the microprocessor 310, digital memory, etc. A temperature sensor 330 allows the microprocessor 310 to report the temperature environment of the controlling module 500 to the web-based software 10 of FIGURE 1.

[0030] The controlling module 500 of FIGURE 3a includes a serial transmit/receive 370 function for communication with peripheral devices such as the filter module 1000. This serial TX/RX 370 function may be implemented as RS-232, RS-422, low voltage differential signaling (LVDS), or other communication technology. The purpose of the serial TX/RX function is to allow the controlling module 500 to act as a transponder for

peripheral devices such as the filter module 1000 of FIGURE 3a. Other potential peripheral devices might include equipment monitoring functions, security monitoring and theft detection functions, network performance measurement functions, etc. The output connector 390 of the controlling module provides main DC power from the AC to DC converter 120 to peripheral devices, serial TX/RX 370 communication functionality, and digital signaling to and from the microprocessor 310. The controlling module 500 may include more than one output connector 390 with the indicated functionality to control filter modules 1000 and other peripherals simultaneously. FIGURE 3a shows a signal output connector 390 for simplicity sake.

[0031] The filter module 1000 is connected to the controlling module 500 through a cable 900. The cable 900 may be of any length compatible with the signaling requirements required for the serial TX/RX 370 function and the digital signaling requirement of the microprocessor 310 and internal digital components of the filter module 1000. This allows the filter module 1000 to be installed remotely from the controlling module 500 or locally with the controlling module 500 based upon customer installation desires.

[0032] FIGURE 3b shows a detailed block diagram of the filter module 1000 of FIGURES 1 and 3a. The filter module 1000 depicted in FIGURE 3b shows eight service provisioning electronic channels represented by an input F connector 11 10, a signal splitter 1120, a provisioning circuit 1130, and an output F connector 1140. The filter module 1000 service provision electronic circuit input F connector 1110 is a connector that is compatible with existing cable television network patch cables, such as an F connector jack. The input F connector 1110 must be capable of passing the entire RF spectrum of 5 MHz to 850 MHz for cable network operations. The output of the input F connector 1 1 10 feeds a signal splitter 1120. The signal splitter 1120 is designed to send a portion of the input signal power to an optional RF power sensor 1 170 circuit through a single-pole, four-throw (SP4T) switch 1160 to allow the Filter Module to sense whether or not the input cables are connected properly to each port. The other output of the signal splitter 1 120 is a low loss path that feeds a service provisioning 3b circuit (designated

Prov. Circuit in Figure 3b) that acts as the mechanism for delivering the service that a customer contracted to obtain from the cable company. The output of the service provisioning 1 130 circuit is the output F connector 1 140 that will connect to the cable going to the customer premise. The filter module 1000 embodiment represented by Figure 3b accommodates eight (8) independent service provisioning ports per device primarily due to the prevalence of existing eight (8) port taps in the cable network, but could be more or less based upon the CATV providers wishes. The optional RF power sensor 1170 circuit is designed to provide an analog voltage corresponding to a measurement of the input power. The input to the optional RF power sensor 1170 circuitry is accommodated via two single-pole, four-throw (SP4T) switches 1160 to individually direct each service provisioning port input to the optional RF power sensor 1 170 circuit. In this way, the filter module 1000 can sense whether or not the input ports are connected. It is intended that all existing tap ports be connected to a filter module 1000 in a given installation environment even if there are more tap ports than customers. The output of an existing tap port has full connectivity. By connecting the existing tap port output to a filter module 1000 input, the service to a customer can be controlled through the functions of the filter module 1000. The safest method for a non-paying customer who is disconnected by the filter module 1000 to 'steal' the signal from the cable company, the thief would have to disconnect the cable going to his premise from the output of the filter module 1000 and also disconnect the input to the filter module 1000 to reconnect his premise cable directly to the tap, assuming that all tap outputs are connected to a filter module 1000 input. By measuring the input power for each port input via the optional RF power sensor 1170 circuit, the filter module 1000 can recognize the change in connectivity state and alert the cable television provider to the possibility of cable theft. The DC to DC converter 1200 and 1210 circuits are designed to convert the DC voltage input from the controlling module 500 to voltages compatible with the devices within the filter module 1000. Note that there are anticipated to be a DC to DC converter 1200 circuit for the RF electronics and a separate DC to DC converter 1210 circuit for the digital electronics even if the voltages required by the circuits are the same. This separation is desirable to help ensure the minimization of digital switching noise corrupting the RF signal integrity. The serial Tx/Rx 1190 function allows the filter

