This disclosure relates to service group aggregation.
A Data-Over-Cable Service Interface Specification (DOCSIS) system can be used to deliver high-definition digital entertainment and telecommunications such as video, voice, and high-speed Internet to subscribers over an existing cable television network. The cable television network can take the form of an all-coax, all-fiber, or hybrid fiber/coax (HFC) network. A multiple service operator (MSO) can deliver these services to subscribers by using cable modem termination systems (CMTSs) located at a headend or hub and customer premise equipment (CPE) devices located at subscriber premises. A CMTS routes traffic (e.g., data, video, and voice signals) to and from CPE devices on downstream and upstream channels, respectively. The CPE device can include cable modems (CMs), which can include embedded multimedia terminal adapters (eMTAs).
This disclosure generally describes DOCSIS-based network architectures that may conserve network components (e.g., including fiber, optical bandwidth, and headend components, among others) and/or can be more efficiently reconfigured to meet the changing demands of a network.
Various implementations of this disclosure form a chain of fiber nodes in a system (e.g., a DOCSIS-based system) to aggregate the service groups served by the fiber nodes to form a super-service group. Various implementations of this disclosure can also use multiple channels of a multiplexed data stream to transmit the signals from the super-service group. By forming a chain of fiber nodes and using multiple channels to transmit the signals from the super-service group, a DOCSIS system can be more efficiently reconfigured to segment a super-service group when the need arises. Thus, the fiber nodes of a super-service group can be separated into smaller segments.
As shown in
The fiber node 230 also includes an upstream optical transmitter that combines the electrical signals received from the CMs 220 in service group 260 and converts the resulting electrical signals to optical signals and transmits the optical signals upstream to the headend/hub 210 via the fiber 214.
In the headend/hub 210, a receiver 240 can operate to convert the upstream optical signals to electrical signals, which represents the electrically combined signals from the four ports 230a-d of the fiber node 230. The receiver 240 can then output these electrical signals 250 to one of its RF output ports.
Service group aggregation is a technique that can be used to expand the number of fiber nodes and thus CMs dedicated to a single receiver thereby, among other things, reducing the number of receivers needed in the headend/hub 210.
Referring to
More specifically, the optical signals 405(n) from the first fiber node 230(n) in the chain, which represent the combined signals from the CMs in service group 260(n) served by fiber node 230(n), are received by the next fiber node in the chain, i.e., fiber node 230(n−1). Fiber node 230(n−1) can extract the digital signals from the optical signals 405 received from fiber node 230(n) and combine them with the digital signals representing the combined signals from the CMs in service group 260(n−1). Fiber node 230(n−1) can then convert the resulting digital signals, which represent the combined signals from the CMs in service groups 260(n) and 260(n−1), to optical signals 405(n−1) and can transmit the optical signals to the next fiber node in the chain, i.e., fiber node 230(n−2). This process can be repeated up to the last fiber node 230(1) in the chain. The optical signals 405(1) output from fiber node 230(1), which represent the combined signals from the CMs in service groups 260(1), . . . , 260(n), are transmitted upstream via fiber 414 to a single receiver 440. In this way, the number of fiber nodes dedicated to a single receiver is increased thereby reducing the number of receivers needed in the headend/hub 210. From the headend/hub 210 perspective, there exists one super-service group 460 that includes all the CMs that are served by fiber nodes 230(1), . . . , 230(n). The receiver 440 can convert the upstream optical signals 405(1) to electrical signals 450 and output these signals to one of its RF output ports.
The capacity of a fiber link (for example, fiber link 414) in a network can become exhausted. There can be numerous reasons for the reduced capacity. For example, there can be an increase in the data rates of the CMs served by a fiber node(s) (e.g., CMs that are served by fiber nodes 230(1), . . . , 230(n)) that utilize the fiber link thereby reducing an upstream fiber link. As another example, there can be an increase in the delivery of expanded services, which results in more traffic to be transmitted over a fiber link. Node segmentation/splitting is a technique that can be used to expand the capacity of a network without using additional fiber.
Referring to
At the headend/hub 510, in a receiver 540′, a converter 570 can convert the optical signals to electrical signals 560′, which represent the multiplexed data stream 560. The resulting multiplexed data stream 560′ can be de-multiplexed by demultiplexer 575 into two electrical signals 530′ and 540′ representing electrical signal 530 and 540, respectively. The resulting electrical signals 530′ and 540′ can be further processed (e.g., by a digital-to-analog converter and amplifier) and then output to two separate RF output ports.
