EP1730943A1

EP1730943A1 - Method and system for providing xdsl and telephone service via telecommunication networks

Info

Publication number: EP1730943A1
Application number: EP05709018A
Authority: EP
Inventors: Jan Ulander
Original assignee: NORDIA INNOVATION AB
Current assignee: NORDIA INNOVATION AB
Priority date: 2004-03-17
Filing date: 2005-03-15
Publication date: 2006-12-13
Also published as: SE0400669D0; WO2005091613A1

Abstract

A method and system for providing digital subscriber line (xDSL) and telephone service to subscribers via a telecommunication network. The Installation of xDSL for providing broadband service is performed by connecting the subscriber line in the central office main distribution frame (MDF) to a high-speed data network 126. In an embodiment of the invention, the method comprises the steps of: connecting the subscriber lines 140 to a pool of integrated filter board(s) 160 on the exchange side for separating the signal components relating to the telephone service from signal components relating to the digital data signals, routing the signal components relating to the telephone service to a new physical port on the exchange, re-configuring the logical port on the exchange to correspond with the new physical port in order to retain the subscriber's previous telephone service and number, and routing the digital data signals from the pooled integrated filter board(s) to a modem bank for transmission to and from the data network 126. In a further embodiment, the system for providing DSL service is operable in cooperation with an automated cross-connect system 400 installed within the MDF. The automated cross-connect system performs automated routing of subscriber lines to the pooled integrated filter board(s) for onward connection to the exchange and data network 126.

Description

Description METHOD AND SYSTEM FOR PROVIDING xDSL AND TELEPHONE SERVICE VIA TELECOMMUNICATION NETWORKS FIELD OF THE INVENTION

[1] The present invention relates generally to the installation of telecommunication services, and more particularly, to a method and system for providing xDSL and telephony services to subscribers using telecommunication networks.

[2] BACKGROUND OF THE INVENTION

[3] The pervasive influence of the Internet, combined with the increased dependency on the Internet for a growing number of consumer services, has fuelled an increasing demand for broadband services. The growing demand has made providing digital subscriber line (DSL) services an important issue for traditional telephone operators to derive new sources of revenue and to improve customer retention. The term DSL and its various forms is often referred to as xDSL, which represents a group of higher bit- rate digital subscriber line communications schemes using the standard copper wire twisted pair subscriber lines to provide office or residential broadband access to the Internet. An example of a version of xDSL that is in common use is Asymmetrical Digital Subscriber Line (ADSL). ADSL is primarily aimed at the residential market and provides greater bandwidth for downstream data than for upstream data and works by reserving a portion of the available channel bandwidth for support of traditional analog telephone service, also often referred to as Plain Old Telephone Service (POTS). Other examples of DSL include High data rate Digital Subscriber Line (HDSL), and Very high data rate Digital Subscriber Line (VDSL), and Symmetric DSL (SDSL) which provide equal bandwidth in both the upstream and downstream directions. SDSL does not provide support for POTS and is better suited to business applications such as network server communications, etc.

[4] In a typical telecommunication network, the central office houses a telephone exchange to which subscriber home and business lines are connected to the network on what is called a local loop. As mentioned earlier, many of the connections to residential and business subscribers are made using copper wires or twisted pairs that collectively form a large copper network operated by the telecom provider. Within the central office the line connections between the exchange side and the subscriber side are connected to a main distribution frame (MDF), which is usually the point at which cross-connections between the subscriber lines and the exchange are made. Virtually all aspects of the telecommunication network are automated with the notable exception of the copper network. As a consequence, the central office must dispatch technicians to the MDF site to manually perform installations of telephone and other services such as xDSL which are highly labor intensive processes that result in one of the most significant costs faced by telecom providers.