module 1000 to communicate with the controlling module 500. Each filter nodule 1000 has a unique identifier that is used to identify the appropriate device. This allows multiple filter modules 1000 to be connected to a single controlling module 500 without creating addressing conflicts and potential control problems. Additionally, all communications between a filter module 1000 and the controlling module 500 are initiated by the controlling module 500 to minimize communication clashes that may occur on the serial communication lines by multiple devices attempting to transmit at the same time. The microprocessor 1180 function provides for a programmable means of supporting the filter module 1000 communication and control tasks. Messages or data sent from the controlling module 500 are received by the filter module 1000 microprocessor 1 180 and the appropriate commands are executed or data/measurements sent back to the controlling module 500 through the serial Tx/Rx 1 190 function. Finally, the support electronics 1150 function includes the power-up reset logic for the microprocessor, LED's, crystal oscillator circuits, temperature sensing to monitor the temperature of the filter module 1000, etc.

[0033] FIGURE 3 c shows a detailed block diagram of the service provisioning circuit 1130 of FIGURE 3b. The service provisioning 1130 circuit allows the RF cable signal to be directed to one of four paths: a digital spectrum filter 1 132 which is designed to pass 5 MHz to 50 MHz and approximately 550 MHz to 1 GHz, a 75ω terminated path 1134 that is designed to disconnect service to the customer, a through path 1137 to provide all services, and an optionally programmable basic cable filter 1135 that is designed to pass 5 MHz to a programmable upper limit of approximately 360 MHz and approximately 535 MHz to 1 GHz. The optionally programmable basic cable filter 1 135 may be replaced by a fixed filter circuit with the disadvantage that the product implemented in this fashion is a specific solution for a given geographical area. Different cities and geographies have different basic cable line-ups which result in different frequency cutoff requirements for the basic cable filter. By making the filter digitally tunable, the optionally programmable basic cable filter 1 135 may be deployed in a broader number of applications without the need to redesign the basic cable filter. An SP4T switch 1 131 and 1 133 is implemented at the service provisioning 1130 circuit input and output to select the appropriate filter

based upon the service to be provided to the customer. The digital spectrum filter 1 132 is used to pass the upstream (>550 MHz) and downstream (5 MHz to 50 MHz) signal paths to the customer for cable modem operations while blocking the analog television spectrum. The 75ω termination path 1134 is used to disconnect customers from the network while also providing the manual tap with a properly terminated disconnection to avoid potential problems with impedance mismatches and the resulting impact to the taps' reflection coefficient. The thru path 1137 is used to select full connectivity to provide premium services to the customer. Finally, the optionally programmable basic cable filter 1135 is used to provide basic cable services along with services that may require a cable modem (internet or digital telephone). The optionally programmable basic cable filter 1 135 is used to filter out only a portion of the analog television bandwidth that is reserved for 'extended' basic services. Basic cable is not homogenous across networks or regions. Thus, by making the filter programmable, the basic cable lineup can change to include additional channels or exclude previously offered channels. In the current instantiation of the present invention, the optionally programmable basic filter 1135 can be programmed for basic cable channel cutoffs between CH 22 and CH47. It should be noted that the optionally programmable basic filter 1135 also allows channels 76 thru 79 to pass. These channels are usually reserved for local government access use and are required to be offered as part of basic cable. The optionally programmable basic cable filter 1135 is digitally tunable through the use of a digital to analog converter circuit 1136 that controls the voltage tunable components in the circuit to alter the filters' cutoff frequency. Table I ₅ below, provides a list of common services provided by a cable television operator and the corresponding filter module 1000 service provisioning 1130 circuit path for each service along with additional requirements that may be necessary to fulfill the service.

[0034] Table I. CATV Services and Corresponding Provisioning Circuit Paths

[0071] FIGURE 4 shows square wave 1, quasi-square wave 2, and sine wave 3 representation of the different types of AC power that may exist in the cable network. The power in modern cable networks in the United States have voltages ranging from 60

VAC to 90 VAC at a 60 Hz cycle rate where the cycle rate is computed as 1/T in Figure 4. These voltage levels represent the root-mean-squared voltage levels. For the square wave 1 of FIGURE 4, the peak voltage is'equal to the root mean squared voltage or V _P k =

Vi _ms . For the sine wave 3 of FIGURE 4, the peak voltage is equal to -Jl times the root mean squared voltage or V _pk = 4ϊ V _n ^ _s . The square wave 1 and sine wave 3 represent the minimum and maximum peak voltage bounds for the AC power in cable television networks. Thus, the minimum peak voltage would occur in a 60V AC system that uses a square wave 1 generator and the minimum peak voltage would be 60 V. The maximum peak voltage would occur in a 90 VAC system that uses a sine wave 3 generator and the maximum peak voltage would be 127.3 V. These bounds will be useful for the discussion of FIGURE 5.

