Integrated service network-building method and integrated service light station equipment based on the HFC broadband network
The present invention relates to integrated service cut-in method and equipment based on broadcasting and TV HFC net, be specifically related to a kind of cable TV network optical node place of being installed on, be used for the integrated service light station of cable TV network TV signal opto-electronic conversion and IP wideband data opto-electronic conversion and data retransmission.
Cable TV network adopts the network configuration form of HFC (Hybrid Fiber Coaxial).The cable TV network broadband technology refers to based on the hfc plant structure, adopt DOCSIS (Data Over Cable Service InterfaceSpecification) standard, use the equipment such as CM (Cable Modem cable modem), CMTS (Cable ModemTermination System cable modem CMTS) that the internet is accessed in the HFC cable TV network, thereby a technology of broadband network services is provided to the cable TV network user.HFC is comprised of headend room, fiber optic backbone and coaxial cable distribution net three parts usually.The Headend machine room mixes numerous TV signal after treatment, then converts light signal to and carry out long-distance transmissions by fiber optic backbone, after having arrived the user area, then carries out opto-electronic conversion, and this point is called as " optical node ".The rf signal that converts is delivered to huge numbers of families by coaxial cable after amplifying, distributing.The DOCSIS standard refers to be applied to the interface specification of HFC net transmitting data service, and how definition provides bi-directional data traffic by the cable modem, is supported in the transmission that realizes the IP packet between computer network and cable television network front end and user.CMTS belongs to head end (local side) equipment, usually is deployed in the front end of cable TV network, and its core component comprises modulation /demodulation feature board and 10G CPU Control Unit.It has FPDP and prevention at radio-frequency port, connects respectively Internet and HFC net.CMTS receives the modulation signal (being called upward signal) of sending from user side CM, demodulates IP packet wherein, and is forwarded to Internet according to destination address; Simultaneously, the CMTS data-signal (being called downstream signal) after modulation that also will come from Internet sends to the CM of user side.CMTS plays the bridge transformation between data network and HFC net.CM is as ustomer premises access equipment, between the terminal prot and user side CPE (Customer Premises Equipment) equipment of HFC net.CPE can be PC, can be also interactive set-top box, IP phone machine etc.
Existing cable TV network Broadband Access Scheme is CMTS to be concentrated be deployed in headend room, as shown in Figure 1.This cut-in method is fine in operator at the Develop Data business initial stage, can cover whole network in the short time, but drawback is also clearly, mainly has the problem of following several respects:
1, " funnel noise " serious interference
Because the CMTS in headend room need cover several to tens optical nodes, number of users reaches several more than thousand ten thousand families even, the various noise signals that come from transmission line and user family can be converged to the rf inputs of CMTS by data feedback channel, industry is referred to as " funnel noise ".Funnel noise has 70% to be various household electrical appliance or the space radiation that comes from user family, and the number of users that CMTS covers is more, and " funnel " is larger, and funnel noise is also larger.When this noise collection effect to one higher level, will affect the stability of CMTS work, can't proper communication when serious.
2, bandwidth resources are low per family
Because the CMTS that is deployed in headend room will cover a lot of users, along with the increase of broadband user's networking rate, the bandwidth resources that obtain per family will be more and more less, be difficult to satisfy user's online demand.
3, the complicated network structure, networking cost is high
Network configuration is comparatively complicated as can be seen from Fig. 1, and the network path from user side CM to the headend room data switching exchane is:
CM---cable distribution network---optical node (optical workstation contains the emission of descending light-receiving and up light)---optical fiber---back transmission optical receiver and descending optical sender---CMTS---switch.
Each optical node needs to install optical workstation, and up optical receiver is installed headend room is will be with it corresponding, and this bidirectional rebuilding that makes each optical node only equipment cost will reach 5000～8000 yuan.For satisfying each Internet user's bandwidth demand, at headend room, a large amount of CMTS equipment will be installed also, and the CMTS equipment price that machine room uses is generally at 10～200,000 yuan.So, the construction cost of cable TV broadband network just is in higher state.
Summary of the invention
For the prior art above shortcomings, the purpose of this invention is to provide a kind of funnel noise that can reduce the HFC broadband network disturbs, improve bandwidth, simplified network structure, reduction networking cost per family, integrated service cut-in method and the integrated service light station based on the HFC broadband network that are easy to safeguard.
For achieving the above object, the present invention has adopted following technical scheme:
Integrated service network-building method based on the HFC broadband network, its characteristics are traditional CMTS and traditional optical receiver and optical transceiver (or ONU) the rear optical node place that directly is arranged at the HFC system that becomes one, realize simultaneously the opto-electronic conversion of TV and IP data at the optical node place, produced thus a kind of new network equipment---integrated service light station (Integrated Service Optical Node, ISON).Further optimization as the technical program, adopted the method that remote monitoring module is set in integrated service light station inside, realized that being distributed in HFC in the management of headend room centralized monitor nets the integrated service light station equipment of each optical node and the broadband user of institute's load thereof.