Thus, using node segmentation/splitting, the N cable modems in one service group (for example, service group 260 of
In a system including a super-service group as a result of service group aggregation, when the capacity of the upstream fiber link (e.g., fiber link 414 of
In view of the foregoing, it would be constructive to aggregate service groups in a DOCSIS system to form a super-service group, among other things, to use the capacity of receivers in the headend/hub more fully, while also planning for more efficiently reconfiguring the system to segment the super-service group once the system has become exhausted. Accordingly, it can be helpful to develop more efficient systems and methods to aggregate service groups to form a super-service group and to later segment/split the super-service group when the need arises.
Referring to
In some implementations, the resulting electrical signal 635a or 635b can be further processed (e.g., amplified, filtered, and/or digitized). In
Referring to
A receiver 620(n) can extract the digital signals from the optical signals 605(n+1) received from the previous fiber node 630(n+1). Demultiplexer 612(n) is operable to de-multiplex the digital signals 621 received from receiver 620(n) and can transmit the separate signals 637a, 637b on separate output ports corresponding to the different channels on which the demultiplexed signals 637a, 637b are to be transmitted.
The combiner 617(n) can receive as its input the output signals 637a, 637b from the demultiplexer 612(n) and the resulting electrical signals 635a or 635b from combiner 613(n). The inputs can be received on separate input ports based on the channel for which the input signals are to be transmitted. Thus, in the example of
The combiner 617(n) can include a separate output port for each channel for which a signal can be transmitted. The combiner 617(n) is operable to combine the signals received from different inputs for the same channel and can transmit the resulting signals 639a or 639b on an output port for the channel. Thus, combiner 617(n) combines the resulting signal 635a (if any), which is received on a CH1 input, with signal 637a (if any), which also is received on a CH1 input, and transmits a combined signal 639a on a CH1 output port. Similarly, combiner 617(n) combines the resulting signal 635b (if any), which is received on a CH2 input, with signal 637b (if any), which also is received on a CH2 input, and transmits a combined signal 639b on a CH2 output port.
In the example of
The output signals 639a, 639b from combiner 617(n) are multiplexed by a multiplexer 625(n) to produce a single multiplexed data stream 626. In some implementations, the multiplexer 625(n) can be a time division multiplexer (TDM).
Optical transmitter 628(n) then converts the multiplexed digital signals 626 to optical signals 605(n) to be transmitted to the next fiber node 630(n−1) in the chain or the headend/hub if fiber node 630(n) is the last fiber node in the chain (i.e., fiber node 630(1)).
Referring back to
Referring to
The receiver 620(3) can extract the digital signals from the optical signals 605(4) received from fiber node 630(4). Since the optical signals 605(4) received from fiber node 630(4) represent signals transmitted on CH1, demultiplexer 612(3) de-multiplexes the digital signals to produce output signals 637a, which are output on its CH1 output port. The output signals 637a represent the electrical signal from all the CMs in service group 660(4).
The combiner 617(3) can transmit signals 637a, which represents the electrical signals from all the CMs in service group 660(4), on its CH1 output port as output signal 639a. The combiner 617(3) can also transmit signal 635b, which represents the electrical signals from all the CMs in service group 660(3), on its CH2 output port as output signal 639b.
The output signals 639a (representing the electrical signal from all the CMs in service group 660(4)) and 639b (representing the electrical signals from all the CMs in service group 660(3)) from combiner 617(3) are multiplexed by a multiplexer 625(3) to produce a single multiplexed data stream 626. For example, the electrical signals from all the CMs in service group 660(4) (e.g., output signal 639a(3)) can be allocated to a first TDM channel representing CH1, and the electrical signals from all the CMs in service group 660(3) (e.g., output signal 639b(3)) can be allocated to a second TDM channel representing CH 2.
The optical transmitter 628(3) can then convert the multiplexed digital signals 626 to optical signals 605(3) to be transmitted to fiber node 630(2).
In fiber node 630(2), combiner 613(2) receives the electrical signals from all the CMs in service group 660(2) at its CH1 input port and combines these electrical signals to produce a resulting electrical signal 635a that is output on its CH1 output port.
The receiver 620(2) can extract the digital signals from the optical signals 605(3) received from fiber node 630(3). Since the optical signals 605(3) received from fiber node 630(3) represent signals transmitted on CH1 and CH2, demultiplexer 612(2) de-multiplexes the digital signal to produce output signals 637a (representing the electrical signals from all the CMs in service group 660(4)), which are transmitted on its CH1 output port and output signals 637b (representing the electrical signals from all the CMs in service group 660(3)), which are transmitted on its CH2 output port.
