FREQUENCY BANDS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 62/084,091 entitled "CATV NETWORK INTERFACE ΙΙΝΓΓ WETF! SELECTABLE

UPSTREAM/DOWNSTREAM FREQUENCY BANDS" filed on November 25, 2014, and which is hereby incorporated by reference in its entirety.

BACKGROUND

[0002] Typically when a CATV operator wants to change the upstream/downstream frequency plan/band, all amplifiers need to be replaced or reconfigured. The network interface unit (NIU) is a small amplifier in an end user premise. When the upstream/downstream frequency plan changes, the existing NIU is typically replaced with a new one configured for the new upstream/downstream frequency band.

SUMMARY

[0003] The Embodiments of the present invention provide an enhanced network interface unit and will be understood by reading and studying the following specification.

[0004] In one embodiment, a network interface unit comprises: at least one network connector configured to receive signals from and send signals to a cable television (CATV) headend; a first diplexer comprising a first high pass filter and a first low pass filter, each having a respective cut off frequency configured for a first upstream/downstream radio frequency (RF) band; a second diplexer comprising a second high pass filter and a second low pass filter, each having a respective cut off frequency configured for a second upstream/downstream RF band; a third diplexer comprising a third high pass filter and a third low pass filter, each having a respective cut off frequency; a cable modem port configured to output downstream RF signals received from the a third high pass filter to a cable modem and to output upstream RF signals received from the cable modem to the third low pass filter; a coupling device configured to couple either the first high pass filter or the second high pass filter to the third high pass filter, the coupling device further configured to couple the third low

DRAWINGS

[0005] Understanding that the drawings depict only exemplary embodiments and are not therefore to be considered limiting in scope, the exemplary embodiments will be described with additional specificity and detail through the use of the accompanying drawings, in which:

[0006] Figure 1 is a high level block diagram of one embodiment of an exemplary enhanced network interface unit.

[0007] Figure 2 is a high level block diagram of another embodiment of an exemplary enhanced network interface unit.

[0008] Figure 3 is a high level block diagram of another embodiment of an exemplary enhanced network interface unit.

[0009] Figure 4 is a high level block diagram of another embodiment of an exemplary enhanced network interface unit.

[0010] Figure 5 is a block diagram of one embodiment of an exemplary CATV network utilizing enhanced network interface units.

[0011] In accordance with common practice, the various described features are not drawn to scale but are drawn to emphasize specific features relevant to the exemplary embodiments.

DETAILED DESCRIPTION

[0012] In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific illustrative embodiments. However, it is to be understood that other embodiments may be utilized and that logical, mechanical, and electrical changes may be made. Furthermore, the method presented in the drawing figures and the specification is not to be construed as limiting the order in which the individual steps may be performed. The following detailed description is, therefore, not to be taken in a limiting sense. [0013] The embodiments described below enable an enhanced network interface unit to selectively utilize one of two or more frequency bands. Furthermore, the exemplary enhanced network interface units described herein enable selection of the radio frequency (RF) band via action by an end user without the need for a technician to visit the end user premises.

[0014] Figure 1 is high level block diagram of one embodiment of an exemplary enhanced network interface unit (NIU) 100. As used herein, an enhanced network interface unit is a CATV network interface unit with selectable upstream/downstream frequency bands.

Furthermore, as used herein downstream refers to a communication direction from a CATV headend toward an end user premise and upstream refers to a communication direction from the customer user premise toward the CATV headend. Thus, an upstream path refers to the components coupled together to communicate signals in the upstream direction and a downstream path refers to the components coupled together to communicate signals in the downstream direction.

[0015] In the example shown in Figure 1 , the enhanced NIU 100 includes two network connectors 102-1 and 102-2. As used herein, network connectors are connectors that communicatively couple the NIU 100 to a CATV network. In particular, in this example, network connectors 102-1 and 102-2 are implemented as coaxial RF connectors, such as female F-connectors configured to mate with a corresponding male F-connector. Such connectors are known to one of skill in the art and not discussed in further detail herein. Each connector 102-1 and 102-2 is associated with a respective upstream/downstream RF band. For example, in this exemplary embodiment, connector 102-1 is associated with an RF band having a downstream spectrum of approximately 87.5 MHz to approximately 1200 MHz and an upstream spectrum of approximately 15 MHz to approximately 65 MHz. Connector 102-2, in this exemplary embodiment, is associated with an RF band having a downstream spectrum of approximately 250 MHz to approximately 1200 MHz and an upstream spectrum of approximately 15 MHz to approximately 200 MHz. However, it is to be understood that other frequency spectrums can be used for the respective upstream/downstream RF bands in other embodiments.

