Patent Document

DESCRIPTION OF THE RELATED ART 
     1. Field of the Invention 
     This invention relates to the field of telecommunications, and more particularly to the field of providing increased bandwidth in telephone networks. 
     2. Background of the Invention 
     The development of computer technology has permitted a dramatic increase in the capability to store and manipulate information. The advent of computer networks, such as the Internet, has permitted a similarly dramatic increase in the ability of geographically distributed users to share such information. The number of persons and applications that rely on network computing continues to increase significantly each year, representing a large contributor to economic growth in the United States and elsewhere. 
     One of the most significant limitations to network computing applications is the rate at which data can be transferred over networks, typically referred to as “bandwidth.” The largest original network is the conventional telephone network, which consists of twisted pairs of copper wires linked between central offices and remote users. An example of a portion of a conventional telephone network is depicted in FIG.  1 . Although computers are able, via modems and similar technology, to use conventional telephone networks, such networks are subject to a number of limitations. Among other things, telephone networks were originally intended for analog voice telephony. As digital applications using increasing amounts of data are required, telephone networks may provide inadequate bandwidth for such applications. 
     Many efforts have been undertaken to increase bandwidth in computer networks. Telecommunications providers have built networks using new technologies such as fiber optics. Cable television providers have sought to provide computing capabilities using networks of coaxial cable. Dedicated copper pairs, such as Ti lines, have been installed to provide increased bandwidth between certain sites. Systems such as ISDN have been established to provide increased bandwidth for certain applications. Protocols and methodologies such as Asymmetric Digital Subscriber Line (“ADSL”) and Very-high-speed Digital Subscriber Line (“VDSL”) technologies have been established to make more effective use of the existing telephone network and other networks, permitting, for example, bandwidth to be extended to the megabit per second range over conventional telephone networks. 
     None of these efforts represents a complete solution. Dedicated lines and new networks will require years of installation. ADSL and VDSL are only effective to a degree in increasing communication speed without further changes to networks. ISDN is limited and difficult to use. Cable networks do not reach all users. Accordingly, a need continues to exist for systems and methods that improve bandwidth delivery to users and take advantage of the existing telephone networks. 
     SUMMARY OF THE INVENTION 
       
     Systems and methods are provided herein for increasing bandwidth using existing twisted pair telephone networks. In particular, systems and methods are provided for permitting statistical sharing of bandwidth of many twisted pair wires in a given neighborhood. 
     Systems and methods are provided wherein an active subscriber would communicate over several twisted pair wires in the neighborhood, thereby obtaining a dramatic increase in bandwidth. 
     In an embodiment, systems and methods described herein could permit an increase in the distance capability of ADSL/VDSL technology. 
     Disclosed herein is a method for sending and receiving broadband data over twisted pair wire lines between a central office and a remote subscriber, including providing twisted pair wire lines from a remote location to a location proximal to a subscriber, providing a plurality of packet switch nodes at the location proximal to the subscriber and networking the packet switch nodes with the twisted pair wire lines from the remote location. 
     A packet switch node is provided that is capable of identifying packets addressed to a particular subscriber and sending packets to the particular subscriber. The packet switch node may include a modem, such as an ADSL or VDSL modem. The packet switch node may include one or more splitters, a packet switch, and a modulator. It should be understood that the term “packet switch node,” as used herein, encompasses a variety of such nodes and is not limited to a mere packet switch. 
     Methods and systems disclosed herein may further include a neighborhood node at a remote location from the subscriber that is connected between the telecommunications line from the central office and the twisted pair lines that lead to the packet switch nodes. The neighborhood node may be connected to the central office by an optical fiber. The neighborhood node may be particularly useful for VDSL transmissions. The neighborhood node may be capable of converting incoming information from the central office into packets and capable of addressing each packet to a selected subscriber. 
