WO2002045383A2 - Appareil de connexion de lignes d'abonnes numeriques a un materiel de central telephonique - Google Patents

Appareil de connexion de lignes d'abonnes numeriques a un materiel de central telephonique Download PDF

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Publication number
WO2002045383A2
WO2002045383A2 PCT/CA2001/001698 CA0101698W WO0245383A2 WO 2002045383 A2 WO2002045383 A2 WO 2002045383A2 CA 0101698 W CA0101698 W CA 0101698W WO 0245383 A2 WO0245383 A2 WO 0245383A2
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WO
WIPO (PCT)
Prior art keywords
signals
unit
interface
units
access apparatus
Prior art date
Application number
PCT/CA2001/001698
Other languages
English (en)
Inventor
Tet Hin Yeap
John James Schellenberg
Original Assignee
Esion Networks Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CA002327118A external-priority patent/CA2327118A1/fr
Priority claimed from CA002331549A external-priority patent/CA2331549A1/fr
Priority claimed from CA002346573A external-priority patent/CA2346573A1/fr
Application filed by Esion Networks Inc. filed Critical Esion Networks Inc.
Priority to AU2002223347A priority Critical patent/AU2002223347A1/en
Publication of WO2002045383A2 publication Critical patent/WO2002045383A2/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
    • 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
    • H04L12/2869—Operational details of access network equipments
    • H04L12/2878—Access multiplexer, e.g. DSLAM
    • H04L12/2892—Access multiplexer, e.g. DSLAM characterised by the access multiplexer architecture
    • H04L12/2896—Distributed processing, e.g. on line cards
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q1/00—Details of selecting apparatus or arrangements
    • H04Q1/02—Constructional details
    • H04Q1/10—Exchange station construction
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q1/00—Details of selecting apparatus or arrangements
    • H04Q1/02—Constructional details
    • H04Q1/14—Distribution frames
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements
    • H04Q3/58—Arrangements providing connection between main exchange and sub-exchange or satellite
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/1301—Optical transmission, optical switches
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13039—Asymmetrical two-way transmission, e.g. ADSL, HDSL
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13107—Control equipment for a part of the connection, distributed control, co-processing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13383—Hierarchy of switches, main and subexchange, e.g. satellite exchange

Definitions

  • the invention relates to apparatus for connecting digital subscriber lines DSLs) to central office equipment.
  • the existing telecommunications system now is being used to deliver high speed data to/from subscribers using the existing subscriber loops, i.e. which already carry so-called POTS telephone signals.
  • digital data signals for transmission to the central office are converted, using a high speed modem, to an analog signal having a relatively high frequency; much higher than that of the POTS signal.
  • the modem converts high frequency analog signals received f om the central office into digital data signals. Both the high frequency signals and the POTS signals travel along the same twisted wire pair, simultaneously if required.
  • the twisted wire pairs of several subscribers are routed to a so-called pedestal.
  • pedestals are connected by a distribution cable to what is known in North America as an outside plant interface (OPI).
  • OPI outside plant interface
  • connector blocks connect the individual twisted wire pairs to respective conductors of a feeder cable which conveys the signals to and from the central office.
  • a bank of POTS splitters/combiners conveniently high pass/low pass filters, separate the high frequency analog signals from the POTS signals received from the loops, or combine high frequency analog signals and POTS signals destined for the loops.
  • a POTS switch conveys the POTS signals to and from the public service telephone network (PSTN) in the usual way.
  • PSTN public service telephone network
  • the high frequency analog signals are supplied to, or received from, one or more so-called digital subscriber loop access multiplexers (DSLAMs).
  • DSLAMs digital subscriber loop access multiplexers
  • Each DSLAM comprises analog interface circuitry (usually called “analog front end” (AFE) circuitry) which comprises hybrids, amplifiers, and so on, for processing the high frequency analog signals in the usual way, a bank of analog-to-digital (A-D) converters for digitizing the high frequency analog signals from the DSL lines and supplying the resulting digital data signals to a bank of digital signal processor (DSP) modems and a bank of digital-to-analog (D-A) converters for converting digital data signals from the DSP modem to high frequency analog signals for transmission via the DSLs.
  • the DSLAM also includes a data network interface unit which conveys the digital data signals to/from the data network using, for example, SONET or ATM protocol.
  • ADSL asynchronous digital subscriber loop
  • the present invention seeks to ameliorate one or more of these problems and, to this end, provides access equipment in which, in effect, a first part of the DSLAM is located at the central office and a second part is located at a location closer to the subscriber stations, such as at a remote central office or at a junction where a plurality of individual subscriber loops are connected to a distribution cable or a feeder cable.
  • access apparatus for connecting to a data network a plurality of digital subscriber lines for carrying high frequency analog signals to and from subscriber stations, said apparatus comprising a local part and a remote part and means for communicating signals between the local part and remote part via a high speed link, the local part adapted for location at a central office and comprising a data network interface unit for exchanging digital data signals with said data network via a data switch, said remote part being adapted for location at a position intermediate the central office and said subscriber stations and comprising an analog interface unit, the apparatus further comprising a modem unit in one of said local part and remote part and between the data network interface unit and said analog interface unit, said analog interface unit for converting said high frequency analog signals into modulated digital signals and vice versa, and said modem unit for demodulating said modulated digital signals to form digital data signals for supply to said data network interface unit and for modulating said digital data signals to form said modulated digital signals for supply to said analog interface unit.
  • the intermediate position is at a junction, for example a so-called outside plant interface, where a feeder cable from the central office is coupled to several distribution 5 cables, each of which is connected to several twisted wire pairs of individual subscriber stations.
  • a feeder cable from the central office is coupled to several distribution 5 cables, each of which is connected to several twisted wire pairs of individual subscriber stations.
  • a POTS splitter/combiner may be provided to receive the high frequency analog signals from the analog interface unit and POTS signals from a POTS switch and convey them to the DSL lines, or vice versa. 10
  • the data network interface unit (31) may be coupled to a plurality of said second parts, each at a different intermediate position.
  • an access unit at the 15 central office provides a plurality of interfaces for conveying different kinds of high speed signals between the DSL lines and the data network interface unit.
  • the second part may include a multiplexer, for concentrating the high frequency signals before they are conveyed to the central office.
  • the remote second parts may be coupled to the central office by more than one path, 20 e.g. more than one optical fiber bundle, so as to improve continuity of service.
  • each DSL has a dedicated high speed DSP modem. This is very expensive, involves high power consumption and is difficult/expensive to upgrade. In addition, it allows only one dedicated specific line code per line, which means that, as standards change, it is necessary to change line cards. 25 Because existing systems are so hardware intensive, known systems have only a small number of lines per DSLAM. It is believed that, at present, 1344 DSL lines is the maximum and the line cards occupy a rack approximately 2 metres high.