[0016] The enhanced NIU 100 also includes two diplexers 104-1 and 104-2. Each of the diplexers 104-1 and 104-2 corresponds to a respective one of the connectors 102-1 and 102-2 and is configured for the associated upstream/downstream RF band. For example, in this exemplary embodiment, the high pass filter 108-1 in diplexer 104-1 has a cut off frequency of approximately 87.5 MHz (i.e. frequencies above 87.5 MHz are passed) and the low pass filter 110-1 has a cut off frequency of approximately 65 MHz (i.e. frequencies below 65 MHz are passed). Similarly, the high pass filter 108-2 in diplexer 104-2 has a cut off frequency of approximately 250 MHz and the low pass filter 110-2 has a cut off frequency of approximately 200 MHz.

[0017] Coupled to the diplexers 104-1 and 104-2 is a coupling device 112. In this embodiment the coupling device is implemented as a combiner/coupler 112. The combiner/coupler 112 includes a passive combiner 114 configured to combine the output of high pass filter 108-1 with the output of high pass filter 108-2. The combiner/coupler 112 also includes a passive splitter 1 16 configured to split an upstream signal to be output to both the low pass filter 1 10-1 and 1 10- 2. In the downstream direction, the output of the passive combiner 114 is amplified by an amplifier 118. Suitable amplifiers for amplifying the downstream RF signal are known to one of skill in the art. The amplified downstream RF signal is then split in splitter 120. The splitter 120 outputs the amplified signal to a splitter 122 and to a diplexer 124.

[0018] The splitter 122 provides a copy of the downstream RF signal to each of splitters 132 and 134. Splitter 132 splits the received downstream RF signal to provide a copy of the downstream RF signal to each of connectors 136 and 138. Similarly, the splitter 134 splits the received downstream RF signal to provide a copy of the downstream RF signal to each of connectors 140 and 142. Connectors 136, 138, 140, and 142 (also referred to herein as distributive ports) are each implemented as coaxial RF connectors similar to connectors 102-1 and 102-2. The connectors 136, 138, 140, and 142 provide ports for distribution of the downstream signal to multiple devices at the end user premise. It is to be understood that the splitters 122, 132, and 134 can be implemented using passive RF splitters. Each splitter is selected/configured to keep signal loss within a predetermined maximum value, as known to one of skill in the art.

[0019] The diplexer 124 includes a high pass filter 126 and a low pass filter 128. In some embodiments, the diplexer 124 is configured similarly to one of the diplexers 104-1 or 104-2. For example, in this exemplary embodiment, the high pass filter 126 has a cut off frequency of approximately 250 MHz and the low pass filter 128 has a cut off frequency of approximately 200 MHz, similar to the diplexer 104-2. In other embodiments, the diplexer 124 is configured differently than both of diplexers 104-1 and 104-2. The diplexer 124 outputs the downstream RF signal received from the splitter 120 to a connector 130 (also referred to herein as a cable modem port). The connector 130 is configured to couple the enhanced NIU 100 to a cable modem via a respective cable. In some embodiments, the connector 130 is also a coaxial RF connector similar to connectors 102-1 and 102-2.

[0020] In the upstream direction, a signal received from the cable modem over the connector 130, is provided to the low pass filter 128 of diplexer 124. The upstream signals are passed from the diplexer 124 to the passive splitter 1 16 in the combiner/coupler 112 which splits the upstream signal to be provided to the diplexers 104-1 and 104-2. Hence, in this exemplary embodiment, an end user can select the upstream/downstream RF frequency band by choosing which connector 102-1 or 102-2 in which to insert the coaxial cable that receives a signal from a CATV headend. Since the enhanced NIU 100 is configured to support two upstream/downstream RF frequency bands, a technician is not needed to re-configured or replace the NIU in order to change the RF frequency bands used. It is to be understood that the NIU 100 can include other components not shown. For example, in some embodiments an amplifier similar to amplifier 118 can be included in the upstream path between low pass filter 128 and coupling device 112.