[0072] FIGURE 5 shows a detailed schematic diagram of an instantiation of the present invention whereby one or more filter modules 1000 are remotely controlled by a controlling module 500. This particular instantiation utilizes a commercially available cable modem such as the Webstar DPC2100R2 series cable modem from Scientific Atlanta for the cable modem emulation electronics 200 of FIGURE 3 and does not contain the optional RF power sensor 270 of FIGURE 3.

[0073] FIGURE 6a is a detailed schematic of an instantiation of the input connector 101, signal splitter 1 10, and AC to DC Converter 120 of FIGURE 4. Jl of FIGURE 6a represents the input connector 101 of FIGURE 3a. Jl in this instantiation of the invention is anticipated to be a printed circuit board mounted F connector with four ground connections and a single center conductor carrying the composite RF and AC power connector. The signal splitter 110 of FIGURE 3a is comprised of the components Fl, C5, L75, Ll, L2, Rl, R2, and C2. Fl is a positive temperature coefficient (PTC) fuse designed to cause an open circuit condition when a steady-state current flow through the device exceeds its specification. The purpose of including a PTC fuse at the controlling module 500 input is to safeguard the network and installation locations against hazards due to potential short circuit conditions that may develop within the controlling module 500 or the security device 1000. Fl must be capable of handling up to approximately 130

peak volts, must be capable of passing the full spectrum of DC to 1 GHz, and should be chosen for over-current conditions exceeding the anticipated current draw of the controlling module 500 and attached filter modules 1000 or other peripherals.

[0074] The capacitor, C5, is chosen to present a low impedance to signals between 5 MHz and 850 MHz and a high impedance to the 60 Hz AC power signal and lower order harmonics if the power signal is a square wave 1 of FIGURE 4 or quasi-square wave 2 of FIGURE 4. The impedance, Z, of the capacitor, C5, is given by

[0075] Eq. 1 Z =

2 * ;r *f *C5

[0076] Where: π if the value pi which is equal to 3.141592.... ε f is the frequency in hertz ε C5 is the capacitance of the component, C5, in Farads ε Z is the resulting impedance magnitude in Ohms

[0077] In addition to impedance considerations, the capacitor, C5, must also be capable handling potential high voltages on the cable line due to power transients or lightning strikes. It is also desirable for C5 to have a low effective series resistance and effective series inductance. If a suitable single capacitor cannot meet the designers' requirements two or more capacitors may be put in parallel with one another.

[0078] The components L75, Ll, L2, Rl, R2, and C2 are chosen to present a low impedance to the 60 Hz AC power signal and a high impedance to the RF signals between 5 MHz and 850 MHz. The components L75, Ll, L2, Rl, and R2 represent a distributed RF choke. Cable systems are 75 ω systems, so the composite impedance of the distributed RF choke should be at least greater than 750 ω over the 5 MHz to 850 MHz frequency range to avoid unnecessary insertion loss due to the presence of the RF choke. Inductive components such as L75, Ll, and L2 have an effective capacitance between turns of the wire coil which produces a self capacitance that in combination with

the inductance produces an LC resonance. For broadband applications such as this, the resonances often lie with the band of the RF signal. Reduction in the number of turns of the inductor can push any LC resonances above the passband, but this reduction will also result in a lower inductance limiting the effectiveness of the inductor at the low end (5 MHz) of the band. The distributed choke in the present invention overcomes these problems by having an inductor, L75, with a low number of turns with good rejection capabilities in the mid and upper frequencies of the RF signal band and resonances outside the band of the RF signal in series with inductors, Ll and L2, which have a higher number of turns for low frequency rejection. The impedance, Z, of the inductive components is given by

[0079] Eq. 2 Z = 2 * ;r * f * L

[0080] Where: π if the value pi which is equal to 3.141592.... ε f is the frequency in hertz ε L is the inductance in Henry's ε Z is the resulting impedance magnitude in Ohms

[0081] The resistors, Rl and R2, are in parallel with the inductors, Ll and L2, to reduce the Q of the LC resonance of the inductors which has the effect of dulling the response of any in-band resonances of Ll or L2. The capacitor, C2, is chosen to present a low impedance to signals between 5 MHz and 850 MHz to provide an RF path to ground on the power output leg of the signal splitter 110 of FIGURE 3 a and a high impedance to the 60 Hz AC power signal.

