Abstract:
A system and method for delivering digital subscriber line (DSL) service to a subscriber. In a telecommunications network, the signal passing through a protector field is diverted to a cross connect block that can be selectively configured to establish a communication route between the cross connect block and a splitter selectively receiving a DSL signal. The combined signal is then placed back upon the network by the cross connect block, which directs the combined signal back to the protector field.

Description:
RELATED APPLICATIONS 
     This application is a continuation of application Ser. No. 10/725,108, filed Dec. 1, 2003; now U.S. Pat. No. 7,409,053 which is a continuation-in-part of U.S. patent application Ser. No. 10/301,960, filed Nov. 22, 2002, now U.S. Pat. No. 7,155,004; the disclosures of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to digital subscriber lines, and, more specifically, to a new system and method for adding digital subscriber line service to one or more lines of a telephone network. 
     Digital subscriber line (DSL) technology allows for high-bandwidth networking connections to be made over ordinary copper telephone lines. Traditional phone service typically relies on unshielded twisted pair (UTP) copper lines to connect homes and small businesses to the communications network operated by the telephone company (TELCO). Every one of these networks includes a central offices (CO) that services a defined region, with each CO responsible for connecting and routing calls directed to sites that reside both internal to and external of the network 
     Branching out from the central office are numerous remote terminals (RT) located throughout the region being served by the CO, with each RT providing the phone service for the subscribers located within a specific area or neighborhood. One of the primary components that make up a remote terminal (RT) is a pair gain system, also known as a derived carrier system, or digital loop carrier system. In simplest terms, the pair gain system provides the TELCO with the capability to carry multiple services over a lesser number of lines, for example, five conversations over one telephone line. The pair gain system also is responsible for generating the dial tone signal one hears when they first pick up a telephone handset, indicating that an active connection is present. 
       FIG. 1  depicts a typical telephone connection between a pair gain system  10  of a remote terminal (RT) (not shown) and a subscriber  30 . As indicated in  FIG. 1 , the connection between the pair gain system  10  and subscriber  30  is not accomplished directly, but instead in two legs. The first connection  10   a  exists between the pair gain system  10  and a cross connect block  20 , while the second connection  20   a  is made between the cross connect block  20  and a subscriber  30 . As indicated by its name, the purpose of the cross connect block  20  is to allow easy matching and connecting of two or more connections to one another, thereby facilitating the addition or removal of phone services to or from the subscriber. 
     To further illustrate the use of a cross connect block  20 , consider the following example involving a typical modern day residence. New homes are often pre-wired to handle multiple telephone lines, i.e. six lines, to allow for future expansion. In this situation, there would be six connections running between the subscriber&#39;s house  30  and the cross connect box  20 . However, if the subscriber only has two active phone lines, then only two connections representing the active circuits would run from the pair gain system  10  to the cross connect box  20 . Later, if the subscriber wishes to add a new telephone line for a fax machine, a technician would have to run a new connection between the pair gain system  10  and the cross connect block  20 , matching the new connection at the cross connect block  20  to the appropriate connection already present that runs to subscriber&#39;s house  30 . 
     Note that each of connections  10   a  and  20   a , along with the connections discussed below, although drawn as single lines in the figures, actually represent a cable pair, such as, for example, typical unshielded twisted pair (UTP) copper lines. For the remainder of the application, the terms “connection” and “cable pair” should be considered interchangeable. In view of this, it should be further understood that terminals for receiving these connections, such as can be found on cross connect block  20 , are comprised of two conductors, with each conductor receiving one cable of the cable pair. 
       FIG. 2  depicts the same connection as previously depicted in  FIG. 1 . However, unlike the previous depiction,  FIG. 2  provides a more detailed illustration of cross connect block  22 , which is illustrated as an insulation-displacement connection (IDC) block. Unlike blocks that rely on screw-terminals or a wire wrapping technique to secure wires to the block, IDC blocks provide for a gas-tight connection without requiring the removal of insulation covering the wire. Connection is achieved once a wire is placed into an IDC block contact, and then punched down, typically via an insertion tool, pressing the wire against the contact to form the gas-tight connection. Due to ease of use and effectiveness, cross connect blocks utilizing IDC contacts have become the standard within the telecommunications industry. 
     As DSL technology is relatively new compared to typical telephonic communication involving analog signals, many of the remote terminals (RT) that are part of a telephone company&#39;s (TELCOs) network were not designed to allow easy incorporation of newer technology such as DSL. Accordingly, the TELCOs have had to develop ways to effectively provide DSL service to their subscribers utilizing the existing equipment on the network. 