[0021] Figure 2 is a high level block diagram of another embodiment of an exemplary enhanced NIU 200. The enhanced NIU 200 is similar to the enhanced NIU 100 discussed above.

However, in lieu of the passive combiner/coupler 112 discussed above, the coupling device in the enhanced NIU 200 is implemented as an RF switch 250. In this embodiment, the RF switch 250 comprises two single -pull/double-throw switches 251-1 and 251-2. However, in other embodiments a single double -pull/double-throw switch can be used. Suitable switches for use in implementing the RF switch 250 include, but are not limited to, the PE42421 , the PE42721, the PE42722, and the PE42750 UltraCMOS® RF switches manufactured by Peregrine

Semiconductor.

[0022] In this exemplary embodiment, the enhanced NIU 200 includes detection circuits 252-1 and 252-2 which are configured to detect insertion of a coaxial RF connector into the respective connectors 102-1 and 102-2. For example, the circuits 252-1 and 252-2 can be configured to detect the electrical connection when the coaxial RF connector of a network cable is inserted, such as through use of an internally shorted F connector as opposed to the conventional external terminating resistor. When insertion of the coaxial RF connector is detected, the respective circuit 252-1 or 252-2 actuates the switch 250 to couple the corresponding diplexer 104-1 or 104-2 to the upstream and downstream paths. Thus, an end user can select the

upstream/downstream RF frequency band and actuate the switch 250 by changing the connector 102-1 or 102-2 to which the coaxial cable is connected. In other embodiments, however, the switch 250 is switched through user manipulation of a mechanical actuator, such as, but not limited to, a sliding switch, a push button, etc. In addition, although two separate detection circuits 252-1 and 252-2 are shown in this example, it is to be understood that a single detection circuit coupled to both network connectors 102-1 and 102-2 can be used in other embodiments.

[0023] The use of the switch 250 in lieu of the passive coupler/combiner 112 used in enhanced NKJ 100 can provide some performance benefits. For example, the switch 250 can provide better noise and/or gain performance than the combiner/coupler 112. In particular, the specific switch selected to implement switch 250 may cause less signal loss than the passive

combiner/coupler 112 and the combination of the switch 250 with the amplifier 118 may have better noise performance than the combination of the passive combiner/coupler 112 with the amplifier 118.

[0024] Figure 3 is a high level block diagram of another embodiment of an exemplary enhanced NKJ 300. The enhanced NIU 300 also includes a passive combiner/coupler 112 similar to the enhanced NIU 100 discussed above. However, the enhanced NIU 300 utilizes a single network connector 360 for all of the selectable upstream/downstream RF bands rather than individual coaxial RF connectors corresponding to a respective one of the upstream/downstream RF bands as is described above with respect to the enhanced NIU 100.

[0025] In order to select the desired upstream/downstream RF band, an end user can mechanically actuate a switch 362 through manipulation of a mechanical actuator 363. The switch 362 is coupled between the connector 360 and the respective diplexers 104-1 and 104-2. By actuating the switch 362, the diplexer configured for the desired upstream/downstream RF frequency band is coupled to the connector 360. Thus, an end user is able to select the desired upstream/downstream RF frequency band without disconnecting and reconnecting a coaxial cable and without a technician visit to reconfigure or replace the enhanced NIU 300. The switch 362 can be implemented using a suitable RF switch, such as those mentioned above. [0026] Figure 4 is a high level block diagram of another embodiment of an exemplary enhanced NIU 400. Similar to the enhanced NIU 300 discussed above, the enhanced NIU 400 also includes a single RF network connector 360. However, in place of the passive combiner/coupler 112 used in the enhanced NIUs 300 and 100, the enhanced NIU 400 implements a switch 250 similar to the enhanced NIU 200 discussed above.

[0027] In some embodiments, manipulation of the same mechanical actuator 363 switches both the switch 250 and the switch 362. For example, the same sliding switch, toggle switch, or push button can be used to switch both switch 250 and switch 362 simultaneously. In other embodiments, separate mechanical actuators are used to switch the switch 250 independently of switch 362.

