CN1479979A - High speed access system over copper cable plant - Google Patents
High speed access system over copper cable plant Download PDFInfo
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- CN1479979A CN1479979A CNA008200548A CN00820054A CN1479979A CN 1479979 A CN1479979 A CN 1479979A CN A008200548 A CNA008200548 A CN A008200548A CN 00820054 A CN00820054 A CN 00820054A CN 1479979 A CN1479979 A CN 1479979A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0056—Systems characterized by the type of code used
- H04L1/0057—Block codes
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0056—Systems characterized by the type of code used
- H04L1/0071—Use of interleaving
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
- H04L12/2854—Wide area networks, e.g. public data networks
- H04L12/2856—Access arrangements, e.g. Internet access
- H04L12/2863—Arrangements for combining access network resources elements, e.g. channel bonding
- H04L12/2867—Physical combinations
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
- H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
- H04M11/062—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors using different frequency bands for speech and other data
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
- H04L1/0002—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate
Abstract
A system for transporting a high speed data stream over a plurality of relatively low bandwidth unshielded twisted copper pairs within the local loop plant or in any environment having a plurality of copper lines, such as on campuses, within large buildings, etc. The copper twisted pairs are transformed from a plurality of low bandwidth, low reliability links into a high reliability, very high bandwidth long range communication channel utilizing optimized xDSL transmission technologies over the plurality of copper pairs. A transmit data processor perform scrambling, FEC encoding and interleaving on the data before it is divided and dispatched to the plurality of modem elements for transmission over the local loop plant, either bidirectionally or unidirectionally.
Description
Technical field
The present invention relates generally to telecommunication system, particularly the system of transmitting high speed data on unshielded twisted pair copper cable equipment.
Background technology
The demand of data communication service is just with very high speed increment.It mainly is the result of internet and other data-intensive high-bandwidth applications that the end user needs increasing bandwidth.In recent years, the internet is being explosive increase aspect the traffic of end user's number and transmission.The user needs higher bandwidth to be connected with other end users and internet access faster.The Another reason of demand is that more and more enterprises brings into use data communication network (comprising the traffic on the internet) to transmit document and Email in office and between the office.
Enterprise and user increase the demand of broadband services, insert connection because they no longer satisfy the dialing internet.Most of enterprise and user need the access bandwidth of several megabits, and purpose is to participate in eization, and integrates its telecommunication service.
Because increasing end user produces the more and more data traffic, therefore can sharp increase to the demand of more and more faster data link.Satisfy current demand when at present, telecommunications company is attempting estimating tomorrow requirement hastily.Yet stoping telecommunications provider that the major obstacle of broadband services is provided is the local loop that is called " dirt road on the Infobahn ".In order to provide high bandwidth to insert, must pave the way to dirt road, for this reason, ILEC and CLEC must devote considerable time and fund aspect the upgrading of large-scale optical fiber infrastructure.
Current, some operator is using optical cable to provide to satisfy the required large-bandwidth pipe of current bandwidth demand.Yet optical fiber can not replace traditional copper cable equipment.Optical fiber is mainly used in brand-new cable and installs, and perhaps sometimes is used to connect central office (CO) and remote node, is commonly referred to optical fiber to the curbside (FTTC).Although the installation optical cable is from the curbside, node or terminal block still be made of non-shielding copper stranded conductor to " last mile " of user terminal.
Nowadays, deployed fiber also lower in the domestic local loop of the U.S..Have only 3% office building in 750,000 office buildings, 9% curbside rack and 19% Cabinet utilize optical cable to be connected to CO.In Europe, optical cable is disposed lower.In following 15 years, deployed fiber can only reach 50% in the domestic local loop of the U.S..With regard to the U.S., people estimate that the expense that optical fiber is registered one's residence is hundreds billion of U.S. dollars.Therefore, every the building that is deployed to local loop need expend plenty of time and fund, mainly runs the commercial city and can so not do.
The response user is to the demand of bandwidth, and many companies are providing the substitute of last mile copper stranded conductor, as LEO satellite broadband, and optical fiber, CATV cable, wireless local loop (WLL) and other technologies.Another kind of available techniques is the xDSL modem technology.Many ILEC, the CLEC and the ISP that are carrying out keen competition have accepted the DSL technology as the most direct solution, satisfy current demand by obtain more bandwidth from copper cable equipment, and need not to wait for tediously long optical fiber installation process.Yet the many new technologies of forward are such, and operator must as distance limit, lack the service parameter assurance and how much lack the reliability that optical fiber provides in the face of disposing the difficulty of DSL.
Digital Subscriber Line (DSL) technology means utilizes the miscellaneous service of advanced modulation demodulator element in the digital signal in copper stranded conductor transmitting data source.DSL modulator-demodulator element allows to go up with the high data rate transfer data at public switched telephone network (PSTN).DSL modulator-demodulator element can use ripe known signal treatment technology, and with the rate transmissioning data of several megabits, wherein above-mentioned signal processing technology allows while transferring voice and data on same analogue copper twisted wire.
Usually, two modulator-demodulator elements of DSL service needed, a CO who is positioned at traditional LEC (ILEC).Yet CLEC can dispose its DSL couple in multiplexer in the CO of RBOC, so that move on the copper stranded conductor of unbundling, provide broadband connection to enterprise.
The existing copper ring apparatus
Fig. 1 represents to connect via the low bandwidth copper stranded conductor block diagram of the first example existing network of central office (CO) and other CO and subscriber terminal equipment (CPE).The example network of reference number 10 signs comprises: place the CO12 of telephone service switch 24, ATM switch 28, DSL couple in multiplexer (DSLAM) 30 and main-frame (MDF) 26.The existing copper cable equipment that nowadays example network 10 expressions are generally used.
Polytype telecommunication apparatus can be connected to switch 24, as be equipped with the computer 14 of the modulator-demodulator of dialing mechanism, ISDN or other suitable types, telephone set 16, via the PBX 18 of T1 or other T carrier lines, PSTN 20 and ISP (ISP) 22.Many circuits 32 are connected to MDF 26 with switch 24.The function of MDF is to stop leaving hundreds of or thousands of copper cables 34 that CO arrives user terminal.Switch 24 stops arriving via passive MDF 26 twisted-pair feeder of copper cable equipment 34, and wherein copper cable equipment is the thick cable that comprises 1000 to 3000 pairs of copper stranded conductors.Cable 34 guiding need be divided into cable the cablet diverse location of (comprising 100 to 1000 pairs of twisted-pair feeders usually).
Cable is finally cut apart the cablet that arrives different user terminals along above-mentioned direction.For example, cable 36 is connected to the terminal block 40 that is positioned at node # 1, the latter is by being connected to the end user than short distance with twisted-pair feeder.For example, via T1 line, node # 1 is connected to a plurality of CPE such as telephone set 42 and PBX 43.Cable 38 is connected to another terminal block 44 that is positioned at node # 2, and the latter connects a plurality of telephone sets 50.In addition, cable 39 is connected to another terminal block 46 that is positioned at node # 3, the latter connects a plurality of telephone service device 52.Another bunch cable is connected to the 2nd CO 46, and the latter connects a plurality of phones 52.Passive bus 48 connects MDF 26 and phone 56 and terminal 58 by modulator-demodulator 54, connects MDF 26 and phone 64 and LAN 60 by modulator-demodulator 62.Usually in curbside rack or basement, passive bus is installed at building.
Fiber-To-The-Node
Fig. 2 represents to connect via lightguide cable link the block diagram of the second example existing network of CO and a plurality of nodes.The example network of reference number 70 signs comprises CO 86, and the latter comprises switch 82, ATM switch 80 and optical multiplexer 84.Switch 82 is connected to the personal computer 72 that modulator-demodulator is installed, telephone set 74, PBX 76 (by T or other T carrier lines) and PSTN 78.Utilize optical cable 88 that switch 82 is connected to one or more nodes 90.Be positioned at first optical multiplexer 84 of CO end and the optical fiber at second optical multiplexer, the 92 termination two ends that are positioned at node side.
The optical multiplexer that is called the optic network control device, with high speed optical transmission be converted to such as telephone service or data service (as T1, T3) and so on low speed electrical signal data stream (electrical stream).For example, optical multiplexer 84 will be converted to the high speed optical signal from the data service based on the signal of telecommunication of switch 82.In addition, this multiplexer will be from the signal multiplexing of ATM switch 80 to optical cable 88.
At node 90, optical multiplexer 92 is converted to electrical signal data business such as T1, T3 with optical signalling.DSLAM 94 transfers the signal to the user terminal by twisted-pair feeder.The type of the DSL signal of transmission comprises ADSL 98, and HDSL 108, the DSL of VDSL 106 or any other type.CPE comprises the DSL modulator-demodulator 96 that communicates by twisted-pair feeder and DSLAM.DSL connects the ISP that allows to be connected to such as the data generating apparatus the PC 100 by CO 86 connections.The DSL link also can be via optical fiber link 88, and (that is, less than 4kHz) is forwarded to switch with the voice on the twisted-pair feeder.
Another example comprises the optical multiplexer 91 that links to each other with DSLAM, and this multiplexer is via various DSL, as VDSL 106 and HDSL 107, to one or more multitenant units (MDU) 102,104 transport services.Node also can be placed one or more digital loop operators (DLC) multiplexer, and the latter connects CO and user terminal by the twisted-pair feeder along " last mile ".
Copper cable equipment
The copper cable equipment that is called local loop equipment is for being connected to dwelling house and enterprise telephone operator's infrastructure of the CO of telephone operator.The deployment of copper stranded conductor is very general, designs but use for low bandwidth at first.
Telephone operator determines required number of twisted pairs according to the regional density of population, street layout, existing right-of-way etc., copper cable equipment is installed then, so that provide professional to each terminal.In the mode of scattering, the copper cable that its number is enough to provide for particular locality service is installed from CO.Cable is linked, thereby the line of proper number is to arriving each street.Usually distance C O is far away more, and the line of cable is to few more.
Loop cable layout generally includes service cable, and the latter links to each other with the distribution cable of the serving area interface that is positioned at the junction box.Opposite with distribution cable, service cable is normally planned for the longer time limit between installing and discarding.Dissimilar cables are installed and are comprised the high-altitude cable that is installed on the electric pole, from the pipeline of below, pavement or be embedded in the cable that passed in the pipeline the groove.
The length of local loop can reach 18,000 feet or longer.To suffer more signal attenuation than 18,000 feet longer loops.Yet existing cable equipment comprises equipment of producing before the many decades and the equipment of producing recently.Up to the present, reducing the standard mode that decays is to use thick specification cable and the inductive load coil is installed.
The noise in adding signal to, the signal that pair cable also can be decayed and be transmitted on the pair cable.For length is that 15,000 feet, specification are for 26 the twisted-pair feeder, the decay of signal (or loss) for 40dB (frequency is 40kHz) to 100dB (frequency is 1MHz).If there is the bridge joint head, it is even worse then to decay.The bridge joint head is the branch road that connects on some point of cable.Note that when connecting same pair cable, the bridge joint head occurs by one or more branch roads.If pair cable is told an electric wire (, lead-in) during by user terminal, and is connected to user terminal, also the bridge joint head can appear.The loop pair cable extends to outside the pad, and becomes a bridge joint head.
Another problem that needs to handle is the noise that exists in the copper cable equipment.For DSL, noise effect is positioned at the receiver at twisted-pair feeder two ends.Noise comes from many roots, but the most problematic noise source crosstalking from other twisted-pair feeders in the cable.Crosstalk is that different DSL transmitters or other technologies by the frequency acceptance band that uses receiver generate.If noise source is enough strong, then when receiving the signal that is transmitted, cause error.
When frequency increased, crosstalking can be even worse.Therefore, to audio frequency, crosstalking not is problem.Yet for the frequency of other data communication packages such as ISDN, ADSL, RADSL, SDSL and the frequency of the T carrier line such as T1 and T3 (is E1 and E3 in Europe), crosstalking is a problem.Be called external business from other the professional signals outside the transmission kind.From crosstalking of external business, other DSL transmitters that for example move on same cable generate most of limit interferences.
Loop qualification limit procedure is checked the local loop configuration, because the less circuit of decaying is subjected to the influence of particular crosstalk less.Simultaneously, installed device type is recommended in this process check, and other lines in this cable on the existing system that transmits.Because the different up-downgoing data of different DSL scheme transmission are so need this process.Some scheme is separated transmission (that is, descending) frequency from link service provider to user and the transmission from user to link service provider (that is, up) frequency.
Although the various DSL technology of exploitation can satisfy individual user's needs in the past few years, can only on several miles distance, realize 1 to 8Mbps speed.In addition, as mentioned above, DSL adjust the distance, crosstalk or the interference and the line quality of other types very sensitive.The attempt of exploitation ADSL is: by transmission of high-rate data in one direction and low-rate data is provided in the opposite direction, interference is dropped to minimum level.
Solution to the problems described above be install in the position of as close as possible user terminal couple in multiplexer (as, DSLAM or DLC).By optical cable couple in multiplexer is connected to CO (as shown in Figure 2) then.Usually in local loop, dispose optical fiber link, so that between the communication node between CO and the telecommunication apparatus in curbside rack, machine room or building, provide the high bandwidth transmission line.
Above-mentioned node is generally tens of in building, campus, the street and provides service to hundreds of low bandwidth end users.Above-mentioned node comprises the multiplexing equipment such as DLC, DSLAM and WLL base station.
The function of multiplexing equipment is with each end user's low speed data transmission and routine call service signal, is combined as the high bandwidth pay(useful) load, and is transferred to CO by optical fiber link.Note that optical fiber link is reliably, be not subjected to the influence of electrical noise, and can the very high data flow of transmission speed.
As mentioned above, the shortcoming of optical fiber link is that optical fiber link is not also popularized very much, therefore disposes on a large amount of new line that need.Not only need great amount of investment, and need the very long set-up time.In many cases, when the needs deployed fiber just can provide faster, more reliable symmetric data professional, darkling Chang'an ETL estimated time of loading and the high expense relevant with fiber deployment seriously hindered the use of optical fiber.
Summary of the invention
The present invention has solved the problem relevant with prior art by the system that is called high speed access system (HSAS) is provided, and HSAS can transmit high-speed data-flow on a large amount of low bandwidth unshielded twisted pairs in local loop equipment.The present invention is not limited to the application on the local loop equipment, but can use the present invention in the environment with a large amount of copper stranded conductors such as campus, building.By utilizing optimization xDSL transmission on a large amount of copper stranded conductors,, change a high bandwidth long haul communication channel very reliably into a large amount of low bandwidth links of the copper stranded conductor in the local loop.This system comprises with lower device, a ultrahigh speed bandwidth channel is divided into a plurality of low rate data streams so that carry out the device of transmitted in both directions on a plurality of xDSL modulator-demodulator elements.The high-speed transfer platform of the application of the invention need not to utilize optical fiber to replace the interior existing copper twisted wire of local loop equipment, and can avoid high expense and the tediously long set-up time relevant with optical fiber.
The present invention can avoid the current xDSL technology of implementing of utilizing to set up link from CO to end user.Although HSAS provides the high-speed link from CO to the node, the link on the xDSL technology can provide more short-range " tap part (that is, from the node to end user) ".
The present invention can be decomposed into a plurality of parallel data passages with a high-speed data-flow, and wherein each passage is suitable for transmitting the lower signal of its bandwidth ratio original data stream.The delay of data rate, BER and each passage does not rely on other passages, and according to the mass change of passage.Note that HSAS comprise can utilize known multiplex technique with a plurality of low rate data streams (as, T1, T3, E1, E3, ISDN etc.) assemble and to be the device of single high speed data link.
Before transmission on the passage, high-speed data is by scrambler, FEC encoder and interleaver.Then treated data are distributed to a plurality of modulator-demodulator elements of forming by xDSL modulator-demodulator element.The purpose of data being carried out above-mentioned processing is to improve reliability, increases noise and the vulnerability to jamming of crosstalking, simultaneously the transmission delay associated on reduction and each passage.
The scramble and the algorithm that interweaves can provide crosstalk interference that (1) caused the signal of last transmission by other lines and (2) noise (as, background noise, impulsive noise, intrusion noise (that is the noise that causes by different xDSL information sources in external source, the same binding or All other routes interruption)) decorrelation and resilience.
The FEC encoding scheme can be added the redundant system overhead data in the transmission pay(useful) load.Redundant data is used to proofread and correct makes the error that receives data generation error, thereby improves effective data rate of each transmission of not collinear centering, because it can provide the low noise coefficient of safety.
Via the high speed modem such as the xDSL modulator-demodulator, two-way or each parallel data passage of one-way transmission on twisted-pair feeder.Preferably, transmission is optimized according to the space structure and the related electrical characteristic thereof of cable.
By using well-known TDM or FDM technology, HSAS can be simultaneously on twisted-pair feeder transmission existing telephone business (as, POTS) and high-speed data channel.
HSAS also comprises to remote node provides power supply so that be the device of HSAS with other assemblies (optional) power supply that is positioned at remote node.On the identical twisted-pair feeder of transmitting high speed data link, transmit electricity.Power supply is divided into a plurality of tributaries feed current, wherein on twisted-pair feeder, carries each electric current.
The HSAS of receiving terminal that is positioned at passage receives each data channel from each twisted-pair feeder via the assisted modulation demodulator, and the space structure by using relevant this cable and the information of electrical characteristic are improved reception (optional) simultaneously.Collect the reception data of modulator-demodulator element output then, form high-speed data-flow.Then data stream is carried out deinterleaving, fec decoder and descrambling, purpose is to improve the quality that receives data, reduces the BER that receives data.Its result is original high-speed data-flow.Simultaneously, receiving course provides the difference that a plurality of twisted-pair feeders are subjected to postpone to carry out the method for equilibrium treatment.
Telephone service is separated from high-speed data-flow., high-speed data-flow be separated into a plurality of low speed tributary thereafter, as T1, E1, ISDN etc.
Remote power supply is supplied with and is collected from a plurality of twisted-pair feeders, and gathering is that single power supply is so that be the assembly and the power devices of remote node.
Measure according to HSAS, determine the information of the space structure and the electric parameter of relevant cable.Test module be suitable for each line of period measurement pair and every other line between the crosstalking and the NEXT transfer function of different frequency.Need test at the two ends of communication channel, and can in binding, test, so as to provide each line in the relevant binding to the information of position and each line between the information of NEXT transfer function.
Can on the twisted-pair feeder of arbitrary number, test,,, thereby help to distribute each bar twisted-pair feeder in the binding so that extract the information of the space structure of relevant certain binding or more bindings even twisted-pair feeder is positioned at other bindings.Therefore, measure information and the binding internal information between the binding of isolating of crosstalking that provides between relevant each binding.
If measurement is limited in the binding, then can not obtain information between binding.At this moment, can obtain the information of relevant copper cable equipment there from operator or manufacturer.When HSAS is connected to a plurality of twisted-pair feeder that resides in the specific binding, can utilize this information to improve xDSL modulator-demodulator transmission performances.Can provide line that NEXT isolates transfer function to line to matrix, as the measurement result of operator or cable manufacturer.
Can utilize by the information of measurement acquisition or from operator or manufacturer's there acquired information, improve the xDSL transmission performances in the following manner.At first, in the xDSL receiving element, carry out NEXT and eliminate when handling, use this information.Especially, calculate line between the NEXT transfer function time use this information, wherein the NEXT transfer function is used for estimating crosstalk, and eliminates crosstalking in the received signal.
Secondly, the line that is used for determining worst interference to and only these lines are eliminated using NEXT, eliminate the complexity of handling thereby reduce NEXT.
The 3rd, be used to the information that provides relevant with transmitter.Especially, select the line upward signal (that is, from remote node to CO) more responsive at more close binding center, because can protect these lines better to not being subjected to external disturbance to transmission.Can the line of more close binding outside on transmit the more downstream signal of robust (that is, from CO to the remote node).When sending asymmetric data stream on each twisted-pair feeder, above-mentioned processing is very useful.For example, ADSL transmits on two rightabouts of different Cu twisted wire simultaneously.