  • the DMUX is coupled to a DSP which can select only one of the digital signals from the DMUX at any given time.
  • the DSP is shared by the plurality of data streams. According to Scott, this is feasible because the data is "bursty" in nature.
  • DSL signals are not particularly bursty in nature, so any improvement would be limited.
  • the system introduces significant overhead. Consequently, this DSP sharing scheme is not entirely satisfactory.
  • DSL access equipment comprising a pool of DSP modems, a bank of analog interface circuits and circuit switching means for connecting the DSP modems selectively to the subscriber lines for at least the duration of a call.
  • access apparatus for connecting a plurality of DSL lines to a data network, comprising
  • a plurality of analog interface units (29, ... 29 N ) connected to a plurality of DSL lines, respectively, for converting DSL signals to modulated digital signals, or vice versa,
  • a set of one or more digital signal processor (DSP) modem units (30 l3 ..., 30 M ) for processing the modulated digital signals and routing resulting digital data signals to the data network and for processing digital data signals from the data network and supplying the resulting modulated digital signals to respective ones of the analog interface units
  • circuit switching means (92) for connecting the DSP modem units selectively to the DSL lines for at least the duration of a call.
  • the switching means may make virtual connections between respective ones of the interface units whose associated DSL lines are active and said one or more DSP modem units, the switching means maintaining each said connection for the duration of a session or call.
  • the switching means may select a particular DSL line in response to a signal from an activity processor which detects activity on the DSL lines.
  • each interface unit may be arranged to exchange signalling with a subscriber' s modem connected thereto by the associated DSL line so as to set up a session and an activity processor in the switching means detects such signalling indicative of the user's desire to establish a session and connects the corresponding DSL to a selected one of the DSP modem units.
  • the activity processor can be programmed so that, in normal circumstances, the duration of the session may be determined by the user, either by setting the session duration at its commencement, or simply by ending the session at will, e.g. by going off-line.
  • each of the DSL lines can be connected to any DSP modem unit that is not busy.
  • each DSP modem unit that is not busy.
  • the DSP may process signals from several of the DSL lines simultaneously, i.e. a single DSP may implement several modems.
  • the apparatus comprises one or more pools of DSP and a modem unit plurality of groups of said interface units, the interface units in a particular group being connected to said one or more DSP modem pools by means of a high bandwidth communications channel, for example an optical fiber, optical free space link, and so on.
  • a high bandwidth communications channel for example an optical fiber, optical free space link, and so on.
  • the groups of interface units will be at different physical locations which may be within a particular central office, in remote distribution boxes, or even in different central offices.
  • Each interface unit then may comprise means for extracting the modulated digital signals and an optical fiber interface for effecting parallel to serial conversion of the modulated digital signals and routing the serial digital signals via the high bandwidth link.
  • This reduces the need for data buses between the interface circuitry and the DSPs, thereby reducing physical requirements and allowing a large number of interface units at remote locations to be connected easily to one DSP pool.
  • the interface circuitry may be arranged to route signals from only active lines onto the high bandwidth data link.
  • Such a pool of DSP modem units may be provided at each OPI interface and coupled on the one hand to the plurality of DSL lines and on the other hand via a multiplexer/demultiplexer and an optical interface to the central office.
  • Figure 1 labelled PRIOR ART is a simplified block schematic diagram illustrating an existing central office connecting a plurality of subscriber stations to a "backbone" broadband data network;
  • Figure 2 illustrates the components of a digital subscriber loop access multiplexer in the central office of Figure 1
  • Figure 3 is a simplified block schematic diagram similar to Figure 1 but illustrating a central office connecting a plurality of subscriber stations to a "backbone" broadband data network using an access apparatus arrangement embodying the present invention
  • Figure 4 is a simplified detail view showing connection of an OPI subsystem in the arrangement of Figure 3;
  • Figure 5 illustrates how components at the central office of Figure 3 are connected to components at the OPI;
  • Figure 6 corresponds to Figure 5 but illustrates an alternative configuration
  • Figure 7 corresponds to Figure 3 but illustrates an alternative access arrangement suitable for use with existing DSLAMs (digital subscriber loop access multiplexers) in the central office;
  • DSLAMs digital subscriber loop access multiplexers
  • Figure 8 illustrates interconnection of parts of the access arrangement of Figure 7
  • Figure 9 illustrates a modification of the access arrangement of Figure 7 in which modem units are provided at the central office and an OPI subsystem at a remote location;
  • Figure 10 illustrates in more detail equipment at the central office and the OPI subsystem
  • Figure 11 illustrates another embodiment of the invention in which the OPI subsystem of Figure 10 interfaces with a data network interface at the central office;
  • Figure 12 illustrates an arrangement for interfacing different kinds of digital subscriber lines carrying different kinds of high speed signals to the same central office
  • Figure 13 illustrates a DSL access subsystem suitable for use in the central office of Figure 12;
  • Figure 14 illustrates a modification to the OPI subsystem or its equivalent to reduce the number of optical interface units;
  • Figure 15 illustrates an arrangement for providing redundancy in the connections between the central office and the remote locations
  • FIG 16 is a simplified schematic diagram of a digital subscriber loop access module (DSLAM) having a shared pool of DSP modems;
  • DSLAM digital subscriber loop access module
  • Figure 17 is a simplified block diagram of an arrangement in which several banks of analog interface units are coupled to pools of DSPs modems by optical communications channels;
  • Figure 18 is a much-simplified block schematic diagram of a system in which banks of analog interface units associated with different central offices are coupled to a common DSP modem pool;
  • Figure 19 is a much-simplified block schematic diagram of a system similar to that of Figure 18 but in which some of the central offices are each coupled to analog interface units at associated outside plant interface units;
  • Figure 20 illustrates deployment of the DSP sharing equipment at a central office;
  • Figure 21 illustrates an OPI subsystem having a shared pool of DSP modems controlled dynamically by a session switch.
  • the station apparatus at the premises 10 ..., 10 N of a plurality of subscribers/users comprise, for example, conventional analog telephone sets 11,,..., 11 N , respectively, and computers 12 l .., 12 N , respectively, which are connected to a central office 13 by digital subscriber loops DSL l .., DSL N , respectively.
  • DSL l .., DSL N digital subscriber loops
  • Telephone set 1 l x and computer 12 x are connected by way of an aerial drop cable 14 x to an aerial terminal box 15.
  • Telephone set 11 N and computer 12 N are connected by way of a buried drop cable 17 N to a pedestal unit 18.
  • the aerial terminal box 15 and the pedestal unit 18 each connect the station apparatus of, for example, 10 to 20 such subscribers to an outside plant interface (OPI) unit 16 via aerial distribution cable segment 19A and buried distribution cable segment 19B, respectively, and main distribution cable 20.