Wherein, the integrated service light station that traditional CMTS and traditional optical receiver and IP optical transceiver (or ONU) are become one and form, based on the DICSIS agreement, utilize ETX modularization CPU and CMTS core component modulation mediation function plate to carry out integrated design, realization is completed opto-electronic conversion with TV signal and the unification of IP data, is blended in Coaxial Cables after processing separately.
A kind of integrated service light station equipment, its characteristics be, comprises casing, is positioned at integration module and the interface of casing; Described integration module is integrated with CMTS functional module, radiofrequency signal photoelectric converting function module and IP data photoelectricity conversion functional module; Described interface comprises the input interface that is comprised of TV optical interface and IP data light interface, and the coaxial cable radio frequency output interface; Wherein, the TV optical interface is connected with radiofrequency signal photoelectric converting function module; Radiofrequency signal photoelectric converting function module is used for the TV light signal is converted to the signal of telecommunication; IP data light interface is connected with IP data photoelectricity conversion functional module; IP data photoelectricity conversion functional module is used for the opto-electronic conversion of IP packet, and is connected with the data port of CMTS functional module; Modulation, solution mediation that the CMTS functional module is used for the IP data-signal forward; The radio frequency of CMTS functional module divides uplink and downlink two passages, IP data-signal after wherein down going channel will be modulated reaches blender to be mixed with the TV signal after opto-electronic conversion, and mixed signal is exported from duplexer filter through equilibrium, distribution with after amplifying processing again; Data feedback channel is connected with duplexer filter, be used for and take out and to deliver to CMTS from the upward signal of user side from duplexer filter, deliver to data-signal photoelectric converting function module after the processing such as CMTS is tuning with this upward signal process, amplification, demodulation and be converted into light signal, finally send to IP backbone.
Adopt the inventive method and equipment, the structure of HFC broadband network is simplified, as shown in Figure 2.Path, networking from user side CM to the headend room data switching exchane is:
CM---cable distribution network---integrated service light station---optical fiber---machine room light end equipment---switch.
The formed cable TV network broadband access equipment of the present invention---integrated service light station except having traditional television transmission optical receiver function, can also receive and forward the IP data, completes the transmission of hfc plant integrated service signal.
Compared to existing technology, the present invention has following advantage:
1, having reduced " funnel noise " disturbs:
In the present invention, the function of CMTS is placed in each optical node place, coverage only has tens to several one hundred houses, greatly reduces from the funnel noise of hfc plant, makes the work of CMTS module more stable.Simultaneously, even a section is disturbed the proper communication that also is unlikely to have influence on other sections user, make the whole system antijamming capability greatly strengthen.
2, bandwidth increases per family:
Due to the use of the technology of the present invention, make the bandwidth resources of fiber optic backbone be brought into play, the number of users that integrated service light station covers under an optical node only has tens to several one hundred houses, and the data bandwidth that therefore obtains per family improves greatly.
3, simplify the structure of HFC broadband network, reduced networking cost:
Because integrated service light station has adopted modularized design, CMTS has adopted integrated design, makes the overall cost of equipment lower many than traditional CMTS equipment; Simultaneously, because network configuration is simplified, optical workstation and the up optical receiver (approximately 5000～8000 yuan of each optical nodes) that must use in the traditional scheme have been saved.Therefore, under equal total bandwidth condition, use technical solution of the present invention and equipment can greatly reduce networking cost.
4, safeguard that simply during fault, coverage is little, and easily locate:
Owing to having adopted the remote centralized control administrative skill in integrated service light station, make the technical staff can understand in real time the running status of equipment, configuration parameter, leading subscriber.Also designed fault alarm function in management software.
Description of drawings
Fig. 1 is existing HFC broadband network network-building method network topological diagram;
Fig. 2 is for adopting the network topological diagram of the integrated service network-building method based on the HFC broadband network of the present invention;
Fig. 3 is the internal circuit module map of integrated service light station equipment in the present invention.
Fig. 4 is the inside theory diagram of CMTS module in the present invention.
Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail:
A kind of integrated service network-building method based on the HFC broadband network, traditional CMTS, radiofrequency signal optical-electrical converter and data-signal optical-electrical converter are become one, become integrated service light station, be installed on the optical node place of HFC, realizing simultaneously the opto-electronic conversion of TV signal and IP data-signal, and the forwarding of IP packet.This equipment also has remote monitoring function, realizes each integrated service light station equipment of the managing distributed deployment of headend room centralized monitor and the broadband user of institute's load thereof.