The 4th, be used for providing variable gain control, thereby can on the twisted-pair feeder at more close binding center, enable higher through-put power each transmitting data stream on the different twisted-pair feeders.Therefore can significantly improve transmission capacity and scope, will remain at the global radiation spectral power that the binding outer wall is measured simultaneously in the telecommunications rule of appointment (as, in the PSD rule).The gain controlling of using can be that frequency is selected, and changes gain to adapt to the crosstalk attenuation of each characteristic frequency.
The 5th, be used on organizing, transmitting high-speed data-flow at each defiber, by controlling each line to the phase mutual interference between the group, transmit different data flow by the mode of above explanation.Note that different interference anti-interference result described below can provide the better isolation between the different data streams.
The 6th, when finding one or more twisted-pair feeder because high decay, exist loading coil or other damages become the low quality line to the time, HSAS or to get rid of above-mentioned line from a plurality of line centerings of transmitting high speed data stream use right perhaps reduces its transmission rate.Thereby can under the situation that the heavy circuit that need not to provide the technical staff to know is regulated, utilize the low quality line right.Forbid that it is to have one or more redundant twisted-pair feeder that a twisted-pair feeder or many twisted-pair feeders provide professional prerequisite.
The advantage of HSAS comprises:
(1) provides the high-speed data communication channel, therefore can on a plurality of twisted-pair feeders, transmit the existing telephone business simultaneously.
(2) a plurality of twisted-pair feeders by transmitting high speed data and existing telephone business are for the assembly that is positioned at remote node provides remote power feeding.
(3) provide the high-speed link that is gathered into by a plurality of low rate data streams.
(4) synergy between the various xDSL links of realizing forming by the gathering high-speed link.By use each modulator-demodulator element than low tolerance, realize enough system-level noise margins.Therefore, when two systems kept the same noise tolerance limit, the bit rate of HSAS was higher than the bit rate of a plurality of xDSL modulator-demodulator elements.Usually adopt the noise margin of 6dB to mean that its SNR reduces 6dB, also can keep its performance level (BER, speed and scope) even note that xDSL modulator-demodulator element.Because the spatial manipulation scheme of HSAS described below and noise " on average " is assigned to the fact on all circuits, thus HSAS can by each modulator-demodulator element than the low noise tolerance limit, keep system-wide noise margin.This means that the bit rate of HSAS is higher than the bit rate of a plurality of xDSL modulator-demodulator elements when two systems keep the same noise tolerance limit.
(5) handling failure xDSL modulator-demodulator element is because this system can dynamically change the speed of modulator-demodulator element, to adapt to variable line and environmental condition.
(6) provide resilience for going offline, wherein go offline to being cut off or the serious circuit of demoting of its transmission characteristic.
(7) can increase the external interference anti-interference effect of high-speed link to the vulnerability to jamming of noise source, wherein noise source each line of forming cable on distribution and inhomogeneous.Its reason is that online centering is carried out space scramble processing to data before the transmission.When receiving terminal carries out descrambling, noise is propagated on the space of many circuits, thereby can reduce the influence to whole link.
Controlled trading off between the data rate of vulnerability to jamming, delay and the high-speed link of (8) assurance scope, quality, the resilience that goes offline, external noise.
Therefore be appreciated that the present invention at digital communicating field, particularly in the communication on local loop equipment, have clear superiority.The present invention can provide high-speed communication channel on the unshielded twisted pair product, continue to provide the existing conventional telephone service simultaneously.
, multichannel multiplexing by using decomposed, the error correction on a plurality of channel, and the spatial mappings and the NEXT technology for eliminating that pass through cable obtain the improvement of xDSL transmission performance, the system that causes transmitting high speed data on unshielded twisted pair, this system not only flexibly but also to noise had very strong vulnerability to jamming.This system can be used as the alternative of high performance price ratio, to need in the local loop equipment to replace spending the optical fiber that a large amount of expenses and time disposes.
Therefore, according to the present invention, a kind of device of the channel high-speed data-flow of forming at a plurality of low bandwidth copper stranded conductors is provided, this device comprises: the encoder that the error correction coding scheme is applied to high-speed data-flow, the a plurality of modulator-demodulator elements that link to each other with a plurality of copper stranded conductors, each modulator-demodulator links to each other with a copper stranded conductor, and to be independent of the data rate operation of other modulator-demodulator elements, transmitter will be divided into a plurality of low rate data streams that need utilize a plurality of modulator-demodulator elements to transmit through the high-speed data-flow of coding, transmitter is suitable for the data rate according to each modulator-demodulator, low rate data streams is forwarded to each modulator-demodulator, a plurality of data flow that gatherer receives a plurality of modulator-demodulator elements, be combined as a high-speed data-flow, decoder is suitable for receiving the data flow of gatherer output, and use the error correction decoding scheme, thereby generate initial high-speed data-flow.
According to the present invention, a kind of method that is used to select the parameter of the code word that encoder generates is provided, so that required line fault resilience is provided, minimum bit-error rate (BER) and maximum bandwidth, this parameter is made up of K and R, wherein K-R represents the byte number in the pay(useful) load part of code word, R represents the byte number in the redundancy section of code word, wherein code word is distributed to a plurality of modulator-demodulator elements, so that on a plurality of low bandwidth copper stranded conductors, transmit, the data rate of each modulator-demodulator is independent of other modulator-demodulator elements, this method may further comprise the steps: to all effective combinations of codeword size K and redundant length R, according to its corresponding data rate, calculate the maximum number of byte of the code word of each modulator-demodulator transmission, all combinations to line fault, calculate the summation of the figure place of the single codeword that needs transmission, if summation is less than R/2, then mark should make up, to all marker combination, calculate its overhead, and from all combinations of the K that calculates its interconnected system expense and R, the combination of selective system expense minimum.
In addition, according to the present invention, a kind of method of transmitting high-speed data-flow on a plurality of low bandwidth copper stranded conductors is provided, this method may further comprise the steps: a plurality of modulator-demodulator elements are provided, each modulator-demodulator links to each other with a twisted-pair feeder, high-speed data-flow is divided into a plurality of low rate data streams, to be distributed to a plurality of modulator-demodulator elements, on a plurality of twisted-pair feeders, transmit a plurality of low rate data streams by a plurality of modulator-demodulator elements, according to the quality of relevant twisted-pair feeder, revise the speed of each modulator-demodulator, receive a plurality of low rate data streams on a plurality of twisted-pair feeders, a plurality of low rate data streams of combined reception, thus initial high-speed data-flow generated.
According to the present invention, a kind of method that is used to select the parameter of the code word that encoder generates is provided, so that required line fault resilience is provided, minimum bit-error rate (BER) and maximum bandwidth, this parameter is made up of K and R, wherein K-R represents the byte number in the pay(useful) load part of code word, R represents the byte number in the redundancy section of code word, wherein code word is distributed to a plurality of modulator-demodulator elements, so that on a plurality of low bandwidth copper stranded conductors, transmit, the data rate of each modulator-demodulator is independent of other modulator-demodulator elements, this method may further comprise the steps: to all effective combinations of codeword size K and redundant length R, according to its corresponding data rate, calculate the maximum number of byte of the code word of each modulator-demodulator transmission, all combinations to line fault, calculate the summation of the figure place of the single codeword that needs transmission, if summation is less than R/2, then mark should make up, to all marker combination, calculate its overhead, and from all combinations of the K that calculates its interconnected system expense and R, the combination of selective system expense minimum.
In addition, according to the present invention, a kind of transmitter is provided, be used between a plurality of modulator-demodulator elements, distributing high-speed data-flow, this transmitter comprises a two-dimentional buffer, buffer is made up of a plurality of memory cell that are arranged as many row and columns, every row is related with different modulator-demodulators, a monadic symbols with the maximum transmission rate transmission is shown in every tabulation, the input sequencer is suitable for high-speed data-flow is distributed to memory cell in the buffer, according to the specific data rate of respective modem, determine to be distributed to each row data volume, the output sequencer is suitable for the content with the memory cell in the buffer, is distributed to a plurality of modulator-demodulator elements.
Description of drawings
Followingly illustrate the present invention with reference to accompanying drawing, wherein accompanying drawing is:
Fig. 1 represents to connect via the low bandwidth copper stranded conductor block diagram of the first example existing network of central office (CO) and other CO and various subscriber terminal equipment (CPE);
Fig. 2 represents to connect via lightguide cable link the block diagram of the second example existing network of CO and a plurality of nodes;
Fig. 3 represents to be used for the block diagram of illustrated example network, and this network is connected to certain node via the high-speed link on the copper cable equipment of the high speed access system (HSAS) that adopts the present invention with CO;
Fig. 4 represents a plurality of cable bindings in the bunch of cables;
Fig. 5 represents to be used to illustrate the block diagram of the present invention's HSAS, and the purpose of structure the present invention's HSAS is to utilize the integrated routine call business of Time Division Multiplexing;
Fig. 6 represents to be used to illustrate the block diagram of the present invention's HSAS, and the purpose of structure the present invention's HSAS is to utilize the integrated routine call business of frequency division multiplexing (FDM);
Fig. 7 represents to be used to describe in detail the block diagram of exit portion of the present invention's HSAS;
Fig. 8 represents to be used to describe in detail the block diagram of intake section of the present invention's HSAS;
Fig. 9 represents to be used to illustrate the flow chart of the present invention's circuit isolation measurement method;
Figure 10 represents to be used to describe in detail and comprises the block diagram of xDSL modem portion that NEXT eliminates the HSAS of the present invention of operation;
Figure 11 represents the block diagram of the another kind of execution mode of HSAS constructed according to the invention;
Figure 12 represents to be used to illustrate the outlet at the copper cable equipment that is positioned at two ends constructed according to the invention and the block diagram of inlet HSAS;
Figure 13 is a flow chart, the initial method of expression the present invention's HSAS;
The structure of Figure 14 representation space frame and units concerned's symbol time (UST);
Figure 15 represents the K bytecode block that uses in the FEC part of HSAS;
Figure 16 is a block diagram, the signal that expression is docked with the FEC encoder section of HSAS;
Figure 17 is a block diagram, represents the signal that partly docks with the fec decoder device of HSAS;
Figure 18 is a block diagram, represents the signal that partly docks with the transmitter of HSAS;
Figure 19 is a block diagram, represents the signal that partly docks with the gatherer of HSAS;
Figure 20 is a block diagram, represents the transmitter part of HSAS in detail;
Figure 21 is a block diagram, represents the gatherer part of HSAS in detail;
Figure 22 represents the format sample of transmission table memory;
Figure 23 represents the content of the first example transmission table memory, wherein places single codeword in the transmission table;
Figure 24 represents the content of the second example transmission table memory, wherein places two code words in sending table; And
Figure 25 is a flow chart, the flywheel air-frame method for synchronous of expression the present invention's HSAS.
Embodiment
Symbol used herein
This document is used following symbol.
Term definition
The ADSL ADSL (Asymmetric Digital Subscriber Line)
The ASIC application-specific integrated circuit (ASIC)
The ATM asynchronous transfer mode
The BER error rate
The CATV cable TV
The CEF cable is introduced equipment
The CLEC Competitive Local Exchange Carrier
The CO central office
The CPE subscriber terminal equipment
The CPU central processing unit
The DC direct current
DLC digital loop operator
The DSL Digital Subscriber Line
DSLAM DSL couple in multiplexer
EOC embedding operation channel
FCC Federal Communications Committee
The FDM frequency division multiplexing
The FEC forward error correction
The FEXT far-end cross talk
The FFT fast fourier transform
The FPGA field programmable gate array
FTTC optical fiber is to the curbside
The HDSL high-speed digital subscriber line
The HSAS high speed access system
The integrated access device of IAD
The IC integrated circuit
The IFFT inverse fast Fourier transform
The LEC that ILEC is traditional
The ISDN integrated services digital network
ISP ISP
The LAN local area network (LAN)
The LEO Low Earth Orbit
The MDF main-frame
The MDU multitenant unit
The MIB management information bank
The NEXT near-end cross
The NMS network management system
NOC Network Operation Center
The PBX PBX
The PC personal computer
The PDN packet data network
The simple plain old telephone service of POTS
The PSD power spectral density
The PSTN public switched telephone network
PTT mail post office
RADSL rate adaptation Digital Subscriber Loop
RBOC regional Bell operating company
The SCM traffic channel module
The SDSL symmetric digital subscriber line
The SNMP Simple Network Management Protocol
The SNR signal to noise ratio
The TDM time division multiplexing
The UST unit symbol time
The VDSL very high speed digital subscriber lines
The WAN wide area network
WLL line local loop
The WWW World Wide Web (WWW)
Definition used herein
This document is used to give a definition.
Term definition
There is source node to provide the node of source device, this node or concentration of transmissions
Link or distribution transmission link.
The CO end is positioned at the HSAS equipment of CO.CO end HSAS is responsible for
HSAS initiates to connect the process of setting up, and is responsible for generating high-speed link.
Go offline be cut off or its transmission characteristic seriously demote (as because
The modulator-demodulator element related one or more with it
Fault, perhaps since one or more line fault cause
The transmission characteristic degradation) circuit.
Distribution cable or from the terminal point of feeder cable, through reaching than short distance
The whole user's of tapping cable cable.
Feeder cable is to the blister copper cable of one or more service area feed signals.Feedback
Electrical cables can have 3000 pairs of copper cash.Its terminal point is a line
Center, passive bus or terminal block.
Link effectively is with the connection available bandwidth, comprises dedicated bandwidth and idle bandwidth.
Wide
The also untapped link effective bandwidth of the current connection of link idle band part.
Wide
The link performance ginseng is used for predicting the twisted-pair feeder that (1) specific required bandwidth needs
Keep count of or reliability class (that is BER, that (2) need
And do not having to reduce under the situation of loss of data
The max line way) one or more parameters.Can estimate
Or measurement above-mentioned parameter.
The accumulation position of all modulator-demodulator elements of the current use of link rate
Speed.
Link is provided with the user-defined one or more parameters of ginseng, comprises (1) chain
Maximum BER or (2) on number road are not having the feelings of loss of data
The max line way that can reduce under the condition.
The Link State high-speed link has following three kinds of states: (1) up-can use
In connection; (2) do not have between the down-HSAS equipment
Connect; And (3) reset-learning state two ends
Cooperate the synchronous modem element, the mapping twisted-pair feeder connects
Connect, the NTXT matrix of measurement circuitry is searched maximum possible
The accumulation bit rate, and attempt to generate high-speed link.
The modulator-demodulator modulator-demodulator has following four kinds of orthogonal states: (1) synchronously-
State realized synchronously, occurs line fault when synchronous when losing;
(2) shine upon-connection has been mapped to the spy of the other end
The modulator-demodulator of setting the tone; (3) use in-HSAS
Use; And (4) safeguard-are safeguarding modulatedemodulate
Transfer device, so high-speed link can not use this modulator-demodulator
Bandwidth.
Passive bus provides the node at line center, joins to a plurality of users from this node
Line.
Remote node is positioned at the HSAS equipment of remote node.
HSAS
Summary
By the unshielded twisted pair copper cable equipment that the uses local loop apparatus and method as the high speed data transfer medium are provided, the invention solves the problems referred to above relevant with prior art.The present invention aims to provide the transmission equipment of a kind of high bandwidth, high data rate, and the non-shielding copper cash that this equipment uses lower bandwidth in local loop equipment is to as transmission medium.The high data rate of supporting is the data rate that optical fiber link is supported, as 34,45,155Mbps or higher.The present invention can be transmitted above-mentioned high data rate signal with symmetry or asymmetric manner, and can be in several miles reliable transmission, have alternative high performance price ratio, that can dispose fast thereby provide, to replace the optical fiber in the loop.
The present invention includes the transmitting and receiving apparatus that is positioned at the data channel two ends, data channel can be moved on both direction simultaneously, thereby a kind of bidirectional high speed transmission equipment is provided.Application-specific of the present invention is the copper cable environment division of local loop, wherein local loop is connected to remote node with CO, as, the telecommunications patch case in Cabinet, curbside rack or the building basement, its median centre or passive bus reside in the above-mentioned position.By using above-mentioned transmission equipment, can on the existing copper cable infrastructure of local loop, provide broadband services.The present invention is not limited to use the present invention on local loop equipment, but can use the present invention in having the environment of various copper cash, utilizes and use the present invention in the campus, in building.
The feed line of local loop partly generally includes the non-shielding copper twisted pairs that is used to be connected CO and remote node with distribution.The longest part of the local loop of this part cable most critical, and formation usually.In order to obtain the link of more speed, operator wishes to utilize optical fiber to replace above-mentioned part.The objective of the invention is to,, stop and utilize optical fiber to replace above-mentioned part by improving above-mentioned partial data transmission.
Fig. 3 represents to be used for the block diagram of illustrated example network, and this network is connected to certain node via the high-speed link on the copper cable equipment of the high speed access system (HSAS) that adopts the present invention with CO.Use the present invention to need not to dispose the optical fiber that replaces copper cable equipment.
Usually, the network of reference number 110 signs comprises the high speed access system of the present invention (HSAS) 130,146 that links to each other with the two ends of copper cable equipment 150.The one end resides in the CO120, and the other end resides in the remote node 144.Conversely, HSAS is connected to a plurality of equipment, this equipment comprises switch 122, integrated access device (IAD) 124 on the T1 line, the packet data network on the T3 line (PDN), the PBX 132 on the T1 line, local peer inserts 136, and the intra-office LAN 138 that links to each other with internet 134.Conversely, switch 122 is connected to PSTN 116,, switch 122 is connected to ISP 114 via T1 line via the TI circuit.Via analog line, IAD 124 is connected to PSTN.
Remote node comprises the 2nd HSAS 146, terminal block 148 and one or more multiplexer 154.Via T1 line, multiplexer is connected to various CPE such as PBX 152, via T1 line, multiplexer is connected to IAD 162.IAD has one or more coupled equipment 164, as telephone set.Via twisted-pair feeder, a plurality of DSL modulator-demodulator elements 160 that will be positioned at user terminal are connected to the DSLAM 158 that is positioned at remote node.Via the high-speed link such as T3 line, DSLAM is connected to HSAS 146, thereby, data is sent to CO via copper cable equipment 150.Local peer inserts 136 devices as control, the local and remote HSAS of management.
In the example shown, second switch 122 provides required additional capabilities.In CO 120 and remote node 144, dispose HSAS, rather than deployed fiber.Via HSAS 146, at the high-speed link of the copper cable its upper side administration multiplexer 154 in from the switch in the CO 122 and other equipment to remote node, the high data rate traffic that this aggregation of links stops at HSAS 130.Via HSAS equipment 130,146, re-route a plurality of twisted-pair feeders 140 of previous MDF 170 of connection and terminal block 148, thereby will be connected to twisted-pair feeder 156 from the twisted-pair feeder 128 of MDF, the latter is the input of terminal block 148.Note that twisted-pair feeder 140 is parts of blister copper cable 150.
At CO end, HSAS 130 combinations from various data sources (as, switch 122, PBX 132 etc.) data and from the telephone service of twisted-pair feeder 128, through a plurality of copper stranded conductors 140 data splitting is sent to remote node 144 then.At node side, HSAS 146 receives combined information by a plurality of twisted-pair feeders 140, then this information is divided into the high speed data link 147 and the low rate telephone service of inputoutput multiplexer 154, wherein via copper stranded conductor 156, telephone service is routed to terminal block 148.
Note that example application shown in Figure 3 only represents that the present invention's of HSAS may use example.Be appreciated that, between two positions that a plurality of copper stranded conductors connect, dispose high-speed transmission equipment if desired, and whether simultaneously on above-mentioned copper stranded conductor provide telephone service, those of skill in the art all can be applied to HSAS of the present invention various other application if no matter needing.
Fig. 4 represents a plurality of cable bindings in the bunch of cables.Blister copper cable 180 comprises many bindings 182.Each binding contains 10,12,13,25,50 or more to copper twisted pairs 184.Cable 180 comprises a plurality of cable bindings 182.Link between the HSAS equipment comprises many copper stranded conductors 184.Note that a plurality of twisted-pair feeders that are used to connect two HSAS equipment not necessarily in same binding, but can cross over a plurality of bindings.In addition, can be by belonging to the different set of twisted pair of same cable, connect a plurality of HSAS system.