[0082] The components R16, D4, R17, D5, D6, DlO, C19, C32, C43, C44, C46, and C47 half-wave rectify the 60 Hz AC power signal, reduce the peak voltage to the input voltage range of the switching regulation circuitry, and provides voltage hold-up during the negative voltage half-cycle of the AC power input. The resistor, Rl 6, is used to help limit the in-rush currents at initial application of power. The diodes, D4 and D5, are used to create the half- wave rectifier circuit. The zener diodes, D6 and DlO, are optional

components used to limit the peak voltage present at the node, Vin of Ul, to within the requirements of the components attached to the node. The capacitors, Cl 9 and C32, are anticipated to provide bulk capacitance for maintaining the voltage between rectification cycles. While two capacitors are shown in the current instantiation, one may be adequate or more than two required depending upon the components chosen. To prevent large input transients, it is desirable to have a low equivalent series resistance for the total capacitance at the node, Vin of Ul . The capacitors, C43, C44, C46, and C47, are anticipated to be low ESR capacitors such as ceramics. The rationale for using both bulk capacitors and ceramics is that bulk capacitor technologies generally do not have adequate ESR for applications such as this while ceramic capacitors or other low ESR technologies do not have adequate total capacitance at the anticipated required voltage levels. Thus, the parallel combination of the two technology types represents a good approach for implementation.

[0083] The AC to DC converter 120 is anticipated to be a switching power supply that supplies a voltage output, VDC Out, at a max output current of I _MAX with a regulation efficiency of ε. Thus, the power that must be supplied from the cable television system can be computed as:

[0085] Where: VDC Out is the AC to DC Converter 120 output voltage ε I _MAX is maximum AC to DC Converter 120 output voltage ε is the efficiency of the regulator ε PsouR _C E is the power that must be supplied from the cable television system

[0086] With the voltage regulation circuitry designed for this instantiation of the present invention, the maximum current draw from the host cable system occurs when the host system has a minimum peak voltage. The minimum peak voltage (60 V) available from

the potential AC voltage waveforms occurs when the voltage waveform is a 60 VAC square wave as determined previously. Thus, the minimum rectified voltage present at the node, Vin of Ul, when the capacitors, Cl 9 and C32 are fully charged is given by:

[0087] Eq. 4 V _{in of} ui = 60 V - V _Zen er - We * Rl 6 - 0.7 V

[0088] Where: V _{1n of} ui is the voltage present at the node, Vin of Ul, when the capacitors,

C19 and C32, are fully charged ε Vz _ener is the voltage drop across the Zener diodes, D6 and DlO ε Is _ou r _ce * Rl 6 is the voltage drop across the resistor, Rl 6 ε 0.7 V is the estimated voltage drop across the diode, D5

[0089] Now, given the result of Eq. 4, the power that must be supplied from the cable television system can be written as:

[0090] Eq. 5 PsOURCE = (60 V - V _Zener - Isource * Rl 6 - 0.7 V) * I _Sθ urce

[0091] Equating the result of Eq. 5 to the result of Eq. 3 and solving for Is _o urc _e yields

[0092] Eq. 6

[0093] Where: I _SO U _R CE is the current that must be supplied by the cable television system ε (60 V - Vzener - Isource * Rl 6 - 0.7 V) is the voltage present at the node,

Vin of Ul, when the capacitors, Cl 9 and C32, are fully charged ε Rl 6 is the in-rush current suppression resistor ε VDC Out is the AC to DC Converter 120 output voltage ε I _MAX is maximum AC to DC Converter 120 output voltage

ε is the efficiency of the regulator

[0094] The choice of Vz _ener is determined by the reduction in the maximum peak voltage required to limit the voltage present at the node, Vin of Ul, based upon the requirements of the components attached to this node. As shown in the discussion for Figure 5, the maximum peak voltage would occur when the input AC power waveform is a sine wave. Rl 6 is then chosen based upon the maximum current draw from the host cable television system for each installed instantiation of the present system. Eq. 7 is a restatement of Eq. 6 for the solution of Rl 6 if the maximum current that must be supplied by the cable television system is known.

(60 V - Vzener - 0.7V) * IsOURCE - 1

[0095] Eq. 7 R16 =

ISOURCE 0 , ^!