       FIG. 3  depicts a typical approach to incorporating DSL service with a remote terminal (RT). The dial tone or pair gain signal generated by the pair gain system  10  is directed to a splitter  50  via connection  10   a . Splitter  50  also receives a connection  40   a  from a DSL system  40 . DSL system  40  includes the equipment necessary for processing and directing the data signals back and forth between subscriber  30  and a digital subscriber line access multiplexer (DSLAM) (not shown). The DSLAM, which is operated by a service provider, takes all of the subscribers&#39; DSL connections and aggregates them onto a single, high-density connection to the Internet. For the current illustrative example involving the integration of DSL at an RT, the DSL system may be physically mounted inside the cabinet housing the RT, or placed in its own cabinet mounted onto or next to the RT depending on factors such as size limitations and ease of access. 
     The role of splitter  50  is to combine the lower frequency signal from the pair gain system  10  with the higher frequency DSL data signal in such a way that they don&#39;t interfere with one another. Similarly, splitter  50  must also be capable of separating the signal sent by the subscriber  30  back into its two constituent components and then direct them back to the appropriate system. In  FIG. 3 , splitter  50  is depicted as an independent component separate from DSL system  40 . Alternatively, splitter  50  may be incorporated into DSL system  40 . 
     The combined signal produced by splitter  50  is delivered to cross connect block  20  over connection  50   a , where it is then directed to subscriber  30  over connection  20   a . Subscribers  30  can then access the higher frequency DSL signal by means of a DSL modem connected between their computing device and the telephone line(s) running throughout their residence. At the same time, standard telephones continue to have access to the lower frequency analog signals also routed over the line(s). 
     To accomplish the arrangement illustrated in  FIG. 3 , a service technician is required to go onsite and perform wiring locally at the remote terminal (RT) that is servicing the subscriber. In order to combine the signal coming from the pair gain system  10  with the DSL data signal, the pair gain system  10  that normally is directly wired to cross connect block  20  must now be rerouted so that it interfaces with splitter  50 . At splitter  50 , the signal from the pair gain system  10  is combined with the DSL data signal, which also runs through splitter  50 . The combined dial tone and DSL signal must then be placed back into communication with subscriber  30 , requiring a new connection between splitter  50  and cross connect block  20 . Due to these re-wiring requirements, the telephone service of subscriber  30  is disrupted; preventing them from making or receiving any telephone calls. Furthermore, the duration of this disruption can vary depending on the knowledge and skill of the service technician, along with the condition of the RT and the network. 
     If a DSL subscriber decides he or she no longer wants DSL service, the service technician must access the remote terminal (RT) again and disrupt the connection  40   a  that provides communication between the DSL system  40  and splitter  50 . The splitter  50  must also be removed from the system, once again disrupting the subscriber&#39;s telephone service. Additionally, during the process of reconnecting pair gain system  10  back to cross connect block  20 , there is always the chance that a mistake could be made, resulting in an improper connection to exist. This can lead to subscriber  30  going without telephone service for an extended duration until the problem can be corrected. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a new system and method of delivering digital subscriber line (DSL) service to a subscriber. The signal passing through a protector field is diverted to a cross connect block that can be selectively configured to establish a communication route between the cross connect block and a splitter selectively receiving a DSL signal. The combined signal is then placed back upon the network by being directed back to the protector field by the cross connect block 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a simplified depiction of a typical neighborhood setup for distributing telephonic communication service to a subscriber. 
         FIG. 2  is equivalent to  FIG. 1 , but with the cross connectivity block shown in further detail. 
         FIG. 3  is a simplified depiction of a typical setup for distributing telephonic communication service along with digital subscriber line data service to a subscriber. 
         FIG. 4  is a simplified depiction of a setup in accordance with one embodiment of the present invention for distributing telephonic communication service along with digital subscriber line data service to a subscriber. 
         FIG. 5  is an additional simplified depiction of a setup in accordance with one embodiment of the present invention for distributing telephonic communication service along with digital subscriber line data service to a subscriber. 
         FIG. 6  is a simplified depiction of a protector field monitoring the line from a pair gain system. 
         FIG. 7  is a simplified depiction of a setup in accordance with an embodiment of the present invention for distributing telephonic communication service along with digital subscriber line data service to a subscriber. 