Usually with the feeder cable of blister copper cable 180 as one or more serving area interfaces, serving area interface connects feeder cable and distribution cable, and distribution cable is through reaching user terminal than short distance.Slightly pull 180 and comprise 1000 to 3000 pairs of copper stranded conductors.At the CO end, cable is introduced equipment (CEF) (that is, the cable vault) via cable and is entered, and copper stranded conductor stops at distributing frame.Distributing frame will be thicker the external equipment pair cable be connected to terminal equipment, the latter is connected to network with twisted-pair feeder.
The characteristic of the copper conductor in the cable is that the relative position between the twisted-pair feeder in the electric parameter NEXT between twisted-pair feeder and FEXT crosstalk and the structure of binding (that is, isolating relatively) and the binding (that is distance) is closely related." dielectric property (Media Characteristics for High-Speed DigitalTransmission in NTT ' s Local Networks) of the high-speed figure transmission in the NTT local area network (LAN) ", the ieee communication journal, vo1.E.80-B, No.2, in February, 1997, p 345-356 describes above phenomenon in detail, and this paper quotes as a reference.
HSAS equipment comprises some parts, and can realize in different ways.Some exemplary embodiment below are provided, and a kind of execution mode adopts the Time Division Multiplexing mode that HSAS equipment is described, another kind of execution mode adopts frequency division multiplexing (FDM) mode that HSAS equipment is described.Below describe above dual mode in detail.
The HSAS:TDM execution mode
Fig. 5 represents to be used to illustrate the block diagram of the present invention's HSAS, and the purpose of structure the present invention's HSAS is to utilize the integrated routine call business of Time Division Multiplexing.The HSAS of reference number 190 signs comprises: one or more traffic channel module (SCM) 192, telephone service module 194, send data processor 198, receive data processor 218, transmitter 200, gatherer 216, whole modem module 203, switch 206, master controller 229, test module 210 and power supply unit 214, wherein whole modem module 203 comprise that label is a plurality of modulator-demodulators 204 and the described below cross-interference elimination device (optional) of #1 to #M.
SCM serves as from the input data link 222 of CO and the ultrahigh speed bidirectional line interface between the HSAS equipment 190.SCM provides circuit termination, synchronous and clock recovery at its receiver, provides circuit termination, line coding and signal to amplify at its transmitter.SCM can provide stabilizing clock and input traffic to HSAS from the input data link.In the opposite direction, SCM receives the data flow that outputs to data link 222.Support several data speed, for example, T1 (1.544Mbps), T3 (45Mbps), E1 (2.048Mbps), E3 (34Mbps), OC-3 (155Mbps) and STM-1 (155Mbps).Be appreciated that also and can support other speed, comprise higher rate or low rate more.According to the present invention, in SCM, provide multiplexer, so that will a plurality of low rate inlet flows such as T1 or E1 be multiplexed with the inlet flow of higher rate.Note that the data link that to support multiple other types, and the present invention is not limited to link described herein.Be appreciated that the technical staff knows the structure of above data-interface.
Via bus 220, will arrive data processor 198 from the data forwarding of SCM.Data processor 198 is suitable for receiving the single high-speed data-flow from a plurality of SCM 192.Input traffic is carried out scramble (scramble), FEC coding and interleaving treatment, be input to transmitter 200 then, thereby improve noise and the immunity of crosstalking.Transmitter comprises one or more transmission tables, utilizes to send the data that table buffering need send to each modulator-demodulator 204.The data that are input to transmitter are divided into a plurality of data flow than low rate, and each data flow is suitable for particular modem.Be appreciated that this system can comprise other well-known signals, the part realization of data processing block and processing block disclosed herein, and do not deviate from scope of the present invention.
Can use any appropriate method to distribute inlet flow to each modulator-demodulator.A kind of method is a circulate circle figurate number position mapping techniques.Second method is the circular mapping of Inverse Multiplexing over ATM.The technical staff knows above two kinds of distribution methods.The third distribution method is below described.
Via bus 202, these data are sent to modulator-demodulator 204 from transmitter 200.Modulator-demodulator comprises the DSL modulator-demodulator element of any adequate types, as meets T1E1.4HDSL2 standard modem element.By switch 206, the output of modulator-demodulator is connected to copper equipment 208.
On receive direction, via bus 202, the low-rate signal with on a plurality of twisted-pair feeders of modulator-demodulator 204 receptions is forwarded to gatherer 216, and is combined as single high-speed data-flow.Then above-mentioned high-speed data-flow is input to and receives data processor 218, the latter carries out deinterleaving (de-interleave), fec decoder and descrambling (de-scramble) to the data flow that receives.This data forwarding to SCM and telephone service module, is imported data link and telephone service circuit to be sent to respectively.
As selection, can use the xDSL assembly that can on the uplink and downlink direction, transmit to realize that line is to selecting.At this moment, according to the order of master controller, in transmitter 200 and gatherer 216, realize that the flexible data of said modules is switched.Therefore, the function of switch module 206 being reduced to, is that test purpose is carried out circuit and switched.
During operation, be suitable for keeping communication link between them at the main controller module of the CO of communication channel end and remote node end.This communication link is used for following purpose, as coordinating the operation at two ends, swap operation state etc.
When needs when remote equipment provides electric power, the HSAS that is positioned at CO end comprises the DC/DC conversion equipment, is used for low voltage is converted to high voltage.By using well-known differential supply scheme,, on two or many twisted-pair feeders, transmit composite signal as balun (that is, balancedunbalanced) method.Can use well-known standard handovers technology or use the DC/DC transducer that to have bought from the market, realize above-mentioned conversion.
At the remote node end, power supply unit comprises and is used to collect one or more feed currents to generate the device of single integrated drive generator.By using well-known rectifying device in the electronic technology, progressively reduce combination voltage.In addition, power supply unit is suitable for supporting battery charge, and comprises the reserve arrangement that can not interrupt, more than two kinds of technology are known technologies.
Be positioned at the CO end of communication channel and the test module of remote node end,, carry out and measure by the coordination between two test modules on a certain communication link on one or more twisted-pair feeder.The storage measurement structure is used for the master controller of CO end and remote node end.
Test module comprises conveyer, and the latter can generate the tone with different frequency and amplitude variable.This module also comprises frequency selective reception device, and this device is suitable for amplifying the signal of reception, uses variable band-pass filter to filter this signal for reducing noise jamming, and measures synthetic received power.Simultaneously, the circuit that test module is suitable for providing suitable stops, if any measurement needs.Note that and to use any appropriate device that comprises the standardized digital signal treatment element to realize above the transmission and receiving system.By utilizing xDSL modulator-demodulator element to transmit various known data sequences, also can realize above measurement.Receive known array at the other end, compare then.
Utilize switch 206, the twisted-pair feeder that disconnection is being measured is connected with modulator-demodulator 204, is connected to the test module 210 that is positioned at CO end and remote node end then.Master controller 229 can be redirected on current other twisted-pair feeders of measuring in advance with the pay(useful) load transmission on the twisted-pair feeder of wishing to measure.Its prerequisite is to exist the redundant line be used to measure purpose right.
By coordinating to be positioned at two test modules at channel two ends, measure.For example, for measurement circuitry decay, the test module that is positioned at a certain end sends a signal, then by certain communication link on the twisted-pair feeder of testing, with the Frequency Transfer of this signal to the other end.In response, the test module that is positioned at the other end with its filter be tuned to characteristic frequency, measure the power that receives then.Then,, power measurement is passed back to the other end, so that further handle by this communication link.
The HSAS:FDM execution mode
Fig. 6 represents to be used to illustrate the block diagram of the present invention's HSAS, and the purpose of structure the present invention's HSAS is to utilize the integrated routine call business of frequency division multiplexing (FDM).The HSAS of reference number 230 signs comprises: one or more traffic channel module (SCM) 234, send data processor 236, receive data processor 268, transmitter 240, gatherer 266, whole modem module 243, switch 246, test module 262, separator 248, master controller 269, mains switch 256 and power supply unit 254, wherein whole modem module 243 comprise that label is a plurality of modulator-demodulators 244 and the described below cross-interference elimination device (optional) of #1 to #M.
For the class of operation of the TDM mode of the operation of the HSAS of FDM structure and HSAS shown in Figure 5 seemingly.Therefore this paper no longer repeats its detailed description.Yet the main distinction that note that two kinds of execution modes is to upload at twisted-pair feeder the mechanism of transmission of electricity call business data.In the TDM execution mode, utilize the multiplexed data signal telephone service signal of the upper frequency of modulator-demodulator 244 outputs, cause carrying out in time multiplexing composite signal.In the FDM execution mode, by using separator 248, multiplexing telephone service signal on frequency.
Mains switch 256 is suitable for receiving a plurality of low speed telephone service circuits 260 and from one or more power line 255 of the High voltage power supply equipment 254 of CO end.The corresponding power supply unit that will be positioned at remote node is connected to and is suitable for collecting in the load of assisting feed current of a plurality of circuits 250.
The surveillance equipment that mains switch 255 comprises simultaneously and the CO end links to each other with each telephone service circuit 260 of remote node end (as, transducer).Via the high impedance device, surveillance equipment is connected on the telephone service circuit, thus the not normal running of interfering phone business.
Mains switch 256 also comprise many switches (as, dynamo-electric or solid-state), each switch is connected to separate lines.Each switch can be connected to telephone service circuit 260 or high voltage source 255 with split circuit 258 according to order.
At CO end, voltage switch is fit to, thereby when not having simultaneous telephone service session on the specific circuit, mains switch can disconnect above-mentioned specific circuit 264 and telephone service circuit 260, and this circuit is connected to power supply unit 254.At the remote node end, all circuits that mains switch is suitable for self-separation device in future are connected to load rather than are connected to the telephone service circuit, thereby can upload the through one or more auxiliary currents of transmission of electricity current feed at copper stranded conductor 250.When utilizing power supply to replace the telephone service signal, standard circuit is stopped being applied to battery supply being applied on the end-user device of remote node end on the telephone service circuit of CO end.
At CO end, the telephone service conversation request of the surveillance equipment in the mains switch 256 on can detection line j (that is, detect in the POTS circuit off-hook).In response, mains switch disconnects circuit j and the power supply 254 in a plurality of circuits 258.If the remote node end detects the telephone service session, then mains switch can disconnect this circuit and load.Note that and to adopt any appropriate device to detect the telephone service conversation request, comprise existing simulation off-hook detection circuit or well-known Digital Signal Processing.
Simultaneously, CO end and remote node end communicate, to coordinate the handover operation at two ends.When stopping the detected telephone service session of surveillance equipment, the mains switch of CO end and remote node end can switch back to circuit j the power feed position.
Importantly, mains switch is suitable for carrying out switching according to time coordination, thereby can realize switching synchronously and suitable electric wiring discharge at CO end and remote node end simultaneously.
Above-described process is statistical " multiplexing " process, according to the telephone service traffic, powers to remote node.Mains switch comprises the device of the demand of utilizing the long-range node side of telephone service traffic statistics numeral balance.
Provide rechargeable battery at the remote node end,, and guarantee to provide battery to end user's CPE with restarting of the HSAS that guarantees the remote node end.When battery when discharging fully, the cell switch of CO end is suitable for applying strict upper bound to the telephone service traffic, until battery is fully charged.
Universal component
Fig. 7 represents to be used to describe in detail the block diagram of exit portion of the present invention's HSAS.The exit portion of the HSAS equipment of reference number 270 signs comprises: SCM 274, processor 276, whole modem module 279, clock circuit 282 and telephone service module 284, wherein whole modem module 279 comprise link to each other with twisted-pair feeder 280 and cross-interference elimination device described below (optional), label is a plurality of xDSL modulator-demodulator elements 278 of xDSL # 1 to xDSL #M.
In the present embodiment, HSAS equipment 270 comprise a processor 276 (as, microcomputer, microprocessor, programmable logic array etc.), the latter can receive ultrahigh speed data flow and the clock signal from SCM274.SCM is suitable for extracting clock signal, and generates data-signal according to input data link 272.Clock signal is input in the clock circuit 282, and the latter can be divided into this clock signal one or more low-speed clocks, is used for the timing and synchronously of the transmission process of xDSL modulator-demodulator element 278.Can use known assemblies and known technology such as PLL, counter, the realization clock is cut apart.
Low speed telephone service, ISDN, low speed n*64 kbps data service, switch type 56 that telephone service module 284 is well-suited for such as voice or POTS provide interface, and the middling speed interface such as T1 (1.544Mbps) or E1 (2.048Mbps) is provided.At the telephone service end, circuit 283 provides required bidirectional line expiry feature with relevant interface, protection as everyone knows (as, luminous, overvoltage, overcurrent etc.), physical layer signaling, line fed etc.
At the HSAS end, the telephone service module provides multiplexer, and this device is suitable for utilizing the TDM technology that the low speed telephone service is multiplexed into digital data link 286.Use TDM by input high-speed data-flow output, multiplexing above multiplexing telephone service with SCM 274.On copper stranded conductor 280, synthetic multiplex data signal is transferred to the far-end of communication channel.At receiving terminal, telephone service connected from high-speed data multichannel decomposes (Fig. 8) on the data link 305 on the road.The telephone service module 302 that is arranged in remote port can be used the telephone service of the known technology multichannel decomposition of electronic technology from data link 305, and this telephone service of reconstruct.
When using TDM transmission telephone service line signal shown in Figure 5, telephone service module 284 utilizes 285 pairs of telephone service signals of clock to sample.By using clock signal 285, telephone service module 284 is directed to data flow 286 the TDM multiplex element 277 of installing in the processor 276.The data flow that TDM multiplex element 277 will be multiplexed with higher rate from data flow and the telephone service data 286 of SCM.
The data flow of higher rate is divided into the Frame that a plurality of length are L,, Frame is carried out scramble, error correction coding and interleaving treatment, via the data circuit 288 of modulator-demodulator Tx, be forwarded to modulator-demodulator 278 then by using well-known technology.For example, by using well-known parity check code or Reed Solomon sign indicating number, generate the error correction coding overhead data.The result of error correction coding is the code word of K for the length of transmission in each transmission cycle.Can carry out pre-programmed to processor 276, to carry out this type of encryption algorithm.Can adopt the coding integrated circuit that can buy from the market (as, be positioned at the integrated circuit that the AdvancedHardware Architectures company of State of Washington Pullman produces) or FPGA instrument.Can be in processor 276 many these type of encryption algorithms of precoding, wherein each algorithm is suitable for the reliability requirement that specific circuit state, effective transmission speed and external piloting control system device or CPU select.
Base (clock signal 281) during given general transmission can be derived the common transmission frame timing cycle of all transfer elements (that is xDSL modulator-demodulator element 278).In the above frame period, (wherein the effective speed of 0＜i＜M) (is designated as t corresponding to the bit number that transmits in each transmission cycle to each transfer element i
i).
For the M that a combines transfer element 278, think that length K is smaller or equal to the bit number t that transmits in each transmission cycle
iSummation.For each frame period, be that the code word of K is divided into t with length
iThe t of bit
IPart, wherein transmission i part on the i transfer element.
Just as known in the art, on a plurality of transfer elements 278, before the transmission, be the Frame of K bit by using the timely weaving length of interleaving treatment, realize the error correction robustness in the transmission course.
At receiving terminal, for the Frame of correct reorganization transmission, master controller transmits transmission parameter to receiving HSAS.For example, this type of parameter comprises employed interweave and the error correction coding scheme, frame length, the effective speed of each transmission channel.Above-mentioned communication can utilize one or more overhead data channels, perhaps uses the embedding operation channel as the part of xDSL modulator-demodulator element.As selection, can use control channel to transmit above parameter, wherein HSAS is multiplexed into this control channel on the high-speed link that connects two ends.
Because transmission is adjusted into transfer element 278 during data base when general, so the data that can use the framing signal adjustment of the xDSL modulator-demodulator element that is positioned at receiving terminal to receive.As selection, can on copper stranded conductor, send and be exclusively used in universal synchronization clock above-mentioned purpose, that use for CO end and remote node end.
Fig. 8 represents to be used to illustrate the block diagram of intake section of detailed the present invention's HSAS.The intake section of the HSAS equipment of reference number 290 signs comprises: whole modem module 291, buffer 294, processor 296, SCM 298, synchronously and control circuit 304 and telephone service module 302, wherein whole modem module 291 comprises that label is a plurality of xDSL modulator-demodulator elements 292 and the described below cross-interference elimination device (optional) of xDSL # 1 to xDSL#M.
The transmission signals that xDSL modulator-demodulator element 292 receives on the twisted-pair feeder 290, xDSL modulator-demodulator element 292 can be exported data 301 and and a plurality of synchronizing signals of reception.Synchronizing signal is input to synchronously and control circuit 304.Adjust the signal 301 that buffering receives in the buffer 294 in speed, be input to processor 296 then.The processor high-speed data-flow of can recombinating, and these data are forwarded to SCM 298 with relevant clock.SCM exports its speed high-speed data-flow 300 approximate with the speed of the initial high-speed data-flow 272 (Fig. 7) that transmits.
As together with 276 explanations of the processor in the outlet 270 (Fig. 7) of HSAS,, a plurality of low rate data streams are reassembled as high-speed data-flow by circulation mapping method or Inverse Multiplexing over ATM technology.
Simultaneously, processor 276 can be applied to identical error correction coding scheme the data by a plurality of twisted-pair feeders 308 receptions.Error correction coding processing and utilizing redundant system overhead data, it is wrong to be corrected in the institute that finds in the reception data.This processor is used deinterleaving processing and scramble process to receiving data, thereby these data are adjusted into the original transmitted sequence.This processor utilizes the time stamp synchro system overhead data that receives on a plurality of data flow 301.These data are used to adjust and compensate the delay between the low rate channel of different rates.
Together with the TDM realization of HSAS shown in Figure 5, except that high-speed data-flow 300, in the data that processor 296 can also receive from a plurality of low rate data streams 301, extracted data signal 305.Data-signal 305 is input in the telephone service module, and the telephone service module is carried out multichannel and is decomposed, so that provide suitable telephone service signal for coupled a plurality of telephone wires.Can use well-known time-division multiplex technology, from the data that receive by copper stranded conductor, extract telephone signal.Output signal 305 transmits through the multiplexing telephone service of the TDM of over-sampling.In addition, provide recovered clock signal 309 to the telephone service module.
From inlet HSAS 290, in the receiving unit of xDSL modulator-demodulator element 292, receive a plurality of data flow 301 of different rates, and the timing signal 303 (that is, clock and framing signal) of each element generation.Timing signal is directed to synchronously and control circuit 304, utilizes this signal to derive the control signal 307 of buffer 294.For the data flow of each reception provides a buffer 294.
Buffer can be adjusted the data of reception, postpones with the difference that compensates in the various data flow.Framing signal is served as the reference point of adjusting processing.
1. with t
IBit combination is that length is the code word of K bit.
2. if when transmission, carried out scramble or interleaving treatment, then rearranged everybody order.
3. carry out the error correction decoding function, the institute that uses the redundant data correction to find is wrong.Every frame remains the code word that length is the L bit.
4. utilize TDM technology multichannel from error correction data decompose relevant telephone service data flow and with its synchronous relevant clock.
5. by data circuit and relevant clock line, SCM 298 is arrived in remaining high-speed data transfer.
It is multi-thread to transmission equipment that modulator-demodulator element among the HSAS is formed one two-way (or unidirectional), and this equipment connects a plurality of copper stranded conductors on a plurality of digital data streams (arrive the M outlet data stream 288 of cable and from the M entry data stream 308 of cable) and this cable.Note that data flow can have different rates.Each modulator-demodulator element comprises one of known xDSL technology such as HDSL, SDSL, HDSL2, ADSL, VDSL or any other suitable xDSL technology.
Each modulator-demodulator element is supported the single low rate data streams (288 among Fig. 7,301 among Fig. 8) of digital end, and is to receive and/or send (that is transmitting-receiving) this data flow to prepare on one or more twisted-pair feeder of cut cable (280,290).The number that note that the twisted-pair feeder of each modulator-demodulator element can be greater than 1, and its number depends on and is the selected xDSL technology of application-specific.