As shown in Figure 2, Headend and data center were two unrelated machine rooms originally, and the Optical Fiber Transmission by is separately mixed after opto-electronic conversion separately to optical node, utilizes the cable distribution network of HFC to be transferred to huge numbers of families.The bandwidth that can guarantee like this data backbone network part is not fully exerted.At equipment of the present invention---in integrated service light station, TV signal becomes radiofrequency signal after opto-electronic conversion, is sent to each user by cable distribution network after amplifying.The data light signal becomes digital pulse signal after opto-electronic conversion, wherein comprise receive and send two-way.This digital signal process CMTS module is modulated, demodulation, makes the digital signal of sending and receiving become analog signal in order to transmit in cable.Cable distribution network adopt the mode of frequency division be divided into data feedback channel (5～65MHz) with down going channel (88～860MHz), the CMTS module carries out the digital signal that will send to send into down going channel after the QAM modulation, and together enters cable distribution network after TV signal is mixed; Simultaneously, the cable distribution network data feedback channel has that (content of modulation comes from the data of CPE from the modulation signal of user side CM, as PC etc.), leach by the CMTS module by duplexer filter and carry out demodulation, restore user's data-signal, through opto-electronic conversion, enter Internet by optical fiber transmission to switch again.Like this, the access task of HFC broadband network is accomplished, and has realized the comprehensive transmission of TV and broadband data service.
The operation principle of integrated service light station: the effect of integrated service light station is the unified opto-electronic conversion that realizes TV and data light signal, and with data transmission together with the radiofrequency signal of TV is blended in cable after modulation or demodulation process.This equipment has TV and two optical interfaces of data, two prevention at radio-frequency port.Its theory diagram is seen Fig. 3, Fig. 4.
Fig. 3 is the internal circuit module map of cable TV network broadband access equipment in the present invention.This device assumes the task of opto-electronic conversion, has wherein both comprised TV signal, comprises again the IP data-signal.The former carries out opto-electronic conversion by the photoelectric converting function module, the latter realizes opto-electronic conversion by data photoelectricity conversion functional module, completed modulation, demodulation and the forwarding of data-signal by the CMTS module, can transmit in cable system, final two kinds of signals of telecommunication mixing arrives each user by coaxial cable.Specifically, this equipment comprises casing, is positioned at integration module and the interface of casing; Described integration module is integrated with CMTS functional module, radiofrequency signal photoelectric converting function module and IP data photoelectricity conversion functional module; Described interface comprises the input interface that is comprised of TV optical interface and IP data light interface, and the coaxial cable radio frequency output interface; Wherein, the TV optical interface is connected with the light-receiving functional module; Radiofrequency signal photoelectric converting function module is used for the TV light signal is converted to electrical signal; IP data light interface is connected with IP data photoelectricity conversion functional module; IP data photoelectricity conversion functional module is used for the opto-electronic conversion of IP packet, and is connected with the data port of CMTS functional module; Modulation, solution mediation that the CMTS functional module is used for the IP data-signal forward; The radio frequency of CMTS functional module divides uplink and downlink two passages, IP data-signal after wherein down going channel will be modulated reaches blender to be mixed with the TV signal after opto-electronic conversion, and mixed signal is exported from duplexer filter through equilibrium, distribution with after amplifying processing again; Data feedback channel is connected with duplexer filter, be used for and take out and to deliver to CMTS from the upward signal of user side from duplexer filter, deliver to data-signal photoelectric converting function module after the processing such as CMTS is tuning with this upward signal process, amplification, demodulation and be converted into light signal, finally send to IP backbone.
Fig. 4 is the theory diagram of CMTS module.The basic role of CMTS exactly to data-signal modulate, demodulation so that can transmission in HFC net.the course of work of explaining CMTS from reception and the process of transmitting of data now: according to the DOCSIS agreement, the data-signal that sends from user's PC network interface card enters CM, be that the upward signal that 0.2～6.4MHz does not wait enters the data feedback channel (5～65MHz) that HFC nets through becoming bandwidth after QPSK (or QAM) modulation, isolate this signal by duplexer filter in integrated service light station, give CMTS, first amplify, tuning, carry out demodulation after the processing such as filtering, demodulation packet is out delivered to the core of CMTS again---DOCSIS MAC process chip, determine the whereabouts of this packet by it: through pci bus to CPU, to the 100M Ethernet card, be connected with optical transceiver and reach Internet, or pass to other CM via down going channel.And the data that come from Internet are converted to the Ethernet signal of telecommunication through optical transceiver module (or ONU), deliver to CPU after the 100M Ethernet card receives, then are connected with DOCSIS MAC chip through pci bus.Under the control of CPU, the MAC chip is delivered to the Corticofugal Modulation of Somatosensory chip with this packet, export intermediate-freuqncy signal after the QAM modulation, any one bandwidth that is converted in 88～860MHz after filtering again, amplification is the radiofrequency signal of 8MHz (or 6MHz), with mix mutually from the radio television signal after opto-electronic conversion, from the front end input of duplexer filter, from the cable distribution network of common port output access HFC.User side CM receives after this downstream signal demodulation and replys packet, is linked into PC from the network interface card interface of CM.So just completed from user's PC and sent data to Internet, receive from the whole communication process of the data of Internet again.