[5] Fig. 1 illustrates an exemplary prior art connection of a conventional analog phone connection from the subscriber phone 100 to the central office exchange via the MDF. The subscriber phone 100 and corresponding subscriber line 102 connects to a connector block within the MDF cabinet. The MDF typically comprises columns of connector blocks 110 for the line side that connect to the subscriber lines. Furthermore, there are columns of connector blocks 112 on the exchange side for which lines from the exchange are connected within the MDF. A cross-connection is generally made by physically placing a jumper wire 114 to connect the subscriber line to the exchange, for example, subscriber line 102 to port 1. The exchange is further connected to the public switched telephone network (PSTN) for routing incoming and outgoing calls to and from the subscriber line. The connector blocks used in MDFs are basically similar, however, there are minor variations that are currently in use, the most common being the LSA-Plus connector block manufactured by KRONE Inc., a subsidiary of GenTek Inc. of Hampton, New Hampshire, USA. The KRONE connector blocks are typically able to accommodate up to 2 x 10 line pairs at a time. Thus there can be 10 subscriber line pairs connected to the connector block for connection to the exchange ports 1-10 respectively. Additional subscriber line pairs are cross-connected to the exchange via further connector blocks to further exchange ports.

[6] Fig. 2 illustrates an exemplary prior art process for connecting a subscriber line 102 to a central office data network 126 for delivering high-speed xDSL service. The data network can be the Internet, local public or private Intranets, or other types of data networks. The subscriber phone apparatus 100 and computer equipment 101 are connected to a splitter 103 and connected the subscriber line 102. At the MDF the line is connected to connector block 110 however, instead of connecting a jumper wire directly to the exchange side connector block 112, jumper wire 118 is typically connected to connector block 120, which feeds into a filter device 122 comprising high and low pass filters for separating the low frequency analog phone signals from the high frequency data signals on the subscriber line. The high frequency signal components are supplied to, or received from, one or more so-called digital subscriber loop access multiplexers (DSLAMs). The DSLAM contains 'analog front end' (AFE) circuitry that includes amplifying circuitry for processing the high frequency signals by digitizing the high frequency signals from the xDSL lines and supplying the resulting digital data signals to a digital signal processor (DSP) modem 124 for transmission to and from the data network 126. [7] The low frequency phone signals from the low pass filter is typically routed to a connector block 130 on the line side in order to make a cross-connect back to the connector block 112 for connection to physical exchange port 1 which maintains the original subscriber telephone service and number. In this case, the physical port is the same as the logical port in the exchange. It is readily apparent that the installation of xDSL service made in this way is rather labor intensive since the central office must dispatch a technician to manually install appropriate cross-connects for each subscriber line. Another disadvantage of the above technique is that it requires the use of additional connector blocks on both the subscriber and exchange side for the rerouted jumper wires, which adds to operator costs. When installing xDSL to an existing subscriber line, the existing jumper wire needs to be removed and two new jumper wires added, which often makes it is necessary to expand the MDF. This means there are additional requirements for additional connector blocks, jumper wires, floor space, and labor for each new installation. When a large number of xDSL installations are performed, the amalgamation of jumper wires may cause a multiple of signalling problems. For example, the extending wiring adds capacitance and resistance and may pick up considerable electromagnetic interference from external sources such as cross talk from adjacent active pairs. All of these effects can disrupt xDSL broadband digital service and reduce the performance provided to the subscriber.

[8] Furthermore, the additional components that include filter components and connector blocks etc. require floor space that must be housed within the limited confines of the MDF site. This puts a premium on space and adds to the overall costs to the telecom operator. For telecom operators holding down costs has become a significant priority, especially in today's competitive deregulated environment. However, DSL technology provides an attractive platform for delivering broadband services to homes and small businesses thereby increasing the number of value-added services that can be offered by telecom operators. As a result telecom operators have long desired to hold down costs by reducing the amount of labor required to install and maintain services.

[9] In view of the foregoing, it is desirable to reduce the overall cost surrounding the implementation and deployment issues for broadband access via digital subscriber line (DSL) services by reducing the labor requirements for new installations, while still fulfilling customer preferences and needs.