  • OPI outside plant interface
  • the OPI 16 itself connects the pairs of conductors in the main distribution cable 20 to corresponding pairs of conductors of a feeder cable 21, which connects to the central office 13.
  • each subscriber loop is connected to both the corresponding one of the telephone sets 1 l ... 11 N and the associated one of the computers 12 j ,... 12 N .
  • Each computer is connected by a high speed modem (not shown) which converts the digital data from the computer to a high frequency analog signal, or vice versa.
  • the high frequency analog signals HF l5 ... , HF N will have a frequency in the range from about 25 kHz to several megahertz
  • the POTS (plain old telephone system) signals P 1? ..., P N from the conventional telephone sets 1 l l .., 11 N will be at a much lower frequency, less than 25 kHz.
  • the pairs of conductors of feeder cable 21 terminate at a POTS splitter unit 22 which comprises a bank of lowpass/high pass filters for separating the high frequency analog signals HF l .., HF N and low frequency POTS telephone signals P l5 ..., P N .
  • the POTS splitter 22 supplies the POTS signals P l3 ..., P N to a POTS switch 23 for routing to the conventional telephone network (PSTN) 24, and supplies the high frequency analog signals HF j ,..., HF N to a digital subscriber loop access multiplexer (DSLAM) 25.
  • the DSLAM 25 converts the high frequency analog signals HF «
  • HF N to corresponding digital signals D l .., D N , respectively, performs framing, converts them to optical format (e.g. SONET or ATM) and then supplies them via optical fiber 26 to data network switch 27 which aggregates optical signals from a plurality of DSLAMs to form an optical signal (e.g. SONET 0C192/ATM) for routing to the broadband "backbone" data network 28.
  • optical format e.g. SONET or ATM
  • data network switch 27 which aggregates optical signals from a plurality of DSLAMs to form an optical signal (e.g. SONET 0C192/ATM) for routing to the broadband "backbone" data network 28.
  • SONET 0C192/ATM optical signal for routing to the broadband "backbone" data network 28.
  • the apparatus is bidirectional, i.e. the optical signals from the data network 28 and POTS signals from the PSTN network 24 will be processed and routed in the opposite direction to respective ones of the subscriber loops, the POTS splitter 22
  • the nature of the data network switch 27 will depend upon the data network 28. It is envisaged that it will be, for example, an Asynchronous Transfer Mode (ATM) switch or a Synchronous Optical Network (SONET) switch.
  • ATM Asynchronous Transfer Mode
  • SONET Synchronous Optical Network
  • the known DSLAM 25 comprises a bank of so-called analog front end (AFE) units 29 l .., 29 N connected to a bank of DSP modems 30 x , ... 30 N , respectively, which are connected to a data network interface unit 31.
  • the POTS splitter unit 22 comprises a bank of POTS splitter filters 22 l .., 22 N , which are connected to the AFE units 29 x , ... 29 N , respectively, and to respective ones of a bank of digital signal processor (DSP) modems 30 ..., 30 N .
  • DSP digital signal processor
  • a data network interface unit 31 connects the bank of modems 30 l3 ..., 30 N to data network switch 27 ( Figure 1) via optical fiber 26 using, for example, SONET OC12.
  • Each analog front end (AFE) unit comprises analog interface circuitry (hybrids, amplifiers, and so on), for processing high frequency analog signals in the usual way, a bank of analog-to-digital (A-D) converters for digitizing the high frequency analog signals and supplying the resulting digital signals to one of the DSP modems 30 l3 ... 30 N , and a bank of digital-to-analog (D-A) converters for converting digital signals from the DSP modem sets to high frequency analog signals for transmission via the POTS splitter 22 to the subscriber loops.
  • AFE analog front end
  • the data network interface unit 31, which serves to communicate digital signals between the DSL AM's DSP modems 30,,..., 30 N and the data switch 27, may itself comprise a switch using synchronous optical network (SONET), asynchronous transfer mode (ATM), or other technology according to the kind of data network to which the data switch 27 is connected.
  • SONET synchronous optical network
  • ATM asynchronous transfer mode
  • arrangement is bidirectional i.e. the DSLAM 25 and POTS splitter bank 22 operate in a complementary manner to process signals transmitted from the subscribers and route them to the POTS network 24 and data network 28. It should also be appreciated that, as indicated in Figure 1, there will usually be many more DSLAMs and POTS splitters coupling other OPIs to the data network switch 27.
  • the subscriber loops designated D SL ⁇ ... DSI ⁇ , in Figure 1, each comprise the several concatenated pairs of conductors extending between the corresponding subscriber's station apparatus 1 l l9 ... 11 N and 12 l .. 12 N and the DSLAM 25.
  • signal attenuation over twisted wire pair subscriber loops limits the data rate and the distance from the central office (DSLAM) to the subscriber apparatus.
  • FIG. 3 differs from the arrangement illustrated in Figure 1 in that the POTS splitter 22 and the bank 29 of analog front end (AFE) units 29 x , ... , 29 N are located, with an optical interface unit 33 , in an OPI sub- system 32 adjacent the OPI unit 16, conveniently on the same plinth; and the remaining DSLAM parts, namely the bank 30 of DSP modems 30 l5 ..., 30 N and the network interface unit 31, are located, as before, in the central office 13.
  • AFE analog front end
  • An additional optical interface 34 connected to the DSP modem unit 30 ( Figure 3) communicates via an optical fiber bundle 35C with the optical interface unit 33 connected to the bank 29 of AFEs 29 l .., 29 N in the OPI subsystem 32.
  • the optical interfaces 33 and 34 may conveniently use SONET, e.g. OC12 or OC48.
  • the optical interface 34 is coupled to other similar OPI subsystems (not -shown) by additional optical fiber bundles 35 A, 35B, 35C, etc.
  • the OPI subsystem 32 is coupled to the OPI 16 by an OPI extension unit 16A mounted to the OPI unit 16, either in the same cabinet or attached to it.
  • OPI extension unit 16A mounted to the OPI unit 16, either in the same cabinet or attached to it.
  • the OPI unit 16 there are the usual two BIX connector blocks 38 and 39, the latter connected to the main distribution cable 20 ( Figure 3) and the former connected to the POTS feeder cable 21.
  • the terminals of BIX connector block 38 would be connected to respective ones of the terminals of BIX connector block 39 by jumpers 40 (one only is shown).
  • jumpers 40 one only is shown.
  • some of the jumpers 40 specifically those of subscribers requiring both POTS and DSL service, are omitted (one only is shown by a broken line). They are replaced by sets of conductors 42 A and 42B which are connected to "dummy" BIX connector blocks 43 and 44, respectively, in the OPI extension unit 16A.