         FIG. 8  is a simplified depiction of an alternative setup in accordance with an embodiment of the present invention for distributing telephonic communication service along with digital subscriber line data service to a subscriber. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     One embodiment of the present invention will now be discussed in reference to  FIG. 4 . Like the basic distribution setup depicted in  FIG. 1 , the pair gain system  10  of  FIG. 4  connects to cross connect block  20  by connection  10   a , while the cross connect block  20  connects to subscriber  30  by connection  20   a . Through these two connections, subscriber  30  is provided with telephone service. 
     In order to provide DSL service to subscriber  30 , a service technician accesses the cross connect block  20  that serves subscriber  30  and reroutes the telephone signal of subscriber  30  so as to combine it with a DSL signal. However, unlike prior methods of accomplishing this, according to the present embodiment the technician maintains connections  10   a  and  20   a , thereby allowing phone service to subscriber  30  to continue during the installation of DSL service. 
     Instead of rewiring connection  10   a , a new connection  20   b  is made between the cross connect block  20  and splitter  50 , with connection  20   b  attaching to block  20  at the same terminal that receives connection  10   a . This places connection  10   a  in communication with connection  20   b  so that signals traveling through one will proceed to the other. An example of a cross connect block  20  with this “double terminate” feature, where more than one connection can be established to the same terminal on the block, are the Series 2 Connecting Blocks made by Krone. A connection  40   a  between splitter  50  and the DSL system  40  is also established. Lastly, a connection  50   a , which will carry the combined dial tone/DSL signal, is made between splitter  50  and cross connect block  20 . Similar to connection  20   b , connection  50   a  is attached to block  20  at the same terminal that attaches to connection  20   a , so that these two connections are placed in communication with one another. During this entire process, the signal path made up of connection  10   a , cross connect block  20  and connection  20   a  remains undisturbed. As such, telephone service to subscriber  30  is never disrupted. 
     In order to “turn on” the DSL service for subscriber  30 , the service technician then modifies cross connect block  20  so as to disrupt the signal path running through block  20 . As passage through the cross connect block  20  is no longer possible, the signal generated by pair gain system  10  proceeds to be redirected over connection  20   b  into the splitter  50 , where it is combined with the DSL signal carried by  40   a . The combined signal is then carried over connection  50   a  and connection  20   a  to subscriber  30 , who never notices a disruption in his or her telephone service while DSL service was activated. 
       FIG. 5  depicts the same circuit as previously depicted in  FIG. 4  with the exception that cross connect block  20  is now illustrated as an IDC cross connect block  22 . As before, the service technician establishes connections  22   b  and  50   a , which effectively adds DSL system  40  and splitter  50  in parallel to the IDC block  22 . To then activate DSL service to the subscriber, the technician inserts a disconnect plug  24  designed to be received by IDC block  22 . Upon its insertion, disconnect block  24  effectively disrupts or opens the signal path that previously allowed the signal from pair gain system  20  to “cut through” the cross connect block. As a result, the signal is rerouted to splitter  50  as before, thereby activating DSL service to subscriber  30  without providing any noticeable disruption in telephone service. 
     If subscriber  30  desires to deactivate his or her DSL service, the service technician simply repeats the process in reverse. Specifically, disconnect plug  24  is removed from IDC block  22 . With plug  24  absent, the signal path through the block is once again established and the signal from pair gain system  10  takes the direct path consisting of connections  10   a  and  22   a , instead of being redirected through splitter  50 . Connections  22   b  and  50   a  can then be removed safely. As during the DSL installation stage, subscriber  30  notices no disruption in their telephone service while the DSL service is being uninstalled. 
     Additionally, unlike prior DSL installation methods, according to the current embodiment, connection  10   a  between the pair gain system  10  and IDC connect block  22  and connection  22   a  between IDC connect block  22  and subscriber  30  is never disrupted or removed. As a result, there is no chance of a misappropriate connection being made by the technician upon removal of DSL service, thereby significantly reducing the chances that a subscriber will have to go without telephone service due to technician error. 
     The DSL delivery system and method described in the above embodiments is also advantageous as it provides the technician a good opportunity to check the condition of the subscriber&#39;s line. For example, just prior to disrupting the signal path through the cross connect block by insertion of the disconnect plug, the technician can instead insert a test cord in place of the disconnect plug. This then allows the technician to “look both ways” along the line to detect signs of possible problems that could affect either telephone or DSL service. 