The modulator-demodulator element that uses is suitable for two-way (that is symmetry) communication or (2) asymmetric communication such as ADSL support (1) such as HDSL or the HDSL2.When using the asymmetric modem element, transmission occurs on the both direction of different twisted-pair feeders.As hereinafter will describing in detail, can be according to application, for optimal allocation, the NEXT of the data flow of line centering eliminates and gain controlling structure special device, to avoid interference other signals in the copper cable equipment.
Note that for every twisted-pair feeder above-mentioned xDSL technology can be moved with different rates, this depends on the characteristic of every circuit.According to the present invention, the information of the interior spatial structure by the relevant used cable (cable as shown in Figure 4) that provides to HSAS is provided can strengthen the performance of the modulator-demodulator element among the HSAS aspect speed and scope.This type of information comprises the structure and the composition of the binding in the cable.The relative position and the electric parameter (comprise and crosstalking) thereof that also comprise the twisted-pair feeder in the binding.Cause the main cause of crosstalking to be near radiation, that is, and NEXT.Utilization is represented the useful information of relevant NEXT at the numerical value of the transfer function of the different frequency of the CO of any two specific twisted-pair feeders end and the measurement of remote node end.
To HSAS equipment provide with different bindings or single binding in a plurality of lines to relevant above-mentioned information, its method is (1) by test module of installing in the HSAS, carries out hand dipping or measures automatically; (2) cable manufacturer's information applicatory may comprise crosstalking and the nominal decay of copper stranded conductor in the binding under the worst case; Or (3) measured automatically by the adaptive filtering device, and this filter is used to realize that NEXT eliminates.In the thick laundering period, filter makes its transfer function be fit to expression NEXT transfer function, for example, uses LMS adaptive method (NEXE is eliminated error as adapting to the feedback of handling).In the accurate laundering period, that is, when operation, use NEXT to eliminate Error Feedback and continuously accurately adapt to.
As selection, HSAS comprises the NEXT cancellation element that utilizes well-known Digital Signal Processing to realize.The NEXT cancellation element be suitable for according to the transmission line of measuring between the operation of NEXT transfer function.In receiving element, disturb in order fully to reduce the NEXT that causes from crosstalking of other transmitters, carry out following process.Usually, the NEXT arrester can generate the estimation of NEXT transfer function.By using this function, generate the estimation of disturbance NEXT signal, from received signal, deduct this estimation then.
To j=1 to the transmission twisted-pair feeder of N and i=1 to the reception twisted-pair feeder of M, carry out this process.H
Ij(f) expression depends on the measuring frequency of line to the NEXT transfer function between i and the j.R to received signal
iWith transmission signals T
jSample, by using well-known Fourier techniques in the signal processing technology, be transformed to frequency domain then.
Utilize the received signal after formula 1 calculates the NEXT elimination.
RX wherein
i(f) i received signal after expression NEXT eliminates.Subsequently, by using well-known inverse fourier transform technology, with RX
i(f) be transformed to time domain, thereby time-domain signal is provided.
As selection, such just as known as technical staff, by using NEXT transfer function H
Ij(t) time-domain representation, the received signal after calculated in time domain NEXT eliminates fully.In the time domain and frequency domain realization that NEXT eliminates, utilize LMS automatic adaptation FIR filter to estimate the NEXT transfer function.
According to the present invention, test module 210 (Fig. 5), 262 (Fig. 6) are suitable for period measurement H
Ij(f), wherein can be with H
Ij(f) be expressed as the two-dimensional matrix that is called crosstalk matrix.Test module monitoring cable parameter, and the change of compensation discovery.Cable data depends on the environmental factor such as temperature and humidity.When calculating the NEXT cancellation element in the future, the H that test module generates through upgrading
Ij(f) replace old H
Ij(f).As selection, can the use test functions of modules and the combination of LMS automatic adaptation FIR filter, realize above the adaptation.
Can eliminate process to carrying out above-mentioned NEXT to all transmission lines, or only to the part transmission line to carrying out above process, to reduce computational complexity.At this moment, computational process only comprises that the line with serious NEXT problem is right.Test module is suitable for selecting according to crosstalk matrix.
As selection, the modulator-demodulator element that uses among the HSAS can comprise discrete multi-tone (MDT) modulator-demodulator element.This null modem element is suitable for each different tone is independently carried out NEXT removing method of the present invention.Thereby can be that each line is right independently of one another, for example eliminate resource, select the worst interfering frequency flexibly for distributing.
The self adaptation of crosstalk matrix is estimated
If (1) do not have relevant NEXT transfer function H
Ij(f) or H
Ij(t) (that is) metrical information, crosstalk matrix, perhaps the dynamically adapting of (2) previous transfer function of measuring changes in time, and then the NEXT cancellation element is suitable for the characteristic that adaptive feedback method that the operation technique personnel know is estimated transfer function.By using heuristic can realize this type of feedback method, wherein to each may match (i, j), with NEXT transfer function H
Ij(f) or H
Ij(t) different parameters collection substitution has in the addition elimination process of negative sign.For each parameter set, measure the energy of received signal RX (f).
Select its energy to reach the parameter set of minimum value, as H
Ij(f) or H
IjThe estimation transfer function of specific set of parameters (t) uses this function then in NEXT elimination process.Receive twisted-pair feeder to every and repeat said process.
Another kind of appropriate methodology comprises use adaptive filtering device, wherein utilizes this filter to realize the NEXT elimination algorithm.In the thick laundering period, above-mentioned filter makes its transfer function adapt to coupling NEXT transfer function, for example uses the LMS adaptive method, and NEXE is eliminated the feedback of error as the procedure of adaptation.In the accurate laundering period, for example when operation, above-mentioned filter uses NEXT to eliminate Error Feedback and realizes continuously accurately adaptation.
Through-put power control and entrance and exit PSD control
When (1) HSAS equipment of the present invention can use one or more whole bindings as the communication channel of high speed data link transmission and when (2) implement NEXT elimination algorithm described herein, can carry out following performance enhancing.
At first, select the line signal more responsive to noise at more close center in the binding, owing to can protect of the interference of these lines better to the interference source that is not subjected to the binding outside to transmission.Can on the twisted-pair feeder on more close binding surface, transmit the more signal of robust.
Can use above-mentioned technology to provide more insulation blockings for the line of more close center (be generally to) being gone up the more responsive signal of transmission at the line of more isolating.The required SNR surplus of the sensitivity of signal and its operation is directly proportional.The SNR surplus that needs is high more, and sensitivity is high more.For the particular modem element, the sensitivity of up-downgoing transmission direction can be different.
In addition, can use above-mentioned technology to provide more insulation blockings as the signal that transmission has higher PSD radiation.Thereby higher channel capacity is provided, transmission environment is caused more interference.When using asymmetric xDSL technology on each twisted-pair feeder, above-mentioned technology is very appropriate.The well-known ADSL scheme of a kind of applications exploiting of this kind principle, thus on the different Cu twisted wire, transmit two opposite up-downlink directions simultaneously.
As selection, by use the line of more isolating to and use well-known full duplex echo cancellation technology, can utilize constructed on identical copper stranded conductor directional transmissions ADSL signal.
Can perhaps by utilizing the HSAS user interface to carry out manual distribution, realize that line is to selecting by the master controller of switch according to the information that provides to the end user.
Secondly, the not collinear variable gain controlling schemes in the binding to each last transmitting data stream, based on certain line arbitrarily pair with near the line on binding surface between the isolation of measurement.When implementing this scheme, line can transmit more high power more to isolating more under the situation of not violating the PSD rule, wherein the peak power sent from binding of PSD rule limits.This scheme can significantly strengthen the transmission performance on the twisted-pair feeder.As selection, above gain controlling scheme can be that frequency is selected, thereby makes gain adapt to line with characteristic frequency to related isolation.
The structure of above-described gain controlling comprises that (1) directly applies to the gain controlling of xDSL modulator-demodulator element and/or the gain controlling line amplifier on (2) each copper stranded conductor.
As long as the modulator-demodulator element is suitable for supporting outside gain controlling, just gain controlling can be directly applied to xDSL modulator-demodulator element.Note that if the xDSL element based on well-known DMT technology, then can be used various gain control on each different tone, thus the gain control that provides frequency to select.
Can only on each copper stranded conductor on the direction of transfer, use the gain controlling line amplifier.Knowing in electronic technology, can utilize the operational amplifier that has the numerical control switch to realize this class A amplifier A, wherein the numerical control switch is selected different resistance values in the feedback loop of amplifier.By using test entity such as test module 262 (Fig. 6) to test the up-to-date isolation parameters of acquisition, the cycle is upgraded gain control parameter.
The PSD rule that is no more than most of country /region in order to ensure the total radiant power on binding surface (for example, the rule that the FCC of the U.S. or other PTT in the world work out) boundary line that is provided with, test module is suitable for measuring carrying out PSD near the cycle on the twisted-pair feeder of binding outer surface, thereby monitors and provide feedback to gain control process.Measure the element that uses by switching NEXT, the execution cycle test.As mentioned above, can under the situation that does not reduce channel performance, carry out above-mentioned measurement.For above-mentioned each binding, when the spectral power radiation is in the boundary line of FCC or PTT promulgation, can on than the independent binding of blister copper cable, transmit a plurality of high-speed links.
The circuit isolation measurement
Fig. 9 represents to be used to illustrate the flow chart of circuit isolation measurement method.A plurality of shielding wires that the circuit partition method can be located and shine upon in the given binding are right, and these lines are to being used for the power control of entrance and exit PSD controlling schemes.At first, open and the xDSL modulator-demodulator element of each line, and on this circuit, do not transmit any signal (step 630) linking to each other.Then, utilize built-in inside SNR meter or received power meter in the xDSL modulator-demodulator element that major part can buy from the market, measure the right noise level (step 632) of each line.Because the modulator-demodulator element at these circuit two ends does not transmit, so the power of disturbance that the power measurement representative receives on specific circuit.Therefore, the relative measurement isolated of the circuit that this measurement can be interpreted as isolating with external disturbance.Lower received power or SNR measure the relative isolation that expression strengthens.
Then according to the order of degree of isolation to isolation measurement ordering (step 634).Measure for SNR, low SNR represents high the isolation.Then according to sensitivity, to the signal ordering (step 636) that on all routes, sends to disturbance.With two list mapping to together, so that the circuit (step 638) of more isolating to more responsive signal allocation.Note that the switch 206 (Fig. 5) that can use between modulator-demodulator element and circuit, distribute.Note that simultaneously this method can shine upon the isolation of circuit, and do not consider the position of this circuit in binding, also do not consider the position of the binding in this wire harness.
Below explanation utilize crosstalk matrix determine in the given binding (that is, the line at more close center to) shielding wire more right be equipped with selection method.
To each row i of crosstalk matrix, calculate the summation of the norm of all elements the element on diagonal of a matrix.Can be with summation R
iBe interpreted as the measurement of the right summation of crosstalking of every other line in the binding on the circuit i.Then according to its quantity logarithm value R
iOrdering.R
iHigh more, line is to the closer to the center.
In addition, when distributing a plurality of lines to high-speed link to 140 (Fig. 3), use following scheme line to putting into one or more groups, every group is the part of different bindings.Note that and adopt unknown mode partition line between all bindings right this moment.
Two adjacent lines in given certain binding between worst case under isolation function H (f) (measurement unit is dB), and two lines of different bindings between worst case under isolation function H
b(f) (manufacturer provides by cable), each line on the transmission tone signal S (f) (f is a low frequency, as 100kHz).Right each line of other lines on, measure the received power of same frequency.
Note that and utilize test module 210 (Fig. 5), 262 (Fig. 6) to carry out transmission and measurement.The power level (dB) of transmission signals S (f) is the noise limit power level, that is, and and N (f)+H (f)+H
b(f)-3dB.
Only the line in the right same binding of transmission line on, receive and also to measure the signal that surpasses noise lower limit.Think that the institute with direct or indirect transmission relation is wired to belonging to same binding.For example, iff online to receiving line on 2 and 3 to the transmission on 1, then line to 2 and 3 and line have direct transmission relation to 1.If it is online to receiving that line to the transmission on 3, thinks that then line has indirect reception/transmission relation with line to 1 to 4, thereby line is assigned to same binding to 4 on 1 and 4.
In addition, with a plurality of lines to after being mapped to different bindings, it is right to use the line that any means in the said method shines upon in each binding, so that carry out power control and entrance and exit PSD control.
The optimal allocation of through-put power
As mentioned above, the function of transmission equipment is a plurality of signals of transmission in certain binding or on a plurality of copper stranded conductors in a plurality of bindings of certain wire harness.In order to observe the PSD rule, the through-put power of these signals must be observed the PSD shielding of above-mentioned rule predetermining.The purpose of above-mentioned rule predetermining limit is, avoids in certain binding or the no control of the various xDSL business that send in a plurality of bindings of certain wire harness intersects the destroying infection of disturbance.
Therefore, use separately, should verify that whole PSD of this binding outer surface observe the PSD shielding rules if the HSAS system is distributed in whole binding.In this binding, HSAS can be according to making the optimized mode of total throughout select the PSD of different modulating demodulator element, and the total PSD that is radiated on the copper stranded conductor of this binding outside from this binding observes all PSD shielding rules applicatory simultaneously.
A kind of method that realizes above-mentioned processing is the through-put power that changes the right modulator-demodulator element of the inner wire of using binding, and continuous measurement simultaneously resides in the power on the circuit of this binding periphery.Can utilize with the line that resides in the binding periphery to inside received signal wattmeter or SNR meter built-in in the modulator-demodulator element that links to each other, major part can have been bought from the market, carry out power measurement.
As selection, can be with line to being connected to test module 210 (Fig. 5), to measure its PSD.Utilization online to and the modulator-demodulator element between switch 206 (Fig. 5) connect.In order to measure the PSD of different frequency, test module 210 can utilize various well-known Digital Signal Processings, as the technology based on Fourier transform.
The invention provides a kind of method of distributing through-put power, its NEXT elimination algorithm described herein that neutralizes is realized this method together.
The optimal allocation of transmission frequency bandwidth
Except that above-mentioned explanation, can utilize the various lines of above explanation that mapping method is distributed transmission frequency bandwidth.According in binding more shielding wire carry out above-mentioned distribution to distributing more multiband transmission manner.Total PSD on the copper stranded conductor that is radiated this binding outside from binding is maintained in the PSD shielding rules.Note that can be in the combination of common frequency of utilization of same HSAS and power distribution method.
Remote power feeding
With reference to Fig. 5, the HSAS that is suitable for the TDM operation comprises a power supply unit 214 that links to each other with a plurality of modulator-demodulator elements 204.HSAS can make up remote power feeding and transmission data on twisted-pair feeder channel 208.In only relevant present embodiment, on one or more copper stranded conductor, apply dc voltage with the TDM mode.The line that distributes for electric power transfer is to fixing, and can dynamically not change usually.
To be positioned at the DC output of the power supply unit 214 of CO end, be divided into a plurality of smaller DC electric current tributaries, wherein the line of one or more distribution on each tributary of transmission.Note that via copper stranded conductor independently and conduct the DC electric current of each polarity.Can use any suitable technique, as the multiport line transformer technology of knowing in the electronic technology, that the DC circuit bank is synthetic a pair of.
At the remote node end, collect and make up a plurality of DC electric currents, adjust then, with power supply as other equipment (optional) of the HSAS equipment that is positioned at remote node and this node.In addition, also can use battery, wherein utilize the electric current that provides battery charge.If the electric current supply discontinuity perhaps when overpower consumption occurring in short-term, provides back-up source by battery.
NEXT eliminates
Figure 10 represents to be used to describe in detail the whole modem module block diagram partly of the HSAS of the present invention that comprises NEXT elimination operation.In the present embodiment, the HSAS of reference number 310 signs comprises: label is a plurality of xDSL transmitters 314 of xDSL transmitter # 1 to xDSL transmitter #M, i xDSL receiving element #i 332, come control channel 322, the i NEXT of autonomous controller to eliminate parts #i 342 and analog interface circuit 324.Note that the xDSL technology that adopts according to reality, can realize transmitter 314 and receiver 332 separately, also can in an ASIC or IC, realize transmitter 314 and receiver 332 simultaneously.
Each xDSL transmitter 314 is connected to Tx data flow 312, and each transmitter comprises: radiating portion 316 is used for the D/A converter 318 and the numerical control variable gain amplifier 320 of switching emission symbol.Master controller generates gain control signal 321, and receives by control channel 322.
HSAS also comprises M xDSL receiving element 332 (only showing for the purpose of clear).Each receiving element 332 is suitable for receiving the analog signal from analog interface 324, and the data flow 340 of output reception.Each receiving element comprises: the analog signal conversion that is used for receiving is the A/D converter 334 of number format, adder 336 and receiving unit 338.
Analog interface circuit 324 comprises the simulated assembly such as hybrid circuit, line transformer, is used to carry out the partial function or the repertoire of following function.
1. according to the suggestion of the particular vendor of the xDSL technology that is realized, realize that the xDSL circuit stops and protection.
When uses on twisted-pair feeder 326 by use standard mixed circuit component two-way xDSL technology (as, in the time of HDSL), separate emission 328 and reception 330 signals.
3. for being positioned at the electric component transmission feed current of remote node.The feed current that power supply unit 214 (Fig. 5) is generated is divided into a plurality of tributaries electric current, by one or more copper stranded conductor, each tributary current delivery is arrived remote node.Analog interface can comprise the protective circuit in each tributary.Protective circuit can prevent short circuit, leakage, overcurrent, heat shutdown etc.
NEXT eliminates 342 pairs of i received signals of parts #i and carries out NEXT elimination operation.These parts are suitable for receiving through holding wire 341 the transmission signals T of M number format
i(t) all or part of, its time of reception are that A/D converter 320 is converted to before the analog signal.Note that to rely on the copper equipment that uses, by avoiding handling the complexity that whole signals can reduce system.When via when NEXT eliminates different bindings that operation almost completely isolates and determines not collinear right route, above-mentioned processing is particularly useful.
The frequency domain of NEXT elimination parts realizes being suitable for receiving the NEXT transfer function H of autonomous controller
Ij(f) (that is crosstalk matrix).As selection, the time domain that NEXT eliminates parts realizes that reception comes the NEXT transfer function H of autonomous controller
Ij(t).As selection, NEXT eliminates the NEXT transfer function of parts reception from the adaptive filtering device, wherein uses the adaptive filtering device in the realization of NEXT elimination algorithm itself.
In the initial thick laundering period, above-mentioned filter makes its transfer function be fit to the not collinear internal NEXT transfer function of coupling, for example, uses the LMS adaptive method.NEXE is eliminated error as adapting to the feedback of handling.In the accurate laundering period after a while, for example in the accurate adaptation that run duration carries out, above-mentioned filter uses NEXT to eliminate Error Feedback and realizes continuously accurately adapting to and following the tracks of the NEXT transfer function.In frequency domain is realized, NEXT arrester calculation combination signal ∑ T
j(f) H
Ij(f), perhaps in time domain realizes, calculation combination signal ∑ T
j(t) H
Ij(t).Note that in frequency domain is realized, must at first use well-known Fourier techniques (as, FFT) with signal T
j(t) be transformed to frequency domain.
From received signal, deduct this composite signal by adder 336 then.Note that can carry out NEXT in time domain or frequency domain eliminates operation.When in frequency domain, carrying out, before execution has the add operation of negative sign, by use well-known Fourier techniques (as, IFTT) the NEXT estimated signal is transformed to time domain.
Then, partly provide the NEXT erasure signal output of adder 336 to the Rx of modulator-demodulator element 338, and as the adaptation feedback signal of NEXT arrester 342.This feedback is used for the adaptation of NEXT arrester.Note that if when carrying out the elimination operation, use the automatic adaptation FIR filter, then adapt to handle and to use well-known LMS algorithm.