     Provided herein is a telecommunications network, including a plurality of twisted pair lines, a neighborhood node between the central office and the subscriber capable of converting incoming information from the central office into packets and capable of addressing each packet to a selected subscriber, a plurality of packet switch nodes for identifying packets addressed to a particular subscriber and for sending packets to the particular subscriber, each of the packet switch nodes having a splitter for separating voice data from other data, a network connection between the neighborhood node and the packet switch node, the network connection using at least one of ADSL and VDSL technology for transmission of data packets and a connection between the packet switch nodes. The packet switch nodes may have a connection to a subscriber&#39;s house, such as via a drop wire. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 depicts the wiring of the present telephone network; 
     FIG. 2 depicts an embodiment of a modified wireline network according to the present disclosure; 
     FIG. 3 depicts an alternative embodiment of a modified wireline network according to the present disclosure; 
     FIG. 4 depicts an embodiment of a packet switch node of the wireline network of FIG. 2 or FIG. 3; and 
     FIG. 5 depicts an alternative embodiment of a packet switch node of the wireline network of FIG. 2 or FIG.  3 . 
    
    
     DETAILED DESCRIPTION 
     The wiring of the present telephone network is shown in FIG. 1, using an example of three houses. Each house  100 ,  101 ,  103  is connected directly to a central office (“CO”)  102  with wires  104 , which in an embodiment is a twisted pair wire, that is carried on telephone poles  108  to a neighborhood. Twisted pair connectors  112  are mounted on telephone poles  108  to connect drop wires  114  to the houses  100 ,  101 ,  103 . Each house  100 ,  101 ,  103  has a dedicated drop line  114  that can only be used by the house to which it is connected. 
     Referring to FIG. 2, a modified telephone network  120  is depicted. The network  120  includes the central office  102 , the houses  100 ,  101 ,  103 , the twisted pair wires  104 , the telephone poles  108  and the drop wires  114  to each house  100 ,  101 ,  103 . In the network  120 , a plurality of packet switch nodes  122 ,  123 ,  125  are disposed on the telephone poles  108 . The packet switch nodes  122 ,  123 ,  125  are then connected to each other by connection wires  124 , which might be twisted pair, coaxial, fiber optic or other wires. As a result, the individual twisted pair wires  104  from the central office  102  are networked with each other, allowing each subscriber to use  15  multiple lines, if available. For example, a user at house  101  would use drop wire  114  to connect to packet switch node  123 , from which the user could connect to packet switch node  122  and packet switch node  125  (through the connection wire  124 ). As a result, the user could have access to three of the twisted pair wires  104 , providing an increase in available bandwidth from the CO  102 . Past history indicates that only 10% of the subscribers are active at any one time. Consequently, each active subscriber could obtain a significant increase in bandwidth during times that other subscribers are not active. 
     Referring to FIG. 3, in an embodiment the network  120  may also further include a neighborhood node  130 , which may be connected to the central office  102  by wire, which in an embodiment may be an optical fiber  132 . This embodiment may be useful for VDSL, in which the twisted pairs from the CO  102  could be replaced with the optical fiber  132  that would connect to the neighborhood node  130 , which might be located at a predetermined distance, such as within three thousand feet, of the subscribers. The neighborhood node  130  may be one that is capable of converting the incoming information from the CO  102  to packets; each addressed to the subscribers located at the houses  100 ,  101 ,  103 . The connection between the neighborhood node  130  and the packet switch nodes (PSN)  122 ,  123  and  125  would utilize ADSL/VDSL technology and ADSL/VDSL modems (avoiding the necessity of having ADSL/VDSL modems in the houses  100 ,  101 ,  103 ). The packet switch nodes  122 ,  123 ,  125  would recognize the packet address of a given packet and send the packet information to the appropriate house. 
     Referring still to FIGS. 2 and 3, the operation of an embodiment of a system and method as disclosed herein is provided. In one example, it may be assumed that the house  100  is active and that the houses  101  and  103  are inactive. (The actual number of houses served by a particular neighborhood node  130  could be much larger, at least several hundred houses with VDSL and at least thousands of houses with ADSL). The CO  102  would use twisted pair wires  104  for houses  100 ,  101  and  103  to send information to the house  100 . The CO  102 , (or the neighborhood node  130 ), would address all packets to the house  100 . In one embodiment, a third of the packets would be sent to house  100  via packet switch node  122 , another third of the packets would be sent to the house  100  by packet switch node  123  and  122 , and the final third of the packets would be sent to the house  100  by packet switch node  122 ,  123  and  125 . Thus, more twisted pair wires  104  can be employed to deliver a particular set of information to a single subscriber. 