[ 10] SUMMARY OF THE INVENTION

[11] Briefly described and in accordance with embodiments and related features of the invention, there is provided a method and system for providing digital subscriber line (xDSL) and telephone service to subscribers via a telecommunication network. In accordance with a first embodiment of the present invention, installation of xDSL for providing broadband service is performed by connecting, via the main distribution frame (MDF), the subscriber line to a central office high-speed data network. In addition, the subscriber lines may be connected to a central office exchange to provide conventional telephone service. The exchange includes a plurality of physical ports and corresponding programmable logical ports for providing conventional telephone service. Furthermore, the MDF includes a plurality of connector blocks used for connecting the subscriber lines to the various services. The method of installing xDSL service for subscribers with previous telephone service comprises the steps of: connecting the subscriber line to an integrated filter board(s) for separating the signal components relating to the telephone service from signal components relating to the digital data signals, routing the signal components relating to the telephone service to a new physical port on the exchange, re-configuring the logical port on the exchange to correspond with the new physical port in order to retain the subscriber's previous telep hone service and number, and routing the digital data signals from the integrated filter board to a modem bank for transmission to and from the data network. New subscribers without previous telephone service can be routed directly to the integrated filter board for onward connection to the data network and exchange, without the need for port reconfiguration.

[12] In a second embodiment, the system for providing xDSL service is operable in cooperation with an automated cross-connect system used for remotely managing cross- connects within the central office MDF. The automated cross-connect system comprises a plurality of modular cross-connect boards inserted into or attached to the connector blocks within the MDF. To install DSL service, the automated cross-connect system automatically routes the subscriber line pairs to the integrated filter board for onward connection to the exchange and data network. The invention significantly reduces the amount of labor required for installing xDSL service to subscribers by providing a pooled solution for subscriber lines connected to integrated filter board(s) on the exchange side. This enables remote installation of xDSL and telephony services from the central office without the need for manual intervention by technicians at the MDF site.

[13] BRIEF DESCRIPTION OF THE DRAWINGS

[14] The invention, together with further objectives and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:

[15] Fig. 1 illustrates an exemplary connection of a conventional subscriber phone 100 to the central office exchange via the MDF;

[16] Fig. 2 illustrates an exemplary xDSL installation in the MDF for delivering highspeed DSL service to local subscriber loops; [17] Fig. 3 shows an exemplary xDSL installation in accordance with the first embodiment of the present invention;

[18] Fig. 4 shows an exemplary DSL installation operating in cooperation with an automated cross-connect system in accordance with a second embodiment;

[19] Fig. 5 is an exploded side view illustration of an integrated filter arrangement and integrated filter board inserted into a connector block;

[20] Fig. 6 shows side view illustration of an exemplary installation combining the access board with twin filter board connected as a unit inserted into connector blocks;

[21] Fig. 7 depicts a top view of the twin filter board inserted into the connector block in accordance with the invention; and

[22] Fig. 8 depicts a top view of the integrated twin filter board in accordance with another aspect of the invention.

[23] DETAILED DESCRIPTION OF THE INVENTION

[24] For xDSL related service, the subscriber's telephone network carrier installs an xDSL modem unit at the network end of the user's existing twisted-pair copper telephone wiring. Typically, this modem is installed in the serving central office or in the remote terminal of a digital loop carrier system. The subscriber connects a compatible xDSL modem to the subscriber premises end of the telephone wiring that is connected to the central office data network via subscriber line to the MDF.

[25] Fig. 3 shows an exemplary installation of xDSL and telephone service to a subscriber 100,101 via a telecommunication network. When the subscriber orders xDSL broadband service, the central office technician connects the subscriber line to the high-speed data network 126. However, instead of connecting the subscriber 100 to his own signal filter device and modem, where the telephone signals are routed back to the original physical exchange port, the connection is routed to a integrated filter board 160 containing a bank of combined high and low pass signal filters located in the MDF. The output from the filter comprising the low pass signal components is plugged into a new physical port on the exchange. This means that the original physical port 1 that subscriber 100 previously used for phone service has now changed. In order to maintain the subscriber's original phone service and number, the new physical port has been reconfigured to the original logical port 1, as shown in the figure. Furthermore, the original physical port 1 on the exchange that hosted the original telephone connection is reconfigured to logical port 41 from the previously associated with the new physical port. The reconfiguration of the logical ports on the exchange is performed by software at the central office at the time of installation. Virtually all modern telephone exchanges have the capability to reconfigure the port assignments with software commands as opposed to the analog exchanges used in the past.