For realizing above-mentioned inventive method, producing integrated service light station is prerequisite.This equipment needs to adapt to install and work in the field, and when completing TV signal and IP data-signal opto-electronic conversion, also wanting can be by remote monitoring, management.This will first carry out modularized design with CMTS, and TV signal light-receiving functional module, IP data light transmission-receiving function module, remote monitoring module etc. are integrated in the casing of water-proof sealing, adopt the fan-free heat dissipation design.Inner integrated radiofrequency signal photoelectric conversion module and IP data photoelectricity conversion functional module is detachable, that is the user can the selective light interface, also can select electrical interface; The electrical interface of TV signal is F type radio frequency socket, and the electrical interface of data-signal is the RJ45 socket.
1. make the CMTS modularization
For realizing the CMTS modularization, adopted ETX CPU module in the present invention.ETX is a kind of CPU template of microminiaturization, is one of standard of being widely applied in recent years of embedded-type control field.The ETX module is integrated central processing unit, memory interface, demonstration, network interface, USB and standard I/O function etc. on the 95x114mm size, and the high-density connector by 4 100pin is connected with support plate.Such design makes its expansion more flexible, and system upgrade is also easy, and reduces to greatest extent the cable connection.The X86-based of ETX can satisfy requirement of the present invention fully.Because this template has adopted standard interface, the support plate of CPU design is also than being easier to, and can simultaneously the modulation /demodulation feature board be designed with it on a pcb board, makes independently CMTS module, realizes integrated.In addition, adopt the ETX stay in place form, can select CPU low in energy consumption, be conducive to reduce the power consumption of complete machine.When carrying out integrated design, the wiring of pcb board will notice that the PCI lead-foot-line of ETX Connection Block should follow isometric principle, and analog circuit ground wire and digital circuit ground wire are separated, and reduces and disturbs.
2. the design of remote monitoring module
The parameter of remote monitoring is main supply power voltage, cabinet inside temperature, optical signal power, radiofrequency signal power, the CM operating state in machine, the parameter of controlling is the restarting of setting, complete machine of adjustment, the CMTS downstream signal frequencies of radiofrequency signal power, and the parameter that configure is mainly mandate, fault alarm thresholding of mode of operation, the CM of CMTS etc.All monitor datas are transferred to headend room with the form of IP packet by data optical fiber, realize under the webmastering software interface to all integrated service light stations in netting and with user's centralized monitor, management.
3. integrated each functional module
With integrated installations such as CMTS module, TV light-receiving functional module, IP data light transmission-receiving function module, remote monitoring module and power supplys in the casing of airtight waterproof.Wherein TV light-receiving functional module is the core component of traditional optical receiver; IP data photoelectricity conversion functional module is Ethernet optical transmit-receive function module, or ONU functional module (OpticalNetwork Unit); Both but first line of a couplet fiber optic Ethernet, also can connect EPON (Ethenet Passive Optical Network).Both are all matured products, can be supporting by purchasing, then integrate with the CMTS module.
4. heat dissipation design
At first be that circuit design stage just runs through the thought that reduces power consumption, reduce the generation of heat, select low-power chip.Aspect heat radiation, utilize the aluminum alloy heat sink section bar to make the airtight waterproof casing, heating column is installed in the relevant position at the bottom of shell, directly passes to whole housing with the heat that the heater members on circuit board is produced, to reach the purpose of quick heat radiating.
5. Software for Design
The operating software of equipment is the remote monitoring function that increases on the basis of the existing product JH-HE2086 of our company equipment, the control interface of integrating monitoring module on the basis of existing webmastering software JH-NMSv3.3, make the network manager in the distance machine room can control the working condition of each equipment and broadband user's CM operating state.The remote monitoring and administration module has adopted based on SNMP standard network management protocol.
The integration module that its characteristics are to comprise casing, interface and are positioned at casing.Described integration module has comprised CMTS function, TV signal photoelectric converting function, IP data photoelectric converting function, remote monitoring function.And this equipment is installed and used take the field and is target, takes the fan-free design, by airtight casing heat radiation.This equipment is to design based on same goal of the invention with said method, and equipment and method belong to same technical scheme, can see an integral body of tight contact.Integrated service light station has TV signal optical interface, IP data-signal optical interface and radio frequency interface, and optical interface wherein connects respectively the backbone network of TV and data, and radio frequency interface connects coaxial cable distribution net.Surf the Net at the Cable of user terminal Application standard Modem.But equipment remote monitoring, management, installation and maintenance is very convenient.