  • Dummy BIX connector blocks 43 and 44 are smaller than BIX connector blocks 38 and 39 because, at least at present, it is likely that fewer than 20 per cent of the subscribers served by OPI 16 will require DSL service.
  • more BLX connector blocks could be added to the OPI extension unit 16 A.
  • the terminals of BIX connector block 43 are connected by conductor pairs of a first, "POTS-only” cable 45 to a first port 46 of the POTS splitter bank 22, while the terminals of BIX connector blocks 44 are connected by conductor pairs of a second, "POTS and DSL" cable 47 to a second port 48 of the POTS splitter bank 22.
  • a third port 49 of the POTS splitter bank 22 is coupled to the bank of AFE circuits 29 ..., 29 N which, in turn, are coupled via optical interface unit 33 to optical fiber 35C.
  • the technician will remove the first jumper from the first terminals of the BIX connector blocks 38/A and 39/ A, respectively, and connect in its place the ends of the bridging conductors 42 A and 42B. That completes the conversion of the first subscriber loop from "POTS only” to "POTS and high speed data", i.e., to become a DSL.
  • Each of the other jumpers can be removed in turn and the corresponding bridging 5 conductors connected in its place. Since only one subscriber loop is disconnected at any given time, and only for the time taken to remove the jumper and connect the two bridging conductors, interruption of service to the subscribers is minimal.
  • the optical interface unit 33 converts the optical signals arriving from the central office 13 into modulated digital signals which it supplies to the bank of AFE units
  • Corresponding analog high frequency data signals HF l3 ..., HF N from the AFE units 29 l .., 29 N , respectively, are supplied to the POTS splitter bank 22 which routes them, via port 48 and the corresponding conductor pairs of the POTS + DSL cable 47 and BIX connector blocks 44 and 39, to main distribution cable 20 and hence to the subscriber premises 10 l .., 10 N .
  • POTS signals P l5 ..., P N from the POTS switch 23 ( Figure 3) at the central office 13 will be routed via feeder cable 21 to connector block 38 in the OPI 16 and, from there, via conductors 42 A, BIX block 43 in the OPI extension 16 A, and POTS-only cable 45 to port 48 of the POTS splitter unit 22.
  • the POTS signals P l .., P N leave the POTS splitter 22 via port 48 and then follow the same path to the subscribers as the high frequency analog
  • DSL and POTS signals from the subscribers to the central office will follow the same paths, respectively, but in the opposite direction.
  • the network interface unit 31 , DSP modem bank 30 and optical interface unit 34 are distributed among a set of printed circuit cards.
  • optical interface circuit 51 l5 a data network processor 52 x and a backplane bus interface and controller unit 53
  • the optical interface circuit 51 j is connected by optical fiber 26 and switch 27 to backbone data network 28, and converts optical (e.g. ATM or SONET) signals received from the switch 27 into electrical serial digital signals which it supplies to the data network processor 52 t .
  • optical e.g. ATM or SONET
  • cards 50 2 , 50 3 , 50 4 and 50 5 are of identical construction, only card 50 5 will be
  • card 50 5 carries a backplane bus interface unit 55 5 , a network processor 56 5 , a set of thirty-two DSP modems 30 j , ..., 30 ⁇ , a multiplexer 58 5 , a demultiplexer 59 5 and an optical (SONET) interface 34 s .
  • the backplane bus interface unit 55 5 controls the flow of signals between backplane bus 54 and network processor 56 5 , which detects packet addresses in the digital data signals and routes the digital data signals to appropriate ones of the modems 30 5 1, ..., 303 5 2 , .
  • Themodems 30 5 ,..., 30 5 modulate the digital data signals to form modulated digital signals and supply them to the multiplexer 58 5 which multiplexes them to form a serial signal.
  • Optical interface 34 5 converts the serial signal to a corresponding SONET optical signal
  • SONET OC12 for example, and transmits the optical signal via the optical fibre 35C 5 to the
  • the OPI subsystem 32 comprises a bank of complementary cards 61 2 ,..., 61 s each carrying abank of individual AFE circuits and coupled to a respective one of the cards 50 2 ,..., 50 5 by a corresponding one of the bundle of optical fibers 35 C 2 ,..., 35C 5 .
  • AFE cards 61 2 ,..., 61 5 are identical, only one will now be described.
  • AFE card 61 5 carries an optical interface circuit 33 5 , a multiplexer 63 5 , a demultiplexer 64 s , a bank of thirty-two AFE circuits 29 5 , ..., 29 5 , , and a microcontroller 65 5 which controls the other components on the card 61 5 .
  • the optical interface circuit 33 5 converts the serial optical signal from fibre 35C 5 into a serial electrical digital signal, de-frames it, etc., and supplies the resulting serial digital signal to demultiplexer 64 5 .
  • the demultiplexer 64 5 demultiplexes the serial digital signal and supplies the resulting individual modulated digital signals to respective ones of the bank of AFE circuits 29 5 , ..., 29 .
  • the AFE circuits 29 ⁇ , ..., 29 convert the modulated digital signals to analog high frequency signals and supply them via cable 60 to the bank of POTS splitters 22 l .., 22 128 for routing onto the POTS and DSL cable 47.
  • the cable 47 also carries the POTS signal from cable 45 ( Figure 4) as discussed previously.
  • high frequency analog signals coming from the subscribers via cable 60 can be processed in the opposite direction by the AFE circuits, multiplexed by multiplexers 63 5 , converted by optical interface 33 5 into a SONET optical signal and routed to the central office 13.
  • the optical interface 34 5 will convert the received optical signal and supply the corresponding electrical serial digital signal to demultiplexers 59 5
  • the demultiplexers 59 5 has 32 outputs each coupled to a respective one of the modems. Following processing by the modems, the signals will be routed via the network processor 56 5 and the backplane bus interface unit 55 5 onto the backplane bus 54.
  • Figure 6 illustrates how the arrangement of Figure 5 may be modified by moving the DSP modems from the central office 13 to the
  • the portion of the data network interface unit 31 carried by card 50Aj is the same as that shown in Figure 5.
  • the cards 50A 2 ,..., 50A 5 comprise only backplane bus interfaces 55 2 ,..., 55 s , respectively, network processors 56 2 ,..., 56 5 , respectively, multiplexers 58 2 ,..., 58 5 , respectively, demultiplexers 59 2 ,..., 59 5 , respectively, and optical interfaces 34 2 ,..., 34 5 , respectively, these components
  • the network processors 56 2 ,..., 56 5 decipher the addressing in the parallel digital signals from the backplane bus interface and controller 53,.
  • the packetized digital signals which still include the addressing for the respective modems, are multiplexed by multiplexers 58 2 ,..., 58 5 , the multiplexed signals converted to optical signals
  • optical interfaces 34 2 ,..., 34 s respectively, and the optical signals transmitted to the OPI subsystem 32.