The combiner 617(2) can combine signal 635a, which represents the electrical signals from all the CMs in service group 660(2), with signal 637a, which represents the electrical signals from all the CMs in service group 660(4), and transmit the combined signal 639a on CH1 output port. Combiner 617(2) can transmit signal 637b, which represents the electrical signals from all the CMs in service group 660(3), on its CH2 output port as output signal 639b.
The output signals 639a (representing the electrical signal from all the CMs in service group 660(2) and service group 660(4)) and 639b (representing the electrical signals from all the CMs in service group 660(3)) from combiner 617(2) are multiplexed by a multiplexer 625(2) to produce a single multiplexed data stream 626. For example, the electrical signals from all the CMs in service groups 660(2) and 660(4) (i.e., output signal 639a) can be allocated to a first TDM channel representing CH1, and the electrical signals from all the CMs in service group 660(3) (i.e., output signal 639b) can be allocated to a second TDM channel representing CH2.
The optical transmitter 628(2) can then convert the multiplexed digital signals 626 to optical signals 605(2) to be transmitted to fiber node 630(1).
In fiber node 630(1), combiner 613(1) can receive electrical signals from all the CMs in service group 660(1) at its CH2 input port the and can combine these electrical signals to produce a resulting electrical signal 635b that is output on its CH2 output port.
The receiver 620(1) extracts the digital signals from the optical signals 605(2) received from fiber node 630(2). Since the optical signals 605(2) received from fiber node 630(2) represent signals transmitted on CH1 and CH2, demultiplexer 612(1) can de-multiplex the digital signal to produce output signals 637a (representing the electrical signals from all the CMs in service groups 660(2) and 660(4)), which are transmitted on its CH1 output port and output signal 637b (representing the electrical signals from all the CMs in service group 660(3)), which are transmitted on its CH2 output port.
Combiner 617(1) can transmit signal 637a, which represents the electrical signals from all the CMs in service groups 660(2) and 660(4), on its CH1 output port as output signal 639a. Combiner 617(1) can combine signal 635b, which represents the electrical signals from all the CMs in service group 660(1), with signal 637b, which represents the electrical signals from all the CMs in service group 660(3), and output the combined signal 639b on its CH2 output port.
The output signals 639a (representing the electrical signals from all the CMs in service groups 660(2) and 660(4)) and 639b (representing the electrical signals from all the CMs in service groups 660(1) and 660(3)) from combiner 617(1) can be multiplexed by a multiplexer 625 to produce a single multiplexed data stream 626. For example, the electrical signals from all the CMs in service groups 660(2) and 660(4)(i.e., output signal 639a(1)) can be allocated to a first TDM channel representing CH1, and the electrical signals from all the CMs in service groups 660(1) and 660(3) (i.e., output signal 639b(3)) can be allocated to a second TDM channel representing CH2.
The optical transmitter 628(1) can then convert the multiplexed digital signals 626 to optical signals 605(1) to be transmitted upstream via fiber 614 to a single receiver 640 at the headend/hub 610.
Referring to
By forming a chain of fiber nodes to aggregate the service groups served by the fiber nodes to form a super-service group and using multiple channels to transmit the signals from the CMs in the super-service group, a DOCSIS system can be more efficiently reconfigured to segment a super-service group once the system has become exhausted by, for example, changing a control signal in the receiver.
Generally, in the example system 800 of
More specifically, the fiber node 830(1) can receive an optical signal 805(2) from fiber node 830(2) representing electrical signals from all the CMs in service group 860(3) transmitted on CH1 and electrical signals from all the CMs in service group 860(2) transmitted on CH2. The fiber node 830(1) can also receive an optical signal 805(4) from fiber node 830(4), the optical signal 805(4) representing electrical signals for all the CMs in service group 860(4) transmitted on CH2.
The receiver 820A can extract the digital signals from the optical signals 805(2) received from fiber node 830(2). Because the optical signals 805(2) received from fiber node 830(2) represent signals transmitted on CH1 and CH2, demultiplexer 812A de-multiplexes the digital signal to produce output signals 837Aa (representing the electrical signals from all the CMs in service group 860(3)), which are output on the its CH1 output port and output signals 837Ab (representing the electrical signals from all the CMs in service group 860(2)), which are output on its CH2 output port.
