Abstract:
A system and method for delivering digital subscriber line (DSL) service to a subscriber from a remote terminal of a telephone network. Included is a first route for delivering a telephone signal to the subscriber, and a second route for passing the telephone signal through a DSL system before delivering the signal to the subscriber. A disruptor is then used to selectively activate either the first or second route.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to digital subscriber lines, and, more specifically, to a new method for delivering digital subscriber line service from a remote terminal of a telephone network. 
     BACKGROUND OF THE INVENTION 
     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 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. Further, the duration of this disruption can vary depending on the knowledge and skill of the service technician, along with the condition of the RT. 
     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. A first route for communicates a pair gain signal from a pair gain system, through a cross connect block, to the subscriber. A second route, which partially overlaps the first route, communicates the pair gain signal from the pair gain system, through a DSL system, to the subscriber. A disruptor is then used to selectively activate one of the first and second routes. 
    
    
     
       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. 
     
    
    
     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 the above discussion, Applicant&#39;s new method and system for delivering DSL is described, for illustrative purposes, in relation to a remote terminal (RT) servicing a specific area or neighborhood of subscribers. However, the new system and method is not limited to integrating signals at or near an RT, but can also be used at various other locations within the network. For example, the new system and method could be advantageously used in a controlled environment vault (CEV) utilized by TELCOs to house underground remote terminals and other networking equipment. Alternatively, the invention as presented in the embodiments above may also be beneficially used at a central office (CO) of the TELCO. 
     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.