[0028] Figure 5 is a block diagram of an exemplary CATV network 500 utilizing one or more enhanced network interface units such as the enhanced NIUs discussed above with respect to Figures 1-4. The network 500 includes a CATV headend 501. The CATV headend 501 includes a Cable Modem Termination System (CMTS) 503, a Public Switched Telephone Network (PSTN) gateway 505, and an RF combiner 513. The PSTN gateway 505 is coupled to the public switched telephone network 509 and the CMTS 503 is coupled to a wide area network, such as the internet 511. Downstream real time communication signals from the PSTN 509 are received at the PSTN gateway 505 and communicated to the CMTS 503. The CMTS 503 combines the signals from the PSTN gateway 505 with downstream data signals from the internet 511 and outputs the combined signals to the RF combiner 513. The RF combiner 513 combines the signals from the CMTS 503 with television (TV) program feeds. The TV program feeds can be obtained from a satellite, antenna, or terrestrial distribution system, as known to one of skill in the art.

[0029] The combined RF signal from the RF combiner 513 is communicated over a network 515 to end user premises 517. The network 515 can be implemented using suitable physical layer cabling, such as but not limited to, fiber optic cables and copper cables. The downlink signals are distributed to the end user premises 517 using techniques known to one of skill in the art. In particular, the RF signals are communicated over a predetermined downlink frequency band.

[0030] Each of the enhanced NIUs 521 are configured to support more than one downlink frequency band. As discussed above, an end user can selectively choose the downlink frequency band. For example, an operator may increase the downstream RF band to provide more bandwidth and/or shift the downstream RF band to accommodate an increased corresponding upstream RF band. An end user can selectively switch the upstream/downstream RF bands in response to the changed RF bands, as discussed above. In conventional systems, a technician would have to replace or reconfigure the NIU to accommodate the change in

upstream/downstream RF bands. However, through the use of the enhanced NIUs discussed above, the switch in RF frequency bands can be made through simple action by the end user, such as by changing the port or actuating a switch. Thus, the enhanced NIUs described herein can facilitate updates or changes to a network, such as transitioning from Data Over Cable Service Interface Specification (DOCSIS) 3.0 to DOCSIS 3.1, for example.

[0031] The enhanced NIUs 521 can provide downstream signals to multiple devices. For example, the enhanced NIUs 521 can provide downstream TV programming to television sets 531 and downstream data signals to a cable modem 523. The cable modem, in turn, can communicate signals to one or more end user devices 525, such as, but not limited to, an internet protocol (IP) phone, a computer, wireless devices, etc. In addition, upstream signals from the one or more end user devices 525 are sent upstream via the cable modem 523 and the enhanced NIU 521. At the cable headend 501, the CMTS 503 and PSTN gateway 505 direct the upstream signals to the PSTN 509 or internet 511 accordingly, using techniques known to one of skill in the art.

EXAMPLE EMBODIMENTS

[0032] Example 1 includes a network interface unit, the network interface unit comprising: at least one network connector configured to receive signals from and send signals to a cable television (CATV) headend; a first diplexer comprising a first high pass filter and a first low pass filter, each having a respective cut off frequency configured for a first upstream/downstream radio frequency (RF) band; a second diplexer comprising a second high pass filter and a second low pass filter, each having a respective cut off frequency configured for a second

upstream/downstream RF band; a third diplexer comprising a third high pass filter and a third low pass filter, each having a respective cut off frequency; a cable modem port configured to output downstream RF signals received from the a third high pass filter to a cable modem and to output upstream RF signals received from the cable modem to the third low pass filter; a coupling device configured to couple either the first high pass filter or the second high pass filter to the third high pass filter, the coupling device further configured to couple the third low pass filter to at least one of the first low pass filter and the second low pass filter.

[0033] Example 2 includes the network interface unit of example 1 further comprising an amplifier coupled between the coupling device and the third high pass filter, the amplifier configured to amplify downstream RF signals from the coupling device.

[0034] Example 3 includes the network interface unit of example 2 further comprising one or more distributive ports coupled to an output of the amplifier and configured to output downstream RF signals received at the network interface unit from the CATV headend.