[0096] During the negative half-cycle of the AC voltage signal, the voltage present at the node, Vin of Ul, must not drop below a minimum voltage, V _mιn , to avoid dropouts in the regulated voltage output, VDC Out. To determine the minimum bulk capacitance required to hold up the voltage above the V _min threshold can be estimated by assuming that the rectifier load is approximately resistive. The minimum resistance of the rectifier load, R _min , coincides with the condition when the minimum peak voltage (60 V) available from the potential AC voltage waveforms occurs. R _mm can be determined as:

10097] Eq. 8 ^ (60 V - V^- 0.7V) - Wc _E »R16

ISOURCE

[0098] Where: R _mm is the modeled minimum resistance of the rectifier load ε (60 V - Vzener - Isource * Rl 6 - 0.7 V) is the voltage present at the node,

Vin of Ul, when the capacitors, C19 and C32, are fully charged ε Rl 6 is the in-rush current suppression resistor ε I _SOURCE is calculated current of Eq. 6

[0099] The bulk capacitance obtained by C19 and C32 must be capable of holding up the voltage above V _min during the negative voltage half-cycle under the minimum peak voltage condition given by a 60 VAC square wave input. Thus,

[00100] Eq. 9 Vmm < (60 V - Vzener - Isource * Rl 6 - 0.7 V) * β •»— < ^CI9+C32)

[00101] Where: V _min is the minimum voltage present at the node, Vin of Ul, to avoid dropouts in the regulated voltage output, VDC Out. ε (60 V - Vz _ener - So _u r _ce * Rl 6 - 0.7 V) is the voltage present at the node, Vin of Ul, when the capacitors, C19 and C32, are fully charged ε t is time ε R _mιn is the modeled minimum resistance of the rectifier load ε C 19 + C32 is the bulk capacitance

[00102] Using 1/120 ^th of a second as the time duration of the negative half cycle of the voltage waveform and solving for the bulk capacitance, C19+C32 yields

[00103] Eq. 10

- 1

C19 + C32 = 120

[00104] The regulator circuit in the instantiation of the present invention is designed around the Linear Technology LTC3703 which is Ul of FIGURE 5a. The LTC3703 is a synchronous step-down switching regulator controller that can directly step-down voltages from 100V. The LTC3703 drives external N-channel MOSFET's using a constant frequency, voltage mode architecture. A precise internal reference provides 1% DC voltage output accuracy. A high bandwidth error amplifier and line feed forward compensation provide very fast line and load transient response. Strong gate drivers allow the LTC3703 to drive multiple MOSFETs for higher current applications.

The operating frequency is user programmable from 100 kHz to 600 kHz and can also be synchronized to an external clock for noise-sensitive applications. Current limit is programmable with an external resistor and utilizes the voltage drop across the synchronous MOSFET to eliminate the need for a current sense resistor. The LTC3703 datasheet can be consulted to determine the component values and application considerations for selection of the components outlined within the dashed line of FIGURE 6a.

[00105] The optional components, C121, Cl 19, C122, C120, and L73, form a pi filter to increase the noise immunity and transient suppression of the LTC3703 regulator. Pi filters are well-known in the art.

[00106] FIGURE 5b is a detailed schematic of an instantiation of the microprocessor 310, the temp sensor 330, the DC to DC converter 250, and the microprocessor support electronics 350.

[00107] UlO, CI l, and optional C29 represent the temperature sensor 330 components. UlO is a broad range precision temperature sensor whose output voltage is linearly proportional to the temperature, such as the LM34 by National Semiconductor. The temperature sensor device in this instantiation has an analog output whose voltage level is linearly proportional to the Fahrenheit temperature and must be connected to one of the internal analog to digital converter inputs of the microprocessor 310. This instantiation has an advantage over linear temperature sensing circuits calibrated in degrees Kelvin in that a large constant voltage is not required to be subtracted from its output to obtain conventional Fahrenheit scaling. The capacitor, CI l, is a power supply de-coupling capacitor while the optional capacitor, C29, may help enhances noise immunity on the analog signal line.

[00108] The components U12, RlO, C24, R9, R27, D3, R13, R26, D2, R12, R25,

Dl, RI l, Yl , C3, and C4 represent the microprocessor support electronics 350 for the instantiation of the present invention.

[00109] U12 is a 64K X 8 (512 Kbit) serial electrically erasable PROM, such as the 24LC512 by Microchip Technology, for external program and data memory storage. The preferred device has a page write capability for rapid programming and must be capable of random or sequential reads up to the memory boundary. For the 24LC512, functional address lines allow up to eight devices on the same bus, for a 4 Mbit address space. R9 and RlO are optional pull-up resistors, while C24 is a power supply decoupling capacitor.