     In an alternative embodiment of the invention, pair gain system  10  connects to a protector block or field  12  in such a manner that all signals being delivered to, or coming from, pair gain system  10  first pass through protector field  12 . One such example of a pair gain system  10  communicating with a protector field  12  is illustrated in  FIG. 6 . The purpose of protector field  12  is similar to that of a line conditioner or circuit breaker, protecting both personnel and equipment from abnormal voltages and currents that can be introduced to the network and which could otherwise travel along one or more connections back to the pair gain system  10  and associated equipment. Associated with each connection, or cable pair, running through the protector field  12  is a protector module  14  that traditionally plugs into the protector field  12 , such as by inserting one or more conductors, projecting out from the surface of the protector module  14 , into one or more corresponding receptacles built into the protector field  12 . Typical network signals, represented by standard voltage and current signals traveling along a cable pair, are directed into the protector field  12 , pass through an associated protector module  14  and then travel back out of the protector field  12  on to the appropriate destination. In contrast, an abnormal voltage and/or current being transmitted along a cable pair enters the protector field  12  and is subsequently reduced or eliminated by the protector module  14 , which shunts the harmful voltage and/or current to ground. One or more of the protector modules  14  can also be removed from the protector field  12 , thereby opening the circuits associated with the removed protector modules  14  and assuring the safety of a technician or other personnel who are physically working with the equipment. 
     In the example illustrated in  FIG. 6 , pair gain system  10  and protector field  12  are located within a controlled environment vault (CEV)  16 , which traditionally is some form of low maintenance, water-tight container or enclosure that provides a permanent housing for various components of the telecommunications network, such as remote switches and pair gain and fiber transmission systems. Alternatively, pair gain system  10  and protector field  12  may be located in a central office (CO), remote terminal (RT), or any other setting where the equipment, along with the personnel working on the equipment, could be subject to harmful voltages carried along the network. 
     The present embodiment uses a cross connect block  20 , preferably having a “double terminate” feature as discussed above, to provide for the addition of DSL service to one or more lines of a telecommunications network. According to this embodiment, however, the cross connect block  20  can be readily “spliced” into a network by means of an adapter  60  that interfaces with a protector field  12 . 
     One example of the present embodiment will now be discussed in reference to  FIG. 7 . A pair gain system  10  transmits a pair gain signal over one or more cable pair lines  10   b  that are fed through a protector field  12  before the pair gain signal can proceed over the network to one or more subscribers. For illustrative purposes, it will be presumed for the remainder of the discussion that connections  10   b  and  12   a  represent a single cable pair delivering services to a single subscriber. However, it should be understood that these connections frequently comprise a plurality of cable pair lines providing telephony and other services to a plurality of subscribers. Traditionally, the pair gain signal transmitted through cable pair  10   b  enters the protector field  12  and passes through a protector module  14  associated with that specific cable pair line before being relayed out to the remainder of the network and on to a subscriber. The present embodiment of the invention alters this configuration so as to shunt the pair gain signal over to the cross connect block  20 , which then provides for the selective addition of a DSL signal to the line. The above action is specifically accomplished by means of an adapter  60  that interfaces with the protector field  12 . 
     As illustrated in  FIG. 7 , adapter  60  is configured in a manner similar to that of protector module  14 . This allows for the adapter  60  to interface with protector field  12  in the same manner as the protector module  14 , such as, for example, by inserting one or more conductors, which project out from the adapter  60 , into the one or more receptacles normally utilized by the protector module  14 . To complete the circuit, the protector module  14  then interfaces with the adapter  60 . According to the current embodiment, the adapter  60  is configured with one or more receptacles arranged in a manner similar to the receptacles of the protector field  12 . This allows the protector module  14  to readily interface with the adapter  60  by inserting the conductors projecting out from the protector module  14  into the receptacles of adapter  60 . 
     The adapter  60  electrically communicates with the cross connect block  20 , connecting to one input terminal of the cross connect block  20  through connection  60   a , and to one output terminal of the block  20  through connection  60   b . In a manner similar to the previous embodiments, a connection  20   b  is made between the cross connect block  20  and splitter  50 , with connection  20   b  attaching to block  20  at the same terminal that receives connection  60   a . This places connection  60   a  in communication with connection  20   b  so that signals traveling through one will proceed to the other. A connection  40   a  between splitter  50  and the DSL system  40  is also established. In addition, a connection  50   a , which carries the combined pair gain/DSL signal, is made between splitter  50  and the cross connect block  20 . Similar to connection  20   b , connection  50   a  is attached to block  20  at the same terminal that attaches to connection  60   b , so that these two connections are placed in communication with one another. 