If use DMT xDSL modem technology, then can carry out NEXT separately and eliminate processing each different tone (or carrier wave), use the frequency domain representation of transmission and received signal to carry out subtraction thus.
Each receiver 332 needs a NEXT to eliminate parts 342, and can use any appropriate device of Digital Signal Processing of knowing in the electronic technology and so on, realizes this parts.Can adopt similar fashion, perhaps, realize adder 336 by revising the xDSL assembly.Note that and on a slice or several whole IC, to realize that simultaneously transmitter, receiver, NEXT eliminate parts and adder.
Note that simultaneously analog interface stops and power supply circuits without any need for circuit, because switch 246, separator 248 and mains switch 256 can provide above-mentioned functions at the execution mode of the HSAS that is used for the FDM operation shown in Figure 6.
Figure 11 represents the block diagram of the another kind of execution mode of HSAS constructed according to the invention.In the present embodiment, the HSAS of reference number 350 signs comprises: a plurality of SCM 354, data scrambler 358, FEC encoder 360, interleaver 362, transmitter 364, whole modem module 367, gatherer 374, deinterleaver 376, fec decoder device 378, descrambler 380 and master controller 382, wherein modem module 367 comprise label for modem section # 1 to a plurality of modulator-demodulator elements 368 of #M and above the explanation cross-interference elimination device (optional).
HSAS utilizes copper stranded conductor that high bandwidth channel end to end is provided.Required copper stranded conductor number depends on many factors, as the type of the modulator-demodulator element that uses, the length of cable, the BER of expectation, desired bit rate etc.In order to describe, following form is provided, this tabular goes out as the needed demand pairs of the function of cable distance and bit rate.
Table 1: the demand pairs that need
Distance (thousand feet) bit rates (Mbps) 68 10 12 14 15 16 17 18 19 20 21
15 11 17 24 28 31 39 43 49 57 64
20 9 14 21 29 37 42 52 57 65
25 8 11 18 24 37 46 52 65 72
30 9 13 19 29 44 56 63
35 11 15 23 34 51 65
40 12 16 24 38 59
45 14 18 27 43 66
The listed demand pairs of table 1 are based on following hypothesis calculating: use HDSL2 modulator-demodulator element, do not have NEXT to eliminate and handle, the highest BER is 10
-10
During operation, HSAS serves as the interface between SCM and the copper equipment.Bit stream by SCM 354 receives from the high data rate of importing data link is forwarded to scrambler 358 via bus 356 then, and FEC encoder 360 and interleaver 362 arrive soon after.It is single high-speed data-flow that SCM is suitable for one or more high speed input data link are assembled.Then via bus 366, with the data flow distribution that generates thus or send to a plurality of modulator-demodulator elements.Each modulator-demodulator with its transfer of data to a twisted-pair feeder 370 of copper cable equipment 372.
SCM serves as line interface unit, this device be suitable for input traffic (as, T1, E1, T3, E3, OC-3 etc.) be converted to general format, and be placed on the bus 356 and be used for subsequent treatment.In transmission direction, scrambler receives the data on the bus, and before using error correction these data is carried out randomization.On receive direction, descrambler 380 receives and has carried out the data of error correction decoding, and carries out descrambling, to generate from the initial data of other end transmission.Scramble/scramble process comprises all standard techniques, as technology based on the linear feedback shift register that has suitable generator, and generator such as 1+x
5+ x
23Or 1+x
18+ x
23
Utilize 360 pairs of these data of encoder to carry out the FEC coding then, the effect of encoder is to add error correction information to bit stream.For example, can use well-known Reed Solomon coding.Note that can adopt commercial coding integrated circuit (as, be positioned at the integrated circuit that the Advanced Hardware Architectures company of State of Washington Pullman produces) or FPGA instrument, realize the FEC encoder.The length of the FEC code word that generates is 3 to 255 bytes, and the correct word joint number can be arbitrary number, as 8.On receive direction, the data of utilizing fec decoder device 378 to handle through deinterleaving, the effect of decoder is to utilize the redundant code of transmitting with pay(useful) load, the mistake in the correction bit stream.
Interleaver 362 is suitable for getting rid of the burst noise in one or more circuit.Interleaver can handle the noise duration be approximately 250 to 500 person of outstanding talent second.Interleaver can be divided into incoming bit stream many smaller portions, thereby even lack certain part, FEC still can generate correct data.The code word of interleaver buffering input is so that have the data of enough dividing processing.To be forwarded on the twisted-pair feeder from the dividing data of different code words then, thereby in office when limit the (as 500 bold and unconstrained seconds), a partial data in each each code word of twisted-pair feeder channel.Make this system to eliminate and surpass the total burst noise of all circuits of specifying the time limit (as 500 bold and unconstrained seconds).Interleaver is suitable for having variable depth, wherein by master controller the degree of depth is set.Note that for delay is dropped to minimum level HSAS of the present invention can move under the situation of interleaver not having.
The stand-by period of adding in the transmission time changed with bit rate and expectation duration of needing protection.For example, support the stand-by period of 500 bold and unconstrained second noise compensations to be about 11.8 to 12.4 bold and unconstrained seconds, the stand-by period of supporting 250 person of outstanding talent's second noise compensations was 5.5 to 6.2 bold and unconstrained seconds.
Transmitter (dispatcher) 364 receives treated high speed bit stream, carries out rate transition and data are sent (that is distribution) to each modulator-demodulator element 368.Transmitter is suitable for high-speed data-flow is divided into the low speed bit stream of a plurality of suitable modulator-demodulator element transmission.Therefore, the function class of execution is similar to inverse multiplexing high-speed data-flow on the low capacity copper stranded conductor.Transmitter is responsible for data symbol is sent to different modulator-demodulator elements, thereby only at the partial data of each each code word of twisted-pair feeder channel.In case locking system goes offline.
The effect of modulator-demodulator element is the data that receive from transmitter, and according to the specific xDSL technology that adopts these data is converted to line code.Example xDSL technology comprises ADSL, HDSL, HDSL2, SDSL and VDSL.Each modulator-demodulator element is suitable for the circuit of following processing: (1) collects the data that transmitter is transmitted, (2) make the data sync that transmits data and receiving modem to modulator-demodulator, (3) according to the technology of using data are modulated, (4) numerical chracter is outputed to D/A converter, and (5) are put into this symbol on the copper stranded conductor via the AFE (analog front end) interface.
The function of master controller 382 be between the control module and HSAS and peripheral link between the HSAS interface.It is suitable for carrying out the control of the external module of configuration, initialization, performance monitoring storage, maintenance and HSAS.Master controller be suitable for supporting with external clock synchronously, the generation system clock transmits SCM clock control information to set up master/slave node to remote node.
According to the parameter that is loaded in each system, each HSAS is configured to main equipment or slave unit.The HSAS that is configured to main equipment is responsible for the bit rate that (1) determines each modulator-demodulator element, (2) set up and (promptly from the modulator-demodulator logical links between the node, determine the mapping between physics and the logic modulator-demodulator element/circuit), (3) set up Traffic Channel, (4) determine to be positioned at the configuration of scrambler/descrambler, FEC encoder/decoder, interlacing device and de-interlacing device, transmitter and the gatherer at two ends, (5) provide from node carry out synchronous system clock (as, use the clock of modem recovery).
Bus 356 is used to connect the traffic between SCM and the data handling component (that is scrambler 358/ descrambler 380).This bus is suitable for whole bandwidth of transmitting high speed data input link.This bus preferably includes the bus of grouping (that is, piece or cell) type, and consequently (1) is converted to the system clock of HSAS with the various clock frequencies on the SCM interface, and (2) are provided as the mechanism that the special source of input data marks (as, SCM interface number).
Revise the length of grouping (or cell), to support interface with different clock speed.The title of grouping comprises the information of the data length of relevant each transmission.This bus is suitable for supporting the velocity adaptive between SCM and the HSAS system clock, and mark is from the information of SCM input, and promptly synchrodata frame is again supported SCM to switch and switched so that enable port for redundancy purpose.
Bus 366 is used to transmit the traffic between transmitter/gatherer and the modulator-demodulator element.Give a plurality of modulator-demodulator elements with the information distribution of transmitter output.In order to recover this data at receiving terminal, on each modem line, add an air-frame (explanation hereinafter), make can the collect data of automodulation demodulator element of receiver, and assemble this data by transmission sequence.In addition, air-frame makes this system can support to have the modulator-demodulator element of variable delay.
Bus 366 is two-way, allows the traffic on the both direction.In transmission direction, will be by transmitter such as (1) air-frame and CRC information, (2) error correction information, (3) clock synchronization data and (4) allow the information of every frame synchronization modulator-demodulator element many speed locating information once and so on, are put on this bus.
Each modulator-demodulator element is suitable for support variable data rate, and as the data rate of n*64kbps, wherein the scope of n is 1 to 36, and its minimum speed limit is 64kbps, and flank speed is 36*64=2.304Mbps (maximum of HDSL2).Determine peak data rate according to the modem technology and other factors that adopt.
Figure 12 represents to be used to illustrate the outlet at the copper cable equipment that is positioned at two ends constructed according to the invention and the block diagram of inlet HSAS.The figure shows the relative section of the inlet HSAS of the relative section of outlet HSAS of reference number 390 sign and reference number 390 signs.Outlet HSAS390 comprises: a plurality of SCM 394 that link to each other with one or more input data link 392, receive the data scrambler 398 of data from SCM via bus 396, FEC encoder 400, interleaver 402, transmitter 404, via whole modem module 407 and master controller 434 that bus 406 links to each other with transmitter, wherein modem module comprises that label is a plurality of modulator-demodulator elements 408 and the above-described cross-interference elimination device (optional) of modulator-demodulator element # 1 to #M.
According to the present invention, can be asymmetric speed with this system construction, asymmetric speed refers to that the data rate of the modulator-demodulator element at circuit two ends may not be identical.Because modulation scheme and speed that the modulator-demodulator element on all directions uses can change, so HSAS supports configuration, wherein the transmitter number of each end is different with the receiver number.Yet in any case the number that is positioned at the transmitter of a certain end must equal to be positioned at the number of the receiver of the other end, vice versa.
Master controller 434 comprises one or more interfaces of different external equipments.The figure shows from master controller 434 via the connection of LAN/WAN 438 to network management system (nms) 436, and the connection that inserts 440 equipment from master controller 434 to local peer.In addition, master controller can comprise: (1) supports the standard SNMP agent functionality of MIB-II, as interface based on the NMS of outside SNMP, (2) world wide web (www) interface and TL-1 interface, wherein last interface prepares, safeguards or other interface operable that back one interface conducts interviews by RS-232 for local peer, NOC technical staff or other staff as NOC technical staff or local peer.Modulator-demodulator element 408 is transferred to each twisted-pair feeder 410 on the copper cable equipment 412.
Inlet HSAS 448 comprises: modem module 415, deinterleaver 422, fec decoder device 424, descrambler 426, the one or more SCM 430 that link to each other with descrambler 426 via bus 428, one or more output data links 432 and master controller 442, wherein modem module comprises a plurality of modulator-demodulator elements 416 that link to each other with gatherer 420 via bus 418.One or more interfaces that master controller comprises and the external equipment such as NMS 444, local peer access 446 or any other equipment communicates are so that manage, prepare, safeguard or monitor.
The system wake-up process
Below describe the initialization of HSAS in detail or wake up.Figure 13 represents to be used to illustrate the flow chart of initial method of the present invention's HSAS.First step is to power up step (step 450).In this step, the HSAS that is positioned at CO end powers up, and supposes HSAS is connected to direct current in the CO.Yet remote node may not possess locally supplied power source, therefore needs the HSAS of CO end to carry out remote power feeding.
In the TDM of HSAS execution mode (Fig. 5), can provide remote power feeding simultaneously with telephone service.Therefore, can provide power supply for remote node immediately.
Yet, in the FDM of HSAS execution mode (Fig. 6), can not provide remote power feeding simultaneously with telephone service.Therefore, mains switch 256 can be configured to all switches the power supply setting.At remote node, be equipped with battery to guarantee the reliable initialization of HSAS.
Then this system is configured (step 451).At this moment, be positioned at the master controller of the HSAS of CO end and remote node end, (1) initialization needs all component of the one or more parameters of initialization, (2) identification module and the ability and the configuration (the particularly ability of xDSL modulator-demodulator element and configuration) of having installed, (3) are carried out self-test and (4) to the hardware and software system and are set up and being connected of one or more user interfaces.
Then, all modulator-demodulator elements are set to minimum data rate (step 452).At this moment, be with minimum data rate transport data with the modulator-demodulator arrangements of components, so that set up the low-speed communication channel of CO end and remote node end.After setting up channel, two ends exchange for information about.
Then, if realize the FDM execution mode of HSAS, then the HSAS in the CO begins to remote node power supply (step 453).This step allows to transmit telephone service to remote node.Estimate the flank speed (step 454) of each modulator-demodulator on each link then.By using one or more characteristics of measuring cable with lower module (or mechanism): test module, handover module, close beta mechanism in the modulator-demodulator element, NEXT eliminates the internal measurement mechanism (eliminating error as NEXT) in the parts and CO holds and the coordination of the master controller of remote node end.Internal measurement mechanism in the modulator-demodulator element comprises the BER meter, SNR meter, Line Attenuation meter and/or noise margin meter.Measurement comprise decay that each line is right and relevant with frequency wired between crosstalk transfer functions versus (isolation).Note that can be according to the right spatial configuration of line in the above-mentioned measurement derivation binding.Then, master controller according to above-mentioned measurement together with the transmission characteristic of xDSL modulator-demodulator element and required link performance, calculating optimum transmission parameter.
The calculating that master controller is carried out comprises or multi-mode operation in the following operation:
1. calculate the NEXT transfer function matrix H of all twisted-pair feeders or part twisted-pair feeder
Ij(f) (frequency domain realization) or H
Ij(t) (time domain realization).
2. for relatively more responsive transmission distributes the distinct line at more close binding center right, for not too responsive (as, descending) transmission distributes the line of more close binding outer surface right.
3. determine right permission through-put power and the corresponding gain of each line.Gain can be selected for frequency.Gain and the through-put power that allows are to determine according to the right locus of each line, therefore will from the spectral power radiation envelope of binding maintain in the boundary line of PSD rule predetermining.
4. determine the optimal transmission rate of each twisted pair wire links on all directions.Note that the speed between the different links can be different, and the speed on each direction of particular link can be different.Computation rate is so that the total throughout optimization of this system.Optimization is preferable, because the modulator-demodulator element may have the mutual degradation effect with rate variation (PSD as the transmission of, modulator-demodulator changes with data rate).Therefore, in some cases, particularly do not use that NEXT eliminate to handle or only partial line on use NEXT and eliminate in the situation about handling, the total throughout of optimization system also needs to make the throughput of each modulator-demodulator element to reach maximum (following explanation).
5. determine the most significant data speed under load of each data flow (that is link) on each direction.
6. select transmission and receive the error correction coding scheme of using in the data processor.The encoding scheme at two ends can be different.Select based on one or more system requirements, system requirements such as BER, the resilience that goes offline postpones impulsive noise resilience, bit rate, scope etc.
After computational process finished and determines the maximum transmission rate of each link (both direction of link), the modulator-demodulator element was set to iptimum speed, and iptimum speed may be also may not be the previous maximum of calculating (step 456).The parameter of determining is forwarded to tx data processor, reception data processor, modulator-demodulator element and the switch that is positioned at CO end and remote node end.Initialization link transmission, and the data communication of beginning high-speed link.
After utilizing best data rate setup of modulator-demodulator element and setting up data link, measure link parameter (step 458).After high speed data link brings into operation, utilize (1) test module, the internal measurement mechanism in the internal measurement mechanism in (2) modulator-demodulator element or (3) NEXT elimination parts (as, NEXT eliminates the LMS filter), measure.Internal measurement mechanism in the modulator-demodulator element comprises the BER meter, SNR meter, Line Attenuation meter and/or noise margin meter.Whether inspection has modulator-demodulator to lose synchronously and/or can not normally move (step 460) then.
If have modulator-demodulator to lose synchronously or can not normally move, then change the data rate (step 460) of this modulator-demodulator, begin to repeat this process from step 454 then.Note that since the PSD of modulator-demodulator with its rate variation, so can increase or changing down.Note that the speed that increases or reduce modulator-demodulator will change the SPECTRAL REGION at transmission of power place, thereby change is to the interference of its adjacent modems, and to the sensitivity of the interference emission (that is, crosstalking) of its adjacent modems.If modulator-demodulator is synchronous and can normally moves, then, dispose form and FEC parameter (step 462) in transmitter and the gatherer according to the speed of each modulator-demodulator.Note that and to use different FEC and to send configuration at two HSAS that are positioned at both link ends.
A kind of possible mode of the iptimum speed of modulator-demodulator element of selecting is, adjusting between its speed so that its actual SNR (using inner SNR meter to measure) and the SNR that keeps required BER standard needs has enough surpluses.For all modulator-demodulator elements, HSAS carries out the speed adjustment iterative process that begins from certain fixed rate.Subsequently, the speed of modulator-demodulator element or increase or reduction, so that increase the speed of its surplus modulator-demodulator higher than required surplus.Equally, reduce the speed of its surplus modulator-demodulator element lower than required surplus.Above-mentioned iterative process continues, near the predetermined value of surplus in required surplus.
As selection, can with 64kbps step-length, attempt all speed combinations of each modulator-demodulator.Select to provide the speed combination of best comprehensive high-speed link bit rate then.
Cycle monitors, the measure link transmission parameter (as, the SNR of each link and BER, the quantity of the crc error relevant etc. with each link) so that the variation of HSAS adaptation (1) internal operation condition or (2) built-in system fault (as, the modulator-demodulator element fault, bus failure etc.) (step 464).The response link is measured, and HSAS can revise one or more transmission parameters.HSAS is suitable for transmission course is remained on optimum state as far as possible.Especially, master controller utilizes above-mentioned measurement result to upgrade optimum channel and calculates, and responds this calculating to revise suitable assembly.
If certain modulator-demodulator loses synchronously or finds that certain modulator-demodulator can not normally move (promptly, surpass the one or more performance threshold such as BER, SNR, crc error) (step 466), then change its data rate, and this process begins repetition from step 454.
Note that initialization procedure can comprise an iterative process as selection, be configured in the modulator-demodulator element that data rate, scope and reliability aspect have low link performance thus.According to channel condition, pass in time and improve link performance gradually.
Forward error correction
Below describe the FEC Code And Decode part of HSAS in detail.In order to help to improve the performance of high speed data link, HSAS is suitable for the handling failure circuit.Faulty line is the circuit that (1) physical break or end are opened, (2) its impedance obviously increases so that hinders the circuit of transmission, (3) its noise level has reached degree like this so that transmit the badly damaged circuit that maybe can not transmit, or (4) its modulator-demodulator element breaks down or its performance has dropped to the following circuit of certain predetermined threshold value.
HSAS comprises the error correction coding scheme of handling failure circuit, thereby transfer of data can not suffer damage.In order to improve coefficient of safety, HSAS can be configured to the BER operation higher than required BER, for example, need be with 10
-10During work, with 10
-15Work.Therefore, when breaking down circuit, the added value of BER is still below required BER.Yet, preferably BER is configured to the threshold value that is provided with the user near but better stablize BER than this threshold value.This kind FEC encoding scheme can provide the vulnerability to jamming to background noise, impulsive noise and external disturbance.
The structure of Figure 14 representation space frame and association table bit sign time (UST).USB is defined as the duration of a symbol of modulator-demodulator transmission that utilizes minimum speed limit.For example, for the modulator-demodulator that speed is 64kbps, UST is 125 microseconds.Air-frame 520 is made up of a plurality of code words 526.Each code word comprises many symbols, and wherein byte of each symbolic representation, and its duration changes with the speed of the modulator-demodulator element of this symbol of transmission.The code word that comprises all modulator-demodulator elements by the air-frame of transmitter generation.An element in each row 522 of air-frame and M the modulator-demodulator element is connected.The synchronizing symbol that will comprise the duration and be UST adds the starting position of each air-frame in interior heading message 528.The length that note that title is longer than the UST (as, 125 microseconds) of the slowest modulator-demodulator transmission.