[00110] D3, R27, and Rl 3 form a light-emitting diode (LED) circuit. The light emitting diode, D3, can be turned on or off by the microprocessor 310 and acts as visual indication of the state of the dynamic host configuration protocol (DHCP) when the controlling module 500 is requesting an internet protocol (IP) address. When the microprocessor 310 output is a TTL high or ' 1 ', the LED will be on and when the microprocessor output is a TTL low or O', the LED will be off. In the present instantiation, the LED, D3, is solid if DHCP is ready and will blink if a failure has occurred. The function of the LED, D3, can be changed by changing the microprocessor 310 software.

[00111] D2, R26, and Rl 2 form another light-emitting diode circuit. In the present instantiation, D2 will blink every 15 seconds to visually signal that the microprocessor 310 software is operating normally. The function of the LED, D2, can be changed by changing the microprocessor 310 software.

[00112] Dl, R25, and RI l form a third light emitting diode circuit as part of the microprocessor support electronics 350. In the present instantiation, Dl is on to signal that external communications with a peripheral device such as the security camera 1000 is operating normally. The function of the LED, Dl, can be changed by changing the microprocessor 310 software.

[00113] Yl, C3, and C4 form the clock oscillator circuit for the microprocessor

310. Yl is a crystal oscillator such as an HCM49-10.000MAJB-UT, 10 MHz oscillator by Citizen America. The oscillator serves as the timing reference for the microprocessor 310. Capacitors, C3 and C4, serve as optional load capacitance to the crystal.

[00114] The components U2, C 124, C 126, L74, C 125, and C 127 represent the DC to DC converter 250 of the instantiation of the present invention. U2 is a 3-terminal regulator, such as a μA78M05 by Texas Instruments, designed to step-down the voltage from VDC Out to +5 VDC. The components C 124, C 126, L74, C 125, and C 127 form a pi filter to provide enhanced noise suppression to the +5 VDC output from the regulator.

[00115] The component U3 represents the microprocessor 310 of the instantiation of the present invention. The microprocessor 310 of the instantiation of the present invention must have serial communication ports, parallel ports for direct processor interface, self-programmability meaning that the device can write to its own program memory spaces under direct software control, and built-in analog to digital conversion ports. A device meeting these characteristic requirements is the PICF6627 by Microchip Technology.

[00116] FIGURE 5c is a detailed schematic of the instantiation of the optional communication controller 290 of the controlling module. U4 is an Ethernet controller, such as the RTL8019AS by Realtek. The Ethernet controller, U4, will connect directly to the Ethernet communication port of the cable modem and also to the microprocessor 310 bus. Use of an Ethernet controller allows the present instantiation to use existing, commercially available cable modems such as the Webstar DPC2100R2 series cable modem from Scientific Atlanta. Optional light emitting diode circuits represented by Rl 9, D7, R20, D8, R21, and D9 allow visual indication of the link status, transmit activity, and receive activity for the Ethernet controller.

[00117] FIGURE 5d is a detailed schematic of the instantiation of the serial

TX/RX 370 function and the output connect 390. In the present instantiation, two output

connectors 390 are implemented. The serial TX/RX 370 function of the instantiation of the present invention translates TTL serial information into RS-232 signaling for transport to peripheral devices such as the security camera 1000. A device such as the LTl 38 ICS by Linear Technology will accomplish the requirements of the serial TX/RX 370 function. The output connectors 390 provide the necessary serial communication, analog signaling, digital bus connections, power, and ground to operate peripheral devices. The power signal, VDC Out, is connected to the output connector 390 through a positive temperature coefficient fuse, F2 and F3, to avoid damaging the controlling module 500 circuitry due to an over-current condition in a peripheral device.

[00118] FIGURE 5e through 5i is a detailed schematic of the instantiation of the filter module 1000 of the present device. Direct implementation of this instantiation would allow for the control of up to four service provisioning 1130 circuits. This instantiation also includes the programmable basic filter option.