     Operation of the system illustrated in  FIG. 7  will now be discussed. The pair gain signal is first transmitted to the protector field  12  via cable pair  10   b . The signal enters the protector field  12  and gets passed on to the adapter  60 , which shunts the signal to the cross connect block  20  over connection  60   a . If cross connect block  20  is configured so that no DSL service is provided on the current subscriber line, the pair gain signal will simply pass from connection  60   a , through the cross connect block  20 , onto connection  60   b , which brings the signal back to the adapter  60 . The pair gain signal then passes through the protector module  14  and then back through the adapter  60  and the protector field  12  before being transmitted out to the subscriber over cable pair  12   a.    
     Similar to the previous embodiments, a service technician can “turn on” DSL service for a subscriber by modifying the cross connect block  20  so as to disrupt the signal path running through the block  20 . Upon the adapter  60  diverting the pair gain signal over to the cross connect block  20 , the signal proceeds to be redirected over connection  20   b  into the splitter  50 , whereupon the pair gain signal becomes combined with the DSL signal carried by connection  40   a . The combined signal is then carried over connection  50   a  to the cross connect block  20 , and over connection  60   b  back to the adapter  60 . The combined signal is then passed through the protector module  14  and eventually redirected out upon the network to the subscriber. 
     Upon returning from the subscriber over cable pair  12   a , the pair gain signal, and DSL signal, if present, are directed into the protector field  12  and passed through the adapter  60  on to the protector module  14 , which removes any harmful over-voltages or over-currents. The pair gain signal, or pair gain/DSL combined signal, is then passed back through the adapter  60 , which shunts the signal(s) over to the cross connect block  20 . If DSL service is not being provided, the signal passes through block  20 , is returned to adapter  60 , and is subsequently directed out of the protector field  12  back to the pair gain system  10 . If DSL service is being provided, the combined signal is directed over connection  20   b  to the splitter  50 , which separates the two signals, directing the DSL signal back to the DSL system  40  while the pair gain signal is directed back to the adapter  60  and on to the pair gain system  10 . 
     As in the previous embodiment illustrated in  FIG. 5 , the cross connect block  20  associated with adapter  60  is an insulation-displacement connection (IDC) cross connect block. Accordingly, to activate DSL service to a subscriber, a service technician only has to insert a disconnect plug  24  into the IDC block, thereby disrupting the signal path that previously allowed the signal from pair gain system  10  to “cut through” the cross connect block  20 . As a result of the disruption caused by the disconnect plug  24 , the signal is rerouted to splitter  50 , thereby activating DSL service for a subscriber without providing any noticeable disruption in telephone service. To deactivate DSL service, the service technician simply removes the disconnect plug  24  from the cross connect block  20 . 
     In the example illustrated in  FIG. 7 , protector field  12  is depicted as monitoring a single connection or cable pair, and thus requires a single adapter  60  to which attaches a single protector module  14 . However, according to an additional embodiment of the invention, a protector field  12  can monitor a plurality of lines, and thus require a plurality of adapters  60  for shunting the one or more signals carried on each line to a cross connect block  20 . For illustrative purposes, consider the following example, where one hundred cable pairs provide telephony service to one hundred subscribers. As such, the protector field  12  monitoring the one hundred cable pairs requires one hundred protector modules  14 , each module  14  being associated with one cable pair. To “splice” in one or more cross connect blocks  20 , one hundred adapters  60  are interfaced with the protector field  12 , each adapter  60  plugging in to one of the receptacles traditionally reserved for a protector module  14 . Each of the one hundred adapters  60  is subsequently also interfaced with one of the protector modules  14 . In the above example, all one hundred adapters  60  connect to the same cross connect block  20  assuming that a sufficient number of input terminals is provided on the block  20 . However, according to an alternative example, more than one cross connect block  20  can be present, with each block  20  connecting to only a limited number of the adapters  60  interfaced with the protector field  12 . 
     In the above embodiments, adapter  60  interfaces with a protector field  12  and a protector module  14  in such a manner as to allow a cross connect block  20  to be easily “spliced” or inserted into the network. However, according to an alternative embodiment of the invention, an example of which is illustrated in  FIG. 8 , the adapter does not interface with a protector module  14 , but instead incorporates the protector module  14  entirely as an integral subcomponent. Specifically, the adapter is configured to not only temporarily divert a signal over to a cross connect block  20 , but also to provide the voltage and current monitoring function traditionally provided by the separate protector module  14 . As a result, the present embodiment can be implemented within a telecommunications network by simply removing the traditional protector module  14  and replacing it with one of the “multi-function” adapters. 
     While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.