The function of air-frame is a plurality of code words of encapsulation, compensates the difference of modem rate, and does not consider the speed of each modulator-demodulator element of transmitted codewords.Air-frame makes all modulator-demodulator elements can be synchronized to the Frame that is fixed on sometime, and does not consider the speed of modulator-demodulator.The cycle of air-frame is 4 to 12 microseconds.
On twisted-pair feeder during transmission symbol the duration of symbol with the changes in data rate of particular modem.For the symbol of the modulator-demodulator transmission that utilizes higher rate, its duration is shorter.Therefore, compare with the modulator-demodulator element that speed is lower, the higher modulator-demodulator element of speed can transmit more code words in preset time.
Therefore, utilize the duration of considering modem rate to represent code word.For example, the duration of the code word of modulator-demodulator # 2 is more than the twice of duration of code word of modulator-demodulator #1.Because more than the fast twice of speed of the speed ratio modulator-demodulator # 2 of modulator-demodulator #1.Modulator-demodulator #M is set to higher rate, therefore can transmit more code words during air-frame.If the modulator-demodulator element that uses adopts the HDSL2 technology, then the code word of minimum length in time is corresponding to the bit rate of 36*64kbps=2.304Mbps.
Be positioned at the vertical shading part 529 expression zero paddings of the afterbody of each row 522, wherein zero padding added to the afterbody of each air-frame of each modem line.The code word that is inserted in the air-frame is not preferably crossed frame boundaries.Therefore, must use zero padding institute gapped.As selection, air-frame can be divided into many subdivisions, wherein the duration of each several part is a UST.Whole code words are put in each subdivision, and utilize zero byte to fill all exceptional spaces, thereby fill the space between last code word and the UST border.So that the hardware buffer scheme that is relatively easy to is provided.
Note that other cycles that also can use the UST cycle, and think within the scope of the invention.The UST cycle is preferably 125 microseconds, because should represent the least common denominator of all possibility bit rates the cycle.In other words, after a UST, can guarantee all at least one complete symbols of modulator-demodulator element transmission.
Below describe FEC and relevant process thereof in detail.The FEC coding/decoding of HSAS and transmission/the collection part is suitable for (1) provides resilience for line fault, thereby can forever not reduce the performance of system, (2) performance of raising system on the performance of using conventional copper cable transmission method to realize, and (3) when operation increase system to noise (, thermal noise, impulsive noise etc.) vulnerability to jamming.Only for a limited number of faulty line provides resilience, the user specifies this number when starting.
Figure 15 represents to be used for to illustrate the logic diagram of the K bytecode block that the FEC part of HSAS is used.The codeword block of reference number 470 signs comprises pay(useful) load part of being made up of K-R byte 472 and the redundancy section of being made up of R byte 474.Value K represents block length, that is, the total bytes in the code word, R are represented the redundancy bytes number that this code word comprises.The code word that note that Figure 15 is represented the logic perspective view of code word.Yet, when reality realizes, can arrange payload bytes and redundancy bytes by different order.For example, if the equipment of encoding device for buying from the market, as the equipment of buying from the Advanced HardwareArchitectures company that is positioned at State of Washington Pullman, then the value of K is 3 to 255 bytes, and the value of R is 1 to 20 byte.
In another embodiment, the FEC encoder comprises Reed Solomon block encoder.This encoder can be proofreaied and correct R/2 symbol error.For the resilience of the given number that goes offline, can select K and R, thereby when the circuit that specifies number went offline, the symbol error also was no more than R/2.The if symbol error surpasses R/2, and then Reed Solomon error correction no longer provides vulnerability to jamming.
Yet,, perhaps, can address the above problem by the detection failure circuit and by making decoder use the information that is called " wiping " information by in R, increasing " standby " position (as parity bit).When line fault occurring, can use with the present invention and wipe, because the error indication detection line fault that the modulator-demodulator element can utilize the fec decoder device to generate.For example, the modulator-demodulator element can use CRC mechanism, SNR meter or loss of signal indication to detect error.The function of FEC encoder is to add required redundant code, to proofread and correct the error that causes owing to line fault, improves the vulnerability to jamming to various noises.In another embodiment, encoder is carried out the Reed Solomon block encoding processing of knowing in the coding techniques.Except that the transmission rate and BER value of modulator-demodulator,, determine coding parameter according to the user's relevant detailed description with the fault wire way of needs processing, required coded system expense, required BER etc.
Note that transmitter is to FEC encoder request msg when operation.Therefore, the input rate of encoder is the speed of transmitter request msg.Because the speed of input traffic can be different with transmitter, so HSAS can insert " free time " piece when needed before encoder.
The function of transmitter is as far as possible in the best way, will be distributed to the modulator-demodulator element after interleaving treatment through coded data.Transmitter comprises a double-buffer memory, therefore can at any time write data in the buffer, reads the data that need be forwarded to the modulator-demodulator element simultaneously from another buffer.FEC and transmitter can synchronized with each otherly move, that is, transmitter is to the FEC request msg, and FEC is in its input input equal amount of data.Can revise the parameter (that is, sending table) of FEC and transmitter, and not traffic impacting transmission.
Transmitter is suitable for generating confession FEC and transmitter carries out synchronous air-frame.Air-frame makes receiving modem can compensate owing to the modulator-demodulator arrangements of components being the difference delay that different bit rates causes.As mentioned above, send data by the bus such as synchronous bus to the modulator-demodulator element.Data send in dedicated time slot, receive.Each time slot can transmit data according to the flank speed of each modulator-demodulator.Note that a plurality of modulator-demodulators can share certain given time slot, prerequisite is the maximum bit rate that the summation of data rate is no more than all combination modulator-demodulator elements.
Figure 16 is a block diagram, the signal that expression is docked with the FEC encoder section of HSAS.Send the input data from scrambler or SCM (when forbidding the scramble function) to the encoder of reference number 480 signs.Data are that the mode with byte stream sends, and byte stream reads from input with asynchronous system.Clock provides with data.Master controller is set the codeword size K of code word, redundant big or small R of code word and the change request signal that utilizes the signal indication parameter modification.
According to the present invention, can in an air-frame, use many set of code words parameter (K, R).Cycle is switched the code word parameter, to consider the best of breed of coded system expense to error correcting capability.For example, at an air-frame in the duration, preferably use higher redundancy (being the coded system expense) until definite line status (going offline or working line), can use lower redundancy (being the coded system expense) then, because under the situation of low coded system expense, can utilize and wipe the error correcting capability that indication strengthens the fec decoder device.
Encoder is suitable for exporting the code word that length is K, and wherein K-R byte risen in input traffic, and R byte added by encoder.When the subsequent step request, utilization is read clock and obtain byte from the FEC encoder.First byte is designated as the time indication that next step provides first byte that reads code word.Descending Connection Step uses and reconfigures signal execution coding and send parameter modification.Encoder also receives the air-frame sideband signal from transmitter, to help synchronous data flow.
Figure 17 is a block diagram, represents the signal that partly docks with the fec decoder device of HSAS.From the rapid output of previous step, be generally gatherer or deinterleaver, be that the code word of K is input in the decoder of reference number 490 signs with length.Data are to import in the mode of byte stream, with asynchronous system byte stream are written in the decoder.Writing clock provides with enter code word.Master controller is set the codeword size K of code word, redundant big or small R of code word and the change request signal that utilizes the signal indication parameter modification.Decoder is suitable for to the data flow of subsequent step output with the asynchronous system transmission.
Figure 18 is a block diagram, represents the signal that partly docks with the transmitter of HSAS.The transmitter of reference number 500 signs is suitable for utilizing request signal (that is, reading clock) to read the input data of (supposing interleaver is merged in the transmitter) among the FEC.It is first byte in the code word that the indication of first byte of FEC is used to refer to the byte that needs to receive.The air-frame border is generated by transmitter, is used to refer to the position on air-frame border, and wherein the FEC encoder need use this position.
Transmitter is suitable for to the throttling of a plurality of modulator-demodulator element output word.The data available signal is indicated operable valid data.By address wire, data wire and the data clock that utilizes modulator-demodulator, transfer of data is arrived the modulator-demodulator element.These data are to transmit in the time slot of fixing duration.
Master controller comprises transmission sequence (transmitter utilizes this sequence to determine the byte of distributing to the modulator-demodulator element), air-frame size and the sequence that is used to write data into the modulator-demodulator element.
Figure 19 is a block diagram, represents the signal that partly docks with the gatherer of HSAS.The gatherer of reference number 510 signs is suitable for receiving the data from a plurality of modulator-demodulator elements.These data are by using the address wire of request line and modulator-demodulator, being transmitted by the modulator-demodulator element.The data clock that the modulator-demodulator element utilizes modulator-demodulator to provide transmits data on data circuit.Whether the frame available signal designation data from modulator-demodulator is effective.The signal that reconfigures from modulator-demodulator is used to refer to the parameter modification that will carry out.
Gatherer is suitable for data available signal, the indication of first byte and the indication of air-frame border to FEC (supposing its inner integrated deinterleaver) dateout and indication valid data.
Master controller is set the collection sequence (gatherer utilizes this sequence to determine the byte of modulator-demodulator element distribution) of gatherer, and this sequence is used to read the size of modulator-demodulator element and air-frame.
Figure 20 is a block diagram, represents the transmitter part of HSAS in detail.The function of transmitter is the data to available modulator-demodulator element distribution FEC encoder (supposing deinterleaver is integrated in the transmitter) output.Suppose to have determined in a manner described the speed of each modulator-demodulator element.Speed is determined when starting, but can be made amendment according to environmental change.The speed of each modulator-demodulator can be at 64kbps to changing between the 2.304Mbps (that is, 1*64kbps is to 36*64kbps).
Below describe the method that sends and collect data in detail, for purposes of illustration, the operating rate of supposing the modulator-demodulator element arrives 2.304Mbps (promptly at 64kbps, 1*64kbps is to 36*64kbps) between change, the UST cycle of selecting is 125 microseconds, codeword size K changes between 3 to 255 symbols, and redundant length R changes between 1 to 20.
The transmitter of reference number 550 signs preferably includes a double buffering device, the data that input buffer 552 receives from FEC by incoming line 554.Via circuit 564 content of output buffer 552 is sent to available modulator-demodulator element.An element in M modulator-demodulator element of each row 556,562 expression, each row 551,561 expression is with a symbol of maximum transmission rate transmission.The size of each buffer is the number M*36 of modulator-demodulator element, and when whole M modulator-demodulator elements all transmitted with flank speed, the size of buffer should be above number.The actual symbolic number that is written in each row depends on the true bit rate of particular modem.Note that the modulator-demodulator element of supporting flank speed, need the bigger line buffer of memory capacity.
The input sequencer 558 of pre-programmed or dynamic-configuration is determined from the distribution order of the input data of FEC output.Equally, the output sequencer 560 of pre-programmed or dynamic-configuration is determined the distribution order of the dateout from transmitter to the modulator-demodulator element.After repeatedly preserving input buffer, restart input sequence.
Being assumed to be the bit rate that the modulator-demodulator element assigns is the integral multiple of 64kbps, and then each row is suitable for expression symbol (that is, 8 bits) required time of transmission, and the time is the microseconds of 8 bits/(64kbps)=125.The one-period minimum of input sequencer comprises that line number multiply by columns, that is, and and M*36.
The number of input sequencer FEC code word in the cycle is fixed, but the size of code word is unfixed.For the remainder bytes after the filling code word in the input buffer, utilization zero or idle characters load.As selection, air-frame can be divided into many subdivisions that the duration is a UST.An integer code word is put in each subdivision, and with zero byte filling exceptional space, to fill the gap between last code word and the UST border.Thereby provide easier hardware buffer scheme.
By using the sequencer of pre-programmed or dynamic-configuration, the output of output buffer is sent to the modulator-demodulator element.Transmitter can send to data the modulator-demodulator bus 366 (Figure 11) that comprises a plurality of time slots.Each time slot represents that speed is the data flow of 4.096Mbps or any other appropriate speed.
Figure 21 is a block diagram, represents the gatherer part of HSAS in detail.The gatherer of reference number 570 signs comprises a double buffering device, the data that input buffer 572 receives from the modulator-demodulator element by circuit 572.Via circuit 579 content of output buffer 574 is sent to the fec decoder device.The similar of the structure of input buffer 572 and output buffer 574 and transmitter 550 (Figure 20).An element in each line display M modulator-demodulator element, each tabulation show a symbol with the maximum transmission rate transmission.The size of each buffer is the number M*36 of modulator-demodulator element, and when whole M modulator-demodulator elements all transmitted with flank speed, the size of buffer should be above number.The actual symbolic number that is written in each row depends on the true bit rate of particular modem.Note that the modulator-demodulator element of supporting flank speed, need the bigger line buffer of memory capacity.
The input sequencer 576 of pre-programmed or dynamic-configuration is determined from the distribution order of the input data of modulator-demodulator element output.Equally, the output sequencer 578 of pre-programmed or dynamic-configuration is determined the distribution order of the dateout from gatherer to the fec decoder device.
Send the air-frame synchronization character to all modulator-demodulator element cycles, so that in channel.Transmission utilizes the air-frame synchronization character to compensate the different delays of every circuit with the receiving modem element.Gatherer is suitable for receiving the indication that begins from the air-frame of modulator-demodulator element, and assembles (that is, collecting) data from the modulator-demodulator element according to input sequencer 576.Only note that it is synchronous just to send air-frame when separately synchronization character of predetermined most of modulator-demodulator elements calibrations.Note that simultaneously according to the similar fashion that sends data to bus, the data of the automodulation demodulator bus of collecting.
As mentioned above, can be with the part of interleaver as transmitter.No matter the sort of situation takes place, (K R), wherein is distributed to the modulator-demodulator element by transmitter with code word always interleaver receives code word from the FEC encoder.The distribution of code word is preferably, even line fault or the impulsive noise such as luminous occur, corrupt symbols also is no more than R/2.For this reason, the code word that on the space that all modem line are passed through, in time interweaves.Execution interweaves so that at any time, has the R/2 FEC redundant symbol duration of the pulse of measured length (as, 500 microseconds) really that is no more than each FEC code word on the modem line.Propagated code word on the line by past, realized above-mentioned processing along with the time.
For getting rid of the duration is the pulse of T, need have the interleaver of following delay or stand-by period:
Wherein T is the duration of impulsive noise, and K is the length of block code, and R is the redundant symbol number.
For example, for getting rid of the pulse of duration T=500 microseconds, suppose block code length K less than 255, R is greater than 2, and then by using formula (3), maximum delay is 85 milliseconds.In order to ensure the reasonable delay of interleaver, preferably limit R/K and be no less than 10% or 20%.Should consider this restriction when selecting the FEC parameter.Note that ratio is high more, the stand-by period is good more, but its cost is to increase overhead.
Below describe the feasible method of selecting the FEC code word in detail.According to the present invention, when definite FEC code word parameter (that is, K and R) and the input sequencing table in definite transmitter and gatherer, need the modulator-demodulator element function many factors relevant of considering and expecting with the working point.
Especially, this method is preferably considered following parameter: the number of modulator-demodulator element, the bit rate of modulator-demodulator element, required line fault resilience, required system BER, the restriction of the BER of the modulator-demodulator under the worst case and relevant FEC overhead ratio.This method can be determined the length K of FEC code word, redundant length R and sending order table.
The purpose of FEC parameter selection method is that search can provide required line fault resilience, overall BER and can make bandwidth reach the combination of maximum FEC codeword size and FEC redundancy.The line number of this method hypothesis modulator-demodulator, the bit rate relevant and need prevent that the line number of line fault from being known with each line.It below is the pseudo-code inventory of this method.
Inventory 1:FEC parameter selection method
1. to all effective combinations of codeword size K and redundant length R, repeating step A and B, wherein the scope of K is 3 to 255, the scope of R is 1 to 20:
A. utilize following formula, according to the bit rate of respective modem, calculating will be whenever
Bar circuit i goes up the maximum number of byte of the code word that sends,
Wherein bit_rate (i) is the bit rate of modulator-demodulator i, and M is the number of modulator-demodulator element.
B. to institute the repeating step i that might make up and the ii (by using and the corresponding line fault number of maximum resilience) of line fault:
I. for secant: the figure place summation of the single codeword that calculating will be transmitted.
If summation＜R/2 (that is, resilience line fault) ii., then marker combination (K, R); If summation 〉=R/2, then not marker combination (K R), and turns back to step B.
C. for all combinations of mark in step B (K, R), utilize following formula computing system expense:
Wherein num_code is the code word number that can transmit in 125 microseconds.The total bit of denominator for can in 125 microseconds, transmitting.
From all combinations of calculating its overhead value (K, R) in, the combination of selective system expense minimum.
Below describe the method for the input sequence that is used for definite transmitter in detail.According to this method, the maximum number of byte of each code word that the big or small K of code word, redundant R and each modulator-demodulator can send is known.
At first, create a table, its line number equals the modulator-demodulator parts number, and its columns equals maximum bit rate divided by the bit rate resolution, as, 2.048Mbps/64kbps=32.Figure 22 represents to send the example of storage list.The table of reference number 580 signs comprises 6 row 582 and 36 row.Table 2 is listed the peak data rate of 6 modulator-demodulator elements.
Modem rate (Kbps)
1 36*64
2 18*64
3 10*64
4 5*64
5 3*64
6 14*64
In this example, the minimum transfer duration of cell is 8/ (36*64 * 10
3) second, corresponding to the bit rate of fast modulator-demodulator.The maximum duration is 125 microseconds, corresponding to the bit rate of slow modulator-demodulator.Utilize box in this table to represent the actual transmissions duration of a data byte.For the modulator-demodulator that bit rate is 36/N * 64Kbps, transmission comprises N cell in this table.For example, the bit rate of modulator-demodulator # 1 is 36*64kbps, so the duration of the cell 584 of modulator-demodulator # 1 is the shortest.The bit rate of modulator-demodulator #6 is 14*64kbps, so the duration of cell 586 is longer than the duration of modulator-demodulator #1.The bit rate of modulator-demodulator #5 is 3*64kbps, so cell 588 has the long duration.
Pseudo-code inventory in the inventory 2 is represented transmitter input sequence method.
Inventory 2: transmitter input sequence method
1. at first utilize the first module lattice filler cells lattice of first modulator-demodulator.
2. fill then and send table:
A. to all code words in the one-period (i.e. 125 microseconds), repeat:
I. to all bytes in the code word, repeat:
A. search next available modulator-demod lattice.
B. whether check that the maximum number of byte with a code word sends to this modulator-demodulator (calculate, see inventory 1) in step 1-A; If more than be judged as very, then this byte is put in this cell, if be false, then forward step a to.
B. check to send unfilled cell in the table, utilize " sky " symbol to fill the cell of finding.
In order to help to understand transmission input sequence method of the present invention, below provide two illustrated example.
Figure 23 represents the content of the first example transmission table memory, wherein places single codeword in the transmission table.In first example, use following parameter:
Codeword size=18 bytes
Redundant length=12 bytes
Modulator-demodulator parts number/line number (M)=4
Modulator-demodulator element # 1 to the line speed of #4 is: R
1, 2*R
1, 2*R
1, R
1(R wherein
1Be an effective modulator-demodulator bit rate)
The figure place of every circuit is: 3,6,6,3
Faulty line resilience number is 1
The table of reference number 610 signs comprises 4 row 612 and many cells 614.Utilize A1 to 18 bytes of A18 mark code word with and position in form.First module lattice allocation units lattice since first modulator-demodulator cycle through each modulator-demodulator, until whole codeword is input in the table.After filling, this table is outputed to the modulator-demodulator element by output sequencer 560 (Figure 20).