[0035] Example 4 includes the network interface unit of any of examples 1 -3, wherein the at least one network connector comprises a first network connector and a second network connector; wherein the first network connector is coupled to the first diplexer and the second network connector is coupled to the second diplexer; wherein the coupling device includes a passive combiner configured to couple the first high pass filter and the second high pass filter to the third high pass filter, the passive combiner further configured to couple the third low pass filter to the first low pass filter and to the second low pass filter.

[0036] Example 5 includes the network interface unit of any of examples 1 -4, wherein the at least one network connector comprises a first network connector and a second network connector; wherein the first network connector is coupled to the first diplexer and the second network connector is coupled to the second diplexer; wherein the coupling device comprises at least one switch configured to selectively couple one of the first high pass filter and the second high pass filter to the third high pass filter, the at least one switch further configured to selectively couple the third low pass filter to one of the first low pass filter and the second low pass filter.

[0037] Example 6 includes the network interface unit of example 5, further comprising: a first detection circuit coupled to the first network connector and configured to cause the at least one switch to couple the first high pass filter to the third high pass filter and to couple the third low pass filter to the first low pass filter upon detecting an insertion of a network cable in the first network connector; and a second detection circuit coupled to the second network connector and configured to cause the switch to couple the second high pass filter to the third high pass filter and to couple the third low pass filter to the second low pass filter upon detecting an insertion of a network cable in the first network connector.

[0038] Example 7 includes the network interface unit of any of examples 5-6, further comprising a mechanical actuator configured to cause the at least one switch to be selectively coupled to one of the first diplexer and the second diplexer based on user manipulation of the mechanical actuator.

[0039] Example 8 includes the network interface unit of any of examples 1-7, wherein the at least one network connector comprises a single network connector; wherein the network interface unit further comprises: a switch coupled to the single network connector, the switch configured to selectively couple the single network connector to either the first diplexer or the second diplexer; wherein the coupling device is a passive combiner configured to couple the first high pass filter and the second high pass filter to the third high pass filter, the passive combiner further configured to couple the third low pass filter to the first low pass filter and to the second low pass filter.

[0040] Example 9 includes the network interface unit of any of examples 1-8, wherein the at least one network connector comprises a single network connector; wherein the CATV network interface unit further comprises: a first switch coupled to the single network connector, the first switch configured to selectively couple the single network connector to one of the first diplexer and the second diplexer; wherein the coupling device comprises at least one second switch configured to selectively couple one of the first high pass filter and the second high pass filter to the third high pass filter, the at least one second switch further configured to selectively couple the third low pass filter to one of the first low pass filter and the second low pass filter.

[0041] Example 10 includes the network interface unit of example 9, wherein both the first switch and the at least one second switch are actuated based on user manipulation of a single mechanical actuator.

[0042] Example 1 1 includes the network interface unit of any of examples 1-10, wherein the cut off frequency for the first high pass filter is approximately 87.5 MHz, the cut off frequency for the first low pass filter is approximately 65 MHz, the cut off frequency for the second high pass filter is approximately 250 MHz, and the cut off frequency for the second low pass filter is approximately 200 MHz. [0043] Example 12 includes the network interface unit of example 1 1, wherein the cut off frequency for the third high pass filter is approximately 250 MHz and the cut off frequency for the third low pass filter is approximately 200 MHz.

[0044] Example 13 includes a cable television (CATV) network, the network comprising: a CATV headend comprising a cable modem termination system (CMTS) coupled to a wide area network and an RF combiner configured to combine downstream signals from the CMTS with downstream television program feeds; and a plurality of network interface units

communicatively coupled to the CATV headend, each of the plurality of network interface units located in a respective end user premise; wherein at least one of the plurality of network interface units is an enhanced network interface unit configured to selectively switch between a first signal path comprising a first diplexer, and a second signal path comprising a second diplexer based on an input to the at least one of the plurality of network interface units, wherein the first diplexer and second diplexer are configured to pass different upstream/downstream frequency bands.