[00119] FIGURE 5e is a detailed schematic of the instantiation of a service provisioning electronic channel. Jl of FIGURE 5e represents the input connector 1110 of FIGURE 3b. Jl in this instantiation of the invention is anticipated to be a printed circuit board mounted F connector with four ground connections and a single center conductor carrying the RF signal. The components Cl, C2, C3, Rl, R2, and R3 represent the signal splitter 1120. The capacitors, C1-C3, are anticipated to be ceramic capacitors capable of passing the RF signal while simultaneously acting as a DC block. The resistors, R1-R3, form a broadband resistive signal splitter which depending upon the values of Rl, R2, and R3 can provider the designer with a wide range of split ratios. For low-loss, Rl and R2 are designed to be small values of resistance. The low loss output of the signal splitter 1120 feeds a SP4T switch 1 131. A variety of semiconductor devices such as the Hittite Microwave HMC241QS16E may be used to implement the switch function. The components, C 15, C 16, C 17, C 18, C 19, C20, C26, C21, C22, C24, C25, LlO, LI l, L12, L13, L14, L15, L16, L17, and L18, represent a lumped element implementation of the digital spectrum filter 1 132. The components L13, L14, L15, L16, C21, C22, and C24 are designed to pass the low frequency portion of the digital spectrum

filter (approximately <50 MHz). The components C16, C17, C18, C19, LlO, LI l, and Ll 2 are designed to pass the high frequency portion of the digital spectrum filter (approximately >550 MHz). The components L17, L18, C25, and C26 are optional components forming notch filters to help sharpen the filter skirts or the remove a narrow portion of the in-band frequency spectrum from passing to the output. It should be noted that the number of poles in each filter may be required to be more or less than the given instantiation based upon the chosen filter type and customer requirements. The capacitor C29 acts as the through path 1 137 between the SP4T switches 1 131 and 1133. The capacitor C29 is anticipated to be a ceramic capacitor capable of passing the RF signal with very low loss while simultaneously acting as a DC block between the two switches. The components C27, C28, R7, and R8 represent the 75-ohm termination 1134 path. The capacitors C27 and C28 are anticipated to be ceramic capacitors capable of passing the RF signal with very low loss while acting as a DC block. The resistors, R7 and R8, are designed to be equal to the characteristic impedance of the cable network which is anticipated to be 75 ohms. The components C4, C5, C6, C7, C8, C9, ClO, CI l, C12, Cl 3, C14, Ll, L2, L3, L4, L5, L6, L7, L8, L9, Dl, D2, D3, R4, R5, and R6 represent the programmable basic filter 1135. The components C5, C6, C7, C8, Ll, L2, and L3 are designed to pass the high frequency portion of the basic cable spectrum (approximately > 535 MHz) to pass government access channels and the downstream internet band. The components L4, L5, L6, L7, C9, ClO, CI l ₅ Dl, D2, D3, R4, R5, and R6 are designed to implement the programmable low-pass filtering function. The components, Dl, D2, and D3, are anticipated to be varactors such as the SMV- 1253 by Skyworks. As the voltage present at the varactor cathode is altered, the device capacitance changes altering the frequency response of the filter. The capacitors C9, ClO, and CI l are placed in series with the varactors to give each varactor a slightly different tuning range allowing the designer to use a broad range of different filter architectures to implement the programmable low pass filter function. The resistors, R4-R6, are utilized to provide a high impedance path to the controlling digital to analog converter 1 136. It should be noted that the number of poles in each filter may be required to be more or less than the given instantiation based upon the chosen filter type and customer requirements. The components, L8, L9, C 12, and C 13, are optional components forming notch filters to help

sharpen the filter skirts or the remove a narrow portion of the in-band frequency spectrum from passing to the output. The optional quad digital to analog converter 1136 is used to translate a digital value into a voltage to presented to the cathode of the varactor diodes, D1-D3. The presented voltage will correspond to a given frequency response which in turn will determine the television channels filter out of the spectrum that will be presented at the device output. In this way, the optionally programmable basic cable filter 1 135 may be pre-programmed for a range of responses corresponding to a wide range of basic cable spectrums. This information may then be stored in memory in the filter module 1000 support electronics 1150. When the filter module 1000 is installed, the optionally programmable basic cable filter 1135 response is determined based upon provisioning information sent from the web-based software 10 to the controlling module 500. This provisioning information is then passed along from the controlling module 500 to each filter module 1000. The provisioning information includes the channel at which basic service is to be cutoff. This information is used as a 'look-up' address to the memory in the support electronics 1150 which contains the digital value for each service provisioning circuit 1 130. It should be noted that each of the optionally programmable basic cable filters 1 135 may be programmed for the same filter response in a given filter module 1000 or they may each be different allowing the cable company to expand the number of different basic cable services that it offers. The optional quad digital to analog converter 1136 must be capable of independently controlling the voltage to each service provisioning channel based upon microprocessor 1180 control. The AD5624 made by Analog Devices is one such component capable of implemented to the requirements of the quad digital to analog converter 1136 function. The output SP4T switch 1133, represented by U2, may be implemented by a variety of semiconductor devices such as the Hittite Microwave HMC241QS16E. Finally, the output F connector 1140, represented schematically be J2, is anticipated to be a printed circuit board mounted F connector with four ground connections and a single center conductor carrying the RF signal.