Figure 24 represents the content of the second example transmission table memory, wherein places two code words in sending table.In second example, use following parameter:
Codeword size=20 bytes
Redundant length=12 bytes
Modulator-demodulator parts number/line number (M)=4
Modulator-demodulator element # 1 to the line speed of #4 is: R
1, 2*R
1, 2*R
1, 3*R
1(R wherein
1Be an effective modulator-demodulator bit rate)
The figure place of every circuit is: 3,5,5,8
Faulty line resilience number is 1
The table of reference number 620 signs comprises 4 row 622 and many cells 624.Utilize A1 to 20 bytes of A20 mark first code word with and position in form.Utilize B1 to 20 bytes of B20 mark second code word with and position in form.First module lattice allocation units lattice since first modulator-demodulator cycle through each modulator-demodulator, until two code words are input in the table.
As mentioned above, the present invention includes and be used for helping transmission and receive the data synchronization device.With the data of transmitter output, be distributed to have different bit rates, a plurality of modulator-demodulator elements of delay and jitter.At receiving terminal, gatherer can be combined into this set of streams single data flow.For accurate combination, the data flow that essential each modulator-demodulator element synchronously receives.
Air-frame comprises the synchronous title that is positioned at its starting position.At receiving terminal, by receiving complete air-frame, provide data flow that each modulator-demodulator element receives synchronously.The overhead that air-frame needs synchronously should be low as far as possible.In example provided herein, be 125 microseconds synchronizing cycle, the air-frame period T
SFBe 8 milliseconds, be calculated as follows overhead.
In the duration is on all modulator-demodulator elements of 125 microseconds, simultaneously transmission space frame title.Therefore, the actual symbol number in the air-frame title depends on the bit rate of modulator-demodulator.The above-mentioned situation of title division 528 expressions of air-frame 520 (Figure 14).In each cycle, the input sequencer in the transmitter transmits a header byte to each modulator-demodulator.Although can comprise definite-time synchronizing cycle, also can comprise variable byte number, this depends on the data rate of the modulator-demodulator related with this circuit.
Receiver can be adjusted the data flow that receives according to detected air-frame title.Each modulator-demodulator element among the HSAS is suitable for detecting synchronizing symbol.Simultaneously to transmit the duration be the UST synchronizing symbol of (as, 125 microseconds) cycle on all modem line.Buffer in each modulator-demodulator can absorb any delay that may exist on the particular modem line.Because each modulator-demodulator moves with different bit rates, postpone so introduce inevitably.For example, when using the HDSL2 modulator-demodulator, trellis code modulator in the transmitter and the Viterbi decoder in the receiver all can cause delay, thereby postpone to depend on the duration of bit rate.In order to compensate, the synchronous detection signal of all modulator-demodulator elements is focused in the main sync detection circuit.This circuit can make up the synchronization scenario from all modulator-demodulator elements, generates single detection signal then.
Each modulator-demodulator can be according to the air-frame that receives on circuit separately, synchronous data flow.When by the buffer in the synchronous different modulating demodulator of the main sync detection circuit element, gatherer begins to read the data in each modulator-demodulator element.Can realize main sync detection circuit with any suitable method.When air-frame duration during greater than maximum delay, " flywheel " or the correlator technology can operation technique known realize main sync detection circuit.Correlator needs a large amount of memories, but can prevent the BER degradation.For example, Figure 25 is a flow chart, the flywheel air-frame method for synchronous of expression the present invention's HSAS.This flywheel method need need considerably less memory, but demoted by BER.This method can be searched for synchronous title in the inlet flow in each modulator-demodulator is fixed time window really.First threshold is used to detect the synchronous time of advent, and second threshold value is used for synchronization loss.
At first, modulator-demodulator is searched for synchronous title (step 530).If find synchronously, then enter Synchronous Processing and initiate state (step 532), and modulator-demodulator is searched for synchronous title (step 534) once more.If do not find that then the value of counter sync_count is set to 1 (step 548) synchronously, and this method continues step 532.Then sync_count is added 1 (step 536) synchronously if find.
The value and the first threshold (threshold_1) (step 538) that compare sync_count then.If sync_count is smaller or equal to threshold_1, then this method continues step 532.If sync_count greater than threshold_1, then announces (step 540) synchronously.
The next title (step 542) synchronously of modulator-demodulator search.Then the second counter missed_sync_count is not added 1 (step 542) synchronously if find.Compare missed_sync_count and second threshold value (threshold_2) (step 544) then.If missed_sync_count is greater than threshold_2, then this method turns back to step 530.If missed_sync_count is smaller or equal to threshold_2, then synchronization loss is sustainable, and this method continues step 542.If find (step 542) synchronously, then the value of missed_sync_count is set to the greater (step 546) among missed_sync_cpunt-1 or zero, and modulator-demodulator continues search (step 542) synchronously.
Claims are intended to cover essence and interior all feature and advantage of the present invention of scope that belong to the present invention.Those of skill in the art expect various modifications and changes easily, so the present invention is not limited to minority execution mode described herein.Be appreciated that all suitable changes, modification and equivalent all do not deviate from the spirit and scope of the invention.
Claims (147)
1. the device of a channel high-speed data-flow of forming at a plurality of low bandwidth copper stranded conductors, this device comprises:
The error correction coding scheme is applied to the encoder of described high-speed data-flow;
The a plurality of modulator-demodulator elements that link to each other with described a plurality of copper stranded conductors, each modulator-demodulator links to each other with a described copper stranded conductor, and data rate, delay, signal to noise ratio and error rate operation to be independent of other modulator-demodulator elements;
Transmitter, be responsible for described high-speed data-flow through coding is divided into a plurality of low rate data streams that need utilize described a plurality of modulator-demodulator element to transmit, described transmitter is suitable for the data rate according to each modulator-demodulator, and low rate data streams is forwarded to each modulator-demodulator;
Gatherer is responsible for a plurality of data flow with described a plurality of modulator-demodulator elements receptions, is combined as a high-speed data-flow;
Decoder is suitable for receiving the data flow of described gatherer output, and uses the error correction decoding scheme, thereby generates initial high-speed data-flow.
2. according to the device of claim 1, wherein said transmitter is included in and is distributed to described a plurality of modulator-demodulator element carries out interleaving treatment before to described high-speed data-flow through coding device.
3. according to the device of claim 1, wherein said gatherer comprises the device that the high-speed data-flow of described reception is carried out deinterleaving.
4. the device according to claim 1 also comprises interleaver, interleaver is divided into a plurality of short data segment with the code word that described encoder generates, described short data segment is forwarded to described transmitter, thereby in any time limit, can only be on described a plurality of copper stranded conductors the part of transmitted codewords, to prevent burst noise.
5. the device according to claim 1 also comprises scrambler, and scrambler is suitable for before the described error correction coding scheme of described encoder applies described high-speed data-flow being carried out scramble to be handled.
6. the device according to claim 1 also comprises descrambler, and descrambler is suitable for that the high-speed data-flow to described reception carries out descrambling before described decoder carries out error correction decoding.
7. according to the device of claim 1, wherein said a plurality of copper stranded conductors comprise local loop equipment.
8. according to the device of claim 1, wherein said a plurality of modulator-demodulator elements comprise a plurality of ADSL (Asymmetric Digital Subscriber Line) (ADSL) modulator-demodulator element.
9. according to the device of claim 1, wherein said a plurality of modulator-demodulator elements comprise a plurality of high-speed digital subscriber lines (HDSL) modulator-demodulator element.
10. according to the device of claim 1, wherein said a plurality of modulator-demodulator elements comprise a plurality of high-speed digital subscriber lines 2 (HDSL2) modulator-demodulator element.
11. according to the device of claim 1, wherein said a plurality of modulator-demodulator elements comprise a plurality of symmetric digital subscriber lines (SDSL) modulator-demodulator element.
12. according to the device of claim 1, wherein said a plurality of modulator-demodulator elements comprise a plurality of very high speed digital subscriber lines (VDSL) modulator-demodulator element.
13. according to the device of claim 1, wherein said a plurality of modulator-demodulator elements comprise a plurality of Discrete multi-tones (DMT) modulator-demodulator element.
14. the device according to claim 1 also comprises one or more traffic channel module, each traffic channel module is suitable for providing the interface between telecommunications or data service and the described high-speed data-flow.
15. according to the device of claim 14, wherein said traffic channel module is suitable for the interface as the T1 telephone service.
16. according to the device of claim 14, wherein said traffic channel module is suitable for the interface as the E1 telephone service.
17. according to the device of claim 14, wherein said traffic channel module is suitable for the interface as the T3 telephone service.
18. according to the device of claim 14, wherein said traffic channel module is suitable for the interface as the E3 telephone service.
19. according to the device of claim 14, wherein said traffic channel module is suitable for the interface as the Integrated Service Digital Network telephone service.
20. according to the device of claim 14, wherein said traffic channel module is suitable for the interface as simple outdated telephone service (POTS).
21. the device according to claim 1 also comprises test module, test module is suitable for the line parameter circuit value of period measurement one or more twisted-pair feeder.
22. according to the device of claim 21, wherein said line parameter circuit value comprises crosstalking between the described twisted-pair feeder of different frequency.
23. according to the device of claim 21, wherein said line parameter circuit value comprises near-end cross (NEXT) transfer function of different frequency.
24. the device according to claim 1 also comprises with lower device, the line parameter circuit value of period measurement one or more twisted-pair feeder so that according to described measurement, transmits the more device of sensitive traffic on the twisted-pair feeder of more close binding center.
25. the device according to claim 1 also comprises with lower device, the line parameter circuit value of period measurement one or more twisted-pair feeder so that according to described measurement, transmits the more device of robust data stream on the twisted-pair feeder of more close binding external position.
26. the device according to claim 1 also comprises with lower device, the line parameter circuit value of period measurement one or more twisted-pair feeder, so that according to described measurement, for each line in the binding to variable gain control is provided, thereby for the line at more close binding center to distributing the more device of large transmission power.
27. the device according to claim 1 also comprises with lower device, when the quality of specific twisted-pair feeder drops to certain threshold value when following, gets rid of the device of described specific twisted-pair feeder from a plurality of twisted-pair feeders that transmit described high-speed data-flow.
28. the device according to claim 1 also comprises: lay respectively at the two ends of described copper stranded conductor and first test module that links to each other with communication link and second test module, described first test module can transmit a plurality of audio frequency with different frequency and various amplitude, described second test module can be measured the received power that respectively receives audio frequency, and by described communication link to the described first test module delivering power test result.
29. the device according to claim 1 also comprises cross-interference elimination device, it comprises:
Measure the device of a plurality of cable data, wherein cable data comprises the near-end cross between the twisted-pair feeder; And
Measure according to described cable data, from the data flow of described reception, eliminate the device of near-end cross.
30. the device according to claim 1 also comprises near-end cross (NEXT) cancellation element, it comprises:
Be used to generate the device of the estimation of the NEXT transfer function of crosstalking that near the radiant body the modulator-demodulator element causes;
Generate the device of the estimation of NEXT interference signal according to the NEXT transfer function of described estimation; And
From the signal that the modulator-demodulator element receives, deduct the device of the estimation of described NEXT interference signal.
31. the device according to claim 1 comprises also that with lower device the internal structure of spatial mappings cable and the one or more bindings groups that comprise described a plurality of copper stranded conductors is to provide the device of binding and the copper stranded conductor relative position in binding.
32. the device according to claim 31 comprises also that with lower device the line that distributes more close center for uplink is to also distributing the right device of line of more close external position for downlink transfer.
33. the device according to claim 31 also comprises with lower device, is the not collinear corresponding device that limits the spectral radiance of described binding outside with the selectivity gain controlling simultaneously in the binding according to its relative position.
34. the device according to claim 31 also comprises with lower device, the different bindings in the described cable is distributed to the device of different high-speed data-flows.
35. the device according to claim 1 also comprises with lower device, transmits the device of described high-speed data-flow and existing low speed telephone service signal on described a plurality of copper stranded conductors simultaneously.
36. the device according to claim 1 also comprises with lower device, uses time-division multiplex technology, with the device of the multiplexing a plurality of low speed telephone wires of described high-speed data-flow.
37. the device according to claim 1 also comprises with lower device, uses time-division multiplex technology, multichannel is decomposed the device of a plurality of low speed telephone wires from described high-speed data-flow.
38. the device according to claim 1 also comprises with lower device, uses frequency multiplexing technique, with the described high-speed data-flow that higher frequency spectrum is formed, the device of multiplexing a plurality of low frequency telephone wires.
39. according to the device of claim 38, wherein said multiplexer comprises one or more separators.
40. the device according to claim 1 also comprises with lower device, uses frequency multiplexing technique, multichannel is decomposed the device of a plurality of low frequency telephone wires from the described high-speed data-flow that higher frequency spectrum is formed.
41. according to the device of claim 40, wherein said multichannel decomposer comprises one or more separators.
42. the device according to claim 1 also comprises mains switch, mains switch is suitable for a plurality of telephone wires are switched to described a plurality of copper stranded conductor, when not having concurrent telephone service session, described mains switch can disconnect the particular telephone line in the copper stranded conductor, and described copper stranded conductor is connected to power supply, so that be the remote node power supply.
43. the device according to claim 1 also comprises with lower device, is the device of the one or more assembly power supplies in the remote node of the other end of described a plurality of copper stranded conductors.
44. the device according to claim 1 also comprises with lower device, according to the quality of respective lines, assigns the device of data rate for the modulator-demodulator element.
45. the device according to claim 1 also comprises the device that measurement circuitry is isolated, it comprises:
When the modulator-demodulator element is not opened the device of described a plurality of modulator-demodulator elements when described copper stranded conductor transmits signal;
Measure the device of the noise level on each copper stranded conductor, the noise level meter timberline road of measurement and the relative isolation of external disturbance; And
Distribute the device of more isolating circuit to sensitive signal more.
46. device according to claim 1, wherein when line fault occurring, described encoder is suitable for first error rate that provides lower than the customer requirements error rate (BER), and when one or more circuit breaks down, the 2nd BER is provided, wherein said the 2nd BER is than a described BER height, but still lower than the BER of described customer requirements.
47. according to the device of claim 1, wherein said error correction coding scheme comprises the ReedSolomon block encoding.
48. according to the device of claim 1, wherein said error correction decoding scheme comprises the decoding of ReedSolomon piece.
49. according to the device of claim 1, wherein said encoder can generate a plurality of code words that length is K, each code word comprises pay(useful) load part of being made up of K-R byte and the redundancy section of being made up of R byte.
50. device according to claim 1, wherein said encoder can generate a plurality of code words, each code word comprises pay(useful) load part of being made up of K-R byte and the redundancy section of being made up of R byte, when wherein selecting K and R to go offline down to one or more circuit, error also is no more than the R/2 byte, thereby provides appointment several resilience that goes offline.
51. the device according to claim 1 also comprises with lower device, be used to select the parameter of the code word that described encoder generates so that provide required line fault resilience, minimum bit-error rate (BER) and the device of high bandwidth, described parameter comprises K and R, wherein K-R represents the byte number of the pay(useful) load part of described code word, and R represents the byte number of the redundancy section of described code word.
52. the device according to claim 1 also comprises device, the parameter that is used to select the code word that encoder generates is so that provide required line fault resilience, the device of minimum bit-error rate (BER) and high bandwidth, described parameter comprises K and R, wherein K-R represents the byte number of the pay(useful) load part of described code word, R represents the byte number of the redundancy section of described code word, wherein described code word is distributed to described a plurality of modulator-demodulator element, so that on described a plurality of low bandwidth copper stranded conductors, transmit, each modulator-demodulator element has the data rate that is independent of other modulator-demodulator elements, postpone, signal to noise ratio and BER, this device comprises:
To all effective combinations of codeword size K and redundant length R,, calculate the device of the maximum number of byte of the code word that each modulator-demodulator element sends according to its corresponding data rate;
To all combinations of line fault, the device of the summation of the figure place of the single codeword that calculating need be transmitted;
If described summation is less than R/2, then mark is somebody's turn to do the device of combination;
To all marker combination, calculate the device of its overhead; And
From all combinations of the K that calculates its interconnected system expense and R, the device of the combination of selective system expense minimum.
53. according to the device of claim 1, wherein said transmitter comprises is used for span frame so that the device that transmits that on each described twisted-pair feeder described air-frame comprises a title division and a plurality of code word.
54. a transmitter that is used for distribution high-speed data-flow between a plurality of modulator-demodulator elements, this transmitter comprises:
A two-dimentional buffer, buffer is made up of a plurality of memory cell that are arranged as many row and columns, and every row is related with different modulator-demodulators, and a monadic symbols with the maximum transmission rate transmission is shown in every tabulation;
An input sequencer is suitable for described high-speed data-flow is distributed to memory cell in the described buffer, according to the specific data rate of respective modem, determines to be distributed to data volume of each row; And
An output sequencer is suitable for the content with the memory cell in the described buffer, is distributed to described a plurality of modulator-demodulator element.
55. according to the device of claim 54, wherein said input sequencer comprises filling device, is used for:
Utilization is filled the memory cell of described buffer since the byte of the first module of first row;
Search the next storage available in the described buffer;
If also the byte of the highest permission number of certain code word is not placed in the particular row, then in next storage available, puts a byte; And
In the one-period of described input sequencer, all code words are repeated the described step of searching and place.
56. according to the device of claim 55, wherein said filling device comprises and utilizes null symbol to fill the device that all do not fill memory cell.
57. the transmitter according to claim 1 comprises also that with lower device the difference that the device of cycle transmission space frame alignment word on described a plurality of copper stranded conductors, described air-frame synchronization character can compensate on each described twisted-pair feeder postpones.
58. the method for a transmission high-speed data-flow on a plurality of low bandwidth copper stranded conductors said method comprising the steps of:
A plurality of modulator-demodulator elements are provided, and each modulator-demodulator links to each other with a twisted-pair feeder;
Described high-speed data-flow is divided into a plurality of low rate data streams, and to be distributed to described a plurality of modulator-demodulator element, each low rate data streams has independently data rate, delay and the error rate (BER);
On described a plurality of twisted-pair feeders, transmit described a plurality of low rate data streams by described a plurality of modulator-demodulator elements;
According to the quality of relevant twisted-pair feeder, revise the speed of each modulator-demodulator;
Receive a plurality of low rate data streams on described a plurality of twisted-pair feeder; And
Make up a plurality of low rate data streams of described reception, thereby generate initial high-speed data-flow.
59. according to the method for claim 58, wherein said partiting step may further comprise the steps, and described high-speed data-flow is carried out the step of interleaving treatment before being distributed to described a plurality of modulator-demodulator element.
60. according to the method for claim 58, wherein said combination step comprises the step of the high-speed data-flow of described reception being carried out deinterleaving.
61. method according to claim 58, wherein said partiting step is further comprising the steps of, the code word that will generate by described high-speed data-flow is encoded is divided into the step of a plurality of short data segment, described short data segment is distributed to described a plurality of modulator-demodulator element, thereby in any time limit, can only be on described a plurality of copper stranded conductors the part of transmitted codewords, to prevent burst noise.
62. the method according to claim 58 is further comprising the steps of, described high-speed data-flow is carried out scramble handle.
63. the method according to claim 58 is further comprising the steps of, and the high-speed data-flow of described reception is carried out scramble process.
64. according to the method for claim 58, wherein said a plurality of copper stranded conductors comprise local loop equipment.
65. according to the method for claim 58, wherein said a plurality of modulator-demodulator elements comprise a plurality of ADSL (Asymmetric Digital Subscriber Line) (ADSL) modulator-demodulator element.
66. according to the method for claim 58, wherein said a plurality of modulator-demodulator elements comprise a plurality of high-speed digital subscriber lines (HDSL) modulator-demodulator element.
67. according to the method for claim 58, wherein said a plurality of modulator-demodulator elements comprise a plurality of high-speed digital subscriber lines 2 (HDSL2) modulator-demodulator element.
68. according to the method for claim 58, wherein said a plurality of modulator-demodulator elements comprise a plurality of symmetric digital subscriber lines (SDSL) modulator-demodulator element.
69. according to the method for claim 58, wherein said a plurality of modulator-demodulator elements comprise a plurality of very high speed digital subscriber lines (VDSL) modulator-demodulator element.
70. according to the method for claim 58, wherein said a plurality of modulator-demodulator elements comprise a plurality of Discrete multi-tones (DMT) modulator-demodulator element.