[26] The output from the high pass filter comprising the digital signal components is sent to an xDSL modem 150, which is typically a modem shelf comprising a bank of modems, is generally installed in the serving central office or in the remote terminal of a digital loop carrier system that are further connected to the data network 126. Installed with the subscriber's computer equipment is compatible high-speed modem (not shown) that converts high frequency analog signals into modulated digital signals and vice versa, which are demodulated at the central office modem 150. Typically, the high frequency analog signals have a frequency in the range from about 25 kHz to several megahertz, whereas the POTS (Plain Old Telephone Service) signals have a much lower frequency i.e. less than 25 kHz, for example.

[27] The described solution allows all subscribers serviced by the MDF to be connected to the integrated filter boards at the time xDSL service is installed. This has the advantage of eliminating redundant wiring for individual filter and modem connections. Significant savings are achieved by reducing the amount of expensive labor time when performing multiple subscriber installations, since it will only require the technician to plug a jumper wire into the integrated filter board. The corresponding step reconfiguring the logical exchange ports can be performed at the central office or at the MDF site by the technician. Further advantages of the technique include the elimination of the need for additional connector blocks and extra jumper wiring previously used to route the POTS lines back to the original exchange ports.

[28] Although the described solution provides notable benefits over the prior art, even further savings in labor can be achieved when the invention is combined with an automated system designed for remotely making cross-connects in an MDF, as well as non-central office sites such as street cabinets and drop points. An example of such a system is the Nexa™ Automated Cross-Connect System manufactured by Network Automation AB of Stockholm, Sweden, which is described in Swedish patent application no. 0303332-1. The system permits the automation of cross-connects remotely from the central office that reduces costs by significantly reducing the amount of labor required by onsite technicians for establishing the cross-connects. The cross-connects are remotely controlled using modular cross-connect (switch matrix) boards connected to the connecter blocks that replace the previous manually intensive process for installing jumper wires. The invention leverages the automated system to provide near labor-free installation of xDSL services.

[29] Fig. 4 shows the xDSL system for providing broadband service that is operable in cooperation with an automated cross-connect system 400, in accordance with a second embodiment. The automated cross-connect system 400 enables so-called any-to-any connections from any of the subscriber line pair to any physical (or logical) port on the exchange. The process for xDSL installations can be similarly automated by utilizing the automated cross-connect system to automatically route subscriber lines to the integrated filter board. By way of example, subscriber line 100,101 is connected at the MDF via connector block 110 as described previously. However, the output lines from the connector block are coupled to the cross-connect system 400, which establishes on demand a cross-connection to the integrated filter board 160 comprising a bank of filters components integrated on the board. The low pass telephone output signal from the subscriber line is routed to the logical exchange port 1 to provide normal telephone service. The exchange ports are then reconfigured by software to enable the subscriber to remain on logical port 1 to retain the same phone number. The high pass output signal is routed to modem 150 for connection to the data network 126, thus making the entire xDSL installation process transparent to the users.

[30] It will be appreciated that in this example the connector blocks have the capacity to connect up to 10 line pairs thereby requiring rerouting of subscriber lines to additional integrated filter boards as the numbers of subscriber xDSL installations increase. However, the invention is no way limited to the capacity of the particular connector blocks used since other connector block types may be utilized with the invention.

[31] The automated cross-connect system utilizes a plurality of interconnected modular cross-connect boards that are connected to the connector blocks in the MDF on both the line and the exchange sides. The connector blocks used in the embodiment are manufactured by KRONE Inc., which have the capability for allowing boards to be inserted into them. It should be noted that the invention could be used with other types of connector blocks whereby the boards can be connected thereto in ways other than by insertion. With regard to the embodiment, the xDSL integrated filter boards are similarly inserted into to the connector blocks of the MDF along with the modular cross-connect blocks. This provides a pooled solution to eliminate the need for filters for the individual lines.

[32] Fig. 5 is an exploded side view illustration of an integrated filter board inserted into an exemplary MDF connector block. It should be noted that the integrated filter board 160 includes a bank of integrated filters on the filter board and that the enlarged view of a single component is shown for the sake of simplicity. The inputs to the filters arrive from the subscriber line or jumper side (J) contact pin of the connector block. Each filter component comprises a high pass and low pass filter component integrated on a PCB board by conventional well-known techniques. The output from the high pass filter 164 is connected to the output port leading to the modem shelf 150, which is further connected to the data network 126. The output from the low pass filter 166 is routed to the exchange port via the line side (L) contact pin in the connector block. The number of filter components on the access board typically corresponds with the number of line pairs handled by the connector block, which in this example is 10 pairs.