  • optical signals that are carried by the optical fibres 35C 2 ,..., 35C 5 comprise the "raw" packetized data signals, so each has a lower bandwidth than the signals carried by these optical fibers in the embodiment of Figure 5,
  • 25 typically one quarter to one tenth.
  • the actual bandwidth will depend upon the modem and particular protocol involved.
  • the optical signals from fibers 35C 2 ,..., 35C 5 are converted by optical interfaces 33 2 , ..., 33 5 and demultiplexed by demultiplexers 64 2 , ..., 64 5 , respectively, to form corresponding sets of demultiplexed digital data signals.
  • Microcontrollers 65 2 , ... , 65 5 control the various components on their respective cards, as before, and other connections, routings, etc. are similar to those in the embodiment of Figure 5.
  • the data network interface unit 31 ( Figure 2) is a complicated piece of equipment because it needs to be able to process different kinds of signals to facilitate, for example, video conferencing, broadcasting and so on. For this reason, it is better to locate it at the central office 13 rather than at the OPI unit 16 or OPI subsystem 32.
  • 5 Figures 7 and 8 illustrate a further embodiment of the invention which is for use when central office 13 has a DSLAM 25 whose interior is not accessible for one reason or another.
  • the reverse AFE unit 66 comprises a bank of cards 67 2 ,..., 67 5 carrying AFE circuit groups 29_4 2 , ...29_4 2 ; ...;29A 5 , ... 29A 5 , respectively, multiplexers 58 2 ,..., 58 5 , respectively, demultiplexers 59 2 ,..., 59 5 , respectively, and optical interfaces 34 2 ,..., 34 5 .
  • Each of the multiplexers 58 2 ,..., 58 5 multiplexes the high-frequency modulated digital signals from the associated one of the reverse AFE circuits to form a serial signal which the associated one of the optical interfaces
  • optical fibers 35C 2 , ..., 35C 5 to an OPI subsystem 32 that is substantially identical to that described with reference to Figure 5.
  • Figures 9 and 10 illustrate a modification to the arrangement of Figures 7 and 8 to reduce further the bandwidth required for the optical link between the central office 13 and the OPI subsystem 32, specifically by adding a bank of modems 30 to OPI subsystem 32 and a similar bank of modems 30A to the reverse AFE unit 66 in the central office 30, as shown in Figures 9 and 10.
  • the demodulated digital data signals are multiplexed by multiplexers 58 2 ,... 58 5 , converted to optical signals by the optical interfaces 34 2) ...34 5 , respectively, and transmitted to the OPI subsystem 32.
  • the optical signals are converted by optical interfaces 33 2 ,... 33 5 to electrical signals, demultiplexed by demultiplexers 64 2 ,... 64 5 , modulated by the modems
  • the OPI subsystem 32 of Figures 9 and 10 could be used where a central office 13 does not have a DSLAM 25 and reverse AFE unit 66, but has only the data network interface part 31 of the DSLAM.
  • the AFE unit 29 at the OPI subsystem 32 could be connected, via modem bank 30, optical interface 33 and optical fiber bundle 35 to an optical interface 34 associated with the data network interface 31 at the central office 13.
  • the data network interface unit 31, the modem bank 30 and AFE unit 29 at the OPI subsystem 32 constitute parts of a distributed DSLAM, with optical interfaces 33 and 34 and optical fiber 35C interconnecting the parts.
  • the cards at the central office 13 would be similar to the cards 50A 2 ,... 3 50A 5 in the arrangement of Figure 6.
  • a central office 13 serves several DSL subscriber stations lOA/1, 10A/2, 10B and 10C by way of OPI units 16 A, 16B and 16C, respectively.
  • OPI units 16A and 16B are shown connected via pedestal units 18A and 18B, respectively, to sets of subscribers, while OPI unit 16C is shown connected directly to a multiple dwelling unit (MDU).
  • MDU multiple dwelling unit
  • a pedestal unit typically will connect to about 10 subscriber stations while an OPI unit will connect to between 500 and 1,000 subscriber stations.
  • Each of the OPI units 16 A,..., 16C will have an AFE subsystem (not shown) associated with it, through not necessarily at the same physical location.
  • the AFE subsystem could be any of those described hereinbefore.
  • a first OPI 16A has a co-located OPI subsystem 32A connected to the central office 13 by an optical fiber bundle 35 A.
  • the OPI 16A is connected to ADSL/VDSL subscribers (only one is shown) 10A via a pedestal 18 A and directly to an office tower 18A x by a distribution drop cable 17B l3 for delivery of Ethernet over DSL service to occupants of the office tower 18A1.
  • a second OPI 16B is shown connected to central office 13 and via a second pedestal unit 18B to VDSL subscribers 10B (only one is shown).
  • the associated OPI unit 32B is co-located with the pedestal unit 18B and connected to the central office 13 directly by an optical fiber bundle 35B.
  • a third OPI 16C is shown connected to the central office 13 by the usual feeder cable 21 C and to a multiple dwelling unit (MDU) 10C by a distribution cable 19C.
  • MDU multiple dwelling unit
  • the distribution cable/drop 19C is connected to an OPI subsystem 32C which is connected directly to the central office 13 by an optical fiber bundle 35C.
  • the three access configurations, A, B and C shown in Figure 12 are examples only. They may be modified or combined in various ways according to the kinds of subscriber to be served and the particular services to be delivered.
  • the pedestal unit 18A also could have an OPI subsystem associated with it and connected to the central office directly by an optical fiber bundle.
  • the three OPI subsystems 32A, 32B and 32C may be any combination of those disclosed hereinbefore, and need not be identical to each other.
  • the feeder cables 21 A, 2 IB and 21C are connected to a
  • the optical fiber bundles 35 A, 35B and 35C are connected to a universal DSL access unit 80 which couples their DSL signals directly to the data network switch 27.
  • the DSL access unit 80 also is connected via a DSLAM 25 to the data network switch 27, to allow for those situations where there is excess capacity in the existing DSLAM 25, in which case DSL access unit 80 routes the incoming digital signals to the DSLAM interface unit 84 which converts them to high frequency analog signals and supplies them to the DSLAM 25. The latter processes them in the usual way before supplying corresponding data signals to the data network switch 27.
  • the DSLAM 25 and DSLAM interface unit 27 are, of course, bidirectional.
  • the DSL access unit 80 is able to connect to many OPI subsystems 32 distributed over a wide region. Hence it can serve as an aggregator. 5
  • the DSL access unit 80 comprises an optical interface unit 82, a configuration switch
  • the optical interface unit 82 converts the serial signals received from the corresponding one of the optical fibers to electrical data signals and demultiplexes them; or, conversely, multiplexes and converts signals destined for the DSL subscribers.