[0045] Example 14 includes the network of example 13, wherein the at least one enhanced network interface unit comprises: at least one network connector configured to receive signals from and send signals to the CATV headend; the first diplexer comprising a first high pass filter and a first low pass filter, each having a respective cut off frequency configured for a first upstream/downstream radio frequency (RF) band; the second diplexer comprising a second high pass filter and a second low pass filter, each having a respective cut off frequency configured for a second upstream/downstream RF band; a third diplexer comprising a third high pass filter and a third low pass filter, each having a respective cut off frequency; a cable modem port configured to output downstream RF signals received from the a third high pass filter to a cable modem and to output upstream RF signals received from the cable modem to the third low pass filter; a coupling device configured to couple either the first high pass filter or the second high pass filter to the third high pass filter, the coupling device further configured to couple the third low pass filter to at least one of the first low pass filter and the second low pass filter.

[0046] Example 15 includes the network of example 14 further comprising an amplifier coupled between the coupling device and the third high pass filter, the amplifier configured to amplify downstream RF signals from the coupling device. [0047] Example 16 includes the network of example 15 further comprising one or more distributive ports coupled to an output of the amplifier and configured to output downstream RF signals received at the network interface unit from the CATV headend.

[0048] Example 17 includes the network of any of examples 14-16, wherein the at least one network connector comprises a first network connector and a second network connector; wherein the first network connector is coupled to the first diplexer and the second network connector is coupled to the second diplexer; wherein the coupling device includes a passive combiner configured to couple the first high pass filter and the second high pass filter to the third high pass filter, the passive combiner further configured to couple the third low pass filter to the first low pass filter and to the second low pass filter.

[0049] Example 18 includes the network of any of examples 14-17, wherein the at least one network connector comprises a first network connector and a second network connector; wherein the first network connector is coupled to the first diplexer and the second network connector is coupled to the second diplexer; wherein the coupling device comprises at least one switch configured to selectively couple one of the first high pass filter and the second high pass filter to the third high pass filter, the at least one switch further configured to selectively couple the third low pass filter to one of the first low pass filter and the second low pass filter.

[0050] Example 19 includes the network of example 18, further comprising: a first detection circuit coupled to the first network connector and configured to cause the at least one switch to couple the first high pass filter to the third high pass filter and to couple the third low pass filter to the first low pass filter upon detecting an insertion of a network cable in the first network connector; and a second detection circuit coupled to the second network connector and configured to cause the switch to couple the second high pass filter to the third high pass filter and to couple the third low pass filter to the second low pass filter upon detecting an insertion of a network cable in the first network connector.

[0051] Example 20 includes the network of any of examples 18-19, further comprising a mechanical actuator configured to cause the at least one switch to be selectively coupled to one of the first diplexer and the second diplexer based on user manipulation of the mechanical actuator.

[0052] Example 21 includes the network of any of examples 14-20, wherein the at least one network connector comprises a single network connector; wherein the network interface unit further comprises: a switch coupled to the single network connector, the switch configured to selectively couple the single network connector to either the first diplexer or the second diplexer; wherein the coupling device is a passive combiner configured to couple the first high pass filter and the second high pass filter to the third high pass filter, the passive combiner further configured to couple the third low pass filter to the first low pass filter and to the second low pass filter.

[0053] Example 22 includes the network of any of examples 14-21 , wherein the at least one network connector comprises a single network connector; wherein the CATV network interface unit further comprises: a first switch coupled to the single network connector, the first switch configured to selectively couple the single network connector to one of the first diplexer and the second diplexer; wherein the coupling device comprises at least one second switch configured to selectively couple one of the first high pass filter and the second high pass filter to the third high pass filter, the at least one second switch further configured to selectively couple the third low pass filter to one of the first low pass filter and the second low pass filter.

[0054] Example 23 includes the network of example 22, wherein both the first switch and the at least one second switch are actuated based on user manipulation of a single mechanical actuator.

[0055] Example 24 includes the network of any of examples 14-23, wherein the cut off frequency for the first high pass filter is approximately 87.5 MHz, the cut off frequency for the first low pass filter is approximately 65 MHz, the cut off frequency for the second high pass filter is approximately 250 MHz, and the cut off frequency for the second low pass filter is

approximately 200 MHz.

[0056] Example 25 includes the network of any of examples 14-24, wherein the cut off frequency for the third high pass filter is approximately 250 MHz and the cut off frequency for the third low pass filter is approximately 200 MHz.

[0057] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiments shown. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.