[00120] FIGURE 5f is a detailed schematic implementation of the optional RF power sensor 1 170 circuit and preceding SP4T switch 1 160. U9 represents the SP4T

switch used to present a portion of the input RF signal from the signal splitter 1 120 output to the optional RP power sensor 1170 based upon commands from the microprocessor 1180. The SP4T switch 1160, represented by U9, may be implemented by a variety of semiconductor devices such as the Hittite Microwave HMC241QS16E. The output of the SP4T switch 1 160 is input to the optional RP power sensor 1170 circuit to convert the RF signal into a voltage which is input to an analog to digital converter port on the microprocessor 1180. The digitized voltage is compared to a threshold level to determine the connectivity status of the filter module 1000 input cable for a given port. If the digitized voltage is greater than the threshold, the cable is assumed to be connected properly. If the digitized voltage is less than the threshold, the cable is assumed to be disconnected from the port or other problem with the filter module 1000 input. This condition results in an alarm condition which is sent to the controlling module 500 from the filter module 1000. The alarm condition would specify which port was alarming, the digitized voltage value, the time of the alarm, and other relevant information. The controlling module 500 would pass the information along to the web-based software 10 of FIGURE 1 to notify the cable operator of the condition. A device such as the LTC5507 by Linear Technology will implement the requirements of the optional RF power sensor for this application.

[00121] FIGURE 5g is a detailed schematic of the support electronics 1150, I/O connectors 1220 and 1230, and serial TX/RX 1 190 functions of the present invention. The serial TX/RX 1 190 function of the instantiation of the present invention translates TTL serial information into RS-232 signaling for transport to the controlling module 500 or other peripheral devices such as another filter module 1000. A device such as the LTl 38 ICS by Linear Technology will accomplish the requirements of the serial TX/RX 1190 function. The I/O connectors 1220 and 1230 provide the necessary serial communication, analog signaling, digital bus connections, power, and ground to communicate with the controlling module 500 or other peripheral devices. Ul 8 is a broad range precision temperature sensor whose output voltage is linearly proportional to the temperature, such as the LM34 by National Semiconductor. The temperature sensor device in this instantiation has an analog output whose voltage level is linearly

proportional to the Fahrenheit temperature and must be connected to one of the internal analog to digital converter inputs of the microprocessor 1 180. This instantiation has an advantage over linear temperature sensing circuits calibrated in degrees Kelvin in that a large constant voltage is not required to be subtracted from its output to obtain conventional Fahrenheit scaling. The capacitor, C 133, is a power supply de-coupling capacitor while the optional capacitor, C 139, may help enhances noise immunity on the analog signal line. The component J9 is used as a programming port to programming the non-volatile memory contained within the microprocessor 1180. The components R33, R34, and Dl 3 implement a light-emitting diode circuit which is programmed to be blinked on and off at a rate of approximately 1 Hz to allow a human being to ensure that the microprocessor 1 180 is up and running during test and troubleshoot operations.

[00122] FIGURE 5h is a detailed schematic of the DC to DC converter 1200 and

1210 functions of the present invention. U20, C142, C136, L75, C135, and C137 form the DC to DC converter 1210 for the digital electronic circuits. U20 is a 3-terminal regulator, such as a μA78M05 by Texas Instruments, designed to step-down the voltage from VDC Out to +5 VDC. The components C142, C136, L75, C135, and C137 form a pi filter to provide enhanced noise suppression to the +5 VDC output from the regulator. The components UI l, C125, C123, L74, C126, and C124 form the DC to DC converter 1200 for the RF circuitry. Separate converter circuits provide the advantage of minimization of digital switching noise corrupting the RF signal integrity. Finally, the components C121, Cl 19, C 122, C 120, and L73 form a pi circuit to filter the input +12V power signal.

[00123] FIGURE 5i is a detailed schematic of the microprocessor 1180 of the present invention. The component U14 represents the microprocessor 1180 of the instantiation of the present invention. The microprocessor 1180 of the instantiation of the present invention must have serial communication ports, parallel ports for direct processor interface, self-programmability meaning that the device can write to its own program memory spaces under direct software control, and built-in analog to digital

conversion ports. A device meeting these characteristic requirements is the PICF6627 by Microchip Technology.