     The packet switch nodes  122 ,  123  and  125  could be connected with conventional twisted pair wire cut in short sections sufficient to connect adjacent telephone poles  108 , such as sections of one hundred feet. The relatively short sections of one hundred feet would allow communication at high speed among the packet switch nodes  122 ,  123  and  125 . For still higher speeds the connection between the packet switch nodes  122 ,  123  and  125  could be replaced with a different wire, such as a coaxial cable line. 
     For an ADSL implementation, the neighborhood node  130  could consist of another CO  102 . In such an embodiment, the number of subscribers served could be in the multiple thousands, and the distance to the subscriber could be longer, such as twelve thousand feet. 
     The diagrams of FIGS. 2 and 3 show downstream communication. The same wiring with appropriate electronics could provide bi-directional communication. It should also be noted that the increased bandwidth could be traded to provide longer distances for ADSL/VDSL deployment. This could be achieved by reducing the bandwidth per twisted pair wire  104  between neighborhood node  130  and the packet switch nodes  122 ,  123 ,  125 . 
     One implementation of a packet switch node is shown in FIG.  4 . The ADSL signal from the neighborhood node  130  is connected to a first splitter  132  that separates the voice data  144  from other data, such as ADSL data. The splitter may include a high pass filter  133  and a low pass filter  135 . The ADSL data may then be recovered by an ADSL modem  134  whose output is a baseband digital signal  138 . The digital signal  138  is input to a packet switch  140  whose output is connected to a modulator  142 . The modulator  142  will shift the spectrum of the baseband digital signal  138  so that it does not overlap with voice signal  144 , which may be a conventional four kHz voice signal. The voice signal  144  may then be combined with the output signal of the modulator  142  in a second splitter  148 , which may include a high pass filter  150  and a low pass filter  152 . The output of the second splitter  148  may be connected to the house  100 ,  101 ,  103 , such as via the drop wire  114 . 
     At the entrance of the house  100 ,  101 ,  103 , the voice may be separated from the data with a splitter, and the data may be converted to baseband with a demodulator. 
     In another embodiment, as an alternative to the embodiment of FIG. 4, the modulator  142  and the second splitter  148  may be eliminated, leaving the embodiment of FIG.  5 . In this arrangement, the data of the baseband digital signal  138  could be delivered to the house with a separate drop wire  114  from the drop wire  114  used for the voice signal  144 . This embodiment would also eliminate the need for a splitter or demodulator in the house  100 ,  101 , or  103 . This embodiment would require the installation of a second drop wire  114  to the house. 
     The systems and methods described herein would provide particular benefits if a large percentage of the phone customers would subscribe to the ADSL/VDSL service, since this would allow maximum sharing of the twisted pair lines. During initial introduction of ADSL/VDSL service, a smaller percentage of customers may be expected to subscribe; thus, placing a packet switch node on each telephone pole might not be cost effective in the initial stage. A possible deployment strategy could consist of placing a PSN on the subscriber&#39;s telephone pole and on the telephone pole of the nearest neighbor. This would provide a twofold increase in bandwidth initially. As the percent of ADSL/VDSL subscribers increases, the bandwidth per subscriber will increase. An alternate strategy could be to place a PSN on the subscriber&#39;s telephone pole only. In this case there would be no increase in bandwidth initially. This deployment strategy might still be consistent with subscriber&#39;s requirements, given that the demand for bandwidth is expected to increase with time. 
     In addition to increasing the bandwidth due to sharing of twisted pairs, the existing bandwidth can be utilized more efficiently. For example, when multiple subscribers request the same TV program, it need only to be sent once via a multi-cast to multiple subscribers. In particular, the transmission can include packets that identify the addresses of multiple households for receipt of the transmission, and the packet switch nodes  122 ,  123  and  125  can address the transmission to each house  100 ,  101 ,  103  that has ordered the transmission. 
     While certain embodiments of the invention are depicted herein, it should be understood that other embodiments would be understood to one of ordinary skill in the art and that such embodiments are encompassed herein.

Technology Category: h