  • configuration switch 83 routes the signals from the optical interface unit 82 to the data network interface unit 31 or to the DSLAM interface unit 84 as appropriate; or vice versa.
  • the configuration switch 83 usually will be controlled in known manner, using an Element Management System (not shown), to couple the optical interfaces to the interface cards selectively and to provide any required traffic shaping, or bandwidth allocation.
  • the DSL access unit 80 may be configured to handle several different kinds of DSL signal.
  • the DSL access unit 80 may comprise a broadcast video unit 85, a POTS circuit emulator 86 and a class 5 switch interface unit 87.
  • the optical interface unit 82 interfaces with several optical fiber bundles 35 2 ,..., 35 M which are connected to separate OPI subsystems, respectively.
  • the subscriber stations requiring DSL services could be using ADSL, VDSL, Ethernet, or other suitable communications protocol.
  • the DSL access unit 80 allows multiple users to share a single data
  • the DSLAM interface unit 84 allows some of the users to be connected to an existing DSLAM 25, if appropriate.
  • each of the optical fiber bundles 35 2 to 35 M is coupled to a respective one of the optical interfaces 82 2 ,..., 82 M .
  • the switch unit 83 couples them to the
  • the data network interface card 31, interactive or broadcast video card 85, POTS circuit emulator card 86 and DSLAM interface card 84 are connected to, respectively, an OC12/OC48 fiber, an OC12 fiber, a T1/DS3/OC3 connection, and a series of DSL analog signal lines DSL l .. DSI ⁇ ,.
  • the switch unit 83 may comprise an asynchronous transfer mode (ATM) switch, or equivalent, which is configured by way of an Element Management System (EMS - not shown) to connect any of the optical interfaces 82 2 ,..., 82 M to any one of the cards 31 and 84 - 87, the particular connection made being determined by the service provider's administrator according to the subscriber's service to be delivered.
  • the card 31, i.e. the data network interface card provides an interface to the data network switch 27 shown in Figure 12.
  • the interactive or broadcast video card 85 will provide more functionality as appropriate and interface to a broadband video network (not shown).
  • the POTS circuit emulator card 86 is used to provide voice service, i.e. POTS service, over the DSL line, which may be desirable if a subscriber needs a second line for voice, and will connect to the POTS switch 23.
  • voice service i.e. POTS service
  • the DSLAM interface card 84 will comprise a DSL modem and an AFE for interfacing to the DSLAM 25, i.e. it is a reverse AFE unit similar to that shown in Figure 10.
  • the class 5 switch interface unit 87 may be provided for routing ATM traffic or the like between the DSL subscribers and one or more class 5 switches.
  • optical switch unit 90 could comprise an upstream switch 90/1 and a downstream switch 90/2, each connected between the optical interfaces 33 2 ,..., 33 4 and the bank of line cards 61 2 ,..., 61 N which may be any of those shown in Figures 5, 6, 8 and 10 it should be noted that there are fewer optical interfaces than in the embodiments of Figures 5, 6, 8 and 10.
  • the optical interfaces 33 2 ,... 33 4 are shown connected to optical fibers 35 2 ,... 35 4 , respectively, which are connected to the central office 13.
  • the statistical multiplexer switches 90/1 and 90/2 may each comprise a small ATM switch.
  • the switches 90/1 and 90/2 will route the active DSL signals to selected ones of the optical fibers 35 2 ,..., 35 4 .
  • switch unit 90 allows the customer to increase the transport capacity of the OPI subsystem by plugging more optical interfaces into the DSL access unit. If there were two or more optical fibers and optical interfaces, the switch could share the DSL traffic between them equally, or in any other desired proportions.
  • FIG. 15 illustrates how such redundancy could be achieved using two DSL access units 80/1 and 80/2 at the central office 13, both connected to the data network switch 27 directly.
  • DSL access unit 80/1 also is connected via conventional DSLAM 25 and DSL access unit 80/2 also is connected to POTS switch 23 so as to provide for a second or a third POTS service over DSL.
  • a first OPI subsystem 32/1 is coupled to DSL access unit 80/1 by two optical fibers
  • OPI subsystem 32/2 is connected to DSL access unit 80/2 by a first optical fiber 35/2 3 , and to the DSL access unit 80/1 by a second optical fiber 35/2 2 , providing 1 + 1 redundancy in the interconnections.
  • each channel of the DSLAM 25 is dedicated to a respective one of the subscriber loops DSL l3 ... 3 DSL N , as are each channel of the DSLAM 25 or DSP modem bank AFE unit in the above-described embodiments of the present invention.
  • Figure 16 illustrates a DSLAM which may replace one or each of the DSLAMs in the central office 13 in Figure 1, i.e., which may be connected between the POTS splitter 22 and the switching device 27, or in a comparable location in the embodiment illustrated in Figure 3.
  • the embodiment of Figure 16 could be used in any of the above-described embodiments of the invention but, in practice, would only be used where the modem unit was at the central office 13.
  • the DSLAM shown in Figure 16 comprises an AFE unit 29 comprising a bank of analog interface units 29 ..., 29 N connected to the digital subscriber loops DSL l3 ..., DSL N , respectively, a pool 3 OP of digital signal processor modems 30 l3 ..., 30 M , a circuit switch 92 connected between the analog interface units 29 l3 ..., 29 N and the modems 30 1; ..., 30 M , and a network interface unit 31 connecting the modems 30 ! ,..., 30 M to the network switch 27 ( Figure 1) via an optical fiber 26.
  • An activity and accounting processor 93 associated with the circuit switch 92 monitors the analog interface units 29 l3 ...
  • a memory 94 is associated with the network interface unit 31 and the DSP modem pool 30.
  • the network interface unit 31 may write to the memory 94 whereas the processors 30 l .., 30 M can both write to, and read from, the memory 94.
  • the memory 94 stores line codes, line condition information, and other operational data.
  • the line code selection may be initiated by the activity processor 93 in response to a demand from the user station when setting up the session. For example, the user station might select either Asymmetric DSL or Symmetric DSL according to the nature of the session.
  • the DSLAM shown in Figure 16 allows any one of the DSL lines DSL l5 ..., DSL N to be connected to any one of the modems 30 l .., 30 M . It is envisaged that, under normal traffic conditions, only ten per cent of the DSL lines DSL l5 ..., DSL N will be active so the number of DSP modems need be only one tenth of the number N of DSLs.
  • FIG 17 illustrates a further embodiment of the invention in whichJ OPI subsystems
  • Each of the optical interface units 33/1,..., 33/L converts the digital signals of only the "active" DSLs from the corresponding group of interface units 29 l .., 29 N into a serial optical signal and transmits the serial optical signal via the associated one of the optical fibers to the central office 13.