[33] Fig. 6 shows side view illustration of an exemplary installation configuration using a combination of a cross-connect access board and integrated twin filter board inserted into a set of connector blocks and operating as a unit. The embodiment is particularly suited for operating in conjunction with an automated cross-connected system installed in the MDF, such as the Nexa™ automated cross-connect system using modular cross- connect boards inserted into the connector blocks. The access board and twin filter board together provide direct access to the lines and the exchange. It is possible that the cross-connect system employs a center stage made up of a plurality of cross- connect boards to accommodate higher capacity MDFs.

[34] In the exemplary configuration, with the installation of the automated cross- connect system in an MDF using connector blocks capable of handling 10 line pairs such as the KRONE LSA-Plus connector blocks, an access board (cross-connect board) and twin filter board are linked together and inserted into two connector blocks to operate as a unit. This is possible since the cross-connect or access boards are capable of cross-connecting 20x20 line pairs each compared to the 10 pairs of the connector block. Thus an additional board is inserted into an adjacent connector block for connecting a second set of 10 line pairs to the access board for cross-connecting a total of 20 line pairs. Since the additional board is only used for connecting the second set of line pairs it is possible to include or integrate the filter components on the board i.e. it also functions as a twin filter board as shown in the figure. The twin filter board filters out the data signals on the subscriber line and sends them on to the modem bank for connection to the central office data network. It will be appreciated by those skilled in the art that the line capacities mentioned relate to the capacities of the connector blocks, which are exemplary that may result in other board installation configurations and that invention is in no way limited to the numbers expressed since other capacities may be used.

[35] Fig. 7 depicts a top view of the twin filter board 160 inserted into the connector block in accordance with the present invention. The twin filter board is a PCB comprising a bank of integrated filters (only a single component is shown for simplicity) implemented with conventional circuit board techniques. The subscriber line 162 is input into the filter bank whose high frequency output 164 is routed to a connector port leading to the modem shelf 150, whereas the low frequency output 166 is routed to a connector port leading to the exchange port via the access board coupling. With the twin filter board arrangement, it is possible to include up front at least 50 percent of line capacity for current and potentially new xDSL installations while requiring no additional space in MDF, and in the case of operating with the automated cross-connect system, requires no additional space in the center stage. The pooled solution eliminates the need for filters on all lines and provides scalable xDSL installations without the need for extra connector blocks or additional floor space. [36] Fig. 8 depicts a top view of the twin filter access board also referred to as an integrated filter/modem board in accordance with another aspect of the invention. With current integrated circuit techniques it is possible to incorporate an xDSL modem bank 170 into the filter board in order to further streamline the system. Significant savings in labor costs can be achieved for installations by routing subscriber lines to the pooled integrated filter/modem boards on the exchange side for connection directly to the data network. Similarly, the technique provides gains in efficiency and lower costs by enabling up front reliable installation of xDSL components for which service can be initiated to subscribers by remote automation from the central office. Furthermore, cost reductions can be realised by eliminating separately the maintained external modem bank without requiring additional space in the MDF.

[37] The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed, since many modifications or variations thereof are possible in light of the above teaching. Accordingly, it is to be understood that such modifications and variations are believed to fall within the scope of the invention. The embodiments were chosen to explain the principles of the invention and its practical application, thereby enabling those skilled in the art to utilize the invention for the particular use contemplated. Still, it is to be appreciated that the invention can be operated independently within the MDF or in conjunction with automated cross-connect system functionality. It is therefore the intention that the following claims not be given a restrictive interpretation but should be viewed to encompass variations and modifications that are derived from the inventive subject matter disclosed.

Claims

[1] A system for providing digital subscriber line (DSL) services using a telecommunication network comprising a main distribution frame (MDF) for connecting a subscriber line to a data network 126 for providing highspeed data services and, to a central office exchange including physical and logical ports for providing conventional telephone service, wherein the MDF comprises a plurality of connector means for connecting the subscriber lines to said services, the system is characterized in that, an integrated filter board 160 comprising a plurality of filters for separating the signal components on the subscriber line relating to the telephone service from signal components relating to the digital data signals for transmission to and from the data network 126; a modem bank 150 comprising a plurality of modems for sending and receiving the digital data signals to and from the data network 126 to the subscriber line; and means for configuring the any logical port on the exchange to correspond with any physical port in order to maintain previous subscriber telephone service.