The receiver 820B can extract the digital signals from the optical signals 805(4) received from fiber node 830(4). Because the optical signals 805(4) received from fiber node 830(4) can represent multiple signals transmitted on CH2, demultiplexer 812 de-multiplexes the digital signals to produce output signals 837Bb, which are output on its CH2 output port. The output signals 837Bb represent the electrical signal from all the CMs in service group 860(4).
The combiner 817 can combine signal 835a, which represents the electrical signals from all the CMs in service group 860(1), with signal 837Aa, which represents the electrical signals from all the CMs in service group 860(3), and transmit the combined signal 839a on a CH1 output port. The combiner 817 can also combines signal 837Ab, which represents the electrical signals from all the CMs in service group 860(2), with signal 837Bb, which represents the electrical signals from all the CMs in service group 860(4), and transmit the combined signal 839b on a CH2 output port.
The output signals 839a (representing the electrical signal from all the CMs in service group 860(1) and service group 860(3)) and 839b (representing the electrical signals from all the CMs in service group 860(2) and service group 860(4)) from combiner 817 are multiplexed by a multiplexer 825 to produce a single multiplexed data stream 826. For example, the electrical signals from all the CMs in service groups 860(1) and 860(3) (e.g., output signal 839a) can be allocated to a first TDM channel representing CH1, and the electrical signals from all the CMs in service group 860(2) and 860(4) (e.g., output signal 839b) can be allocated to a second TDM channel representing CH2.
The optical transmitter 828 can then convert the multiplexed digital signals 826 to optical signals 805(1) to be transmitted upstream via fiber 814 to a single receiver 840 at the headend/hub 810.
Referring to
At stage 1105, a chain of N=4 fiber nodes is formed. As shown in
At stage 1110, at each fiber node, a multiplexed data stream is formed. At each fiber node, the multiplexed data stream includes traffic from the service group served by the fiber node and traffic from the service groups served by the fiber nodes preceding the fiber node, if any, in the chain. At each fiber node, the multiplexed data stream can include at least two channels and traffic from each of the service groups included in the multiplexed data stream can be included in a designated one of the at least two channels of the multiplexed data stream.
For example, in the example implementation of
As discussed above, in fiber node 630(4), a multiplexed signal that includes traffic from service group 630(4) can be generated. More specifically, as discussed above, in fiber node 630(4), a multiplexed signal can be generated where the electrical signals from all the CMs in service group 660(4) can be allocated to a first TDM channel representing CH1. In fiber node 630(3), a multiplexed signal can be generated that includes traffic from service groups 630(3) and 630(4). More specifically, as discussed above, in fiber node 630(3), a multiplexed signal can be generated where the electrical signals from all the CMs in service group 660(4) can be allocated to a first TDM channel representing CH1, and the electrical signals from all the CMs in service group 660(3) can be allocated to a second TDM channel representing CH 2. In fiber node 630(2), a multiplexed signal can be generated that includes traffic from service groups 630(2), 630(3), and 630(4). More specifically, as discussed above, in fiber node 630(2), a multiplexed signal can be generated where the electrical signals from all the CMs in service groups 660(2) and 660(4) can be allocated to a first TDM channel representing CH1, and the electrical signals from all the CMs in service group 660(3) can be allocated to a second TDM channel representing CH2. In fiber node 630(1), a multiplexed signal can be generated that includes traffic from service groups 630(1), 630(2), 630(3), and 630(4). More specifically, as discussed above, in fiber node 630(1), a multiplexed signal can be generated where the electrical signals from all the CMs in service groups 660(2) and 660(4) can be allocated to a first TDM channel representing CH1, and the electrical signals from all the CMs in service groups 660(1) and 660(3) can be allocated to a second TDM channel representing CH2.
At stage 1115, at each fiber node, except the last fiber node in the chain, the multiplexed data stream generated in the fiber node is transmitted to the next fiber node in the chain.
For example, in the implementation of
The processes and logic flows described in this specification are performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output thereby tying the process to a particular machine (e.g., a machine programmed to perform the processes described herein). The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).
Computer readable media suitable for storing computer program instructions and data include all forms of non volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.
To provide for interaction with a user, embodiments of the subject matter described in this specification can be operable to interface with a computing device having a display, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer.
While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.
Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.
Particular embodiments of the subject matter described in this specification have been described. Other embodiments are within the scope of the following claims. For example, the actions recited in the claims can be performed in a different order and still achieve desirable results, unless expressly noted otherwise. As one example, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some implementations, multitasking and parallel processing may be advantageous.