  • optical fibers 35/1,..., 35 L are
  • circuit switch 92 of the DSLAM shown in Figure 16 has been divided into circuit switch unit 92/1 associated with the processor pool 3 OP and session switch units
  • each of the activity processors 95/1,..., 95/L will supply to the
  • a DSL tone having a frequency higher than the limit of the lowpass filters, for example at least 25 kHz.
  • the tone indicates that service is available.
  • a particular user station say user station 10 n (not shown) in OPI subsystem 32 wishes to begin a session, it will detect the first tone and emit its own tone, requesting service.
  • the activity processor 95/1 will detect the tone and send to the session processor 93/1 a request to set up a virtual connection via one of the DSP modems 30 l ..,30 M .
  • the session processor 93/1 will send a reply to the activity processor 95/1 to the effect that modem 30 M is to be used, whereupon activity processor 95/1 will advise the modem of user station 10 n that a connection is available and the user station may begin transmitting.
  • the session will continue until the user station 10 n terminates it, perhaps by sending a suitable signal to activity processor 95/1 which then will send a signal to the session processor 93/1 advising it to terminate the virtual connection and, once the connection has been terminated, providing the DSL tone again on the corresponding DSL line.
  • the DSL line then is available and the processor modem 30 M has capacity to handle another session.
  • the activity processor 95/1 may cause termination if and when there has been no activity on the line for a predetermined "time out" period. It should be appreciated that each of the D SPs implementing the modems 30 l5 ... , 30 M may process several signals simultaneously and that, as before, different line codes from memory 94 may be used for the different signals.
  • An advantage of this arrangement is that it allows the user stations to select different line codes according to the kind of session being requested and, for example, the kind of bandwidth required. For example, a user might select Asymmetric DSL for Internet browsing and Symmetric DSL for networked video games or "video-on-demand".
  • the selected DSP modem may demultiplex the serial digital signals for processing and then multiplex them again for transmission to the data network.
  • Figure 18 illustrates a system in which the DSP pool 3 OP is located in a main central office 13 and the groups 1...L of analog interface units (AFES) are housed in respective ones of a plurality of remote central offices.
  • the analog interface units and the central DSP modem pool unit 3 OP of DSL Access unit 80 will be similar to those shown in Figure 17. In this case, however, the optical fibers 35 j -..., 35 L interconnect the groups of interface units in a ring configuration.
  • the main central office 13 is coupled to a plurality of remote or local central offices 13/1, 13/2,..., 13/7 by trunks 100/1, 100/2, 100/3,..., 100/8 in the usual way.
  • the main central office 13 has a central processor pool 3 OP similar to that shown in Figure 17 and several of the local central offices 13/1, 13/2, 13/4, 13/6 and 13/7 have analog interface units similar to those shown in Figure 3 and 9 with AFE POTS splitter (not shown in Figure 12) similar to those shown in Figure 4.
  • these central offices will have subscriber stations so close that the subscriber loops are short enough to support high speed access.
  • the main central office 13 and two local central offices 13/3 and 13/5 are shown connected to OPI subsystems 32, 32/3 and 32/5, respectively, located in or adjacent OPI boxes 16, 16/3 and 16/5 which, typically, connect to subscriber stations that are more distant than, say, 2 kilometers from the main central office 13.
  • OPI subsystems 32, 32/3 and 32/5 includes a bank of analog interface units similar to those described hereinbefore with reference to Figure 17 and a bank of POTS splitters 22, each for separating DSL and POTS signals passing between the local central office and the associated one of the subscriber stations.
  • Central offices 13, 13/3 and 13/5 each will be configured like that shown in Figure 3, but with the DSP modem unit 30 and optical interface unit 34 replaced by those shown in the central processor pool shown in Figure 17.
  • the arrangement at the OPI unit may be as shown in Figure 4.
  • the OPI subsystem would include the switch 90, as shown in Figure 14.
  • each of the AFEs in a particular group has variable gain so as to allow adjustment of signal levels in the cable and reduce cross talk and other interference to which the user signals might be subjected.
  • the embodiments shown in Figures 6 and 11 locate the DSP modems 3O 5 , ... ,30? at the OPI subsystem 32, which is desirable because it reduces demand on bandwidth of the optical fiber 35.
  • size constraints may make it difficult to locate a large number of such DSP modems at the OPI subsystem 32. Accordingly, it may be preferred to provide a DSP modem pool 3 OP at the OPI subsystem 32 and share the DSP modems between the subscriber lines.
  • the OPI subsystem 32 then would be similar to that shown in Figure 16 but with the data network interface 31 replaced by an optical interface (OI) unit 33 and a multiplexer/demultplexer 130.
  • the activity and accounting processor 93 of Figure 16 is replaced by an activity processor 131, and the accounting function will be handled by a processor 132 at the central office 13. Otherwise the equipment at the central office 13 will be as shown in Figures 6 and 11, including optical interface 34, multiplexer and demultiplexer 58/59 (shown as one box for convenience and data network interface 31.
  • the OPI subsystem comprises a circuit switch 92 for selecting an available one of the DSP modems 30 b ..., 30 M in dependence upon activity detected by the activity processor 131.
  • a processor such as one ofthe DSPs, could run software for generating the required TDR signal and transmitting it via the session switch, optical fiber, and activity switch to the appropriate one ofthe AFEs at the OPI 16, which would transmit the corresponding electrical pulses onto the subscriber loop and return the reflections signals to the DSP for processing to derive the loop characteristics and suitability for high speed data, or lack thereof.
  • the invention is applicable to "voice over DSL" systems, in which case the POTS splitter unit would be omitted and the DSLAM parts modified appropriately.
  • Embodiments ofthe first aspect ofthe invention allow DSL service to be provided for a greater number of subscribers at reasonable cost. It will be appreciated that embodiments of the present invention using DSP-sharing require less costly equipment, specifically fewer modems, than existing designs and can be upgraded relatively easily.
  • a significant advantage is that the line codes can, if desired, be selected on a "per call" basis and the set of line codes form which the selection is made, i.e. stored in memory 94, can be changed relatively easily, which facilitates upgrading to accommodate new line codes or simply changing line codes according to specific requirements.