71. the method according to claim 58 is further comprising the steps of, and one or more traffic channel module are provided, each traffic channel module is suitable for providing the interface between telephone service and the described high-speed data-flow.
72. according to the method for claim 71, wherein said traffic channel module is suitable for the interface as the T1 telephone service.
73. according to the method for claim 71, wherein said traffic channel module is suitable for the interface as the E1 telephone service.
74. according to the method for claim 71, wherein said traffic channel module is suitable for the interface as the T3 telephone service.
75. according to the method for claim 71, wherein said traffic channel module is suitable for the interface as the E3 telephone service.
76. according to the method for claim 71, wherein said traffic channel module is suitable for the interface as the Integrated Service Digital Network telephone service.
77. according to the method for claim 71, wherein said traffic channel module is suitable for the interface as simple outdated telephone service (POTS).
78. the method according to claim 58 is further comprising the steps of, the line parameter circuit value of period measurement one or more twisted-pair feeder.
79. according to the method for claim 78, wherein said line parameter circuit value comprises crosstalking between the described twisted-pair feeder of different frequency.
80. according to the method for claim 78, wherein said line parameter circuit value comprises near-end cross (NEXT) transfer function of different frequency.
81. the method according to claim 58 is further comprising the steps of, the line parameter circuit value of period measurement one or more twisted-pair feeder, so that according to described measurement, and the more responsive data flow of transmission on the twisted-pair feeder of more close binding center.
82. the method according to claim 58 is further comprising the steps of, the line parameter circuit value of period measurement one or more twisted-pair feeder so that according to described measurement, transmits the more data flow of robust on the twisted-pair feeder of more close binding external position.
83. the method according to claim 58 is further comprising the steps of, the line parameter circuit value of period measurement one or more twisted-pair feeder, so that according to described measurement, for each line in the binding to variable gain control is provided, thereby for the line at more close binding center to distributing more large transmission power.
84. the method according to claim 58 is further comprising the steps of, when the quality of specific twisted-pair feeder drops to certain threshold value when following, gets rid of described specific twisted-pair feeder from a plurality of twisted-pair feeders that transmit described high-speed data-flow.
85. the method according to claim 58 is further comprising the steps of:
Measure a plurality of cable data, wherein cable data comprises the near-end cross between the twisted-pair feeder; And
Measure according to described cable data, from the data flow of described reception, eliminate near-end cross.
86. the method according to claim 58 is further comprising the steps of:
The estimation of the NEXT transfer function of crosstalking that near the radiant body the generation modulator-demodulator element causes;
Generate the estimation of NEXT interference signal according to the NEXT transfer function of described estimation; And
From the signal that the modulator-demodulator element receives, deduct the estimation of described NEXT interference signal.
87. the method according to claim 58 is further comprising the steps of, the internal structure of spatial mappings cable and the one or more bindings groups that comprise described a plurality of copper stranded conductors is to provide binding and the copper stranded conductor relative position in binding.
88. 7 method is further comprising the steps of according to Claim 8, the line that distributes more close center for uplink is to also distributing the line of more close external position right for downlink transfer.
89. 7 method is further comprising the steps of according to Claim 8, is that not collinear correspondence in the binding limits the spectral radiance of described binding outside simultaneously with the selectivity gain controlling according to its relative position.
90. 7 method is further comprising the steps of according to Claim 8, and different high-speed data-flows is distributed in the different bindings in the described cable.
91. the method according to claim 58 is further comprising the steps of, transmits described high-speed data-flow and existing low speed telephone service signal on described a plurality of copper stranded conductors simultaneously.
92. the method according to claim 58 is further comprising the steps of, uses time-division multiplex technology, with the multiplexing a plurality of low speed telephone wires of described high-speed data-flow.
93. the method according to claim 58 is further comprising the steps of, uses time-division multiplex technology, multichannel is decomposed a plurality of low speed telephone wires from described high-speed data-flow.
94. the method according to claim 58 is further comprising the steps of, uses frequency multiplexing technique, with the described high-speed data-flow that higher frequency spectrum is formed, multiplexing a plurality of low frequency telephone wires.
95. the method according to claim 58 is further comprising the steps of, uses frequency multiplexing technique, multichannel is decomposed a plurality of low frequency telephone wires from the described high-speed data-flow that higher frequency spectrum is formed.
96. the method according to claim 58 is further comprising the steps of:
A plurality of telephone wires are switched to described a plurality of copper stranded conductor;
When not having concurrent telephone service session, disconnect the particular telephone line in the copper stranded conductor; And
Described copper stranded conductor is connected to power supply, so that be the remote node power supply.
97. the method according to claim 58 is further comprising the steps of, is the one or more assembly power supplies in the remote node of the other end of described a plurality of copper stranded conductors.
98. the method according to claim 58 is further comprising the steps of, according to the quality of respective lines, for the modulator-demodulator element is assigned data rate.
99. the method according to claim 58 is further comprising the steps of:
When the modulator-demodulator element is not opened described a plurality of modulator-demodulator element when described copper stranded conductor transmits signal;
Measure the method for the noise level on each copper stranded conductor, the noise level meter timberline road of measurement and the relative isolation of external disturbance; And
Distribute the circuit of more isolating to sensitive signal more.
100. the method according to claim 58 is further comprising the steps of, described high-speed data-flow is encoded, so that when line fault occurring, first error rate lower than the customer requirements error rate (BER) is provided, and when one or more circuit breaks down, the 2nd BER is provided, and wherein said the 2nd BER is than a described BER height, but still lower than the BER of described customer requirements.
101. the method according to claim 58 is further comprising the steps of, utilizes the ReedSolomon block encoding that described high-speed data-flow is carried out error correction coding.
102. the method according to claim 58 is further comprising the steps of, utilizes the decoding of ReedSolomon piece that described high-speed data-flow is carried out error correction decoding.
103. the method according to claim 58 is further comprising the steps of, described high-speed data-flow is carried out error correction coding, to generate length is a plurality of code words of K, and each code word comprises pay(useful) load part of being made up of K-R byte and the redundancy section of being made up of R byte.
104. the method according to claim 58 is further comprising the steps of, described high-speed data-flow is carried out error correction coding, to generate a plurality of code words, each code word comprises pay(useful) load part of being made up of K-R byte and the redundancy section of being made up of R byte, when wherein selecting K and R to go offline down to one or more circuit, error also is no more than the R/2 byte, thereby provides appointment several resilience that goes offline.
105. the method according to claim 58 is further comprising the steps of:
Described high-speed data-flow is carried out error correction coding;
Select the parameter of the code word that described coding step generates, so that required line fault resilience, minimum bit-error rate (BER) and high bandwidth are provided; And
Wherein said parameter comprises K and R, and wherein K-R represents the byte number of the pay(useful) load part of described code word, and R represents the byte number of the redundancy section of described code word.
106. a parameter that is used to select the code word that encoder generates is so that provide required line fault resilience, the method of minimum bit-error rate (BER) and high bandwidth, described parameter comprises K and R, wherein K-R represents the byte number of the pay(useful) load part of described code word, R represents the byte number of the redundancy section of described code word, wherein described code word is distributed to a plurality of modulator-demodulator elements, so that on a plurality of low bandwidth copper stranded conductors, transmit, each modulator-demodulator element has the data rate that is independent of other modulator-demodulator elements, postpone, signal to noise ratio and BER, described method comprises:
To all effective combinations of codeword size K and redundant length R,, calculate the maximum number of byte of the code word of each modulator-demodulator element transmission according to its corresponding data rate;
To all combinations of line fault, calculate the summation of the byte number of the single codeword that needs transmission;
If described summation is less than R/2, then mark should make up;
To all marker combination, calculate its overhead; And
From all combinations of the K that calculates its interconnected system expense and R, the combination of selective system expense minimum.
107. the method according to claim 58 is further comprising the steps of, span frame is so that transmit on each described copper stranded conductor, and described air-frame comprises a title division and a plurality of code word.
108. a method that is used for distribution high-speed data-flow between a plurality of modulator-demodulator elements, described method comprises:
A two-dimentional buffer is provided, and buffer is made up of a plurality of memory cell that are arranged as many row and columns, and every row is related with different modulator-demodulators, and a monadic symbols with the maximum transmission rate transmission is shown in every tabulation;
Described high-speed data-flow is distributed to memory cell in the described buffer,, determines to be distributed to data volume of each row according to the specific data rate of respective modem; And
With the content of the memory cell in the described buffer, be distributed to described a plurality of modulator-demodulator element.
109. according to the method for claim 108, the step of the described high-speed data-flow of wherein said distribution is further comprising the steps of:
Utilization is filled the memory cell of described buffer since the byte of the first module of first row;
Search the next storage available in the described buffer;
If also the byte of the highest permission number of certain code word is not placed in the particular row, then in next storage available, puts a byte; And
In the one-period of described method, all code words are repeated the described step of searching and place.
110. according to the method for claim 109, wherein said filling step comprises and utilizes null symbol to fill all unfilled memory cell.
111. the method according to claim 58 is further comprising the steps of, the difference that cycle transmission space frame alignment word on described a plurality of copper stranded conductors, described air-frame synchronization character can compensate on each described twisted-pair feeder postpones.
112. according to the device of claim 1, wherein said traffic channel module is suitable for the interface as digital synchronization series (SDH) STM-1 business.
113. according to the device of claim 1, wherein said traffic channel module is suitable for the interface as synchronous optical network OC-3 business.
114. the device according to claim 31 also comprises with lower device, near the line of center on transmit sensitive data more and the line of more close external position on the device of the insensitive data of transmission.
115. according to the method for claim 71, wherein said traffic channel module is suitable for the interface as digital synchronization series (SDH) STM-1 business.
116. according to the method for claim 71, wherein said traffic channel module is suitable for the interface as synchronous optical network OC-3 business.
117. 7 method is further comprising the steps of according to Claim 8, near the line of center on transmit sensitive data more and the line of more close external position on the insensitive data of transmission.
118. the method for a Rouser, the channel that this device is formed via a plurality of low bandwidth copper stranded conductors transmits high-speed data-flow on a plurality of modulator-demodulator elements, each modulator-demodulator element has data rate, delay, signal to noise ratio and the error rate (BER) that is independent of other modulator-demodulator elements, said method comprising the steps of:
Each modulator-demodulator element is set to lowest bitrate;
Estimate the flank speed of each the modulator-demodulator element on every link;
Each modulator-demodulator element is set to optimal bit rate; And
The parameter of measure link, and response measurement result revise losing synchronously or the data rate of the modulator-demodulator element that can not normally move.
119. the method according to claim 118 is further comprising the steps of, according to the data rate of each modulator-demodulator element, configuration data sends and the forward error correction table.
120. the method according to claim 118 is further comprising the steps of, cycle monitoring, measure link parameter, and revise the data rate of described modulator-demodulator element according to measurement result, so that transmission adapts to the variation of described channel.
121. according to the method for claim 118, the step of the optimal bit rate of the described modulator-demodulator element of wherein said calculating is further comprising the steps of, to all or part of described twisted-pair feeder, calculates near-end cross (NEXT) transfer function matrix H
Ij(f).
122. method according to claim 118, the step of the optimal bit rate of the described modulator-demodulator element of wherein said calculating is further comprising the steps of, for the line of more close binding center to distributing more sensitive data, and for the line of more close described binding outside to distributing insensitive data.
123. according to the method for claim 118, the step of the optimal bit rate of the described modulator-demodulator element of wherein said calculating is further comprising the steps of, determines the maximum transmission power and the gain of each twisted-pair feeder.
124. according to the method for claim 118, the step of the optimal bit rate of the described modulator-demodulator element of wherein said calculating is further comprising the steps of, determines optimal transmission rate on each direction of each twisted pair wire links.
125. according to the method for claim 118, the step of the optimal bit rate of the described modulator-demodulator element of wherein said calculating is further comprising the steps of, determines the active data pay(useful) load speed of every link on each direction.
126. according to the method for claim 118, the step of the optimal bit rate of the described modulator-demodulator element of wherein said calculating is further comprising the steps of, the error correction coding scheme of be chosen in transmission on the described link, using when receiving data.
127. the method according to claim 58 also comprises wake up process, wake up process may further comprise the steps:
Each modulator-demodulator element is set to lowest bitrate;
Estimate the flank speed of each the modulator-demodulator element on every link;
Each modulator-demodulator element is set to optimal bit rate; And
The parameter of measure link, and response measurement result revise losing synchronously or the data rate of the modulator-demodulator element that can not normally move.
128. the method according to claim 127 is further comprising the steps of, according to the data rate of each modulator-demodulator element, configuration data sends and the forward error correction table.
129. the method according to claim 127 is further comprising the steps of, cycle monitoring, measure link parameter, and revise the data rate of described modulator-demodulator element according to measurement result, so that transmission adapts to the variation of described channel.
130. the method for the near-end cross (NEXT) in the cancellation element, the channel that this device is formed via a plurality of low bandwidth copper stranded conductors transmits high-speed data-flow on a plurality of modulator-demodulator elements, each modulator-demodulator element has data rate, delay, signal to noise ratio and the error rate (BER) that is independent of other modulator-demodulator elements, said method comprising the steps of:
The estimation of the NEXT transfer function of crosstalking that near the radiant body the generation modulator-demodulator element causes;
Generate the estimation of NEXT interference signal according to the NEXT transfer function of described estimation; And
From the signal that the modulator-demodulator element receives, deduct the estimation of described NEXT interference signal.
131. near-end cross (NEXT) arrester in the light transmission equipment, transmission equipment is suitable for transmitting high-speed data-flow via the channel that a plurality of low bandwidth copper stranded conductors are formed on a plurality of modulator-demodulator elements, each modulator-demodulator element has data rate, delay, signal to noise ratio and the error rate (BER) that is independent of other modulator-demodulator elements, and described arrester comprises with lower device:
Be used to receive a plurality of transmission signals T that one or more transmitter generates
j(t) device;
Be used to estimate NEXT transfer function H
Ij(t) device, transfer function H
Ij(t) transfer function between every pair of modulator-demodulator element of expression;
By the NEXT transfer function generation composite signal ∑ T of use with every pair of modulator-demodulator element associated
j(t) * H
Ij(t) device;
Be suitable for from the signal that receives, deducting described composite signal so that generate the subtracter of NEXT erasure signal; And
Utilize the device of described NEXT erasure signal as the feedback signal of revising described NEXT arrester.
132. the NEXT arrester according to claim 131 also comprises with lower device, is respectively each carrier wave or tone and carries out the device that NEXT eliminates processing.
133. the NEXT arrester according to claim 131 also comprises with lower device, generates different NEXT erasure signals to be input to the device of each receiver in the described equipment.
134., wherein utilize expression transmission signals T according to the NEXT arrester of claim 131
j(f) frequency domain and expression NEXT transfer function H
Ij(f) frequency domain is carried out described NEXT and is eliminated processing, by using ∑ T
j(t) H
Ij(t) generate composite signal.
135. the method for the line in the measurement mechanism to isolating, the channel that this device is formed via a plurality of low bandwidth copper stranded conductors transmits high-speed data-flow on a plurality of modulator-demodulator elements, each modulator-demodulator element has data rate, delay, signal to noise ratio and the error rate (BER) that is independent of other modulator-demodulator elements, said method comprising the steps of:
Not under the situation of line transmissioning signal, open the transceiver of the modulator-demodulator element that links to each other with each circuit;
Measure the right noise level of each line, noise level is represented the level of isolation with specific circuit; And
To right to the line that disturbs more responsive data signal distribution more to isolate.
136. according to the method for claim 135, wherein said measuring process may further comprise the steps, and utilizes the received signal power table as a described modulator-demodulator element part, carries out power measurement.
137. according to the method for claim 135, wherein said measuring process may further comprise the steps, and utilizes the signal to noise ratio (snr) meter as a described modulator-demodulator element part, carries out power measurement.
138. according to the method for claim 135, wherein said measuring process may further comprise the steps, and utilizes the test module that is suitable for measuring power spectral density (PSD), carries out power measurement.
139. method of in device, distributing through-put power, the channel that this device is formed via a plurality of low bandwidth copper stranded conductors in many bindings transmits high-speed data-flow on a plurality of modulator-demodulator elements, each modulator-demodulator element has data rate, delay, signal to noise ratio and the error rate (BER) that is independent of other modulator-demodulator elements, said method comprising the steps of:
Utilize the inner wire of certain binding right, change the through-put power of modulator-demodulator element;
Measure the power on this binding perimeter circuit; And
Adjust it and measure the through-put power that power surpasses the modulator-demodulator element of predetermined threshold.
140. according to the method for claim 139, wherein said measuring process may further comprise the steps, and utilizes the received signal power table as a described modulator-demodulator element part, carries out power measurement.
141. according to the method for claim 139, wherein said measuring process may further comprise the steps, and utilizes the signal to noise ratio (snr) meter as a described modulator-demodulator element part, carries out power measurement.
142. according to the method for claim 139, wherein said measuring process may further comprise the steps, and utilizes the test module that is suitable for measuring power spectral density (PSD), carries out power measurement.
143. method of in device, distributing transmission frequency bandwidth, the channel that this device is formed via a plurality of low bandwidth copper stranded conductors in many bindings transmits high-speed data-flow on a plurality of modulator-demodulator elements, each modulator-demodulator element has data rate, delay, signal to noise ratio and the error rate (BER) that is independent of other modulator-demodulator elements, said method comprising the steps of:
Not under the situation of line transmissioning signal, open the transceiver of the modulator-demodulator element that links to each other with each circuit;
Measure the right noise level of each line, noise level is represented the level of isolation with specific circuit; And
For the more shielding wire in the binding to distributing the wideer wideband transmit of bandwidth.
144. according to the method for claim 143, wherein said measuring process may further comprise the steps, and utilizes the received signal power table as a described modulator-demodulator element part, carries out power measurement.
145. according to the method for claim 143, wherein said measuring process may further comprise the steps, and utilizes the signal to noise ratio (snr) meter as a described modulator-demodulator element part, carries out power measurement.
146. according to the method for claim 143, wherein said measuring process may further comprise the steps, and utilizes the test module that is suitable for measuring power spectral density (PSD), carries out power measurement.
147. device according to claim 1, wherein said decoder comprises with lower device, the feedback information that utilizes fault modulator-demodulator element announcement to form generates the device of erasure information with the performance that strengthens described decoder, and erasure information is indicated incorrect reception data.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/IL2000/000705 WO2002035906A2 (en) | 2000-11-01 | 2000-11-01 | High speed access system over copper cable plant |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1479979A true CN1479979A (en) | 2004-03-03 |
Family
ID=11043006
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA008200548A Pending CN1479979A (en) | 2000-11-01 | 2000-11-01 | High speed access system over copper cable plant |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP1346398A2 (en) |
| CN (1) | CN1479979A (en) |
| AU (1) | AU2001211726A1 (en) |
| WO (1) | WO2002035906A2 (en) |
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| CN102638383A (en) * | 2008-01-16 | 2012-08-15 | 瑞博强芯（天津）科技有限公司 | ADSL (asymmetrical digital subscriber line) bandwidth aggregation method, realizing system and device |
| CN101888281A (en) * | 2009-05-11 | 2010-11-17 | 华为技术有限公司 | Encoding method and device, decoding method and device as well as communication system |
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| CN106068615B (en) * | 2014-01-28 | 2019-08-23 | 马维尔国际贸易有限公司 | The communication system for telephone wire access with stability of crosstalk |
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| US10601463B2 (en) | 2014-01-28 | 2020-03-24 | Maxlinear Asia Singapore Private Limited | Communication system for telephone line access with crosstalk stability |
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| US10797901B2 (en) | 2016-08-05 | 2020-10-06 | Huawei Technologies Co., Ltd. | Power adjustment method, network management system, cable modem termination system, and cable modem |
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| TWI785752B (en) * | 2021-08-23 | 2022-12-01 | 中華電信股份有限公司 | Network provisioning system and network provisioning method based on cable |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2002035906A2 (en) | 2002-05-10 |
| AU2001211726A1 (en) | 2002-05-15 |
| WO2002035906A3 (en) | 2003-04-03 |
| EP1346398A2 (en) | 2003-09-24 |
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