[2] The system according to claim 1 wherein, the connector means are MDF connector blocks suitable for connecting subscriber lines and, wherein for DSL service, said subscriber line is re-routed to the integrated filter board 160 attached to the connector block such that the separated telephone signal component is re-routed from a first physical port to a second physical port on the exchange, and digital data signal components are routed to the modem bank.

[3] The system according to any one of claims 1 or 2 wherein, the logical port on the exchange re-configured by software within the central office to permit a re-routed subscriber line from a first physical port to a second physical port on the exchange such that the subscriber telephone service and number remains the same.

[4] The system according to claim 1 wherein, the plurality of filters on the access board are integrated filters for separating the high and low frequency components signals on the subscriber line.

[5] The system according to any of the above claims wherein, the integrated filter board further comprises the modem bank comprising a plurality of modems allowing the integrated filter/modem board to be connected directly to the data network.

[6] The system according to claim 1 wherein, the system for providing DSL service is operable in cooperation with an automated cross-connect system 400 for remotely managing cross-connects comprising a plurality of modular cross-connect boards connected to the connector blocks installed within the MDF, wherein said automated cross-connect system provides automated routing of subscriber lines to the integrated filter board for onward connection to the exchange and data network.

[7] The system according to claim 6 wherein, the integrated filter board is operable to connect to a modular cross-connect access board relating to the automated cross-connect system, whereby the modular cross-connect access board and the integrated filter board are installed into a pair of connector blocks as a unit.

[8] The system according to claim 6 comprising means for remotely installing telephone and/or digital data services via the automated cross-connect system installed in non-central office sites such as street cabinets and drop points.

[9] A method of providing digital subscriber line (DSL) and telephone services using a telecommunication network comprising a main distribution frame (MDF) for connecting a subscriber line to a data network 126 for providing high-speed data services and, to a central office exchange including physical and logical ports for providing conventional telephone service, wherein the MDF comprises a plurality of connector means for connecting the subscriber lines to said services, characterized in that the method comprising the steps of: connecting the subscriber line 140 to a integrated filter board(s) 160 for separating the signal components relating to the telephone service from signal components relating to the digital data signals; routing the signal components relating to the telephone service to be received at a physical port on the exchange; configuring the logical port on the exchange to correspond with the physical port receiving the routed signal components relating to the telephone service; and routing the digital data signals from the integrated filter board(s) to a modem bank for transmission to and from the data network.

[10] The method according to claim 9 wherein, the logical port on the exchange configured by software within the central office to permit the subscriber line connected to a new physical port on the exchange to retain their previous telephone service and number.

[11] The method according to claim 9 wherein, the integrated filter board(s) is attached to the connector means in the MDF, wherein the integrated filter board(s) comprises a plurality of filters, each for separating the signal components for different subscriber lines.

[12] The method according to claim 9 wherein, the digital data signals are processed by the modem bank comprising a plurality of modems that are located on the integrated filter board(s) such that the integrated filter/ modem boards are connected directly to the data network.

[13] The method according to any one of claims 9-12 wherein, said providing of DSL and telephone services is operable in cooperation with an automated cross-connect system 400 for remotely managing cross-connects comprising a plurality of modular cross-connect boards attached to the connector blocks installed within the MDF, wherein said automated cross- connect system performs automated routing of subscriber lines to the integrated filter boards for onward connection to the exchange and data network.

[14] The method according to claim 13 wherein, the integrated filter board(s) is operable to connect to a modular cross-connect access board relating to the automated cross-connect system, whereby the modular cross-connect access board and the integrated filter board(s) are installed into pairs of connector blocks and operates as a unit.

[15] The method according to claim 9 wherein, an installation of telephone and/ or digital data services for a subscriber line is installed remotely and automatically from the central office.

[16] The method according to claim 9 wherein, the logical port on the exchange is configured to correspond with the physical port using software commands from the central office.

[17] The method according to claim 9-13 or wherein, the said method for installing telephone and/or digital data services can be further performed in non-central office sites such as street cabinets and drop points.