  • An advantage of embodiments ofthe invention in which the DSLs share DSP modems is that they avoid the redundancy which results from inactive DSLs being connected, as in prior art DSL access arrangements.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Astronomy & Astrophysics (AREA)
  • General Physics & Mathematics (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)
  • Use Of Switch Circuits For Exchanges And Methods Of Control Of Multiplex Exchanges (AREA)
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Abstract

Afin de pouvoir offrir un service de ligne d'abonné numérique (DSL) à plusieurs abonnés, une partie au moins du multiplexeur d'accès en boucle d'abonné numérique est située à un emplacement, par exemple au niveau d'une unité d'interface d'installation extérieure (16), laquelle se situe entre les locaux de l'abonné ((101,... 10N) et le central téléphonique (13) logeant l'autre partie du multiplexeur d'accès en boucle d'abonné numérique. Une fibre optique achemine les signaux entre les deux parties de ce multiplexeur, réduisant ainsi la longueur de la portion de fil à paire torsadée de la boucle d'abonné. Afin de réduire la complexité et les coûts en matériel, l'invention concerne un appareil de connexion de plusieurs lignes d'abonnés numériques à un réseau de données (28), lequel appareil comprend plusieurs unités d'interface connectées respectivement à plusieurs lignes d'abonnés numériques, aux fins de conversion des signaux analogiques de fréquence élevée en signaux numériques, ou vice versa; en outre cet appareil comprend au moins un modem processeur de signaux numériques (30) conçu pour traiter les signaux numériques et acheminer les signaux traités en direction du réseau de données, ainsi que pour traiter des signaux provenant du réseau de données et fournir les signaux numériques résultants aux unités d'interface. Un commutateur de session (92) peut servir à établir des connexions virtuelles entre des unités d'interface dont les lignes d'abonnés numériques sont actives, et les modems processeurs de signaux numériques, et il maintient chaque connexion pendant la durée d'une session. Grâce à un tel agencement, un groupe de processeurs de signaux numériques peut être partagé par un nombre beaucoup plus grand de lignes d'abonnés numériques.
PCT/CA2001/001698 2000-11-30 2001-11-30 Appareil de connexion de lignes d'abonnes numeriques a un materiel de central telephonique WO2002045383A2 (fr)

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AU2002223347A AU2002223347A1 (en) 2000-11-30 2001-11-30 Apparatus for connecting digital subscriber lines to central office equipment

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
CA2,327,118 2000-11-30
CA002327118A CA2327118A1 (fr) 2000-11-30 2000-11-30 Multiplexeur d'acces pour lignes d'abonnes numeriques
CA002331549A CA2331549A1 (fr) 2001-01-18 2001-01-18 Arrangements d'acces de lignes d'abonne numeriques
CA2,331,549 2001-01-18
CA2,346,573 2001-05-07
CA002346573A CA2346573A1 (fr) 2001-05-07 2001-05-07 Dispositions pour connecter des lignes d'abonne numeriques a l'equipement de central
US31135701P 2001-08-13 2001-08-13
US60/311,357 2001-08-13

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002058405A2 (fr) * 2001-01-18 2002-07-25 Esion Networks Inc. Procede et appareil de conversion de lignes d'abonnes dans le but d'assurer a la fois un service telephonique traditionnel et un service de transmission de donnees a grande vitesse
EP1389029A1 (fr) * 2002-07-30 2004-02-11 Alcatel Un système d'accès DSL, une unité centrale de terminaison DSL et une unité distante de terminaison DSL realisant un DSLAM
WO2004045223A1 (fr) * 2002-11-06 2004-05-27 Infratel Communications, Llc Interface de télécommunications
WO2005029907A1 (fr) * 2003-09-23 2005-03-31 British Telecommunications Public Limited Company Telecommunications a large bande
WO2007028852A1 (fr) * 2005-08-05 2007-03-15 Heikki Laamanen Méthode pour établir une connexion d’abonné et système exploitant la méthode
EP2037665A3 (fr) * 2007-09-14 2010-03-31 NEC Corporation Dispositif de communication, système de communication, procédé de contrôle et support d'enregistrement
WO2012080512A1 (fr) 2010-12-17 2012-06-21 Telefonica, S.A. Système pour xdsl de longue portée par fibre
DE102014224289A1 (de) * 2014-11-27 2016-06-02 Tyco Electronics Services Gmbh Verteilereinrichtung für die Kommunikations- und Datentechnik

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002058405A2 (fr) * 2001-01-18 2002-07-25 Esion Networks Inc. Procede et appareil de conversion de lignes d'abonnes dans le but d'assurer a la fois un service telephonique traditionnel et un service de transmission de donnees a grande vitesse
WO2002058405A3 (fr) * 2001-01-18 2003-04-03 Esion Networks Inc Procede et appareil de conversion de lignes d'abonnes dans le but d'assurer a la fois un service telephonique traditionnel et un service de transmission de donnees a grande vitesse
EP1389029A1 (fr) * 2002-07-30 2004-02-11 Alcatel Un système d'accès DSL, une unité centrale de terminaison DSL et une unité distante de terminaison DSL realisant un DSLAM
WO2004045223A1 (fr) * 2002-11-06 2004-05-27 Infratel Communications, Llc Interface de télécommunications
US7567550B2 (en) 2003-09-23 2009-07-28 British Telecommunications Plc Broadband communications
AU2004305665B2 (en) * 2003-09-23 2009-02-26 British Telecommunications Public Limited Company Broadband communications
WO2005029907A1 (fr) * 2003-09-23 2005-03-31 British Telecommunications Public Limited Company Telecommunications a large bande
WO2007028852A1 (fr) * 2005-08-05 2007-03-15 Heikki Laamanen Méthode pour établir une connexion d’abonné et système exploitant la méthode
EP1941663A1 (fr) * 2005-08-05 2008-07-09 Heikki Laamanen Méthode pour établir une connexion d abonné et système exploitant la méthode
EP1941663A4 (fr) * 2005-08-05 2010-11-10 Heikki Laamanen Méthode pour établir une connexion d abonné et système exploitant la méthode
EP2037665A3 (fr) * 2007-09-14 2010-03-31 NEC Corporation Dispositif de communication, système de communication, procédé de contrôle et support d'enregistrement
WO2012080512A1 (fr) 2010-12-17 2012-06-21 Telefonica, S.A. Système pour xdsl de longue portée par fibre
ES2385617A1 (es) * 2010-12-17 2012-07-27 Telefónica, S.A. Sistema para xdsl de largo alcance sobre fibra.
US9002205B2 (en) 2010-12-17 2015-04-07 Telefonica, S.A. System for long reach xDSL over fiber
DE102014224289A1 (de) * 2014-11-27 2016-06-02 Tyco Electronics Services Gmbh Verteilereinrichtung für die Kommunikations- und Datentechnik
DE102014224289B4 (de) * 2014-11-27 2016-10-13 Tyco Electronics Services Gmbh Verteilereinrichtung für die Kommunikations- und Datentechnik
US10327047B2 (en) 2014-11-27 2019-06-18 Commscope Technologies Llc Distribution frame device for communications and data technology
US11438677B2 (en) 2014-11-27 2022-09-06 Commscope Technologies Llc Distribution frame device for communications and data technology

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